JPH01146115A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To miniaturize a device and to fix the recording face density of a magnetic recording medium by setting the azimuth angle of a core to zero and specifying the center position of rotation of a swing arm actuator and the radius of rotation of the core. CONSTITUTION:The width and the direction of a core gap in each position are indicated by lengths FF' and GG', and a radius EF of rotation of the core as well as the direction of a segment EG and the direction of the core gap form an angle alpha, and the core gap forms an azimuth angle Ax in a position F corresponding to an inner radius Ri of the core gap is zero and th azimuth angle Ax in a position G corresponding to an outer radius Ro is set to Ao, an angle OGB (alpha+Ao) is set to about right angles for the purpose of satisfying alpha 90 deg.-Ao. When the value determined by Ao=cos<-1>(Ri/Ro) is set as the azimuth angle in the position G at this time, the track density is raised according as the core gap goes to the outer side, and the reduction of line density is cancelled.

Description

[Detailed Description of the Invention] [Summary] The present invention relates to a magnetic disk device, and in particular to an access mechanism for a swing (rotary type) arm actuator that keeps the recording surface density of a magnetic recording medium constant. The purpose of the present invention is to provide a magnetic disk device capable of keeping the recording surface density of the magnetic recording medium constant, a magnetic recording medium having an inner diameter Ri and an outer diameter Ro;
In a magnetic disk device comprising a magnetic head and its swing arm actuator, α is an angle between a line connecting the rotation center of the swing arm actuator to the core gap of the magnetic head and the direction of the core gap, When the azimuth angle of the core at the position of the inner diameter Ri of the magnetic recording medium is set to zero, and the azimuth angle of the core at the position of the outer diameter RO is set to Ao, Ao = cos-' (Ri/Ro) and α
The rotation center position of the swing arm actuator and the rotation radius of the core are configured so as to satisfy both equations: =9Q' -AoO.

[Industrial application field]

The present invention relates to a magnetic disk drive, and more particularly to an access mechanism for a swing arm actuator of a magnetic head that keeps the recording surface density of a magnetic recording medium constant.

[Conventional technology]

Magnetic disk drives are required to improve the recording density of magnetic recording media and to be smaller and lighter, and the outer diameter of magnetic disk drives is also being reduced from the conventional 14 inches to 3.5 inches.

On the other hand, in devices that aim to downsize the positioner that positions the magnetic head in the radial direction of the magnetic recording medium, swing (rotary) arm actuators, which are mechanically simple and similar to record players and can be easily stored compactly, are being used. It has become.

FIG. 4 shows a block diagram of main parts of a conventional magnetic disk device and an enlarged view of a floating magnetic head. In this figure, 1 is a magnetic recording medium that rotates in the direction of arrow P. Reference numeral 2 denotes a swing arm actuator, in which a lightweight arm 2° and an actuator 3 are integrally constructed, and the tip of the arm 2° rotates in the direction of arrow Q about a rotation center E.

A slider 4 is held at the tip of the arm 2° via a gimbal spring (not shown). An enlarged view of the back of the slider 4 is shown in the oval frame on the left.

A magnetic head 5 is provided at the end of the slider 4. 6 is the core gap position of the magnetic head 5, arrow S indicates the direction of the extension line of the core gap, and H indicates the core gap dimension. 7 indicates the air bearing surface of the slider 4, and C indicates the rotation radius of the core gap position 6 with respect to the rotation center E.

[Problem that the invention seeks to solve]

As the outer diameter of magnetic recording media has become smaller from 14 inches to 3.5 inches, the ratio of the outer diameter/inner diameter of the area used by the medium has increased from 1.3 to 2, and the recording frequency remains constant. In this case, there is a drawback that the linear density of recording decreases toward the outer layer.

The present invention has been made in view of the above-mentioned conventional drawbacks, and an object of the present invention is to provide a magnetic disk device that can reduce the size of the device and keep the recording surface density of a magnetic recording medium constant.

[Means for solving problems]

FIG. 1 is a diagram showing the principle of the present invention. Inner diameter Ri.

In a magnetic disk device comprising a magnetic recording medium 1 having an outer diameter Ro, a magnetic head, and a swing arm actuator thereof, a line connecting the rotation center of the swing arm actuator to a core gap of the magnetic head, and the core thereof. The angle formed with the gap direction is set to α, the azimuth angle of the core at the position of the inner diameter Ri of the core of the magnetic recording medium is set to zero, and the outer diameter R
When the azimuth angle of the core at the position O is AO, Ao = cos-' (Ri/Ro) and at
The rotation center position of the swing arm actuator and the rotation radius of the core are configured so as to satisfy both equations #90' and Ao.

[For production]

By setting the azimuth angle at the position of the inner diameter (Ri) of the core to zero and satisfying both of the above equations, the azimuth angle increases toward the outer side.

That is, the track density in the radial direction of the magnetic recording medium can be increased. This compensates for the drawback of the linear density, which decreases toward the outer layer.

Furthermore, by satisfying both of the above equations, the radius of rotation of the core becomes the minimum necessary length, and the mass of the movable part can be reduced.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

Note that, in order to make the explanation of the configuration and operation easier to understand, the same parts are given the same reference numerals throughout all the figures, and repeated explanation thereof will be omitted.

In FIG. 1, 1 is a magnetic recording medium, Ri indicates an inner diameter, and Ro indicates an outer diameter. E is the rotation center position of the swing arm actuator, G and F are the inner diameter Ri and outer diameter RO of the core gap of the magnetic head, respectively.
indicates the position corresponding to That is, the lengths EF and EG
is the radius of rotation of the core of the swing arm actuator, and arc FC indicates its rotation locus.

