JPH09133967A - Liquid crystal projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent exhaust air from directly blowing off a peripheral equipment and a human being by providing an exhaust port exhausting remaining heat from a light source on the front surface of the same set as the projecting surface of a projection lens and discharging the exhaust air from the light source in the forward direction of the set. SOLUTION: A metal halide lamp 1 being the light source is arranged right beside the projection lens 9. A ventilating fan 11 is arranged on the same surface as the projecting direction of the lens 9 with respect to a lamp house 10, and the exhaust port 12 is arranged on the front surface of the set. Infrared rays and ultraviolet rays 43 emitted from the lamp 1 are transmitted through an infrared and ultraviolet H transmitting condensing reflector 2, and the heat remaining inside the lamp house 10 is discharged by the fan 11 from the exhaust port 12. At such a time, since the exhaust air 13 is discharged in nearly the same direction as projected video light 44, the operator positioned avoiding the light 44 or the observer of the video, and further the peripheral equipment are not directly exposed to the exhaust air 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal projector in which illumination light emitted from a light source is incident on a liquid crystal panel, modulated by the liquid crystal panel into image light, and then the image light is enlarged and projected onto a screen by a projection lens. Is.

[0002]

2. Description of the Related Art Conventionally, as a liquid crystal projector, a light source (corresponding to the light source 1) and a dichroic mirror (corresponding to the dichroic mirrors 10 and 14) are shown in FIG. 1 of JP-A-4-68689, for example. , A transmissive liquid crystal panel (corresponding to the liquid crystal panels 12a to 12c) and a projection lens, and the irradiation light emitted from the light source is color-separated by the dichroic mirror into illumination lights of three primary colors of red, blue, and green. There is known a system in which a liquid crystal panel is transmitted and modulated into image light, red, blue, and green image lights are recombined by a dichroic mirror and enlarged and projected on a screen by a projection lens.

[0003]

However, in the liquid crystal projector using the conventional transmissive liquid crystal panel, there is a problem in the position of the exhaust port for discharging the residual heat inside the set.

FIG. 4 is a side view of an optical system of a conventional liquid crystal projector. Metal halide lamp 21 which is the light source
The irradiating light 41 emitted from is reflected by the infrared-UV transmitting and condensing reflector 22, passes through the reflecting mirror 23, and is red by the dichroic mirrors 24r, 24b, and 24g.
The colors are separated into three primary colors, blue and green. Each irradiation light passes through the plano-convex lens 25 and then is transmitted through the transmissive liquid crystal panel 2.
6r, 26b, 26g is modulated to the image light 42,
To Penetrate. The image lights 42 of the three primary colors of red, blue and green are color-synthesized by the dichroic mirrors 14r, 14b and 14g, and enlarged and projected by the projection lens 29.

Here, the metal halide lamp 2 which is the light source
The infrared rays and the ultraviolet rays 43 emitted from 1 are transmitted through the infrared ultraviolet ray transmitting and condensing reflector 22, are absorbed inside the lamp house 30, and become heat. The heat trapped inside the lamp house 30 is exhausted rearward by the exhaust fan 31 from the exhaust port 32 located on the rear surface of the set. Assuming that the exit surface of the projection lens is the front surface of the set, the conventional liquid crystal projector has a configuration in which the light source and the projection lens are located on the diagonal of the set, and the light source is located behind the set. It was Therefore, the exhaust port for exhausting the residual heat from the light source has been arranged on the back surface of the set or on either side surface.

In order to increase the brightness of the liquid crystal projector,
There is a tendency to use a metal halide lamp or a halogen lamp having a high output of 150 W to 400 W as a light source. Due to infrared rays and ultraviolet rays generated from the lamp, heat near the lamp house becomes considerably high. Therefore, the exhaust temperature when exhausting the heat inside the lamp house is 4
It may exceed 0 degrees. Conventionally, the hot air discharged from the exhaust port has been a problem that cannot be ignored.

First, when using a liquid crystal projector,
There was a problem that the operator or the viewer of the image was directly exposed to the heat. Further, when using a liquid crystal projector, peripheral devices such as a personal computer, a VTR, and an LD, which are video signal generators, are often installed right next to or behind the set. In that case, the exhaust port of the liquid crystal projector is adjacent to the intake port of the cooling device of the peripheral device, and the hot air emitted from the exhaust port is sucked into the intake port of the peripheral device, causing a problem that the peripheral device fails due to heat. Was there.

