JPH11353810A - Recording medium and reproducing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize an appropriate large capacity concerning a recording medium by setting a data recording density in a header region and that in a recording and reproducing region at different values from each other. SOLUTION: A header is a reproduction-dedicated region. In an MO area used as a region accepting magneto-optical recording/reproduction, user data or the like are recorded. As a data modulation method, a (1-7) run length limited code modulation method ('(1-7)RLL') is employed. The frequency of a reproduction clock DCK in the MO area is set, for example, at 2fc, where fc is a clock frequency in the case of an MO disk. On the other hand, in the header, a (2-7) run length limited code modulation method ('(2-7)RLL') is employed as the modulation method that is different from that employed in the MO area. In addition, a frequency of the reproduction clock DCK is set either at 2fc, which is the same as that in the MO area, or at αfc (where 1<α<=2) which is different from that in the MO area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium such as a magneto-optical disk and a reproducing apparatus corresponding to the recording medium.

[0002]

2. Description of the Related Art In a recording medium such as an optical disk, a magnetic disk, a magneto-optical disk, a magnetic tape, and an optical tape,
One problem is increasing the density, and various technologies for high-density recording and reproduction have been developed. For example, a magneto-optical disk called an MO disk is mainly used for recording and reproduction of computer data, but the MO disk (5.25-inch disk) is compared with the first generation disk. At present, the density is about eight times higher.

[0003]

Here, further densification is an issue. However, increasing the density in the track pitch direction requires the performance of the current mass production level pickup, such as the limit of the laser spot diameter. From now on, it has become very difficult. Also, in order to maintain compatibility with the lower disk, it is not appropriate to significantly change the sector format on the disk to increase the density. It is also conceivable to increase the bit density, that is, the density in the track line direction. However, increasing the density beyond the current level is difficult because the inter-bit interference becomes too large.

[0004]

SUMMARY OF THE INVENTION In view of the foregoing problems, an object of the present invention is to provide a recording apparatus capable of appropriately increasing the capacity and providing a reproducing apparatus compatible with such a recording medium. And

Therefore, the recording medium of the present invention is designed so that the data recording density in the header area is different from the data recording density in the recording / reproducing area. For example, in the header area, data according to the first modulation method is recorded, and in the recording / reproducing area, data recording density is different by performing data recording according to the second modulation method capable of higher density recording than in the first modulation method. To be something. In addition, the recording / reproducing area has a recording layer formed so as to enable the magnetic super-resolution reproducing method, thereby achieving a large capacity. Also, the first
Is a (2-7) run-length limited code modulation scheme, and the second modulation scheme is a (1-7) run-length limited code modulation scheme. Further, the data recording is performed so that the data reproduction from the header area and the data reproduction from the recording / reproduction area can be executed by using the clock of the same frequency.

[0006] A reproducing apparatus according to the present invention comprises a first decoding means corresponding to a first modulation method, a second decoding means corresponding to a second modulation method, and information read from a recording medium. Switching means for selectively supplying the first decoding means and the second decoding means to execute a decoding process, and control for controlling the switching operation of the switching means at a timing corresponding to the header area and a timing corresponding to the recording / reproducing area. Means.

In recent years, as one of the technologies aimed at increasing the density of a magneto-optical disk, a magnetic super-resolution reproduction method (magnetic super-resolution: MSR: Magnetically induced Super Resolutio) has been proposed.
n) has been proposed. The MSR reproduction method is a technique that can read recorded information in an area smaller than a laser spot using magnetic films having different temperature characteristics. That is, with respect to a medium (MSR medium) having a recording area in which magnetic films having different temperature characteristics have a two-layer structure, high-density recorded information is read without reducing the laser spot diameter. be able to.

For example, by using this MSR method,
The recording capacity of the magneto-optical disk can be greatly increased. However, the MSR method is available only for M
Not the entire area of the O disk. The MO disk employs a data unit called a sector as a basic data format on the disk. The sector is composed of a header area in which preformat data is recorded by embossed pits, and a data area as a magneto-optical area. It is formed by a recording / reproducing area in which recording / reproducing is possible. In such an MO disk, the recording film corresponding to the MSR method can be formed in the recording / reproducing area, and the MSR method cannot be implemented in the header area. Under such circumstances, with the configuration of the recording medium and the reproducing apparatus of the present invention described above, when the recording density is improved by, for example, the MSR method, the data format in the header area and the recording / reproducing area is devised, A more suitable recording medium and reproducing device are realized.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a magneto-optical (MO) disk and a recording / reproducing apparatus corresponding thereto will be described as embodiments of a recording medium and a reproducing apparatus of the present invention.

