JP2005338159A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector having structure to facilitate miniaturization even when the projector is so constituted that a smooth and good-quality moving picture display can be obtained. <P>SOLUTION: By the action of a polarization separation prism 130 which separates the illumination luminous flux from a light source device 110 to two illumination luminous fluxes and of an afocal optical element 14 for compressing the two illumination luminous fluxes separated by the polarization to a direction perpendicular to an illumination optical axis 100Aax and parallel to a polarization separation plane 132, the projector irradiates the illumination luminous fluxes having such sectional shapes as to illuminate a part of the image forming regions relating to a first direction and the entire part of the image forming regions relating to a second region on the respective image forming regions of the liquid crystal devices 400R, 400G and 400B and scans the illumination luminous fluxes along the first direction on the image forming regions in synchronization with the image writing frequencies of the liquid crystal devices 400R, 400G and 400B by a rotary prism 770. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a projector.

FIG. 10 is a diagram for explaining a conventional projector. FIG. 10A is a diagram showing an optical system of a conventional projector, and FIGS. 10B and 10C are diagrams for explaining the problems of such a conventional projector.
In the projector 900A, since the liquid crystal devices 400R, 400G, and 400B used as the electro-optic modulation device are hold type display devices having luminance characteristics as shown in FIG. 10B, they are shown in FIG. Unlike the case of the CRT which is an impulse type display device having such luminance characteristics, there is a problem that a smooth moving image display cannot be obtained due to a so-called tailing phenomenon. (Refer nonpatent literature 1.).

FIG. 11 is a diagram for explaining another conventional projector. FIG. 11A is a diagram showing an optical system of another conventional projector, and FIG. 11B and FIG. 11C are diagrams showing an optical shutter used in such another conventional projector. .
In the projector 900B, as shown in FIG. 11A, optical shutters 420R, 420G, and 420B are arranged on the light incident side of the liquid crystal devices 400R, 400G, and 400B, and light is intermittently blocked by these optical shutters. This solves the problem described above. That is, the so-called tailing phenomenon is alleviated so that a smooth and high-quality moving image display can be obtained (for example, see Patent Document 1).
"Image quality of video display on hold type display" (Technical Report of IEICE, EID99-10, pages 55-60 (1999-06)) JP 2002-148712 A (FIGS. 1 to 7)

  However, in such other conventional projectors, there is a problem in that the light use efficiency is significantly reduced because light is intermittently blocked by the optical shutter.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a projector in which the light use efficiency is not significantly reduced even when a smooth and high-quality moving image display is obtained. And

(1) The projector of the present invention is a light source device that emits an illumination light beam that is substantially parallel to the illuminated region side, and transmits an illumination light beam related to one polarization component of the illumination light beam from the light source device, and converts it into the other polarization component. A polarization separation prism having a polarization separation surface that reflects the illumination light beam, a reflection surface that reflects the illumination light beam related to the other polarization component from the polarization separation surface in a direction parallel to the illumination optical axis, and polarization separated An afocal optical element that compresses two illumination light beams in a first direction perpendicular to the illumination optical axis and parallel to the polarization separation surface, and on an image forming region of an electro-optic modulation device that is an object to irradiate the illumination light beams Illumination for irradiating a part of the image forming area with respect to the first direction and an illumination light beam having a cross-sectional shape that illuminates the entire image forming area with respect to the second direction perpendicular to the first direction. apparatus An electro-optic modulation device that modulates an illumination light beam from the illumination device according to image information, a projection optical system that projects the light beam modulated by the electro-optic modulation device, the illumination device, and the electro-optic modulation device And scanning means for scanning the illumination light beam along the first direction on the image forming region in synchronization with the screen writing frequency of the electro-optic modulation device.

For this reason, according to the projector of the present invention, a part of the image forming area in the first direction among the vertical and horizontal directions in the image forming area of the electro-optic modulation device, and the entire image forming area in the second direction. An illumination light beam having a cross-sectional shape for illuminating (that is, a cross-sectional shape compressed in the first direction) is scanned along the first direction on the image forming region in synchronization with the screen writing frequency of the electro-optic modulator. Therefore, the light irradiation region and the light non-irradiation region are sequentially scrolled alternately in the image forming region of the electro-optic modulation device. As a result, the tailing phenomenon is alleviated and a smooth and high-quality moving image display can be obtained.
According to the projector of the present invention, the illumination light beam having the cross-sectional shape compressed in the first direction as described above is realized by the function of the illumination device having the polarization separation prism and the afocal optical element as described above. Therefore, unlike the case where an optical shutter is used, the illumination light beam from the light source device can be guided to the image forming area of the electro-optic modulation device without waste, and the light use efficiency can be greatly reduced. Disappear.
For this reason, the projector of the present invention is a projector in which the light use efficiency is not significantly reduced even when smooth and high-quality moving image display is obtained, and the object of the present invention is achieved.

Further, according to the projector of the present invention, normally, the two illumination light beams separated by polarization pass through the afocal optical element due to the fact that the light emitting area of the arc tube used in the light source device has a finite size. Since mixing is gradually performed, the light intensity distribution along the second direction is leveled on the image forming region of the electro-optic modulation device, and the light intensity distribution along the second direction is relatively low. It will be uniform.
Further, since the illumination light beam irradiated on the image forming area of the electro-optic modulator is scanned along the first direction on the image forming area of the electro-optic modulator, the light intensity along the first direction The non-uniform distribution is not a problem.
Therefore, according to the projector of the present invention, smooth and high-quality moving image display can be obtained without using a relatively expensive integrator optical system such as a lens integrator.

  In the projector according to the aspect of the invention, the illumination light beam irradiated on the image forming area of the electro-optic modulation device may include a part of the image forming area in the first direction among the vertical and horizontal directions in the image forming area of the electro-optic modulation device. The second direction has a cross-sectional shape that illuminates the entire image forming region (that is, a cross-sectional shape compressed in the first direction). The degree of compression is appropriately adjusted by the design of the afocal optical element. can do.

