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Home | Alpha Telephone | Domain Names | Web Hosting | Get Traffic | xrEvidence | xrSoccer United States Patent
Light source device for endoscope using DMD A larger number of micromirrors arranged on an illumination optical path of a lamp in a light source device for supplying an illumination light to an endoscope and by using a silicon chip as a base are arranged the micromirrors in a two-dimensional are set at two angles. When the micromirrors are set at one of the two angles, a reflected light is supplied to the light guide. When the micromirrors are set at the other angle, the micromirrors are driven such that the reflected light is not supplied to the light guide. An intensity of illumination light supplied to the light guide or the like is adjusted at a high speed by using a brightness level by selected the micromirrors at the two angles respectively, so that an endoscope image which can be easily observed is obtained.
Attorney, Agent or Firm: What is claimed is: 1. A light source device used in an endoscope device comprising: a light source lamp, arranged at a predetermined position in the light source device, for generating light supplied to an endoscope; a mirror device which uses a silicone chip as a base, which is arranged on an optical path of the light in the light source device, and which has reflective surfaces formed by a plurality of micromirrors for receiving the light, the micromirrors being movable in a predetermined angular range; a receptacle to which a light guide for transmitting the light to an object to be photographed is connected, and which has a face on a proximal side of the light guide arranged at a predetermined position in the light source device; an optical system which is arranged on an optical path of reflected light from the micromirrors from the light generated by the light source lamp when the angles of the micromirrors are at a predetermined position, and which directs the reflected light to the end on the proximal side of the light guide, the optical system forming an optical positional relationship between the micromirrors and the face on the proximal side of the light guide; a light adjustment circuit for outputting an adjustment signal for adjusting the light incident on the optical system; a mirror device drive circuit for outputting a drive signal for setting each of the micromirrors formed in the mirror device at a position on the basis of the adjustment signal output from the light adjustment circuit, the mirror device drive circuit operating the plurality of micromirrors at an angle at which at least some reflected light by the micromirrors from the light generated by the light source lamp is incident on the optical system and an angle at which the reflected light is not incident on the optical system. 2. A light source device according to claim 1, wherein in the mirror device, the micromirrors are two-dimensionally arranged in an arrangement state in which reflected light reflected by one of the micromirrors is incident on the light guide connected to the connector support through the optical system when the micromirror is set at an angle at which the micromirror directs reflected light in a first direction, and reflected light reflected by the micromirror is not incident on the optical system and is not incident on the light guide connected to the connector support when the micromirror is set at an angle at which the micromirror directs reflected light in a second direction different from the first direction. 3. A light source device according to claim 1, wherein a light distribution of light from the distal end of the light guide can be adjusted by the light adjustment circuit. 4. A light source device according to claim 1, wherein the optical system is a condensation optical system, and the condensation optical system condenses the light reflected by the mirror device on the face of the proximal side of the light guide arranged at an almost pupil position with respect to the micromirrors. 5. A light source device according to claim 1, wherein the optical system uniformly distributes light incident on the mirror device. 6. A light source device according to claim 1, wherein the optical system guides light reflected by the mirror device to the face of the proximal side of the light guide arranged at an almost image forming position with respect to the micromirrors. 7. A light source device according to claim 6, further comprising a video processing device for generating a video signal responsive to an image pickup element arranged in the endoscope, the video processing device having a decision circuit for deciding whether the luminance level of the video signal departs from a reference range. 8. A light source device according to claim 7, wherein the mirror device drives the mirror device such that an intensity of light irradiated on a part of the object corresponding to a video signal portion which is determined by the decision circuit when a portion which departs from the reference range. This application claims benefit of Japanese application No. Hei 11-235710 filed in Japan on Aug. 23, 1999, 2000-016312 filed in Japan on Jan. 25, 2000, 2000-018951 filed in Japan on Jan. 27, 2000, 2000-018952 filed in Japan on Jan. 27, 2000, 2000-029516 filed in Japan on Feb. 7, 2000, 2000-030828 filed in Japan on Feb. 8, 2000, 2000-030829 filed in Japan on Feb. 8, 2000, 2000-044900 filed in Japan on Feb. 22, 2000, 2000-175796 filed in Japan on Jun. 12, 2000, the contents of which are incorporated by this reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source device for an endoscope for controlling an intensity of an illumination light delivered to a light guide of an endoscope by using a DMD. 2. Description of the Related Art An endoscope device for performing endoscbpe inspection by using an endoscope has popularly been used in medical fields and industrial fields. The endoscope inspection is performed to various objects to be observed (object to be inspected) such as a tubular object or a recessed surface, e.g., the inner wall of a stomach. For example, observation is performed such that a planar portion is magnified and closely observed. For this reason, illumination is desirably performed such that an endoscope image in which an object to be observed can be easily diagnosed or inspected is objected. Therefore, for example, DE19741616 discloses a method of eliminating dotted reflective luminescent spots generated on the surface of a mucosa by using one matrix field constituted by a optical elements capable of reflection and/or absorption as an illumination device. However, the detailed configuration of the method is not disclosed. OBJECTS AND SUMMARY OF THE INVENTION It is an object to provide a light source device for an endoscope device which can easily perform such illumination that an endoscope image which can be easily diagnosed or inspected a depending on an object to be observed. It is another object of the present invention to provide an endoscope device which can perform brightness control at a high response speed. It is still another object of the present invention to provide a light source device and an endoscope device which can be easily set in a white balance state. According to the present invention, there is provided an endoscope device for observing the inside of an object to be inspected,-comprising: a light source lamp for generating an illumination light supplied to an endoscope; the mirror device constituted by a silicon chip, arranged on an optical path of the illumination light generated from the light source lamp, and having a reflective surface formed by a plurality of micromirrors on a light-exposing side of the illumination light, the micromirrors on the reflective surface being designed such that the micromirror can be moved within a predetermined angle range; a receptacle to which a light guide of the endoscope is connected; the receptacle being arranged on an optical path of a reflected light obtained by reflecting the illumination light generated from the light source lamp when the angles of the micromirrors formed in the mirror device are fixed to a predetermined position; an image pickup element for picking up the image of an object to be photographed illuminated with the illumination light; a video signal processing circuit for performing video signal processing of an output signal from the image pickup element; an illumination light intensity setting circuit for setting an intensity of illumination light illuminating the object; an illumination light intensity adjustment circuit for outputting an adjustment signal for adjusting the illumination light being incident on the light guide of the endoscope in the form of a pattern on the basis of the illumination light intensity set by the illumination light intensity setting circuit and the video signal processed by the video signal processing circuit; and a mirror element drive circuit for outputting a drive signal for changing each micromirror formed in the mirror device to arbitrary angle positions on the basis of the adjustment signal output from the illumination light adjustment circuit, the mirror element drive circuit operating each micromirror between a first angle position at which at least a part of a reflected light obtained such that the illumination light generated by the light source lamp is reflected on the reflective surfaces of the mirror device is incident on the light guide and a second angle position at which the part of the reflected light is not incident on the light guide. The mirror device is driven by the video signal obtained by picking up the image of the object through the mirror element drive circuit, so that an image having such brightness that the object can be easily diagnosed or inspected at a high response speed. BRIEF DESCRIPTION OF DRAWINGS FIGS. 1 to 13 are related to the first embodiment of the present invention, FIG. 1 is a diagram showing the appearance of an endoscope device; FIG. 2 is a diagram showing the configuration of an operation panel arranged on a light source device in FIG. 1; FIG. 3 is a block diagram showing the configuration of the light source device in FIG. 1; FIGS. 4 to 11 are diagrams conceptually showing first to eighth patterns of the reflective surface pattern of a DMD in FIG. 3; FIG. 12 is a graph for explaining an operation of the light source device in FIG. 3 when the shape of an object to be observed is a convex shape; FIG. 13 is a graph for explaining an operation of the light source device in FIG. 3 when the shape of an object to be observed is a tubular shape; FIGS. 14 to 16 are related to the second embodiment of the present invention, and FIG. 14 is a block diagram showing the configuration of a light source device; FIG. 15 is a first graph for explaining an operation of the light source device in FIG. 14; FIG. 16 is a second graph for explaining an operation of the light source device in FIG. 14; FIGS. 17 to 22 are related to the third embodiment of the present invention, and FIG. 17 is a block diagram showing the configuration of an endoscope device; FIGS. 18A to 22D are diagrams for explaining operations of the endoscope device in FIG. 17; FIG. 23 is a block diagram showing the configuration of an endoscope device according to the fourth embodiment of the present invention; FIGS. 24 to 26 are related to the fifth embodiment of the present invention, and FIG. 24 is a block diagram showing the configuration of the endoscope device; FIG. 25 is a graph showing the configuration of an RGB rotating filter in FIG. 24; FIG. 26 is a chart for explaining an operation of the endoscope device in FIG. 24; FIGS. 27 to 36 are related to the sixth embodiment of the present invention, and FIG. 27 is a block diagram showing the configuration of an endoscope device; FIG. 28 is an enlarged view of an optical system in the light source device in FIG. 27; FIG. 29 is a view for explaining an operation performed by a light modulation device; FIG. 30 is a view showing an optical system in which a light reflected by the light modulation device is irradiated on an object to be photographed; FIG. 31 is a view showing an optical system near an integrator; FIGS. 32A to 32C are diagrams showing light distribution patterns; FIG. 33 is a view for explaining an operation performed when light distribution control is performed by a light distribution pattern; FIGS. 34A to 34C are diagrams of other light distribution patterns; FIG. 35 is a view showing the optical system of a light source device according to the first modification of the sixth embodiment; FIG. 36 is a view showing the optical system of a light source device according to the second modification of the sixth embodiment; FIGS. 37 to 40D are related to the seventh embodiment of the present invention, and FIG. 37 is a perspective view showing the appearance of an endoscope device according to the seventh embodiment; FIG. 38 is a block diagram showing the detailed configuration of FIG. 37; FIG. 39 is a perspective view showing the configuration of a light modulation device; FIGS. 40A to 40D are views showing typical examples of light distribution patterns of the RGB filter of the light modulation device; FIGS. 41 to 42D are related to the eighth embodiment of the present invention, and FIG. 41 is a block diagram showing the configuration of an endoscope device according to the eighth embodiment; FIGS. 42A to 42D are views for explaining an operation; FIGS. 43 and 44 are related to the ninth embodiment of the present invention, and FIG. 43 is a block diagram showing the configuration of an endoscope device according to the ninth embodiment; FIG. 44 is an explanatory view showing the structure and the operation of a light modulation device; FIGS. 45 to 46B are related to the tenth embodiment of the present invention, and FIG. 45 is a block diagram showing the configuration of an endoscope device according to the tenth embodiment; FIGS. 46A and 46B are views for explaining an operation; FIGS. 47 to 50 are related to the eleventh embodiment of the present invention, and FIG. 47 is block diagram showing the configuration of an endoscope device; FIG. 48 is a chart for explaining R, G, and B field sequential illumination; FIG. 49 is a diagram for explaining a light intensity control pattern; FIG. 50 is a diagram showing a drive pattern of a light modulation device when colors are balanced; FIGS. 51 to 53 are related to the twelfth embodiment of the present invention, and FIG. 51 is a block diagram of an endoscope device; FIG. 