×

Quarter-wave film for brightness enhancement of holographic thin taillamp

  • US 5,745,266 A
  • Filed: 10/02/1996
  • Issued: 04/28/1998
  • Est. Priority Date: 10/02/1996
  • Status: Expired due to Term
First Claim
Patent Images

1. A holographic rear exterior lamp for a vehicle, comprising:

  • a light pipe having first and second opposing surfaces;

    a rear exterior lamp hologram attached to one of said first and second opposing surfaces of said light pipe;

    a polarization rotating retarder film attached to one of said first and second opposing surfaces oppositely from said rear exterior lamp hologram;

    means for providing a reconstruction beam;

    holographic coupling means attached to one of said first and second opposing surfaces of said light pipe for coupling said reconstruction beam into said light pipe such that a portion of said reconstruction beam propagates as internally reflected light pursuant to internal reflection within said light pipe, said rear exterior lamp hologram and said polarization rotating retarder film;

    said polarization rotating retarder film configured to impart a substantially halfwave retardance to internally reflected light that passes twice therethrough;

    whereby said rear exterior lamp hologram diffracts a portion of said internally reflected light to provide rear exterior lamp illumination.

View all claims
  • 4 Assignments
Timeline View
Assignment View
    ×
    ×