JP2743507B2 - Recording medium and signal reproducing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium and a signal reproducing apparatus, and more particularly to a recording medium and a signal reproducing apparatus, in which a frame synchronization signal recorded by a displacement in a width direction of a recording track on which main information is recorded is a main information. And a signal reproducing apparatus for reproducing the recording medium.

[Summary of the Invention]

The present invention relates to a recording medium and a signal reproducing apparatus, and in a recording medium in which main information is recorded on a recording track along a track direction, each frame serving as an information recording unit has the same format as the frame synchronization format of the main information. A signal reproducing apparatus for providing a recording medium on which a frame synchronization signal is recorded and formed in advance by a displacement in a track width direction, and reproducing the recording medium, comprising a frame synchronization signal reproducing circuit recorded by a displacement in a track width direction. And a signal reproduction device having a frame synchronization signal reproduction circuit having the same configuration as the main information.

[Conventional technology]

In a recording medium, for example, a magneto-optical disk, a guide groove (groove) is provided in advance in a spiral or concentric manner on the magneto-optical disk, and the previously formed groove or an area (land) between adjacent grooves is used for recording. A track is used to record and reproduce data on the track using the magneto-optical effect. In this track, a synchronization (sync) signal, an address, data, and the like are alternately recorded, and data management is performed based on the synchronization signal and the address information. That is, for example, a frame (segment) in which data is recorded in a predetermined unit is synchronized by a synchronization signal, and
Data is recorded and reproduced in frame units or block (sector) units. As a format of these synchronization signals and address information, for example, a so-called CD (compact detector) format shown in FIG. 4 is used in consideration of compatibility.

Therefore, nothing is written (in the initial state)
When using an optical disk, it is necessary to first perform formatting, and write a synchronization signal and address information required for recording / reproducing on the optical disk in the track direction, for example, as a magneto-optical signal. Here, the CD format will be briefly described. In FIG. 4, 1 is the information recording unit.
A block (one sector) is composed of 98 frames from the 0th frame to the 97th frame, and one frame is composed of 588 bits. In one frame, recording areas for a frame synchronization signal, a subcode, and data (including parity) are provided. That is, at the beginning of one frame, 24
A frame synchronization signal of 14 bits and a 14-bit subcode area are provided, each of which is connected via a connection bit of 3 bits. The remaining 544 bits have 32 symbols (3 symbols).
Two bytes) of sample data and parity data are modulated and arranged by a so-called EFM (8-14 modulation) method. The frame synchronization signal has a so-called out-of-rule pattern, which is not in the EFM method, because the 11-bit inversion interval continues twice.

Japanese Patent Application Laid-Open No. 63-87682 discloses a technique in which a wobbling track for detecting a tracking error is FM-modulated (ATIP) with a time code and recorded and formed. In this technology, for example, a carrier signal of a sine wave of 22.05 kHz is FM-modulated based on a time code signal of a frequency sufficiently lower than the carrier to form a wobbling track, and a tracking error signal is generated during reproduction. At the same time, the time code is demodulated to obtain a time code as position information.

[Problems to be solved by the invention]

However, in this prior art, for the detection and processing of the wobbling signal of the track, a conventionally used LSI or circuit such as an LSI (Large Scale Integrated Circuit) for a CD format cannot be used. The time information of this wobbling signal is 1
Only a single piece of information is inserted between blocks, the amount of information is small, and when used for data storage, accurate positioning of the optical pickup could not be performed.

The present invention has been made in view of the above circumstances,
By recording a frame synchronization signal in a predetermined format such as the CD format that is widely used as a displacement in the track width direction, the purpose is to provide a recording medium and a signal reproducing device that can use existing LSIs and circuits for the CD format as they are. It is assumed that.

[Means for solving the problem]

In a recording medium according to the present invention, in a recording medium in which main information is recorded on a recording track along a track direction, a frame synchronization signal having the same format as the frame synchronization format of the main information is provided for each frame serving as an information recording unit. It is formed by recording in advance by displacement in the track width direction.

