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:
Mar. 06, 2001
Filed:
Feb. 03, 1999
Shirou Wakahara, Chiba, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A region with high resistance equal to the atmosphere is provided in a transfer roller. A discharge electrode capable of performing discharge between a base member and the discharge electrode is arranged within the region. When a predetermined electric potential is applied to the discharge electrode from a transfer power supply, the electric potential is separated and respectively applied to a first region in the transfer roller and a second region between the transfer roller and a photosensitive drum. At this time, since both the first and second regions are regions of high resistance, the electric potential applied to each region is equal, and therefore the electric field can never be concentrated in the second region. Moreover, since a predetermined electric field is formed in the first region, even when the transfer roller and photosensitive drum come into contact with each other, a transfer current can never collect in the contact. Thus, when a high electric potential is applied to the transfer roller, it is possible to avoid toner from unpreparedly flying from the photosensitive drum to paper, and prevent concentration of the transfer current in a region between the transfer roller and photosensitive drum, where the paper is not present.