JPH0799598B2 - Magneto-optical recording method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] When bits “1” or “0” are continuously written in a recording track of a magnetic recording film, a clock signal of a signal train cannot be easily obtained and a signal train There is a risk of jittering and incorrect reading. To prevent this, conventionally, the area of pit "1" (or "0") is magnetized (or magnetized area).
1 and the bit "0" (or "1") area was recorded with the magnetization amount (or magnetization area) 0, but instead, the "1" (or "0") area was magnetized. A method is proposed in which the amount (or magnetization area) is set to 1 and the area of the bit “0” (or “1”) is set to the magnetization amount (or magnetization area) 1 / N and recording is performed. By doing so, a signal is always obtained, and the above problems are solved.

[Industrial application field]

 The present invention relates to a erasable magneto-optical recording system.

Magneto-optical recording has come to be widely used as a storage system for information processing devices and for compact discs for audio and video.

In magneto-optical recording, a magnetized area and a non-magnetized area are provided in a recording track on a magnetic recording surface, and writing (recording) is performed in correspondence with bits "1" and "0".

Reading is performed by irradiating the recording track with light and scanning, and utilizing the Kerr effect or Faraday effect of light.

That is, reading is performed by utilizing the fact that the polarization direction of the reflected or transmitted light on the magnetic recording surface differs between the magnetized region and the non-magnetized region.

[Conventional technology]

FIGS. 2 (1) and 2 (2) are views for explaining a conventional writing method for magneto-optical recording.

FIG. 2 (1) shows the case where the recording bit is magnetized.

In the figure, black circles shown in the recording tracks of the magnetic recording film indicate magnetized portions.

Recording is performed with a bit "1" (or "0") area having a magnetization amount of 1 and a bit "0" (or "1") area having a magnetization amount of 0.

FIG. 2 (2) shows a case where the recording bit is demagnetized (erased).

In the figure, the white circles shown in the magnetized (represented by black) recording tracks of the magnetic recording film indicate the non-magnetized portions.

Set the area of bit "1" (or "0") to the non-magnetization amount 1,
Recording is performed by setting the area of bit "0" (or "1") to zero non-magnetization amount.

At this time, if bits "1" (or "0") continue,
Since the magnetization (or non-magnetization) signal cannot be continuously obtained, the clock signal of the signal sequence cannot be easily obtained (because the control function for correcting the clock signal generator is required), and the recording medium. If there is a change in the moving speed or the geometrical dimension of the medium surface, jitter will occur in the signal train and the signal will be read incorrectly.

[Problems to be solved by the invention]

In the conventional writing method of magneto-optical recording, if a bit "1" (or "0") continues, jitter occurs in the signal train, and a clock signal cannot be easily obtained, and the signal may be erroneously read.

[Means for solving problems]

To solve the above problems, (1) make the first and second areas of the recording track of the magnetic recording film correspond to the bits "1", "0" or "0", "1", respectively, and set N to 1 or more. A large positive number, and the magnetization amount of the first region is 1
On the other hand, a magneto-optical recording / writing method in which the amount of magnetization of the second area is 1 / N, (2) Bits "1" and "0" are set in the first area and the second area of the recording track of the magnetic recording film, respectively. "Or" 0 "," 1 ", N is a positive number larger than 1, and the magnetization area of the second region is 1 / N with respect to the magnetization area 1 of the first region. This is achieved by the writing method.

(1) and (2) can be applied to the case where the recording bit is magnetized and written to the non-magnetized recording track, or the case where the recording bit is non-magnetized and written to the magnetized recording track.

When carrying out the present invention, (1) is the amount of magnetization, and (2)
Is performed by controlling the magnetized area.

[Action]

In the present invention, when writing in magneto-optical recording, the magnetization or non-magnetization does not necessarily have to be completely magnetized (physically saturated magnetization, area total area magnetization) or completely non-magnetized (complete erase).
Even if the magnetization or non-magnetization is intentionally decided, that is, even if the magnetization or non-magnetization is imperfect as a result, the recording is not hindered, and the signal train generated by the imperfection is always obtained. Therefore, the above-mentioned problems are solved.

That is, in the case of the present invention, since a clock signal is always obtained, it is not necessary to use a clock signal generator together, but even if it is used together, a clock signal always obtained from a magnetic recording medium is easily and momentarily. Since the shifted phase is corrected and accurate synchronization can be achieved, the reading accuracy can be improved.

〔Example〕

FIGS. 1 (1) and 1 (2) are views for explaining the writing method of the present invention for magneto-optical recording.

FIG. 1 (1) shows the case where the recording bit is magnetized.

In the figure, black circles shown in the recording tracks of the magnetic recording film indicate magnetized portions.

Set the magnetization amount (or magnetization area) of the bit "1" (or "0") area to 1 and the magnetization amount (or magnetization area) of the bit "0" (or "1") area to 1 / N. To record.

FIG. 1 (2) shows the case where the recording bit is demagnetized.

In the figure, white circles shown in the magnetized (represented by black) recording tracks of the magnetic recording film indicate non-magnetized portions.

Set the non-magnetization amount (or non-magnetization area) of the bit "1" (or "0") region to 1, and set the non-magnetization amount (or non-magnetization area) of the bit "0" (or "1") region. Record at 1 / N.

〔The invention's effect〕

As described in detail above, according to the present invention, it is possible to improve the writing system of magneto-optical recording, facilitate signal processing, and reduce the read error rate.

[Brief description of drawings]

1 (1) and 1 (2) are diagrams for explaining the writing method of the present invention for magneto-optical recording, and FIGS. 2 (1) and 2 (2) are diagrams for explaining a conventional writing method for magneto-optical recording. Is.

Claims (2)

[Claims] 1. A first area and a second area of a recording track of a magnetic recording film are made to correspond to bits "1", "0" or "0", "1", respectively, and N is a positive number larger than 1, A magneto-optical recording / writing method wherein the magnetization amount in the second region is 1 / N with respect to the magnetization amount 1 in the first region. 2. A first area and a second area of a recording track of a magnetic recording film are made to correspond to bits "1", "0" or "0", "1", respectively, and N is a positive number greater than 1. A magneto-optical recording / writing method, wherein the magnetization area of the second region is 1 / N with respect to the magnetization area 1 of the first region.