JP2009075228A - Optical synthesis apparatus, optical engine, and image projection display unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily remove color shift due to displacement after alignment adjustment adhesion or soldering of a liquid crystal display element, or due to change with time. <P>SOLUTION: Provided is a means for minutely inclining an optical element of a liquid crystal display element (reflective light valve) or a polarized beam splitter with respect to the optical axis of a color synthesizing means (dichroic prism). In one embodiment, a liquid crystal display element 7 is mounted on a holder 6 of a movable member. A plurality (3 pieces) of screw parts 5a are provided in the holder 6. The holder 6 is supported rotatably on the alignment plate 1 by fitting an elastic member 2 into the screw parts 5a and inserting the screw parts 5a through a hole part provided in an alignment plate 1 and fastening the screw part with nut 5. The alignment plate 1 is fixed on a frame 8 via a pin 8a. Color shift is eliminated by minute change of inclination of the liquid crystal display element 7 according to fastening degree of the nut 5. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a light combining device having a plurality of polarization separating elements and liquid crystal display elements and color combining means, an optical engine for a projector equipped with the light combining device, a rear projector equipped with the optical engine, The present invention relates to an image projection display device such as a front projector, and more particularly to a technique for adjusting a color shift due to a change with time after alignment adjustment by allowing a tilting of an optical element of a polarization separation element or a liquid crystal display element.

  Conventionally, a polarization separation element that separates light from a light source into red, blue, and green light, a liquid crystal display element that modulates each light, and driving means, and red, blue, and green light modulated by the liquid crystal display element. In a liquid crystal projector having a color synthesizing unit for synthesizing, a projection lens for projecting a synthesized image, etc., a liquid crystal display element has been performed by a complicated mechanical mechanism when performing alignment adjustment or the like on the synthesizing unit for each color light.

  On the other hand, recently, with the miniaturization and high definition of liquid crystal display elements, high-accuracy fixing methods are becoming mainstream. Adhesive methods and solder-based fixing methods have become common. Yes. As a method using an adhesive, for example, a method in which adhesion is performed after alignment adjustment between a liquid crystal display element and a color light combining unit as disclosed in Patent Document 1 is known. A fixing method using solder instead of an adhesive is also well known.

  The adhesive is generally an ultraviolet curable adhesive. After alignment adjustment, the adhesive is cured by irradiation with ultraviolet rays. Alternatively, in the case of soldering, the sheet metal holding the liquid crystal display element is plated in advance, and solder is poured into a gap of about 1 mm and fixed. In the case of an adhesive, it can be easily cured by ultraviolet irradiation, but the liquid crystal display element is likely to be displaced due to changes over time due to moisture absorption or thermal expansion, and color misregistration is likely to occur. There is. In the case of solder, there is little change with time, but there is a problem that the displacement due to thermal expansion is large because the heat of the solder is high when soldering after alignment adjustment of the liquid crystal display element.

  As an improvement plan thereof, as described in Patent Document 2, the liquid crystal display element is attached to the synthesizing means via an intermediate member having a temporary fixing adhesive temporary fixing portion and a main fixing solder fixing portion. There is also a method like this.

Japanese Patent Laid-Open No. 10-010994 Japanese Patent Laid-Open No. 2001-1000018

  As in the method described in Patent Document 1, in a method in which adhesion is performed after alignment adjustment of the liquid crystal display element, a positional shift due to curing shrinkage of the adhesive or a change with time occurs, so that a color shift occurs and the quality is maintained. However, there is a problem in adopting it as a fixing method when performing high-accuracy adjustment accompanying downsizing and high definition of the liquid crystal display element size. In addition, this method requires an adjustment member for adjusting the position of the liquid crystal display element, and there are problems such as an increase in the number of parts, accumulation of errors in accuracy, and an increase in adjustment allowance.

