WO2004068487A1 - Data recording device, data recording method and program - Google Patents

Abstract

A data recording device comprising a controlling means for switching the pulse duty of a recording pulse in accordance with the temperature of a recording medium and/or the vicinity thereof is disclosed. The pulse duty is lowered according to the temperature to the extent that the power of a laser diode does not exceed its rated value. Namely, the pulse duty of the recording pulse is switched in stages so that the pulse duty is lowered, thereby preventing deterioration of recording characteristics when the temperature is high and so that the pulse duty is heightened so as to have the peak power of the laser diode equal to or lower than the maximum rated value when the temperature is low.

Description

 TECHNICAL FIELD The present invention relates to a data recording device, a data recording method, and a program for recording data on a magneto-optical disk of magnetic field modulation pulse recording, and more particularly, to cope with a change in environmental temperature. A data recording device, a data recording method, and a program. .

 This application claims priority on the basis of Japanese Patent Application No. 2003-2003, filed on January 31, 2003 in Japan. This application is incorporated herein by reference. BACKGROUND ART Disk-shaped recording media such as optical disks and magneto-optical disks as portable media have become widespread. In particular, a magneto-optical disk (MO disk) that can be rewritten overnight is suitable as a medium for computer use.

As a recording / reproducing device corresponding to the above-described magneto-optical disk, there is known a device adopting a magnetic field modulation system as a data recording system. In the magnetic field modulation method, a magnetic field modulated by recording data is applied from a magnetic head to the recording surface of the disk, and a constant amount of laser light is continuously irradiated (simple magnetic field modulation method), or pulse light emission is synchronized with the recording data. (Laser strobe magnetic field modulation method). As a result, an N or S magnetic field corresponding to the recording data is applied to the recording surface of the disk, and data as magnetic field information is recorded. In such a magnetic field modulation method, it is known that the asymmetry (asymmetry) of recording pits (recording signals) is small in principle, and as a result, a severe read data level can be obtained. For example, it is also effective when a multi-value detection method such as a partial response method is adopted. In recent years, as a technique for increasing the recording density of such a magneto-optical disc, a magneto-optical disc having at least three layers, a moving layer, a switching layer, and a memory layer, has been used as a magnetic layer to record data on a memory layer. A technique called domain wall displacement super-resolution magneto-optical reproduction (DWDD), which utilizes the fact that the size of the magnetic domain is substantially enlarged in the moving layer, has attracted attention. ing.

The DWDD irradiates a laser beam for reproduction during the reproduction of an information signal, and the magnetic coupling between the memory layer and the moving layer corresponding to the region in the switching layer where the Curie temperature or higher is cut off In this way, the domain wall moving in the region of the moving layer corresponding to the region where the magnetic coupling has been cut is detected, whereby the size of the magnetic domain recorded in the memory layer is substantially reduced. It expands in the moving layer and increases the reproduction carrier signal.

 By the way, in such a magneto-optical disk recording and Z or reproducing apparatus, an optical pickup used for recording and / or reproducing an information signal on the disk is affected by an ambient environmental temperature. Servo characteristics may deteriorate. Therefore, an optical pickup drive control device that controls the drive of the optical pickup without depending on the environmental temperature is described in Japanese Patent Laid-Open Publication No. 7-014192.

 In the technology described in this publication, a sensor for detecting the temperature of the optical pickup, an electronic volume for variably adjusting the constant of the drive control of the optical pickup, and an electronic program based on the temperature information detected by the temperature sensor. It has a control unit that controls variable adjustment, and the drive control constant is modulated according to the temperature information detected by the temperature sensor, so that drive control can be performed in response to changes in the temperature characteristics of the optical pickup. The purpose of the present invention is to prevent the deterioration of the servo characteristics due to environmental temperature.

However, changes in the environmental temperature may not only degrade the servo characteristics but also degrade the recording characteristics. Generally, in magnetic field modulation pulse recording, the quality of recording marks can be improved by reducing the recording pulse width. In particular, in a system with a high recording density in which the above-mentioned DWDD is adopted, the mark cannot be recorded clearly at high temperatures at the time of recording, and the recording characteristics are easily degraded. It is preferable to reduce the pulse width. In order to obtain the laser power necessary to raise the laser temperature to the desired temperature, the peak power of the recording pulse must be further increased, and a larger LD (laser diode) emission power is required. Therefore, the pulse width cannot be narrowed unnecessarily. In this specification, the energy of laser light obtained from the pulse width and peak power of a recording pulse is referred to as laser power (average power). DISCLOSURE OF THE INVENTION A data recording apparatus according to the present invention applies a modulation magnetic field modulated by recording data to a recording medium as a recording magnetic field, and irradiates a recording surface of the recording medium with laser light. In a data recording apparatus for performing data recording on a recording medium, control means for switching a pulse width of a recording pulse for driving the light source of the laser beam to emit light according to the temperature of the recording medium and Z or its vicinity is provided. It is characterized by having. In the present invention, the pulse width of the recording pulse is switched according to the temperature of the recording medium and / or the vicinity thereof.For example, the pulse width is reduced at a high temperature to prevent the recording characteristics from deteriorating, and the pulse is reduced at a low temperature. It is possible to obtain a desired laser beam capable of increasing the width to raise the temperature of the recording medium to a certain temperature. Further, the control means reduces the pulse width as the temperature of the recording medium and / or the vicinity thereof increases, and increases the pulse width as the temperature of the recording medium and Z or the vicinity thereof decreases. The pulse width can be switched stepwise, and a predetermined temperature range is set, and the pulse width is set to a small value within the range that does not exceed the peak power rating of the recording pulse as the optimum pulse width corresponding to this. can do.

 Further, the control means switches the pulse width according to the temperature of the recording medium and / or the vicinity thereof and the pulse width with reference to a table indicating necessary peak power measured in advance. By referring to the table, the pulse width can be quickly and accurately switched and selected.

The data recording method according to the present invention includes the steps of: In a data recording method of applying data to a recording medium as a field and irradiating a recording surface of the recording medium with a laser beam to record data on the recording medium, the recording medium and / or its vicinity A control step of switching a pulse width of a recording pulse for driving the light source of the laser beam to emit light in accordance with the temperature of the laser beam. A program according to the present invention causes a computer to execute the above-described data recording process. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graph showing the recording characteristics of an MD (mini-disc) 3 at a high temperature (at 70).

 FIG. 2 is a graph showing the required peak power for each pulse width of the recording pulse at each disk temperature.

 FIG. 3 is a block diagram showing a recording / reproducing apparatus according to the embodiment of the present invention. FIG. 4 is a block diagram showing a main part for performing recording pulse control of the recording / reproducing apparatus according to the embodiment of the present invention.

 FIGS. 5A to 5D show recording data, a recording pulse when the disk temperature is 60, a recording pulse when the disk temperature is 30 and a recording when the disk temperature is 0, respectively, in the recording and reproducing apparatus according to the embodiment of the present invention. FIG. 4 is a schematic diagram showing a pulse.

 FIG. 6 is a diagram showing another example of the recording / reproducing apparatus according to the embodiment of the present invention, and is a cross-sectional view schematically showing a disk capable of detecting a temperature.

 FIG. 7 is a diagram for explaining the specifications of the next-generation MD 1 and the next-generation MD 2 shown as specific examples of the present invention, and a conventional mini-disc.

 FIG. 8 is a diagram illustrating an RS-LDC block with BIS of an error correction method in the next-generation MD1 and the next-generation MD2 shown as a specific example of the present invention.

 FIG. 9 is a diagram for explaining a BIS arrangement in one recording block of the next-generation MD 1 and the next-generation MD 2 shown as a specific example of the present invention.

FIG. 10 shows an area on a disk surface of a next-generation MD 1 shown as a specific example of the present invention. It is a schematic diagram explaining a structure.

 FIG. 11 is a schematic diagram illustrating an area configuration on a disk surface of a next-generation MD 2 shown as a specific example of the present invention.

 FIG. 12 is a schematic diagram illustrating an area configuration on a board when mixed with data and PC data on a next-generation MD1 disc shown as a specific example of the present invention.

 FIG. 13 is a schematic diagram illustrating a data management structure of the next-generation MD 1 shown as a specific example of the present invention.

 FIG. 14 is a schematic diagram illustrating the data management structure of the next-generation MD 2 shown as a specific example of the present invention.

 FIG. 15 is a schematic diagram illustrating the relationship between the data block and the ADIP sector structure of the next-generation MD1 and the next-generation MD2 shown as a specific example of the present invention.

 FIG. 16A is a schematic diagram showing the ADIP data structure of the next-generation MD2, and FIG. 16B is a schematic diagram showing the ADIP data structure of the next-generation MD1.

 FIG. 17 is a schematic diagram illustrating a modification of the data management structure of the next-generation MD 2 shown as a specific example of the present invention.

