JPH04123303A - Magnetic disk device and magnetic head - Google Patents

Abstract

PURPOSE:To increase the number of tracks to record data with a high density by providing plural magnetic cores for optimum core dimensions in respective areas in the radial direction of a magnetic disk. CONSTITUTION:Plural cores 3 to 5 having optimum core dimensions are provided for plural areas No 1 to No 3 in the radial direction of the used magnetic disk. One of the areas No 1 to No 3 of the magnetic disk to which a magnetic head 1 belongs is discriminated, and driving of cores is switched in accordance with the output of this discriminating means. Since each core has optimum core dimensions for each area in the radial direction of the magnetic disk, required recording/reproducing characteristics on the inside of the radial direction are secured, and excess characteristics on the outside in the radial direction are prevented. Thus, the number of tracks is increased, and data is recorded on the magnetic disk with a high precision.

Description

[Detailed Description of the Invention] [Summary] Regarding ferrite magnetic heads used in magnetic disk devices, the present invention aims to increase the number of tracks while ensuring the required recording and reproducing characteristics at the innermost radial portion of the magnetic disk. A magnetic head is constructed with the aim of achieving high disk density, and is characterized by having a plurality of cores each having an optimal core dimension for a plurality of radial regions of the magnetic disk used. do.

[Industrial Application Field] The present invention relates to a magnetic disk device and a magnetic head used therein.

In a magnetic disk device that rotates a magnetic disk, which is a recording medium, at a constant angular velocity, there is a difference in the relative speed of the magnetic disk to the magnetic head depending on the radial position of the magnetic disk, so there is a difference in the characteristics between recordings. arise. If the characteristics of the magnetic head are determined based on the radially innermost area, the characteristics will be excessive in the radially outer C area.
E-recording density is required.

(Prior Art) Fig. 4 is a schematic perspective view of a conventional magnetic head, and Fig. 5 is a plan view of the conventional magnetic head.This magnetic head 10 is attached to a spring arm 11, and is wound around a magnetic core 13. This magnetic head 1 consists of a coil 14 attached to the
0 is a so-called monolithic type, and the magnetic head 1° is made of a ferromagnetic material such as ferrite.

A pair of sliders 15 and 16 are provided on both sides of the magnetic head 10 in the moving direction A of the magnetic disk (not shown), and the magnetic head '10 is moved away from the magnetic disk by the air flow caused by the rotation of the magnetic disk. They are positioned at predetermined intervals.

[Problem to be solved by the invention]

According to the above-mentioned conventional magnetic head F'' 10, since one magnetic head has only one magnetic core 13, when a magnetic disk (not shown) as a recording medium is rotated at a constant angular velocity, There are differences in the recording and reproducing characteristics of the magnetic head depending on the radial position of the magnetic disk. When the characteristics are determined, the characteristics are excessive in the radially outer region.The characteristics of such a conventional magnetic head are shown in Table 1 below.

□□□□□□ Nicore width in one core - 12,0 μm, rotation speed = 360 Orpm Write frequency I F / 2 F = 0.94/3.751'
Number of lHz tracks = 1333 (track width = 15μ
m) As can be understood from Table 1, in the conventional magnetic head 1o using a single magnetic core 13, when the characteristics of the magnetic head are defined with the radially innermost part of the magnetic disk as a reference, the radially outer area This results in excessive characteristics, making it impossible to fully utilize the recording capacity of the magnetic disk, which becomes an obstacle to increasing density. Incidentally, the value of ■2, which represents the output when recording and reproducing at the highest frequency, is approximately twice as large at the outermost point in the radial direction as at the innermost point.

