JP3428004B2 - Color separation light emitting device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color separation / light emission device, and more particularly to an improvement of a light emission part and a color separation part of a light source for liquid crystal, in which light utilization efficiency is improved and size reduction is taken into consideration.

[0002]

2. Description of the Related Art Conventionally, twisted nematic (Twist)
A liquid crystal display device 1 using liquid crystal having a d, Nematic) structure includes a light emitting portion 2 and a display portion 4, as shown in FIG. The light emitting unit 2 includes a polarizing plate 3A, and the display unit 4 includes a liquid crystal plate 5 and a polarizing plate 3B, which are arranged in parallel so as to be orthogonal to the optical axis.

A pair of polarizing plates 3 are provided on both sides of the liquid crystal plate 5.
A and 3B are arranged. This pair of polarizing plates 3
It is assumed that A and 3B are arranged in parallel Nicols.

In the liquid crystal display device 1 thus constructed, the parallel light L1 incident on the polarizing plate 3A is linearly polarized L2.
And is incident on the liquid crystal plate 5.

When no voltage is applied to both sides of the liquid crystal plate 5, the linearly polarized wave L2 has a plane of polarization of 90 due to the liquid crystal plate 5.
It is rotated once and tries to enter the polarizing plate 3B. But,
Since the polarization direction of the polarizing plate 3B is orthogonal to that of the polarizing plate 3A, the rotated linearly polarized light L2 is absorbed by the polarizing plate 3B. For this reason, when the display state of the liquid crystal plate 5 is viewed from the direction of the arrow G, it becomes a dark state.

On the other hand, when a voltage higher than the specified voltage is applied to both sides of the liquid crystal plate 5, the linearly polarized wave L2 is maintained in that state and passes through the polarizing plate 3B. When the display state of the plate 5 is seen, it becomes a bright state.

By the way, the light emitting portion 2 of the liquid crystal display device 1
In Fig. 3, a structure for emitting linearly polarized light L2 by a polarizing plate 3A for supplying linearly polarized light L2 to the liquid crystal plate 5 and a light source (not shown) for supplying parallel light L1 to the polarizing plate 3A Has become.

However, the light emitting portion 2 having such a structure
However, there were the following problems. (1) Of the parallel light L1, the light excluding the linearly polarized light L2 is absorbed by the polarizing plate 3A, so that the utilization efficiency of the parallel light L1 is low.

(2) The polarizing plate 3A that has absorbed the light becomes hot and burns, especially when the amount of absorbed light is large, and the polarizing plate 3A cannot perform the polarizing action.

(3) In order to avoid this problem of scorching, a separate fan for heat radiation must be attached to the polarizing plate 3A, and the light emitting section 2 itself becomes large.

(4) When a fan is attached, dust entrained by the flow of air adheres to the liquid crystal plate 5, and noise is generated by the motor for rotating the fan.

(5) When the liquid crystal plate 5 is dusty, when the liquid crystal plate 5 is used in a liquid crystal projector or the like, image defects due to the dust occur on the image display surface. I will end up. In particular, when it is used in a color liquid crystal projector or the like, it becomes so-called color stain.

As described above, there is a light emitting section which solves the problems described in the above (1) to (5), for example, a light emitting device proposed by the same applicant (Japanese Patent Laid-Open No. 5-11217).
The present invention improves the light emitting portion (light source and optical system) of a liquid crystal display device and contributes to downsizing and performance improvement of the liquid crystal display device.

In a color liquid crystal display device typified by a color liquid crystal projector that requires high resolution, three liquid crystal plates are used, and various efforts are made to reduce the size and improve the performance. , A liquid crystal projector proposed by the same applicant (Japanese Patent Laid-Open No. 4-21839).
Issue gazette).

Hereinafter, in the prior art, the above (1)-
Two specific examples of the color separation light emitting device which solves the problem raised in (5) will be described with reference to FIGS. 4 and 5.

4 and 5, the direction indicated by the arrow B is the B direction, the direction indicated by the arrow C orthogonal to the B direction is the C direction, and the direction indicated by the arrow D opposite to the B direction is the D direction. I will call it. Further, the linearly polarized wave composed of the separated P wave and S wave will be described with a configuration in which the S wave is converted to the P wave.

As shown in FIG. 4, the color separation light emitting device 1A of the first example according to the prior art emits light for improving the efficiency of light when the light emitted from the light source 7 is linearly polarized. Light part 2
A and the light emitted from the light source are separated into three color lights of R, G and B, and the respective lights are made incident on the liquid crystal plates 21, 23 and 25 for red, green and blue. Color separation unit 13
And R, G, B formed on each liquid crystal plate 21, 23, 25
And a color synthesizing unit 19 that synthesizes the screens of FIG.

The light emitting portion 2A converts the light-reflecting inner surface into a spherical shape, the light source 7 arranged at the center of the spherical surface formed on the reflector 6, and the divergent light L10 into parallel light L11. The collimator lens 8, the cold filter 9 that allows passage of light other than heat rays, the quarter-wave plate (λ / 4) 10 that converts circularly polarized light into circularly polarized light, and the parallel light L11 that is linearly polarized P wave and S wave. It is composed of a polarization beam splitter (PBS) 11 that separates the light into waves and a reflection mirror 12 that reflects the light of the S wave by 180 degrees.

The reflector 6, which constitutes the light emitting section 2A,
Collimator lens 8, cold filter 9, 1/4
The wavelength plate 10 and the polarization beam splitter 11 are arranged in parallel with each other in a state of being orthogonal to the optical axes E1 and E2 of the light source 7.

The color separation section 13 separates only red light into C
Red reflective dichroic mirror (DM
(R)) 14, a red mirror 15 for changing the direction of red light in the D direction, a blue reflection dichroic mirror 16 for separating only blue light and reflecting in the C direction, and changing the direction of green light in the C direction. It is composed of a first mirror 17 for green and a second mirror 18 for green which turns in the B direction.