 FIG. 18 is a block diagram illustrating a disk drive device that performs recording and reproduction with compatibility with the next-generation MD 1 and the next-generation MD 2 as a specific example of the present invention.

FIG. 19 is a block diagram illustrating a media drive section of the disk drive device. BEST MODE FOR CARRYING OUT THE INVENTION In a magnetic field modulated pulse recording method, the temperature of a portion of a magneto-optical disk irradiated with laser light rises and the Curie point, which is the critical temperature at which spontaneous magnetization disappears, or When the temperature reaches the vicinity temperature, the spontaneous magnetization disappears or becomes extremely small. Therefore, the spontaneous magnetization of the above-mentioned portion can be aligned in a certain direction by applying a magnetic field having an appropriate intensity from the outside. In addition, laser light is applied as a pulse for each clock. By doing so, the edges of the pits become clear and high-density recording pits can be formed.

 In such a magnetic field modulated pulse recording method, if the temperature of the magneto-optical disk rises due to an increase in the environmental temperature inside or outside the device, the magneto-optical disk rises to the Curie point even if the laser power of the light beam is small. Recording becomes possible. However, in systems that record very small marks, noise increases at high temperatures, making it difficult to record clean pits and deteriorating recording characteristics. On the other hand, when the temperature of the disk is low, pits can be recorded clearly, but large laser power is required. Based on such findings, the inventors of the present application have conducted intensive experiments and researches. As a result, by switching the pulse width of the recording pulse for driving the light source of the laser light in accordance with the temperature of the disk, it is possible to obtain a favorable temperature in all temperature ranges. It has been found that recording characteristics can be obtained. In other words, by setting the pulse width to be narrow when the disk temperature is high, and by setting the pulse width to be wide when the disk temperature is low, the peak power range that does not exceed the rating of the laser emission power is obtained. High-definition pits can be recorded regardless of the disk temperature. Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

 In general, it is known that, in the case of a magneto-optical disk of pulse magnetic field modulation, the recording characteristics are improved when the recording is performed with a narrow pulse width because the mark is formed more clearly. This tendency is particularly noticeable in systems where extremely small marks must be written, such as DWDD.

FIG. 1 is a graph showing the recording characteristics of an MD (mini-disc) 3 at a high temperature (disc temperature Td = 70 ° C.). The MD 3 will be described later. In Fig. 1, the horizontal axis shows the average value of the recording laser power of the light beam (mean-Pw), the vertical axis shows the bit error rate, and the maximum pulse width in the pulse period. Bit error rate a1, with respect to the laser power of a recording pulse having a pulse width (Pulse duty) of 40%, 50%, and 60% when the pulse width is 100%. 1 and 01 are shown. As shown in Fig. 1, especially at high temperatures, the wider the pulse width, the higher the bit error rate, and the difference in pulse width causes the error rate to fluctuate greatly, maintaining the quality of the recorded pits. Becomes difficult. However, in order to reduce the bit error rate by narrowing the pulse width, a large peak power is required to maintain the laser power required for the recording operation, and the laser output means LD (Laser The burden on Diode) increases. In particular, when the temperature of the disk is low, a high laser power is required to raise the temperature of the disk to the Curie temperature. Therefore, when the pulse width is small, a large peak power is required, which is a particularly severe condition.

 That is, at high temperatures, the laser beam required for recording to raise the disk to the Curie temperature may be small, but the ratio of the change in bit error rate to the change in pulse width is large. The degree of deterioration of the recording characteristics increases. On the other hand, at low temperatures, even if the pulse width changes, the bit error rate does not change much, and the recording characteristics do not deteriorate much, but a high laser power is required. Note that the bit error rate starts to deteriorate in proportion to the temperature of the disk. For example, the bit error rate rapidly deteriorates at a high temperature exceeding, for example, 60 ° C. However, in all magneto-optical disks that require recording of high-density and clear pits, the pit error rate deteriorates as the temperature increases, and the temperature at which the bit error rate starts to deteriorate rapidly increases. The deteriorating temperature and the like are not particularly limited because they differ depending on the disk film design and the like.

 Fig. 2 is a graph showing the required peak power for each pulse width of the recording pulse at each disk temperature, with the horizontal axis representing the disk temperature and the vertical axis representing the objective emission power (peak power). It is. Figure 2 shows that the average value of the recording power (laser power) at the disk temperature T d = 25 is P w = 4.5 mW, and the recording power temperature gradient (the rate of change of the objective emission power with respect to temperature) is The measurement results are shown for a disk with K w = —0.6% / ° C. Figure 2 shows the recording pulse with a pulse width (Pulse duty) of 40%, 50%, and 60% when the maximum pulse width in the pulse period is 100%. The peak powers a 2, b 2 and c 2 of the recording pulse of FIG.

As shown in Fig. 2, when the disk is at the same temperature, a narrow peak of the recording pulse as shown by the dashed line a2 requires a higher peak power, but the recording pulse as shown by the dashed line c2. If the width of the laser beam is wide, the peak Can be obtained. Also, when the disk temperature is high, even if the recording pulse width is narrow, a very high peak power is not required, whereas when the disk temperature is low, a large laser power is required. A large recording pulse width or high peak power is required, and a narrow pulse width may exceed the maximum rating of the OP (optical pickup) with the output power indicated by the broken line L1.

 Here, in the case shown in Fig. 2, when the maximum rating of the OP is 1 OmW, the recording pulse c2 of Pulse duty = 60% does not exceed the rating of the OP in the measurement shown in Fig. 2. On the other hand, the recording pulse b 2 with Pulse duty = 50% is less than 10 ° C, and the recording pulse a 2 with Pulse duty = 40% exceeds the rating of OP at less than 45 ° C.

 Therefore, as shown in Fig. 1, the pulse width is reduced at high temperatures where the difference in recording characteristics due to the difference in pulse width is severe, and the pulse width is increased at low temperatures where pulse width dependence is small but large power is required. Thus, by switching the pulse width depending on the temperature, it is possible to suppress the maximum output of the OP while guaranteeing the recording characteristics.

 For example, in the example shown in Fig. 2, as shown by the solid line L2, the pulse width is set in three stages: Pulse duty = 40%, 50%, and 60%. In, the smallest pulse width is selected and switched among the pulse duties provided in stages. That is, from −10 ° C to + 10 ° C, Pulse duty = 60%, from +10 to +50, Pulse duty = 50%, from +50 to + 70 ° C, Pulse duty = 50% By switching stepwise with duty = 40%, the output power does not exceed the rating of the OP in all temperature ranges, and the error rate is reduced by narrowing the pulse width in the high temperature region. And high-definition marks can be recorded.

The pulse width can be switched at each disk temperature by measuring each pulse width and the objective output power (peak power) for that pulse width, or based on the results of such an experiment, at different disk temperatures. The target output power (peak power) with respect to the pulse width can be calculated and tabulated, and this can be referred to. And when the disk temperature is low, the LD The pulse width is increased to avoid exceeding the rating, and when the disk temperature is high, the laser power may be smaller than at low temperatures, so that the pulse width during recording can be narrowed. The recording quality can be maintained even at a high temperature. That is, if a minimum pulse width that does not exceed the maximum rating of the OP is selected, the recording characteristics can be guaranteed over the entire temperature range.

 In the examples shown in FIGS. 1 and 2 above, the disk temperature T d is obtained by directly measuring the temperature of the disk.However, in a recording device in which the temperature of the disk cannot be directly measured, the temperature near the disk is measured. Provide a sensor or check the relationship between the temperature inside the device or the temperature outside the device and the temperature of the disk in advance, and determine the optimum pulse width and peak power of the recording pulse from the temperature inside the device or the temperature outside the device. Can be selected. Further, as described later, it is also possible to provide a temperature detecting means on the disk itself and select an optimum pulse width and peak power of the recording pulse according to the temperature detection result.

 FIG. 3 is a block diagram showing a recording / reproducing device. As shown in Fig. 3, the recording / reproducing apparatus includes a spindle motor 2 for driving the magneto-optical disk 1 to rotate at a predetermined rotation speed, a spindle control unit 3 for controlling the rotation speed of the spindle motor 2, An optical pickup 4 for irradiating a laser beam to the optical disc 1 and a laser control unit 5 for controlling on / off of a laser output of the optical pickup 4 and an output level. Further, it has a host computer 90 connected to the interface section 19 and a controller 6 for receiving a recording request and a reproduction request from the host computer 90 and executing a data recording / reproducing operation. Furthermore, an encoder 25 for encoding the recording data, a magnetic head 27 for applying a magnetic field of N or S according to the recording data, and a magnetic head driver 2 for controlling the magnetic head 27 6 and.

The magneto-optical disk 1 is driven to rotate at a predetermined rotation speed by a spindle motor 2. The rotation speed support control of the spindle motor 2 is performed by the spindle control unit 3. For example, the spindle control unit 3 detects the rotation speed of the spindle motor 2 based on an FG pulse (frequency signal synchronized with the rotation speed) from the spindle motor 2 and the like, and supplies the reference speed information SK from the controller 6 to the reference speed. The information SK is compared with the rotation speed of the spindle motor 2, and the disk rotation operation at the required rotation speed is realized by accelerating and decelerating the spindle motor 2 based on the error information.

