JP3042460B2 - Projection display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection type display device, and is applied to a three-plate color projector or the like using a reflection type spatial light modulator. The present invention relates to an improvement for preventing deterioration and an arrangement of optical elements for miniaturizing the apparatus.

[0002]

2. Description of the Related Art In a three-plate type color projector, white light obtained from a powerful light source such as a metal halide lamp is converted into three light beams.
Adopts a method of decomposing into primary colors, guiding each color-separated light to a spatial light modulator such as a liquid crystal panel driven by a video signal related to each corresponding color, modulating, combining each modulated light and projecting. doing. And in the color separation / light guide optical system of the device,
In general, in order to obtain a high-brightness projection image and to suppress the occurrence of color shading, it is common to design the light path length from the light source to the spatial light modulator of each corresponding color to be equal.

For example, in a projection display device using a reflection type spatial light modulator, a cross type dichroic mirror in which the reflection surfaces of two dichroic mirrors cross each other in an X-shape is used as color separation means. A device in which the color separation / light guiding optical system is symmetrical with respect to the three primary colors so that the optical path length from the light source to each spatial light modulator is equal (Japanese Patent Application No. 9-10065).
Also, in a projection display device using a transmissive spatial light modulator, two independent dichroic mirrors are used as color separation means, and the optical paths of the three primary colors are configured asymmetrically, but the optical path length increases. A device in which a correction lens for correcting the light quantity loss is provided in the optical path of the color of light, and the optical path length from the light source to each spatial light modulator is made substantially equal (International Publication Number: WO94 / 2
2042) has been proposed.

As an example of applying the color separation / light guide optical system of the apparatus according to the international application to an apparatus using a reflection type spatial light modulator, a projection type optical system as shown in FIGS. A display device is conceivable. As shown in FIG. 7, the optical structure of the device is roughly divided into a lower layer color separation / light guide optical system, an intermediate layer polarization selection optical system, and an upper layer modulation / color synthesis / projection optical system. 8 to 10 show plan views of those optical systems as viewed from below.

In each of the figures, 1 is a light source, 2 is a collimator lens, 3 is a first integrator, 4 is a second integrator, 5 is a cold mirror, 17 is white light, which is cyan light (mixed color light of green light and blue light). : gb) and a dichroic mirror that separates red light r, 18 is a dichroic mirror that separates cyan light into green light g and blue light b, 19B, 19B ', 19R, 20G, 20B and 20R are reflection mirrors and 9, 9' Is a correction lens for correcting light loss, 11G,
11B and 11R are condenser lenses, 12G, 12B and 12R are first polarizing beam splitters, 13G, 13B and 13R are second polarizing beam splitters, and 14G, 14B and 14R are reflection type spatial light modulation using liquid crystal. Section, 15 is a crossed dichroic prism for color synthesis, 16
Is a projection lens. 8 to 10, the reflecting mirrors 20G, 20B, 20R, the condensing lens and the first polarizing beam splitter units 11G, 12G, 11B, 12B, 11R, 12
R, and the second polarization beam splitter and the unit 13G / 14G, 13B / 14B, 13R / 14R of the spatial light modulator are attached as side views as viewed from the direction of the arrow indicated by the two-dot chain line, respectively. The optical functions within each level are also shown.

First, in a color separation / light guide optical system, white light w emitted from a light source 1 which is an elliptical reflecting mirror is once focused on a second focal point of the reflecting mirror, and then converted into a parallel light by a collimator lens 2. Then, the first integrator 3 at the next stage is irradiated. Here, the first integrator 3 and the second integrator 4 are each formed by arranging minute lenses (lens segments) vertically and horizontally.
The light beam transmitted through each lens segment of the second integrator 4 is focused on the corresponding lens segment of the second integrator 4,
The luminance distribution of the light source image is averaged by the integrator 4, and as a result, readout light having a uniform illuminance distribution for each of the spatial light modulators 14G, 14B, and 14R can be obtained.
Further, the white light w transmitted through the second integrator 4 is reflected by the cold mirror 5, and at that time, unnecessary infrared light contained in the white light w is removed.

