| 摘要 |
A thermoplastics data storage member (1) carries information (10) which can be imaged using non-coherent light and, in addition to and distinct from that information, control data (7, 9, 11) which defines a two-co-ordinate system for the member which controls random access to the information. A reading apparatus comprises a non-laser optical system (49, 57) for imaging selected areas (5) of the information and a servo-system, including a microprocessor (107) and transducers (86, 87) for reading the control data, for positioning a reading head (49) of the optical system in desired locations relative to the storage member (1). The invention affords cheap optical data bases readable by apparatus not requiring a laser optical system. |