 The rotating optical disk 1 is irradiated with laser light from the optical pickup 4. The optical pickup 4 includes a laser light source 4c such as a laser diode or a laser coupler, an optical system 4e such as various lenses or a beam splitter, an objective lens 4a serving as a laser beam output end, and reflection from a disc. A detector 4 d for detecting light, a two-axis mechanism 4 b for holding the objective lens 4 a movably in the tracking direction and the focusing direction, and the like are provided. On / off of the laser output from the laser light source 4 c and the output level in the optical pickup 4 are controlled by the laser control unit 5.

The recording / reproducing apparatus is connected to the host computer 90 by the interface section 19, and the data recording / reproducing operation is performed when the controller 6 receives a recording request and a reproducing request from the host computer 90. Will be executed. During recording, data to be recorded is supplied from the host computer 90 together with the recording request. The recording data D _REC is supplied from the encoder section 19 to the encoder 25, where necessary encoding processing is performed.

 The recording / reproducing apparatus according to the present embodiment employs a laser strobe magnetic field modulation method as a recording method. In this recording method, the recording data encoded by the encoder 25 is read by a magnetic head driver. The magnetic head driver 26 applies an N or S magnetic field from the magnetic head 27 according to the recording data. Then, the laser control unit 5 outputs a recording pulse for driving the laser diode of the laser light source 4 c in synchronization with the timing of the recording data applied as a magnetic field by the magnetic head 27. . As a result, the laser output from the laser light source 4c is pulse-emitted at a timing suitable for data recording.

As described above, in order to make the pulse width and peak power of the recording pulse correspond to the temperature of the magneto-optical disk 1 as described above, for example, to detect the temperature of the magneto-optical disk 11, A temperature sensor 20 is provided for the The temperature detection result of the temperature sensor 20 is supplied to the laser control unit 5, and the laser control unit 5 outputs a recording pulse whose pulse width and peak power are variably set based on the temperature detection result. Be composed. Data relating to the temperature of the disk 1 is also input to the controller 6, which controls the pulse width and peak power of the recording pulse of the laser controller 5.

 As shown in Fig. 2, the laser controller 5 controls the recording pulse width variably in advance at various different temperatures, measures the error rate and the required peak power at that time, and controls each temperature. On the other hand, calculate the pulse width and the peak power data that can use the narrowest recording pulse that can be recorded with the peak power that does not exceed the OP rating, or obtain it experimentally and make a table to measure The reading is performed by reading out these values according to the set temperature and setting them in the laser control unit 5, or by an appropriate calculation based on this temperature.

FIG. 4 is a block diagram showing a main part related to control of a recording pulse of the recording / reproducing apparatus. FIG. 5 is a diagram showing recording data D _REC and recording pulses that are switched according to the detected temperature information. FIGS. 5A to 5D show the recording data D _REC and the disk temperature, respectively. 3 is a schematic diagram showing a recording pulse at 60 ° C., a recording pulse at a disk temperature of 30 and a recording pulse at a disk temperature of 0 ° C. FIG.

 As shown in FIG. 4, the laser control unit 5 includes a pulse width setting circuit 5a for setting a pulse width, and a pulse height setting circuit 5 for setting a peak power of a recording pulse. A recording pulse is generated in the evening based on the timing and output to the laser diode of the laser light source 4c.

 In the pulse height setting circuit 5b, for example, the recording pulse is amplified to drive the laser diode with an appropriate laser power to a required level, and then output to the laser diode of the laser emission source 4c. . The pulse width of the recording pulse is controlled by the pulse width setting circuit 5a. The pulse width setting circuit 5a switches and sets the recording pulse to a pulse width optimal for the disk temperature based on a pulse width setting control signal Sc transmitted from the controller 6.

Also, since the laser power of the recording pulse is made different between the case where the data is N-pole and the case where the data is S-pole, the encoder 25 is used for the laser control unit 5. Input the recording data, determine the magnetic field polarity corresponding to the input recording data, and execute the setting of the recording pulse peak at the appropriate timing corresponding to the magnetic field polarity. Be composed.

 The controller 6 is supplied with the temperature information from the temperature sensor 20, and reads, for example, a pulse width and a peak power corresponding to the temperature from a table of a memory 6a provided in the controller 6, based on the temperature information. The pulse width setting circuit 5a and the pulse height setting circuit 5b are controlled.

 Specifically, for example, referring to a table created based on FIG. 2 and the like, as shown in FIG. 5A, when the detected temperature is less than 10 ° C., the pulse width with respect to the pulse cycle is 60% ( (duty = 60%), when the detection temperature is 10 ° C or more, and less than 50 ° C, the looseness is 50% (duty = 50%), and when the detection temperature is 50 ° C or more. Controls the pulse width setting circuit 5a so that the pulse width can be switched to a pulse width of 40% (duty = 40%). At the same time, the required peak power is obtained at each temperature, and the pulse height setting circuit 5b is controlled based on this.

 As described above, the pulse width is switched according to the temperature, so that the peak power does not exceed the rating of the OP, is less than the maximum rating of the OP, and is the narrowest pulse width among the pulse widths set in steps. Can be selected, and the quality of recording pits at high temperatures can be maintained. The pulse width may be set continuously and variably according to the temperature.However, as shown in FIG. 2, when the pulse width is switched stepwise according to the temperature, the switching in the pulse width setting circuit 5a is performed. Control is easy and the load on the equipment is small.

 Returning to FIG. 3, the data reading position by the optical pickup 4 can be moved in the radial direction. Although not specifically shown, a sled mechanism is provided to allow the entire optical pickup 4 to move in the radial direction of the disc, thereby performing a large movement of the reading position, and moving the objective lens 4a. The biaxial mechanism 4b moves the disc in the radial direction, that is, the reading position is moved slightly by the tracking servo operation.

Instead of the thread mechanism for moving the optical pickup 4, a mechanism for sliding the disk 1 together with the spindle motor 2 may be provided. Also, the objective The focus control of the laser spot LSP is performed by moving the lens 4a to and away from the disk 1 by the biaxial mechanism 4b.

 As the detector 4d of the optical pickup 4, for example, a 4-division detector having a 4-division light-receiving area, or a detector that detects magnetic field data for each polarization component by the magnetic Kerr effect and obtains an RF signal as magneto-optical data Evening is provided. From each light receiving area of this detector 4d, a current signal S1 corresponding to the amount of received light is output, and these are supplied to the I / V conversion matrix amplifier 7. The I / V conversion matrix amplifier 7 performs current-voltage conversion on the received light amount signal S1 and calculates necessary signals such as an RF signal, push-pull signal, and focus error signal FE by processing signals from each light receiving area. Generate.

 A focus error signal F E serving as focus state error information is supplied to the controller 8. The thermo-controller 8 is equipped with a focus phase compensation circuit and a focus driver, etc., as a focus processing unit, and generates a focus drive signal based on the focus error signal FE to apply the focus drive signal to the focus coil of the 2-axis mechanism 4b. Apply. As a result, a focus support system for converging the objective lens 4a to the just force point is formed.

 From the IZV conversion matrix amplifier 7, an RF signal used for generating a service clock SCK and a data clock DCK is output as a signal S2. Here, the signal S2 is also branched and supplied to the controller 6, and is used for detecting an offset level in an asymmetry correction process described later. The signal S2 is converted into a signal S3 digitized by the A / D converter 10 by removing the low frequency fluctuation of the RF signal by the clamp circuit 9. This signal S3 is supplied to the controller 6, the PLL circuit 11 and the tracking error generator 16.

The PLL circuit 11 controls the oscillation frequency of the internal oscillator based on the phase error between the signal S3 and the oscillation output, and performs a predetermined frequency division process to generate the support clock SCK synchronized with the RF signal. generate. The support clock SCK is used as a sampling clock in the A / D converter 10 and is supplied to the timing controller 17. Also, the PLL circuit 11 divides the service clock SCK to generate the data clock DCK, and the timing controller 17 It is supplied to the control unit 5. Also used as sampling clock in A / D converter 13.

 The timing controller 17 generates a necessary timing signal for each section based on the servo clock SCK: and the data clock DCK. For example, a sampling timing Ps for extracting a support for a three-phase tracking operation, a synchronization timing DSY for a decoding operation in the data detection unit 14 and the like are generated.

 The PLL circuit 11, the timing controller 17, and the tracking error generator 16 generate a tracking error signal TE by so-called three-phase tracking control, and supply the generated signal to the support controller 8.

 From the I / V conversion matrix amplifier 7, an RF signal and a push-pull signal used for data extraction are output as a signal S4. This signal S becomes a signal S 5 digitized by the A / D converter 13 after the low frequency fluctuation of the RF signal is removed by the clamp circuit 12.