Next, the white light w reflected by the cold mirror 5 and changed in direction by 90 ° in the horizontal plane enters the dichroic mirror 17, and the dichroic mirror 17 is turned by 90 ° in the horizontal plane by its wavelength-selective reflection film. The reflected light is separated into the reflected cyan light gb and the transmitted red light r. The cyan light gb reflected by the dichroic mirror 17 is incident on the next dichroic mirror 18, and is separated into reflected green light g and transmitted light blue light b, which have been converted in the horizontal plane by 90 °. Therefore, the white light w
Is separated into three primary color lights by two dichroic mirrors 17 and 18.

The green light g reflected by the dichroic mirror 18 is directly incident on the reflecting mirror 20G, and its optical path is vertically changed by 90 °. The red light r transmitted through the dichroic mirror 17 is reflected by a reflecting mirror 19R in a horizontal plane. At 9
After the direction is changed by 0 °, it is 9 in the vertical direction by the reflection mirror 20R.
The light is changed in the direction of 0 ° and enters the condenser lenses 11G and 11R disposed immediately above the reflection mirrors 20G and 20R, respectively. On the other hand, the blue light b transmitted through the dichroic mirror 18 is condensed by two correction lenses 9 and 9 ′ and is corrected by two reflection mirrors 19B and 19B.
In response to the 90 ° directional change in the horizontal plane by 19B ′, the light enters the reflecting mirror 20B in a mode in which the optical path is detoured to the side, and is turned 90 ° in the vertical direction by the reflecting mirror 20B and disposed immediately above. The light enters the condenser lens 11B.

Next, each of the units 11G and 11G comprising the condenser lens and the first polarization beam splitter in the polarization selection optical system.
As shown in FIG. 9, the three units 12G, 11B, 12B, 11R, and 12R are arranged symmetrically with respect to the projection direction so that the three units are in contact with the corners. The primary color lights g, b, and r incident on the optical lenses 11G, 11B, and 11R are converted into parallel lights, respectively.
To the polarization beam splitters 12G, 12B, and 12R. Each of the polarizing beam splitters 12G, 12B, and 12R is a polarizing film 12g, 12b, in which a large number of two types of films having different refractive indexes are alternately stacked.
12r, P in each primary color light g, b, r
Only the polarization components g (p), b (p), and r (p) are transmitted, and the S polarization components g (s), b (s), and r (s) are reflected toward the outside of the arrangement region. That is, P of each primary color light g, b, r separated at this stage
The polarization components g (p), b (p), and r (p) are selected as use light,
The S polarized light components g (s), b (s), and r (s) are discarded outside the system. Therefore, the second polarization beam splitters 13G, 13B, 13B, 13P, 13G, 13B, and 13 (P) have the P polarization components g (p), b (p), r (p) selected by the respective polarization beam splitters 12G, 12B, 12R. 13R
Will be incident.

