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:
Dec. 09, 1997
Filed:
Dec. 12, 1994
Sherman T King, San Francisco, CA (US);
Tommy C Lee, Danville, CA (US);
Niantsu Wang, Milpitas, CA (US);
Yen-Fah Chu, San Jose, CA (US);
Scott A Kimura, San Jose, CA (US);
Guorjuh T Hwang, Milpitas, CA (US);
AurVision Corporation, Fremont, CA (US);
Abstract
In the preferred embodiment, the RGB analog signals generated by a VGA card in a personal computer are applied to a first input of an analog multiplexer. The digital video data stored in a video memory buffer on a video card is converted to RGB analog signals using a D/A converter, and these analog signals are applied to a second input of the analog multiplexer. An analog comparator compares a preselected color key to the analog output of the VGA card. When there is a match, the analog comparator controls the multiplexer to pass the analog video data to the monitor for display. When the color key is not detected, the data from the VGA card is transmitted to the monitor for display. Other features for improving the video overlay precision and the quality of the displayed image are also described.