First, the disc of this embodiment will be described. M
In the O disk, a data string formed on a track of the disk has a continuous unit of sector.
One sector is roughly divided into a header and an MO area as shown in FIG. 1, although an example of the sector format will be described later with reference to FIG.

The header is a reproduction-only area in which data based on so-called emboss pits is recorded, and an address and the like are recorded as described later. The MO area is an area in which magneto-optical recording / reproduction is possible, in which user data and the like are recorded.

Here, in the case of this example, the MO area is the MSR
The area is formed with a recording film, that is, data is reproduced by the MSR reproduction method. Therefore, the data recording density is about 2 times higher than that of the conventional MO disk (for example, 8 times dense disk).
Double the density can be realized. As a data modulation method, a (1-7) run-length limited code modulation method (hereinafter, referred to as "(1-7) RLL") is adopted. The frequency of the reproduction clock DCK is about twice as high as that of a conventional MO disk because the recording density is about twice that of the conventional MO disk. For example, assuming that the clock frequency in the case of the conventional MO disk is fc, the reproduction clock DC in the MO area of this example is
It is assumed that the frequency of K is 2fc.

On the other hand, in the header, data is recorded by the pits preformatted as described above. Here, as a data modulation method different from the MO area, a (2-7) run-length limited code modulation method is used. (Hereinafter referred to as “(2-7) RLL”). It is also assumed that the frequency of the reproduction clock DCK is 2fc, which is the same as the MO area, or αfc which is different from the MO area but higher than the previous frequency fc (where 1 <α ≦ 2).

That is, in the MO disk of this example, MSR reproduction is performed in the MO area, and the data modulation method is (1-7) RLL and (2-7) RLL in the MO area and the header.
, And that the recording density differs according to them.
Further, the reproduction clock DCK includes an example in which the MO area and the header have the same frequency and an example in which the reproduction clock DCK has a different frequency.

Note that the reproduction clock DCK in the MO area
Is not limited to 2fc. Where M
The use of the SR method is merely "2fc" as an example in which double density is also possible. The clock frequency αfc in the header is used in the sense that it is the same as the MO area or a frequency slightly lower than the MO area.

With respect to such an MO disk of this example,
Hereinafter, the MSR reproduction method, the sector format, and the M
The grounds and effects of the configuration of the O disk will be described.

An MSR (magnetic super-resolution) reproducing method will be described with reference to FIG. FIG. 2A shows a recording track Dt and a laser beam spot Bs irradiated thereon, and FIG.
Indicates a part of the cross section of the magneto-optical disk. To obtain the MSR effect, as shown in FIG. 2B, the magneto-optical disk needs to have a recording layer and a reproducing layer, each of which has different magnetic characteristics depending on the temperature. The reproducing layer is a layer that masks the recording layer Ms from the beam spot Bs of the laser beam Lb. Then, as can be seen from FIGS. 2A and 2B, by irradiating the reproducing layer with laser power for reproduction, a small window (aperture A) is formed on the reproducing layer.
p) is formed, and the magnetization direction mt of the recording bit Rb of the lower recording layer is transferred to the aperture Ap. By observing the direction of magnetization mt transferred to the reproducing layer, it is possible to read the recording bits Rb recorded at high density even with the laser beam Lb having a large spot diameter.

By irradiating the laser beam Lb with the reproducing laser power in this manner, the magnetization direction mt is transferred from the recording layer to the reproducing layer. The size of the aperture Ap is determined by the reproducing laser power at that time. In other words, since the area where the transfer is performed from the recording layer to the reproduction layer can be controlled, if the reproduction laser power is properly controlled, the frequency characteristics of the signal reproduced from the disk can be extended. If such an MSR technique is used, for example, high-density recording and reproduction twice or more can be performed even if the beam spot diameter is the same as the conventional one. In the disc of the present embodiment, such recording and reproduction by the MSR method is performed in the MO area of FIG.