  Also in the improvement measure described in Patent Document 2, color misregistration occurs due to thermal expansion of metal parts. That is, in Patent Document 2, the liquid crystal display element is temporarily fixed with respect to the synthesizing means through the temporary fixing portion of the ultraviolet curable adhesive provided on the intermediate member by adjusting the alignment, and then the solder provided on the intermediate member. Although it is permanently fixed by the fixing portion, even if it is temporarily bonded with ultraviolet rays, high heat is transmitted to the sheet metal when soldering, and the glass transition temperature of ultraviolet rays is easily reached, resulting in color shift.

  The present invention provides a photosynthesizing device capable of easily adjusting a minute positional shift or a time-dependent positional shift due to adhesive fixing or soldering fixing after alignment adjustment of a liquid crystal display element, and preventing the color shift, and mounting the photosynthesis apparatus An object of the present invention is to provide an optical engine capable of high-definition display without being affected by the positional deviation of the liquid crystal display element, and an image projection display device equipped with the optical engine.

  The invention of claim 1 is a light synthesizing apparatus having a plurality of polarization separating elements, an optical element of a liquid crystal display element, and color synthesizing means, and means for adjusting the inclination of the optical element with respect to the optical axis of the color synthesizing means. It is provided.

  According to a second aspect of the present invention, in the photosynthetic device according to the first aspect, the liquid crystal display element is attached to a movable member, a plurality of screw portions are provided on the movable member, and the screw portions are provided on the fixed member via an elastic member. The movable member is held on the fixed member by passing through the formed hole and tightened with an adjusting screw nut, and the inclination of the liquid crystal display element can be adjusted according to the tightening condition of the adjusting screw nut. And

  According to a third aspect of the present invention, in the photosynthesizing device according to the first aspect, the polarization separation element is attached to a movable member, a plurality of holes are provided in the movable member, and a plurality of screw portions provided in the fixed member are elastic members. Through the hole of the movable member through the bolt and tightening with an adjustment screw nut, holding the movable member on the fixed member, and adjusting the inclination of the polarization separation element according to the tightening degree of the adjustment screw nut It is possible to do this.

  According to a fourth aspect of the present invention, in the photosynthetic device according to the first aspect, the liquid crystal display element is attached to a movable member, the movable member is held on a fixed member via a plurality of piezoelectric elements, and the piezoelectric element is driven. The tilt of the liquid crystal display element can be adjusted.

  According to a fifth aspect of the present invention, in the photosynthesis device according to the fourth aspect, the piezo element is an XY two-axis drive type in which the liquid crystal display element is moved in the X and Y directions perpendicular to the optical axis of the color synthesis means. A piezo element is used.

  A sixth aspect of the present invention is the photosynthesizing device according to the first aspect, wherein the polarization separating element is attached to a movable member, the movable member is held by a fixed member via a plurality of piezoelectric elements, and the piezoelectric element is driven. The tilt of the polarization separation element can be adjusted.

  According to a seventh aspect of the present invention, in the light combining device according to the first aspect, the liquid crystal display element and the polarization separating element are integrated into a unit, and means for adjusting the inclination with respect to the optical axis of the color combining means is provided. It is characterized by.

  According to an eighth aspect of the present invention, there is provided the light combining device according to the seventh aspect, wherein a plurality of piezos driven in the Z axis are arranged in the X and Y directions orthogonal to the optical axis (Z axis) of the color combining means. By providing an element and driving the piezo element, it is possible to adjust an inclination of an integrated unit of the liquid crystal display element and the polarization separation element.

  According to a ninth aspect of the present invention, in the photosynthesis device according to the seventh or eighth aspect, the polarization separation element is a polarization beam splitter, and the liquid crystal display element is attached to the polarization beam splitter.

  A tenth aspect of the invention is characterized by an optical engine equipped with the photosynthesis device according to any one of the first to ninth aspects.

  The invention of claim 11 is characterized by an image projection display device equipped with the optical engine of claim 10.

