JPH0194558A - Magneto-optical disk device - Google Patents

Abstract

PURPOSE:To attain recording and reproducing whose transfer rate is made double by arranging magneto-opical heads by corresponding to the respective quartered disk recording areas and adding the external magnetic fields for erasing and recording of the respective recording areas by switching magnetizing direction. CONSTITUTION:A magneto-optical disk 1 is divided into four recording areas 1a-1d from its outer circumference to inner circumference and magneto-optical heads 3a, 3b, 4a and 4b loaded on head sliders 7 and 8 are provided on the lower side facing to the disk 1. An erasing action before recording erases the recording areas of the disk 1 in parallel by the four magneto-optical heads 3a, 3b, 4a and 4b in the condition of switching the external magnetic fields of electromagnets 5 and 6 to downward magnetic fields. After that, an information recording is executed in parallel in the condition of switching the external magnetic fields (upward) and a parallel reproducing is executed at the time of reproducing. Thus, the recording and reproducing can be executed with the transfer rate made double.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magneto-optical disk device for recording and reproducing information such as images on a magneto-optical disk.

[Prior Art] Conventionally, as a magneto-optical disk device for recording and reproducing image information etc. on a magneto-optical disk, for example, the one shown in FIG. 3.4 is known.

FIG. 3 shows a magneto-optical disk serving as a recording medium, and FIG. 4 shows the configuration of a magneto-optical disk device.

The magneto-optical disk 1 is divided into an outer recording area 1e and an inner recording area 1f, as shown in FIG. 3, and is rotated at a constant speed by a spindle motor 2, as shown in FIG. A magneto-optical head 13a having erasing and reproducing functions is located at a lower position facing the inner and outer recording areas ie and 1f of the magneto-optical disk 1.

13b, and a magneto-optical head 1 with recording and reproducing functions.
4a and 14b are arranged at different positions in the circumferential direction (for example, 180° different positions).

The magneto-optical beds 13a and 13b for erasing and reproducing are mounted on a head slider 7, and the head slider 7 is moved in the radial direction along the slider rail 11 by a slider drive magnet 9, and the magneto-optical head 13a covers the outer recording area 1e. , and the inner recording area by the magneto-optical head 13b! 1i11
f can be traced.

This point is the magneto-optical head 14a for recording and reproduction.

The same applies to the magneto-optical head 14b, and the magneto-optical head 14a, 1
4b is mounted on the head slider 8, and the slider drive vi
i'510 allows movement in the radial direction along the guide rail 12.

On the other hand, magneto-optical heads 13a, 13b and 14a.

Permanent disks 1aUi 15, 16 are arranged at positions above the magneto-optical disk 1 facing each of the disks 14b. The permanent magnet 15 applies, for example, a downward external magnetic field as an erasing magnetic field to the magneto-optical disk 1, while the permanent magnet 16
applies an external upward magnetic field in the opposite direction as a recording magnetic field.

Recording and reproducing operations by such a conventional device are as follows.

First, the recording operation begins with the magneto-optical heads 13a and 1 prior to recording.
3b, the recording area of the magneto-optical disk 1 is erased. This erasing operation is performed by irradiating a strong laser beam spot light onto the corresponding recording area of the optical disk 1 from the magneto-optical heads 13a and 13b to heat it above a critical temperature, and during the cooling process, an external magnetic field from the permanent magnet 15 is applied to the magnetization direction. Align it downward.

The portion of the magneto-optical disk 1 that has been erased in this way rotates approximately half a turn to form the magneto-optical heads 14a and 14 for recording and reproducing.
When the position b is reached, the permanent magnet 14 is heated to a critical temperature or higher by irradiation with a laser beam spot light modulated by the recording signal, for example, a spot light corresponding to recording bit "1", and in the cooling process, the permanent magnet 14 is heated. A recording operation is performed by reversing the magnetization direction upward by an external magnetic field.

On the other hand, during reproduction, the magneto-optical head 13a.

13b or 14a, 14b is used as a reproducing head, for example, the magneto-optical head 13a.

A weak laser beam spot light is irradiated onto the magneto-optical disk 1 from the laser beam 13b, and a recorded signal is reproduced by reading the polarization direction depending on the magnetization direction of the reflected light.

