Radiant energy – Photocells; circuits and apparatus – Photocell controlled circuit
Reexamination Certificate
2007-05-21
2008-12-09
Epps, Georgia Y. (Department: 2878)
Radiant energy
Photocells; circuits and apparatus
Photocell controlled circuit
C250S2140DC, C250S2140LS, C250S2140RC
Reexamination Certificate
active
07462813
ABSTRACT:
The semiconductor device includes a first photodiode, a second photodiode which is shielded from light, a first circuit group including a voltage follower circuit, a second circuit group, and a compensation circuit, in which an output from the first photodiode is inputted to the voltage follower circuit of the first circuit group, an output from the first circuit group is inputted to the compensation circuit, and an output from the second photodiode is inputted to the compensation circuit through the second circuit group. By adding or subtracting these inputs in the compensation circuit, an output fluctuation due to temperature of the first photodiode is removed. Note that a reference potential is supplied to the first photodiode so that an open circuit voltage is outputted, and a potential is supplied to the second photodiode so that a forward bias is applied to the second photodiode.
REFERENCES:
patent: 4659930 (1987-04-01), Johnson et al.
patent: 5198660 (1993-03-01), Yokoyama et al.
patent: 5410145 (1995-04-01), Coroy
patent: 6183131 (2001-02-01), Holloway et al.
patent: 6921891 (2005-07-01), Seitz
patent: 2003/0086476 (2003-05-01), Mizuta
patent: 2004/0095986 (2004-05-01), Tsuchiya
patent: 04-268816 (1992-09-01), None
patent: 05-215602 (1993-08-01), None
Arao Tatsuya
Hirose Atsushi
Epps Georgia Y.
Legasse Jr. Francis M
Robinson Eric J.
Robinson Intellectual Property Law Office P.C.
Semiconductor Energy Laboratory Co,. Ltd.
LandOfFree
Semiconductor device and method with a light shielded second... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Semiconductor device and method with a light shielded second..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Semiconductor device and method with a light shielded second... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-4051562