JPH10268235A - Projection display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make possible driving all light valves in the same direction without the necessity that only a sheet of light valve among three sheets of light valves is left/right inversion driven for other light valves. SOLUTION: P polarization light (signal light) to be color synthesized by a cross dichroic prism 9 among modulated light of G light emitted from the light valve 8G does not receive a reflective action until it is emitted from the prism 9. Since respective S polarization light (signal light) to be color synthesized by the prism 9 among modulated light of B light and R light respectively emitted from the light valves 8B, 8R are reflected respectively once by polarization separation parts of polarizing beam splitters 7B, 7R until they are emitted from the prism 9, and are reflected respectively again by dichroic films 9B, 9R in the prism 9, they receive respectively total twice of reflective actions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an R light (red light),
By using a liquid crystal light valve for G light (green light) and B light (blue light), each color light incident on the light valve is modulated and emitted, and the emitted light is synthesized and projected. The present invention relates to a projection display device for obtaining a projection image.

[0002]

2. Description of the Related Art Liquid crystal light valves are arranged for R light, G light, and B light, respectively, and the light source light is separated into R light, G light, and B light, respectively, and incident on the light valves. 2. Description of the Related Art There is known a projection display device in which incident light of each color is modulated and emitted by each light valve with each color signal, and the emitted light of each color is synthesized and projected by a projection lens.

[0003] Japanese Patent Application Laid-Open No. 1-129287 discloses an example of the projection type display device. A conventional projection display device disclosed in this publication will be described with reference to FIG. FIG. 6 is a schematic configuration diagram showing this conventional projection display device.

In this conventional projection display device, a lamp 2
Light emitted from the light source constituted by the light source 01 and the concave mirror 202 is reflected by the B light reflecting dichroic mirror 203 in the direction perpendicular to the incident optical axis;
B light reflecting dichroic mirror 2 in the same direction as the incident optical axis
The light is color-separated into mixed light of G light and R light that pass through the light emitting element 03. The B light reflected by the B light reflecting dichroic mirror 203 travels by changing the optical axis vertically by the bending mirror 204 and enters the B light liquid crystal light valve 208. The mixed light of the G light and the R light transmitted through the dichroic mirror 203 is reflected by the G light reflecting dichroic mirror 205.
G light reflected perpendicular to the incident optical axis,
G light reflecting dichroic mirror 20 in the same direction as the incident axis
5 is separated into R light that passes therethrough. The G light reflected by the G light reflecting dichroic mirror 205 enters the G light liquid crystal light valve 208G. On the other hand, the R light transmitted through the G light reflecting dichroic mirror 205 travels while changing the optical axis in the opposite direction by the bending mirrors 206 and 207, and is incident on the R light liquid crystal light valve 208R.

[0005] Liquid crystal light valves 208B, 208G, 2
08R is a so-called transmissive liquid crystal light valve,
Each pixel has a predetermined number of pixels and a switching element such as a TFT for switching the pixel. The transmissive light valve selects a pixel by the switching element in accordance with a signal for each color, and transmits only the light incident on the pixel at the selected location among the incident light of each color. Modulate
It has a function of emitting the modulated light as signal light.

[0006] Liquid crystal light valves 208B, 20 for each color light
The modulated lights of the respective colors emitted from 8G and 208R are incident on the cross dichroic prism 209 from the respective side surfaces, and are color-combined by the cross dichroic prism 209. That is, the incident modulated light of G light passes through the dichroic films 209B and 209R as it is, and the modulated light of B light is reflected by the B light reflecting dichroic film 209B.
, And the modulated light of the R light is reflected by the R light reflecting dichroic film 209 </ b> R, and is emitted as color combined light from another side of the cross dichroic prism 209 which is different from the incident side of each light. This combined color light is enlarged and projected by a projection lens 210 on a screen (not shown).

[0007]

However, as in the above-mentioned conventional projection display device, the light valves 208B, 208B for the respective colors are used.
A cross dichroic prism 20 as a color combining optical system for combining colors of the respective color lights emitted from 208G and 208R.
9, the three liquid crystal light valves 208B, 208G, and 208 are used as shown in FIG.
One of the light valves 208G of the 208R is
The left and right reversal display had to be displayed on the light valves 208B and 208R. That is, in the cross dichroic prism 209, the light valve 208
B, 208G, and 2R of each color light emitted from 208R.
One color light (B light and R light) is subjected to the reflection action once, while one color light (G light) is not affected by the reflection action. Therefore, one light valve 208G is replaced by the other two light valves. The display had to be displayed as left and right inverted with 208B and 208R.

Therefore, the other light valves 208B, 2B serve as a drive driver circuit for the light valve 208.
A driving driver circuit for performing left-right inversion driving, which is different from the driving driver circuit for 08R, had to be used.
Thus, two types of drive driver circuits must be prepared, and each light valve 208B, 208G, 20
Since the standardization of the drive driver circuit for 8R could not be achieved, the cost was unavoidable.

The present invention has been made in view of such circumstances, and a cross dichroic prism or a cross dichroic prism is used as a color synthesizing optical system for synthesizing colors of R light, G light and B light. Nevertheless, it is not necessary to drive only one of the three light valves left and right with respect to the other light valves, and all the light valves can be driven in the same direction. It is another object of the present invention to provide a projection type display device capable of standardizing drive driver circuits for all light valves.

[0010]

According to a first aspect of the present invention, there is provided a projection type display device for separating light from a light source into R light, G light and B light. And first, second, and third polarization-separating each color light separated by the color separation optical system into two polarized lights.
And a first, second, and third light valve that modulates one polarized light of each color light, which is polarized and separated by the first, second, and third polarization separating optical systems, respectively. A first, a second, and a third analysis optical system for analyzing each light modulated by the first, second, and third light valves, respectively; and a first, second, and third optical system. A color synthesizing optical system for color synthesizing each light detected by the light analyzing optical system, and a projection optical system for projecting the light synthesized by the color synthesizing optical system, and the color synthesizing optical system includes: A cross dichroic prism or a cross dichroic mirror, wherein the first, second and third
When the left and right displays of the light valve are the same, the images by the first, second and third light valves are properly combined.