52 is a chart for explaining a drive manner of a light modulation device in case of a field sequential method; FIG. 53 is a chart for explaining a drive manner of the light modulation device in case of a simultaneous method; FIGS. 54 to 59E are related to the thirteenth embodiment of the present invention, and FIG. 54 is a perspective view showing the appearance of an endoscope device according to the thirteenth embodiment; FIG. 55 is a block diagram showing the internal configuration of a light source device or the like; FIG. 56 is a block diagram showing the configuration of a video signal processing circuit; FIG. 57 is a block diagram showing the configuration of a decision circuit; FIGS. 58A to 58C are charts showing manners in which an image pickup period is changed depending on movement of an object to be photographed; FIGS. 59A to 59E are charts showing read and write operations of a chromatic signal in/from a memory; FIGS. 60A to 61H are related to the fourteenth embodiment of the present invention, and FIGS. 60A and 60B are charts for explaining an operation of the fourteenth embodiment; FIGS. 61A to 61H are timing charts for explaining operations; FIGS. 62 to 66 are related to the fifteenth embodiment of the present invention, and FIG. 62 is a block diagram showing the configuration of an endoscope device according to the fifteenth embodiment; FIG. 63 is a block diagram showing the configuration of a video signal processing circuit; FIGS. 64A to 64C are explanatory diagrams of a change from a primary color system to a complementary color system depending on the brightness of an object to be photographed; FIG. 65 is a graph showing the relationships between brightnesses (distances) and accumulation times when a light of a primary color system and a light of a complementary color system are emitted; FIG. 66 is a timing chart of read and write operations for a signal obtained by image pickup from/into a memory when a light of a complementary color system is emitted; FIGS. 67 to 75 are related to the sixteenth embodiment of the present invention, and FIG. 67 is a perspective view showing the appearance of an endoscope device according to the sixteenth embodiment; FIG. 68 is a block diagram showing the configuration of a light source device or the like; FIG. 69 is a block diagram for explaining an operation for causing a main part of FIG. 68 to correspond to a light modulation device and a CCD pixel; FIG. 70 is a circuit diagram showing the configuration of a peak point detection circuit; FIG. 71A is a diagram showing a portion near an end face of a light guide on an incident side, FIG. 71B is a diagram showing the relationship between an element of the light modulation device and a fiber diameter of the light guide; FIG. 72 is a flow chart showing the contents of a corresponding process between the light modulation device and a CCD pixel in an initial setting: FIG. 73 is a flow chart showing the contents of a process of correcting a brightness to an appropriate brightness when bright spots/dark spots in an endoscope observation; FIGS. 74A to 74F are graphs for explaining operations in FIG. 73; FIG. 75 is a circuit diagram showing the internal configuration of a decision circuit; FIGS. 76 to 78 are related to the seventeenth embodiment of the present invention, and FIG. 76 is a block diagram showing the configuration of an endoscope device according to the seventeenth embodiment; FIGS. 77A and 77B are waveform charts showing a brightness pattern signal and a synthesis pattern signal; FIG. 78 is a view showing the basic configuration of an optical system subsequent to a light modulation device; FIGS. 79A and 79B are related to the eighteenth embodiment, and FIG. 79A is a diagram showing a portion near an end face of a light guide on an incident side; FIG. 79B is a diagram showing the relationship between an element of the light modulation device and a fiber diameter of the light guide; FIG. 80 is a block diagram showing the configuration of an endoscope device according to the nineteenth embodiment of the present invention; FIGS. 81 to 82B are related to the twentieth embodiment of the present invention, and FIG. 81 is a block diagram showing the configuration of an endoscope device according to the twentieth embodiment; FIGS. 82A and 82B are diagrams for explaining the structure of a new operation panel; FIGS. 83 and 84 are related to the twenty-first embodiment of the present invention, and FIG. 83 is a block diagram showing the configuration of an endoscope device according to the twenty-first embodiment; FIG. 84 is a diagram showing gamanner in which an illumination light is supplied to a light guide constituted by a group of microlenses; FIGS. 85 to 87C are related to the twenty-second embodiment of the present invention, and FIG. 85 is a block diagram showing the configuration of an endoscope device according to the twenty-second embodiment; FIGS. 86A to 86C are charts for explaining the operation of performing field sequential illumination and image pickup by a visual light; FIGS. 87A to 87C are charts for explaining the operation of performing field sequential illumination and image pickup by a special light; FIGS. 88 to 91 are related to the twenty-third embodiment of the present invention, and FIG. 88 is a block diagram showing the configuration an endoscope device according to the twenty-third embodiment, FIG. 89 is a diagram showing regulative patterns of supply reflection/non-supply reflection performed when a light modulation device is driven; FIGS. 90A to 90C are charts for explaining a drive timing of the light modulation device, a timing of infrared detection, and the like; FIG. 91 is a flow chart showing the contents of the process of infrared level detection; FIGS. 92 to 95 are related to the twenty-fourth embodiment of the present invention, and FIG. 92 is a block diagram showing the configuration of an endoscope device; FIG. 93 is a flow chart for explaining the operation of an infrared level detection circuit in FIG. 92; FIG. 94 is a view showing a configuration in which a cooling fan is arranged in a light source device in FIG. 92; FIG. 95 is a view showing a modified configuration in which a cooling fan is arranged in a light source device in FIG. 88; FIGS. 96 to 97B are related to the twenty-fifth embodiment of the present invention, and FIG. 96 is a block diagram showing the configuration of an endoscope device; and FIGS. 97A and 97B are chart for explaining operations. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The first embodiment of the present invention will be described below with reference to FIGS. 1 to 13. As shown in FIG. 1, an endoscope device 1 according to this embodiment is constituted by an endoscope 2 consisting of a rigid endoscope used to observe a meniscal of a joint, and a light source device 3 for supplying an illumination light to the endoscope 2. The endoscope 2 is constituted by an insertion portion 4 inserted into a body cavity; a grasping portion 5 arranged to be connected to the proximal end of the insertion portion 4; an eyepiece portion 6, arranged on the grasping portion 5, for observing the image of an observed portion in a body by an image transmission means (e.g., an image guide fiber or a relay lens) (not shown) arranged in the insertion portion 4; and a light guide cable 9 extending from the grasping portion 5 and having a light guide connector 8 to be connected to a receptacle 7 of the light source device 3 at the proximal end of the light guide cable 9. When the light guide connector 8 is connected to the receptacle 7 of the light source device 3, an illumination light is supplied to the light guide cable 9 and an incident end (on the light source device 3 side) of a light guide 10 equiped in the insertion portion 4, and the illumination light is transmitted through the light guide 10 to illuminate an observed portion from the distal end of the insertion portion 4. In addition to the recptacle 7, an operation panel 11 as shown in FIG. 2 is arranged in the light source device 3. The operation panel 11 is constituted by a brightness level operation portion (BRIGHTNESS) 12 and a correction level operation portion (COMPENSATION) 13 having a pattern setting switch 13a for performing pattern selection (to be described later). Various settings are performed by the two operation portions, so that a desired illumination light (to be described later) is supplied to the endoscope 2. The light source device 3, as shown in FIG. 3, comprises a light source lamp 21 for emitting an illumination light, a lamp power supply 20 for supplying a power to the light source lamp 21, a parabolic mirror 22 on which a film having infrared transmission characteristics for outgoing the illumination light emitted from the light source lamp 21 as a parallel light is coated, and a DMD (Digital Micromirror Device) 24 for reflecting the parallel light from the parabolic mirror 22 through a lens 23 to condense the parallel light to the incident end of the light guide 10. The DMD 24 is available from, e.g., Texas Instruments. The DMD 24 is an element in which a micromirror having a size of 640.times.480 is arranged on a silicon chip and which is held by a holding member on a yoke rotated about diagonals between two stable states and rotated in a horizontal direction within a range of .+-.10.degree.. The DMD 24 is designed such that the parallel light from the parabolic mirror 22 through a lens 23 is reflected from the reflective surface of the 640.times.480 mirror of the DMD 24 through the lens 23 to be condensed and incident on the light guide 10 (another embodiment (to be described later), see, e.g., FIG. 29. In FIG. 29, the DMD is indicated by 60). As the lamp power supply 20, a lamp such as a xenon lamp or a metal halide lamp having a short arc is appropriately used. The light source device 3 comprises a DMD drive circuit 25 for rotationally control the mirrors of the DMD 24, a pattern selection circuit 26 for receiving a pattern selection in a pattern selection portion 13a of the operation panel 11 to select reflective surface patterns of the mirrors of the DMD 24, and a pattern setting circuit 27 for controlling the DMD drive circuit 25 on the basis of the reflective mirror pattern selected by the pattern selection circuit 26 to set each mirror of the DMD 24 in a desired reflective mirror pattern. When the mirrors of the DMD 24 are inclined at 0.degree. to +10.degree. in one direction by the pattern selection portion 13a, a reflected light is not incident on the light guide 10. In the mirrors, reflection is indicated by white, and non-reflection is indicated by black. In this case, in the DMD mirror arrangements, as conceptual reflective mirror patterns, various reflective mirror patterns as shown in FIG. 4 (first pattern) to FIG. 11 (eighth pattern) are obtained. More specifically, when a convex object to be observed is used, alight being incident on the light guide 10 and reflected from the mirrors of the DMD 24 arranged at the central portion is not converged. In this case, an excessive light is not output from the central portion. Forth is reason, the reflective mirror pattern of the DMD 24 is changed as shown in FIG. 4 (first pattern) to FIG. 7 (fourth pattern), and an optimum pattern appropriate to the condition is selected, so that the light can be incident on the light guide 10. Similarly, when the object to be observed is tubular, by using the reflective mirror patterns shown in FIG. 8 (fifth pattern) to FIG. 11 (eighth pattern), the light can be converged to the light guide while the intensity of a around light such as peripheral. These reflective mirror patterns are generated by the pattern setting circuit 27. The generated reflective mirror patterns are output to the DMD drive circuit 25, the positions of the respective mirrors of the DMD 24 are controlled by the DMD drive circuit 25. The pattern selection circuit 26 is connected to the pattern setting circuit 27, and a pattern is selected by the pattern setting switch 13a for each input object image so as to set whether the object to be observed is convex or tubular. Unless the conditions for converging a light to the. light guide 10 are not changed depending on the object to be observed, even though the object is tubular, the patterns cannot cope with the thick tube. Therefore, a setting of a correction level matched by changing the reflective patterns of the DMD 24 can be performed by the correction level operation portion 13 of the operation panel 11. The parallel light emitted from the light source lamp 21 through the lens 23 is reflected by the mirrors of the DMD 24. However, a reflection distribution is dependent on the reflective mirror pattern of the DMD 24 at this time. More specifically, since a light being incident on the light guide 10 decreases, a part which is not reflected by the mirrors is reflected such that the distribution of a non-reflective mirror is shaped into a mosaic by setting in the brightness level operation portion 12 and the correction level operation portion 13, so that the intensity of an intermediate light is obtained. In this manner, the distribution of the light being incident on the light guide 10 is corrected as shown in FIG. 12 depending on FIG. 4 (first pattern) to FIG. 7 (fourth pattern) when the object to be observed has a convex shape, and the distribution is corrected as shown in FIG. 13 depending on FIG. 8 (fifth pattern) to FIG. 11 (eighth pattern) when the object to be observed is has a tubular shape. Although the fiber position of an incident end and the fiber position of an outgoing end do not have a one-to-one correspondence in general, in this embodiment as described above, since pattern setting and correction are performed to a radial distribution of a parallel light transmitted through the light guide, the fiber position of the incident end and the fiber position of the outgoing end need not have a one-to-one correspondence. However, as the light guide, a fiber bundle such as an image guide in which the fiber position of the incident end and the fiber position of the outgoing end have a one-to-one correspondence can also be used, as a matter of course. The operation of this embodiment will be described below. In the endoscope device 1 of this embodiment, when a knee joint is observed by the endoscope 2, the endoscope 2 is inserted into the lumen of the joint in a state in which reflux liquid flows to perform observation. Although the meniscal of the knee joint can be observed in this state, since the patella consisting of a bone