JPS62175902A - Magnetic recording method - Google Patents

Abstract

PURPOSE:To decrease the recording demagnetization, and to improve the recording efficiency to a vertical magnetic recording medium by making the vertical magnetic recording medium contact a gap part, moving the relative moving direction of a ring type magnetic head and the vertical magnetic recording medium so that a magnetic thin film of the ring type magnetic head becomes a leading edge side, and executing the recording. CONSTITUTION:As for a ring type magnetic head H, a magnetic thin film 5 whose saturation magnetization is larger than that of a winding magnetic material 4 and a thin film magnetic material 4' is formed between the thin film magnetic material 4' and a nonmagnetic layer 6. When a vertical magnetic recording medium 1 executes a relative movement, with respect to the ring type magnetic head H in the direction as indicated with an arrow 8, the magnetic thin film 5 becomes a leading edge side. As for the ring type magnetic head H, a large vertical magnetic field is generated in the vicinity of the magnetic thin film 5, and also an inclination in the medium running direction of its magnetic field strength becomes sharp. In this way, to the vertical magnetic recording medium 1, recording can be executed better than a conventional ring type magnetic head, and also, when the relative moving direction is set to the direction as indicated with the arrow 8, the recording demagnetization decreases, comparing with the reverse case, and a large residual magnetization is left in the vertical magnetic recording medium.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic recording method that provides a large short wavelength reproduction output.

BACKGROUND OF THE INVENTION Perpendicular magnetic recording is attracting attention as a magnetic recording system with poor short wavelength recording characteristics. This method requires a magnetic layer with perpendicular magnetic anisotropy. When a signal is recorded in such a magnetic layer, the residual magnetization is oriented in a direction substantially perpendicular to the film surface. Therefore, as the wavelength of the signal becomes shorter, the demagnetizing field within the medium decreases, and a larger reproduction output can be obtained. A perpendicular magnetic recording medium has a magnetic layer on a substrate made of Co-0r, Go-V, C
A perpendicular magnetic anisotropic film such as o-Ru or Co-Or-Rh is formed by sputtering or vacuum evaporation.

As a magnetic head for recording signals on a perpendicular magnetic recording medium, a ring-type magnetic head that has been in practical use or a known single-pole perpendicular magnetic head has been considered. Ring-type magnetic heads have a weak perpendicular magnetic field component, making it difficult to record signals on perpendicular magnetic recording media, whereas single-pole perpendicular magnetic heads have a weak perpendicular magnetic field component, which makes it difficult to record signals on perpendicular magnetic recording media. and excellent recording characteristics can be obtained.

Problems to be Solved by the Invention As mentioned above, if a single-pole perpendicular magnetic head is used,
Nearly ideal recording is performed on the perpendicular magnetic recording medium. However, this single-pole type perpendicular magnetic head generally has a problem in that the reproduction efficiency is low and the reproduction output is quite small. Furthermore, when a ring-type magnetic head is used, although the reproduction efficiency is high, satisfactory recording on a perpendicular magnetic recording medium is difficult, and the reproduction output is low, which is still insufficient for practical use.

Means for Solving the Problems The present invention provides a ring-shaped magnetic head in which a pair of magnetic bodies is arranged in a gap section through a magnetic thin film and a non-magnetic layer having a higher saturation magnetization than the magnetic bodies, A perpendicular magnetic recording medium is brought into contact with the perpendicular magnetic recording medium, and recording is performed by moving the relative movement direction of the ring-shaped magnetic head and the perpendicular magnetic recording medium so that the magnetic thin film of the ring-shaped magnetic head is on the leading edge side.

Operation The ring-type magnetic head of the present invention in which the magnetic thin film with high saturation magnetization is formed on one side of the gap generates a stronger perpendicular magnetic field than the conventional ring-type magnetic head. Furthermore, if the direction of relative movement between the perpendicular magnetic recording medium and the ring-shaped magnetic head is set so that the magnetic thin film on the gap surface of the ring-shaped magnetic head is on the leading edge side, recording demagnetization is reduced, and the perpendicular magnetic recording medium recording efficiency increases.

The embodiment diagram shows a schematic diagram of recording signals on a perpendicular magnetic recording medium using the ring-type magnetic head of the present invention.

In the figure, (1) is a perpendicular magnetic recording medium, (2) is a substrate, (3) is a perpendicular magnetic anisotropic film, H is a ring-shaped magnetic head of the present invention, and (4) is a winding through which a signal current flows. (4s is a magnetic material provided with a magnetic thin film (hereinafter referred to as thin film magnetic material), (5) is a magnetic thin film, (6) is a non-magnetic layer, (7) indicates a winding through which a signal current flows.

In the perpendicular magnetic recording medium (11), a perpendicular magnetic anisotropic film (3) is formed on a substrate (2) made of a polymer material or the like.The perpendicular magnetic anisotropic film (3) is generally 0o- (1
! r film is used, and there are T1, 0, 0. There may also be a nonmagnetic layer such as, or a soft magnetic film such as permalloy. Basically, the magnetic head is similar to a general ring-type magnetic head, consisting of a pair of windings f; layer (6
) are facing each other. The ring-type magnetic head H of the present invention comprises a thin film magnetic material (4)' and a non-magnetic layer (6).
), a magnetic thin film (5) having a larger saturation magnetization than the winding magnetic material (4) and the thin film magnetic material 4)' is formed.

The arrow (8) in the figure indicates the direction of relative movement of the perpendicular magnetic recording medium (1) with respect to the ring-shaped magnetic head H of the present invention.

