JP2003331419A - Information recording apparatus and information recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the superposing of a DC component generated in a non- user data area on data of the area while suppressing the power consumption. <P>SOLUTION: The method comprises: selecting a level of a laser power to be a reproduction level until a prescribed period of time t2 elapses after the start of the non-user data area (S201); calculating a DC level of a reproduced signal (S204); recording pattern data to suppress the DC level up to the end of the non-user data area (S205 to S207) when the DCLV (DC level) is a threshold value STDDC or more as a result of the arithmetic operation (S204); maintaining the reproduction laser power until a timing when the recording position reaches an end t3 of the non-user data area if the DCLV of the arithmetic result is less than the threshold value STDDC (S209), then selecting the recording laser power for recording a DC free pattern at the end of the non-user data area to thereby limit the laser power for the non-user data area and suppress the power consumption. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording device and an information recording method, and is particularly suitable for use in an information recording device and an information recording method for recording information by an AC coupling system.

[0002]

2. Description of the Related Art Optical discs such as magneto-optical discs and phase change discs have been commercialized as recording media on which information can be written. When recording / reproducing information on / from these discs, data is generally exchanged by an AC coupling method. Therefore, when high density recording is performed on such a disc, it is very difficult to record and reproduce the signal component in the low frequency region with high efficiency.

Therefore, a method has been widely adopted in which digital data is modulated by a modulation method such as EFM modulation and RLL modulation to suppress the direct current component and the low frequency component, and then the data is recorded on the disc. There is.

On the other hand, in a digital disc, a method of wobbling a wall of a groove (recording track groove) formed on the disc as a method of retaining address information in a physical format can be adopted.
Such a method has recently been standardized in AS-MO (Adv.
advanced Storage Magnet Opt
It is also adopted in the standard of the digital disk).

Further, in a disc complying with the AS-MO standard, fine clock marks serving as a reference for generating a clock used in recording or reproducing data are formed at a predetermined cycle. Specifically, the fine clock mark is provided with a groove (groove portion) having a length of about 3 to 4 data channel bits in a predetermined cycle in a land (a flat area between adjacent grooves), and the groove is also formed in a predetermined cycle in a predetermined cycle. It is formed by providing a land (flat portion) having a length of about 4 data channel bits.

The area in which the wobble is formed is not normally used as a recording area for digital data because the intensity of the reflected beam becomes unstable. Further, the area of 6 data channel bits before and after the fine clock mark area (fine clock mark area) is not used for recording digital data in order to avoid the adverse effect of the fine clock mark.

Further, there is a defect area on the disc where data cannot be recorded / reproduced properly due to repeated recording / erasing or aging. Therefore, the recording of digital data is performed on the wobble area, the fine clock mark area, and the area (user data area) on the groove and land excluding the defect area.

As described above, the recording of the data in the user data area is performed after the modulation such as the EFM modulation and the RLL modulation is performed in order to suppress the DC component and the low frequency component. However, since data is not recorded in the non-user data area other than the user data area, that is, the wobble area, the fine clock mark area, and the defect area, when the beam scans the non-user data area during reproduction, the reproduction signal Contains a DC component and a low frequency component. For this reason,
When the beam scans the user data area subsequently, a DC component or low frequency component is superimposed on the reproduction signal,
There arises a problem that the data string recorded in the user area cannot be correctly reproduced.

Therefore, in order to eliminate such inconvenience, in the invention described in Japanese Patent Application Laid-Open No. 2001-143398 filed by the applicant earlier, a DC free pattern is recorded in the non-user data area as well. , And prevents the reproduced signal from the non-user data area from containing a DC component and a low frequency component.

[0010]

However, according to the invention described in Japanese Patent Laid-Open No. 2001-143398, a DC free pattern is recorded unconditionally in the non-user data area. The power consumption of the device is higher than that when the DC free pattern is not recorded in the non-user data area. In particular, when the device is small and portable, the problem of power consumption is important and may hinder commercialization of the device.

On the other hand, when the DC component is not superposed on the reproduced signal from the non-user data area, such as when the DC free pattern is already recorded in the non-user data area, the DC free pattern is re-recorded again. Is useless. In order to reduce power consumption, it is necessary to suppress such unnecessary re-recording as much as possible. On the other hand, in the case of so-called certified recording, such as when setting the recording laser power, accurate recording / reproduction is required, so it is better to eliminate the adverse effect of the DC component rather than the power consumption.

Therefore, the present invention solves this problem,
An object of the present invention is to provide an information recording device and an information recording method capable of suppressing the superimposition of the DC component and the low frequency component at the same time while suppressing the power consumption.

[0013]

In view of the above problems, the present invention has the following features.

According to a first aspect of the present invention, in an information recording apparatus for recording information on a recording medium, a start detecting means for detecting the start of a non-user area, a recording limiting means for stopping the recording of information, and a reproduction signal. D for detecting the superimposed DC level
C level detection means, DC level comparison means for determining whether the detected DC level exceeds a predetermined threshold value, and pattern data recording means for recording pattern data for suppressing the DC level, During the predetermined period from the start of the non-user area, the recording limiting unit stops the recording of information, and the DC level detecting unit detects the DC level superimposed on the predetermined period. After the predetermined period, the DC level is detected. By the DC
When the level exceeds the threshold value, the pattern data recording means records the pattern data in the non-user area.

According to a second aspect of the invention, in the information recording apparatus according to the first aspect, the pattern data recording means is D
DC free pattern recording means for recording DC free pattern data without C level superimposition, and pattern data recording for the non-user area is performed by recording DC free pattern data by the DC free pattern recording means. An information recording device characterized by.

According to a third aspect of the present invention, in the information recording apparatus according to the first aspect, the pattern data recording means is a DC bias pattern recording means for recording a data pattern having a biased DC level, and a DC level superposition. Not DC
DC free pattern recording means for recording free pattern data, and pattern data recording to the non-user area is performed by the DC bias pattern recording means.
After recording the C-weighted pattern, the DC free pattern recording means records the DC free pattern data.

According to a fourth aspect of the invention, in the information recording apparatus according to any one of the first to third aspects, when the DC level does not exceed the threshold value due to the DC level,
It is characterized in that the pattern data is recorded in the non-user area by the pattern data recording means only in the end portion of the non-user data area.

According to a fifth aspect of the invention, in an information recording apparatus for recording information on a recording medium, a start detecting means for detecting the start of a non-user area, a recording limiting means for stopping the recording of information, and a reproduction signal. The recording discriminating means discriminates whether or not information is recorded based on the recording data, and the pattern data recording means for recording pattern data for suppressing the DC level. The recording is performed for a predetermined period from the start of the non-user area. The limiting means stops the recording of information, and the recording discriminating means discriminates whether or not the information is recorded in the non-user data area. After the predetermined period, the recording discriminating means records information in the non-user data area. When it is determined that the pattern data has not been recorded, the pattern data recording means writes the pattern data in the non-user area. Recorded, characterized in that.

According to a sixth aspect of the present invention, in the information recording apparatus according to the fifth aspect, when the recording discriminating means discriminates that the information is recorded in the non-user data area, the non-user data is recorded. Only at the end of the area,
The pattern data recording means records the pattern data in the non-user area.