Next, a specific sector format will be described with reference to FIG. On the magneto-optical disk, user data is recorded in units of recording / reproducing sectors. As shown in FIG. 3A, one sector includes a header, a transition area TA1, an ALPC gap,
VF03, sync, data field, postamble PA2, buffer, and transition area TA2. The numbers given in the figure represent the number of bytes.

Such one sector is roughly divided into an address portion (that is, a header) and a data portion, and an ALPC gap and a transition area TA before and after the data portion.
1, TA2 are arranged. The header is a read-only area in which so-called embossed pits are preformatted and recorded, and is other than the header, that is, the transition area TA1.
The section from to the transition area TA2 is an MO area. In this MO area, the MSR effect described with reference to FIG. 2 can be obtained.

FIG. 3B is an enlarged view of a 64-byte header serving as an address portion. The header is a sector mark SM (8 bytes), VFO1 in the VFO field.
(26 bytes), address mark AM1 (1 byte),
ID field ID1 (5 bytes), VFO field VFO2 (16 bytes), address mark AM2
(1 byte), ID2 of ID field (5 bytes),
And postamble PA1 (1 byte) are arranged in order.

The sector mark SM is a mark for identifying the start of a sector, and a pattern not generated in the (1-7) RLL code or the (2-7) RLL code is formed by embossing. The VFO field in one sector is used for synchronizing a VF0 (Variable Frequency Oscillator) in a PLL unit of a recording / reproducing apparatus, which will be described later, and includes VFO1, VFO2, and VFO0.
Consists of three. In other words, these become PLL pull-in areas. VFO1 and VFO2 are formed in the address portion by embossing. VF03 is shown in FIG.
As shown in (a), it is provided in the data section, and is recorded magneto-optically when a recording operation is performed on that sector.

In VFO1 and VFO2, (2-7) RL
A signal of a predetermined pattern for performing PLL pull-in (generation of a reproduction clock) for reading data (address) in the header recorded in the L format is read. On the other hand, in the VFO3, a signal of a predetermined pattern for performing PLL pull-in (generation of a reproduction clock) for reading data (address) in a header recorded in (1-7) RLL format is recorded. . For example, VF
03 has a pattern (2T pattern) in which channel bits '0' and '1' alternately appear. Therefore, if the time corresponding to the time length of one channel bit is T, a reproduced signal whose level is inverted every 2T is obtained when the VFO field is reproduced.

The address mark AM is used to provide byte synchronization to the device for a subsequent ID field, and has a predetermined pattern. The ID field is
The address of a sector, that is, information of a track number and a sector number, and a CRC byte for error detection for the information are provided. Each 5-byte ID field I
D1 and ID2 are address information of a sector, and these are the same data. That is, the address is recorded twice in one sector.

The postamble PA1 in the header and PA2 in the data portion have predetermined patterns, respectively.

In FIG. 2 (a), the ALPC gap area provided via the transition area TA1 following the header secures the time required by the apparatus for processing after reading the header and secures the VF03 after VF03. It is provided for the purpose of tolerance of positional deviation, a test of laser power at the time of recording, and the like.

Further, as shown in FIG.
O3, sync field, data field, postamble PA2, and buffer field.
The sync field (4 bytes) is provided for the device to obtain byte synchronization for the subsequent data field, and has a predetermined bit pattern.

The data field is provided for recording user data. 204 as user data
8 bytes are reserved, plus error detection,
The recording of the parity for correction and the like results in 2498 bytes. Although not shown, a resync pattern for synchronization is arranged at a predetermined position in the data field. The buffer field is used as a tolerance for electrical or mechanical errors.

In the disc of this embodiment, as described with reference to FIG. 1, MSR reproduction is performed in the MO area, and the data modulation method is (1-1-) in the MO area and the header.
7) RLL and (2-7) RLL are different, and the recording density is different depending on them. The reproduction clock DCK includes an example in which the same frequency is used in the MO area and the header, and an example in which the reproduction clock DCK has a different frequency. First, the grounds and effects of the configuration of the MO disk when the reproduction clock DCK has different frequencies in the MO area and the header will be described with reference to FIG.

