A signal-processing CMOS image sensor using a simple analog operation

Abstract

We have developed a high-density CMOS image sensor with a normal mode and three signal-processing function modes: wide dynamic-range mode, motion-detection mode, and edge-extraction mode. Small pixel size and real-time operation are achieved by using a four-transistor and one-capacitor pixel scheme and column-parallel on-chip analog operation. The chip includes 512 (H) ×384 (V) effective pixels. Each pixel has a sufficient fill factor of 24% in an area of 9.3×9.3 μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The dynamic range at the wide dynamic-range mode is a maximum 97 dB against 51 dB at the normal-readout mode. The chip consumes 79 mW, and the gain-control amplifier and 8-b analog-to-digital converter operate at 46 frames/s using a 3.3-V single power supply.