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. 23, 2001
Filed:
Aug. 29, 1994
John S. Beeteson, Romsey, GB;
Christopher C. Pietrzak, Winchester, GB;
International Business Machines Corporation, Armonk, NY (US);
Abstract
A display system for displaying a visual image in response to a video signal (,), comprising; a liquid crystal display panel (,) divided into a plurality of addressable, variable brightness sections (,); address circuit (,) for generating a section address corresponding to a section in response to a timing signal (,); driver circuit (,) for varying the brightness of the section in response to a brightness signal (,) derived from the video signal (,); characterised in that the display system further comprises: a memory (,) for storing a predetermined correction signal (,) corresponding to the section; and control circuit (,) coupled to the driver circuit (,) for varying the brightness signal (,) to reduce brightness non-uniformities in the displayed image in response to the video signal (,) and the correction signal (,) in combination. The control circuit preferably includes a summing circuit for adding the correction signal to the video signal to produce a summed signal for determining the brightness signal. In another preferred embodiment the control circuit includes a voltage control circuit for varying the amplitude of the brightness signal in response to the correction signal.