| 摘要 |
PURPOSE:To attain scrolling of a character screen to be superimposed with simple circuit constitution by changing gradually the phase of a horizontal and vertical synchronizing signal included in a television signal forming a pick-up screen. CONSTITUTION:In designating a character from a keyboard 8, a character designation signal 300 is transmitted to a character generator 7. In designating further the character size, a character size designation signal 400 is applied to a character size identification circuit 9 and a character generator 7 and a character data with a required size is stored in a prescribed area of a RAM in a character generator 7. On the other hand, a horizontal synchronizing signal 100 and a vertical synchronizing signal 200 from a video processing circuit 2 are ged respectively to horizontal and vertical read circuits 5, 6, where the phase of the horizontal and the vertical synchronizing signal is changed, the result is fed to a character generator 7 as a read start signal. Then the character data from the character generator 7 is converted into a proper video signal and superimposed on the television signal by a mixer 3.
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