DE10017943C2 - Information storage device - Google Patents

Abstract

In an information storage device for optically recording and / or reading information on and / or from a recording medium, a laser beam generating part generates a laser beam that irradiates the recording medium. A modulation part applies a modulation at a frequency different from a data recording frequency to the laser beam generated by the laser beam generation part. A modulation control part controls the modulation that is applied to the laser beam by the modulation part.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates generally Information storage devices, and particularly one Information storage device that stores information on a Recording medium recorded optically.

Lately, attention has turned to opti discs as external recording media of computers systems concentrated. With optical disks, the Spei capacity compared to floppy disks and removable hard drives ten can be increased significantly more by magnetizing Dimples on a medium using laser beams in the Submicrometer range are formed.

In addition, it is on a magneto-optical Plate containing a magnetic cross-recording medium Use of a rare earth element - transition metal is possible to write information. Thus there is Desire to further develop the optical disc.

For example, the magneto-optical disk has a memory capacity of 540 MB or 640 MB on one side of a 3.5 inch optical disc. That is, as a single 3.5-inch floppy disk has a storage capacity of 1 MB, has a single 3.5 inch magneto-optical disc Storage capacity, which is about 540 disks to 640 disks is equivalent. The magneto-optical disk is a memory medium, in which a writing of information with very high density is possible.

In view of this technical environment from a height ren storage capacity of the magneto-optical disk at high Taking advantage of density becomes highly reliable ability to write and read information.  

If conventionally data on the magneto-optical Recorded data will be recorded immediately after Record through a verification function with a Read reference level that is lower than a level of one normal error correction function. If errors with one Rate that will be higher than the reference level a reserved area on the magneto-optical disk used to record the data.

On the other hand, data recorded on sectors net, which be once through the verification function were voted to be correctly recorded under be read every condition.

If so read the data on the sectors again conventionally, each of the parameters becomes a Filters, an equalizer, a slice level, a read patterns and the like are set to correct the error to improve performance and also correct the data read.

However, it is an optimal goal to improve the quality of the to improve drawing in order to reduce error rates in the Maintain read operation.

2. Description of the related art

Fig. 1 is a block diagram showing a conventional magneto-optical disk drive.

A conventional magneto-optical disk drive 1 as an information storage device mainly includes a control unit 10 and a housing 11 .

The control unit 10 essentially comprises an MPU 12 for controlling an entire magneto-optical disk drive 1 , an interface 17 for sending data to and receiving commands from a higher unit, an optical disc controller (ODC) 14 to perform processes related to reading data from, or writing data to, a magneto-optical medium, a DSP [Digital Signal Processor] 16 and a buffer memory 18 .

The buffer memory 18 is used jointly by the MPU 12 , the optical disk controller 14 and the interface 17 . In the optical disk controller 14 , a formatter 14-1 and an ECC (Error Correcting Code) processor unit 14-2 are provided. When a write access is performed, the formatter 14-1 forms a recording format by dividing NRZ (non-return-to-zero) write data into zero sector units of the medium. The ECC processor unit 14-2 then provides an ECC code in each sector of written data. If necessary, the ECC processor unit 14-2 provides a CRC (Cyclic Redundancy Check) code (code for the cyclical redundancy check).

Furthermore, each sector of data is converted to data with the ECC, for example based on 1-7 RLL (Run Length Limited) coding. When the read access is performed, demodulated sector read data is decoded according to the 1-7 RLL code. Then, after the CRC check is carried out by the ECC processing unit 14-2 , an error detection is carried out to correct the data. Further, the formatter 14-1 forms a stream of NRZ read data by connecting sets of NRZ data together in sector units. As a result, the stream of NRZ read data is transmitted to the higher unit.

An LSI write circuit 20 is provided for the optical disk controller 14 , and a write modulation unit 21 and a laser diode (LD) control circuit 22 are provided for the LSI write circuit 20 . The laser diode control circuit 22 outputs control signals to a laser diode unit 30 , which is provided on an optical unit of the housing 11 .

A set of a laser diode 30-1 and a monitoring photodetector (PD) 30-2 is provided in the laser diode unit 30 . The write modulation unit 21 converts write data based on the PPM (pit position modulation) recording method or the PWM [Pulse Width Modulation] recording method. The recording medium is formatted in accordance with the zoned CAV (Zoned Constant Angular Velocity) format.

In the PPM recording process, data is extracted speaking of the presence of a mark recorded that is provided on the recording medium. With the PWM Recording methods, data according to the foreground or back edge of the mark recorded on the on drawing medium is provided.

When a cassette with a magneto-optical disc is loaded in a magneto-optical disc drive, an ID part of a magneto-optical disc is read. The MPU 12 recognizes the type, that is, the capacity of the recording medium from the dimple interval that is provided in the ID part, and reports the type of the LSI write circuit 20 .

The write data from the magneto-optical disk controller 14 are converted into PWM record data by the write modulation unit 21 . The PWM recording data, which are converted by the write modulation unit 21, are supplied to the laser diode control circuit 22 . The laser diode control circuit 22 controls the laser diode 30-1 to emit the laser based on the PWM record data converted by the write modulation unit 21 .

A high-frequency fade-in circuit 23 cross- fades a write data signal at a high frequency in order to suppress a back-talk phenomenon.

