JPS5924210A - Magnetic head - Google Patents

Abstract

PURPOSE:To obtain a surface-opposed type magnetic head with a unique and newal construction which can minimize the clearance between a magnetographic medium and a head as much as possible by arranging a lead section of a magnetosensitive element outside the area where the magnetosensitive element faces a magnetic lattice to reduce the interval between detection surfaces of the both as much as possible. CONSTITUTION:A magnetic head H comprises a magnetosensitive element 1, a chip carrier 2 carrying elements, a holder 3 for supporting the chip carrier in a recess 3', a lead 5 of the element, a terminal 9 connected to the lead, a bias magnet 8 mounted on the back of the holder 3 and the like, the magnetosensitive element 1 arranged to face in surface a magnetic lattice 4 of a magnetic drum M. A lead section, for example, wire bonded section is arranged outside the area where the magnetosensitive element 1 faces the magnetic lattice 4 and resin molded 7 as required. This can set the interval between detection surfaces of the magnetic lattice 4 and the magnetosensitive element 1 as small as possible thereby reducing the clearance. A protective cover 6 covers the surface facing the magnetic lattice 4 except for the lead section 5 in the detection surface of the magnetosensitive element 1 and is fixed on the holder 3.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to magnetic heads, and particularly to improvements in thin film magnetic heads that utilize a surface-facing detection method for magnetic recording media.

BACKGROUND TECHNOLOGY AND PROBLEMS A surface-encapsulated thin-film magnetic head composed of a ferromagnetic metal magnetoresistive thin-film element is arranged with its magnetic detection surface facing the recording surface of a magnetic recording medium, for example, a magnetic grating of a magnetic scale. There is. In this case, if the magnetic recording medium (the pitch of the magnetic grating) is increased, the clearance between the head and the recording surface must be reduced, and the magnetic detection surface of the magnetically sensitive element must be protected, and the lead wires from the element must be treated. Alternatively, special measures will be required for the arrangement structure for the magnetic recording medium.

For example, in a conventional head structure, the lead wire that electrically connects the magnetic sensing element and the chimp carrier holding the element is usually at a height above the sensing surface of the element, so the magnetic sensing surface of the element is placed on the magnetic lattice surface. When arranged facing each other, the distance between the detection surfaces (clearance) depends on the height of the lead wire, and cannot be made lower than the height of the lead wire, so there is a limit to reducing the clearance.

The magnetically sensitive element used in a thin film magnetic head consists of a ferromagnetic thin film placed on a substrate (chip carrier) and an electrically insulating film formed on the surface of the ferromagnetic thin film. Therefore, it is susceptible to friction or contact, and when abrasion or scratches occur, the resistance value changes easily and the function and performance as a thin film magnetic head is lost. Therefore, a surface-to-surface structure is used to reduce the clearance. needs to be given due consideration.

OBJECTS OF THE INVENTION The purpose of the present invention is to solve the problems of the prior art by using a thin film magnetic head. An object of the present invention is to provide a surface-facing magnetic head having a unique and novel structure that can minimize the clearance between a magnetic recording medium and the head and is suitable for magnetic scales, magnetic drums, and the like.

SUMMARY OF THE INVENTION In order to achieve this object, the present invention arranges the lead wire portion of the magnetic sensing element outside the area facing the magnetic grating, thereby making the distance between the sensing surfaces (clearance) between the two as narrow as possible. It is characterized by

EXAMPLES The present invention will be described below with reference to examples shown in the drawings.
In FIGS. 1(a), 1(b), and 1(C), M is a ring-shaped magnetic drum, and H is a surface-facing thin film magnetic head.

The magnetic head H includes a magnetic sensing element 1, a chip carrier 2 on which the element is placed, a holder 3 supported in a recess 3 of the chip carrier, a lead wire 5 of the element, a terminal 9 connected to the lead wire, and It consists of a bias magnet 8 and the like attached to the back side of the holder 3, and the magnetic sensing element 1 is arranged so as to face the magnetic grating 4 of the magnetic drum M.

Now, as mentioned above, the height of the lead wire part, for example, the wire bonding part, above the detection surface of the magnetically sensitive element 1 is an important problem in terms of clearance reduction. The magnetic sensing element 10 is disposed outside the area facing the magnetic sensing element 4, and a resin mold 7 is applied thereto as required.

If the distance is 5 km, the distance between the detection surfaces between the magnetic grating 4 and the magnetic sensing element 1 can be set as narrow as possible, and the clearance will be reduced.

Next, as mentioned above, in a surface-facing magnetic head structure, the ferromagnetic thin film that constitutes the magnetic sensing element is easily damaged, so the sensing surface of the magnetic sensing element must be protected and the required sensing surface spacing must be maintained. For example, a protective cover 6 with high workability as shown in the figure is provided.

This protective cover 6 covers the lead wire portion 5 on the detection surface of the magnetic sensing element 1.
Covering the same group opposite to the magnetic grid 4 except for the holder 3
Fixed to.