Red reflective dichroic mirror 14, blue reflective dichroic mirror 16 and green first mirror 1
7 are on the optical axes E1 and E2 of the light source 7, respectively, and are arranged at an appropriate interval in a state of being inclined by 45 degrees to the right for turning the light in the C direction.

The width W1 of the light beam received by the mirrors 14, 16 and 17 is sufficiently wider than the light beam width W2 of the polarization beam splitter 11 which emits the P wave.

The red mirror 15 has an optical axis E1 of the light source 7,
Arranged on the parallel lines F1 and F2, which are appropriately spaced from E2, and at a position orthogonal to the red reflection dichroic mirror 14 for red, in a state of being inclined 45 degrees upward to the right so as to turn the light beam in the D direction. Has been done.

The second green mirror 18 has parallel lines F1 and F2 which are maintained at appropriate intervals from the optical axes E1 and E2 of the light source 7.
It is arranged at a position which is above and orthogonal to the first green mirror 17, and is inclined 45 degrees downward to the right so as to change the direction of the light beam in the B direction.

The color synthesizing section 19 includes a red condenser lens 20 for converging red light rays, a red liquid crystal plate (LCD (R)) 21 for forming a red image, and a blue condenser lens 22 for converging blue light rays. , A blue liquid crystal plate (LCD (B)) 23 for forming a blue image, a green condenser lens 24 for converging a green light beam, a green liquid crystal plate (LCD (G)) 25 for forming a green image, and 3 It is composed of a dichroic prism 26 for synthesizing colors and a projection lens (PL) 29 for enlarging and projecting an image. Of these, the dichroic prism 26 includes a red reflective film (DP (R)) 27 and a green reflective film (DP (G)) 2
8 and.

The color separation part light-emitting device 1 configured as described above.
In the first example of A, the light emitted from the light source 7 is emitted as divergent light L10 directly or by being reflected by the spherical surface formed on the reflector 6.

The divergent light L10 becomes a parallel light L11 by the collimator lens 8. The collimated light L11 is incident on the cold filter 9, and the heat ray of the collimated light L11 that is incident is indicated by the arrow B.
Direction, and the other parallel light L11 passes through.

The parallel light L11 that has passed through is a quarter wave plate 1
It passes through 0 as it is and enters the polarization beam splitter 11.

The polarization beam splitter 11 splits the incident parallel light L11 into P waves and S waves which are linearly polarized waves. In this case, the P wave passes through the polarization beam splitter 11,
The wave reflects in the C direction.

The S wave reflected in the C direction is reflected by the reflecting mirror 1.
It is reflected in the direction of 180 degrees by 2 and enters the polarization beam splitter 11 again. Polarization beam splitter 11
Reflects the S-wave that is incident again in the direction of arrow B.

The S wave, which is the linearly polarized wave reflected in this way, is incident on the quarter-wave plate 10 to be circularly polarized wave and
Is emitted in the direction.

The circularly polarized wave emitted in the B direction passes through the cold filter 9, is focused on the light source 7 by the collimator lens 8 and is reflected by the reflector 6 in the D direction, and at the same time, becomes a reverse rotating circularly polarized wave. After being reflected, the collimator lens 8 collimates the collimated light L11 and passes through the cold filter 9. The reverse-rotated circularly polarized wave that has passed through the cold filter 9 passes through the quarter-wave plate 10,
It is converted into a P wave which is a linearly polarized wave rotated by a degree. This converted P-wave passes through the polarization beam splitter 11 and D
Emit in the direction.

In this way, the P wave emitted from the light source 7 and first passing through the polarization beam splitter 11 and the P wave obtained by converting the S wave reflected by the polarization beam splitter 11 are added. That is, since all the direct polarized light from the light source 7 can be taken in without being discarded, the amount of P-wave light emitted from the polarization beam splitter 11 in the direction of arrow D increases.

Further, the polarizing plate 3A for absorbing the light shown in FIG.
Since the structure has been removed, the utilization efficiency of the parallel light L11 by the divergent light L10 emitted from the light source 7 becomes relatively high.

Therefore, a fan for heat dissipation, which has been conventionally required, is no longer required, and the liquid crystal plates 21 and 2 are arranged in the traveling direction of the P wave.
When 3, 25 are arranged, the liquid crystal plates 21, 23, 2
It is possible to solve the problem that 5 (5 in FIG. 3) has dust.

Further, noise due to the motor for rotating the fan does not occur. Therefore, when this color separation / light emission device 1A is applied to a liquid crystal projector or the like, it has characteristics that there is no image deterioration due to dust and the sound is also quiet.

On the other hand, in the light emitted from the light emitting portion 2A in the D direction, only the red color is separated by the red reflection dichroic mirror 14 and reflected in the C direction, and the direction is changed to the d direction by the red mirror 15, and the condenser is formed. After being focused by the lens 20, the light enters the red liquid crystal plate 21. As a result, a red image is formed by the red liquid crystal plate 21.

Of the colors transmitted through the red reflective dichroic mirror 14, blue light is separated by the blue reflective dichroic mirror 16, focused by the condenser lens 22, and a blue image is formed by the blue liquid crystal plate 23. .

Further, the blue reflection dichroic mirror 14
The green light transmitted through the
After being reflected by the second mirror 18 for green, the second mirror 18 for green changes the direction to the direction A, and after the light is focused by the condenser lens 24, it enters the liquid crystal plate 25 for green to form a green image.

In this way, each liquid crystal plate 21, 23, 25
The red image, the blue image, and the green image formed by are incident on the cross dichroic prism 26.

The incident red image is changed in direction C by the red reflection film 27 of the cross dichroic prism 26, the incident blue image is transmitted through the cross dichroic prism 26, and the incident green image is cross dichroic. The direction is changed to the C direction by the green reflecting film 28 of the prism 26. That is, the cross dichroic prism 26 has a function as a three-color combining device.

The image combined by the cross dichroic prism 26 is enlarged and projected through a projection lens 29 onto a screen (not shown) or the like.

