JP3250319B2 - Magnetic head polishing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video tape recorder (VTR) and a digital audio tape recorder (D).
The present invention relates to a magnetic head polishing apparatus for polishing a tape sliding surface of a magnetic head chip attached to a rotary magnetic head mechanism used in AT) or the like.

[0002]

2. Description of the Related Art In general, a rotary magnetic head mechanism used in a VTR or the like has a rotor of a motor and a rotary drum having a magnetic head mounted on a rotary shaft. A general mechanism that rotates integrally is known.

FIGS. 6 and 7 show a magnetic head portion. As shown in FIGS. 6 (b) and 7 (b), the magnetic head portion is attached to a base 61 attached to a rotating drum and fixed to the base 61. And a magnetic head chip 64 attached to the base 61, wound with a winding 63, and electrically connected to the substrate 62.

The tape sliding surface 65 that slides on the magnetic tape at the tip of the magnetic head chip 64 is rounded, and a curved surface in the tape sliding direction is called a large radius R (see FIG. a)), a curved surface in the thickness direction is formed into a small radius r having a small radius (FIG. 7).
(A)). Such a curved surface is generally polished using a wrapping tape (abrasive tape).

As shown in FIGS. 8 to 10, this polishing is performed by a cylindrical member (referred to as a "cup") 70 as a rotating body composed of a lower cup 68 and an upper cup 69 and rotationally driven as shown by an arrow B. A magnetic head chip 64 mounted on a base 61 is mounted on the rotating drum via the base 61, and a wrapping tape 71 is wound around the cup 70 and is gradually moved as shown by an arrow C. The tip 64 is being polished. Since the abrasion of the lapping tape 71 in the once polished portion is greatly reduced, if the rotation direction of the cup 70 is kept constant, the manner of cutting the sliding direction of the magnetic head chip 64 will be different. In order to prevent this, the rotation direction of the cup 70 is rotated forward and backward at regular intervals.

In order to avoid using a certain place of the wrapping tape 71 continuously, the wrapping tape 71 is gradually fed in the direction of arrow C and the cup 70 is moved up and down in the axial direction as described above. (Arrow D). When the cup 70 moves up and down, the magnetic head chip 64 comes into contact with the lapping tape 71 according to the locus indicated by the symbol E in FIG. 10 and is polished.

The magnetic head chip 64 thus formed
The accuracy of the vertex position P of the small radius (r) (FIGS. 7A, 11 and 12) on the tape sliding surface 65 determines the quality of the magnetic head chip 64. In general, it is most desirable that the apex position P is set to a half position of the sliding surface thickness T as shown in FIG. 11 (a) so as to be vertically symmetrical, as shown in FIG. 12 (a). It is not desirable that the apex position P deviates to one side from the half position of the sliding surface thickness T, which results in a defective product.

As a method of inspecting this, a method using an interference objective lens 80 is generally used, as shown in FIG. This method is based on the reflected light from the reference mirror surface 81,
The reflected light from the polished tape sliding surface 65 of the magnetic head chip (illustrated in this figure with an enlarged thickness) interferes with the half mirror surface 82 and is observed through the interference objective lens 80. I have.

When measured by this method, the contour lines of the tape sliding surface 65 are bright and dark as shown in FIGS. 11 (b) and 12 (b) showing the measurement results of FIGS. 11 (a) and 12 (a), respectively. Observed as interference fringes 83. As shown in the figure, a pair of parallel filled glass portions 8 are provided on the tape sliding surface 65.
4, a recording / reproducing track portion 85 sandwiched between the pair of glass portions 84, and a gap 86 located at the center of the track portion 85.

Since the radius R and the small radius r are generally different values, the interference fringes 83 are substantially elliptical. When the vertex position P coincides with the center of the sliding surface thickness T (FIG. 11A), the center position of the interference fringe 83 also coincides with the vertex position P (FIG. 11B). . In many cases, it is required that the center position of the interference fringes 83 does not deviate from the track portion 85. The center position of the interference fringe 83 is shown in FIG.
When the magnetic head chip 64 is largely off the track portion 85 as shown in FIG. 2B, the tape sliding surface 65 has the shape shown in FIG. 12A. It becomes defective.

[0011]

The polishing of the tape sliding surface 65 of the conventional magnetic head chip 64 is performed while the magnetic head chip 64 is mounted on the base 61. If a defective product occurs, there is a disadvantage that the defective product must be discarded with the base 61 attached.