component, the patella has a reflectance higher than that of an ordinary tissue, and the patella is located at the center. For this reason, when an external TV camera is connected to the eyepiece portion 6 to perform observation using the TV device, a so-called white out state occurs disadvantageously. Therefore, the operation panel 11 is operated to make it possible to perform correction, and a reflective surface pattern of each mirror state of the DMD 24 corresponding to a convex shape is selected. Therefore, when a correction level is selected by the degree of a white out state, the white out state of the central portion can be avoided, and the around tissue state can be observed at an appropriate level. This embodiment has the following effect. Conventionally, when an output from the light source device is controlled to be decreased, a total of light intensity decreases, and the peripheral tissue to be observed becomes dark. As a result, observation cannot be properly performed. However, the method according to the present invention can be performed without any problem. The object is tubular. For this reason, by changing only the setting of a convex shape, the light source device can be effectively used. The second embodiment of the present invention will be described below with reference to FIGS. 14 to 16. The second embodiment is almost the same as the first embodiment. For this reason, only different points will be described, the same reference numerals as in the first embodiment denote the same parts, and a description thereof will be omitted. In a light source device 3a according to this embodiment, as shown in FIG. 14, in order to reflecting a light being incident on the light guide 10 by the plurality of mirrors of the DMD 24, an optical system constituted by a mirror 31 for converting an optical path to converge a light to the light guide and a filter 32 for cutting an infrared ray is arranged between the DMD 24 and a light source lamp 21a. The light source lamp 21a according to this embodiment is a lamp obtained such that a xenon gas is filled in a short arc discharge tube in which a reflective mirror 33 having a parabolic surface is formed on a ceramics. In this embodiment, a TV camera (not shown) is detachably connected to the eyepiece portion 6, and an image pickup element 34 arranged on the TV camera is designed to photograph an endoscope image. An electronic endoscope in which the image pickup element 34 is arranged inside the distal end of the insertion portion 4 may be used. An image pickup signal from the image pickup element 34 is converted into a video signal which can be observed with a monitor 37 by means of a video signal processing circuit 36 in a camera control unit (to be referred to as a CCU hereinafter) 35. The video signal from the video signal processing circuit 36 is also output to the light source device 3a of this embodiment. In the light source device 3a, the video signal is output to a video signal inversion circuit 42 through a video signal input circuit (buffer circuit) 41. In the video signal inversion circuit 42, the video signal is inverted to generate a base signal of a correction signal to the DMD 24. Thereafter, the level of the inverted signal from the video signal inversion circuit 42 is shifted by a level shift circuit 43 to a level set by a brightness setting circuit 45. The set level in the brightness setting circuit 45 can be set by the brightness level operation portion 12 of the operation panel 11. In this manner, the correction level is made variable by the level shift in the level shift circuit 43, so that the level is adjusted to obtain an appropriate observed image. An output from the level shift circuit 43 is output to the DMD drive circuit 25, and an inverted image of an endoscope image obtained by image pickup is input to the DMD 24 as a correction signal. The operation of this embodiment will be described below. The level of a video signal serving as a tubular object to be observed is shown in FIG. 15, and a correction signal obtained at this time is shown in FIG. 16. In case of the tubular object, as shown in FIG. 15, the peripheral portion reaches the maximum amplitude of the video signal to be clipped, a "white out" state is set. Therefore, as a correction method, when an object has a screen center as a center, the DMD drive circuit 25 is controlled by using a correction signal obtained such that an inverted signal from the video signal inversion circuit 42 as shown in FIG. 16 is shifted by a level set by the brightness setting circuit 45, and an illumination light is supplied to the light guide 10 through the DMD 24 to illuminate an observed portion, so that the video signal is not set in the "white out" state clipped at the periphery. When the object is observed by using the screen center as the center, the optimum state can be obtained, and the signal level falls within the range in which observation can be performed. When the object is not observed by using the screen center as the center, and the inverted image is input to the DMD 24, an incident light to the light guide 10 is being incident at a level obtained by integrating the image by coaxial circles. For this reason, the brightness of the center is enhanced, an outgoing light from the light source is controlled to decrease the peripheral brightness. When the convex object is used, a phenomenon which is contrast to the phenomenon of the convex object occurs. The brightness at the center decreases, and an outgoing light from the light source which does not darken the periphery is obtained. When an object to be observed is not tubular and convex, an incident light to the light guide is incident at a level at which the image is integrated by coaxial circles. For this reason, when one half of the screen is bright, and the other half is dark, lights having averaged levels (light distribution is not changed) are incident on the light guide. Therefore, when an object which is axially symmetrical with respect to the screen center, correction is made. Otherwise, correction is not made as a result, a light distribution can be used without being changed. This embodiment has the following effect. The first embodiment describes a method of making correction by selecting a panel operation. However, the panel operation must be performed, and the operation is cumbersome. However, in this embodiment, the correction can be automatically made. More specifically, since distribution of an incident light to the light guide is automatically controlled on the basis of a video signal, an operator can continue appropriate observation without operating the operation panel. In the embodiments described above, as a portion to which the endoscope is applied, a thin tubular object, e.g., a bronchus or a urinary duct may be used. In addition,the present invention can also be effectively used in pipe inspection with an industry endoscope. In addition, as the endoscope, not only a rigid endoscope but also a flexible endoscope can be used. The third embodiment of the present invention will be described below with reference to FIGS. 17 to 22. As shown in FIG. 17, an endoscope device 51 according to this embodiment comprises a rigid endoscope 52 for obtaining a tissue image in a living body through, e.g., a trocar or the like, a light source device 54 for supplying an illumination light to the rigid endoscope 52 through a light guide 53, a TV camera head 55, which is detachably connected to an eyepiece portion arranged on the rigid endoscope 52 on the hand side, for picking an image obtained by the rigid endoscope 52, and a camera control unit (to be referred to as a CCU hereinafter) 56 for processing an image pickup signal obtained by image pickup by the TV camera head 55 to display an observed image on a monitor 57. A light source lamp 111 turned on by a lamp power supply 137 is arranged on the light source device 54, and a light from the light source lamp 111 is incident on a planar mirror 59 through an infrared cut filter 112. The reflected light from the planar mirror 59 is incident on a light modulation device 60, and the reflected light from the light modulation device 60 is converged by a convergent lens 58 to be incident on the light guide 52 by the optical lens system 58 for converging a light to the light guide 52. The optical system 58 is constituted by a single lens and a group of lenses. Here, the light source lamp 111 has a parabolic surface, is designed to emit a parallel light, and is constituted by a high-pressure discharge tube such as a xenon lamp or a metal halide lamp having a high luminance. The light modulation device 60 is an element in which a micromirror having a size of 640.times.480 is arranged on a silicon chip and which is held by a holding member on a yoke rotated about diagonals between two stable states and changed in a horizontal direction within a range of .+-.10.degree.. This element is called a DMD (Digital Micromirror Device). On the other hand, a CCD 118 is arranged in the TV camera head 55, and the TV camera head 55 is connected to the CCU 56 with a connector 119. The camera control unit 56 comprises a CCD drive circuit 121 for driving the CCD 118, a video signal processing circuit 122 for processing an image pickup signal from the CCD 118 to output a video signal (e.g., an NTSC TV signal) to the monitor 57, a timing generation circuit 123 for generating a timing signal for synchronizing an image pickup timing of the CCD 116 and signal processing in the video signal processing circuit 122, and a bright signal generation circuit 124 for detecting the brightness of an image from the video signal from the CCD drive circuit 121 to generate a brightness signal. The CCU 56 has an operation panel 63 having a brightness switch, and an operation signal of the bright switch is input to a brightness setting circuit 132 to set a brightness level serving as a reference. An output from the brightness setting circuit 132 is input to a brightness comparison circuit 133, and the brightness comparison circuit 133 compares the level of the output with the brightness level generated by the bright signal generation circuit 124 from an output from the video signal processing circuit 122 to generate a brightness control signal (comparison result). The control signal (comparison result) generated by the brightness comparison circuit 133 is input to a brightness pattern generation circuit 64 of the light source device 54. An output from the brightness pattern generation circuit 64 outputs a brightness pattern (to be described later) in the light modulation device 60 to a pattern synthesizing circuit (to be referred to as a synthesizing circuit hereinafter) 65. An operation switch which makes an instruction to uniformly illuminate a convex or concave object to be observed is arranged on the operation panel 131 of the light source device 54, and the operation switch inputs a selection signal to a light distribution pattern generation circuit 66. The light distribution pattern generation circuit 66 generates a pattern shown in FIG. 9 to input the pattern to the pattern synthesizing circuit 65. The pattern synthesizing circuit 65 synthesizes patterns as shown in FIGS. 18A and 18B with light distribution patterns as shown in FIGS. 19A to 19D to obtain patterns as shown in FIGS. 20A to 20D. The patterns in FIGS. 20A to 20D are input to a DMD control circuit 67 as control signals, and the DMD control circuit 67 controls a DMD drive circuit 68 to cause the DMD drive circuit 68 to drive a two-dimensional arranged element of the light modulation device 60. Here, FIG. 18A shows a brightness pattern obtained when the pattern is determined as a dark pattern by the brightness comparison circuit 133, and FIG. 18B shows a brightness pattern obtained when the pattern is determined as a bright pattern by the brightness comparison circuit 133. FIGS. 19A to 19D show light distribution pattern for an concave object to be observed. FIGS. 20A to 20D show synthesis patterns obtained by synthesizing brightness patterns with the light distribution patterns for the concave object to be observed. FIGS. 20C and 20D show the patterns whose brightnesses are controlled to be slightly darkened. In the pattern synthesizing circuit 65, to keep uniformity, simple addition is not performed to a concentrated dark portion, but an exclusive OR operation is performed to the portion. In addition, FIGS. 21A to 21D show light distribution patterns for a convex object to be observed or an intraluminalorgan. On the basis of patterns obtained by synthesizing the brightness patterns shown in FIGS. 18A to 18B with the light distribution patterns, the light modulation device 60 is driven. When the micromirror serving as the two-dimensional arranged element of the light modulation device 60 is positioned at +10.degree., a light is incident on the light guide 53. When the micromirror is positioned at -10.degree., a light is not incident on the light guide 53. A portion to be brightened controls the pattern signal at +10.degree.. Changes of patterns added to the light modulation device 60 are shown in FIGS. 22A and 22D. In FIGS. 22A and 22D, the intensity of an incident light to the light guide 53 obtained by brightness control is the intensity of an intermediate passing light by performing, e.g., pulse drive to the micromirror serving as the two-dimensional arranged element of the light modulation device 60. FIGS. 22A to 22D show patterns obtained when the central portion is more bright. In FIGS. 22A and 22D, the patterns having intermediate levels are added. In this manner, gradual patterns can be performed as control including a smaller change. The synthesizing circuit 65 switches a brightness pattern from the brightness pattern generation circuit 64 and a synthesized pattern from the light distribution pattern generation circuit 66 in a time series manner on the basis of a brightness signal input from the brightness comparison circuit 133. The operation of this embodiment will be described below. The TV camera head 55 is connected to the rigid endoscope 52, and the rigid endoscope 52 is inserted into the trocar inserted into a abdominal subjected to insufflation to perform endoscope observation. An endoscope image is picked by the CCD 116, and signal processing is performed by the CCU 56 to make it possible to perform observation with the monitor 57. At this time, the timing generation circuit 123 outputs a signal corresponding to the brightness of the endoscope image. It is detected by comparison in the brightness comparison circuit 133 