Next, as shown in FIG. 10, units 13G and 14G, 13B and 14B, each comprising a second polarizing beam splitter and a spatial light modulator in the modulation / color combining / projection optical system.
13R and 14R are also arranged symmetrically with respect to the projection direction so as to face the incident surface of the cross-type dichroic mirror 15. Then, the first polarization beam splitters 12G, 12G
B, 12R, this second polarization beam splitter 13G, 1
The polarizing films 13B and 13R also transmit only the P-polarized light components g (p), b (p) and r (p) and reflect the S-polarized light components g (s), b (s) and r (s).
g, 13b, and 13r, and the polarizing films 13g, 13b, and 13r have tilt directions in relation to the corresponding first polarizing beam splitters 12G, 12B, and 12R and the respective polarizing films 12g, 12b, and 12r. Have a 90 ° twist relationship, the second polarization beam splitter 13
Each of the P-polarized light components g (p), b (p), and r (p) incident on G, 13B, and 13R becomes the vibration direction of the S-polarized light component with respect to the polarizing films 13g, 13b, and 13r. Therefore, the polarized light component is reflected by the polarizing films 13g, 13b, 13r of the second polarizing beam splitters 13G, 13B, 13R, is converted by 90 ° from the vertical direction to the horizontal direction, and the corresponding spatial light modulator 14G, Light enters 14B and 14R. Each of the spatial light modulators 14G, 14B, and 14R modulates and reflects the incident polarization component by controlling the alignment state of the liquid crystal layer in pixel units based on the video signals of the three primary colors. Since the light changes to a polarization component in the vibration direction opposite to the incident light according to the degree of modulation, the modulated light g ′ (p), b ′ (p),
r ′ (p) enters the polarizing films 13g, 13b, 13r. Here, since the polarizing films 13g, 13b, and 13r reflect only the S-polarized component and transmit the P-polarized component as described above, the re-entered modulated light g ′ (p), b ′ (p), r ′ (p) passes through the polarizing films 13g, 13b, and 13r and enters the crossed dichroic prism 15 for color synthesis. On the other hand, though not shown, the polarization films g ′ (s), b ′ (s), and r ′ (s) for the unmodulated components are polarized films 13g, 13b, and 13 ′.
After being reflected by r, the light travels backward in the optical path and returns to the light source 1. The cross type dichroic prism 15 has a configuration in which a dichroic mirror surface 15b that reflects only blue light b and a dichroic mirror surface 15r that reflects only red light r are crossed, and the second polarization beam splitter 13B, The modulated light b ′ (p) and r ′ (p) incident from 13R are respectively converted in the horizontal direction by 90 °, and the modulated light g ′ (p) incident from the second polarizing beam splitter 13G is transmitted as it is. Accordingly, the modulated lights of the three primary colors are combined and incident on the projection lens 16, and a color image enlarged by the projection lens 16 is displayed on a screen (not shown).

[0011]

By the way, Japanese Patent Application Laid-Open No. H10-157, in which color separation is performed by using the above-mentioned cross type dichroic mirror.
In the case of the projection display device of No. 9-10065, the problem of color shading does not occur because the optical path lengths for the three primary colors can be configured to be equal, but the cross type dichroic mirror has two wavelength-selective reflection films. Since it is configured in such a manner that the glass plates are crossed, the incident light is multiply reflected in the glass near the crossing portion and is not output to the outside, and a dark shadow is generated near the center in the projected image. Further, since each spatial light modulator is of a reflection type, a non-modulated polarized light component corresponding to the degree of modulation is returned and enters the crossed dichroic mirror as return light. In such a case, there is a tendency for the light to pass through the crossed dichroic mirror or to be internally reflected multiple times and to enter the spatial light modulator of another color. It causes deterioration.

On the other hand, in the projection type display device shown in FIGS. 7 to 10, since the two independent dichroic mirrors 17 and 18 are used for the color separation means, the above-mentioned problem does not occur. As shown in FIG. 8, since the color separation / light guide optical system is configured outside the planar development region of the polarization selection optical system and the modulation / color synthesis / projection optical system, a large optical system is provided on both sides and behind. There is a problem that a configuration space is required, and the size of the device cannot be reduced. That is, the polarization selection optical system and the modulation / color combining optical system are relatively compact because the units are arranged symmetrically with respect to the cross-type dichroic prism 15, but are relatively compact.
The spatial volume occupied by the entire device increases due to the expansion of the planar deployment area of the light guide optical system, and the entire housing must necessarily be designed large.

Accordingly, the present invention provides a color separation means in a three-panel projection display device using a reflection type spatial light modulator, in which two independent dichroic mirrors are applied without using a crossed dichroic mirror. It has been created for the purpose of providing an optical configuration that can be configured and that can reduce the size of the entire device.

[0014]

