JP2001056953A - Information recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve stability of recording and reproduction by providing a light beam emitted on a recording medium with modulation by a frequency different from a data recording frequency, and suppressing backtalk at the time of reading, writing, and erasing. SOLUTION: A high-frequency superposing circuit 93 comprises a write system circuit 93a, an erase system circuit 93b, and a read system circuit 93c, and is enabled to set write, erase, and read each to an amplitude and a frequency for high-frequency superposition. For example, the high-frequency superposition is set to a range of 50 MHz-1 GHz, an amplitude modulation factor is set to 0-350% in the read system, and a modulation factor is set to 0-200% in the erase and write systems. In the case of write processing, when a data is written in a desired block, reading is performed for confirmation, and if the data is erroneous, the erase system circuit 93b is initiated. An EP high-frequency superposition DAC register 110 is set to high-frequency superposition power, and a variable current source 114 pulls out a corresponding constant current from a laser diode 30-1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an information storage device, and more particularly to an information storage device for optically storing information on a recording medium. In recent years, optical disks have been in the limelight as external storage media for computers. Optical discs use laser light to create submicron-order magnetic recording pits on the media, which can significantly increase the storage capacity compared to conventional external storage media such as floppy disks and hard disks. It is attracting attention as a simple storage medium.

Further, a magneto-optical disk, which is a perpendicular magnetic storage medium using a rare earth-transition metal material, is rewritable, and is expected to be further developed in the future. The magneto-optical disk has a storage capacity of 540 MB and 640 MB on one side of 3.5 inches, for example.
This means that the storage capacity of one 3.5-inch floppy disk is about 1 MB, and one optical disk has a storage capacity of 540 floppy disks and 640 floppy disks. As described above, the magneto-optical disk is a rewritable storage medium having a very high recording density.

In such an environment, a magneto-optical disk has only a high storage capacity, and high reliability in data recording and reproduction is required. In recording data, the recorded data is reproduced on the spot at a lower level than a normal error correction function, and when an error occurs beyond a specified value, processing such as switching to a reserved area is performed.

[0004] On the other hand, at the time of reproduction, data in a sector that has been judged to have been recorded by verification at the time of recording must be able to be reproduced under any circumstances. In addition to improving the performance of the error correction processing, various parameters such as a filter, an equalizer, a slice level, and a read pattern are adjusted at the time of the retry processing so that the data is correctly reproduced.

However, basically, improving the quality at the time of recording is the best way to secure a margin at the time of reproduction. In view of such a conventional situation, when the present invention irradiates a laser beam onto a medium and performs servo or data reproduction by returning the laser beam, the quality of the previous signal is degraded due to a back talk phenomenon caused by the characteristics of the laser. The purpose is not to let them.

[0006]

2. Description of the Related Art FIG. 1 shows a block diagram of a conventional magneto-optical disk drive. The conventional magneto-optical disk drive 1 mainly includes a control unit 10 and an enclosure 11. The control unit 10 mainly controls the MP that performs overall control of the magneto-optical disk drive.
U12, an interface 17 for exchanging commands and data with a higher-level device, an optical disk controller (ODC) 14 for performing processing necessary for reading and writing data from and to a magneto-optical disk medium, a DSP (Digital Si
gnal Processer) 16 and a buffer memory 18.

The buffer memory 18 includes the MPU 12, the optical disk controller 14, and the upper interface 17
Shared by The optical disk controller 14 includes a formatter 14-1 and an ECC processing unit 14-2. At the time of write access, the formatter 14
-1 generates the recording format by dividing the NRZ write data into sector units of the medium,
-2 generates and adds an ECC code for each sector write data unit, and further generates and adds a CRC code if necessary.

Further, the ECC-encoded sector data is converted into, for example, a 1-7 RLL code. At the time of read access, the demodulated sector read data is
The inverse conversion from the LL code is performed, the ECC processing unit 14-2 performs a CRC check, and then performs error detection and correction. Further, the formatter 14-1 concatenates NRZ data in sector units to form a stream of NRZ read data, which is transferred to a higher-level device. Let it.

A write LSI circuit 20 is provided for the optical disk controller 14, and the write LSI circuit 20
Is provided with a light modulation unit 21 and a laser diode control circuit 22. The control output of the laser diode control circuit 22 is given to a laser unit 30 provided in the optical unit on the enclosure 11 side. The laser diode unit 30 integrally includes a laser diode 30-1 and a monitor detector 30-2. The write modulation unit 21 converts the write data into a PPM recording system, that is, a pit position modulation recording system, or a PWM system.
The data is converted into a data format of a recording method, that is, a pulse width modulation recording method. The recording format of the recording medium is zone CAV.

The PPM recording method is a recording method for recording data in accordance with the presence or absence of a mark on a medium.
The WM recording method is a recording method in which an edge, that is, a leading edge and a trailing edge of a mark correspond to data. When the magneto-optical disk cartridge is loaded into the magneto-optical disk drive, first, the ID portion of the magneto-optical disk is read, and the MPU 12 recognizes the type of the recording medium, that is, the capacity, from the pit interval, and writes the type result to the write LSI circuit 20. Notify.

The data write data from the magneto-optical disk drive 14 is converted by the write modulation unit 21 into PWM recording data. The PWM recording data converted by the write modulation unit 21 is supplied to a laser diode control unit 22. Laser diode control unit 2
2 drives the laser diode 30-1 to emit light in accordance with the PWM recording data converted by the light modulation unit 21.

