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. 12, 2000
Filed:
Aug. 17, 1998
Kouji Ishigaki, Kanagawa, JP;
Haruji Mizuishi, Tokyo, JP;
Masaru Tanaka, Kanagawa, JP;
Hiroyuki Ohkaji, Kanagawa, JP;
Kenzou Tatsumi, Kanagawa, JP;
Hiroshi Mizusawa, Tokyo, JP;
Ken Amemiya, Tokyo, JP;
Hideki Zenba, Kanagawa, JP;
Mayumi Ohori, Kanagawa, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
An image forming apparatus transfers a toner image from a photoconductive image carrier to a recording medium with a transfer roller and senses the density of a particular toner pattern formed on the image carrier with an optical sensor. A voltage of a first polarity opposite the polarity of the toner is applied to the transfer roller when the toner image is to be transferred to the recording medium. A voltage of a second polarity identical to the polarity of the toner is applied to the transfer roller when the toner pattern is to be moved between the image carrier and the transfer roller. Thus, even when a toner pattern is brought to the transfer roller, the transfer roller is not released from the photoconductive element.