JPH07118079B2 - Magnetic recording medium - Google Patents

Description

The present invention relates to a magnetic recording medium having a structure in which magnetic recording layers are laminated.

[Prior Art] Conventionally, in a magnetic recording medium having a two-layer structure with different coercive force, by recording normal data in the lower layer of high coercive force and then recording dummy data in the upper layer of resistance magnetic force,
A recording system for preventing data duplication has been proposed (Japanese Patent Laid-Open No. 61-115201).

In the magnetic recording medium of such a recording system, regular data is read after erasing the dummy data in the upper layer.

[Problems to be Solved by the Invention] However, in the above conventional magnetic recording medium, when recording or erasing the dummy data of the upper layer, even if the recording current of the magnetic head is changed, the influence on the lower layer cannot be avoided. , Had the problem of increasing the possibility of errors in legitimate data.

[Means for Solving Problems] A magnetic recording medium according to the present invention has a magnetic recording layer formed by laminating two magnetic layers over the entire recording area.
It is characterized in that the orientation directions of the two magnetic layers are substantially orthogonal to each other.

[Operation] Since the orientation directions are orthogonal to each other in this manner, by performing azimuth recording in accordance with the orientation direction, the upper layer recording can be performed without affecting the recording data of the lower layer. Data can also be read independently in each layer.

Embodiments Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic plan view of an embodiment of a magnetic recording medium according to the present invention.

In the figure, the magnetic layer 2 has a two-layer structure of a lower layer 2a and an upper layer 2b. The respective orientation directions a and b of the lower layer 2a and the upper layer 2b form a certain angle with respect to the longitudinal direction of the magnetic layer 2, and both form an angle of θ. In this embodiment, θ =
Although it is 90 °, it is of course sufficient that the angles are such that they do not interfere with each other.

Since the orientation directions are orthogonal in the upper and lower layers in this way, the coercive forces of the upper and lower layers 2b and 2a may be equal, but it is desirable to make the coercive force of the lower layer 2a larger than that of the upper layer 2b, and the difference of about 3 times. Would be ideal.

In order to record data using this embodiment, the data is first recorded on the lower layer 2a in the alignment direction a by the azimuth recording method.
Record Da, then data on the upper layer 2b according to the orientation direction b.
Record Db.

In this embodiment, since the data Da and Db can be read independently, the recording density of one magnetic layer 2 can be doubled as compared with the conventional one.

Also, if one of them is used as dummy data, when reading legitimate data, it is possible to erase / delete dummy data as in the past.
Rewriting is unnecessary.

Furthermore, since both the data Da and Db can be used as dummy data, it is difficult to discriminate the regular data even if a magnet viewer or the like is used.

FIG. 2 (A) is a schematic plan view showing an example of a magnetic card using this embodiment, and FIG. 2 (B) is a sectional view thereof.

In each figure, a lower layer 2a of high coercive force, an upper layer 2b of resistance magnetic force and a protective film 3 are laminated on a base material 1 to form upper and lower layers 2a and 2b.
The magnetic layer 2 is constituted by. Then, the data Da and Db are recorded according to the respective orientation directions a and b of the upper and lower layers 2a and 2b. That is, it is possible to record twice as much data as the conventional one on one magnetic layer, and it is possible to significantly improve the recording capacity of a magnetic card or the like having a limited area.

[Effects of the Invention] As described in detail above, the magnetic recording medium according to the present invention has the lower layer by performing azimuth recording according to the orientation direction because the orientation directions in each layer are substantially orthogonal. It is possible to perform recording on the upper layer without affecting the recording data of (1) and read data independently for each layer.

As described above, since there is little interference between the data in each layer, the data can be recorded in each layer, and the amount of data that is twice the normal amount can be recorded in one data track.

[Brief description of drawings]

FIG. 1 is a schematic plan view of an embodiment of a magnetic recording medium according to the present invention, and FIG. 2 (A) is a schematic plan view showing an example of a magnetic card using this embodiment. (B) is the sectional drawing. 1 ... Substrate 2 ... Magnetic layer 2a ... Lower layer 2b ... Upper layer 3 ... Protective film a ... Lower layer orientation direction b ... Upper orientation direction Da, Db ... Data

Claims (1)

[Claims] 1. A magnetic recording medium having a magnetic recording layer formed by laminating two magnetic layers over the entire recording area, wherein the orientation directions of the two magnetic layers are substantially orthogonal to each other.