JPH0660833U - Projection type image display device - Google Patents

Abstract

(57) [Abstract] [Purpose] Improving the brightness of a projected image without shortening the life of the light source, and uneven brightness, uneven color of the projected image,
Prevents uneven brightness. A light source section, liquid crystal panels 11, 12 and 13 that are modulated by a transmittance of light emitted from the light source section according to image information and are inclined in a vertical direction by a preferential viewing angle, and a liquid crystal panel that transmits the liquid crystal panel. In the liquid crystal projector including the projection lens 16 that projects the generated light and is movable in the vertical direction,
Two light sources 1a in which the light source units are arranged to face each other in the vertical direction,
1b.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a projection type image display device such as a liquid crystal projector.

[0002]

[Prior art]

 Conventionally, in a projection type image display device disclosed in Japanese Patent Application Laid-Open No. 4-138445, etc., after the light from a light source unit is split into light of three primary colors of red, green and blue by a dichroic mirror, the split light is split. Is transmitted through an image forming panel such as a liquid crystal panel through a condenser lens, and then the light having image information transmitted through this image forming panel is combined by a dichroic mirror, and the combined light is projected on a screen by a projection lens. Then the image is displayed.

In the above-mentioned projection type image display device, the light source unit is composed of a high-intensity light source such as a metal halide lamp, and a reflector having a rotating quadric surface for condensing light from the light source into substantially parallel light. ing. Conventionally, such a light source unit is composed of one light source, and in order to improve the brightness of the projected image, the light collection efficiency by the reflector is increased or the light emission amount of the light source itself is increased. By doing so, high brightness is achieved.

However, in order to increase the brightness of the projected image as described above, there is a limit to the increase in the brightness by the method of increasing the light-collecting efficiency by the reflector, and the method of increasing the light emission amount of the light source itself does not increase the brightness of the light source. There is a problem that the life is shortened.

Further, with such one light source, the image projected on the screen is likely to be affected by uneven brightness and uneven color due to the characteristics of each light source, and a portion corresponding to the center of the light source. Then, the brightness becomes uneven, and as it gets away from it, the brightness becomes uneven. In particular, the adverse effects of such uneven brightness, uneven color, and uneven brightness appear significantly in the moving direction when the projection lens is moved to adjust the optical axis.

When the image forming panel is formed of a liquid crystal panel, in order to obtain maximum brightness and contrast, the liquid crystal panel is usually tilted by a preferential viewing angle vertically with respect to the direction orthogonal to the optical axis of the light source. ing. However, the light emitted from one light source is incident at the optimum priority viewing angle at which the maximum brightness can be obtained in the center of the image forming part of the liquid crystal panel, but at the upper and lower end parts of the image forming part, the optimum priority viewing angle is obtained. Since the light is incident at an angle that is far from the angle, the brightness of the projected image is bright at the center of the image and dark at the upper and lower ends, resulting in uneven brightness.

[0007]

[Problems to be solved by the device]

 The present invention has been made in view of the drawbacks of the above-mentioned conventional example, and improves the brightness of the projected image without shortening the life of the light source, and suppresses uneven brightness, uneven color, uneven brightness, etc. of the projected image. Another object of the present invention is to provide a projection type image display device.

[0008]

[Means for Solving the Problems]

 The projection type image display device of the present invention comprises a light source unit, an image forming panel for modulating the transmittance of light emitted from the light source unit according to image information, and a projection lens for projecting light transmitted through the image forming panel. The light source unit is composed of a plurality of light sources.

Further, the projection type image display device of the present invention is characterized in that the projection lens is movable and a plurality of light sources of the light source unit are arranged in a moving direction of the projection lens.

Further, in the projection type image display device of the present invention, the image forming panel is a liquid crystal panel tilted by a predetermined angle with respect to a direction orthogonal to the optical axis of the light source unit, and The light source is arranged in the tilt direction of the liquid crystal panel.

[0011]

[Action]

 According to the above configuration, the amount of light from the light source is increased without increasing the amount of light emitted from each light source, and the light from a plurality of light sources is superimposed. Are canceled out, and uneven brightness of the projected image is suppressed.

Further, according to the above configuration, since the light emitted from the light source is superimposed in the moving direction of the projection lens, uneven brightness, uneven color and uneven brightness in the moving direction are reduced.

Further, according to the above configuration, since the plurality of light sources are arranged in the tilt direction of the liquid crystal panel, the incident angles of the light from the light sources are substantially equal to each other in the tilt direction of the liquid crystal panel. The liquid crystal panel can allow light to enter at an angle substantially equal to the optimum priority viewing angle in the entire tilt direction.

[0014]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing a configuration of a liquid crystal projector which is a projection type image display device of the present embodiment, and FIG. 2 is a diagram showing a relationship between a light source and a liquid crystal panel in the liquid crystal projector.

