Electric lamp and discharge devices: systems – Plural power supplies – Plural cathode and/or anode load device
Reexamination Certificate
2005-01-11
2005-01-11
Wong, Don (Department: 2821)
Electric lamp and discharge devices: systems
Plural power supplies
Plural cathode and/or anode load device
C315S291000, C315S307000, C315S156000, C315S157000, C315S158000
Reexamination Certificate
active
06841947
ABSTRACT:
The present invention provides for systems and methods for dimming a LED matrix functioning as a backlight to an avionics display. A system according to an embodiment of the present invention comprises a processor for receiving inputs of ambient lighting and temperature, as well as light generated by the LED matrix. The processor provides modulated pulse wave signals (square waves) to two control circuits for controlling the LED matrix in two modes. At low dimming levels, the processor modulates the duty cycle of a first square wave for affecting the light level and maintains a minimal duty cycle of a second square wave. Once the highest light level is obtained by increasing the duty cycle of the first square wave, the processor then modulates a second square wave by increasing its duty cycle. The duty cycle of the second square wave is modified by a circuit to produce a voltage level which is provided as an input to control light level of the LED matrix. As the duty cycle of the second signal is increased, so is the voltage level provided to the LED matrix and the light generated by the LED matrix.
REFERENCES:
patent: 4958915 (1990-09-01), Okada et al.
patent: 5019808 (1991-05-01), Prince et al.
patent: 5105127 (1992-04-01), Lavaud et al.
patent: 5272327 (1993-12-01), Mitchell et al.
patent: 5296783 (1994-03-01), Fischer
patent: 5406305 (1995-04-01), Shimomura et al.
patent: 5428265 (1995-06-01), Booth et al.
patent: 5719474 (1998-02-01), Vitello
patent: 5724062 (1998-03-01), Hunter
patent: 5783909 (1998-07-01), Hochstein
patent: 5933089 (1999-08-01), Katada
patent: 5939830 (1999-08-01), Praiswater
patent: 6081073 (2000-06-01), Salam
patent: 6144359 (2000-11-01), Grave
patent: 6215680 (2001-04-01), Rolston
patent: 6281640 (2001-08-01), Kim
patent: 6291942 (2001-09-01), Odagiri et al.
patent: 6366350 (2002-04-01), Thornburg et al.
patent: 6388388 (2002-05-01), Weindorf et al.
patent: 6452582 (2002-09-01), Rolston
patent: 6590561 (2003-07-01), Kabel et al.
patent: 20010035848 (2001-11-01), Johnson et al.
patent: 20020035848 (2002-03-01), Johnson et al.
patent: 20020130786 (2002-09-01), Weindorf
patent: 20020135572 (2002-09-01), Weindorf
patent: 20020140880 (2002-10-01), Weindorf et al.
patent: 0 786 714 (1997-07-01), None
patent: 0 786 714 (1997-07-01), None
patent: 1 017 257 (2000-07-01), None
patent: 1 204 088 (2002-05-01), None
patent: 1 204 088 (2002-05-01), None
English Abstract of EP 0786714.
Garmin AT, Inc.
Rolf Devon A.
Tran Chuc
Wong Don
LandOfFree
Systems and methods for controlling brightness of an... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Systems and methods for controlling brightness of an..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Systems and methods for controlling brightness of an... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3402075