JP4679868B2 - Projection device - Google Patents

Description

  The present invention relates to a projection apparatus for a projection type project using a light valve for image generation such as a liquid crystal panel or a DVD (digital micromirror device), and more particularly, a color image using a plurality of reflection type light valves. The present invention relates to a projection apparatus that enlarges and projects the image on the screen.

  For example, a projection projector for displaying color images irradiates three liquid crystal panels with R, G, and B primary color lights to carry R, G, and B image information, and synthesizes these color lights. What is projected on the screen is widely known.

  In recent years, rear projection TVs and front projectors have been commercialized as projection devices that perform enlarged projection using a light valve typified by a liquid crystal panel. These projection apparatuses are required to have higher image quality and lower cost. In order to reduce the cost, a so-called color sequential display device that uses a single light valve, uses R, G, and B lighting that is time-divided within one frame display, and displays white is also commercialized. Yes.

  However, a display device using a so-called color sequential method has a problem of hindering high image quality such as a color break that occurs when a moving image is displayed or an eye moves. Therefore, in order to satisfy both high image quality and low cost, the so-called multi-plate method using R, G, B color illumination light corresponding to each color and using three light valves is more advantageous. .

  A multi-panel display device requires focus adjustment and position adjustment of a plurality of panels. In addition, the higher the image quality, the smaller the pixel pitch and the like.

  In Patent Document 1, in a projection optical system using a reflection type light valve, the projection optical system is compact by performing color separation of irradiation light from a light source and color synthesis of color light from a reflection type light valve by one optical member. A reflection type projection optical system has been proposed that can reduce the manufacturing cost and manufacturing cost, and can display a color image with little color unevenness on a screen.

In Patent Document 2, white illumination light in a linearly deflected state is transmitted through a first wavelength selective retarder, separated by a deflecting beam splitter and a dichroic prism, converted into image light by a light valve, and synthesized by a dichroic prism and a deflecting beam splitter. A projection apparatus has been proposed that improves the contrast of a projected image by displaying a color image incident on a deflector via a second wavelength-selective retarder and projected onto a screen by an imaging optical system. .
JP 2000-131649 A JP 2003-185773 A

  However, the above invention has the following problems.

  According to Patent Document 1, in a projection optical system using a reflection type light valve, the projection optical system is such that color separation of light emitted from a light source and color composition of color light from a reflection type light valve are performed by one optical member. Although the system is made compact, the arrangement of the reflection type light valve is not mentioned, and the reflection type projection optical system is not made compact.

  According to Patent Document 2, the contrast of a projected image is improved by using a plurality of reflection type light valves. However, the arrangement of the reflection type light valves is not mentioned, and the projection apparatus can be made compact. It is not done.

  Therefore, the present invention makes a light valve corresponding to R, G, and B in such a manner that the polarization direction deflected by the polarization separation element and the polarization direction by the color synthesis element are orthogonal to each other, and the light valves are arranged on the same plane. It is an object of the present invention to provide a projection apparatus in which the prism, polarization separation element, light valve, and the like are easily assembled and the entire apparatus is made compact by being held and integrated on the same member.

According to the first aspect of the present invention, a light source that emits light of a plurality of colors, a plurality of polarization separation elements provided corresponding to each of the color lights emitted from the light source, and the light transmitted through or reflected by each of the polarization separation elements A light valve provided corresponding to each polarized light; and a color composition element, wherein the light valve modulates the polarized light of each color light transmitted or reflected by the polarization separation element, and the polarization separation. The element detects each color light modulated by the light valve, and the color composition element corresponds to each polarization light in the projection device that color-synthesizes each color light detected by the polarization separation element. A mounting member for mounting the light valve provided in the middle, and an intermediate member provided corresponding to each light valve for integrating the light valve and the mounting member. A first member in contact with the light valve, a second member in contact with the mounting member, and the first member in parallel with a plane orthogonal to the polarized light with respect to the second member. said intermediate member comprising a first moving means for moving the said gap between the intermediate member and the mounting member is positioned fixed, it said that the plane polarized light is irradiated in the light valves are positioned on the same plane wherein and an adjustment means for adjusting the height of each light valve, and the respective color light and forms a surface that is color synthesis is light detecting by the polarization separating element and each color light by the color combining element, said polarization A surface formed by each color light detected by a separation element and each color light modulated by the light valve is substantially orthogonal, and the light valve is arranged on the same plane of the mounting member. .