Information based on the PWM recording data is recorded on the recording medium by the laser emitted by the laser diode 30-1 .

When data is read, reflected light from the magneto-optical disk is detected by an MO / ID detector 32 . After a detection signal of the MO / ID detector 32 is amplified by a head amplifier 34 , the signal is fed to an LSI reading circuit 24 . The LSI read circuit 24 includes a read demodulation unit 25 and a frequency synthesizer 26 .

In the read demodulation unit 25 of the LSI read circuit 24 , an AGC (Automatic Gain Control) circuit (automatic gain control circuit), a filter and a sector mark detection circuit are internally provided. On the basis of an MO signal or an ID signal, which is provided via the head amplifier 34 after it is detected by the MO / ID detector 32 , a read clock and read data are generated, and the PWM record data are stored in the NRZ -Demodulated data.

The frequency synthesizer 26 includes a PLL circuit that includes a programmable frequency divider. Furthermore, the frequency synthesizer 26 is controlled based on zoned areas on the recording medium determined by the MPU 12 and generates a reference clock with an identical frequency based on each zoned area of the recording medium as a reading clock. The frequency synthesizer 26 generates the reference clock for a frequency f0,
that is, f0 = (m / n) .f1,
based on a frequency division ratio (m / n) set by the MPU 12 and corresponding to a zone number, and a frequency fi of a reference signal. A denominator n of the frequency division ratio (m / n) is a value corresponding to the capacity of the recording medium. Further, a counter m of the frequency division ratio (m / n) is a value corresponding to a position in the zoned area of the recording medium. The counter m corresponds to one of the zone numbers of the zoned areas of each recording medium type and is previously stored in an information table.

The read data, which are demodulated by the LSI read circuit 24 , are supplied to the optical disk controller 14 . After 1-7 RLL encoded data is decoded and the CRC check and the ECC process are performed by an encoding function of the ECC processor unit 14-2 , the NRZ read data for each sector is decoded. After the Forma tierer 14-1 forms a data stream by connecting the NRZ read data sector by sector, the data stream is then transmitted through the buffer memory 18 via the interface 17 .

A detection signal of a temperature sensor 36 , which is provided in the housing 11 , is supplied to the MPU 12 via the DSP 16 . Based on the ambient temperature in the magneto-optical disk drive 1 , which is detected by the temperature sensor 36 , the MPU 12 controls the laser energy for reading, writing or erasing at a suitable level.

The MPU 12 controls a spindle motor 40 , which is provided in the housing 11 , using a driver 38 via the DSP 16 . Since the recording format for the MO cassette is a zoned CAV format, the MPU 12 rotates the spindle motor 40 at a constant speed, such as 4500 rpm.

In addition, the MPU 12 controls an electromagnet 44 , which is provided in the housing 11 , via the DSP 16 and a driver 42 . The electromagnet 44 is opposed to a beam irradiation side of the MO cartridge loaded in the magneto-optical disk drive 1 and externally supplies a magnetic field to the recording medium when data is recorded or erased. A permanent magnet is combined with the electromagnet 44 .

The DSP 16 includes a servo function to position a laser beam from the laser diode 30-1 on the recording medium and controls the search for a target track and the positioning on the track. This search control is carried out simultaneously while a write or read access is being performed by the MPU 12 based on a command reported by a higher unit.

Detection signals from an FES [focus error signal] (focus error signal) detector 45 and a TES [track error signal] (track error signal) detector 47 are supplied to the DSP 16 . A detection signal, which is detected by the FES detector 45 , is fed to an FES detection circuit 46 , which is connected to the DSP 16 . The FES detection circuit 46 generates a focus error signal from the detection signal, which is detected by the FES detector 45 .

Furthermore, the detection signal, which is detected by the TES detector 47 , is fed to a TES detection circuit 48 , which connects to the DSP 16 . The TES detection circuit 48 generates a tracking error signal from the detection signal, which is detected by the TES detector 47 .

A tracking error signal is supplied to a TZC (Track Zero Cross) detection circuit 50 from the TES detection circuit 48 . The TZC detection circuit 50 detects a track zero crossing level from the track error signal. For example, the TZC detection circuit 50 detects an intermediate value of an upper level and a lower level of the tracking error signal as a zero crossing level.

A lens position sensor 54 is provided in an optical head to detect a lens position of an objective lens that directs the laser beam onto the recording medium. A detection signal from the lens position sensor 54 is supplied to the DSP 16 . The DSP 16 is connected by drivers 58 , 62 and 66 to a focus actuator 60 , a lens actuator 64 and a positioner 68 such as a voice coil motor (VCM) and controls a position of the objective lens by operating the focus actuator 60 , of the lens actuator 64 and the positioner 68 based on the detection signal of the lens position sensor 54 , the focus error signal and the tracking error signal.

A mechanical configuration of the magneto-optical disk drive 1 will now be described.

Fig. 2 is a diagram showing an internal configuration of the conventional magneto-optical disk drive.

Regarding the configuration of the magneto-optical disk drive 1 , a loading mechanism 71 , a spin motor 40 , an optical head 73 , a positioner 74 , a fixed optical system 78 and an electromagnet 75 are internally mounted in a housing 67 .