The recording medium includes a laser diode 30-1.
The information corresponding to the PWM recording data is recorded by the light emission driving of. At the time of reading, the reflected light from the magneto-optical disk is detected by the MO / ID detector 32. MO / ID
The detection signal from the detector 32 is supplied to the read LSI circuit 24 after being amplified by the head amplifier 34.
The read LSI circuit 24 has a read demodulation unit 25 and a frequency synthesizer 26.

The read demodulation unit 25 of the read LSI circuit 24 has a built-in circuit function such as an AGC circuit, a filter, a sector mark detection circuit, etc., and is detected by the MO / ID detector 32 and supplied via a head amplifier 34. A read clock and read data are generated from the ID and MO signals, and the PWM recording data is demodulated to the original NRZ data.

The frequency synthesizer 26 is composed of a PLL circuit having a programmable frequency divider.
The reference clock having a specific frequency corresponding to the zone of the medium is generated as a read clock by being set and controlled by the zone 12 according to the zone set in the medium. The frequency synthesizer 26 generates a reference clock having a frequency f0 f0 = (m / n) · fi according to a division ratio (m / n) set by the MPU 12 according to the zone number. Here, the dividing ratio (m / n)
Is a specific value corresponding to the capacity of the medium. The numerator division value m is a value set according to the zone position of the medium, and is prepared in advance as table information of a value corresponding to the zone number for each medium.

The read data demodulated by the read LSI circuit 24 is given to the optical disk controller 14 and
-7 ECC processing unit 14 after reverse conversion of RLL code
The NRZ sector data is restored by receiving the CRC check and the ECC process by the encoding function of No. 2 and connected to the stream of the NRZ read data by the formatter 14-1, and then transferred to the host device by the host interface 17 via the buffer memory 18. Is done.

A detection signal from a temperature sensor 36 provided on the enclosure 11 side is supplied to the MPU 12 via the DSP 16. The MPU 12 controls the read, write, and erase powers of the laser diode control unit 22 to optimal values based on the environmental temperature inside the device detected by the temperature sensor 36. MPU12 is D
The driver controls the spindle motor 40 provided on the enclosure 11 side via the SP 16. MO
Since the recording format of the cartridge is zone CAV, the spindle motor 40 is set to, for example, 4500 rpm.
m at a constant speed.

The MPU 12 controls a magnetic field applying unit 44 provided on the enclosure 11 side via a driver 16 via a DSP 16. The electromagnet 44 is arranged on the side opposite to the beam irradiation side of the MO cartridge loaded in the apparatus, and supplies an external magnetic field to the medium during recording and erasing. A permanent magnet may be combined with the electromagnet 44.

The DSP 16 has a servo function for positioning the beam from the laser diode 30 with respect to the medium, and performs seek control for seeking on a target track and performing on-track. This seek control is performed by MPU1
2 is executed concurrently with the write access or read access to the higher-order command. The DSP 16 is supplied with detection signals from the FES detector 45 and the TES detector 47. The detection signal detected by the FES detector 45 is supplied to an FES detection circuit 46 connected to the DSP 16. The FES detection circuit 46 generates a focus error signal from the detection signal detected by the FES detector 45.

The detection signal detected by the TES detector 47 is transmitted to the TES detection circuit 4 connected to the DSP 16.
8 is supplied. The TES detection circuit 48 generates a tracking error signal from the detection signal detected by the TES detector 47. The optical head is provided with a lens position sensor 54 that detects a lens position of an objective lens that irradiates the medium with a laser beam. The detection signal of the lens position sensor 54 is supplied to the DSP 16. DSP
Reference numeral 16 is connected to the focus actuator 60, the lens actuator 64, and the positioner 68 via the drivers 58, 62, and 66. The focus actuator 60 is connected to the focus actuator 60 in accordance with the detection signal of the lens position sensor 54 and the focus error signal and the tracking error signal. The position of the objective lens is controlled by controlling the lens actuator 64 and the positioner 68.

Next, the mechanical configuration of the magneto-optical disk drive 1 will be described. FIG. 2 shows an internal configuration diagram of an example of a conventional magneto-optical disk drive. The internal structure of the magneto-optical disk drive 1 is such that a loading mechanism 71, a spindle motor 40, an optical head 73, a positioner 74, a fixed optical system 78, an electromagnet 75, and the like are built in a housing 67.

The magneto-optical disk cartridge 70 is inserted into the apparatus from the inred door 69. The magneto-optical disk cartridge 70 inserted into the apparatus is loaded by the loading mechanism 71 to a predetermined mounting position inside the apparatus. When the magneto-optical disk cartridge 70 is loaded to a predetermined mounting position in the apparatus by the loading mechanism 71, the magneto-optical disk 72 built in the magneto-optical disk cartridge 70 is engaged with the spindle motor 40.

The spindle motor 40 rotates the magneto-optical disk 72. The optical head 73 is a magneto-optical disk 72
And irradiates one surface of the magneto-optical disk 72 with laser light. The optical head 73 includes the positioner 7
4 and held by the positioner 74 on the magneto-optical disk 7.
2 in the radial direction, that is, the direction of arrow A. The optical head 73 is supplied with laser light from a fixed optical system 78. The fixed optical system 78 supplies a laser beam to the optical head 73 and detects the laser beam reflected by the magneto-optical disk 72 and returned through the optical head 73.