According to the present invention, a wavelength-selective reflecting film for two different colors of light of three primary colors is crossed ,
An emission surface and three incidence surfaces were formed around the cross axis.
For the crossing type dichroic prism,
Indicates the projection lens, and the output surface faces each input surface.
The first to third polarization beam splitters are disposed in the above-described manner, and reflection-type spatial light modulators are respectively provided on surfaces of the respective polarization beam splitters on the side opposite to the crossed dichroic prism and on the opposite side. and modulating and color synthesis, a projection optical system which is opposed is disposed, the light source is decomposed into three primary colors white light generated by the said modulation, color synthesis and the projection optical system
In a projection display device in which a color separation / light guide optical system for guiding light to an entrance surface of a first to a third polarization beam splitter is configured for each layer, the first to third modulation / color synthesis / projection optical systems are provided .
The polarizing beam splitters are arranged with the direction of the polarizing film set such that their incident surfaces are on the layer side of the color separation / light guide optical system, while the color separation / light guide optical system is Sheets
It consists of a dichroic mirror and a reflection mirror,
Incident light is separated into three primary colors, and the first and second lights are separated.
Color light to first and second polarizing beam splitters respectively
And the third color light is arranged on the projection lens.
Consists of a first optical system that transmits light to the side and multiple reflection mirrors
And the third color light transmitted through the first optical system is
The third polarizing beam splitter is detoured on the projection lens side.
And a second optical system for incidence on the litter
The first and second optical systems are connected to each other by the cross type dichroic pre-press.
From the direction of the cross axis of the wavelength-selective reflective film in the mechanism
Occupied by the modulation / color synthesis / projection optical system when viewed from the perspective
The present invention relates to a projection display device characterized in that the projection display device is configured in a rectangular area defining an area .

According to the present invention, the color separation / light guide optical system performs color separation by two independent dichroic mirrors as in the projection type display device (FIGS. 7 to 10) described in the prior art. There is no problem when using the dichroic mirror. On the other hand, when two independent dichroic mirrors are used, a symmetrical light guide system cannot be configured as in the case of using a crossed dichroic mirror, and the optical path of at least one of the three primary color lights Need to be guided to the corresponding polarizing beam splitter of the modulation / color synthesis / projection optical system in a manner of leading to a large plane area in the hierarchical direction occupied by the color separation / light guide optical system as shown in FIG. Become. In the present invention, the respective polarization beam splitters modulation and color synthesis, a projection optical system with incident surface thereof is arranged to be hierarchical side of the color separating-guiding optical system, the color separation-guiding optical system Pertaining to third color light by two optical systems
Route the optical path to the projection lens side , and
The optical optical system (the first optical system and the second optical system) is
Cross axis of wavelength-selective reflective film in Loic prism
The modulation, color synthesis, and projection optics are
In a rectangular area that defines the
You. Therefore, the space occupied by the color separation / light guide optical system is planar.
With a configuration smaller than that of the modulation / color synthesis / projection optical system
Therefore, the size of the device can be reduced.

[0016] As apparent from FIG. 7 showing a hierarchical structure of a prior art projection display apparatus, a projection lens 16 of the modulation and color synthesis and the projection optical system on its underside for projecting forward is A large space is configured. Accordingly , the third color light is bypassed as in the color separation / light guide optical system of the present invention.
If the optical path to such guides constitute the space to the third polarization <br/> beam splitter side of the projection lens, as can be interposed reasonably correction lens during Dohikariro Become .

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the projection display apparatus of the present invention will be described below in detail with reference to FIGS. FIGS. 1 to 3 show perspective views of the arrangement of each optical element of the apparatus with the viewpoint set to diagonally upward, diagonally laterally and diagonally downward, respectively. FIG. 4 shows a light source unit and color separation.・
5 is a plan view of the hierarchy of the light guide optical system as viewed from below, FIG. 5 is a plan view of the polarization selection optical system as viewed from below, and FIG. 6 is a plan view of the modulation, color synthesis, and projection optical system as viewed from below. It is. 4 to 6, as in FIGS. 8 to 10, side views of each optical element which is difficult to understand in a plan view as viewed from the direction of an arrow indicated by a two-dot chain line are attached as reference figures. Yes, the optical functions within each layer are also shown.

This device, like the projection display device shown in the prior art, has a lower layer color separation / light guide optical system, an intermediate layer polarization selection optical system, and an upper layer modulation / color synthesis / projection. It is composed of an optical system. In each drawing, the optical elements indicated by the same reference numerals as those shown in FIGS. 7 to 10 are the same, and the description thereof is omitted here. As is clear from comparison between FIGS. 5 and 9 and FIGS. 6 and 10, the polarization selection optical system and the modulation / color synthesis / projection optical system have the same basic configuration and optical system as those of the prior art. The only difference is that each optical element that handles blue light and red light is arranged in an inverse relationship with respect to a plane passing through the optical axis of the projection lens 16.

