Patent ID: 8754956

Claim:
A method for analog to digital conversion, comprising: converting a first analog signal output from a first pixel included in a pixel array to a first digital signal by comparing the first analog signal to a ramp signal; generating a first digital code in response to a clock signal; holding a generated first digital code until logic of a first signal changes, the first signal being related to at least a portion of the first digital signal; converting a second analog signal output from a second pixel included in the pixel array to a second digital signal by comparing the second analog signal to the ramp signal; and generating a second digital code in response to the clock signal from a held first digital code until logic of a second signal changes, the second signal being related to at least a portion of the second digital signal, wherein the first pixel and the second pixel are connected to the same column, and wherein a slope of the ramp signal is set based on a number of pixels in a subsampling block including the first pixel and the second pixel.