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US 4,967,403 AGranted
Multi-format optical disk and reading device
AssigneeSony Corporation
InventorsHiroshi Ogawa, Yoichiro Sako
Life of this patent
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AssigneeSony Corporation
InventorsHiroshi Ogawa, Yoichiro Sako
Estimating the term…
A disk device which reproduces at least a disk (1) in which a servo signal region (3) in which a pit for servo and the like are formed and a data and address signal region (4) on which data and address are written are alternatingly provided along the circumferential direction of the disk (1), and in which signals are recorded depending upon two or more kinds of physical changes on the data and address signal regions (4) among the servo signal regions (3). A signal recorded depending upon one physical change is switched into a signal recorded depending upon another physical change in the servo signal region (3) or in a no-signal recording region (5c). Therefore, margin is provided for the operation of switching the signals of various recording types, and stable operation can be maintained even when the data are transferred at higher speeds.
A disk apparatus for at least reproducing a disk-shaped recording medium wherein servo signal regions in which pits for tracking are recorded at alternately offset positions with respect to the center of the track and pits for clock generation are recorded at the center position of the track, as servo signals, and data address signal regions into which at least data signals and address signals are written are formed alternately in the circumferential direction of the disk, and wherein signals are recorded in either a first signal format or a second signal format in each said data address signal region, such that there are signals in only one of said formats in any one of said data address signal regions, comprising:
A disk-shaped recording medium for use in an apparatus for reading said medium, comprising a disk having tracks containing alternating servo signal regions and data address signal regions formed circumferentially around said disk, wherein said servo signal regions contain pits for tracking recorded at alternately offset positions with respect to the center of the track and pits for clock generation recorded at the center position of the track, as servo signals, and said data address signal regions contain at least data signals and address signals written in either a first or second signal format, and wherein signals recorded in said first format and signals recorded in said second format are separated by either a recording area sufficient to allow said apparatus for reading said disk to switch between the signals recorded in said first format and the signals recorded in said second format or one of said servo signal regions.
Dependencies are inferred from the claim text.