FIG. 2 shows the main parts of another embodiment of the invention.

In the same figure, the magnetic sensing element 1 is installed in the holder recess 3' so that its detection surface protrudes by a slight height Δh with respect to both sides 3A and 3BK of the holder, and the protective cover 6 is placed on the detection surface. With this structure, there is no gap between the protective cover 6 and the detection surface of the magnetically sensitive element 1, and therefore the distance between the detection surface and the magnetic grating 4 can be effectively further narrowed. I can do it.

FIG. 3 shows the main parts of yet another embodiment of the invention. In the figure, the protective cover 6 is attached to both end faces of the holder 3 with an adhesive 10 so that the thickness of the adhesive 10 does not interfere with the reduction of the distance between the detection surfaces.

FIGS. 4 and 5 respectively show the main parts of still other embodiments of the present invention. In these embodiments, in order to prevent the surface of the protective cover 6 from coming into direct contact with the recording surface of the magnetic grating 4, magnetic grating contact parts 3A and 3B are provided on both fJJfi parts 3A and 3B of the holder 3. It is something.

For example, as shown in FIG. 4, a contact portion 3A between the recording surface of the magnetic grating 4 of the magnetic scale M and the holder 3.

3B are in contact with each other, and this contact portion functions as a guide for maintaining a constant distance between the detection surface of the magnetic sensing element 1 and the magnetic lattice surface. Further, the protective cover 6 is attached with an adhesive or a molding agent 1], and as shown in the figure, it has a certain gap from the magnetic lattice surface and does not come into direct contact with it.

FIG. 5 shows the case of a rotary encoder, a rotational speed detector, etc., and the contact portions 3A' and 3B are tapered inward so as to come into contact with the surface of the rotary magnetic grating 4.

FIG. 6 shows a specific example of a rotational speed detector (magnetic rotary encoder) equipped with a thin film magnetic head according to the present invention. In the figure, the rotary magnetic grating 4 is located at the flange F of the rotor R.
The above-mentioned thin film magnetic head M is fixed to the
is provided.

In this case, the clearance between the magnetic detection surface of the thin film magnetic head and the recording surface of the magnetic grating is set to 0.1 to 0.2101, for example, assuming that the scale pitch of the magnetic grating is 0.6 van.

As described in detail, according to the present invention, the clearance between the magnetic grating and the magnetically sensitive element can be significantly reduced, making it possible to increase the recording density of the magnetic grating, and also to protect the magnetically sensitive element. Not only is this reliable and easy, but the clearance can be maintained constant, resulting in stable output.

[Brief explanation of the drawing]

FIG. 1(a) is a schematic diagram showing an embodiment of the present invention, FIG. 1(b) is a cross-sectional view taken along line A-A, and FIG. 1(C) is a schematic diagram showing an embodiment of the present invention.
The B-line arrow view and FIGS. 2 to 5 are schematic diagrams showing the main parts of other embodiments of the present invention, respectively, and FIG. 6 shows the configuration of an example of an integrated body in which the present invention is applied to a rotational speed detector. This is a partially cutaway view. M...Magnetic scale, H...Magnetic head, 1...
Magnetic sensing element, 3... Holder, 4... Magnetic grating, 5...
...Lead wire, 6...Protective cover. Patent Applicant Sony Magnescale Co., Ltd. Agent Patent Attorney Eiji 1) Takeshi 3rd Part Procedural Amendment (
, 5. November 1980, 1982 Patent Application No. 134438 2 Name of the invention Magnetic head 3 Relationship to the case of the person making the amendment Patent applicant address name Sony Magnescale Co., Ltd. 4th agent 〒10
5 Address: Shiba 3-chome Building, 3-2-14 Shiba, Minato-ku, Tokyo October 26, 1982 (shipment date) 6 Subject of amendment (1) Document certifying authority of agency and (2) Invention in the description Column 7 for detailed explanation of wJ Positive contents (υ As shown in the attached document (2) Page 2, line 1 O of the specification of the present application is “Increasing the recording density of the body (shortening the pitch of the magnetic lattice), the head 2-

Claims (4)

[Claims] (1) The detection surface of the magnetically sensitive element and the recording surface of the magnetic recording medium are arranged to face each other, and the lead wire portion of the magnetically sensitive element is arranged outside the area facing the magnetic recording medium. Features a magnetic head. (2) I! that a protective cover was provided to cover the detection surface of the magnetically sensitive element! ! A magnetic head according to claim 1, wherein the magnetic head has a magnetic head having a magnetic field. (3) The magnetic head according to claim 2, wherein the magnetically sensitive element and the protective cover are arranged on a holder, and the magnetically sensitive element surface protrudes from the protective cover mounting surface of the holder. . (4) The magnetic head according to claim 2, wherein the magnetic sensing element and the protective cover are arranged in a holder, and the holder is provided with a contact portion that contacts the magnetic recording medium.