Optics: image projectors – Housing
Patent
1995-05-23
1998-12-01
Dowling, William
Optics: image projectors
Housing
353 57, 353 87, G03B 2114
Patent
active
058427619
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a liquid crystal projector which uses a liquid crystal panel, and more specifically it relates to the supporting structure of a liquid crystal panel, and specifically to the supporting structure of an illumination unit or projection lens element which illuminates a liquid crystal panel, and to the protection of components inside the liquid crystal projector from heat generated within a liquid crystal projector which uses a liquid crystal panel.
2. Description of the Related Art
Liquid crystal projectors include a three-layer type which uses three liquid crystal panels, one for each of the colors red, green, and blue, and a single-layer type with just a single layer, in which are located red, green, and blue filters, and in recent years a liquid crystal projector of this single-layer type, which is compact and lightweight, making it convenient for portable use, has begun to be commercially available.
The Unexamined Patent Publication Hei 4-27929 explains, in detail, this prior art.
FIG. 7 shows an example of a prior art liquid crystal projector of the single-layer type, this prior art liquid crystal projector being described, in general, below.
An illumination unit 203 includes a light source 220 and a reflector 230, and an explosion-proof tube (not shown in the drawing) is often used to house the light source 220. The light emitted from the illumination unit 203 is collected by a condenser lens 202, enters an entrance-side polarizer 101, passes through a liquid crystal cell 111, passes through an exit-side polarizer 112, passes through a projection lens 300, and is then output from the liquid crystal projector 200. The original image which is projected is formed by the entrance-side polarizer 101, the liquid cell 111, and the exit-side polarizer 112.
The circuit 600 which performs drive control, the condenser lens 202, the projection lens 300, the liquid crystal cell 111, the above-noted illumination unit 203 and the fan 400 which air cools the inside of the liquid crystal projector 200 are covered by the frame structure 500.
In a liquid crystal projector such as described above, the structure includes a large number of elements, and in addition to housing these elements in a small space, it is necessary to ensure that the installation of such elements is such that it facilitates the maintenance of such elements. As shown in FIG. 7, in the prior art, a supporting structure 204 was provided at the condenser lens 202, a supporting structure 104 was provided at the entrance-side polarizer 101, and the liquid crystal cell 111 and exit-side polarizer 115 were held between a supporting frame structure 116.
Because assembly was done by mounting the condenser lens 202, the entrance-side polarizer 101, and such components into the supporting structure such as the supporting structure 204, it was necessary to have a supporting structure for each mounted component, making necessary a large space inside the liquid crystal projector. In order to support the entrance-side polarizer 101 and condenser lens 202 in the lateral direction (in the direction of the observer with respect to the drawing) in the prior art, depressions and protrusions were provided in the mounting frame structure mounted in the lateral direction to provide a structure to support these components, and this involved the problem of the labor required to fit the edges of these components between the depressions and protrusions in the frame structure. In addition, the liquid crystal panel unit 110 shown in FIG. 7 uses screws to implement it as a unit, the tightening of these screws presenting the problems of added labor steps in both assembly and maintenance.
In addition, in the prior art liquid crystal projector as described above, a high-intensity xenon lamp, halogen lamp, metal halide lamp, or the like is used as the light source 220, this type of lamp generating a considerable amount of heat. In the prior art liquid crystal projector as shown in FIG. 7, because t
REFERENCES:
patent: 4925295 (1990-05-01), Ogawa et al.
patent: 4976429 (1990-12-01), Nagel
patent: 5092671 (1992-03-01), Van Os
patent: 5170196 (1992-12-01), Itoh
patent: 5287132 (1994-02-01), Suzuki et al.
patent: 5347324 (1994-09-01), Sasaki et al.
patent: 5418586 (1995-05-01), Fujimori et al.
Futakami Shigeru
Matsuyama Katsuo
Okano Terutaka
Citizen Watch Co. Ltd.
Dowling William
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