JP2006078626A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector attaining high-luminance and natural white balance while restraining signal processing utilizing a luminance value to the minimum. <P>SOLUTION: In the projector 10, respective color light beams LB, LR and LG, that is, image light beams modulated by respective liquid crystal panels 51b, 51r and 51g are composed by a cross dichroic prism 60, and then made incident on a projection lens 70. The image light beam made incident on the projection lens 70 is projected to a screen. In the case of assembling the color separation optical system 40 or the like of the projector 10, the illuminance of the green light beam LG illuminating the liquid crystal panel 51g can be changed by adjusting the position of the reflection mirror 42c, so that the respective liquid crystal panels 51b, 51r and 51g can be illuminated with desired balance. Therefore, the white balance of a color image composed by passing through the respective liquid crystal panels 51b, 51r and 51g and projected to the screen by the projection lens 70 is easily adjusted. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a projector that projects an image using a light modulation device such as a liquid crystal panel.

  As an illumination device for a liquid crystal panel incorporated in a conventional projector, light source light from a white light source is separated into three colors, a relay optical system is disposed on the red illumination optical path, and the optical path lengths for the remaining green and blue There are those that compensate for the difference (see Patent Documents 1, 2, and 3).

  As another lighting device for liquid crystal panels, the light source light from the white light source is separated into three colors, and a relay optical system is arranged on the blue illumination light path, and the difference in optical path length with respect to the remaining two colors is determined. There is something to compensate (see Patent Document 4). In this projector, among the three lenses constituting the relay optical system, the center lens can be moved in the optical axis direction, for example, so that the size of the illumination area with respect to the liquid crystal panel can be enlarged and reduced. Is being used effectively.

As another illumination device for a liquid crystal panel, light source light from a white light source is separated into three colors, and light guide means such as a relay optical system is disposed on the green illumination light path, and the remaining two colors are provided. There is one that compensates for the difference in optical path length (see Patent Document 5).
Japanese Patent Laid-Open No. 10-171045 JP 2003-287804 A JP-A-11-242184 JP 11-64977 A WO94 / 22042

  However, in an illuminating device in which a relay optical system is arranged on the red illumination optical path, red is relatively weak compared to other colors due to the use of, for example, a high-pressure mercury lamp as a light source, and white balance is reduced. It may not be possible to adjust properly. In such a case, white balance can be achieved by signal processing for adjusting the luminance value of the image signal to be input to the liquid crystal panel, but there is a problem that the brightness and contrast of the image are lowered.

  In addition, in the illumination device in which the lens provided in the blue light path is movable in the optical axis direction, it is possible to reduce the loss of green light that is relatively short of light amount, and to prevent the waste of illumination light. The white balance bias due to the light emission characteristics of a high-pressure mercury lamp or the like cannot be positively resolved.

  Also, in an illuminating device in which a relay optical system is arranged on the green illumination optical path, the white balance often varies greatly from product to product due to light emission characteristics such as a high-pressure mercury lamp, and the image signal to be input to the liquid crystal panel Signal processing for greatly adjusting the luminance value of the.

  Accordingly, the present invention provides a high-brightness and natural white balance while minimizing signal processing using luminance values even when using a lamp light source having a certain tendency in spectral characteristics such as a high-pressure mercury lamp. An object of the present invention is to provide a projector that can achieve the above.

  In order to solve the above-described problems, a projector according to the present invention includes (a) an illumination device that emits illumination light, and (b) the first to third color lights branched from the illumination light emitted from the illumination device. A color separation optical system that guides the first to third color lights to the first to third optical paths, respectively, and (c) a first optical system disposed on the first to third optical paths and illuminated by the first to third color lights, respectively. To a third light modulation device, wherein (d) the distance from the illumination device to the third light modulation device is the distance from the illumination device to the first light modulation device and the second light modulation from the illumination device. (E) in the third optical path, the first lens disposed on the light incident side, the second lens disposed on the light exit side, and the first and second lenses A third lens disposed between and a first lens side of the third lens A relay optical system including a first mirror for bending the optical path disposed and a second mirror for bending the optical path disposed on the second lens side of the third lens; (f) At least one of the first and second mirrors is held on the third optical path, and at least one of the first and second mirrors can be displaced along the reflecting surface in a direction in which the light source image becomes more blurred. A mirror support member is provided. The first and second mirrors of the color separation optical system are held at a tilt angle of, for example, 45 ° with respect to the optical axis of the third optical path by the mirror support member. In this case, the third optical path is It is bent 90 ° at the position of the first and second mirrors.