According to a seventh aspect of the invention, in an information recording method for recording information on a recording medium, a recording limiting step of limiting recording for a predetermined period after the start of the non-user area, and a predetermined period after the start of the non-user area. A DC level detecting step of detecting a DC level superimposed on a reproduction signal during a period of, and a DC level comparing step of determining whether or not the detected DC level exceeds a predetermined threshold after the predetermined period has elapsed, When it is determined that the detected DC level exceeds the threshold value, the D level is determined based on the DC level.
It is characterized by including a data pattern setting step of setting a recording data pattern for suppressing the C level and a data pattern recording step of recording the set recording data pattern in the non-user area.

According to an eighth aspect of the present invention, in the information recording method according to the seventh aspect, when it is determined that the detected DC level does not exceed the threshold value, the end portion of the non-user data area. Only, the pattern data for suppressing the DC level is recorded.

According to a ninth aspect of the present invention, in an information recording method for recording information on a recording medium using a laser beam, the laser power is set to a reproduction laser power for a predetermined period after the start of the non-user area. A limiting step; a DC level detecting step of detecting a DC level to be superimposed on a reproduction signal in a predetermined period after the start of the non-user area based on a reproduction signal reproduced by the beam of the reproduction laser power; A DC level comparing step of determining whether the DC level exceeds a predetermined threshold value, and, if it is determined that the detected DC level exceeds the threshold value, the D level is determined based on the DC level.
A data pattern setting step of setting a recording data pattern for suppressing the C level; a laser power returning step of returning the laser beam to the recording laser power;
A data pattern recording step of recording the set recording data pattern in the non-user area.

According to a tenth aspect of the present invention, in the information recording method according to the ninth aspect, when it is determined that the detected DC level does not exceed the threshold value, the setting of the reproduction laser power is continued. Then, after that, at the timing when the end portion of the non-user area is reached, the laser beam is returned to the recording laser power and D is applied to the non-user area.
The pattern data for suppressing the C level is recorded.

According to an eleventh aspect of the present invention, in an information recording method of recording information on a recording medium, a recording limiting step of limiting recording for a predetermined period after the start of the non-user area, and the non-recording step based on a reproduction signal. A recording determination step of determining whether information is recorded in the user area, and pattern data for suppressing the DC level when it is determined that information is not recorded in the non-user area is used for the predetermined period. And a pattern data recording step of recording in the non-user area after a lapse of time.

According to the twelfth aspect of the invention, in the information recording method according to the eleventh aspect, when it is determined that the information is recorded in the non-user area, the end portion of the non-user area is reached. The pattern data for suppressing the DC level is recorded at the end portion of the non-user area at the timing.

The invention of claim 13 is an information recording method for recording information on a recording medium using a laser beam,
A laser power limiting step of setting the laser beam to a reproduction laser power for a predetermined period after the start of the non-user area, and a recording determination step of determining whether or not information is recorded in the non-user area based on a reproduction signal. When it is determined that information has not been recorded in the non-user area, the laser beam is switched to the recording laser power, and pattern data for suppressing the DC level is applied to the non-user area after the predetermined period has elapsed. And a pattern data recording step of recording the pattern data.

In the fourteenth aspect of the invention, when it is determined in the thirteenth aspect that information is recorded in the non-user area, the setting of the reproduction laser power is continued, and thereafter the non-user area is set. Information recording, characterized in that pattern data for suppressing the DC level is recorded in the non-user area by returning the laser beam to the recording laser power at the timing when the end portion of the user area is reached.

The invention of claim 15 is the invention of claims 8, 10, and 1.
In any one of 2 and 14, the DC free pattern data in which the DC level is not superimposed is recorded in the end portion of the non-user data area.

In each of the above claims, the "non-user area" is such that data recording / reproduction is not originally performed such as the address area, the fine clock mark area, and the defect area described in the above-mentioned section of the prior art. A region. The "DC level" is the level of the DC component that is superimposed on the reproduction signal. In addition, "biased DC
"Pattern data having levels" is, for example, 000 ...
, Or continuous data of 111 ..., By recording the data, positive or negative DC component is superimposed on the reproduced signal.

Further, the "DC free pattern data" is data in which a direct current component is not superposed or hardly superposed on a reproduced signal depending on the recording of the data. Such "DC free pattern data" may generally be "10101010 ..." As long as it is a data pattern in which logic levels having a predetermined length are alternately opposite.
, "11001101100 ...", "111
"0001111000 ..." And so on. In addition, even if the data patterns having the predetermined length are not the opposite logic patterns alternately, "100001000001000 ..."
The data pattern may be such that "1" is recorded at a predetermined interval as described above. In this case, in general,
The interval between "1" and "1" may be set shorter than the maximum length of the digital modulation method.

The features of the present invention will be further clarified by the following description of the embodiments.

The "start detecting means" in the claims mainly corresponds to the address detecting circuit 105 in the embodiment. The "recording limiter" in the claims mainly corresponds to the timing generation circuit 115 in the embodiment. The "DC level detecting means" in the claims corresponds to the DC level calculating unit 121 in the embodiment. The “DC level comparing means” in the claims corresponds to the DC level comparing unit 126 in the embodiment. The "pattern data recording means" in the claims is the first in the embodiment.
Pattern generating circuit 120, second pattern generating circuit 1
19 and the selector circuit 122 mainly correspond. The "DC bias pattern recording means" in the claims mainly corresponds to the second pattern generating circuit 119 and the selector circuit 122 in the embodiment. “D” in the claims
The “C free pattern recording means” is the first in the embodiment.
The pattern generation circuit 120 and the selector circuit 122 of FIG.

The "recording restriction step" in the claims corresponds to step S201 in the embodiment. The "DC level detecting step" in the claims corresponds to step S202 in the embodiment. The “DC level comparison step” in the claims corresponds to step S204 in the embodiment. The “data pattern setting step” in the claims corresponds to steps S206 and S207 in the embodiment. The “pattern data recording step” in the claims corresponds to step S206 and step S207 in the embodiment.
The “laser power limiting step” in the claims corresponds to step S201 in the embodiment. The “laser power restoration step” in the claims corresponds to step S205 in the embodiment. The "recording determination step" in the claims is step S204 in the embodiment.
Corresponds.

However, the following embodiment is merely one embodiment of the present invention, and the meanings of the terms of the present invention and each constituent element are limited to those described in the following embodiment. Not something.

[0035]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

First, the structure of the magneto-optical disk will be described with reference to FIG. The magneto-optical disk 100 has frames (frames), which are recording units, arranged at equal intervals, and each frame has 39 segments (Segm).
ent) S0, S1, S2, ... S38.

The magneto-optical disk 100 has a planar structure in which the grooves 1 and the lands 2 are alternately formed in the radial direction, and the grooves 1 and the lands 2 are arranged spirally or concentrically. And the length of each segment is 532
It is a DCB (Data Channel Bit), and a fine clock mark (FC) indicating phase information of a clock for recording and reproducing data is provided at the beginning of each segment.
M: Fine Clock Mark) 3 is formed. The fine clock mark 3 is provided with lands having a constant length at a constant interval in the groove 1 and a land 2
It is formed by providing a groove having a constant length at regular intervals. Then, in the segment S0 which is the head of the frame, following the fine clock mark 3, the address information (Ad
are pre-formatted by the wobbles 4, 5, 6, 7, 8, 9 when the magneto-optical disc 100 is manufactured.

The wobble 4, wobble 5, wobble 6, wobble 7, and wobble 8, wobble 9 are formed on the opposite walls of the groove 1 and have the same address information recorded therein. By this, the magneto-optical disk 1
Even when the laser beam is shifted from the center of the groove 1 or the land 2 due to the tilt or the like at 00, the address information can be accurately detected by the wobble formed on any wall surface.

