JP2513224B2 - Manufacturing method of magnetic head for flexible magnetic disk - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method of manufacturing a magnetic head used for recording / reproducing a flexible magnetic disk such as a video floppy disk, and more particularly to polishing a tip end surface of the magnetic head. Is.

[Outline of Invention]

According to the present invention, a flexible lapping disk, which is rotated in the same manner as a magnetic disk, is pressed on a tip end surface of a magnetic head for a flexible magnetic disk by a pad member arranged on the side opposite to the magnetic head with the lapping disk sandwiched therebetween to be deformed. By contacting and rotating the lapping disk, the tip surface of the magnetic disk is abraded under almost the same conditions as the contact with the magnetic disk, and a narrow spacing can be achieved for the entire area of the head end surface of the magnetic disk, resulting in a good contact. It was made possible.

[Prior Art] For example, in a video floppy disk, a still image for one field is recorded on one circular track. This disc has 50 tracks from the outermost track to the innermost track, but if you use two of these tracks as a frame image, you can get a still image of higher quality. In this case, there are 25 frame images in total. Is obtained. A pointed thin-film in-line double-gap head is considered as a magnetic head for recording and reproducing this frame image.

Since the video floppy disk has a small outer diameter, it is easily affected by the fixed end of the center hub, and the head hits easily change when the head moves from the innermost circumference to the outermost circumference. A so-called movable pad in which the pad is moved in response to the movement of the head in order to reduce the influence of the fixed end is conceivable, but this method has a drawback that the mechanism becomes complicated and the cost becomes high.

Therefore, as disclosed in Japanese Utility Model Application No. 60-199942 and drawings, there has been proposed a device using a parallel groove type fixed pad, which has a relatively simple mechanism and is suitable for a magnetic head for a disk. A hit is obtained, which is advantageous in cost.

[Problems to be solved by the invention]

Even in the mechanism using the parallel groove type fixed pad, the tip end surface of the magnetic head is formed into a spherical surface due to the contact with the disk. Variation occurs. That is, variations in the absolute value of the spherical radius of the head, sag of the head edge, and inability to control the aspect ratio of the head radius are variations in the overall shape.

Also, since the head chip is ground to a spherical shape and then attached to a linear arm, the tip shape of the head tends to vary, and the deformed shape of the disk does not always become a spherical shape with a parallel groove type fixed pad, and with a spherical head. There is a problem that a good hit cannot be obtained.

In view of the above point, the present invention provides a method of manufacturing a magnetic head that can obtain an optimum hit for a magnetic disk when a parallel groove type fixed pad is used.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention supports a magnetic head by a jig and makes it correspond to one side of a flexible lapping disk mounted on a spindle so as to rotate like a magnetic disk. A pad is provided on the opposite side of the magnetic head across the disk, the pad member is pressed against the other surface of the lapping disk, and one surface is deformably abutted against the tip end surface of the magnetic head. The lapping disk is rotated by so that the tip surface of the magnetic head is polished.

[Work]

By arranging the magnetic head and the pad member in a corresponding manner with the flexible lapping disk rotated in the same manner as the magnetic disk, and pressing the pad member against the lapping disk, the lapping disk is similar to the magnetic disk with respect to the magnetic head. The magnetic disk is slidably contacted in a deformed manner, so that the tip end surface of the magnetic disk is polished and formed into a shape that provides an optimum hit corresponding to the magnetic disk.

〔Example〕

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

Reference numeral (1) is a magnetic head used for recording and reproduction on a flexible magnetic disk such as a video floppy disk, which is attached to the linear arm (2). This magnetic head is, for example, a pointed thin-film in-line double-gap head, in which two gaps g ₁ and g ₂ having a track width of 60 μm are arranged in a straight line with a guard band of 40 μm separated from each other. It is required in a wide range of 160 μm or more.

(3) has the same structure as that of rotating a magnetic disk by a spindle, and instead of the magnetic disk, a flexible lapping disk (4) is used for this spindle (3).
Are fitted and attached via a center hub (5).

And, one side of this wrapping disc (3),
In the figure, the magnetic head (1) is attached to the jig (6) via the linear arm (2) on the lower surface side, and is arranged corresponding to this magnetic head (1), that is, the lapping disk (3) is sandwiched. A quadrilateral frame-shaped pad member (7) is arranged on the opposite side (upper surface side) while being supported by a lifting support arm (8).

By lowering the pad member (7) in this state, the lapping disk (3) is pressed from the upper surface side and the lower surface side is pressed against the magnetic head (1). For this reason, the lapping disk (3) is changed into a mountain shape with the contact portion with the magnetic head (1) as the top and the contact portion at the lower end of the peripheral surface of the pad member (7) as the lower peripheral edge.

Then, by rotating the spindle (3), the lapping disk (3) also rotates, and the tip end surface (1a) of the magnetic head (1) is ground into a spherical shape.

In polishing the tip surface (1a) of the magnetic head (1), the spherical radius of the tip surface can be controlled by the pressing force of the pad member (7) against the lapping disk (3), that is, the mountain shape of the lapping disk (3) described above. Deformation is large when the pressing force is strong, and therefore the head tip surface (1a) has a small spherical radius and a sharp shape, and when the pressing force is low, it is small and therefore the head tip surface (1a) has a large spherical radius and a smooth shape. Becomes

The spherical radius aspect ratio of the head end surface (1a) is the inner diameter of the pad member (7), that is, the vertical width (radial direction of the disk D) a and the horizontal width (circumferential direction of the disk D) as shown in FIG. It can be controlled by changing the ratio with b, and when the vertical width a is made larger than the horizontal width b, an elliptical surface shape having a major axis in the disk radial direction and a minor axis in the circumferential direction is formed.