(2) In the projector described in (1), it is preferable that the afocal optical element includes two cylindrical lenses having refractive power in the first direction.

  By configuring in this way, the degree of compression of the illumination light beam irradiated onto the image forming region of the electro-optic modulator can be easily adjusted by adjusting the focal length and arrangement of these two cylindrical lenses. Can do. As these two cylindrical lenses, two convex lenses can be used, and one convex lens (arranged on the light source device side) and one concave lens (arranged on the electro-optic modulation device side) can also be used. .

(3) In the projector according to (1), the afocal optical element includes two cylindrical lenses having refractive power in the first direction and two having refractive power in the second direction. It is preferable to have a cylindrical lens.

  With this configuration, by adjusting the focal length and the arrangement of the two cylindrical lenses having refractive power in the first direction and the two cylindrical lenses having refractive power in the second direction, Since the length along the first direction and the length along the second direction of the illumination light beam irradiated onto the image forming area of the optical modulation device can be easily adjusted, electro-optical modulation is possible. The size of the polarization separation prism with respect to the size of the illuminated area of the apparatus can be made arbitrary, and the degree of design freedom can be increased.

(4) In the projector described in (1), the afocal optical element system includes one spherical lens, one cylindrical lens having refractive power in the first direction, and the second direction. It is preferable to have one cylindrical lens having refractive power.

  With this configuration, the effect (3) can be realized by three lenses (that is, one spherical lens and two cylindrical lenses).

(5) In the projector according to any one of (1) to (4), the light of the illumination light beam that is reflected by the light exit surface or the polarization separation surface of the illumination light beam that passes through the polarization separation surface of the polarization separation prism. A λ / 2 plate is preferably disposed on the exit surface.

  The illumination device used for the projector of the present invention can be suitably used for a projector using any electro-optic modulation device such as a liquid crystal device using polarized light or a micromirror device that does not need to use polarized light. By configuring as above, the polarization component of the illumination light beam emitted from the polarization separation prism can be changed to the illumination light beam of one of the polarization components or the other polarization component. The projector can be used more suitably.

(6) In the projector according to any one of (1) to (5), the illumination light beam from the illumination device is separated into a plurality of color lights between the illumination device and the electro-optic modulation device. And a plurality of electro-optic modulators for modulating a plurality of color lights from the color separation optical system according to image information corresponding to the respective color lights. Preferably it is.

  With this configuration, a projector in which the light use efficiency is not significantly reduced even when smooth and high-quality moving image display can be obtained is a full-color projector with excellent image quality (for example, a three-plate type). Will be able to.

(7) In the projector according to (6), the scanning unit is disposed at a position substantially conjugate with the electro-optic modulation device between the illumination device and the color separation optical system, and the illumination optical axis. A rotating prism having a rotation axis perpendicular to the rotating prism, and the rotating prism causes the light irradiation area and the light non-irradiation area to be written on the screen of the electro-optic modulation device on the image forming area of the electro-optic modulation device. It is preferable to be configured to be sequentially scrolled in synchronization with the frequency.

  With this configuration, it is possible to realize a smooth scroll operation of the light irradiation region and the light non-irradiation region in the image forming region of each electro-optic modulation device in the full color projector.

  In the projector described in (7) above, it is preferable that a light-reflecting surface of the rotating prism has a reduced reflection film. With this configuration, the light transmittance in the rotating prism is improved, so that the light use efficiency can be minimized, and the stray light level is reduced and the contrast is improved.

(8) In the projector according to any one of (1) to (7), the light source device is parallel to an ellipsoidal reflector and an arc tube having a light emission center near the first focal point of the ellipsoidal reflector. It is preferable to have a lens.

  By comprising in this way, a more compact light source device is realizable compared with the light source device using a paraboloid reflector.

(9) In the projector according to (8), it is preferable that the polarization separation prism and the collimating lens are integrated.

  By comprising in this way, the reflection loss in the light-projection surface of a parallelization lens and the light-incidence surface of a polarization separation prism can be eliminated, and light utilization efficiency can be improved. Further, in the assembly process of the projector, it is possible to suppress the deterioration of the positional accuracy between the collimating lens and the polarization separation prism and the increase in the number of assembly steps.

(10) In the projector according to any one of (1) to (7), the light source device includes a parabolic reflector and an arc tube having a light emission center near a focal point of the parabolic reflector. It is preferable.

  By configuring in this way, it is possible to obtain a substantially parallel illumination light beam without using a parallelizing lens. Therefore, compared with a light source device using an ellipsoidal reflector that requires a parallelizing lens, the number of parts is reduced. Fewer light source devices can be realized.

(11) In the projector according to any one of (8) to (10), the light emitting tube emits light emitted from the light emitting tube toward the illuminated region, or the ellipsoidal reflector or the paraboloid. It is preferable that a reflecting means for reflecting toward the reflector is provided.

With this configuration, light emitted from the arc tube toward the illuminated area is reflected toward the ellipsoidal reflector or the parabolic reflector, so that the illuminated area side end of the arc tube is covered. It is not necessary to set the size of the ellipsoidal reflector or parabolic reflector to the size, and the ellipsoidal reflector or the parabolic reflector can be miniaturized, and as a result, the projector can be miniaturized. it can.
In addition, since the ellipsoidal reflector or the parabolic reflector can be reduced in size, the focusing angle and beam spot of the beam focused from the ellipsoidal reflector toward the second focal point of the ellipsoidal reflector can be reduced. Since the diameter of the light beam emitted from the parabolic reflector to the subsequent optical system can be reduced, the size of the collimating lens, the size of the polarization separation prism, the size of the afocal optical element, the size of the scanning means The size of the color separation optical system can be further reduced, and the projector can be further reduced in size.

  The projector of the present invention will be described below based on the embodiments shown in the drawings.

