JPH0383234A - Recording medium - Google Patents

Abstract

PURPOSE:To attain accurate positioning at the time of reproducing a record and the like and to speed up access by recording address information by the displacement in the direction of a track width at every frame. CONSTITUTION:A synchronizing signal with a format similar to that of main information is previously recorded in the part of a main information frame synchronizing signal by the displacement of the track width. Thus, a block address can be detected by reading one frame at the most and accurate positioning at the time of reproducing a record and the like is attained, whereby access is speeded up. When a sector mark for block synchronization is recorded in the head of a block consisting of plural frames, the head of the block can easily be detected.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a recording medium, and particularly to a recording medium in which address information is recorded by widthwise displacement of a recording track on which main information is recorded, and the recording medium. The present invention relates to a recording medium in which block head information representing a blurred head frame is recorded by displacement in the width direction of a track.

[Summary of the invention]

The present invention relates to a recording medium in which main information is recorded on a recording track along the track direction, in which address information is prerecorded and formed by displacement in the track width direction for each frame serving as an information recording unit. The present invention provides a recording medium in which block head information is recorded and formed in the head frame of a block constituted by a plurality of frames by the displacement in the track width direction.

[Conventional technology]

In a recording medium, such as a magneto-optical disk, a tracking guide groove is previously formed on the disk in a spiral or concentric shape, and the pre-formed guide groove (
It is known that the so-called pre-group) or land area between groups is used as a recording track, and data is recorded and reproduced on this recording track along the track direction using the magneto-optic effect. . Addresses and data are generally recorded alternately on this recording track, and data management is performed based on this address information.Data is recorded in blocks or sectors based on this address information. , and is now being played again.

By the way, Japanese Unexamined Patent Publication No. 63-87682 discloses a technique for recording and forming a wobbling track for detecting tracking errors by performing FM modulation using a time code. In this technique, for example, 20.05
A wobbling track is formed by FM modulating a kHz sine wave carrier signal based on a time code signal having a frequency sufficiently lower than that of the carrier wave, and a tracking error signal is obtained during playback, and this time code is is demodulated to obtain a time code as position information.

[Problems to be Solved by the Invention] However, in this prior art, there is a problem that the signal reproduced from the FM-modulated wobbling track is susceptible to noise, and the time information of this wobbling signal is lost within one block. Accurate positioning is difficult because only one block of information is stored, the amount of information is small, the extraction accuracy is low, and decoding is not possible unless one block is read.

The present invention has been made in view of the above-mentioned circumstances, and uses address information recorded in advance by displacement in the track width direction and further block head information to enable accurate positioning during data recording and reproduction. The objective is to provide a recording medium that allows high-speed access to desired blocks and furthermore to desired frames.

[Means to solve the problem]

A recording medium according to the present invention is a recording medium in which main information is recorded on a recording track along the track direction, and in which address information is prerecorded and formed by displacement in the track width direction for each frame serving as an information recording unit. Moreover, in such a recording medium, block head information is recorded and formed in the head frame of a block composed of a plurality of frames by the displacement in the track width direction.

[Effect]

According to the recording medium according to the present invention, address information can be obtained for each frame based on a reproduced signal that detects a displacement in the track width direction, and information on the beginning of a block can also be obtained.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a recording format of a recording track of a magneto-optical disk, which is an embodiment of a recording medium according to the present invention, together with recorded information based on displacement in the track width direction. The magneto-optical disk used in this embodiment is one in which a perpendicularly magnetized film having a magneto-optic effect is formed on a transparent substrate, and a tracking guide groove is formed in a spiral or a spiral shape on the magneto-optical disk. They are pre-formed in concentric circles (so-called pre-groups), and these pre-groups or the lands between the groups are used as recording tracks. Further, in this recording track, for example, a baseband signal of secondary information exclusive for reproduction including at least a control signal (synchronization, clock, etc.) is displaced in the track width direction (track width direction deviation or track width direction modulation). The record is formed in advance by.

