JP2004240022A - Projection display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projection display apparatus which employs arrangement of a cross dichroic mirror to thereby increase the flexibility of the arranging place of light source light and miniaturize a projection optical system and therefore is made compact. <P>SOLUTION: The projection display apparatus is provided with the cross dichroic mirror separating the light source light to first color light and mixed light of second color light and third color light, a first optical path bending mirror for changing the optical path of the first color light, a second optical path bending mirror for changing the optical path of the mixed light, a color separation optical system separating the mixed light to the second color light and the third color light, light valves for each color light on which the separated color light is made incident and which emit the modulated color light, a color composite optical system color-compositing the color light emitted from the light valves, and a projection lens for projecting the composite light from the color composite optical system. Two dichroic mirrors constituting the cross dichroic mirror are arranged perpendicularly to a first plane, and the first and the second optical path bending mirrors are arranged perpendicularly to a second plane, and the first plane and the second plane are orthogonal to each other. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a projection display device using a light valve.
[0002]
[Prior art]
Using a reflective light valve for red light, green light, and blue light, a projection type display device that can make the same light path length to the reflective light valve for each color light after color separation of the light source light is proposed. (See Patent Document 1).
[0003]
In the projection display device having the configuration disclosed in Patent Document 1, since the optical path length of each color light after color separation can be made the same, a good projection can be achieved without inserting a relay lens in the optical path of a specific color. A projection display device capable of projecting an image can be provided.
[0004]
[Patent Document 1]
JP-A-10-133301
[Problems to be solved by the invention]
However, in the above-described projection display device, the distance between the optical members of the projection optical system including the light valve and the cross dichroic prism depends on the distance and size between the color separation optical system and the folding mirror. There is a problem that it is difficult to reduce the size of the entire projection display device including the projection optical system.
[0006]
The present invention has been made in view of the above problems, and has as its object to provide a small projection display device.
[0007]
[Means for Solving the Problems]
To achieve the above object, according to the present invention, there is provided a cross dichroic mirror for color-separating a light source light into a first color light traveling in opposite directions to each other, a mixed light of a second color light and a third color light, and the first color light A first bending mirror that changes the traveling direction of the mixed light, a second bending mirror that changes the traveling direction of the mixed light, and the mixed light whose traveling direction is changed by the second bending mirror. A color separation optical system that separates the color light into the second color light and the third color light, and the color-separated first color light, second color light, and third color light are respectively incident thereon and emit the modulated color lights. A light valve arranged for each color light to be emitted, a color synthesis optical system that performs color synthesis of each color light emitted from the light valve, and a projection lens system that projects synthesized light from the color synthesis optical system. The cross dichro Two dichroic mirrors constituting a vertical mirror are arranged perpendicular to a first plane, the first and second folding mirrors are arranged perpendicular to a second plane, and the first plane And the second plane are orthogonal to each other.
[0008]
Further, in the projection display device of the present invention, the light valve is a reflection type light valve, and the polarization type light splitter in which the color-separated color lights are arranged for each color light in the reflection type light valve for each color light. And the light reflected and emitted from the reflection type light valve is made incident on the polarization beam splitter arranged for each color light, and the analysis light detected by the polarization beam splitter is analyzed by the color combining optics. It is preferable to be configured so as to enter the system and perform color synthesis.
[0009]
Further, in the projection type display device of the present invention, the color synthesizing optical system includes a cross dichroic prism, and the polarizing beam splitters arranged for the respective color lights are directly attached to the cross dichroic prism of the color synthesizing optical system to be integrated. It is preferred that the
[0010]
Further, in the projection display device of the present invention, ends of the first and second folding mirrors on the cross dichroic mirror side are inserted into a space between two dichroic mirrors constituting the cross dichroic mirror. Is preferred.
