| 摘要 |
PURPOSE:To attain easy to see reproduction of a character at the superimposing mode in a character multiplex broadcast at the 21-pin mode by changing the correcting amount of a frequency characteristics from that at the 8-pin mode when a 21-pin input is used at the RGB mode. CONSTITUTION:Since a collector of a transistor (TR) 22 is grounded forcibly when a changeover switch 21 is selected to the 21-pin mode, a TR for correcting frequency included in signal output amplifier circuits 1-3 is turned off and no frequency characteristics correction is applied. A collector voltage of a TR22 is dependent on the base voltage at the 8-pin mode and the TR22 is turned on at the television mode and the video mode, then no frequency characteristics correction is applied, but since the TR22 is turned off at the RGB mode, the frequency characteristics is corrected. Thus, the frequency characteristics is corrected only at the RGB 8-pin mode only, and the signal of all the modes is reproduced beautifully on the screen of a cathode-ray tube. |
