Optical correlator

Claim 1

IN AN OPTICAL CORRELATOR IN WHICH A RADIANT ENERGY SENSOR GENERATES SIGNALS IN RESPONSE TO LIGHT TRANSMITTED FROM AN ILLUMINATED BODY AND PASSING THROUGH A ROTATABLE TRANSPARENCY REPRESENTATIVE OF THE LIGHT TRANSMITTING CHARACTERISTICS OF SAID BODY IN REDUCED SCALE, THE IMPROVEMENT WHICH COMPRISES; A FIRST SHUTTER HAVING ALTERNATELY ARRANGED DIFFUSING AND NONDIFFUSING PORTIONS, SAID FIRST SHUTTER BEING POSITIONED ADJACENT TO SAID TRANSPARENCY AND OPTICALLY ALIGNED THEREWITH AND SAID FIRST SHUTTER BEING ROTATED CONTINUOUSLY AT A FIRST SPEED FOR PERIODICALLY DIFFUSING ALL LIGHT TRANSMITTED THROUGH SAID TRANSPARENCY FOR CAUSING THE SIGNALS GENERATED BY SAID SENSOR TO INCLUDE FIRST ALTERNATING COMPONENTS AT A FIRST FREQUENCY, A SECOND SHUTTER HAVING A MINOR PORTION OF ITS AREA TRANSPARENT AND THE REMAINDER OPAQUE, SAID SECOND SHUTTER ALSO BEING POSITIONED ADJACENT TO SAID TRANSPARENCY AND OPTICALLY ALIGNED THEREWITH, SAID SECOND SHUTTER BEING ROTATED CONTINUOUSLY, IN AXIAL ALIGNMENT WITH SAID TRANSPARENCY, AT A SECOND SPEED, FOR PERIODICALLY PASSING LIGHT TRANSMITTED FROM SAID BODY THROUGH SAID TRANSPARENCY WHEREBY IF SAID TRANSPARENCY IS NOT ALIGNED ROTATIONALLY WITH SAID ILLUMINATED BODY, THE SIGNALS GENERATED BY SAID SENSOR INCLUDE SECOND ALTERNATING COMPONENTS AT A SECOND FREQUENCY, FIRST MEANS FOR DETECTING SAID FIRST COMPONENTS FOR GENERATING ERROR SIGNALS INDICATIVE OF TRANSLATION MISALIGNMENT, AND SECOND MEANS FOR DETECTING SAID SECOND COMPONENTS FOR GENERATING ERROR SIGNALS INDICATIVE OF ROTATIONAL MISALIGNMENT.