Switchable color filter

Details Switchable color filter Switchable color filter

2006-10-24

2006-10-24

Schechter, Andrew (Department: 2871)

Liquid crystal cells, elements and systems

Particular structure

Interconnection of plural cells in series

C349S077000, C349S078000, C349S074000

Reexamination Certificate

active

07126654

ABSTRACT:
A liquid crystal switchable color filter switches between three color bands and is preferably used for time-sequential devices, such as projection devices, direct view displays and video cameras. The color filter may employ circularly polarizing selective reflection bands of at least four cholesteric filters together with three liquid crystal switches and related retarder layers. In one embodiment, the handedness of the second cholesteric is equal to the handedness of the third cholesteric filter and opposite to the handedness of the first and fourth cholesteric filter and, for the blocking state of a color band, the optic axis of the corresponding liquid crystal switch is parallel or perpendicular to the polarization direction. This concept leads to improved, excellent color saturation and requires less stringent production tolerances than in the prior art. Moreover, it advantageously allows overlapping color transmission bands thus improving the light efficiency.

REFERENCES:
patent: 5235443 (1993-08-01), Barnik et al.
patent: 5325218 (1994-06-01), Willett et al.
patent: 5389698 (1995-02-01), Chigrinov et al.
patent: 5602661 (1997-02-01), Schadt et al.
patent: 5686931 (1997-11-01), Fünfschilling et al.
patent: 5838407 (1998-11-01), Chigrinov et al.
patent: 6046790 (2000-04-01), Hara et al.
patent: 0 689 084 (1995-12-01), None
patent: 0 713 126 (1996-05-01), None
patent: 0 756 193 (1997-01-01), None
patent: WO 95/34022 (1995-12-01), None
patent: WO 99/49360 (1999-09-01), None
patent: WO 99/64924 (1999-12-01), None
patent: WO 00/36463 (2000-06-01), None

Affiliated with

Also associated with

Rating

Switchable color filter does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Switchable color filter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Switchable color filter will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3676485