Next, a signal reproducing apparatus according to the present invention provides a signal reproducing apparatus for reproducing a recording medium in which a frame synchronization signal having the same format as the frame synchronization format of main information recorded on a recording track is recorded and formed in advance in a track width direction. In the apparatus, a frame synchronization signal reproduction circuit for the main information and a frame synchronization signal reproduction circuit for a signal recorded by the displacement in the track width direction have the same configuration.

[Action]

According to the recording medium of the present invention, the frame synchronization signal from the reproduction signal whose displacement in the track width direction is detected and the frame synchronization signal from the reproduction signal of the main signal recorded on the track become the same.

Further, according to the signal reproducing apparatus of the present invention, the frame of the main signal on the track can be synchronized with the reproduced signal that has detected the displacement in the track width direction, and an existing LSI or the like can be used.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing an entire magneto-optical disk and an essential part of a track as an embodiment of a recording medium according to the present invention.
A magneto-optical disk 1 having a magneto-optical effect as a recording medium, for example, has a pre-groove formed spirally or concentrically, or a land portion between grooves as a recording track 2, and a magneto-optical signal (MO signal) is recorded on the track 2. ) Is recorded as main information. That is, on the track 2, a frame synchronization signal, an address, and data are alternately recorded in the track direction in accordance with a predetermined format, for example, a so-called CD (compact disk) format.
Data is recorded and reproduced in frame (segment) units or block (sector) units in accordance with address information by establishing frame synchronization.

In the track 2, a frame synchronization signal of the same format as the frame synchronization signal on the track, for example, a frame synchronization signal of the CD format is recorded and formed in advance in the track width direction. Specifically, as shown in FIG. 1, a channel clock cycle in the CD format is T, and a pattern (out-of-rule pattern) in which the reversal interval is 11T and is twice continuous, which is not in the so-called EFM (8-14 modulation) system. Correspondingly, as the displacement in the track width direction,
A frame synchronization signal is recorded and formed. After this frame synchronization signal, for example, secondary information such as address information may be recorded and formed by displacement in the track width direction.

FIG. 2 shows an embodiment of a signal reproducing apparatus for reproducing a signal from a magneto-optical disk in which a frame synchronization signal identical to the frame synchronization signal of the main information on a track is recorded in advance by a track width displacement. Show.

In FIG. 2, the magneto-optical disk 1 is driven to rotate at a constant linear velocity (CLV) or a constant angular velocity (CAV) by a spindle motor 21. A laser beam from a laser light source 22 such as a laser diode is
After being converted into parallel rays by the light beam, the light is irradiated onto the magneto-optical disk 1 via the beam splitter 24 and the objective lens 25. The reflected beam from the magneto-optical disk 1 is a beam splitter
The polarization beam splitter is separated by 24 and passes through an optical system 37 such as a half-wave plate, a converging lens, and a cylindrical lens.
It is incident on 26. In the polarization beam splitter 26, the P-polarized light (polarized light parallel to the incident surface) and the S-polarized light (polarized light perpendicular to the incident surface) are separated, and the photodetector 2
Light is incident on 7 and 28, respectively.

The detector 27 has, for example, a light-receiving surface divided into four parts, and detects a tracking error signal and a focus error signal. The information signal recorded by the displacement in the track width direction is obtained as a high-frequency component of the tracking error signal. The output of the detector 27 is input to the positive (+) input terminal of the differential amplifier 29,
Is output to the negative (-) input terminal of the differential amplifier 29. In the differential amplifier 29, the output of the detector 28 is subtracted from the output of the detector 27, so that the magneto-optical The magneto-optical signal (MO signal) that has been recorded is reproduced.

The RF signal is supplied to a PLL (Phase Lock Loop) circuit 30. In the PLL circuit 30, a clock synchronized with the RF signal is reproduced. Next, in the synchronous reproduction circuit 31,
Frame synchronization and block synchronization are derived from the synchronization signal and clock in the track width direction recording signal. That is, as shown in FIG. 1, for example, a frame synchronization signal pattern that does not exist in the EFM system is detected, the frame synchronization is pulled in, and the block synchronization is pulled in. With these synchronization signals, the control circuit 32 performs constant linear velocity control of the spindle motor 21 and control for seeking (moving) the optical pickup to the target address.

