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:
Aug. 20, 1991
Filed:
Dec. 28, 1989
Kenichi Matsumoto, Tokyo, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An image forming apparatus of the type having a transfer device for transferring images formed on an image carrying member to a transfer material such as a paper sheet. The apparatus comprises an image carrying member; a charging device for charging the image carrying member; a measuring device for measuring the surface potential of the image carrying member; and a transfer device for forming a transfer electric field by means of which images formed on the image carrying member are transferred to a transfer material. The measuring device measures the surface potential of the image carrying member when it is charged but is not undergoing image transfer and measures the surface potential of the image carrying member when it is charged and is undergoing image transfer. The transfer electric field formed by the transfer device is controlled on the basis of the measurement results thus obtained by the measuring device.