PURPOSE: To rapidly detect the density of a document by setting the home position of an optical system within the scanning range of the optical system and detecting the density of the document with the aid of reflected light from the optical system while the document is fed by a document feeder.
CONSTITUTION: The leading edge and the trailing edge of the document are detected by a document detection switch 7 and the detection signal is used to control the scanning of the optical part and a copying action in accordance with the size of the document. The home position of the 1st optical system 2a is set within the scanning range and the light source 21 of the 1st optical system 2a is made to emit light while the document is fed and moved to a specified position on a document platen by a conveying belt 65, and the density of the document is measured by an exposure sensor 8. As to the measurement of the density of the document, it is also possible to detect the density of the document which is being conveyed by the conveying belt 65 while the 1st optical system 2a is moved from the home position to a scanning start position with the feeding action of the document.
KUSUMOTO HIROSHI
ISHII YOSHIFUMI
KITAGAWA SHOICHI
ISHIDA HIDEKI