[Problems to be Solved by the Invention] However, in such conventional magneto-optical disk devices, the transfer rate and recording time of recording signals are fixed depending on the number of recording heads. Devices intended for recording and reproducing black and white standard image quality have had a problem in that they cannot perform reversible reproduction of black and white high image quality or color standard image quality, which requires a higher transfer rate.

That is, 3 times the color subcarrier frequency Fsc, 0.5 times and 0
．． Y signal, B-Y signal and R-Y at 5 times sampling frequency
Based on the 3:20 component method, which targets color standard image quality that samples and records signals, black and white standard image quality uses color subcarrier frequency FSC for each of the Y signal, B-Y signal, and R-Y signal. It can be regarded as a so-called 2:O:O component method that samples as 2 times, 0 times, and 0 times of
signal and R-Y signal four times the color subcarrier frequency Fsc,
It can be regarded as the so-called 4:O:O component method that samples at 0x and 0x, and for devices intended for black and white standard image quality, it is possible to use black and white high image quality or color standard image quality, which requires twice the transfer rate. Unable to record and play back.

Therefore, as shown in Fig. 5, we have considered an apparatus in which two devices are provided for the black-and-white standard image quality shown in Fig. 4, and four optical lamination heads are used for recording operations, doubling the transfer rate. However, the number of heads increases to eight including those for erasing and reproducing, resulting in a complicated and large device configuration and an increase in cost.

[Means for Solving the Problems] The present invention has been made in view of these conventional problems, and makes it possible to perform recording and reproduction at twice the transfer rate without increasing the number of heads. The purpose is to provide a magneto-optical disk device.

In order to achieve this objective, the present invention divides the recording area of the magneto-optical disk into four recording areas in the radial direction from the outer circumference to the inner circumference, and erases data in each of the four divided recording areas of the magneto-optical disk. , four magneto-optical heads with recording and reproducing functions are arranged in correspondence, and an external magnetic field for erasing and an external magnetic field for recording are applied to each recording area of the magneto-optical disk by switching the magnetization direction. It is designed to arrange electromagnets that can be used.

[Function] In the magneto-optical disk device of the present invention having such a configuration, the erasing operation prior to recording is performed by switching the external magnetic field of the electromagnet to the erasing magnetic field (downward magnetic field) and using the four-divided light beam. The recording area of the magnetic disk is erased in parallel by four magneto-optical heads, and then the external magnetic field of the electromagnet is converted into a recording magnetic field (
(upward), information is recorded in parallel by four magneto-optical heads. Furthermore, during reproduction, parallel reproduction is performed using four heads. As a result, the transfer rate can be doubled without increasing the number of heads, and recording and reproduction of high black and white image quality or color standard image quality can be performed.

[Embodiment] FIG. 1 shows a recording area division state of a magneto-optical disk used in the present invention, and FIG. 2 shows an example of the device configuration.

As shown in FIG. 1, the magneto-optical disk 1 used in the present invention has, for example, four recording areas bi'la and ib in the radial direction from the outer circumference to the inner circumference.

It is divided into IC and 1d.

As shown in FIG. 2, the magneto-optical disk 1 whose recording area is divided into four is driven by a spindle motor 2 at a constant speed, e.g.
Rotates at 0 rpm.

Two magneto-optical heads 3a and 3b mounted on a head slider 7 are provided at a lower position facing the magneto-optical disk 1, and the head slider 7 is moved radially along the slider rail 11 by a slider drive magnet 9. It is movable. In addition to the movement of the magneto-optical disks 3a, 3b by the head slider 7, the magneto-optical heads 3a, 3b themselves have a built-in driving mechanism such as a galvanometer mirror, so that after positioning by the head slider 7, the galvano-mirror mechanism built in the head is moved. This allows the laser beam to scan in the radial direction of the magneto-optical disk 1.

Also, the magneto-optical head 3a mounted on the head slider 7
, 3b are provided with magneto-optical heads 4a and 4b mounted on a head slider 8 at positions radially shifted by 180 degrees. The head slider 8 can be moved in the radial direction by a slider drive magnet 10 and a guide rail 12, and the magneto-optical heads 4a, 4b themselves have a built-in beam scanning mechanism using a galvano mirror or the like.

