TELETEXT INFORMATION SUPERIMPOSING ADAPTOR AND ITS SYSTEM BY THE TELETEXT ADAPTOR

摘要

PROBLEM TO BE SOLVED: To display teletext superimposingly in a video image during display by placing the adaptor between a decoding video equipment converting a given video signal into a composite video signal and a display device displaying the video signal. ;SOLUTION: A control circuit 14 counts the number of scanning lines and positions a vertical and horizontal position based on a separated output signal separated by a synchronizing separator circuit 13 and requests a teletext signal to an address management circuit 16, processes an output operation instruction signal by the circuit 16 and gives a tread instruction to the circuit 16 and a storage circuit 17. A communication control circuit 15 receives the input of a superimposing teletext signal and the circuit 16 generates a write read address based on the output signal from the circuit 15. A conversion circuit 19 addlies matrix conversion to the teletext signal with output signals from the address instruction circuit 18 and the circuit 14 and outputs sequentially to a mask gate circuit 21 via a shift register circuit 20. The circuit 21 counts a timing when a character is superimposed on a video image and a superimposing circuit 22 synthesizes the output teletext of the circuit 21 with the superimposed video image and sends the result to a display device 3.;COPYRIGHT: (C)1998,JPO