Next, as shown in FIG. 5, the color separation and emission device 1B of the second example according to the prior art improves the efficiency of light when the light emitted from the light source 7 is linearly polarized. And a light emitting portion 2B for separating the light emitted from the light source 7A into light of three colors of R, G, and B, and making the respective lights enter the liquid crystal plates for red, green, and blue. A color separation unit 13A for
It is composed of a color synthesizing section 19 which synthesizes R, G, and B screens formed on each liquid crystal plate to form a color screen.

The light emitting portion 2B has a cold reflector 6A having a spherical inner surface for reflecting light, a light source 7A arranged at the center of a spherical surface formed on the cold reflector 6A, and a divergent light L10 to a parallel light L11. Anamorphic lenses 30 and 31, a cold filter 9A that allows the passage of rays other than heat rays, and a P wave and S that are parallel polarizations of the parallel light L11.
Polarization beam splitter (PBS) 11A for separating into waves
A half-wave plate (λ / 2) 32 for converting an S wave facing the S wave side of the polarization beam splitter 11A in parallel with the optical axes E1 and E2 into a P wave, and the optical axes E1 and E2. It is composed of a reflecting mirror 12A inclined at 45 degrees with respect to.

The cold reflector 6A, the anamorphic lenses 30 and 31, the cold filter 9A, and the polarization beam splitter 11A which constitute the light emitting portion 2B are orthogonal to the optical axes E1 and E2 of the light source 7A. Are arranged in parallel.

Further, the half-wave plate 32 is arranged facing the S-wave emission side of the polarization beam splitter 11A,
45 to the right so that the light rays are reflected to the outside in the D direction.
It has a structure in which a reflecting mirror 12A that is inclined at an angle is arranged.

The color separating section 13A separates only red light and reflects it in the C direction by a red reflection dichroic mirror (D
M (R)) 14A, a red mirror 15A for changing the direction of red light to the D direction, a blue reflection dichroic mirror 16A for separating only blue light and reflecting in the C direction, and a direction of green light in the C direction. It is composed of a first green mirror 17A for changing and a second green mirror 18A for changing its direction in the B direction.

The red reflection dichroic mirror 14A, the blue reflection dichroic mirror 16A, and the green first mirror 17A are on the right side of the light sources 7A parallel to the optical axes E1 and E2, that is, about 1/2 wavelength. It is a position centered on the plate 32, and is arranged at an appropriate interval in a state of being inclined by 45 degrees to the right for turning light in the C direction.

Then, the mirrors 14A, 16A, 17
The width W1 of the light beam received by A is determined by the polarization beam splitter 11
The width is sufficiently wider than the width W2 obtained by adding the light beam width ½ · W2 that emits the P wave of A and the light beam width ½ · W2 that can be reflected by the reflection mirror 12A.

That is, the light emitting section 2B of the second example has a structure in which the S wave of the linearly polarized wave is converted into the P wave by the ½ wavelength plate 31 and is emitted in the D direction, and has been described above. This is different from the structure as in the first example in which the S wave is returned to the light source 7A side and converted into the P wave.

Therefore, the light beam width of the polarization beam splitter 11A on the side from which the P wave is emitted is determined by the mirrors 14A, 16A,
It is necessary to make the width at least half (1/2 · W2) of the light beam width W1 that can be received by 17A and the other half width (1/2 · W2) that can be reflected by the reflection mirror 12A.

Other color separating section 13A and color combining section 19
Since the configuration of and is similar to that of the first example, the same reference numerals are given and the description of the configuration is omitted.

In the color separation and emission device 1B of the second example configured as described above, the light L10 emitted from the light source 7A is emitted directly or as a divergent light L10 by being reflected by the spherical surface formed on the cold reflector 6A. To do. In addition, only the visible light is reflected by the cold reflector 6A to be divergent light L10,
Other light passes through.

The divergent light L10 is the anamorphic lens 3
In the vertical cross section, the parallel light L11 is directly obtained by 0 and 31, and in the horizontal cross section, the parallel light L11 is reduced in width.

The collimated light L11 is supplied to the cold filter 9A.
Incident on. Of the incident parallel light L11, the heat ray is returned in the direction of arrow B, and the other parallel light L11 passes through. The parallel light L11 enters the polarization beam splitter 11A.

The polarization beam splitter 11A splits the incident parallel light L11 into P waves and S waves which are directly polarized waves.
The P wave passes through the polarization beam splitter 11A, and the S wave is C
Reflect in the direction. The reflected S wave is made incident on the half-wave plate 32 to be a P wave, and is reflected by the reflecting mirror 12A to D wave.
The light is changed in direction and emitted from the light emitting portion 2B.

Thus, the P wave emitted from the light source 7A and first passing through the polarization beam splitter 11A and the P wave converted from the S wave reflected by the polarization beam splitter 11A are added. Therefore, the amount of P-wave light emitted from the polarization beam splitter 11A in the D direction increases. That is, similar to the first example described above, the structure is such that all the light rays can be incident on the color separation unit 13A without discarding the direct polarized light from the light source 7A.

Further, the polarizing plate 3 for absorbing the light explained in FIG.
Since there is no A, the utilization efficiency from the divergent light L10 emitted from the light source 7A to the parallel light L11 becomes high.

Therefore, similarly to the first example described above, the fan for heat dissipation, which has been conventionally required, is not required, and when the liquid crystal plate is arranged in the traveling direction of the P wave, the liquid crystal plate is dusted. The problem of being marked can be solved.

Further, noise due to the motor for rotating the fan does not occur. Therefore, when the color separation / light emission device 1B is applied to a liquid crystal projector or the like, it has characteristics that there is no image deterioration due to dust and the sound is quiet.

On the other hand, the light emitted from the light emitting section 2B is incident on the color separating section 13A to be color separated. Then, the color composition unit 19 performs color composition of the light rays of red, blue, and green. Since this is the same as the first example, the description thereof is omitted.

