JPH08212618A - Optical information recording device - Google Patents

Abstract

(57) An object of the present invention is to provide an optical information recording device which does not require complicated management and control even when re-reading information to a magneto-optical disk. The present invention is characterized in that, in an optical information recording apparatus using a magneto-optical disk, an erasing mode is performed before a recording mode is performed. That is,
When the recording operation is instructed to the optical information recording device, the erasing operation is performed regardless of the presence or absence of the recorded pattern on the magneto-optical disk, and the recording operation is continued.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording / reproducing device.

[0002]

2. Description of the Related Art Recently, as a high density and large capacity memory,
Optical discs have been attracting attention, and information recording / reproducing devices using the optical discs have been put to practical use. In this device,
For example, a laser beam carrying image information is focused on a spot having a diameter of about 1 μm to irradiate the optical disk to form a bit having a width of 0.6 to 1 μm and a length of 1 to 2 μm for recording. The reproduction is performed by reflected light.

Conventionally, there are two types of recording media for forming an optical disk used in such an apparatus. One is a write-once (DRAW) recording medium in which information cannot be erased and rewritten, and the other is an erasable recording medium in which information can be erased and rewritten multiple times. Although only the write-once type recording medium has been put into practical use in the above information recording / reproducing apparatus, the erasable type recording medium is superior from the viewpoint of economical and effective use of the medium. Therefore, it is expected that a system using this recording medium will be put to practical use.

This erasable recording medium is, for example, Gd,
The recording film is an amorphous alloy film composed of rare earth elements such as Tb, Dy, and Ho and transition metals such as Fe and Co. The characteristic of this recording film is that it has an easy axis of magnetization in a direction perpendicular to the film surface, and recording / reproducing uses the direction of magnetization of each magnetic domain.

That is, in a recording film on which no recording is performed, all magnetic domains are magnetized in the same direction, and by selectively changing the magnetization direction of a specific magnetic domain with respect to this magnetization state, Recording is performed and reproduction is performed by reading this state. Specifically, the characteristic feature of the recording film is that it maintains a magnetically ordered state at room temperature, easily reaches the Curie point by irradiation with a laser beam, and becomes a disordered state at this time.

Thus, the recording film is irradiated with a laser beam carrying information, the energy of the laser beam locally raises the recording film, and the coercive force of this part is reduced. At this time, a magnetic field in a specific direction (a direction opposite to the initial magnetization direction) is applied from the outside to match the magnetization only in the local part to the specific direction. The recording film other than the one irradiated with the laser beam maintains the initial order state even when an external magnetic field is applied, and the magnetization direction does not change. This creates a pattern of magnetization in different directions during the magnetization of uniform directions. That is, recording is made.

Next, in such recording, information is erased according to the substantially same principle, and the external magnetic field to be applied may be reversed from that at the time of recording. For example, irradiating a portion of the recording film on which recording as described above with a laser beam,
The temperature of this portion is made to reach near the Curie point, and the coercive force is reduced. Then, a magnetic field in the opposite direction to that at the time of recording is applied, and the direction of magnetization of the relevant portion is reversed. As a result, the direction of magnetization becomes the same as before recording, and information is erased.

For such recording and erasing, the reproduction of information utilizes the rotation of the plane of polarization of the laser beam. Magnetic domains are vertically arranged on the recording film surface. When a laser beam is applied to such a recording surface, the plane of polarization of the reflected beam is rotated depending on the direction of the magnetic domains. Therefore, if this rotation is detected, the direction of the magnetic domain on the recording film can be detected. this is,
It is the reproduction of information.

A disk as a memory using the recording film having the above characteristics is called a magneto-optical disk. Consider the case of rewriting to this magneto-optical disk. Since recording is performed, magnetic domains in the second direction opposite to the magnetic domains in the uniform first direction are distributed on the recording film. Further writing to such a recording film corresponds to changing the distribution of magnetic domains in the opposite direction during uniform magnetization. This change in the distribution of magnetization consists of recording and erasing, but they are common in that they are irradiated with a laser beam, but they differ greatly in that the directions of the external magnetic fields applied are opposite. If this is grasped by the system, it is necessary to control the direction of the external magnetic field depending on whether recording or erasing.

