| 摘要 |
<p>An apparatus for improving the focus of a digital optical record and playback system is described which provides plural simultaneous focal paths of different lengths for playing back or recording a digital optical data record. These focal paths may interact a common bit portion on a data record, successive bit positions in the same row of data on the record, or bit portions on adjacent tracks of data on the record. In certain embodiments, a selection circuit is utilized for evaluating the focal paths and selecting one which results in an improved focus. Data records having recorded bits of data of extended depth are also described to facilitate focusing during playback of the data record.</p> |