[0062]

However, the color separation light-emitting devices 1A and 1B of the first and second examples of the prior art described above are the light sources 7 and 7A and the liquid crystal plates 21 and 23, respectively.
25 becomes longer and the apparatus itself becomes larger, and since the distance between the light sources 7, 7A and the liquid crystal plates 21, 23, 25 is long, the divergent light L12 from the light emitting units 2A, 2B becomes the color combining unit 19.
There is a problem that the amount of light incident on the liquid crystal plates 21, 23 and 25 is reduced, and the light utilization efficiency cannot be increased.

Therefore, there is a problem to be solved in a color separation light emitting device which has high light utilization efficiency and can be miniaturized.

[0064]

In order to solve the above problems, a color separation light emitting device according to the present invention comprises a light source, a reflector arranged to reflect light emitted from the light source,
Arranged on the opposite side of the light source from the reflector 1
A quarter wave plate and the light source are arranged behind the quarter wave plate to separate the light emitted from the light source into two linearly polarized waves of P wave and S wave, and one of the linearly polarized waves is A polarization splitting unit that emits from one surface and outputs the other linearly polarized wave from the other surface, and is disposed in proximity to one surface of the polarization splitting unit, and is output from one surface of the polarization splitting unit. And a first color selection unit that transmits only a specific primary color light from the linearly polarized light and reflects two primary color lights other than the specific primary color light, and is arranged in proximity to the other surface portion of the polarization separation unit. A second color selecting unit that reflects the specific primary color light from the linearly polarized light emitted from the other surface of the polarization separating unit and transmits two primary color lights other than the specific primary color light; The specific primary color light transmitted through the second color selection means A color separation unit that separates the other two primary color lights into a single primary color light, a specific primary color light that has passed through the first color selection unit, and a single primary color light that has been separated by the color separation unit. An image is formed from each of the three primary color lights, and a color combining unit that combines the formed images is provided.

Further, the specific primary color light transmitted by the first color selection means is red light; the first color selection means and the second color selection means are color separations that are dichroic filters. It is a light emitting device.

[0066]

The color separation light-emitting device according to the present invention having the above-described structure has the following actions.

(1) The light emitted from the light source is split into two linearly polarized waves of P wave and S wave, and a specific primary color light is transmitted to one emission side of the linearly polarized wave to be converted. By disposing the color selecting means and arranging the second color selecting means for transmitting the two primary color lights other than the specific primary color light on the output side of the other linearly polarized wave, one of the color separations is performed at the polarization conversion position. Since it can also serve as a unit, the optical path can be shortened to improve the light utilization efficiency and the device can be downsized.

(2) Since the first color selecting means transmits only the red light, the optical path of the red light can be shortened.

(3) Since the first and second color selecting means are formed by the dichroic filter, it is possible to perform the selection according to the frequency band of the light ray of the specific color.

[0070]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Color separation and light emitting devices according to first and second embodiments of the present invention will be described below with reference to FIGS. The first and second embodiments will be described with reference to the conventional techniques described with reference to FIGS. 4 and 5 above. Further, the linearly polarized light obtained by separating the light from the light source into the P wave and the S wave may be unified into either one of the polarized waves, but the S wave is converted into the P wave as in the prior art. , P
An explanation will be given with a configuration in which waves are unified.

As shown in FIG. 1, the color separation / light emission device 35 of the first embodiment according to the present invention is for increasing the efficiency of light when the light emitted from the light source is linearly polarized. Light emitting part 3
6 and a color separation unit that separates the light emitted from the light source 7 into three color lights of R, G, and B, and makes the respective lights enter the liquid crystal plates for red, green, and blue. , A color synthesizing unit for synthesizing the R, G, and B screens formed on the respective liquid crystal plates into a color screen.

The light emitting section 36 converts the so-called linearly polarized wave into P wave and S wave.
It is composed of a polarized light separating means for separating the light into a wave and a converting means for returning the separated S wave to the light source side. The reflector 37, the light source 39, the collimator lens 40, the cold filter 41, and the quarter-wave plate 42. And the polarization beam splitter 4
3, a blue-green transmission dichroic filter 44, a red transmission dichroic filter 45, and a half-wave plate 4
6 and 6.

The light source 39 is arranged at the focal position of the inner spherical surface 38 formed on the reflector 37, and emits light in all directions.

The collimator lens 40 has a function of converting the divergent light L10 in the D direction into parallel light L11 or converging the parallel light L11 in the B direction to the light source 39.

The cold filter 41 has the function of reflecting the heat rays of the incident light in the direction opposite to the incident direction and passing the rays other than the heat rays as they are.

The quarter-wave plate 42 has a function of converting linearly polarized light in the B direction into circularly polarized light and converting circularly polarized light in the D direction into linearly polarized light.

The polarization beam splitter 43 has a function of separating the parallel light L11 incident in the D direction into P waves and S waves which are linearly polarized waves, passing the P waves, and reflecting the S waves in the C direction. .

Blue-green pass dichroic filter 44
Corresponds to so-called second color selection means, and is arranged in a state of facing the emission side of the polarization beam splitter 43 from which the P wave is emitted, and allows blue light and green light to pass in the D direction, and red light. It has the function of reflecting light in the opposite direction, that is, in the B direction.

The red transmission dichroic filter 45 is
It corresponds to the so-called first color selection means, and is provided in a state of being close to and facing the side of the polarization beam splitter 43 from which the S wave is emitted, and of the S waves reflected in the C direction, only red light is emitted. It has a function of transmitting and reflecting blue light and green light in opposite directions.

The half-wave plate 46 is arranged outside the red transmissive dichroic filter 45 so as to face it.
It has a function of aligning so-called polarized waves for converting waves into P waves.

The color separation section 47 separates a so-called P-wave light beam into a plurality of specific colors, in the embodiment, white light into red light, blue light and green light. For red light, the direction of red light is changed. It is composed of a mirror 48, a blue reflection dichroic mirror 49 that separates only blue light, a green first mirror 50 and a green second mirror 51 that change the direction of green light.

