JP2001290216A - Light source device and projection type display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projection type display device capable of projecting a highluminance projected image, and to provide a light source device used for the display device. SOLUTION: This display device is equipped with the light source 1, a 1st lens plate 2 where plural lenses are arranged to be planar and on which light from the light source 1 is made incident, a 2nd lens plate 4 where plural lenses are arranged to be planar and on which emitted light from the lens plate 2 is made incident, a polarizing beam splitter array 5 arranged in the vicinity of the emitting surface of the lens plate 4, a 1st 1/2 wavelength phase plate 6 arranged at a specified position on the emitting surface of the array 5, a color separation optical system 7 color-separating the emitted light from the array 5 and the phase plate 6 to 1st color light beam, 2nd and 3rd color light beams, a 2nd 1/2 wavelength phase plate 10 changing the vibrating direction of either the 1st color light beam or the 2nd and the 3rd color light beams, and a synthesizing optical system 11 synthesizing either the 1st color light beam or the 2nd and the 3rd color light beams whose vibrating direction is changed with the color light beam whose vibrating direction is not changed.

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 for combining light emitted from a plurality of liquid crystal light valves and projecting the combined light with a projection optical system, and more particularly to a light source device used for the device. It is.

[0002]

2. Description of the Related Art FIG. 7 shows an example of a conventionally known projection display device. Light source 10 comprising a lamp and a concave mirror
The light source light emitted from 1 is white light, and includes R (red) light, G (green) light, and B (blue) light components as components. Before color-separating the light source light into the respective color light components, first, a polarization conversion device 11 for converting the light into specific linearly polarized light.
By 0, the light is converted into, for example, P-polarized light.

The polarization converter 110 is a fly-eye integrator and a polarization beam splitter array disposed on the exit surface of the fly-eye integrator, and uses a device in which a half-wave phase plate is disposed on a predetermined exit surface. The light emitted from the polarization conversion device 110 is, for example, a color separation optical system including a cross dichroic mirror 102 in which a dichroic mirror 102R having R light reflection characteristics and a dichroic mirror 102B having B light reflection characteristics are arranged in an X-shape on the optical axis. To separate the G light into the transmitted G light parallel to the incident optical axis, and the R light and the B light traveling in directions opposite to each other and perpendicular to the optical axis.

The color separated G light is transmitted to a transmission type liquid crystal light valve 107G for G light, and the R light and B light are respectively reflected and folded by mirrors 103, 104 and 104, respectively.
The optical axis is bent by 106 and enters the transmission type liquid crystal light valve 107R for R light and the transmission type liquid crystal light valve 107B for B light, respectively. Light bulb 1 for each color light
07G, 107R, and 107B can modulate incident polarized light (for example, P-polarized light) with each color image signal, and emit modulated light as S-polarized light.

[0005] The light valves 107G, 107 for each color light
The modulated light (S-polarized light) emitted from the R and 107B is converted into a cross dichroic prism 108 constituting a color combining optical system.
Are combined from different incident surfaces, and the combined light is projected by a projection lens 109 on a screen (not shown) as a full-color image. The cross dichroic prism 108 has an R light reflecting dichroic film 10 inside.
8R and the B light reflecting dichroic film 108B are arranged in an X-shape.

[0006]

Since the above-mentioned conventional projection type display device has the polarization conversion device 110, it is more reliable than the case where the same light source is used as compared with the case without the device. Thus, the illumination brightness for illuminating the light valve can be improved, and the brightness of the projected image can be improved. However, in recent projection apparatuses, it is desired to further increase the brightness of a projected image.

An object of the present invention is to provide a projection display device capable of projecting a high-brightness projection image and a light source device used therefor.

[0008]

The present inventor has focused on the characteristics of the dichroic film constituting the cross dichroic prism in the above-mentioned projection type display device. It has been found that B light is S-polarized light, and that G light transmitted through the dichroic prism is made to enter as P-polarized light, which gives better results than conventional conventional S-polarized light.

As a means, only the G light component of the white light before entering the color separation optical system in advance is converted to S light.
If light having S-polarized light as R light and B light components is incident on the polarized light, the modulated light emitted from the liquid crystal light valve for each color becomes P-polarized light for the G light, and that for R light and B light. It has been found that the emitted modulated light can be S-polarized light, and that the brightness of the combined light can be improved.

According to a first aspect of the present invention, a light source and a plurality of lenses are arranged in a plane, a first lens plate for receiving light from the light source, and a plurality of lenses are arranged in a plane. A second lens plate for receiving light emitted from the lens plate of the second type;
A polarizing beam splitter array arranged near the exit surface of the lens plate, a first half-wave phase plate arranged at a specific position on the exit surface of the polarizing beam splitter array, the polarizing beam splitter array and the first A color separation optical system that separates light emitted from the half-wave phase plate into first color light, second and third color light, and the first color light or the second or third color light.
A second half-wave phase plate that converts one of the color lights in the vibration direction, and the first color light in which the vibration direction is changed or one of the second and third colors is not converted. A light source device comprising a combining optical system for combining color light.

