JPH0997431A - Optical recording medium recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a record in a uniform shape corresponding to a data irrespective of a deviation of a recording characteristic of an optical recording medium by setting a bias component of recording power to be given to a light emitting means to an optimum value based on the recording characteristic, and recording the data accordingly. SOLUTION: A recorded program 12 is read out again to control a laser power control circuit 6 by a system control circuit 5, and a detected optimum value is set. Afterward, when a usual data is to be recorded, the laser power control circuit 6 is controlled by the device so as to record the data giving bias power with this optimum value. Thus, since the optimum value of the bias power corresponding to sensitivity of an inserted magnetic optical disk is set, the record in the uniform shape is obtained without being influenced by any deviation in sensitivity corresponding to a value of the data.

Description

Detailed Description of the Invention

[0001]

[Table of Contents] The present invention will be described in the following order. TECHNICAL FIELD OF THE INVENTION Conventional Technology Problems to be Solved by the Invention Means for Solving the Problems (FIG. 1) Embodiments of the Invention (FIGS. 1 to 4)

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording medium recording device, and can be applied to, for example, a magneto-optical disk recording / reproducing device.

[0003]

2. Description of the Related Art Conventionally, there is a magneto-optical disk recording / reproducing apparatus which records data by a mark edge recording (mark length recording) method in order to record data at a high density by an optical modulation method. In this mark edge recording method, a strong laser beam is applied to the magnetic film for a time corresponding to the data value while scanning the track. As a result, a reversal magnetization region, that is, a mark having a length according to the irradiation time is formed in the magnetic film.

Incidentally, in the mark edge recording method, the length of the mark is judged by detecting the start end and the end of the mark, and this length is used as the value of the reproduction data.

[0005]

By the way, the magneto-optical disk recording / reproducing apparatus for recording by the above-mentioned optical modulation system has the power of the laser light at the time of recording (the height of the waveform of the laser light).
Was fixed. For example, in order to facilitate recording, the magnetic film on the track is preheated with a certain bias power, and is heated up to the Curie point with a fixed recording power including the bias power only when forming a mark. It was

However, the easiness of warming of the magnetic film of the magneto-optical disk, so-called sensitivity, differs depending on the manufacturer and the lot. For this reason, when a mark is written with the same recording power, the length and width of the mark differ depending on the manufacturer and the lot of the magneto-optical disk. As described above, since the sensitivity of the magneto-optical disk differs depending on the manufacturer and the lot, when using the magneto-optical disk of different manufacturers and lots, the marks are not always formed in the uniform shape having the length and width corresponding to the data. There was a problem that it was not done.

A difference in mark length causes a data error. If the mark width is increased, the marks of adjacent tracks may be destroyed or high-density recording may not be possible. Therefore, when data is reproduced, it is easy for a phenomenon that the values and margins of important items such as carrier signal to noise ratio, so-called C / N and jitter, are different for each magneto-optical disk.

The present invention has been made in consideration of the above points, and when the data is recorded by irradiating the light flux obtained from the light emitting means which gives the recording power including the bias component, the recording characteristics of the optical recording medium are An object of the present invention is to propose an optical recording medium recording device capable of forming a data recording portion into a uniform shape corresponding to data regardless of deviation.

[0009]

In order to solve such a problem, the present invention has a light emitting means for generating a light beam by applying a recording power and a light modulating means for modulating the light beam. An optical recording medium recording device that irradiates an optical recording medium to record data on the optical recording medium, detects the recording characteristic of the optical recording medium, and sets the value of the bias component of the recording power based on the detected recording characteristic. To do.

The recording characteristic of the optical recording medium is detected, and based on this recording characteristic, the bias component of the recording power applied to the light emitting means is set to an optimum value for recording, and the recording power including the bias component is applied. When the data is recorded by irradiating the light flux obtained from the light emitting means, the data recording portion can be formed into a uniform shape corresponding to the data regardless of the deviation of the recording characteristics of the optical recording medium.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows an optical recording medium recording apparatus as a whole, for example, a magneto-optical disk recording / reproducing apparatus 1, in which computer data is digitally recorded / reproduced on an optical recording medium, for example, a magneto-optical disk 2 by a mark edge recording method.
The magneto-optical disk recording / reproducing apparatus 1 detects the recording characteristics of the magneto-optical disk 2, for example, the sensitivity to laser light when forming a mark, based on the error rate of data.