[0011]
In the projection display device of the present invention, the first and second folding mirrors are polygons formed by cutting adjacent two corners of four corners of a square mirror. In addition, it is preferable that the portion formed by cutting is inserted into a space between two dichroic mirrors constituting the cross dichroic mirror.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0013]
FIG. 1 is a schematic configuration diagram of an optical system of a projection display device according to a first embodiment of the present invention, and FIG. 2 is a perspective configuration diagram of an optical system of the projection display device according to the first embodiment. is there. FIG. 3 is a schematic configuration diagram of an optical system of a projection display according to a second embodiment of the present invention.
[0014]
(1st Embodiment)
FIG. 1 is a schematic configuration diagram of an optical system of a projection display according to a first embodiment of the present invention. In FIG. 1 and FIG. 2, an X axis, a Y axis, and a Z axis orthogonal to each other are defined as illustrated. In FIG. 1, the Z axis indicates a direction perpendicular to the paper surface.
[0015]
1 and 2, a substantially parallel light beam from a light source (not shown) formed of a lamp and a concave mirror having a parabolic shape is applied to an illumination optical system (not shown) having a first lens plate, a second lens plate, and a condenser lens. The light source beam 101 has an optical axis parallel to the Z axis. When cut along a plane parallel to the XY plane perpendicular to the optical axis, the light source light beam 101 having a substantially circular shape enters a cross dichroic mirror 105 that is arranged perpendicular to the YZ plane and orthogonal to each other (X type). The cross dichroic mirror 105 includes a reflecting dichroic mirror 105B that reflects blue light (hereinafter, referred to as B light), a red light (hereinafter, referred to as R light), and a green light (hereinafter, referred to as G light). And a reflection dichroic mirror 105GR that reflects the mixed light (hereinafter referred to as light). The light source light beam 101 incident on the cross dichroic mirror 105 is reflected by the reflection dichroic mirror 105B and travels in the + Y axis direction parallel to the Y axis, and is reflected by the reflection dichroic mirror 105GR in the -Y axis direction parallel to the Y axis. Is separated into mixed light of the R light and the G light that travels.
[0016]
The mixed light of the R light and the G light is incident on the bending mirror 107 arranged perpendicularly to the XY plane, travels in the + X-axis direction parallel to the X-axis and travels, and forms an angle of 45 degrees with the optical axis. And is incident on a G light reflecting dichroic mirror 109 arranged perpendicular to the XY plane. The mixed light is reflected by the G light reflecting dichroic mirror 109 and travels in the + Y axis direction parallel to the Y axis, and R passes through the G light reflecting dichroic mirror 109 and travels in the + X axis direction parallel to the X axis. It is color-separated into light. Thus, a color separation optical system is configured.
[0017]
The B light is incident on the bending mirror 108 arranged perpendicular to the XY plane, travels in the + X-axis direction parallel to the X-axis, travels, passes through the field lens 110B, and is incident on the polarization beam splitter 111B. . The polarization beam splitter 111B reflects the incident light on the polarization separation unit 111B-P and emits the light to be incident on the reflection light valve 112B for B light.
[0018]
The G light reflected by the G light reflecting dichroic mirror 109 passes through the field lens 110G and enters the polarization beam splitter 111G, and the light reflected and emitted by the polarization separation unit 111GP enters the reflection type light valve 112G.
[0019]
The R light transmitted through the G light reflecting dichroic mirror 109 passes through the field lens 110R and is incident on the polarization beam splitter 111R, and the light reflected and emitted by the polarization separation unit 111R-P is incident on the reflection type light valve 112R.
[0020]
The respective color lights emitted from the polarization beam splitters 111B, 111G, 111R for the respective color lights and respectively incident on the light valves 112B, 112G, 112R for the respective color lights are respectively transmitted by the light valves 112B, 112G, 112R based on the color signals. After being modulated, the mixed light of the modulated light and the non-modulated light is reflected and emitted, respectively, is again incident on the polarization beam splitters 111B, 111G, and 111R, and is separated by the polarization splitters 111B-P, 111GP, and 111RP. In the above, only the modulated light is detected as transmitted light and extracted, and each is incident on the cross dichroic prism 113 constituting a color synthesis optical system which is directly bonded and integrated with the polarization beam splitters 111B, 111G, 111R for each color light. Is done.
