JP3039029B2 - Data recording / reproducing method for optical disk - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data recording / reproducing method for an optical disk which is useful for recording and reproducing data on / from an optical disk having a light-sensitive recording medium as a recording surface. Things.

[0002]

2. Description of the Related Art An optical disk system capable of recording various data on an optical disk by irradiating a spiral track with a laser beam and reading the recorded data includes a track on which data on the optical disk is arranged. And the sample servo system in which tracks for arranging data are discretely arranged are formed by sample servo pits.

FIG. 7 shows an example of the format of a magneto-optical disk in which a recording track is formed by sample servo pits. S _{1 to} S ₄₂ represent, for example, sectors divided into 42 in the circumferential direction. Show. The tracks of each sector unit, as shown in FIG. 8 (a), the header H ₁ is an area in which the address data by pit by pre embossing or the like is recorded, test writing area (see recording area W _T) magneto-optical recordable portion consists of a header H ₂ Metropolitan provided as an address test area AD
There are formed, it is further formed the subsequent example 20-byte data area capable of data writing is divided into data segments SG ₁ to SG ₃₀ 30.

FIG. 8 (b) shows each data segment (SG
₁ to SG ₃₀₎ or obtained by further enlarging the header H _2,
In these areas, the servo bytes SB are arranged first, followed by the data bytes DB or the reference recording area W.
_T is provided .

A pair of wobbling pits P ₁ and P ₂ deviated at least from the center of the track T to the outer peripheral side and the inner peripheral side, and the servo byte SB are arranged on the center line of the track T. clock pit P ₃ are formed in advance by embossing. Also, pits P ₄ and P ₅ forming a gray code indicating track information
Are similarly formed. Also, the wobbling pit P
_1, P ₂ and the intermediate clock pit P ₃ is the mirror surface M, a laser beam reflected from the mirror surface M with a focus servo signal is detected, the laser power control - le can also be performed.

In such a magneto-optical disk, a tracking error signal is formed by calculating reflected light when the wobbling pits P ₁ and P ₂ are detected at sample points t ₁ and t _{2. 3} the clock signal is formed by a signal detected by the sample point t _3.

[0007] In the header H ₂ and the data segments SG ₁ to SG ₃₀ of the magneto-optical disk, it irradiates the laser beam to the recording surface along the track, applying a magnetic field from the other surface of the magneto-optical disk, When the recording surface is above the Curie point, it is magnetized in the direction of the applied magnetic field and data is recorded. When reading information from a magneto-optical disk on which data is recorded,
The recording data is read by detecting the reflected light of the laser beam using the magnetic force effect.

The read reproduction signal is binarized by waveform shaping, and recording data is read. When detecting binary data from a reproduction signal read from a magneto-optical disk, the reproduction signal level is digitized by an A / D converter as it is, and various clock signals are generated in the state of a digital signal and recorded. Data is to be extracted.

[0009]

By the way, the level of the reproduced signal fluctuates between various types of magneto-optical disks or between the recording portions of one magneto-optical disk due to various factors, and the reproduced signal becomes A
In some cases, the dynamic range of the A / D converter deviates greatly, and there is a problem that an appropriate signal reproduction process is not performed.

The factors of the level difference of the reproduction signal between the various magneto-optical disks include, for example, the difference in the material of the recording layer of the magneto-optical disk, the reflectivity of the disk, and the like, and the RF in one magneto-optical disk. The factor of the level variation is (space) on the inner peripheral side and the outer peripheral side when the magneto-optical disk is rotationally driven at CAV (constant angular velocity ).
Differences in frequency characteristics and variations in reflectance in the circumferential direction due to the formation of the recording layer can be cited.

If the gain of the reproduced signal is set small so that the reproduced signal always falls within the dynamic range of the A / D converter in consideration of these level fluctuation factors, the dynamic range of the A / D converter can be effectively used. The digital signal used cannot be obtained, and the S / N ratio also deteriorates. Conversely, if the gain of the reproduction signal is set to a certain large value and the dynamic range of the A / D converter is to be used effectively as much as possible, the reproduction signal may have an A
May deviate from the dynamic range of the A / D converter
Sex is increased.

Further, even if an appropriate gain of the reproduced signal with respect to the dynamic range of the A / D converter is obtained, if the reproduced signal is superimposed with a DC component, the reproduced signal cannot be converted into the dynamic range of the A / D converter. Will be deviated from In other words, if the DC component is different for each disk, for example, inputting an appropriate gain to the reproduced signal can provide an input to the A / D converter suitable for the dynamic range of the A / D conversion process. Therefore, a digital signal that effectively utilizes the dynamic range cannot be obtained.