Further, in a magnetic head portion of a type in which a plurality of magnetic head chips 64 are assembled on the base 61, since the plurality of magnetic head chips 64 are polished simultaneously, the respective tips of the plurality of magnetic head chips are respectively polished. Since the shape cannot be finished arbitrarily and the amount of polishing cannot be controlled individually, there is a disadvantage that the depth accuracy and the like are deteriorated.

In view of the above, the present invention proposes a magnetic head polishing apparatus capable of precisely finishing the same magnetic head chip.

[0014]

A magnetic head polishing apparatus according to the present invention is, for example, as shown in FIGS.
The wrapping tape 8 is brought into contact with the spindle 1 by using the guide shaft 7a, and the spindle 1 is rotated to polish the tape sliding surface 65 of the magnetic head chip 64 and to attach the lapping tape 8 to the spindle 1. Chip mounting means 19 and 22 are provided on the spindle 1 for pressing and mounting inside the outer peripheral surface of the spindle 1 so that the tape sliding surface 65 of the magnetic head chip 64 projects from the outer peripheral surface of the spindle 1. In the magnetic head polishing apparatus, the spindle 1 includes a main spindle 18 having a chuck portion for chucking the magnetic head chip 64 on an upper surface, and an upper spindle 21 connected above the main spindle 18. It is coaxial with the main spindle 18, has the same diameter and is movable only in the vertical direction. The outer circumferential surface the magnetic head chip 64
With the exception of the window 24 from which the projection protrudes, it is closely connected to the outer peripheral surface of the main spindle 18 and the window 24 is connected to the main spindle 18 and the upper spindle 21 connected thereto.
The chuck portion comprises a magnetic head chip mounting surface 25, a step 26 provided on one side thereof, and a chip chuck 19 for pressing the magnetic head chip 64 against the step 26 with spring pressure. Spindle 2
Reference numeral 1 denotes a built-in chip pressing shaft 22 for pressing the magnetic head chip 64 chucked by the chuck portion from above in the axial direction by spring pressure.

[0015]

[0016]

According to the present invention, since the tape sliding surface 65 of the magnetic head chip 64 is polished by a single chip, the radius R, the small radius r, and the radius top position P can be set freely. Can be finished with the same precision.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a magnetic head polishing apparatus according to an embodiment of the present invention; FIG. 1 is a plan view showing the entirety of a magnetic head polishing apparatus according to the present embodiment. In FIG. 1, reference numeral 1 denotes a spindle to which a magnetic head chip 64 is attached and which is rotated at a predetermined speed as described later. Reference numeral 11 denotes a wrapping tape table. A wrapping tape supply reel 8S for supplying the wrapping tape 8 is provided on one side of the wrapping tape table 11, and the wrapping tape 8 is wound on the other side of the wrapping tape table 11. A wrapping tape take-up reel 8T is provided.

A pressing plate 7 is provided between the wrapping tape supply reel 8S and the wrapping tape take-up reel 8T so as to be slidable in the spindle 1 direction. A U-shaped notch as shown in FIGS. 1 and 2 is provided on the spindle 1 side of the pressing plate 7, and the spindle 1 is arranged in the U-shaped notch.

Guide shafts 7a, 7a are provided at the two ends of the U-shaped notch of the pressing plate 7, respectively.
The guide shafts 7a, 7a are provided with nip shafts 30a, 30a for holding the wrapping tape 8 together with the guide shafts 7a, 7a. In FIG. 1, reference numerals 7b and 7b denote guide shafts provided on the pressing plate 7 and 31a, 31a, 31b and 31b denote guide shafts provided on a wrapping tape table. , This guide shaft 31
a, 31a and nip shafts 30b, 30b for sandwiching the wrapping tape 8 are provided.

As shown in FIG. 2, the pressing plate 7 is pulled in the direction of the spindle 1 and a tension control spring 32 for adjusting the force of pressing the wrapping tape 8 against the spindle 1 is provided.

In this embodiment, the wrapping tape 8 from the wrapping tape supply reel 8S is connected to the guide shaft 31.
b, 31a, 7b, 7a, a predetermined angle of the outer peripheral surface of the spindle 1, and the guide shafts 7a, 7b, 31a, 31b, and are wound around the wrapping tape winding reel 8T.
In this case, the nip shafts 30a, 30a and the guide shaft 31 provided for the guide shafts 7a, 7a
a, 31a provided for the nip shafts 30b, 30
b prevents the wrapping tape 8 from loosening during polishing.