The magneto-optical disk recording / reproducing apparatus 1 sets the bias component of the recording power applied to the laser diode, for example, the optimum value of the bias power, based on the detected sensitivity. The magneto-optical disc recording / reproducing apparatus 1 outputs the recording power including the bias power of the optimum value from the laser diode to heat the magneto-optical disc 2. This allows
The magneto-optical disc recording / reproducing apparatus 1 can form marks having a uniform length and width corresponding to the data value on the magneto-optical disc 2 without being affected by the deviation of the sensitivity of each magneto-optical disc 2. Further, the magneto-optical disk device 1 uses an optical modulation method in which erasing and recording of data are separately performed, and recording is performed by a ternary multi-pulse recording method to prevent tear mark shape of a mark.

As shown in FIG. 2B, the magneto-optical disc recording / reproducing apparatus 1 associates the length of the mark 4 on the track 3 with the period of the data logical "1" level. FIG.
As shown in (C), the first value used in the ternary multi-pulse recording method is the value of the bias power. The second value is the minimum period 2 where T is the basic unit period of data recording.
It is the value of the recording power required when recording a mark having a length corresponding to T.

The third value is a value of the recording power required when a mark having a length corresponding to a period of 3T or more is recorded and subsequently applied after the recording power of the second value. When recording a mark of any length, the laser power is dropped to almost 0 level by 0.5T from the end of the mark. As a result, as shown in FIG.
The mark 4 is formed in a predetermined length by residual heat.

Incidentally, the optical modulation system records a signal by applying a magnetic field in a fixed direction and changing the light intensity of the semiconductor laser. The multi-pulse recording method is a recording method of intermittently irradiating a strong laser beam that heats up to the Curie point and using residual heat to form the marks 4 of the same width on the magnetic film. The teardrop shape of the mark means that when the laser beam is continuously irradiated while the track 3 is scanned, the residual heat of the rapidly heated region spreads to the surroundings and becomes wider as it goes toward the end of the mark 4. Is spread.

As shown in FIG. 1, the magneto-optical disc recording / reproducing apparatus 1 is wholly controlled by measuring means, detecting means and setting means, for example, a system control circuit 5. First, when recording data, the magneto-optical disk recording / reproducing apparatus 1
A drive signal S1 corresponding to the data is supplied from a modulating means, for example, a laser power control circuit 6 to a light emitting means, for example, a laser diode (not shown) in the pick-up 7 to drive it. As a result, the laser diode causes the drive signal S
A light beam having an intensity corresponding to 1 is emitted to form a mark on the magneto-optical disk 2.

At this time, the magneto-optical disk recording / reproducing apparatus 1
Feed back the optical signal S2 detected by the pick-up 7 to the laser power control circuit 6 to control the emission power of the laser diode to a predetermined value. Next, when reproducing data, the magneto-optical disk recording / reproducing apparatus 1 decodes the optical signal S3 detected by the pickup 7 by the demodulation / decoding circuit 8 to generate reproduced data S4, and outputs this reproduced data S4.

Incidentally, the magneto-optical disk recording / reproducing apparatus 1
The servo circuit 9 controls a lens actuator (not shown) included in the pick-up 7 to focus on the magneto-optical disk 2 and scan a track on the magneto-optical disk 2. The magneto-optical disc recording / reproducing apparatus 1 controls the position of the pick-up 7 in the radial direction of the magneto-optical disc 2 by the servo circuit 9.
Scan the upper track. Further, in the magneto-optical disc recording / reproducing apparatus 1, the spindle servo circuit 10 controls the rotation of the magneto-optical disc 2.

Next, when the sensitivity of the magneto-optical disk 2 is detected and the optimum value of the bias power is set, the magneto-optical disk recording / reproducing apparatus 1 records test data having different bias power values on the magneto-optical disk 2. Then, the optimum value of the bias power is detected and set based on the error rate of the reproduction data S4 due to this test data.

