Programmable resolution imager for imaging applications

Abstract

In this paper a programmable imager with averaging capabilities will be described which is intended for averaging of different groups or sets of pixels formed by n×n kernels, n×m kernels or any group of randomly-selected pixels across the array. This imager is a 64×64 array which uses passive pixels with electronic shutter and anti-blooming structure that can be randomly accessed. The read-out stage includes a sole charge amplifier with programmable gain, a sample-and-hold structure and an analog buffer. This read-out structure is different from other existing imagers with variable resolution since it uses a sole charge amplifier, whereas the conventional structure employs an opamp per column plus another global opamp. This architecture allows a reduction of the fixed-pattern noise observed in standard imagers. The prototype also includes an analog to digital converter which provides the digital output of the images.