In this embodiment, the wrapping tape 8 moves upward or downward by a thickness of the magnetic head chip 64, for example, 0.9 mm with respect to the spindle 1 each time the spindle 1 makes one rotation of the wrapping tape table 11. I will do it. Thus, the magnetic head chip 64
Is always performed on a new portion of the wrapping tape 8, so that the polishing efficiency can be improved.

Next, the spindle 1 according to this embodiment will be described. As shown in FIG. 3, the spindle 1 according to this embodiment has the same diameter as the main spindle 18 and has the same diameter as the main spindle 18 and is movable only in the vertical direction along the sliding shaft 27 with respect to the main spindle 18. The main spindle 18 is provided with a chuck portion for chucking the magnetic head chip 64 on the upper surface of the main spindle 18.

The main spindle 18 and the upper spindle 21
Are overlapped with each other except for the window 24 projecting the magnetic head chip 64. In this case, the window 24 is formed by the main spindle 18 and the upper spindle 21. The shape of the window 24 is substantially the same as the cross-sectional shape of the magnetic head chip 64 to be polished, which is substantially parallel to the tape sliding surface.

A chuck portion provided on the upper surface of the main spindle 18 has a width substantially equal to the width of the magnetic head chip 64 and a magnetic head chip mounting surface 25 extending from the outer periphery to the sliding shaft 27.
And a step 2 provided on the left side in FIG.
6 and a chip chuck 19 for pressing the magnetic head chip 64 against the step 26 with spring pressure.

The tip chuck 19 pivotally supports an intermediate portion of the arm 19a. One end 19b of the arm 19a is brought into contact with the side surface of the magnetic head chip 64, and the other end of the arm 19a is pressed by a spring 19c. The pressing force of the one end 19b of the arm 19a against the magnetic head chip 64 is, for example, 200 g.

As shown in FIGS. 3 and 4, a groove 25a is formed at the boundary between the magnetic head chip mounting surface 25 and the step 26, and the groove 25a allows the edge of the magnetic head chip 64 to be formed at any part. , So that the edge portion is prevented from being applied. In the chuck portion, the other edge of the magnetic head chip 64 is also prevented from touching any portion.

As shown in FIG. 3, a suction port 25b for sucking the magnetic head chip 64 is provided in a portion of the magnetic head chip mounting surface 25 corresponding to the mounting portion of the magnetic head chip 64.

In this embodiment, the upper spindle 2
1, a chip pressing shaft 22 for pressing the magnetic head chip 64 chucked by the chuck portion on the upper surface of the main spindle 18 from above in the axial direction by the spring pressure of the spring 23 is incorporated. An elastic member 22a such as rubber is provided on a surface of the tip pressing shaft 22 which is in contact with the magnetic head chip 64 so that the tip pressing shaft 22 can press the magnetic head chip 64 reliably and without damaging it. .

In this embodiment, as shown in FIG. 5, a tip protrusion amount adjusting device 6 for adjusting the protrusion amount of the magnetic head chip 64 mounted on the upper surface of the main spindle 18 of the spindle 1 from the outer peripheral surface of the spindle 1. Is provided. When the tip protrusion amount adjusting device 6 adjusts the tip protrusion amount, the tip protrusion of the operating rod 33 has a diameter of, for example, 0.6 m.
The tip protruding rod 36 of m is disposed so as to be in contact with the rear part of the magnetic head chip 64, and the tip protruding rod 36 is driven by a stepping motor of, for example, 0.5 μm / 1 pulse constituting a fine movement mechanism. Is dragged forward, and the amount of protrusion is measured by the laser displacement measuring device 5 so as to be a predetermined amount.

In this case, a spring pressure relieving device 34 is provided to relieve the pressing spring pressure of the chip chuck 19. When the tip protrusion amount adjusting device 6 adjusts the tip protrusion amount, the spring pressure relaxation device 34 controls the relaxation lever 35.
Is brought into contact with the other end of the arm 19a, and the pressing force of the tip chuck 19 due to the spring pressure is reduced from, for example, 200 g to about 50 g.

In this embodiment, after the pressing force of the tip chuck 19 is reduced to, for example, about 50 g, the suction port 2
The magnetic head chip 64 is vacuumed from 5b.
The protrusion amount is adjusted by the protrusion amount adjusting device 6.