[0013]

According to the present invention, an address test area in which address data and a reference recording area are formed in each sector area and a data recording area are formed in order to solve such problems. As a data recording / reproducing method for a magneto-optical disk, at the time of recording, not only predetermined recording data is recorded in a data recording area, but also a specific pattern signal is recorded in a reference recording area. The optimum gain of the reproduction signal for the processing range of the A / D converter is calculated from the signal level of the reproduction signal of the specific pattern signal recorded, and the calculated optimum gain is used as the data recorded in the data recording area. Of the reproduction signal to which the gain has been applied and the A / D conversion The calculated offset value to the middle level value means processing range substantially coincides, and is to provide a reproduced signal of the data.

[0014]

By calculating the optimum gain and the optimum offset using the actual reproduction signal in the reference recording area,
An optimum gain and an optimum offset for signal processing can be given to a reproduction signal of data recorded in the data recording area in units of sectors.
That is, if the gain is set so that the level of the reproduction signal in the reference recording area is substantially equal to the conversion range of the A / D converter, the amplitude level of the reproduction signal of the recording data can maximize the conversion range of the A / D converter. Amplitude level that can be used for
Further, if an offset value is given so that the midpoint level value of the amplitude of the reproduced signal to which the gain is given and the midpoint level value of the processing range of the A / D conversion means are substantially equal to each other, the recording can be performed. The reproduced signal of the data is most suitable for the conversion range of the A / D converter.

By obtaining the optimum gain in sector units in this manner, the reproduction signal level between the disks can be improved.
Regardless of the difference in the disk, the output of the A / D converter is always obtained as digital data that effectively uses the dynamic range.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG.
FIG. 1 shows a schematic diagram of a recording / reproducing circuit to which the method is applied. Numeral 1 denotes a magneto-optical disk having a track format substantially similar to that described with reference to FIGS. 1 is a spindle motor 2
, So that it is driven to rotate at a constant angular velocity (CAV). An optical head 3 for irradiating a laser beam during recording or reproduction is arranged below the magneto-optical disk 1.

As is well known, the optical head 3 is composed of an optical system including a laser light source, a collimator lens, a beam splitter, a two-axis device for controlling an objective lens, and the like. A polarization beam splitter and a detector for detecting the In particular, the reflected light is split into a P deflection component and an S deflection component by the polarization beam splitter 3C, and is detected by the two detectors 3A and 3B.

The outputs of the detectors 3A and 3B are supplied to a differential amplifier 4, and the difference between the two outputs is obtained by the differential amplifier 4 to extract a reproduction signal of magneto-optically recorded data.

The detector 3A is, for example, a light receiving element having a divided surface. When a servo byte SB of each segment is scanned, an RF signal of the embossed pit is extracted by a detection circuit 5 to detect various servos. A signal is formed and supplied to a servo circuit 6 to drive the two-axis device to perform tracking servo and focus servo, and to a control data reproduction circuit 7 to form a clock signal and the like. To the system control
Output to the control unit 8. The playback information is also supplied to the address decoder in the control data reproducing circuit 7 the address information obtained by scanning the header H ₁ that the address data is recorded in each sector are extracted, the system controller - Le 8 Supplied.

Further, 11 is a clamp circuit of a reproduction signal read from the magneto-optical disk 1, the clamp circuit 11 is multiplied by the clamped signal recorded as a clamp reference as described below, the clamp level G ₀ is used as the gain reference of the subsequent gain adding circuit.

Reference numeral 12 denotes a fixed gain adding circuit. In the fixed gain adding circuit 12, a reproduced signal is described later based on the fixed gain characteristic specified by the above-described design conditions of the optical system or each circuit section. The gain for fine adjustment is added so that the amplitude level becomes a certain level appropriate for the dynamic range in the A / D converter 14.

Numeral 13 denotes a setting gain adding circuit, which responds to a level difference of a reproduced signal generated due to a difference between various conditions in the disk or in the disk, for example, as shown in FIG. This is to add a gain g set to an appropriate amplitude level for the dynamic range A in the / D converter 14. However, the gain setting operation is intended to be made based on the reproduction signal according to the scan of the reference recording area W _T of the header H ₂ that is the reference recording area, during the gain setting operation, i.e. the header H ₂ at each sector when the reproduction signal according to the scan of the reference recording area W _T is supplied set gain adding circuit 13
Is fixed at g = 1. The gain setting operation will be described later.