The cassette with the magneto-optical disk 70 is inserted into the disk drive 1 from an inlet door 69 . The tape with the magneto-optical disk 70, which is inserted into the disk drive 1, is loaded by the loading mechanism 71 to a predetermined position in the disk drive. 1

When the cassette with the magneto-optical disk 70 is loaded to the predetermined position by the loading mechanism 71 , a magneto-optical disk 72 which is mounted in the cassette of the magneto-optical disk 70 is engaged with the spindle motor 40 .

The spindle motor 40 rotates the magneto-optical disk 72 . The optical head 73 is positioned to a Oberflä surface of the magneto-optical disc to face 72, and directs a laser beam on the surface of the magneto-optical disk 72nd The optical head 73 is supported by the positioner 74 and also moved by the positioner 74 in a radial direction of the magneto-optical disk 72 , that is, in a direction indicated by an arrow A.

A laser beam is supplied to the optical head 73 from the fixed optical system 73 . While the fixed optical system 78 to the optical head 73 supplies a laser beam, said fixed optical system 78 detected at the same time a laser beam which returns through the optical head 73rd

On the other side of the surface of the magneto-optic plate 72 , the electromagnet 75 is positioned so as to face the optical head 73 . Information is recorded on the magneto-optical disk 72 by a magnetic field applied by a laser beam emitted from the optical head 73 and the electromagnet 75 .

A configuration of the fixed optical system 78 of the magneto-optical disk drive 1 will now be described.

Fig. 3 is a schematic diagram showing the fixed optical system of the conventional magneto-optical disk drive.

The fixed optical system 78 includes the laser diode 30-1 of FIG. 1, a collimator lens 30-11 , the monitoring photodiode (monitoring PD) 30-2 of FIG. 1, an optical composite element 30-3 , beam splitter 30-4 and 30-6 , a lens 30-5 , a Wollaston prism unit 30-7 , the FES detector 45 of FIG. 1, the TES detector 47 of FIG. 1 and the MO / ID detector 32 of FIG. 1.

The laser diode 30-1 emits a laser beam. The laser beam emitted from the laser diode 30-1 is supplied to the collimator lens 30-11 . The collimator lens 30-11 collimates the laser beam which is emitted and emitted by the laser diode 30-1 .

The laser beam collimated 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 through the collimator lens 30-11 into two beams which are directed in different directions. One laser beam is guided in one direction to the magneto-optical disk 72 , and another laser beam is guided in another direction to the monitoring photodiode 30-2 .

The monitoring photodiode 30-2 monitors the amplitude of the laser beam which is supplied to the magneto-optical disk 72 , which beam results from the separation by the optical composite element 30-3 . A laser beam reflected from the magneto-optical disk 72 is supplied to the composite optical element 30-3 . The composite optical element 30-3 diffracts the laser beam reflected from the magneto-optical disk 72 toward a plurality of detectors such as the MO / ID detector 32 , the FES detector 45 and the TES detector 47 . Further, the laser beam reflected from the magneto-optical disk 72 and supplied through the composite optical element 30-3 is transmitted through the beam splitter 30-4 in one direction toward the MO / ID detector 32 and in another direction toward that FES detector 45 and the TES detector 47 split.

The laser beam, which was split off by the beam splitter 30-4 in the direction towards the MO / ID detector 32 , is supplied to the MO / ID detector 32 through a Wollaston prism unit 30-7 . The MO / ID detector 32 detects data elements and an ID element from the laser beam reflected from the magneto-optical disk 72 . On the other hand, the laser beam that has been split in the direction toward the FES detector 45 and the TES detector 47 is further separated into an FES element and a TES element by using the lens 30-5 and the beam splitter 30-6 passes through. As a result, the FES element is supplied to the FES detector 45 , and the TES element is supplied to the TES detector 47 .

Each of the signals detected by the FES detector 45 , the TES detector 47 and the MO / ID detector 32 is supplied to the control unit 10 shown in FIG. 1.

In this type of conventional information storage device, as mentioned above, when a laser beam is continuously emitted, a part of the laser beam is caused, which is reflected by the magneto-optical disk 72 and returns to the laser diode 30-1 and with a broken line in FIG. 3 Line is shown, a secondary resonance in the laser diode 30-1 . Thus, the laser diode 30-1 can not emit a stable laser beam. That is, there is a feedback phenomenon.

To suppress the feedback phenomenon, the laser diode 30-1 is controlled to be ON or OFF in response to a frequency determined by the path length. The ON / OFF control is referred to as high-frequency fade-in operation.

Traditionally, this is high frequency fade-in ration only carried out when data is read.

Fig. 4 is a diagram for explaining a state of a high-frequency fade-in operation of the conventional magnetic to-optical disk drive.

In Fig. 4, a horizontal axis denotes a drive current ILD of the laser diode 30-1 , and a vertical axis denotes a laser energy PLD of the laser diode 30-1 .

In FIG. 4, characteristics shown in the first quadrant A1 with a continuous line, CHARACTERI stiken the laser diode 30-1, and the drive current as shown A4 in the fourth quadrant when an erase, write or read operation is performed, is supplied at timings shown in the third quadrant A3. Further, when the laser diode 30-1 is driven by the drive current shown in the fourth quadrant, the laser emission operation is performed with the characteristics shown in the first quadrant A1, and a laser is emitted with the laser energy as it is shown in the second quadrant A2.

