JP3413685B2 - Projector device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projector for projecting an image reproduced by an image display panel such as a liquid crystal display panel onto a screen via a projection lens. 2. Description of the Related Art Heretofore, three image display panels such as a liquid crystal display panel (LCD) were used, and white light was separated by a color separation mirror (dichroic mirror) on each of these image display panels. There is a projector device in which primary color lights (red (R), green (G), and blue (B)) are incident correspondingly, and light beams transmitted through the video display panel are combined and projected on a screen. Proposed. [0003] Each of the above-mentioned image display panels displays an image of a corresponding primary color component of an original image in light and dark. [0004] As shown in FIG. 2, this projector device has a light source 101. This light source 10
The first luminous flux emitted from the first dichroic mirror 102 is combined with the first primary color light (for example, R) by the
And third primary color light (for example, G and B).
The first primary color light is deflected by 90 ° and the second and third
Primary color light goes straight. [0005] The first primary color light is applied to a first mirror 103.
, And is transmitted through the first video display panel 104 to be a color combining prism (dichroic prism).
105. [0006] The second and third primary color lights enter a second dichroic mirror 106 and are separated into the second primary color light and the third primary color light. The second primary light is deflected by 90 ° and the third primary light goes straight. [0007] The second primary color light passes through the second video display panel 107 and enters the color combining prism 105. The third primary color light is deflected by 90 ° by the second mirror 108,
09, the third image display panel 1 is deflected by 90 °.
Then, the light is transmitted to the color synthesizing prism 105. The color synthesizing prism 105 synthesizes the incident primary color lights and makes the light enter the projection lens 111.
The projection lens 111 projects the incident light beam on the screen 112 as an image. A projector device described in Japanese Patent Application Laid-Open No. 5-107658 discloses a projector as shown in FIG.
The light source 201 has a light source 201, and a white light beam emitted from the light source 201 is converted by a first dichroic mirror 202 into first primary color light (for example, R) and second and third primary color light (for example, G and B). And separated into The first primary color light is 9
The light is deflected by 0 °, and the second and third primary color lights travel straight. The first primary color light is deflected by 90 ° by the one surface portion 208 of the double-sided mirror, is deflected by 90 ° by the first mirror 210, is further deflected by 90 ° by the second mirror 211, and is deflected by 90 °. A color combining prism (dichroic prism) 213 is transmitted through the image display panel 212.
Is incident on. The second and third primary color lights are deflected by 90 ° by a third mirror 203 and are incident on a second dichroic mirror 204. The second dichroic mirror 204 converts the incident light beam into a second primary color light and a third primary color light.
And primary color light. The second primary light is deflected by 90 ° and the third primary light goes straight. The second primary color light is deflected by 90 ° by the other surface 207 of the double-sided mirror, passes through the second image display panel 209, and enters the color combining prism 213. The third primary color light is deflected by 90 ° by the fourth mirror 205, and the third primary color light is reflected by the third image display panel 2.
06, and enters the color synthesis prism 213. The color combining prism 213 combines the incident primary color lights and makes the light enter the projection lens 214. The projection lens 214 projects the incident light beam on the screen 215 as an image. The projector described in Japanese Patent Application Laid-Open No. 5-66505 is also disclosed in Japanese Patent Application Laid-Open No. 5-10505.
It has a configuration similar to that of the projector device described in JP-A-7658. That is, as shown in FIG. 4, the projector device has a light source 301, and a white light beam emitted from the light source 301 is converted into a first primary color light (for example, R) by a first dichroic mirror 302.
The light is separated into second and third primary color lights (for example, G and B). The first primary color light goes straight, and the second and third primary color lights are deflected by 90 °. The first primary color light is deflected by 90 ° by the one surface portion 307 of the double-sided mirror, is deflected by 90 ° by the first mirror 308, is further deflected by 90 ° by the second mirror 309, and is deflected by 90 °. A color combining prism (dichroic prism) 313 is transmitted through the image display panel 310.
Is incident on. The second and third primary color lights are deflected by 90 ° by a third mirror 303 and are incident on a second dichroic mirror 304. The second dichroic mirror 304 converts the incident light beam into a second primary color light and a third primary light.
