| 摘要 |
Beam scan velocity modulation (SVM) apparatus with a svm disabling circuit employed for picture sharpness enhancement is disclosed. The beam SVM includes a picture display device, a source of a first video signal having a picture information displayed on the device when the source is selected, an OSD/TELETEXT display generator having on-screen display information or teletext display information displayed on the device when the generator is selected, a scan velocity modulating circuit coupled to the source for modulating information displayed on the device in accordance with the video content of the first video signal, and a svm disabling circuit responsive to the pulses and the dc voltage and coupled to the scan velocity modulating circuit for modifying operation of the scan velocity modulating circuit when the OSD/TELETEXT display generator is selected. The generator produces pulses, on a line by line basis, and a certain level of dc voltage, indicative of insertion of the picture information and of a full-screen teletext display information. With the beam scan velocity modulation apparatus with svm disabling circuit, an OSD display over a certain display size or a full-screen teletext display is obtained on the screen without any ghost image caused by luminance signal.
|
