| 摘要 |
<p>A device for reading and/or recording information from/in an information track on the disc-shaped information carrier (1), comprising scanning means (2) for scanning the information track with a linear velocity at a variable distance (r) from a point of rotation of the information carrier (1) and comprising drive means (3) for causing the information carrier (1) to rotate at an angular velocity. When the distance (r) increases, the angular velocity of the information carrier (1) will essentially decrease and the linear scanning velocity will essentially increase (curves in area 30). As a result, a short access time and a high average information rate is obtained. For a minimum access time to be obtained, the relation between angular velocity and distance (r) is such that in the case of a rapid displacement the minimum necessary velocity adaptation is at most equally long as the time required for the rapid displacement (curve 33). The velocity that must be attained depends on the maximum and minimum information reading, recording and processing rates.</p> |
