Abstract

An achromatized all-holographic straight-line scanner for use in laser diode printers has been developed. The scanner consists of a compact holographic disk and a new holoplate and needs no other auxiliary optics to scan and focus the laser beam. Conventional holographic scanners having optical power suffer from scanning-beam aberration and chromatic aberration caused by mode hopping of the laser diode. To make a low-cost holographic line scanner more practical, resolution as high as 400 dpi must be attained. Moreover, scanners free from chromatic aberrations, especially in scan direction, need to be developed. To meet the requirements, we devised a simple holographic-disk scanner using a holoplate. Our holoplate compensates for shifts in position of the scanning beam caused by the laser diode hopping modes in both scan and cross-scan directions. High resolution can be obtained by using a compound optical system having a variable spatial-frequency disk and a holoplate.

© 1991 Optical Society of America