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. 29, 1980
Filed:
Jul. 24, 1978
Masao Masumura, Tokyo, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
An electrostatic charge is applied to the entire surface of a photoconductive drum (12) and a light image of a negative original document (16) such as a microfilm is radiated onto an image area of the drum (12) to form an electrostatic image. A developing unit (17) applies a toner substance (18) charged with the same polarity as the electrostatic image to the drum (12) to develop the electrostatic image into a toner image. The toner adheres to areas of the electrostatic image having low potential, thereby forming a positive toner image which is transferred and fixed to a copy sheet (19). The developing unit (17) comprises a biasing member (22), (27) for producing an electric field of the same polarity as the electrostatic image for repelling the toner substance against the drum (12), the electric field being insufficiently strong to cause the toner substance to adhere to non-image areas of the drum (12).