METHOD AND APPARATUS FOR MERGING INDEPENDENTLY GENERATED INTERNAL VIDEO SIGNAL WITH EXTERNAL VIDEO SIGNAL

摘要

Disclosed is a method and apparatus for mixing internally generated or stored video with an external video and driving an LCD display device. External video is clocked into a dual port external frame store. Internal video is either internally generated or read from an internal mass store device and stored in an internal frame store and in a preferred embodiment, the internal video data includes an embedded code which serves to select on a pixel by pixel basis the appropriate frame store signal, either external or internal for display on the LCD panel. By adjusting the start number on row and column counters for reading out data from the external frame store, panning of an external video image can be accomplished. By repeating the readout of the external frame store selectively, a "zoom" of the image can be provided to an LCD display device. By reversing either the direction in which the external video is stored in the frame store or the direction in which columns of information are read out, the displayed image can be reversed permitting rear projection of an accurate image.