  In a general video projector, the position of the liquid crystal display element is adjusted to 1 to 2 μm in the X and Y directions for an element with one pixel of about 15 μm, and finally the change with time (temperature change, humidity change, vibration drop, etc.) In addition, a positional deviation up to about half a pixel (7.5 μm) is allowed. However, even in this specification, when looking at the drawing and discussing it, when observing a single line in the drawing near the screen, the color shift of the half pixel looks red and blue and the visibility is clearly worsened. . Since the width of a single line is about 1 mm, it can be easily seen that the line is color-shifted when viewed in the vicinity.

  According to the apparatus of the present invention, it is possible to easily correct a minute shift of 1 to 2 degrees by slightly tilting the optical element of the liquid crystal display element or the polarization separation element with respect to the optical axis of the color synthesizing unit. It becomes.

  Also, in the past, once the liquid crystal display element was fixed after alignment adjustment, it was difficult for both the serviceman and the user to make adjustments. However, according to the device of the present invention, the liquid crystal display element is always ready after alignment adjustment. In addition, the color shift can be prevented by adjusting the inclination of the polarization separation element. For this reason, the merge of the alignment assembling adjustment standards of the liquid crystal display elements in the production line can be expanded, and the yield can be improved.

  Also, dichroic prisms for liquid crystal display elements and color composition means are expensive, and if the positional deviation during bonding after alignment assembly cannot be satisfied, the adhesive and solder will be removed and reused for reassembly. This leads to an increase in man-hours and work time. According to the apparatus of the present invention, since adjustment is possible at any time, it is possible to reduce man-hours and work time for reassembly. Furthermore, it becomes possible for the service person to easily adjust the color misregistration at the customer site, thereby reducing the cost. In addition, it is possible to provide a user with a high-definition image without color misregistration for a long time.

  The device of the present invention has various effects other than those described here. This will be described in the following description of embodiments.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  This is because the liquid crystal display element is attached to a liquid crystal display element holder which is a movable member, a plurality (three) of screw parts are provided on the holder, and each screw part is provided on an alignment plate which is a fixed member via an elastic member. The liquid crystal display element holder is rotatably held on the alignment plate by passing through the hole and tightening with the adjustment screw nut, and the tilt of the liquid crystal display element can be finely adjusted according to the tightening condition of the adjustment screw nut. It is.

  FIG. 1 is a partially exploded perspective view of an optical engine for a projector equipped with a light combining unit having a liquid crystal display element tilt adjusting mechanism of the present embodiment, and FIG. 2 is an exploded view of the liquid crystal display element tilt adjusting mechanism in FIG.

  In FIG. 1, reference numeral 4 denotes a dichroic prism as a color synthesizing means. A triangular holder plate 10 is fixed to each of the three light incident surfaces of the dichroic prism 4, and a projection lens 11 is attached to the light emitting surface. It has been. A plate-like polarization separation element 9 is fixed to a 45 ° inclined surface in front of each holder plate 10. On the other hand, a pin frame 8 is fixed to the upper surface of each holder plate 10, and a liquid crystal display element (reflection type light valve) 7 is rotatably held on the pin frame 8 via a liquid crystal display element tilt adjusting mechanism 3. ing. As shown in FIG. 2, the liquid crystal display element tilt adjusting mechanism 3 includes an alignment plate 1, an elastic member 2, three adjusting screw nuts 5, and a liquid crystal display element holder 6. Pins 8 a are provided at the four corners of the pin frame 8, and the pins 8 a of the pin frame 8 are passed through holes provided at the same four corners of the alignment plate 1 to be fixed by alignment adjustment (positioning). Thus, the alignment plate 1 is fixed. Holes are provided at predetermined positions (three locations) of the alignment plate 1. In addition, tilt adjusting screw portions 5a are provided at similar predetermined positions (three locations) on the upper surface of the liquid crystal display element holder 6, and the liquid crystal display element 7 is fixed to the lower surface. The elastic member 2 is fitted to the inclination adjusting screw portion 5 a provided in the liquid crystal display element holder 6, the screw portion 5 a is passed through the hole portion provided in the alignment plate 1, and tightened with the adjusting screw nut 5. Thus, the liquid crystal display element holder 6 is rotatably held by the alignment plate 1.