FIG. 4A shows the characteristics of the current 8-fold dense MO disk, and FIG. 4D shows the characteristics of the MO disk of this embodiment. First, as shown in FIG. 4A, in an 8 × density disc, the modulation method is (1-7) RL in both the header and the MO area.
L and the same recording density. Therefore, the frequency of the reproduction clock DCK is the same, and the frequency is assumed to be fc.

Considering further improvement in recording density (increase in recording capacity) from such an 8 times dense disk, the above-mentioned MS
It is conceivable to adopt R technology. However, if it is not preferable to greatly change the sector format in consideration of the compatibility and the like, since the MSR effect cannot be obtained in the header, the M area is not used in the MO area as shown in FIG.
Although the SR method is adopted, the header remains unchanged. In this case, for example, due to the MSR effect, in the MO area, for example, a double density (that is, 16 times) as compared with FIG.
(Density). However, since the header remains the same, the increase in the recording capacity of the entire disc is limited by the loss in the header.

Then, it is considered that the overall capacity is increased by increasing the density of the header. Therefore, FIG.
As shown in (c), the frequency of the reproduction clock DCK is αfc
The recording density is reduced to a state where In other words, a certain degree of high density is performed within the range possible with the current laser spot diameter. Here, the minimum inversion interval in (1-7) RLL is 2T. However, an increase in the clock frequency and an increase in the minimum repetition frequency means that the time width of this 2T becomes considerably small, and the reproduction system Margin is too small. That is, good reproduction becomes difficult.

FIG. 6 shows (1-7) RLL and (2-
7) Difference in recording density of RLL is shown. That is, the same data 1
When the bytes are modulated, the data recorded on the disc includes (1-7) RLL and (2) as shown in FIG.
-7) The recording density differs depending on the RLL. That is, (1-7) R
LL has a higher density. The minimum inversion interval of (1-7) RLL is 2T, and the minimum inversion interval of (2-7) RLL is 3T.
It becomes T.

In the case of FIG. 4 (c), the margin of the reproducing system cannot be taken satisfactorily. Therefore, in FIG. 4 (d), which represents the disk of this embodiment, (2)
-7) The RLL system is adopted. In this case, even if the reproduction clock frequency = αfc, the minimum inversion interval is 3
Since it is T, the minimum repetition frequency decreases, and a sufficient reproduction margin can be obtained. However, (2-7) R
Since the sacrifice of the recording capacity due to the adoption of the LL method is not so large, in the disk of this example, a sufficient reproduction margin can be obtained with a large increase in the recording density.

Next, the reproduction clock frequency is set to the header and MO.
Consider the example of the present invention from the viewpoint of wanting to be the same in the area. This will be described with reference to FIG.

FIG. 5 (a) shows the characteristics of the current 8-fold dense MO disk as in FIG. 4 (a), and FIG. 5 (c) shows the characteristics of the MO disk of this example. First, as shown in FIG. 5A, in an 8 × dense disk, the modulation method is (1-7) RLL and the recording density is the same in both the header and the MO area. Therefore, the frequency of the reproduction clock DCK becomes the same fc.

In order to further improve the recording density (increase the recording capacity) from such an 8-fold dense disk, it is conceivable to employ the above-mentioned MSR technique, and to set the recording density of the header and the MO area to be the same and to increase the reproduction clock frequency. Consider trying to be the same. Then, as shown in FIG. 5B, the MO area has a double density (ie, 16 times higher density) due to the MSR effect, and pits are formed at twice the density in the header in accordance with the density. Will do.

However, since the MSR effect cannot be obtained with the header, such a high density is practically impossible.
That is, an appropriate reproduction margin cannot be obtained. Therefore, in FIG. 5C showing the disc of this example, the (2-7) RLL system is adopted at the expense of a slight improvement in recording density. Then, in this case, even if the reproduction clock frequency is the same as that of the MO area, for example, 2fc, the minimum repetition frequency is reduced because the minimum inversion interval is 3T, and a sufficient reproduction margin can be obtained.

That is, in the disc of this example, the MSR reproduction is performed in the MO area, and the data modulation method is (1-7) RLL and (2-7) RLL in the MO area and the header.
And the recording density is different according to these. Further, the reproduction clock DCK is set to the same frequency in the MO area and the header, and to a different frequency. An example can be considered, but with such a disk of this example, it is possible to realize remarkable high density and maintain good reproduction performance.

