The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 13, 1993
Filed:
Oct. 09, 1991
Fuji Xerox Co., Ltd., Tokyo, JP;
Abstract
An apparatus for performing a copying operation contains a photosensitive drum, a focusing optical system for directing reflected light from an original image onto the photosensitive drum, a lamp for lighting the original image, a light quantity sensor for detecting the quantity of reflected light from the original image and for controlling the quantity of light of the lamp on the basis of the detected value of the quantity of reflected light, a first filter provided in an optical path of the focusing optical system so as to cut-off light having a wavelength not longer than a predetermined value, and a second filter provided on a light-detection surface of the light quantity sensor. The second filter has a cut-off wavelength point shorter than the first filter.