In the liquid crystal projector of the present embodiment, the light source section is composed of two light sources 1a and 1b made of metal halide lamps, reflectors 2a and 2b respectively corresponding to the light sources 1a and 1b, and the light sources 1a and 1b. It is composed of reflection mirrors 3a and 3b that reflect light toward the liquid crystal panel and the projection lens. The two light sources 1a and 1b are opposed to each other in the vertical direction, and the light emitted from the light sources 1a and 1b is irradiated by the reflectors 2a and 2b in the directions opposite to each other. The direction of the irradiated light is changed by 90 ° by the reflection mirrors 3a and 3b.

In FIG. 1, 4 and 5 are dichroic mirrors for separating light, 6 and 7 are reflectors, 8 and 9 and 10 are condenser lenses, 11 and 12 and 13 are liquid crystal panels (image forming panels), and 14 , 15 is a dichroic mirror for photosynthesis, and 16 is a projection lens. The projection lens 16 is movable in the vertical direction (the direction of arrow A) for adjusting the optical axis, that is, in the same direction as the direction in which the light sources 1a and 1b face each other.

The light whose direction is changed by the reflection mirrors 3 a and 3 b is split into three primary colors of red (R), blue (B) and green (G) by the dichroic mirrors 4 and 5. The transmittance of the dispersed light is modulated in the liquid crystal panels 11, 12 and 13 on each optical path according to the image information of each color component. The modulated lights are combined by the dichroic mirrors 14 and 15 and enlarged and projected on the screen by the projection lens 16.

In the liquid crystal projector of this embodiment, as shown in FIG. 2, the liquid crystal panels 11, 12 and 13 are inclined by a preferential viewing angle θ in the vertical direction with respect to the direction orthogonal to the optical axes from the light sources 1a and 1b. ing. The light sources 1a and 1b are arranged so that their light source optical axes 17a and 17b are vertically spaced from the center O of the liquid crystal panels 11, 12 and 13 by the same distance a, and the distance a is set to the liquid crystal panel 11, It is about 10% with respect to the vertical length b of the image forming regions 12 and 13.

In the liquid crystal projector of this embodiment as described above, the light emitted from the two light sources 1 a and 1 b is transmitted through the liquid crystal panels 11, 12 and 13, and the transmitted light is reflected by the projection lens 16. Since the image is projected on the screen, the brightness of the image projected on the screen can be increased without increasing the light amount of each of the light sources 1a and 1b. Further, the color unevenness and the brightness unevenness of the projected image due to the respective characteristics of the light sources 1a and 1b are canceled by superimposing the lights from the two light sources 1a and 1b.

Further, since the light sources 1a and 1b are arranged so as to face each other in the vertical direction, the lights emitted from the two light sources 1a and 1b are superimposed in the vertical direction, and the projection lens is moved in the vertical direction. The unevenness of the brightness of the projected image that occurs when the projection is performed can also be suppressed.

Since the two light sources 1a and 1b are arranged in the vertical direction in which the liquid crystal panels 11, 12 and 13 are inclined by the preferential viewing angle, the light emitted from the light sources 1a and 1b is the liquid crystal panel. Light is incident at an angle equal to the optimum priority viewing angle in the vertical direction of the image forming units 11, 12, and 13, and the unevenness of the brightness of the projected image in the vertical direction is reduced.

In the above embodiment, the distance a from the center O of the liquid crystal panels 11, 12, 13 of the light source optical axes 17a, 17b is the length of the liquid crystal panels 11, 12, 13 in the upper and lower directions of the image forming areas. It is about 10% with respect to the height b, but if it is about 7 to 13%, it is possible to realize the above-described uniform brightness of the projected image of the present invention.

[0024]

[Effect of device]

 According to the present invention, the amount of light from the light source unit is increased to improve the brightness of the projected image without shortening the life of the light source, and uneven brightness, uneven color, uneven brightness, etc. of the projected image can be eliminated. It is possible to provide a projection-type image display device which is prevented.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a projection-type image display device of the present invention.

FIG. 2 is a diagram showing a relationship between a light source unit and a liquid crystal panel of the projection type image display device of the present invention.

[Explanation of symbols]

 1a, 1b Light source 11, 12, 13 Liquid crystal panel (image forming panel) 16 Projection lens

Front page continuation (72) Creator Miho Hoshino 2-18 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd.

Claims (3)

[Scope of utility model registration request] 1. A projection-type image including a light source section, an image forming panel that modulates a transmittance of light emitted from the light source section according to image information, and a projection lens that projects light transmitted through the image forming panel. In the display device, the projection-type image display device, wherein the light source section is composed of a plurality of light sources. 2. The projection image display apparatus according to claim 1, wherein the projection lens is movable, and a plurality of light sources of the light source unit are arranged in a moving direction of the projection lens. 3. The image forming panel is a liquid crystal panel tilted at a predetermined angle with respect to a direction orthogonal to the optical axis of the light source section, and a plurality of light sources of the light source section are arranged in a tilt direction of the liquid crystal panel. The projection-type image display device according to claim 1, characterized in that.