JPH0335421A - Oblique orientating device - Google Patents

Abstract

PURPOSE:To enable oblique orientation only by arranging magnets face-to-face by setting the specified relation for the lengths of the respective magnets in the magnetic recording medium traveling direction on a faced surface. CONSTITUTION:A pair of magnets 1 and 2 are arranged face-to-face in a vertical direction with a magnetic recording medium 3 between. In the magnetic recording medium traveling direction on the faced surface, respective end faces on an exit side are deviated and arranged and a magnetic field in an oblique direction to a magnetic film surface 3a is generated. At such a time, when the lengths of the respective magnets in the magnetic recording medium traveling direction on the faced surface are defined as the L1 and L2, the relation of the 1.5L1<L2<5L1 is established. By changing the lengths in this range, the inclination of the magnetic field to be generated on the exit side is changed from a low angle side to a high angle side corresponding to this change of the length. Thus, only by arranging the magnets face-to-face, the oblique orientation can be executed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a magnetic field orientation device used in manufacturing coated magnetic recording media, and in particular, to a magnetic field orientation device that aligns magnetic powder obliquely with respect to a magnetic coating surface. This invention relates to an oblique orientation device.

[Summary of the invention]

The present invention provides an oblique orientation device that orients magnetic powder obliquely with respect to a magnetic coating surface. By making the lengths different, it is possible to achieve diagonal orientation simply by arranging these magnets facing each other, and it also aims to precisely control the inclination of the magnetic field generated in the diagonal direction over a wide range. .

(Prior Art) Generally, the mainstream method of magnetic recording is to use magnetization in the in-plane longitudinal direction of a magnetic recording medium. However, when trying to further improve recording density using this method, fIIi in the medium
As the magnetic field increases, there is a limit to the recording density, and the recording density cannot be improved that much.In other words, although this method improves the characteristics in the long wavelength region, it has the disadvantage that the characteristics in the short wavelength region are inferior. .

For this reason, a perpendicular magnetic recording method has conventionally been proposed in which recording is performed by magnetization in the thickness direction of a magnetic recording layer of a magnetic recording medium. According to the perpendicular magnetic recording method, the Muff field becomes smaller as the recording density increases, so it is known that it is superior to the above-mentioned recording using in-plane longitudinal magnetization, especially in high-density recording and short wavelength recording. It is being

However, when acicular magnetic powder or the like is oriented in a direction perpendicular to the magnetic recording layer, the characteristics in the short wavelength region are improved, but there is a drawback that the characteristics in the long wavelength region are degraded.

Therefore, an oblique alignment technique has been proposed that can improve the shortcomings of the in-plane longitudinal recording method and the perpendicular magnetic recording method and can exhibit high output from a long wavelength region to a short wavelength region.

For coating-type magnetic recording media, diagonal orientation technology improves electromagnetic conversion characteristics by orienting magnetic powder obliquely to the magnetic coating surface, and improves electromagnetic conversion characteristics from long wavelength to short wavelength. The aim is to achieve high output.

In addition to coating-type magnetic recording media, there are also vapor-deposition-type magnetic recording media in which an obliquely vapor-deposited film is formed by obliquely vapor-depositing Co-Cr, etc.; Since it is necessary to manufacture the magnetic recording medium using a device such as a sputtering device or a sputtering device, the manufacturing cost is inevitably high, which is disadvantageous compared to a coating-type magnetic recording medium. Therefore, it is desirable to use a coated magnetic recording medium with diagonal orientation.

Up until now, to achieve diagonal orientation for coating-type magnetic recording media, a pair of magnets was tilted at a predetermined angle with respect to the magnetic coating surface to generate an oblique magnetic field, and this magnetic field caused the magnetic coating to become oriented. This is done by tilting the magnetic powder obliquely to the surface of the magnetic coating.

[Problem to be solved by the invention]

However, in this case, the magnetic field on the low angle side (
When the in-plane direction of the Mi magnetic coating film is 0 degrees and the vertical direction is 90 degrees, a low angle refers to a range of 0 degrees to 30 degrees. Since it is necessary to change the inclination of the pair of magnets that are placed in between, there is a problem in that the device becomes large.

The present invention has been proposed in view of the above-mentioned conventional circumstances, and it enables diagonal alignment simply by arranging magnets facing each other, and also allows the inclination of the magnetic field generated in the diagonal direction to be widened over a wide range. It is an object of the present invention to provide an oblique alignment device that can be controlled accurately and that can be downsized.