According to a second aspect of the present invention, in the light source device of the first aspect, the first color light is G (green) light, the second and third color lights are B (blue) light, and R (red) light. A light source device characterized by the following.

The invention according to claim 3 is the light source device according to claim 1, wherein the color separation optical system comprises a dichroic mirror.

According to a fourth aspect of the present invention, there is provided the light source device according to the first, second, or third aspect, wherein the polarization combining optical system is a polarization beam splitter. .

According to a fifth aspect of the present invention, there is provided the light source device according to the first aspect, a color separation optical system that separates light from the light source device into R light, G light, and B light; A light valve for R light, a light for G light, and a light for B light, each of which receives B light; a color combining optical system for combining light emitted from the light valves for R light, G light, and B light; A projection display device comprising: a projection optical system for projecting light combined by the optical system.

According to a sixth aspect of the present invention, in the projection display device of the fifth aspect, the color combining optical system is a cross dichroic prism, and the R light reflecting dichroic film and the B light reflecting dichroic film. And the first color by the light source device is G light,
The projection type display device is characterized in that the three color lights are R and G lights.

According to a seventh aspect of the present invention, there is provided a light source device for emitting linearly polarized light, wherein the emitted light has a first color component, a second color component, and a third color component. And a light source device characterized in that the polarization directions of the second and third color components are different.

The invention according to claim 8 is the light source device according to claim 7, wherein the first color light is G (green) light, the second and third color lights are B (blue) light, and R (red) light. A light source device characterized by the following.

According to a ninth aspect of the present invention, the light source and the plurality of lenses are arranged in a plane, the first lens plate for receiving the light from the light source, and the plurality of lenses are arranged in a plane. A second lens plate for receiving the light emitted from the first lens plate, a dichroic prism array disposed near the exit surface of the second lens plate, and a polarizing beam splitter array disposed near the exit surface of the dichroic prism array. A half-wave phase plate arranged at a specific position on the exit surface of the polarizing beam splitter array, and a plurality of dichroic prisms constituting the dichroic prism array include a first color light, a second color light, A light source device, wherein a dichroic film for separating three colors is disposed.

Further, according to a tenth aspect of the present invention, the light source and the plurality of lenses are arranged in a plane, the first lens plate for receiving light from the light source, and the plurality of lenses are arranged in a plane. A second lens plate for receiving light emitted from the first lens plate,
A polarizing beam splitter array disposed near the exit surface of the second lens plate, a dichroic prism array disposed near the exit surface of the polarized beam splitter array,
A dichroic prism array having a half-wavelength phase plate disposed on a predetermined exit surface among the exit surfaces; a plurality of dichroic prisms constituting the dichroic prism array include a first color light and a second color light; ,
A light source device, wherein a dichroic film for color-separating the third color light is disposed.

Further, according to the present invention, the light source and the plurality of lenses are arranged in a plane, the first lens plate for receiving the light from the light source, and the plurality of lenses are arranged in a plane. A second lens plate for receiving light emitted from the first lens plate,
A polarizing beam splitter array disposed near the exit surface of the second lens plate, a dichroic prism array disposed near the exit surface of the polarized beam splitter array,
A half-wave phase plate disposed on a predetermined exit surface of the exit surfaces of the polarization beam splitters constituting the polarization beam splitter array array, and a plurality of dichroic prisms constituting the dichroic prism array, A light source device, wherein a dichroic film that separates the first color light and the second and third color lights is disposed.

According to a twelfth aspect of the present invention, in the light source device according to the ninth, tenth or eleventh aspect, the first color is G light, and the second and third colors are R and B. The light source device is light.

According to a thirteenth aspect of the present invention, there is provided a light source device according to the ninth, tenth, or eleventh aspect, and a color separation optical system for separating light from the light source device into R light, G light, and B light. A light valve for R light, G light, and B light, into which the R light, G light, and B light are respectively incident, and a color that combines emission light from the R light, G light, and B light light valves. A projection display apparatus comprising: a combining optical system; and a projection optical system for projecting light combined by the color combining optical system.

According to a fourteenth aspect of the present invention, in the projection display device of the thirteenth aspect, the first color light is G (green) light,
The projection display device is characterized in that the second and third color lights are R (red) light and B (blue) light.

According to a fifteenth aspect of the present invention, in the projection type display device according to the thirteenth aspect, the color synthesizing optical system is a cross dichroic prism, and includes an R light reflecting dichroic film and a B light reflecting dichroic film. A projection type display device characterized by being arranged in an X-shape.

