| 摘要 |
<p>21 The invention relates to optical memories making use of optical interaction between an incident ray and an information medium (83) capable of having data written thereon and of having data read therefrom, which data is organized in a adjacent track elements which are marked by prerecorded patterns. The invention provides an information medium (83) and a reader device therefor (84, 85, 86, 87, 88) including means (89, 91, 92, 93, 94) for sampled tracking of the track elements on the basis of patterns which are offset from the track scan line, said patterns forming discontinuous periodic wave sequences whose offset edges are symmetrically disposed about the middle of the inter-track gap. The invention is particularly applicable to optical memories using a preformated disk capable of recording, of being read, and where appropriate of being erased, with data in digital form.</p> |
