JPH05334606A - Magneto-optical recording method - Google Patents

Abstract

PURPOSE:To perform write with the optimum recording condition even when heat is generated in an electromagnet by continuous write. CONSTITUTION:When a record is written in magneto-optical recording, the temperature of the electromagnet 31 is detected by a sensor 35, and a current is supplied to a coil 33 conforming to the temperature. and a constant magnetic field can be generated. Simultaneously. atmospheric temperature is detected by the sensor 35, and the output of a laser diode LD 15 is controlled in accordance with sensitivity fluctuation by the temperature of a magneto-optical disk 51.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magneto-optical recording method for recording (including erasing) information by using an externally applied magnetic field supplying element composed of an electromagnet.

[0002]

2. Description of the Related Art Magneto-optical recording records information on a recording medium as the direction of magnetization. When recording this information, as shown in FIG. 3, a laser diode (LD) 15 is applied by the objective lens 13 of the optical head 11 while applying a magnetic field to the magneto-optical disk 51 by the electromagnet 31 (externally applied magnetic field supply element). To irradiate or align the magnetization in the direction of the magnetic field of the electromagnet 31.

Generally, in a magneto-optical disk recording apparatus, in order to operate the apparatus stably, the temperature inside the apparatus is sensed and the control is performed according to the temperature. In particular, the laser diode 15 has a strong dependence on temperature, and if the temperature fluctuates, the reproduction laser power changes and the stability of the reproduction signal is impaired.

Therefore, in order to prevent this, the LD temperature sensor 17 senses the temperature, and by feeding back this information, the LD driver 27 causes the laser diode 15 to emit light at a constant reproduction laser power, thereby improving reproduction stability. Have secured.

[0005]

However, it has been found that sufficient recording stability cannot be ensured only by conventional temperature sensing.

That is, it has been found that if the electromagnet 31 abnormally generates heat due to continuous operation of the electromagnet 31, the recording conditions are not satisfied, the recording sensitivity is changed, and the recording stability is deteriorated.

The recording condition is not satisfied because the electromagnet 31
This is because the recording magnetic field of the set value cannot be generated due to the heat generation of. On the other hand, the recording sensitivity changes because the electromagnet 31
The ambient temperature rises due to the heat generated by the
This is because the recording sensitivity of is changed and stable recording cannot be performed.

An object of the present invention is to solve the above problems and improve the recording stability in magneto-optical recording.

[0009]

According to a first magneto-optical recording method of the present invention, while an externally applied magnetic field supplying element composed of an electromagnet applies a magnetic field to a magneto-optical recording medium, light is irradiated by an optical head to record information. A magneto-optical recording method for recording is characterized in that the temperature of the electromagnet is detected and the current supplied to the electromagnet is controlled in accordance with the detected temperature so as to generate a predetermined magnetic field.

The second magneto-optical recording method of the present invention is
In the magneto-optical recording method of recording information by irradiating a laser beam with an optical head while applying a magnetic field to the magneto-optical recording medium by an externally applied magnetic field supply element composed of an electromagnet, the magneto-optical recording is performed by detecting the temperature of the electromagnet. It is characterized in that the temperature of the recording medium is detected and the laser output is controlled in response to a change in the sensitivity of the magneto-optical recording medium due to the temperature.

The temperature signal from the electromagnet is used for the stable generation of the magnetic field and the light emission by the laser output according to the recording sensitivity,
The above two controls can be performed simultaneously.

[0012]

1 is a block diagram showing an embodiment of the present invention, showing an optical modulation type magneto-optical disk device. FIG. 2 is a perspective explanatory view showing the relationship between the electromagnet 31, the MG temperature sensor 35, and the magneto-optical disk 51.

An electromagnet (externally applied magnetic field supply element) 31 and an optical head 11 are provided opposite to each other on both sides of a replaceable magneto-optical disk 51 which rotates around a rotary shaft 53. The electromagnet 31 extends in the radial direction of the magneto-optical disk 51 over the entire length of the recording area (see FIG. 2).