The area in which the address information is recorded and the area in which the fine clock mark 3 is formed are not used as an area for recording user data. The segment Sn is composed of the fine clock mark 3 and the user data UserData n-1.

Next, the detailed structure of each segment will be described with reference to FIG. Of the segments S0, S1, S2, ..., S38 that compose the frame, the segment S0 is a preformatted address segment on the magneto-optical disk 100, and the segments S1 to S38 are reserved as user data recording areas. Data segment.

The segment S0 is composed of a fine clock mark area FCM of 12 DCB and an address (Address) of 520 DCB. Further, the segment S1 is a fine clock mark area F of 12 DCB.
CM, 4DCB Pre-Write, 320DCB
Header, 190DCB Data and 4DC
B-Post-Write. Further, each segment from the segment S2 to the segment S38 has a fine clock mark area FCM of 12 DCB.
And 4DCB Pre-Write, 512DCB D
ATA and Post-Write of 4DCB.

Here, Pre-Write indicates writing of data, and is composed of, for example, a predetermined pattern "0011". Also, Post-Wri
te indicates the end of data, and is composed of, for example, a predetermined pattern “1100”.

Further, the user data area of the segment S1 is provided with a header (Header) which is a fixed pattern for confirming the position of data at the time of reproduction, phase compensation of the reproduction clock, adjustment of laser power and the like. The fixed pattern recorded in the header is a pattern in which the direct current component is suppressed (referred to as a "DC-free pattern", the same applies below)
For example, 2T domains formed in a predetermined number at 2T intervals and 8T domains formed in a predetermined number at 8T intervals are recorded.

Then, phase compensation is performed by adjusting the sampling timing of the analog signal obtained by reproducing the 2T domain so as to match the phase of the clock used for recording and reproducing data. Further, the 2T domain and the 8T domain are reproduced, and the laser power is adjusted so that the ratio of the reproduction signal intensity of the 2T domain to the reproduction signal intensity of the 8T domain becomes 50% or more. Also, the position of the data at the time of reproduction is confirmed by reproducing the 8T domain and confirming that the position of the digital signal obtained by binarizing the reproduction signal matches the position of the digital signal of the 8T domain predicted in advance. To do. Furthermore, Pre-
Write, Post-Write, and Head
Each pattern of r is recorded continuously with the user data when recording the user data.

Next, the configuration of the data recording / reproducing apparatus according to the embodiment will be described with reference to FIG.

The data recording / reproducing apparatus 200 includes a spindle motor 101, an optical pickup 102, a fine clock mark detection circuit (FCM detection circuit) 103, and a P
LL circuit 104, address detection circuit 105, BPF
106, an AD converter 107, and a waveform equalization circuit 108
, Viterbi decoding circuit 109, and unformat circuit 1
10, a data demodulation circuit 111, and a BCH decoder 11
2, a header detection circuit 113, and a controller 114
, Timing generation circuit 115, and BCH encoder 1
16, a data modulation circuit 117, and a format circuit 1
18, the second pattern generation circuit 119, the first pattern generation circuit 120, the DC level calculation unit 121, the selector circuit 122, the magnetic head drive circuit 123, the laser drive circuit 124, and the magnetic head 125. Equipped with.

The spindle motor 101 rotates the magneto-optical disk 100 at a predetermined rotation speed. Optical pickup 1
Reference numeral 02 irradiates the magneto-optical disk 100 with laser light and detects the reflected light. The FCM detection circuit 103 detects a fine clock mark detection signal (FCMT) indicating the position of the fine clock mark 3 based on a signal (TPP) detected by the optical pickup 102 from the fine clock mark 3 of the magneto-optical disk 100 by the tangential push-pull method. ) Is detected. Then, the detected fine clock mark detection signal (FCMT) is sent to the PLL circuit 104.
To the timing generation circuit 115.

The PLL circuit 104 includes the FCM detection circuit 10
A clock (CK) is generated based on the signal (FCMT) output from the circuit 3, and the generated clock (CK) is output to each circuit such as the address detection circuit 105 and the AD converter 107.

The address detection circuit 105 inputs the address signal (ADA) detected by the optical pickup 102 from the segment S0 of the magneto-optical disk 100 by the radial push-pull method and synchronizes with the clock (CK) input from the PLL circuit 104. Address information (AD) is detected. It also generates an address synchronization signal (ADR) synchronized with the detection of the address signal. Then, the detected address information (AD) is output to the controller 114, and the generated address synchronization signal (ADR) is output to the header detection circuit 113.
To the timing generation circuit 115.

The BPF 106 removes the high frequency band and the low frequency band of the reproduction signal (RF) reproduced from the magneto-optical disk 100.
The AD converter 107 converts the reproduction signal (RF) from an analog signal into a digital signal in synchronization with the clock (CK) from the PLL circuit 104. The waveform equalization circuit 108
The reproduced signal (RF) converted into a digital signal in synchronization with the clock (CK) from the PLL circuit 104 is PR.
(1, 1) Waveform equalization is performed. That is, the data before and after the detection signal is equalized so that waveform interference occurs on a one-to-one basis.

Further, the Viterbi decoding circuit 109 converts the reproduction signal (RF) from multi-value to binary in synchronization with the clock (CK) from the PLL circuit 104, and the converted binary reproduction signal is unformatted. 110 and the head detection circuit 113.

The unformat circuit 110 is a pre-write circuit recorded in the user data area of the magneto-optical disk 100 from the header detection circuit 113.
Using post-write (Post-Write) and header timing as input, the pre-write (Pre-Write) and post-write (Post-W) are performed from the binary reproduction signal in synchronization with the clock (CK) from the PLL circuit 104.
write) and the header are removed.

The data demodulation circuit 111 is the PLL circuit 10
The unformatted binary reproduction signal is input in synchronization with the clock (CK) from 4 and demodulation for canceling the digital modulation performed at the time of recording is performed. BCH decoder 1
Reference numeral 12 performs error correction on the demodulated reproduction signal and outputs it as reproduction data.

The header detection circuit 113 is the controller 1
The position of the header included in the reproduction signal is detected based on the address information input from the address register 14 and the address synchronization signal (ADR) input from the address detection circuit 105, and the PLL
Pre-write (Post-Write), post-write (Post-Write), and header timing signals are generated from the reproduction signal in synchronization with the clock (CK) from the circuit 104. Then, the generated timing signal of the header is output to the unformat circuit 110 and the data demodulation circuit 111.

The controller 114 inputs the address information (AD) detected by the address detection circuit 105 and controls a servo mechanism (not shown) based on the address information (AD) to access the optical pickup 102 to a desired position. The address information (AD) is sent to the header detection circuit 113 in synchronization with the clock (CK) from the PLL circuit 104.
And the timing generation circuit 115 is controlled.

The timing generation circuit 115 receives the DC level measurement window signal DCE based on the address synchronization signal ADR and the like.
Various timing signals such as N, write pattern selection signal WSEL, magnetic head drive window signal WMEN, recording laser power window signal WPEN, etc. are generated.

The BCH encoder 116 adds an error correction code to the recorded data. The data modulation circuit 117 modulates the recording data in a predetermined method. Format circuit 1
Reference numeral 18 synchronizes with the clock (CK) from the PLL circuit 104, and prewrites (Pre-Write) to the recording data based on the timing signal from the timing generation circuit 115.
e), header, and post light (Post-Wri
te) is added to format the recording data in the user data area, and the formatted data (W
FMT) is output to the selector circuit 122.

