Active-Pixel Sensors With "Winner-Take-All" Mode

Circuits to generate the intensity reading and the coordinates of the brightest pixel in each image would be added to imaging photodetector arrays of the active-pixel-sensor (APS) type, according to a proposal. For a given APS, the additional circuitry for locating the brightest pixel would be installed at the periphery of the basic APS circuit. The additional circuitry would thus not degrade the original optical properties or interfere with the original electronic functions of the APS. The APS could be operated in its normal image-readout mode or, optionally, it could be operated with the additional circuitry in the brightest-pixel mode. Potential applications could include star tracking or fast tracking of a moving laser-beam spot in laser communication system.