Further, in this embodiment, the laser displacement measuring device is located at a position facing the surface of the spindle 1 which does not come into contact with the wrapping tape 8 and where the tape sliding surface 65 of the magnetic head chip 64 attached to the spindle 1 can be observed. The laser displacement measuring device 5 measures the polishing amount of the tape sliding surface of the magnetic head chip 64.

In this embodiment, the interference fringe microscope 15 is arranged at a position facing the spindle 1 and at which the tape sliding surface 65 of the magnetic head chip 64 attached to the spindle 1 can be observed. Magnetic head chip 64
Observe the polished surface of.

Since the present embodiment is constructed as described above, when the tape sliding surface 65 of the magnetic head chip 64 is polished, the magnetic head chip 64 is moved to the magnetic head chip mounting surface 25 on the upper surface of the main spindle 18 of the spindle 1. Is chucked by a chip chuck 19. At this time, spindle 1
The tape sliding surface 65 of the magnetic head chip 64 rotates in the direction of the laser displacement measuring device 5.

The amount of protrusion of the magnetic head chip 64 is adjusted by the tip protrusion amount adjusting device 6 while observing with the laser displacement measuring device 5. Thereafter, the tip protrusion amount adjusting device 6 and the spring pressure relief device 34 are separated from the spindle 1 and the elastic member 22a of the tip pressing shaft 22
The magnetic head chip 64 is pressed, and at this time, the main spindle 18 and the upper spindle 21 are connected.

At this time, the magnetic head chip 6 is
Only 4 protrudes from the outer peripheral surface of the spindle 1.
Next, the wrapping tape winding guide shaft 7a is moved toward the spindle 1, and the wrapping tape 8 is wound over a predetermined angle on the outer peripheral surface of the spindle 1.

Thereafter, the spindle 1 is rotated to polish the tape sliding surface 65 of the magnetic head chip 64. At this time, the wrapping tape table 11 moves up or down by the thickness of the magnetic head chip 64 by one rotation of the spindle 1, and the polished surface of the magnetic head chip 64 is always polished by the new wrapping tape 8. And good polishing can be performed.

While the magnetic head chip 64 is being polished, the amount of polishing is continuously measured by the laser displacement measuring device 5. In this case, since the polishing amount was measured during polishing, this polishing amount was set to ± 0.5.
There is an advantage that can be controlled in μm.

When the polishing reaches the set polishing amount, the magnetic head chip 64 moves the spindle 1 to the interference fringe microscope 1.
Stop in the direction of 5. Next, the guide shafts 7a for winding the wrapping tape are moved backward together with the pressing plate 7, and the wrapping tape 8 is separated from the spindle 1.

Thereafter, the interference fringe microscope 15 is moved to the spindle side, and the tape sliding surface 6 of the magnetic head chip 64 is moved.
5 is taken, the radius R, small radius r, and radius top position of the tape sliding surface 65 are measured by image processing, and further, scratches, chips, cracks, and dirt are confirmed. judge.

According to this embodiment, since the tape sliding surface 65 of the magnetic head chip 64 is polished with a single chip, the radius R, the small radius r, and the radius top position can be freely set. There is an advantage that the same magnetic head chip 64 can be precisely finished. Therefore, according to the present embodiment, the magnetic head chip 6
4 has the advantage that the shape and dimensions of the tape sliding surface 65 can be finished with high precision, the magnetic conversion characteristics of the magnetic head can be improved, and the life can be extended.

Further, in a magnetic head of a type in which a plurality of magnetic head chips are assembled on a base, the shape, gap position and round top position of each tape sliding surface of the magnetic head chip can be freely set, so that an optimum magnetic head is manufactured. There are benefits that can be done.

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

[0045]

According to the present invention, since the tape sliding surface 65 of the magnetic head chip 64 is polished in chip units, the radius R, the small radius r, and the radius top position can be freely set. There is an advantage that the same magnetic head chip 64 can be precisely finished. Therefore, according to the present invention, the shape and dimensions of the tape sliding surface 65 of the magnetic head chip 64 can be finished with high precision, and the magnetic conversion characteristics of the magnetic head can be improved and the life can be extended.

Further, according to the present invention, in a magnetic head of a type in which a plurality of magnetic head chips are assembled to a base, the shape, gap position and radius top position of each tape sliding surface of the magnetic head chip can be set freely. There is an advantage that an optimum magnetic head can be manufactured.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of a magnetic head polishing apparatus according to the present invention.