According to the first aspect, when the color synthesizing optical system is a cross dichroic prism or a cross dichroic mirror, and the first, second, and third light valves have the same left and right display, 1, 2nd and 3rd
Each image by the light valve is appropriately synthesized. Therefore, it is not necessary to drive only specific light valves among the first, second, and third light valves to the left and right inversion with respect to the other light valves, and drive all the light valves in the same direction. It is possible to standardize the drive driver circuits for all the light valves.

The projection display apparatus according to a second aspect of the present invention is the projection display apparatus according to the first aspect, wherein the first polarization separation optical system and the first analysis optical system are the same. The second polarization beam splitter is shared with the second polarization beam splitter.
And the second analysis optical system are shared by the same second polarization beam splitter, and the third polarization separation optical system and the third analysis optical system are the same third polarization beam splitter. This is shared by the polarizing beam splitter.

A projection display apparatus according to a third aspect of the present invention comprises a color separation optical system for separating light from a light source into R light, G light, and B light, and each color separated by the color separation optical system. A first and a second polarization splitting light into two polarized lights, respectively.
And the third polarization separation optical system, and the first, second and third polarization separation optical systems.
A first, a second, and a third light valve that respectively modulate one polarized light of each color light that has been polarized and separated by the polarized light separating optical system, and a first light valve, a second light valve, and a third light valve that respectively modulate each light. First, second, and third optical analysis systems that respectively analyze the detected light, and color synthesis of the respective light that are respectively analyzed by the first, second, and third optical analysis systems. A color combining optical system, and a projection optical system that projects light that has been color combined by the color combining optical system,
The first polarization separation optical system and the first analysis optical system are shared by the same first polarization beam splitter, and the second polarization separation optical system and the second analysis optical system are the same. The third polarization beam splitter is shared by the second polarization beam splitter, the third polarization separation optical system and the third analysis optical system are shared by the same third polarization beam splitter, and the color combining optical system is a cross dichroic prism or A cross dichroic mirror, wherein the color synthesizing optical system passes through the first, second, and third analyzing optical systems of the respective color lights modulated by the first, second, and third light valves, respectively; Each light to be color-combined by each of the first, second, and third light valves is emitted, and then the light is combined by the color-combining optical system and emitted by the color-combining optical system. Reflection work When L, M, and N are mutually independent integers equal to or greater than 0, the number of times of receiving is represented by 2L, 2M, or 2N, or represented by 2L + 1, 2M + 1, or 2N + 1, respectively. is there. In this embodiment, the number of times that each light is subjected to the reflection action may be the same for all, or may be any two.
Only one may be the same or all may be different from each other.

According to the third aspect, the color synthesizing optical system is a cross dichroic prism or a cross dichroic mirror, and a color dichroic prism or a cross dichroic mirror among the color lights modulated by the first, second, and third light valves, respectively. After each light to be color-combined by the color-combining optical system through the first, second and third analyzing optical systems respectively exits the first, second and third light valves, the color-combining optical system By the time the colors are synthesized at and the color synthesis optical system is emitted, L,
When M and N are each independently an integer of 0 or more, they are represented by 2L, 2M, and 2N, respectively (that is, zero or even times), or 2L +
1, 2M + 1, 2N + 1 (that is, an odd number).

Therefore, even though the color synthesizing optical system is a cross dichroic prism or a cross dichroic mirror, the first, second, and third light valves have the same left and right display, and the first, second, and third light valves are identical. The images from the second and third light valves are properly combined. For this reason, it is not necessary to drive only specific light valves among the first, second and third light valves to the left and right inversion with respect to the other light valves, and drive all light valves in the same direction. It is possible to standardize the drive driver circuits for all the light valves.

A projection display apparatus according to a fourth aspect of the present invention comprises a color separation optical system for separating light from a light source into R light, G light and B light, and each color separated by the color separation optical system. A first and a second polarization splitting light into two polarized lights, respectively.
And the third polarization separation optical system, and the first, second and third polarization separation optical systems.
A first, a second, and a third light valve that respectively modulate one polarized light of each color light that has been polarized and separated by the polarized light separating optical system, and a first light valve, a second light valve, and a third light valve that respectively modulate each light. First, second, and third optical analysis systems that respectively analyze the detected light, and color synthesis of the respective light that are respectively analyzed by the first, second, and third optical analysis systems. A color combining optical system, and a projection optical system that projects light that has been color combined by the color combining optical system,
The first polarization separation optical system and the first analysis optical system are shared by the same first polarization beam splitter, and the second polarization separation optical system and the second analysis optical system are the same. The third polarization beam splitter is shared by the second polarization beam splitter, the third polarization separation optical system and the third analysis optical system are shared by the same third polarization beam splitter, and the color combining optical system is a cross dichroic prism or A cross dichroic mirror, wherein the color synthesizing optical system passes through the first, second, and third analyzing optical systems of the respective color lights modulated by the first, second, and third light valves, respectively; Each light to be color-combined by each of the first, second, and third light valves is emitted, and then the light is combined by the color-combining optical system and emitted by the color-combining optical system. Reflection work Number of times to receive is what all the same.

According to the fourth aspect, the color synthesizing optical system is a cross dichroic prism or a cross dichroic mirror, and the color synthesizing optical system includes a first one, a second one, and a third one. After each light to be color-combined by the color-combining optical system through the first, second and third analyzing optical systems respectively exits the first, second and third light valves, the color-combining optical system The number of times that the light is subjected to the reflection action until the color is synthesized by and is emitted from the color synthesizing optical system is the same.