[0025]

FIG. 1 is a block diagram of a projection display according to a first embodiment of the present invention. The light source light flux emitted from the light source 1 composed of a lamp and a concave mirror is a substantially parallel light flux, and first, the first lens plate 2 and the second lens plate 4
And a so-called fly-eye integrator. In the present embodiment, a configuration in which the bending mirror 3 is disposed between the first lens plate 2 and the second lens plate 4 is employed. The first lens plate 2 has the same outer shape, and has a configuration in which lenses 2a having proportional shapes of liquid crystal light valves 17R, 17G, and 17B, which will be described later, are arranged in a plane. It has a configuration in which lenses 4a corresponding to the respective focal positions of the lenses 2a of the lens plate 2 are arranged in a plane. For this reason, the light source luminous flux incident on the first lens plate 2 is divided into the number of the lenses 2a by an opening formed by the outer shape of the lens 2a of the first lens plate 2, and the light incident on each lens 2a corresponds. The light is condensed on the lens 4a of the second lens plate 4 to form a bright spot.

In the vicinity of the exit surface of the second lens plate 4, a columnar polarizing beam splitter having a square cross section is arranged in parallel with its polarization separating portions, and the side surfaces are bonded together to be integrated. A polarization beam splitter array 5 in which a half-wave phase plate 6 is disposed is provided on the exit surface of the polarization beam splitter. The length of one side of the cross-sectional shape of the polarizing beam splitter is approximately の of the width of the lens 4 a of the second lens plate 4, and corresponds to the boundary of the lens 4 a of the second lens plate 4. And a configuration in which a polarizing beam splitter is arranged at a position corresponding to the center of the lens 4a. The half-wave phase plate 6 is arranged only on the exit surface of the polarization beam splitter arranged at a position corresponding to the boundary of the lens 4a.

The light emitted from the bright spot formed on the lens 4 a of the second lens plate 4 is transmitted to the polarizing beam splitter array 5.
Out of the lens 4a only enters the polarization beam splitter disposed at a position corresponding to the center of the lens 4a. Then, the light is reflected by the polarization splitter of the polarization beam splitter, and undergoes polarization separation into S-polarized light that enters an adjacent polarization beam splitter and P-polarized light that is transmitted as it is. The P-polarized light exits the exit surface as it is, and the S-polarized light enters the adjacent polarization beam splitter, is reflected by the polarization separation unit, and is emitted from the adjacent polarization beam splitter. Since the half-wave phase plate 6 is disposed on the exit surface of the adjacent polarization beam splitter, the emitted light is converted into P-polarized light. As described above, all light sources are converted into P-polarized light.

The P-polarized white light converted as described above is incident on a dichroic mirror 7 having B and R light reflection characteristics disposed on the optical axis, and transmits a G light component that travels through the dichroic mirror 7 and a light component. It is color-separated into R and B light traveling with the axis changed at right angles. The B and R lights travel by changing the optical axis by the bending mirror 8 and enter the polarization beam splitter 11 as P-polarized light. The direction of the G light is changed by the folding mirror 9 and is converted into S-polarized light by the half-wavelength phase plate 10 arranged on the light incident surface of the polarizing beam splitter 11.
The light enters from the incident surface of the polarization beam splitter 11.

B, which has entered the polarizing beam splitter 11,
Since the R light is P-polarized light, it passes through the polarization splitting portion as it is and is emitted from the emission surface. On the other hand, since the G light is S-polarized light, it is reflected by the polarization splitting unit and is emitted from the same exit surface as the G light.

As described above, the white random polarized light is converted to white P-polarized light, and the P-polarized light is further converted to dichroic light by the light source for emitting white random polarized light, the polarization converter including the fly-eye integrator, the polarization beam splitter array, and the like. The G light of the R, G, and B light is converted into S-polarized light by a predetermined light conversion device including a mirror 7 and a polarizing beam splitter 11 having a half-wavelength phase plate 10 disposed on a predetermined incident surface. , B light and P-polarized light. The above configuration forms a special light source having a function of emitting light having different polarization directions of a predetermined color light (G light) component and other color light (R, G light) components in the same direction.

In this embodiment, the color combining of the S-polarized G light and the P-polarized B and R lights is performed by using the polarizing beam splitter 11, but in addition, a G light reflecting dichroic film may be used. The color synthesis may be achieved by using a dichroic prism having the same.

As described above, the light source device is configured so that G light is S-polarized light and R and B lights are P-polarized light, as described later. For R and B light, P-polarized light, S-polarized light,
This is because it is desirable to use S-polarized light and P-polarized light for the G light. However, depending on the function of the liquid crystal light valve, the incident polarized light and the emitted modulated light may be the same. Since this is determined by the type of liquid crystal which is the modulation layer to be used, in this case, in order to apply to this embodiment,
G light must be incident and emitted as P polarized light and R and B light as S polarized light. To do this, the half-wave phase plate 6 arranged on the exit surface of the polarization beam splitter array 5 constituting the polarization conversion device is arranged at a position corresponding to the center of the lens 4a of the second lens plate 4. And the dichroic mirror 7 is formed so as to have the property of reflecting G light by arranging the light emitted from the polarization conversion device as S-polarized light. A light source having P-polarized light for G light and S-polarized light for R and B lights can be formed by arranging the half-wave phase plate 10 on the G light incident surface 11.