that the signal is darker than a reference set signal from the brightness setting circuit 132 or brighter than the reference set signal. The comparison result is input to the pattern generation circuit 64. In the pattern generation circuit 64, mosaic patterns (shown in FIGS. 18A and 18B) which are gradually changed depending on a brightness are generated. In addition, when the operation switch of the operation panel 31 is selected depending on an object to be observed, the light distribution patterns in FIGS. 19A to 19D or in FIGS. 21A to 21D are output from the light distribution pattern generation circuit 66, and both the patterns are synthesized by the synthesizing circuit 65 to generate patterns shown in FIGS. 20A to 20D or the like. The two-dimensional arranged element of the light modulation device 60 is driven through the DMD control circuit 67 and the DMD drive circuit 68 in an all level reflection or shielding reflection state (in addition, an intermediate level reflection state). For example, as a comparison result, it is determined that the endoscope image is dark with respect to the reference set signal. In this case, a pattern in which an illumination light is brighter than that of the previous state is generated, and the pattern generation circuit 64 is operated such that the number of all level reflections of the two-dimensional arranged element of the light modulation device 60 is increased. In this manner, an emission light (illumination light) from the light source device 54 becomes bright, and the endoscope image can be observed at appropriate brightness. In contrast to this, if it is determined the emission light is too bright, such a pattern that the number of two-dimensional arranged elements in a shielding reflection state in the light modulation device 60 increases is set, and an operation is performed to decrease the intensity of an illumination light from the light source device 54. According to this embodiment, the light modulation device 60 can control the intensity of the illumination light in a state in which a rate of usage of the light for a reflection method. This embodiment has the following effect. Drive patterns the number of which is equal to the number of two-dimensional arranged elements of the light modulation device 60 constituted by a DMD are used in maximum usage or at an intermediate level, brightness control can be performed in a very wide dynamic range. In addition, since the response speed of the micromirror of the light modulation device 60 is very high, i.e., about 2 .mu.m, high-speed brightness control can be performed. The DMD can make the rate of usage of the light higher than the transmittance of a liquid crystal due to the reflection method. Although the intermediate level of the intensity of an incident light to the light guide 53 can be obtained by pulse control by a pattern (see FIGS. 22A to 22D), an intermediate level obtained by continuously changing the level of the intensity of the incident light to the light guide 53 by PWM (pulse width control) or PFM (pulse frequency modulation) can also be obtained. The fourth embodiment of the present invention will be described below with reference to an endoscope device according to the fourth embodiment in FIG. 23. In this embodiment is almost the same as the third embodiment. For this reason, only different points will be described, the same reference numerals as in the third embodiment denote the same parts, and a description thereof will be omitted. In this embodiment, as shown in FIG. 23, a correction pattern generation circuit 71 is connected to the pattern generation circuit 66, and a serial communication I/F 72 is arranged in the correction pattern generation circuit 71 as an interface to an external device 73 (personal computer or the like). A storage circuit 74 in which a correction pattern from the external device 73 is stored is connected to the correction pattern generation circuit 71. In the external device 73, a CPU 81 is connected to a BUS 82, an A/D conversion circuit 85, having an input/output interface of a DISSP-I/F 84, for A/D-converting a video signal from the video signal processing circuit 122 and a serial communication I/F 86 for performing communication with the serial communication I/F 72 of the insertion portion 4. A keyboard 87 is connected to the KEY-I/F 83, and a display 88 is connected to the DISSP-I/F 84, so that the external device 73 can be operated. In the light source device 54, the illumination light of the light source lamp 111 is incident on a concave mirror 61 through an infrared cut filter 112. The concave mirror 61 has a reflective surface for converging a light. The reflected light from the concave mirror 61 is incident on the light modulation device 60, and the reflected light from the light modulation device 60 is incident on the light guide 53. The other configuration is the same as that of the third embodiment. The operation of this embodiment will be described below. In the external device 73, a control pattern in which an appropriate brightness and light distribution can be performed on the basis of a video signal is formed, and the pattern is loaded on the light source device 54, so that optimum control can be performed. A correction pattern is stored in the storage circuit 74, and the correction pattern is selected by operating an operation panel 131 of the light source device 54. In this case, an external correction pattern stored in the storage circuit 74 is output to the synthesizing circuit 65 by the correction pattern generation circuit 71. In the synthesizing circuit 65, correction patterns and the brightness patterns shown in FIGS. 20A to 20D are alternately selected in a time series manner. Selection time is controlled such that a ratio of a light distribution to a brightness is determined by a brightness level, and a brightness and a light distribution (correction) which are appropriate to observation are obtained. The other operation is the same as that in the third embodiment. This embodiment has the following effect. In this manner, in this embodiment, in addition to the effect of the third embodiment,a brightness pattern can be set from the outside. For this reason, in particular, an industrial endoscope can applied in a wide range and used in a non-destructive testing or the like. The endoscope cannot be completely controlled by only a predetermined control pattern. The range in which the endoscope is applied can be increased. The fifth embodiment of the present invention will be described below with reference to FIGS. 24 to 26. Since the fifth embodiment is almost the same as the third embodiment, only different points will be described. The same reference numerals as in the third embodiment denote the same parts in the fifth embodiment, and a description thereof will be omitted. In this embodiment, as shown in FIG. 24, an electronic endoscope 141 is used in place of the rigid endoscope 52. As a signal line connected to the CCD 116 arranged on the distal end of the insertion portion of the electronic endoscope 141, the connector 119 arranged at the distal end of the cable extending from a connector 142 connected to the light source device 54 is detachably connected to the CCU 56. In the light source device 54, an illumination light from the light source lamp 111 through a infrared cut filter is incident from an optical system lens 92 for decreasing the diameter of a flux of light passing through the filter of an RGB rotation filter 91 onto the mirror 61 through an optical system lens 93 for returning the diameter of the flux of light passing through the RGB rotation filter 91. Here, the RGB rotation filter 91 is designed R, G, and B filters shown in FIG. 25 are rotated to emit field sequential lights of R, G, and B. The light reflected from the concave mirror 61 is incident on the light modulation device 60, and the light reflected by the two-dimensional array pattern of the micromirror of the light modulation device 60 is incident on the incident end face of the light guide 2 by a convergent lens 44. The RGB rotation filter 91 is rotated by a motor 94, and the rotation is detected by a rotation sensor 95, so that the rotation is controlled to be synthesized with an image pickup timing from the CCU 56. An output from the rotation sensor 95 is input to a rotation detection circuit 96, a rotation detection signal is input to a rotation control circuit 97, and a drive signal is generated by the rotation control circuit 97 to establish synchronization with a timing output from the timing adjustment circuit 135. The drive signal is input to a motor drive circuit 98 A CCD 18 has no monochromatic transfer region, and is of a type in which an image is picked up by field sequence of RGB. A light shield period (read period of CCD signal) of a field sequential method is set at an image pickup timing on the basis of a signal from the timing adjustment circuit of the light modulation device. This relationship is shown in FIG. 16. Light distribution and brightness control are performed in the same manner as that of the third embodiment, the light distribution control and the brightness control are performed when a field sequential light is output. The other configuration is the same as the configuration in the third embodiment. The operation of this embodiment will be described below. Even in field sequence, the light modulation device 60 is driven by a pattern for controlling light distribution and brightness in field sequential emission, and control is performed to establish a state appropriate to observation. The other operation is the same as that of the third embodiment. This embodiment has the following effect. In this manner, in this embodiment, in addition to the effect of the third embodiment, control of light distribution and control of brightness can be performed by the field sequential method, and a high response speed and a wide dynamic range can be obtained. A method by outputting a pattern matched to an observation station is applied to brightness control. However, brightness control performed by pulse width modulation such as PWM or PFM can also be realized. The target object can be achieved by combining a pattern control method and a pulse width control method. The sixth embodiment of the present invention will be described below with reference to FIGS. 27 to 36. Since the sixth embodiment is similar to the third embodiment, only different points will be described. The same reference numerals as in the third embodiment denote the same parts in the sixth embodiment. An endoscope device 151 according to this embodiment shown in FIG. 27 is constituted by an electronic endoscope 152, the light source device 54, the CCU 56, and the monitor 57. In the light source device 54, as shown in FIG. 28, a light of the light source lamp 111 is incident on an integrator (rod lens) 116 by a convergent lens system 115 arranged on the optical path of the light. A light uniformed by the integrator 116 is converted into a parallel flux of light by a collimator lens system 153 to be incident on the light modulation device 60 arranged on the illumination optical path. The light reflected by the light modulation device 60 is incident from the end face of a light guide connector 155 of the electronic endoscope 152 arranged on the light guide connector support 54a of the light source device 54 onto a light guide 156 serving as a light transmission means (light guide means) by a condensation optical system constituted by, e.g., a single lens or a group of lenses. (As will be described below in FIG. 30), in this case, if the light modulation device 60 is set as an object point, arrangement is performed such that a pupil is projected on the end face of the light guide 156, thereby making it possible to perform light distribution control of coaxial circles. The electronic endoscope 152 shown in FIG. 27 has. an insertion portion 157 inserted into a body cavity, and an operation unit 158 is arranged at the rear end of the electronic endoscope 152. A light incident on the light guide 156 is transmitted to the distal end portion of the insertion portion 157, and the light is delivered from the distal end face of the insertion portion 157 to illuminate an object to be photographed such as an affected part in the body cavity. The image of the illuminated object is formed at a focusing position of an objective lens 159 by the objective lens 159. A CCD 110 is arranged at the focusing position to perform photoelectric conversion. The CCD 110 is connected to a signal line, and the signal line is inserted through the cable 112 extending from the rear end of the electronic endoscope 152 to be connected to the CCU 56 through a signal connector. In the light modulation device 60, as shown in FIG. 29, a large number of micromirrors 166 are arranged at grating points on a silicon substrate 165 such that the micromirrors 166 can be freely pivote dat, e.g., .