| 摘要 |
Increased usage of available recording space in the optical memory is ensured by release of reference tracks for the recording of data, and thus improving the density of information recording. The tracks of reference on the recording coat are on the optical information carrier, and the data are optically coupled to two or more optical heads. Each of the latter comprises a source of modulated coherent radiation, movable optical element, light beam splitter and photodetector. One output of the detector is connected to the controller while the outputs are tied to the coherent radiation source of the optical heads. The other output of the photodetector is linked to the two autofocusing sets the output of which is connected to the movable optical element. The input of the tracking unit is electrically connected to the third output of a photodetector, while the tracks commutator is included between the third output of the photodetector and the tracking unit. - The optical data carrier has the cylindrical substrate (2) with ends closed by plugs (3), and its inside surface carries the recording coat (4) with the section (5) having prerecorded tracks. The optical information carrier is held in the hermetic container (6) where the transparent zones (7) hold the fixed optical elements in form of immersion lenses (8). The optical heads (10) comprises a modulated source (11), movable optical element (12) and a photodiode (14). The tracker unint (16) is linked to the commutator (17), while the controller (18) is connected to the data and computer system via buses (19).
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