JPS6124006A - Magnetic head - Google Patents

Abstract

PURPOSE:To reduce crosstalk and to prevent magnetic powder from adhering by forming a sheet contact part of a shield plate with a titanium copper group alloy. CONSTITUTION:The 1st and 2nd head chips H1, H2 comprising a main core 1 and a reinforcement core 2 are coupled while clipping the shield plate 3. The main core 1 is provided with a front gap 4 and magnetic poles 1a, 1b opposing togeter with a prescribed interval and formed with a magnetic material having a high permeability such as ''Sendust'' and a high saturated magentic flux density. The sheet contact part 8 of the shield plate 3 is formed with a titanium copper alloy. Since the titanium alloy group material excellent in the shield effect and small in the specific resistance is used at the tip of head having the largest crosstalk, the crosstalk at the tip is decreased remarkably and the magentic body of sheet is not exfoliated and no magnetic property is adhered.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a two-channel μ-inline magnetic head used for electronic camera equipment.

(b) Prior Art Various forms of two-channel in-line magnetic heads are described in Japanese Patent Publication No. 55-2647, but none of them are considered suitable for electronic camera devices. I lack an example of the size of the core, but from its configuration,
In other words, since the tape contacting surface is composed of two cores and a non-magnetic material sandwiched between them K, which gives it wear resistance, it is recognized as a large tape suitable for audio applications. This is because it will be done.

Referring to FIG. 8, the magnetic head for an electronic camera device to which the present invention is directed has a track width (5) of approximately 60 μm;
Track pitch (B) is 100 μm, two heads (h
Since the head is extremely small and the interval (C) between hl) (hl) is specified as 40 pm, and the two heads are very close to each other, crosstalk becomes a major problem. Incidentally, in audio devices, the head spacing (C) is as wide as several hundreds of micrometers, so a sufficient amount of crosstalk prevention material can be packed between the heads, so crosstalk rarely becomes an issue. Also in the magnetic head to which the present invention is applied, attempts have been made to insert a shielding material into the space between the cores in order to reduce crosstalk or interference between the two heads. However, in electronic camera devices, the relative speed between the sheet and the head is as high as 5 to 7.5 rrVs, so with many metal shielding materials, adhesion occurs between the material and the magnetic surface, causing the magnetic surface of the sheet to peel off. Otherwise, a phenomenon in which magnetic powder adheres to the tip of the head occurs, so it is necessary to use a sliding material such as glass or ceramic at least for the sliding portion. On the other hand, the leakage between the heads is mostly distributed from the sheet contacting part to the depth part, centering around the head gap where the magnetic resistance of the herad core is highest, so the sheet sliding part is made of a material that does not have a shielding effect, such as glass or ceramic. This was inconvenient from the point of view of reducing crosstalk.

(c) Thinning point to be solved by the invention Therefore, the present invention solves the problems of crosstalk and adhesion of magnetic powder in a magnetic head for an electronic camera device in which the distance between two heads is small.

2) Means for solving the problem: At least the sheet abutting portion of the shield plate is formed of a titanium-copper alloy.

(E) Function Titanium-copper alloys rarely peel off the magnetic surface of the sheet and do not attract magnetic powder. It also has sufficient shielding effect.

(F) Embodiment In FIGS. 1 and 2, (Hl) and (H2) are the first and second head chips consisting of a main core (1) and a reinforcing core (2), respectively, and V-, A/ They are combined by sandwiching the do board (3). The main core 111Fi includes a front gap (4) and magnetic pole parts (la) and (lb) facing each other at a constant interval, and is made of a magnetic material having high permeability and high saturation magnetic flux density, such as sendust. The reinforcing core (2) includes a U-shaped magnetic body part (5) made of an oxide magnetic material, and a non-magnetic body disposed above the magnetic body part and configured to close the opening of the magnetic body part (6). It has a magnetic body part (6) and a coil 1v in the center.
(r)) is provided with a through hole (7) for winding it. The seat contact part (8) of the shield plate (3) is made of titanium copper alloy, and the other parts! 91tj: Made of silver. As will be described later, the other portions may be made of +91 Fi copper or may be an alloy of silver and copper.