+-.10.degree., so that a light receiving surface 167 is formed. With respect to an incident light from the (light source lamp 111) collimator lens system 153, when the micromirrors 166 is set at, e.g., -10.degree., as indicated by solid lines, the micromirrors 166 are set such that a reflected light is incident on the light guide 156 through the condensation optical system 154. As indicated by a dotted line, when the micromirrors 166 are set at +10.degree., the reflected lights are reflected in different directions, and the reflected lights are not incident on the light guide 156. FIG. 30 shows a manner in which a light reflected by the light modulation device 60 is projected on an object to be photographed. If the light guide 156 is regarded as an object point, the light modulation device must be arranged at an approximate pupil position or near the pupil position, and the condensation optical system 154 must be arranged to condense the light to an end face 156a of the light guide 156 on the incident side. If the light modulation device 60 is regarded as an object point, it can be said that a light is condensed by the condensation optical system 154 to the end face 156a on the incident side of the light guide 156 arranged at the approximate pupil position or near the pupil position. The light incident on the end face of proximal 156a is transmitted to a distal end face (end face on delivery side) 156b by the light guide 156, and a light delivered from the distal end face 156b is projected on the object to be photographed. As indicated by a dotted line, an illumination lens system 168 may be arranged opposite to the distal end face 156b (FIG. 30). FIG. 31 shows an optical system near the integrator 116. As shown in FIG.28 since the light source lamp 111 causes a luminescent spot of the ends of two electrodes to emit light, the emitted light is shielded at a portion near the optical axis by the electrodes arranged in the direction of the optical axis. Therefore, when the light is guided to the light modulation device 60, the light modulation device 60 may set an uneven illumination state. In this embodiment, in order to eliminate the uneven illumination, as shown in FIG. 31, a light from the luminescent spot of the lamp 111 is incident on the integrator 116 having the incident end face arranged at the approximate pupil position by the convergent lens 115. When the integrator 116 is arranged at the approximate pupil position, the illuminance distribution of the incident end face of the integrator 116 is high at the center and is low at the around. However, when total reflection is repeated in transmission by the integrator 116, the illuminance distribution on the emission end face is made uniform. When the integrator 116 is arranged such that the emission end face and the front focal point position approximately coincide with each other, and when the light modulation device 60 is arranged at a position spaced apart from the rear focal point position of the collimator lens 153, the distribution of a shielded portion (hatched portion shown in FIG. 31 is a shielded portion 111b obtained by the electrodes) indicated by a hatched portion in FIG. 31 is made uniform, and a uniform parallel light can be supplied to the light modulation device 60. In this embodiment, depending on the bright/dark characteristics of an object to be photographed (object to be observed), when the object is tubular, a plurality of selection switches 131a for selecting an object which is convex at the center or the like are arranged on the operation panel 131. By the selection operation of the selection switches 131a, the light distribution pattern generation circuit 66 generates a corresponding light distribution pattern. The other configuration in this embodiment is the same as that in FIG. 17. The operation of this embodiment will be described below. In this embodiment, a light reflected by the light modulation device 60 is guided to the end face 156a on the incident side of the light guide 156 of the electronic endoscope 152 arranged at the approximate pupil position by the condensation lens system 154, and a light transmitted from the distal end face 156b of the light guide 156 is delivered to illuminate an object to be photographed such as an affected part. When a tubular object to be photographed has a dark central portion and a bright periphery is used, the selection switch 131a for the tubular object is operated, light distribution patterns shown in FIGS. 32A, 32B, and 32C are generated. In this case, when the difference of the brightnesses of the central portion and the around portion is on a low level, the pattern in FIG. 32A is obtained; when the difference is on an intermediate level, the pattern shown in FIG. 32B is obtained; and when the difference is on a high level, the pattern shown in FIG. 32C is obtained. The light distribution pattern generated by the light distribution pattern generation circuit 66 and a brightness pattern from the pattern generation circuit 64 are synthesized with each other by the synthesizing circuit 65 to output the synthesized pattern to the DMD drive circuit 68 through the DMD control circuit 67, and the light modulation device 60 is driven by an output signal from the DMD drive circuit 68. FIG. 33 shows a manner in which an object to be photographed is illuminated with a light reflected by the light modulation device 60 having a micromirror having the light distribution pattern in FIG. 32A. In FIG. 33, a micromirror portion in which a light is not incident on the light guide is indicated by a hatched portion. In this case, a micromirror (hatched portion) having a distance d from an optical axis O is in a state in which a light is not incident on an end face 106a on the incident side of a light guide 106. When the light is incident at the angle, a coaxial angle distribution is obtained on the emission side due to the characteristics of the light guide. When a light is irradiated from a distal end face 106b of the light guide 106 onto the object, the peripheral portion is darker than the central portion. More specifically, in FIG. 33, for example, in a state in which an angle-.theta. portion indicated by a halftone portion is shielded by a shield reflection portion having the distances d to d1, when a light is incident on the end faces 106a on the incident side of the fibers of the light guide 106, the light is transmitted through the fibers and emitted from the distal end face 106b, the light is emitted to the object in a state in which the angle-.theta. portion is darker than the central portion in the form of coaxial circles. Therefore, on the light modulation device 60 side, for example, when all ring portions each having the distances d to d1 are set in the state of the shield reflection state, the angle-.theta. portion of the object on the object side is entirely dark. In general, on the light modulation device 60 side, in the ring portion having a distance from the optical axis O, when a ratio of the area of the shielded portion in the ring portion to the area of the ring portion is high, the coaxial angle portion corresponding to the distance becomes dark. FIG. 33 shows a manner in which a light is incident or emitted by one fiber. However, the same operation is performed by a bundle of fibers. For this reason, when a tubular object to be photographed is illuminated by employing the light distribution pattern, the dark portion on the center side can be illuminated with a light having a higher intensity. In comparison with a case in which an object is uniformly illuminated, the brightness distribution of an object image is flattened and easily diagnosed. Therefore, with simple brightness correction, an image having a brightness at which the image can be diagnosed can be obtained. According to the embodiment, when the simple light distribution pattern is used as described above, an illumination state in which a tubular object can be easily diagnosed can be set. In addition, when an object to be photographed having a central portion which is projected as a projection is uniformly illuminated, the projected portion is too bright. For this reason, when the selection switches 131a, arranged on the operation panel 131, for an object having a central portion which is projected is selectively operated, light distribution patterns shown in FIGS. 34A, 34B, and 34C are generated. In this case, the difference between the brightness of the central projected portion and the brightness of the peripheral portion is on a low level, the light distribution pattern shown in FIG. 34A is obtained; when the difference is on an intermediate level, the pattern shown in FIG. 34B is obtained; when the difference is on a high level, the pattern shown in FIG. 34C is obtained. Also in this case, by a simple light distribution, an illumination state in which diagnosis can be easily performed can be set even though an object to be photographed which is projected at the central portion is used. In the embodiment, when the light modulation device 60 is arranged at the pupil position, coaxial light distribution control is performed. The other operation is performed as in the third embodiment. The embodiment has an advantage that such illustration that an image which can be easily diagnosed by a light distribution pattern depending on the brightness/darkness distribution of an object to be photographed is performed. As shown in FIG. 30, an optical system in which the convergent lens 154 is arranged to locate the light modulation device 60 at an approximate pupil position can be applied to a light source device having a configuration different from the optical system shown in FIG. 27. FIG. 35 shows an optical system in a modification in which uneven illumination is prevented from being performed. In this modification, a vertical light source lamp 111 perpendicular to an optical axis is employed. As described above, for example, the light source lamp 111 shown in FIG. 28 is of a horizontal type in which both the electrodes are arranged in the direction of an optical axis. However, in FIG. 35, both the electrodes are vertical to the optical axis. A light forwardly emitted from a portion between both the electrodes and a light backwardly emitted and reflected by a spherical mirror 171 are incident on a convergent lens system 172 for converging a parallel flux of light to be converted into a parallel flux of light. The flux of light passes through an IR/UV cut filter 173 for cutting infrared rays and ultraviolet rays, and only a white light component is transmitted through the IR/U cut filter 173. The white light component is incident on the light modulation device 60. The reflected light reflected by the light modulation device 60 arranged at an approximate pupil position is converged by the convergent lens system 154 to be incident on the light guide 156 in which the end face 156a on the incident side is arranged. In this case, the shield by both the electrodes does not affected to the light being incident on the light modulation device 60, uneven illumination is reduced. FIG. 36 shows a modification in which a light reflected by the mirror 61 in FIG. 17 is incident on the light modulation. device 60, for example. The light from the lamp 111 is reflected by a concave mirror 181 having a converging function to be converged on one point. Thereafter, the converged light is enlarged and reflected by the concave surface of a spherical mirror 182 to obtain a parallel flux of light. The resultant light is incident on the light modulation device 60 arranged at an approximate pupil position, and the reflected light is incident on the end face 156a on the incident side of the light guide 156 by the convergent lens 154. In the embodiments described above, even though the light guide is a bundle of optical fibers which are not arrayed, an intensity distribution obtained by an incident angle of the incident light is stored, and the intensity distribution is used as the intensity distribution of an emitted light. For this reason, light distribution control is effectively operated. As the light guide, not only a light guide constituted by a bundle of optical fibers, but also a liquid type light guide may be used. In the third to sixth embodiments, as the light source lamp 111, a lamp having a high luminance is preferably used, and a high-pressure arc discharge lamp such as a xenon lamp or a metal halide lamp is preferably used. As the lamp 111, a tungsten lamp or a halogen lamp may also be used. In addition, in each of the embodiments described above, a rigid endoscope, an electronic endoscope, or the like is used as an endoscope. However, another endoscope (rigid endoscope, optical flexible endoscope, electronic endoscope, side-viewing endoscope, and a stereoscopic endoscope, or the like), e.g., any endoscope in which an illumination light is supplied from a light source device to be irradiated from the distal end onto a portion to be observed may be used. The seventh embodiment of the present invention will be described below with reference to FIGS. 37 to 40. An endoscope device 201A according to the seven them bodiment of the present invention shown in FIG. 37 comprises a TV-camera-connected endoscope 204A obtained by connecting a TV camera 203 to an optical endoscope device 202, a light source device 205 for supplying an illumination light to the optical endoscope device 202, a camera control unit (to be referred to as a CCU hereinafter) 206 for performing signal processing to an image pickup element incorporated in the TV camera 203, and a monitor 207 for displaying a video signal from the camera control unit 206. The optical endoscope device 202 is constituted by, e.g., a rigid endoscope. The rigid endoscope has a rigid and narrow and long insertion portion 208, a grasping portion (operation portion) 209 arranged at the rear end of the insertion portion 208 and having a large diameter, and an eyepiece portion 210 arranged at the rear end of the grasping portion 209. A light guide connector 212 at the other end of a light guide cable 211 having a proximal end connected to the grasping portion 209 is detachably connected to a light guide connector support 213 of the light source device 205. A camera head 214 of the TV camera 203 is connected to the eyepiece portion 210, and a signal connector 216 at the end of a camera cable 215 extending from the camera head 214 is detachably connected to a signal connector support 217 of the CCU 206. In addition to the light guide connector support 213, a power supply switch and an operation panel 218 are arranged on the front surface of the light source device 205, and a light intensity setting switch 219 is arranged on the operation panel 218. The signal receptacle 217 and a color balance setting switch 220 are arranged on the front surface of the CCU 206. FIG. 38 shows the detailed configuration of FIG. 37. A light guide 221 for transmitting an illumination light is equipped in the insertion portion 208 of the optical endoscope 202, and an illumination light from the light source device 205 is supplied to the light guide cable 221 through a light guide cable 211 (of light guide). This illumination light is transmitted to the distal end face, and forwardly delivered through a projection lens system 222 attached to an illumination window to illuminate a portion to be observed such as an affected part in a peritoneal cavity. An objective lens system 223 is attached to an observation window adjacent to the illumination window to form an optical image of the illuminated object to be photographed. This image is transmitted to the eyepiece portion 210 by a relay lens system 224. Magnifying observation can be performed from the eyepiece portion 210 through an eyepiece lens 225. At the same time, when the camera head 214 is connected to the eyepiece portion 210, an image is formed through an image forming lens 226, e.g., a charge coupling element (to be abbreviated as a CCD) is arranged at the image forming position as an image pickup element, and photoelectric conversion is performed by the CCD 227. A color separation filter 228 such as a mosaic filter or the like for separating wavelength components