JP2985298B2 - Recording method on perpendicular magnetic recording medium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording method for a perpendicular magnetic recording medium suitable for application to a magnetic recording apparatus for magnetically recording digital data on a perpendicular magnetic recording medium (floppy disk, video tape, etc.). .

[0002]

2. Description of the Related Art A perpendicular magnetic recording medium (floppy disk, video tape, or the like) which has been easily magnetized perpendicularly in advance has been proposed. In order to record a signal on such a perpendicular magnetic recording medium or to reproduce a signal recorded on the perpendicular magnetic recording medium, the signal is obtained by magnetizing a magnetic material of a known magnetic recording medium in the horizontal direction. As in the magnetic recording / reproducing apparatus for recording and reproducing the signal recorded on the magnetic recording medium, the recording is performed by supplying a recording current to the magnetic head or reproducing the signal from the magnetic head. For such a perpendicular magnetic recording medium, Co-Cr (cobalt-chromium) or the like is used.
As a recording method, there are two methods of so-called rectangular wave recording using a rectangular wave as a recording signal and sine wave recording using a sine wave as a recording signal. As shown in FIG. 3E, in either of the above-mentioned two systems, that is, whether a rectangular wave is used as a recording signal or a sine wave is used as a recording signal, a magnetic head is read from a perpendicular magnetic recording medium on which a signal is once recorded. Thus, the waveform reproduced in this manner becomes a dipulse waveform.

[0003]

By the way, of the two methods described above, namely, a case where a rectangular wave is used as a recording signal and a case where a sine wave is used as a recording signal, when a sine wave is used as a recording signal, As shown in FIG. 3F, the reproduction waveform may be an abnormal waveform in which the dipulse waveform shown in FIG. 3E is disturbed. When such an abnormal waveform is generated, FIG.
As shown in FIG. 3E, in the dipulse waveform shown in FIG. 3E, two or more peaks appear where there is only one peak, which causes the reproduction system circuit for detecting the peak to operate erroneously. Therefore, C / N (Color / Nois
In addition to e) and S / N (Sound / Noise), there is a disadvantage of deteriorating the error rate.

[0004] The present invention has been made in view of the above point, and when a signal recorded from a perpendicular magnetic recording medium is reproduced, the C / N, S / N and error rate of the signal are not degraded. It is intended to propose a recording method on a recording medium.

[0005]

According to the method of recording on a perpendicular magnetic recording medium of the present invention, for example, as shown in FIG. 1, a current I [ AT0-p] and the recording wavelength λ [μm] are I /
λ> 0.1 [AT0-p / μm].

[0006]

According to the present invention described above, the perpendicular magnetic recording medium 1 is provided.
When performing recording with a sine wave, the relationship between the current I [AT0-p] flowing through the magnetic head 2 and the recording wavelength λ [μm] is I / λ>
Since it is set to 0.1 [AT0-p / μm], it is possible to prevent the C / N, S / N and error rate of the signal from deteriorating when the signal recorded from the perpendicular magnetic recording medium 1 is reproduced. .

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an example of a recording method for a perpendicular magnetic recording medium according to the present invention will be described in detail with reference to FIG.

In FIG. 1, for example, a signal (sine wave) from a signal processing circuit 4 is arbitrarily recorded on a magnetic recording medium 1 via a recording amplifier 3 and a magnetic head 2 by a recording apparatus as shown in FIG. Recording was performed at the current I [AT0-p] and an arbitrary recording wavelength λ [μm], and the recorded signal was reproduced. As a result, a point of the arbitrary recording current I and the recording wavelength λ where an abnormal waveform was observed was evaluated as “× ”, And“ ○ ”indicates an arbitrary recording current I and a recording wavelength λ where no abnormal waveform was observed. The boundary between these "x" points and "o" points is indicated by a solid line a satisfying I = 0.106 λ. As is clear from FIG. 1, it has been found that an abnormal waveform is more likely to occur as the recording current I decreases and as the recording wavelength increases. That is,
It was found that no abnormal waveform was generated by satisfying I> 0.1λ.

The condition under which this abnormal waveform does not occur is I
It will be described that> 0.1λ. In the case of perpendicular magnetic recording, the recording current signal (sine wave) as shown in FIG. 3A (the ordinate represents the recording current I and the abscissa represents the time t) increases to a certain degree or more (in FIG. 3A, I0 ≦ | I |) Since the magnetic field reverses the magnetization in the medium for the first time, in the case of sine wave recording, a region b where the magnetization is not reversed occurs. For this reason, the magnetization distribution at the time of the magnetization reversal is shown in FIG.
And the horizontal axis is time t). When the width (time) of the magnetization inversion where the magnetization M is substantially zero becomes a certain value or more as shown in FIG. 3C, the waveform of the reproduction signal of the magnetization inversion becomes as shown in FIG. An abnormal waveform as shown in FIG. Therefore, the presence or absence of an abnormal waveform can be determined depending on whether the region b where the magnetization reversal is not performed is wide or narrow.

[0010] and abnormal waveform does not occur here when regions not magnetized inversion b are certain width x ₀ or less. Then, Equation 1 is assumed.

(Equation 1) The function of the recording current in FIG.

(Equation 2) At this time, Equation 3 is derived from Equation 2 for the slope at t = 0.

(Equation 3) Further, a region where the recording current signal of FIG.
Equation 4 is obtained when the recording current signal for the width t0 of b is linearly approximated.

(Equation 4) By substituting Equation 3 into Equation 1, Equation 5 is derived.

(Equation 5) Here, since v / f = λ (recording wavelength), x ₀ is as shown in Expression 6, and therefore Expression 7 is satisfied.

(Equation 6)

(Equation 7) That is, when I / λ is larger than a certain value, no abnormal waveform is generated.

As is apparent from the above description, the relationship between the current I [AT0-p] flowing through the magnetic head 2 and the recording wavelength λ [μm] is such that I / λ> 0.1 [AT0-p / μm]. ,
When a signal recorded from the perpendicular magnetic recording medium 1 is reproduced, the C / N, S / N and error rate of the signal can be prevented from deteriorating.

[0012]

It should be noted that the present invention is not limited to the above-described embodiment, but can adopt various other configurations without departing from the gist of the present invention.

[0014]

According to the present invention described above, when recording is performed on a perpendicular magnetic recording medium with a sine wave, the relationship between the current I [AT0-p] flowing through the magnetic head and the recording wavelength λ [μm] is I / λ. >
Since it is set to 0.1 [AT0-p / μm], it is possible to prevent the C / N, S / N and error rate of the signal from deteriorating when the signal recorded from the perpendicular magnetic recording medium is reproduced. There is a benefit. In addition, there is an advantage that digital recording and reproduction can be performed using a sine wave recording current signal without using a rectangular waveform recording current signal having a complicated waveform.

[Brief description of the drawings]

FIG. 1 is a graph showing the presence / absence of an abnormal waveform depending on a recording current and a wavelength for explaining a recording method on a perpendicular magnetic recording medium of the present invention.

FIG. 2 is a diagram showing a configuration example of a recording apparatus for explaining a recording method on a perpendicular magnetic recording medium according to the present invention.

FIG. 3 is a waveform diagram.

[Explanation of symbols]

 1 Magnetic recording medium 2 Magnetic head 3 Recording amplifier 4 Recording signal processing circuit

Claims (1)

(57) [Claims] When performing recording with a sine wave on a perpendicular magnetic recording medium, the relationship between a current I [AT0-p] flowing through a magnetic head and a recording wavelength λ [μm] is I / λ> 0.1 [AT0-p / μm]
A recording method for a perpendicular magnetic recording medium, characterized in that: