AUTOMATIC GAIN CONTROL CIRCUIT

摘要

An automatic gain control circuit (29) generates, based on comparison between an average brightness (Y1) of brightness data output for each frame from an image sensor and a target brightness (T), an integration time adjustment signal (A2) for adjusting an integration time during which the image sensor is exposed, a gain adjustment signal (A1) for adjusting gain of an amplifier that amplifies an output signal of the image sensor, and a frame rate adjustment signal for changing a frame rate. The automatic gain control circuit includes an exposure control circuit (35) for adjusting a blanking time (BR) of each frame and generating, as the frame rate adjustment signal, a maximum integration time adjustment signal (A4) for switching a maximum integration time (MAX-EXP) of the image sensor.