US 9,812,474 B2
Imaging apparatus and imaging system
Tomoyuki Yagi, Honjo (JP); Toshio Kameshima, Kumagaya (JP); Katsuro Takenaka, Honjo (JP); Sho Sato, Tokyo (JP); Hideyuki Okada, Honjo (JP); Atsushi Iwashita, Saitama (JP); Eriko Sato, Tokyo (JP); and Takuya Ryu, Kokubunji (JP)
Assigned to CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed by CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed on Mar. 23, 2015, as Appl. No. 14/665,045.
Claims priority of application No. 2014-073725 (JP), filed on Mar. 31, 2014.
Prior Publication US 2015/0279882 A1, Oct. 1, 2015
Int. Cl. H01L 27/146 (2006.01); H04N 5/3745 (2011.01); H04N 5/341 (2011.01); H04N 5/365 (2011.01); H04N 5/376 (2011.01); G01T 1/17 (2006.01); H04N 5/32 (2006.01); H04N 5/357 (2011.01); H04N 5/363 (2011.01); H04N 5/378 (2011.01)
CPC H01L 27/14609 (2013.01) [G01T 1/17 (2013.01); H04N 5/32 (2013.01); H04N 5/341 (2013.01); H04N 5/3575 (2013.01); H04N 5/363 (2013.01); H04N 5/3651 (2013.01); H04N 5/3658 (2013.01); H04N 5/378 (2013.01); H04N 5/3745 (2013.01); H04N 5/3765 (2013.01)] 14 Claims
OG exemplary drawing
 
1. An imaging apparatus comprising:
a pixel that generates charge;
an integral amplifier that integrates charge transferred from the pixel;
a low pass filter to which output of the integral amplifier is supplied and whose time constant is variable;
a first sample-and-hold circuit that samples and holds output of the low pass filter before the charge is transferred from the pixel to the integral amplifier;
a second sample-and-hold circuit that samples and holds output of the low pass filter after the charge is transferred from the pixel to the integral amplifier;
a differential circuit that outputs a difference between a signal held by the first sample-and-hold circuit and a signal held by the second sample-and-hold circuit; and
a control circuit that changes the time constant of the low pass filter,
wherein the control circuit decreases the time constant of the low pass filter after the sampling by the first sample-and-hold circuit ends, and increases the time constant of the low pass filter in the middle of the sampling by the second sample-and-hold circuit.