APPARATUS FOR DOCUMENT RECOGNITION BY MODULATED REFLECTED LIGHT

摘要

Apparatus for document recognition comprising a conveyor means for continuous conveyance of documents being oriented in a predetermined direction along a predetermined path, a light source (1) an optical system for focussing a light beam (11) from the light source onto said path, first and second light detectors (4, 14) for diffused reflected light at opposite angles to the normally incident light beam and a signal processing means for light detector output signals making up a quotient signal and a sum signal for a decision as to recognition. In said path at the light beam spot a light diffusing member (8) is arranged in the form of a transparent and piano-parallel plate; the cross-section (15) thereof is an isosceles trapezium and the short face thereof is frosted.