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:
Oct. 31, 1995
Filed:
Jun. 01, 1994
Seiji Uchiyama, Tokyo, JP;
Akio Noguchi, Yokohama, JP;
Yukihide Ushio, Tokyo, JP;
Shinpei Matsuo, Tokyo, JP;
Youji Serizawa, Yokohama, JP;
Makoto Takeuchi, Yokohama, JP;
Kazurou Yamada, Tokyo, JP;
Junichi Kato, Yokohama, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
In a laser beam printer, automatic optical quantity (APC) control is performed based on an optical quantity detection output to generate a laser beam having a predetermined quantity of light. In each scanning cycle, APC is effected by utilizing a period (unblanking period) in which the laser device is forcibly actuated to generate a horizontal synchronization signal. The unblanking period may be changed according to the print paper size or image formation/non-image-formation periods. Also, light quantity control may be effected through a plurality of scanning cycles before image formation and may be effected by utilizing the unblanking period during the period corresponding to the intervals of print sheets. Techniques also provided to prevent a transfer unit from being contaminated by toner images formed as a byproduct of APC.