JPH03224135A - Recording system, recording medium and recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent the displacement in the transverse direction of grooves from adversely affecting at the time of reproduction of recording data by recording control information with the displacement in the transverse direction of the tracks and coinciding the displacement point in the transverse direction of the tracks with the recording region of connecting bits. CONSTITUTION:From the 1st frame up to the 98th frame where data are recorded are previously displaced in the transverse direction by (22TX2+17TX32) in a frame period for each group 1 where the period of channel clocks is designated as T. The displacement in the transverse direction by the period of 22T is the information as a frame synchronizing signal and the displacement in the transverse direction by the period of 17T is the information for clock formation and leading-in of synchronism. The data are so recorded in the data and parity recording regions of 32 symbols that the displacement point (edge) 1a of the group displaced transversely at every 17T coincides with the connecting bit recording region 1b of the data and parity. The need for discriminating the recording information near the displacement point in the transverse direction is eliminated in this way and the good reproducing which is free from the influence of the displacement in the transverse direction is executed at the time of data reproducing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording method, a recording medium, and a recording/reproducing apparatus suitable for application to, for example, a magneto-optical disk.

[Summary of the invention]

The present invention is a recording method suitable for application to magneto-optical disks, etc., and is a recording method for data modulated by a modulation method that inserts connection bits between consecutive modulated data and satisfies a predetermined modulation rule. Control information is recorded by the width direction displacement of the track, and the point of width direction displacement of this track is aligned with the recording area of the connection bit, so that there is no influence of the width direction displacement when reading the recorded data of the track. .

Further, the present invention provides a recording medium suitable for a magneto-optical disk or the like, in which a track whose width is displaced at a repeating period matching the modulation unit length including connection bits is provided, and the track is disposed at a predetermined times the maximum reversal interval in the modulation method. A track with a synchronization section whose width is displaced longer than the repetition period is provided to enable good signal reproduction.

Furthermore, the present invention provides a recording and reproducing device suitable for a recording and reproducing device for a magneto-optical disk, which detects a width displacement of a track whose width is displaced at a repetition period matching a modulation unit length including a connection bit, and detects a width displacement of a track including a connection bit. A common circuit is used to detect bits formed by modulation with a repetition period matching the modulation unit length, so that the circuit can be shared between, for example, a magneto-optical disk and a compact disk for digital audio. It is something.

[Conventional technology]

In an optical 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 (
A device has been developed in which a so-called group) or a land portion between groups is used as a recording track, and data is recorded and reproduced on this recording track along the track direction using a magneto-optical effect. Such a recording medium records and reproduces data magneto-optically while optically detecting the guide groove and applying tracking servo.

By the way, in a recording medium in which such groups are used as recording tracks, the groups are displaced in the width direction at predetermined intervals in advance during disk molding, and control information such as address information and synchronization information is recorded by this width direction displacement. It is suggested that it be kept. For example, as shown in FIG. 4, groups a provided along the scanning direction of the optical head are arranged at intervals based on address information converted into digital data, or intervals based on a synchronization signal necessary for reproduction, etc.
It is slightly displaced in the width direction perpendicular to the scanning direction.

Then, when recording data in this group a,
The polarity within the group is changed by the magneto-optic effect regardless of the displacement in the width direction, and various data are recorded. The signals recorded within the group due to this magneto-optic effect are described below as M
It is called O times signal. How can control information such as address information and synchronization information be recorded efficiently?

[Problem to be solved by the invention]

However, when the group is displaced in the width direction in this way,
When reproducing the MO multiplied signal recorded in the group, there is a possibility that the edge portion e, which is the displacement point in the width direction of the group, will have an adverse effect. That is, for example, when the edge portion of the MO multiplied signal and the edge portion e due to the displacement in the width direction are close to each other, some kind of influence will occur, such as making it difficult to accurately distinguish the edge portion of the MO multiplied signal.

An object of the present invention is to prevent the widthwise displacement of a group from having an adverse effect on the reproduction of recorded data.

[Means to solve the problem]

The recording method of the present invention is a recording method for data modulated by a modulation method that inserts connection bits between consecutive modulated data and satisfies a predetermined modulation rule, and records control information by displacement in the width direction of a track. The displacement point in the width direction of this track is made to coincide with the recording area of the connection bit.

Further, the recording medium of the present invention is provided with a track whose width is displaced at a repetition period matching the modulation unit length including connection bits, and whose width is displaced at a predetermined times the maximum inversion interval in the modulation method and longer than the repetition period. A track for synchronous sections is provided.