The first pattern generation circuit 120 generates the DC free pattern data WPT1 which is a fixed pattern in which the DC component is suppressed and outputs it to the selector circuit 122. The second pattern generation circuit 119 generates a data pattern WPT2 in which the DC level is biased to the positive side and a data pattern WPT3 in which the DC level is biased to the negative level, and outputs the data pattern WPT3 to the selector circuit 122. For example, set WPT2 to the power supply level,
WPT3 may be directly connected to the ground level.

The selector circuit 122, on the basis of the timing signal (WSEL) from the timing generation circuit 115, the various data WFMT, WPT1, WPT2,
Any one of WPT3 is selected and output to the magnetic head drive circuit 123.

The magnetic head drive circuit 123 drives the magnetic head 125 based on the output from the selector circuit 120 in synchronization with the timing signal from the timing generation circuit 115. The laser drive circuit 124 drives a semiconductor laser (not shown) in the optical pickup 102 based on the timing signal from the timing generation circuit 115. The magnetic head 125 applies a magnetic field magnetically modulated by the recording data or the data pattern to the magneto-optical disk 100 based on the drive from the magnetic head drive circuit 123.

The DC level calculation circuit 121 synchronizes the reproduction DC level DCLV in the address area with AD10 in synchronization with the timing signal from the timing generation circuit 115.
It is calculated based on the reproduced data from 7. The calculation may be performed by any method as long as the DC level can be measured, and for example, averaging calculation or the like can be adopted. The calculated DC level DCLV is output to the timing generation circuit 115 and referred to for generating the various timing signals.

Next, the configuration and operation of each section in the recording / reproducing apparatus will be described.

A method of detecting address information, a fine clock mark, and a magneto-optical signal from the magneto-optical disk 100 will be described with reference to FIG. Wobble 4,
An area 10 in which 5, 6, 7 and the fine clock mark 3 are formed, and an area 30 in which the fine clock mark 3 is formed constitute a preformatted area which is preformatted when the magneto-optical disc 100 is manufactured, and user data The area 20 in which is recorded constitutes a user data area.

The photodetector 1020 in the optical pickup 102, which irradiates the magneto-optical disk 100 with the laser beam LB and detects the reflected light, has six detection areas 1020A and 1020A.
20B, 1020C, 1020D, 1020E, 102
It has 0F. Of these six detection areas, area A1
020A and area B1020B, area C1020C and area D1020D, and area E1020E and area F1020.
F is arranged in the track direction DR1 of the magneto-optical disk,
Area A1020A, Area C1020C, Area B1020
B and the area D1020D are arranged in the tracking direction DR2 of the magneto-optical recording medium. Therefore, the area A10
20A, a region B1020B, a region C1020C, and a region D1020D detect the reflected light in the A region, B region, C region, and D region of the laser light LB irradiated on the magneto-optical disk, respectively.

The areas E1020E and F1020F are
A polarization plane obtained by diffracting the laser light reflected by the entire A area, B area, C area, and D area of the laser light LB into two directions having different polarization planes by a Wollaston prism (not shown) in the optical pickup 102. Of different laser beams are detected.

The reproduction signal RF of the magneto-optical signal recorded in the area 20 which is the user data area has the laser light intensity [E] detected in the area E1020E of the photodetector 1020 and the laser light intensity [E] detected in the area F1020F. It is detected by calculating the difference with F]. That is, the difference detector 400 detects the laser light intensity [E] and the region F detected in the area E1020E.
The difference from the laser light intensity [F] detected at 1020F is calculated, and the reproduction signal RF = [E] − [F] is output.

Further, the reproduction signal of the address information recorded in the wobbles 4, 5, 6, 7 of the area 10 constituting the preformatted area is detected by the radial push-pull method, and the laser light intensity detected in the area A1020A [ A]
And the sum of the laser light intensity [B] detected in the area B1020B and the laser light intensity [C] detected in the area C1020C and the laser light intensity [D] detected in the area D1020D. To be detected.

That is, the address information is detected by the adders 500 and 501 and the subtractor 502 which form the circuit 50. The adder 500 outputs [A + B] obtained by adding the laser light intensity [A] detected in the area A1020A and the laser light intensity [B] detected in the area B1020B, and the adder 501 detects the light in the area C1020C. The obtained laser light intensity [C] and the laser light intensity [D] detected in the area D1020D are added to output [C + D]. Then, the subtractor 502 subtracts the output [C + D] of the adder 501 from the output [A + B] of the adder 500 and outputs a reproduction signal RPP = [A + B]-[C + D] of address information.

The fine clock mark FCM of the area 30 which constitutes the preformatted area is detected by the tangential push-pull method, and the area B1020 is detected.
Laser light intensity [B] detected in B and area D1020D
Area A10 from the sum with the laser light intensity [D] detected in
Laser light intensity [A] detected at 20 A and area C102
It is detected as a value obtained by subtracting the sum with the laser light intensity [C] detected at 0C.

That is, the fine clock mark is the circuit 5
It is detected by the adders 503 and 504 and the subtractor 505 which form 0. The adder 503 outputs [B + D] obtained by adding the laser light intensity [B] detected in the area B1020B and the laser light intensity [D] detected in the area D1020D, and the adder 504 detects the light in the area A1020A. The obtained laser light intensity [A] and the laser light intensity [C] detected in the region C1020C are added to output [A + C].
Then, the subtractor 505 outputs the output of the adder 503 [B +
The output [A + C] of the adder 504 is subtracted from D] to reproduce the fine clock mark reproduction signal TPP = [B + D] −.
Outputs [A + C].

With reference to FIG. 5, the structure of the PLL circuit 104 constituting the data recording device 200 shown in FIG. 3 will be described.

The PLL circuit 104 is the phase comparison circuit 104.
1, LPF 1042, VCO 1043, 1/53
And a frequency divider 1044. 1/532 frequency divider 104
Reference numeral 4 divides the clock (CK) output from the voltage controlled oscillator (VCO) 1043 into 1/532. The phase comparator 1041 compares the phase of the clock (CK1) divided by the 1/532 frequency divider 1044 with the phase of the fine clock mark detection signal FCMT, and generates an error voltage according to the phase difference. Therefore, this PLL circuit 104
Is synchronized with the fine clock mark detection signal FCMT and is 1/5 of the fine clock mark detection signal FCMT.
A clock (CK) having a period of 32 is generated.

The detection of the fine clock mark FCM and the generation of the clock (CK) will be described with reference to FIG.

Photodetector 102 in optical pickup 102
0 detects the fine clock mark signal (TPP) by the tangential push-pull method as described with reference to FIG. The fine clock mark signal (TPP) is input to the FCM detection circuit 103.

The FCM detection circuit 103 generates a pulse signal (FCMP) synchronized with a point P (located at the center of the fine clock mark 3) at which the polarity of the input fine clock mark signal (TPP) changes, and generates a pulse. A fine clock mark detection signal (FCMT) synchronized with the rising edge of each pulse component of the signal (FCMP) is generated.

In the fine clock mark signal (TPP) of FIG. 6, the laser light is the groove 1 of the magneto-optical recording medium.
The fine clock mark signal detected when traveling on the land 2 has been described, but when the laser light travels on the land 2, only the polarity of the fine clock mark signal detected changes and the point P does not change. When traveling with laser light, pulse signal (FCMP),
And a fine clock mark detection signal (FCMT) can be generated.

The fine clock mark detection signal (FCMT) detected by the FCM detection circuit 103 is input to the PLL circuit 104. Then, as described with reference to FIG. 6, the fine clock mark detection signal (F
A clock (C) which is synchronized with CMT) and which is obtained by dividing the fine clock mark detection signal (FCMT) by 1/532.
K) is generated.