[0021]
The analysis light of the B light is reflected by the B light reflecting dichroic film 113B formed inside the dichroic prism 113. The analysis light of the R light is reflected by the R light reflecting dichroic film 113R disposed orthogonal to the B light reflecting dichroic film 113B formed inside the dichroic prism 113. The analysis light of G light passes through both dichroic films 113B and 113R. In this way, the color composition is achieved, the light is emitted from the dichroic prism 113, enters the projection lens system 114, and projects a full-color image on a screen (not shown).
[0022]
An aperture stop 115 is disposed in the projection lens system 114, and a principal ray defined by the aperture stop 115 is transmitted by the field lenses 110B, 110G, and 110R to the cross dichroic prism 113 and the polarization beam splitters 111B, 111G, In the places where the light valve 111R and the light valves 112B, 112G, 112R are arranged, it is guaranteed that the telecentric state is parallel to the optical axis. In this way, a projection display device using the reflection type light valves 112B, 112G, 112R is configured.
[0023]
In the first embodiment, the end portions 107a and 108a of the bending mirrors 107 and 108 are inserted into the spaces between the two dichroic mirrors 105B and 105GR constituting the X-shaped cross dichroic mirror 105, respectively. Have been. At this time, the bending mirrors 107 and 108 are arranged so as not to be inserted in the light beam of the light source light beam 101 incident on the two dichroic mirrors 105B and 105GR. In order to insert the bending mirrors 107 and 108 as deeply as possible outside the light source light beam 101 in the space between the two dichroic mirrors 105B and 105GR, as shown in FIG. , 107c, 108b, and 108c are formed by partially cutting corners. This allows the folding mirrors 107 and 108 to be inserted deeply into the space of the cross dichroic mirror 105.
[0024]
In addition to cutting the two corners of the folding mirror, by making the shape of the folding mirror into an elliptical shape, a circular shape, a triangular shape, a trapezoidal shape, or the like, a part of the folding mirror can be placed in the space of the cross dichroic mirror. It becomes possible to insert. Thus, the shape of the folding mirror can be changed as appropriate.
[0025]
As a result, the optical path length between the cross dichroic mirror 105 and the bending mirrors 107 and 108 can be shortened for each of the B, R, and G light beams.
[0026]
In the first embodiment, as described above, by shortening the optical path length between the cross dichroic mirror 105 and the bending mirrors 107 and 108, the polarization beam splitters 111B, 111G and 111R arranged for each color light are reduced. And the cross dichroic prism 113 constituting the color synthesizing optical system can be shortened and directly bonded to be integrated. As a result, the size of the projection optical system such as the light analysis and color combining optical system can be reduced, and the size of the projection display device can be reduced.
[0027]
Further, in the conventional projection display device, the light source, the color separation optical system, and the projection optical system are arranged on the same plane, so that the two-dimensional size cannot be reduced. In the embodiment, since the light source can be disposed above the color separation optical system and the projection optical system, the two-dimensional size can be reduced.
[0028]
(2nd Embodiment)
FIG. 3 is a schematic configuration diagram of an optical system of a projection display according to a second embodiment of the present invention.
In the second embodiment, a case is shown in which the cross dichroic mirror 105 of the first embodiment is applied to a projection display device having a transmissive light valve. The same members as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.
[0029]
In FIG. 3, a substantially parallel light beam from a light source including a lamp (not shown) and a concave mirror having a rectangular parallelepiped shape passes through an illumination optical system (not shown) having a first lens plate, a second lens plate, and a condenser lens, and the Z axis. Is a light source light beam 101 having an optical axis parallel to. When cut along a plane parallel to the XY plane perpendicular to the optical axis, the light source light beam 101 having a substantially circular shape enters a cross dichroic mirror 105 that is arranged perpendicular to the YZ plane and orthogonal to each other (X type). The cross dichroic mirror 105 includes a reflecting dichroic mirror 105B that reflects B light and a reflecting dichroic mirror 105GR that reflects mixed light of R light and G light, which are arranged orthogonal to each other. The light source beam 101 incident on the cross dichroic mirror 105 is reflected by the reflection dichroic mirror 105B and travels in the + Y-axis direction parallel to the Y axis, and the B light reflected by the reflection dichroic mirror 105GR in the -Y axis direction parallel to the Y axis. Is separated into mixed light of the R light and the G light that travels.