Embodiment 1
FIG. 1 is a diagram illustrating an optical system of the projector according to the first embodiment. FIG. 1A is a view of the optical system as viewed from above, and FIG. 1B is a view of the optical system as viewed from side.
FIG. 2 is a diagram for explaining the illumination device in the projector according to the first embodiment. 2A is a view of the illumination device as viewed from above, FIG. 2B is a view of the illumination device as viewed from the side, and FIG. 2C is a contour plot of the light intensity distribution in the cross section of the illumination light beam. It is a figure shown by.
In FIG. 2 (c), the drawings indicated by (a) to (c) are diagrams showing the light intensity distribution in the cross section of the illumination light beam at the positions indicated by the symbols (a) to (c) in FIG. 2C shows the shape of the polarization splitting prism, and the broken line in FIG. 2C shows the shape of the image forming area of the liquid crystal device.

  FIG. 3 is a diagram illustrating the relationship between the rotation of the rotating prism and the illumination state on the image forming area of the liquid crystal device. FIG. 3A is a cross-sectional view of the rotating prism when viewed along the rotation axis. FIG. 3B is a view when the rotating prism is viewed along the illumination optical axis. FIG. 3C is a diagram showing the irradiation state of the illumination light beam on the image forming area of the liquid crystal device.

  In the following description, the three directions orthogonal to each other are the z direction (the illumination optical axis direction in FIG. 1A) and the x direction (the direction parallel to the paper surface in FIG. 1A and orthogonal to the z axis). ) And y direction (direction perpendicular to the paper surface in FIG. 1A and perpendicular to the z axis).

  As shown in FIGS. 1A and 1B, the projector 1000A according to the first embodiment separates the illumination device 100A and the illumination light flux from the illumination device 100A into three color lights of red, green, and blue. Color separation optical system 200, three liquid crystal devices 400R, 400G, and 400B as electro-optic modulation devices that modulate each of the three color lights separated by color separation optical system 200 according to image information, and these three liquid crystals The projector includes a cross dichroic prism 500 that combines color lights modulated by the devices 400R, 400G, and 400B, and a projection optical system 600 that projects the light combined by the cross dichroic prism 500 onto a projection surface such as a screen SCR. .

  As shown in FIGS. 1, 2A, and 2B, the illuminating device 100A includes a light source device 110 that emits a substantially parallel illumination light beam toward the illuminated region, and among the illumination light beams from the light source device 110. A polarization separation surface 132 that transmits an illumination light beam (for example, a P-polarized light beam) according to one polarization component and reflects an illumination light beam (for example, an S-polarization light beam) according to the other polarization component, and the other polarization component from the polarization separation surface 132 The polarization separation prism 130 having a reflecting surface 134 that reflects the illumination light beam (for example, S-polarized light beam) according to the above in a direction parallel to the illumination optical axis 100Aax, and the two polarization-separated illumination light beams perpendicular to the illumination optical axis 100Aax. In addition, an afocal optical element 140A that compresses in a first direction (that is, y direction) parallel to the polarization separation surface 132 is included.

  The polarization separation prism 130 includes a polarization cube prism including a polarization separation surface 132 therein and a cube prism including a reflection surface 134 therein.

As shown in FIG. 2B and FIG. 2C, the afocal optical element 140A causes two polarized light beams separated by polarization to be perpendicular to the illumination optical axis 100Aax and parallel to the polarization separation surface 132. In the first direction, compression is performed at a compression ratio of 1/2.
As shown in FIG. 2A, the afocal optical element 140A causes two polarized light beams to be separated into a second direction (that is, x) perpendicular to the illumination optical axis 100Aax and perpendicular to the first direction. Direction).
As a result, as shown in FIG. 2C, the illuminating device 100A has a first direction (see FIG. 2) in the rotating prism 770 at a position conjugate with each image forming region of the liquid crystal devices 400R, 400G, and 400B. Illumination luminous flux having a cross-sectional shape that illuminates a part of the image forming area in the second direction (2c) and the entire image forming area in the second direction (left and right direction in FIG. 2c). As a result, as shown in FIG. 3 (c), the first direction (vertical direction in FIG. 3 (c)) on the image forming area of each of the liquid crystal devices 400R, 400G, and 400B. A part of the image forming area is irradiated with an illumination light beam having a cross-sectional shape that illuminates the entire image forming area in the second direction (left-right direction in FIG. 3C).

  Between the afocal optical element 140A and the rotating prism 770, there is an opening corresponding to the shape of the image forming area of the liquid crystal devices 400R, 400G, 400B, and a light shielding mask 150A for removing unnecessary ambient light. Has been placed.

  The light source device 110 includes an ellipsoidal reflector 114, an arc tube 112 having a light emission center near the first focal point of the ellipsoidal reflector 114, and a parallelizing lens 120 that converts the focused light from the ellipsoidal reflector 114 into substantially parallel light. And have. The arc tube 112 is provided with an auxiliary mirror 116 as a reflecting means for reflecting the light emitted from the arc tube 112 toward the illuminated area toward the ellipsoidal reflector 114.

  As the color separation optical system 200, an equal optical path optical system having the same optical path length from the illumination device 100A to the liquid crystal devices 400R, 400G, and 400B is used.

  As the liquid crystal devices 400R, 400G, and 400B, a wide vision liquid crystal device having a planar shape of “longitudinal dimension along the y direction: lateral dimension along the x direction = 9: 16 rectangle” is used.

  In the projector 1000A according to the first embodiment, as shown in FIG. 1A, a rotating prism 770 as a scanning unit includes liquid crystal devices 400R, 400G between the illumination device 100A and the liquid crystal devices 400R, 400G, 400B. , 400B and the conjugate position. The rotation has a function of scanning the illumination light beam along the first direction on the image forming area of the liquid crystal devices 400R, 400G, and 400B in synchronization with the screen writing frequency of the liquid crystal devices 400R, 400G, and 400B. ing.