This blue reflection dichroic mirror 49
And the first mirror 50 for green color are respectively arranged on the optical axes E1 and E2 of the light source 39 and are inclined at an angle of 45 degrees to the right to change the direction of light to the C direction and are spaced at appropriate intervals. There is.

The red mirror 48 has parallel lines F1 and F2 which are maintained at appropriate intervals from the optical axes E1 and E2 of the light source 39.
The red light rays which are above and which are transmitted through the red reflection dichroic filter 45 are arranged in a state of being inclined by 45 degrees to the right so as to change the direction to the D direction.

The second mirror 51 for green has parallel lines F1 and
It is on F2 and is arranged with an inclination of 45 degrees downward to the right so that the green ray reflected by the mirror 50 in the C direction is turned to the B direction.

The color synthesizing section 52 synthesizes light of so-called plural specific colors, and in the embodiment, red light, blue light,
The display means for displaying green light on the liquid crystal plate and the synthesizing means for synthesizing the respective images displayed on the liquid crystal plate, and specifically, a red condenser lens 53 for converging red light rays, and A red liquid crystal plate 54 which is arranged to face the condenser lens 53 and forms a red image.
And a green condenser lens 55 for converging green light rays.
And a liquid crystal plate 56 for green which is arranged facing the condenser lens to form a green image, a condenser lens 57 for blue which converges a blue ray, and a blue image which is arranged facing the condenser lens 57. A blue liquid crystal plate 58 to be formed, a dichroic prism 59 for synthesizing three colors by arranging the liquid crystal plates 54, 56 and 58 on one side of each rectangular shape, and a projection lens (PL) for enlarging and projecting an image. ) And is composed of.

The dichroic prism 59 corresponds to a so-called color synthesizing means, and a light ray red reflection film 61 for reflecting the red color from the liquid crystal plate 54 in the C direction and a green color reflection for reflecting the green light ray from the liquid crystal plate 56 in the C direction. And a membrane 62. That is, the dichroic prism 59 has a function of combining the three colors and emitting the combined color in the direction of the projection lens 60.

The color separation light emitting device 35 having the above structure operates as follows. The light emitted from the light source 39 is directly incident on the collimator lens 40, or is reflected by the reflecting surface of the reflector 37 (only visible light) and is incident on the collimator lens 40 as divergent light L10.

The incident divergent light L10 is converted into parallel light L11 by the collimator lens 40. The converted parallel light L11 enters the cold filter 41. The heat rays of the incident parallel light L11 are returned in the B direction, and the parallel rays L11 other than the heat rays pass through the cold filter 41.
The parallel light L11 that has passed through the cold filter 41 is ¼
The light passes through the wave plate 42 as it is, and the polarization beam splitter 4
It is incident on 3.

The parallel light L11 incident on the polarization beam splitter 43 is separated into a P wave and a S wave which are linearly polarized waves, and P
The wave goes straight on, and the S wave is reflected in the C direction.

The S-wave reflected in the C direction transmits only the red color in the C direction by the red transmission dichroic filter 45, and the other colors are reflected in the direction opposite to the C direction.

The red ray transmitted in the C direction is 1/2
The wave plate 46 converts the S wave into the P wave, the red mirror 48 changes the direction to the D direction, and the light is emitted to the color separation unit 47.

The other P wave passes through the polarization beam splitter 43 and is transmitted through the blue-green transmission dichroic filter 4
4, blue and green are transmitted and red is reflected in the B direction.

The linearly polarized S-wave blue light and green light reflected by the red transmission dichroic filter 45 are returned to the B direction by the polarization beam splitter 43, and
The light enters the / 4 wavelength plate 42, is circularly polarized by the ¼ wavelength plate 42, and is emitted in the B direction.

The circularly polarized wave emitted in the B direction passes through the cold filter 41 and is focused on the light source 39 by the collimator lens 40. Similar to the first path, the focused light is reflected by the reflector 37 and at the same time converted into the reverse circularly polarized wave, and then converted into the parallel light L11 by the collimator lens 40 and passes through the cold filter 41. The reverse-rotated circularly polarized wave that has passed through the cold filter 41 passes through the quarter-wave plate 42 and is converted into a P-wave that is a linearly polarized wave that is rotated by 90 degrees.

The converted P-wave blue light and green light pass through the polarization beam splitter 44 and the blue-green pass dichroic filter 44 and are emitted to the color separation section 47.

On the other hand, of the P waves that have traveled straight through the polarization beam splitter 43, blue light and green light pass through the blue-green pass dichroic filter 44 and are emitted from the light emitting section 36, but red light is in the B direction. Reflected in.

The P-wave red light reflected in the B direction is 1 /
The light enters the four-wave plate 42, is converted into circularly polarized light by the quarter-wave plate 42, and is emitted in the B direction.

The circularly polarized wave emitted in the B direction passes through the cold filter 41 and is focused on the light source 39 by the collimator lens 40. Similar to the first path, the focused light is reflected by the reflector 37 and at the same time converted into the reverse circularly polarized wave, and then converted into the parallel light L11 by the collimator lens 40 and passes through the cold filter 41.

The circularly polarized wave of the reversely rotated red ray that has passed through the cold filter 41 passes through the quarter-wave plate 42 and is converted into a linearly polarized S wave that is rotated by 90 degrees.

The red light converted into the S wave is reflected in the C direction by the polarization beam splitter 43, passes through the red transmission dichroic filter 45 and the ½ wavelength plate 46, and is emitted from the light emitting section 36. become.

The S wave from the beginning emitted from the light emitting section 36,
And S-wave red light converted from P-wave and 1 /
The two-wave plate 46 converts the P-wave, and the red mirror 48 changes the direction to the D direction.
Are focused by and are incident on the red liquid crystal plate 54 to form a red screen.

Further, P from the beginning when the light emitting section 36 is emitted
The blue light and the green light converted from the S wave and the S wave into the P wave pass through the blue-green transmission filter 44 and enter the blue reflection dichroic mirror 49.