of R, G, and B is arranged on the image pickup surface of the CCD 227 to separate colors to the pixels. A light source lamp 231 for generating an illumination light is arranged in the light source device 205. The light from the light source lamp 231 is converted by, e.g., a parallel lens (collimator lens) 232 into a parallel flux of light, and the parallel flux of light is incident on a light modulation device 233 of a reflective type. The light reflected by the light modulation device 233 and being incident on a convergent lens system 234 is condensed by the condensation lens system 234 to be incident on one end face of an integrator 235. The incident light is made uniform and transmitted from the other end face. The light is condensed by a condensation lens 236 to be incident on the end face on proximal side of the light guide connector 212. The light passes from the distal end face of the light guide 221 through the projection lens system 222 to illuminate a portion to be observed, and the optical image of a portion to be observed is formed by the objective lens system 223. The image is transmitted through the relay lens system 224 to form an image on the CCD 227. A CCD drive signal is applied from a CCD drive circuit 241 in the CCU 206 into the CCD 227. The signal is subjected to photo electric convers iontoreadan accumulated signal charge, and is input to a video signal processing circuit 242 in the CCU 206. The video signal processing circuit 242 separates the input CCD output signal into a luminance signal and a color-difference signal by a color separation circuit, and the luminance signal and the color-difference signal are converted into RGB chrominance signals by a matrix circuit. The RGB chrominance signals are output to the monitor 207 as standard video signals (together with not shown a synchronous signal). Timing signals are input from a timing generation circuit 243 to the CCD drive circuit 241 and the video signal processing circuit 242. The CCD drive circuit 241 and the video signal processing circuit 242 perform generation of a CCD drive signal and video processing in synchronism with the timing signals. In the video signal processing circuit 242, RGB chrominance signals from the video signal processing circuit 242 are input to a detection circuit (correction signal generation circuit) 244. When the color balance setting switch 220 is operated, by controlling a CPU 245, the respective RGB chrominance signals in one frame period are integrated with each other to detect a shift value (or a relative ratio of the respective chrominance signals) from, e.g., a reference value (to achieve a color balance), thereby generating a correction signal. The correction signal is converted into a transmission signal by a communication control unit 246 for performing communication control, and the resultant signal is transmitted to an I/F 251 on the light source device 205 located outside the CCU 206 by a transmission cable 248 through an interface (to be abbreviated as an I/F)247. In the light source device 205, a signal transmitted to the I/F 251 is converted (modulated) into a signal before transmission by a communication control unit 252. There sultant signal is input to a control signal generation circuit 253. A timing signal from the timing generation circuit 243 is also input to the control signal generation circuit 253. The control signal generation circuit 253,controls the (light modulation device) drive circuit 254 in synchronism with the timing signal, so that the light modulation device 233 can be driven by a drive circuit 254. FIG. 39 shows the light modulation device 233. In the light modulation device 233, micromirrors (to be simply abbreviated as mirrors) 261 which are operated by an electrostatic field effect and constituted by, e.g., 15-micron-square aluminum materials are regularly and two-dimensionally arranged. The respective mirrors 261 are supported by mirror holding posts on a yoke which can be stably set in two states about diagonals, and can be rotated in the horizontal direction to be kept at, e.g., about .+-.10.degree.. This is called a DMD. In this embodiment, R, G, and B color filters 262 are formed on the reflective surfaces of the micromirrors 261 by, e.g., screen printing or the like in the form of a checkered pattern to form a two-dimensional array element. More specifically, the light modulation device 233 is obtained such that the R, G, and B color filters 262 are formed on the reflective surfaces of the micromirrors 261 in a light modulation device body 233' serving as the DMD. In this embodiment, by applying a drive signal from the drive circuit 254, the mirrors are set at +10.degree. or -10.degree.. When the mirror is set at, e.g., -10.degree., the mirror reflects a light from the light source lamp 231 such that the light is incident on the convergent lens system 234. However, when the mirror is set at +10.degree., the mirror reflects the light from the light source lamp 231 in a direction in which the light is not incident on the convergent lens system 234. For this reason, in this specification, it is called shield or OFF that the mirror 261 of the light modulation device 233 is set at +10.degree. by the drive circuit 254, and it is called non-shield or ON that the mirror 261 is set at -10.degree.. In this embodiment, when the image of a white object to be photographed is picked up, a shift value representing that the level of the chrominance signal is shifted from the reference value is detected, and a correction signal corresponding to the shift value. A drive signal pattern for turning on/off all the mirrors of the light modulation device 233 of the drive circuit 254 is controlled, so that a setting to a white balance state in which the levels of the respective chrominance signals are equal to each other (uniform) can be easily performed by the light source device 205 side. FIGS. 40A to 40D show array patterns of the R, G, and color filters 262 arranged in the two-dimensional array element constituting the light modulation device 233. FIG. 40A shows a mosaic array pattern, and FIG. 40B shows a case in which the R (Red), G (Green), and B (Blue) filters are arrayed in a (longitudinal) line. FIGS. 40D and 40C show the same case in which the filters are arrayed at random such that the filters are not arrayed in a line (veered array). The control signal generation circuit 253 can know the information of an array pattern of the R, G. and B color filters 262 arranged in the two-dimensional array element constituting the light modulation device 233 with an internal memory or the like. The embodiment has the following characteristic feature. That is, the color balance setting switch 220 is operated, so that an illumination light which keeps a white balance state can be easily supplied by the light source device 205. The operation of the embodiment will be described below. The TV camera 203 is attached to the optical endoscope device 202, and the light guide connector 212 of the optical endoscope device 202 is connected to the light source device 205. The signal connector 216 of the TV camera 203 is connected to the CCU 206, the endoscope device 201A is set such that the monitor 207 is connected to the CCU 206. Before a surgery is performed, an object to be photographed such as a sheet of white paper or a white gauze is placed in front of the distal end of the endoscope 202 to obtain a white observation image, and the color balance setting switch 220 is pressed to perform a color balance setting operation. At this time, a color correction signal is transmitted from the CCU 206 to the light source device 205, and a control signal for generating a drive signal for driving the light modulation device 233 of the light source device 205 by the control signal generation circuit 253 on the basis of the correction signal. The ratio of the intensities of R, G, and B lights supplied to the light guide 221 when the light modulation device 233 is driven are controlled to achieve a color balance. For example, when a correction signal which can achieve a color balance when the ratio of the intensities of the R, G, and B lights is set to be 6:2:4 is input to the control signal generation circuit 253, a drive signal which turns off an RGB array pattern indicated by a hatched portion in FIG. 40A when the array pattern shown in FIG. 40A is employed is generated. In FIG. 40A, of 20 R, G. and B color filters 262 which constitute one unit, the 6 R color filters 262 are turned on, the 2 G color filters 262 are turned on, and the 4 B color filters 262 are turned on, so that a color balance is maintained. More specifically, control is performed such that R:G: B=6:2:4 is established, and the colors are mixed by the integrator 235 to achieve a uniform color. The colors are mixed at a ratio of R:G:B=6:2:4, and the light from the distal end of the endoscope 202 illuminates the white object to be photographed. Even in the array pattern shown in FIG. 40B, when the correction signal is input to the control signal generation circuit 253, of 15 color filters constituting one unit shown in FIG. 40B, 3 R color filters 262 are turned on, one G color filter is turned on, and 2 B color filters 262 are turned on, so that a color balance is maintained. More specifically, control is performed such that a ratio of R:G:B=6:2:4 (=3:1:2), and the colors are mixed by the integrator 235 to achieve a uniform color. The colors are mixed at a ratio of R:G:B=6:2:4, and the light from the distal end of the endoscope 202 illuminates the white object to be photographed. In this case, since the color filters 262 are set for lines, respectively, a uniforming function obtained by integrator 235 is sufficiently achieved. Even though control is performed such that a ratio of R:G:B=6:2:4 (3:1:2) is established for each of the RGB lines, the same effect as described above can be obtained. As in the RGB pattern in FIG.40C, the color filters are arranged at random such that the color filters are not arranged in a stripe, or control is performed by using the RGB array pattern shown in FIG.40D, so that an illumination light of the light source device 205 can be uniformly irradiated on the object without causing the integrator 235 to uniformly synthesize a color balance. In this manner, a setting is performed by control on the light source device 205 side to achieve a color balance, and a white object to be photographed is displayed in white on the monitor 207. Preparation for actually performing (endoscope inspection) is completed. For example, pneumoperitoneum is performed to a peritoneal cavity by a pneumoperitoneum device (not shown), and a surgery is observed by the endoscope device 201A under the endoscope. Since an appropriate color balance is set, observation having good color reproduction can be performed. When, e.g., a metal halide lamp is used in the embodiment, the metal halide lamp has a characteristic feature that a color balance of emission lights is changed by aging of the metal halide lamp. The aging deteriorates the color reproduction of an endoscope image. However, as in the embodiment, a color balance is achieved before use, and the color balance is corrected every aging. For this reason, preferable color reproduction can be achieved. When a light source device changed into a xenon lamp is used for the light source lamp 231 in the embodiment, by setting the ratio of RGB emission lights according to the xenon lamp, preferable color reproduction can be similarly achieved. As the light source lamp 231, not only a metal halide lamp or a xenon lamp, but also a discharge tube or a tungsten lamp may be used. Even though these lamps are used, the same effect as described above can be obtained. According to the embodiment, a state in which emission lights have a preferable white balance or the like can be simply obtained by the light source device 205 having the simple configuration. A complex setting operation for a gain to R, G, and B signals in a color balance setting circuit is not required on a video processing means in a prior art. In the embodiment, when a white object to be photographed is set, and the color balance setting switch 220 is operated, a correction signal for driving the light modulation device 233 is input from the detection circuit 244 on the CCU 206 side to the control signal generation circuit 253 of the light source device 205 through the communication control unit 246. The light modulation device 233 is controlled such that the control signal generation circuit 253 emits an illumination light whose color balance is automatically achieved by the correction signal. Not only this configuration, but also the following configuration may be used. A signal for a manual operation is input to the control signal generation circuit 253, so that an illumination light whose a color balance (white balance) is achieved is emitted. For example, in a state in which the image of a white object to be photographed is picked up, the light intensity setting switches 219 for R, G, and B arranged in the light source device 205 are operated such that the image is displayed in white on the monitor 207, and the control signal generation circuit 253 operates the intensity setting switches for R, G, and B to increase/decrease a ratio of ON/OFF states of the micromirrors 261 having the color filters 262 formed thereon. When the object is displayed in white on the monitor 207, a completion switch is pressed to store the data of the state in the internal memory of the control signal generation circuit 253. There after, a drive pattern of the light modulation device 233 may be determined by the data. The eighth embodiment of the present invention will be described below with reference to FIG. 41 and FIGS. 42A to 42D. The same reference numerals as in the seventh embodiment denote the same parts in the eighth embodiment, and a description thereof will be omitted. A field sequential endoscope device 201B shown in FIG. 41 is constituted by an electric endoscope 204B, a light source device 205, a CCU 206B, and a monitor (see FIG. 37) 207. The electric endoscope 204B has a narrow and long insertion portion 208 having flexibility, an operation portion 209 arranged on the rear end of the insertion portion 208, and a universal cable 211B extending from the operation portion 209. A light guide 221 for transmitting an illumination light is inserted into the insertion portion 208 of the electric endoscope 204B, the light guide 221 is inserted into the universal cable 211B, and a light guide connector 212 on the end portion of