That is, when recording the test data, the system control circuit 5 causes the recording program 12 from the sensitivity measurement and optimum bias power setting program storage unit 11.
Is read out and the value of the bias power is set to a certain value according to the measurement stage, and the laser power control circuit 6, the servo circuit 9 and the spindle servo circuit 10 are controlled. However, in the magneto-optical disc recording / reproducing apparatus 1, the portion of the recording power value that exceeds the bias power value is
It is controlled to a constant value regardless of the increase / decrease in the value of the bias power. As a result, a plurality of test data are recorded on the magneto-optical disk 2 with the laser light having the intensity according to the recording power increased or decreased according to the value of the bias power.

When reading the reproduction data S4 based on the test data, the system control circuit 5 reads the reproduction measurement program 13 from the sensitivity measurement / optimum bias power setting program storage unit 11, and the laser power control circuit 6, the servo circuit 9 and the spindle. The servo circuit 10 is controlled. As a result, the system control circuit 5 reads the reproduction data S4 based on the test data,
The reproduced data S4 is compared with the test data to detect a data error.

Further, the system control circuit 5 calculates the error rate of the reproduced data S4 due to the test data for each measurement step based on the number of test data and the number of data errors. Further, the magneto-optical disk recording / reproducing apparatus 1 uses the measurement result such as the measurement data S in which the bias power value and the error rate are associated with each other.
5 is stored in the storage means, for example, the measurement data storage unit 15 of the work data storage unit 14. In this way, the system control circuit 5 changes the value of the bias power at each measurement stage and repeats the sensitivity measurement.

When the measurement is completed, the system control circuit 5 reads the optimum value detection program 16 from the sensitivity measurement / optimum bias power setting program storage unit 11 and reads the measurement data S5 from the work data storage unit 14. Subsequently, the magneto-optical disc recording / reproducing apparatus 1 compares the magnitudes of the error rates by the optimum value detection program 16,
The bias power value corresponding to the minimum error rate is detected as the optimum bias power value.

This means that the sensitivity of the magneto-optical disk 2 is converted into the optimum value of the bias power for detection.
Incidentally, there is a tendency that the optimum value of the bias power is large when the sensitivity is low, and the optimum value is small when the sensitivity is high. The sensitivity is
It is determined by parameters such as the heat capacity of the magnetic film, the thermal conductivity, and the reflectance of the surface. Then, the system control circuit 5 reads the recording program 12 again and controls the laser power control circuit 6 to set the detected optimum value. Thereafter, the magneto-optical disk recording / reproducing apparatus 1
Controls the laser power control circuit 6 so that, when recording normal data, the bias power is given at this optimum value for recording.

In the above configuration, the magneto-optical disk recording / reproducing apparatus 1 follows the sensitivity measurement and optimum bias power setting procedure shown in FIG. 3 when detecting the sensitivity of the magneto-optical disk and setting the optimum value of the bias power. Works. That is, when the new magneto-optical disk 2 is inserted, the magneto-optical disk recording / reproducing apparatus 1 starts from the start step SP0, sets the sector to be measured to, for example, an arbitrary unrecorded sector at step SP1, SP2
Move on to.

At step SP2, the magneto-optical disc recording / reproducing apparatus 1 clears the measurement step j to j = 0 and proceeds to step SP3. At step SP3, the magneto-optical disk recording / reproducing apparatus 1 sets the value of the bias power to the j-th value.
The value of the stage (here, the 0th stage), for example, the minimum value is set, and the process proceeds to step SP4. In step SP4, the magneto-optical disk recording / reproducing apparatus 1 erases the sector to be measured and measures the test data by the ternary multi-pulse recording method with the bias power of the value of the jth stage (here, the 0th stage). The data is recorded in the sector and the process proceeds to step SP5.

At step SP5, the magneto-optical disc recording / reproducing apparatus 1 reproduces the test data, stores the error rate data Data (j) associated with the bias power value, and proceeds to step SP6. At step SP6, the magneto-optical disc recording / reproducing apparatus 1 increments the measurement step j to j = j + 1, moves to step SP7, and moves to the measurement step j.
Determines whether the set number n has reached the set number n.