Reference numeral 14 denotes a fixed offset adding circuit. The fixed offset adding circuit 14 is a fixed gain adding circuit 1.
Similarly to 2, based on the fixed offset characteristic specified by the above-described design conditions of the optical system or each circuit section, the reproduced signal is controlled so as not to deviate from the dynamic range of the A / D converter 16 described later. Some appropriate offset is added.

Numeral 15 denotes a setting offset adding circuit, which converts a reproduced signal into a dynamic signal in the A / D converter 16 in accordance with an offset level difference superimposed on a reproduced signal generated due to a difference in conditions between disks or within a disk. An offset Of set so as not to deviate from the range A is added. This offset setting operation is intended to be made on the basis of the reproduction signal to the scanning of the gain and similar reference recording area W _T, in offset setting operation, that is, the scanning of the reference record area W _T header H ₂ at each sector When such a reproduction signal is supplied, the reproduction signal is not given an offset by the setting offset adding circuit 15. The offset setting operation will be described later.

Reference numeral 16 denotes an A / D converter. The output of the A / D converter 16 is supplied to a data detection unit 17 constituted by a digital circuit or a hold circuit 19 via a difference detection circuit 18. . The difference detection circuit 18 uses a single clock.
Because it detects the difference value position in the reproduction signal amplitude level detected when the gain g = 1 and is according to the reference recording area W _T is reproduced signal is supplied in the setting gain adding circuit 13 For example, it corresponds to the value of a in FIG.

The value of a is held in the hold circuit 19, and the average value of the value of a detected n times, for example, is calculated. The reason why the hold circuit 19 takes the average value of n times is that a detection error due to a disk defect is detected.
Due to factors such as The value of a output from the hold circuit 19 is supplied to a division circuit 20 that holds a value A corresponding to the dynamic range of the A / D converter 16, and A ÷ a is calculated.

When a reproduction signal relating to the recording data is supplied, the output of the difference detection circuit 18 is supplied to a data detection section 16 which performs, for example, code conversion and recording by a difference method. Data sampling,
Reproduction of a read clock and the like are performed.

The output of the A / D converter 16 is also supplied to a midpoint detection circuit 21. The midpoint detection circuit 21 calculates (top value + bottom value) / 2 to obtain the value of the amplitude midpoint of the reproduced signal. b is supplied to the hold circuit 22. The hold circuit 22 averages the value b at the midpoint of the amplitude n times.

Reference numeral 23 denotes a d-value generator for generating a fixed value d which is a value of a difference from the clamp level G ₀ in the clamp circuit 11 to the base level of the A / D converter 16.
Is a M _A value generation unit that generates a middle value M _A of the dynamic range A of the A / D converter 16.

Further, reference numeral 25 denotes an addition circuit for adding the value b at the midpoint of the amplitude output from the hold circuit 22 to the value d output from the d-value generator 23, and reference numeral 26 denotes the value output from the d-value generator 23. An addition circuit 27 adds d and the value M _A output from the M _A generation unit. Reference numeral 27 denotes a value (b + d) output from the addition circuit 25 and a value g (= A ÷) output from the division circuit 20.
a) is a multiplication circuit for multiplying by a), and 28 is a subtraction circuit for subtracting the value {g (b + d)} output from the multiplication circuit 27 from the value (M _A + d) output from the addition circuit. Also,
29a is output from the subtraction circuit _{28 {M A -g (b +} d) +
This is a D / A converter that converts d｝ into an analog signal.

On the other hand, a magnetic head unit 40 is provided at a position facing the optical head 3 with respect to the magneto-optical disk 1,
A magnetic field that is reversed by the recording data is applied. That is, the recording data supplied from the terminal 41 is subjected to predetermined code modulation and blocking in the recording data processing unit 42, further added with an error correction code and the like, and supplied to the magnetic head 40 as recording data. .

In the data recording / reproducing method for a magneto-optical disk according to the present embodiment, for example, when the recording data processing section 42 performs signal processing, the reference data section 43 outputs, for example, N
Continuous signals 1T which is the maximum recording frequency is supplied in RZI modulation, it is adapted to be recorded in a header of H ₂ region of FIGS. 5 (a) described above (see recording area W _T).