From US 4,416,002 A is a recording / re-recording system with a laser beam and a plate system the task known to detect track position errors and To prevent dislocations. This publication discloses no indication of a means to reduce crosstalk grace when data is recorded, read or deleted become.

A light modulation method is known from US Pat. No. 5,631,890 ren known for optical disk drives, in which a Laser beam is modulated to crosstalk only when Reduce reading. An indication of a reduction in the Crosstalk when writing data is this pressure font not to be extracted.

SUMMARY OF THE INVENTION

The object of the present invention is to provide information Mation storage device to provide a demeanor quality of reading, erasing and writing Prevent data from appearing and the Reliability when reading, deleting and writing data can improve.

The above objects of the present invention will be achieved by an information storage device for optical Record and / or read information on and / or achieved by a recording medium containing: one Laser beam generating part that generates a laser beam, which irradiates the recording medium; a modulation part which is a modulation with a frequency that differs from a data recording frequency to which Applies laser beam generated by the laser beam  part is generated; and a modulation control section that the Modulation controls that by the modulation part on the Laser beam is applied.

According to the present invention, it is possible to use one Crossfade laser beam with a high frequency so that the feedback phenomenon is suppressed. Therefore, the Feedback is suppressed when data is saved be written or deleted, and then the Stability when recording and writing information be improved. In addition, the present invention  can be used to reduce the appearance of feedback press that by identical characteristics or the environment of the Device is caused, and then stability improved when recording and writing information become.

Other objectives, features and advantages of the present Invention will emerge from the following detailed description in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a block diagram showing a conventional magneto-optical disk drive;

Fig. 2 is a diagram showing an internal configuration of the conventional magneto-optical disk drive;

Fig. 3 is a schematic diagram showing a fixed optical system of the conventional magneto-optical disk drive;

Fig. 4 is a diagram for explaining a state of a high-frequency fade-in operation of the conventional magnetic-to-optical disk drive;

Fig. 5 is a block diagram showing a magneto-optical disk drive according to an embodiment of the present invention;

Fig. 6 is a block diagram showing main parts of the LSI write circuit according to the embodiment of the present invention;

Fig. 7 is a block diagram showing a circuit for generating a confi guration Hochfrequenzeinblendsignals according to the embodiment of the present invention;

Fig. 8 is a block diagram showing a variant of the circuit configuration for generating the blend Hochfrequenzein signal according to the embodiment of the present invention;

Fig. 9 is a flowchart for explaining a Prozes ses for the read operation according to the embodiment of the present invention;

Fig. 10 is a flowchart for explaining a first variation of the reading process according to the embodiment of the present invention;

Fig. 11 is a flowchart for explaining a two-th variant of the reading process according to the embodiment of the present invention;

Fig. 12 is a flowchart for explaining a variant of the drit th reading process according to the embodiment of the present invention;

Fig. 13 is a flowchart for explaining a four-th variant of the reading process according to the embodiment of the present invention;

Fig. 14 is a flow chart for explaining the write-making process according to the embodiment of the present OF INVENTION;

Fig. 15 is a flowchart for explaining a Vari ante the writing process according to the embodiment of the present invention;

Fig. 16 is a diagram showing a condition in which the high-frequency fade-in operations are performed on the reading system; and

Fig. 17 is a diagram showing a condition in which the high-frequency fade-in operation is performed on the erase system, the write system and the read system.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Fig. 5 is a block diagram showing a magneto-optical disk drive according to an embodiment of the present invention. In Fig. 5, parts that are the same as those of Fig. 1 are given the same reference numerals and their explanations are omitted.

A magneto-optical disk drive 90 , which corresponds to an information storage device according to the embodiment, includes processes of an MPU 91 and a configuration of an LSI write circuit 92 , whereby a high frequency can be faded in when data is written, erased or read.

In the embodiment, it is possible to fade in high frequencies by the MPU 91 and the LSI write circuit 92 so as not to suppress the feedback phenomenon not only when data is read but also when data is erased or written. In addition, in the configuration of the embodiment, it is possible to set the amplitude and frequency different from each of a write process, an erase process and a read process to fade in a high frequency. It is also possible to change the amplitude and frequency to suppress the feedback when an error occurs or an ambient temperature is changed. In this case, a frequency range between 50 MHz and 1 GHz is used to fade in a high frequency. And the amplitude in a reading system is in the range between 0 and 35% with respect to the modulation rate, and the amplitude in an erasing system or a writing system is between 0 and 200% in terms of the modulation rate. The modulation rate is also given by the following expression:

(B / a) .100%

where a denotes a direct current energy and b the ampli called tude.

Furthermore, it is possible in this embodiment, the Modulation rate to control an appropriate ratio for everyone of the reading process, the writing process and the Setting the deletion process to a high frequency dazzle.  

A high-frequency fade-in circuit 93 , which is provided in the LSI write circuit 92 , controls the fade-in of a high frequency.

Fig. 6 is a block diagram showing main parts of the LSI write circuit according to the embodiment of the present invention.

The Hochfrequenzeinblendschaltung 93 includes a write circuit 93a, an erase circuit 93 b, and c a read circuit 93rd The write circuit 93 a generates a write current based on write data when data is written, and fades in a high frequency with the write current.