And primary color light. The second primary light is deflected by 90 ° and the third primary light goes straight. The second primary color light is deflected by 90 ° by the other surface portion 312 of the double-sided mirror, passes through the second video display panel 311, and enters the color combining prism 313. The third primary color light is deflected by 90 ° by the fourth mirror 305, and the third image display panel 3
06, and is incident on the color synthesis prism 313. The color combining prism 313 combines the incident primary color lights and makes the light enter the projection lens 314. The projection lens 314 projects an incident light beam on a screen 315 as an image. Incidentally, in the projector device shown in FIG. 2, the optical path length from the light source of each primary color light to the corresponding video display panel is different from each other. Therefore, the light intensity of the light flux incident on each image display panel is different from each other, and there is a possibility that an image on the screen 112 may have uneven brightness or color. In the projector device shown in FIGS. 3 and 4, the optical path lengths from the light source of each primary color light to the corresponding video display panel are made equal to each other. However, in these projector devices, a double-sided mirror is used in the optical path. Since this double-sided mirror must face both sides to the optical path, it can support only the peripheral part, and it is difficult to position and robustly support it. Will be invited. Further, in these projector devices, the luminous flux from the light source is color-separated into three primary colors by two dichroic mirrors, so that the color separation characteristics cannot be made sharp. It is difficult to improve color reproducibility (color distinction) in a projected image. Accordingly, the present invention has been proposed in view of the above-described circumstances, and has no luminance unevenness or color unevenness, and can project an image having good color reproducibility. It is an object of the present invention to provide a projector device which is easy to perform. In order to solve the above problems and achieve the above object, a projector apparatus according to the present invention comprises a light source, a light beam emitted from the light source, and a first light beam. The primary color light and the second and third primary color light
A cross dichroic mirror that separates with a separation angle of 0 ° and a first dichroic mirror passing through the cross dichroic mirror
A first mirror for deflecting the primary color light by 90 °, and the first mirror
The first primary color light deflected by the mirror is deflected by 90 °, transmitted through the first video display panel, and incident on the first incident surface of the color combining prism, and passed through the cross dichroic mirror. The second and third primary color lights are 90
A third mirror for deflecting, and separating the second and third primary color lights deflected by the third mirror into the second primary color light and the third primary color light, and separating the second primary color light with the second primary color light. And a dichroic mirror that deflects the third primary color light by 90 °, and the second dichroic mirror that passes through the dichroic mirror.
A fourth mirror that deflects the primary color light by 90 °, transmits the second image display panel, and makes it incident on a second incident surface of the color combining prism opposite to the first incident surface; and a dichroic mirror. The deflected third primary color light is deflected by 90 °, transmitted through a third image display panel, and is perpendicular to the first and second incident surfaces of the color combining prism.
And a fifth mirror for making the light incident on the light incident surface of the light source. The color synthesizing prism combines the respective primary color lights transmitted through the respective image display panels and causes the combined light to enter a projection lens. The optical path length to each video display panel
They are almost equal to each other. In the projector according to the present invention, the optical path lengths of the primary color lights emitted from the light source and separated by the cross dichroic mirror and the dichroic mirror from the light source to the corresponding video display panels are substantially equal to each other. Since they are made equal, no color unevenness or luminance unevenness occurs on an image projected by combining the primary color lights. In this projector device,
Since the separation of the light beam from the light source is performed by a total of three pieces of the cross dichroic mirror and the dichroic mirror, the color selection characteristics can be made steep. Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the projector device according to the present invention separates a light source 1 and a white light beam emitted from the light source into three primary colors (red (R), green (G), and blue (B)). In addition, it is configured to have a plurality of dichroic mirrors and mirrors for guiding the first to third video display panels 7, 13, and 15 corresponding to the respective primary color light beams. The light source 1 and the video display panels 7, 1
3, 15, each of the above dichroic mirrors and mirrors,
It is fixed and disposed in an outer housing (not shown). The light source 1 has a light-emitting portion such as a metal halide lamp or a halogen lamp and a light-collecting / reflecting mirror. Each of the video display panels 7, 13, 15 is
For example, a liquid crystal display (LCD) displays an image of a corresponding primary color component of the original image in light and dark (transmission density). The white luminous flux emitted from the light source 1 is cross-dichroic mirror 2 by a first primary luminous flux (for example, red luminous flux (R)) 3 and second and third primary luminous fluxes (for example, green (G)). And blue (B)) 4. The cross dichroic mirror 2 is composed of two
The dichroic mirrors are configured to intersect at right angles to each other at the center. Accordingly, the first primary color light beam 3 is deflected by 90 °, and the second and third primary color light beams 4 are deflected by 90 ° to the opposite side. That is, the separation angle between the first primary color light beam 3 and the second and third primary color light beams 4 is 180 °. The first primary color light beam 3 is supplied to a first mirror 5
, Is further deflected by 90 ° by the second mirror 6, passes through the first video display panel 7,
First of color synthesis prism (dichroic prism) 16
Is incident on the incident surface of. The second and third primary color light beams 4 are deflected by 90 ° by the third mirror 8 and enter the dichroic mirror 9. The dichroic mirror 9 separates the incident light beam into a second primary color light beam (for example, G) 10 and a third primary color light beam (for example, B) 11. The second primary color beam 10 goes straight and the third primary color beam 11 is deflected by 90 °. The second primary color light beam 10 is deflected by 90 ° by the fourth mirror 12 and the second image display panel 13
And is incident on a second incident surface of the color combining prism 16 which faces the first incident surface. The third primary color light beam 11 is deflected by 90 ° by the fifth mirror 14, passes through the third video display panel 15, and passes through the first color combining prism 16.