On the other hand, the MO signal is supplied to the PLL circuit 33 and the signal detection circuit 36. In the PLL circuit 33, a clock synchronized with the MO signal is reproduced, similarly to the RF reproduction system. Next, in the synchronous reproduction circuit 34, the frame and the block are synchronized. In the control circuit 33, the spindle motor 21
And the control of the seek of the optical pickup. In the signal detection circuit 36, the main information (data) recorded on the track along the track direction
Is played.

By the way, as described above, by setting the format of the frame synchronization signal recorded by the displacement in the track width direction to be the same as the format of the frame synchronization signal of the main information, the PLL circuit 30 of the RF signal system, the synchronization reproduction circuit 31, The control circuit 32 can be the same as the PLL circuit 30, the synchronous reproduction circuit 31, and the control circuit 32 of the MO signal system, and the LS used for the RF signal system
The I and the circuit can be the same as the conventional LSI and the circuit used for the MO signal system. In other words, the format of the frame synchronization signal to be recorded by the displacement in the track width direction is set to be the same as the format of the frame synchronization signal of the CD format, for example, so that an LSI developed and widely used for the CD format can be used as it is. Can be.

Also, by using the frame synchronization signal and address information recorded by the displacement in the track width direction, even if the main information is not written on the track, that is, even if the optical disc is in an initial state that has not been formatted, the PLL is pulled in. Control of the constant linear velocity of the spindle motor 21 by the control circuit 32, decoding of the subcode,
A seek or the like can be performed.

As described above, a medium such as an optical disk in which information such as a frame synchronization signal and an address is recorded in advance by a displacement in the width direction of the recording track itself is mass-produced through a disc manufacturing and a pressing process using a master disk or a stamper. It is possible.

The present invention is not limited to the above-described embodiment. As shown in FIG. 3, a switch 39 may be provided so that the synchronizing signal reproducing system may be a single circuit. In this case, in the switch 39,
The selection terminal 39a of the switch 39 is connected to the non-selection terminal 39b when using the RF signal system, and the selection terminal 39a of the switch 39 is connected to the non-selection terminal 39b when using the MO signal system. Other configurations and operations are the same as those of the embodiment of FIG. 2 described above, and the corresponding portions are denoted by the same reference symbols and description thereof is omitted.

〔The invention's effect〕

As is clear from the above description, according to the recording medium of the present invention, the format of the frame synchronization signal recorded by the displacement in the track width direction is changed to the format of the frame synchronization signal of the main information recorded on the recording track. By doing so, it is possible to make the synchronization signal reproduction system of the main information and the track width direction displacement recording information the same configuration.

In addition, even if the main information to be recorded along the track direction on the track is not yet written (formatted), the PLL is pulled in by the signal reproducing device using the existing LSI and the rotation control of the spindle motor is performed. , Subcode decoding, seeking, and the like.

[Brief description of the drawings]

FIG. 1 shows a configuration of a main part of an optical disc and a track, which are one embodiment of a recording medium according to the present invention,
FIG. 2 is a block circuit diagram of a first embodiment of the signal reproducing apparatus according to the present invention, and FIG. 3 is a block circuit diagram of a second embodiment of the signal reproducing apparatus according to the present invention. The figure is CD
It is a figure showing a format. 1 ... Magneto-optical disk 2 ... Track 30, 33 ... PLL circuit 31, 34 ... Synchronous reproduction circuit

Claims (2)

(57) [Claims] 1. A recording medium on which main information is recorded on a recording track along a track direction, wherein a frame synchronization signal having the same format as the frame synchronization format of the main information is provided for each frame serving as an information recording unit in a track width direction. A recording medium which is preliminarily recorded and formed by displacement. 2. A signal reproducing apparatus for reproducing a recording medium in which a frame synchronization signal having the same format as the frame synchronization format of main information recorded on a recording track is recorded and formed in advance by displacement in the track width direction. A reproducing apparatus, wherein a frame synchronizing signal reproducing circuit for main information and a frame synchronizing signal reproducing circuit for a signal recorded by the displacement in the track width direction have the same configuration.