JP2867590B2 - projector - Google Patents

Description

The present invention relates to a configuration of a projector.

[Prior Art] FIG. 2 shows a basic configuration of a conventional liquid crystal projector. In FIG. 2, 4 is a light source, 15 is a blue reflection dichroic mirror (hereinafter, BD, M) 16, 16 is a green reflection dichroic mirror (hereinafter, GD, M), and 7a, 7b, 7c are reflection mirrors. , 12 is a green-liquid crystal light valve (hereinafter, G-LV), 13 is a blue-liquid crystal light valve (hereinafter, BL, V), 14 is a red-liquid crystal light valve (hereinafter, RL, V), 9 is a synthetic prism, 10 is a projection lens, and 11 is a screen. A liquid crystal light valve is an element capable of sandwiching a liquid crystal material between two glass substrates and controlling light passing therethrough by an applied voltage. In recent years, an active matrix liquid crystal light valve in which a thin film transistor is formed on a glass substrate and light transmittance can be individually controlled for each pixel has been put to practical use.

The light emitted from the light source 4 is BD-M14 and GD-M15.
The light is separated into three primary colors of blue, green, and red, and reaches liquid crystal light valves 13, 12, and 14 corresponding to the respective colors. In each liquid crystal light valve, the transmittance of each color is controlled for each pixel, and an optical image is formed. The optical image of each color is light-synthesized by the synthesizing prism 9 and then projected on a screen 11 by a projection lens 10. The 9a surface of the combining prism 9 is formed with a blue reflection and green transmission reflection film, and the 9b surface is formed with a red reflection and green transmission reflection film.

FIG. 3 is a pixel arrangement diagram of a projection image of a conventional liquid crystal projector. In FIG. 3, reference numeral 17 denotes a pixel. The portions other than the pixels are portions where light does not pass. In an active matrix liquid crystal light valve, a portion that does not transmit light is formed to protect a thin film transistor. Each pixel is adjusted so that red, green, and blue are at the same position. The size of the liquid crystal light valve of each color and the number of pixels are the same.

[Problems to be Solved by the Invention] However, in the above-described conventional technology, the resolution of an image is determined by the number of pixels held by the liquid crystal light valve of each color.
Therefore, in order to improve the resolution, it is necessary to have as many pixels as possible. However, increasing the number of pixels requires high-level fine processing, lowers the yield, increases costs, and reduces the area (aperture ratio) of the pixel portion of the entire screen, thereby reducing the screen. There is a problem that the brightness of the image is reduced.

Therefore, the present invention is to solve such a problem, and an object of the present invention is to provide a projector that has a remarkably high resolution of a projected image and a bright projected image.

[Means for Solving the Problems] A first liquid crystal projector according to the present invention includes a light source, a color light separating unit that separates light emitted from the light source into green color light, red and blue color light, and the color light. A polarization separation unit that separates the green color light separated by the separation unit into light of two types of polarization components, a first light valve that modulates the red and blue color lights separated by the color light separation unit, A second light valve that modulates one of the polarized light components of the green color light separated by the separating unit; and a light of the other polarized light component of the green color light separated by the polarized light separating unit. And a synthesizing means for synthesizing the lights modulated by the first to third light valves, respectively.

Further, the second projector of the present invention includes a color light separating unit that separates the light emitted from the light source into three color lights of red, green, and blue, and two types of green color light separated by the color light separating unit. Polarized light separating means for separating the light into polarized light components,
A first light valve that modulates red color light separated by the color light separation means, a second light valve that modulates blue color light separated by the color light separation means, and light separated by the polarization separation means. Among the green light, a third light valve that modulates one of the polarized light components, and a fourth light valve that modulates the other polarized light component of the green light separated by the polarization separating means. A light valve and a combining means for combining light modulated by the first to fourth light valves, respectively.

[Embodiment] FIG. 1 is a configuration diagram of an embodiment of a projector according to the present invention, where 1 is a first green-liquid crystal light valve, 2
Is a second green-liquid crystal light valve, 3 is a red, blue-liquid crystal light valve, 4 is a light source, 5 is a red-blue reflecting dichroic mirror, 6 is a green beam splitter, 7a, 7b, 7c is a reflecting mirror, and 9 is a composite mirror. A prism, 10 is a projection lens, and 11 is a screen.