Further, the recording/reproducing device of the present invention detects the width displacement of a track whose width is displaced at a repetition period matching the modulation unit length including connection bits, and modulates the track width at a repetition period matching the modulation unit length including connection bits. The detected bits are detected using a common circuit.

[Effect]

According to the recording method of the present invention, the connection bit recorded on the track coincides with the width direction displacement point, and there is no need to use this connection bit to determine the recorded information, so the recorded information near the width direction displacement point There is no need to determine the width, and there is no influence of width direction displacement during playback.

Further, according to the recording medium of the present invention, by providing a synchronous section track whose width is displaced longer than the repetition period at a predetermined times the maximum inversion interval in the modulation method, good signal reproduction can be achieved by detecting this synchronous section track. can.

Furthermore, according to the recording/reproducing apparatus of the present invention, by matching the widthwise displacement of the track and the formation of bits to the same modulation unit length including the connection bit, the recording medium on which the track displaced in the widthwise direction is formed and the bits can be matched. The circuit of the recording/reproducing device can be shared with the formed recording medium.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 1 to 3.

FIG. 1 shows how recording tracks of a magneto-optical disk are formed according to an embodiment of the present invention. The magneto-optical disk of this example on which this track is formed is one in which a perpendicularly magnetized film having a magneto-optical effect is formed on a transparent substrate, and a tracking guide groove (group) is formed on the magneto-optical disk. ) are formed in advance in a spiral or concentric shape, and this group is used as a recording track (in Fig. 1, the tracks are shown as straight lines).
. In this case, in this example, various data as control information is recorded in advance in the group by displacement in the width direction when the disk is formed. This control information recording format is based on the recording format of a so-called CD (compact disc) for recording digital audio signals and the like. That is, in the general CD format, one block (one sector), which is an information recording unit, consists of 98 frames from frame 0 to frame 97. The structure of each frame is shown in Figure 2. One frame is 588 times the channel clock period T (588T).
Each frame includes recording areas for a frame synchronization signal, subcode, and data (including parity). Also, at the beginning of one frame, 24T (
A frame synchronization signal (24 channel bits) and a subcode area of 14T are provided, and these are connected via 3T connection bits, and the remaining 544T contains 32 symbols (32 bytes) of data and parity. It is modulated and arranged using the EFM (8-14 modulation) method.

Data modulation using this EFM method converts the original data of 8 bits per symbol into a 14-bit pattern, and also modulates 3 bits between each symbol so that the connection state between the 14-bit patterns satisfies a predetermined condition. Insert a bit connection bit (merging bit). These 3 bottles)
Four patterns of 00 00 10 01 are prepared as connection bits, and one of the patterns is selected depending on the preceding and succeeding data. The DC component of the recording signal is controlled by inserting this connection bit, and the connection bit itself does not contain any information.

Returning now to the explanation of the magneto-optical disk according to an embodiment of the present invention, data modulated by the EFM method according to the above-mentioned CD format is recorded in the groups provided on the magneto-optical disk of this embodiment. In this case, one block (one sector) is 100 frames from the 0th frame to the 99th frame, data is recorded in 98 frames from the 1st frame to the 98th frame, and the 0th frame and the 99th frame are This is used as a recording area for block-based address signals and synchronization signals. From the 1st frame to the 98th frame, data and parity recorded following the frame synchronization signal area, subcode area, and connection bits before and after the frame consist of 32 symbols, each symbol being a pattern of 14 bits. and 3 connection bits.

In this example, the 1st frame to the 98th frame in which this data is recorded are stored in each group (1) in advance at a frame period of (22T x 2) as shown in FIG.
+17T x32) to displace it in the width direction. In this case, the width direction displacement with a period of 22T is information as a frame synchronization signal, and the width direction displacement with a period of 17T is information for clock generation and synchronization pull-in. Then, EFM is applied to this group (1) due to the magneto-optic effect.
When recording data modulated by this method, a frame synchronization signal, a subcode, and connection bits before and after the subcode are recorded at the location where the first 22T continues twice. in this case,
As the frame synchronization signal, for example, a signal in which 11T continues twice is recorded, similar to the frame synchronization signal of a CD. In addition,
11T is the maximum inversion interval wkTxAx of the EFM method.

In the data and parity recording area of 32 symbols, the displacement point of group (1) whose width is displaced every 17T (
Data is recorded so that edge) (la) matches the data and parity connection bit recording area (1b). At this time, for example, the edge (1a) is set approximately at the center of the connection bit recording area (1b) where 3 bits are recorded.

