Scanner document speed encoder

Abstract

A scanner, through which a document moves while being scanned by a moving beam of light, includes a wheel that rotates responsive to document movement. The wheel includes a multi-sectioned optical encoder upon which the scanning beam of light impinges when in a position at which it does not impinge upon the document. The scanner also includes an optical detector which receives light that is not absorbed by the optical encoder sections. Thus, the optical detector generates an electrical signal that indicates document movement speed. A preferred embodiment the scanner includes a pair of cup-shaped wheels one of which carries the optical encoder that encircles an inner surface of the wheel adjacent to a lip thereof. An axle, also included in the preferred embodiment, spans between, is coupled to, and supports the wheels for rotation in unison about a longitudinal axis parallel to the axle.

Dependencies are inferred from the claim text.