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:
May. 07, 2002
Filed:
Dec. 21, 1999
Peter J. Janssen, Scarborough, NY (US);
Lucian Remus Albu, New York City, NY (US);
John E. Dean, Stormville, NY (US);
Philips Electronics North America Corporation, New York, NY (US);
Abstract
In an electro-optic display device, such as a liquid crystal display device which serves as a modulator for projected light, a global ramp generator is used in conjunction with track and hold circuits to convert incoming digital display signals to analog signals, and to address the individual pixels of the display device with such analog signals. A plurality of column drivers, each coupled to the ramp generator and to the pixels in a column of the display device, track and hold the ramp voltage signal when it reaches a value corresponding to the desired brightness level of a particular pixel in the respective column. At least one current source is provided, coupled to the signal source output, for supplying current to the signal source output, as needed, to compensate for switching the capacitive load of the column drivers on and off. As a result, transient voltages in the ramp signal are avoided.