More specifically, let us consider a case where the recording "01100" is made on the film where the recording "10001" has already been made.

[1] → “0” for the first bit
The above-described erasing operation requires the above-described recording operation of “0” → “1” for the subsequent two bits, and the next one bit is “0” → “0”. It is not necessary to do so, and finally, the erase operation of "1" → "0" is required again. Therefore, in the case of rewriting on the magneto-optical disk, not only the operation of recording, but also the operation of further erasing and the operation of not performing depending on the state before recording is required.

When such an operation is treated from the viewpoint of recording accuracy, the size of the laser beam used and the irradiation position do not exactly match at the time of recording and erasing, so the magnetization state of the magnetic domains on the recording medium is completely changed. Not doing so could result in incorrect information.

Further, considering such operation from the standpoint of the system, it is necessary to manage the state of the previous recording film, and three operations must be selectively executed according to this. . Therefore, the system needs to manage addresses for recording and erasing,
Moreover, the address management is complicated and complicated, and the control of the device is complicated.

[0014]

Conventionally, in the case of rewriting to a magneto-optical disk, not only the operation of recording but also the operation of further erasing depending on the state before recording and the operation of not performing anything are required. Will be.

When such an operation is treated from the viewpoint of recording accuracy, the size of the laser beam used and the irradiation position do not exactly match at the time of recording and erasing, so the magnetization state of the magnetic domains on the recording medium is completely changed. Not doing so could result in incorrect information.

Further, considering such operation from the standpoint of the system, it is necessary to manage the state of the previous recording film, and three operations must be selectively executed according to this. . Therefore, the system needs to manage addresses for recording and erasing,
In addition, the address management is complicated and complicated, and the control of the device is complicated.

An object of the present invention is to eliminate the above drawbacks and to provide an optical information recording apparatus which does not require rough management and control even when rewriting information on a magneto-optical disk.

[0018]

The present invention is characterized in that, in an optical information recording apparatus using a magneto-optical disk, an erasing mode is carried out before a recording mode is carried out. That is, when the recording operation is instructed to the optical information recording device, the erasing operation is performed regardless of the presence or absence of the recorded pattern on the magneto-optical disk, and the recording operation is continued.

[0019]

FIG. 1 is a diagram showing a schematic configuration of an optical information recording / reproducing apparatus which is an apparatus according to an embodiment of the present invention and which uses a magneto-optical disk as a recording medium. Magneto-optical disk 1
Is driven to rotate at a predetermined speed by the rotation motor 3 connected to the rotation motor control unit 2. Reference numeral 4a is a magnetic field generating element composed of an electromagnet, and 4b is an optical head composed of a laser, a photodetector, an optical element, etc. for irradiating a laser beam on the magneto-optical disk 1, and further for tracking, focusing control and signal detection. Hereinafter, the electromagnet 4a and the optical head 4b are collectively referred to as a magneto-optical head 4. The magneto-optical head 4 is held on a feed motor 6 connected to a feed motor controller 5, and moves to an arbitrary radial position of the magneto-optical disk 1.

The optical information recording / reproducing apparatus in this embodiment has a recording mode and a reproducing mode, and when executing the recording / reproducing mode, a recording / reproducing mode instruction signal, a recording / reproducing sector number, a recording / reproducing mode. The number of information bits, recording information, etc. are transferred to the magneto-optical disk device control unit 8 via the interface 7 by the external system, and each of the recording mode control unit 9 and the reproduction mode control unit 10 makes a unit of sector having a certain number of information bits. The mode is executed.

FIG. 2 shows a schematic structure of a sector, which is a unit for recording and reproducing information. The synchronizing signal (1) 21 for reproducing the address number of the sector and the start position of the address number. (1) 22 indicating the sector address of the sector
23, gap 24, sync signal for reproducing recorded information
(2) 25, (2) 26 indicating the start position of the record information, an information signal 27 having a constant number of information bits, and a control signal 28 indicating the correctness of the record information. Here, sync signal (1) 21, header (1) 22,
The sector address 23 is pre-formatted at the time of manufacturing the magneto-optical disk, or is formatted according to the system specifications prior to recording information on the magneto-optical disk.