This signal S5 is supplied to a data detector (ie, a decoder) 14. Performs data Decorating one de processing based on synchronization evening timing DSY the timing controller 1 7 The data detecting unit 1 4 generates on the basis of the data clock DCK, to obtain reproduction data D _PB. For example, a waveform equalization process, a demodulation process for a modulation process adopted as a recording format, an error correction process, and the like are performed and _encoded as reproduced data _DPB . The reproduction de Isseki D _PB will be supplied to the host combi Interview Isseki 9 0 via the interface unit 1 9.

It should be noted that the present invention is not limited to only the above-described embodiment, and it is needless to say that various changes can be made without departing from the gist of the present invention. For example, as described above, the temperature of the disk can be detected by providing a temperature sensor 20 such as a temperature sensor near the magneto-optical disk 11 as described above. As described in Japanese Patent Publication No. 857, use a material whose resistance value changes due to heat, for example, a disk in which an oxide semiconductor such as manganese or cobalt used for thermistor is sandwiched all over. Alternatively, the temperature of the disk may be detected from the change in the resistance value of the thin layer, and the pulse width and the peak pulse may be adjusted according to the detection result. Specifically, as shown in FIG. At 0, a thermistor layer 362 showing a resistance value according to temperature is sandwiched between the resin layers 361, and the thermistor layer 362 is a disc 300 at the hap portion of the disc 300. It is exposed on the surface of 0 and also serves as an electrode. A resin portion 363 is formed inside the thermistor layer 362, and a hole for a spindle is formed in the center of the disc 300. The exposed portion of the sagittal layer 362 is formed concentrically with respect to the disc 300, and the exposed portion is kept in electrical contact from both sides of the disc 300 by contacts. A current is applied to the miso layer 362, the resistance value is measured by measuring the voltage appearing at the contact, and this resistance value is converted into a temperature to measure the temperature of the disk 300. is there.

 Further, for example, in the above-described embodiment, the description has been given as a hardware configuration. However, the present invention is not limited to this, and arbitrary processing may be performed by executing a computer program on a CPU (Central Processing Unit). It is also possible to realize by executing. In this case, the computer program can be provided by being recorded on a recording medium, or can be provided by being transmitted via the Internet or another transmission medium.

 Next, a specific example of such a recording / reproducing device (disk drive device) will be described. The disk drive device shown in this specific example applies a signal system different from the recording format normally used as a recording / reproducing system for the disk-shaped recording medium to a disk-shaped recording medium employing a conventional magneto-optical recording system. By doing so, it is possible to increase the recording capacity of a conventional magneto-optical recording medium. Furthermore, by applying the high-density recording technology and the new file system, it is possible to dramatically increase the recording capacity while maintaining compatibility with the conventional magneto-optical recording medium, housing outline, and recording / reproducing optical system. It provides a recording format that is made possible.

Here, the case where the present invention is applied to a minidisk (registered trademark) type recording medium as a disk-shaped magneto-optical recording medium will be described first. Here, in particular, we will use the next-generation MD 1 as a disk that uses a conventional magneto-optical recording medium to increase its recording capacity by applying a recording format different from the commonly used recording format. A disc that achieves an increase in recording capacity by applying a new recording format to a new recording medium capable of high-density recording will be described as “next-generation MD2”. In the following, a description will be given of specification examples of the next-generation disc MD1 and the next-generation disc MD2, and a process of applying the address conversion method according to the present invention to generate recording data for these two discs.

 1. Disc specification and area structure

First, the specifications of the conventional minidisk, next-generation MD1, and next-generation MD2 will be described with reference to FIG. The physical format of the mini disc (and MD-DATA) is defined as follows. The track pitch is 1.6 μπι and the bit length is 0.59 ii / bit. The laser wavelength λ is λ = 780 nm, and the numerical aperture of the optical head is NA = 0.45. As a recording method, a group recording method that uses a group (a groove on the disk surface) as a track for recording and reproduction is adopted. In addition, the addressing method is to form a single spiral dub on the disk surface and form a wobble meandering at a predetermined frequency (22.5 KHz) on both sides of this group. In this method, the absolute address is FM-modulated based on the above frequency and recorded on a wobbled groove track. Your name, in the present specification, the absolute address to be recorded AD IP (Address in Pregroove) Tomore one as Woburu ₀

 In the conventional MD, 32 sectors, which are the main data section, are added with 4 sectors, which are link sectors, and recording is performed with a total of 36 sectors as one cluster unit. The ADIP signal includes a cluster address and a sector address. The class address consists of an 8-bit cluster H and an 8-bit cluster, and the sector address consists of a 4-bit sector.

 In addition, the conventional mini-disc employs the EFM (8-14 conversion) modulation method as the modulation method of the recording data. As an error correction method, AC IRC (Advanced Cross Interleave Reed-Solomon Code) is used. Dei-Yu-in-Yu-Leave is a folding type. As a result, the data redundancy is 46.3%.

The data detection method in the conventional mini-disc is the bit-pipit method, and the CLV (Constant Linear Velocity) is adopted as the disc drive method. The linear velocity of CLV is 1.2 mZ s. The standard data rate for recording and playback is 133 kB / s, and the recording capacity is 164 MB (140 MB for MD-DATA). In addition, the minimum data rewrite unit (unit cluster) consists of 36 sectors consisting of 32 main sectors and 4 link sectors as described above.

 Next, the next-generation MD 1 shown as this specific example will be described. In the next-generation MD 1, the physical specifications of the conventional mini-disc and the recording medium described above are the same. Therefore, the track pitch is 1.6 / xm, the laser wavelength λ is λ = 780 ηπι, and the aperture ratio of the optical head is NA = 0.45. The recording method is a group recording method. The address method uses ADIP. As described above, since the configuration of the optical system, the ADIP address reading method, and the servo processing in the disk drive device are the same as those of the conventional mini-disc, compatibility with the conventional disc has been achieved.

 The next-generation MD 1 uses the RLL (1-7) PP modulation method (RLL: Run Length Limited, PP: Parity preserve / Prohibit rmtr (repeated minimum transition runlength)) that is suitable for high-density recording as a recording data modulation method. Is adopted. As the error correction method, an RS-LDC (Reed Solomon-Long Distance Code) method with BIS (Burst Indicator Subcode), which has higher correction capability, is used.

To be more specific, 2052 bytes of EDC (Error Detection Code) of 4 bytes added to 2048 bytes of user data supplied from the host application etc. As shown in Fig. 8, 32 sectors of SectorO to Sector31 are grouped into a block of 304 columns x 216 rows. Here, scramble processing is performed on the 2052 bytes of each sector to obtain an exclusive OR (Ex-OR) with a predetermined pseudo random number. A 32-byte parity is added to each column of the scrambled block to form an LDC (Long Distance Code) block of 304 columns × 248 rows. The LDC block is subjected to an interleaving process to form a block of 152 columns and 496 rows (Interleaved LDC Block), and as shown in FIG. 55 columns x 496 rows, A 2.5-byte frame sync code (Frame Sync) is added to the first position so that one line corresponds to one frame, and has a structure of 157.5 bytes X 496 frames. Each row in FIG. 9 corresponds to 496 frames of Frame 10 to Frame 505 in the data overnight area in one recording block (cluster) shown in FIG. 15 described later.

 In the above data structure, the data-in-leave is a block-complete type. This results in a data redundancy of 20.50%. As a data detection method, a Viterbi decoding method using PR (1, 2, 1) ML is used.

 The CLV method is used as the disk drive method, and its linear velocity is 2.4 mZs. The standard data rate for recording and playback is 4.4 'MB / s. By using this method, the total recording capacity can be reduced to 300 MB. By changing the modulation scheme from EFM to RLL (1-7) PP modulation scheme, the window margin is changed from 0.5 to 0.666, so that a 1.33 times higher density can be realized. The cluster, which is the minimum data rewrite unit, is composed of 16 sectors and 64 kB. By changing the recording modulation method from the CIRC method to the R SL DC method with BIS and the method using the difference in sector structure and Viterbi decoding, the data recovery efficiency is reduced from 53.7% to 79.5%. , 1.48 times higher density can be realized.

 Taken together, the next-generation MD1 can achieve a recording capacity of 300 MB, about twice that of a conventional minidisc.

 On the other hand, the next-generation MD 2 is a recording medium to which a high-density recording technology such as a domain wall displacement detection method (DWD: Domain Wall Displacement Detection) is applied. Have different physical formats. The next-generation MD2 has a track pitch of 1.25 m and a bit length of 0.16 m / bit, and has a higher density in the line direction.

 Also, in order to be compatible with the conventional mini-disc and the next-generation MD1, the optical system, readout method, servo processing, etc. conform to the conventional standards, the laser wavelength λ is λ = 780 nm, and the optical head The aperture ratio is NA = 0.45. The recording method is a group recording method, and the address method is a method using ADIP. The outer shape of the housing is the same as that of the conventional mini disk and next-generation MD1.