The features of the apparatus according to this embodiment reside in the configuration of the color separation / light guide optical system shown in FIGS. 2 and 3, and particularly in FIG. 4, and the arrangement of the optical elements. In each figure, 6 is a dichroic mirror that separates white light into magenta light (mixed color light of red light and blue light: rb) and green light g, 8 is a dichroic mirror that separates magenta light into red light r and blue light b, 7
G and 7R each indicate a reflection mirror. First, white light emitted from the light source 1 is converted into read light having a uniform illuminance distribution from which infrared light has been removed by the collimator lens 2, the first and second integrators 3 and 4, and the cold mirror 5. Although the direction is changed by 90 ° in the horizontal plane, the optical axis of the white light w after the direction change is parallel to the optical axis of the projection lens 16 of the modulation / color synthesis / projection optical system, and the polarization selection optical system (FIG. 5). ) Is set in the direction perpendicular to the optical axis of the condenser lens 11B.

The dichroic mirror is arranged such that the white light w is inclined at 45 ° to the optical axis.
6, the dichroic mirror 6 transmits the magenta light rb as it is, but reflects the green light g and
The direction is changed by 0 °. The dichroic mirror 6 is arranged at a position where the optical axis of the reflected green light g crosses the optical axis of the condenser lens 11G perpendicularly.

Green light g reflected by the dichroic mirror 6
Is incident on a reflection mirror 7G disposed immediately below the condenser lens 11G in a form inclined at 45 ° with respect to the optical axis, and is reflected by the reflection mirror 7G so as to be 90 ° in the vertical direction. The direction is changed and made incident on the condenser lens 11G. Further, the magenta light rb transmitted through the dichroic mirror 6 is incident on the dichroic mirror 8 disposed immediately below the condenser lens 11B in a state of being inclined by 45 ° with respect to the optical axis.

The dichroic mirror 8 transmits the red light r of the incident magenta light rb as it is, but reflects the blue light b and changes the direction by 90 ° in the vertical direction. Therefore, the blue light b enters the condenser lens 11B in the polarization selection optical system (FIG. 5). And, as shown in FIG.
The optical path length from the light source 1 to the reflection mirror 7G is equal to the optical path length from the light source 1 to the dichroic mirror 8, and the optical path length of the polarization separation optical system and the modulation / optical Since the color synthesis / projection optical system is an optical system having symmetry with respect to each primary color light, the spatial light modulator for the green light g and blue light b of the modulation / color synthesis / projection optical system from the light source 1 The optical path lengths up to 14G and 14B are equal.

On the other hand, the red light r transmitted through the dichroic mirror 8 is incident on a correction lens 9 arranged on the optical axis of the transmitted light, and after being subjected to a predetermined light collecting action by the lens 9,
The direction is changed by 90 ° in the horizontal plane by the reflection mirror 10,
The light is subjected to a predetermined light condensing action by another correction lens 9 ′ disposed on the optical axis after the direction change, and further, is changed in direction by 90 ° in a horizontal plane by a reflection mirror 10 ′. The light enters the reflection mirror 7R disposed directly below the condenser lens 11R in the polarization selection optical system (FIG. 5) in an inclined manner. Then, the red light r reflected by the reflection mirror 7R is made incident on the condenser lens 11R. That is, red light r
With respect to, a detour optical path is formed on the space side formed below the projection lens 16 of the modulation / color synthesis / projection optical system to guide light to the condenser lens 11R for the corresponding color, and the light source 1 emits red light. Correction lenses 9, 9 'in the bypass light path that the light path length to the spatial light modulator 14R for the light r is longer than the light path length for the green light g and the blue light b and color shading occurs.
To prevent this.

Incidentally, in the case of the projection type display device of this embodiment, the rectangular area defining the area occupied by the color separation / light guide optical system in a plane corresponds to the area 31 surrounded by the dotted line in FIG. The square area defining the area occupied by the color combining / projecting optical system in a plane corresponds to the area 32 surrounded by the dotted line in FIG.
32 included. Therefore, the external housing of the device is [(region 32
And the light source unit area 1 to 5) × (height for three layers)].