In FIG. 1, a specific example of the recording format of the main information recorded along the track direction of the recording track is similar to the format of a so-called CD (compact disc). In other words, one block (one sector), which is a unit of information recording, is from the 0th frame to the 97th frame.
frame is 588 times the channel clock period T (588T), and l frame is 588 times the channel clock period T (588T)
Within the frame, recording areas are provided for frame synchronization signals, subcodes, and data (including parity). In other words, 24T (24T) is placed at the beginning of one frame.
A frame synchronization signal (channel bit) and a 14T subcode area are provided, and these are connected via 3T connection bits, and the remaining 544 bits contain 32 symbols (32 bytes) of sample data and parity data. The signal is modulated by the so-called EFM (8-14 IS) method. The frame synchronization signal is 11T
The two consecutive inversion intervals result in a so-called out-of-rule pattern, which is not found in the EFM method. The 14T subcode area corresponds to the above l symbols.

The recording track itself on which such main information is recorded is, as described above, previously recorded by being displaced in the track width direction by a subsidiary information signal.

Here, in the specific example of FIG. 1, the recorded information due to the above width direction displacement includes a synchronization signal in the same format as the main information in the frame synchronization signal portion of the main information, that is, a synchronization signal with the same format as the main information, that is, the inversion interval is LIT twice consecutively. The synchronization signal is arranged, and the inversion intervals are set as 7T, 7T, 4T, 4T, and 447 at the beginning of the frame including the 22T frame synchronization back
It consists of In the data area of 544T below, secondary information such as address information is recorded and formed by displacement in the track width direction with reference to a clock having a period that is an integral multiple of the channel clock period T of the main information. . In the example shown in Figure 1, 1 bit slot uses the PR (phase encoding) method of 8T, but other methods include the so-called bi-phase mark method and EFM (8-T).
In addition, the synchronization signal is for synchronizing frame units, but the block (sector) described above is composed of a plurality of (98) frames. In order to synchronize in units of , the first 2 beams (16T) of the 544T are used as sector marks (block marks) SM for block synchronization. That is, "11" is written in the sector mark of the first frame of the block using the above PE method, and "11" is written in the sector mark of the other frames.
By writing "10" in advance, the first frame of the block can be distinguished from other frames.

Specifically, as shown in FIG. 3, the area following this sector mark contains a minute address MA expressed in an 8-bit BCD (binary coded decimal) code.

Second address SA expressed in 8-bit BCD code,
A block address BA expressed by an 8-bit BCD code, a frame address FA expressed by an 8-bit BCD code, and the sector mark, minute address,
SM, MA, SA, BA, and FA, which are inverter information of second address, block address, and frame address, are arranged.

Therefore, sector mark, minute address, second address,
The block address and frame address are recorded twice in each frame by displacing the track in the track width direction.

As for the specific values of these addresses, for example, in order to maintain compatibility with the CD format, the minute address MA is set to "00" to "99" in BCD code, and the second address SA is set to "00" to "99" in BCD code. ” to “59”, and the block address BA is r00J to “74” in BCD code.
Let it be j. Also, frame address FA is BCD code "00" to "97", therefore, minute address M
A, the number of blocks that can be identified using the second address SA and block address BA is 449,999.

By the way, when the number of blocks to be used exceeds the above 449999, the minute address MA, second address SA, and block address BA shown in FIG. 2 are all converted into a 24-bit block address BA as shown in FIG.
(Hexadecimal) code r000000J~rFFFFFF
By using FJ, 16777215 blocks can be identified.

As mentioned above, the recording/reproducing operation of a recording medium, such as a magneto-optical disk, in which a synchronizing signal, a frame address, and a block address are prerecorded by displacing the track in the track width direction will be described with reference to FIG.

In FIG. 4, a magneto-optical disk 10 is rotated by a spindle motor 11 at a constant linear velocity (CLV). After the laser beam from the laser light source 12 is made into parallel light beams by the collimator lens 13, it is passed through the beam splitter 1.
4. The magneto-optical disk 1 is passed through the objective lens 15 of the two-axis device that controls focusing and tracking.
0 is irradiated. The reflected beam from the magneto-optical disk 10 is separated by a beam splinter 14, and an optical system 16 including a 1/2 wavelength plate, a converging lens, a cylindrical lens, etc.
The light is incident on the polarizing beam splitter 17 via the polarizing beam splitter 17. In this polarizing beam splitter 17, P polarized light (polarized light parallel to the plane of incidence) 7i! The S-polarized light component and the S-polarized light (polarized light perpendicular to the plane of incidence) are separated and input to detectors 18 and 19 for detecting so-called tracking error signals, focus error signals, and magneto-optical signals (MO signals).