However, using an optical system equivalent to the conventional mini-disc and the next-generation MD1, When reading track pitches and line densities (bit lengths) that are narrower than before, the constraints on de-track magazines, crosstalk from lands and groups, crosstalk between wobbles, focus omissions, and CT signals are eliminated. There is a need. Therefore, in the next-generation MD2, the feature is that the groove depth, inclination, width, etc. of the group have been changed. Specifically, the groove depth of the group is 160 nm to 180 nm, the slope is 60 ° to 70 °, and the width is 600 ηπ! 8800 nm.

 The next-generation MD 2 uses a RLL (1-7) PP modulation method (RLL; Parity preserve / Prohibit rmtr (repeated minimum transition runlength)) that is compatible with high-density recording as a modulation method for recording data. ). As an error correction method, an RS-LDC (Reed Solomon-Long Distance Code) method with BIS (Burst Indicator Subcode), which has higher correction capability, is used.

 Data interleaving is block-completed. This results in a data redundancy of 20.50%. As a data detection method, a Viterbi decoding method using PR (1, -1) ML is used. The cluster, which is the minimum data rewriting unit, is composed of 16 sectors and 64 kB.

 The disk drive system uses Z CAV (Zone Constant Angular Velocity) system, and its linear velocity is 2.0 m / s. The standard data rate for recording and playback is 9.8MB Zs. Therefore, in the next-generation MD 2, the total recording capacity can be increased to 1 GB by adopting the DWDD method and this drive method.

 An example of the area structure on the board of the next-generation MD 1 shown in this specific example is schematically shown in FIGS. The next-generation MD 1 is the same medium as the conventional mini-disc, and the innermost side of the disc is provided with a PTOC (Premastered Table Of Contents) as a pre-mastered area. Here, disc management information is recorded as emboss pits due to physical structural deformation.

The outer periphery of the Plymouth area is a recordable area where magneto-optical recording is possible, and is a recordable / reproducible area in which a group is formed as a guide groove of a recording track. The innermost side of this recordable area is a UTOC (User Table Of Contents) area, in which UTOC information is described and There is provided a buffer area with the remastered area and a power calibration area used for adjusting the output power of the laser beam.

 As shown in Fig. 11, the next-generation MD2 does not use pre-pits to increase the density. Therefore, the next-generation MD2 has no PTOC area. The next-generation MD2 has a unique ID area (Uniaue ID; UID) that records information for copyright protection, information for data tampering check, and other non-public information in the inner peripheral area of the recorder pull area. ) Is provided. This UID area is recorded by a recording method different from the DWDD method applied to the next-generation MD2.

 Here, audio tracks and data tracks for music data can be mixedly recorded on the discs in the next-generation MD1 and the next-generation MD2. In this case, for example, as shown in FIG. 12, an audio recording area AA in which at least one audio track is recorded in a data area, and a data recording area DA for PC in which at least one data track is recorded. Are formed at arbitrary positions.

 A series of audio tracks ゃ data overnight tracks need not necessarily be physically continuously recorded on the disc, but may be divided into a plurality of parts and recorded as shown in FIG. Parts refer to sections that are physically continuously recorded. That is, even when there are two physically separated PC data recording areas as shown in FIG. 12, the number of data tracks may be one or plural. However, although Fig. 12 shows the physical specifications of the next-generation MD 1, the audio recording area AA and the PC data recording area DA are also mixed for the next-generation MD 2. Can be recorded.

 A specific example of a recording / reproducing device compatible with the next-generation MD 1 and the next-generation MD 2 having the above-described physical specifications will be described in detail later.

 2. Disk management structure

 The disk management structure of this specific example will be described with reference to FIGS. Fig. 13 shows the data management structure of the next-generation MD1, and Fig. 14 shows the data management structure of the next-generation MD2.

As mentioned above, the next-generation MD 1 is the same medium as the conventional mini-disc. Therefore, in the next-generation MD1, the PTOC is recorded using non-rewritable embossed pits as used in conventional minidiscs. In this PTOC, the total capacity of the disk, the UTO C position in the UTO C area, the position of the power calibration area, the start position of the data area, the end position of the data area (lead-out position), and the like are recorded as management information. ing.

 In the next-generation MD1, the AD IP address 0000 to 002 has a power calibration area (Rec Power Calibration Area) for adjusting the write output of the laser. . In the following 000 3 to 00 05, UTO C is recorded. The UTOC includes management information that is rewritten according to recording / erasing of a track (audio track Z data track), and manages the start position and end position of each track and the parts constituting the track. It also manages free areas where no tracks have been recorded in the data storage area, that is, parts in the writable area. On UTOC, the entire PC data is managed as a single track that does not depend on MD audio data. Therefore, even if the audio track and the data track are mixedly recorded, the recording position of the PC data divided into a plurality of parts can be managed.

 Also, UTOC data is recorded in a specific ADIP cluster in this UTOC area, and the contents of UTOC data are defined for each sector in this ADIP class. Specifically, UTOC sector 0 (the first AD IP sector in this AD IP cluster) manages tracks and parts corresponding to free areas, and UTOC sector 1 and sector 4 store character information corresponding to the tracks. Managing. In the UTOC sector 2, information for managing the recording date and time corresponding to the track is written.

UTOC sector 0 is a data area in which recorded data, a recordable unrecorded area, and data management information are recorded. For example, when recording data on a disk, the disk drive searches for an unrecorded area on the disk from UTOC sector 0 and records the data here. At the time of reproduction, the area in which the data track to be reproduced is recorded is determined from UTOC sector 0, and the reproduction operation is performed by accessing the area. In the next-generation MD1,? Ding 0. And 1100〇 are recorded as data modulated by a conventional mini-disc system, here the EFM modulation method. Therefore, the next-generation MD 1 has an area recorded as data modulated by the EFM modulation method and an area recorded as high-density data modulated by the RS-LDC and RLL (1-7) PP modulation methods. Will have.

 In addition, even if the next-generation MD1 is inserted into the conventional disk drive of the conventional mini disk, this medium does not correspond to the disk drive of the conventional mini disk in the alert track described in the AD IP address 0032. The information for notifying that is stored. This information may be an audio message such as "This disc is a format not compatible with this playback device" or a warning sound message. In addition, if it is a disk driver device provided with a display unit, it may be a day for displaying this fact. This alert track is recorded by an EFM modulation method so that it can be read by a disk driver device compatible with a conventional mini disk.

 In the AD IP address 0034, a disc description table (DDT) indicating disc information of the next-generation MD1 is recorded. The DDT describes the format, the total number of logical clusters in the disk, the ID unique to the medium, update information of this DDT, bad cluster information, and the like.

 Since the DDT area is recorded as high-density data modulated by RS-LDC and RLL (1-7) PP modulation, a guard band area is provided between the alert track and the DDT. .

 In addition, the youngest AD IP address where high-density data modulated by the RLL (1-7) PP modulation method is recorded, that is, the start address of the DDT has a logical cluster number (Logical Cluster Number) of 0000 here. Number; L CN). One logical cluster is 65,536 bytes, and this logical class is the minimum unit for reading and writing. The AD IP addresses 0006 to 003 1 are reserved.

The subsequent AD IP addresses 0036 to 0038 are provided with a secure area (Secure Area) that can be made public by authentication. With this secure area, It manages attributes such as open / closed for each class that constitutes data. In particular, in this secure area, information for copyright protection, information for data tampering check, etc. are recorded. In addition, other various non-public information can be recorded. This non-disclosure area is designed so that only a specially authorized specific external device can access it in a limited manner, and includes information for authenticating this accessible external device.

 From the AD IP address 0 38, a user area (User Area) (arbitrary data length) and a spare area (Spare Area) (data length 8) which can be freely written and read are described. When the data recorded in the user area is arranged in ascending order of the LCN, it is divided into user sectors (User Sector) with 2,048 bytes as one unit from the top, and it is received from an external device such as a PC. The file is managed by the FAT file system with a user sector number (USN) with the first user sector being 0000.

 Next, the data management structure of the next-generation MD2 will be described with reference to FIG. The next generation MD2 does not have a PTOC area. Therefore, the disc management information such as the total capacity of the disc, the position of the calibration area, the start position of the data area, and the end position of the data area (reset position) are all stored as PD PTCPreFormat Disc Parameter Table). Recorded in AD IP information. The data is modulated by an RS-LDC with BIS and an RLL (1-7) PP modulation method, and recorded by a DWDD method.

 In the lead-in area and the lead-out area, a laser power calibration area (Power Calibration Area; PCA) is provided. In the next-generation MD2, the ADN address following the PCA is set to 0000 and the LCN is added. In the next-generation MD2, a control area equivalent to the UTOC area in the next-generation MD1 is prepared. Figure 14 shows a unique ID area (Unidue ID; UID) for recording information for copyright protection, information for checking data tampering, and other non-public information. This UID area is recorded at a further inner peripheral position of the lead-in area by a recording method different from a normal DWDD method.