The reproduction clock frequency is the same as the header and MO
VFO for the header, even if the area is slightly different
1 or VFO2, P for MO area by VFO3
There is no problem because LL pull-in is performed. However, depending on the degree of the difference between the clock frequencies, it may be necessary to switch the coefficients in the PLL unit of the reproducing apparatus. On the other hand, if the clock frequency is the same, such coefficient switching is not necessary. Whether the clock frequencies are the same or different may be determined in consideration of various design circumstances.

Next, the configuration and operation of the recording / reproducing apparatus corresponding to the disk of this embodiment as described above will be described.

As an apparatus for reproducing a magneto-optical disk, a bit-by-bit decoding method or a Viterbi decoding method is used in an RF signal reproducing system. The recording / reproducing apparatus of this embodiment has a reproducing system for performing Viterbi decoding. FIG. 7 shows a block diagram of the recording / reproducing system. FIG. 8 shows the configuration of the drive controller 2 in FIG. FIG.
Block diagram mainly shows only the processing system of the recording and reproduction signal,
The servo system and others are omitted.

The recording, reproduction, and erasure of information are performed by the operation of the optical pickup 7 and the magnetic head 5 while the magneto-optical disk 6 is rotated and driven by the spindle motor 9 in the recording / reproducing apparatus. The position control (seek, tracking servo, thread servo) of the optical pickup 7 and the magnetic head 5 during recording, reproduction, and erasing, the focus servo of the laser light from the optical pickup 7, and the rotation servo of the spindle motor 9 are shown in the figure. Not done by the servo system.

A drive controller (hereinafter, referred to as a controller) 2 serves as a master controller of the recording / reproducing apparatus and controls various operations and communicates with the host computer 1. That is, the controller 2 controls the operation of recording the supplied data on the disk 6 in response to the recording instruction from the host computer 1, and also reads the requested data from the disk 6 in response to the instruction from the host computer 1. Control of the transfer to the host computer 1.
The controller 2 also has a function of encoding and decoding data. The detailed configuration of the controller 2 will be described later with reference to FIG.

The CPU 3 is a part for controlling each part for a recording / reproducing operation based on an instruction from the controller 2.

At the time of recording, the controller 2 receives user data to be recorded in accordance with a command from the host computer 1, performs encoding based on the user data as information words, and converts the RLL (1, 7) code as a code word. Generate. This code word is used as recording data WDATA as a laser power control unit (hereinafter referred to as LPC).
4 is supplied. Further, the controller 2 instructs the LPC 4 as a WGATE signal on the light emission operation in the recording mode and its timing.

The LPC 4 generates a laser drive current so that the laser output from the optical pickup 7 is executed at the time of reproduction, recording, and erasing. The laser emission level at the time of reproduction, recording, and erasing, that is, the laser drive current value is set in accordance with an instruction from the CPU 3. When recording is instructed by the WGATE signal, the LPC 4 controls the laser power of the optical pickup 7 to form a pit row having a magnetic polarity on the magneto-optical disk 6 in accordance with the supplied recording data WDATA. In this way, recording is performed. At the time of this recording, the magnetic head 5 applies a bias magnetic field to the magneto-optical disk 6.

At the time of reproduction, the controller 2 and C
The following operation is performed by the control of PU3.

The controller 2 receives the RGATE signal, IDG
The ATE signal is supplied to the LPC 4 and the RF block 20 to control the reproduction operation. That is, the controller 2 is an RGA
The TE signal instructs the LPC 4 to continuously emit light using the laser power as the reproduction level, and also instructs the RF block 20 to perform a reproduction process. As described above, the sector format of the disk 6 includes a header (address portion) and a data portion.
The E signal indicates the operation timing in each area, and the operation of the LPC 4 and the RF block 20 is performed accordingly. For example, the IDGATE signal is
Is output as a signal as shown in FIG.