And a third incident surface perpendicular to the second incident surface. The color synthesizing prism 16 is formed in the shape of a square column having four planes on the peripheral side, and the first and third incident surfaces are opposed to each other in parallel with each other.
Is perpendicular to the first and third incident surfaces, and a surface facing in parallel with the second incident surface is an exit surface. The color synthesizing prism 16 includes first to third colors.
The primary color light beams 3, 10, and 11 incident from the incident surface are combined, emitted from the exit surface, and incident on the projection lens 17. The projection lens 17 projects an incident light beam on a screen 18 as an image. In this projector device, the first and second mirrors 5 and 6 and the third and fourth mirrors 8 and 12 are located at positions symmetrical with respect to the cross dichroic mirror 2. Since the fourth mirror 12 and the fifth mirror 14 are arranged at symmetrical positions with respect to the dichroic mirror 9, the light sources of the primary color light beams 3, 10, 11 are arranged. The optical path lengths from 1 to the corresponding image display panels 7, 13, 15 are substantially equal to each other. Therefore, in this projector device, color unevenness and brightness unevenness do not occur in the image on the screen 18 projected by combining and projecting the primary color light beams 3, 10, and 11. In this projector device,
Since the color separation of the white light beam from the light source 1 is performed by the cross dichroic mirror 2 and the dichroic mirror 9, a total of three dichroic mirrors are used.
The color selection characteristics become steep, and an image with good color reproducibility can be projected. Further, in this projector device, the primary color light beams 3, 10, and 11 pass through the cross dichroic mirror 2 so that when entering the video display panels 7, 13, and 15, they are mutually polarized. The directions are equal. Therefore, in this projector device, when each of the video display panels 7, 13, 15 is a liquid crystal display panel, the polarization directions of the polarizing filters of these video display panels 7, 13, 15 must be equal to each other. And assembly and manufacturing can be facilitated. As described above, in the projector device according to the present invention, each primary color light emitted from the light source and separated by the cross dichroic mirror and the dichroic mirror extends from the light source to the corresponding video display panel. Are substantially equal to each other. For this reason, in this projector device, on the image projected by combining the above primary color lights,
No color or luminance unevenness occurs. In this projector device,
Since the separation of the light beam from the light source is performed by a total of three pieces of the cross dichroic mirror and the dichroic mirror, the color selection characteristics can be made steep. Further, in this projector device, since a double-sided mirror is not used for the optical path column, manufacture is easy. That is, the present invention can provide a projector device which is free from unevenness in brightness and color, can project an image having good color reproducibility, and is easy to manufacture. is there.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view showing a configuration of a projector device according to the present invention. FIG. 2 is a plan view showing a configuration of a conventional projector device. FIG. 3 is a plan view showing another example of the configuration of the conventional projector device. FIG. 4 is a plan view showing still another example of the configuration of the conventional projector device. DESCRIPTION OF SYMBOLS 1 Light source 2 Cross dichroic mirror 3 First primary color light 5 First mirror 6 Second mirror 7 First video display panel 8 Third mirror 9 Dichroic mirror 10 Second primary color light 11 Third primary color light 12 Fourth mirror 13 Second video display panel 14 Fifth mirror 15 Third video display panel 16 Color combining prism

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02F 1/13-1/141 G03B 33/12

Claims (1)

(57) [Claim 1] A light source and a light beam emitted from the light source are incident, and this light beam is converted into a first primary color light and second and third primary color lights by 180 A cross dichroic mirror for separating with a separation angle of ゜, a first mirror for deflecting the first primary color light passing through the cross dichroic mirror by 90 °, and a first primary color deflected by the first mirror 90 light
A second mirror that deflects the light, transmits the first image display panel, and enters the first entrance surface of the color combining prism, and deflects the second and third primary color lights that have passed through the cross dichroic mirror by 90 ° A third mirror to be split, and the second and third primary color lights deflected by the third mirror are separated into the second primary color light and the third primary color light,
A dichroic mirror that causes the second primary color light to travel straight and deflects the third primary color light by 90 °; and a 9 dichroic mirror that passes the second primary color light through the dichroic mirror.
A fourth mirror that deflects by 0 °, transmits through the second video display panel, and impinges on the second incident surface of the color combining prism opposite to the first incident surface, and is deflected by the dichroic mirror The third primary color light is deflected by 90 °, transmitted through a third image display panel, and made incident on a third incident surface of the color combining prism perpendicular to the first and second incident surfaces. A fifth mirror, wherein the color synthesizing prism synthesizes each primary color light transmitted through each image display panel and makes it incident on a projection lens, from the light source of each primary color light to each corresponding image display panel. Are optical devices having substantially the same optical path length.