Of the light emitted from the light source 4, red and blue are reflected by the red-blue reflecting dichroic mirror 5, further reflected by the reflecting mirror 7 a, and reach the red-blue liquid crystal light valve 3. On the other hand, the green light transmitted through the red-blue reflecting dichroic mirror 5 enters the green beam splitter 6. In the green beam splitter 6, S-polarized light of green light is reflected and P-polarized light is transmitted. Therefore, the S-polarized light component of the green light is
When the light reaches the liquid crystal light valve, the P-polarized light component
The light is reflected at b and 7c and reaches the second green-liquid crystal light valve. Light whose transmission amount is controlled by each liquid crystal light valve, that is, an optical image is synthesized by the synthesis prism 9,
The light is projected on a screen 11 through a projection lens 10. The 9a surface of the synthetic prism 9 is made of a reflective film for red-blue reflection and green transmission.
On the surface, reflection films for reflecting green P-polarized wave and transmitting green S-polarized wave are respectively formed.

FIG. 4 is a pixel arrangement diagram of a green projected image of the projector according to the present invention. 18 is a pixel of the first green-liquid crystal light valve, and 19 is a pixel of the second green-liquid crystal light valve. In the pixel arrangement of FIG. 4, the number of green pixels is doubled, and therefore the horizontal resolution is also doubled. Normally, the human eye has a higher resolution for green and a lower resolution for red and blue, so that merely increasing the number of green pixels makes it appear that the resolution of the entire screen has increased.

FIG. 5 is a pixel arrangement diagram of a projected image of the projector according to the present invention. 18 is a pixel of the first green-liquid crystal light valve, 19 is a pixel of the second green-liquid crystal light valve, 2
Numerals 0 and 21 are red-blue liquid crystal light valve pixels, 20 is a red pixel, and 21 is a blue pixel.

FIG. 6 is a sectional view of a red-blue liquid crystal light valve. A thin film transistor 23 is formed on a glass substrate 22, and a pixel electrode 24 is further formed. Meanwhile, the opposite glass substrate
In 25, red filters 26 and blue filters 27 are alternately arranged. A light-shielding film 28 for protecting the thin film transistor from light is formed between filters corresponding to the pixels, and a counter electrode 29 is further formed. A liquid crystal material 30 is sealed between the glass substrate 22 and the opposite glass substrate 25.

5 and 6, the number of pixels corresponding to red and blue is reduced by half. However, as described above, the resolution of human eyes is lower than that of red and blue, so there is no significant effect on the image. .

FIG. 7 is a layout diagram of a green projection image of another embodiment of the projector according to the present invention. Reference numeral 18 denotes a pixel of the first green-liquid crystal light valve, and reference numeral 19 denotes a pixel of the second green-liquid crystal light valve. With this arrangement, scanning in the odd field of the TV signal is performed on the nth and (n + 1) th columns, the (n + 2) th and (n + 3) th columns, the (n + 4) th and (n + 5) th columns,. The scanning in the even-numbered field is performed in the combination of the (n + 1) th column and the (n + 2) th column, the (n + 3) th column and the (n + 4) th column... In the arrangement of FIG. 7, the vertical resolution is improved as well as the horizontal resolution.

FIG. 8 is a block diagram showing another embodiment of the projector according to the present invention. This is an example in which two green-liquid crystal light valves and one red-liquid crystal light valve and one blue-liquid crystal light valve are used. In FIG. 8, 31 is a light source, 32 is a red-blue reflecting dichroic mirror, 33 is a green beam splitter, 34 is a red reflecting dichroic mirror, 35, 3
6, 37 are reflection mirrors, 38 is a blue-liquid crystal light valve, 39 is a red-liquid crystal light valve, 40 is a first green-liquid crystal light valve, 41 is a second green-liquid crystal light valve, 42, 43, 44. Is a combining prism, and 45 is a projection lens.

In the configuration shown in FIG. 8, the resolution is doubled for green and the same for red and blue than the conventional configuration. Further, since the utilization rate of green light is doubled, a bright image is obtained.

