Optical signal processor

Abstract

An array of optically sensitive devices senses printed matter with each device in the array producing an output signal representing a single black or white element in a multi-element picture being sensed by the whole array. These output signals are fed into an analog charge transfer shift register and passed serially in a fixed sequence through an output stage of the shift register. As the signal from each device passes through this output stage the device becomes what is hereafter referred to as the device of interest and the signal produced by it is analyzed to determine whether it is a black or white element. Other output stages simultaneously sense data from devices located around the device of interest to define a subarray within the original detected array while the last of these output stages is fed to a peak comparator to sense the brightest and darkest matter detected in the recent past by any element of the array. The results of these sensings are processed in accordance with a preselected algorithm to generate a digital signal wich is an indication of whether the device of interest has detected black or white. As the outputs of the array are shifted through the shift register each device of the array at one time or another is the device of interest of the subarray. The digital values of light intensity from all the devices in the array are then fed to a computer for analysis to determine what has been optically detected by the whole array.