Optical: systems and elements – Projection screen
Reexamination Certificate
1999-12-08
2002-05-14
Adams, Russell (Department: 2851)
Optical: systems and elements
Projection screen
C359S449000, C359S460000, C353S051000, C353S070000, C353S078000
Reexamination Certificate
active
06388810
ABSTRACT:
FIELD OF THE INVENTION
The present invention pertains to projection systems, and more specifically, to a rear projection console with at least one image-carrying light beam that reflects upon a unique layout of mirrors before impinging upon the rear of the display screen to produce a relatively large, contiguous image thereupon.
BACKGROUND OF THE INVENTION
The use of mirrors to change the direction of a light beam carrying an image is a common practice in rear projection devices. Typically, a light source will bounce from one mirror to another and so on until the light reaches the rear side of a display screen contained within a cabinet, where the image contained within the light will be projected thereon. Traditionally however, these types of mirrors have been fixed, preventing a user from adjusting the image projected to a desired place on the rear projection screen. Typically, the image that is projected is of a single size, even though it may be desirous to enlarge or shrink the image size. Also, in very large applications where an image or images are projected onto a plurality of screens, a seam can appear where image boundaries meet, thereby producing a non-contiguous image.
One of the more difficult design problems in rear projection imagers is the placement of mirrors to optimize limited console space. Many different configurations have been disclosed that reflect images in different ways inside of cabinets, with the initial beam of light being bounced off of at least one mirror in various dispositions. The present invention address the difficulty of limited cabinet space by teaching the projection of an image onto one mirror situated at an oblique angle to the screen, from there onto another mirror positioned at an acute angle with the screen, and finally on through itself to the projection screen. This particular arrangement of mirrors which causes the light to pass through itself without significant degradation of image quality, uses the limited console space in an efficient manner to reduce the actual space required to project an image onto a rear projection screen.
Traditionally in rear projection systems, the mirrors used to reflect a light with an image contained therein have been securably mounted within the rear projection cabinet. By rigidly securing the mirrors within the cabinet, a user is unable to position the image on the screen as desired through mirror manipulation. While this is perhaps a minor inconvenience in a home viewing environment, in applications such as the present invention where multiple projectors can be linked to produce a contiguous image, the inability to shift image position upon the rear projection screen using mirror manipulation is a problem. The present invention facilitates the need for image stability by making the image projector and the mirrors fixedly mounted within the console, yet facilitates the need for image adjustment by allowing alignment adjustment to occur at the second mirror.
In the present invention, the second mirror can also be replaced by either a convex or concave mirror to magnify or reduce the image size as it appears on the display screen. While the use of irregularly shaped mirrors to distort light waves is not new, their use in that manner in combination with a light beam crossing over itself is. In practical application, the irregularly shaped mirrors will allow a sized image on the projection screen otherwise not possible with the limited volume of the console.
In one embodiment of the invention the imager, the mirrors and the display screen rigidly mounted to minimize relative movements between the units thereby minimizing the likelihood of relative movements between the units. In another embodiment the units while rigidly mounted can be made postionable to enable an operator to fine tune the position of the images on the display screen.
Therefore, it is a purpose of this invention to create a compact projection system with an imager that projects an imager-carrying light through a configuration of mirrors and through itself before impinging on the rear of a display screen.
It is a further purpose of this invention to create a projection system that operates in a confined area, or an area of limited space.
It is a further purpose of this invention to create a projection system that can interlock with at least one other projection system of like construct to produce a seamless, contiguous image on a display screen.
It is still another purpose of this invention to create a projection system with mirrors that can be irregularly shaped to produce a magnified or reduced image upon a display screen.
DESCRIPTION OF THE PRIOR ART
U.S. Pat. No. 3,947,104 shows a compact imaging apparatus which projects an image upwards using a series of two fixed mirrors.
U.S. Pat. No. 4,875,064 shows a projecting apparatus that enlarges and displays an image on a liquid crystal display panel onto a screen provided in the projector apparatus.
U.S. Pat. No. 5,278,595 shows a liquid crystal television system that utilizes two fixed mirrors.
U.S. Pat. No. 5,521,659 shows a rear projection display apparatus designed to reduce parallax viewing error so that a user may interact with the display screen using a device such as a light pen.
SUMMARY OF THE INVENTION
The present invention comprises a rear projection console with at least one projector and a set of mirrors operating together to form an image-carrying light beam to travel within the console and across itself before the image-carrying light impinges upon the rear of the display screen to produce a relatively large, contiguous image with the at least one projector and set of mirrors being confined in a relatively small console area. The invention utilizes a unique layout of mirrors, projectors and light paths to create a single, contiguous image on a display screen.
REFERENCES:
patent: 3947104 (1976-03-01), Waly et al.
patent: 4875064 (1989-10-01), Umeda
patent: 5223869 (1993-06-01), Yanagi
patent: 5278595 (1994-01-01), Nishida et al.
patent: 5521659 (1996-05-01), Arnott
patent: 5871266 (1999-02-01), Negishi et al.
patent: 6233024 (2001-05-01), Hiller et al.
patent: 6254239 (2001-07-01), Hibner, II et al.
Monson Robert James
Smith Michael Edward
Bowen Glenn W.
Cruz Magda
Hogan Patrick M.
Lockheed Martin Corporation
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