Rear projection screen
First Claim
Patent Images
1. A lenticular lens comprising a base portion, a first side portion, a second side portion, and a tip portion opposite said base portion;
- said first side portion having an average slope of between approximately 70° and
85°
with respect to said base portion;
said second side portion having an average slope of between approximately 70° and
85°
with respect to said base portion;
said first average slope and said second average slope being selected so that said first side portion and said second side portion are substantially internally reflective;
said tip portion being contiguous with both said first side portion and second side portion, said tip portion comprising two convex cylindrical portions of equal radii and a central concave cylindrical portion and said tip portion being substantially refractive, wherein the ratio of the height of said lens to the width of said base portion is greater than 3;
2 and the ratio of the width of said base portion to the width of said tip portion is greater than 2;
1.
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Accused Products
Abstract
A rear projection screen is disclosed which uses a front surface lenticular array to distribute light from projection light sources through a horizontal angle of virtually 180° with uniform luminance. Each lenticular element of the array is characterized by having a height to width ratio of at least 3:2 and a pitch width to tip width ratio of at least 2:1. The lenticular array is further characterized as having the capability of having up to two-thirds of the front surface area black masked. When used in a color television system, the rear projection screen exhibits minimal color shift.
86 Citations
25 Claims
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1. A lenticular lens comprising a base portion, a first side portion, a second side portion, and a tip portion opposite said base portion;
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said first side portion having an average slope of between approximately 70° and
85°
with respect to said base portion;said second side portion having an average slope of between approximately 70° and
85°
with respect to said base portion;said first average slope and said second average slope being selected so that said first side portion and said second side portion are substantially internally reflective; said tip portion being contiguous with both said first side portion and second side portion, said tip portion comprising two convex cylindrical portions of equal radii and a central concave cylindrical portion and said tip portion being substantially refractive, wherein the ratio of the height of said lens to the width of said base portion is greater than 3;
2 and the ratio of the width of said base portion to the width of said tip portion is greater than 2;
1. - View Dependent Claims (2, 3, 4, 5, 6, 24)
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7. A rear projection screen comprising, light collimating means on a rear portion of the screen for receiving and collimating divergent light rays from an image projector, said rays being representative of an image to be displayed by said screen;
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light diffusing means for receiving and diffusing said collimated light rays from said light collimating means; and light spreading means on the front surface of said screen for receiving said diffused light rays from said light diffusing means and deflecting respective ones of said rays to display said image with substantial uniform brightness over a wide viewing angle; said light spreading means comprising a plurality of closely spaced generally parallel lenticular lenses; at least some of said lenticular lenses comprising a base portion, a first side portion, a second side portion and a tip portion opposite said base portion; side first side portion having an average slope of between approximately 70° and
85°
with respect to said base portion;said second side portion having an average slope of between approximately 70° and
85°
with respect to said base portion;said first average slope and said second average slope being selected so that said first side portion and said second side portion are substantially internally reflective; said tip portion being contiguous with both said first side portion and second side portion, said tip portion comprising two convex cylindrical portions of equal radii and a central concave cylindrical portion and said tip portion being substantially refractive, wherein the ratio of the height of said lenses to the width of said base portion is greater than 3;
2 and the ratio of the width of said base portion to the width of said tip portion is greater than 2;
1. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15, 25)
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16. A rear projection screen comprising, light collimating means on a rear portion of the screen for receiving and collimating divergent light rays from an image project, said rays being representative of an image to be displayed by said screen;
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light diffusing means for receiving and diffusing said collimated light rays from said light collimating means; and light spreading means on the front surface of said screen for receiving said parallel rays from said light collimating means and deflecting respective ones of said rays to display said image with substantial uniform brightness over a wide viewing angle; said light spreading means comprising a plurality of closely spaced generally parallel lenticular lenses; at least some of said lenticular lenses being comprised of a base portion, a first side portion, a second side portion and a tip portion opposite said base portion; said first side portion and said second side portion each being substantially internally reflective, said tip portion being substantially refractive, the ratio of the height of said lens to the width of said base portion being greater than 3;
2 and the ratio of the width of said base portion to the width of said tip portion being greater than 2;
1. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23)
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Specification