  That is, in the projector 1000A according to the first embodiment, the image P of the emission center of the arc tube 112 on the illumination optical axis 100Aax is rotated by the rotating prism 770 as shown in FIGS. 3 (a) and 3 (b). As a result, the image is scrolled up and down around the rotation axis 772 of the rotating prism 770. As a result, as shown in FIG. 3C, when the rotating prism 770 rotates, the light irradiation region and the light non-irradiation region are sequentially scrolled alternately in the image forming regions of the liquid crystal devices 400R, 400G, and 400B. It becomes like this.

For this reason, according to the projector 1000A according to the first embodiment, a part of the image forming area in the first direction among the vertical and horizontal directions in the image forming areas of the liquid crystal devices 400R, 400G, and 400B, and the second direction. Each forms an image in synchronization with the screen writing frequency of the liquid crystal devices 400R, 400G, and 400B using an illumination light beam having a cross-sectional shape that illuminates the entire image forming region (ie, a cross-sectional shape compressed in the first direction). Since scanning can be performed along the first direction on the area, the light irradiation area and the light non-irradiation area are sequentially scrolled alternately in the image forming areas of the liquid crystal devices 400R, 400G, and 400B. It becomes like this. As a result, the tailing phenomenon is alleviated and a smooth and high-quality moving image display can be obtained.
Further, according to the projector 1000A according to the first embodiment, the function of the illuminating device 100A including the polarization separation prism 130 and the afocal optical element 140A described above is used to convert the illumination light beam having the cross-sectional shape compressed in the first direction. Therefore, unlike the case where an optical shutter is used, the illumination light beam from the light source device 110 can be guided to the image forming areas of the liquid crystal devices 400R, 400G, and 400B without waste, and the light use efficiency is improved. Will not drop significantly.
For this reason, the projector 1000A according to the first embodiment is a projector in which the light use efficiency is not significantly reduced even when smooth and high-quality moving image display is obtained.

In addition, according to the projector 1000A according to the first embodiment, the two illumination light beams separated by polarization are usually afocal optical elements due to the fact that the light emitting area of the arc tube used in the light source device has a finite size. Since it is gradually mixed while passing through 140A, the light intensity distribution along the second direction is leveled on the image forming regions of the liquid crystal devices 400R, 400G, and 400B, and along the second direction. The light intensity distribution is relatively uniform.
The illumination light beam irradiated onto the image forming areas of the liquid crystal devices 400R, 400G, and 400B is scanned along the first direction on the image forming areas of the liquid crystal devices 400R, 400G, and 400B. The non-uniformity of the light intensity distribution along the direction is not a problem.
Therefore, according to the projector 1000A according to the first embodiment, smooth and high-quality moving image display can be obtained without using a relatively expensive integrator optical system such as a lens integrator.

  In the projector 1000A according to the first embodiment, the illumination light beam irradiated on the image forming areas of the liquid crystal devices 400R, 400G, and 400B is in the first direction among the vertical and horizontal directions in the image forming areas of the liquid crystal devices 400R, 400G, and 400B. Has a cross-sectional shape that illuminates a part of the image forming region and the entire image forming region in the second direction (that is, a cross-sectional shape compressed in the first direction). It can be appropriately adjusted depending on the design of the afocal optical element 140A.

  In the projector 1000A according to the first embodiment, the afocal optical element 140A includes two cylindrical lenses 142A and 144A having a positive refractive power in the first direction. For this reason, by adjusting the focal length and arrangement of these two cylindrical lenses 142A and 144A, the degree of compression of the illumination light beam irradiated onto the image forming regions of the liquid crystal devices 400R, 400G, and 400B can be easily adjusted. be able to.

In the projector 1000A according to the first embodiment, as shown in FIG. 2A, a λ / 2 plate 136 is disposed on the light exit surface of the illumination light beam that passes through the polarization separation surface 132 of the polarization separation prism 130. . For this reason, the polarization component of the illumination light beam emitted from the polarization separation prism 130 can be a polarized light beam of one polarization component (for example, an S-polarized light beam), and thus is preferably used for a projector using a liquid crystal device that uses polarized light. be able to.
In the projector 1000A according to the first embodiment, a λ / 2 plate may be disposed on the light exit surface of the illumination light beam reflected by the polarization separation surface 132 in the polarization separation prism 130.

  As shown in FIG. 1A, the projector 1000A according to the first embodiment separates the illumination light beam from the illumination device 100A into a plurality of color lights between the illumination device 100A and the liquid crystal devices 400R, 400G, and 400B. The color separation optical system 200 is further provided. For this reason, even if smooth and high-quality moving image display is obtained, a projector in which the light use efficiency is not significantly reduced can be a three-plate full-color projector with excellent image quality.

  In the projector 1000A according to the first embodiment, as described above, the rotating prism 770 is disposed at a position conjugate with the liquid crystal devices 400R, 400G, and 400B between the illumination device 100A and the color separation optical system 200, and illumination. The rotation axis 772 is perpendicular to the optical axis 100Aax, and the light irradiation area and the light non-irradiation area on the image forming area of the liquid crystal devices 400R, 400G, 400B are written on the screen of the liquid crystal devices 400R, 400G, 400B by the rotation. It is configured to be sequentially scrolled in synchronization with the frequency. For this reason, in each image forming area of the liquid crystal devices 400R, 400G, and 400B in the full-color projector, a smooth scroll operation of the light irradiation area and the light non-irradiation area can be realized.

  In the projector 1000A according to the first embodiment, a light reflection surface of the rotating prism 770 is formed with a reduced reflection film. For this reason, since the light transmittance in the rotating prism 770 is improved, a decrease in light use efficiency can be minimized, and the stray light level is reduced and the contrast is improved.