Referring to FIG. 7, address detection circuit 105
Detection of address information and generation of an address detection signal will be described.

The optical pickup 102 detects the address signal (RPP) recorded by wobble by the radial push-pull method as described with reference to FIG. 4, and the address signal (RPP) is input to the address detection circuit 105. It The address detection circuit 105 uses the address signal (RP
P) is binarized to generate a binarized signal (ADD), and the address information (AD) is detected based on the binarized signal (ADD).

By the way, as described with reference to FIG. 4 above, the method of reproducing the data recorded in the area 20 which is the user data area and the method of reproducing the areas 10 and 30 forming the pre-format area are Different from each other. Therefore, considering that the data is reproduced from the area 20, it corresponds to that no data is recorded in the areas 10 and 30, and the data recorded in the area 20 is reproduced intermittently. As a result, when the data is reproduced from the area 20 following the area 10, the data is reproduced from the area 20 following the area where the data is not reproduced, so that a DC component is superimposed on the reproduced signal, which makes accurate reproduction difficult. Become. this is,
The same applies when reproducing data from the area 20 following the area 30.

Therefore, in the present embodiment, the area 1
Data is recorded in the areas 0 and 30 by the same method as the method of recording data in the area 20. As a result, the data can be reproduced from the areas 10 and 30 by the same method as that of the area 20, and thus, when the data is reproduced from the area 20, the DC component is not superimposed on the reproduction signal.

However, if data is uniformly recorded in all the sections of the areas 10 and 30, the beam must be continuously emitted with the recording laser power during the scanning of the area. However, since the regions 10 and 30 frequently appear on the grooves and lands as described above, if data is uniformly and unconditionally recorded in all the sections of the regions 10 and 30, it is consumed when scanning the regions. The total amount of power consumed will be quite large. In particular,
Since the area 10 has a long scanning section, if the DC free pattern is recorded during the entire period, a considerable amount of power will be consumed.

Therefore, in this embodiment, the regions 10 and 3 are
In the area 0, the data is not unconditionally recorded in the entire area in the area 10, and the data is recorded only in the area which is sufficient and minimum so that the DC component is not superimposed on the reproduced signal from the area 20. To suppress the increase in power consumption. That is, data is recorded in the area 10 only for a certain section before entering the area 20. In addition, such data recording is
DC free pattern data W from the pattern generation circuit of
PT1 and data WPT from the second pattern generation circuit
2 or WPT3.

DC free pattern data is recorded in the area 30 which is a fine clock mark area.
However, the same applies to the area 30 as in the area 10.
The recording of the DC free pattern is partially limited to the area 20.
Data may be recorded only in a certain section immediately before.

In FIG. 8, area 10 (non-user data area)
The data recording method for the above is conceptually shown. As shown, the DC free pattern data WPT1 is recorded in the section C immediately before the data area. Further, in the section B before the section C, the data WPT2 or WPT3 having a biased DC level is recorded. Whether the recording data in the section B is the data WPT2 or WPT3 is determined depending on which of the plus and minus DC components is superimposed on the reproduction signal in the preceding section A. That is,
If the positive DC component is superimposed, WPT3 is recorded, and if the negative DC component is superimposed, WPT2 is recorded. This cancels the superimposed DC component.

In section A, the laser intensity is set to about the reproduction power. Then, in the section A, the data is not recorded, and the DC component superimposed on the reproduction signal is detected by the DC level calculation circuit 121. Then, according to the detection result, the timing generation circuit 115
Selects either data WPT2 or WPT3,
This is recorded in section B. By such data recording, the reproduced signal distorted due to the superposition of the DC component in the section A is shifted to the normal reproduced signal level. After that, the DC free pattern is recorded in the section C to suppress the superposition of the DC component. The recording of the DC free pattern also serves as run-up recording for stabilizing the recording laser power in the user data area.

The lengths of the section B and the section C are set to the most preferable lengths by repeating recording and reproduction on the disc and examining and analyzing the actual measurement results. Usually, the length of the section obtained by adding the section B and the section C is such that a distorted reproduction signal is raised to a normal reproduction signal level by subsequent reproduction of the user data area when no data is recorded in the non-user data area. It is sufficient to set the section to the same extent as or a little shorter than the necessary section.

Next, the operation of the recording / reproducing apparatus will be described.

First, the operation during reproduction will be described. R output from the optical pickup 102 during reproduction
The F signal is processed as described above by the reproduction system from the BPF 106 to the BCH decoder 112. This allows
Reproduced data is generated and output to a subsequent circuit (not shown). At the same time, the radial push-pull signal from the optical pickup is input to the address detection circuit 105, whereby address data (AD) and address synchronization signal (ADR) are generated and output.

Further, the tangential push-pull signal from the optical pickup is input to the FCM detection circuit 103, which produces a fine clock mark detection signal (FCMT). The fine clock mark detection signal (FCMT) is input to the PLL circuit 104, which generates a clock signal. The clock signal is used as a reproduction clock in each unit.

Next, the recording operation will be described. The recording data is added with error correction by the BCH encoder 116, and then modulated by the data modulation circuit 117 into a predetermined modulation method. Then, format circuit 1
At 18, the prewrite data and the like are added and input to the selector circuit 122. Also, such recording data WSE
Together with L, the selector circuit 122 has the first pattern generating circuit 120 or the second pattern generating circuit 119.
From, the pattern data WPT1, WPT2, WPT3 are respectively input.

The selector circuit 122 selects any one of these input data at the timing when the recording position on the magneto-optical disk reaches a predetermined position and outputs it to the magnetic head recording circuit 123. As a result, the recording data WFMT or the pattern data WPT1, WPT2, W is recorded on the groove or land of the magneto-optical disc 100.
Any of PT3 is recorded.

Such timing control is performed according to the timing signal WSEL from the timing generation circuit 115. That is, the timing generation circuit 115 has the segment 1 (S1) to the segment 38 (S) shown in FIG.
38) user data area (User Data n-)
The recording data WFMT is recorded in 1), and any of the pattern data WPT1, WPT2, and WPT3 is recorded in the address area (Address) of the segment 0 (S0), and the segment 1 (S1) to the segment 38 (S38). ) FCM area 3 has a data pattern WP
The timing signal WSEL is output to the selector circuit 122 so that T1 is recorded.

FIG. 9 shows a timing chart of various signals when data is recorded in the address area. In addition,
For convenience of explanation, the timing chart in the FCM section is not shown.

On the basis of the address synchronization signal ADR from the address detection circuit 105, the timing generation unit 115 causes the DC
The level measurement window signal DCEN is generated. Upon receiving the DC level measurement window signal DCEN, the DC level calculation unit 12
1 calculates the reproduction DC level in the section where the DC level measurement window signal DCEN is High, and the reproduction DC level DCL at the same time when the DC level measurement window signal DCEN becomes Low.
Output as V.

Further, the timing generating circuit 115 has a DC-free data pattern WPT1, data patterns WPT2, W having a DC level biased to plus or minus.
PT3 and formatted recording data WFMT
A write pattern selection signal WSEL for selecting any one of them as the recording data WDAT is output.

During the write pattern selection signal WSEL,
"X" from timing t1 to timing t2 indicates that none of the data patterns WPT2, WPT3 and the recording data WFMT is selected. Further, "WPT2orWPT3" from t2 to t3 is the data pattern WPT.
Indicates that either 2 or WPT3 is selected. Whether the data pattern WPT2 or WPT3 is selected depends on the reproduction D from the DC level calculation unit 121 as described above.
Determined by C-level DCLV. Further, “WPT1” from t3 to t4 indicates that the DC-free data pattern WPT1 is selected.

