Television – Video display – Projection device
Patent
1992-12-22
1995-02-28
Groody, James J.
Television
Video display
Projection device
348783, 348 15, 359727, 359460, 359453, H04N 714
Patent
active
053941985
ABSTRACT:
A folded, magnifying, front projection arrangement for video displays includes a video image source, such as a flat panel display unit out of the user's field of view, projects its image onto a concave mirror also out of the user's field of view. The video image source is maintained off-axis with respect to the optic axis of the concave mirror and at a distance from the concave mirror between one and two times the distance from the concave mirror to its principal focal surface, which would be the principal focal plane if the concave mirror were a spherical or a parabolic mirror. The concave mirror, in turn, reflects and focuses the light from the video image source onto a projection screen, within the user's field of view, resulting in a magnified image. The distortion of the projected image that would otherwise result from off-axis projection is compensated for by maintaining the plane of the video image source at a non-perpendicular angle to the optic axis of the mirror. As a result, the image formed on the projection screen is undistorted and in focus across its full width and breadth. Since the projection screen is not an active element, a small aperture, or hole, can easily be cut through it so that a video camera, for capturing the image of the viewer of the screen, may be positioned behind it. The image resulting from such camera placement provides good eye contact to a remote party viewing the image.
REFERENCES:
patent: 4167311 (1979-09-01), Pund
patent: 4355329 (1982-10-01), Yoshida et al.
patent: 4400725 (1983-08-01), Tanigaki
patent: 4890314 (1989-12-01), Judd et al.
patent: 5111498 (1992-05-01), Guichard et al.
patent: 5117285 (1992-05-01), Nelson et al.
patent: 5157503 (1992-10-01), Dugdale
patent: 5162897 (1992-11-01), Jitsukata et al.
AT&T Corp.
Burgess Glenton B.
Groody James J.
Rosenthal Eugene J.
LandOfFree
Large-screen display system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Large-screen display system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Large-screen display system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-851635