[0030]
The mixed light of the R light and the G light is incident on the bending mirror 107 arranged perpendicularly to the XY plane, travels in the + X-axis direction parallel to the X-axis and travels, and forms an angle of 45 degrees with the optical axis. And enters a G light reflecting dichroic mirror 213 arranged perpendicular to the XY plane. The mixed light is reflected by the G light reflecting dichroic mirror 213 and travels in the + Y axis direction parallel to the Y axis, and R travels through the G light reflecting dichroic mirror 213 and travels in the + X axis direction parallel to the X axis. It is color-separated into light. Thus, the color separation optical system is configured.
[0031]
Further, the B light is incident on the bending mirror 108 arranged perpendicular to the XY plane, travels in the + X-axis direction parallel to the X-axis, travels, and travels at an angle of 45 degrees to the optical axis. The light is changed by the change mirror 211 in the −Y-axis direction parallel to the optical path Y-axis, and enters the transmission light valve 221B for B light via the field lens 218B.
[0032]
The G light reflected by the G light reflecting dichroic mirror 109 has its optical path changed in the + X axis direction parallel to the X axis by an optical path changing mirror 217 provided at an angle of 45 degrees with respect to the optical axis, and passes through a field lens 218G. The light enters the mold light valve 221G.
[0033]
The R light transmitted through the G light reflecting dichroic mirror 213 has its optical path changed in the + Y axis direction parallel to the Y axis by an optical path changing mirror 215 provided at an angle of 45 degrees with respect to the optical axis, and is transmitted through the field lens 218R. The light enters the mold light valve 221R.
[0034]
Each of the transmission light valves 221B, 221G, and 221R for each color light has a polarizing plate provided on the incident surface side and the exit surface side. The analysis light modulated and detected by the transmission type light valves 221B, 221G and 221R for each color light is integrated with the transmission type light valves 221B, 221G and 221R for each color light by an integrated member (not shown). The light is incident on the cross dichroic prism 113 constituting the color synthesizing optical system. The analysis light of the B light is reflected by the B light reflecting dichroic film 113B formed inside the dichroic prism 113. The analysis light of the R light is reflected inside the dichroic prism 113 by the R light reflection dichroic film 113R disposed orthogonal to the B light reflection dichroic film 113B. The analysis light of G light passes through both dichroic films 113B and 113R. In this way, color synthesis is achieved, the light is emitted from the dichroic prism 113, enters the projection lens system 223, and projects a full-color image on a screen (not shown).
[0035]
An aperture stop 225 is arranged in the projection lens system 223, and a principal ray defined by the aperture stop 225 is located at a position where the transmission type light valves 221B, 221G, and 221R are arranged with respect to the optical axis. And is in a parallel telecentric state.
[0036]
In the second embodiment, the bending mirrors 107 and 108 are, like FIG. 2, two dichroic mirrors 105B and 105GR that constitute a cross dichroic mirror 105 whose ends 107a and 108a are arranged in an X-shape. Are inserted in the spaces between the two. At this time, the bending mirror is arranged so as not to be inserted into the light beam of the light source light beam 101 incident on the two dichroic mirrors 105B and 105GR. In order to insert the bending mirrors 107 and 108 as deep as possible outside the light source light beam 101 in the space formed by the two dichroic mirrors 105B and 105GR, the two corners 107b, 107c and 108b of the bending mirrors 107 and 108, respectively. 108c is formed by partially cutting a corner. This allows the folding mirrors 107 and 108 to be inserted deeply into the space of the cross dichroic mirror 105.
