Active pixel switching system for photoelectric sensing and evaluation of pictures uses several photo sensors with switches producing currents proportional to incident light intensity

摘要

The photo sensors (100) are includes in pixel switching circuits (121-124). They are connected to feedback switches (101,102) which may consist of a transistor or separate circuit elements (103,104) with a switch (105) which may consist of a transistor. Switches (106) may connect the photo sensors to a calibration current generator. The calibration system reduces errors due to differences in the dark currents of the photo sensors.