  In the projector, the mirror support member can displace at least one of the first and second mirrors in a direction in which the light source image becomes more smeared along the reflection surface, and the amount of displacement of the one mirror is appropriately set. By adjusting, partial “vignetting” can be generated in the illumination light. That is, the illumination light can be discharged as unnecessary light outside the third optical path by an appropriate amount. As a result, the illuminance of the illumination light on the image forming area of the third light modulation device can be adjusted to a substantially target value, and a target white balance can be achieved. Note that, by setting the direction in which at least one of the first and second mirrors is displaced to be a direction in which the light source image becomes more unclear, vignetting can be generated in the illumination light at a portion where the light source image becomes clearer. Therefore, the uniformity of the illumination light incident on the third light modulation device is hardly impaired.

  In a specific aspect or aspect of the present invention, in the projector, the first to third color lights are blue light, red light, and green light, respectively. In this case, since the relay optical system is arranged on the third optical path for green light, a loss of green light is likely to occur. However, a lamp light source with a large amount of green light is rather advantageous for achieving natural white balance. Will have a negative impact. In this case, since the green light has a relatively high visibility, it has a great influence on the white balance. However, since at least one of the first and second mirrors constituting the relay optical system can be displaced, the green light It is possible to adjust the illuminance on the image forming area of the third light modulation device to substantially the target value.

  In another specific aspect of the invention, the relay optical system forms a light source image in the vicinity of the third lens, and the mirror support member attaches at least one of the first and second mirrors to the third lens. Displacement in the direction away from the lens causes vignetting on the third lens side. In this case, using the fact that the light source image is formed in the vicinity of the third lens, the illumination light incident on the third light modulation device is displaced by displacing at least one mirror in the direction away from the third lens. The amount of light can be adjusted easily and reliably.

  In another specific aspect of the present invention, a mirror closer to the light source image formed in the vicinity of the third lens among the first and second mirrors can be displaced. In this case, vignetting can be generated in the illumination light by the mirror corresponding to the portion where the light source image becomes clearer, so that the uniformity of the illumination light incident on the third light modulation device can be further improved.

  In another specific aspect of the present invention, the illumination device includes a light source device that generates light source light and a uniformizing optical system that equalizes the light source light from the illumination device. In this case, since the illumination light incident on the relay optical system can be made uniform in advance, the third light modulation device can be illuminated with illumination light with high uniformity.

  In another specific aspect of the invention, the homogenizing optical system includes two fly's eye optical systems. In this case, a large number of light source images corresponding to the arrangement of the optical elements of the fly-eye optical system are formed, for example, in the vicinity of the third lens in the relay optical system. By cutting by moving the mirror, it is possible to efficiently adjust the illuminance on the image forming area of the third light modulation device.

  In another specific aspect of the present invention, a light combining optical system for combining image light of each color obtained by modulating the first to third color lights with the first to third light modulation devices, and the light combining optical system And a projection optical system for projecting synthetic light emitted from the projector. In this case, the color image synthesized by the light synthesizing optical system can be projected on the screen at a desired size by the projection optical system.

  In another specific aspect of the invention, the mirror support member includes a guide member that holds at least one of the first and second mirrors slidably along the direction of the reflecting surface, and the first and second mirrors. A drive member that moves at least one of the mirrors along the guide member. In this case, at least one of the mirrors can be displaced simply and with high accuracy.

