Projection television using a holographic screen
AssigneeThomson Licensing
InventorsEstill Thone Hall, Jr., Wendy Rene Pfile, Eugene Murphy O'Donnell
Life of this patent
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Abstract
A projection television receiver having red, green and blue image projectors for respective images of different colors and a high gain projection screen formed by at least one hologram disposed on a substrate superimposed on at least one light transmissive panel. The high gain holographic screen provides increased horizontal viewing performance over lenticular (e.g., fresnel) screens without reliance on screens having wide horizontal half viewing angles.
Claims25
A projection television, comprising:
- a plurality of image projectors (14, 16, 18) for respective images of different colors;
- a projection screen (22) having at least one holographic element (26) disposed on a substrate (24) superimposed on at least one light transmissive panel (38), said screen (22) receiving images from said projectors (14, 16, 18) on a first side and displaying said images on a second side with controlled light dispersion of said displayed images;
- and,
- said holographic element controlling said light dispersion so as to maximize peak center gain, whereby brightness levels over a predetermined range of horizontal viewing angles are higher than would be predicted by the ½ brightness angle of said screen.
A method for increasing brightness levels in a projection television having a plurality of image projectors (14, 16, 18) for respective images of different colors and a holographic screen (22) receiving images from said projectors (14, 16, 18) on a first side and displaying said images on a second side, comprising the steps of:
- defining a predetermined range of horizontal viewing angles for said screen;
- and,
- holographically controlling light dispersion of said displayed images to maximize peak center gain,
- whereby brightness levels over said predetermined range of horizontal viewing angles are higher than would be predicted by the ½ brightness angle of said screen.
Dependencies are inferred from the claim text.