| 摘要 |
<p>A scanning waveform generator for operation at a first or a second scanning frequency comprises a source (IC100) of a parabolic shaped signal having a frequency selectable between the first or second scanning frequency. A means (456) for generating a switching signal indicative of a video signal operating at one of a first or a second scanning frequency. A means (CS50, CS60 C4, C5, 460) for generating a sawtooth shaped waveform is coupled to the switching signal for switching between the first or the second scanning frequency. A means (U1, R6) for generating an S correction signal is coupled to the source (IC100) and to the sawtooth generating means (CS50, CS60 C4, C5, 460). A means (R1, C1, Q1) for filtering the parabolic signal is controllably coupled to the switching signal generator(456), and is also coupled to the S correction signal generating means (U1, R6). The filtered parabolic signal has an substantially the same shape during the first or second scanning frequency.</p> |