  FIG. 1 is a diagram illustrating a projector according to an embodiment of the invention. The projector 10 includes a light source device 20 that generates light source light, a uniformizing optical system 30 that uniformizes illumination light from the light source device 20, and illumination light that has passed through the uniformizing optical system 30 in three colors of red, green, and blue. A color separation optical system 40 that divides into colors, a light modulation unit 50 that is illuminated by illumination light of each color emitted from the color separation optical system 40, and a cross dichroic prism that combines modulated light of each color from the light modulation unit 50 60 and a projection lens 70 that projects image light that has passed through the cross dichroic prism 60 onto a screen (not shown). Among the above, the light source device 20 and the uniformizing optical system 30 function as an illumination device that emits illumination light.

  Here, the light source device 20 includes a lamp main body 21 that forms a substantially dot-like light emitting portion, and a parabolic concave mirror 22 that collimates the light source light emitted from the lamp main body 21. Among these, the lamp body 21 is composed of, for example, a high-pressure mercury lamp, and emits substantially white light source light. Further, the concave mirror 22 reflects the light beam emitted from the lamp body 21 and causes it to enter the uniformizing optical system 30 as a parallel light beam. Instead of the parabolic concave mirror 22, a concave mirror that is not parabolic, such as a spherical surface or an elliptical surface, may be used. When such a concave mirror is used, a parallel light beam can be emitted from the light source device 20 by arranging a parallelizing lens between the concave mirror 22 and the homogenizing optical system 30.

  The homogenizing optical system 30 includes a pair of fly-eye optical systems 31 and 32 for wavefront division, a superimposing lens 33 for superimposing wavefront divided light, and a polarization conversion member 34 for converting illumination light into a predetermined polarization component. And enables Koehler illumination in cooperation with the light source device 20. The pair of fly-eye optical systems 31 and 32 includes a plurality of element lenses arranged in a matrix. The element lenses divide the illumination light from the light source device 20 and individually collect and divide the illumination light. The polarization conversion member 34 converts the illumination light emitted from the fly-eye optical systems 31 and 32 into one type of polarized light (for example, only the S-polarized component perpendicular to the paper surface of FIG. 1) and supplies it to the next-stage optical system. The superimposing lens 33 allows the illumination light having passed through the polarization conversion member 34 to appropriately converge as a whole, and enables superimposing illumination on the light modulation devices of the respective colors provided in the light modulation unit 50. In other words, the illumination light that has passed through both the fly-eye optical systems 31 and 32 and the superimposing lens 33 passes through the color separation optical system 40 described in detail below, and the light modulation device for each color constituting the light modulation unit 50, that is, the liquid crystal for each color. The image forming areas of the panels 51b, 51r, and 51g are uniformly superimposed and illuminated.

  The color separation optical system 40 includes first and second dichroic mirrors 41a and 41b, reflection mirrors 42a, 42b, and 42c, field lenses 43r and 43b, and first to third lenses 45a, 45b, and 45c. The first dichroic mirror 41a reflects blue light LB among three colors of red, green, and blue (R, G, and B) and transmits green light LG and red light LR. The second dichroic mirror 41b reflects the red light LR out of the incident green light LG and red light LR and transmits the green light LG. In the color separation optical system 40, the illumination light emitted from the light source device 20 through the uniformizing optical system 30 first enters the first dichroic mirror 41a. The blue light LB reflected by the first dichroic mirror 41a is guided to the first optical path OP1 and enters the field lens 43b for adjusting the incident angle via the reflection mirror 42a. Further, the red light LR transmitted through the first dichroic mirror 41a and reflected by the second dichroic mirror 41b is guided to the second optical path OP2 and enters the field lens 43r. Further, the green light LG that has passed through the second dichroic mirror 41b is guided to the third optical path OP3, and passes through the lenses 45a, 45b, and 45c via the reflection mirrors 42b and 42c. The relay optical system including the reflecting mirrors 42b and 42c and the lenses 45a, 45b, and 45c is provided in the third optical path OP3 for green having the longest optical path distance from the light source device 20 to the liquid crystal panels 51b, 51r, and 51g of the respective colors. Has been placed. This relay optical system transmits the image of the first lens 45a almost directly to the third lens 45c via the second lens 45b, thereby preventing a decrease in light use efficiency due to light diffusion or the like. is doing. Among these, the reflection mirrors 42b and 42c are disposed at an inclination angle of 45 ° with respect to the optical axis of the three optical paths OP3, and the optical path direction can be bent by 90 °. As will be described in detail later, one reflecting mirror 42c constituting the relay optical system is movable along the reflecting surface in a direction away from the central lens 45b.