Returning to FIG. 1, the light emitted from the special light source device enters a cross dichroic mirror 12 constituting a color separation optical system. The cross dichroic mirror 12 is a dichroic mirror 12 having R light reflection characteristics.
Dichroic mirror 12 having R and B light reflection characteristics
B and X are arranged on the optical axis in an X-shape. The S-polarized G light component of the incident light passes through the cross dichroic mirror 12, travels in the same direction as the incident optical axis, and is incident on the G light transmission light valve 17G. On the other hand, the R light of the P-polarized R and B lights is reflected by the dichroic mirror 12R, and the B light is reflected by the dichroic mirror 12B, and travels in directions opposite to each other and perpendicular to the incident optical axis. Each of the light beams travels in a different direction by the bending mirrors 14, 16, 13, and 15, respectively.
R and 17B.

Each color light valve 17R, 17B, 1
7B has a function of emitting, as modulated light, linearly polarized light having a different vibration direction depending on an image signal with respect to the incident polarized light. That is, the emission modulation light of the G light valve 17G is P-polarized light, and that of the R and B light valves is S-polarized light. These are incident on the cross dichroic prism 18 constituting the color combining optical system from different incident surfaces.

The cross dichroic prism 18 has a structure having an R light reflecting dichroic film and a B light reflecting dichroic film arranged inside thereof so as to be perpendicular to each other. The incident S-polarized R light is reflected by the R-light reflecting dichroic film, the S-polarized B light is reflected by the B-light reflecting dichroic film in the same direction, and the P-polarized G light is transmitted through both dichroic films. The R
The light travels in the same direction as the light and the B light, and is emitted from the emission surface as a combined light of the R, G, and B lights.

Here, a description will be given of the fact that a projected image with higher luminance can be synthesized when the G light is P-polarized light and the R and B lights are S-polarized light, with reference to FIG.

FIG. 6A shows the transmittance-wavelength characteristic of the B light reflecting dichroic film of the cross dichroic prism 18, and FIG. 6B qualitatively describes the same characteristic of the R light reflecting dichroic film. The vertical axis indicates transmittance, and the horizontal axis indicates wavelength. Note that the solid line is the characteristic for S-polarized light,
The dashed line indicates the characteristic for P-polarized light. FIG. 6C shows the light amounts (vertical axis) and wavelengths (horizontal axis) of each of the R, G, and B lights separated by the color separation optical system incident on the incident surface of the dichroic prism 18. FIG. 6D shows the light intensity and wavelength of each color light in the combined light combined by the cross dichroic prism 18 when the incident G light is P-polarized light and the R and B lights are S-polarized light in the present embodiment. It shows the relationship. The incident B light according to FIG.
Since the light is reflected by the S-polarized light characteristic of FIG. The incident R light shown in FIG. 6C is also reflected by the S-polarized light characteristic shown in FIG. The G light according to FIG.
(A) and according to the P-polarization characteristic of FIG.
In FIG. 6A, the P-polarized light is shifted to the shorter wavelength side than the S-polarized light, and in FIG. 6B, the P-polarized light is shifted to the longer wavelength side. It can be seen that light passes through both films without loss.

On the other hand, FIG. 6E shows the relationship between each color light and the wavelength in the combined light when the incident light R, G, and B light shown in FIG. 6C are all S-polarized light. FIG.
In FIG. 6A and FIG. 6B, it can be understood that the G light in the transmitted light undergoes a reflection effect at the wavelengths on both sides of the incident light, and the transmitted light is reduced.

FIG. 6F similarly shows a case where the incident light R, G, and B light shown in FIG. 6C are all P-polarized light. No, but B
A part of the long wavelength part of the light and a part of the short wavelength part of the R light are not reflected but transmitted and cut, and are not emitted as combined light.

As described above, when the cross dichroic prism 18 is used as the synthesizing optical system, S-polarized light is input as R and B light, and G light that is transmitted through the prism 18 to be synthesized light is input as P-polarized light. In this case, it is possible to obtain a synthesized light having the largest light amount.

The combined light emitted from the cross dichroic prism 18 enters a projection lens 19, and a high-brightness projected image can be projected on a screen (not shown).

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

In FIG. 2, a light source light beam emitted from a light source 1 comprising a lamp and a concave mirror is a substantially parallel light beam, and firstly, a so-called fly-eye integrator comprising a first lens plate 2 and a second lens plate 4. Incident. The first lens plate 2 has the same outer shape, and has a configuration in which a lens 2a having a proportional shape of a liquid crystal light valve illumination unit described later is arranged in a plane, and the second lens plate 4 is the same as the first lens plate 2. It has a configuration in which lenses 4a corresponding to respective focal positions of the lens 2a are arranged in a plane. For this,
The light source luminous flux incident on the first lens plate 2 is
The number of the lenses 2a is divided by the apertures formed by the outer shape of the lens 2a, and the light incident on each lens 2a is condensed on the corresponding lens 4a of the second lens plate 4 to form a bright spot.