  In the projector 1000A according to the first embodiment, as shown in FIGS. 1, 2A, and 2B, the light source device 110 is in the vicinity of the ellipsoidal reflector 114 and the first focal point of the ellipsoidal reflector 114. Since the arc tube 112 having the emission center and the collimating lens 120 are provided, a more compact light source device can be realized as compared with a light source device using a parabolic reflector.

In the projector 1000A according to the first embodiment, as shown in FIGS. 1, 2A, and 2B, light emitted from the arc tube 112 to the illuminated region side is elliptical on the arc tube 112. An auxiliary mirror 116 is provided as a reflecting means that reflects toward the reflector 114.
For this reason, since the light emitted from the arc tube 112 toward the illuminated area is reflected toward the elliptical reflector 114, the elliptical reflector 114 is sized so as to cover the illuminated area side end of the arc tube 112. Therefore, the ellipsoidal reflector 114 can be downsized, and the projector 1000A can be downsized. This also reduces the size of the collimating lens 120, the size of the polarization separation prism 130, the size of the afocal optical element 140A, the size of the rotating prism 770, the size of the color separation optical system 200, and the like. This means that the projector 1000A can be further downsized.

[Embodiment 2]
FIG. 4 is a diagram for explaining the illumination device in the projector according to the second embodiment. FIG. 4A is a view of the lighting device as viewed from above, and FIG. 4B is a view of the lighting device as viewed from the side.

  The projector 1000B according to the second embodiment is different from the projector 1000A according to the first embodiment in the configuration of the afocal optical element. That is, in the projector 1000A according to the first embodiment, the afocal optical element 140A includes the two cylindrical lenses 142A and 144A having positive refractive power in the first direction, whereas the second embodiment is different from the first embodiment. In the projector 1000B according to FIG. 4, as shown in FIG. 4, the afocal optical element 140B is disposed on the light source device 110 side and has a positive refractive power cylindrical lens 142B and the liquid crystal devices 400R, 400G, and 400B are disposed on the negative side. A cylindrical lens 144B having refractive power is included.

  As described above, the projector 1000B according to the second embodiment is different from the projector 1000A according to the first embodiment in the configuration of the afocal optical element, but similarly to the projector 1000A according to the first embodiment, the light source Of the illumination light flux from the apparatus 110, the polarization separation surface 132 that transmits the illumination light flux related to one polarization component and reflects the illumination light flux related to the other polarization component, and the illumination light flux related to the other polarization component from the polarization separation surface 132 A polarization separation prism 130 having a reflection surface 134 that reflects in a direction parallel to the illumination optical axis 100Bax, and a first polarization beam that is polarized and separated from the two illumination light fluxes perpendicular to the illumination optical axis 100Bax and parallel to the polarization separation surface 132 Liquid crystal device 400R, 4 which has an afocal optical element 140B that compresses in the direction and is the target to irradiate the illumination light beam On the image forming area of 0G, 400B (not shown), a part of the image forming area is illuminated in the first direction, and the entire image forming area is illuminated in the second direction perpendicular to the first direction. The illumination apparatus 100B which irradiates the illumination light beam which has such a cross-sectional shape is provided. Further, it is arranged between the illumination device 100B and the liquid crystal devices 400R, 400G, and 400B, and the illumination light beam is synchronized with the screen writing frequency of the liquid crystal devices 400R, 400G, and 400B along the first direction on the image forming area. A rotating prism 770 for scanning is provided. For this reason, it has the same effect as the projector 1000A according to the first embodiment.

  It should be noted that the afocal optical element 140B in the projector 1000B according to the second embodiment converts the two separated illumination light beams into the illumination optical axis 100Bax as in the case of the afocal optical element 140A in the projector 1000A according to the first embodiment. Is compressed in a first direction parallel to the polarization splitting surface 132 at a compression ratio of ½, but not compressed in a second direction perpendicular to the illumination optical axis 100Bax and perpendicular to the first direction. .

[Embodiment 3]
FIG. 5 is a diagram for explaining the illumination device in the projector according to the third embodiment. FIG. 5A is a view of the lighting device as viewed from above, and FIG. 5B is a view of the lighting device as viewed from the side.

  The projector 1000C according to the third embodiment is different from the projectors 1000A and 1000B according to the first or second embodiment in the configuration of the afocal optical element. That is, in the projector 1000A according to the first embodiment, the afocal optical element 140A has two cylindrical lenses 142A and 144A having positive refractive power in the first direction, and the projector 1000B according to the second embodiment. , The afocal optical element 140B includes a cylindrical lens 142B having a positive refractive power disposed on the light source device 110 side and a cylindrical lens 144B having a negative refractive power disposed on the liquid crystal devices 400R, 400G, and 400B side. On the other hand, in the projector 1000C according to the third embodiment, the afocal optical element 140C has two cylindrical lenses 142C and 144C having positive refractive power in the first direction and positive and negative in the second direction. Cylindrical with a refractive power of Lens 146C, has a 148C.

  As described above, the projector 1000C according to the third embodiment is different from the projectors 1000A and 1000B according to the first or second embodiment in the configuration of the afocal optical element, but the projector 1000A according to the first or second embodiment. Similarly to the case of 1000B, the polarization separation prism 130 similar to that used in the projectors 1000A and 1000B according to the first or second embodiment and the two separated illumination light beams are perpendicular to the illumination optical axis 100Cax and the polarization separation surface 132. On the image forming area of the liquid crystal devices 400R, 400G, and 400B (not shown) to be illuminated, which has an afocal optical element 140C that compresses in a first direction parallel to the first direction. Illuminate a part of the image forming area, and the entire image forming area in the second direction perpendicular to the first direction. And a lighting apparatus 100C for irradiating illumination light having the profile as. Further, the rotating prism 770 similar to that used in the projectors 1000A and 1000B according to the first or second embodiment is provided. For this reason, it has the same effect as the projectors 1000A and 1000B according to the first or second embodiment.

