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Rear projector

  • US 20080158518A1
  • Filed: 12/26/2007
  • Published: 07/03/2008
  • Est. Priority Date: 12/27/2006
  • Status: Active Grant
First Claim
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1. A rear projector for performing image projection, comprising:

  • a screen including a rotationally symmetric Fresnel lens; and

    a projection optical system being nonaxisymmetric and making a central principle ray incident obliquely on the screen in the image projection, the projection optical system having at least one reflection surface formed of a rotationally asymmetric free curved surface;

    wherein the Fresnel lens has aberration that cancels out pupil aberration of the projection optical system so that principal rays of beams exiting from the Fresnel lens become substantially parallel to each other.

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