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:
Feb. 03, 1998
Filed:
Jul. 21, 1995
Peter Krause, Singapore, SG;
Aik Keong Ong, Tampines, SG;
Apple Computer, Inc., Cupertino, CA (US);
Abstract
The present invention, generally speaking, provides for automatic cutoff control in a DC coupled CRT video drive using a low DC supply voltage and circuitry that is lower in power consumption than conventional circuitry for the comparable video performance. A simple, easy to implement solution is achieved with an extremely low component count. Cutoff control response is fast, allowing discontinuous operation of auto cutoff control. In one embodiment of the invention, a cutoff control signal is applied to individual CRT G1 terminals. Fast response cutoff control drive is realized using an IC current source and a single transistor current-to-voltage (CTV) converter. Supply voltage variations on the video driver are clamped via a clamping device to the negative supply voltage of the G1 CTV converter.