Fresnel lens for use with rear projection display
AssigneeInFocus Corporation
InventorsMark David Peterson, Jeffrey Alan Gohman
Life of this patent
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Abstract
The ultra-thin rear projection display device described herein includes a wide angle lens system and one or more planar mirrors that are parallel to a screen on which an image is to be displayed. In one embodiment, the screen that has multiple groove angles to provide better illumination than screens with a single groove angle.
Claims25
A Fresnel lens having a center location and an input ray side and an exit ray side, comprising:
- a single set of concentric grooves, said single set comprising:
- a first zone on the input ray side having a first groove angle, for circular grooves about a groove center location, within the first zone;
- and
- a second zone on the input ray side having a second groove angle, for circular grooves about said groove center location, within the second zone, with said groove center location offset from the lens center location.
A Fresnel lens having a center location, comprising:
- a first reflective zone comprising:
- a first region having a first groove angle, for circular grooves about a groove center location, within the first region;
- and
- a second region having a second groove angle, for circular grooves about said groove center location, within the second zone, with said groove center location offset from the lens center location and the first region and the second region on a first side of the lens;
- and
- a second refractive zone.
A Fresnel lens having a center location and an input ray side and an exit ray side, comprising:
- a single set of concentric grooves, said single set comprising:
- a first zone on the input ray side having a first set of grooves with a first groove angle, said first set of grooves being circular grooves about a groove center location, within the first zone;
- and
- a second zone on the input ray side having second set of grooves with a second groove angle, said second set of grooves being circular grooves about said groove center location, within the second zone, with said groove center location offset from the lens center location, and with said first zone partially surrounding said second zone and said first groove angle less than said second groove angle;
- and
- where grooves at one edge of the lens have a different groove angle than grooves at an opposite edge of the lens.
A Fresnel lens having a center location and an input ray side and an exit ray side, comprising:
- a single set of concentric grooves, said single set comprising:
- a first zone on the input ray side having at least two grooves with a common first groove angle, for circular grooves about a groove center location, within the first zone;
- and
- a second zone on the input ray side having at least two grooves with a common second groove angle, for circular grooves about said groove center location, within the second zone, with said groove center location offset from the lens center location.
Dependencies are inferred from the claim text.