The timing generator 115 also generates a magnetic head drive window signal WMEN and a laser drive window signal WPEN in synchronization with the write pattern selection signal WSEL. Driving of the magnetic head is prohibited while the magnetic head drive window signal WMEN is Low. Also, the laser drive window signal W
In the PEN, the reproduction laser power is set from the timing t1 to the timing t2, and the recording laser power is set from the timing t2.

The magnetic head 12 is driven by the magnetic head drive window signal WMEN and the laser drive window signal WPEN.
5 and the drive of the optical pickup 102 are controlled. In combination with the selection control by the write pattern selection signal WSEL, the timing t1 to t in the address area.
During the period of 2, the reproduction by the reproduction laser power is executed and t
DC biased positive or negative during the period from 2 to t3
Recording of the data pattern WPT2 or WPT3 having a level is executed, and recording of the DC free pattern WPT1 is executed during the period from t3 to t4.

Incidentally, the timings t1 and t shown in the figure
Reference numeral 4 is synchronized with the address synchronization signal ADR, and timings t2 and t3 are timings experimentally determined based on the reproduction DC level DCLV.

FIG. 10 shows a flowchart of the above recording operation. When the recording operation is started, the print data WFMT is printed in step S103 until the FCM area or the address area is detected in steps S101 and S102.
Is selected and recorded. FCM in step S101
When the area is detected, the process proceeds to step S111, and the DC free pattern WPT1 is selected and recorded.

When the start of the address area is detected in step S102, the laser power is switched to the reproduction power in step S104. And step S1
At 05, the calculation of the DC level based on the reproduction signal is started. This calculation is performed until it is detected in step S106 that time t2 has elapsed from the start of the address area. Then, when the elapse of the time t2 is detected, the calculation result of the DC level is referred to in step S107, and the data pattern WPT having the DC level biased to plus or minus based on the calculation result of the DC level.
Either 2 or WPT3 is selected.

Then, in step S108, the laser power is set to the recording laser power, and in step S109
, One of the selected data patterns (WPT
2 or WPT 3) recording is started. This recording is performed at time t from the start of the address area
This is performed until it is detected that 3 has elapsed.

However, when the elapse of the time t3 is detected,
In step S111, recording of the DC free pattern WPT1 is started. Such recording is performed until the start of the user area is detected in step S112. Thereafter, when the start of the user area is detected, step S10
Returning to 1, the same operation as above is repeated.

In the above embodiment, the data pattern WPT2 or WPT3 having a DC level biased toward plus or minus and the DC free pattern WPT1 are recorded in the address area.
It is also possible to record only the data pattern WPT2 or WPT3 having a DC level biased to plus or minus or only the DC free pattern WPT1 in the address area.

FIG. 11 shows a data pattern WPT2 or WPT having a positive or negative biased DC level.
The flowchart in the case of recording only 3 is shown. In addition,
The same step numbers are attached to the same steps as those in FIG.

When the start of the address area is detected in step S102, the laser power is switched and the DC level is calculated in steps S104 and S105 as described above. Then, when it is determined in step S120 that t21 has elapsed from the start of the address area, either of the data patterns WPT2 or WPT3 is selected and recorded in steps S107 to S109 as described above. . On the other hand, in the FCM area, step S1
In 01 and S111, the DC free pattern is recorded.

According to this control flow, by recording the data pattern WPT2 or WPT3 in the address area, the distortion of the reproduced signal due to the superimposition of the DC level is gradually eliminated before reaching the user data area. Then, at the timing of reaching the user data area following the address area, the DC level superimposed on the reproduction signal is reduced to such an extent that reproduction is not hindered.

Incidentally, the timing t21 set in step S120 is the data pattern WPT after that.
It is experimentally set on the basis of the calculation result DCLV of the reproduction DC level so that the DC level of the reproduction signal can be sufficiently reduced by recording 2 or WPT3.

FIG. 12 shows a flowchart for recording only the DC free pattern WPT1 in the address area. The same steps as those in FIG. 11 have the same step numbers.

When the start of the address area is detected in step S102, the same as above, in step S104,
The laser power is switched. Then, when it is determined in step S130 that t22 has elapsed from the start of the address area, step S10 is performed as described above.
8, the DC free pattern is recorded in S111.

According to this control flow, the recording of the DC free pattern WPT13 in the address area gradually eliminates the distortion of the reproduced signal due to the superimposition of the DC level before reaching the user data area. Then, at the timing of reaching the user data area following the address area, the DC level superimposed on the reproduction signal is reduced to such an extent that reproduction is not hindered.

The timing t22 set in step S130 is the DC free pattern W after that.
It is experimentally set in advance so that the DC level of the reproduction signal can be sufficiently reduced by the recording of PT1.

By the way, in the above-mentioned embodiment, the data recording control is explained by taking the address area as an example. Similarly, the data having the DC level biased toward plus or minus is also applied to the defect area on the disk. Pattern WPT2 or WPT3 and DC free pattern WPT
1 and 1 may be sequentially recorded.

As described in the section of the prior art, the magneto-optical disk 100 may have a defect area in which user data cannot be recorded due to a loss. In such a case, the controller 114 shown in FIG. 3 uses the address information detected by the address detection circuit 105 and the DMA (Defect Management).
The defect frame is specified by the address information information of the defect frame recorded in Area) in advance. Then, the detection signal of the defect frame is output.

Therefore, by outputting the detection signal of the defect frame to the timing generation circuit 115, the timing generation circuit 115 can determine the section of the defect frame. Then, the timing generation circuit 115 sets the laser power to the reproduction laser power in response to the start of the defect frame on the basis of the defect frame detection signal, and sets the data pattern WPT2 or WPT3 at a predetermined timing, and A timing signal for recording the DC free pattern WPT1 is generated. As a result, similarly to the above, it becomes possible to record a data pattern capable of eliminating the superimposition of the DC level in the defect frame section.

Next, another embodiment obtained by improving the above embodiment will be described.

In this embodiment, the DC free pattern WPT1 or the data pattern with a biased DC level is not always recorded in the non-user data area. For example, when the DC free pattern is already recorded, etc. If the DC component from the non-user data area is smaller than the threshold value, the DC free pattern is recorded only immediately before the user data area.

In the case of so-called certified recording such as when the recording laser power is set, the DC free pattern is recorded in the entire non-user data area. That is, at the time of such certified recording, accurate recording / reproduction is required, so that the adverse effect of the DC component is eliminated rather than the aspect of power consumption.

FIG. 13 shows the structure of a recording / reproducing apparatus which realizes such an embodiment. The same parts as those of the recording / reproducing apparatus of FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted.

Compared to the recording / reproducing apparatus shown in FIG. 3, the DC level comparing unit 126 and MPU 127 are added in this embodiment. Here, the DC level comparison unit 126
The calculation result DCLV from the C level calculation unit 121 is the threshold value S
It is determined whether it is TDDC or more, and the determination result is output to the timing generation circuit 115. MPU 127 is DC
The threshold STDDC is supplied to the level comparing section 121, and an identification signal CERTIFY for identifying whether the recording is certified recording is supplied to the timing generating circuit 115.

When the timing generation circuit 115 determines that it is in the certify mode based on the identification signal CERTIFY, the DC free pattern is recorded in the entire address area. That is, the timing generation circuit 115
Causes the selector 122 to select the DC free pattern data WPT1 from the first pattern generation circuit 120 in synchronization with the start of the address area. This allows
Recording of DC free pattern data is started in the address area.