Next, FIG. 3 shows the configuration of a recording/reproducing apparatus for reading data recorded in group (1) thus formed. The recording and reproducing apparatus shown in FIG. 3 is capable of reproducing a magneto-optical disk in which group (1) is formed and a CD (or a CD-ROM in a similar format) in which bits are formed as tracks. In Fig. 3, (11) is a terminal to which data recorded by physical changes in the track (bit formation and group width displacement) is read out and supplied as an RF (high frequency) signal; 12) is a terminal to which the M○ times signal recorded by the magneto-optic effect is read out and supplied within the group;
The signals supplied to the respective terminals (11) and (12) are connected to the first and second fixed contacts (31) of the changeover switch (3).
) and (32). Switching of this changeover switch (3) is controlled by a changeover control signal supplied to a changeover control signal input terminal (20) together with a changeover switch (4) to be described later. Then, the movable contact (3) of the changeover switch (3)
The RF multiplied signal obtained in 3) is an M○ multiplied signal, and the binarization circuit (
13), and this binarization circuit (13) converts the RF multiplied signal MO multiplied signal into a high level signal "1" or a low level signal "
0” into binary data.Then, the binary data output from the binarization circuit (13) is sent to the synchronization detection circuit (14).
and is supplied to the demodulation circuit (16) and the PLL circuit (18).

The synchronization detection circuit (14) detects a frame synchronization signal recorded at the beginning of each frame based on the clock supplied from the PLL circuit (18), and sends the detected synchronization signal to the disk rotation control circuit ( 15) and apply rotational speed servo.

Further, the demodulation circuit (16) demodulates the data recorded in each frame based on the clock supplied from the PLL circuit (18) side, and converts the demodulated data into the error correction circuit (17).
).

Then, the PLL circuit (18) generates a frequency of 4.3218 MHz based on the reproduction data output by the binarization circuit (13).
This output clock is supplied to the first fixed contact (41) of the changeover switch (4) via the 1/2 frequency divider (19), and the output clock is directly connected to the changeover switch (4). is supplied to the second fixed contact (42). Then, the signal obtained at the movable contact (43) of this changeover switch (4) is supplied to the synchronization detection circuit (14). In addition, the output clock of the PLL circuit (18) is directly converted to the demodulation circuit (
16).

The switching control signals obtained at the switching control signal input terminal (20) include both selector switches (3) and (4) when accessing (during recording and reproducing) a magneto-optical disk in which a group is formed. Both have movable contacts (33).

(43) to the first fixed contacts (31) and (41). In addition, when reproducing the recorded data (MO double signal) of the magneto-optical disk in which the group is formed, both the changeover switches (3) and (4) have movable contacts (33),
(43) with the second fixed contacts (32), (42). In addition, when playing a CD on which bits have been formed, use the selector switch (3).
is connected to the first fixed contact (31), and the changeover switch (
4) with the second fixed contact (42).

Next, the operation of the recording/reproducing apparatus shown in FIG. 3 will be explained. First, we will explain the case of recording and reproducing on a magneto-optical disk in which group (1) as shown in FIG. )
, (4) Both have movable contacts (33).

(43) are connected to the first fixed contacts (31) and (41), and the position where the first 22T of each recorded frame continues twice is detected by the displacement of the group in the width direction. That is, the 4,3218 MHz clock output from the PLL circuit (18) is divided into 1/2 and supplied to the synchronization detection circuit (14), so that the 22T (22Ti; The frame synchronization signal (twice the frame synchronization signal 11T of the ICD format) can be detected by the synchronization detection circuit (14), and the rotation of the disk can be synchronized. In this state, the data modulated by the EFM method is
The signal is recorded as an O times signal (recording circuitry is omitted). In this case, in the data and parity recording area of each frame, groups (1
) The data is recorded so that the width direction displacement point (edge) (1a) coincides with the data and parity connection bit recording area (1b).

When reproducing a magneto-optical disk, the 22T frame synchronization signal recorded by the group width displacement is first detected and accessed in the same manner as during recording, and then the changeover control signal (3 ), (4) both movable contacts (33), (43) are connected to the second fixed contact (3).
2) and (42) to detect and reproduce the 11T frame synchronization signal recorded as the MO multiplied signal. In this case, the PLL circuit (18) outputs 4,3218M
Since the Hz clock is directly supplied to the synchronization detection circuit (14), a frame synchronization signal of 11T, which is twice 22T, can be detected.