An electromagnet 75 is disposed on the other surface of the magneto-optical disk 72 so as to face the optical head 73. The magneto-optical disk 72 stores information by a laser beam emitted from the optical head 73 and a magnetic field applied from the electromagnet 75.
Next, the configuration of the fixed optical system 78 of the magneto-optical disk drive 1 will be described. FIG. 3 shows a schematic configuration diagram of a fixed optical system of a conventional magneto-optical disk drive.

The fixed optical system 78 includes the laser diode 30
-1, collimator lens 30-11, monitor photodiode (monitor PD) 30-2, composite optical element 30-
3, beam splitters 30-4 and 30-6, lens 30
-5, a Wollaston unit 30-7, a focus error signal detector 45, a tracking error signal detector 47, and an MO / ID detector 32.

The laser diode 30-1 emits a laser beam. The laser beam emitted from the laser diode 30-1 is supplied to a collimator lens 30-11. The collimator lens 30-11 converts the laser beam radially emitted from the laser diode 30-1 into parallel light. The laser beam converted into parallel light by the collimator lens 30-11 is supplied to the composite optical element 30-3. The composite optical element 30-3 separates the laser beam supplied from the collimator lens 30-11 in two directions. One of the laser beams separated by the composite optical element 30-3 is supplied to the magneto-optical disk 72, and the other is supplied to the monitor PD 30-2.

The monitor PD 30-2 includes a composite optical element 30.
The light amount of the laser beam supplied to the magneto-optical disk 72 from the other laser beam separated by -2 is monitored. Further, the reflected light from the magneto-optical disk 72 is supplied to the composite optical element 30-2. Composite optical element 30-2
Represents the reflected light from the magneto-optical disk 72 as the MO / ID detector 32, the FES detector 45, and the TES detector 4.
Fold in the direction of the various detectors 7. Composite optical element 30
The reflected light from the magneto-optical disk 72 supplied from -2 is split by the beam splitter 30-4 into the direction of the MO / ID detector 32 and the directions of the FES detector 45 and the TES detector 47.

MO / I by beam splitter 30-4
The light split in the direction of the D detector 32 is transmitted through the Wollaston unit 30-7 to the MO / ID detector 32.
Supplied to The MO / ID detector 32 detects a data component and an ID component from the reflected light from the magneto-optical disk 72. The light split by the beam splitter 30-4 in the direction of the FES detector 45 and the TES detector 47 is transmitted to the lens 30-5 and the beam splitter 30-6.
Is divided into an FES component and a TES component through
The component is supplied to the FES detector 45, and the TES component is supplied to the TES detector 47.

The FES detector 45 detects a focus error signal component from the reflected light from the magneto-optical disk 72. The TES detector 47 detects a tracking error signal component from the reflected light from the magneto-optical disk 72. FES detector 45, TES detector 47, M
Each signal detected by the O / ID detector 32 is supplied to the control unit 10.

In this type of conventional information storage device, when the laser light is continuously emitted, a part of the return light from the magneto-optical disk 72 is transmitted to the laser diode 30-1 as shown by a broken arrow in FIG. Returning, the laser diode 30-1 undergoes secondary resonance and cannot perform stable laser emission.
Back talk phenomenon occurs. In order to suppress this backtalk phenomenon, the on / off control of the laser diode 30-1 is performed according to the frequency determined by the optical path length. This on / off control is called high frequency superposition.

Conventionally, this high frequency superposition has been performed only at the time of reading. FIG. 4 is a diagram for explaining a state of high-frequency superposition of an example of a conventional magneto-optical disk drive. FIG.
The horizontal axis indicates the drive current ILD of the laser diode 30-1, and the vertical axis indicates the light emission amount PLD of the laser diode 30-1.

In FIG. 4, the characteristic indicated by the solid line in the first quadrant A1 is the characteristic of the laser diode 30-1.
When erasing and writing / reading are performed at the timing shown in FIG. 3, a drive current is supplied as shown in the fourth quadrant A4. When the laser diode 30-1 is driven by the drive current shown in the fourth quadrant A4, light emission is performed with the characteristics shown in the first quadrant A1 and light is emitted with the laser power shown in the second quadrant A2. .

[0032]

However, in this type of conventional information storage device, the difference in the type of medium, the reflectance of each individual medium, the change in environmental temperature, the characteristic difference inherent to the laser diode, and the like cause a problem. There were problems such as occurrence of talks. Conventionally, high frequency superimposition is not applied for the purpose of suppressing the back talk phenomenon at the time of erasing or writing, so the back talk phenomenon occurs at the time of erasing or writing, the recording signal is deteriorated, and the data recording / reproducing is performed. There is a problem that the reliability of the device decreases.

The present invention has been made in view of the above points, and has as its object to provide an information storage device capable of improving the reliability of data recording and reproduction.

[0034]

According to a first aspect of the present invention, there is provided an information storage device for optically recording and / or reproducing signals on and from a recording medium, wherein a light beam generator for generating a light beam for irradiating the recording medium is provided. Means, modulation means for applying a predetermined modulation to the light beam generated by the light beam generation means at a frequency different from the data recording frequency, and modulation control means for controlling the modulation applied to the light beam by the modulation means. Is provided.

According to the first aspect, high-frequency superimposition can be applied to the light beam so as to suppress the backtalk phenomenon at the time of reading, writing, and erasing. The phenomenon can be suppressed, and the stability of information recording and reproduction can be improved.
Further, it is possible to cope with the suppression of the back talk phenomenon due to the individual characteristics of the device and the use environment, and it is possible to improve the stability of information recording and reproduction.