In this way, the 4
Each of the magneto-optical heads 3a, 3b, 4a, and 4b has erasing, recording, and reproducing functions.

On the other hand, the magneto-optical disk 1 is connected to the magneto-optical heads 3a and 3b.
An electromagnet 5 is disposed at an upper position facing the magneto-optical disk 1 in between, and the electromagnet 5 can switch the direction of the magnetic field applied to the magneto-optical disk 1 by a magnet switching circuit 16.

That is, during erasing, the electromagnet 5 applies a downward erasing magnetic field to the magneto-optical disk 1, while during recording, it applies an upward recording magnetic field to the magneto-optical disk 1 in the opposite direction.

Further, the magneto-optical disk 1 is connected to the magneto-optical heads 4a and 4b.
An electromagnet 6 is disposed at an upper position opposite to the magneto-optical disk 1, and the electromagnet 6 can also switch the direction of the external magnetic field applied to the magneto-optical disk 1 by means of a magnet switching circuit 17. During erasing, a downward erasing magnetic field is applied. , an upward recording magnetic field is applied during recording.

Next, the operation of the above embodiment will be explained.

First, recording and reproducing operations that require a high transfer rate, such as black and white high image quality or color standard image quality, are as follows.

First, in the erasing operation performed prior to recording, the magnet switching circuits 16 and 17 apply an erasing magnetic field with the direction of the external magnetic field applied to the magneto-optical disk 1 by the electromagnets 5 and 6 facing downward. In this way, with the electromagnets 5 and 6 applying an erasing magnetic field to the magneto-optical disk 1, the magneto-optical head 3
A traces the outermost recording area 1a, the magneto-optical head 3b traces the third recording area 1C from the outer periphery, the magneto-optical head 4a traces the second recording area 1b from the outer periphery, and the magneto-optical head 4a traces the second recording area 1b from the outer periphery. 4b traces the innermost recording area 1d. Such a magneto-optical head 3a
, 3b, 4a, and 4b by tracing each recording area 1a to 1d, the tracing portion is heated to a critical temperature or higher by irradiating a strong laser beam spot light from a magneto-optical head, and in the cooling process, the electromagnet 5 or 6 The erased portion is aligned in the downward magnetization direction by receiving a downward erase magnetic field.

When the erasing operation of the recording areas 1a to 1d is completed in this way, the magnet switching circuits 16 and 17 switch the direction of the current flowing through the electromagnets 5 and 6 to the opposite direction, so that the external Apply a magnetic field. When an external magnetic field for recording is applied, the magneto-optical heads 3a, 3b, 4a,
A recording signal is supplied in parallel to 4b, and the spot light of a strong laser beam modulated by the recording signal is irradiated, that is, the spot light is irradiated with the signal bit "1" to heat the irradiated part to a temperature higher than the critical temperature, During this cooling process, the magnetization direction is reversed to an upward direction determined by the external magnetic field of the electromagnet 5 or 6, and a signal is recorded.

On the other hand, the reproducing operation is performed by four magneto-optical heads 3a, 3b, 4a.
, 4b in parallel to the corresponding recording area of the magneto-optical disk 1, and by reading the polarization direction depending on the magnetization direction of the reflected light, the recorded signal can be reproduced. can.

In this way, the four magneto-optical heads 3a, 3b, 4b, 4a
Since the recorded signal is distributed to four areas by recording and reproducing using parallel magneto-optical heads, the transfer rate can be reduced to 2.
It is possible to record and play back double the black and white high image quality and color standard image quality.

In addition, when recording and reproducing at a high transfer rate by dividing the recording area of the magneto-optical disk 1 into four, the recording area of one recording area becomes narrower, so the recording and reproducing time is half the time compared to the standard transfer rate. becomes.

On the other hand, in the above embodiment, in addition to recording and reproducing at twice the transfer rate, it is also possible to perform recording and reproducing at the same standard transfer rate as in the conventional device.