  Illumination light enters each of the three polarization separation elements 9 via an optical system (not shown), passes through each polarization separation element 9, and is separated into red (R), green (G), and blue (B) components. Then, it enters each liquid crystal display element (reflection type light valve) 7. The RGB three-color image light reflected by each liquid crystal display element 7 is reflected by each polarization separation element 9, enters the dichroic prism 4 from three directions, and is synthesized from the remaining one direction of the dichroic prism 4. Exit. The synthesized light image is projected through a projection lens 11 onto a screen (not shown).

  Here, when the optical axes of the three RGB image lights incident on the dichroic prism 4 are tilted, the image projected on the screen through the projection lens 11 is slightly displaced, and the RGB colors are color-shifted.

  According to the configuration of FIG. 1, by tightening or loosening the three adjusting screw nuts 5 of the liquid crystal display element tilt adjusting mechanism 3, the liquid crystal display element holder 6 is slightly rotated and the liquid crystal display element 7 is slightly tilted. be able to. When the liquid crystal display element 7 is tilted, the optical axis of the image light of the color component incident on the dichroic prism 4 is also tilted. Therefore, when the color of RGB causes color misregistration, the color misregistration of RGB can be removed by tilting the liquid crystal display element 7 in the direction of removing the color misregistration.

  It should be noted that the rotation center for fine adjustment of the tilt of the liquid crystal display element 7 can be easily adjusted by shifting it from the reflecting surface of the liquid crystal display element 7 in the direction of the optical axis, and the rotation center should be at an optimum position according to the design. Is desirable.

FIG. 5 is a cross-sectional view showing a detailed configuration of the liquid crystal display element tilt adjusting mechanism 3. The liquid crystal display element holder 6, which is a movable member, is provided with tilt adjustment screw portions (three pieces) 5 a on the upper surface, and the liquid crystal display element 7 is fixed to the lower surface. The elastic member 2 is fitted into an inclination adjusting screw portion 5a provided on the upper surface of the liquid crystal display element holder 6, and the inclination adjusting screw portion 5a is inserted into a hole provided in the alignment plate 1 serving as a fixing member. Pass through and tighten with adjusting screw nut 5. As shown in FIG. 1, pins 8 a are provided at the four corners of the pin holder 8. Similarly, holes are provided at the four corners of the alignment plate 1. A pin 8a provided on the pin frame 8 is passed through a hole provided in the alignment plate 1, and the hole 21 is filled with an adhesive 21, so that the entire tilt adjusting mechanism is moved to six axes (X, Y, Z). axial with each of the axial rotation about X _θ, Y _θ, Z after 6 axes) alignment in _theta, by curing by irradiating ultraviolet rays to the adhesive 21, the entire the liquid crystal display device tilt adjustment mechanism pin frame 8 is held. The liquid crystal display element holder 6 is held by the alignment plate 1 so as to be rotatable by the screw portion 5a, the adjusting screw nut 5, and the elastic member 2.

  The elastic member 2 may be made of silicon rubber, butyl rubber, coil springs or plate springs. In short, the liquid crystal display element holder 6 may be held even if the adjusting screw nut 5 is loosened to some extent.

  In such a configuration, by tightening or loosening the adjustment screw nut 5, the elastic member 2 expands and contracts, the liquid crystal display element holder 6 rotates slightly, and the liquid crystal display element 7 can be tilted slightly. The center of rotation when the liquid crystal display element 7 is tilted can be moved in the X and Y directions perpendicular to the optical axis by being located away from the reflection surface of the liquid crystal display element 7. Color shift can be prevented.

  Since the spherical portion 5b is provided at the lower portion of the adjusting screw nut 5, the liquid crystal display element holder 6 does not rattle in the X and Y directions because it is positioned by the hole portion of the alignment plate 1 and the spherical portion 5b. There is no longer to do. The adjustment screw nut 5 may have a conical shape, and can be removed similarly.

