Photosensitive energy detection system

Claim 1

IN AN OPTICAL SYSTEM INCLUDING RADIANT ENERGY COLLECTION APPARATUS HAVING A FIELD OF VIEW, SAID COLLECTION APPARATUS BEING ADAPTED TO IMAGE SAID FIELD OF VIEW AT A PREDETERMINED FOCAL PLANE, A RETICLE COMPRISING: A BODY HAVING A CROSS-SECTIONAL CONSTRUCTION PRESENTING A PLURALITY OF AREAS RELATIVELY OPAQUE TO RADIANT ENERGY DEFINING A PLURALITY OF OTHER AREAS RELATIVELY TRANSPARENT TO RADIANT ENERGY; AND DRIVE MEANS FOR MOVING SAID RETICLE IN A MANNER SUCH THAT PORTIONS THEREOF INTERCEPT AND PASS COMPLETELY THROUGH SAID IMAGED FIELD OF VIEW PERIODICALLY, WHEREBY NO PORTION OF SAID RETICLE LIES IN SAID IMAGED FIELD OF VIEW DURING ANY COMPLETE CYCLE OF MOVEMENT OF SAID RETICLE, THE SIZE, SHAPE AND DIRECTION OF MOVEMENT OF SAID RETICLE TRANSPARENT AREAS, AND THE SIZE AND SHAPE OF SAID IMAGED FIELD OF VIEW BEING SUCH THAT THE SPACING OF SAID TRANSPARENT AREAS IS SUBSTANTIALLY EQUAL TO THE RECIPROCAL OF THE CORRESPONDING SPACE FREQUENCY AT ONE NULL OF THE FOURIER TRANSFORM OF THE TOTAL AREA WITHIN BOTH A RETICLE TRANSPARENT AREA AND SAID IMAGED FIELD OF VIEW; AND ENERGY SENSITIVE MEANS POSITIONED TO RECEIVE ENERGY TRANSMITTED THROUGH SAID RETICLE TRANSPARENT AREAS FOR PRODUCING AN ELECTRICAL SIGNAL IN RESPONSE TO VARIATIONS IN THE ENERGY RECEIVED, THE RETICLE CROSS-SECTIONAL CONSTRUCTION BEING SUCH THAT SAID ELECTRICAL SIGNAL IS MINIMAL IN RESPONSE TO A UNIFORMLY BRIGHT FIELD OF VIEW.