Further, since the entire lamp house including the light source has a large amount of heat, the liquid crystal panel disposed near the light source inside the set is affected by the heat of the light source, which causes deterioration of image quality.

It is an object of the present invention to provide an optical system configuration in which exhaust gas from the light source of the liquid crystal projector is exhausted in the front direction of the set so that the peripheral devices and persons are not directly exhausted.

Another object of the present invention is to provide a compact optical system configuration while maintaining stable image quality by disposing a liquid crystal panel which is easily affected by heat from a light source.

[0011]

In order to solve the above problems,
In the present invention, attention is paid to the fact that the operator or peripheral equipment is not located on the optical axis of the outgoing image light in the front direction of the set of the liquid crystal projector, and the exhaust port for exhausting heat generated from the light source is provided on the front side of the set (projection). The optical system is arranged so that the exit surface of the lens is located) and the exhaust direction is almost the same as the direction of the image light emitted from the projection lens.

In the projection type projector, the operator of the projector and the viewer of the image will naturally avoid the front of the set because they will block the image light if they are located in front of the set. The same applies to peripheral devices, and they are generally not placed in front of the set. Therefore, by adopting the above configuration, the problem that the exhaust air from the liquid crystal projector is directly applied to the peripheral device and the person is solved.

Further, in the present invention, since the above-mentioned constitution is possible and the light source is arranged away from the liquid crystal panel,
A reflective liquid crystal panel is used as the liquid crystal panel, and the light source is arranged right next to the projection lens.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a top view showing an outline of an optical system of a liquid crystal projector according to a first embodiment of the present invention. As shown in FIG. 1, the metal halide lamp 1, which is a light source, is arranged right next to the projection lens 9. The exhaust fan 11 is arranged on the same surface as the emission direction of the projection lens with respect to the lamp house 10, and the exhaust port 12
Is located on the front of the set.

FIG. 2 is a side view of the optical system of the liquid crystal projector of this embodiment. In FIG. 2, the projection lens 9 and the minute mirror 4 located behind the lamp house 10 and the reflection mirror 3 are illustrated by broken lines. As shown in FIG. 2, the dichroic prism 6 is composed of three prisms, and is configured to separate white light emitted from a light source into three primary colors of red, blue and green. Reflective liquid crystal panels 7r, 7b and 7g corresponding to the three primary colors are attached to the upper surface, lower surface and rear surface of the dichroic prism 6, respectively.

The operation of the liquid crystal projector of this embodiment will be described below with reference to FIGS. 1 and 2. Illumination light 41 emitted from the metal halide lamp 1 is reflected by the infrared-ultraviolet transmitting and condensing reflector 2 and is moved in a substantially parallel optical path by the reflecting mirror 3 and the minute mirror 4, and then the plano-convex lens 5 is used.
It is incident on the dichroic prism 6 via. The irradiation light 41 is separated into three primary colors of red, blue, and green by the dichroic prism 6, and the respective reflection type liquid crystal panels 7r,
The light is incident on 7 b and 7 g, is modulated into the image light 42, is then reflected, and is color-synthesized by the dichroic prism 6.

The color-combined image light 42 is transmitted through the plano-convex lens 5.
Through the aperture stop 7 and then enters the projection lens 9 to become the outgoing image light 44 expanded by the projection lens and exits from the exit surface of the projection lens.

The infrared rays and the ultraviolet rays 43 emitted from the metal halide lamp 1 are transmitted through the infrared ultraviolet ray transmitting and condensing reflector 2 and absorbed by the inner wall of the lamp house 10,
Change into heat. The heat trapped inside the lamp house is exhausted from the exhaust port 12 by the exhaust fan 11.

At this time, in the liquid crystal projector of the present embodiment, the exhaust 13 is discharged in substantially the same direction as the emitted image light 44, so that the operator or the image observer positioned away from the emitted image light 44, and Peripheral equipment directly exhausts 13
Never be exposed to.

Further, the hot air trapped in the lamp house 10 is promptly discharged to the front, and the dichroic prism 6
Is placed away from the light source, the liquid crystal panel 7
The a, 7b, and 7c are less susceptible to the heat of the light source, and the deterioration of the image quality due to the heat can be avoided.

