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. 15, 1993
Filed:
Apr. 01, 1992
Shigekazu Enoki, Kawasaki, JP;
Koji Suzuki, Yokohama, JP;
Naoki Iwata, Tokyo, JP;
Yuichi Ueno, Kawasaki, JP;
Junko Tomita, Tokyo, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A developing device incorporated in an image forming apparatus and including a developing roller or similar developer carrier for transporting a developer to a developing region where it faces an image carrier, so as to develop a latent image electrostatically formed on the image carrier. The developer carrier has a first and a second substance different in charging characteristic from each other and exposed to the outside on the surface of the developer carrier in a regular or irregular pattern. At least one of the first and second substances is charged to predetermined polarity on the surface of the developer carrier to form a great number of microfields. Alternatively, the developer carrier may have a conductive base and a surface layer provided on the base and constituted by a conductive substance in which insulating particles are dispersed. At least the insulating particles are charged on the surface of the developer carrier to form a number of microfields. The movement of the developer is controlled by an electric field determined by a relation of a potential deposited on the image carrier, an electric field ascribable to the bias applied from a bias applying source, and an electric field developed on the developer carrier.