On the other hand, a projection display device shown in the prior art
In the case of (FIG. 7), a rectangular area defining the area occupied by the color separation / light guide optical system in a plane is an area surrounded by a dotted line in FIG.
A rectangular area corresponding to the area 33 and defining the area occupied by the modulation / color synthesis / projection optical system in a plane corresponds to an area 34 (equivalent to the area 32) surrounded by a dotted line in FIG. In this case, the region 33 is not included in the region 34, and greatly expands to both sides with respect to the region 34 by the arrangement region of the mirrors 17, 19R, 19B ', and 19B. As is clear from FIG. 7, the mirrors 17, 18, and 19 B greatly extend rearward by the arrangement area. Therefore, when designing the outer housing, [(region 33 and region
If the volume given by the rectangular area defining the area occupied by 34 and the area of the light source section 1 to 5) × (height of three layers) is a guide, it will be an extremely large housing, Even if the housing is designed so that the wall is formed along the outside of each optical element to reduce the volume, the area occupied in a plane is much larger than that of the embodiment and the housing is larger. The shape of the body becomes complicated, and in any case, the size of the apparatus is increased and the manufacturing cost is increased.

In other words, according to the apparatus of this embodiment, the color separation / light guide optical system is composed of two dichroic mirrors.
6, 8 and reflection mirrors 7G, 7R, 10, 10 'and correction lenses 9, 9' are configured in the minimum plane area to guide each primary color light to the polarization selection optical system, making the device extremely compact. It is possible to configure. In the projection display device shown in the prior art, six reflection mirrors 19R, 20R, 20G, 19B, 19B ', 2
Although 0B is used, the apparatus of this embodiment requires only four reflection mirrors 7G, 7R, 10, and 10 ', and the number of parts can be reduced.

In both the device shown in the prior art and the device of this embodiment, a polarization selection optical system is interposed as an intermediate layer, but the polarization selection optical system is not an essential optical system. This is because the polarization selection function can be provided in each of the polarization beam splitters 13G, 13B, and 13R of the modulation, color synthesis, and projection optical systems. This is because by selecting the components, it is possible to display a high-quality image with a high contrast ratio.

[0028]

According to the projection display apparatus of the present invention having the above configuration, the following effects can be obtained. The first aspect of the present invention provides a color separation / light guide optical system and a modulation / color synthesis /
In a projection type display device in which a projection optical system and a hierarchy are configured for each layer, a color separation / light guide optical system is configured by two independent dichroic mirrors and a plurality of reflection mirrors, so that a cross-type dichroic mirror is used. In this way, it is possible to prevent the shadow of the intersection, unnecessary bright lines, and abnormal colors from being generated in the projected image. On the other hand, if the color separation / light guide optical system is configured as described above, it must be routed in such a manner as to bypass the optical path of at least one of the three primary color lights. by modulating elements, color synthesis and the projection optical system is disposed at snaps manner in plan view in the area corresponding to the rectangular area demarcating a region it occupied in plan, implement small <br/> type of device I do. The second aspect of the present invention is a color separation / light guide optical system.
Comparison of the detour optical path of the second optical system with the projection lens side in the system
The purpose and color of the device is to reduce the size of the device by making the optical path length of each primary color light substantially equal by interposing a correction lens in the detour optical path without difficulty, utilizing the fact that it is configured in a large space. Simultaneous countermeasures against shading are also provided.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an arrangement relationship of optical elements of a projection display device according to an embodiment of the present invention when viewed obliquely from above.

FIG. 2 is a perspective view showing an arrangement relationship of optical elements of the projection display device as viewed from an oblique side.

FIG. 3 is a perspective view showing an arrangement relationship of optical elements of the projection display device as viewed obliquely from below.

FIG. 4 is a plan view of the hierarchy of the light source unit and the color separation / light guide optical system as viewed from below.

FIG. 5 is a plan view of the hierarchy of the polarization selection optical system as viewed from below.