Therefore, even though the color synthesizing optical system is a cross dichroic prism or a cross dichroic mirror, the first, second, and third light valves have the same left and right display, and the first, second, and third light valves are identical. The images from the second and third light valves are properly combined. For this reason, it is not necessary to drive only specific light valves among the first, second and third light valves to the left and right inversion with respect to the other light valves, and drive all light valves in the same direction. It is possible to standardize the drive driver circuits for all the light valves.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a projection type display device according to the present invention will be described in detail with reference to the drawings.

(First Embodiment) First, the first embodiment of the present invention will be described.
The projection display device according to the embodiment will be described with reference to FIG. FIG. 1 is a schematic configuration diagram showing a projection display device according to the present embodiment.

In the projection type display device according to the present embodiment,
As shown in FIG. 1, light source light emitted from a light source 1 composed of a lamp and a concave mirror such as an elliptical mirror shapes an unillustrated ultraviolet cut filter, infrared cut filter, and light source light flux into substantially parallel light. Via a shaping lens, B
The light is reflected by the cross dichroic mirror 2 formed by combining the light reflecting dichroic mirror 2B with the R light and G light reflecting dichroic mirrors 2GR in an X-shape.

The B light of the light source light incident on the cross dichroic mirror 2 is reflected by the B light reflecting dichroic mirror 2B, changes the optical axis in a right angle direction, and proceeds.
Further, the light travels while changing the optical axis in a direction perpendicular to the direction of the bending mirror 4, and is used as a polarization separation optical system and an analysis optical system.
The light enters the polarization beam splitter 7B for light.

On the other hand, the mixed light of the R light and the G light of the light source light incident on the cross dichroic mirror 2 is reflected by the dichroic mirror 2GR, changes the optical axis in a right angle direction, travels, and further bends the mirror. The light is reflected by 5 and travels while changing the optical axis at right angles to the optical axis.
The light is incident on the G light reflecting dichroic mirror 6 arranged at an incident angle of degrees. The G light of the mixed light that has entered the G light reflecting dichroic mirror 6 is reflected by the G light reflecting dichroic mirror 6, travels by changing the optical axis in a right-angle direction, and travels through the polarization separation optical system and the analyzer The light is incident on a G light polarizing beam splitter 7G that is commonly used as an optical system.
The R light of the mixed light incident on the G light reflecting dichroic mirror is reflected by the G light reflecting dichroic mirror 6.
Is transmitted as it is, and is incident on a polarization beam splitter 7R for R light which is commonly used as a polarization separation optical system and an analysis optical system.

As can be seen from the above description, the cross dichroic mirror 2 and the G light reflecting dichroic mirror 6 constitute a color separation optical system for separating light from the light source 1 into R light, G light and B light. I have.

B incident on the polarizing beam splitter 7B
The light is polarized and separated by the polarization splitting unit of the polarization beam splitter 7B into P-polarized light of B light transmitted through the polarization splitting unit and S-polarized light of B light reflected by the polarization splitting unit. . The P-polarized light of the B light transmitted through the polarization splitting portion of the polarization beam splitter 7B is reflected by the reflection type liquid crystal light valve 8 for the B light disposed near the exit surface of the polarization beam splitter 7B.
B is incident. The S-polarized light of the B light reflected by the polarization splitter of the polarization beam splitter 7B is discarded.

G incident on the polarizing beam splitter 7G
The light is polarized and separated by the polarization splitter of the polarization beam splitter 7G into S-polarized light of G light reflected by the polarization splitter and P-polarized light of G light transmitted through the polarization splitter. . The S-polarized light of the G light reflected by the polarization splitting portion of the polarization beam splitter 7G is incident on a G-light reflective liquid crystal light valve 8G arranged near the exit surface of the polarization beam splitter 7G. The P-polarized light of the G light transmitted through the polarization splitter of the polarization beam splitter 7G is discarded.

R incident on the polarization beam splitter 7R
The light is polarized and separated by the polarization splitter of the polarization beam splitter 7R into P-polarized light of R light transmitted through the polarization splitter and S-polarized light of R light reflected by the polarization splitter. . The P-polarized light of the R light transmitted through the polarization splitter of the polarization beam splitter 7R is reflected by the reflection type liquid crystal light valve 8 for the R light disposed near the exit surface of the polarization beam splitter 7R.
It is incident on R. The S-polarized light of the R light reflected by the polarization splitter of the polarization beam splitter 7R is discarded.

As described above, by adopting the configuration in which the cross dichroic mirror 2 and the dichroic mirror 6 are arranged, the optical path length from the light source 1 to the reflective light valves 8B, 8G, and 8R for each color light is the same for each color. Can be