Therefore, the present invention provides a magnetic disk device that can increase the number of tracks and achieve higher density of the magnetic disk while ensuring the required recording and reproducing characteristics on the innermost radial side of the magnetic disk, and a magnetic disk device used therein. The purpose of the present invention is to provide a magnetic head with

[Means to solve the problem]

In order to solve such problems, according to the present invention, as shown in FIG. 1, in a ferrite magnetic head used in a magnetic disk device, multiple regions ( A magnetic head is provided, characterized in that it has a plurality of cores (3, 4, 5) each having an optimal core dimension for a floor L (Nt12, Nα3).

Further, according to the present invention, a plurality of cores (3, 4, 5) each having an optimal core dimension for a plurality of radial regions (Nα1, 2, Nα3) of the magnetic disk used are provided. a magnetic head (1) having a magnetic head (1), and the plurality of areas (distances 1, No., 2, N) for recording or reproduction by the magnetic head (1).

There is provided a magnetic disk drive including means for identifying which of the above 3) the core belongs to, and means for switching the driving of the core in accordance with the output of the identifying means.

[Operation] The area of the magnetic disk (No. 1) to which the magnetic head (1) belongs
, Nα2, Nα3), and the driving of the core is switched according to the eight identification means. Each core has an optimal core dimension for each area in the radial direction of the magnetic disk, ensuring the required recording and playback characteristics in the radially inner area while preventing excessive characteristics in the radially outer area. This makes it possible to increase the number of tracks and increase the density of the magnetic disk.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a plan view of the magnetic disk of the present invention, and FIG. 2 shows three and five sections of the magnetic disk in the radial direction. From the inside in the radial direction to the outside: Area No. 1, Area No. 2.
, an area hα3.

The magnetic head 1 of the present invention includes three magnetic cores 3.4.5,
It consists of a coil 6 wound around each of these magnetic cores 3.4.5. The magnetic core 3.4.5 is made of ferromagnetic material such as ferrite. Furthermore, the present invention also provides metal-in-
It is also applicable to Gintsubu magnetic heads. A pair of sliders 7.8 are provided on both sides of the magnetic head I in the moving direction A of the magnetic disk, and their functions are similar to those of the conventional magnetic head described above.

The magnetic cores 3.4.5 of the embodiment are embedded between a pair of sliders 7.8 parallel to the sliders and spaced apart from each other, each magnetic core 3.4.5 having a different core dimension. In the embodiment, the magnetic core 3 used in the inner region No. 1 of the magnetic disk has the largest core width of 12μ, and the magnetic core 4 used in the middle region M2 has a core width of 10.5μ.
The magnetic core 4 used in outer region No. 2 has a core width of 9.0 μ.

However, the dimensions of each magnetic core 3.4.5 other than the core width, such as the number of turns of the coil 6, the gap length, and the gap depth, are the same. The characteristics of the magnetic head of this embodiment are shown in Table 2 below.

Write frequency I F / 2 F = 0.94/3.75
As can be understood from Table 2, in the magnetic head 1 of the embodiment using a plurality of magnetic cores 3.4.5 with different core dimensions, the required magnetic head 1 in the area Nα1 of the magnetic disk where the magnetic recording condition is the worst It is possible to increase the number of tracks while maintaining recording and reproducing characteristics. In other words, in the conventional magnetic core (core width 12μ), the number of tracks is 1333 (15mm).
μ), but as in the example, the magnetic disk is
The number of tracks can be increased to 155 by dividing the area into two areas and using a magnetic disk with the optimum width for each area.
It was possible to increase the number to 0. That is, in area N01 of the magnetic disk (area with a radius of 23.5 mm to 30.5 mm), a magnetic core 3 with a core width of 12.0 μ is used, and in area N
α2 (area with a radius of 30.5III to 37.5 mm)
Here, magnetic core 4 with a core width of 10.5μ is used, and area No.
, 3 (area with a radius of 37.5+++ m to 43.5 m), a magnetic core 4 with a core width of 9.0 μm is used.

