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:
Apr. 18, 2000
Filed:
Oct. 13, 1998
Yasushi Shimizu, Toride, JP;
Akira Domon, Kashiwa, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An image forming apparatus includes a photosensitive member and a developer carrying member spaced from the photosensitive member by a gap. The developer carrying member carries a developer containing an externally added strontium titanate. A bias voltage is applied between the photosensitive member and the developer carrying member with a substantially rectangular waveform. This bias voltage forms an oscillating electric field therebetween. The electric field provided by the difference between a jump peak voltage of the bias voltage and the potential of the photosensitive member at a portion exposed to the light is not less than 4.1 V/micron. The electric field provided by a difference between the jump peak voltage and a potential of the photosensitive member at a portion not exposed to light is not more than 3.5 V/micron. The electric field provided by a difference between a returning peak voltage of the bias voltage and a potential of the photosensitive member at a portion not exposed to light is not more than 2.9 V/micron. A ratio of a portion of the voltage for the direction toward the photosensitive member is 20 to 50%.