Patent ID: 7800660
Filing Date: 2010-09-21
Classification: H04N

Abstract:
1. An image data processing circuit of a solid state image pickup device from which a dark current component signal and a pixel signal are sequentially output on a line unit basis, comprising: a first holding circuit for holding the dark current component signal in a reference line as a reference dark current component signal; a first subtraction circuit to which the dark current component signal and the pixel signal are sequentially entered on the line unit basis; a differential circuit for obtaining, as a dark current change amount, a change amount with respect to the reference dark current component signal, of the dark current component signal included in a preceding line output from the solid state image pickup device prior to the line entered to the first subtraction circuit; a second subtraction circuit to which the dark current component signal and the pixel signal as analog signals output from the solid state image pickup device are entered; a first selector to which an output of the solid state image pickup device and an output of the second subtraction circuit are entered; an AD converter provided on a connection path between the first selector and the first subtraction circuit and converting an analog output of the first selector to a digital output; and a second selector to which an output of the first subtraction circuit and an output of the AD converter are entered, wherein the first subtraction circuit subtracts the dark current change amount from the dark current component signal and the pixel signal which are entered, wherein in the case where a subtracting process of subtracting the dark current change amount from the dark current component signal and the pixel signal is performed in the first subtraction circuit, the first selector selects an output of the solid state image pickup device and the second selector selects an output of the first subtraction circuit, and wherein in the case where the subtracting process is performed in the second subtraction circuit, the first selector selects an output of the second subtraction circuit and the second selector selects an output of the AD converter.