The lengths FF" and CG' indicate the width and direction of the core gap at each position. The angle α is the radius of rotation E of the core.
F and EG are the angles formed between the force direction and the core gap direction, and Ax indicates the azimuth angle formed by the core gap at any position on the arc FC.

As shown in the figure, the azimuth angle Ax at the position F corresponding to the inner diameter Ri of the core gap is set to zero, and the outer diameter Ro
In order to satisfy the following equation, α≒90°−Ao・・・・・・・・・■, using χ as a rib to the azimuth angle at the position G corresponding to All you have to do is arrange it accordingly.

At this time, the following formula, 80=cos-I(R1/Ro) ・ ・ ・ ・
・ ・ ・ ・ ・ If the value determined by
−1(Ri/Rx). That is, by providing an azimuth angle corresponding to the ratio of an arbitrary track radius Rx to an inner diameter Ri, the track density can be increased as the core gap moves toward the outer side. Furthermore, as shown in the figure, the outer track width Wo created by the core width at the outer diameter Ro becomes smaller than the inner track width Wi created by the core width at the inner diameter Ri, corresponding to the change in the azimuth angle Ax, and the track density increases. can be increased to cancel the linear density reduction mentioned above.

Furthermore, in FIG. 2, the distance between the rotation center O of the magnetic recording medium and the rotation center E of the swing arm actuator is a, and the rotation radius of the core is C. Angle A indicates the inner angle between the track radius Ri and the rotation radius C of the core when the core is located at the inner diameter R10F point, and angle A'' indicates the inner angle between the track radius Ro and the core when the core is located at the outer diameter Ro point G point. The interior angle of the rotation radius C is shown.

In triangles OFB and OGE, according to what geometry teaches, a2= (Ri)"+c" -2(Ri) c-cos
A...■a2= (Ro)2+c”-2(Ro)
c-cosA'...■, the values of Ri and Ro are known, A'=90', and the value of A can be found from 2■, so the distance a and The radius of rotation C of the core can be determined by 2 and .

For example, when using a magnetic recording medium with an outer diameter of 3.5 inches, the distance a for determining the rotation center position E of a swing arm actuator with an azimuth angle of 40% when the inner diameter Ri is 20 mm and the outer diameter Ro is 40 mm. And finding the rotation radius C of the core, Ao = 60 degrees, a = 53 open,
c=34.6mm.

If the above dimensions are taken, the areal density will be constant between the inner and outer parts. The conventional recording capacity when using this magnetic recording medium is 1 at the inner F point, Ri/Ro = 0.5 at the outer G point, and (Ri+Ro)/2Ro = (Ri+Ro)/2Ro = 0.5 on the outer G point. It becomes 0.75.

- In the method of Rikiki's invention, the average recording capacity over the entire surface of the medium is 1, which is an increase of 110.75=1.33 times compared to the conventional method. Furthermore, since the arm length is reduced to the minimum necessary dimension, the mass of the movable part of the swing arm actuator can also be reduced. If the azimuth angle and Yaw angle (also called yaw angle, steering angle) of the slider are made equal as before, a Ya-angle of 60° will be required, and if the flying height becomes too low, an offset angle can be set. Decrease in flying height can be reduced.

FIG. 3 shows an explanatory diagram of Yaw angle setting according to an embodiment of the present invention. In the figure, 4° is the slider at position F with inner diameter Ri, angle Yi is the Yaw angle of slider 4° at the same position, 4" is the slider at position G with outer diameter RO, and angle Yo is the slider 4" at the same position. Ya
Shows crocodile angle. For example, if the offset angle is 20°, as shown in the figure, Yaw angle Yi = -20', Ya - angle Yo
This can be solved by dividing it into = 40°.

[Effects of the Invention] - As is clear from the above description, according to the present invention, it is possible to easily achieve a constant areal density, thereby increasing the capacity of a small magnetic disk device, downsizing it, and improving access time. be.

[Brief explanation of the drawing]

Fig. 1 is a diagram of the principle of the present invention, Fig. 2 is a detailed explanatory diagram of the present invention, Fig. 3 is an explanatory diagram for setting the Ya angle in an embodiment of the present invention, and Fig. 4 is a conventional magnetic disk device. A configuration diagram and an enlarged view of the main parts are shown. In Figures 1 and 4, 1 is the magnetic recording medium, 2 is the swing arm actuator, E is the rotation center of the swing arm actuator, 6, F and G are the core gap positions, S is the core gap direction, and Ri is the inner diameter. , Ro is the outer diameter, α is the angle between the line connecting the rotation center E to the core gap position 6 of the magnetic head and the core gap direction S, Ao is the azimuth angle at the position of the outer diameter RO, and C is the core gap direction. The radius of rotation is shown respectively.

Claims (1)

[Scope of Claims] A magnetic disk drive comprising a magnetic recording medium having an inner diameter (Ri) and an outer diameter (Ro), a magnetic head, and a swing arm actuator thereof, comprising: a rotation center of the swing arm actuator; Let the angle between the line connecting the core gap of the magnetic head and the core gap direction be (α), and the azimuth angle of the core at the position of the inner diameter (Ri) of the magnetic recording medium is set to zero, When the azimuth angle of the core at the position of the outer diameter (Ro) is (Ao), Ao = cos^-^1 (Ri/Ro) and α≒90°
A magnetic disk drive characterized in that the rotation center position of the swing arm actuator and the rotation radius of the core are set so as to satisfy both equations: -Ao.