According to a second aspect of the present invention, the amplitude of the modulation of the light beam is controlled. According to the second aspect, by controlling the amplitude of the modulation, the backtalk phenomenon can be suppressed, and the stability of information recording and reproduction can be improved. Claim 3 controls the frequency of modulation applied to the light beam. According to the third aspect, by controlling the frequency of the modulation applied to the light beam, the backtalk phenomenon can be suppressed, and the stability of information recording and reproduction can be improved.

According to a fourth aspect of the present invention, an error in the information read information is detected, and modulation is applied when the error is detected. According to the fourth aspect, errors caused by back talk can be suppressed, and the stability of information recording and reproduction can be improved. Claim 5 controls whether or not the modulation operation is possible.

According to the fifth aspect, since the modulation is only turned on / off, the control becomes easy. According to a sixth aspect of the present invention, the environmental temperature is detected, and the modulation is controlled according to the detected temperature. According to the sixth aspect, since information recording and reproduction can be performed while suppressing a backtalk phenomenon caused by an environmental temperature, the stability of information recording and reproduction can be improved regardless of the environmental temperature.

According to a seventh aspect, the modulation operation is controlled at the time of reading information. According to the seventh aspect, it is possible to suppress occurrence of an error at the time of reading information or backtalk caused by a change in environmental temperature, and to improve stability of an information reproducing operation.
An eighth aspect of the present invention controls a modulation operation when erasing information recorded on a recording medium.

According to the eighth aspect, it is possible to suppress occurrence of an error at the time of erasing information and backtalk caused by a change in environmental temperature, and to improve the stability of the erasing operation of information. According to a ninth aspect, when information is recorded on a recording medium, modulation is controlled. According to the ninth aspect, it is possible to suppress occurrence of an error at the time of recording information and backtalk generated according to a change in environmental temperature, and to improve stability of the information recording operation.

[0041]

FIG. 4 is a block diagram showing an embodiment of the present invention. In the figure, the same components as those of FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. The magneto-optical disk drive 90 according to the present embodiment performs processing of the MPU 91 and write L
The configuration of the SI circuit section 92 is such that high-frequency superposition can be performed in any of writing, erasing, and reading.

In this embodiment, the MPU 91 and the write LS
The I-circuit unit 92 enables high-frequency superimposition on the laser beam in order to suppress the backtalk phenomenon not only at the time of reading but also at the time of erasing and writing. The amplitude and frequency of the high frequency superposition can be set separately,
The amplitude and frequency of the high-frequency superposition are changed so as to suppress the backtalk phenomenon when an error occurs or when the environmental temperature changes.
At this time, the frequency range of the high frequency superimposition is 50 MHz to 1
GHz. The amplitude of the high frequency superposition is 0 to 350% in the read system and 0 to 350% in the erase / write system.
200%. The modulation degree is represented by (b / a) * 100 [%], where a is DC power and b is amplitude.

In this embodiment, the modulation degree of the high frequency superimposition can be controlled so as to have an appropriate ratio with respect to the read / write / erase power. The control of the high frequency superposition is controlled by a high frequency superposition circuit 93 provided in the write LSI circuit section 92. FIG. 6 is a block diagram showing a main part of a write LSI circuit according to one embodiment of the present invention.

The high frequency superimposing circuit 93 includes a write circuit 93
a, an erase circuit 93b and a read circuit 93c. The write circuit 93a generates a write current in accordance with the write data at the time of data writing, and gives high frequency superposition to the generated write current. The write circuit 93a includes a write power current DAC register 101, a write power high frequency superimposed DAC register 10
2, DAC 103, 104, variable current source 105, 10
6, gate circuits 107 and 108.

Digital data corresponding to the write power is set in the write power current DAC register 101. Digital data corresponding to the high frequency superimposed power to be superimposed on the write power is set in the write power high frequency superimposed DAC register 102. In DAC103,
Data according to the write power set in the write power current DAC register 101 is supplied. DAC103
Converts the data supplied from the write power current DAC register 101 into an analog signal.

The DAC 104 is supplied with data corresponding to the high frequency superimposed power to be superimposed on the write power set in the write power high frequency superimposed DAC register 102. The DAC 104 converts data according to the high-frequency superimposed power set in the write power high-frequency superimposed DAC register 102 into an analog signal. The analog signal converted by the DAC 103 is supplied to the variable current source 105.
The variable current source 105 draws a constant current according to the analog signal supplied from the DAC 103 from the laser diode 30-1 via the gate circuit 107.

The analog signal converted by the DAC 104 is supplied to a variable current source 106. Variable current source 106
Supplies a constant current corresponding to the analog signal supplied from the DAC 104 through the gate circuit 108 to the laser diode 3.
Pull in from 0-1. The gate circuits 107 and 108 include:
A write gate signal indicating a period to be written is supplied. The gate circuits 107 and 108 control the drawing of the write current from the laser diode 30-1 by the variable current sources 106 and 107 according to the write gate signal. At this time, a high-frequency superimposed signal is supplied to the gate circuit 108 in addition to the write gate signal. The gate circuit 108
During the ON period of the write gate signal, a current corresponding to the high frequency superimposed signal is drawn from the laser diode 30-1.

At the time of writing, the gate circuits 107 and 108
Controls the drawing current from the laser diode 30-1, and the laser diode 30-1 is controlled by the current obtained by superimposing the high-frequency superimposition signal on the write current. At the time of writing, the laser diode 30-1 emits light by a current obtained by superimposing a high-frequency superimposed signal on a write current, and information is written to the magneto-optical disk.

