Patent ID: 8797440
Filing Date: 2014-08-05
Classification: H04N

Abstract:
1. A solid-state imaging device comprising: an analog-to-digital conversion circuit which subjects a first pixel voltage and a second pixel voltage from pixels respectively comprising photoelectric conversion elements to first and second signal processing, and outputs a digital value corresponding to a difference value between the first pixel voltage and the second pixel voltage; a reference voltage generation circuit which outputs reference voltages having first and second pulse waveforms to the analog-to-digital conversion circuit, the reference voltages being compared with the first and second pixel voltages to obtain the digital value, the reference voltage generation circuit including: an integration circuit which comprises an operational amplifier having an output terminal coupled with the analog-to-digital conversion circuit and first and second input terminals, a capacitive element having one end connected to the second input terminal of the operational amplifier and the other end connected to the output terminal of the operational amplifier, a bias circuit connected to the first input terminal of the operational amplifier and supplying a bias voltage to the first input terminal of the operational amplifier; and a current source circuit connected to the second input terminal of the operational amplifier and supplying first and second currents to the second input terminal of the operation amplifier, wherein in the first signal processing which compares the reference voltage with the first pixel voltage by the analog-to digital conversion circuit, the reference voltage generation circuit supplies the first current of the current source circuit to the second input terminal of the operational amplifier, and generates the first pulse waveform, after the first signal processing, the reference voltage generation circuit supplies the second current of the current source circuit to the second input terminal of the operational amplifier, and returns a voltage value of the first pulse waveform to an initial value, and in the second signal processing which compares the reference voltage with the second pixel voltage by the analog-to-digital conversion circuit, the reference voltage generation circuit supplies the first current to the second input terminal of the operational amplifier, and generates the second pulse waveform.