Optical: systems and elements – Projection screen – Unitary sheet comprising plural refracting areas
Reexamination Certificate
2007-01-23
2007-01-23
Ben, Loha (Department: 2873)
Optical: systems and elements
Projection screen
Unitary sheet comprising plural refracting areas
C359S487030, C359S493010, C359S742000
Reexamination Certificate
active
11075583
ABSTRACT:
A secondary image suppression system (SISS) for minimizing secondary ghost images in a screen assembly for a rear projection system. The secondary image suppression system includes a circular polarizing assembly positioned to receive light from a rear projection lens of a rear projection system. The circular polarizing assembly includes a linear polarizer and a quarter wave retarder. The linear polarizer and the quarter wave retarder are serially positioned relative to each other and are assembled with a high power Fresnel lens using index matching media such that internal reflections are minimized. The high power Fresnel lens is positioned to receive output from the circular polarizing assembly. During use, light from a projection lens of a rear projection system is introduced through the circular polarizing assembly and through the high power Fresnel lens toward a viewing screen. Any significant secondary ghost images are eliminated by the circular polarizing assembly. The SISS may be combined with a high contrast screen assembly to improve high ambient contrast while avoiding the necessity for beaded films or other structured screens that could cause viewing artifacts.
REFERENCES:
patent: 2378252 (1945-06-01), Staehle
patent: 4083626 (1978-04-01), Miyahara
patent: 4116911 (1978-09-01), Miyahara
patent: 4895429 (1990-01-01), Iwahara
patent: 5146365 (1992-09-01), Minoura
patent: 5307205 (1994-04-01), Ludwig
patent: 5448401 (1995-09-01), Takuma
patent: 5477380 (1995-12-01), Watanabe
patent: 5563738 (1996-10-01), Vance
patent: 5581407 (1996-12-01), Mitani
patent: 5694245 (1997-12-01), Goto
patent: 6151162 (2000-11-01), Van De Ven
patent: 6163402 (2000-12-01), Chou
patent: 6262841 (2001-07-01), Dike
patent: 6307675 (2001-10-01), Abe
patent: 6327083 (2001-12-01), Goldenberg
patent: 6407859 (2002-06-01), Hennen
patent: 6414789 (2002-07-01), Braun
patent: 6449089 (2002-09-01), Moshrefzadeh
patent: 6466368 (2002-10-01), Piepel
patent: 6483612 (2002-11-01), Walker
patent: 6519087 (2003-02-01), Moshrefzadeh
patent: 6636355 (2003-10-01), Moshrefzadeh
patent: 6710941 (2004-03-01), Hennen
patent: 6714327 (2004-03-01), Abersfelder
patent: 6717626 (2004-04-01), Kondo
patent: 6768566 (2004-07-01), Walker
patent: 6987624 (2006-01-01), Watanabe et al.
patent: 2001/0001582 (2001-05-01), Walker
patent: 2002/0154401 (2002-10-01), Hennen
patent: 2002/0159109 (2002-10-01), Walker
Kalmanash Michael H.
Krishnamurthy Sushil
Sundaresan Gayathri
Ben Loha
Dinh Jack
Eppele Kyle
Jensen Nathan O.
Rockwell Collins, Inc.
LandOfFree
System for eliminating secondary images in rear projection... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with System for eliminating secondary images in rear projection..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and System for eliminating secondary images in rear projection... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3774832