The write circuit 93 a includes a WP [write-power] - (write power) current DAC register 101, a WP (write energy) -Hochfrequenzeinblend DAC register 102, DACs 103 and 104, variable current sources 105 and 106 , Gate circuits 107 and 108 .

Digital data based on the write energy is set in the WP current DAC register 101 . Digital data based on high-frequency fade-in energy for fading the write energy is set in the WP high-frequency fade-in DAC register 102 .

The DAC 103 is supplied with data based on the write energy set by the write energy current DAC register 101 . The DAC 103 converts the data supplied by the write power current DAC register 101 into an analog signal.

The DAC 104 is supplied with data based on the high-frequency fade-in energy, which is intended to fade the write energy and is set by the WP high-frequency fade-in DAC register 102 . The DAC 104 converts data into an analog signal based on the high-frequency fade-in energy set by the WP high-frequency fade-in DAC register 102 .

The analog signal converted by the DAC 103 is supplied to the variable current source 105 . The variable current source 105 receives a constant current based on the analog signal supplied by the DAC 103 from the laser diode 30-1 in FIG. 5 via the gate circuit 107 .

The analog signal converted by the DAC 104 is supplied to the variable current source 106 . The variable current source 106 receives a constant current based on the analog signal supplied by the DAC 104 from the laser diode 30-1 in FIG. 5 via the gate circuit 108 .

The gate circuits 107 and 108 are supplied with a write gate signal for a write time for writing data. Gate circuits 107 and 108 control an incoming write current from laser diode 30-1 through variable current sources 105 and 106, respectively, in response to the write gate signal. In this case, the gate circuit 108 is supplied with a high frequency fade-in signal in addition to the write gate signal. The gate circuit 108 receives a current based on the high-frequency fade-in signal from the laser diode 30-1 for an ON time of the write gate signal.

When data is written, an incoming current from the laser diode 30-1 is controlled by the gates 107 and 108 , and the laser diode 30-1 is controlled by a current that fades the write current at the high frequency fade-in signal. Accordingly, when data is written, the laser diode 30-1 emits a laser beam by the current that fades the write current at the high-frequency fade-in signal, and then information is written on the magneto-optical disk.

The erase circuit 93 b contains an EP (erase power) current DAC register 109 , an EP high-frequency fade-in DAC register 110, DACs 111 and 112 , variable current sources 113 and 114 and gate circuits 115 and 116 .

Digital data based on the extinguishing energy are stored in the EP stream DAC register 109. Digital data on  the basis of a high-frequency fade-in energy for cross-fading of the extinguishing energy are stored in the EP high-frequency fade-in DAC Register 110 set.

The DAC 111 is supplied with data based on the erasing energy, which is set by the EP current DAC register 109. The DAC 111 converts the data supplied by the EP stream DAC register 109 into an analog signal.

The DAC 112 is supplied with data based on the high-frequency fade-in energy which is intended to fade the erase energy and is set by the EP high-frequency fade-in DAC register 110. The DAC 112 converts data into an analog signal based on the high frequency fade in energy set by the EP high frequency fade in DAC register 110.

The analog signal converted by the DAC 111 is supplied to the variable current source 113 . The variable current source 113 receives a constant current based on the analog signal supplied by the DAC 111 from the laser diode 30-1 through the gate circuit 115 .

The analog signal converted by the DAC 112 is supplied to the variable current source 114 . The variable current source 114 receives a constant current based on the analog signal supplied by the DAC 112 from the laser diode 30-1 through the gate circuit 116 .

An erase gate signal for an erase time for erasing data is supplied to the gate circuits 115 and 116 . The gate circuits 115 and 116 control an incoming erase current from the laser diode 30-1 through the variable current sources 113 and 114 in response to the erase gate signal. In this case, the gate circuit 116 is supplied with a high-frequency fade signal. Gate circuit 116 controls an incoming high frequency fade current from laser diode 30-1 through variable current source 114 in response to the high frequency fade signal for the ON time of the erase gate signal.

In this way, when data is erased, an incoming current from the laser diode 30-1 is controlled by the gate circuits 115 and 116 , and the laser diode 30-1 is controlled by a current which is faded in by the erase energy at the high-frequency fade-in energy. Accordingly, when data is erased, the laser diode 30-1 emits a laser beam by the current faded in by the erase energy at the high-frequency fade-in energy, and then information written on the magneto-optical disk is erased.

The reading circuit 93 c contains an RP (read power) current DAC register 117 , an RP (read energy) high-frequency fade-in DAC register 118 , DACs 119 and 120 , variable current sources 121 and 122 and Gates 123 and 124 .

Digital data based on the read energy is set in the RP current DAC register 117 . Digital data based on a high-frequency fade-in energy for fading the read energy is set in the RP high-frequency fade-in DAC register 118 .

The DAC 119 is supplied with data based on the read energy set by the RP current DAC register 117 . The DAC 119 converts the data supplied by the RP current DAC register 117 into an analog signal.

The DAC 120 is supplied with data based on the high-frequency fade-in energy which is intended to fade over the read energy and is set by the RP high-frequency fade-in DAC register 118 . The DAC 120 converts the data into an analog signal based on the radio frequency overlay energy set by the RP radio frequency overlay DAC register 118 .