When playing a CD on which bits have been formed, the changeover control signal is used to connect the changeover switch (3) to the first fixed contact (31), and connect the changeover switch (4) to the second fixed contact. Since it is connected to the fixed contact (42), the PLL circuit (18) outputs 4,3218 MH.
The z clock is directly supplied to the synchronization detection circuit (14), and the 11T frame synchronization signal formed as a bit is detected and reproduced.

As described above, according to this example, the recording/reproducing device uses a magneto-optical disk in which groups are formed and a C in which bits are formed.
The circuit can be shared with disks such as D. in this case,
The frame synchronization signal recorded by the widthwise displacement of the group has a period of 22T, which is an integer multiple of the frame synchronization signal (IIT) of the signal modulated by the EFM method, so it can be done simply by switching the frequency divider (19). Synchronous detection can be easily performed. In addition, in the data and parity recording area of each frame formed in the group of the magneto-optical disk, the group is displaced in the width direction every 17T, which is one symbol unit, so it is arranged in one symbol unit (one byte unit). You can search for recorded data. And the period of the frame synchronization signal (
22T) is longer than the 17T width direction displacement, so the frame synchronization signal can be detected reliably. Furthermore, since the connection bit part of the data and parity recording area of each frame is aligned with the widthwise displacement point of the group, the widthwise displacement point of the group will not have an adverse effect when reproducing the recorded data (M○ times signal). In other words, the connection bit section controls the DC component, and the connection bit itself does not contain any information, and the 14-bit data recording section overlaps with the displacement point in the width direction. Therefore, width direction displacement has no effect on data playback.

In the above-mentioned embodiment, data recording on the magneto-optical disk was performed in a so-called group recording in which the data was recorded within a group, but it is also possible to perform a so-called land recording in which data is recorded in a land between adjacent groups. Also good. Furthermore, in the above-described embodiment, the edge is set approximately at the center of the connection bit recording area where 3 bits are recorded.
It is only necessary that one of the connection bit recording areas coincides with an edge. Furthermore, in addition to the magneto-optical disks shown in the above-mentioned embodiments, for example, organic dye-based optical disks may be used.

The present invention can be applied to various recording media such as various write-once disks, overwritable disks, optical cards, and magneto-optical cards. Furthermore, it goes without saying that the present invention is not limited to the above-mentioned embodiments, and can take various other configurations.

〔Effect of the invention〕

According to the recording method of the present invention, a connection bit recorded on a track becomes a displacement point in the width direction, and there is no need to use this connection bit to determine recorded information, so it is not necessary to determine recorded information near the width direction displacement point. Therefore, it is possible to perform good reproduction without being affected by displacement in the width direction during data reproduction.

Further, according to the recording medium of the present invention, by providing a synchronous section track whose width is displaced longer than the repetition period at a predetermined times the maximum reversal interval in the modulation method, the synchronous section track can be reliably detected and synchronized. Good signal reproduction is possible by detecting section tracks.

Furthermore, according to the recording/reproducing apparatus of the present invention, by matching the widthwise displacement of the track and the formation of bits to the same modulation unit length including the connection bit, the recording medium on which the track displaced in the widthwise direction is formed and the bits can be matched. The circuit of the recording/reproducing device can be shared with the formed recording medium.

[Brief explanation of drawings]

FIG. 1 is a route diagram showing a track formation state according to an embodiment of the present invention, FIG. 2 is an explanatory diagram showing a modulation state by the EFM method, and FIG. 3 is a configuration showing a circuit configuration of a recording/reproducing apparatus according to an embodiment. FIG. 4 is a route map showing an example of a conventional recording medium. (1) is a group, (1a) is an edge (width direction displacement point)
, (1b) is the connection bit, (14) is the synchronization detection circuit, (
16) is a demodulation circuit, and (18) is a PLL circuit. Agent Hidemori Matsukuma

Claims (1)

[Claims] 1. A recording method for data modulated by a modulation method that inserts connection bits between consecutive modulated data and satisfies a predetermined modulation rule, in which control information is recorded by displacement in the width direction of a track, and , A recording method characterized in that a displacement point in the width direction of the track is made to coincide with a recording area of the connection bit. 2. A track whose width is shifted at a repetition period matching the modulation unit length including connection bits is provided, and a track whose width is shifted at a predetermined times the maximum inversion interval in the modulation method and longer than the repetition period is provided. A recording medium characterized by: 3. Detection of width displacement of a track whose width is displaced at a repetition period matching the modulation unit length including connection bits, and detection of bits formed by modulation at a repetition period matching the modulation unit length including connection bits. , a recording/reproducing device characterized in that a common circuit is used for the recording and reproducing apparatus.