A/D CONVERTER AND READING CIRCUIT

摘要

An A/D convert (11) performs sampling of a signal (S1) by a plurality of times during a period (T1) and sampling of a signal (S2) by a plurality of times during a period (T2). During the period (T2), the A/D conversion circuit (17) provides a digital signal in accordance with a signal from an output (15b) of a gain stage (15). The digital signal may have a value "1" or a value "0". The A/D conversion circuit (17) includes a circuit (18) which provides a signal S_A/DM corresponding to the number of appearances of the value "1". A switch (24) operates in response to the clock fs and is used to sample the signal from a pixel (2a). A capacity circuit (27) includes a switch (29) and a capacitor (31) between an inversion input (23a) and a non-inversion output (23b). The switch (29) operates in response to clockf3 and is used for integration to the capacitor (31).