Here, the reflection type light valve, in particular, the electric writing type reflection type light valve adopted as the light valves 8B, 8G, 8R in the present embodiment will be described with reference to FIG. FIG. 5 is a schematic cross-sectional view showing an example of an electric writing type reflective light valve. As shown in FIG. 5, the electric writing type reflective light valve includes a transparent glass substrate 301, a transparent conductive film (ITO) electrode 302, a liquid crystal alignment film 303, a TN liquid crystal layer 304, a liquid crystal alignment film 305, a reflection electrode 306, Reflective electrode 306 and TFT
Conductors 307 and 308 connecting to the drain 312,
It includes a TFT drain 312, a TFT gate 310, a TFT source 311, a TFT oxide layer 309, and a silicon substrate 313. In FIG. 5, 314 is a TFT source diffusion region, and 315 is a TFT drain diffusion region. When a voltage is applied to the gate 310, TF
T switches to electrode 3 via drain 312
A voltage is applied between the liquid crystal layer 06 and the counter electrode 302, and the liquid crystal molecules of the liquid crystal layer 304 at the selected location are aligned by an electric field due to the applied voltage, and the liquid crystal layer 304 at the location is １ ／ wavelength. Acts as a plate. Therefore, the polarized light that has entered the relevant portion becomes circularly polarized light, enters the metal reflective electrode 306, is reflected by the electrode 306 in the opposite direction, and when passing through the liquid crystal 304 again, is different from the circularly polarized light as incident light. The light is emitted as linearly polarized light whose polarization direction has been changed by 90 degrees. On the other hand, in a place where a voltage is not applied to the gate 310 and the TFT is not switched and is not selected, no electric field is generated between the electrode 306 and the counter electrode 302, and the liquid crystal molecules in the liquid crystal layer 304 dissolve both the alignment films 303 and 303. The incident polarized light is rotated according to the direction determined by the alignment direction of the liquid crystal molecules 305, is rotated according to the liquid crystal molecules, travels, is reflected by the metal electrode 306, and is again rotated according to the twist of the liquid crystal molecules. The light then travels and is emitted as polarized light having the same polarization direction as the incident light. The polarized light whose polarization direction is shifted by 90 degrees from the polarization direction of the incident light can be emitted only at the selected location. The above is the function of the electric writing type reflection type light valve. The electric writing type reflection type light valve basically converts the polarization direction of the reflected outgoing light at an electrically selected location to a polarization direction different from the incident light. It has a function to make In the case of an electric writing reflective light valve having such a structure, T
Since the FT can be disposed below the electrode 306, the area of the electrode 306 can be increased, and the aperture ratio can be significantly increased.

As another example of the reflection type light valve, a light writing type reflection type light valve is known. In the present embodiment, the light writing type reflection type light valve is adopted as the light valves 8B, 8G, 8R. Of course, it may be possible. In this case, each light valve 8B, 8G,
A writing optical system for providing writing light to 8R is arranged.

In the case of the present embodiment, as described above, P-polarized light of B light and R light enters the light valves 8B and 8R, and S-polarized light of G light enters the light valve 8G. Light valve 8B, 8R
The alignment films 303 and 305 are configured so that, when not selected, P-polarized light enters and is rotated.
The alignment films 303 and 305 are configured such that, when not selected, S-polarized light enters and is rotated.

If, for example, a half-wave plate is attached to the exit surface of the polarizing beam splitter 7G, the light incident on the light valve 8G will also be P-polarized light, so that all the light valves 8B, 8G, 8R When the alignment films 303 and 305 are not selected, it can be configured so that P-polarized light is incident and rotated, and light valves having the same configuration can be used as the light valves 8B, 8G, and 8R. Of course, instead of attaching a half-wave plate to the exit surface of the polarizing beam splitter 7G, the polarizing beam splitters 7B and 7B
A half-wave plate may be attached to the exit surface of R.

Referring again to FIG. 1, the light valve 8
Modulated light of B light and R light modulated by B and 8R and emitted therefrom (the modulated light is a mixture of S-polarized light (signal light) at a selected location and P-polarized light at a non-selected location. ) Are again incident on the polarization beam splitters 7B and 7R, respectively.
The light is analyzed at R and 7R, respectively. That is, only the S-polarized light of the modulated light of the B light and the R light is reflected by the polarization splitters of the polarization beam splitters 7B and 7R, respectively, and proceeds toward the cross dichroic prism 9 as a color combining optical system ( That is, the P-polarized light of the modulated light of the B light and the R light is transmitted through the polarization splitting portions of the polarization beam splitters 7B and 7R, returned to the light source direction, and discarded.

On the other hand, the modulated light of the G light modulated by the light valve 8G and emitted from the light valve 8G (the modulated light includes P-polarized light (signal light) at a selected position and S-polarized light at a non-selected position. Are incident again on the polarization beam splitter 7G, and the polarization beam splitter 7G
It is analyzed at G. That is, P of the modulated light of G light
Only the polarized light passes through the polarization splitting section of the polarization beam splitter 7G and proceeds toward the cross dichroic prism 9 as a color combining optical system (that is, is analyzed).
The S-polarized light of the modulated light is a polarized beam splitter 7
The light is reflected by the G polarization separation unit, returns to the light source direction, and is discarded.

The B light and the R light (S-polarized light) emitted from the polarization beam splitters 7B and 7R enter the cross dichroic prism 9 from directions opposite to each other, and are emitted from the polarization beam splitter 7G. The G-light (P-polarized light) is incident on the cross dichroic prism 9 from the side surface orthogonal to the incident surface of the R and B light.

The cross dichroic prism 9 includes a B light reflecting dichroic film 9B or an R light reflecting dichroic film 9R on a predetermined projection surface of four right-angled isosceles triangular prisms.
Is formed, and the right angle portion of the prism is aligned,
In addition, the B light reflecting dichroic film 9B and the R light reflecting dichroic film 9R are bonded so as to form an X-shape. The detection light of the R light and the B light incident on the cross dichroic prism 9 is converted to the dichroic films 9B and 9R.
The analysis light of the G light reflected by the light beam and incident on the cross dichroic prism 9 is reflected by the dichroic film 9.
B, 9R, all of the detection light travels in the same optical axis direction (left direction in FIG. 1) and exits from the cross dichroic prism 9. As described above, the analysis light of each color is synthesized.

The color-combined light enters the projection lens 10 and is projected on a screen (not shown) as a full-color enlarged image.

As can be understood from the above description, the P-polarized light to be color-combined by the cross dichroic prism 9 via the polarizing beam splitter 7G among the modulated G light emitted from the G light valve 8G. The signal light) is incident on the projection lens 10 without being subjected to a reflection effect from when the light is emitted from the light valve 8G to when the color is synthesized by the cross dichroic prism 9 and before the light exits the cross dichroic prism 9.

