Electric lamp and discharge devices: systems – Plural load device systems
Reexamination Certificate
2006-05-02
2006-05-02
Dinh, Trinh Vo (Department: 2821)
Electric lamp and discharge devices: systems
Plural load device systems
C315S313000, C315S291000
Reexamination Certificate
active
07038402
ABSTRACT:
Methods and systems to achieve linear and exponential control over a current to drive color LEDs have been achieved. Current digital-to-analog converters (IDAC) comprising each an exponential current digital-to analog converter and a linear IDAC, being cascaded to each other are used for a linear and an exponential control of a current driving a set of color LEDs, preferably RGB LEDs. The linear part of the IDAC, which is converting the mantissa of a floating-point number is used to control the color composition of the color LEDs. The exponential part of the IDAC, which is converting the exponent of the floating-point number is used to control the brightness of the color LEDs. While fading from one color to a next color a linear color change is required. The exponential part of the IDAC is used to dim the LEDs from bright to dark and vice versa. In order to get the visual perception of a linear dimming an exponential current change is required.
REFERENCES:
patent: 4244024 (1981-01-01), Marzalek et al.
patent: 4539883 (1985-09-01), Chihana
patent: 4631696 (1986-12-01), Sakamoto
patent: 6008820 (1999-12-01), Chauvin et al.
patent: 6340868 (2002-01-01), Lys et al.
patent: 6362578 (2002-03-01), Swanson et al.
patent: 6388388 (2002-05-01), Weindorf et al.
patent: 6586890 (2003-07-01), Min et al.
patent: 6596977 (2003-07-01), Muthu et al.
patent: 6774583 (2004-08-01), Zeng
patent: 2003/0057890 (2003-03-01), Lys et al.
patent: 2003/0234621 (2003-12-01), Kriparos
patent: 2005/0063586 (2005-03-01), Munsil et al.
Co-pending U.S. Appl. No. DS-04-044, filed Nov. 16, 2004, Serial No. 10/990,004, assigned to the same assignee, “Floating Point IDAC”.
Adler Andreas
Peschke Carlo
Ackerman Stephen B.
Cabucos Marie Antoinette
Dialog Semiconductor GmbH
Dinh Trinh Vo
Saile George D.
LandOfFree
Combined exponential/linear RGB LED I-sink digital-to-analog... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Combined exponential/linear RGB LED I-sink digital-to-analog..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Combined exponential/linear RGB LED I-sink digital-to-analog... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3542776