Patent ID: 6195078
Filing Date: 2001-02-27
Classification: H04N

Abstract:
An on-screen display system, comprising:a character buffer containing a plurality of entries, each entry specifying one of a predetermined plurality of display characters;an attribute buffer containing a plurality of entries respectively corresponding to the plurality of entries in the display character buffer, each entry specifying an attribute of the corresponding display character; andcontrol circuitry for substantially simultaneously retrieving corresponding entries from the character and attribute buffers and generating a signal representing the image of the display character specified in the retrieved display character entry having the attribute specified in the retrieved attribute entry; whereineach entry in the attribute contains data specifying one of a plurality of entries in a palette memory; and said control circuitry comprises:a character read-only memory, coupled to the character buffer, and containing a plurality of arrays of pixels, each pixel being one of a foreground pixel or a background pixel, respectively corresponding to the predetermined plurality of display characters, for producing a signal representing a pixel in the pixel array corresponding to the display character specified by the retrieved display character entry;said palette memory is coupled to the attribute buffer and contains a plurality of entries specifying respective image characteristics for foreground pixels and background pixels for producing respective signals representing the image characteristics of foreground and background pixels in the palette entry specified by the retrieved attribute entry, said palette memory also containing an attribute control signal;selector means for receiving said pixel representative signal and attribute control signal; anda multiplexer, having first and second data input terminals responsive to the foreground and background pixel image representative signals from the palette memory, and having a control input connected to said selector for receiving either the pixel representative signal for producing the OSD image representative signal.