| 摘要 |
PURPOSE:To display freely the time, channel number, etc. at the upper or lower edge area of a screen, by generating electron beams in the vertical flyback time of a TV signal and then modulating the electron beams with a displaying signal. CONSTITUTION:A TV composite video signal is applied to an input terminal 23, and vertical and horizontal synchronizing signals are separated and extracted by a synchronism separating circuit 24. A line cathode driving circuit 26 divides vertically a screen into plural sections and then generates an electron beam for each section. This electron beam is generated even in the vertical flyback time. A displaying signal producing circuit 38 is actuated only in a period during whic the lowest vertical section is displayed in the vertical flyback time. Then the time, channel number, etc. are displayed at the lower edge area of the screen. |
