JP2002287247A - Color separating/synthesizing optical system and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To present a bright and whiter display, as for a white display on a display device. SOLUTION: The projector is provided with dichroic mirrors 101, 102 and 103 for separating light emitted from an illuminating optical system 520 into red, green, blue and yellow light, liquid crystal light valves 130R, 130G, 130B and 130Y for each color light for modulating each color light in accordance with obtained image information, and dichroic prisms 141 and 142 for fetching each color light modulated by the liquid crystal light valves in, synthesizing and emitting the light, and the dichroic prisms 141 and 142 are constituted so that red, green and blue light may be always taken into the prisms and yellow light may be taken into the prisms in addition to the red, green and blue light only in the prescribed case.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color separation / synthesis optical system which separates light into a plurality of color lights, processes an image, combines them again to produce a display image, and a projector using the same.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram showing a known optical system in a projector. According to this, the projector 5
Reference numeral 00 denotes a light source (not shown) such as a high-pressure mercury lamp or a metal halide lamp, an integrator lens including a reflector 510, a first lens array 521 and a second lens array 522, a polarization conversion element array 523 for aligning the polarization direction of light, and superposition. An illumination optical system 520 having a lens 524 and the like; a color light separation optical system 530 for separating a light beam W emitted from the illumination optical system 520 into red, green, and blue color light beams R, G, and B; Of the color light beams separated by the separation optical system 530, a relay optical system 540 that guides the blue light beam B to the corresponding liquid crystal panel 550B, and three liquid crystals as light modulating means that modulates each color light beam according to given image information. Panel 550R, 550G, 550
B, a cross dichroic prism 560 as a color light synthesizing optical system for synthesizing the modulated color light beams, and a projection lens 570 for enlarging and projecting the synthesized light beam on a projection surface.

Here, the illumination optical system 520 adjusts the polarization direction of light to s- or p-polarized light so that each liquid crystal panel 550R, 550R,
50G and 550B have the function of uniformly entering the light on the panel surface. The light adjusted in this manner by the illumination optical system 520 is converted into red,
The liquid crystal panel 550 separates the light into green and blue light.
After being modulated by R, 550G, and 550B, they are combined by a cross dichroic prism 560 to be a display image, and projected from a projection lens 570.

[0004]

However, in the case of image processing using only the so-called RGB three colors of red, green and blue of the light beam W emitted from the light source as described above, yellow light is required due to the characteristics of the lamp. Since light near the light is not intentionally used, there is a problem that an image is apt to be dark when displaying white. In the case of processing using only three colors of red, green and blue, there is still room for improvement from the viewpoint of color reproducibility. SUMMARY OF THE INVENTION The present invention has been made in response to the above problems, and has a color separation / combination optical system capable of appropriately securing the brightness of an image even when displaying white, and a color separation capable of providing excellent color reproducibility. An object of the present invention is to provide a synthetic optical system and improve the display capability of a display device such as a projector using the same.

[0005]

According to the present invention, there is provided a color separation / combination optical system which separates light into red, green, blue and yellow light, and modulates each of the color lights in accordance with given image information. A modulating device for each color light, and a color light synthesizing device which takes in each color light modulated by the modulating device, and synthesizes and emits the light; Only in the case of, yellow color light is taken in in addition to red, green and blue color light. Thereby, for example, when a display image includes a white display in which the image is most likely to be darkest, light in a yellow wavelength band is captured,
The displayed image becomes brighter.

Further, the color separation / combination optical system of the present invention comprises a color light separation device for separating light into four, five or six kinds of color lights;
A modulation device for each color light that modulates each color light according to the given video information, and a color light synthesis device that takes in each color light modulated by each modulation device, synthesizes and emits the light, I do. In this case, the type of color light
For example, red, green, and blue are required three types, orange,
Any necessary type can be selected from the three types of yellow and cyan. According to this, it is possible to obtain an image having excellent color reproducibility according to the number of color lights separated and processed.

Further, the projector according to the present invention separates the light into a plurality of color lights, modulates each of the color lights according to given image information, and then synthesizes the respective color lights to form a display image. The color separation / synthesis optical system is used as a separation / synthesis unit. As a result, a projector capable of securing appropriate brightness or a projector having excellent color reproducibility can be obtained.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a configuration diagram showing an optical system of a projector using a color separation / synthesis optical system 100 according to Embodiment 1 of the present invention, which performs image processing of four types of color light of red, green, blue, and yellow. Synthetic optical system 100
Before and after, the illumination optical system 520 having the same operation as the conventional one
And a projection lens 570 are arranged.