The operation of executing the recording information transferred from the external system according to the recording mode according to the present invention by the recording mode control unit 9 will be described in detail with reference to FIG. FIG.
(a) is a diagram showing a state before a recording mode is executed in a recording area on a magneto-optical disk designated by an external system. That is, it is assumed that the number of information bits transferred by the external system corresponds to the number of sectors, and recording to the sectors 33a ₁ to 33a _i is designated. 31a _{1 to} 31a _i are
This is an area in which information on sector addresses of the 33a _{1 to} 33a _i sectors is formatted, and is composed of the sync signal (1) 21, the header (1) 22, and the sector address 23 shown in FIG. 2, and includes 31a ₁ to 31a _i. Address numbers are increasing in sectors. 32a _{1 to} 32a _i are information signal recording areas,
Gap 24 shown in FIG. 2, sync signal (2) 25, header
(2) 26, information signal 27, and control signal 28. Further 32a ₁ ,
Some information bits have already been recorded in the shaded areas of 32a ₃ , ... 32a _2-i , and no information has been recorded in the blank areas of 32a ₂ , ... 32a _i. The directions of the magnetic domains are uniformly aligned with the system-defined direction.

When the recording mode instruction signal, the recording information bit, and the recording sector are transferred by the external system,
The recording mode control unit 9 sets the direction of the magnetic field generated by the electromagnet 4a as a predetermined information erasing direction, sends the magneto-optical head 4 to the radial position of the designated sector, reproduces and detects the sector address, and designates it. The areas 32a ₁ to 32a _i of the formed sectors are sequentially erased according to the above principle regardless of the presence or absence of information. 3 (b) is a diagram showing a state of the specified recording sector after the erase operation, and 31b ₁ ~31b _{i
31a i ~31a i, 32b 1 ~32b} i and 32a ₁ ~32a _i, 33
b _{1 to} 33b _i and 33a ₁ to 33a _i indicate the same area, respectively. 32b _{1 to} 32b _i indicate a state in which the magnetic domains in the area for recording information are uniformly deviated in a certain direction determined by the system by this erasing operation.

After such an erasing operation is completed, the recording mode control unit 9 next reverses the direction of the magnetic field generated by the electromagnet 4a and sends the magneto-optical head 4 to the head sector position of the designated sector. Is detected and the magnetic domains are aligned in a certain direction by the erase operation. 32b ₁ to 32b
_The information transferred from the external system is sequentially recorded in the area _i , and the recording mode ends. FIG. 3 (c), a diagram showing a state of the specified recording sector after the information recording, 31C ₁ ~31C
_i and 31b ₁ to 31b _i , 32c _{i to} 32c _i and 32b _{1 to} 32
b _i, 33c ₁ ~33c _i and 33b ₁ ~33b _i each represent the same region, 32C ₁ ~32c _i indicates that new information bits, etc. are recorded.

As described above, according to this embodiment, when the recording mode is executed, the erasing operation of the recording area is always performed prior to the recording of the information bit. It is possible to provide an easy-to-use optical information recording / reproducing apparatus which does not require management on the system side to determine whether or not information has already been recorded on the recording medium or has already been erased. Further, in this embodiment, the electromagnet 4a is used as the external magnetic field generating element for generating the magnetic field at the time of recording / erasing, but a permanent magnet capable of changing the direction of the external magnetic field by mechanical movement such as rotation or parallel movement at the time of recording / erasing is used. You may use. Further, in this embodiment, the external magnetic field generating element also has a structure in which it is moved in the radial direction by the feed motor 6, but this is also made possible by moving the external magnetic field generating element in the radial direction to a sufficient length. It can also be fixed. (Other Embodiment of the Invention) FIG. 4 is a diagram showing a schematic configuration of an optical information recording / reproducing apparatus according to another embodiment of the present invention. The device in this embodiment has two sets of magneto-optical heads. The magneto-optical disk 41 is rotationally driven by a rotary motor 43 connected to the rotary motor control unit 42 so as to have a predetermined speed. Reference numerals 44a and 44a 'are magnetic field generating elements composed of permanent magnets having polarities opposite to each other, and 44b and 44b' are lasers for irradiating a laser beam on the magneto-optical disk 41, and for detecting signals for tracking and focusing control. An optical head consisting of a photodetector and optical elements, such as 44a, 44b, and 44
Two sets of magneto-optical heads 44, 4 by a'and 44b 'respectively
Make up 4 '. The magneto-optical heads 44 and 44 'are feed motors 46 and 46' connected to feed motor control units 45 and 45 ', respectively.
It can be moved to an arbitrary radial position on the magneto-optical disk 41 while being held on it.