  When a 1 mm wide line is shifted by 0.5 mm on the screen, the tilt is about 40 seconds at the polarization separation element. Therefore, it is possible to easily adjust the color misregistration by slightly tilting the liquid crystal display element and the polarization separation element described later.

  This is because the polarization separation element is attached to a polarization separation element holder that is a movable member, a plurality of (three) holes are provided in the holder, and a plurality of screw portions provided on a support base that is a fixing member are attached to an elastic member. The holder is rotatably held on the support base by passing through the hole of the holder and tightening with the adjustment screw nut, and the tilt of the polarization separating element can be adjusted according to the tightening condition of the adjustment screw nut. is there.

  FIG. 3 is a partially exploded perspective view of a projector optical engine equipped with a light combining unit having a polarization separation element tilt adjustment mechanism of the present embodiment, and FIG. 4 is a front view of the polarization separation element holder in FIG. In the figure, the same parts as those in FIG.

  Also in FIG. 3, triangular holder plates 10 are bonded and fixed to the three light incident surfaces of the dichroic prism 4. As shown in FIG. 1, a projection lens is attached to the light exit surface side of the dichroic prism 4, but is omitted in FIG. A pin frame 8 is attached to the upper surface of each holder plate 10, and the pins provided at the four corners of the pin frame 8 are passed through the holes provided at the four corners of the liquid crystal display element alignment holder plate 18, The liquid crystal display element alignment holder plate 18 is held by the pin frame 8 by filling the hole with an adhesive and curing the adhesive after adjusting the alignment. The liquid crystal display element (reflection type light valve) 7 is fixed to the lower surface of the alignment holder plate 18.

  On the other hand, the support base 13 is fixed to the 45 ° inclined surface in front of each holder plate 10. Inclination adjusting screw portions 17 are provided at predetermined positions on three sides of the support base 13, and as shown in FIG. 4, the same predetermined positions on the three sides of the polarization separation element holder 15 to which the plate-like polarization separation element 9 is fixed. Is provided with a hole 15a. The elastic member 14 is fitted to the screw portion 17 of the support base 13, the screw portion 17 is passed through the hole 15 a of the polarization separation element holder 15, and is tightened by the adjusting screw nut 16, so that the polarization separation element holder 15 is The support base 13 is rotatably held. The support base 13, the elastic member 14, the polarization separation element holder 15, and the adjustment screw nut 16 constitute the polarization separation element tilt adjustment mechanism 12.

  According to the configuration of FIG. 3, by tightening or loosening the three adjusting screw nuts 16 of the polarization separation element tilt adjustment mechanism 12, the polarization separation element holder 15 rotates slightly, and the polarization separation element 9 becomes minute. Can be tilted. When the polarization separating element 9 is tilted, the optical axis of the image light of the color component incident on the dichroic prism 4 is tilted as in the case where the liquid crystal display element 9 is tilted, and RGB color shift can be removed.

  The material of the elastic member 14 may be silicon rubber or butyl rubber, as well as a coil spring or a plate spring, like the elastic member 2 described above. In short, even if the adjustment screw nut 16 is loosened to some extent, the polarization separation element holder 15 may be held.

  The liquid crystal display element (reflective light bubble) is aligned in advance after assembling the polarization separation element in a state of approximately 45 °. As described above, the pin frame 8 is bonded and fixed to the upper portion of the holder plate 10, and the pin 8a provided in the pin frame and the hole provided in the liquid crystal display element alignment holder plate 18 are filled with an adhesive, After alignment adjustment, the adhesive is cured by irradiating ultraviolet rays. Thereby, the alignment holder plate 18 is fixed. When the alignment holder plate 18 provided with the liquid crystal display element 7 is fixed with an adhesive, the adhesive shrinks during UV curing, and the liquid crystal display element is displaced, thereby causing a color shift. By optimizing the curing conditions (light quantity of ultraviolet rays, irradiation time, distance from the adhesive), etc., the misregistration can be suppressed to 1 μm or less, but in order to reduce the misregistration, generally the light quantity is reduced, It is common to cure over a long time. Here, if the positional deviation occurs, it is useless even if the six-axis alignment adjustment of the liquid crystal display element is performed, and the readjustment is necessary after removing the adhesive. Adjustment of the alignment of the liquid crystal display element takes a lot of man-hours and the removal of the adhesive is not easy. Therefore, it is very advantageous to be able to finely adjust the color misregistration by tilting the polarization separation element after the alignment adjustment adhesive curing. Of course, tilting the liquid crystal display element as shown in FIG.