During recording and reproduction at this standard transfer rate, the magnet switching circuit 16 applies a downward erasing magnetic field to the magneto-optical disk 1 from the electromagnet 55, while the magnet switching circuit 17 applies an upward recording magnetic field to the magneto-optical disk 1 using the electromagnet 6. The magneto-optical disk 1 is further divided into four parts, with the magneto-optical heads 3a and 3b serving as erasing and reproducing heads, and the magneto-optical heads 4a and 4b serving as recording and reproducing heads.
The recording area is divided into outer recording areas 1a and 1b and inner recording areas 1C and 1d, and magneto-optical heads 3a and 1d are respectively installed.
, 4a and 3b, 4b, and thereby the third,
Recording and reproduction can be performed at the standard transfer rate, which is exactly the same as that of the conventional apparatus shown in FIG.

In the embodiments shown in FIGS. 1 and 2, the four magneto-optical heads 3a, 3b, 4a, 4b are associated with the recording orders 1ii1a to 1d of the magneto-optical disk 1 divided into four. is the outermost recording area 1a, the magneto-optical head 3
b is the third recording area from the outer periphery 1C1 magneto-optical head 4a
is the second recording area 1b from the outer periphery, and the magneto-optical head 4b is the innermost recording area 1d, but the correspondence between the divided recording areas and the magneto-optical head is not limited to this, for example, the magneto-optical head 3a to the outermost recording area 1a, the magneto-optical head 3b to the second recording area 1b from the outer periphery, the magneto-optical head 4a to the third recording area 1C from the outer periphery, and the magneto-optical head 4b to the innermost recording area 1b. It may be made to correspond to the recording area 1d.

[Effects of the Invention] As explained above, according to the present invention, the recording area of a magneto-optical disk is divided into four areas in the radial direction, and four magneto-optical heads are installed corresponding to each recording area. Since recording and playback can be performed in parallel, it is possible not only to record and play back at a standard transfer rate using two heads, but also to record and play back at a high-speed transfer rate with double the transfer rate using the same device.
For example, when recording and playing back black-and-white standard image quality at a standard transfer rate, switching to a high-speed transfer rate allows you to record and play back black-and-white high image quality or color standard image quality, which requires twice the transfer rate, on one device. It can be done efficiently.

Further, the present invention is not only used for recording and reproducing images, but can also be used as a high-speed transfer rate recording/recording device for computers, for example.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the divided state of the recording area of the magneto-optical disk used in the present invention, FIG. 2 is a diagram showing the configuration of an apparatus showing an embodiment of the present invention, and FIG. 3 is a diagram of the conventional magneto-optical disk. FIG. 4 is an explanatory diagram showing an example of a conventional device, and FIG. 5 is an explanatory diagram showing an example of a conventional device for increasing the transfer rate. 1: Magneto-optical disks 1a to 1d: Divided recording area 2 Spindle motors 3a, 3b, 4a, 4b: Optical 1M head (for erasing, recording, and reproduction) 5.6: Electromagnet 7.8: Head slider 9 .10 Nishi slider drive magnet 11.12 Ni guide rail 16.17: Magnet switching circuit Patent applicant Nippon Kogaku Kogyo Co., Ltd.

Claims (2)

[Claims] (1) A magneto-optical disk whose recording area is divided into four areas in the radial direction from the outer circumference to the inner circumference, and a magneto-optical disk that is movably provided in the radial direction in correspondence with each recording area of the magneto-optical disk. four magneto-optical heads each having erasing, recording and reproducing functions, and arranged relative to the four magneto-optical heads with the magneto-optical disk interposed therebetween;
A magneto-optical disk device comprising an electromagnet that applies an erasing magnetic field in a predetermined direction to the magneto-optical disk during erasing and applies a recording magnetic field in the opposite direction to the magneto-optical disk during recording. (2) The four magneto-optical heads are divided into two sets of two, each set of magneto-optical heads is mounted on each of two sets of head sliders arranged at different positions in the circumferential direction, and each set of magneto-optical heads is mounted on each of two sets of head sliders arranged at different positions in the circumferential direction. Two sets of electromagnets are arranged facing the head, one of the magneto-optical heads in one set corresponds to the outermost recording area, and the other magneto-optical head corresponds to the third recording area from the outer periphery. and one of the magneto-optical heads of the other set corresponds to the second recording area from the outer periphery, and the other magneto-optical head corresponds to the innermost recording area. The magneto-optical disk device according to scope 1.