[0037]
In addition to cutting the two corners of the folding mirror, by making the shape of the folding mirror into an elliptical shape, a circular shape, a triangular shape, a trapezoidal shape, or the like, a part of the folding mirror can be placed in the space of the cross dichroic mirror. It becomes possible to insert. Thus, the shape of the folding mirror can be changed as appropriate.
[0038]
As a result, in the second embodiment, the optical path length between the cross dichroic mirror 105 and the bending mirrors 107 and 108 can be shortened for each of the B light, the R light, and the G light, and the projection optical system can be used. Since the size can be reduced, the size of the projection display device using the transmission type light valve can be reduced.
[0039]
The arrangement of the cross dichroic mirror according to the present invention can be replaced with the arrangement of the conventional cross dichroic mirror. By arranging the cross dichroic mirror shown in the embodiment of the present invention, the degree of freedom of the arrangement position of the light source light is increased and the size of the projection optical system can be reduced, so that the size of the projection display device can be reduced. It becomes possible.
[0040]
It should be noted that the present invention is not limited to the above-described embodiment, but can be variously modified within the scope described in the claims of the present application.
[0041]
【The invention's effect】
As described above, according to the present invention, a small projection display device can be provided.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an optical system of a projection display device according to a first embodiment of the present invention.
FIG. 2 is a perspective configuration diagram of an optical system of the projection display device according to the first embodiment.
FIG. 3 is a schematic configuration diagram of an optical system of a projection display device according to a second embodiment of the present invention.
[Explanation of symbols]
101 Light source beam 105 Cross dichroic mirror 107, 108 Folding mirror 109 Dichroic mirror 110B, 110G, 110R Field lens 111B, 111G, 111R Polarizing beam splitter 112B, 112G, 112R Reflective light valve 113, 213 Cross dichroic prism 114, 221 Projection lens System 115, 225 Aperture stop 211, 215, 217 Optical path changing mirror 218B, 218G, 218R Field lens 221B, 221G, 221R Transmission light valve

Claims (5)

A cross dichroic mirror that separates the light source light into a first color light and a mixed light of the second color light and the third color light;
A first bending mirror that changes the traveling direction of the first color light to travel;
A second bending mirror that changes the traveling direction of the mixed light to travel,
A color separation optical system that separates the mixed light whose traveling direction has been changed by the second bending mirror into the second color light and the third color light;
A light valve arranged for each color light into which the color-separated first color light, second color light, and third color light are respectively incident and emit each modulated color light;
A color synthesizing optical system for color synthesizing each color light emitted from the light valve,
Having a projection lens system for projecting synthesized light from the color synthesis optical system,
The two dichroic mirrors constituting the cross dichroic mirror are arranged perpendicular to the first plane,
The first and second folding mirrors are arranged perpendicular to a second plane;
The projection display device, wherein the first plane and the second plane are orthogonal to each other. The light valve is a reflective light valve,
The color-separated color lights are made incident on the reflection-type light valves for the respective color lights via polarization beam splitters arranged for the respective color lights, and the light reflected and emitted from the reflection-type light valves is output for the respective color lights. 2. The projection display device according to claim 1, wherein the light is made incident on the polarization beam splitter disposed in the optical system, and the analysis light detected by the polarization beam splitter is made incident on the color synthesis optical system to perform color synthesis. 3. . The color combining optical system is composed of a cross dichroic prism,
The projection type display device according to claim 2, wherein the polarization beam splitters arranged for the respective color lights are directly attached to and integrated with a cross dichroic prism of the color combining optical system. 2. The end of the first and second folding mirrors on the cross dichroic mirror side is inserted into a space between two dichroic mirrors constituting the cross dichroic mirror. 3. 4. The projection display device according to 2 or 3. The first and second bending mirrors are polygons formed by cutting adjacent two corners of a square mirror, and the cut and formed portions are the cross dichroic. The projection type display device according to claim 4, wherein the projection type display device is inserted in a space between two dichroic mirrors constituting a mirror.

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