Thereafter, at the timing when the user data area is reached, the timing generation circuit 115 causes the selector circuit 122 to select the recording data WFMT from the format circuit 118. As a result, the DC free pattern is recorded in the entire address area.

Next, a normal recording operation will be described.

14 and 15 show timing charts of various signals during normal recording. First, FIG.
Is the calculation result DCLV from the DC level calculation circuit 121.
Is a timing chart when is equal to or more than the threshold value from MPU 127.

On the basis of the address synchronization signal ADR from the address detection circuit 105, the timing generator 115 outputs a DC signal.
The level measurement window signal DCEN is generated. The DC level calculation unit 121 calculates the reproduction DC level in the section where the DC level measurement window signal DCEN is High, and outputs the reproduction DC level DCLV at the same time when the DC level measurement window signal DCEN becomes Low.

The DC level comparison unit 126 compares the reproduction DC level DCLV with the threshold DC level STDDC given from the MPU 127, and outputs a comparison result CMPDC. Since the relationship of DCLV ≧ STDDC is established in this timing chart, the timing generation circuit 115
The comparison result CMPDC is received, and the data pattern WPT is received.
2 or WPT3 and DC free pattern WPT1 are recorded, and the formatted recording data W is recorded in the data area.
A write pattern selection signal WSEL for selecting the recording data WDAT so as to record the FMT is output.

The timing generator 115 also generates the magnetic head drive window signal WMEN and the laser drive window signal WPEN in synchronization with the write pattern selection signal WSEL.

The timings t1 and t shown in FIG.
3 is synchronized with the address synchronization signal ADR. The timing t2 takes into account the timing determined experimentally so that the reproduction DC level DCLV can be obtained with high accuracy, and further stable DC by recording the data pattern thereafter.
The timing is set so that reproduction can be performed. Such timing is experimentally determined by the actual measurement result.

Next, FIG. 15 shows a timing chart when the calculation result DCLV from the DC level calculation circuit 121 is less than the threshold value from the MPU 127.

In such a case, the timing generation circuit 115
Receives the comparison result CMPDC, records the data pattern WPT only in a short period in which the influence of the beam shift can be avoided in the address area, and records the formatted recording data WFMT in the data area. Light pattern selection signal WS to be selected
Output EL.

The timing generator 115 also generates the magnetic head drive window signal WMEN and the laser drive window signal WPEN in synchronization with the write pattern selection signal WSEL.

The timings t1 and t shown in the figure
3 is synchronized with the address synchronization signal ADR. The timing t2 is a timing that is experimentally determined so that the reproduction DC level DCLV can be accurately obtained. Further, t3 is a timing determined experimentally so that the influence of the beam shift can be avoided.

As can be seen from the above timing chart, the recording in the non-user data area is performed by calculating the DC level for a certain period from the start of the non-user data area, and the non-user data area is recorded based on the operation result. Determines the need for data recording. That is, if the calculation result is equal to or more than the threshold value, it is determined that data such as a DC free pattern is not recorded in the non-user data area, and the pattern data is recorded in the latter half portion thereof. If the DC level calculation result is less than the threshold value, it is determined that the DC free pattern or the like is recorded in the non-user data area, and the DC free pattern data is recorded only in a portion immediately before the user data area. To record.

In such a case, when the predetermined data is already recorded in the non-user data area, it is considered that it is not necessary to record any data in the non-user data area. However, in the above embodiment, even in such a case, the DC free pattern data is recorded only in a part immediately before the user data area. This is because if no data is recorded in the non-user data area, a beam shift occurs due to a sudden power change when the laser power is switched to the recording level in the user data area that follows,
This is because good recording may not be performed.

The beam shift will be described with reference to FIG. When the reproducing power changes to the recording power, the wavelength of the laser beam changes due to the rapid power change. When such a wavelength change occurs, the refractive index of the beam shaping prism changes, and the beam optical path changes from the solid line to the broken line, as shown in the figure. As a result, a deviation occurs at the light collecting point on the disc. A certain period of time is required until the servo follows the disturbance of tracking due to this deviation. Therefore, the follow-up period is
It becomes difficult to make accurate recordings.

For this reason, as described above, the DC free pattern is always recorded immediately before the user data area. That is, the recording of the DC free pattern serves as the run-up period for accurately recording the data in the user data area.

FIG. 17 shows a flowchart of the recording operation (in the normal recording mode) for the non-user data area.

When the non-user data area is reached, the laser power is set to the reproduction level in step S201,
In step S202, the DC level on the reproduced signal is calculated. Then, if it is determined in step S203 that t2 has elapsed from the non-user data area, then in step S204, it is determined whether the DC level calculation result DCLV is equal to or greater than the threshold STDDC. If the threshold value is exceeded, the laser power is set to the recording level in step S205. Then, in step S206, either WPT2 or WPT3 is selected based on the calculation result DCLV, and this is recorded for a certain period. Then, in step S207, the DC free pattern WPT1
Is selected and recorded until it reaches the user area.

On the other hand, in step S204, the calculation result D
If it is determined that CLV is less than the threshold value STDDC, the process proceeds to step S209, and it is determined whether t3 has elapsed from the non-user data area. If it is determined that t3 has elapsed, the laser power is set to the recording level in step S210, and the DC free pattern is recorded in step S207.

In the above embodiment, when the calculation result DCLV is greater than or equal to the threshold value STDDC, the WPT
Although the DC free pattern WPT1 is recorded after recording either 2 or WPT3, only the DC free pattern may be recorded from t2 instead.

According to the above embodiment, when the DC free pattern or the like is already recorded, the recording of the pattern data as in the previous embodiment is not performed and only a part immediately before the user data area is recorded. Since the DC free pattern is recorded, the power consumption can be further reduced as compared with the previous embodiment.

Although various embodiments according to the present invention have been described above, it goes without saying that the present invention is not limited to such embodiments and various modifications can be made.

For example, although the magneto-optical disk has been described as an example in the above embodiments, the present invention can be applied to other recording media for recording / reproducing information by the AC coupling method. Further, the recording medium in the above embodiment is
Although it has a groove and land structure, it is of course applicable to media having other track structures.

Further, in the above-mentioned embodiment, the DC free pattern is recorded in the FCM area as it is, but instead of this, the FC free pattern is recorded as in the above-mentioned embodiment.
It is also possible to record only the data pattern WPT2 or WPT3 in the M area and record both the data pattern WPT2 and the DC free pattern WPT1.

In addition, the non-user area is not limited to the FCM area, the address area, and the defect frame area, but can be variously changed according to the structure and data structure of each medium.

The embodiments of the present invention can be appropriately modified in various ways within the scope of the technical idea of the present invention.

[0148]

As described above, according to the present invention, the pattern data having a biased DC level or the pattern data for suppressing the DC level such as the DC free pattern is recorded in the non-user area. When reproducing such a non-user area, the direct current component is not superimposed on the reproduced signal,
Therefore, a good reproducing operation can be realized. In addition, since the pattern data is not recorded in the entire non-user area but the pattern data is recorded only in a portion immediately before the user area, when the DC free pattern data is recorded in the entire non-user area. In comparison, it becomes possible to significantly reduce the power consumed for recording in the non-user area.

As described above, according to the present invention, it is possible to simultaneously suppress the superposition of the DC component in the non-user area and reduce the power consumption.
It has a remarkable effect.