In FIG. 1, light from a light source (not shown) is reflected by a reflector 510, and the liquid crystal light valves 130R and 130R are formed by an integrator lens composed of a first lens array 521 and a second lens array 522.
OG, 130B, and 130Y are adjusted so as to be uniformly incident on the panel surface, and the polarization direction of the light is adjusted to s or p polarization by the polarization conversion element array 523. Be injected. The light exiting the illumination optical system 520 in this way is separated by the dichroic mirror 101 into red / yellow light and blue / green light. The separated red / yellow light is further separated into red light and yellow light by the dichroic mirror 102, and the red light enters a liquid crystal light valve (a light modulation device including a liquid crystal panel and a polarizing plate) 130R and is given. The yellow light enters the liquid crystal light valve 130Y and is similarly modulated.

On the other hand, the blue / green light separated by the dichroic mirror 101 is
, The green light is further separated into green light and blue light, and the green light is incident on the liquid crystal light valve 130G and is modulated according to the given image information, while the blue light is relay optical system (relay lenses 121, 122, 123) and mirror 111,
The light enters the liquid crystal light valve 130B via 112 and is similarly modulated.

The liquid crystal light valves 130Y, 130G, 1
Each color light that has exited 30B is converted to a dichroic prism 141.
And enters the dichroic prism 142. On the other hand, the red light that has exited the liquid crystal light valve 130R also enters the dichroic prism 142 via the total reflection prism 151. Dichroic prism 142
Combines the combined light from the dichroic prism 141 and the red light from the liquid crystal light valve 130R, and emits the combined light to the projection lens 570.

In the above configuration, the liquid crystal light valves 130R, 130G, and 130B corresponding to red, green, and blue color lights.
Is always on during the operation of the projector.
On the other hand, the liquid crystal light valve 130Y corresponding to yellow light
Usually, it is turned off, and it is turned on only in a specific case. For example, a sensor (not shown) for detecting color information of a display image projected by the projection lens 570 is provided, and a display that recognizes that the sensor is a white display is provided.
Only when it is determined that 50% of the entire display screen is occupied (this value is arbitrary), the liquid crystal light valve 130Y is turned off.
N is controlled.

In the projector according to the first embodiment, the white display image is synthesized including the yellow light in addition to the red, green, and blue color lights, so that the brightness is increased by that amount and white is displayed whiter. it can.

Embodiment 2 FIG. FIG. 2 is a configuration diagram showing an optical system of a projector using a color separation / combination optical system 200 according to Embodiment 2 of the present invention. The color separation performs image processing of four types of color light of red, green, blue, and yellow. An illumination optical system 520 and a projection lens 570 having the same function as the conventional one are arranged before and after the combining optical system 200.

In FIG. 2, light that has exited the illumination optical system 520 is reflected by dichroic mirrors 201 and 202 on a blue and blue scale.
It is separated into green light and red / yellow light. Red isolated
The yellow light is transmitted through the mirror 212 to the dichroic mirror 2
04, where it is separated into red and yellow light. The separated red light enters the liquid crystal light valve 230R via the mirror 216 and is modulated according to the given image information, while the yellow light enters the liquid crystal light valve 230Y via the mirror 214 and is similarly modulated. Then, these lights enter the dichroic prism 242 and are combined.

On the other hand, dichroic mirrors 201 and 20
The blue / green light separated by 2 enters the dichroic mirror 203 via the mirror 211, where it is separated into blue light and green light. The separated blue light is reflected by a mirror 215.
The liquid crystal light valve 230B is incident on the liquid crystal light valve 230B and modulated according to the given image information, while the green light is reflected by the mirror 213.
, And enters the liquid crystal light valve 230G, and is similarly modulated. Then, these lights enter the dichroic prism 241 and are combined.

Light exiting the dichroic prism 241 and the dichroic prism 242 is reflected by mirrors 217 and 21.
8, the light enters the dichroic prism 243, is synthesized there, and is emitted to the projection lens 570.

In the projector according to the second embodiment, the display colors are synthesized including yellow light in addition to red, green, and blue light, so that the color separation reproducibility can be improved. When yellow light has an unfavorable effect on a specific color light display, when the color light display is performed,
By turning off the liquid crystal light valve 130Y corresponding to yellow light according to Embodiment 1, the yellow light can be excluded from the combined light.

