Patent ID: 8018516
Filing Date: 2011-09-13
Classification: H04N

Abstract:
1. A signal processing method for a solid-state image sensor in which a high sensitivity pixel whose sensitivity to brightness is high and a low sensitivity pixel whose sensitivity to brightness is low are arranged according to a given pixel pattern and multiple ones of given pixel pattern are arranged in a matrix, and in which each signal charge accumulated in the high sensitivity pixel and the low sensitivity pixel due to light from an object is converted into an electric signal and from which the electric signal is output, the method comprising: (a) comparing a first threshold value and a high-sensitivity-pixel output signal, which is an electric signal converted from a signal charge accumulated in the high sensitivity pixel, thereby determining whether or not the high-sensitivity-pixel output signal reaches a level of a saturated-high-sensitivity-pixel output signal, which is the high-sensitivity-pixel output signal when the signal charge accumulated in the high sensitivity pixel is saturated; (b) if the high-sensitivity-pixel output signal does not reach the level of the saturated-high-sensitivity-pixel output signal at (a), calculating a difference value between the high-sensitivity-pixel output signal and an amplified low-sensitivity-pixel output signal obtained by multiplying a low-sensitivity-pixel output signal by a sensitivity ratio, the low-sensitivity-pixel output signal being an electric signal converted from a signal charge accumulated in the low sensitivity pixel, and the sensitivity ratio being obtained by dividing a sensitivity value of the high sensitivity pixel by a sensitivity value of the low sensitivity pixel; and (c) outputting one of a first image signal and a second image signal which are different from each other, according to whether or not an absolute value of the difference value at (b) is smaller than a second threshold value.