Solid-state image pickup device, image pickup device, and signal reading method including an averaging circuit for averaging accumulated signals

Abstract

A solid-state image pickup device in which a first substrate and a second substrate including circuit elements forming pixels and disposed therein are electrically connected by a connection unit, may include an averaging circuit that averages signals accumulated in signal accumulation circuits respectively included in the two or more pixels that are pixels included in the same group and are averaging targets, and an output circuit that outputs the averaged signals from the pixels. The pixels may be classified into a plurality of groups and each group may include the plurality of pixels. The pixels may include photoelectric conversion elements disposed in the first substrate, and the signal accumulation circuits that are disposed in the second substrate and accumulate signals that are generated by the photoelectric conversion elements and are input via the connection unit.