According to a second aspect of the invention, in the projection device according to claim 1, characterized in that in response to the position where the light valve is disposed between the polarization separation element and the color combining element are integrated .

  In the present invention, the plane including the incident light to the color combining element of each color and the output light from the color combining element and the plane including the incident light to the polarization separating element of each color and the output light from the polarization separating element are substantially the same. By adopting an orthogonal configuration, all the light valves can be arranged on the same plane. In addition, since the light valves corresponding to R, G, and B are held in the same member and integrated, the optical axes of the irradiation light incident on the projection apparatus can be aligned. Furthermore, since a unit structure in which multiple light valves and mounting members are integrated is adopted, a simple structure for mounting a unit in which multiple light valves and mounting members are integrated after assembly of the color composition element and polarization separation element can do.

  An example of the embodiment of the present invention will be described below.

  FIG. 1 is a schematic view of a projection apparatus according to the present embodiment. The projection apparatus according to this embodiment includes light valves (5a, 5b, 5c) corresponding to illumination lights (101a, 101b, 101c) of R, G, and B colors, and illumination lights (101a, 101b, 101c) of the colors. Each color whose polarization state is modulated in units of pixels by the polarization separation elements (4a, 4b, 4c) and the light valves (5a, 5b, 5c) that separate the illumination light incident on the light valves (5a, 5b, 5c) from Color synthesizing element 1 for synthesizing the output light. The light valves (5a, 5b, 5c) are arranged on the same plane 6, and the light valves (5a, 5b, 5c) are integrated with the mounting member 7.

  FIG. 2 is a side view and a top view of the projection apparatus according to the present embodiment shown in FIG. In FIG. 2, reference numerals 103 a and 103 c represent incident light to the color composition element 1, and reference numerals 104 a and 104 c represent output light from the color composition element 1. The plane including the incident light 103a to the color synthesizing element 1 and the output light 104a from the color synthesizing element 1 and the plane including the incident light 102a to the polarization separating element 4a and the output light 103a from the polarization separating element 4a They are substantially orthogonal to each other.

  As shown in FIG. 1, illumination light (101a, 101b, 101c) is incident on the light valves (5a, 5b, 5c) from above through the polarization separation elements (4a, 4b, 4c). The illumination light that has passed through the polarization separation elements (4a, 4b, 4c) becomes linearly polarized light and illuminates the light valves (5a, 5b, 5c). When the light valve (5a, 5b, 5c) is a reflection type light valve or the like, it is modulated for each pixel by an image signal corresponding to each color, is reflected by rotating incident polarized light, and polarized light separating elements (4a, 4b, 4c). Head to. The polarization separation elements (4a, 4b, 4c) guide the modulated output light of each color to the color composition element 1 as reflected light.

  As the polarization separation elements (4a, 4b, 4c), a plate-type polarization separation element in which a gold wire lattice called a wire grid is provided on a transparent substrate, a polarization separation prism formed of a dielectric multilayer film, or the like is used. In particular, when a plate-type polarization separation element is used, since most of the optical path is an air medium, there is an advantage that focus shift due to chromatic aberration is smaller than when a prism is used.

  As the color synthesizing element 1, a cross-type dichroic prism is suitable. Incident light of each color incident on the color composition element 1 is reflected by the dichroic films (2, 3) and output as a color image 201. When applied to a projection magnifying apparatus, the image is enlarged and projected by a projection lens (not shown) or the like.

  As described above, the plane including the incident light to the color combining element of each color and the output light from the color combining element, and the plane including the incident light to the polarization separating element of each color and the output light from the polarization separating element are mutually By adopting a substantially orthogonal configuration, all the light valves can be arranged on the same plane. In addition, since the light valves corresponding to R, G, and B are held on the same member and integrated, the optical axes of the irradiation light incident on the projection apparatus can be aligned (upward in the case of FIG. 1). . In addition, since a unit structure that integrates multiple light valves and mounting members is adopted, a simple structure that attaches a unit that combines multiple light valves and mounting members after assembly of the color composition element and polarization separation element. It can be.

  In addition, a so-called polarization conversion element that combines a polarization separation element and a half-wave plate is arranged in the illumination optical path, so that the illumination light has a uniform polarization so as to transmit the polarization separation element of the present invention with high efficiency. Also good. By adopting such a configuration, a projection apparatus with higher light utilization efficiency can be realized.

  Next, in order to arrange the surface of each light valve (5a, 5b, 5c) on the same plane, the projection device in which each light valve (5a, 5b, 5c) is attached to the attachment member 7 via an intermediate member This will be described with reference to FIG.