[Means to solve the problem]

The oblique alignment device of the present invention has been proposed to achieve the above object, and includes a pair of magnets that can be arranged vertically with a magnetic recording medium in between, and the opposing surfaces of these magnets are arranged vertically with a magnetic recording medium in between. When the length in the running direction of the magnetic recording medium is Li, Li, 1.5 Ll <Li <5
It is characterized by the relationship Ll.

The magnetic recording medium to be applied in the present invention is a coating type magnetic recording medium, and the magnetic powder in the magnetic coating film coated on the non-magnetic support can be any conventionally known magnetic powder, and there are no limitations. To give six examples, γ
-Fe, O, +Fe.

Oa+r-Fe, O, and Bertolide compound of Fe5Oi, Co-containing r FezO3, Co-containing Fe5O4
, CO-containing y-Fe, a bertolide compound of 03 and Fe5Oa, Crow containing one or more metal elements 1 such as Te, Sb, Fe.

Oxides containing Bi etc., metals such as Fe, Co, Ni, Fe-Co, Fe-Ni, Fe-Co-Ni, F
e-Co-B, Fe-Co-Cr-BMn-Bi,
Examples include alloys such as Mn-Al and Fe-Co-V, and acicular fine particles such as iron nitride.

In addition, in order to perform oblique orientation using the apparatus of the present invention, it is necessary to apply a magnetic paint containing the above-mentioned magnetic powder onto a non-magnetic support according to a conventional method, and then ensure that the magnetic paint film is not yet dry and fluid. At this time, in magnetic field orientation, the gradient of the magnetic field on the exit side in the direction of travel of the magnetic recording medium is extremely important, and the gradient of the magnetic powder is determined according to the gradient of this magnetic field. be done. Therefore, in the oblique orientation according to the present invention, each end face on the exit side in the running direction of the magnetic recording medium of the opposing surfaces of a pair of magnets disposed vertically with the magnetic recording medium in between is arranged so as to be offset from each other. , generates a magnetic field in an oblique direction to the magnetic coating surface. Also, at this time, when the lengths of the opposing surfaces of each magnet in the magnetic recording medium running direction are L1 and L2, 1-5 Ll<Lx
The relationship is 〈5 Ll, and the slope of the magnetic field is regulated. Here, if the length L2 of one magnet becomes <1.5LI with respect to the length Ll of the other magnet, the inclination of the magnetic field becomes close to perpendicular, which is undesirable. When the length Ll of the magnet is >5L, it becomes difficult to ensure the strength of the diagonal magnetic field. Therefore, the length of the facing surface of each magnet in the magnetic recording medium running direction is ! , 5 L
It is assumed that l < L, <5 Ll.

In addition, the shape of each of the above magnets is not particularly limited, but
Since the direction of the magnetic field generated on the exit side in the running direction of the magnetic recording medium must be aligned in a substantially constant direction, at least the end face on the exit side must have a linear surface that is substantially orthogonal to the running direction of the magnetic recording medium. Therefore, it does not matter what shape the magnet has on the inlet side in the running direction of the magnetic recording medium.The above magnet can be a permanent magnet or an electromagnet, and if an electromagnet is used, Direct current must flow through the coil.

Further, the length of the magnet in the direction perpendicular to the running direction of the magnetic recording medium needs to be larger than the width of the magnetic recording medium, and although the upper limit is not particularly limited, it is naturally limited by the device. On the other hand, it is desirable that the lengths of the magnets in the direction orthogonal to the magnetic recording medium be the same as possible, but there may be some difference as long as there is not much difference in the direction of the magnetic field.

[Effect]

In the present invention, the lengths of the opposing surfaces of the pair of magnets disposed vertically with the magnetic recording medium in between in the magnetic recording medium traveling direction are different, so that when these magnets are disposed facing each other, the exit side The end faces of the magnetic tubes are arranged offset from each other, and the magnetic field generated on the exit side is naturally oblique with respect to the magnetic coating surface.

Further, the length of the opposing surface of one of the magnets in the magnetic recording medium running direction may be varied within a predetermined range with respect to the length of the opposing surface of the other magnet in the magnetic recording medium running direction. For example, the slope of the magnetic field generated on the exit side changes accordingly from the low angle side to the high angle side.

〔Example〕

Hereinafter, specific embodiments to which the present invention is applied will be described with reference to the drawings.

As shown in FIGS. 1 and 2, the oblique alignment device of this embodiment has a pair of magnets (1) and (2) arranged vertically with a magnetic recording medium (3) in between. The tank is bottomed.

The above magnets) (1) and (2) both have magnetic cores (for example, iron cores) having a rectangular planar shape.
The coils (6) and (7) are wound a predetermined number of times around the coils (4) and (5). The above magnetic core (4
), (5) is the running direction of the magnetic recording medium (arrow a in the figure).
The widths W, , W□ in a direction substantially perpendicular to the recording medium (3) are at least larger than the width of the recording medium (3). Further, both widths W+ and WI are set to be approximately the same width, so that the direction of the generated magnetic field is aligned in one direction.

