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Rear projection screen containing Fresnel lens sheet utilizing alternative focal lengths

  • US 6,046,847 A
  • Filed: 04/08/1998
  • Issued: 04/04/2000
  • Est. Priority Date: 04/11/1997
  • Status: Expired due to Term
First Claim
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1. A rear projection screen comprising a Fresnel lens sheet and a lenticular lens sheet, said Fresnel lens sheet and said lenticular lens sheet being arranged in a face-to-face disposition, said Fresnel lens sheet having annular Fresnel lens elements disposed concentrically on a front surface of the Fresnel lens sheet for controlling light rays incident on a rear surface thereof to pass therethrough to the lenticular lens sheet, said lenticular lens sheet including parallel lenticular lenses facing said Fresnel lens elements;

  • wherein said Fresnel lens elements include;

    a first group of Fresnel lens elements having a first focal length (f1); and

    a second group of Fresnel lens elements having a second focal length (f2).

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