As shown in FIG. 3, for example, a reference recording area W _T of a header H ₂ in which a 1T continuous signal is recorded, and each data segment S in which predetermined recording data is recorded.
The leading portion of the data byte DB in G _{1 to} SG ₃₀ is
The pre-write area PW protrudes into the area of the servo byte SB and performs magneto-optical recording. A recording signal is added to the pre-write area PW by the recording data processing unit 42 during recording so that the signal length of the signal to be recorded is, for example, about three clocks at which the reproduction signal is saturated during reproduction. In practice, the reference data section 43 is included in the recording data processing section 42. The signal to be recorded in the reference recording area W _T of the header H ₂ is not limited to a continuous signal of 1T.

[0034] Thus referring recording area W _T for example 1T
In the present embodiment a signal is recorded, the optimum gain setting gain adding circuit 13 based on the reproduction signal of the reference recording area W _T at the time of reproduction is calculated, also setting the offset adding circuit 1
5 are calculated. These calculation operations will be described with reference to FIG.

The reproduction signal read from the magneto-optical disk 1 by the optical head 3 is supplied to the clamp circuit 11 via the signal processing section 10 as described above. clamp level G as shown in FIG. 4 (a) at the saturation level by the reproduction signal from the pre-write area PW provided at the beginning of the region W _T
Clamp to ₀ .

After this clamp level G ₀ is set as a gain reference, it is supplied to a set gain adding circuit 13.
Reproduced signal of the recorded 1T signal in the reference recording area W _T becomes a signal having an amplitude level a, as shown, set gain additional circuit as described above when playing a portion of the reference record area W _T Since the gain g of 13 is set to 1, the difference detection circuit 18 and the hold circuit 19 calculate the amplitude level a. This value of a is determined by the A / D converter 1
The value A is supplied to a division circuit 20 that holds the value of A indicating the dynamic range of 6, and A ÷ a is calculated for the value of A.

The value of A ÷ a, which is the output of the division circuit 20, is converted into an analog signal by the D / A converter 38a as the value of the gain g and supplied to the set gain adding circuit 13.
Thereafter, the gain g is given to the reproduction signal in the setting gain adding circuit 13. This set gain g
(= A ÷ a), that is, as shown in FIG. 2, the signal of the amplitude level a is the dynamic range A of the A / D converter 16.
Is adjusted to a gain value to be almost full scale.

However, the gain g set as described above
4A, the reproduced signal shown in FIG. 4A may deviate from the dynamic range A of the A / D converter 16 and overflow as shown in FIG. 4B. Therefore, at the same time, an optimum offset value Of to be added is calculated so that the reproduced signal given the gain g falls within the dynamic range A of the A / D converter 16 as shown in FIG. This offset Of is given by the set offset adding circuit 15.

The optimum offset Of is calculated based on the midpoint M _A of the dynamic range A of the A / D converter 16, the appropriate gain g calculated as described above, and the clamp level G ₀ . A fixed value d, which is a difference value of the dynamic range A to the base level, and a value b at the midpoint of the amplitude of the reproduced signal before adding the appropriate gain g based on the base level of the A / D converter 16 are used. Thus, the calculation is performed by the following expression: Of = M _A −g (b + d) + d.

That is, as can be seen from FIG. 4B, the offset Of is the midpoint value B of the reproduced signal after the addition of the appropriate gain g, with reference to the base level of the A / D converter 16, and the dynamic range. This is the difference from the midpoint value _{A of A,} and is expressed as Of = M _A -B. Here, the value B is to the value B ₁ indicating the level from the amplitude midpoint of the gain g added after the reproduction signal to a gain reference value G ₀ is obtained by subtracting the value d (B = B ₁ -
d). The value B ₁ is a value b ₁ indicating a level from the midpoint of the amplitude of the reproduced signal before the gain g is added to the gain reference value G _0.
With a gain g (B ₁ = g · b ₁ ). Further, as can be seen from FIG. 4A, b ₁ = b + d.

Accordingly, it is derived that Of = M _A -B Of = M _A -B ₁ + d Of = M _A -g · b ₁ + d Of = M _A -g (b + d) + d.