The analog signal converted by the DAC 119 is supplied to the variable current source 121 . The variable current source 121 receives a constant current based on the analog signal supplied by the DAC 119 from the laser diode 30-1 through the gate circuit 123 .

The analog signal converted by the DAC 120 is supplied to the variable current source 122 . The variable current source 122 receives a constant current based on the analog signal supplied by the DAC 120 from the laser diode 30-1 through the gate circuit 124 .

The gate circuits 123 and 124 are supplied with a read gate signal for a read time for reading data. The gate circuits 123 and 124 control the incoming read current from the laser diode 30-1 through the variable current sources 121 and 122, respectively, in response to the read gate signal. In this case, the gate circuit 124 is supplied with a high-frequency fade signal. The gate circuit 124 controls the incoming high frequency fade in current from the laser diode 30-1 through the variable current source 122 in response to the high frequency fade in signal for the ON time of the read gate signal.

In this way, when data is read, an incoming current from the laser diode 30-1 is controlled by the gate circuits 123 and 124 , and the laser diode 30-1 is controlled by a current that is faded in by the read energy at the high-frequency fade-in energy. Accordingly, when data is read, the laser diode 30-1 emits a laser beam by the current faded in by the read energy at the high-frequency fade-in energy, and then information is read from the magneto-optical disk.

In this method, the amplitude for each of the write operation, the erase operation or the read operation is determined by the digital data which is faded in by the WP high frequency DAC register 102 , the EP high frequency fade in DAC register 110 and the RP high frequency fade in, respectively -DAC registers 118 are set, controlled independently. Thus, it is possible to write, erase, or read data using the appropriate high-frequency fade-in energy.

Now an adjustment operation of the high frequency becomes glare signals described.

Fig. 7 is a block diagram showing a circuit for generating a confi guration Hochfrequenzeinblendsignals according to the embodiment of the present invention.

A write synthesizer 200 is used to generate the high frequency fade-in signal which is applied to the gate circuits 108 , 116 and 124 in FIG. 6. The write synthesizer is connected to the MPU 91 via a bus 94 , for example, and outputs a high-frequency fade-in signal that has a frequency based on the data supplied by the MPU 91 .

With this configuration, it is possible to change a frequency of the high-frequency fade-in signal supplied to the gate circuits 108 , 116 and 124 in FIG. 6. Therefore, it is possible to set an appropriate frequency of the high frequency fade-in signal, whereby the Rücksprerschei tion can be suppressed.

In this embodiment, the radio frequency becomes on dazzle signal for the write operation, the erase operation and shared the read operation. Alternatively, however an identical high-frequency insertion signal for each of the above Operation can be provided.

Fig. 8 is a block diagram showing a variant of the circuit configuration for generating the blend Hochfrequenzein signal according to the embodiment of the present invention.

In this variant of the embodiment, a write register 201 , an erase register 203 and a read register 205 are connected to the MPU 91 via the bus 94 . The MPU 91 sets digital data in the write register 201 based on a frequency of the high-frequency fade-in signal to be faded in when data is written. The MPU 91 also sets digital data in the read register 205 based on a frequency of the high-frequency fade-in signal to be faded in when data is read.

The write register 201 supplies the digital data set by the MPU 91 to a write synthesizer 202 . The write synthesizer 202 supplies the high-frequency fade-in signal at the frequency based on the digital data set by the write register 201 to the gate circuit 108 in FIG. 6.

The erase register 203 supplies the digital data set by the MPU 91 to an erase synthesizer 204 . The erase synthesizer 204 supplies the high-frequency fade signal with the frequency based on the digital data set by the erase register 203 to the gate circuit 116 in FIG. 6.

The read register 205 supplies the digital data set by the MPU 91 to a read synthesizer 206 . The read synthesizer 206 supplies the high-frequency fade signal at the frequency based on the digital data set by the read register 205 to the gate circuit 124 in FIG. 6.

With this configuration, the MPU 91 sets identical data in the write register 201 , the erase register 203 or the read register 205 . Therefore, it is possible to fade in the high-frequency fade-in signal which has an identical frequency in the write operation, the erase operation or the read operation.

An operation of the MPU 91 will now be described.

First, the operation of the MPU 91 when reading data is described.

Fig. 9 is a flowchart for explaining a Prozes ses for a read operation according to the embodiment of the present invention.

In an initial state, data is set in the RP high frequency fade-in DAC register 118 in Fig. 6 so as not to fade in a high frequency (step S1-1).

Reading of data is started (step S1-2).

It is determined whether data has been read correctly and corrected by the ECC at step S1-2 leads (step S1-3).

If it is determined at step S1-3 that data is correct are read and a correction by the ECC is correct the process is ended.

On the other hand, if it is determined at step S1-3 that data has not been read correctly or a correction by the ECC has not been carried out correctly, data is set in the RP high frequency fade-in DAC register 118 in Fig. 6 to fade in a high frequency (Step S1-4).

It is determined whether the number of rereading is less than a specified number (step S1-5).

If it is determined in step S1-5 that the number of repeated readings less than a specified number the process goes to step S1-2. And the high one Frequency is faded in by the data at step S1-4 have been set and the read operation is performed.