Next-generation MD1 and MD2 files are both FAT file systems Is managed based on For example, each data track has its own FAT file system. Alternatively, one FAT file system can be recorded over multiple data tracks.

 3. AD IP sector / class structure and data block

 Next, the relationship between the ADIP sector structure of the next-generation MD 1 and the next-generation MD 2 shown as a specific example of the present invention and the data blocks will be described with reference to FIG. Conventional mini-disc (MD) systems use a cluster Z sector structure that corresponds to the physical address recorded as ADIP. In this specific example, a cluster based on an AD IP address is referred to as an “AD IP cluster” for convenience of explanation. In addition, clusters based on addresses in the next-generation MD1 and next-generation MD2 are referred to as “Recording Blocks” or “Next-Generation MD Classes”. In the next-generation MD1 and the next-generation MD2, the data track is treated as a data stream recorded by the class unit, which is the minimum unit of address, as shown in Fig. 15.

 As shown in Fig. 15, in the next-generation MD1, one conventional cluster (36 sectors) is divided into two, and one recording block is composed of 18 sectors. In the next-generation MD2, it is composed of 16 sectors.

 The structure of one recording block (one next-generation MD class) shown in Fig. 15 consists of 512 frames consisting of a preamble of 10 frames, a postamble of 6 frames, and a data section of 496 frames. Have been. Further, one frame in this recording block includes a synchronization signal area, data, BIS, and DSV.

 In addition, of the 512 frames of one recording block, each of the 496 frames in which main data is recorded, divided into 16 equal parts, is called an address unit. Each address unit consists of 31 frames. The address unit number is called an address unit number (AUN). This AUN is a number assigned to all address units, and is used for address management of recording signals.

Physical class / sector structure described in AD IP like next generation MD1 When recording high-density data modulated by the 1-7 PP modulation method on a conventional mini-disc that has a disc, the AD IP address originally recorded on the disc and the address of the data block actually recorded There is a problem that it will not work. The random access is performed based on the AD IP address. In the random access, when reading the data overnight, the recorded data can be read even if the vicinity of the position where the desired data is recorded is accessed. However, when writing data, it is necessary to access the correct location so that already recorded data is not overwritten. For this reason, it is important to accurately determine the access position from the next-generation MD class / next-generation MD sector associated with the AD IP address.

 Therefore, in the case of the next-generation MD1, a high-density data class is grasped by a data unit obtained by converting an ADIP address recorded as a wobble on the medium surface according to a predetermined rule. In this case, an integer multiple of the ADIP sector is set to the high-density data class. Based on this concept, when describing a next-generation MD cluster for one AD IP cluster recorded on a conventional mini-disc, each next-generation MD cluster must be divided into 1/2 AD IP clusters (18 sectors). To correspond to.

 Therefore, in the next-generation MD1, the 1Z2 cluster of the conventional MD class is associated as the minimum recording unit (Recording Block).

 On the other hand, in the next-generation MD2, one cluster is treated as one recording block.

 In this specific example, as described above, a data block in units of 2,048 bytes supplied from the host application is defined as one logical data sector (Logical Data Sector; LDS). A set of 32 recorded logical data sectors is referred to as a logical data cluster (Logical Data Cluster; LDC).

With the data structure described above, when recording the next-generation MD data at an arbitrary position, it can be recorded on the medium with good timing. In addition, by including an integer number of next-generation MD clusters in the AD IP cluster which is a unit of the AD IP address, the next-generation MD data class is obtained from the AD IP cluster address. The rules for converting the address into the address are simplified, and the circuit or software for conversion can be simplified.

 Although FIG. 15 shows an example in which two next-generation MD clusters are associated with one ADIP cluster, three or more next-generation MD clusters can be allocated to one ADIP cluster. At this time, one next-generation MD cluster is not limited to the point composed of 16AD IP sectors, and the difference in data recording density between the EFM modulation method and the RLL (1-7) PP modulation method and the next-generation MD cluster It can be set according to the number of constituent sectors and the size of one sector.

 FIG. 15 shows a data structure recorded on a recording medium, but an AD IP signal recorded on a group wobble track on the recording medium is then converted to an AD IP demodulated signal shown in FIG. The data structure when demodulated by the demodulator 38 is described below.

 FIG. 16A shows the data structure of the ADIP of the next-generation MD2, and FIG. 16B shows the data structure of the ADIP of the next-generation MD1.

 In the next-generation MD1, the synchronization signal, cluster H (Cluster H) information and cluster L (Cluster L) information indicating the cluster number and the like on the disk, and sector information (Sector) including the sector number and the like in the cluster Is described. The synchronization signal is described by 4 bits, the cluster H is described by the upper 8 bits of the address information, the class L is described by the lower 8 pits of the address information, and the sector information is described by 4 bits. . CRC is added to the last 14 bits. As described above, the 42-bit ADIP signal is recorded in each ADIP sector.

 In the next-generation MD 2, 4-bit synchronization signal data, 4-bit Cluster H information, 8-bit Cluster M information and 4-bit Cluster L information, 4-bit sector information is described. The BCH parity is added to the latter 18 bits. Similarly, in the next-generation MD2, a 42-bit ADIP signal is recorded in each ADIP sector.

In the AD IP data structure, the configuration of the Cluster H information, the Cluster M information, and the Cluster L information described above can be determined arbitrarily. Also, other additional information can be described here. For example, as shown in Figure 17 In the next-generation MD2 AD IP signal, the cluster information is represented by the upper 8 bits of Cluster H and the lower 8 bits of Cluster L, and is represented by the lower 8 bits. Disk control information can be described instead of the cluster L that is used. The disc control information includes a servo signal correction value, a reproduction laser power upper limit, a reproduction laser power linear velocity correction coefficient, a recording laser power upper limit, a recording laser power linear velocity correction coefficient, a recording magnetic sensitivity, and a magnetic-laser pulse phase difference. , Parity, and the like.

 4. Disk drive unit

 With reference to FIGS. 18 and 19, a specific example of the disk drive device 210 that supports recording and reproduction of the next-generation MD 1 and the next-generation MD 2 will be described. Here, the disk drive device 210 can be connected to a personal computer (hereinafter, abbreviated as PC) 200, and the next-generation MD 1 and the next-generation MD 2 can be used not only for audio data but also as an external storage for a PC or the like. .

 The disk drive device 210 includes a media drive unit 211, a memory transfer controller 212, a class buffer memory 211, an auxiliary memory 214, a USB interface 211, 216, and a USB A hub 217, a system controller 218, and an audio processing unit 219 are provided.

 The media drive unit 211 performs recording / reproducing on individual disks 290 such as a loaded conventional mini-disc, next-generation MD 1 and next-generation MD 2. The internal configuration of the media drive unit 211 will be described later with reference to FIG.

 The memory transfer controller 212 controls playback of data from the media drive unit 211 and transmission / reception of recording data to be supplied to the media drive unit 211. The class buffer memory 213 buffers the data read by the media drive unit 211 from the data tracks of the disk 290 in units of high-density data clusters under the control of the memory transfer controller 212. The auxiliary memory 214 stores various management information and special information such as UT OC data, CAT data, unique ID, and hash value read from the disk 290 by the media drive unit 211, and a memory transfer controller 212. Is stored based on the control of.

System controller 218, USB interface 216, USB hub 2 Communication is possible with the PC 200 connected via the PC 17. By controlling communication with the PC 200, reception of commands such as write requests and read requests, status information, It transmits other necessary information, etc., and controls the entire disk drive device 210 as a whole.

 For example, when the disk 290 is loaded in the media drive unit 211, the system controller 218 instructs the media drive unit 211 to read management information and the like from the disk 290 and transfers the memory The management information such as PTOC and UTOC read by the controller 212 is stored in the auxiliary memory 214.

 The system controller 218 can recognize the track recording state of the disk 290 by reading the management information. In addition, by reading the CAT, the high-density data cluster structure in the data track can be grasped, and the PC 200 can respond to the access request to the data track from the data track. In addition, the disk authentication processing and other processing are executed using the unique ID and the hash value, and these values are transmitted to the PC 200, and the disk authentication processing and other processing are executed on the PC 200.

 When a request for reading a certain FAT sector is issued from the PC 200, the system controller 218 sends a signal to the media drive unit 211 to execute reading of a high-density data cluster including this FAT sector. give. The read high-density data cluster is written to the class buffer memory 21 by the memory transfer controller 21. However, when the data of the FAT sector has already been stored in the cluster buffer memory 21, the reading by the media drive unit 211 is unnecessary.

 At this time, the system controller 218 sends a signal to read the data of the requested FAT sector from the high-density data class data written in the cluster buffer memory 213, and the USB interface 2 15, control for transmission to the PC 200 via the USB hub 217 is performed.

