JPS62192906A - Magnetic head - Google Patents

Abstract

PURPOSE:To prevent the deterioration of picture quality by providing a press contact part having a curvature in a running direction of a metal group medium and an output shoulder having a notch parted from the metal group medium from the prolonged line of the curvature of the press contact part so as to improve the spacing loss. CONSTITUTION:The press contact part 16a is a region shown in hatched lines from a part 15a of an incoming core 12c to a part 15b of an outgoing core 12d and a proper curvature R1 is provided to apply desired recording/ reproduction and smooth running with the metal group medium 11 in the running direction 11a of the metal group medium 11. Then the region from a part 15a on the incoming core 12c to the incoming end 12e among non-contact region with the metal group medium 11 is the incoming shoulder 16b. The region from the part 15b on the outgoing core 12d to an outgoing end 12f is an outgoing shoulder 16c, which is provided with a notch 16e so as to be parted from the medium 11 from the prolonged line 16d of the curvature R1 of the press contact part 16a in the running direction 11a of the medium 11.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is a highly reliable magnetic head that is applied to a magnetic head, particularly a metal magnetic recording medium containing metal magnetic powder, and a metal thin film magnetic recording medium having a magnetic thin film as a magnetic layer. The present invention relates to a magnetic head.

Conventional technologyIn the field of magnetic recording, the high density of magnetic recording density has increased to 2.
/゛Mainly achieved through improvements in magnetic recording media and magnetic heads. Taking magnetic recording media as an example, 7Fe203
, Go-7Fe205, 0r02, etc., instead of oxide magnetic powders such as Go-7Fe205, 0r02, etc., magnetic recording media containing metal and alloy-based magnetic powders such as Go and Go-Fe (metal magnetic recording media are abbreviated as MP) Ya, Go, Ni.

Efforts are being made to put into practical use a magnetic recording medium (referred to as ME for metal thin film type magnetic recording medium) whose magnetic layer is a magnetic thin film made of a metal or alloy mainly composed of Fe, etc., and the above-mentioned MP
In addition, with the spread of ME magnetic recording media (hereinafter referred to as metal-based media), there is a need for highly reliable magnetic heads that can be applied to these metal-based media.

Hereinafter, a magnetic head conventionally used for the metal-based medium will be described with reference to the drawings.

Figure 7 is a plan view of a magnetic head used for metal-based media, viewed from above the metal-based medium (the medium runs within the plane of the paper), and Figure 8 is a magnetic head seen from the side of the metal-based medium. Figure 3 shows a front view of the magnetic core of the head. In FIGS. 7 and 8, 1 is a metal-based medium, arrow S is the traveling direction of the metal-based medium 1, and 2a is the rotating direction of the magnetic head (the magnetic head is in-plane in FIG. 7). ), 2b
is the magnetic gap of the magnetic head, 2C is the magnetic gap 2
Among the magnetic cores sandwiching b and opposing magnetic cores, the magnetic core that comes into contact with the metal medium 1 of the rotating magnetic head first (abbreviated as 1- and referred to as the entrance core), and 2d comes into contact next. Porcelain core (abbreviated as exit core), 2e and 2f
are the ends of the inlet core and the outlet core, 3a and 3b are holding members arranged to hold the magnetic cores 2C and 2d, and 4 is a part for passing the winding to be wound around a part of the magnetic core. A winding groove (the winding is omitted in FIGS. 7 and 8).

The surface of the magnetic head that faces the metal medium 1 in the running direction of the metal medium 1 is an entrance shoulder eb, which will be described later.

Contact portion Sa (the area indicated by diagonal lines in FIG. 7).

In the figure, the length of the metallic medium 1 in the running direction centered on the magnetic gap 2b is indicated by 21o. Tsuzen 2e
o=1 mm. ) and the exit shoulder portion 6C both have a curvature R1.

The operation of the conventional magnetic head constructed as described above mounted on the cylinder of an 8 mm video A-chip recorder will be described with reference to FIGS. 9(A) to 9(H).

