| 摘要 |
<p>The high density storage technique disc replay unit is used for frequency modulated and PCM sound recorded signals. Without interfering with the recorded sound signal additional information can be stored on the disc which is replayed as video text on a conventional TV set. A rotating disc (2) is tracked by a head (3) which provides an audio output (4,5,7,8,9) to stereo replay equipment and additionally, video text (11) in a form which can be displayed on a TV set (14). The video text signal (12) modulates a carrier which the TV monitor will accept and may be in PCM or FM form. The TV monitor (14) would normally use an antenna (15) for off-air reception and have changeover facility to receive the disc information. The disc information, i.e. video text, may be informative about the stereo work being heard. The supplementary information (12) is accompanied by indicator signals which a decoder (10) can recognise and use to power (Us) an indicator lamp so warning the user that the disc carries supplementary information.</p> |
