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:
Jan. 24, 1989
Filed:
Mar. 08, 1988
Frederick J Kahn, Palo Alto, CA (US);
Elizabeth A Nevis, Menlo Park, CA (US);
Jerry Leff, Saratoga, CA (US);
Greyhawk Systems, Inc., Milpitas, CA (US);
Abstract
A liquid crystal cell for an image projection apparatus has a liquid crystal layer sandwiched between two conductive layers. The layer surface is divided into one or more regions and one of the sandwiching conductive layers is divided into separate sections each matching a different region. Busbars are bonded on the other of these conductive layers along the edges and boundary lines between adjacent regions (resistors) such that negative and positive writing/erasing can be performed in selected region or regions. By applying one or more current pulses in one or more of these resistors, the corresponding region or regions can be more completely erased and a uniform dark background can be created therein.