  The light modulator 50 includes three liquid crystal panels 51b, 51r, and 51g on which the three colors of illumination light LB, LR, and LG are incident, and three sets of polarized light disposed so as to sandwich the liquid crystal panels 51b, 51r, and 51g. Filters 52b, 52r, and 52g. Here, for example, the blue light LB liquid crystal panel 51b and the pair of polarizing filters 52b and 52b sandwiching the liquid crystal panel 51b constitute a liquid crystal light valve for two-dimensionally modulating the illumination light. Similarly, the liquid crystal panel 51r for red light LR and the corresponding polarizing filters 52r and 52r also constitute a liquid crystal light valve, and the liquid crystal panel 51g for green light LG and the polarizing filters 52g and 52g also form a liquid crystal light valve. Constitute.

  In the light modulation unit 50, the blue light LB guided to the first optical path OP1 enters the irradiated surface of the liquid crystal panel 51b through the field lens 43b. The red light LR guided to the second optical path OP2 enters the irradiated surface of the liquid crystal panel 51r via the field lens 43r. The green light LG guided to the third optical path OP3 is incident on the irradiated surface of the liquid crystal panel 51g via the lenses 45a, 45b, and 45c. Each of the liquid crystal panels 51b, 51r, and 51g is a non-luminous and transmissive light modulation device for changing the spatial distribution of the polarization direction of incident illumination light, and is incident on each of the liquid crystal panels 51b, 51r, and 51g. The polarization state of each color light LB, LR, LG is adjusted in units of pixels in accordance with drive signals or image signals input as electrical signals to the liquid crystal panels 51b, 51r, 51g. At that time, the polarization filters 52b, 52r, and 52g adjust the polarization direction of the illumination light incident on the liquid crystal panels 51b, 51r, and 51g, and at the same time, emit light from the light emitted from the liquid crystal panels 51b, 51r, and 51g. The modulated light in the polarization direction is extracted.

  The cross dichroic prism 60 is a light combining optical system, and a state in which a reflection film (for example, a dielectric multilayer film) 61 for reflecting B light and a reflection film (for example, a dielectric multilayer film) 62 for reflecting green light are orthogonal to each other. It is built in. The cross dichroic prism 60 reflects the blue light LB from the liquid crystal panel 51b by the reflection film 61 and emits it to the right in the traveling direction, and the red light LR from the liquid crystal panel 51r goes straight and exits through the reflection films 61 and 62. The green light LG from the liquid crystal panel 51g is reflected by the reflective film 62 and emitted to the left in the traveling direction. The image light combined by the cross dichroic prism 60 in this way is projected as a color image on a screen (not shown) at an appropriate magnification through a projection lens 70 which is a projection optical system.

  FIG. 2 is a development view for explaining the state of the light beam in the third optical path OP3 of the projector 10 shown in FIG. 1, and more specifically, a method for adjusting the light amount of only the green light LG in the color separation optical system 40. It is a figure to do. Among these, FIG. 2A shows an initial standard state, and FIG. 2B shows a state in which the reflection mirror 42c for adjusting the light amount in the relay optical system is displaced.

  In the state shown in FIG. 2A, the image forming area of the liquid crystal panel 51g is uniformly illuminated by the green light LG emitted from the uniformizing optical system 30 and passing through the lenses 45a, 45b, and 45c. Note that the optical path bending reflecting mirrors 42b and 42c constituting the relay optical system are not shown as actual objects for the purpose of explaining the imaging state, and are shown as reflecting surfaces M1 and M2, respectively.

