| 摘要 |
<p>RECORD MEDIUM, METHOD OF MAKING SAME, AND METHOD AND APPARATUS FOR RECORDING INFORMATION ON AND REPRODUCING INFORMATION FROM SAID RECORD MEDIUM A novel record medium, its method of manufacture, and a method and apparatus for recording information on and reproducing information from said record medium are disclosed. The record medium comprises a disc-like body having a surface provided with a first portion adapted to have signal information recorded thereon and a circular track distinct from the first portion having reference information therein. When used to record signal information in the first, or signal information portion thereof, the record medium is rotated about an axis while the signal information is recorded thereon. The reference information in the circular track is predetermined, detectable pattern which is sensed while the record medium rotates. In the event of eccentric rotation, the record medium undergoes a lateral displacement with respect to a center, or drive shaft, whereby the circular track is shifted with respect to a fixed pattern detecting station. This, in turn, results in a relative shift in the detectable pattern whereby the eccentric rotation is sensed. The signal recording apparatus is adjusted in response to sensed eccentric rotation so as to compensate for such rotation. Similarly, when the record medium is used for the reproduction of previously recorded information, eccentric rotation of the medium is sensed by detecting a shift in the detectable pattern provided in the circular track so as to correspondingly adjust the signal playback apparatus to compensate for such eccentric rotation. -i-</p> |