the universal cable 211B is detachably connected to the light source device 205. An illumination light supplied from the light source device 205 is transmitted through the light guide 221, and the illumination light is emitted from the distal end face to a portion to be observed through an illumination lens 222 attached to an illumination window. A CCD 227 is arranged at the image forming position of an objective lens system 223 attached to an observation window adjacent to the illumination window to perform photoelectric conversion of a formed optical image. The electric endoscope 204B is an electronic endoscope, for field sequential image pickup, which employs a monochromatic CCD 227 having no color separation filter 228 arranged on an image pickup surface of the CCD 227. A signal line connected to the CCD 227 is inserted into a scope cable 215B extending from the light guide connector 212, and a signal connector 216 arranged on the end portion of the signal line is detachably connected to the CCU 206B. The CCU 206B employs a field sequential video signal processing circuit 242B in place of the synchronous video signal processing circuit 242A in the CCU 206 in FIG. 38. A CCD drive circuit 241 has the same configuration as that in FIG. 38. However, since the control signal generation circuit 253 selectively sequentially controls the regions of respective colors on the basis of the timing generation circuit 243 to irradiate a field sequential light on the object to be photographed, luminance components corresponding to the colors can be obtained by image pickup for each frame. In the field sequential video signal processing circuit 242B, a CCD output signal input from the CCD 227 is converted into a digital signal by an A/D conversion circuit (not shown) in the video signal processing circuit 242B. The digital signals are sequentially stored in three frame memories and are simultaneously read in a read operation. RGB chrominance signals are D/A-converted to be output to the monitor 207. The RGB chrominance signal is also input to the detection circuit 244. When the color balance setting switch 220 is operated, the detection circuit 244 detects a shift value from a reference value as described in the seventh embodiment, and transmits a correction signal to the light source device 205. In the seventh embodiment, the correction signal is a signal for driving and controlling the R, G, and B color filters (mirrors having these filters) of the light modulation device 233 (or DMD 233') at once. However, in the eighth embodiment, correction signals are sequentially output to the light source device 205 in synchronism with the R, G, and B field sequential illumination lights. In this embodiment, although the light source device 205 has the same configuration as that of the seventh embodiment, the light source device 205 operates to perform field sequential illumination. The level or time of an emission light from the light source device 205 is made variable according to an image pickup timing of a color field sequential method to achieve a color balance. The operation of the embodiment will be described below. As shown in FIG. 41, the endoscope device 201B is set to turn on the power supply, as shown in a DMD drive state in FIG. 42A, drive signals for sequentially setting a mirror having an R color filter 262 arranged thereon, a mirror having a G color filter 262 arranged thereon, and a mirror having a B color filter 262 arranged thereon in ON states (more specifically, as shown in FIG. 42C, in ON/OFF states by PWM control including an OFF period) are output to cause the R, G, and B illumination light stoper form R, G, and B field sequential illumination. In this case, as shown in FIG. 42B, the DMD 233' is set in a shield state (OFF) of +10.degree. such that a shield period is formed after R, G, and B illumination periods. In an R illumination period in which an R emission light is output, the image of an object to be photographed is picked up to perform charge by the CCD 227 accumulation. After the R illumination, all the mirrors of the DMD 233' are turned off in a read period in which signals accumulated by the CCD 227 are read to set a shield state. Signals read from the CCD 227 are temporarily stored in an R signal memory in a video signal processing circuit 242B. A G emission light is output, and charge accumulation is performed by the CCD 227 in the G illumination period. After the G illumination period, all the mirrors of the DMD 233' are turned off in a read period in which signals accumulated by the CCD 227 to set a shield state. The signals read from the CCD 227 are temporarily stored in the G signal memory in the video signal processing circuit 242B. A B emission light is output, and charge accumulation is performed by the CCD 227 in the B illumination period. After the B illumination period, all the mirrors of the DMD 233' are turned off in a read period in which signals accumulated by the CCD 227 to set a shield state. The signals read from the CCD 227 are temporarily stored in the B signal memory in the video signal processing circuit 242B. The RGB chrominance signals temporarily stored in the R, G, and B signal memories in the video signal processing circuit 242B are simultaneously read and output to the monitor 207 to display an object image as a color image. In this case, when a white object to be photographed is set as an object to be photographed, and the color balance setting switch 220 is operated, RGB chrominance signals in one color frame period are input to the detection circuit 244. A correction signal for achieving a color balance is generated by the detection circuit 244 to be input to the control signal generation circuit 253 of the light source device 205. Before correction (i.e., in a state in which no correction state is input), the control signal generation circuit 253 controls the drive circuit 254 such that R, G, and B emission lights are PWM-controlled by data from an internal memory 253a in which the correction signal obtained in a previous setting. However, when the correction signal is input, the internal memory 253a is updated by a newly input correction signal, and a control signal for performing PWM control by the correction signal is output to the drive circuit 254. For example, when a correction signal for achieving a balance at a ratio of the intensities of R, G, and B lights=7:6:4 is generated, the control signal generation circuit 253 controls the drive circuit 254 such that the DMD emission light of PWM control as shown in FIG. 42C is output. The ratio of the R, G, and B emission lights is 7:6:4 in the R, G, and B illumination periods, and field sequential illumination lights achieving a white balance are output. In endoscope inspection performed thereafter, the drive circuit 254 is controlled by using data stored in the memory 253a, the ratio of the intensities of R, G, and B emission lights obtained by the DMD 233' is kept at 7:6:4. In this manner, in endoscope inspection for an ordinary body cavity, a state in which field sequential illumination is performed in a white balance state is maintained. According to the embodiment, as in the seventh embodiment, the color balance setting switch 220 is pressed before endoscope inspection is performed, so that a setting can be performed such that field sequential illumination lights in a color balance state can be easily emitted from the light source device 205. In the description of the embodiment, the matrix pattern shown in FIG. 42A is employed to control emission lights by PWM control shown in FIG. 42C, thereby achieving a color balance. However, the emission lights are controlled by the matrix pattern shown in FIG. 42D, so that a color balance can be achieved. FIG. 42D is obtained such that, in FIG. 42A, in place of PWM control of mirrors having R, G, and B color filters in R, G. and B illumination periods, of 10 mirrors having R, G, and B color filters arranged thereon, the mirrors are turned on at a ratio of 7:6:4, so that a field sequential light having a color balance can be emitted. More specifically, in accordance with the R, G, and B illumination periods, the emission intensities of respective colors can be controlled by a number controlled by the emission side of the two-dimensional array element. More specifically, the patterns of different two-dimensional array elements are used for R, G, and B as shown in FIG. 42D, ON/OFF control is performed such that the numbers of two-dimensional array elements for R, G, and B are kept at a ratio of R:G:B=7:6:4, so that an illumination light having a color balance can be emitted. In addition, according to the embodiment, without arranging a new shield means, the effect of shield can be obtained by using the light modulation device 233. The ninth embodiment of the present invention will be described below with reference to FIGS. 43 and 44. The same reference numerals as in the seventh embodiment denote the same parts in the ninth embodiment, and a description thereof will be omitted. As shown in FIG. 43 an endoscope device 201C according to the ninth embodiment of the present invention employs a light source device 205C which employs a light modulation device 233C which is partially different from the light modulation device of the seventh embodiment. In the seventh embodiment, the R, G, and B color filters 62 are formed on the micromirrors 261 by screen printing or the like. In the ninth embodiment, the light modulation device 233C in which R, G, and B filters 265 arranged in a checked pattern are formed immediately before the micromirrors 261 is employed. FIG. 43 is a block diagram for explaining the schematic configuration and the operation of the light modulation device 233C. As shown in FIG. 44, the light modulation device 233C comprises a light modulation device body 233' having the micromirrors 261 and the R, G, and B filters 265 arranged in a checked pattern before the light modulation device body 233' (note that the light modulation device 233 according to the seventh embodiment has a configuration in which the R, G, and B filters 262 are directly formed on the micromirrors 261 in the light modulation device body 233'). As shown in FIG. 44, the micromirrors 261 set at -10.degree. and +10.degree. are defined as micromirrors 261a, 261b, and 261c, a light is incident on the light modulation device 233C through the parallel lens 232, the reflected light is incident on the condensation lens system 234 when the micromirror is set at -10.degree., and is set in a state similar to a shield state in which the light is completely deviated from the incident direction of the condensation lens system 234 when the micromirror is set at +10.degree.. The micromirrors 261 are set at -10.degree. or +10.degree.by a drive signal from a drive circuit 254, and an illumination light from the light source lamp 231 is reflected. The light is set in a shield state in which the light is used or not used in illumination, so that an operational effect which is substantially the same as that of the seventh embodiment can be obtained. The tenth embodiment of the present invention will be described below with reference to FIGS. 45 to 46B. The same reference numerals as in the seventh embodiment denote the same parts in the seventh embodiment, and a description thereof will be omitted. An endoscope device 201E according to the tenth embodiment of the present invention shown in FIG. 45, for example, in the seventh embodiment, the CCU 206 further comprises a brightness light intensity adjustment signal generation unit 281 to obtain a CCU 206E having the following configuration. The brightness light intensity adjustment signal generation unit 281 integrates a chrominance signal output from a video signal processing circuit 242E in an appropriate frame period to generate an average brightness signal. A shift signal from a signal from a reference value setting unit 282 for outputting a reference level signal corresponding to a reference brightness is output to a communication control unit 246 as a light intensity adjustment signal. The communication control unit 246 transmits the light intensity adjustment signal to an I/F 251 through I/F 247, modulated by a communication control unit 252, and output to a control signal generation circuit 253. The control signal generation circuit 253 controls a drive circuit 254 depending on the light intensity adjustment signal when an automatic light intensity adjustment switch 283 is turned on and keeps a white balance state to increase or decrease an illumination light intensity. The control signal generation circuit 253 performs control such that an average brightness signal is equal to a reference level. The value of the reference level of the reference value setting unit 282 can be variably set by a setting switch 284. The other configuration is the same as that in the seventh embodiment. The operation of the this embodiment will be described below. An operation performed when a power supply is turned on and when a color balance setting switch 220 is operated is the same as that in the seventh embodiment. A state in which an illumination light is emitted in a white balance state is set. In this case, the white balance state is kept as described in the operation in the seventh embodiment, a ratio of R, G, and B color filters used in illumination is set to be a:b:c. In this case, when a portion to be observed is observed, when a brightness signal in an illumination state at this time, e.g., a brightness light intensity adjustment signal for increasing an illumination light intensity by d% is generated, on the basis of the number of R, G, and B color filters which are turned on at this time, the R, G, and B filters are turned on at rates of a/(a+b+c).times.d/100, b/(a+b+c).times.d/100, and c/(a+b+C).times.d/100. In this case, the ratio of a:b:c is set to be 3:2:1. When a brightness light intensity adjustment signal for increasing an illumination light intensity by 50% is generated in the state shown in FIG. 46A, the state shown in FIG. 46B is obtained. More specifically, in the state in FIG. 46A (R, G, and B color filters are arrayed in a vertical line, six of the nine R color filters are turned on, four of the nine G color filters are turned on, and two of the nine B color filters are turned on), when a brightness light intensity adjustment signal for increasing the illumination light intensity by 50%, as shown in FIG. 46B, a state in which nine of the nine R color filters are turned on, six of the nine G color filters are turned on, three of the