Abstract: Scanning beam display systems using fluorescent screens and various servo feedback control mechanisms to control display imaging qualities, including techniques and mechanism for measuring and correcting pyramidal errors of a polygon scanner.

Abstract: Three aspect of a interferometer system for testing and characterizing micro-optical components an automatic system for testing a plurality of micro-optical components in sequence, a special holding device including a vacuum chuck arrangement allows for individual micro-optical components to be picked up and held during testing, and a modified Linnik objective is used with short coherent light and preferably a opaque reference sphere to carry out reflection tests on micro-optical component having at least one curved surface.

Abstract: An improved motor control circuit is disclosed in which energy stored in the motor is transferred back to the power supply rather than being passively dissipated. The sense of a feedback signal is reversed at a summation node by combining the signal with an inverted, amplified reproduction of the signal.

Abstract: A non-contact, laser strain extensometer for use in materials testing utilizes a revolving laser beam to measure the separation of benchmarks placed on the specimen to be tested. The reflection of the laser beam from the benchmarks is focused on a photosensor to generate electronic pulses. The time duration between these pulses can be precisely measured using electronic counters. This time duration correlates with the distance separating the benchmarks. The revolving beam can be generated either by rotating polygonal mirror or an oscillating mirror.