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:
Dec. 13, 1994
Filed:
Jul. 16, 1992
Takao Umeda, Mito, JP;
Tetsuya Nagata, Hitachi, JP;
Yasuo Takuma, Hitachi, JP;
Tatsuo Igawa, Kitaibaraki, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi Koki Co., Ltd., Tokyo, JP;
Abstract
A parallel circuit of a capacitor and a varistor is connected between a ground and an aluminum cap of a photosensitive drum having a photoconductor sheet wound on a surface of an aluminum drum. The capacitor is charged by a charger. A developer roll connected to a bias voltage supply is provided with a retraction mechanism and is controlled so that the developer roll is separated from the drum mechanically upon start of operation of a recording apparatus until a potential of the cap is increased to a predetermined value and a developing agent layer does not come into contact with the cap. Alternatively to retraction of the developing roll, the developing roll may be stopped to control a height of bristle of developing agent or a bias voltage of the developer may be reversed.