On the other hand, if it is determined at step S1-5 that the number of rereading not less than one is the specified number, the reading process is ended (Step S1-6).

The high frequency fade-in process, as mentioned above, based on an occurrence of errors when data be read, ON or OFF. Therefore it is possible that To suppress the occurrence of errors.

In this embodiment, the radio frequency fade in process simply ON or OFF, but a high level Frequency to fade in can be based on the number of repeated reading can be changed.  

A flowchart for explaining a first variation of the reading process Fig. 10 according to the embodiment of the present invention. In Fig. 10, steps that are the same as those of Fig. 9 are given the same reference numerals and their explanations are omitted.

In the first variant, if data is not successful read richly (steps S1-2 and S1-3), the number repeated reading N whenever data is read are incremented by 1 (step S2-1). At step S2-2 it is determined whether the number of rereading N, the incremented at step S2-1 is even.

If the number of rereading N at step S2-2 is even, a high frequency level becomes Fade in set to be higher (step S2-3). On the other hand, if the number of times is repeated at step S2-2 ten reading N is odd, the level of a high Fre lower fade-in frequency. While the number of the repeated reading N is less than a specified one Is the level of a high frequency to fade in the changed to be lower or higher, and the Read operation is repeated.

According to the first variant, it is possible if a Le error has occurred, an appropriate level of high frequency to fade in by changing the level too find and read data at the same time.

In the first variant, the level of a high Fre changed the fade-in sequence. Alternatively, one can Frequency changed to fade in a high frequency become.

Fig. 11 is a flowchart for explaining a two-th variant of the reading process according to the embodiment of the present invention. In Fig. 11, steps that are the same as those of Fig. 10 are given the same reference numerals and their explanation is omitted.

The second variant is based on the a frequency to fade in at step S2-1 high frequency set to be higher when the Repeated reading N is even, and Fre the frequency for fading in a high frequency is set, to be lower if the number of times repeated Reading N is odd. While the number of times repeated Reading N is less than a specific number, the Frequency to fade in a high frequency changed to to be higher or lower and data is repeated read.

According to the variant, it is possible if there is a reading error occurred, an appropriate level of a high Fre to find a fade in by changing the level and read data at the same time.

In the first and second variants, the level and the frequency for fading in a high frequency on the N changed based on the number of repeated reads. however can easily be a function of a temperature Condition of the magneto-optical disk can be changed. So the level of a high frequency to fade in on the Base of temperature changed. The amplitude that the Fade in a high frequency based on the temperature is controlled, is between 0 and 50% in terms of Modulation rate. The modulation rate is the same as that in the explanation regarding the amplitude to fade in a high frequency in the reading system or in the erase or writing system.

Fig. 12 is a flowchart for explaining a variant of the drit th reading process according to the embodiment of the present invention. In Fig. 12, steps that are the same as those of Fig. 10 are given the same reference numerals and their explanation is omitted.

If, in the third variant, data in step S1-2 are not read successfully, the temperature is measured sen (step S4-1).

If the temperature is measured in step S4-1, it is determined whether a result of the temperature measurement in the Comparison to a previously measured temperature 5 ° C above or below (step S4-2).

As a result of the determination at step S4-2, if the result of the temperature measurement compared to that before measured temperature is 5 ° C above or below Level of a high frequency changed to fade in to be lower or higher (step S4-3).

For example, the determination result at step S4-2 if the result of the temperature measurement is + 5 ° C higher than the previously measured temperature, the level of one high frequency to fade in to be higher. If, on the other hand, the result of the temperature measurement is -5 ° C is lower than the previously measured temperature, the High frequency level set to fade in to be lower.

After the level to fade in a high frequency is changed at step S4-3, the temperature at Step S4-1 was measured in a register than before measured temperature stored (step S4-4).

The above process is repeated until data is successful be read or the number of repeated reads N die specific number exceeds.

In this variant, the level of a high frequency changed to fade in based on a temperature. Alternatively, a frequency for fading in a high frequency changes based on a temperature become.

Fig. 13 is a flowchart for explaining a four-th variant of the reading process according to the embodiment of the present invention. In Fig. 13, steps that are the same as those of Fig. 12 are given the same reference numerals and their explanation is omitted.

In the fourth variant, if the determin result in step S4-2 a measuring temperature of 5 ° C above or is below a previously measured temperature that Frequency set to fade in a high frequency to to be lower or higher (step S5-1).

For example, if a measured temperature is 5 ° C above the previously measured temperature, the frequency becomes Fade in a high frequency set to get higher his. On the other hand, if a measured temperature is 5 ° C below a previously measured temperature, the frequency set to fade in a high frequency to low to be more.

If an error occurred during the reading process is the level of a high frequency to fade in changed as mentioned above and data is repeated read. As a result, the error suppressed by the feedback phenomenon is caused.

A write process for the write operation will now be performed wrote.

Fig. 14 is a flowchart for explaining the writing process according to the embodiment of the present OF INVENTION dung.

In an initial state, in the writing process, data is set in the EP high-frequency fade-in DAC register 110 of Fig. 6 so as not to fade in a high frequency in the erasing system (step S6-1).

A write pad is erased where to write data are (step S6-2). The data is then screamed ben (step S6-3).

When the data is written in the write pad, the written data is read for verification (Step S6-4).  