On the other hand, the lengths Ll and Lx of the opposing surfaces of the magnetic cores (4) and (5) in the running direction of the magnetic recording medium are such that at least the magnetic powder contained in the magnetic coating film (3a) is ), (5) are long enough to be oriented in the magnetic field while traveling between them, and these are 1.5 Ll <L,
The relationship is <sLl. In other words, magnetic coating (
Length L2 of the magnetic core (5> disposed on the opposite side to 3a)
is the other magnetic core (
4) The length is at least 1.5 times larger and smaller than 5 times.

In addition, if these relationships are satisfied, the above magnetic core (4)
(5) Contrary to the above example, a magnetic core (5
), it is also possible to arrange a magnetic core (4) having a small length Ll in the running direction of the magnetic recording medium on the side opposite to the magnetic coating film (3a).

Both magnetic cores (4) and (5
) are arranged facing each other at a predetermined interval 11 in the vertical direction with the magnetic recording medium (3) in between, and each of the end surfaces (4a) and (5a) on the exit side in the running direction of the magnetic recording medium is connected to the magnetic recording medium. It is arranged substantially perpendicular to the running direction. Further, each end face (4a), (5a) of the magnetic cores (4), (5) on the exit side in the running direction of the magnetic recording medium.
) are arranged offset from each other. That is, the end surface (4a) on the exit side of the other magnetic core (4) disposed on the magnetic coating film (3a) side is connected to the end surface (5a) on the exit side of one magnetic core (5) facing this. On the other hand, the magnetic recording medium (3) is arranged shifted toward the entrance side where it travels. Furthermore, the above-mentioned bimagnetic core (4).

(5) means that not only on the exit side in the running direction of the magnetic recording medium but also on the inlet side in the running direction of the magnetic recording medium, the end face (4b) on the inlet side of the other magnetic core (4) is one magnetic core (5). The magnetic recording medium is disposed offset from the end face (5b) on the inlet side in the running direction of the magnetic recording medium.

Further, DC type R (8), (9) are connected to both ends of the coils (6), (7) respectively wound around both magnetic cores (4), (5). Therefore, the above DC 'r! Both magnetic cores (4),
(5) A magnetic field in a fixed direction is generated between the two. Note that the DC power supplies (8) and (9) are provided separately and independently for each magnetic core (4) and (5), respectively;
It may also be used as a common power source.

In the oblique alignment device configured in this way, the coils (
6) When direct current is applied to (7), the magnetic coating film (3a
) A magnetic field is generated in a direction from the magnet (1) disposed on the side toward one magnet (2) disposed opposite thereto. The magnetic field generated here is proportional to the length of the opposing surface of one magnet (2) in the running direction of the magnetic recording medium, and the length of the opposing surface of the other magnet (1) in the running direction of the magnetic recording medium. 1.5L.

<L, <51. , so the magnetic coating film (3a
) is generated so as to spread in a fan shape from the other magnet (1) disposed on the side toward the one magnet (2) disposed opposite thereto. Particularly in oblique orientation, the gradient of the magnetic field H9 on the exit side in the running direction of the magnetic recording medium [
That is, the angle θ1 between the direction of the magnetic field H generated on the exit side and the opposing surface (2a) of one magnet (2) facing the other magnet (1) is important, and the inclination of this magnetic field Hl is The magnetic powder is oriented according to θ1. The slope θ1 of the magnetic field H6 on the exit side is the magnetic chamber II (3a
) can be easily changed by varying the length L8 in the running direction of the magnetic recording medium of the opposing surface of one magnet (2) disposed on the opposite side from the magnet (2) within the above range.
For example, the length of the opposing surface of one of the magnets (2) in the running direction of the magnetic recording medium is determined by the length of the opposing surface of the other magnet (2).
If the relationship of 1) is 5L with respect to the length Ll of the opposing surface in the running direction of the magnetic recording medium, the inclination θ1 of the magnetic field Hl on the exit side becomes small and becomes a low angle. On the other hand, the length Ll of the opposing surface of one magnet (2) in the running direction of the magnetic recording medium is relative to the length L+ of the opposing surface of the other magnet (1) in the running direction of the magnetic recording medium. If the relationship is t, 5L, then the slope θ1 of the magnetic field H on the exit side becomes large and becomes a high angle. That is, by appropriately changing the length Ll of the opposing surface of the other magnet <2) in the magnetic recording medium running direction, the inclination θ1 of the magnetic field Hl on the exit side in the magnetic recording medium running direction can be changed from a low angle to a high angle. can be easily and precisely controlled over a wide range.