A dichroic prism array 60 and a polarizing beam splitter array 50 are arranged near the exit surface of the second lens plate 4. The dichroic prism array 60 has a columnar dichroic prism 61 having a square cross section, a dichroic film portion 61G having the G light reflection characteristic arranged in parallel with each other, and a side surface of the prism 61 bonded and integrated. is there. The polarization beam splitter array 50 is obtained by integrating a polarization beam splitter 51 having the same cross-sectional shape as that of the dichroic prism array 60 by arranging polarization separation units 51p in parallel with each other and bonding the side surfaces of the polarization beam splitter 51 to each other. Then, the polarization beam splitter array 50
1 / on the exit surface of the particular polarizing beam splitter
The two-wavelength phase plate 6 is arranged. The composite prism device configured as described above is arranged.

FIG. 3 is an enlarged view of the composite prism apparatus. The cross-sectional shapes of the dichroic prism 61 forming the dichroic prism array 60 and the polarizing beam splitter 51 forming the polarizing beam splitter array 50 are as described above. And the length of one side thereof is approximately の of the width of the lens 4 a of the second lens plate 4. Then, the dichroic prism 61 and the polarization beam splitter 51 are arranged at a position corresponding to the boundary of the lens 4a of the second lens plate 4 and a position corresponding to the center of the lens 4a. The half-wave phase plate 6 is arranged only on the exit surface of the polarizing beam splitter 51 arranged at a position corresponding to the boundary of the lens 4a.

The light emitted from the luminescent spot formed at the center of the lens 4 a of the second lens plate 4 firstly enters the dichroic prism 61 of the dichroic prism array 60.
And only enters the polarizing beam splitter disposed at a position corresponding to the center of the lens 4a (in FIG. 3, only the center lens 4a is described, but actually the light emitted from the bright spots on all the lenses 4a). Is similarly applied). The light incident on the dichroic prism 61 is reflected by the G light reflecting dichroic film 61G and is incident on the adjacent dichroic prism 61 with the G light (indicated by a one-dot chain line), and R (dashed line) traveling through the film as it is , B light (solid line).

The G light is reflected by the G light reflecting dichroic film 61G of the adjacent dichroic prism.
The polarization beam splitter 51 enters the polarization beam splitter 51 and undergoes polarization separation into S polarization of G light reflected by the polarization separation of the polarization beam splitter and incident on an adjacent polarization beam splitter, and P polarization of G light transmitted and transmitted as it is. The S-polarized light of the G light that has entered the adjacent polarization beam splitter 51 is reflected by the polarization separation unit, and the polarization beam splitter emits the S-polarized light as it is.

The P-polarized light of the G light transmitted through the polarization splitting portion of the polarization beam splitter is emitted, but 1 /
Since the two-wavelength phase plate 6 is disposed, the light is converted into S-polarized light and emitted. As described above, the G light component is emitted as S-polarized light from the compound prism device in the optical axis direction.

On the other hand, the R and B lights of the light emitted from the luminescent spot to the lens 4a pass through the dichroic film 61G of the dichroic prism 61, and enter the polarization beam splitter 5b.
1 and is polarized and separated into S-polarized light and transmitted P-polarized light that are reflected by the polarization splitter and are incident on the adjacent polarization beam splitter. R incident on the adjacent polarization beam splitter,
The S-polarized light of the B light is reflected by the polarization splitter and exits the polarization beam splitter, but is converted into P-polarized light by the half-wave phase plate 6 disposed on the exit surface. The P-polarized light of the R and B lights transmitted through the polarizing beam splitter is emitted as it is. In this way, the R and G lights become P-polarized light and exit the composite prism device in the direction of the optical axis.

The light source of white random polarized light emitted from the light source as described above is converted into a P-polarized light and a G-light by the light source device formed by the so-called fly-eye integrator and the above-described composite prism device. The component is S
The polarized light can be emitted in the same optical axis direction.

As described above, the light source device is configured so that the G light is S-polarized light and the R and B lights are P-polarized light, as will be described later. For R and B light, P-polarized light, S-polarized light,
This is because it is desirable to use S-polarized light and P-polarized light for the G light. However, depending on the function of the liquid crystal light valve, the incident polarized light and the emitted modulated light may be the same. Since this is determined by the type of liquid crystal which is the modulation layer to be used, in this case, in order to apply to this embodiment,
G light must be incident and emitted as P polarized light and R and B light as S polarized light. To achieve this, the half-wavelength phase plate disposed on the exit surface of the polarization beam splitter array constituting the composite prism device is placed on the polarization beam disposed at a position corresponding to the center of the lens 4a of the second lens plate 4. By arranging on the surface of the splitter, G light of the light emitted from the polarization conversion device can be P-polarized light, and B and R lights can be S-polarized light.