  In addition, when a metal support member is basically used, thermal expansion occurs and the liquid crystal display element is displaced. One pixel of the liquid crystal display element is about 20 to 10 μm, and if one pixel is shifted, the color shift is shifted by one line. For this reason, the support member such as the holder plate 10 may be made of glass, but the strength is a problem. Further, when metal is used, processing distortion and the like are gradually eliminated, and positional deviation may occur. It is difficult to remove all of these movements, and it is easiest to fine-tune at a place that is stable over time, and it is possible to reduce subsequent positional deviation.

  As described above, when a line having a width of 1 mm is shifted by 0.5 mm on the screen, the inclination is about 40 seconds for the plate-shaped polarization separation element. Therefore, it is possible to easily adjust the color misregistration by slightly tilting the polarization separation element and the liquid crystal display element with respect to the slight positional deviation after the alignment adjustment bonding and fixing of the liquid crystal display element.

  Although FIG. 1 and FIG. 3 show the configuration including either the liquid crystal display element tilt adjustment mechanism or the polarization separation element tilt adjustment mechanism, a configuration including both of them may be employed.

  In this case, a liquid crystal display element (reflection type light valve) is tilted using a small piezo element instead of an elastic member or an adjustment screw nut. FIG. 6 is a cross-sectional view of the liquid crystal display element tilt adjusting mechanism of this embodiment, and the same parts as those in FIG. Except for the liquid crystal display element tilting mechanism, the overall structure of the photosynthetic unit is the same as that shown in FIG.

  In FIG. 6, a liquid crystal display element (reflective light valve) 7 is fixed to the lower surface of the liquid crystal display element holder 6 as a movable member, as in FIG. In addition, small piezo elements 22 (three) driven in the Z-axis direction are provided. The other end face of the small piezo element 22 is fixed to the alignment plate 1 as a fixing member. As shown in FIG. 1, pins 8 a are provided at the four corners of the pin holder 8, and holes are provided at the same four corners of the alignment plate 1. The pin 8a provided on the pin frame 8 passes through the hole provided in the alignment plate 1, and the hole 21 is filled with the adhesive 21. After adjusting the alignment, the adhesive 21 is cured, and the inclination is obtained. The entire adjustment mechanism is held by the pin frame 8.

  In such a configuration, by driving the small piezoelectric element 22 in the Z-axis direction, the liquid crystal display element holder 6 can be slightly rotated and the liquid crystal display element 7 can be slightly tilted. Therefore, for example, it is possible to easily adjust the color shift while driving the small piezo element 22 from the outside of the projector system and viewing the screen. Further, by providing a color misregistration detection sensor on the screen and drivingly controlling the small piezoelectric element 22 in accordance with the detection signal of the sensor, the color misregistration can be automatically adjusted. As the color misregistration detection sensor, a four-divided light receiving element is used. Spot light is incident on this, and the four output signals from the four-divided light receiving element are compared to detect color misregistration. Such four-divided light receiving elements are provided at positions separated from the image display area on the screen corresponding to the three colors of RGB.

  In addition, although the thermal expansion of components occurs due to the temperature rise by the lamp in the projector and the liquid crystal display element is displaced, this can be automatically removed by adopting the automatic control configuration.