Furthermore, in addition to this, the following method can be used to control the slope θ1 of the magnetic field H6 on the exit side in the running direction of the magnetic recording medium.

For example, it is controlled by changing the distance between opposing magnets (1) and (2). That is, the third
As shown in the figure, these magnets (1), (2)
If the distance l between them is made longer than the arrangement position shown in FIG. 2 above, the slope θ of the magnetic field Hl on the exit side in the running direction of the magnetic recording medium becomes small, and conversely, as shown in FIG. When the distance Htt between magnets (1) and (2) is shortened, the slope θ of the magnetic field Hl on the exit side increases.

In addition, as shown in Figure 5, these magnets (1)
, (2) The inclination θ of the magnetic field H3 on the exit side in the running direction of the magnetic recording medium can also be controlled by shifting one of the magnets in the running direction of the magnetic recording medium or in the opposite direction. . That is, one magnet (2) disposed on the opposite side to the magnetic coating film (3a)
By shifting the magnetic recording medium in the running direction of the magnetic recording medium, the distance between each end face (4a) and (5a) on the exit side in the running direction of the magnetic recording medium is changed to control the slope θ4 of the magnetic field Hl on the exit side. At this time, if the other magnet (2) is shifted too much, the inclination θ4 of the magnetic field Hl on the exit side becomes too low, making it difficult to ensure the strength of the magnetic field. The end faces (4b) and (5) of magnets (1) and (2) on the inlet side where
b) It is desirable to keep them at a position where they substantially match each other.

In order to orient magnetic powder obliquely using the oblique orienting device having the above configuration, it is carried out as follows.

First, the magnetic cores (
4).

A direct current is applied to each of the coils (6) and (7) wound around (5), and the magnetism is confirmed! ! A magnetic field is generated in a direction from the other magnet (1) disposed on the 1 m (3a) side toward one magnet (2) disposed opposite thereto.

Next, a magnetic recording medium (3) in which a magnetic coating film (3a) containing magnetic powder is formed on a non-magnetic support is attached to the magnetic coating film (3a).
Both of the above magnets (1) before 3a) is still dry,
(2) In the meantime, run in the direction a in the figure.

At first, the magnetic powder aligns according to the inclination of the magnetic field generated near the entrance side of the magnets (1) and (2), but as it travels between the magnets (1) and (2), it aligns at each position. The magnetic powders are aligned according to the gradient of the magnetic field Hl, and finally the magnetic powders are oriented according to the gradient θ1 of the magnetic field Hl on the exit side.

Thereafter, by performing steps such as drying in a series of steps, an obliquely oriented magnetic recording medium can be obtained.

〔Effect of the invention〕

As is clear from the above description, in the present invention,
Since the opposing surfaces of a pair of magnets arranged vertically with the magnetic recording medium in between have different lengths in the running direction of the magnetic recording medium, diagonal orientation can be achieved simply by arranging these magnets facing each other. In addition, by changing the length of the opposing surface of one of these magnets in the magnetic recording medium running direction, the gradient of the magnetic field generated on the exit side can be varied over a wide range from the low angle side to the high angle side. can be easily and precisely controlled.

In addition, in the apparatus of the present invention, the magnetic field on the exit side can be increased by simply changing the length in the running direction of the magnetic recording medium of the opposing surface of one of the pair of magnets disposed with the magnetic recording medium in between. Since the inclination of the magnetic field can be easily controlled, the inclination of the magnetic field can be controlled without having to move both magnets as in the conventional case, and the device can be made more compact.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view showing an embodiment of an oblique orientation device to which the present invention is applied, and FIG. 2 is a schematic diagram of the device viewed from the side. Figures 3 and 4 are schematic diagrams showing other examples of changing the gradient of the magnetic field on the exit side in the running direction of the magnetic recording medium, and Figure 3 shows when the gradient of the magnetic field on the exit side is increased. Schematic diagram of
FIG. 4 is a schematic diagram when the gradient of the magnetic field on the exit side is made small. FIG. 5 is a schematic diagram showing still another example of changing the inclination of the magnetic field on the exit side in the running direction of the magnetic recording medium. 1.2... Magnet 3... Magnetic recording medium 3a... Magnetic t! ! film

Claims (1)

[Claims] It has a pair of magnets arranged vertically with a magnetic recording medium in between, and when the lengths of the opposing surfaces of these magnets in the running direction of the magnetic recording medium are L_1 and L_2. 1.5L_1<L_
A diagonal alignment device characterized by a relationship of 2<5L_1.