Figures 9(A) to 9) show metallic media 1 under the following conditions.
This is a time-series diagram schematically showing phenomena that occur on the surface of a magnetic head when a conventional magnetic head and a conventional magnetic head come into contact with each other.

Further, in this figure, the cylinder is omitted and only the metal medium 1 and the magnetic head are shown. In the figure, a side view of the magnetic head viewed from above the metal medium 1 is shown in the -1 step, and a front view of the magnetic core of the magnetic head viewed from the side of the metal medium 1 is shown as means. In the 8mm video recorder, the running speed of the metal medium 1 is 14.4mm/5e.
The rotational speed of the a1 magnetic head is approximately 8 m/sec.

Problems to be Solved by the Invention When the magnetic head contacts the metal medium 1 under such high speed rotation, a part of the magnetic layer of the metal medium 1 is scraped by the magnetic head. The dropped and scraped part adheres to the contact portion 6a of the magnetic head [Fig. 9(A)
, (B) shows the deposit as 7iL. ], As the magnetic spatula rotates at high speed, the object 7a moves on the contact portion 6a in a direction opposite to the rotational direction 2a of the magnetic head, and the moving direction is indicated by 7b), on the contact portion 6a. After moving, it is concentrated on the exit shoulder 6C [Fig. 9(C),
In (D), it is shown as a deposit 7C on the exit shoulder 6C)
.

On the exit shoulder parts sc, -f-, the deposits 7a that have sequentially moved on the contact part 6a accumulate, and the deposits 7a are combined with the materials already attached on the exit shoulder part 6C (the ninth Figures (E) and (F)
7d) is formed, and eventually the combined object 7d does not reach only the exit shoulder 6C, but extends into the abutting portion 6a. [Indicated by 7e in FIGS. 9(G) and (H). ] The above-mentioned phenomenon also occurred in video tape recorders that used magnetic recording media using oxide magnetic powder as the magnetic powder before 8 mm video tape recorders became widespread. However, in a conventional videotape recorder, the wavelength of the luminance signal is 1.1 to 1.411 m, whereas in the case of an 8 mm video tape recorder, the wavelength of the luminance signal is 0.75 μm 1 PA in the case of NTSC.
In the case of L, it is 0.6 μm and handles signals with extremely short wavelengths.When a situation like that shown in Figure 91 (G) and (5) occurs, the spacing between the magnetic head and the metal medium is The spacing loss (indicated by do in FIGS. 9(G) and (B)) occurs more significantly than in conventional video recorders, resulting in a total deterioration of image quality.

Means for Solving All Problems In order to solve the above problems, the magnetic head of the present invention includes a contact portion having a curvature of R1 in the running direction of the metal medium, and a curvature of R1 in the contact portion. The outlet shoulder portion is provided with a cut portion so as to be located further away from the metal medium than the extension line.

Operation The present invention relies on the above-described configuration, and when a traveling metal medium and a high-speed rotating magnetic head come into contact with each other, a part of the magnetic layer of the metal medium After moving to the contact part with the magnetic head and then moving toward the exit shoulder, it falls to the exit shoulder where the entire cutout is provided, and then continues to fall 7. Although the part of the magnetic layer and the combined material are formed on the exit shoulder, they do not extend to the abutting part and remain in the exit shoulder, thereby reducing the A magnetic head due to the intrusion of the combined object into the abutting portion.
It is possible to improve the spacing loss caused by spacing between metal media, that is, to effectively improve the deterioration in image quality.

EXAMPLE Hereinafter, a magnetic head of the present invention will be explained with reference to the drawings. FIG. 1 is a front view of the magnetic core of the magnetic head of the first embodiment of the present invention, which is applied to a metal-based medium, as seen from the side of the metal-based medium, and FIG. This is a plan view of the system medium seen from the upper side (the medium runs within the plane of the paper).

