| 摘要 |
A method of controlling the viewing of television programmes according to their content involves sending codes using an auxiliary data channel which indicate the level of sexual, violent, distressing, etc. content. These codes are assembled into a teletext signal and detected at a receiver. The receiver is programmed by entering corresponding codes which indicate allowable or forbidden content and cause the display to be blanked and the sound to be muted in dependence on the transmitted codes. The codes are additionally inserted in displayable form in a teletext page to enable a viewer without an automatic means of controlling the display of the programme to monitor the classification of a programme being viewed. A system, programme source and receiver are also described. |