  On the other hand, even in the state shown in FIG. 2B, the image forming area of the liquid crystal panel 51g is almost uniformly illuminated by the green light LG emitted from the uniformizing optical system 30 and passing through the lenses 45a, 45b, and 45c. In this state, the light amount adjusting reflecting mirror 42c provided at the rear stage of the central lens 45b slides along the reflecting surface M1 and moves away from the lens 45b, whereby the light beam of the green light LG is partially blocked. Vignetting has occurred. As a result, the image forming area of the liquid crystal panel 51g is illuminated with a low illuminance corresponding to the amount of movement of the reflecting mirror 42c. At this time, the vignetting of the light beam of the green light LG occurs at the portion close to the position SP of the secondary light source formed on the lens 45b side, that is, in the vicinity of the lens 45b, in the reflection mirror 42c. The illuminance distribution of the green light LG at the top is maintained substantially uniform.

In general, since the green light LG has a relatively high visibility, it has a great influence on the white balance. Further, the light source device 20 including the lamp body 21 made of a high-pressure mercury lamp is likely to vary in the relative light amount of the green light LG. In the present embodiment, the illuminance of the green light LG on the image forming area of the liquid crystal panel 51g is adjusted using the sliding movement of the reflection mirror 42b, so that the white balance of the projector 10 can be adjusted efficiently. Is possible. In the case of a high-pressure mercury lamp, since the amount of green light LG tends to be larger than the amount of blue light LB or red light LR, even if some light loss occurs due to sliding movement of the reflecting mirror 42b, Does not work against white balance adjustment.
In addition to the variation in the relative light quantity of the lamp, the cause of the influence on the white balance is also the variation in the characteristics of the liquid crystal panel 51g, the variation in the wavelength selection characteristics of the dichroic mirrors 41a and 41b, and the cross dichroic prism. However, according to the projector of the present embodiment, the white balance of the projector 10 can be set almost to the target value regardless of various factors that cause variations in the light amount of the green light LG. Contrast is not sacrificed.

  In the above description, the reflection mirror 42b in the front stage of the central lens 45b is fixed and does not move. However, the reflection mirror 42b can be moved instead of or together with the reflection mirror 42c. . In this case, the reflection mirror 42b is moved along the reflection surface M1 so as to be separated from the lens 45b, thereby causing vignetting in a state where a part of the light beam of the green light LG is blocked.

  3 and 4 are diagrams for explaining the operation of the reflecting mirror 42c for adjusting the amount of light shown in FIG. FIG. 3A is a diagram for conceptually explaining the distribution of the green light LG at the position closest to the lens 45b, and FIG. 3B conceptually shows the distribution of the green light LG at the position farthest from the lens 45b. FIG. FIG. 4A shows a case where the reflecting mirror 42c for adjusting the amount of light is moved away from the lens 45b, and FIG. 4B shows that the reflecting mirror 42c is moved closer to the lens 45b. Show the case.

  As shown in FIG. 3A, the fly-eye optical systems 31 and 32 of FIG. 1 are disposed at a position closest to the central lens 45b along the third optical path OP3 in the reflecting mirror 42c due to the nature of the Kohler illumination system. A large number of secondary light source images SSP are formed in a matrix-like arrangement corresponding to the arrangement of the constituent lens elements. Further, as shown in FIG. 3B, at the farthest position from the lens 45b along the third optical path OP3 in the reflecting mirror 42c, the contour of the element lenses constituting the fly-eye optical systems 31 and 32 in FIG. Correspondingly, a large number of defocused images DSP that are blurred are partially overlapped.