On the other hand, each of the S-polarized lights to be color-combined by the cross dichroic prism 9 through the polarizing beam splitters 7B and 7R, respectively, of the modulated lights of the B light and the R light respectively emitted from the light valves 8B and 8R. (Signal light) is emitted from each of the light valves 8B and 8R, is subjected to color synthesis by the cross dichroic prism 9, and is emitted from the cross dichroic prism 9.
The cross dichroic prism 9 is reflected once by the polarization splitters of the polarization beam splitters 7B and 7R, respectively.
In order to be reflected again by the dichroic films 9B and 9R in the inside, respectively, they are respectively subjected to the reflection action twice in total,
The light enters the projection lens 10.

As described above, in the present embodiment, although the color combining optical system is the cross dichroic prism 9, the G light signal light is zero times, and the R light signal light and the B light signal light are two times. Light valve 8
When the left and right displays of B, 8G, and 8R are all the same, the images from the light valves 8B, 8G, and 8R are properly combined. For this reason, the light valves 8B, 8G,
It is not necessary to drive only a specific light valve among the 8Rs with respect to the other light valves left and right, and all the light valves 8B, 8G and 8R can be driven in the same direction. It is possible to standardize the drive driver circuit for the valves 8B, 8G, 8R.

(Second Embodiment) Next, a second embodiment of the present invention will be described.
The projection type display device according to the embodiment will be described with reference to FIG.

FIG. 2 is a schematic configuration diagram showing a projection type display device according to the present embodiment. In FIG. 2, the same or corresponding elements as those shown in FIG. 1 are denoted by the same reference numerals, and redundant description will be omitted.

The projection type display device according to the present embodiment has the same basic structure as the projection type display device according to the first embodiment, except that the polarization beam splitters 7B, 7 for the respective colors are used.
The positions of the light valves 8B, 8G, 8R with respect to G, 7R are different.

That is, the light valves 8R and 8B for the R light and the B light are respectively provided with the polarization beam splitters 7R and 7B for the respective lights.
And the S-polarized light of each color reflected by the polarized light separating unit is incident, and the light valve for G light 8G is configured to receive the P-polarized light transmitted through the polarized light separating unit of the polarization beam splitter 7G. It is.

In this embodiment, the B light color-separated by the cross dichroic mirror 2 travels by changing the direction of the optical axis by the bending mirror 4, enters the polarization beam splitter 7B, and is reflected by the polarization splitter. The S-polarized light of the B light enters the light valve 8B disposed near the exit surface of the polarization beam splitter 7B.

The R light that has been color-separated by the cross dichroic mirror 2 and the dichroic mirror 6 travels through the dichroic mirror 6, enters the polarization beam splitter 7R, and reflects the S light of the R light reflected by the polarization separation unit. The polarized light is incident on the light valve 8R disposed near the exit surface of the polarization beam splitter 7R.

G reflected by the dichroic mirror 6
The light is incident on the polarization beam splitter 7G, and the P-polarized light of the G light transmitted through the polarization splitting unit is incident on the light valve 8G arranged near the exit surface of the polarization beam splitter 7G.

The light valves 8B, 8G, 8R are the first
This is the same electric writing type reflective liquid crystal light valve as that described with reference to FIG. 5 in the embodiment.

As in the first embodiment, since the light valves 8B and 8R and the light valve 8G have different polarization directions of the incident polarized light, the liquid crystal alignment is performed so that the liquid crystal molecules are aligned in different directions. The orientation direction of the film has been changed.
However, as described in the description of the first embodiment, in order to form the alignment films in the same direction, a half-wave plate is attached to the exit surface of the polarizing beam splitter 7G, and the light valve 8G The S-polarized light may be incident on the light source. Of course, instead of attaching a half-wave plate to the exit surface of the polarization beam splitter 7G, a half-wave plate is attached to the exit surfaces of the polarization beam splitters 7B and 7R, and P-polarized light is applied to the light valves 8B and 8R. You may make it enter.

The modulated light of the B light and the R light which are modulated by the light valves 8B and 8R and emitted therefrom (the modulated light includes P-polarized light (signal light) at a selected location and S-modulated light at an unselected location. The polarized light is mixed with the polarized light splitters 7B and 7R, and is analyzed by the polarized light beam splitters 7R and 7R, respectively. That is, only the P-polarized light of the modulated light of the B light and the R light passes through the polarization splitters of the polarization beam splitters 7B and 7R, respectively, and proceeds toward the cross dichroic prism 9 (that is, is analyzed). , B light, and R light, the S-polarized light is a polarized beam splitter 7
The light is reflected by the B and 7R polarization separation parts, returned to the light source direction, and discarded.

On the other hand, the modulated light of the G light which is modulated by the light valve 8G and emitted therefrom (the modulated light includes S-polarized light (signal light) at a selected position and P-polarized light at a non-selected position). Are incident again on the polarization beam splitter 7G, and the polarization beam splitter 7G
It is analyzed at G. That is, S of the modulated light of G light
Only the polarized light is reflected by the polarization splitting section of the polarized beam splitter 7G and travels toward the cross dichroic prism 9 (that is, is analyzed), and the P-polarized light of the modulated light of the G light is polarized beam splitter. The light passes through the 7G polarized light separating portion, returns to the light source direction, and is discarded.

The R and B light beams incident on the cross dichroic prism 9 are reflected by the dichroic films 9B and 9R, respectively, and the G light beam incident on the cross dichroic prism 9 is the dichroic film 9B and 9B. 9R, all the detection lights travel in the same optical axis direction (left direction in FIG. 1) and are emitted from the cross dichroic prism 9. As described above, the analysis light of each color is synthesized.

The color-combined light enters the projection lens 10 and is projected on a screen (not shown) as a full-color enlarged image.