Embodiment 3 FIG. 3 is a configuration diagram showing an optical system of a projector using a color separation / combination optical system 300 according to Embodiment 3 of the present invention, and performs image processing of five types of color light of red, green, blue, yellow, and cyan. Color separation / combination optical system 300
Before and after, the illumination optical system 520 having the same operation as the conventional one
And a projection lens 570 are arranged.

In FIG. 3, light that has exited the illumination optical system 520 is reflected by a dichroic mirror
It is separated into cyan / green light and red / yellow light. The separated red / yellow light enters the dichroic mirror 305 via the mirror 312, where it is separated into red light and yellow light. The separated red light enters the liquid crystal light valve 330R via the mirror 318 and is modulated according to the given image information, while the yellow light enters the liquid crystal light valve 330Y via the mirror 317 and is similarly modulated. And
These lights enter the dichroic prism 342 and are combined.

On the other hand, dichroic mirrors 301 and 30
The blue / cyan / green light separated by 2 enters the dichroic mirror 303 where it is separated into green light and blue / cyan light. The separated green lights are mirrors 314 and 3
The light is incident on the liquid crystal light valve 330G via the optical modulators 15 and 316 and is modulated according to the given image information. On the other hand, the blue / cyan light enters the dichroic mirror 304 via the mirror 311, where it is separated into blue light and cyan light. The separated blue light enters the liquid crystal light valve 330B via the mirror 313 and is modulated according to the given image information, while the cyan light enters the liquid crystal light valve 330C via the mirror 314 and is similarly modulated. Then, these lights enter the dichroic prism 341 and are combined.

Light exiting the dichroic prism 341 and the dichroic prism 342 is reflected by mirrors 319 and 32.
Then, the light enters the dichroic prism 343 via the light source 0, is synthesized there, and is emitted to the projection lens 570.

In the projector according to the third embodiment, the display colors are synthesized including the yellow, cyan and cyan light in addition to the red, green and blue light, so that the color separation reproducibility can be improved. it can. When yellow light or cyan light has an unfavorable effect on a specific color light display, a liquid crystal light corresponding to the yellow light or cyan light should be used in displaying the color light according to the first embodiment. By turning off the bulbs 130Y and 130C, those color lights can be excluded from the combined light.

Embodiment 4 FIG. 4 is a configuration diagram showing an optical system of a projector using a color separation / synthesis optical system 400 according to Embodiment 4 of the present invention. The projector emits six types of color light of red, green, blue, yellow, cyan, and orange. Before and after the color separation / synthesis optical system 400 to be processed, an illumination optical system 520 and a projection lens 570 having the same operation as in the related art are arranged.

In FIG. 4, the light that has exited the illumination optical system 520 is converted into blue light by dichroic mirrors 401 and 402.
It is separated into cyan / green light and red / orange / yellow light. The separated red / orange / yellow light enters the dichroic mirror 404 where it is split into red / orange light and yellow light. The separated yellow light is mirror 418,
The light enters the liquid crystal light valve 430Y via 419 and 420 and is modulated according to the given image information, and then enters the dichroic prism 442. On the other hand, the red / orange light is transmitted through the mirror 412 to the dichroic mirror 406.
Where it is separated into red and orange light.
The separated red light enters the liquid crystal light valve 430R via the mirror 417 and is modulated according to the given video information, while the orange light is incident on the liquid crystal light valve 430O via the mirror 418 and is similarly modulated. The light enters the dichroic prism 442.

On the other hand, dichroic mirrors 401 and 40
The blue / cyan / green light separated by 2 enters the dichroic mirror 403, where it is separated into green light and blue / cyan light. The separated green lights are mirrors 414 and 4
The light enters the liquid crystal light valve 430 </ b> G via the lines 15 and 416 and is modulated according to the given image information. On the other hand, the blue / cyan light enters the dichroic mirror 405 via the mirror 411, where it is separated into blue light and cyan light. The separated blue light enters the liquid crystal light valve 430B via the mirror 413 and is modulated according to the given image information, while the cyan light enters the liquid crystal light valve 430C via the mirror 414 and is similarly modulated. Then, these lights enter the dichroic prism 441 and are combined.

The light exiting the dichroic prism 441 and the dichroic prism 442
Then, the light enters the dichroic prism 443 via the light source 2, is synthesized there, and is emitted to the projection lens 570.

