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:
Sep. 04, 1990
Filed:
May. 23, 1989
Minolta Camera Kabushiki Kaisha, Osaka, JP;
Abstract
An image forming apparatus wherein a photosensitive layer arranged to rotate in one direction is charged by a charger, and a negative electrostatic latent image is formed thereon by an exposure unit and then is subjected to reversal development by a developing device so that a positive noticeable image can be attained. The apparatus has a scorotoron charger for charging the negative latent image which has just been formed by the exposure unit with the opposite polarity thereof. A grid of the scorotoron charger is constituted to be impressed with a voltage with the same polarity as the latent image and a value lower than that of the surface potential, and by the scorotoron charger, the potential of the non-imaged portions of the latent image is lowered around the grid voltage. Further, the developing device is constituted to be impressed with a developing bias voltage with the same polarity as the latent image and a value lower than that of the surface potential but higher than a developing threshold value, whereby toner charged with the same polarity as that charged by the charger sticks to the imaged portions with potential lower than the developing bias voltage, resulting in a positive toner image with sharp line widths.