  Further, according to the projector 1000C according to the third embodiment, the afocal optical element 140C has two cylindrical lenses 142C and 144C having a positive refractive power in the first direction and positive and negative refractive powers in the second direction. The two cylindrical lenses 146C and 148C having the above-described two cylindrical lenses 142C and 144C having a positive refractive power in the first direction and the positive and negative refractive powers in the second direction. By adjusting the focal length and arrangement of the two cylindrical lenses 146C and 148C, the length of the illumination light beam irradiated on the image forming area of the liquid crystal devices 400R, 400G, and 400B along the first direction and the second Therefore, the length along the direction of the liquid crystal device 400R, 400G, 400B can be illuminated. To the size of the area, the size of the polarization separating prism 130 can be any of, so that it is possible to enhance the degree of freedom in design.

  Note that the afocal optical element 140C in the projector 1000C according to the third embodiment is different from the afocal optical elements 140A and 140B in the projector 1000A and 1000B according to the first or second embodiment in that two illumination beams separated by polarization are separated. Is compressed in the first direction perpendicular to the illumination optical axis 100Cax and parallel to the polarization separation surface 132 at a compression ratio of 1/3, while the second perpendicular to the illumination optical axis 100Cax and perpendicular to the first direction. In this direction, compression is performed at a compression ratio of 2/3.

  In the projector 1000C according to the third embodiment, as a part of the afocal optical element 140C, a cylindrical lens 146C having a positive refractive index in the second direction and a cylindrical lens 148C having a negative refractive index in the second direction are provided. However, instead of this, an optical system having two cylindrical lenses having a positive refractive index in the second direction (the first direction is a Keplerian optical system) is used. For the direction of 2, a Galileo optical system can be used. Further, as a part of the afocal optical element 140C, an optical system having two cylindrical lenses 142C and 144C having a positive refractive index in the first direction (a Galileo optical system is used in the first direction). However, instead of this, an optical system having a cylindrical lens having a positive refractive index in the first direction and a cylindrical lens having a negative refractive index in the first direction (Kepler type is used for the first direction). It becomes an optical system).

[Embodiment 4]
FIG. 6 is a view for explaining the illumination device in the projector according to Embodiment 4 of the present invention. FIG. 6A is a view of the lighting device as viewed from above, and FIG. 6B is a view of the lighting device as viewed from the side.

  The projector 1000D according to the fourth embodiment is different from the projector 1000C according to the third embodiment in the configuration of the afocal optical element. In other words, in the projector 1000C according to the third embodiment, the afocal optical element 140C has two cylindrical lenses 142C and 144C having positive refractive power in the first direction and positive and negative refractive powers in the second direction. In contrast to the two cylindrical lenses 146C and 148C, the projector 1000D according to the fourth embodiment has an afocal optical element 140D having one spherical lens 142D and positive refraction in the first direction. One cylindrical lens 144 </ b> D having a force and one cylindrical lens 146 </ b> D having a positive refractive power in the second direction are included.

  With this configuration, the same effect as that obtained by the projector 1000C according to the third embodiment is realized by three lenses (that is, one spherical lens 142D and two cylindrical lenses 144D and 146D). become able to.

  Note that the afocal optical element 140D in the projector 1000D according to the fourth embodiment uses two illumination beams separated by polarization as the illumination optical axis 100Dax, as in the case of the afocal optical element 140C in the projector 1000C according to the third embodiment. In the first direction parallel to the polarization splitting surface 132 at a compression ratio of 1/3, while compressing in the second direction perpendicular to the illumination optical axis 100Dax and perpendicular to the first direction. Compress at a rate of 2/3.

  In the projector 1000D according to the fourth embodiment, as the afocal optical element 140D, one spherical lens 142D, one cylindrical lens 144D having a positive refractive power in the first direction, and positive refraction in the second direction. Although a Galileo optical system having one cylindrical lens 146D having power is used, a cylindrical lens having a negative refractive index in the first direction can be used instead of the cylindrical lens 144D (the first lens For the direction, a Keplerian optical system is used.) Instead of the cylindrical lens 146D, a cylindrical lens having a negative refractive index in the second direction can also be used (the Kepler optical system is used for the second direction). ). In addition, a cylindrical lens having a negative refractive index in the first direction can be used instead of the cylindrical lens 144D, and a cylindrical lens having a negative refractive index in the second direction can be used instead of the cylindrical lens 146D. In this case, both the first direction and the second direction are Keplerian optical systems.)

[Embodiment 5]
FIG. 7 is a diagram for explaining the illumination device in the projector according to the fifth embodiment. A projector 1000E (not shown) according to the fifth embodiment is different from the projector 1000A according to the first embodiment in the configuration of the polarization separation prism. That is, as shown in FIG. 7, the polarization separation prism 130B according to the fifth embodiment includes a polarization cube prism including a polarization separation surface 132 therein and a triangular prism having an inclined surface as a reflection surface 134B.

  As described above, the projector 1000E according to the fifth embodiment is different from the projector 1000A according to the first embodiment in the configuration of the polarization splitting prism, but is similar to the projector 1000A according to the first embodiment. Of the vertical and horizontal directions in the image forming areas 400R, 400G, and 400B (not shown), a part of the image forming area is illuminated in the first direction, and the entire image forming area is illuminated in the second direction. Illuminating light flux having a simple cross-sectional shape (that is, a cross-sectional shape compressed in the first direction) is synchronized with the screen writing frequency of the liquid crystal devices 400R, 400G, and 400B along the first direction on each image forming region. Since scanning can be performed, in each image forming area of the liquid crystal devices 400R, 400G, and 400B, a light irradiation area and a light non-lighting are formed. And the region is to be scrolled in sequence alternately. As a result, the tailing phenomenon is alleviated and a smooth and high-quality moving image display can be obtained.

