JPS5827576B2 - Magnetic transfer method for magnetic recording media - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic transfer method for a magnetic recording medium, in which a magnetic field is applied in the direction of the hard axis of magnetization (hereinafter referred to as "hard axis") of the magnetic recording medium. It is an object of the present invention to provide a magnetic transfer method which allows the magnetization of magnetic particles to be oriented in any direction and enables reliable transfer of signals using only a slight signal magnetic field of a previously recorded magnetic recording medium.

When using a tape recorder to transfer the contents of a recorded magnetic tape (hereinafter referred to as a master tape) to another unrecorded magnetic tape (hereinafter referred to as a slave tape), conventionally,
Two tapes are superimposed and an alternating current bias magnetic field is applied to the tapes in the easy axis (hereinafter referred to as easy axis) direction (longitudinal direction for general magnetic tapes) to change the direction of magnetization of the magnetic particles on the slave tape. It was made easier to transfer the master tape signal in the regular direction.

However, in this conventional method, since the magnetization direction of the magnetic particles on the tape is oriented in the easy axis direction, there are magnetic particles whose magnetization points in the opposite direction to the direction of the magnetic field caused by the signal current, and the signal magnetic field smaller than the bias magnetic field is If this happens, there is a risk that no magnetization will remain on the slave tape in the direction of the signal magnetic field, and that magnetization in the direction when the bias magnetic field exceeds the coercive force of the tape will remain.

As a result, residual magnetization is reduced by that amount, resulting in a drawback that reliable transfer is not possible.

The present invention eliminates the above-mentioned drawbacks, and one embodiment thereof will be described below with reference to the drawings.

FIG. 1 shows a schematic plan view of a magnetic transfer device used in one embodiment of the magnetic transfer method according to the present invention.

In the same figure, a master tape 2 and a slave tape 3 drawn out from supply reels 1 a and 1 b are overlapped with their respective magnetic layers 2 a and 3 a brought into contact with each other, as shown in FIG. It is wound onto the take-up reel 5a t 5b using as a guide.

Reference numeral 6 denotes an auxiliary magnetic field applying device, which is fixed on both sides of the overlapping tapes 2 and 3 so that the magnetic field extends in a direction perpendicular to the longitudinal direction of the tapes 2 and 3 (hard axis direction). Hm)>(auxiliary magnetic field I-Io)>(
The coercive force Hd) of the slave tape 3 is set as follows.

5, the direction of magnetization of the slave tape 3 is the easy axis (+M and -M) in the absence of a magnetic field, as shown in FIG.
X axis) direction (arrow a in Figure 2).

b direction), but the magnetic poles 6 of the auxiliary magnetic field applying device 6
By applying an auxiliary magnetic field Ho in the hard axis (y-axis) direction (directions of arrows c and d in FIG. 2) at points a and 6b, the direction of magnetization becomes My in the hard axis direction.

The magnetization of the magnetic particles of the slave tape 3 oriented in this difficult axis direction is in a state where it cannot remain in that direction (hereinafter referred to as an unstable state) when the magnetic field Ho applied thereto is removed. .

Note that since Hm>Ho>Hd is set as described above, even if the auxiliary magnetic field Ho is applied to the master tape 2, the magnetization of the master tape 2 is not affected.

The magnetic particles of the slave tape 3, which have become unstable due to the auxiliary magnetic field, are subjected to the magnetic field of the magnetic particles recorded on the master tape 2, and the magnetization My, which was oriented in the difficult axis direction, on the slave tape 3 is affected by the auxiliary magnetic field. When exiting, they all turn in the easy axis direction according to the signal magnetic field Hs on the master tape 2,
The signal on the master tape 2 is transferred onto the slave tape 3.

At this time, since the magnetization of the magnetic particles of the slave tape 2 is in an unstable state as described above, even a small signal magnetic field Hs can reliably orient the magnetic particles in the axial direction. can transfer the signal to

Next, if we consider the change in the magnetization of the magnetic particles when a signal is transferred onto the slave tape 3 using the magnetization curve shown in Figure 4, the magnetization will be affected by the magnetic field applied in the difficult axis direction by the auxiliary magnetic field. This results in point C (magnetization in the X-axis direction is zero), and in this state, when the signal magnetic field +Hs (-Hs) of the master tape 2 is applied in the easy axis direction, the magnetization at point C becomes 51 (
When the state S2) is reached and the slave tape 3 and master tape 2 come out of the auxiliary magnetic field, the magnetization at st (82) becomes +M (-M).

In this case, 10M or -M indicates the residual magnetization of the slave tape 3, and 10M or -M magnetization remains in the same direction as the signal magnetic field Hs, and a large residual magnetization can be obtained even with a small signal magnetic field Hs.

In addition, when transferring without applying a magnetic field in the direction of the difficult axis as in the past, the magnetization is not at point C but in the +M or -M state, and in order to change it to the -M or 10M state, the signal is A signal magnetic field larger than the magnetic field Hs must be applied.

Even with the auxiliary magnetic field on the -y axis, residual magnetization of 10M or -M can be obtained with a small signal magnetic field in the same manner as above.

Note that the direction of the auxiliary magnetic field Ho is indicated by the arrow e as shown in FIG.
, f direction (difficult axis direction).

Further, the auxiliary magnetic field does not necessarily have to be a DC magnetic field, but may be an AC magnetic field as long as it is applied in the difficult axis direction of the magnetic tape.

In particular, in the case of a DC magnetic field, reliable transfer can be achieved with a magnetic field smaller than a conventional bias magnetic field, and a smaller device is required compared to the conventional device.

As mentioned above, the magnetic transfer method of the magnetic recording medium according to the present invention applies a magnetic field in the direction of the hard axis of the slave tape to perform transfer, so the magnetic particles on the slave tape become unstable due to the application of the magnetic field in the direction of the hard axis. In this state, since it receives the signal magnetic field from the master tape, the magnetization on the slave tape will be oriented in the easy axis direction according to this magnetic field even with a small signal magnetic field. It has features such as being able to transcribe files and obtain an output slave.

[Brief explanation of the drawing]

1 and 2 are a schematic plan view and an enlarged view of the vicinity of the auxiliary magnetic field applying device of a magnetic transfer device used in one embodiment of the magnetic transfer method for magnetic recording media according to the present invention, respectively, and FIG. 3 is an enlarged view of the vicinity of the auxiliary magnetic field applying device. FIG. 4 is a diagram for explaining the direction of magnetization of magnetic particles on a slave tape according to the method, and FIG. 4 is a diagram for explaining changes in magnetization of magnetic particles recorded by the method of the present invention. 2...Master tape, 2a, 3a...
・Magnetic layer, 3...Slave tape, 6...
...Auxiliary magnetic field application device, 6a t 6b...Magnetic pole.

Claims (1)

[Claims] 1. In a magnetic transfer method for a magnetic recording medium in which a recorded magnetic recording medium and an unrecorded magnetic recording medium are superimposed and information on the recorded magnetic recording medium is transferred to the unrecorded magnetic recording medium, the unrecorded A magnetic transfer method for a magnetic recording medium, characterized in that a magnetic field is applied in the direction of the hard magnetization axis of the magnetic recording medium to perform the transfer.