Patent ID: 9088741
Filing Date: 2015-07-21
Classification: H04N

Abstract:
1. An image sensor comprising: a pixel configured to convert incident light into electrical charges; circuitry configured to read out to a signal line a pixel signal based on the electrical charges; a column processor provided for the pixel and including a switch, an operational amplifier, a column circuit, and a two-stage circuit; a capacitor coupling the signal line to an input of the operational amplifier, wherein a gain of the operational amplifier is adjusted based on the pixel signal; the two-stage circuit having a first stage circuit and a second stage circuit, the first stage circuit receiving a first voltage and the second stage circuit receiving a second voltage, wherein the first voltage and the second voltage are based on a reference voltage, the two-stage circuit has an input electrically coupled to an output of the operational amplifier, the first stage circuit compares the output of the operational amplifier to the reference voltage, the first stage circuit has a reset switch operatively coupled thereto to effect a reset of the first stage circuit, the two-stage circuit detects a signal level of the signal line on an output side of the operational amplifier to obtain a classification signal and outputs the classification signal to the operational amplifier, wherein the gain of the operational amplifier is adjusted based on the classification signal; and a storage device coupled to receive an output from the two-stage circuit.