At the time of reproduction, first, LPC 4
A laser drive current is generated according to the E signal, and the laser output from the optical pickup 7 for the reproducing operation is executed.
The optical pickup 7 irradiates the magneto-optical disk 6 with laser light, and receives reflected light generated thereby. Further, various signals are generated by arithmetic processing of signals according to the amount of reflected light. That is, there are a sum signal R +, a difference signal R-, a focus error signal, a tracking error signal, and the like (not shown). The information reading from the data section in the MO area is performed by the above-described MSR reproduction method.

The sum signal R + is supplied to the changeover switch 10 after the gain is adjusted by the amplifier 8a. The difference signal R− is supplied to the changeover switch 10 after the gain is adjusted by the amplifier 8b.
The gain setting in the amplifiers 8a and 8b is determined by the CPU.
3 is performed. The focus error signal and the tracking error signal are supplied to a servo system (not shown) and used for servo control.

The changeover switch 10 performs a changeover operation in response to the IDGATE signal, and outputs the sum signal R + or the difference signal R +.
Is supplied to the filter unit 11. That is, in a sector format of the magneto-optical disk 6 described later, the sum signal R + is supplied to the filter unit 11 during a period in which a signal reproduced from an address portion formed by embossing is supplied to the changeover switch 10. Further, during a period in which a signal reproduced by the MSR method from a data portion where magneto-optical recording is performed is supplied to the changeover switch 10, the difference signal R− is supplied to the filter unit 11.

The filter section 11 includes a low-pass filter for performing noise cut and a waveform equalizer for performing waveform equalization. The input signal is output to the Viterbi decoder 13
Are equalized so as to obtain a partial response characteristic suitable for the Viterbi decoding method performed by. The A / D converter 12 performs A / D conversion on the output of the filter unit 11 in accordance with the reproduction clock DCK, and outputs a reproduction signal value z [k]. The Viterbi decoder 13 generates decoded data DD by a Viterbi decoding method based on the reproduced signal value z [k]. The decoded data DD is a maximum likelihood decoded sequence for the recording data. Therefore, when there is no decoding error, the decoded data DD matches the recording data.

The decoded data DD is supplied to the controller 2. As described above, the recording data is a codeword generated from user data by encoding such as channel encoding. Therefore, if the decoding error rate is sufficiently low, the decoded data DD can be regarded as recording data as a codeword. The controller 2 outputs the decrypted data DD
Then, user data and the like are reproduced by performing a decoding process corresponding to the encoding such as the channel encoding described above.
Specifically, (2-7) RLL decoding processing is performed on the data from the header (data on the sum signal R +), or on the data from the data section (data on the difference signal R−). In other words, (1-7) RLL decoding processing is performed.

A reproduction clock DCK for such a reproduction process is generated by the PLL unit 14. That is, the output of the filter unit 11 is also supplied to the PLL unit 14, and the PLL unit 1
Reference numeral 4 generates a reproduction clock DCK by a PLL operation on the supplied signal. The reproduction clock DCK is supplied to the controller 2, the A / D converter 12, the Viterbi decoder 13, and the like.
Is performed at a timing according to.

As shown in FIG. 8, the controller 2 includes a control unit 31, an interface unit 32, and a data buffer 3.
3, buffer controller 34, (1-7) decoder 3
5, a (2-7) decoder 36, switches 37 and 38, and an encoder 39 are provided.

The control section 31 is a section that performs control processing as the controller 2 and, for that purpose, also has a function as a timing generator. The reproduction clock DCK generated by the PLL unit 14 is supplied to the control unit 31.
The control unit 32 uses the reproduction clock DCK to generate a signal for controlling operation timing of the apparatus such as switching between recording and reproduction operations. That is, an IDGATE signal, an RGATE signal, and a WGATE signal are generated. In addition, the control unit 31
The necessary instructions for the recording / reproducing operation are given to each part inside and outside the controller 2.

The interface section 32 is a section for transmitting and receiving data to and from the host computer 1. That is, the control unit 31
A recording request and a reproduction request from the host computer 1
The reception of the recording data is performed via the interface unit 2. Transmission of the reproduction data to the host computer is performed via the interface unit 2 according to an instruction from the control unit 31.

The data buffer 33 is a memory for temporarily storing recording data and reproduction data. Writing to and reading from the data buffer 33 is executed by the buffer controller 34. The encoder 39 modulates the recording data taken into the data buffer 33 and modulates the recording data WDAT.
A.