The erase system circuit 23b includes an erase power current DAC register 109, an erase power high frequency superimposed DAC register 110, DACs 111 and 112, variable current sources 113 and 114, and gate circuits 115 and 116. Digital data corresponding to the erase power is set in the erase power current DAC register 109. Erase power high frequency superimposed DAC register 110
, Digital data corresponding to the high frequency superimposed power to be superimposed on the erase power is set.

The DAC 111 has an erase power current D
Data corresponding to the erase power set in the AC register 109 is supplied. The DAC 111 converts the data supplied from the erase power current DAC register 109 into an analog signal. The DAC 112 is supplied with data corresponding to the high-frequency superimposed power to be superimposed on the erase power set in the erase power high-frequency superimposed DAC register 110. The DAC 112 converts data according to the high-frequency superimposed power set in the erase power high-frequency superimposed DAC register 110 into an analog signal.

The analog signal converted by the DAC 111 is supplied to a variable current source 113. Variable current source 113
Supplies a constant current corresponding to the analog signal supplied from the DAC 111 through the gate circuit 115 to the laser diode 3.
Pull in from 0-1. The analog signal converted by the DAC 112 is supplied to the variable current source 114. The variable current source 114 draws a constant current according to the analog signal supplied from the DAC 112 from the laser diode 30-1 via the gate circuit 116.

The gate circuits 115 and 116 are supplied with an erase gate signal corresponding to the erase period. The gate circuits 115 and 116 are connected to the laser diode 30 by the variable current sources 113 and 114 according to the erase gate signal.
It controls the erasing current from -1. At this time, a high frequency superimposed signal is supplied to the gate circuit 116. The gate circuit 116 controls the variable current source 107 to draw a high-frequency superimposed current from the laser diode 30-1 according to the high-frequency superimposed signal during the ON period of the erase gate signal.

As described above, at the time of erasing, the gate circuits 115 and 116 control the current drawn from the laser diode 30-1, and the laser diode 30 is controlled by the current obtained by superimposing the high-frequency superimposed power on the erase power.
-1 is controlled. At the time of erasing, the laser diode 30-
1 is emitted, and the magneto-optical disk is erased.

The read circuit 93c includes a read power current DAC register 117, a read power high frequency superimposed DAC
Register 118, DAC 119, 120, variable current source 1
21 and 122 and gate circuits 123 and 124. Digital data corresponding to the read power is set in the read power current DAC register 117. Digital data corresponding to the high-frequency superimposed power to be superimposed on the read power is set in the read power high-frequency superimposed DAC register 117.

The DAC 119 has a read power current DA
Data corresponding to the read power set in the C register 117 is supplied. The DAC 119 converts the data supplied from the read power current DAC register 117 into an analog signal. Data corresponding to the high-frequency superimposed power to be superimposed on the read power set in the read power high-frequency superimposed DAC register 118 is supplied to the DAC 120. DAC 120 is a read power high frequency superimposed DAC
Data corresponding to the high-frequency superimposed power set in the register 118 is converted into an analog signal.

The analog signal converted by the DAC 119 is supplied to the variable current source 121. Variable current source 121
Supplies a constant current corresponding to the analog signal supplied from the DAC 119 through the gate circuit 123 to the laser diode 3.
Pull in from 0-1. The analog signal converted by the DAC 120 is supplied to the variable current source 122. The variable current source 122 draws a constant current according to the analog signal supplied from the DAC 120 from the laser diode 30-1 via the gate circuit 124.

The gate circuits 123 and 124 are supplied with a read gate signal corresponding to the read period. The gate circuits 123 and 124 control the drawing of the read current from the laser diode 30-1 by the variable current sources 121 and 122 according to the read gate signal. At this time, a high-frequency superimposed signal is supplied to the gate circuit 122. The gate circuit 122 controls the drawing of the high-frequency superimposed current from the laser diode 30-1 by the variable current source 122 according to the high-frequency superimposed signal during the ON period of the read gate signal.

As described above, at the time of reading, the gate circuits 123 and 124 control the current drawn from the laser diode 30-1, and the laser diode 30-1 is controlled by the current obtained by superimposing the high-frequency superimposed power on the read power.
Is controlled. Therefore, at the time of reading, the laser diode 30 is driven by the read power on which the high-frequency superimposed signal is superimposed.
-1 is emitted, and information is read from the magneto-optical disk.

At this time, the amplitude of the high frequency superimposed signal at the time of writing, erasing, and reading is equal to the write power high frequency superimposed signal DA.
C register 102, erase high frequency superimposed DAC register 112, read power high frequency superimposed DAC register 120
, Can be controlled separately by the digital data set in, so that writing, erasing, and reading can be performed with high-frequency superimposed power optimum for writing, erasing, and reading.

Next, the setting of the high frequency superimposed signal will be described. FIG. 7 is a block diagram showing a circuit for generating a high-frequency superimposed signal according to one embodiment of the present invention. Gate circuit 1 of FIG.
The synthesizer 200 is used to generate the high-frequency superimposed signals to be supplied to 08, 116 and 124. Synthesizer 20
Numeral 0 is connected to, for example, the MPU 91 via the bus 94, and outputs a high-frequency superimposed signal having a frequency corresponding to data supplied from the MPU 91.

