Kenneth R Duvall

US Patent:

43951279, Jul 26, 1983

Filed:

Sep 11, 1980

Appl. No.:

6/186364

Inventors:

Kenneth R. Duvall - Washington DC

Assignee:

The United States of America as represented by the Secretary of the
Treasury - Washington DC

International Classification:

G01N 2189
G01B 1106

US Classification:

356430

Abstract:

An optical paper detector for use in conjunction with a printing press for sensing the undesirable condition of more than a single sheet of paper being simultaneously fed to the press. The optical paper detector is comprised of an array of wide angle phototransistors connected in parallel which uniformly sense light transmittance through the paper over a relatively large and continuous area to provide an averaging effect so that the optical paper detector is relatively insensitive to local variations in light transmittance. The optical paper detector is equipped with a flat cover that permits flush mounting and provides a self-cleaning wiping action.