It is determined whether those read in step S6-4 Data was written accurately (step S6-5).

If the determination result at step S6-5 be it is true that the data was written accurately the writing process ends.

On the other hand, when the determination result at Step S6-5 determines that the data is not accurate were written, the EP high-frequency fade-in opera tion ON (step S6-6), which in step S6-1 Was turned off.

If the EP high-frequency fade-in operation at step S6-6 is ON, it is determined whether the number of repeated writing less than a specified Number is (step S6-7).

If the determination result at step S6-7 is the Number of rewrites less than the spec is the counted number, the writing process returns to step S6-2 back, and the delete operation, the write operation, and the Verification read operations are performed again.

If when determining the result in step S6-7, the Number of rewrites equal to the specified Number or greater than this, it is determined that a Error has occurred, and then the writing process ended (step S6-8).

Even if a spelling error occurs, it is open above way possible if the number of repeated Letter is less than the specific number that Eliminate feedback when the erase opera tion is executed, and then it is possible to occur to suppress the typographical error.

In this embodiment, the EP radio frequency becomes one blend operation based on the misspellings ON or Switched off. But both the erase high-frequency fade-in dopes ration as well as the write high-frequency fade-in operation  can be switched ON or OFF based on the typing error be tested.

Fig. 15 is a flowchart for explaining a Vari ante the writing process according to the embodiment of the present invention. In Fig. 15, steps that are the same as those of Fig. 14 are given the same reference numerals and their explanation is omitted.

They are in an initial state of the writing process EP high frequency fade in operation and the WP high frequency fade in Blinding operation OFF (step S7-1). At the step S6-2 to S6-4 are the delete, write and Read operations performed.

If as a result the delete, write and Read operations at step S6-5 determine that the Reading error occurs, the erase high frequency fade-in ration ON (step S7-2), and the write high frequency fade-in operation is also turned ON (step S7- 3).

The erase high-frequency fade-in operation and the write high-frequency fade-in operation are based on the Error condition ON, as mentioned above. Therefore it is possible to reduce an effect caused by the back speech is caused, and the occurrence of the Suppress error when the write operation is complete leads.

The high frequency fade-in operation will now be described with reference to FIGS. 16 and 17. In Figs. 16 and 17, steps that are the same as those of Fig. 4 are given the same reference numerals and their explanations are omitted.

Fig. 16 is a diagram showing a condition in which the high-frequency fade-in operations are performed on the read system, and Fig. 17 is a diagram showing a condition in which the high-frequency fade-in operations are performed on the erase system, the write system, and the read system ,

In this embodiment, the delete and WP High-frequency fade-in operations simply by ON or OFF controlled. But the erase level and the write level or the erase frequency or the write frequency at Fading in a high frequency can be changed. In addition, the RP high-frequency fade-in operation can be performed at be controlled by the same procedure.

The present invention is not specific to that disclosed embodiments, changes and modifications limited, and other changes and modifications can be made without the scope of protection provided Leaving invention.

The present application is based on the Japanese Priority Application No. 11-226822, filed August 10 1999, the entire contents of which are incorporated herein by reference is.

Claims (9)

1. Information storage device for optical recording and / or reading of information on or from a recording medium with
a laser beam generating part ( 30 ) which generates a laser beam which irradiates the recording medium;
marked by
a modulation part ( 93 ) which applies modulation with a frequency different from a data recording frequency to the laser beam generating part, and
a modulation control part ( 91 ) that controls the modulation to be applied by the modulation part to the laser beam generating part ( 30 ) based on an operation mode. 2. Information storage device according to claim 1, characterized in that the modulation control part ( 91 ) can control the amplitude of the laser beam. 3. Information storage device according to claim 1 or 2, characterized in that the modulation control part ( 91 ) can control a modulation frequency to be applied to the laser beam. 4. Information storage device according to claim 1, 2 or 3, characterized in that:
an error detection part ( 14-2 ) detects an information error which results from reading the information,
in which the modulation control part ( 91 ) controls the modulation part ( 93 ) when the fault detection part ( 14-2 ) detects the fault. 5. Information storage device according to claim 4, characterized in that the modulation control part ( 91 ) controls whether an operation of the modulation is carried out or not. 6. Information storage device according to claim 1, 2 or 3, characterized by:
a temperature detection part ( 36 ) which detects an ambient temperature,
in which the modulation control part ( 91 ) controls the modulation part ( 93 ) in dependence on the ambient temperature, which is detected by the temperature detection part. 7. An information storage device according to any one of claims 1 to 6, characterized in that the modulation control part ( 91 ) controls an operation of the modulation to be applied by the modulation part ( 93 ) to the laser beam generating part ( 30 ) which applies the laser beam to the recording medium emitted when information is read out. 8. An information storage device according to any one of claims 1 to 7, characterized in that when information recorded on the recording medium is erased, the modulation control part ( 91 ) controls an operation of the modulation by the modulation part ( 93 ) the laser beam generating part ( 30 ) is to be applied, which emits the laser beam onto the recording medium. The information storage device according to any one of claims 1 to 8, characterized in that when information is recorded on the recording medium, the modulation control part ( 91 ) controls an operation of the modulation to be applied by the modulation part ( 93 ) to a laser beam generating part ( 30 ) which emits the laser beam onto the recording medium.