With such a configuration, the MPU
The gate circuits 108, 116,
The frequency of the high-frequency superimposed signal supplied to the power supply 124 can be changed. Therefore, the high-frequency superimposed signal can be set to an optimum frequency at which no backtalk occurs. In the present embodiment, the high-frequency superimposed signal is used in common for write, erase, and read, but may be supplied separately.

FIG. 8 is a block diagram showing a modification of the setting operation of the high-frequency superimposed signal according to one embodiment of the present invention. In this embodiment, the write register 2 is connected to the MPU 91 via the bus 94.
01, erase register 203, read register 2
05 is connected. The MPU 91 has the write register 20
1 is set with digital data corresponding to the frequency of the high frequency superimposed signal to be superimposed during writing. Also, MPU91
Sets digital data according to the frequency of the high-frequency superimposed signal to be superimposed at the time of erasure in the erase system register 203. Further, the MPU reads the read register 205
, Digital data corresponding to the frequency of the high frequency superimposed signal to be superimposed at the time of reading is set.

The write register 201 supplies the digital data set by the MPU 91 to the write synthesizer 202. The light synthesizer 202
A high-frequency superimposed signal having a frequency corresponding to the digital data set in the write register 201 is supplied to the gate circuit 108 for superimposing the high-frequency superimposed signal. The erase register 203 supplies the digital data set by the MPU 91 to the erase synthesizer 204. The erase synthesizer 204 supplies a high frequency superimposed signal having a frequency corresponding to the digital data set in the erase register 203 to the gate circuit 116 for superimposing the erase high frequency superimposed signal.

The read register 205 supplies the digital data set by the MPU 91 to the read synthesizer 206. The read synthesizer 206 supplies a high frequency superimposed signal having a frequency corresponding to the digital data set in the read system register 205 to the gate circuit 124 for superimposing the read high frequency superimposed signal. MP
By setting data separately in the write register 201, the erase register 203, and the read register 205 by U91, it is possible to superimpose a high-frequency superimposed signal of a different frequency in each of write, erase, and read.

Next, the processing operation of the MPU 91 will be described. First, the operation at the time of data reading will be described.
FIG. 9 is a flowchart of a read process according to an embodiment of the present invention. First, data is set in the read-system high-frequency superimposed DAC register 118 so that high-frequency superposition is not performed as an initial state (step S1-1).

Next, data read is performed (step S1-2). In step S1-2, the data read is EC
It is determined whether or not the processing has been correctly performed including the correction processing by C (step S1-3). In step S1-3, if the data read has been correctly performed including the correction processing by the ECC, the read processing ends as it is.

If it is determined in step S1-3 that the data read was not correctly performed including the correction processing by the ECC, the data is then stored in the read system high-frequency superimposed DAC register 118 so that the high-frequency superposition is performed. It is set (step S1-4). Next, it is determined whether the number of retries is a specified number (step S1-5). Step S
If the number of retries is within the specified number in 1-5, the process returns to step S1-2, where high-frequency superimposition is performed using the data set in step S1-4, and data reading is performed.

If the number of retries exceeds the specified number in step S1-5, it is determined that an error has occurred, and the data read process ends (step S1-6). As described above, the occurrence of an error can be suppressed by turning on / off the high-frequency superimposition in response to the occurrence of an error at the time of reading and performing the reading process under optimal conditions.

In the above embodiment, the read-system high-frequency superposition is simply turned on / off. However, the level of the read-system high-frequency superposition may be changed every number of retries. FIG. 10 shows a first example of the read processing according to the embodiment of the present invention.
9 shows a processing flowchart of a modified example. 9, the same components as those of FIG. 9 are denoted by the same reference numerals, and the description thereof will be omitted.

In this modification, steps S1-2 and S1-
In step 3, when data read cannot be performed, "1" is added to the number N of retry processes for each data read (step S3).
2-1). It is determined whether or not the number of retry processes N obtained in step S2-1 is an even number (step S2-2).
When the number of retries N is an even number in step S2-2, the high frequency superimposition level is increased (step S2-
3) If the number of retries N is an odd number in step S2-2, the high frequency superimposition level is reduced (step S2-
4) While the number of retries N is within the specified value, the data read is repeated while the high-frequency superimposition level is increased or decreased.

According to this modification, when a read error occurs, the high-frequency superimposition level is increased or decreased to search for an optimum high-frequency superimposition level that does not cause backtalk.
Data read can be performed. In the first modification, the high-frequency superimposed level is changed, but the high-frequency superimposed frequency may be changed.

FIG. 11 is a processing flowchart of a second modification of the read processing according to one embodiment of the present invention. In FIG.
The same components as those of 0 are denoted by the same reference numerals, and description thereof will be omitted. In the present modified example, when the number of retry processes N is an even number in the determination of step S2-1, the high frequency superimposed frequency is increased (step S3-1), and the number of retry processes N is an odd number in the determination of step S2-1. Sometimes, the high frequency superimposed frequency is lowered, and while the number of retries N is within the specified value,
Data read is repeated while raising and lowering the high frequency superimposed frequency.

According to this modification, when a read error occurs, the high-frequency superimposed frequency is raised and lowered to search for an optimal high-frequency superimposed frequency at which no backtalk occurs.
Data read can be performed. In the first and second modified examples, the high-frequency superimposition level or the frequency is changed according to the number of retries N. However, since the state of the magneto-optical disk is easily changed according to the temperature, the high-frequency superposition is changed according to the temperature. The level may be variable. Note that the amplitude control width of the high-frequency superimposition according to the temperature is in the range of the modulation factor 0 to 50%. The degree of modulation is the same as the degree of modulation described for the amplitude of the high frequency superposition of the read system and the erase / write system.

