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:
Sep. 26, 2000
Filed:
Jun. 21, 1999
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An image forming apparatus includes a movable image bearing member for bearing different color toner images; a movable intermediary transfer member including an electroconductive layer and a surface layer; first transferring means for applying a voltage to the electroconductive layer to sequentially and superimposedly transfer the different color toner images from the image bearing member onto the intermediary transfer member at a first transfer position; second transferring means for electrostatically transferring the different color toner images from the intermediary transfer member on the transfer material at a second transfer position, wherein the second transferring means is disposed faced to such a side of the intermediary transfer member as receives the toner image; wherein the image forming apparatus is operable with the transfer material having a length measured in a direction of feeding of the transfer material, which is longer than a distance between the first transfer position to the second transfer position in a moving direction of the intermediary transfer member; wherein when a toner image is formed on the transfer material having a length in the transfer material feeding direction longer than the distance, the different color toner images on the intermediary transfer member pass through the first transfer position in a period which is after completion of transfer of the different color toner image from the image bearing member onto the intermediary transfer member by the first transferring means and before transfer of the different color toner images from the intermediary transfer member onto the transfer material by the second transferring means; control means for switching a voltage applied to the electroconductive layer by the first transferring means from a first voltage for transferring a final color toner image from the image bearing member onto the intermediary transfer member to a second voltage having a smaller absolute value than that of the first voltage before a leading edge of the different color toner images on the intermediary transfer member reaches the first transfer position; wherein the second transferring means starts transfer of the toner image from the intermediary transfer member onto the transfer material after the control means switches the voltage to the second voltage.