  3A, 3B, and 3C show how the light valves 5a and 5c are attached to the intermediate members 22a and 22c. The intermediate members (22a, 22c) mainly serve to regulate the optical axis direction. The attachment member 7 and the light valves (5a, 5c) are integrated and held via the intermediate members (22a, 22c). At this time, in order to arrange the light valves (5a, 5c) on the same plane, the display surface of the light valves (5a, 5c) is brought into close contact with the reference reference surface 21-A of the reference member 21. Due to errors in the thickness of the substrate and intermediate member 7 forming the light valves (5a, 5c), the height between the light valves, as shown in FIG. 3 (a), the position in the height direction of the light valves 22a, 22b. Even if they are not aligned, the distance between the intermediate member and the mounting member 7 is adjusted by an adjusting means such as an adhesive to absorb the error amount.

  Specifically, as shown in FIG. 3A, after the intermediate members 22a and 22b are aligned on the reference member 21 in advance, as shown in FIG. The gap between (22a, 22b) and the attachment member 7 is filled and fixed. It is not always necessary to fill, and an adhesive member or the like may be fixed in a bridge shape as long as sufficient fixing strength is obtained. As the adhesive member, a UV adhesive, a thermosetting type, a two-component curable type, or the like is used. And after positioning fixation, as shown to the schematic diagram of FIG.3 (c), the reference member 21 is removed.

  Further, as a means for adjusting the heights of the light valves, the display surface of the light valve and the reference surface 21-A may be illuminated by optical means with a microscope or the like. Or the space | interval of the attachment member 7 and intermediate members (22a, 22c) may be adjusted with a screw feed mechanism, and it may adhere with an adhesive etc. after position adjustment. Depending on the required accuracy, the light valve and the mounting member can be integrated and held by screwing.

  Although not shown in FIGS. 3A, 3 </ b> B, and 3 </ b> C, the light valve 5 b is also held integrally with the mounting member 7 by the method described above.

  As described above, the display portions of the respective light valves can be held on the same plane by integrally holding the plurality of light valves and the mounting member. Further, by assembling and holding the light valve and the mounting member, it is possible to easily assemble the projection apparatus.

  Next, a mechanism for adjusting the position of each light valve (5a, 5b, 5c) on the surface of the mounting member 7 will be described with reference to FIG. The position of the light valves (5a, 5b, 5c) of the respective colors mounted on the mounting member 7 is adjusted in parallel with a surface (surface H shown in FIG. 4) parallel to the display surface of the light valves (5a, 5b, 5c). I was able to do.

  A specific mechanism for adjusting the position of the light valves (5a, 5b, 5c) in parallel with the surface H of the mounting member 7 will be described with reference to FIG. The light valves (5a, 5c) are held integrally with the mounting member 7 by intermediate members (22a, 22c) or the like. The intermediate members (22a, 22c) can be finely shifted or rotated on a surface I parallel to the surface H of the mounting member 7. The intermediate members (22a, 22c) include members (221a, 221b) that are in direct contact with the live valve and members (222a, 222b) that are in direct contact with the attachment member 7. The position of the light valve (5a, 5c) is determined by the screw (223a, 223b) and the spring member (224a, 224b) via the surface I between the member (221a, 221b) and the member (222a, 222b). Can be adjusted. The screws (223a, 223b) have a structure that can slide within the range of the wavy lines of the intermediate members (222a, 222b). With the above configuration, the light valve can be horizontally moved and rotated on the surface I. The movement in the horizontal direction is possible by moving with a pull-in screw, a push-in screw or the like, or by moving an eccentric pin at the end.

  As the spring members (224a, 224b), elastic members such as a string winding shape, a leaf spring, and rubber can be used. For alignment of the members (221a, 221b) and the members (222a, 222b), at least three reference island shapes may be provided on the surface I. Further, the light valve may be fixed and stabilized by an adhesive, such as fixing the light valve by a screw mechanism after horizontal movement or rotation adjustment.

  Although not shown in FIG. 5, the light valve 5b is also held integrally with the mounting member 7 by the method described above.

  With the above configuration, each light valve can be aligned by allowing the light valve to move horizontally and rotate in parallel with the surface of the mounting member.

  Next, a mechanism for adjusting the positions of the color synthesizing element 1 and the polarization separation elements (4a, 4b, 4c) in order to adjust the distance between the emission surface of the color synthesizing element 1 and the light valve surface will be described with reference to FIG. explain. The light valves (5a, 5b, 5c) are held integrally with the attachment member 7.