Here, the blue light is reflected in the C direction, focused by the condenser lens 6, and then enters the blue liquid crystal plate 3 to form a blue image.

The green light transmitted through the blue reflection dichroic mirror 49 is reflected by the first mirror 50 and the second mirror 5.
It is reflected twice by 1 and the condenser lens 5
After being focused by 5, the light is incident on the green liquid crystal plate 56 to form a green image.

As described above, the red-transmitting filter 45 and the S wave are provided on the S-wave emission side of the polarization beam splitter 44.
The ½ wavelength plate 46 for converting into a wave has a structure in which the blue-green transmission filter 44 is provided on the emission side of the P wave to shorten the optical path. Further, since the structure is such that all of the S waves and P waves are taken in without discarding the linearly polarized wave from the light source 39, the structure is easy to be miniaturized while improving the utilization efficiency of light.

In the above embodiment, each liquid crystal plate 54,
Arrangement of 56 and 58, and dichroic mirror 49
It goes without saying that the selection of the color transmission in the dichroic filters 44 and 46 is not limited to the above description as long as they are associated with each other.

Next, a color separation / light emission device of the second embodiment according to the present invention will be described with reference to FIG. The second example of the conventional technique described with reference to FIG. 5 will be described.

As shown in FIG. 2, the color separation light emitting device 63 of the second embodiment according to the present invention is for increasing the efficiency of light when the light emitted from the light source is linearly polarized. Light emitting part 6
4, a color separation unit 75 that separates the light emitted from the light source into three colors of red, blue, and green, and a color combining unit 83 that combines the three colors.

The light emitting section 64 is provided with a polarization separating means for separating a so-called direct polarized wave into a P wave and an S wave, and this S wave has a structure which is not returned to the light source side as in the first embodiment. It has a structure provided with a conversion means for converting the S wave into the P wave and emitting the P wave on the company side of the S wave.

The structure of the light emitting portion 64 is such that a cold reflector 65 whose inner surface for reflecting the separated light is formed into a spherical shape.
And a light source 67 arranged at the center of a spherical surface 66 formed on the cold reflector 65, and a divergent light L10 to a parallel light L11.
Anamorphic lenses 68 and 69 used in place of the collimator lens, a cold filter 70 that allows passage of rays other than heat rays, and a polarization beam splitter that separates parallel light L11 into linearly polarized P waves and S waves ( PBS) 7
1 and the S-wave side of the polarization beam splitter 71, which are arranged in a state of being opposed to the optical axes E1 and E2 in a state orthogonal to each other, and a half-wave plate (λ / 2) 72 for converting the S-wave into a P-wave. It consists of and.

The cold reflector 65, the anamorphic lenses 68 and 69, the cold filter 70, and the polarization beam splitter 71 which constitute the light emitting section 64 are orthogonal to the optical axes E1 and E2 of the light source 67. In the state, they are arranged in parallel with each other.

The anamorphic lenses 68 and 69 are D
It has a function of converting the divergent light L10 in the direction to parallel light L11 (reducing only the horizontal cross section) or converging the parallel light L11 in the B direction to the light source 67.

The polarization beam splitter 71 is approximately half the size of the first embodiment. This is because the S wave separated by the polarization beam splitter 71 is again converted into the light source 6
This is because the structure is such that the S wave is converted into the P wave and is emitted without returning to the 7 side. For details, refer to No. 2 of the prior art.
Please refer to the example of.

The ½ wavelength plate 72 is arranged in a state of facing the S-wave emission side of the polarization beam splitter 71, and has a function of converting the S-wave reflected in the C direction by the polarization beam splitter 71 into a P-wave. Have.

The color separation section 75 is for separating the so-called P-wave light into a plurality of specific colors, and the polarization beam splitter 71.
The blue-green reflective dichroic mirror 73 arranged on the S-wave side of the half-wave plate 72 outside the half-wave plate 72 with a tilt of 45 degrees.
And the optical axis E on the P-wave side of the polarization beam splitter 71.
1, red reflection dichroic mirror 74 arranged at an angle of 45 degrees with respect to E2, and blue condenser lens 7
6 and blue reflection dichroic mirror (DM (B)) 7
7, a concave lens 78, a green first mirror 79, a green second mirror 80, and a red condenser lens 8
1 and a red mirror 82.

Blue-green reflective dichroic mirror 73
Corresponds to a so-called first color selection unit, and is a half-wave plate 72.
Is arranged at an inclination angle of 45 degrees on the outside, and has a function of transmitting the red light of the S wave separated from the polarization beam splitter 71 in the C direction and reflecting the blue light and the green light in the D direction.

Red reflective dichroic mirror (DM
The (R)) 74 corresponds to so-called second color selecting means, and is provided at the exit side of the P-wave of the polarization beam splitter (PBS) 71 by 45.
The polarization beam splitter 71 is arranged at an inclination of 4 degrees.
It has a function of reflecting the red light in the P wave separated in step C in the C direction and transmitting the blue light and the green light as they are in the D direction.

This blue reflective dichroic mirror 77
And the first mirror 79 for green are on the right side parallel to the optical axes E1 and E2 of the light source 67, that is, about the half-wave plate 32.
Is a center position, and the light is turned in the C direction and is inclined at an angle of 45 degrees to the right, and is arranged at appropriate intervals.

The blue condenser lens 76 is a focusing means for focusing the blue light rays and the green light rays, and is arranged at a position close to the red reflecting dichroic mirror 74 which is the second color selecting means.

The concave lens 78 is provided to convert the blue light beam focused by the blue condenser lens into parallel light L13.

The second mirror 80 for green has parallel lines F1 and F that are appropriately spaced from the optical axes E1 and E2 of the light source 67.
2 and is inclined 45 degrees downward to the right so that the light beam from the first green mirror 79 is turned to the B direction.