The optical information recording / reproducing apparatus according to the present embodiment has a recording mode and a reproducing mode as in the above-mentioned embodiment,
When the recording / reproducing mode is executed, the recording / reproducing mode instruction signal, the recording / reproducing sector number, the number of recording / reproducing information bits, the recording information, etc. are transferred from the external system to the magneto-optical disk device controller 48 via the interface 47. Transferred,
Each mode is executed by the recording mode control unit 49 and the reproduction mode control unit 50 in units of sectors each having a fixed number of information bits. When the recording mode instruction signal, the recording information bit, and the recording sector are transferred by the external system, the recording mode control unit 49 sends the magneto-optical heads 44 and 44 'to the radius position of the designated sector and outputs the sector address. Playback detected, first
Further, in the magneto-optical head 44 'which generates a magnetic field in the erasing direction, the directions of the magnetic domains of the information bit recording area of each designated sector are uniformly arranged in a fixed direction in the same manner as in the above-described embodiment. Next, when the sector whose information has been erased by the magneto-optical head 44 'is rotated by the rotary motor 43 and reaches the position of the magneto-optical head 44 for information recording, the information transferred from the external system is sequentially transferred by the magneto-optical head 44. , Is recorded in the area where magnetic domains are aligned in a certain direction by the erase operation.

As described above, according to this embodiment, the same effect as that of the above-described embodiment can be obtained, and further, by having two sets of magneto-optical heads, the time required for executing the recording mode can be reduced to about half. You can

The embodiment of the present invention has been described above.
The invention is not limited to these examples.
For example, the external magnetic field generating element may use an electromagnet or a permanent magnet, and is not limited at all. It is also clear that the structure is not limited at all.
Further, the magneto-optical head is not limited to the embodiment. For example, the optical head and the external magnetic field generating element may be arranged on the same surface side of the magneto-optical disk. Further, the two magneto-optical heads may be arranged on a diagonal line or on a non-diagonal line. The difference in this arrangement may be that the two magneto-optical heads can be accessed independently, or they are provided on the same stage and the magneto-optical head preceding the rotation of the magneto-optical head is set to the erase mode. Good. In the latter case, the access of the two magneto-optical heads is always performed in conjunction.

As described above, any modification can be made without departing from the spirit of the present invention.
It is included in this invention.

[0030]

According to the present invention, since erasure is always performed before recording, management of the recorded area and the unrecorded area of the magneto-optical disk is completely unnecessary when rewriting the magneto-optical disk. The operation of the device is also a certain erasing operation,
Only the recording operation is performed, and the control becomes very easy.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of an optical information recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a sector structure according to an embodiment of the present invention.

FIG. 3 is a diagram showing an operation in a recording mode according to an embodiment of the present invention.

FIG. 4 is a diagram showing a schematic configuration of an optical information recording / reproducing apparatus according to another embodiment of the present invention.

[Explanation of symbols]

 1 ... Magneto-optical disk 4 ... Magneto-optical head

Claims (1)

[Claims] 1. A laser for recording and erasing the information in a recording area of the information in a sector unit including a pre-formatted portion of a recording medium and a recording area of the information. A light irradiating means for irradiating light, an external magnetic field applying means for applying a magnetic field in the first direction or the second direction to the recording medium, and a control means for controlling the external magnetic field applying means and the light irradiating means. An optical information recording apparatus provided with the control means, wherein when the information is recorded, all the areas among all areas composed of a single or a plurality of sector units corresponding to the newly recorded information amount are recorded. After the information signal is erased by irradiating the information recording area with light by the light irradiating means and by applying the magnetic field in the first direction to the recording medium by the external magnetic field applying means, ,Before Light irradiation by the light irradiating means, and the external magnetic field applying means according to a second direction the optical information recording apparatus characterized by being configured to perform recording of information by the application of magnetic field to the recording medium.