When a negative result is obtained in step SP6, the magneto-optical disc recording / reproducing apparatus 1 determines that the measurement has not been completed and returns to step SP3 to repeat the above procedure. When the number of measurement steps j reaches the set number n, the magneto-optical disc recording / reproducing apparatus 1 obtains a positive result in step SP6, determines that the measurement is completed, and proceeds to step SP8. Thereby, as shown in FIG. 4, for example, a parabolic error rate characteristic curve 17 is obtained according to the sensitivity of the inserted magneto-optical disk.

At step SP8, the magneto-optical disk
The recording / reproducing apparatus 1 has an error rate of 10 for example. ^-FourThe following data
Detect the minimum value Min (j) of Data (j). Then, the magneto-optical
The disk recording / reproducing apparatus 1 has a measuring stage obtained from the minimum value Min (j).
The value of the bias power corresponding to the floor j
Set the optimum value in the laser power control circuit 6
Then, move to step SP9 to perform sensitivity measurement and optimum bias.
Finish the power setting procedure.

As a result, the optimum value of the bias power is set according to the sensitivity of the inserted magneto-optical disk. Therefore, the mark formed by using this optimum value of bias power has a uniform shape corresponding to the data value and not affected by the sensitivity deviation. As a result, the data is recorded in the optimum recording state, and the error rate of the reproduced data can be suppressed to the minimum value regardless of the deviation of the sensitivity of the magneto-optical disk.

According to the above configuration, the sensitivity of the magneto-optical disk 2 is measured and detected, and the bias power is set to an optimum value for recording based on this sensitivity, thereby recording the recording power including the bias power. When the data is recorded by irradiating the laser beam obtained from the given laser diode, the mark 4 can be formed into a uniform shape corresponding to the data regardless of the deviation of the sensitivity of the magneto-optical disk 2.

In the above-described embodiment, the case where the waveform in which the portion of the recording power value exceeding the bias power value is controlled to a constant value regardless of the increase or decrease of the bias power value is used is described. The present invention is not limited to this, and can be applied to the case where a portion of the value of the recording power exceeding the value of the bias power decreases along the time axis. In this case, the same effect as described above can be obtained.

Further, in the above embodiment, the case where the test data is recorded in an arbitrary unrecorded sector when the sensitivity is measured has been described, but the present invention is not limited to this, and the inner peripheral side and the outer peripheral side of the disk are described. When the linear velocities are different between and, the test data are recorded at a plurality of radial positions such as the inner and outer circumference sides, and the optimum value of the bias power corresponding to each radial position is detected. The present invention can also be applied to the case of irradiating laser light by switching to different recording power corresponding to.

Further, in the above-mentioned embodiment, the case where the optimum value of the bias power is detected based on the error rate obtained by comparing the reproduced data and the test data has been described, but the present invention is not limited to this. It can also be applied to the case where the optimum value of the bias power is detected based on an arbitrary measured value that changes according to the value of the bias power, such as the change of the C / N and the characteristics of the jitter when the value of the bias power is changed. .

Further, in the above-mentioned embodiment, the case where the optimum value of the bias power is set at the start of use has been described, but the present invention is not limited to this, and the sensitivity is measured according to the temperature change during use. It can also be applied when adjusting the optimum value of the bias power.

Further, in the above-mentioned embodiment, when recording data, the case where the mark is uniformly formed by heating with the laser light emitted from the laser diode driven with the set power and reversing the magnetization direction is described. However, the present invention is not limited to this, and at the time of recording data, the light flux obtained from the light emitting means driven at the set power is irradiated to deform the recording surface such as evaporation and melting, and change the optical physical property value. For example, the present invention can be widely applied to the case where the data recording portion is uniformly formed by giving an arbitrary change.

Further, in the above-mentioned embodiments, the case where the recording power for driving the laser diode is controlled to perform the light modulation has been described, but the present invention is not limited to this, and the intensity of the light flux after being emitted from the light emitting means. It is also applicable to the case of directly modulating.

Further, in the above-mentioned embodiment, the case where the test data is recorded and the optimum value of the bias power is set based on the error rate of the reproduction data S4 by the test data has been described, but the present invention is not limited to this. Alternatively, the present invention can be applied to a case where the recording characteristics are detected by measuring the state of the optical recording medium by an arbitrary method such as measuring the thickness or reflectance of the recording portion.

Further, in the above-mentioned embodiment, the case of recording by the mark edge recording system has been described.
The present invention is not limited to this, and can also be applied to the case of recording by the mark recording method (pit position detection method).