This calculation is performed simultaneously with the calculation of the gain g. That is, (b + d) is performed in the adder circuit 25, and further, the multiplication g (b + d) of (b + d) and the gain g calculated in the division circuit 20 is performed in the multiplication circuit 27. Moreover, it made by the addition circuit 26 _{(M A + d), g} (b in this (M _A + d) from the subtracting circuit 28
+ D) is subtracted. That is, the output of the subtraction circuit 28 is M _A
−g (b + d) + d, and the offset value Of is calculated. This Of value is converted into an analog signal by the D / A converter 29a and supplied to the set offset adding circuit 15. The set offset adding circuit 15 gives the calculated offset Of to the reproduction signal.

That is, in this embodiment, the reproduced signal as shown in FIG. 4A is calculated so as to have an amplitude level suitable for the dynamic range A of the A / D converter 16 as shown in FIG. 4C. The gain g and the offset Of are provided in the setting gain adding circuit 13 and the setting offset adding circuit 15.

The gain g and after the offset Of the set offset adding circuit 15 is set, followed by data of each data segment SG ₁ to SG ₃₀ set the gain adding circuit 13 from the reproduced signal of such the reference recording area W _T The data recorded in the byte DB is reproduced. After the reproduction signal relating to the recorded data is clamped by the reproduction signal of the prewrite area PA, the reference recording area W _T is set in the setting gain adding circuit 13. Is given by the gain g and the offset Of set at the time of reproduction of A /
It is input to the D converter 16. That is, the data byte DB
Of the reproduced signal, the peak-to-bottom width of the amplitude substantially corresponds to the dynamic range of the A / D converter 16.
A / D converter 16 determines the optimum amplitude level for A / D
It is input to the converter 16.

The reproduction signal of the data byte DB output from the A / D converter 16 is supplied to the data detection unit 17 via the difference detection circuit 18, and the recording data is extracted.
However , since the dynamic range of the A / D converter 16 is effectively used, the S / N is improved, and the signal sampling accuracy is also improved.

Thereafter, the reproduction scanning reaches the next sector, is a gain g = 1 setting the gain adding circuit 13 during reproduction of the reference recording area W _T of that sector, again A ÷ a
Is calculated, the gain g (= A ÷ a) is set, and the offset Of is set by the calculation of Of = M _A −g (b + d) + d. When the subsequent data byte DB is reproduced, the gain g and the offset Of set in the reproduction signal are given.

In this embodiment, the reference recording area W
_The reference signal (1T signal) is recorded in _T , and the optimum gain and optimum offset of the reproduction signal of the data byte DB are calculated in sector units from the reproduction signal. Accordingly, even if a reproduced signal level difference and an offset difference are generated, the reproduced signal of the data byte DB is always adjusted to an amplitude level that makes the most effective use of the dynamic range of the A / D converter 16 in response to the difference, and the S / N And the reproduced signal does not deviate from the dynamic range of the A / D converter. Further, the signal of a fixed pattern of 1T recorded in the reference recording area W _T is an advantage that it can also serves as detection read clock phase.

FIG. 5 shows another embodiment of the present invention. The same parts as those in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted. This embodiment further setting gain additional circuit in the example 30, is provided to set the offset adding circuit 31 is controlled on the basis of the disc radius information offset Of _ref gain g _ref, and setting the offset adding circuit 31 of the set gain additional circuit 30 Things.

That is, the track address information obtained from the system control unit 8 is decoded in the decoding processing unit 32 to obtain predetermined radius information, and the gain _gref is set according to the radial position during reproduction, and the D / A conversion is performed. Vessel 3
8b to the setting gain adding circuit 30. Further in accordance with the setting of the gain g _ref, setting the gain adding circuit 13
, The gain reference of the reproduced signal input to the fluctuates, the offset Off _ref in the setting offset adding circuit 31 is set to a predetermined value so as to adjust the fluctuation. In other words, to obtain a value of the offset Of _ref decoding in the decoding processing unit 33 to track address information, and supplies the set offset adding circuit 31 through a D / A converter 29b.

The gain g of the set gain adding circuit 13
And setting operation of the offset Of the set offset adding circuit 15 is substantially similar to that of Example 1, i.e., the reference recording area W _T gain g _ref signal state given that the setting gain additional circuit 19 in reproducing When the amplitude level of the A / D converter 16 is a, the gain g (= A ÷ a) that sets the optimum amplitude level for the dynamic range of the A / D converter 16 is set. g
Is calculated using

In this embodiment, since the appropriate gain and offset corresponding to the difference in the frequency characteristics between the inner and outer circumferences of the disk are given by the set gain adding circuit 30 and the set offset adding circuit 31 based on the radius information, the reference recording area W _T. during reproduction, i.e. even point before being optimum gain g settings in the setting gain adding circuit 13, the amplitude of the reproduced signal of the reference recording area W _T can be increased to some extent. It is possible to increase the amplitude of the reproduction signal of the reference recording area W _T raises the detection accuracy if possible, when also serves as a reproduction signal of the reference recording area W _T as a signal for the read clock detecting this embodiment The example would be very suitable.

