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:
Oct. 09, 1990
Filed:
Apr. 08, 1988
Masahide Ueda, Osaka, JP;
Minolta Camera Kabushiki Kaisha, Osaka, JP;
Abstract
An electrophotographic copying apparatus includes a photosensitive member, a sensitizing charger, a developing unit for developing the electrostatic latent image by a developer incorporating toner and carrier, and a system for compensating toner concentration and charging potential of the photosensitive member surface. The system forms two reference toner images on the photosensitive member surface under different conditions so as to cause the two reference toner images to have different densities and optically measures the densities of the two reference toner images. Toner concentration in the developer can be detected based on the two reference toner image densities. When the toner concentration is less than a specified value, toner is supplied to the developer. Further, the charging potential of the photosensitive member surface is determined based on the toner concentration and the density of the reference toner image formed under the normal image formation condition, and may be corrected in accordance with the determined potential.