As a result, the number of tracks in area No. 1 is 467 (track width 15μ), the number of tracks in area Nα2 is 538 (track width 13μ), and the number of trunks in area No. 3 is 5.
45 pieces (track width 11μ), a total of 1550 pieces. In addition, in Tables 1 and 2, vzy is the output when recording and reproducing at the highest frequency, Res is the resolution,
0/- is the previous history, and S/Nt is the measured value representing the ratio with the signal.

FIG. 3 is a block diagram of the basic circuit of the magnetic head of the present invention. The amplifiers 1 and 2.3 drive the magnetic core 3 for the area kl, the magnetic core 4 for the area N112, and the magnetic core 5 for the area floor 3, respectively.

Switching signal 1 is a signal that turns ON when the magnetic head moves from, for example, area Nα1 to area Nα2, and turns OFF when the magnetic head moves, for example, from area Nα1 to area Nα2.
It turns ON when moving from to area 3 and turns OFF when vice versa.
This is the signal. Therefore, both reswitching signals 1 and 2 are OF.
At F, the magnetic head is in the area 1, and the amplifier 1 is driven through the select circuit to energize the coil of the magnetic core 3. When switching signal 1 is ON and switching signal 2 is OFF, the magnetic head is in region 8112, driving amplifier 2 and energizing the coil of magnetic core 4. When switching signals 1 and 2 are both ON, the magnetic head is in region 8112. NcL3, which drives the amplifier 3 and energizes the coil of the magnetic core 5. In this way, the magnetic cores to be used are divided according to the radial area of the magnetic disk.

In the above example, the core width was changed as three magnetic cores 3.4.5 having different core dimensions.
The core width may not be changed, or at the same time, other dimensions such as the number of turns of the coil 6, gear, length, gap depth, etc. may be changed in order to produce the optimum recording and reproducing characteristics for each area. It may be configured as follows. In addition, in the example, the radial area of the magnetic disk was divided into three areas,
The magnetic core may be divided into two or three or more parts, and a number of magnetic cores with different core dimensions corresponding to the number of divisions may be attached.

C. Effects of the Invention] As explained above, according to the present invention, a magnetic disk used in one magnetic head has a plurality of magnetic cores with optimal core dimensions for each region in the radial direction. This makes it possible to increase the number of tracks, which greatly contributes to higher density recording.

[Brief explanation of drawings]

FIG. 1 is a plan view of the magnetic disk of the present invention, and FIG. 2 shows three areas in which the magnetic disk is divided in the radial direction.
FIG. 3 is a block diagram showing the basic circuit of the magnetic head of the present invention, FIG. 4 is a schematic perspective view of a conventional magnetic head, and FIG. 5 is a plan view of the conventional magnetic head. 1...Magnetic head 2...Substrate 3.4.5...Magnetic core 6...Coil 7.8...Slider A 8...Slider The magnetic head of the embodiment is also shown in Figure 1 of the magnetic disk. Area classification Figure 2 (Area 1) (Area 2) (Area 3) Block diagram of the embodiment Figure 3.4゜5...Core Conventional magnetic head (perspective view) High 4! a Mo5 Figure 10...Magnetic head 13...Core 11...Arm 14...Coil 15, 16...Slider

Claims (1)

[Claims] 1. In a ferrite magnetic head used in a magnetic disk device, each of a plurality of regions (No. 1, No. 2, No. 3) in the radial direction of the magnetic disk used Multiple cores with optimal core dimensions (
3, 4, 5). 2. The magnetic head according to claim 1, wherein the plurality of cores (3, 4, 5) have different core widths. 3. The plurality of cores (3, 4, 5) each have a core width, a number of turns of the coil (6), a gap length, a gap depth,
The magnetic head according to claim 1, wherein at least some of these are different from each other. 4. Multiple areas in the radial direction of the magnetic disk used (
No. 1.No. 2.No. Multiple cores (3, 4,
5) and a magnetic head (1) having the magnetic head (1).
The plurality of areas (No. 1
, No. 2.No. 3), and means for switching the drive of the core according to the output of the identifying means.