Disclosed is a method and apparatus for processing two analog composite video signals to be displayed to a human observer. The system includes at least a first and a second video source for generating first and second analog composite video signals respectively, and a selector coupled to the first...http://www.google.com.tw/patents/US5801785?utm_source=gb-gplus-share專利 US5801785 - Method and system for processing two analog composite video signals
