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:
Jun. 20, 2000
Filed:
Sep. 26, 1997
Toshihiko Takaya, Yamatokoriyama, JP;
Fumio Shimazu, Nara, JP;
Seiichi Yoshida, Nara, JP;
Hideki Ohnishi, Chiba, JP;
Tomohiro Oikawa, Chiba, JP;
Yoshie Iwakura, Nara, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
An image-forming apparatus is provided with: a photoconductor drum having a surface on which a toner image is formed, a transfer drum for transferring the toner image onto a copying material by allowing the copying material to contact the photoconductor drum, and a ground roller for electrostatically attracting the copying material onto the transfer drum prior to transferring the toner image onto the copying material. He transfer drum is constituted by a semi-conductive layer and a dielectric layer that are stacked on a conductive layer. [Supposing that] The nip width between the photoconductor drum and the transfer drum is L1, the rotation speed of the two drums is Vp, and the time constant, which is represented by a product of the resistance and the capacitance between the two drums, is .tau., the relationship represented by L1/Vp<.tau. is satisfied. By defining the time constant of the transfer drum [as described above], it becomes possible to stabilize an electric field made by the transfer drum, and consequently to carry out a desired transferring operation.