Patent ID: 8111312

Claim:
A solid-state imaging device comprising: a plurality of pixels which are arranged in a matrix of rows and columns; a sequential scanning device that selects each row of pixels; a first analog-to-digital converter that (a) receives a pixel signal from the plurality of pixels by means of a vertical signal line and (b) performs a first analog-to-digital conversion on an upper bit portion of the pixel signal; a digital-to-analog converter connected to the output of the first analog to digital converter and that receives the converted upper bit-length portion of the pixel signal from the first analog to digital converter; a subtraction processing unit connected to output of the digital-to-analog converter and the vertical signal line and which outputs the difference between the upper bit length portion of the pixel signal and the pixel signal from the vertical signal line; a second analog-to-digital converter connected to the output of the subtraction processing unit and that performs a second analog-to-digital conversion on the output from the subtraction processing unit, wherein, a current output unit supplies an analog signal representing the lowermost n-m bits to a capacitor using a part of operation clock cycles of the first analog-to-digital converter, the current output unit changes an amount of current to be supplied to the capacitor so as to change a level of the analog signals on the lowermost (n-m) bits, in a monitoring mode, only the first analog to digital conversion is performed, and in an imaging mode, both the first analog-to-digital conversion and the second analog-to-digital conversion are performed.