And the pad member (7) for the magnetic head (1)
The head tip surface (1
The direction and shape of the spherical top of a) can be controlled, and the pressing force of the pad member (7) can be adjusted when the spherical surface of the head tip surface (1a) is formed in two steps or when the head edge is rounded. It can be processed into a desired shape by strengthening it.

In this way, the tip end surface (1a) of the magnetic head (1) can be processed and molded into a desired spherical shape with high precision by pressing with the pad member (7) using the flexible lapping disk (3) (see FIG. 4).

In this example, the pressure contact force between the magnetic head (1) and the lapping disk (3) is adjusted by moving the pad member (7) up and down to change the pad height. 7) Fixed and magnetic head (1)
It may be carried out by moving up and down to change the head height, and it goes without saying that other configurations can be variously changed without departing from the spirit of the present invention.

In this example, since the tip end surface (1a) is shaped while the magnetic head (1) is attached to the linear arm (2), the recording / reproducing apparatus equipped with this magnetic head (1) can move the head. Since it is not necessary to mount a balance adjusting mechanism, the device can be downsized.

In the recording / reproducing apparatus using the flexible magnetic disk, when the moving pad (11) is used as shown in FIG. 5, the magnetic head (1) hits the magnetic disk D at a central angle of 60 ° of the magnetic disk D. , The magnetic head (1) and the pad (11) are brought into contact with the magnetic disk D, and a computer simulation of the deformed disk is performed. As a result, as shown in FIG. It is assumed that the deformed shape of the outer peripheral portion (B in the same figure) does not change, shows a circular equivariant position with the magnetic head (1) as the center, and is spherical.

On the other hand, when the parallel groove type fixed pad (12) is used as shown in FIG. 7, the deformed shape of the magnetic disk D is such that the major axis is in the radial direction of the disk with the magnetic head (1) as the center as shown in FIG. It has an elliptical shape (see A and B in the same figure).

When the parallel groove type fixed pad (12) is used as described above, the disk is deformed into an elliptical shape. However, when the magnetic head (1) having a spherical tip surface is used, the disk in the contact length direction as shown in FIG. And the head curvatures match, but spacing occurs in the contact width direction, and it is impossible to obtain optimum contact at both gaps g ₁ and g ₂ .

Therefore, the tip surface (1a) of the magnetic head (1) is an elliptical surface,
That is, by forming a three-dimensional ellipsoidal surface having a long axis in the radial direction of the disk, the contact with the magnetic disk D becomes extremely good when the parallel groove type fixed pad (12) is used as described later.

That is, the deformed shape of the disk defined by the boundary condition of the edge portion of the pad using the parallel groove type fixed pad (12) and the fixed end of the magnetic disk D with respect to the center hub H is not exactly a spherical surface but in the radial direction of the disk. The shape is close to an elliptical surface having a major axis and a minor axis in the circumferential direction. This can be seen from the results of a thousand interviews using a transparent disk and the results of computer simulation analysis.

The elliptical surface in the vicinity of the head defines the ratio of the major axis to the minor axis of the ellipse as the curvature ratio. For example, the three-dimensional view of the elliptical surface with the curvature ratio of 1.15 and the curvature radius of 15 mm in the major axis direction is as shown in FIG. Then, the equation of this ellipsoid is shown below.

Therefore, if the tip end surface (1a) of the magnetic head (1) is processed to have the same curvature and curvature ratio as the magnetic disk D, the elliptical deformation shape of the disk and the head tip end surface shape match, and a good hit can be obtained. . That is, compatibility between the head gaps g ₁ and g ₂ can be obtained by matching the elliptical deformation shape of the magnetic disk D and the tip end surface shape of the magnetic head (1) (9th embodiment).
(See Figure B).

[Advantages of the Invention] As described above, according to the present invention, the magnetic head for a flexible magnetic disk is formed by polishing on a curved surface having substantially the same shape as the head contact deformation at the time of recording / reproduction of the magnetic disk. A magnetic head that can be obtained, and in particular, when a parallel groove type fixed pad is used, can be processed and formed into a shape that conforms to the deformation of the magnetic disk with high precision and an optimum hit can be obtained, and recording and reproduction can be reliably performed. Is.

[Brief description of drawings]

FIG. 1 is a front view of a magnetic head polished by an apparatus for carrying out the present invention, FIG. 2 is a side view of the same, and FIG. 3 is a cross-sectional plan view showing the relationship between the magnetic head and a pad member. Is a perspective view of an example of a magnetic head manufactured according to the present invention, FIG. 5 is a schematic view of a recording / reproducing apparatus using a moving pad, and FIG.
FIG. 7 is an explanatory view of a deformed state of a magnetic disk in the same device, FIG. 7 is a schematic view of a recording / reproducing device using a fixed pad, and FIG.
FIG. 9 is an explanatory view of a deformed state of the magnetic disk in the same apparatus, and FIG. 9 is an explanatory view of a contact state between the magnetic head and the magnetic disk manufactured according to the present invention. In the figure, (1) is a magnetic head, (2) is a linear arm,
(3) is a spindle, (4) is a lapping disk,
(6) is a jig and (7) is a pad member.

Claims (1)

(57) [Claims] 1. A magnetic head is supported by a jig so as to correspond to one surface of a flexible lapping disk mounted on a spindle so as to be rotated in the same manner as a magnetic disk. A pad member is disposed on the opposite side, the pad member is pressed against the other surface of the lapping disk, one surface is deformably abutted against the tip end surface of the magnetic head, and the lapping disk is moved by the spindle. A method of manufacturing a magnetic head for a flexible magnetic disk, wherein the tip surface of the magnetic head is rotated to be polished.