The red condenser lens 81 is a focusing means for focusing the red light rays similarly to the blue condenser lens 76, and is arranged at a position close to the blue-green reflection dichroic mirror 73 corresponding to the first color selecting means. Has been done.

The red mirror 82 is on the parallel lines F1 and F2 from the optical axes E1 and E2, and the light beam from the blue-green reflective dichroic mirror 81 is directed to the D direction by 45 degrees to the right. It is arranged with an inclination.

The relationship between this polarization beam splitter and each mirror and lens is different from that of the first embodiment, in that the separated S wave is converted into the P wave without returning to the light source side.

Therefore, as in the second example of the prior art, the size of the polarization beam splitter is half that of the first embodiment, and the P from the polarization beam splitter is set.
An optical path width W1 of a size that is sufficient to receive a ray width W2 obtained by adding the ray width of the wave (1/2 · W2) and the ray width of the P wave obtained by converting the S wave (1/2 · W2). It is set to have.

The color synthesizing section 83 is composed of display means for displaying respective images based on so-called plural specific colors, red light, blue light, and green light, and synthesizing means for synthesizing the images. The red liquid crystal plate (LC
D (R)) 84, a green condenser lens 85 for converging green light rays, a green liquid crystal plate (LCD (G)) 86 for forming a green image, and a blue liquid crystal plate (LCD (LCD (G)) for forming a blue image. B)) 87, a dichroic prism 88 for combining the three colors, and a projection lens (PL) 89 for enlarging and projecting an image. Of these, the dichroic prism 88 includes a red reflection film (DP
(R)) 90 and a green reflective film (DP (G)) 91.

The color separation / light emission device of the second embodiment having such a structure operates as follows. The light emitted from the light source 67 is directly incident on the anamorphic lenses 68 and 69, or only the visible light is reflected by the reflecting surface of the cold reflector 65, and is reflected by the anamorphic lenses 68 and 69 as divergent light L10. Incident, parallel light L here
Converted to 11.

The parallel light L11 is incident on the cold filter 70, the heat rays of the incident parallel light L11 are returned to the B direction, and the parallel light L11 other than the heat rays is cold filter 7.
Pass 0. The parallel light L11 that has passed through the cold filter 70 enters the polarization beam splitter 71.

The parallel light L11 incident on the polarization beam splitter 71 is separated into a P-wave and an S-wave, which are linearly polarized waves.
The wave goes straight on, and the S wave is reflected in the C direction.

The S wave reflected in the C direction is converted into a P wave by the half-wave plate 72 and is incident on the blue-green reflection dichroic mirror 73. The converted P-wave red light is transmitted through the blue-green reflection dichroic mirror 73 in the C direction, and the blue light and the green light are reflected in the D direction.

The red light transmitted in the C direction enters the red mirror 82 after being focused by the red condenser lens 81.

Further, the blue light and the green light reflected in the D direction are incident on the blue reflection dichroic mirror 77 after being focused by the blue condenser lens 76.

On the other hand, the P wave traveling straight through the polarization beam splitter 71 in the D direction is the polarization beam splitter 71 as it is.
Is emitted in the D direction from the red reflection dichroic mirror 7
It is incident on 4. Here, the red light is reflected in the C direction, and the other colors are transmitted in the D direction.

The red light reflected in the C direction is focused by the red condenser lens 81 in a state of being added to the red light obtained by converting the S wave into the P wave, and then the red mirror 82.
Incident on.

The blue light and the green light transmitted through the red reflection dichroic mirror 74 in the D direction are added to the blue light and the green light obtained by converting the S wave into the P wave, and the blue condenser lens 76 is added. The light then enters the blue reflection dichroic mirror 77.

In this way, the red light reflected in the C direction by the red reflective dichroic mirror 74 and the red light transmitted in the C direction by the blue-green reflective dichroic mirror 81 are focused by the red condenser lens 81. Then, the direction is changed to the D direction by the red mirror 82 and the light is incident on the red liquid crystal plate 84.

Similarly, the blue light and the green light reflected by the blue-green reflective dichroic mirror 73 and the blue light and the green light transmitted through the red reflective dichroic mirror 74 in the D direction are focused by the blue condenser lens 76. The blue light is reflected by the blue reflection dichroic mirror 77 in the C direction and the green light is transmitted in the D direction. The blue light reflected in the C direction is incident on the blue liquid crystal plate 87.

The green light transmitted through the blue reflection dichroic mirror 77 in the D direction is collimated by the concave lens 78 into parallel light L13.
The first green mirror 79 changes the direction to the C direction, the second green mirror changes the direction to the B direction, and the green condenser lens 85 converts the light into focused light. It is incident on 86.

In this way, also in the second embodiment, all the linearly polarized light from the light source 67 is incident on the respective liquid crystal plates 84, 86 and 87 without being discarded, so that the light utilization efficiency is improved. It has a structure that allows it.

In addition, the light source 67 and the liquid crystal plates 84, 86, 87
A structure in which the optical paths of and are made as short as possible, specifically, the color separation mirrors 73 and 74 are arranged in the position close to the polarization beam splitter 71, and the lenses 76 and 81 are respectively provided for the respective separated colors. Since the mirrors 73, 74 and the like are arranged and guided to the liquid crystal plates 84, 86, 87, it is possible to suppress the attenuation of light due to the lengthened optical path and to reduce the size.

Furthermore, since the condenser lenses 76 and 81 are provided in the positions close to the light rays emitted from the polarization beam splitter 71, the incident and outgoing beam widths of light can be widened and the light utilization efficiency is high. It is also a structure that can be done.

[0142]

The color separation / light emitting device section according to the present invention having the above-described structure has the following effects.

The first color selecting means for separating the light from the light source into two linearly polarized waves of P wave and S wave and transmitting the specific primary color light is provided on one emission side of the linearly polarized wave to be converted. By arranging the second color selection means for transmitting two primary color lights other than the specific primary color light on the output side of the other linearly polarized light,
The position for polarization conversion can also serve as a part of color separation, and an extremely excellent effect that the device itself can be downsized by shortening the optical path length between the light source and the liquid crystal plate is exerted.

