Optics: image projectors – Cabinet encloses projector and one side of screen
Reexamination Certificate
2003-02-26
2004-11-09
Gray, David (Department: 2851)
Optics: image projectors
Cabinet encloses projector and one side of screen
C353S119000, C353S079000, C353S070000, C348S789000
Reexamination Certificate
active
06814449
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a rear projector that displays image on a transmissive screen.
2. Description of Related Art
Conventionally, a rear projector that displays a projected and enlarged image on a screen is known as a large-screen display device.
In such rear projector, the light beam from a light source is irradiated on a transmissive liquid crystal panel, where the light beam is modulated in accordance with image information by the transmissive liquid crystal panel, and is enlarged by a projection lens, of which optical path is changed by a reflection mirror to be introduced to a rear side of a screen.
According to the above arrangement, all of the components can be housed in a movable casing and the image on the screen can be viewed in a well-lighted room.
In order to adjust the position of the image displayed on the screen, a position adjuster, which normally adjusts the position of the projection lens in horizontal or vertical position, is necessary for such rear projector. Such mechanism is shown in, for instance, Japanese Patent Laid-Open Publication No. 2001-94905 and Japanese Patent Laid-Open Publication No. 2002-107663.
However, when such simple position adjuster where the position of the projection lens is horizontally or vertically adjusted is used for adjusting the position of the image, there is certain limit capable of adjusting the display position of the image and undisplayable area for displaying the image is formed on the screen even after adjusting the position of the projection lens.
Further, there is difference in the tolerance of the profile of the casing of the rear projector and the tolerance of the component installed in the casing, the tolerance causing difference in aspect ratio of the displayed image, so that the projection dispersion is generated on the image displayed on the screen.
Minute adjustment is required to optimize the projection dispersion. However, since undisplayable area is formed by the conventional divisional display position adjuster, the image cannot be displayed on the entire screen and, when large undisplayable area is formed, the displayed image runs off the edge of the screen and only the image displayed within the frame of the screen can be recognized by a viewer.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a rear projector capable of facilitating the position adjustment of the image displayed on the screen and optimizing the projection dispersion of the aspect ratio of the image caused by tolerance of components.
A rear projector according to an aspect of the present invention comprises: an image generator having an electric optical device that modulates a light beam irradiated by a light source and forms an optical image in accordance with image information and a projection optical system that enlarges and projects the optical image; a box-shaped casing that houses the image generator; and a screen exposed on one of the lateral sides of the box-shaped casing onto which the optical image generated by the image generator is projected, the casing having a support plate that supports the image generator, the image generator being mounted on a support base having a support surface inclined relative to the support plate, the support plate being provided with an inclination position adjusting mechanism that adjusts the inclination position of the image generator relative to the support plate.
The support plate may be a component independent of the casing, or may be one of the upper side, lateral side or lower side of the casing.
In the above aspect of the present invention, the support plate is provided on the casing and the image generator is located on the support base having a support surface slanted relative to the support plate, where the inclination position adjusting mechanism is provided on the support base. The attitude of the image generator projecting the generated optical image is adjusted by the inclination position adjusting mechanism. Accordingly, distortion of the image displayed on the screen can be optimized by adjusting the attitude thereof and the undisplayable area of the image projected on the screen can be narrowed in adjusting the position of the image projected and displayed on the screen by the image generator. Accordingly, even when the aspect ratio of the displayed image changes according to difference in tolerance of the configuration of the casing of the rear projector and tolerance of the components installed in the casing and dispersion is caused on the image displayed on the screen, optimization is possible by adjusting the attitude of the image generator by the inclination position adjusting mechanism, thus displaying the image on the entire screen.
Further, since the image generator is disposed on the support base having the support surface inclined relative to the support plate, the dimension of the rear projector in a direction to be away from the screen, i.e. the thickness of the rear projector can be reduced, thus reducing the size of the projector.
In the rear projector according to an aspect of the present invention, the support base may preferably be disposed on the support plate in an inclined manner.
According to the above arrangement, self-weight of the image generator can be securely received by the support base and the support plate, thus securely supporting the image generator in accordance with attitude adjustment of the image generator.
In the rear projector according to an aspect of the present invention, the support base may preferably be disposed on the lower side of the support plate in an inclined manner.
According to the above arrangement, the image generator is located between the support plate and the support base and is isolated in the casing from the other components such as the screen. Therefore, even when heat is generated in the image generator, heat migration to the other components such as the screen can be prevented by circulating cooling air along the support plate and the support base.
In the rear projector according to an aspect of the present invention, a planar position adjusting mechanism that adjusts the planar position of the image generator relative to the screen may preferably be provided on the support base.
According to the above arrangement, the planar position of the image generator relative to the screen surface can be adjusted by providing the planar position adjusting mechanism on the support base, so that the focus or the display position of the image displayed on the screen can be adjusted.
Accordingly, even when the aspect ratio of the displayed image is changed on account of difference in the tolerance of the configuration of the casing of the rear projector and the tolerance of the components installed in the casing so that the image displayed on the screen is located beyond the screen frame, undisplayable area can be narrowed by the planar position adjusting mechanism, thus displaying the image on the entire screen.
In the rear projector according to an aspect of the present invention, the planar position adjusting mechanism may preferably comprise a slide adjuster that adjusts the position of the image generator in a direction along the screen and in normal line direction of the screen.
According to the above arrangement, since the planar position adjusting mechanism has the slide adjuster, the planar position of the image generator can be adjusted by moving the slide adjuster, thus easily adjusting the planar position of the image generator.
In the rear projector according to an aspect of the present invention, a rotary position adjusting mechanism that adjusts rotary position of the image generator relative to the screen may preferably be provided on the support base.
According to the above arrangement, since the support base is provided with the rotary position adjusting mechanism, the rotation of the image generator that projects the optical image can be adjusted, thus optimizing the position shift caused by distortion or rotation of the imag
Arai Jun
Yamada Haruyoshi
Gray David
Seiko Epson Corporation
Sever Andrew
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