In FIGS. 1 and 2, 11 is a metal-based medium, and an arrow 112L indicates the running direction of the metal-based medium 11. 12a is the rotational direction of the magnetic head (the magnetic head rotates in the plane in FIG. 1), 12b is the magnetic gap of the magnetic head, and 12c is the magnetic core facing oppositely across the magnetic gap. The metal medium 11 of the rotating magnetic head
12d is the inlet core that comes into contact first, 12d is the outlet core that comes into contact next ~ 12e and 12f are the inlet cores and the ends of the outlet cores, 13a and 13b are for holding the magnetic cores 120 and 12d. The disposed holding member 14 is a winding groove (the winding is omitted in FIGS. 1 and 2) for passing the winding to be wound around a part of the magnetic core 120.

The winding groove 14 is designed to reduce fluctuations in modulation noise when the magnetic head is used for a long period of time.
It is desirable to provide it at 20.

The magnetic cores 120 and 12d include Fe-41-8i.
The holding materials 13a and 13b are soft magnetic materials made of metals and alloys such as Co-Nb-Zr amorphous alloys (called sendust), and glass,
A non-magnetic material such as FF203, Ni--Zn type 7 elite, or an oxide-based magnetic material such as Mn--Zn type ferrite is disposed.

The surface of the magnetic head according to the present invention, which faces the metal medium 11, is roughly divided into three areas called an abutment area, an entrance shoulder area, and an exit shoulder area. That is, the area that actually contacts the metal medium 11 is the contact portion 16a, and the contact portion 1
6a is a part 15a of the entrance core 120 in FIG.
(indicated by a two-dot chain line in FIG. 2) to a part 15b of the outlet core 126 to a region indicated by diagonal lines in FIG. The distance from gap 12b to 162L is 12
The distance from the magnetic gap 12b to the magnetic gap 15bt is indicated by 11), and in the running direction 11a of the metal medium 11, there is a It has a curvature R1.

Then, from the part 152L on the inlet core 12C to the inlet end 12 in the area not actually in contact with the metal medium 11,
The area extending to e is the entrance shoulder portion 16b. The region from 15b on the exit core 12d to the exit end 12f is the exit shoulder 16c, and the exit shoulder 16c is the contact portion 16a in the running direction 10 of the metal medium 11 in the vane 11a. Extension line 16 of curvature R1 (
The cutout portion 16ei is also separated from the metal medium 11.
It is set up. Note that the distance 11 in the running direction of the metal medium 110 in the magnetic head of the present invention from the magnetic gap 12b to 15b on the output core 12d is different from the distance la in FIG. 7 showing the conventional example. There is a relationship of <11o.

The operation of the magnetic head constructed as described above when mounted on the cylinder of an 8 mm video tape recorder will be described with reference to FIGS. 3(A) to 3(F)e.

Figures 3 (M) to (B) are time-series diagrams showing phenomena on the surface of the magnetic head that occur when the metal medium 11 and the magnetic head come into contact under the following conditions. be.

In this figure, the cylinder is omitted and only the metal-based medium and magnetic head are shown.

3(A), 3(C), and 3(E) are plan views of the magnetic head of the present invention viewed from above the metal medium (in FIG. 3).

(n) and (F) show front views of the magnetic core of the magnetic head seen from the side of the metal-based medium. Also, Figure 3 (
).

11...- The numerical values shown in (B) show an example of the dimension of the magnetic head of the present invention mounted on an 8 mm video J-odeso recorder, and the core width is 0.13M track width. 0.020711N, the total length of the core in the running direction of the metallic medium is 2.0 mm, and the core height is 2.0 mm. QMM
, the contact part 16a of the magnetic throat facing the metal medium 11
In addition, the entrance shoulder portion 16b is finished so that the curvature becomes Elff. The exit shoulder portion 16C has a total core height of 1.3 gates at the exit end 12f (no numerical values regarding curvature are specified), and a total core height of 1.3 gates in the length direction of the core from the exit end 12f. c) A cut-off portion 16ef is provided so that the core height of the 6 ynm portion is 1.5 mm.

