JPS6318548A - Magneto-optical recording device - Google Patents

Abstract

PURPOSE:To read from a magneto-optical recording medium while writing an information in the same medium by providing a read-only optical head having an independent driving system other than an optical head for writing, reading, and erasing. CONSTITUTION:The titled device has the optical head 4 for writing, reading, and erasing, and the read-only optical head 5, to both of which independent driving systems are connected. The heads 4 and 5 are made movable relatively along the radial direction against a photomagnetic disk 3 separately by different information signals. In a position opposite the optical head 4 across the magneto- optical disk 3, an auxiliary magnetic field impression means that inverts the direction of magnetization of a vertically magnetized film formed on the disk 3 and align the directions is provided, and the means is employed at the time of erasing/writing information. If a write request is issued against the magneto- optical disk 3, the optical head 4 operates and performs a necessary writing, and if a read request is generated during the said writing operation, the read- only optical head 5 acts to execute a necessary reading.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an optical 1i14A recording device, and more particularly to a magneto-optical recording device that simultaneously reads or writes information.

(Prior Art) Magneto-optical disks have been developed at a rapid pace in recent years as large-capacity optical disks that can be exchanged.

To record information on such a magneto-optical disk, a perpendicular magnetization film is formed on the disk surface, the magnetization direction of this perpendicular magnetization film is first aligned in one direction, and the magnetization is digitally modulated by an information signal. The perpendicularly magnetized film is irradiated with a laser beam, and the temperature of the irradiated area is made to be one above the Curie point temperature.

The perpendicularly magnetized film brought to the Curie point temperature has a coercive force of O, and the magnetization direction can be easily changed by an external auxiliary magnetic field.

Therefore, when a direct current bias magnetic field is applied as an auxiliary magnetic field and the laser beam is used to heat it to the Curie point, the magnetization direction at this portion is reversed to the direction of the applied magnetic field. When the laser beam irradiation situation changes due to the movement of the recording medium, the temperature of the area decreases again, the coercive force increases, and a stable magnetization state can be maintained while the magnetization direction is reversed. In this way, a recording bit string corresponding to the information is formed.

To read information recorded on a magneto-optical disk, a perpendicularly magnetized film is irradiated with a reading laser beam, and the magnetic effect is used to change the direction of the polarization plane of the reflected beam due to differences in the magnetization direction of the perpendicularly magnetized film. and do it.

On the other hand, in order to erase a recorded pit, a laser beam is irradiated onto the recorded pit without tracking the recorded bit string, a DC bias magnetic field is applied in the magnetization direction opposite to the recording pit, and the magnetization direction of the perpendicularly magnetized film is again applied. This is done by aligning the.

Incidentally, FIG. 2 shows an outline of the optical head etc. used to record, reproduce, and erase the above information.

In the figure, ■ is a magneto-optical disk, and 2 is an optical head. The magneto-optical disk 1 is rotated at a constant speed by a drive motor (not shown), and the optical head 2 is moved relative to the disk 1 in the radial direction. And optical head 2
An auxiliary magnetic field applying means (not shown) is installed at a position opposite to the disk 1, and cooperates with the optical head 2 to reverse and align the magnetization directions of the perpendicularly magnetized films on the disk 1, thereby recording information. Or delete it.

(Problems to be Solved by Application) Conventionally, in this type of magneto-optical recording device, since the optical head is configured as described above, it is difficult to record, reproduce, or erase information on the optical disk. When doing so, it was impossible to perform other operations until the process was completed.

This does not cause any particular inconvenience when processing short information such as data, but when processing a large amount of information such as images, it causes the inconvenience that reading cannot be performed while writing.

Therefore, there is a drawback that the efficiency of operating this type of system becomes extremely low.

(Means for Solving the Problems) The problems of the above-mentioned prior art are as follows: 1. An auxiliary magnetic field is provided in cooperation with the light beam irradiated from the optical head of the present invention, and information is written, read, or The problem is solved by a magneto-optical recording device for erasing, characterized in that the magneto-optical recording device is equipped with a read-only optical head having an independent drive system separate from the optical head for writing, reading or erasing. .

(Means) As in the above configuration of the present invention, in addition to the optical head for writing and erasing, it is equipped with a read-only optical head having a drive system independent from the optical head. Even in the prefecture where information is being written to a recording medium, reading from the same medium is repeated.

(Embodiment) A magneto-optical recording device according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic plan view of the apparatus of this embodiment.

In the figure, a magneto-optical disk 3 is rotated by a drive motor (not shown). 4 is an optical head for writing, reading and erasing, and 5 is an optical head for reading only. Each of these optical heads 4.5 is connected to an independent driving system (not shown), and each optical head is individually and independently driven by a different information signal to determine its radius relative to the magneto-optical disk 3. It is possible to move along the direction.

Further, at a position opposite to the magneto-optical disk 3 of the optical head 4, an auxiliary magnetic field applying means (not shown) is provided for reversing or aligning the magnetization direction of the perpendicular magnetization film formed on the magneto-optical disk 3. This applies when information is compromised or deleted.

Note that the above-mentioned auxiliary magnetic field applying means is not necessary for reading information from a magneto-optical disk as in this embodiment.

In the present embodiment of the L4Xli configuration, when a write request is made to the magneto-optical disk 3, the optical head 4 operates to perform the required write. If a read request occurs during this 8-write operation, the read-only optical head 5 operates to perform the required read.

In the device of this embodiment shown in FIG. 1, only one read-only optical head is provided, but one or more optical heads may also be provided. be. By doing so, it becomes possible to perform the necessary read processing in response to one or more read requests during the write operation as described above.

In addition, the wood-sv device is applicable not only to magneto-optical disks but also to other card-like or sheet-like magneto-optical media, and it is possible for each of them to exhibit the above-mentioned effects. .

(Effects of the Invention) As explained above, the magneto-optical recording device of the present invention includes, in addition to an optical head for writing, reading, and erasing, a read-only optical head having a drive system independent of the optical head. Therefore, even in prefectures where information is written to magneto-optical recording media, it is possible to read information from the same medium, which greatly improves the efficiency of this type of system operation. The scope of use of the magneto-optical recording device is expanded.

[Brief explanation of the drawing]

Figure 1 is an embodiment of the present invention! A schematic plan view of Ica, and FIG. 2 is a schematic plan view of a conventional device. 3-... Magneto-optical disk 4... Optical head for writing, reading, and erasing 5...
read-only optical head

Claims (1)

[Claims] (1) In a magneto-optical recording device that writes, reads, or erases information on a magneto-optical recording medium by applying an auxiliary magnetic field in cooperation with a light beam emitted from an optical head, a method for writing, reading, or erasing information. 1. A magneto-optical recording device comprising a read-only optical head having an independent drive system separate from the optical head.