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:
Aug. 04, 1998
Filed:
Apr. 10, 1996
Chester F Bassetti, Pleasanton, CA (US);
NeoMagic Corp., Santa Clara, CA (US);
Abstract
A graphics controller drives a flat-panel display and simultaneously drives an external cathode-ray-tube (CRT) display. Horizontal clock pulses continue to be applied to the flat panel during the CRT's vertical blanking or re-trace period so that the flat panel is not left in a constant state during the entire re-trace period. Leaving the flat panel in a constant state for a long period of time can cause flicker or delayed response immediately after the re-trace period ends. Running the horizontal clocks during the re-trace period can lead to D.C. buildup or rolling flicker, believed to be caused by a polarity-inversion counter in the panel assembly which is not designed to receive additional horizontal clocks beyond the number of lines on the flat panel. D.C. buildup in the flat panel is reduced by adding a high-frequency burst of horizontal clock pulses to the flat panel during the CRT's vertical re-trace period. The burst of clock pulses adjusts the count in the polarity-inversion counter. The number of pulses in the burst is programmable so that the optimum number of pulses in the burst can be determined empirically and adjusted for different panel manufacturers.