FIG. 2 is a plan view showing an example of a main part of the present invention.

FIG. 3 is a partially cutaway perspective view showing an example of a spindle according to the present invention.

FIG. 4 is a partially cutaway front view showing an example of a main part of FIG. 3;

FIG. 5 is a partially cutaway perspective view showing an example of a main part of the present invention.

FIG. 6 is a diagram showing a magnetic head unit.

FIG. 7 is a diagram showing a magnetic head unit.

FIG. 8 is a plan view showing a polishing state of a conventional polishing process.

FIG. 9 is a front view showing a polishing state of a conventional polishing process.

FIG. 10 is a perspective view showing a polishing state of a conventional polishing process.

FIG. 11 is a diagram showing an example of a magnetic head chip in a good state.

FIG. 12 is a diagram showing an example of a magnetic head chip in a poor state.

FIG. 13 is an explanatory diagram showing an inspection method.

[Explanation of symbols]

 Reference Signs List 1 spindle 5 laser displacement measuring device 6 tip protrusion amount adjusting device 7 pressing plate 7a guide shaft 8 wrapping tape 11 lapping tape base 15 interference fringe microscope 18 main spindle 19 chip chuck 21 upper spindle 22 chip pressing shaft 23 spring 24 window 25 chip mounting Mounting surface 25a Groove 26 Step 30a, 30b Nip shaft 32 Tension control spring 34 Spring pressure relieving device 36 Tip protruding rod 64 Magnetic head chip

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B24B 21/00 G11B 5/127 G11B 5/187

Claims (9)

(57) [Claims] 1. A magnetic head chip is mounted on a spindle, a wrapping tape is brought into contact with the spindle by using a guide shaft, and the spindle is rotated to polish a tape sliding surface of the magnetic head chip and to form the magnetic head chip. In a magnetic head polishing apparatus, the spindle is provided with chip mounting means for pressing and mounting inside the outer peripheral surface of the spindle so that the tape sliding surface of the head chip projects from the outer peripheral surface of the spindle. The main spindle comprises a main spindle having a chuck portion for chucking the magnetic head chip on an upper surface, and an upper spindle connected above the main spindle. The upper spindle is coaxial with the main spindle, has the same diameter, and is movable only in the vertical direction. , Except for the window from which the magnetic head chip projects, It said window unit with connecting close to the outer peripheral surface of the main spindle is formed by the upper spindle connected thereto and said main spindle,
The chuck section includes a magnetic head chip mounting surface, a step provided on one side thereof, and a chip chuck for pressing the magnetic head chip against the step with spring pressure, and the upper spindle is chucked by the chuck section. A magnetic head polishing device comprising a built-in chip pressing shaft for pressing the magnetic head chip axially from above with a spring pressure. 2. The magnetic head polishing apparatus according to claim 1, wherein the shape of the window is substantially the same as the cross-sectional shape of the magnetic head chip. 3. The magnetic head polishing apparatus according to claim 1, wherein an elastic member is provided on a surface of the tip pressing shaft that contacts the magnetic head chip. 4. The magnetic head polishing apparatus according to claim 1, wherein the chuck portion chucks the magnetic head chip without touching an edge of the magnetic head chip. 5. The magnetic head polishing apparatus according to claim 1, wherein the chip mounting surface has a suction port for sucking the magnetic head chip. 6. The magnetic head polishing apparatus according to claim 1, wherein a nip shaft for fixing or releasing the wrapping tape to or from the guide shaft is provided near the guide shaft, and a constant force is applied to the guide shaft. Magnetic head polishing apparatus provided with a tension adjusting spring for the magnetic head. 7. The magnetic head polishing apparatus according to claim 1, wherein a fine movement mechanism for adjusting the amount of protrusion of the magnetic head chip and a protrusion adjustment jig provided at a tip end thereof are adjusted. A magnetic head polishing device comprising means. 8. The magnetic head polishing apparatus according to claim 1, further comprising: a spring pressure relieving means for relieving a pressing spring pressure of the chuck portion. 9. The magnetic head polishing apparatus according to claim 1, wherein the lapping tape of the spindle does not come into contact with a displacement measuring device for measuring a polishing amount of the magnetic head chip attached to the spindle during polishing. A magnetic head polishing device provided to face a surface.