FIG. 6 is a plan view of the hierarchy of the modulation / color synthesis / projection optical system as viewed from below.

FIG. 7 is a side view of a projection display device according to the related art.

FIG. 8 is a plan view of the hierarchy of the light source unit and the color separation / light guide optical system as viewed from below.

FIG. 9 is a plan view of the hierarchy of the polarization selection optical system as viewed from below.

FIG. 10 is a plan view of the hierarchy of the modulation / color synthesis / projection optical system as viewed from below.

[Explanation of symbols]

1 ... Light source, 2 ... Collimator lens, 3,4 ... Integrator, 5 ... Cold mirror, 6,8,17,18 ... Dichroic mirror, 7G, 7R, 10,10 ', 19B, 19B', 19R, 20B, 20G , 20R… Reflection mirror, 9,9 ′… Correction lens, 11G, 11B, 11R… Condenser lens, 12G, 12B, 12R, 13G, 13B, 13R… Polarization beam splitter, 12b, 12g, 12r, 13b, 13g, 13r… Polarizing film, 14G, 14B, 14R…
Reflective spatial light modulator, 15 ... crossed dichroic prism for color synthesis, 15b, 15r ... dichroic mirror surface, 1
6 ... Projection lens, 31,33 ... Square area that defines the area occupied by the color separation / light guide optical system in a plane, 32,34 ... Square area that defines the area occupied by the modulation, color synthesis, and projection optical system in a plane region.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI H04N 9/31 H04N 9/31 C (72) Inventor Fujiko Koyama 3-12 Moriyacho, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture Victor Company of Japan Inside the company (72) Inventor Ryusaku Takahashi 3-12-12 Moriyacho, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture Inside of Victor Company of Japan (72) Inventor Yasuo Ishizaka 3--12 Moriyacho, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture Inside Victor Company of Japan (56) reference Patent flat 7-325283 (JP, a) JP flat 5-100247 (JP, a) European Patent application Publication 646828 (EP, a 1) ( 58) investigated the field (Int.Cl. ⁷ , DB name) G02B 27/28 G02F 1/13 505 G02F 1/1335 525

Claims (2)

(57) [Claims] 1. A wavelength-selective reflective film for two different colors of light of three primary colors is crossed, and an emission surface is formed around the cross axis.
Type dichroic pre that has three incident surfaces
Projection lens on the exit surface, and each entrance surface
To the first to third in a state where the emission surfaces are opposed to each other.
With arranging a polarizing beam splitter, the cross-type dichroic spatial light modulator of the respective reflective-type surface of the opposite side and opposite side are opposed modulation and color synthesis disposed between click prism in each of the polarizing beam splitter A projection optical system, and color separation / light guiding optics that separates white light generated by the light source into three primary color lights and guides them to the entrance surfaces of the first to third polarization beam splitters of the modulation / color synthesis / projection optical system . And a projection type display device in which the first and third polarization beam splitters of the modulation / color synthesis / projection optical system are arranged on the layer side of the color separation / light guide optical system. The direction of the polarizing film is set so as to be arranged, while the color separation / light guide optical system is opposite to the two dichroic mirrors.
It is composed of a projection mirror and converts white light coming from a light source into three primary colors.
And separates the first and second color lights into first and second light, respectively.
And the third polarization beam splitter.
First optical system for transmitting colored light to the side where the projection lens is disposed
And a plurality of reflection mirrors, and the first optical system is transparent.
The third color light passed by the projection lens side.
The second light incident on the third polarizing beam splitter
And the first and second optical systems in front of them.
Wavelength Selectivity in Crossed Dichroic Prism
The modulation / modulation when viewed in a plane from the direction of the cross axis of the film.
Within the rectangular area that defines the area occupied by the color synthesis / projection optical system
Projection display device, characterized in that configuration was. 2. The second light in the color separation / light guide optical system.
In the optical path of the optical system, the optical path length from the light source for the third color light to the third polarization beam splitter and the light path from the light source for the first and second color light to the first and second polarization beam splitters
2. The projection display device according to claim 1, further comprising a correction lens for making the optical path length substantially equal to the optical path length .