As can be understood from the above description, in the case of the present embodiment, the cross dichroic prism 9 passes through the polarizing beam splitter 7G of the modulated light of G light emitted from the G light valve 8G. After the S-polarized light (signal light) to be color-combined is emitted from the light valve 8G, the color is combined by the cross dichroic prism 9 and emitted from the cross dichroic prism 9
The light is once reflected by the polarization splitting portion of the polarization beam splitter 7G, undergoes a reflection operation once in total, and is incident on the projection lens 10.

On the other hand, each of the P-polarized lights to be color-combined by the cross dichroic prism 9 through the polarizing beam splitters 7B and 7R among the modulated lights of the B light and the R light respectively emitted from the light valves 8B and 8R. (Signal light) is emitted from each of the light valves 8B and 8R, is subjected to color synthesis by the cross dichroic prism 9, and is emitted from the cross dichroic prism 9.
The light is reflected once by the dichroic films 9B and 9R in the cross dichroic prism 9, respectively, undergoes a reflection action once in total, and is incident on the projection lens 10.

As described above, in this embodiment, although the color synthesizing optical system is the cross dichroic prism 9, all of the G light signal light, the R light signal light, and the B light signal light are used once. Light valve 8
When the left and right displays of B, 8G, and 8R are all the same, the images from the light valves 8B, 8G, and 8R are properly combined. For this reason, the light valves 8B, 8G,
It is not necessary to drive only a specific light valve among the 8Rs with respect to the other light valves left and right, and all the light valves 8B, 8G and 8R can be driven in the same direction. It is possible to standardize the drive driver circuit for the valves 8B, 8G, 8R.

(Third Embodiment) Next, a third embodiment of the present invention will be described.
The projection display device according to the embodiment will be described with reference to FIG.

FIG. 3 is a schematic configuration diagram showing a projection type display device according to the present embodiment. For convenience of explanation, an X axis, a Y axis, and a Z axis that are orthogonal to each other are defined as shown in the drawing. Note that the light source and the projection lens have the same configurations as the light source 1 and the projection lens 10 in FIGS. 1 and 2, and therefore are omitted in FIG.

The projection type display devices according to the first and second embodiments are examples of the projection type display device in which the respective components are arranged in a plane, but the projection type display device according to the present embodiment is the same. This is an example of a projection display device using various components but arranging them three-dimensionally.

In the projection display device according to the present embodiment,
As shown in FIG. 3, light from a light source (not shown) traveling in the Y direction is emitted from a B light reflecting dichroic mirror 13B and an R light reflecting dichroic mirror 13R.
The light is incident on the cross dichroic mirror 13 arranged in the mold. The optical axis and each dichroic mirror 13B,
13R is arranged to have an incident angle of 45 degrees.

The cross dichroic mirror 13 constitutes a color separation optical system, and the light source light incident on the cross dichroic mirror 13 is transmitted through the cross dichroic mirror 13 as it is and travels in the Y direction.
The light is color-separated into B light that is reflected by the dichroic mirror 13B and travels in the X direction and R light that is reflected by the dichroic mirror 13R and travels in the -X direction.

The R light, G light and B light separated by the cross dichroic mirror 13 are
R, 13G, and 13B change the optical axis in the Z direction, respectively, and travel, and enter the polarization beam splitters 15R, 15G, and 15B that are commonly used as a polarization separation optical system and an analysis optical system.

The R light incident on the polarization beam splitter 15R in the Z direction is reflected by the polarization separation unit of the polarization beam splitter 15R in the −X direction by the polarization separation unit and discarded as the S polarized light of the R light. Then, the light passes through the polarized light separating section in the Z direction and is polarized and separated into P-polarized light incident on the reflective liquid crystal light valve 16R arranged near the exit surface of the polarized beam splitter 15R.

The B light incident on the polarization beam splitter 15B in the Z direction is reflected by the polarization separation unit of the polarization beam splitter 15B in the X direction and is discarded after being reflected in the X direction by S polarization light. P transmitted through the polarized light separating section in the Z direction and incident on a reflective liquid crystal light valve 16B arranged near the exit surface of the polarizing beam splitter 15B.
It is polarized and separated into polarized light.

The G light incident on the polarization beam splitter 15G in the Z direction is transmitted by the polarization separation unit of the polarization beam splitter 15G in the Z direction, and the P light of B light that is discarded after being transmitted in the Z direction. S reflected by the polarization separation unit in the Y direction and incident on a reflection type liquid crystal light valve 16G disposed near the exit surface of the polarization beam splitter 15G.
It is polarized and separated into polarized light.

Each color light liquid crystal light valve 16R, 16
Reference numerals G and 16B denote the same electrically-writeable reflective liquid crystal light valves as those described with reference to FIG. 5 in the first embodiment. The fact that the liquid crystal alignment film of the light valve is adjusted by the difference in the polarization direction of the incident polarized light, and that a half-wave plate may be provided instead, This is the same as described in the embodiment.

The B light and R modulated light which are modulated by the light valves 16B and 16R and emitted therefrom (the modulated light includes S-polarized light (signal light) at a selected location and P-polarized light at an unselected location. The light and the light are mixed.) Are again incident on the polarization beam splitters 15B and 15R, respectively, and are analyzed by the polarization beam splitters 15B and 15R, respectively. That is, only the S-polarized light of the modulated light of the B light and the R light is the same as the polarized beam splitter 15B,
The reflected light is reflected by the 15R polarization separation unit, and travels in the -X direction and the X direction toward the cross dichroic prism 17 as a color combining optical system (that is, is analyzed), and modulated light of B light and R light. Among them, the P-polarized light passes through the polarization splitters of the polarization beam splitters 15B and 15R in the −Z direction, returns to the light source direction, and is discarded.