Returning to FIG. 2, the light emitted from the compound prism device enters a cross dichroic mirror 12 constituting a color separation optical system. The cross dichroic mirror 12 has a configuration in which a dichroic mirror 12R having R light reflection characteristics and a dichroic mirror 12B having B light reflection characteristics are arranged in an X-shape on the optical axis with each other.
The S-polarized G light component of the incident light passes through the dichroic mirror 12, travels in the same direction as the incident optical axis, and enters the G light transmission light valve 17G. On the other hand, the R light of the P-polarized R and B lights is reflected by the dichroic mirror 12R, and the B light is reflected by the dichroic mirror 12B, and travels in directions opposite to each other and perpendicular to the incident optical axis. The light travels in different directions by the folding mirrors 14, 16, 13, and 15, respectively, and the light valves 17R, 17R,
7B.

Each color light valve 17R, 17G, 1
7B has a function of emitting, as modulated light, linearly polarized light having a different vibration direction depending on an image signal with respect to incident polarized light. That is, the emission modulation light of the G light light valve 17G is P-polarized light, and that of the R and B light light valves is S polarization.
It becomes polarized light. These are incident on the cross dichroic prism 18 constituting the color combining optical system from different incident surfaces.

The cross dichroic prism 18 has a structure having an R light reflecting dichroic film and a B light reflecting dichroic film arranged inside so as to be perpendicular to each other. The incident S polarized R light is reflected by the R light reflecting dichroic film. , S-polarized B light is reflected in the same direction by a B-light reflecting dichroic film, and P-polarized G light passes through both dichroic films and travels in the same direction as the R light and B light. The light is emitted from the emission surface as a combined light of the G and B lights.

Here, the fact that the G light is P-polarized light and the R and B lights are S-polarized light can synthesize a higher-luminance projected image as in the description of FIG. 6 in the first embodiment.

The combined light emitted from the cross dichroic prism 18 is incident on a projection lens 19, and a high-brightness projected image can be projected on a screen (not shown).

As described above, according to the light source device used in the first and second embodiments, the light source light is linearly polarized light, and only a predetermined color light is converted into a linear light having a vibration direction different from that of the other color light. It has a function of emitting polarized light. For this reason,
Using the light source light, the light is separated into each color light by a color separation optical system, the modulated light is incident on a liquid crystal light valve, and the modulated light is synthesized and projected. A projection device capable of projecting a low-brightness projected image can be provided.

In the composite prism device of the light source device used in the second embodiment, the dichroic prism 61 has a configuration in which the G light reflecting dichroic film 61 is disposed inside as shown in FIG. The dichroic film may be a G light transmitting film. In this case, the G light is transmitted through the dichroic prism, and the R and B lights are reflected.
In order to obtain light, the arrangement position of the half-wavelength phase plate may be arranged on the exit surface of the polarization beam splitter not arranged in FIG.

FIG. 4 is a configuration diagram of a projection type display device according to a third embodiment of the present invention. The only difference from the second embodiment is the configuration of the compound prism device into which the light emitted from the second lens plate 4 is incident, and other light sources, fly-eye integrators, and color separation optics. Since the system, the light valve, the synthetic optical system and the projection lens are equivalent, the same reference numerals are given, and the description of the functions and the like is omitted here.

FIG. 5 is an enlarged configuration diagram of the compound prism device used in this embodiment. Compared to the second embodiment, a polarizing beam splitter array 50 ′ including a plurality of polarizing beam splitters 52 disposed close to the second lens plate 4 is disposed close to or bonded to the exit surface. What is performed is a plurality of G light reflecting dichroic prisms 62.
Is a dichroic prism array 60 '. Furthermore, the polarization beam splitter 52p of the polarization beam splitter 62 and the G light reflecting dichroic film 62G of the dichroic prism 62 are not arranged in parallel but arranged at right angles to each other. Note that this may be parallel as described later. Further, the position of the half-wave phase plate 6 disposed on the exit surface of the dichroic prism 62 is the exit surface although it is disposed at a position corresponding to the boundary of the lens 4a.

As described in the second embodiment, the light emitted from the luminescent spot formed at the center of the second lens plate 4 is a polarized beam splitter disposed near the exit surface of the second lens plate 4. S-polarized light that enters the adjacent polarization beam splitter 52 and is reflected by the polarization splitting unit.
The light is polarized and separated into polarized light and P-polarized light that passes through the polarization separation unit.

The subsequent G light components are indicated by dashed lines in FIG. 5, R light is indicated by broken lines, and B light is indicated by solid lines in the same manner as in the second embodiment.

