Patent ID: 7532148

Claim:
A driving method of a CMOS image sensor comprising: comparing a reset signal sent from a first pixel row in an imaging area with a reference signal sent from a reference signal generating portion; performing a first counting operation in one of a down-count mode and an up-count mode in parallel with comparing the reset signal sent from the first pixel row with the reference signal; comparing an image signal sent from the first pixel row in the imaging area with a reference signal sent from the reference signal generating portion; performing a second counting operation in the other of the down-count mode and the up-count mode in parallel with comparing the image signal sent from the first pixel row with the reference signal; storing a first counting result representing a difference between the image signal and the reset signal from the first pixel row in a memory; comparing a reset signal sent from a second pixel row in an imaging area with a reference signal sent from a reference signal generating portion; performing the first counting operation in one of a down-count mode and an up-count mode in parallel with comparing the reset signal sent from the second pixel row with the reference signal; comparing an image signal sent from the second pixel row in the imaging area with a reference signal sent from the reference signal generating portion; and performing the second counting operation in the other of the down-count mode and the up-count mode in parallel with comparing the image signal sent from the second pixel row with the reference signal, wherein the first counting result is read out from the memory during at least a part of a period of the first counting operation and/or the second counting operation on the image signal and the reset signal from the second pixel row.