US 7,321,464 B2
Electroluminescent light source and display incorporating same
Andrew J. Ouderkirk, Woodbury, Minn. (US); Michael F. Weber, Shoreview, Minn. (US); and Olester Benson, Jr., Woodbury, Minn. (US)
Assigned to 3M Innovative Properties Company, St. Paul, Minn. (US)
Filed on Aug. 31, 2004, as Appl. No. 10/930,988.
Application 10/930988 is a division of application No. 09/626938, filed on Jul. 27, 2000, granted, now 6,804,058.
Application 09/626938 is a continuation of application No. 09/103270, filed on Jun. 23, 1998, abandoned.
Application 09/103270 is a continuation of application No. 08/402349, filed on Mar. 10, 1995, granted, now 5,828,488.
Application 08/402349 is a continuation in part of application No. 08/360204, filed on Dec. 20, 1994, abandoned.
Application 08/360204 is a continuation in part of application No. 08/359436, filed on Dec. 20, 1994, abandoned.
Application 08/359436 is a continuation in part of application No. 08/171239, filed on Dec. 21, 1993, abandoned.
Application 08/171239 is a continuation in part of application No. 08/172593, filed on Dec. 21, 1993, abandoned.
Prior Publication US 2005/0024726 A1, Feb. 03, 2005
This patent is subject to a terminal disclaimer.
Int. Cl. G02B 27/28 (2006.01); G02B 5/30 (2006.01)
U.S. Cl. 359—495  [359/497; 359/500; 359/599; 362/19; 313/112; 313/463; 345/76; 348/800] 5 Claims
OG exemplary drawing
 
1. A light source, comprising:
an electroluminescent panel having a light generating layer; and
a birefringent reflective polarizer film positioned to receive the light generated by the light generating layer, wherein said birefringent reflective polarizer film comprises at least one birefringent material and wherein the birefringent reflective polarizer film transmits light of a first polarization and reflects light of a second polarization back to the light generating layer, and wherein the light generating layer diffusely reflects and randomizes the polarization state of the reflected light and recirculates the reflected light back to the birefringent reflective polarizer film.