Patent ID: 9300889
Filing Date: 2016-03-29
CPC Classification: H03F,H03G,H04N

Claim Text:
1. An imaging apparatus comprising: a pixel including a photoelectric conversion element configured to generate a charge, a floating diffusion unit configured to store charge transferred from the photoelectric conversion element, and an amplifying transistor configured to output a signal based on a potential of the floating diffusion unit; an amplifier circuit configured to amplify the signal output from the amplifying transistor at a predetermined gain; an AD converting unit; and a correcting unit, wherein the amplifying transistor outputs a first signal based on a voltage of the floating diffusion unit which is reset, the AD converting unit compares a first output signal outputted from the amplifier circuit based on the first signal with a reference signal which changes with time, to output a first digital value AD converted from the first output signal, the amplifying transistor outputs a second signal based on a voltage of the floating diffusion unit to which the charge is transferred, the amplifier circuit is set at a first gain when a second output outputted from the amplifier circuit based on the second signal is larger than a threshold, the amplifier circuit is set at a second gain larger than the first gain when the second output outputted from the amplifier circuit based on the second signal is smaller than the threshold, after setting the amplifier circuit at the first or second gain the AD converting unit compares a third output signal outputted from the amplifier circuit based on the second signal with a reference signal which changes with time, so as to output a second digital value AD converted from the third output signal, and the correcting unit performs a correction of at least one of the first and second digital values when an analog signal quantity of the first digital value corresponding to one bit is different from an analog signal quantity of the second digital value corresponding to one bit, so as to reduce a difference between the analog signal quantities of the first and second digital values corresponding to the one bit.