The system for storing and reproducing information, the devices used in the system, the information carrier for reading and recording information blocks, how to implement reference marks on the information carrier, and how to write the information blocks on the information carrier.

摘要

The system of the present invention comprises an apparatus for reading and writing an information block in a disc shaped information carrier 1 and a continuous track 9. In order to represent the track 9, the information carrier 1 has a servo track 4 in which winding information is encoded per track winding 3. The winding number and angular position can be determined from the address of the information block. The angular position is given relative to the reference angular position. This reference angular position is determined by one or more reference marks 21, 22, which are recorded on the information carrier 1 before the first information block. The actual angular position is determined by counting the time against a known rotation time in the reading of the forward pointing reference marks 21, 22. One or more pulses, for example tachopulses, occur every revolution in the device. The position of the reference angular position is determined relative to the pulse by reading the reference marks 21, 22, and then the actual angular position can be determined from the pulse.