Radiant energy quadrant detection device

Claim 1

A radiant energy detector device for generating output signals representing the departure in altitude and azimuth of a target from a predetermined reference axis, comprising: a. an array of four radiant energy detectors arranged in a common plane in a substantially square configuration, each of said detectors occupying a separate quadrant of the square, b. a frame, c. means for mounting said detector array on said frame, d. a lens for focusing radiant energy from said target onto the detector array, e. means for supporting said lens on the frame, f. chopper means mounted in the lens supporting means and positioned between the lens and the detector array for chopping the radiant energy focused onto the target array, g. synchronizing circuit means for generating a synchronous drive signal from said chopper means, h. a pair of electronic circuit means mounted on said frame in proximity to said detector array, each for directly receiving the outputs of a diagonally opposite pair of the detectors and subtracting each of said paired outputs from each other, i. summing circuit means mounted on said frame for receiving the outputs of said pair of electronic circuit means and summing said last mentioned outputs together in a predetermined manner to provide a first signal in accordance with the departure in azimuth of the target from a predetermined axis and a second signal in accordance with the departure in elevation of the target from said axis, j. first and second phase detector circuit means mounted on said frame for receiving said first and second signals respectively and a reference signal from said synchronizing circuit means, and generating pulsating DC signals in response thereto, and k. first and second filter circuit means mounted on said frame for receiving the outputs of said first and second detector circuit means respectively for producing smooth DC signals representing the departure in azimuth and elevation of the target from said reference axis.