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:
Aug. 05, 1997
Filed:
Jul. 06, 1995
Phillip R Luque, Boise, ID (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A toner projection printer is provided with a developer surface which manifests a developer bias, and includes a cloud of entrained toner particles. A platen is positioned opposed to the developer surface and manifests a platen voltage that is attractive to the toner particles. An address plate is positioned between the developer surface and the conductive platen. The address plate includes a determined thickness insulator with through pixel apertures. Each pixel aperture has at least a first conductive electrode ring positioned within the insulator and connected to a drive plate that is also positioned within the insulator. A first drive circuit positioned on one side of the insulator and is capacitively coupled to the drive plate for controllably applying a row drive voltage thereto. A second drive circuit is positioned on a second side of the insulator and is capacitively coupled to the drive plate for controllably applying a column voltage drive thereto). Both the column and row drive voltages are set at levels so that only when both are high can toner particles pass through the pixel aperture and be drawn towards the platen and come under the influence of the platen voltage. Control circuitry operates to enable deposition of row and column dots of toner on a media sheet positioned on the platen.