[Effects of the Invention] As described above, according to the present invention, the resolution of a projected image can be drastically improved even if a light valve having the same number of pixels as in the related art is used. Further, according to the present invention, it is possible to provide a projector capable of projecting a bright image because the light use efficiency is high.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of the projector of the present invention. FIG. 2 is a basic configuration diagram of a conventional liquid crystal projector. FIG. 3 is a pixel arrangement diagram of a conventional liquid crystal projector. FIG. 4 is a pixel arrangement diagram of a green projected image of the projector according to the present invention. FIG. 5 is a pixel arrangement diagram of a projected image of the projector according to the present invention. FIG. 6 is a sectional view of a red-blue liquid crystal light valve. FIG. 7 is a layout diagram of a green projection image in another embodiment of the projector according to the present invention. FIG. 8 is a configuration diagram showing another embodiment of the projector according to the present invention. DESCRIPTION OF SYMBOLS 1 ... 1st green-liquid crystal light valve 2 ... 2nd green-liquid crystal light valve 3 ... red blue-liquid crystal light valve 4 ... light source 5 ... red-blue reflection dichroic mirror 6 ... green beam splitter 7a , 7b, 7c… Reflection mirror 9… Synthetic prism 10… Projection lens 11… Screen 12… Green-liquid crystal light valve 13 …… Blue-liquid crystal light valve 14 …… Red-liquid crystal light valve 15 …… Blue Reflective dichroic mirror 16 Green reflective dichroic mirror 17 Pixel 18 First green-liquid crystal light valve pixel 19 Second green-liquid crystal light valve pixel 20 Red pixel 21 Blue pixel 22 glass substrate 23 thin film transistor 24 pixel electrode 25 counter glass substrate 26 red filter 27 blue filter 28 light-shielding film 29 counter electrode 30 liquid crystal material

Claims (6)

(57) [Claims] 1. A light source; a color light separating unit that separates light emitted from the light source into green color light and red and blue color light; and two types of green color light separated by the color light separation unit. A polarization separation unit that separates the light into polarized light components, a first light valve that modulates the red and blue light separated by the color light separation unit, and one of green light separated by the polarization separation unit A second light valve that modulates the light of the polarized light component; a third light valve that modulates the other light of the polarized light component of the green color light separated by the polarization splitting means; And a synthesizing means for synthesizing light modulated by the third light valve. 2. The pixel according to claim 1, wherein each of the first to third light valves has pixels arranged in a matrix, and the pixels of the second light valve projected on a projection surface; The projector, wherein the pixels of the third light valve projected on the projection surface are shifted from each other. 3. The light valve according to claim 1, wherein each of the first to third light valves has a pixel arranged in a matrix, and the pixel of the first light valve projected on a projection surface; A projector, wherein pixels of the second light valve projected on a projection surface and pixels of the third light valve projected on the projection surface are shifted from each other. 4. A light source; color light separating means for separating light emitted from the light source into three color lights of red, green and blue; and two kinds of polarized light of the green color light separated by the color light separating means. Polarized light separating means for separating light into component light; a first light valve for modulating red light separated by the color light separating means; and a second light for modulating blue light separated by the colored light separating means. A bulb, a third light valve that modulates one of the polarized light components of the green color light separated by the polarized light separating unit, and a third light valve that modulates the green colored light separated by the polarized light separating unit. A projector comprising: a fourth light valve that modulates light of the polarization component; and a combining unit that combines light modulated by the first to fourth light valves. 5. The pixel according to claim 4, wherein each of the first to fourth light valves has pixels arranged in a matrix, and the pixels of the third light valve projected on a projection surface; The projector, wherein the pixels of the fourth light valve projected on the projection surface are shifted from each other. 6. The light valve according to claim 4, wherein each of the first to fourth light valves has pixels arranged in a matrix, and the pixels of the first light valve projected on a projection surface; A pixel of the second light valve projected on the projection surface, a pixel of the third light valve projected on the projection surface, and a pixel of the third light valve projected on the projection surface. A projector characterized in that pixels are shifted from each other.