nine B color filters are turned on is set. With this change, a ratio of the ON R, G, and B color filters is equal to a ratio before the change (i.e., 6:4:2.fwdarw.9:6:3), and a white balance state is maintained. The illumination light intensity increases from 12/27 to 18/27, i.e., by 50%. In this manner, according to this embodiment, automatic brightness control can be easily performed in a state in which a white balance is maintained. In this embodiment, the present invention is applied to a synchronous method. However, the present invention can also be applied to field sequential illumination. As is apparent from the FIGS. 38 and FIG. 41, the light source device 205 can be used as a light source device for a synchronous method and a field sequential method. The light source device can be realized by a simple structure, i.e., such that the light modulation device 233 or the like can be used on a single chip. Even though a single plate is used, the light source device can be used as a light source device of an endoscope device in both the field sequential method and the synchronous method. An embodiment or the like obtained by partially combining the embodiments described above to each other also belongs to the present invention. The eleventh embodiment of the present invention will be described below with reference to FIGS. 47 to 50. As shown in FIG. 47, an endoscope device 301 according to the embodiment comprises an electric endoscope 302 which is inserted into a tubular cavity in, e.g., a body cavity to pick up a tissue image in vivo, a light source device 303 for supplying an illumination light to the electric endoscope 302, and a video signal processing device 306 for processing the image pickup signal picked by the electric endoscope 302. A light guide 307 serving as an optical transmission means for transmitting an illumination light supplied from the light source device 303 to the distal end of an insertion portion 304 is equipped in the electric endoscope 302, and a CCD 308 for picking up the image of a portion to be observed is arranged in the distal end of the insertion portion 304. The electric endoscope 302 is connected to the light source device 303 through a light guide connector 309 and connected to the video signal processing device 306 by a connector 310 through the light guide connector 309. In this manner, an image pickup signal from the CCD 308 is output to the video signal processing device 306 through the light guide connector 309. The optical system of the light source device 303 is described. When an illumination light is generated from an illumination lamp 311, the illumination light is emitted as a parallel light by a parabolic mirror 312 arranged on the illumination lamp 311. An infrared ray of the parallel light emitted from the illumination lamp 31.1 is cut infrared rays by a infrared cut filter 313, and the parallel light is incident on dichroic mirrors 351 and 352. A transmission light of the dichroic mirror 352 is incident on a total reflection mirror 353. Here, the dichroic mirror 351 reflects an R light component and transmits the other light components. The dichroic mirror 352 reflects a G light component and transmits the other light components. The reflected light of the dichroic mirror 351 is incident on a light modulation device 354, and the reflected light from the light modulation device 354 is incident on a total reflection mirror 355. Similarly, the reflected light from the dichroic mirror 352 is incident on a light modulation device 356, and the reflected light from the light modulation device 356 is incident on a dichroic mirror 357. The reflected light from the total reflection mirror 353 is incident on a light modulation device 358 as a B-component, and the reflected light from the light modulation device 358 is incident on the dichroic mirror 359. The reflected light (R) from the total reflection mirror 355 is transmitted through the dichroic mirror 357, and a light transmitted through the dichroic mirror 357 is incident on the dichroic mirror 359 and condensed on the incident end face of the light guide 307 by a condensation lens system 325. The light (B) reflected by the dichroic mirror 357 is incident on the dichroic mirror 359, transmitted through the dichroic-mirror 359, and condensed on the incident end face of the light guide 307 by the condensation lens system 325. The light (G) reflected by the dichroic mirror 359 is condensed on the incident end face of the light guide 307 by the condensation lens system 325. The lights controlled by the light modulation devices 354, 356, and 358 are emitted from the light source device 303 as field sequential lights as shown in FIG. 48. The light modulation devices 354,356, and 358 are elements each having the following configuration. A small micromirror having a size of 640.times.480 is arranged on a silicon chip, and the mirror is held by a holding member on a yoke rotated about diagonals between two stable states and can be changed at +10.degree. in the horizontal direction. The element is called a DMD (digital micromirror device), is driven by a DMD control circuit 360 on the basis of a drive pattern from a drive pattern generation circuit 345, and is arranged such that a reflected light is output from the light source when the micromirror (two-dimensional array element) is set at -10.degree.. In addition, the timing of the shield period of the CCD 308 can be obtained such that shield is performed when the micromirrors (two-dimensional array elements) of the light modulation devices 354, 356, and 358 are controlled at +10.degree.. As the illumination lamp 311, a high-luminance lamp such as a short work xenon discharge tube or a metal halide lamp is preferably used. The video signal processing device 306 comprises a CCD drive circuit 331 for driving the CCD 308, a video signal processing circuit 332 for processing an image pickup signal from the CCD 308 and outputting a video signal (e.g., an NTSC television signal) to a monitor 305, a timing generation circuit 333 for generating a timing signal for synchronizing the image pickup timing of the CCD 308 with signal processing in the video signal processing circuit 332, and a timing synchronous signal generation circuit 334 for outputting a timing synchronous signal synchronized with the timing signal of the timing generation circuit 333. A light source device 303 comprises a sensor 341 for detecting an emission light from the condensation lens system 325, a color detection circuit 342 for detecting a color component of the emission light detected by the sensor 341, a color comparison circuit 344 for comparing a color preset by the color setting circuit 343 with the color component, a drive pattern generation circuit 345 for generating a drive pattern for controlling the light modulation devices 354, 356, and 358 on the basis of a comparison result of the color comparison circuit 344, a DMD control circuit 360 for driving the light modulation devices 354, 356, and 358 on the basis of the drive pattern, a timing synchronous circuit 347 for controlling a generation timing of the drive pattern in the drive pattern generation circuit 345 on the basis of the timing synchronous signal from the timing synchronous signal generation circuit 334, and a lamp power supply 348 for turning on the illumination lamp 311 to constitute a field sequential output light control unit. The operation of the embodiment will be described below. In the light source device 303, an emission light is detected by the sensor 341, and the color component of the detected emission light is detected by the color detection circuit 342. The color component of the emission light detected by the color comparison circuit 344 is compared with an output from the preset color setting circuit 343, and a color control signal is output to the drive pattern generation circuit 345 for generating a drive pattern for controlling the light modulation devices 354, 356, and 358 on the basis of a comparison result. In the drive pattern generation circuit 345, a drive pattern for determining an output level when field sequential colors is output to the DMD control circuit 360. The DMD control circuit 360 drives the light modulation devices 354, 356, and 358 such that the two-dimensional array elements are arranged in the determined drive pattern. The field sequential output light control unit of the light source device 303 sets a reflection state (-10.degree. state) in which the light modulation devices 354, 356, and 358 guide lights to the light guide 307 at field sequential light emission timings by a timing of the timing synchronous circuit 347 which is synchronous with an image pickup timing of the CCD 308 and a reflection state (+10.degree. state) in which the light modulation devices 354, 356, and 358 do not guide lights. Field sequential output timings, as shown in FIG. 48, are timings at which RGB lights are sequentially irradiated. As shown in FIG. 48, the light modulation devices 354, 356, and 358 are set in the -10.degree. reflection state and the +10.degree. reflection state in which lights are not guided by the drive pattern at the field sequential light emission timings, so that the levels of the emission lights of the R, G, and B colors are changed. In the shield period in FIG. 48, all the light modulation devices 354, 356, and 358 are set in the +10.degree. state. In this manner, a color balance can be set at a ratio of R:G:B=8:7:9 as shown in FIG. 50. More specifically, in the drive pattern generation circuit 345, in order to control of output lights of respective colors, the levels of the emission lights are changed by using a light intensity control pattern of the two-dimensional array element as shown in FIG. 49. The embodiment has the following effect. In this manner, in the embodiment, even though the video signal processing device 306 is not set, when the color balance of an illumination light automatic supplied by a light source 303 is made appropriate, an endoscope image can be observed with appropriate color reproduction. In addition, when the light modulation devices are used for respective colors, control can be performed without using a field sequential rotation filter, and light intensity levels of the respective colors can also be adjusted at the same time. The twelfth embodiment of the present invention will be described below with reference to FIGS. 51 to 53. In this embodiment, a light source device has the following structure. That is, as shown in FIG. 51, in place of the electric endoscope 302, a rigid endoscope 382 in which a TV camera head 381 is detachably connected to the eyepiece portion is used. Lights from the illumination lamp 311 are incident on light modulation devices 384, 385, and 386 constituted by DMDs at an angle of +10.degree., and the reflected lights from the light modulation devices 384, 385, and 386 are directed at +10.degree. to be condensed on the light guide 307 by the condensation lens system 325. The light source device comprises an optical prism system 387 for dividing the lights being incident on the light modulation devices 384, 385, and 386 into R, G, and B lights. The configuration of the optical prism system 387 is constituted by five prisms 391, 392, 393, 394, and 395 based on the thought opposite to that of a three-color separation prism. The optical prism system 387 may be called a three-color dividing/synthesizing prism. The optical prism system 387 efficiently transmits the light from the illumination lamp 311, and, at the same time, the positional relationships of the pixels (two-dimensional array elements) of the mirrors of the RGB DMDs are equal to each other, so that effective control can be performed. This configuration is known as the configuration of a projector using DMDS. The embodiment has a characteristic feature in which the DMDs are operated in synchronism with image pickup of a CCD as an illumination light source to be applied to the endoscope device. More specifically, the light from the illumination lamp 311 is incident on the prism 391, and other rays than an infrared ray is reflected by a reflective surface Sa of the prism 391. The light transmitted through the prism 391 is emitted to the opposite surface of the prism 392. It is desirable that an absorbing member for the light transmitted from the prism 392 is arranged. The light reflected by the reflective surface Sa is incident on the prism 393, and a B region is reflected by a reflective surface Sb. The light transmitted through the reflective surface Sb is incident on the prism 394, and an R region is reflected by a reflective surface Sc. The light transmitted through the reflective surface Sc serves as a G region, and the G region is incident on the prism 395. The light transmitted through the prism 395 is incident on the light modulation device 384. Here, in the light modulation devices 384, 385, and 386, micromirrors each having a size of about 15 .mu.m are arranged in the form of a lattice having a size of 1024.times.768, and the angles of the respective micromirrors are controlled to be -10.degree. and +10.degree.. A control signal therefor is generated by a DMD control circuit 370. The micromirrors of the light modulation device 384 are driven by the DMD control circuit 370, and a light reflected by a micromirror controlled at+10.degree.linearly propagates through the prism 395 toward the condensation lens system 325 at an incident angle of 0.degree. set with respect to the light guide. The light of the R region reflected by the reflective surface Sc is incident on the light modulation device 385. Similarly, the positional relationships of the micromirrors of the light modulation device 385 and the light modulation device 384 are equal to each other. Since the mirrors having equal positional relationships are driven at +10.degree., in the same manner as described above, the light reflected by the light modulation device 385 is synthesized with the light of the G region from the light modulation device 384 by the prism 394. The resultant light propagates at a light (G+R) toward the condensation lens system 325. The relationship between the prism 393 and the light modulation device 386 is the same as described above. The lights (G+R+B) are synthesized with each other by the prism 393. The resultant light propagates through the prism 391, is transmitted through the prism 392, is incident on the condensation lens system 325, and is incident on the light guide 307. The light modulation devices 384, 385, and 386 are driven by the DMD control circuit 370 on th |