Optical films
First Claim
1. An optical film structure, comprising:
- a first film comprisinga first smooth side; and
a first structured side opposite the first smooth side, the first structured side comprisinga plurality of first linear prisms, each first linear prism formed by a first near surface and a first far surface, each first linear prism having a first peak at the intersection of the first near surface and the first far surface, the plurality of first peaks forming a first imaginary plane;
wherein the first near surface forms an angle with the first imaginary plane between 35 and 55 degrees; and
wherein the first far surface forms an angle with the first imaginary plane between 35 and 55 degrees; and
a second film adjacent and parallel to the first film comprisinga second smooth side facing the first structured side; and
a second structured side opposite the second smooth side, the second structured side comprisinga plurality of second linear prisms, each second linear prism formed by a second near surface and a second far surface, each second linear prism having a second peak at the intersection of the second near surface and the second far surface, the plurality of second peaks forming a second imaginary plane;
wherein the second near surface forms an angle with the second imaginary plane between 70 and 110 degrees; and
wherein the second far surface forms an angle with the second imaginary plane between 35 and 55 degrees.
1 Assignment
0 Petitions
Accused Products
Abstract
An optical film structure for backlit displays having two films, both in prisms up configuration. The first film, closer to the light guide, has an array of generally symmetric 90-degree prisms facing the viewer. The second film, farther from the light guide, has an array of generally asymmetric prisms facing the viewer, with one face of the prisms inclined at about 45 degrees and the other face generally perpendicular to the plane of the backlight. The prisms of the first and second films may have an azimuthal angle between them, and may have different pitches from each other. The film structure recycles a portion of the light from the light guide, thereby helping to increase uniformity over the area of the display. The film structure also compresses the light emerging from the light guide, thereby providing a more sharply peaked brightness distribution for the viewer.
9 Citations
24 Claims
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1. An optical film structure, comprising:
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a first film comprising a first smooth side; and a first structured side opposite the first smooth side, the first structured side comprising a plurality of first linear prisms, each first linear prism formed by a first near surface and a first far surface, each first linear prism having a first peak at the intersection of the first near surface and the first far surface, the plurality of first peaks forming a first imaginary plane; wherein the first near surface forms an angle with the first imaginary plane between 35 and 55 degrees; and wherein the first far surface forms an angle with the first imaginary plane between 35 and 55 degrees; and a second film adjacent and parallel to the first film comprising a second smooth side facing the first structured side; and a second structured side opposite the second smooth side, the second structured side comprising a plurality of second linear prisms, each second linear prism formed by a second near surface and a second far surface, each second linear prism having a second peak at the intersection of the second near surface and the second far surface, the plurality of second peaks forming a second imaginary plane; wherein the second near surface forms an angle with the second imaginary plane between 70 and 110 degrees; and wherein the second far surface forms an angle with the second imaginary plane between 35 and 55 degrees. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A film structure, comprising:
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film means for providing a second beam having a second primary propagation angle between 45 and 65 degrees and a second beam width from a first beam having a first primary propagation angle between 5 and 25 degrees and a first beam width, the second beam width being less than the first beam width; and film means for providing a third beam having a third primary propagation angle between 80 and 100 degrees and a third beam width from the second beam, the third beam width being less than the first beam width. - View Dependent Claims (15, 16)
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17. An optical film structure, comprising:
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a first film comprising a first smooth side having a first surface normal; and a first structured side opposite the first smooth side, the first structured side comprising a plurality of first linear prisms, each first linear prism formed by a first face and a second face, the first and second faces each forming an angle with the first surface normal between 35 and 55 degrees; and a second film in proximity to the first film comprising a second smooth side opposed to the first structured side and having a second surface normal; and a second structured side opposite the second smooth side, the second structured side comprising a plurality of second linear prisms, each second linear prism formed by a third face and a fourth face, the third face forming an angle with the second surface normal between 0 degrees and 20 degrees, and the fourth face forming an angle with the second surface normal between 35 and 55 degrees. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24)
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Specification