  In FIG. 6, a small piezo element driven in the Z-axis direction is provided, but an XY two-axis drive type small piezo that moves the liquid crystal display element minutely in the X and Y directions perpendicular to the optical axis of the dichroic prism 4 is provided. It is also possible to provide an element. Since the pixel position can be shifted by using an XY two-axis drive type small piezo element instead of the Z-axis drive type small piezo element, the color shift can be removed. In addition, since the pixels can be moved directly in the X and Y directions, the adjustment can be easily performed and the adjustment time can be shortened.

  In this case, instead of an elastic member or an adjustment screw nut, the polarization separation element is tilted using a small piezo element. FIG. 7 is a schematic cross-sectional view of a photosynthetic unit provided with the polarization separation element tilt adjusting mechanism of this embodiment.

  In FIG. 7, plate-like polarized light is passed through a small piezo element 23 (three pieces) driven in the Z-axis direction on the front 45 ° inclined surface of the triangular holder plate 10 provided on the light incident surface of the dichroic prism 4. A separation element 9 is attached. A liquid crystal display element (reflective light valve) is attached to the upper surface of the holder plate 10, but is omitted in FIG. In FIG. 7, only one light incident surface side configuration of the dichroic prism 4 is shown, but the other two light incident surface sides have the same configuration.

  In such a configuration, the polarization separating element 9 can be tilted by driving the small piezoelectric element 23 in the Z-axis direction. Therefore, for example, it is possible to easily adjust the color shift while driving the polarization separation element 9 from the outside of the projector system and viewing the screen. Further, by providing a sensor for detecting color misregistration on the screen and controlling the small piezo element 23 according to the detection signal of the sensor, the color misregistration can be automatically adjusted.

  In this configuration, the liquid crystal display element and the polarization separating means are integrated into one unit, and an inclination adjusting means is provided with respect to the optical axis of the dichroic prism as the color synthesizing means.

  FIG. 8 is a schematic cross-sectional view showing a configuration example of the present embodiment. The holder plate 10, the liquid crystal display element (reflection type light valve) 7, and the plate-like polarization separation element 9 are assembled in advance as a unit of an integrated structure. 2 shows a configuration in which the dichroic prism 4 is attached to the incident surface via small piezo elements (three pieces) 24. In FIG. 8, only the configuration on one light incident surface side of the dichroic prism 4 is shown, but the other two light incident surface sides have the same configuration.

  The small piezo elements 24 are of the Z-axis drive type, and three are provided in the X and Y directions perpendicular to the optical axis with respect to the incident optical axis of the dichroic prism 4. By driving the small piezo element 24, the unitary structure unit of the holder plate 10, the liquid crystal display element 7 and the polarization separating element 9 is slightly tilted, and the color shift on the screen can be removed.

  It should be noted that the pixel position on the screen can be shifted and color misregistration can be eliminated by using an XY drive type small piezo element instead of the Z axis drive type small piezo element. In this case, since the color shift can be adjusted independently in the X and Y directions, the adjustment can be easily performed.

  FIG. 9 is a schematic cross-sectional view showing another configuration example of the present embodiment. This uses a polarization beam splitter 19 instead of the holder plate 10 and the plate-like polarization separation element 9 in FIG. 8, and the liquid display element and the polarization separation means are integrated into a unit, and the dichroic prism 4 The small piezoelectric elements 24 (three) are provided in the X and Y directions perpendicular to the optical axis with respect to the incident optical axis, as in FIG. The small piezoelectric element 24 is an X-axis drive type, but can be replaced with an X, Y drive type.

  As described above, various embodiments of the tilt adjusting unit and the color misregistration adjusting unit of the present invention have been described. According to the projector optical engine equipped with such an adjusting unit, a high-definition optical engine without color misregistration is provided. can do. Further, according to the rear projector or the front projector equipped with such an optical engine, a high-definition image projection display device can be provided.

