Dynamic light scanner, esp. for precisely scanning text or films - has rotating grid performing double refraction with beam retro-reflected along single axis after first refraction

摘要

A dynamic light scanner performs scanning by double refraction of light at at least one grid (1) rotating about its surface normal. After the first refraction one of the two components of the wave vector perpendicular to the grid surface normal is rotated. The result is that, after the second refraction of these components, the wave vector remains constant with grid rotation whereas, the other two componetns vary with grid rotation angle. USE/ADVANTAGE - Precise scanning of printed text and films. Light deflecting element is very stable, having good aerodynamic properties. Scanned line is very narrow and curvature free.