Patent ID: 8102449

Claim:
An image pickup circuit comprising: a plurality of circuit blocks, the plurality being greater than two; and a circuit in communication with each of the plurality of circuit blocks, wherein each of the plurality of circuit blocks includes a plurality of comparing means, each of the comparing means being configured to compare a pixel signal supplied through a vertical signal line connected to vertically aligned pixels in a plurality of pixels arranged in a matrix, each comparing means being configured to receive a slope signal from the circuit whose voltage is changed from an initial voltage at a constant slope, a single counter configured to provide a first count value associated with a first phase and a second count value associated with a second phase, the second phase having a longer duration than the first phase, each of the first and second count values representing an elapsed time since a voltage of the slope signal starts to change from the initial voltage, and a plurality of storage means, each of the storage means being configured to successively store the first count value and the second count value, each of the count values being obtained by the counter in accordance with a respective comparison result of the comparing means, each of the count values corresponding to an elapsed time until the voltage of the slope signal is changed from the initial voltage to a voltage coinciding with the pixel signal, the first and second count values being supplied to a digital Correlated Double Sampling (CDS) circuit that is configured to obtain a difference between the first count value and the second count value.