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:
Mar. 29, 1977
Filed:
Feb. 18, 1975
Hewitt D Crane, Portola, CA (US);
Gerald L Pressman, Cupertino, CA (US);
George J Eilers, Redwood City, CA (US);
Electroprint, Inc., Cupertino, CA (US);
Abstract
A machine for making a copy on a medium such as paper of a visual image. Particles of toner material are accelerated toward the paper through an apertured screen. Formed on the screen is a pattern of electrostatic charge regions that corresponds to the image so that the arrangement of the toner particles impinging on the paper corresponds to the image. A composite apertured screen composed of two conductive layers separated by an insulative layer and having an insulative layer on one outer surface. Means for establishing oppositely polarized fields across the inner insulative layer and across the outer insulative layer. One of the fields is selectively discharged to control the passage of toner particles through the apertures in the screen.