On the other hand, the modulated light of the G light which is modulated by the light valve 16G and emitted therefrom (the modulated light includes a P-polarized light (signal light) at a selected position and an S-polarized light at a non-selected position. Are incident again on the polarization beam splitter 15G and are analyzed by the polarization beam splitter 15G. That is, only the P-polarized light of the modulated light of the G light is transmitted through the polarization splitting unit of the polarization beam splitter 15G, and the cross dichroic prism 1
7 in the −Y direction (that is, analyzed), and G
The S-polarized light of the modulated light is a polarized beam splitter 1
The light is reflected in the −Z direction by the 5G polarization separation section, returned to the light source direction, and discarded.

The detection light (S-polarized light) of the B light and the R light emitted from the polarization beam splitters 15B and 15R and traveling in the -X direction and the X direction, respectively, is transmitted to the cross dichroic prism 17 from the mutually facing side surfaces. And is emitted from the polarizing beam splitter 15G to be −Y
The G-light (P-polarized light) traveling in the direction is incident on the cross dichroic prism 17 from a side surface orthogonal to the incident side of the R-light and B-light detection light.

The cross dichroic prism 17 has the same structure as the cross dichroic prism 9 described above, and has a configuration in which the R light reflecting dichroic film 17R and the B light reflecting dichroic film 17B are arranged in an X-shape. .

The B-light and R-light detection light incident on the cross dichroic prism 17 is applied to the dichroic film 1.
The analysis light of G light reflected by 7B and 17R and incident on the cross dichroic prism 17 passes through the dichroic films 17B and 17R, and both of the analysis lights travel in the same −Y direction and are connected to the cross dichroic prism. Emitted from 17. As described above, the analysis light of each color is synthesized.

The color-combined light is incident on a projection lens 10 (not shown), and is projected as a full-color enlarged image on a screen (not shown).

In the projection type display device according to the present embodiment, since the optical axis of the light emitted from each light valve and reaching the projection lens includes the optical axis in the Z direction, each of the light valves 16R, 16G, Taking into account not only the left and right display but also the upper and lower display of 16B, the light valves 16R, 16
Images of G and 16B are appropriately combined.

Now, assuming that the composite image M emitted from the exit surface of the cross dichroic prism 17 has an “upper” shape as shown in FIG. 3, the display of the light valve 16B is shown in FIG.
As shown in the figure, “up” is indicated by a dotted line with the X direction as the upper side. Dotted lines indicate the display as viewed from the back of the exit surface.

Similarly, the display of the light valve 16R is “up” with the −X direction as the upper side, as viewed from the emission surface. The reason indicated by the dotted line is the same as above.

Similarly, the display of the light valve 16G is "up" with the Z direction as the upper side as viewed from the exit surface. The reason indicated by the dotted line is the same as above.

As described above, by holding the upper and lower positions, it is understood that the left and right display of each of the light valves 16R, 16G, 16B can be all the same.

With the above-described structure, the light valve 16B,
It is not necessary to drive only a specific light valve of the 16G, 16R with respect to the other light valves left and right, and all the light valves 16B, 16G, 16R can be driven in the same direction. Light valve 16
It is possible to standardize drive driver circuits for B, 16G, 16R.

In the projection display device according to the present embodiment, it is needless to say that the optical path length from the light source to each light valve can be the same as in the projection display devices according to the first and second embodiments. .

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described.
The projection type display device according to the embodiment will be described with reference to FIG.

FIG. 4A is a schematic configuration diagram showing a projection type display device according to the present embodiment, and FIG. 4B is a diagram of the light valve 16R viewed in the X direction. In FIG. 4, FIG.
The same reference numerals are given to the same or corresponding elements as those shown in FIG.

The projection type display device according to the present embodiment has the same basic configuration as the projection type display device according to the third embodiment, except that the polarization beam splitters 15B, 1B for each color are used.
Light valves 16B, 16G, 1 for 5G, 15R
The position of 6R is different.

That is, the light valves 16B and 16R for the B light and the R light are provided by the polarization beam splitters 15B and 15B.
Each of the polarization beam splitters 15B, 15R is so set that the S-polarized light of each color reflected by the polarization splitters of the polarization beam splitters 15B, 15R out of the B light and the R light respectively incident on R in the Z direction. The light valve 16G for G light is disposed in the vicinity of the emission surface, and the P light, which is transmitted through the polarization splitting film of the polarization beam splitter 15G, of the G light incident on the polarization beam splitter 15G in the Z direction is incident. , Near the exit surface of the polarizing beam splitter 15G.

The modulated lights emitted from the light valves 16B and 16R are analyzed by the polarization beam splitters 15B and 15R, and transmitted through the polarization beam splitters 15B and 15R, respectively, to thereby analyze the B light and the R light, respectively. Signal light, P-polarized light), and the detection light of the B light and the R light is reflected once by the dichroic films 17B and 17R of the cross dichroic prism 17 for color synthesis, and is emitted as color synthesized light. On the other hand, the modulated light emitted from the light valve 16G enters the polarization beam splitter 15G, is analyzed by the polarization beam splitter 15G, and is reflected once by the polarization splitting film of the polarization beam splitter 15G to generate G light. The light becomes the light detection light, and the G light detection light passes through the cross dichroic prism 17 without being reflected.

The display of each light valve 16B, 16G, 16R of the projection type display according to the present embodiment will be described.

Now, assuming that the composite image M emitted from the exit surface of the cross dichroic prism 17 for color composition has an “upper” shape as shown in FIG. 4, the display images of the light valves 16B and 16R are both Is also an “upper” image with the left and right inverted with the Z direction as the upper side. This is because the image shown by the dotted line is an image viewed from the back surface of the emission surface.

The display on the light valve 16G is an image of the “upper” image which is also inverted left and right with the Y direction as the upper side. The reason indicated by the dotted line is the same as above.

As described above, any of the light valves 16B,
Although the displays of 16G and 16R are also reversed left and right with respect to the emission image M, the display of the specific light valve is not necessarily reversed left and right with respect to the display of the other light valves. , 16G, 16R can be displayed with the same display.