(In other words, the boundary portion 15b between the exit shoulder portion 16c and the contact portion 16a
The difference between the exit shoulder portion 16c and the contact portion 16a is 2.
0-1.5 == 0+5M, magnetic gap 12
Distance I from b to 15b dimension! 1tij, 1.0-0.6
= 0.4, which is smaller than the value of the conventional column, 0.5πm. , ) In an 8 mm video tape recorder, the running speed of the metal medium is 14.4 ynm/w, and the rotational speed of the magnetic head is approximately 3.8 m/sty1. The magnetic layer of the metal medium 11 is formed by contacting with the rotating plate 1-7.
Some of it was scraped off from the magnetic head.
1-1 The scraped off part adheres to the contact portion 16a-)H of the magnetic head (in FIGS. 3(A) and 3(B), it is reduced by the attached material 17a), and the magnetic head. With the high-speed rotation of the contact part 16a-L-, the contact part 16a-L- moves in a direction opposite to the direction of rotation 12a of 2 degrees toward the magnetic field (as shown by the moving direction i17b), and comes into contact with it. After the upper part 18a is fully moved, the exit shoulder 16C- provided with the cut-off part 16ei.
[Falls to -. (In Figure 3 (C) and (D), the falling object 1"rb' (?17c
It is shown in ) On the exit shoulder 16C, objects 17a with a gable that have fallen one after another accumulate, and 5.
1- or 1-1 In the magnetic head of this embodiment, the combined object 17d is the cutout part 1.
6e (111) In order to increase the area from the area of the eyebrow part 16e to the area of the contact part 16a, the difference between the two at the border of the exit shoulder part 160 and the contact part 16a, 41sb. 13
・＼ Combined object 17 (1 has to be exceeded. When the magnetic head of this embodiment was run for 1,000 hours in an 8 mm video tape recorder under normal environment F for 1000 hours, the combined object was 1γd does not increase in the area of the contact portion 16a.

As described above, according to the magnetic head of this embodiment, the contact portion having the curvature R1 in the running direction of the metal medium and the extension line of the curvature R1 in the contact portion also By providing the exit shoulder section with a cut-off part arranged to move away from the metal-based medium, the accumulation phenomenon in some of the abutting parts that constitute the magnetic layer of the metal-based medium can be greatly reduced. By reducing the total spacing loss due to the spacing between the magnetic head and the metal-based medium that accompanies accumulation, it is possible to effectively improve the overall smearing, that is, the deterioration in image quality.

Furthermore, by providing the winding groove 14 on the inlet core 12c, the variation in modulation noise is significantly reduced in the second running time compared to the conventional case. In Figure 3 (person), W, , W2 are 0.020° and 0.13, respectively, and in Figure 3 (B), W3 is 0.6° and W4 is 0.
4, W5 is 1.3. W6 is 1.5. W7 phantom 2.0°W8
is 1.0. W9 is 2.0 (to)].

A second embodiment of the present invention will be described below with reference to the drawings.

FIGS. 4(A) and 4(B) show the second embodiment as a /J model. FIG. Figure 4.
Figure (B) shows a front view of the magnetic head seen from the side of the metal-based medium 11. Inlet core 120ii, soft magnetic material 12C1 made of metal and alloy made of Fe-Ag-3i alloy, Go-Nb-Zr-based alpha alloy, and oxide-based material such as Mn-Zn ferrite in the vicinity of the gap. A magnetic material 12C2i is directly connected to each other, and the output core 12d is similarly constructed by directly connecting a soft magnetic material 12d1 made of the metal or alloy and an oxide magnetic material 12d2 such as Mn-Zn ferrite near the gap. has been done.

The exit shoulder 160 is provided with a cutout 16e shown in the first implementation row.

The magnetic head configured as above is 8 mm bi15 ＼
-7 Mounted on the cylinder of a videotape recorder, 100%
When the operation of the surface of the magnetic head facing the metal medium 11 was observed after running for 0 hours, it was found that the combined object 17d grew from the region of the exit shoulder 160 to the region of the contact portion 18a. The same effect as that shown in the first example 1 was confirmed.