  As a mechanism for adjusting the distance between the polarization separation elements (4a, 4b, 4c) and the color synthesis element 1 such as a dichroic prism, for example, at least three places (8a to 8a) outside the effective area of the polarization separation element 4a shown in FIG. 8c) can be driven in the X direction or the Y direction. Various methods can be used as the driving mechanism. Specifically, the polarization separating element 4a is moved back and forth by providing at least three (8a to 8c) elastic members such as a screw mechanism and a spring mechanism facing the screw mechanism. Even if it moves in the direction, it is held stably. Further, the above-described operation can also be realized by holding the polarization separation element 4a with a holder or the like (not shown) and moving the holder. Specifically, the position of the polarization separation element is adjusted by providing a screw hole in the holder and adjusting the screw feed amount by a screw mechanism attached to the housing member. In addition, when the movement amount is a slight amount of several mm or less, it can be adjusted by an eccentric pin mechanism and a spring mechanism.

  With the above configuration, the polarization separation element is moved from the polarization separation element by moving in the optical axis direction (Y direction) of the incident light from the light valve or in the optical axis direction (X direction) of the outgoing light from the polarization separation element. The optical path length to the emission surface of the synthesis element 1 is adjusted. The light emitted from the color synthesizing element 1 is magnified by the projection lens arranged in the Z direction that is the emission direction of the color synthesizing element 1, so that the reference plane 8 is virtually placed at the position where the projection lens is assembled. The distance between the polarization separation element 4a and the color composition element 1 is adjusted so that the distance from the exit surface of the polarization separation element to the reference surface 8 is kept constant.

  As a means for measuring the distance between the polarization separating element and the color synthesizing element, it is performed by focusing on the panel surface with a microscope having a deep focal depth and reading the feed amount. Alternatively, it can be measured by a laser length measuring device or the like. The optical path length from the point A on the light valve to the point A 'on the reference plane, the optical path length from the point B on the light valve to the point B' on the reference plane, on the light valve At least three of the optical path lengths from the point C to the point C ′ and the optical path lengths from the point D on the light valve to the point D ′ on the reference plane are made equal. In addition, the position of the polarization separation element is adjusted. Further, the distance between one point such as the center of the polarization separation element and the color synthesis element may be adjusted, and the parallelism may be adjusted using a conventional autocollimator or the like.

  The reflected light from the light valve may not be reflected by the polarization separation element depending on the polarization direction and may not travel to the projection lens. Therefore, it can be reflected by the polarization separation element by changing the polarization of the light directed to the projection lens by interposing a quarter wavelength plate or the like between the polarization separation element and the light valve. Although not shown, if a quarter plate necessary for the skew correction of the PBS is provided, this can be realized by rotating the plate. In addition, even a wave plate (not shown) with a small retardation for correcting the residual phase difference of the liquid crystal is realized by rotating it if the light amount that can be adjusted as the return light advances to the projection lens side. Is possible.

  Further, a space may be temporarily held using a manipulator or the like, and the position may be adjusted and then directly or indirectly adhered to the color composition element. Of course, holding means using a screw mechanism can also be employed.

  Although not shown, the reference for attaching the polarization separation element is not described, but a support member such as a sheet metal member may be provided on the color synthesis element, and the polarization separation element may be bonded thereto.

  With the above configuration, the optical path length of the light emitted from each light valve can be kept constant in the process of assembling the light valve. Further, it is possible to adjust the distance to the exit surface of the projection device without moving the light valve.

  Next, before attaching the light valve to the attachment member 7, the polarization separation element and the color composition element are attached to the reference member corresponding to the light valve, and the positional relationship between the polarization separation element and the color composition element is adjusted. A method of adjusting the optical path length until the light emitted from the bulb is emitted from the color synthesis element will be described with reference to FIGS.

  In addition, since it aims at adjusting the focus in a projection lens, you may attach a polarization separation element and a color composition element on the basis of the position of a projection lens. Further, the polarization separation element and the color synthesis element may be attached with reference to a reference plane set at a predetermined interval from the reference member.