The S-polarized light is supplied to the polarization beam splitter 52.
And is separated into S-polarized G light reflected by the G light reflecting dichroic film 62G in the cross dichroic prism 62 and S-polarized R and B light transmitted through the film. The S-polarized R and B lights are emitted as they are, but are converted into P-polarized R and B lights by the １ ／ wavelength phase plate 6 on the emission surface. On the other hand, in the S-polarized G light, the light is reflected by the dichroic film 62G disposed orthogonal to the polarization splitting portion, travels with the optical axis changed in the opposite direction, enters the adjacent dichroic prism, and is incident on the G light dichroic film. And is emitted in the direction of the optical axis.
Since the two-wavelength phase plate 6 is disposed, the light is converted into P-polarized light and emitted.

The G light of the P-polarized light transmitted through the polarization splitter of the polarization beam splitter 52 enters the dichroic prism 62, reflects the dichroic film 62G, enters the adjacent dichroic prism, is reflected by the dichroic film, S at the half-wave plate 6 arranged on the emission surface
The light is converted into polarized light and emitted. On the other hand, R of P-polarized light transmitted through the dichroic film of the dichroic prism 62,
The B light is emitted as it is as P-polarized light.

As described above, G light is S-polarized light,
For the R and B lights, the composite prism device can be emitted in the optical axis direction with P-polarized light. Also, the polarization splitting section 52p of the polarization beam splitter 52 and the dichroic film 62G of the dichroic quick prism 62 are not parallel but orthogonal to each other, so that S-polarized light separated by the polarization beam splitter and adjacent polarization The light reflected by the polarization splitting unit of the beam splitter, and
A configuration in which the traveling direction of the G light that enters the dichroic prism 62 and is reflected by the dichroic film can be returned. For this reason, the number of polarization beam splitters constituting the polarization beam splitter array and the number of dichroic prisms can be reduced as compared with the case where the polarization splitting unit and the dichroic film are made parallel as in the second embodiment. .

In the third embodiment, the half-wave phase plate 6 is arranged on a predetermined exit surface of the dichroic prism. This consists of a polarizing beam splitter array 50 'and a dichroic prism array 60'.
This is because the configuration has a space between the two members, and the 波長 wavelength phase plate 6 is arranged on a predetermined polarization beam splitter emission surface of the polarization beam splitter array. It is also possible to use

Returning to FIG. 4, the light emitted from the above-described composite prism device has, as in the second embodiment, R and B lights having P polarization, G light having S polarization, and a color separation optical system. Are separated into P-polarized R light, S-polarized G light, and P-polarized B light, respectively, and the light valves 17R, 17G, and 17B for the respective color lights.
, Respectively, and emits S-polarized R light, P-polarized G light, and S-polarized B light as modulated light, is color-combined by a cross dichroic prism 18, and is projected on a screen by a projection lens 19.

As described in the second embodiment, in the cross dichroic prism 18, R and B are reflected once by the dichroic films 18R and 18B, respectively, and G light is transmitted through both films and coaxially. In this embodiment, the R and B lights are incident as S-polarized light and the G light is incident as P-polarized light as in the present embodiment. Is possible.

Further, as described in the second embodiment, the polarization characteristics of the incident light and the modulated light of the light valve to be used determine which polarized light should be incident on the light valve as the incident polarized light. Therefore, based on this, the position where the half-wavelength phase plate of the composite prism device is disposed may be determined to adjust the polarization of the R, B, and G lights.

[0070]

As described above, according to the light source device of the present invention, the light source light is linearly polarized light, and only the predetermined color light is emitted as the linearly polarized light having a vibration direction different from that of the other color lights. Has the ability to do. For this reason, using the light source light, the color separation optical system separates the light into each color light,
In a projection type display device in which modulated light is incident on a light valve, and the modulated light is synthesized and projected, a high-brightness projected image with little light loss can be projected.

[Brief description of the drawings]

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

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

FIG. 3 is an enlarged explanatory view of a composite prism device of a projection display device according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram of a projection display device according to a third embodiment of the present invention.

FIG. 5 is an enlarged explanatory view of a composite prism device of a projection display device according to a third embodiment of the present invention.

FIG. 6 is a diagram qualitatively showing the spectral characteristics of the combining optical system and the light amount of each color.

FIG. 7 is a configuration diagram of a conventional projection display device.

[Explanation of symbols]

1: light source, 2: first lens plate, 3: folding mirror,
4: second lens plate, 5, 50, 50 ': polarizing beam splitter array, 6: 1/2 wavelength phase plate, 7: dichroic mirror, 8, 9: bending mirror, 10: 1/2 wavelength phase plate, 11 : Polarization beam splitter, 12: cross dichroic mirror, 13, 14, 15, 16: folding mirror, 17R, 17G, 17B: liquid crystal light valve, 18: cross dichroic prism, 19: projection lens, 60, 60 ': dichroic prism Array, 51, 52: polarizing beam splitter, 61, 62:
Dichroic prism.

