| 摘要 |
In a cathode ray tube capable of displaying a video image in monotone and also, in part, a video image in color by a phosphor pattern having a predetermined shape by an AC reproduction method, only a desired phosphor pattern can be made emit light excellently. At the time of displaying an icon video image in an icon display area, an icon blanking signal (S3) is generated and the level of a signal portion corresponding to phosphor patterns other than the desired phosphor pattern in a video signal is lowered to be below the black level. Consequently, while employing the AC reproduction method, an unnatural operation such that the phosphor patterns other than the desired phosphor pattern emit light dimly is suppressed, and only the desired phosphor pattern can be made emit light excellently. <IMAGE> |