FIG. 6 shows still another embodiment of the present invention, in which a setting gain adding circuit 34 corresponding to the setting gain adding circuits 13 and 30 in FIG. 5 is provided. That is, in the setting gain adding circuit 34, a gain of g _ref × g is given. A setting offset adding circuit 3 corresponding to the setting offset adding circuits 15 and 31 in FIG.
5 are provided. That is, the setting offset adding circuit 35
In, an offset of _Ofref + Of is given.

As means for supplying the set gain and the set offset to the set gain adding circuit 34 and the set offset adding circuit 35, a ROM table 36,
37, a value of the gain g calculated by the division circuit 20 and the decode processing unit 32 are stored in the ROM table 36.
Is provided with radius information. Then, in the ROM table 36, each value of g _ref × g is
The gain is stored in correspondence with the input value of g and the radius information, and by outputting this, the same gain adding operation as in the embodiment of FIG.

Further, the offset value calculated by the subtraction circuit 28 and the radius information from the decode processing unit 33 are supplied to the ROM table 37. In the ROM table 37, Of + Of
Each value of _ref is held corresponding to the input value of _Off and radius information, and by outputting this, the same offset adding operation as in the embodiment of FIG. Will be realized. In this embodiment, the same effects as in the embodiment of FIG. 5 can be obtained.

Although the three embodiments have been described above, the circuit configuration employing the data recording / reproducing method for a magneto-optical disk according to the present invention is not limited to the above embodiments.

[0056]

As described above, in the data recording / reproducing method for an optical disk according to the present invention, a specific pattern signal is recorded in a reference recording area during recording, and a specific pattern signal recorded in the reference recording area is recorded during reproduction. By calculating the optimum gain and the optimum offset for the reproduction signal processing from the signal level of the reproduction signal, and applying the calculated optimum gain and the optimum offset to the reproduction signal of the data recorded in the data recording area. Therefore, even if a reproduced signal level difference occurs due to a difference in various conditions between disks or within a disk, a reproduced signal of data is always obtained as digital data that makes the most effective use of the dynamic range of the A / D converter. Therefore, a more accurate reproduction operation is realized. Another advantage is that a specific pattern signal recorded in the reference recording area can also be used as a signal for detecting a read clock during reproduction.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of a circuit to which a magneto-optical disk data recording / reproducing method of the present invention is applied.

FIG. 2 is an explanatory diagram of a gain given to a reproduction signal in the embodiment.

FIG. 3 is an explanatory diagram of a prewrite area recorded in the present embodiment.

FIG. 4 is an explanatory diagram of a gain and an offset given to a reproduction signal in the embodiment.

FIG. 5 is a block diagram of another embodiment of a circuit to which the method of recording / reproducing magneto-optical disk data of the present invention is applied.

FIG. 6 is a block diagram of still another embodiment of a circuit to which a method for recording and reproducing data on a magneto-optical disk according to the present invention is applied.

FIG. 7 is an explanatory diagram of a format of a magnetic disk.

FIG. 8 is a detailed explanatory diagram of a recording track.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G11B 20/10 321

Claims (1)

(57) [Claims] (1) A concentric or spiral shaped tor
Multiple divided data recording areas are formed on the rack
Data recording / reproducing method for an optical disc
Therefore, at the time of recording, while recording data is recorded in each of the data recording areas, a specific pattern signal is recorded in the reference recording area, and at the time of reproduction for A / D converting a reproduction signal and extracting data, the reference data is recorded. The optimum gain of the reproduction signal for the processing range of the A / D converter is calculated from the amplitude level of the reproduction signal of the specific pattern signal recorded in the recording area, and the calculated optimum gain is recorded in the data recording area. The optimum offset value is applied to the data reproduction signal such that the midpoint level value of the amplitude of the reproduction signal to which the gain is applied substantially coincides with the midpoint level value of the processing range of the A / D converter. Data recording / reproducing of an optical disk, wherein the calculated optimum offset value is provided to a reproduction signal of data recorded in the data recording area. Method.