Further, in the above-mentioned embodiment, the case of recording by the ternary multi-pulse recording system has been described, but the present invention is not limited to this, and binary and quaternary or more may be used. In addition, the first is adjusted according to the recording characteristics of the optical recording medium.
The bias power is set by the value of, and the data recording portion is evenly irradiated by irradiating the light flux obtained from the light emitting means which gives the recording power of the third value obtained by adding the first value and the arbitrary second value. It can also be widely applied to the case of forming.

Further, in the above-mentioned embodiment, the case of recording data on the magneto-optical disk 2 is described, but the present invention is not limited to this, and data is recorded on an optical recording medium having an arbitrary shape by using light. It can also be widely applied when recording.

[0043]

As described above, according to the present invention, the recording characteristic of the optical recording medium is detected, and based on this recording characteristic, the bias component of the recording power applied to the light emitting means is set to the optimum value for recording. As a result, when data is recorded by irradiating a light beam obtained from the light emitting means which gives a recording power including the bias component, the data recording portion is evenly distributed corresponding to the data regardless of the deviation of the recording characteristics of the optical recording medium. An optical recording medium recording device that can be formed into a shape can be realized.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a magneto-optical disk recording / reproducing apparatus according to an embodiment of an optical recording medium recording apparatus according to the present invention.

FIG. 2 is a schematic diagram showing waveforms and mark edge recording timing by a ternary multi-pulse recording method.

FIG. 3 is a flow chart showing a procedure of sensitivity measurement and optimum bias power setting.

FIG. 4 is a characteristic curve diagram showing an error rate characteristic with respect to bias power.

[Explanation of symbols]

1 ... Magneto-optical disk recording / reproducing device, 2 ... Magneto-optical disk, 3 ... Track, 4 ... Mark, 5 ... System control circuit, 6 ... Laser power control circuit, 7 ... Pickup, 8 ... Demodulation and decoding circuit, 9 ...
Servo circuit, 10 ... Spindle servo circuit, 11 ...
Sensitivity measurement and optimum bias power setting program storage unit, 12 ... recording program, 13 ... reproduction measurement program, 14 ... work data storage unit, 15 ... measurement data storage unit, 16 ... optimum value detection program, 17 ... … Error rate characteristic curve.

Claims (10)

[Claims] 1. An optical recording medium, comprising: a light emitting means for generating a light beam by applying a recording power; and a light modulating means for modulating the light beam. The modulated light beam is applied to an optical recording medium to record data on the optical recording medium. An optical recording medium recording apparatus for recording on a medium, wherein the recording characteristic of the optical recording medium is detected, and the value of the bias component of the recording power is set based on the detected recording characteristic. Recording device. 2. A measuring means for measuring the state of the optical recording medium, a storage means for storing the measurement result, a detecting means for detecting the recording characteristic based on the measurement result, and the detected recording characteristic. The optical recording medium recording apparatus according to claim 1, further comprising a setting unit that sets the value of the bias component based on the above. 3. A recording means for recording test data on the optical recording medium by varying the value of the bias component for each measurement step, wherein the measuring means has a value of the bias component for each measurement step. Based on the reproduction result of the test data corresponding to, the state of the optical recording medium is measured, the storage means stores the measurement result associated with the value of the bias component for each measurement step. The optical recording medium recording device according to claim 1 or 2, which is characterized. 4. The measurement result is an error rate of the reproduction result, and the detection means detects the recording characteristic based on the error rate. The optical recording medium recording device according to claim 3. 5. The optical recording medium recording apparatus according to claim 1, wherein the optical recording medium is a disk-shaped optical recording medium. 6. The optical recording medium recording device according to claim 1, wherein the disk-shaped optical recording medium is a magneto-optical disk. 7. The optical recording medium recording apparatus according to claim 1, wherein recording is performed by a mark edge recording method. 8. The optical recording medium recording apparatus according to claim 1, wherein the recording is performed by a multi-pulse recording method. 9. The optical recording medium recording apparatus according to claim 1, wherein the recording power value has a plurality of values different from the above value. 10. The optical recording medium recording apparatus according to claim 1, wherein the modulation means controls the recording power to modulate the light flux.