Abstract: In an optical correlator system having reflective and transmissive optical components positioned along a folded and segmented optical axis or path, one or more optical path extenders are provided for selected optical path segments that require operative path length adjustment so that an electromagnetic radiation beam, which traverses the folded optical path with selected information imparted into and detected from the beam, can be imaged upon a defined and maximum usable area or region both on the reflective components and on an end detector component.

Abstract: An optical correlator system having a plurality of reflective optical components, both active and passive, positioned (1) between a source of electromagnetic radiation, such as a visible beam of coherent light, and an output detector array, and (2) around an asymmetrical perimeter of a planar support body to develop an asymmetrically folded optical axis or path wholly within the body where the path is traversed by the beam SO THAT information processed by the active optical components along the optical path and imparted to the optical beam enable the optical detection of an unknown object at the detector array which is then subject to an identification process.

Abstract: An improved electromagnetic audible signal device has a coil and an associated magnetic core. A flexible striker arm carrying a movable magnetic contact is positioned above the core. A multiconvoluted diaphragm is located above the movable contact and the striker arm. The contact periodically impacts against this diaphragm generating an audible signal. The invention includes a spring and screw arrangement for linearly adjusting the gap between the core and striker arm. The same spring also serves to restore vibrational mechanical energy to the system which would normally be lost to the housing.