Patent ID: 8269867

Claim:
A solid-state image pickup device which can be switched between a plurality of AD conversion resolutions by changing a comparison time period during which a pixel signal output from a pixel and a reference voltage are compared with each other, comprising: a first counter configured to count at least a comparison time period of a first resolution and a comparison time period of a second resolution; a second counter configured to count at least a time period between the comparison time period of the first resolution and the comparison time period of the second resolution; storage means for storing (a) a number of counts representing a difference between the comparison time period for the first resolution that is the lowest resolution among the plurality of AD conversion resolutions and the comparison time period for the second resolution that is different from the first resolution, and (b) a start count value that is a count value of the first counter at which counting to the number of counts is started; and a counter control section to (a) stop counting by the first counter and start counting by the second counter when a set AD conversion resolution is the second resolution and the count value of the first counter reaches the start count value and (b) resume counting by the first counter when the count value of the second counter reaches the number of counts.