  As shown in FIG. 4A, when the reflecting mirror 42c is moved in a direction away from the lens 45b, the effective area of the reflecting mirror 42c is vignetted in a portion near the lens 45b, and the opening of the third optical path OP3. AP1 is obtained by removing all or part of one or more columns on the end side from the secondary light source image SSP. On the other hand, as shown in FIG. 4B, when the reflecting mirror 42c is moved in the direction close to the lens 45b, the effective area of the reflecting mirror 42c is accompanied by vignetting in a portion far from the lens 45b, and the third optical path OP3. The aperture AP2 is formed by partially removing one or more groups on the end side of the defocused image DSP. As a result, in both cases shown in FIGS. 4A and 4B, the amount of green light LG passing through the third optical path OP3 decreases. However, in the case shown in FIG. 4A, the illuminance distribution of the green light LG on the image forming area of the liquid crystal panel 51g is kept uniform only by reducing the number of secondary light source images SSP. On the other hand, in the case shown in FIG. 4B, the illuminance distribution of the green light LG on the image forming area of the liquid crystal panel 51g becomes non-uniform because the defocused image DSP is partially shielded.

  In summary, when the reflecting mirror 42c is moved away from the lens 45b, vignetting of the green light LG occurs, but the illuminance distribution of the green light LG on the image forming region of the liquid crystal panel 51g is maintained uniformly. The On the other hand, when the reflecting mirror 42c is moved in the direction approaching the lens 45b, not only the vignetting of the green light LG occurs but also the illuminance distribution of the green light LG on the image forming region of the liquid crystal panel 51g is made non-uniform. . Therefore, when adjusting the illuminance of the green light LG on the image forming area, it is desirable to move the reflecting mirror 42c in a direction away from the lens 45b. When the reflecting mirror 42c is moved away from the lens 45b, the reflecting mirror 42c is moved stepwise so that the secondary light source image SSP is removed in units of columns from the end side, so that the green light LG is uniform. This is advantageous in securing the property. At this time, the illuminance of the green light LG on the image forming area changes stepwise. Fine adjustment of the illuminance so as to compensate for the change is performed by electrical signal processing of the luminance value of the image signal supplied to the liquid crystal panel 51g. Will be possible.

  FIGS. 5A and 5B are a front view and a side view for explaining a mirror support member which is a mechanism for displacing while supporting the reflection mirror 42c for adjusting the light amount shown in FIG.

  The mirror support member 90 moves the reflection mirror 42c along the guide members 91 and 92, and a pair of upper and lower guide members 91 and 92 that hold the rectangular reflection mirror 42c slidably along the direction of the reflection surface. And a drive member 94. The former guide members 91 and 92 have guide grooves 91a and 92a, and protective members 95 formed on the upper and lower ends of the reflection mirror 42c are fitted into the guide grooves 91a and 92a. As a result, the reflecting mirror 42c can be slid along the direction of the reflecting surface M2 without changing its posture. A spring member 96 is pressed against the back surface of the reflecting mirror 42c. The spring member 96 can prevent rattling in a state where the reflection mirror 42c is urged forward and the reflection mirror 42c is held in the guide grooves 91a and 92a. The latter drive member 94 includes a fixing portion 94a fixed to the corner of the reflecting mirror 42c, a connecting portion 94b connected to the fixing portion 94a, a screw portion 94c extending from the connecting portion 94b, and the screw portion 94c as a guide member 91. The stay 94d is supported on the side. The connecting portion 94b is a columnar member provided with an annular groove around it. The connecting portion 94b is fitted into an opening provided in the fixed portion 94a and rotates around the axis of the screw portion 94c together with the screw portion 94c. The fixing portion 94a has a screw hole to be screwed with the screw portion 94c, and finely moves the reflecting mirror 42c by a desired amount with respect to the stay 94d, that is, the guide member 91 by turning the head 94f of the screw portion 94c. Be able to. That is, the reflection mirror 42c can be advanced and retracted to an appropriate position on the third optical path OP3 (see FIG. 2) by appropriate rotation of the threaded portion 94c, and the vignetting of the green light LG, that is, the light shielding amount can be adjusted. The light amount adjustment related to the green light LG as described above is performed, for example, while balancing with other color lights in the assembly stage of the projector 10. After such adjustment, the reflecting mirror 42c is permanently fixed to the guide members 91 and 92 by fixing the driving member 94 with an adhesive, for example.