  Further, according to the projector 1000E according to the fifth embodiment, the illumination light beam having the cross-sectional shape compressed in the first direction is converted into the polarization separation prism 130B and the afocal optical element 140A (not shown in part). Unlike the case where an optical shutter is used, the illumination light beam from the light source device 110 can be guided to the image forming areas of the liquid crystal devices 400R, 400G, and 400B without waste. As a result, the light utilization efficiency is not significantly reduced.

  For this reason, the projector 1000E according to the fifth embodiment is a projector in which the light use efficiency is not significantly reduced even when smooth and high-quality moving image display is obtained.

[Embodiment 6]
FIG. 8 is a diagram for explaining the illumination device in the projector according to the sixth embodiment. The projector 1000F (not shown) according to the sixth embodiment is different from the projector 1000A according to the first embodiment in the configuration of the illumination device. That is, in the illumination device 100F according to the sixth embodiment, the polarization separation prism 130 and the collimating lens 120 are integrated as shown in FIG.

  As described above, the projector 1000F according to the sixth embodiment differs from that of the projector 1000A according to the first embodiment in the configuration of the illumination device 100F, but the liquid crystal device 400R is similar to the projector 1000A according to the first embodiment. , 400G, 400B (not shown) in the image forming area, a part of the image forming area is illuminated in the first direction and the entire image forming area is illuminated in the second direction. An illumination light beam having a cross-sectional shape (that is, a cross-sectional shape compressed in the first direction) is scanned along the first direction on each image forming region in synchronization with the screen writing frequency of the liquid crystal devices 400R, 400G, and 400B. Therefore, in each of the image forming areas of the liquid crystal devices 400R, 400G, and 400B, the light irradiation area and the light non-lighting are provided. And the region is to be scrolled in sequence alternately. As a result, the tailing phenomenon is alleviated and a smooth and high-quality moving image display can be obtained.

  Further, according to the projector 1000F according to the sixth embodiment, the illumination light beam having the cross-sectional shape compressed in the first direction is converted into the polarization separation prism 130 and the afocal optical element 140A (not shown in part). Unlike the case of using an optical shutter, the illumination light flux from the light source device 110 can be guided to the image forming areas of the liquid crystal devices 400R, 400G, and 400B without waste. As a result, the light utilization efficiency is not significantly reduced.

  For this reason, the projector 1000F according to the sixth embodiment is a projector in which the light use efficiency is not significantly reduced even when smooth and high-quality moving image display is obtained.

  Further, in the projector 1000F according to the sixth embodiment, it is possible to eliminate the reflection loss on the light exit surface of the collimating lens 120 and the light incident surface of the polarization separation prism 130, so that the light use efficiency can be improved. In the assembling process of the projector, there is an effect that it is possible to suppress deterioration in positional accuracy between the collimating lens and the polarization separation prism and an increase in the number of assembling steps.

[Embodiment 7]
FIG. 9 is a diagram illustrating an optical system of the projector according to the seventh embodiment. FIG. 9A is a view of the optical system as viewed from above, and FIG. 9B is a view of the optical system as viewed from side.

  The projector 1000G according to the seventh embodiment is different from the projector 1000A according to the first embodiment in the configuration of the color separation optical system. That is, the color separation optical system 200B of the projector 1000G according to the seventh embodiment uses a double relay optical system as shown in FIGS. 9 (a) and 9 (b).

  As described above, the projector 1000G according to the seventh embodiment is different from the projector 1000A according to the first embodiment in the configuration of the color separation optical system, but the liquid crystal is similar to the projector 1000A according to the first embodiment. Among the vertical and horizontal directions in the image forming areas of the apparatuses 400R, 400G, and 400B, a cross-sectional shape that illuminates a part of the image forming area in the first direction and the entire image forming area in the second direction (that is, The illumination light flux having a cross-sectional shape compressed in the first direction can be scanned along the first direction on each image forming region in synchronization with the screen writing frequency of the liquid crystal devices 400R, 400G, and 400B. Therefore, in each image forming region of the liquid crystal devices 400R, 400G, and 400B, the light irradiation region and the light non-irradiation region are alternately alternated. So it is scrolled. As a result, the tailing phenomenon is alleviated and a smooth and high-quality moving image display can be obtained.

  Further, according to the projector 1000G according to the seventh embodiment, the function of the illumination device 100A including the polarization separation prism 130 and the afocal optical element 140A as described above is used to convert the illumination light beam having a cross-sectional shape compressed in the first direction. Therefore, unlike the case where an optical shutter is used, the illumination light beam from the light source device 110 can be guided to the image forming areas of the liquid crystal devices 400R, 400G, and 400B without waste, and the light use efficiency is improved. Will not drop significantly.

  For this reason, the projector 1000G according to the seventh embodiment is a projector in which the light use efficiency is not significantly reduced even when smooth and high-quality moving image display is obtained.

  The projector of the present invention has been described based on the above embodiments. However, the present invention is not limited to the above embodiments, and can be implemented in various modes without departing from the scope of the invention. For example, the following modifications are possible.

(1) Although the projectors 1000A to 1000G in the above embodiments are transmissive projectors, the present invention can also be applied to a reflective projector. Here, “transmission type” means that an electro-optic modulation device as a light modulation means, such as a transmission type liquid crystal device, transmits light, and “reflection type” This means that an electro-optic modulation device as a light modulation means, such as a reflective liquid crystal device, is a type that reflects light. Even when the present invention is applied to a reflective projector, the same effect as that of a transmissive projector can be obtained.

(2) Although the projectors 1000A to 1000G in the above embodiments use a liquid crystal device as an electro-optic modulation device, the present invention is not limited to this. In general, the electro-optic modulation device may be any device that modulates incident light in accordance with image information, and a micromirror light modulation device or the like may be used. For example, a DMD (digital micromirror device) (trademark of TI) can be used as the micromirror light modulator.

(3) The projectors 1000A to 1000G of the above embodiments use the rotating prism 770 as scanning means, but the present invention is not limited to this, and a galvanometer mirror or polygon mirror can also be used.