  Patterns 32a, 32b, and 32c are provided for adjusting the optical path length in a portion corresponding to the display surface of the light valve (5a, 5b, 5c) of the reference member 31 shown in FIG. The reference member 31 may be a glass substrate with high flatness. In the state of FIG. 7A, the polarization separation element (4a, 4b, 4c) or the color composition so that the optical path length from each pattern 32a, 32b, 32c to the exit surface of the color composition element 1 is constant. The position of the element 1 is adjusted. When the position is determined, the polarization separating elements (4a, 4b, 4c) and the color synthesizing element 1 are integrated. Or you may fix to the attachment member 7 holding the color synthesizing element 1 and the polarization separation elements (4a, 4b, 4c) in advance. Next, the color synthesizing element 1 and the polarization separating elements (4a, 4b, 4c) are separated from the reference member 31, and then assembled into a light valve.

  As described above, by using the reference member 31, the positional relationship between the color synthesizing element 1 and the polarization separation elements (4a, 4b, 4c) is determined in advance, so that the light valves (5a, 5b, Position adjustment in the optical axis direction when attaching 5c) becomes easy.

  Moreover, the color which comprised using the reference member 31 equivalent to the unit which integrated the light valve (5a, 5b, 5c) and the attachment member 7 shown in FIG. 3, and the light valve (5a, 5b, 5c). A projection apparatus can also be constituted by a unit composed of the synthesis element 1 and the polarization separation elements (4a, 4b, 4c). The unit composed of the light valves (5a, 5b, 5c) and the mounting member 7 can be horizontally moved and rotated in the plane perpendicular to the optical axis by the intermediate members (22a, 22b, 22c). The unit composed of the bulb (5a, 5b, 5c) and the mounting member 7 and the unit composed of the color synthesizing element 1 and the polarization separation element (4a, 4b, 4c) are held together and then orthogonal to the optical axis. The position of each light valve (5a, 5b, 5c) is adjusted in the plane.

  A unit in which the display surfaces of the light valves (5a, 5b, 5c) are arranged on the same surface in advance, and a unit comprising the color composition element 1 and the polarization separation elements (4a, 4b, 4c) having the same optical path length. By forming, performance and accuracy can be managed for each unit, and the yield of products can be improved.

  As described above, it is possible to appropriately deal with defects that occur when assembling optical members such as a light valve, a color synthesizing element, and a polarization separating element, a defect of a light valve, a failure, and the like, and adjustment, evaluation, and management can be performed for each unit.

It is the schematic of the projection apparatus which concerns on embodiment of this invention. (A) It is a side view of the projection apparatus which concerns on this embodiment. (B) It is a top view of the projection apparatus which concerns on this embodiment. (A), (b), and (c) are states that the light valve (5a, 5c) is attached to the intermediate member (22a, 22c). It is the schematic of the mechanism which adjusts the position of each light valve on the surface of an attachment member. It is the schematic of the specific mechanism which performs position adjustment of a light valve on the surface of an attachment member. It is the schematic of the mechanism which adjusts the position of a color synthetic | combination element and a polarization separation element. It is the schematic of the mechanism which adjusts the positional relationship of a polarization separation element and a color synthetic | combination element.

Explanation of symbols

1 Color composition element 2, 3 Dichroic film 4a, 4b, 4c Polarization separation element 5a, 5b, 5c Light valve 7 Mounting member 21, 31 Reference member 22a, 22b, 22c Intermediate member

Claims (2)

A light source that emits light of a plurality of colors, a plurality of polarization separation elements provided corresponding to each color light emitted from the light source, and a corresponding one of each polarization light transmitted or reflected by each polarization separation element And a light combining element that modulates the polarized light of each color light transmitted or reflected by the polarization separation element, and the polarization separation element is modulated by the light valve. In the projection device for analyzing each color light, and the color composition element color-synthesizes each color light detected by the polarization separation element,
A mounting member for mounting the light valve provided corresponding to each polarized light,
An intermediate member provided corresponding to each of the light valves that integrates each of the light valves and the mounting member, wherein the first member is in contact with the light valve, and the second member is in contact with the mounting member. And the intermediate member comprising first moving means for moving the first member in parallel with a plane orthogonal to the polarized light with reference to the second member;
The distance between the intermediate member and the mounting member is positioned fixed and an adjustment means for a plane polarized light is irradiated for each light valve to adjust the height of each light valve so as to be positioned on the same plane Have
The surface formed by each color light analyzed by the polarization separation element and each color light color synthesized by the color composition element, each color light analyzed by the polarization separation element and each color modulated by the light valve The surface formed by light is substantially orthogonal,
The projection apparatus, wherein the light valve is disposed on the same plane of the mounting member. Projection apparatus according to claim 1, wherein the corresponding to the position where the light valve is disposed between the polarization separation element and the color combining element are integrated.

Images