In the detector 18, a track error signal is detected by a so-called push-pull method, and a focus error signal is detected by a so-called astigmatism method, and these signals are used for optical pickup tracking and focusing control. In addition, from the high-frequency component of this tracking error signal, the synchronization signal and address information recorded by the track width direction displacement (R
F) The signal can be reproduced. This RF signal is supplied to the clock/synchronization detection circuit 22 and the positive (+) input terminal of the differential amplifier 20. In this clock/synchronization detection circuit 22, after extraction of a clock recorded as a displacement in the track width direction (in other words, recorded in the form of ROM), detection of frame synchronization, and detection of block synchronization, Frame address and block address information are reproduced.

These control signals such as clock and address information are supplied to a data detection circuit 21 for reproducing data recorded as magneto-optical signals on the tracks of the magneto-optical disk (in other words, recorded in the form of RAM). be done. That is, the output signal of the detector 19 is the negative (
-) A reproduction signal (MO signal) of data recorded on the track as a magneto-optical signal is inputted to the input terminal and is reproduced in this amplifier 20, and this MO signal is supplied to this data detection circuit 21, and this Data detection circuit 2
1, reproduction data recorded in the form of RAM is retrieved.

On the other hand, when recording data on the magneto-optical disk 10,
The recording data and the control signal from the clock/synchronization detection circuit 22 are supplied to the recording signal output circuit 23, and in this recording signal output circuit 23, the clock and synchronization signal of the control signal are used to generate a signal for magnetic field modulation recording. This signal is supplied to the drive circuit 24. The drive signal from the drive circuit 24 modulates the magnetic field of the recording head 25 and irradiates the laser beam from the laser light source 12. In this way, record data is recorded in correspondence with the magnetization direction of the perpendicular magnetization film of the magneto-optical disk 10.

As described above, by recording frame addresses and block addresses in advance for each frame, it is possible to detect a block address, which conventionally could not be detected without reading one block, by reading at most one frame. Therefore, when a desired block is desired to be accessed, the block address can be read even from the middle of the block, allowing high-speed access. Furthermore, since a block address is recorded 196 times in one block (98 frames), it is almost impossible for a block address to become unreadable, and the reliability of the block address is extremely high. Furthermore, frame addresses, which were not used in conventional CD formats, can be recorded, making frame-by-frame access possible.

Furthermore, by providing a sector mark at the beginning of each frame as described above and recording information indicating whether or not this is the first frame of a block, the beginning of a block can be easily detected.

It should be noted that the present invention is not limited to the above-mentioned embodiment, and a portion (1 focus) of 8T immediately before the address portion shown in FIG. 1 may be inverted/non-inverted and used as a sector mark.

Furthermore, recording information such as a synchronization signal and address information in the form of a ROM by displacing the above-mentioned track in the track width direction can be easily performed by so-called stamping during the manufacturing of optical discs, and is suitable for mass production of optical discs. suitable for

[Effects of the Invention] As is clear from the above description, according to the recording medium according to the present invention, address information of a frame or a block is transferred for each frame by displacing the track in the track width direction.
), by recording the block address in advance, it is possible to detect a block address by reading at most one frame, whereas conventionally it could not be detected without reading one block. Therefore, when a desired block is to be accessed, the block address can be read even from the middle of the block, allowing high-speed access. Furthermore, since the block address is recorded 196 times in one block, it is almost impossible for the block address to become unreadable, and the reliability of the block address is extremely high. Furthermore, since the frame address is included, frame-by-frame access is possible, and by providing information indicating whether or not this is the first frame of a block at the beginning of each frame, the beginning of a block can be easily detected. be able to.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of a recording format of a recording medium according to the present invention, FIG. 2 is a diagram showing an address format, FIG. 3 is a diagram showing another address format, and FIG. 1 is a block diagram of a magneto-optical recording/reproducing apparatus that performs recording/reproducing of a recording medium according to the present invention. FIG. SM・MA・SA・BA・FA・・Sector mark・Minute address・Seconds address・Block address・Frame address

Claims (2)

[Claims] (1) A recording medium in which main information is recorded along the track direction on a recording track, characterized in that address information is prerecorded and formed by displacement in the track width direction for each frame serving as an information recording unit. Medium. (2) The recording medium according to claim (1), wherein block header information is recorded and formed in the header frame of a block composed of a plurality of frames by the displacement in the track width direction.