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:
Jun. 30, 1992
Filed:
Sep. 25, 1989
Juris A Asars, Murrysville Boro, PA (US);
Westinghouse Electric Corp., Pittsburgh, PA (US);
Abstract
A power saving voltage drive circuit for a TFEL edge emitter device of the type having a plurality of pixels, with each pixel having a first terminal and all pixels on a device sharing a common second terminal, is comprised of a demultiplexing channel driver being selectively connected to the second terminal. A bidirectional switch selectively connects one of the first terminals to a source of voltage thereby enabling current to flow into and out of the pixel. A transformer has a primary winding connected between the first terminal and the bidirectional switch for enabling the pixel to charge to an operating voltage, and a secondary winding connected in series with a diode across the source voltage and ground for limiting the value of that operating voltage. The bidirectional switch is operated so that a substantial portion of the energy used to charge the pixel is returned to the source of voltage at the end of the pulse duration.