  Hereinafter, the operation of the projector 10 according to the present embodiment will be described. The illumination light from the light source device 20 is uniformized through the uniformizing optical system 30 and the polarization direction thereof is aligned, and then color-divided by the first and second dichroic mirrors 41 a and 41 b provided in the color separation optical system 40. , Incident on the corresponding liquid crystal panels 51b, 51r, 51g as the respective color lights LB, LR, LG. Each liquid crystal panel 51b, 51r, 51g is modulated by an image signal from the outside and has a two-dimensional refractive index distribution, and modulates each color light LB, LR, LG in a two-dimensional space in units of pixels. As described above, the color lights LB, LR, LG modulated by the liquid crystal panels 51b, 51r, 51g, that is, the image light, are combined by the cross dichroic prism 60 and then incident on the projection lens 70. The image light incident on the projection lens 70 is projected on a screen (not shown). In the projector 10, the illuminance on the image forming area of the green light LG that illuminates the liquid crystal panel 51g is changed by adjusting the position of the reflection mirror 42c during or after the assembly of the color separation optical system 40 and the like. be able to. That is, each liquid crystal panel 51b, 51r, 51g can be illuminated with a desired balance without using an ND filter that is susceptible to thermal influence. Therefore, the white balance of the color image synthesized through the liquid crystal panels 51b, 51r and 51g and projected onto the screen by the projection lens 70 can be easily adjusted.

  In addition, this invention is not restricted to said embodiment, In the range which does not deviate from the summary, it can implement in a various aspect, For example, the following deformation | transformation is also possible.

  In the projector 10 of the above embodiment, the relay optical systems 42b, 42c, 45a, 45b, and 45c of the color separation optical system 40 are arranged in the third optical path OP3 for green light, but relays are performed in the other optical paths OP1 and OP2. An optical system can be arranged. In this case, the white balance of the illumination light emitted from the light source device 20 can be adjusted as appropriate by moving the reflecting mirrors of the relay optical system disposed in the other optical paths OP1 and OP2 along the projection surface.

  In the projector 10 of the above embodiment, a high-pressure mercury lamp is used as the light source device 20, but another lamp such as a metal halide lamp can be used instead of the high-pressure mercury lamp. Also in this case, the white balance of the illumination light from the lamp light source is appropriately adjusted by moving the reflecting mirror 42c and the like disposed in the third optical path OP3 for green light and the other optical paths OP1 and OP2 along the reflecting surface. Can be adjusted.

  Further, the structure of the mirror support member 90 for finely moving and fixing the reflection mirror 42c constituting the color separation optical system 40 is not limited to the above embodiment, and can be various. For example, the drive member 94 can be omitted. After the reflecting mirror 42c is moved to an appropriate position using the guide members 91 and 92, the reflecting mirror 42c is directly attached to the guide members 91 and 92 and the like using an adhesive. Can be fixed.

  In the above embodiment, the two fly's eye optical systems 31 and 32 are used in order to divide the light from the light source device 20 into a plurality of partial light beams. The present invention can also be applied to a projector that does not use a lens array. Furthermore, the fly-eye optical systems 31 and 32 can be replaced with rod integrators. In this case, the reflecting mirror adjacent to the lens disposed in the vicinity of the position where the secondary light source image is formed in the relay optical system subsequent to the rod integrator is moved away from the lens.

  In the projector 10, the polarization conversion member 34 that converts the light from the light source device 20 into a specific direction of polarization is used. However, the present invention can also be applied to a projector that does not use such a polarization conversion member 34. is there.

  In the above embodiment, an example in which the present invention is applied to a transmissive projector has been described. However, the present invention can also be applied to a reflective projector. Here, “transmission type” means that the light valve including the liquid crystal panel is a type that transmits light, and “reflection type” is a type that the light valve reflects light. Means. In the case of a reflection type projector, the light valve can be constituted only by a liquid crystal panel, and a pair of polarizing plates is unnecessary. The light modulation device is not limited to a liquid crystal panel or the like, and may be a light modulation device using a micromirror, for example.