As described above, in the liquid crystal projector according to the present embodiment, the exhaust port for exhausting the heat of the lamp house is arranged on the entire surface of the set, so that the exhaust is directly supplied to the operator of the liquid crystal projector, the viewer of the image, or the image generation. It has the effect of not spraying on peripheral devices such as sources. In addition, the light source can be kept away from the liquid crystal panel inside the set, which has the effect of reducing the size of the set while suppressing the image quality deterioration of the liquid crystal panel due to temperature rise.

(Second Embodiment) A second embodiment of the present invention will be described below with reference to FIG. FIG. 3 is a top view of the optical system of the liquid crystal projector of this embodiment. The optical system of this embodiment is
The structure is the same as that of the first embodiment except that two metal halide lamps are used as the light source, and the same reference numerals are given to the same portions and the description thereof will be omitted. As shown in FIG. 3, in the present embodiment, two metal halide lamps 1 are arranged on the left and right sides of the projection lens 9, and two exhaust ports are symmetrically arranged on the front side of the set with the projection lens 9 interposed therebetween. It is a configuration.

As described above, also in the present embodiment, as in the first embodiment, the exhaust port for exhausting the heat of the lamp house can be arranged on the front surface of the set, and the exhaust air is not blown to the operator or peripheral equipment. effective. In addition, the light source can be kept away from the liquid crystal panel inside the set, which has the effect of reducing the size of the set while suppressing the image quality deterioration of the liquid crystal panel due to temperature rise.

Furthermore, in this embodiment, the use of two metal halide lamps has the effect of providing an image with even higher brightness.

[0026]

As is apparent from the above description, in the liquid crystal projector of the present invention, exhaust air (hot air) is not directly blown to the operator of the liquid crystal projector or the viewer of the image, and the image can be comfortably viewed. There is an effect that you will be able to.

Further, there is an effect that peripheral devices installed in the periphery are less likely to be affected by heat.

In addition, the light source, which is the maximum heat generating portion, can be kept away from the liquid crystal panel, which is greatly affected by heat, inside the set, and the image deterioration due to the temperature rise can be suppressed.

Further, there is an effect that the set can be made compact.

[Brief description of the drawings]

FIG. 1 is a top view of an optical system of a liquid crystal projector according to a first embodiment of the present invention.

FIG. 2 is a side view of an optical system of the liquid crystal projector of the first embodiment of the present invention.

FIG. 3 is a top view of an optical system of a liquid crystal projector according to a second embodiment of the present invention.

FIG. 4 is a side view of an optical system of a conventional liquid crystal projector.

[Explanation of symbols]

1 ... Metal halide lamp, 2 ... Infrared ultraviolet condensing reflector, 3 ... Reflecting mirror, 4 ... Reflecting mirror, 5 ... Plano-convex lens, 6 ... Dichroic prism, 7r. 7b. 7 g
... Reflective liquid crystal panel, 8 ... Aperture stop, 9 ... Projection lens,
10 ... Lamp house, 11 ... Exhaust fan, 12 ... Exhaust port, 13 ... Exhaust, 21 ... Metal halide lamp, 22 ...
Infrared UV transmitting condensing reflector, 23 ... Reflecting mirror,
24r, 24b, 24g ... Dichroic mirror, 25
... Plano-convex lens, 26r, 26b, 26g ... Dichroic mirror, 27r. 27b. 27 g ... Transmissive liquid crystal panel, 29 ... Projection lens, 30 ... Lamp house, 31 ... Exhaust fan, 32 ... Exhaust port, 33 ... Exhaust, 41 ... Illumination light,
42 ... Image light, 43 ... Infrared rays and ultraviolet rays, 44 ... Outgoing image light.

Claims (2)

[Claims] 1. A liquid crystal projector comprising a light source, a liquid crystal panel, and a projection lens, wherein illumination light emitted from the light source is modulated into image light by the liquid crystal panel and enlarged and projected by the projection lens. There is an exhaust port for exhausting at the front of the same set as the exit surface of the projection lens,
In addition, the liquid crystal projector is characterized in that the exhaust direction is substantially the same as the direction in which the image light is emitted. 2. The liquid crystal projector according to claim 1, wherein a reflection type liquid crystal panel is used, and a light source is arranged substantially adjacent to a side of a projection lens.