Hologram scanner with compensating plate and concave and plane mirrors - diffracts laser beam towards or in opposite direction from midpoint of curved scan line to produce linear trace on projection surface

摘要

A laser diode (10) emits a beam towards a hologram scanning disc (30) which is rotated by a motor (20). The beam exhibits a curved scan line corresp. to the hologram pattern, and the position error of the image projected on to a surface (70) is a measure of the laser temp. difference by wavelength variation. The plane mirror (40) reflects the diffracted beam on to the concave mirror (50) which redirects it through the compensation plate (60), forming a straight line on the projection surface during each scan. USE/ADVANTAGE - For image production. Follows current trends towards compact, lightweight and miniaturised scanning devices for holographic imaging.