Optical disc and apparatus for scanning the optical disc
AssigneeKoninklijke Philips Electronics N.V.
InventorGijsbert J. Van Den Enden
Life of this patent
Estimating the term…
Abstract
An optical disc is described for recording data, which disc has a recording area for recording data encoded in optical marks at a recording density. The recording area has circular or spiral tracks provided with a servopattern comprising headers alternating with track portions. The headers contain position information encoded in preformed marks. The track portions comprise periodic characteristics, e.g. a wobble, to synchronize the data writing and reading operations. For reliably detecting the headers the phase of the periodic characteristics comprises a phase jump at a predetermined distance before each header.
Claims12
An optical disc comprising:
- a substrate;
- and
- a data area on the substrate for information encoded as optical marks at a data density on circular or spiral tracks divided into track portions provided with a servopattern including headers between track portions, the headers include position information encoded at a header density, and the track portions include periodic characteristics, the periodic characteristics have a phase and include a phase jump at a predetermined distance before each header.
A recorder comprising:
- a recording head;
- a recording controller for controlling the recording of data on an optical disc including a recording area having circular or spiral tracks divided into track portions, the track is provided with a servopattern including headers between the track portions, the track portions having periodic characteristics, the headers include position information encoded at a header density, and the recording is controlled depending on the position information;
- and
- a head positioner for positioning the recording head on a track at a position to be recorded;
- and
- means for detecting a phase-jump in the periodic characteristics at a predetermined distance before each header and for retrieving the position information from the headers depending on the detection.
A reader, comprising:
- a read head;
- a read controller for controlling the reading of data from an optical disc including a recording area having circular or spiral tracks divided into track portions, the recording area having a servopattern including headers between the track portions, the track portions include periodic characteristics, the headers include position information encoded at a header density, the reading being controlled depending on the position information;
- and
- a head positioner for positioning the read head on a track at a position to be read controlled by the read controller;
- and
- means for detecting a jump in the phase of the periodic characteristics at a predetermined distance before each header, the reading of the position information from the headers depending on the phase jump detection.
Dependencies are inferred from the claim text.