In the ring-shaped magnetic head H, the vicinity of the gap of the ring-shaped magnetic head core on the side into which the magnetic recording medium (+) enters is called the leading edge, and the opposite side is called the trailing edge. When the perpendicular magnetic recording medium (1) moves relative to the ring-shaped magnetic head H in the direction of the arrow (8) as shown in the figure, the magnetic thin film (5) is on the leading edge side, and the relative movement When the direction is opposite to the arrow (8), the magnetic thin film (5) is on the trailing edge side.

Next, the recording and reproducing characteristics of the perpendicular magnetic recording medium recorded by the magnetic recording method of the present invention will be explained.

A polyimide film with a thickness of 10 μm is used as a substrate, and a T1 film with a thickness of 30 OA is deposited on this by vacuum evaporation method.
Further, on top of this, a film of 2200A thick was formed by vacuum evaporation.
Recording and reproduction were performed on a perpendicular magnetic recording medium on which a 00o-Or film was formed using a ring-type magnetic head H having the structure shown in the figure and a conventional ring-type magnetic head. The T1 film mentioned above is used to increase the perpendicular magnetic anisotropy of the 800o-20Or film thereon. Also, 800
The saturation magnetization of the o-20Or film is 400 emu/cc,
The holding force in the direction perpendicular to the membrane surface is 700τe. Furthermore, as a conventional ring-type magnetic head, the gap length is 0.14 p.
A material made of Mn-Zn ferrite was used.

The ring-shaped magnetic head H in the figure is made of wire-wound magnetic material (4).
, the thin film magnetic material 41' is made of Mn-Zn ferrite, which is the same as the conventional one, and the magnetic thin film (5) is made of Oo-N with a film thickness of 3/J77L.
The nonmagnetic layer (6) was made of an amorphous material made of b-Zr, and the thickness of the nonmagnetic layer (6), that is, the gap length was 0.14 μm. Each magnetic head has a gap width of 30 μm, a gap depth of 10 μm, and a coil winding number of 16 turns. The table shows the reproduction output when recording and reproduction were performed with these magnetic heads.

The recording density of the front signal is 150K FRP. here 15
0 KFRPI is a digital signal recording state in which magnetization reversals occur 150,000 times per inch. Furthermore, the reproduction output value when recording and reproduction is performed using a conventional ring-type magnetic head is OdB.

Ring-type magnetic head H having the structure shown in the table and figure
It can be seen that if the relative movement direction is in the direction of arrow (8) in the figure, a reproduction output 8 (LB) higher than that of the conventional ring type magnetic head can be obtained.Also, if the relative movement direction is in the direction of arrow (8) in the figure In the opposite direction, the output is 3 dB lower than in the direction of arrow (8).

The above experimental results can be interpreted as follows.

In contrast to the conventional ring-type magnetic head, the ring-type magnetic head H of the present invention as shown in the figure generates a large perpendicular magnetic field in the vicinity of the magnetic thin film (7, 1), and the magnetic field strength is The slope becomes steeper.

As a result, it is possible to record better on a perpendicular magnetic recording medium (11) than with a conventional ring-type magnetic head.Furthermore, when the relative movement direction is in the direction of arrow (8) in the figure, recording demagnetization is less than in the opposite case. Therefore, it is considered that a large residual magnetization remains in the perpendicular magnetic recording medium.

Although the playback output in the above table is expressed as a relative value, the absolute playback output when the relative movement direction is in the direction of arrow (8) in the figure with a ring-type magnetic head H having the structure shown in the figure is expressed as a relative value. The value is 380 μV/turn/nL/sec. This value far exceeds the reproduction output of conventionally reported perpendicular magnetic recording media. Note that 380 μV/turn/m7 seconds means that the number of coil turns is 1 turn and the gap width is 11111. This means that the head output per rn/sec relative velocity between the media and the Rad is 380 μV.

Effects of the Invention According to the magnetic recording method of the present invention, a large short wavelength reproduction output can be obtained in the short wavelength region.

[Brief explanation of drawings]

The figure shows a layout of essential parts for recording signals on a perpendicular magnetic recording medium using the ring-type magnetic head of the present invention. 1: Perpendicular magnetic recording medium 2: Substrate 3: Perpendicular magnetic anisotropic film 4.4': Wire-wound magnetic material and thin film magnetic material constituting the head core 5: Magnetic thin film 6: Non-magnetic layer Patent applicant Matsushita Electric Industrial Co., Ltd. Company representative patent attorney
Koki Abe 1 Figure 2 Figure 3 Procedures Amendment (Method) % formula % 2 Name of invention Magnetic recording method 3 Relationship to the person making the amendment Case Address of patent applicant Kadoma, Osaka 571 Address: 1.006 Kadoma, Ichi-Oaza Address: 3-12-11 Minamimachi, Kokubunji-shi, Tokyo 185 January 7, 1988 (Delivery date: January 27, 1988) 6
, Contents of the amendment, page 9, line 4 of the amendment 4. Brief explanation of the drawing ``The drawing is...
・・・・・・・・・ is shown. '', ``Figure 1 is a layout of main parts for recording signals on a perpendicular magnetic recording medium using the ring-type magnetic head of the present invention, Figure 2 is a sectional view of the medium of the present invention, and Figure 3 is a conventional "A cross-sectional view of a perpendicular magnetic recording medium."

Claims (1)

[Claims] A ring-shaped magnetic head is provided in which a pair of magnetic bodies are opposed to each other via a magnetic thin film and a non-magnetic layer having saturation magnetization larger than that of the magnetic bodies to form a gap, a perpendicular magnetic recording medium is brought into contact with the gap, and the ring A magnetic recording medium, characterized in that the direction of relative movement between the ring-shaped magnetic head and the perpendicular magnetic recording medium is such that the magnetic thin film of the ring-shaped magnetic head is on the leading edge side for recording.