  Further, as the projector, there are a front projector that projects an image from the direction of observing the projection plane and a rear projector that projects an image from the opposite side to the direction of observing the projection plane. The projector configuration shown in FIG. Is applicable to both.

It is a figure explaining the optical system of the projector which concerns on embodiment. (A) shows the light beam of the 3rd optical path of a projector, (b) shows the state which displaced the reflective mirror. (A) shows the green light distribution at the position closest to the central lens, and (b) shows the green light distribution at the position farthest from the central lens. (A) shows the case where the reflecting mirror is separated from the lens, and (b) shows the case where the reflecting mirror is brought close to the lens. (A) And (b) is the front view and side view which show a mirror support member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Projector, 20 ... Light source device, 30 ... Uniformation optical system 31, 32 ... Fly eye optical system, 33 ... Superimposing lens, 34 ... Polarization conversion member, 40 ... Color separation optical system, 41a, 41b ... 2nd dichroic Mirror, 42b, 42c ... Reflective mirror, 42b, 42c, 45a, 45b, 45c ... Relay optical system, 45a, 45b, 45c ... Lens, 50 ... Light modulator, 51b, 51r, 51g ... Liquid crystal panel, 52b, 52r, 52g ... Polarizing filter, 60 ... Cross dichroic prism, 70 ... Projection lens, 90 ... Mirror support member, 91, 92 ... Guide member, 94 ... Driving member, AP1 ... Aperture, AP2 ... Aperture, DSP ... Defocused image, LB, LR, LG ... each color light, M1, M2 ... reflective surface, OP1 ... first optical path, OP2 ... second optical path, OP3 ... Third optical path, SSP ... 2 primary light source images

Claims (8)

An illumination device that emits illumination light;
A color separation optical system for branching the first to third color lights from the illumination light emitted from the illumination device and guiding the first to third color lights to the first to third optical paths, respectively;
A first to a third light modulation device respectively disposed on the first to third optical paths and illuminated by the first to third color lights, respectively,
The distance from the illumination device to the third light modulation device is longer than the distance from the illumination device to the first light modulation device and the distance from the illumination device to the second light modulation device,
The third optical path includes a first lens disposed on the light incident side, a second lens disposed on the light exit side, and a third lens disposed between the first and second lenses. A lens, a first mirror for bending an optical path disposed on the first lens side of the third lens, and an optical path bending disposed on the second lens side of the third lens A relay optical system including a second mirror of
At least one of the first and second mirrors is held on the third optical path, and at least one of the first and second mirrors can be displaced along the reflecting surface in a direction in which the light source image becomes more blurred. A projector including the mirror support member.   The projector according to claim 1, wherein the first to third color lights are blue light, red light, and green light, respectively.   The relay optical system forms a light source image in the vicinity of the third lens, and the mirror support member displaces at least one of the first and second mirrors in a direction away from the third lens. The projector according to claim 1, wherein vignetting is generated on the third lens side.   4. The projector according to claim 3, wherein a mirror closer to a light source image formed in the vicinity of the third lens among the first and second mirrors can be displaced.   The said illuminating device is provided with the light source device which generate | occur | produces light source light, and the equalization | homogenization optical system which equalizes the light source light from an illuminating device. projector.   6. The projector according to claim 5, wherein the uniformizing optical system includes two fly-eye optical systems.   A light combining optical system that combines image light of each color obtained by modulating the first to third color lights with the first to third light modulators, and a projection that projects the combined light emitted from the light combining optical system The projector according to any one of claims 1 to 6, further comprising an optical system. The mirror support member includes a guide member that slidably holds at least one of the first and second mirrors along a direction of a reflecting surface, and at least one of the first and second mirrors. The projector according to claim 1, further comprising: a driving member that moves along the axis.

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