Further, when a write request for a certain FAT sector is issued from the PC 200, the system controller 218 causes the media drive unit 211 to read a high-density data cluster including this FAT sector. . Read high-density data The raster is written to the cluster buffer memory 13 by the memory transfer controller 2 12. However, if the data of this FAT sector has already been stored in the cluster buffer memory 21, it is not necessary to read it out by the media drive unit 211.

 Also, the system controller 218 supplies the FAT section data (recorded data) transmitted from the PC 200 to the memory transfer controller 212 via the USB interface 215. Then, the data of the corresponding FAT sector is rewritten in the class buffer memory 2 13.

 Also, the system controller 218 instructs the memory transfer controller 212 to record the data of the high-density data class stored in the cluster buffer memory 213 with the required FAT sector rewritten. The data is transferred to the media drive section 2 1 1 as data. At this time, the media drive section 211 uses the EFM modulation method if the loaded medium is a conventional mini-disc, and the RLL (1-7) PP modulation if the next-generation MD1 or next-generation MD2 is used. The data recorded in the high-density data class are modulated and written using the method.

 Note that, in the disk drive device 210 shown as this specific example, the above-described recording / reproduction control is control when recording / reproducing a overnight track, and recording / reproducing MD audio data (an audio track). The overnight transfer is performed via the audio processing unit 219.

 The audio processing unit 219 includes, as an input system, for example, an analog audio signal input unit such as a line input circuit microphone input phone input circuit, an A / D converter, and a digital audio data input unit. The audio processing unit 219 includes an ATRAC compression encoder Z decoder and a buffer memory for compressed data. Furthermore, the audio processing unit 219 includes, as an output system, a digital audio output unit, a D / A converter, and an analog audio signal output unit such as a line output circuit / headphone output circuit. .

Audio tracks are recorded on the disc 290 when digital audio data (or an analog audio signal) is input to the audio processing unit 219. Input linear PCM digital audio data or analog After being input as a log audio signal, the linear PCM audio data obtained by conversion by the A / D converter is ATRAC-compressed and encoded and stored in the sofa memory. Thereafter, the data is read from the buffer memory at a predetermined timing (data unit equivalent to the AD IP cluster) and transferred to the media drive unit 211.

 In the media drive unit 211, the transferred compressed data is modulated by the EFM modulation method or the RLL (1-7) PP modulation method and written to the disk 290 as an audio track.

 When reproducing an audio track from the disk 290, the media drive section 211 demodulates the reproduced data into an ATRAC compressed data state and transfers the data to the audio processing section 219. The audio processing unit 219 performs ATRAC compression decoding to obtain linear PCM audio data, and outputs the data from the digital audio overnight output unit. Alternatively, a line output / headphone output is performed as an analog audio signal by a D / A converter.

 The configuration shown in FIG. 18 is merely an example. For example, when the disk drive device 210 is connected to the PC 200 and used as an external storage device that records and reproduces only data tracks, the audio processing unit 219 is unnecessary. On the other hand, when the main purpose is to record and reproduce an audio signal, it is preferable to include an audio processing unit 219 and further include an operation unit and a display unit as a user interface. The connection with the PC 200 is not limited to USB. For example, a so-called IEEE 1 (IEEE) standard conforming to the standards of the Institute of Electrical and Electronics Engineers, Inc. (IEEE). In addition to the 394 interface, a general-purpose connection interface can be applied.

Next, the configuration of the media drive section 211 for recording and reproducing the conventional mini-disc, the next-generation MD 1 and the next-generation MD 2 will be described in further detail with reference to FIG. The media drive unit 211 is used to record and play back the conventional mini-disc, next-generation MD 1 and next-generation MD 2.Especially, as a recording processing system, EFM modulation and ACIRC encoding for recording on the conventional mini-disc are used. It is characterized by having a configuration for executing the next generation MD 1 and the next generation MD 2 and a configuration for executing the RLL (1-7) PP modulation · RS-LDC code. In addition, as a regeneration processing system, EFM demodulation for playback of mini-disc 'Construction to execute AC IRC decoding, and data detection using PR (1, 2, 1) ML and Viterbi decoding for playback of next-generation MD 1 and next-generation MD 2 RLL based on (1-7) Demodulation 'The feature is that it has a configuration to execute RS-LDC decoding.

 The media drive unit 211 drives the loaded disk 290 by a spindle motor 221 in a CLV system or a Z CAV system. At the time of recording and reproduction, a laser beam is emitted from the optical head 222 to the disc 290. The optical head 222 outputs a high-level laser (recording pulse) to heat the recording track to the Curie temperature during recording, and detects data from reflected light by the magnetic force effect during reproduction. Provides relatively low level laser output. Therefore, the optical head 222 is equipped with a laser diode as a laser output unit, an optical system including a polarized beam splitter and an objective lens, and a detector for detecting reflected light. The objective lens provided in the optical head 222 is held, for example, by a two-axis mechanism so as to be displaceable in a disk radial direction and in a direction of coming and going to and from the disk.

 Here, in this specific example, a temperature sensor 220 is provided near the disk 290, and the pulse width of the recording pulse output from the optical head 222 in accordance with the temperature detected by the temperature sensor 220. By variably setting the peak power and the peak power, as described above, the recording characteristics are assured with the recording power within the OP rating over the entire temperature range. The setting of the pulse width of the recording pulse and its peak power is performed by a drive controller 241 to be described later. That is, the temperature is supplied from the temperature sensor, and based on this, the pulse width and peak power of the recording pulse for compensating the recording characteristics are calculated as described above, and the calculated pulse width and peak power are calculated. The recording pulse set to is supplied to the laser driver 249 described later, and thus the pulse width and the peak power of the recording pulse output from the optical head 222 are variably set according to the temperature. Note that such setting of the pulse width and the peak power may be performed by a laser driver ZAPC249 described later.

In addition, in this specific example, in order to obtain the maximum reproduction characteristics for the conventional mini-disc and the next-generation MD 1 and the next-generation MD 2 having different physical specifications of the medium surface, A phase compensator for optimizing the bit error rate when reading data from the disk is provided in the reading optical path of the optical head 222.

 A magnetic head 222 is disposed at a position facing the optical head 222 with the disk 290 interposed therebetween. The magnetic head 223 applies a magnetic field modulated by the recording data to the disk 290. Although not shown, a thread mechanism and a thread mechanism for moving the entire optical head 222 and the magnetic head 223 in the disk radial direction are provided.

 The media drive unit 211 includes a recording / reproducing head system using an optical head 222 and a magnetic head 222, a disk rotation driving system using a spindle motor 221, a recording processing system, and a reproducing system. A processing system, a service system, and the like are provided. The recording processing system consists of a unit that performs EFM modulation and AC IRC encoding when recording on conventional mini-discs, and RLL (1-7) PP modulation and RS-LDC encoding when recording on next-generation MD1 and MD2. And a site for performing the following.

 In addition, the playback processing system consists of a part that performs demodulation corresponding to EFM modulation and AC IRC decoding during playback of the conventional mini-disc, and an RLL (1-7) PP during playback of the next-generation MD1 and MD2. A part for performing demodulation corresponding to modulation (RL L (1-7) demodulation based on data detection using PR (1, 2, 1) ML and Viterbi decoding) and RS-LDC decoding will be provided.

 The information (photocurrent obtained by detecting the laser reflected light by the photodetector) detected by the laser irradiation of the optical head 222 on the disk 290 by the laser irradiation is supplied to the RF amplifier 224. The RF amplifier 224 performs current-voltage conversion, amplification, matrix calculation, etc. on the input detection information, and reproduces the reproduced RF signal, tracking error signal TE, focus error signal FE, and group information (reproduced information). Extract AD IP information recorded on disk 290 by wobbling tracks.

At the time of playback of a conventional mini-disc, a playback RF signal obtained by an RF amplifier is processed by an EFM demodulation section 227 and an ACIRC decoder 228 via a comparator 225 and a PLL circuit 226. The reproduced RF signal is binarized by an EFM demodulation section 227 to form an EFM signal train, and then EFM demodulated. Error correction and dinterleaving are performed at 28. If the audio is overnight, the state of the ATRAC compressed data will be at this point. At this time, the selector 229 selects the conventional mini-disc signal side, and the demodulated ATRAC compressed data is output to the data buffer 230 as reproduction data from the disc 290. In this case, the compressed data is supplied to the audio processing unit 219 in FIG.

 On the other hand, when reproducing the next-generation MD1 or MD2, the reproduced RF signal obtained by the RF amplifier passes through the AZD conversion circuit 231, equalizer 232, PLL circuit 233, and PRML circuit 234. The signal is then processed by the RLL (1-7) PP demodulation unit 235 and the RS-LDC decoder 236. The reproduced RF signal is reproduced as an RLL (1-7) code string by detecting data using PR (1, 2, 1) ML and Viterbi decoding in the RLL (1-7) PP demodulation unit 235. Then, the RLL (1-7) demodulation process is performed on this RLL (1-7) code sequence. Further, error correction and interleaving are performed in the RS-LDC decoder 236.

