Solid-state image sensor

A solid-state image sensor comprising:

• a pixel unit in which a plurality of unit pixels for photoelectric conversion of incident light are arranged;
• an AD conversion circuit that performs AD conversion on a potential of an analog signal read from a pixel signal line connected to the plurality of unit pixels;
• and
• a discrimination circuit that discriminates whether or not a reset potential at the potential of the analog signal is higher than a predetermined first reference potential,
• wherein the AD conversion circuit includes
• a counter circuit that performs count processing,
• a first latch circuit that holds at least a discrimination result of the discrimination circuit among the discrimination result of the discrimination circuit and a first output result output from the counter circuit, and
• a comparison circuit that compares the potential of the analog signal with a second reference potential which is a potential of a ramp waveform that changes with time,
• the AD conversion circuit performs AD conversion on the potential of the analog signal during a first count period and a second count period after the first count period,
• the counter circuit,
• sets an initial value of first count processing performed during the first count period as a negative value,
• stops the first count processing with a change in an output signal output from the comparison circuit as a trigger,
• inverts all bits of a first count value when the first count processing is stopped before starting second count processing performed during the second count period, and
• uses a value obtained by inverting all the bits of the first count value as an initial value of the second count processing performed during the second count period,
• the first latch circuit holds a most significant bit of the first count value output from the counter circuit, and
• the AD conversion circuit further includes a second latch circuit that holds all bits of a second count value output from the counter circuit when the second count processing is stopped.

A solid-state image sensor comprising:

• a pixel unit in which a plurality of unit pixels for photoelectric conversion of incident light are arranged;
• an AD conversion circuit that performs AD conversion on (i) a potential corresponding to a difference between a signal potential and a reset potential at a potential of an analog signal read from a pixel signal line connected to the plurality of unit pixels and (ii) a predetermined reference potential;
• and
• a discrimination circuit that discriminates whether or not the reset potential at the potential of the analog signal is higher than a predetermined first reference potential,
• wherein the AD conversion circuit includes
• a counter circuit that performs count processing and
• a first latch circuit that holds a discrimination result of the discrimination circuit.