In the projector according to the fourth embodiment, the display colors are yellow, cyan, cyan, red, green, and blue.
Since the light is synthesized including the light of each color of orange, the color separation reproducibility can be improved.

In each of the above embodiments, various combinations of optical elements such as a dichroic mirror for color separation, a mirror for direction change, and a dichroic prism for photosynthesis can be used in addition to the illustrated ones.
Any combination may be used as long as the required color light and synthetic light can be obtained. Further, in the projectors according to the second to fourth embodiments, by performing the same control as in the first embodiment, a white display image is synthesized including yellow light in addition to red, green, and blue color lights. , The brightness is increased by that amount, and white can be displayed more white.

[0030]

By using the color separation / synthesis optical system of the present invention for a display device such as a projector, an appropriate display brightness can be ensured. Further, by using the color separation / synthesis optical system of the present invention for a display device such as a projector,
Excellent reproducibility of display colors can be achieved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an optical system of a projector using a color separation / synthesis optical system according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing an optical system of a projector using a color separation / synthesis optical system according to Embodiment 2 of the present invention.

FIG. 3 is a configuration diagram showing an optical system of a projector using a color separation / synthesis optical system according to Embodiment 3 of the present invention.

FIG. 4 is a configuration diagram showing an optical system of a projector using a color separation / synthesis optical system according to Embodiment 4 of the present invention.

FIG. 5 is a configuration diagram showing an optical system of a conventional projector.

[Explanation of symbols]

101, 102, 103 ... dichroic mirror, 130R, 130G, 130B, 130Y ... liquid crystal light valve, 141, 142 ... dichroic prism, 201, 202, 203, 204 ... dichroic mirror , 230R, 230G, 230B, 230Y ... liquid crystal light valve, 241, 242, 243 ... dichroic prism, 301, 302, 303, 304, 305 ... dichroic mirror, 330R, 330G, 330B, 330Y, 330
C .... Liquid crystal light valve, 341,342,343 ... Dichroic prism, 401,402,403,404,405,406 ...
Dichroic mirror, 430R, 430G, 430B, 430O, 430Y,
430C ... liquid crystal light valve, 441, 442, 443 ... dichroic prism.

Claims (9)

[Claims] 1. A color light separation device that separates light into red, green, blue, and yellow light, a modulation device for each color light that modulates each color light in accordance with given image information, and a modulation device that is modulated by the modulation device. A color light combining device that takes in each color light, and combines and emits the light, and the color light combining device always takes in each color light of red, green, and blue, and only in a predetermined case, converts the light into red, green, and blue light. In addition, a color separation / synthesis optical system characterized by taking in yellow light. 2. The color separation / synthesis optical system according to claim 1, wherein the predetermined case is a case where the image synthesized by the light synthesis device includes a white display. 3. A color light separation device that separates light into four types of color lights, a modulation device for each color light that modulates each of the color lights according to given video information, and a color light that is modulated by each of the modulation devices. A color separation / synthesis optical system comprising: a color light synthesis device that captures, synthesizes, and emits. 4. The four kinds of color lights are one of three kinds of red, green and blue and one of three kinds of orange, yellow and cyan.
4. The color separation / synthesis optical system according to claim 3, wherein the color separation / synthesis optical system is composed of a plurality of types. 5. A color light separation device for separating light into five types of color lights, a modulation device for each color light that modulates each color light according to given video information, and a color light modulated by each of the modulation devices. A color separation / synthesis optical system comprising: a color light synthesis device that captures, synthesizes, and emits. 6. The five kinds of color lights are any one of three kinds of red, green and blue, and three kinds of orange, yellow and cyan.
6. The color separation / synthesis optical system according to claim 5, wherein the color separation / synthesis optical system is composed of: 7. A color light separation device that separates light into six types of color lights, a modulation device for each color light that modulates each color light according to given video information, and a color light that is modulated by each of the modulation devices. A color separation / synthesis optical system comprising: a color light synthesis device that captures, synthesizes, and emits. 8. The color separation / synthesis optical system according to claim 7, wherein the six types of color light include six types of red, green, blue, orange, yellow, and cyan. 9. A projector that separates light into a plurality of color lights, modulates each of the color lights according to given image information, and then synthesizes each of the color lights to form a display image. A projector using the color separation / synthesis optical system according to claim 1.