 In this case, the next-generation MD 1 and next-generation MD 2 are selected by the selector 229, and the demodulated data is output to the data buffer 230 as reproduction data from the disk 290. At this time, demodulated data is supplied to the memory transfer controller 2 12 in FIG.

 The tracking error signal TE and the focus error signal FE output from the RF amplifier 224 are supplied to a servo circuit 237, and the group information is supplied to an ADIP decoder 238.

AD IP Deco 2 338 extracts the wobble component by band-limiting the group information with a band pass filter, and then performs FM demodulation and bi-phase demodulation to extract the AD IP address. The extracted AD IP address, which is the absolute address information on the disc, is passed through the MD address decoder 239 if the disc is a conventional mini disc and the next-generation MD1, and is used for the next-generation MD2. For example, it is supplied to the drive controller 241 via the next-generation MD2 address decoder 240. The drive controller 241 executes a predetermined control process based on each AD IP address. The group information is returned to the servo circuit 237 for spindle servo control. Further, as described above, the optimum recording pulse width and pulse width And its peak power are calculated and supplied to a laser driver / APC 249 to be described later.

 The servo circuit 237, for example, performs a spindle error for CLV servo control and ZCAV servo control based on an error signal obtained by integrating a phase error between the group information and a reproduction clock (PLL system clock at the time of decoding). Generate one signal. In addition, the servo circuit 237 includes a spindle error signal, a tracking error signal supplied from the RF amplifier 24 as described above, a focus error signal, a track jump command from the drive controller 241, an access command, and the like. Generates various servo control signals (tracking control signal, focus control signal, thread control signal, spindle control signal, etc.) based on the data and outputs the generated signal to the motor driver 242. In other words, various service control signals are generated by performing necessary processes such as a phase compensation process, a gain process, and a target value setting process on the above-mentioned signal and command. The motor driver 242 generates a predetermined servo drive signal based on the servo control signal supplied from the servo circuit 237. The support drive signals include a two-axis drive signal (two types in the focus direction and tracking direction) for driving the two-axis mechanism, a thread motor drive signal for driving the thread mechanism, and a spindle motor. Is a spindle motor drive signal for driving the motor. With such a support drive signal, focus control and tracking control for the disk 290 and CLV control or ZCAV control for the spindle motor 221 are performed. When a recording operation is performed on the disk 290, high-density data from the memory transfer controller 212 shown in Fig. 18 or normal ATRAC compressed data from the audio processing unit 219 is supplied. Is done.

At the time of recording on the conventional mini-disc, the selector 243 is connected to the conventional mini-disc side, and the ACIRC encoder 244 and the EFM modulator 245 function. In this case, if it is an audio signal, the compressed data from the audio processing unit 219 is subjected to the interleaving and error correction code addition by the ACIRC encoder 244, and then to the EFM modulation unit 245. Modulated. The EFM modulation data is supplied to the magnetic head driver 2 46 via the selector 24 3, and the magnetic head 2 23 applies a magnetic field to the disk 290 based on the EFM modulation data. Is recorded.

 When recording to the next-generation MD 1 and the next-generation MD 2, the selector 243 is connected to the next-generation MD 1 and the next-generation MD 2, and the R SL CD encoder 247 and the R L (1-7) PP modulation unit 248 function. . In this case, after the high-density data sent from the memory transfer controller 212 is interleaved by the RS-L CD encoder 247 and error correction code addition of the RSL DC method is performed, the RLL (1-7) At the PP modulation section 248! ^ Then (1-7) modulated.

 The recording data modulated into the RL L (1-7) code string is supplied to a magnetic head driver 246 via a selector 243, and the magnetic head 223 applies a magnetic field to the disk 290 based on the modulation data. By doing so, data is recorded.

 The laser driver / APC 249 causes the laser diode to execute a laser emission operation at the time of reproduction and recording as described above, but also performs a so-called APC (Automatic Laser Power Control) operation. Specifically, although not shown, a detector for a laser beam monitor is provided in the optical head 222, and this monitor signal is fed back to the laser driver / APC 249. ing. The laser driver ZAP C 249 compares the current laser power obtained as a monitor signal with a preset laser power, reflects the error in the laser drive signal, and outputs the error from the laser diode. Control is performed so that the laser power is stabilized at the set value. Here, as the laser power, values as the reproduction laser power and the recording laser power are set in the register inside the laser driver / APC 249 by the drive controller 241. Further, in this example, the optimum pulse width is controlled together with the recording laser power based on the detected temperature near the disk 290.

 The drive controller 241 controls each component based on an instruction from the system controller 218 such that the above operations (access, various support, data write, and data read operations) are executed. . In FIG. 19, each part surrounded by a chain line can be configured as a one-chip circuit.

By the way, if the disc 290 is previously divided into a data recording area and an audio track recording area as shown in FIG. The controller 218 accesses the drive based on the set recording area according to whether the data to be recorded / reproduced is an audio track or a data track. Will be instructed.

 In addition, it is possible to perform control to permit recording of only one of PC data and audio data on the loaded disk 290, and prohibit recording of other data. . That is, control can be performed so that the data for PC and the audio data are not mixed.

 Therefore, the disk drive device 210 shown as this specific example can realize compatibility between the conventional mini-disc, the next-generation MD 1 and the next-generation MD 2 and the temperature of the disk by providing the above-described configuration. If the recording current is high, the recording pulse width is narrowed to improve the recording quality, and at low temperatures, the pulse width is widened so as not to exceed the LD rating. Without this, recording characteristics can be guaranteed over the entire temperature range.

 It should be noted that the present invention is not limited to the above-described embodiment described with reference to the drawings, and various changes, substitutions, or equivalents thereof may be made without departing from the scope and spirit of the appended claims. It is clear to one skilled in the art that INDUSTRIAL APPLICABILITY As described in detail above, the data recording device according to the present invention is a data recording device according to the present invention, in which a modulated magnetic field modulated by recording data is applied to a recording medium as a recording magnetic field. In addition, in a data recording apparatus for performing data recording on the recording medium by irradiating a recording surface of the recording medium with laser light, It has control means for switching the pulse width of the recording pulse that drives the light source of the laser light, so if the disk temperature is high, the pulse width at the time of recording is narrowed to improve the recording quality, and if the temperature is low, the LD is The recording characteristics can be guaranteed over the entire temperature range with a recording power within the 0 P rating by recording with a wider pulse width so as not to exceed the rating.

Claims

O 2004/068487 37 Claims

1. A data recording apparatus that applies a modulation magnetic field modulated by recording data to a recording medium as a recording magnetic field, and irradiates a recording surface of the recording medium with laser light to record data on the recording medium. At

 A recording apparatus comprising: a control unit that switches a pulse width of a recording pulse for driving the light source of the laser beam to emit light according to the temperature of the recording medium and the temperature of or near the recording medium.

 2. The data recording apparatus according to claim 1, wherein the control means variably controls a laser beam according to the temperature of the recording medium and / or its vicinity.

3. The control means reduces the pulse width as the temperature of the recording medium and / or the vicinity thereof increases, and increases the pulse width as the temperature of the recording medium and / or the vicinity thereof decreases. 2. The data recording apparatus according to claim 1, wherein the pulse width is switched stepwise.

 4. The data recording apparatus according to claim 1, wherein the control means sets the pulse width to be small within a range not exceeding a peak power rating of the recording pulse.

 5. The control means switches the pulse width in accordance with the recording medium and the temperature at or near the recording medium and the pulse width with reference to a table indicating required peak power measured in advance. 5. The data recording device according to claim 4, wherein:

6. It has a temperature detecting means for detecting an ambient temperature of the recording medium,

 2. The data recording apparatus according to claim 1, wherein said control means controls said recording pulse based on a temperature detected by said temperature detecting means.

 7. It has a temperature detecting means for detecting the temperature of the recording medium,

 2. The data recording apparatus according to claim 1, wherein said control means controls said recording pulse based on a temperature detected by said temperature detecting means.

8. A data recording method of applying a modulation magnetic field modulated by recording data to a recording medium as a recording magnetic field and irradiating a recording surface of the recording medium with a laser beam to record data on the recording medium. At O 2004/068487

38. An overnight recording method comprising a control step of switching a pulse width of a recording pulse for driving the light source of the laser beam to emit light in accordance with the temperature of the recording medium and Z or its vicinity.

 9. An operation of applying a modulation magnetic field modulated by recording data to a recording medium as a recording magnetic field and irradiating a recording surface of the recording medium with a laser beam to perform data recording on the recording medium. In a program to be executed by a computer,

 A program comprising a control step of switching a pulse width of a recording pulse for driving a light source of the laser beam to emit light in accordance with the temperature of the recording medium and / or the vicinity thereof.