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US 5,844,865 AGranted
System for storing and reproducing information from a disc shaped information carrier
AssigneeU.S. Philips Corporation
InventorJohannus L. Bakx
Life of this patent
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AssigneeU.S. Philips Corporation
InventorJohannus L. Bakx
Estimating the term…
The disclosed system includes a disc-shaped information carrier and an apparatus for reading and writing information blocks in a continuous track. For indicating the track, the information carrier has a servotrack in which a winding number is encoded per track winding. A winding number and an angular position can be determined from the address of an information block. The angular position is given relative to a reference angular position. This reference angular position is determined by one or more reference marks which are written on the information carrier prior to the first information block. The actual angular position is determined by counting the time relative to a known rotation time from the reading of a reference mark onwards. One or more pulses, for example tachopulses, are generated per revolution in the apparatus. The location of the reference angular position is determined relative to the pulses by reading a reference mark and, subsequently, the actual angular position can be derived from the pulses.
A system for storing and reproducing information including a disc-shaped information carrier and an apparatus, comprising means for reading and writing information blocks on a continuous track intended for recording on the information carrier, which track is arranged according to a helical or concentric pattern of windings and is determined by a servotrack on the information carrier, the apparatus including driving means for causing the information carrier to rotate, and a read/write head for scanning the track, and which servotrack has a periodic modulation in which disc information is encoded, characterized in that the disc information comprises winding information in windings which identifies each particular winding of the track, the apparatus also including means for reading and writing through the read/write head at least a first reference mark on the information carrier which reference mark is indicative of the location of a reference angular position, and means for determining an actual angular position relative to the reference angular position wherein the means for reading and writing are adapted for positioning the read/write head in a radial position as a function of the winding information and for effecting the start of the reading or writing operation in dependence on the actual angular position.
An optical information carrier having a continuous recording track which is arranged according to a helical or concentric pattern of windings and which is indicated by a servotrack having a periodic modulation with encoded modulated disc information, wherein the disc information includes radial position information of each winding identifying each winding of the track and an angle number indicating an angular position of a particular winding information frame for the track.
Dependencies are inferred from the claim text.