[Brief description of drawings]

FIG. 1 is a diagram showing a magneto-optical disk and a format thereof according to an embodiment.

FIG. 2 is a diagram showing a data format of a recording data string according to the embodiment.

FIG. 3 is a diagram showing a configuration of a recording / reproducing apparatus according to an embodiment.

FIG. 4 is a diagram showing a photodetector according to an embodiment and a signal generation method using the photodetector.

FIG. 5 is a diagram showing a configuration of a PLL circuit according to an embodiment.

FIG. 6 is a diagram showing a method of generating a clock signal according to the embodiment.

FIG. 7 is a diagram showing a method of generating address data according to the embodiment.

FIG. 8 is a diagram showing a recording concept of a non-user data area according to the embodiment.

FIG. 9 is a diagram showing a timing chart of various signals according to the embodiment.

FIG. 10 is a flowchart showing a recording operation according to the embodiment.

FIG. 11 is a flowchart showing another recording operation according to the embodiment.

FIG. 12 is a flowchart showing still another recording operation according to the embodiment.

FIG. 13 is a diagram showing a configuration of a recording / reproducing apparatus according to another embodiment.

FIG. 14 is a diagram showing a timing chart of various signals according to another embodiment.

FIG. 15 is a diagram showing a timing chart of various signals according to another embodiment.

FIG. 16 is a diagram for explaining the cause of beam shift.

FIG. 17 is a flowchart showing a recording operation according to the embodiment.

[Explanation of symbols]

102 optical pickup 105 address detection circuit 115 Timing generation circuit 119 Second pattern generation circuit 120 first pattern generation circuit 121 DC level calculator 122 selector circuit 124 Laser drive circuit

Claims (15)

[Claims] 1. An information recording apparatus for recording information on a recording medium, a start detecting means for detecting the start of a non-user area, a recording limiting means for stopping the recording of information, and a DC level superimposed on a reproduction signal. DC level detecting means for detecting the DC level, DC level comparing means for determining whether the detected DC level exceeds a predetermined threshold value, and pattern data recording means for recording pattern data for suppressing the DC level. Having a predetermined period from the start of the non-user area, while stopping the recording of information by the recording limiting unit, the DC level detection unit to detect the DC level superimposed in the predetermined period, after the predetermined period, When the DC level exceeds the threshold value due to the DC level, the pattern data recording means causes the non-user Recording the pattern data in the frequency band, the information recording apparatus characterized by. 2. The pattern data recording means according to claim 1, further comprising a DC free pattern recording means for recording DC free pattern data in which DC levels are not superimposed, and the pattern data recording for the non-user area is the DC. An information recording apparatus characterized by being recorded by recording DC free pattern data by a free pattern recording means. 3. The DC according to claim 1, wherein the pattern data recording means records a data pattern having a biased DC level.
The DC bias pattern recording unit includes a bias pattern recording unit and a DC free pattern recording unit that records DC free pattern data in which a DC level is not superimposed. The DC bias pattern recording unit records the DC bias pattern by the DC bias pattern recording unit. After that, the DC free pattern recording means records the DC free pattern data, and the information recording apparatus is characterized in that. 4. The pattern data recording means according to claim 1, wherein when the DC level does not exceed the threshold value due to the DC level, the pattern data recording means applies only to the end portion of the non-user data area. An information recording apparatus, wherein the pattern data is recorded in a non-user area. 5. An information recording apparatus for recording information on a recording medium, a start detecting means for detecting the start of a non-user area, a recording limiting means for stopping recording of information, and recording of information based on a reproduction signal. Recording determination means for determining whether or not the data is recorded, and pattern data recording means for recording pattern data for suppressing the DC level, and the recording restriction means stores information for a predetermined period from the start of the non-user area. When the recording is stopped, the recording discriminating means discriminates whether or not the information is recorded in the non-user data area, and after the predetermined period, the recording discriminating means records the information in the non-user data area. If it is determined that there is no, the pattern data recording means records the pattern data in the non-user area, Information recording apparatus characterized and. 6. The pattern data recording method according to claim 5, wherein when the recording determining means determines that information is recorded in the non-user data area, only the end portion of the non-user data area is recorded. An information recording apparatus, wherein the pattern data is recorded in the non-user area by means. 7. An information recording method for recording information on a recording medium, a recording limiting step of limiting recording for a predetermined period after the start of the non-user area, and a reproduction signal during a predetermined period after the start of the non-user area. A DC level detection step of detecting a DC level superimposed on the DC level, a DC level comparison step of determining whether the detected DC level exceeds a predetermined threshold value after the predetermined period has elapsed, and the detected DC level. Is determined to exceed the threshold, a data pattern setting step of setting a recording data pattern for suppressing the DC level based on the DC level, and the set recording data pattern in the non-user area. A pattern data recording step of recording, and an information recording method comprising: 8. The detected DC according to claim 7.
When it is determined that the level does not exceed the threshold value, pattern data for suppressing the DC level is recorded only in the end portion of the non-user data area, the information recording method. 9. An information recording method for recording information on a recording medium using a laser beam, the laser power limiting step of setting the laser beam to a reproduction laser power for a predetermined period after the start of a non-user area, A DC level detecting step of detecting a DC level to be superimposed on a reproduction signal in a predetermined period after the start of the non-user area based on the reproduction signal reproduced by the beam of the reproduction laser power, and the detected DC level is predetermined. A DC level comparing step of determining whether the DC level is exceeded, and a recording data pattern for suppressing the DC level based on the DC level when the detected DC level is determined to exceed the threshold. A data pattern setting step for setting, and a laser pattern for returning the laser beam to the recording laser power. Information recording method characterized in that it comprises a chromatography returning step, and a pattern data recording step of recording on the non-user area of the set recording data pattern. 10. The detected D according to claim 9.
When it is determined that the C level does not exceed the threshold value, the setting of the reproduction laser power is continued, and thereafter,
An information recording method, wherein pattern data for suppressing a DC level is recorded in the non-user area by returning the laser beam to a recording laser power at a timing when the end portion of the non-user area is reached. 11. An information recording method for recording information on a recording medium, comprising: a recording limiting step of limiting recording for a predetermined period after the start of the non-user area, and information recording in the non-user area based on a reproduction signal. A recording determination step of determining whether or not recording is performed, and pattern data for suppressing a DC level when it is determined that information is not recorded in the non-user area is stored in the non-user area after the predetermined period. An information recording method, comprising: a pattern data recording step of recording in an area. 12. The DC according to claim 7, when the information is recorded in the non-user area, at the timing when the end portion of the non-user area is reached.
An information recording method, characterized in that pattern data for suppressing a level is recorded in a terminal portion of the non-user area. 13. An information recording method for recording information on a recording medium using a laser beam, comprising: a laser power limiting step of setting the laser beam to a reproduction laser power for a predetermined period after the start of a non-user area; A recording discriminating step for discriminating whether or not information is recorded in the non-user area based on a signal and a laser beam for recording the laser beam when it is discriminated that no information is recorded in the non-user area. And a pattern data recording step of recording pattern data for suppressing the DC level in the non-user area after the lapse of the predetermined period, the information recording method. 14. When it is determined in claim 13 that information is recorded in the non-user area,
Pattern data for continuing the setting of the reproduction laser power and thereafter returning the laser beam to the recording laser power and suppressing the DC level in the non-user area at the timing when the end portion of the non-user area is reached. A method for recording information, characterized by recording. 15. The method according to claim 8, wherein D is added to the end portion of the non-user data area.
An information recording method characterized by recording DC free pattern data in which C level is not superimposed.