When writing (erasing) information, the optical head 11 is moved while the magnetic field required for writing is applied to the surface of the recording medium of the magneto-optical disk 51, and the laser light from the laser diode 15 is spotted. Irradiate. A current is supplied from the CPU 21 to the electromagnet 31 by the MG driver 43 so that an appropriate magnetic field is applied to the magneto-optical disk 51. However, if the temperature fluctuates,
The relationship between the supply current amount I and the generated magnetic field strength H changes. Specifically, the strength of the generated magnetic field decreases due to the temperature increase. Therefore, in the present invention, the temperature of the electromagnet 31 is detected by the MG sensor 35, and the current amount obtained by adding the increment necessary for generating the proper magnetic field based on the HI curve under the temperature condition by the sensor processing circuit 41 is It is supplied to the electromagnet 31 by the MG driver 43. As a result, information is written / erased while a proper magnetic field is always applied.

On the other hand, the temperature of the laser diode 15 is LD
The temperature sensor 17 detects the variation, and the sensor processing circuit 23 supplies the variation to the LD power controller 25.
The LD driver 27 controls the laser diode 15 so that a predetermined light emission output is obtained.

However, if the temperature of the magneto-optical disk 51 fluctuates due to the heat generation of the electromagnet 31, the recording sensitivity characteristic of the disk 51 also differs, and it is necessary to change the appropriate light emission output of the laser diode 15 accordingly.

Therefore, in the present invention, the temperature of the electromagnet 31 detected by the MG temperature sensor 35 is processed by the sensor processing circuit 41, and the temperature increase is input to the CPU, and the laser is controlled by the LD power controller 25 based on the information. By controlling the light emission output of the diode 15, it becomes possible to perform writing corresponding to the fluctuation of the recording sensitivity of the magneto-optical disk due to the temperature rise. As described above, by performing recording corresponding to the ambient temperature at the time of recording, it is possible to form a recording magnetic domain with little jitter and high resolution.

Further, as shown in FIG. 2, the MG temperature sensor 35 is not on the magneto-optical disk 51 (magneto-optical recording medium) side, but on the surface not facing the magneto-optical disk 51, specifically, the back surface of the electromagnet 31. Is attached to. As described above, by mounting the MG temperature sensor 35 on the surface that is not affected (small) by the wind generated by the rotation of the magneto-optical disk 51, the temperature of the electromagnet 31 can be accurately and directly detected without disturbance, and the accuracy is high. Recording stability can be realized.

[0019]

According to the present invention, it is possible to record information under the optimum recording condition by detecting the temperature of the electromagnet and controlling the magnetic field strength generated by the electromagnet.

Further, according to the present invention, the recording condition in which the jitter margin is large and the high resolution is ensured is realized by detecting the temperature of the electromagnet and performing the recording corresponding to the sensitivity variation of the recording medium due to the ambient temperature change. it can.

Moreover, as the constituent parts, the temperature sensor and the processing circuit therefor, which have been conventionally used, may be increased by one system, and a complicated circuit structure is not required. Also,
The controllable state can be achieved without changing the mechanical basic configuration of the device.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of a magneto-optical recording method of the present invention.

FIG. 2 is an explanatory diagram showing a positional relationship between an MG temperature sensor, an electromagnet, and a magneto-optical disk.

FIG. 3 is an explanatory diagram showing an example of a conventional magneto-optical recording method.

[Explanation of symbols]

 11 Optical Head 13 Objective Lens 15 Laser Diode 17 LD Temperature Sensor 21 CPU 23 Sensor Processing Circuit 25 LD Power Controller 27 LD Driver 31 Electromagnet 33 Coil 35 MG Temperature Sensor 41 Sensor Processing Circuit 43 MG Driver 51 Magneto-Optical Disk 53 Rotation Axis

Claims (2)

[Claims] 1. A magneto-optical recording method for recording information by irradiating light from an optical head while applying a magnetic field to a magneto-optical recording medium by an externally applied magnetic field supply element composed of an electromagnet, detecting the temperature of the electromagnet, A magneto-optical recording method characterized in that a current supplied to an electromagnet is controlled in accordance with a detected temperature so as to generate a predetermined magnetic field. 2. A magneto-optical recording method for recording information by irradiating a laser beam with an optical head while applying a magnetic field to a magneto-optical recording medium by an externally applied magnetic field supplying element composed of an electromagnet, the temperature of the electromagnet being controlled. A magneto-optical recording method comprising: detecting and detecting the temperature of the magneto-optical recording medium, and controlling the laser output in response to a change in the sensitivity of the magneto-optical recording medium due to the temperature.