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. 10, 2009
Filed:
Feb. 27, 2004
David A. Fish, Haywards Heath, GB;
John M. Shannon, Whyteleafe, GB;
Steven C. Deane, Redhill, GB;
Jason R. Hector, Redhill, GB;
David A. Fish, Haywards Heath, GB;
John M. Shannon, Whyteleafe, GB;
Steven C. Deane, Redhill, GB;
Jason R. Hector, Redhill, GB;
Koninklijke Philips Electronics N.V., Eindhoven, NL;
Abstract
In an active matrix display, each pixel has a storage capacitor for storing a voltage to be used for addressing a drive transistor. A discharge transistor is provided for discharging the storage capacitor thereby to switch off the drive transistor. The timing of this is controlled by a light-dependent device which is illuminated by the display element. The drive transistor is controlled to provide a constant light output from the display element, and the duration is controlled in dependence on the data voltage. Optical feedback is used to alter further the timing of operation of the discharge transistor to provide ageing compensation of the display element and compensation for changes in the drive transistor.