Abstract: A compensation system for use in a helmet mounted raster projection system tilizes a microprocessor to control the offset position of the raster line and frame scanners, thereby increasing the stability of the viewed scene. The microprocessor calculates control words which are fed to the scanners via digital to analog converters during the vertical sync of the raster scan. The microprocessor calculates the control words from pilot look data obtained by head and eye trackers compared to previous similar data.

Abstract: A pattern generating circuit is disclosed for providing a fixed test pattern to be broadcast on a video display system such that an individual may test or repair the aforementioned video display system. The pattern generating circuit provides a horizontal sync signal, a vertical sync signal, and first and second video component signals which are then summed by a summing amplifier to form a video signal. The horizontal and vertical sync signals are then supplied to the video display system so as to activate the same. This, in turn, allows the video display system, upon receiving the video signal, to broadcast on its display screen the fixed test pattern.

Abstract: A composite video signal separator for television receivers, laser projecn systems and the like which performs the combined functions of horizontal sync signal separation, vertical sync signal separation, and video signal separation in a single circuit.