That is, when there is a recording request from the host computer, the controller 31 first transmits the transmitted recording data to the data buffer 3 by the buffer controller 34.
3 Then, a recording operation instruction is issued to the CPU 3, the LPC 4, and a servo system (not shown) to execute a required seek process. And when you start recording,
The recording data stored in the data buffer 33 is transferred to the encoder 39, and the encoder 39 executes error correction code processing, (1-7) RLL encoding processing, and the like. As described above, LPC is performed as the recording data WDATA.
4 will be supplied.

The (1-7) decoder 35 and the (2-7) decoder 36 perform a decoding process on the decoded data DD supplied at the time of reproduction. Also, a reproduction clock DCK is supplied for this decoding process. Switches 37, 38
Is switched by, for example, an IDGATE signal.

As an operation at the time of reproduction, in order to reproduce the data requested by the host computer 1, the control unit 31 first causes the optical pickup 7 to seek the sector of the requested data. Then, while reading the sector address, it is confirmed whether or not the target sector has been reached, and when the target sector has been reached, the data operation of the data portion of the sector is started.

During such a series of reproduction operations, the address recorded in the ID field for confirming the address of the sector is read, and then the data recorded in the data field is read. become.

During the period in which the data read from the header of the sector is supplied by the switches 37 and 38 switched by the IDGATE signal, the decoded data DD
Is supplied to the (2-7) decoder 36, and the (2-7) decoded signal is supplied to the control unit 31 via, for example, the buffer controller 34. That is, address data and the like are captured.

On the other hand, while the data read from the data portion of the sector is supplied by the switches 37 and 38, the decoded data DD is supplied to the (1-7) decoder 35, and is decoded (1-7). The received signal is stored in the data buffer 33 via the buffer controller 34, for example. Then, based on an instruction from the control unit 31, the data is transmitted from the interface unit 32 to the host computer 1 at a predetermined time.

That is, in this recording / reproducing apparatus, (2-7) decoding processing is performed for reproducing the header of the sector, and (1-7) decoding processing is performed for reproducing the data portion. Therefore, it is possible to appropriately reproduce the disc of the present example as shown in FIG. 1 and to support the above-described large capacity of the disc of the present example.

The configuration of the disk and the recording / reproducing apparatus described above is merely an example, and various examples can be considered as the present invention. In particular, the technique for increasing the density is not limited to the MSR method. (1-7) RLL, (2-7) R
Although LL is used in combination, other modulation schemes may be used. Of course, in that case, a corresponding decoder is provided on the recording / reproducing apparatus side. Further, the recording and reproducing apparatus corresponding to a magneto-optical disk has been described, but the present invention can be applied to a reproducing apparatus corresponding to another recording medium.

[0068]

As described above, in the recording medium of the present invention, the data recording density in the header area is different from the data recording density in the recording / reproducing area. That is, for example, the data recording area as the magneto-optical area can be increased in density by adopting the MSR method or the like, and a remarkably large capacity can be realized. Further, in the header area, data according to the first modulation method is recorded, and in the recording / reproducing area, data is recorded according to the second modulation method capable of higher density recording than in the first modulation method. When the recording density in the header area is reduced in accordance with the increase in the recording density, a margin in the data reproduction system can be created, and appropriate reproduction processing can be prevented.
In addition, this makes it possible to realize not only the recording / reproducing area but also the header area with a high density, so that the capacity of the entire recording medium can be increased.

The header area is based on the (2-7) RLL modulation system, and the recording / reproducing area is based on the (1-7) RLL modulation system. . For example, if both the header area and the recording / reproducing area use the MSR method, and (1-7) R
Assuming that the recording medium is of the LL modulation method (that is, the recording medium having the largest capacity when assuming that the MSR effect can be obtained even in the header area), the recording of the recording medium of the present invention is considered. The capacity can be kept at a loss of several percent compared to such a recording medium. This is the most efficient increase in capacity, assuming that the MSR effect cannot be obtained in the header area as in the present invention.

The data recording is performed so that the data reproduction from the header area and the data reproduction from the recording / reproduction area can be executed by using the clock of the same frequency.
Clock processing in the playback device can be made easy and stable.