FIG. 12 is a flowchart showing a third modification of the read process according to the embodiment of the present invention. In FIG.
The same components as those of 0 are denoted by the same reference numerals, and description thereof will be omitted. In this modification, when data cannot be read in step S1-2, the temperature is measured (step S4).
-1).

When the temperature is measured in step S4-1,
Next, it is determined whether the temperature measurement result has changed by 5 ° C. or more from the previous temperature measurement value (step S4-2). If the determination result in step S4-2 shows that the temperature measurement result in step S4-1 has changed by 5 ° C. or more from the previous temperature measurement value, the high frequency superimposition level is increased or decreased (step S4-
3).

For example, the determination result in step S4-2,
When the temperature measurement result is + 5 ° C. or more than the previous temperature measurement value, the high frequency superimposition level is increased, and when the temperature measurement result is −5 ° C. or less from the previous temperature measurement value, the high frequency superimposition level is decreased. After the change of the high-frequency superimposition level in step S4-3, the measured temperature measured value is set in the register as the previous temperature measured value in step S4-1 (step S4-4).

Whether the above processing enables data reading,
This is repeated until the number of retries exceeds a specified value. In the above-described modification, the high-frequency superimposed level is changed according to the temperature. However, the high-frequency superimposed frequency may be changed according to the temperature. FIG. 13 is a flowchart illustrating a read process according to a fourth embodiment of the present invention. 12, the same components as those in FIG. 12 are denoted by the same reference numerals, and the description thereof will be omitted.

In this modification, the high frequency superimposed frequency is raised or lowered when the determination result in step S4-2 and the temperature measurement result in step S4-1 change by 5 ° C. or more from the previous temperature measurement value (step S4-2). S5-1). For example, when the temperature measurement result is + 5 ° C. or more from the previous temperature measurement value, the high frequency superimposing frequency is increased, and when the temperature measurement result is −5 ° C. or less from the previous temperature measurement value, the high frequency superimposing frequency is lowered. I do.

Whether the above processing enables data reading,
This is repeated until the number of retries exceeds a specified value. If an error occurs during read processing as described above,
The high-frequency superimposition level and frequency are changed, and a retry process is performed to reduce the occurrence of errors due to back talk.

Next, the write processing will be described. FIG.
9 shows a processing flowchart of a write process according to an embodiment of the present invention. In the write process, as an initial state, the erase system high frequency superposition D
Data is set in the AC register 110 (step S
6-1).

Next, erase is performed on the write block to which data is to be written (step S6-2).
Subsequently, data is written (step S6-3).
When data is written to the write block to which data is to be written in step S6-3, the written data is read for confirmation (step S6-4).

In step S6-4, the data is read, and it is determined whether the data has been correctly written (step S6-5). If the result of determination in step S6-5 is that data has been correctly written, the write process ends. If the result of determination in step S6-5 is that data was not correctly written,
The erase system high frequency superimposition which has been turned off in 6-1 is turned on (step S6-6).

When the erase high-frequency superposition is turned on in step S6-6, it is determined whether the number of retries is within a specified value (step S6-7). If the result of determination in step S6-7 is within the prescribed number of retries, processing returns to step S6-2, where erasing, writing, and verify reading are performed again. If the number of retries exceeds the specified value in step S6-7, the process ends as an error (step S6-8).

As described above, even when a write error occurs, if the number of retries is within the specified value, the high frequency superposition of the erase system is turned on to reduce the influence of the back talk at the time of the erase, and the occurrence of the write error Suppress. In the above embodiment, the erasing high-frequency superimposition is turned on / off in response to the write error. However, it may be controlled so that both the erasing system and the writing high-frequency superposition are turned on / off in response to the write error.

FIG. 15 is a processing flowchart of a modification of the write processing according to one embodiment of the present invention. 14, the same components as those of FIG. 14 are denoted by the same reference numerals, and the description thereof will be omitted. In this modification, the erase system high-frequency superposition is turned off as an initial state, and the write system high-frequency superposition is turned off (step S7-1), and steps S6-1 to S6-4 are performed.
To perform erase, write, and read.

When it is determined in step S6-5 that a read error has occurred as a result of the erase, write, and read in steps S6-2 to S6-4, the erasing system high frequency superposition is turned on (step S7-2). ), And turns on the light system high frequency superimposition (step S7-3). As described above, the erasing system and the writing system high-frequency superimposition are turned on in accordance with the state of the error, the influence of the back talk can be reduced, and the occurrence of an error at the time of writing can be suppressed.

FIGS. 16 and 17 are explanatory diagrams of the operation of the embodiment of the present invention. 4, the same components as those of FIG. 4 are denoted by the same reference numerals, and the description thereof will be omitted. FIG. 16 shows an erase system.
FIG. 17 shows a state in which high frequency superposition is applied to the read system, and FIG. 17 shows a state in which high frequency superposition is applied to the erase system, write system, and read system. In the present embodiment, the erase and write high-frequency superimposition is controlled to be simply turned on and off, but the level and frequency of the erase and write high-frequency superimposition are changed according to the number of retries and the ambient temperature. You may do so. Further, the lead system high frequency superposition may be controlled in the same manner.

[0088]

As described above, according to the first aspect, high-frequency superposition can be applied to the light beam so as to suppress the backtalk phenomenon at the time of reading, writing, or erasing. Even in this case, the backtalk phenomenon can be suppressed, and the stability of information recording and reproduction can be improved. Further, it has features such as being able to cope with the suppression of the backtalk phenomenon due to the individual characteristics of the device and the use environment, and improving the stability of information recording and reproduction.

