Peter James Ford

US Patent:

42681103, May 19, 1981

Filed:

Oct 12, 1979

Appl. No.:

6/084275

Inventors:

Peter W. Ford - Winchester MA

Assignee:

Itek Corporation - Lexington MA

International Classification:

G02B 2717

US Classification:

350 67

Abstract:

Multi-faceted rotating optical scanning system having facet angle corrector means for reducing banding in imagery produced therewith. In accordance with the invention, the corrector means comprises a corrector plate supporting a plurality of transparent discs, each one of said discs being positioned in advance of a different facet of said scanner. Each of the discs is further designed to have a slight wedge angle between its two surfaces such that by independently rotating each disc, a light beam passing through it can be bent by a precise amount to control the angle at which the beam impinges upon the associated facet, and, hence, the angle at which it is reflected therefrom onto an image receiving medium. This system thus permits any banding that might otherwise be caused by relative differences in the angular orientation of each facet to be essentially eliminated in a highly accurate, inexpensive manner.