| 摘要 |
<p>DISC PLAYERS A disc player for reproducing an information signal from R rotating disc having a spiral track on which a digital signal is recorded with a waveform obtained by the run length limited code modulation comprises a control circuit system wherein an interval representing the maximum or minimum run length in a reproduced signal from the disc is utilized for controlling the rotation of a motor for rotating the disc so as to keep the tangential velocity of the spiral track to a pickup device constant at predetermined speed and an additional control circuit system for detecting an interval of a constant level in the reproduced signal exceeding in length the interval representing the minimum run length obtained at the proper rotation of the disc, which appears when the reproduced signal from the disc is not properly obtained and therefore the motor is in danger of running away, and, when such an interval is detected, preventing the motor form running away, for example, by stopping the motor from rotating.</p> |
