High luminosity image projecting device - has laser beam split into horizontally and vertically polarised beams applied to oscillating mirrors to give line scan and deflection

摘要

The device projects images at high luminosity onto a screen, the image being formed by line scanning and each line comprising a series of points. The device comprises a light source such as a laser (1) providing a vertically polarised light beam which is converted by a modulator (2) such as a crystal electroacoustic pockets cell into horizontally and vertically pilorised beams. A prism (3) such as a Glen Thomson prism separates the beams, which are applied to respective mirrors (5,6) oscillating sinusoidally in quadrature to provide a horizontal line scan for each beam. The two beams are reflected off a single mirror (7) oscillating about a horizontal axis onto a screen, this last mirror providing the vertical deflection. Control of the mirror oscillations is used to reduce non-linearity in the sweeps.