Patent Number: 6,310,965

Title: Manuscript document detecting system and method

Abstract: A manuscript document detecting system and method, wherein a rotatable body having a scanning mirror surface is rotated by a motor, and thereby light emitted from an light-emitting-diode (LED) is guided to a surface of a manuscript document. The rotatable body directs, toward a photo-diode (PD), light reflected from the manuscript document and a light-reflection processing device on a rear surface of an outer frame of a manuscript document mounting stand generates a light receiving signal. The rotatable body further includes an encoder having a row of slits mounted on a circular disk. When the slits pass through a photo sensor, pulse signals are output therefrom. Disturbance light reflected when a pressing plate, which holds the manuscript document against the mounting stand, is lifted generates a light receiving signal of a 75% duty cycle. The reflected light from the manuscript document generates a light receiving signal of a 25% duty cycle. The light source is turned on and off or power-modulated with a predetermined period and duty cycle, and the size and position of the manuscript document is detected by use of only the light receiving signal coinciding with the period and the duty cycle of the manuscript document.

Inventors: Murai; Toshiharu (Kawasaki, JP)

Assignee: Ricoh Company, Ltd.

International Classification: H04N 1/00 (20060101); G06K 009/00 ()

Expiration Date: 10/30/2018