FIG. 6 shows a third embodiment ff1J of the present invention. FIG. 5(A) is a plan view of the magnetic head of this embodiment seen from above the metal-based medium 11, and FIG. 5(B) is a front view of the magnetic head seen from the side of the metal-based medium 11. be.

This embodiment is generally the same as the first embodiment already described, but the cutout portion 16e of the exit shoulder portion 160 is
6a and the exit shoulder 16C from the boundary 151) to the exit end 1
A tapered cutout 16a is provided at 2f.

The magnetic head configured as described above also has the first structure. Effects similar to those of the second example have been confirmed.

FIG. 6 shows a fourth embodiment of the invention. FIG. 6(A) is a plan view of the magnetic head of this embodiment seen from above the metal-based medium 11, and FIG. 6(B) is a front view of the magnetic head seen from the side of the metal-based medium 11. It is.

A fourth embodiment of the present invention is generally the same as the first embodiment already described, but has a cutout 16e of the exit shoulder 16c.
is in the vicinity of the exit shoulder 16c of the abutment portion 16a, and the exit shoulder 16 (a cut-off portion 16 where i is cut off) is formed in a reverse tapered shape near the exit shoulder 16c.
ef and H are provided.

The magnetic head configured as described above also has the first structure. 2nd, 3rd
The same effect as the implementation sequence has been confirmed.

In each of the above embodiments, the case where the entrance shoulder 16b has the same curvature R1 as the contact part 16a is shown, but the entrance shoulder 16b has the same cut as the exit shoulder 16c. Even if a droplet is provided, this does not deviate from the spirit of the present invention.

Effects of the Invention As described above, according to the magnetic head of the present invention, the contact portion has a curvature of R1 in the running direction of the metal medium, and 17/, -
7. The magnetic layer of the metal medium is configured by providing an exit shoulder portion with a cutout portion located further away from the metal medium than the extension line of the curvature R1 in the contact portion. The accumulation phenomenon in some of the abutting parts is significantly reduced,
It is possible to significantly improve the spacing loss due to the spacing between the magnetic head and the metal medium that accompanies the accumulation, that is, it is possible to effectively improve the deterioration in image quality.

Furthermore, by providing the winding groove on the inlet core, fluctuations in modulation noise can be reduced even when the magnetic head runs for a long time.

[Brief explanation of drawings]

FIG. 1 is a front view of the magnetic core of a magnetic head according to a first embodiment of the present invention, viewed from the side of a metal medium, and FIG. 2 is a plan view of the magnetic recording medium, viewed from the top side. Figures 3 (A), (C), and (E) are plan views of the magnetic head; Figures 3 (B), (D), and (F) are front views of the same;
4(A) is a plan view of the magnetic head of the second embodiment, FIG. 4(B) is a front view thereof, and FIG. 5(A) is a plan view of the magnetic head of the third embodiment. 5(B) is a front view of the same, and FIG. 6(A) is the 18th... 6(B) is a plan view of the magnetic head of Example 4, FIG. 6(B) is a front view thereof, FIG. 7 is a plan view of a conventional magnetic head, FIG. 8 is a front view thereof, FIG. 9(A), ( C;) , (R:)
, (G) is a plan view of the magnetic head showing the same change over time, and FIGS. 9(B) and (D). Figures 1) and 2) are front views of the same. 11...metallic medium, 11a...travel direction of magnetic recording medium, 12a...61. Rotation direction of the magnetic head, 16a...Abutting portion, 16c...Exit shoulder portion, 16el...Cut portion. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 3
Figure 5 Figure 4 (B) Figure 6 (F3) (E3) Figure 9 7ti 7(,. 7e 7(y

Claims (2)

[Claims] (1) A contact portion having a curvature R_1 in the running direction of the magnetic recording medium, and a cutout portion arranged so as to be farther from the magnetic recording medium than an extension line of the curvature R_1 in the contact portion. A magnetic head characterized by having a protruding shoulder portion. (2) The magnetic head according to claim 1, characterized in that the winding groove of the magnetic head is provided in the entrance core.