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:
Jul. 22, 2014
Filed:
Apr. 19, 2012
Takahito Fuse, Nagareyama, JP;
Takahito Fuse, Nagareyama, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An image forming apparatus including a rotatable photosensitive member, a first charging member for electrically charging the photosensitive member at a first charging portion by applying thereto a first DC voltage, and a second charging member, provided downstream of the first charging portion with respect to a rotational direction of the photosensitive member, for electrically charging the photosensitive member charged by the first charging member, at a second charging portion by applying thereto an oscillating voltage in the form of a second DC voltage superposed with an AC voltage. In addition, a toner image forming portion, provided downstream of the second charging portion and upstream of the first charging portion, forms a toner image on a surface of the charged photosensitive member, a current detecting portion detects a DC current passing through the second charging member, and a controller controls a voltage value of the first DC voltage on the basis of the detected DC current when the first DC voltage is applied to the first charging member and the oscillating voltage is applied to the second charging member. The controller controls the voltage value of the first DC voltage so that an absolute value of the detected DC current is smaller than a predetermined value.