By arranging the first and second color selecting means so as to face the output side of each linear knitting wave, it is possible to prevent the emission of the specific primary color light emitted and to achieve an efficient transmission state. It has an extremely excellent effect that it can be maintained.

By arranging the first and second color selecting means in an inclined state with respect to the output side of each linearly polarized wave, the linearly polarized wave that is not converted (P wave in the embodiment) and the converted linearly polarized wave are obtained. Wave (in the example, P converted from S wave
It is possible to shorten the optical path of a specific primary color light composed of waves), improve the light utilization efficiency, and achieve miniaturization.

Since the first color selecting means transmits only the red light, the optical path of the red light can be shortened, the light utilization efficiency can be improved, and the device itself can be miniaturized. That is, it becomes possible to exert an extremely excellent effect.

The second color selecting means transmits the blue light and the green light other than the red light, thereby shortening the optical paths of the three primary color lights including the red light and improving the light utilization efficiency. In addition, there is an extremely excellent effect that the size of the device can be reduced.

Since the first and second color selecting means are formed by the dichroic filter, it is possible to perform the selection according to the frequency band of the light ray of the specific color, and prevent the color shift around the screen of the captured image. It has an extremely excellent effect that can be achieved.

The inclination of the first and second color selecting means is 45.
Since the angle is 90 degrees, the incident light beam can be emitted in the direction of 90 degrees, the optical path can be simplified, and the size of the apparatus itself can be reduced, which is an extremely excellent effect.

By providing the converging means for converging the light at a position adjacent to the first and second color selecting means, the beam width of the light beam of the selected specific color is widened and the light utilization efficiency is improved. It has an extremely excellent effect that it can be done.

Since the converging means is formed of a condenser lens, the beam width of the light beam of the selected specific color can be widened, and the light utilization efficiency can be improved, which is an extremely excellent effect. .

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a schematic overall configuration of a color separation light emitting device of a first embodiment according to the present invention.

FIG. 2 is an explanatory diagram showing a schematic overall configuration of a color separation light emitting device of a second embodiment according to the present invention.

FIG. 3 is a schematic explanatory view of a device using a liquid crystal having a twisted-matic structure according to the related art.

FIG. 4 is an explanatory diagram showing a schematic overall configuration of a color separation / light emission device of a first example according to the related art.

FIG. 5 is an explanatory diagram showing a schematic overall configuration of a color separation / light emission device of a second example according to the prior art.

[Explanation of symbols]

35 Color Separating and Emitting Device 36 Emitting Unit 37 Reflector 38 Inner Spherical Surface 39 Light Source 40 Collimator Lens 41 Cold Filter 42 Quarter Wave Plate (λ / 4) 43 Polarizing Beam Splitter (PBS) 44 Blue-Green Transmission Dichroic Filter (DF
(GB)) 45 Red transmission dichroic filter (DF
(R)) 46 1/2 wavelength plate (λ / 2) 47 Color separation unit 48 Red mirror 49 Blue transmission dichroic mirror (DM (B)) 50 Green first mirror 51 Green second mirror 52 Color Combiner 53 Red condenser lens 54 Red liquid crystal plate (LCD (R)) 55 Green condenser lens 56 Green liquid crystal plate (LCD (G)) 57 Blue condenser lens 58 Blue liquid crystal plate (LCD (B)) 59 Dichroic prism 60 Projection lens 61 Red reflective film (DP (R)) 62 Green reflective film (DP (G)) 63 Color separation light emitting device 64 Light emitting unit 65 Cold reflector 66 Inner spherical surface 67 Light source 68 Anamorphic lens 69 Anamorphic lens 70 Cold filter 71 Polarization beam splitter (PBS) 72 1/2 Wave plate (λ / 2) 7 Blue-green reflecting dichroic mirror (DM (G
B)) 74 Red reflective dichroic mirror (DM (R)) 75 Color separation section 76 Condenser lens for blue 77 Blue reflective dichroic mirror (DM (B)) 78 Concave lens 79 First mirror for green 80 Second mirror for green 81 Red Condenser Lens 82 Red Mirror 83 Color Composition Section 84 Red Liquid Crystal Plate (LCD (R)) 85 Green Condenser Lens 86 Green Liquid Crystal Plate (LCD (G)) 87 Blue Liquid Crystal Plate (LCD (B)) ) 88 dichroic prism 89 projection lens 90 red reflective film (DP (R)) 91 green reflective film (DP (G))

Claims (3)

(57) [Claims] 1. A light source, A riff arranged to reflect the light emitted from the light source
Lecta, Arranged on the opposite side of the light source from the reflector 1
/ 4 wave plate, The light source is arranged behind the quarter-wave plate and
The light emitted from the source is split into two linearly polarized waves, P wave and S wave.
If they are separated and one of the linearly polarized waves is emitted from one surface,
Polarization separation that emits the other linearly polarized light from the other surface
Means and Arranged close to one surface of the polarized light separating means,
From the linearly polarized light emitted from one side of the polarization separation means
Only the specific primary color light is transmitted and the specific primary color light is transmitted.
Other than the two primary color lights other than the first color selection means, Arranged in close proximity to the other surface of the polarization splitting means,
From the linearly polarized light emitted from the other surface of the polarization splitting means
The specific primary color light is reflected while reflecting the specific primary color light.
Second color selection means for transmitting two primary color lights other than Other than the specific primary color light transmitted through the second color selection means
A color component that separates each of the two primary color lights into a single primary color light
Separation means, The specific primary color light transmitted through the first color selecting unit and the
From two primary colors separated into a single primary color by color separation means
Form each image and combine the formed images.
A color synthesizing means to be formed, A color separation / light emission device comprising: 2. The specific color transmitted by the first color selection means
The primary color light is red light.
Color separation light emitting device. 3. The first color selection means and the second color
The selection means should be a dichroic filter Features
The color separation light emitting device according to claim 1.