FIG. 3 shows that a contact portion (8) made of titanium copper exists over a range from the tip to the depth end (lO) of the head gap. Figure 1~
Apart from FIG. 3, the contact portion (8) made of titanium-copper alloy may be limited in length to directly contact the sheet as shown in FIG. 1. Furthermore, unlike these, there is a shield plate (3)
may be made entirely of titanium-copper alloy. The titanium-copper alloy has a micro-Vickers hardness of 200 or more, as shown in Figure 5, and not only exhibits good workability, but also has an electrical resistivity of 15 x 10" or less of 7 m, which is S4. .

Furthermore, the inventors have confirmed that since the titanium steel alloy is precipitation hardenable, high-speed sliding of the sheet causes the adhesion of magnetic powder. FIG. 5 shows part of the results of an experiment conducted by the inventor to determine whether magnetic powder adheres to the metal surface when a magnetic sheet is slid at high speed on various metal materials. The test results show that the titanium-copper alloy material hardly attracts magnetic powder.

Furthermore, FIG. 6 shows the crosstalk radius of the head and the specific resistance of the shield material when shielded with various materials. From the practical review of crosstalk, it is at least 125.
dB or less, and from that point of view, the specific resistance of the shielding material must be at least 15 x 10"7m or less.

From Figure 5, the specific resistance of titanium copper alloy is 11.2X1o.
8'/m, which satisfies this condition. From the above, titanium-copper alloy is a material that has both sliding properties and shielding properties. Therefore, not only the shielding properties at the contact portion (8) but also the desired shielding properties can be obtained even if the other portions (9) K are used. Therefore, the entire shield plate (3) may be made of titanium-copper alloy. When using a titanium steel alloy for the contact part (8) and using another material for the other parts (9), select a material with lower specific resistance, such as silver, copper, or an alloy thereof. be able to. It is clear that these materials have a specific resistance of 2 x 10' rAn or less and have an excellent shielding effect. 7th
In the figure, (a) the contact part (8) is a conventional example using K glass material, (b) is the case where the entire shield plate is made of titanium alloy, and (c) only the Fi contact part (8) is used. This shows the frequency band crosstalk characteristics when made of titanium alloy.

As a preferred embodiment of the present invention, a titanium copper EH material is aged at about 390°C for 1 hour and 30 minutes, and the resistivity is 11.
．． A material with a Vickers hardness of 390, approximately 35 μm from the sheet contact surface to the head depth, and a silver shield material with a K specific resistance of 1.6XIO-8°/m were used for the other parts (9). We created a head with a crosstalk of -35dB.

(G) Effects of the Invention According to the present invention, since the excellent titanium alloy material with low resistivity is used at the tip of the head where crosstalk is greatest, crosstalk at the tip is drastically reduced and the sheet This has the effect of preventing magnetic material from peeling off or adhering to the magnetic material. It also has the effect of being hard to wear due to its high hardness. Therefore, it is extremely effective as a rad for an electronic camera device in which two channel μ-heads are located close to each other.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a magnetic head embodying the present invention, Fig. 2 is an exploded perspective view thereof, Fig. 3 is an explanatory diagram of the main part, Fig. 4 is a perspective view of the main part of another embodiment, and Fig. 5 Figures 6 and 7 are explanatory diagrams of the magnetic head of the present invention. FIG. 8 is a diagram for explaining the standard of the magnetic head to which the present invention is applied. (Hl)...First head chip, (H2)...Second head chip, (3)...Number board, (8)...
・Abutting part, (9)...Other parts.

Claims (2)

[Claims] (1) In a magnetic head for an electronic camera device comprising separate head chips for two channels and a shield plate interposed between the head chips, at least the sheet contacting portion of the shield plate is formed of a titanium alloy. A magnetic head characterized by: (2) Other parts of the shield plate are made of silver, copper, or an alloy thereof.
The magnetic head described in Section 1.