According to the second aspect, by controlling the amplitude of the modulation, the back talk phenomenon can be suppressed and the stability of information recording and reproduction can be improved. Claim 3
According to the method, by controlling the frequency of the modulation applied to the light beam, the backtalk phenomenon can be suppressed and the stability of information recording and reproduction can be improved.

According to the fourth aspect, it is possible to suppress errors caused by back talk and to improve the stability of information recording and reproduction. According to claim 5, the modulation is turned on.
Since it is only turned off, it has features such as easy control. According to the sixth aspect, information can be recorded / reproduced while suppressing a backtalk phenomenon caused by an environmental temperature.
It has such features that the stability of information recording and reproduction can be improved regardless of the environmental temperature.

According to the seventh aspect, it is possible to suppress occurrence of an error at the time of reading information or backtalk caused by a change in environmental temperature, thereby improving the stability of the information reproducing operation. According to the eighth aspect, it is possible to suppress occurrence of an error at the time of erasing information and backtalk generated according to a change in environmental temperature, and to improve the stability of the erasing operation of information.

According to the ninth aspect, it is possible to suppress occurrence of an error at the time of recording information or back talk generated due to a change in environmental temperature, and to improve the stability of the information recording operation.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of a conventional magneto-optical disk drive.

FIG. 2 is an internal configuration diagram of an example of a conventional magneto-optical disk drive.

FIG. 3 is a schematic configuration diagram of a fixed optical system as an example of a conventional magneto-optical disk drive.

FIG. 4 is a diagram for explaining erase, write, and read power of a conventional magneto-optical disk drive.

FIG. 5 is a block diagram of an embodiment of the present invention.

FIG. 6 is a block diagram of a main part of a write LSI circuit according to one embodiment of the present invention;

FIG. 7 is a block diagram of a circuit for generating a high-frequency superimposed signal according to one embodiment of the present invention.

FIG. 8 is a block diagram showing a modification of a circuit for generating a high-frequency superimposed signal according to one embodiment of the present invention.

FIG. 9 is a processing flowchart at the time of reading according to an embodiment of the present invention.

FIG. 10 is a processing flowchart of a first modification of the read processing according to one embodiment of the present invention;

FIG. 11 is a processing flowchart of a second modification of the read processing according to one embodiment of the present invention.

FIG. 12 is a processing flowchart of a third modification of the read processing according to one embodiment of the present invention.

FIG. 13 is a processing flowchart of a fourth modification of the read processing according to one embodiment of the present invention.

FIG. 14 is a processing flowchart of a write process according to an embodiment of the present invention.

FIG. 15 is a processing flowchart of a modified example of the write processing according to one embodiment of the present invention.

FIG. 16 is an operation explanatory diagram of one embodiment of the present invention.

FIG. 17 is an operation explanatory diagram of one embodiment of the present invention.

[Explanation of symbols]

90 Magneto-optical disk drive 91 MPU 92 Write LSI circuit section 93 High frequency superimposing circuit 93a Write system circuit 93b Erase system circuit 93c Read system circuit 101 Write power current DAC register 102 Write power high frequency superimposition register 103, 104, 111, 112, 119, 120 D
AC 105, 106, 113, 114, 121, 122 Variable current source 107, 108, 115, 116, 123, 124 Gate circuit 109 Erase power current DAC register 110 Erase power high frequency superimposed DAC register 117 Read power current DAC register 118 Read power High frequency superimposed DAC register

Claims (9)

[Claims] 1. An information storage device that optically records and / or reproduces a signal on and from a recording medium, comprising: a light beam generating unit that generates a light beam for irradiating the recording medium; and a light beam generating unit that generates the light beam. An information storage device, comprising: a modulation unit that applies a predetermined modulation to the light beam at a frequency different from a data recording frequency; and a modulation control unit that controls the modulation that is applied to the light beam by the modulation unit. 2. The information storage device according to claim 1, wherein said modulation control means is capable of controlling the amplitude of said light beam. 3. The information storage device according to claim 1, wherein the modulation control unit is capable of controlling a frequency of a modulation applied to the light beam. 4. An apparatus according to claim 1, further comprising: an error detection unit configured to detect an error in the information read information, wherein the modulation control unit controls the modulation unit when the error detection unit detects an error. The information storage device according to any one of claims 1 to 3, wherein 5. The information storage device according to claim 4, wherein said modulation control means controls whether or not to perform said modulation operation. 6. The temperature control device according to claim 1, further comprising a temperature detection unit configured to detect an environmental temperature, wherein the modulation control unit controls the modulation unit in accordance with the temperature detected by the temperature detection unit. 4. The information storage device according to claim 3. 7. The information processing apparatus according to claim 1, wherein said modulation control means controls a modulation operation given by said modulation means to a light beam emitted from said light beam generation means to said recording medium when reading information. The information storage device according to claim 1. 8. The modulation control unit controls a modulation operation given by the modulation unit to a light beam emitted from the light beam generation unit to the recording medium when erasing information recorded on the recording medium. The information storage device according to any one of claims 1 to 9, wherein: 9. The modulation control means controls a modulation operation given by the modulation means to a light beam emitted from the light beam generation means to the recording medium when information is recorded on the recording medium. Claims 1 to 1
0. The information storage device according to claim 1.