A Dual Pixel-Type Array for Imaging and Motion Centroid Localization

An imager chip has been designed, fabricated, and tested having two unique pixel types interleaved on the same array. The dual-pixel design enables optimization for two separate tasks. One type of pixel is an active pixel sensor (APS), which is used to produce a low-noise image. The other type is a custom-designed pixel optimized for computing the centroid of a moving object in the scene. The APS array is 120 columns x 36 rows, with a pixel size of 14.7 x 14.7 mu m. The centroid array has 60 columns and 36 rows, with a larger pixel size of 29.4 x 29.4 mu m. The chip was fabricated using standard scalable rules on a 0.5 mu m 1P3M CMOS process. APS images were taken at a frame rate of 30fps-8300fps and centroid data was taken at a rate of 180-3580 (x, y) coordinates per second. The chip consumed 2.6 mW.