Optical recording medium and recording and reproducing apparatus therefor

Claim 2

An optical recording medium having a spiral guide track, said optical recording medium characterised by: an index field (20) formed on the medium and including a first discrimination portion (22) and a jumping region (24) for causing an optical head to perform a jumping operation; and a plurality of sectors (68) each of which includes a sector head region which has a second discrimination portion (26) formed at the head of the sector and an address field (28) which succeeds the second discrimination portion, and a data field (30) succeeding the sector head region and used for recording data.

Claim 3

The optical recording medium of claim 1 wherein said address field contains at least a track address (44), a sector address (46), and a code (48) for correcting error.

Claim 4

The optical recording medium of claim 1 wherein said first and second discrimination portions have different grooved structures.

Claim 5

The optical recording medium of claim 1 wherein each of said first and second discrimination portions comprises a set of similar segments, each of which includes a mark and a space, the mark being formed by gating signal carrying data with a given RF signal (54), the space being formed corresponding DC signal and assuming the form of groove.

Claim 6

The optical recording medium of claim 1 wherein each of said first and second discrimination portions comprises a set of similar segments, each of which includes a mark and a space, the mark and the space being formed according to signals (56) which are phase-modulated with RF signals that are given degrees of phase shift.

Claim 7

The optical recording medium of claim 4 or 5 wherein the frequency of the RF signals is set to a frequency that is equal to or higher than the highest fundamental frequency of the waveform recorded in the data field.

Claim 8

The optical recording medium of claim 4 or 5 wherein said first discrimination portion is longer than said second discrimination portion.

Claim 9

The optical recording medium of claim 1 wherein the highest fundamental frequency of the waveform recorded in the address field and the frequency of given RF signals are submultiples of the frequency of clock pulses used for reading the data fields.

Claim 10

The optical recording medium of claim 1 wherein said data field is interposed between first and second gaps (36,38) on which no information is recorded, the second gap being longer than the first gap by a factor of three or more.

Claim 11

An optical recording and reading apparatus for recording and reading data on an optical recording medium that comprises a spiral track (14), an index field (22), and a plurality of sectors (18), the index field being composed of a first discrimination portion (22) and a jumping region (24) for causing an optical head to perform a jumping operation, each of the sectors being composed of a sector head region (26,28) and a data field (30) formed next to the sector head region and used for recording data, the sector head region being formed by a second discrimination portion (26) formed at the head of the address field and an address field (28) containing at least a track address and a sector address, the address field being formed following the second discrimination portion, said apparatus comprising: a jumping means (82) for detecting the first discrimination portion and causing the optical head to perform a jumping operation in the jumping region; a counter (108) which acts to count the second discrimination portions and which is initialized by a signal produced upon detection of the first discrimination portion; a means (120) for detecting errors produced in reading the address fields; and a gate means (116) for selectively delivering either a signal indicating the sector address or the output from the counter, the gate means being so designed that it allows the counter output to be delivered as a substitutive sector address upon application of the output signal from the detecting means corresponding to reading errors.

Claim 12

An optical recording and reading apparatus for recording and reading data on an optical recording medium that comprises a spiral track (14), an index field (22), and a plurality of sectors (18), the index field being composed of a first discrimination portion (22) and a jumping region (24) for causing an optical head to perform a jumping operation, each of the sectors being composed of a sector head region (26,28) and a data field (30) formed next to the sector head region and used for recording data, the sector head region being formed by a second discrimination portion (26) formed at the head of the address field and an address field (28) containing at least a track address and a sector address, the address field being formed following the second discrimination portion, said apparatus comprising: a jumping means (82) for detecting the first discrimination portion and causing the optical head to perform a jumping operation in the jumping region; a counter (108) which acts to count the second discrimination portions and which is initialized by a signal produced upon detection of the first discrimination portion; a means (120) for detecting errors produced in reading the address fields; and a gate means (116) for selectively delivering either a signal indicating the sector address or the output from the counter, the gate means being so designed that it allows the counter output to be delivered as a substitutive sector address upon application of the output signal from the detecting means corresponding to reading errors.

Claim 13

11 s The optical recording and reading apparatus of claim 10 wherein the output from the counter is used in place of the sector address of an address field which has been incorrectly read only during reading operation and wherein the output from the counter is not used in such a manner during recording operation.

Claim 14

The optical recording and reading apparatus of claim 10 wherein the track addresses contained in those address fields of one turn of the track which do not cause read error are used as correct track addresses.

Claim 15

The optical recording and reading apparatus of claim 10 wherein the data fields store user data to which an address data containing both the track address of a desired sector on which the user data is to be recorded and the sector address is added.

Claim 16

The optical recording and reading apparatus of claim 13 wherein, during reading of data, the address data added to the user data is read and checked that it has been obtained from the desired sector and wherein the user data is sent out only when the result of the checking is affirmative.