Continued on front page F term (reference) 2H088 EA14 EA15 HA13 HA16 HA20 HA25 MA02 MA06 2H091 FA05X FA05Z FA10X FA10Z FA11X FA11Z FA26X FA29Z FA41Z FD01 LA17 MA07 5C060 BC01 EA01 GA01 HC00 HC01 HC09 HC19 JB06

Claims (15)

[Claims] 1. A light source, a plurality of lenses are arranged in a plane, a first lens plate for receiving light from the light source, and a plurality of lenses are arranged in a plane, and the light is emitted from the first lens plate. A second lens plate on which light is incident, a polarizing beam splitter array disposed near an exit surface of the second lens plate, and a first half-wavelength phase disposed at a specific position on the exit surface of the polarization beam splitter array A plate, the polarizing beam splitter array and the first 1 /
A color separation optical system that separates light emitted from the two-wavelength phase plate into first color light and second and third color light; and converts one of the first color light and the second and third color light vibration directions. A second half-wave phase plate, and a synthesizing optical system for synthesizing the first color light or the second or third color light whose vibration direction has been converted and the color light which has not been converted. A light source device comprising: a light source; 2. The light source device according to claim 1, wherein the first color light is G (green) light, and the second and third color lights are B (blue).
A light source device, which is light or R (red) light. 3. The light source device according to claim 1, wherein said color separation optical system comprises a dichroic mirror. 4. The light source device according to claim 1, wherein the polarization combining optical system is a polarization beam splitter. 5. The light source device according to claim 1, a color separation optical system that separates light from the light source device into R light, G light, and B light, and the R light, G light, and B light, respectively. A light valve for R light, a light valve for G light, and a light valve for B light; a light combining optical system for combining light emitted from light valves for R light, G light, and B light; A projection display device comprising: a projection optical system for projecting light. 6. The projection type display device according to claim 5, wherein said color combining optical system is a cross dichroic prism, and an X-type R-light reflecting dichroic film and a B-light reflecting dichroic film inside. Wherein the first color by the light source device is G light, and the second and third color lights are R and G light. 7. A light source device for emitting linearly polarized light, wherein the emitted light has a first color component, a second color component, and a third color component, of which a first color component and another second color component. The light source device, wherein the polarization directions of the components of the third color light have different directions. 8. The light source device according to claim 7, wherein the first color light is G (green) light, and the second and third color lights are B (blue).
A light source device, which is light or R (red) light. 9. A light source, a plurality of lenses arranged in a plane, a first lens plate for receiving light from the light source, and a plurality of lenses arranged in a plane, and the first lens plate emits light. A second lens plate that receives light, a dichroic prism array disposed near an exit surface of the second lens plate, a polarizing beam splitter array disposed near an exit surface of the dichroic prism array, and a polarizing beam splitter array. A half-wave phase plate disposed at a specific position on the exit surface, wherein a plurality of dichroic prisms constituting the dichroic prism array include a first color light, a second color light, and a third color light.
A light source device comprising a dichroic film for separating colors. 10. A light source, a plurality of lenses arranged in a plane, a first lens plate for receiving light from the light source, and a plurality of lenses arranged in a plane. A second lens plate that receives light, a polarizing beam splitter array disposed near an exit surface of the second lens plate, a dichroic prism array disposed near the exit surface of the polarizing beam splitter array, and a dichroic Loic prism array A half-wave phase plate disposed on a predetermined exit surface of the exit surface, wherein a plurality of dichroic prisms constituting the dichroic prism array include a first color light, a second color light, and a third color light.
A light source device comprising a dichroic film for separating color light from color light. 11. A light source, a plurality of lenses arranged in a plane, a first lens plate for receiving light from the light source, and a plurality of lenses arranged in a plane. A second lens plate for receiving light, a polarizing beam splitter array arranged near an exit surface of the second lens plate, a dichroic prism array arranged near an exit surface of the polarizing beam splitter array, and the polarizing beam splitter array And a half-wave phase plate disposed on a predetermined exit surface of the exit surfaces of the polarization beam splitter. The first dichroic prism constituting the dichroic prism array includes a first color light, 2nd, 3rd
A light source device comprising a dichroic film for separating color light from color light. 12. The light source device according to claim 9, wherein the first color is G light, and the second and third colors are R and B lights. Characteristic light source device. 13. A light source device according to claim 9, 10 or 11, a color separation optical system for separating light from the light source device into R light, G light, and B light; A light valve for R light, G light, and B light that respectively receives G light and B light; and a color combining optical system that combines light emitted from the light valves for R light, G light, and B light; A projection display device, comprising: a projection optical system for projecting light combined by the color combining optical system. 14. The projection type display device according to claim 13, wherein the first color light is G (green) light, and the second and third color lights are R (red).
Light, B (blue) light. 15. The projection type display device according to claim 13, wherein the color combining optical system is a cross dichroic prism, and an R light reflecting dichroic film and a B light reflecting dichroic film are arranged in an X shape inside. A projection display device characterized by the following.