With the above configuration, the light valve 16B,
It is not necessary to drive only a specific light valve of the 16G, 16R with respect to the other light valves left and right, and all the light valves 16B, 16G, 16R can be driven in the same direction. Light valve 16
It is possible to standardize drive driver circuits for B, 16G, 16R.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments.

For example, the first to fourth embodiments are examples in which a cross dichroic prism is used as a color synthesizing optical system, but are used as color separation optical systems in the third and fourth embodiments. Needless to say, a cross dichroic mirror having the same configuration as the cross dichroic mirror 13 in FIGS. 3 and 4 may be used as a color combining optical system. Even in this case, the same effects as those of the projection display device according to each of the above-described embodiments can be obtained.

[0092]

As described above, according to the present invention,
Although a cross dichroic prism or a cross dichroic prism is used as a color synthesizing optical system for synthesizing the colors of R light, G light and B light, only one of the three light valves is used. There is no need to perform left-right reversal drive for the other light valves, all the light valves can be driven in the same direction, and drive driver circuits for all the light valves can be standardized.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a projection display device according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a projection display device according to a second embodiment of the present invention.

FIG. 3 is a schematic configuration diagram showing a projection display device according to a third embodiment of the present invention.

FIG. 4 is a diagram showing a schematic configuration of a projection display device according to a fourth embodiment of the present invention and a light valve thereof.

FIG. 5 is a schematic sectional view showing an example of an electric writing type reflection type light valve.

FIG. 6 is a schematic configuration diagram showing a conventional projection display device.

[Explanation of symbols]

Reference Signs List 1 light source 2 cross dichroic mirror 4, 5, 14B, 14G, 14R bending mirror 6G light reflecting dichroic mirror 7B, 7G, 7R, 15B, 15G, 15R polarizing beam splitter 8B, 8G, 7R, 16B, 16G, 16R reflection type Liquid crystal light valve 9, 17 Cross dichroic prism 10 Projection lens 13 Cross dichroic mirror

Claims (4)

[Claims] 1. A color separation optical system that separates light from a light source into R light, G light, and B light, and a color separation optical system that separates each color light separated by the color separation optical system into two polarized lights. A first, a second, and a third polarization separation optical system; and a first, a second, respectively, that modulates one of the color lights separated by the first, second, and third polarization separation optical systems. And a third light valve; a first, a second, and a third light analysis optical system for detecting light beams modulated by the first, second, and third light valves, respectively; A color synthesizing optical system for color synthesizing each light detected by the second and third analysis optical systems, and a projection optical system for projecting the light color synthesized by the color synthesizing optical system. The color combining optical system is a cross dichroic prism or A dichroic mirror, wherein when the first, second and third light valves have the same left and right display, the respective images by the first, second and third light valves are properly combined; A projection type display device characterized by the above-mentioned. 2. The first polarization separation optical system and the first polarization separation optical system.
Are shared by the same first polarization beam splitter, and the second polarization separation optical system and the second analysis optical system are shared by the same second polarization beam splitter. 3. A projection display device, wherein the third polarization separation optical system and the third analysis optical system are shared by the same third polarization beam splitter. 3. A color separation optical system that separates light from a light source into R light, G light, and B light, and a light that separates each color light separated by the color separation optical system into two polarized lights. A first, a second, and a third polarization separation optical system; and a first, a second, respectively, that modulates one of the color lights separated by the first, second, and third polarization separation optical systems. And a third light valve; a first, a second, and a third light analysis optical system for detecting light beams modulated by the first, second, and third light valves, respectively; A color synthesizing optical system for color synthesizing each light detected by the second and third analysis optical systems, and a projection optical system for projecting the light color synthesized by the color synthesizing optical system. The first polarization separation optical system and the first analysis optical system are the same. The second polarization splitting optical system and the second analysis optical system are shared by the same second polarization beam splitter, and the third polarization splitting optical system and The third analyzing optical system is shared by the same third polarizing beam splitter; the color combining optical system is a cross dichroic prism or a cross dichroic mirror; and the first, second, and third light valves The respective lights to be color-combined by the color-combining optical system through the first, second, and third detection optical systems, respectively, of the modulated color lights, respectively, are the first, second, and third lights. L, M, and N are independent of each other, from the time when each light valve is emitted to the time when the light is subjected to the reflection action until the light is synthesized by the color synthesizing optical system and emitted from the color synthesizing optical system. When an integer greater than or equal to zero, 2L, respectively, 2M, 2
N, or 2L + 1, 2M +, respectively
A projection display device represented by 1, 2N + 1. 4. A color separation optical system that separates light from a light source into R light, G light, and B light, and a light that separates each color light separated by the color separation optical system into two polarized lights. A first, a second, and a third polarization separation optical system; and a first, a second, respectively, that modulates one of the color lights separated by the first, second, and third polarization separation optical systems. And a third light valve; a first, a second, and a third light analysis optical system for detecting light beams modulated by the first, second, and third light valves, respectively; A color synthesizing optical system for color synthesizing each light detected by the second and third analysis optical systems, and a projection optical system for projecting the light color synthesized by the color synthesizing optical system. The first polarization separation optical system and the first analysis optical system are the same. The second polarization splitting optical system and the second analysis optical system are shared by the same second polarization beam splitter, and the third polarization splitting optical system and The third analyzing optical system is shared by the same third polarizing beam splitter; the color combining optical system is a cross dichroic prism or a cross dichroic mirror; and the first, second, and third light valves The respective lights to be color-combined by the color-combining optical system through the first, second, and third detection optical systems, respectively, of the modulated color lights, respectively, are the first, second, and third lights. The number of times the light valve is subjected to the reflection action from the emission of each light valve to the emission of the color composition by the color composition optical system and the emission of the color composition optical system are all the same. Type display device.