The reproducing apparatus of the present invention switches the switching means at the timing corresponding to the header area and the timing corresponding to the recording / reproducing area, and performs the decoding operation by the first decoding means corresponding to the first modulation method and the second operation. The decoding operation by the second decoding means corresponding to the above-mentioned modulation method is performed. That is, an appropriate reproducing operation can be performed corresponding to the recording medium of the present invention. When the data is recorded in the header area in the (2-7) RLL modulation method and in the recording / reproducing area in the (1-7) RLL modulation method, the first decoding unit performs the (2-7) RLL modulation method. A decoding process corresponding to the RLL modulation method is performed, and the second decoding unit performs a decoding process corresponding to the (1-7) RLL modulation method, thereby enabling an optimal reproduction operation.

As described above, according to the recording medium and the reproducing apparatus of the present invention, the sector as a data unit on the recording medium is divided into a header area where preformat data is recorded, and a recording / reproducing area where data can be recorded / reproduced. In this case, it is optimal in terms of improving recording density and maintaining reproduction reliability.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a disk according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an MSR in the disk of the embodiment.

FIG. 3 is an explanatory diagram of a sector format of a disk according to the embodiment;

FIG. 4 is an explanatory diagram of a basis for features of the disk of the embodiment.

FIG. 5 is an explanatory diagram of a basis for features of the disk of the embodiment.

FIG. 6 is an explanatory diagram of data densities of (1-7) RLL and (2-7) RLL.

FIG. 7 is a block diagram of a recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 8 is a block diagram of a drive controller of the recording and reproducing apparatus according to the embodiment.

FIG. 9 is an explanatory diagram of an IDGATE signal of the recording / reproducing apparatus of the embodiment.

[Explanation of symbols]

1 host computer, 2 drive controller,
3 CPU, 4 laser power control section, 5 magnetic head, 6 disk, 7 optical pickup, 8 amplifier, 9 spindle motor, 10 switch,
11 filter unit, 12 A / D converter, 13 Viterbi decoder, 14 PLL unit, 31 control unit, 32 interface unit, 33 data buffer, 34 buffer controller, 35 (1-7) decoder, 36 (2
-7) Decoder, 37, 38 switch, 39 encoder

Claims (7)

[Claims] 1. A sector as a data unit on a recording medium is formed by a header area in which preformat data is recorded, and a recording / reproducing area in which data can be recorded / reproduced. A recording medium, wherein a data recording density is different from a data recording density in the recording / reproducing area. 2. The data according to a first modulation method is recorded in the header area, and the first modulation scheme is recorded in the recording / reproducing area.
2. The recording medium according to claim 1, wherein data recording is performed by a second modulation method capable of higher-density recording than the modulation method of (1). 3. The recording medium according to claim 1, wherein a recording layer is formed in the recording / reproducing area so that a magnetic super-resolution reproducing method can be performed. 4. The method according to claim 1, wherein the first modulation scheme is a (2-7) run-length limited code modulation scheme, and the second modulation scheme is a (1-7) run-length limited code modulation scheme. The recording medium according to claim 2, wherein 5. The data recording method according to claim 1, wherein data reproduction from the header area and data reproduction from the recording / reproduction area are performed so that the data reproduction can be performed using a clock having the same frequency. recoding media. 6. A sector as a data unit on a recording medium is formed by a header area in which preformat data is recorded and a recording / reproducing area in which data can be recorded / reproduced. 1, data is recorded according to the modulation method 1, and in the recording / reproducing area,
As a reproducing apparatus corresponding to a recording medium on which data is recorded by a second modulation scheme capable of recording at a higher density than the first modulation scheme, a first decoding unit corresponding to the first modulation scheme; A second decoding unit corresponding to a second modulation method, and a switch for selectively supplying information read from a recording medium to the first decoding unit and the second decoding unit to execute a decoding process. Means for controlling the switching operation of the switching means at a timing corresponding to the header area and a timing corresponding to the recording / reproducing area. 7. The first decoding means performs a decoding process corresponding to the (2-7) run-length limited code modulation method, and the second decoding means performs (1-7)
7. The reproducing apparatus according to claim 6, wherein a decoding process corresponding to a run-length limited code modulation system is performed.