1 is a partially exploded perspective view of a first embodiment of the present invention. The exploded view of the liquid crystal display element inclination adjustment mechanism in FIG. The partial exploded perspective view of the 2nd example of the present invention. FIG. 4 is a front view of the polarization separation element holder in FIG. 3. Sectional drawing which shows the detailed structure of the liquid crystal display element inclination adjustment mechanism of 1st Example of this invention. Sectional drawing which shows the detailed structure of the liquid crystal display element inclination adjustment mechanism of the 3rd Example of this invention. Sectional drawing which shows schematic structure of the 4th Example of this invention. Sectional drawing which shows schematic structure of the 5th Example of this invention. Sectional drawing which shows schematic structure of another structural example of the 5th Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Alignment plate 2 Elastic member 3 Liquid crystal display element inclination adjustment mechanism 4 Dichroic prism 5 Adjustment screw nut 5a Tilt adjustment screw part 6 Liquid crystal display element holder 7 Liquid crystal display element (reflection type light valve)
8 Pin Frame 8a Pin 9 Polarization Separation Element 10 Holder Plate 11 Projection Lens 12 Polarization Separation Element Tilt Adjustment Mechanism 13 Support Base 14 Elastic Member 15 Polarization Separation Element Holder 17 Tilt Adjustment Screw 18 Liquid Crystal Display Element Alignment Holder Plate 19 Polarization Beam Splitter 21, 22, 23, 24 Piezo elements

Claims (11)

A light combining device having a plurality of polarization separation elements, an optical element of a liquid crystal display element, and color combining means,
A light synthesizing apparatus comprising means for adjusting an inclination of an optical element with respect to an optical axis of the color synthesizing means. The photosynthesis apparatus according to claim 1, wherein
The liquid crystal display element is attached to a movable member, the movable member is provided with a plurality of screw portions, the screw portions are passed through holes formed in the fixed member via an elastic member, and tightened with an adjustment screw nut, A photosynthesizing device characterized in that a movable member is held on the fixed member, and the inclination of the liquid crystal display element can be adjusted according to the tightening degree of the adjusting screw nut. The photosynthesis apparatus according to claim 1, wherein
The polarization separating element is attached to the movable member, the movable member is provided with a plurality of holes, and the plurality of screw portions provided in the fixed member are passed through the holes of the movable member through an elastic member to adjust the screw. A photosynthesizing device, wherein the movable member is held on the fixed member by tightening with a nut, and the inclination of the polarization separation element can be adjusted according to the tightening condition of the adjusting screw nut. The photosynthesis apparatus according to claim 1, wherein
The liquid crystal display element is attached to a movable member, the movable member is held on a fixed member via a plurality of piezoelectric elements, and the inclination of the liquid crystal display element can be adjusted by driving the piezoelectric element. Photosynthesis device. The photosynthesis apparatus according to claim 4, wherein
An XY two-axis drive type piezo element that moves the liquid crystal display element in the X and Y directions perpendicular to the optical axis of the color synthesizing unit is used as the piezo element. The photosynthesis apparatus according to claim 1, wherein
The polarization separation element is attached to a movable member, the movable member is held on a fixed member via a plurality of piezoelectric elements, and the inclination of the polarization separation element can be adjusted by driving the piezoelectric element. Photosynthesis device. The photosynthesis apparatus according to claim 1, wherein
A light combining device comprising: the liquid crystal display element and the polarization separating element as an integral unit, and means for adjusting an inclination with respect to an optical axis of the color combining means. The photosynthesis apparatus according to claim 7,
The liquid crystal display element is provided by providing a plurality of Z-axis driven piezo elements in the X and Y directions orthogonal to the optical axis (Z axis) of the color composition means, and driving the piezo elements. And a light synthesizing apparatus characterized in that an inclination of an integral unit of the polarization separation element can be adjusted. The photosynthesis apparatus according to claim 7 or 8,
A light combining device, wherein the polarization separation element is a polarization beam splitter, and the liquid crystal display element is attached to the polarization beam splitter.   An optical engine comprising the photosynthesizing device according to any one of claims 1 to 9.   An image projection display device comprising the optical engine according to claim 10.

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