(4) The projectors 1000 </ b> A to 1000 </ b> G according to the above embodiments include, as the light source device 110, the ellipsoidal reflector 114, the arc tube 112 having the emission center near the first focal point of the ellipsoidal reflector 114, and the collimating lens 120. However, the present invention is not limited to this, and a light source device having a paraboloid reflector and an arc tube having an emission center near the focal point of the paraboloid reflector can be preferably used.

FIG. 3 is a diagram showing an optical system of the projector according to the first embodiment. FIG. 3 is a view for explaining an illumination device in the projector according to the first embodiment. The figure which shows the relationship between rotation of a rotation prism, and the illumination state on the image formation area of a liquid crystal device. FIG. 6 is a diagram for explaining an illumination device in a projector according to a second embodiment. FIG. 6 is a diagram for explaining an illumination device in a projector according to a third embodiment. FIG. 10 is a view for explaining an illumination device in a projector according to a fourth embodiment. FIG. 10 is a view for explaining an illumination device in a projector according to a fifth embodiment. FIG. 10 is a view for explaining an illumination device in a projector according to a sixth embodiment. FIG. 10 shows an optical system of a projector according to a seventh embodiment. The figure shown in order to demonstrate the conventional projector. The figure shown in order to demonstrate another conventional projector.

Explanation of symbols

100A, 100B, 100C, 100D, 100E, 100F ... illumination device, 100Aax, 100Bax, 100Cax, 100Dax ... illumination optical axis, 110 ... light source device, 112 ... light emitting tube, 114 ... ellipsoidal reflector, 116 ... auxiliary mirror, 120 ... Parallelizing lens, 130, 130B ... polarization separation prism, 132 ... polarization separation surface, 134 ... reflection surface, 136 ... λ / 2 plate, 140A, 140B, 140C, 140D ... afocal optical element, 142A, 142B, 142C, 144A , 144B, 144C, 144D, 146C, 146D, 148C ... cylindrical lens, 142D ... spherical lens, 150A, 150B, 150C, 150D ... shading mask, 200, 200B ... color separation optical system, 752 ... field lens, 754 ... relay lens , 70 ... rotating prism, 772 ... rotary shaft, 400R, 400G, 400B ... liquid crystal device, 500 ... cross dichroic prism 600 ... projection optical system, 900A, 900B, 1000A, 1000B, 1000C, 1000D, 1000G ... projector, SCR ... screen

Claims (11)

A light source device that emits an illumination light beam that is substantially parallel to the illuminated region side, and a polarization separation surface that transmits an illumination light beam related to one polarization component of the illumination light beam from the light source device and reflects the illumination light beam related to the other polarization component And a polarization separation prism having a reflecting surface for reflecting the illumination light beam related to the other polarization component from the polarization separation surface in a direction parallel to the illumination optical axis, and the two illumination light beams separated by polarization as the illumination optical axis. An afocal optical element that compresses in a first direction that is perpendicular and parallel to the polarization separation plane, and an image is formed in the first direction on the image forming area of the electro-optic modulation device that is the object to which the illumination light beam is irradiated. An illumination device that irradiates a part of the formation region with an illumination light beam having a cross-sectional shape that illuminates the entire image formation region in a second direction perpendicular to the first direction;
An electro-optic modulation device that modulates the illumination light beam from the illumination device according to image information;
A projection optical system that projects a light beam modulated by the electro-optic modulation device;
A scanning unit disposed between the illuminating device and the electro-optic modulator, and scanning the illumination light beam along the first direction on the image forming region in synchronization with a screen writing frequency of the electro-optic modulator. A projector comprising: The projector according to claim 1, wherein
The projector according to claim 1, wherein the afocal optical element includes two cylindrical lenses having refractive power in the first direction. The projector according to claim 1, wherein
The projector according to claim 1, wherein the afocal optical element includes two cylindrical lenses having refractive power in the first direction and two cylindrical lenses having refractive power in the second direction. The projector according to claim 1, wherein
The afocal optical element includes one spherical lens, one cylindrical lens having a refractive power in the first direction, and one cylindrical lens having a refractive power in the second direction. Projector. The projector according to any one of claims 1 to 4,
A projector, comprising: a λ / 2 plate disposed on a light exit surface of an illumination light beam that passes through a polarization separation surface of the polarization separation prism or a light exit surface of an illumination light beam that is reflected by the polarization separation surface. In the projector according to any one of claims 1 to 5,
A color separation optical system for separating an illumination light beam from the illumination device into a plurality of color lights is further provided between the illumination device and the electro-optic modulation device,
A projector comprising: a plurality of electro-optic modulation devices that modulate a plurality of color lights from the color separation optical system according to image information corresponding to each color light as the electro-optic modulation device. The projector according to claim 6, wherein
The scanning unit includes a rotating prism that is disposed at a position substantially conjugate with the electro-optic modulation device between the illumination device and the color separation optical system and has a rotation axis perpendicular to the illumination optical axis,
The rotating prism is configured such that the light irradiation region and the light non-irradiation region are sequentially scrolled in synchronization with the screen writing frequency of the electro-optic modulation device on the electro-optic modulation device by the rotation. Projector. In the projector according to any one of claims 1 to 7,
The light source device includes an ellipsoidal reflector, an arc tube having a light emission center near the first focal point of the ellipsoidal reflector, and a collimating lens. The projector according to claim 8, wherein
The projector, wherein the polarization separation prism and the collimating lens are integrated. In the projector according to any one of claims 1 to 7,
The light source device includes a parabolic reflector and an arc tube having a light emission center in the vicinity of the focal point of the parabolic reflector. The projector according to any one of claims 8 to 10,
The projector according to claim 1, wherein the arc tube is provided with reflecting means for reflecting the light emitted from the arc tube toward the illuminated area toward the elliptical reflector or the parabolic reflector.