Dynamic magnetic information storage or retrieval – Fluid bearing head support – Disk record
Reexamination Certificate
2002-01-07
2004-08-31
Tupper, Robert S. (Department: 2652)
Dynamic magnetic information storage or retrieval
Fluid bearing head support
Disk record
C360S235600, C360S235800, C360S236000, C360S236200
Reexamination Certificate
active
06785093
ABSTRACT:
This application claims the priority benefit of Japanese Patent Application No. 2001-001966, filed on Jan. 9, 2001, and entitled “Slider, Head Assembly, and Disk drive Unit.”
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to a slider provided with a head for reading/writing data from/on a magnetic disk, more particularly to a technique that can reduce deposition of particles on the slider.
2. Description of the Related Art
A hard disk drive (HDD), which is the most popular recording means of computers, is structured so as to drive a single or a plurality of magnetic disks disposed at the same rotation axis with use of a spindle motor. A head disposed so as to face a magnetic disk is used to read/write data on/from the magnetic disk. This head is driven by an actuator, generally referred to as a voice coil motor (hereafter, to be described as the VCM). The magnetic disk, the head, and the actuator are all housed in an enclosure referred to as a disk enclosure. Such a disk enclosure is configured by a thin box like base, for example, an aluminum alloy base and a top cover for sealing the opening of the base.
Some of such heads used to read/write data have a transducer for writing data and magnetizing means for reading data separately. The magnetizing means for reading is realized actually by, for example, the magneto resistive (MR) effect or the giant magneto resistive (GMR) effect. The magnetizing means for reading, which employs the MR or GMR, is affected less by noise, thereby it can improve the recording density of disks. A head is disposed at a predetermined position of a member referred to as a slider. A slider includes a head sometimes. Sometimes the slider means the head simply. Concretely, sometimes the head and the slider are recognized to be equivalent to each other.
When such a head reads/writes data from/on a magnetic disk, the head (slider) flies above the magnetic disk at a predetermined height. This flight of the head above the magnetic disk is caused by the air bearing induced on the magnetic disk by the rotation of the magnetic disk. This is why the surface of the slider, which faces the magnetic disk, is referred to as an air bearing surface (hereinafter, to be described as the ABS). The property of this ABS affects the flight of the slider significantly.
The flying height of the slider from the magnetic disk should therefore be as low as possible when much consideration is given to reading/writing of data. This is because the mutual magnetic action between the magnetic disk and the head must be secured enough. Consequently, a slider that flies low should be employed for higher density magnetic recording. An excessively low flying height will cause the head to come in contact with fine projections formed on the surface of the magnetic disk, however. It is therefore indispensably important to smooth the surface of the magnetic disk so as to realize high density magnetic recording.
There is a conventional disk drive unit in which the slider is enabled to rest in a retreat area formed on a magnetic disk while the magnetic disk does not rotate and the slider flies from the retreat area when the magnetic disk begins rotating so as move (seek) to a data recorded area of the magnetic disk. This disk drive unit is referred to as a contact start and stop (CSS) type disk drive unit. On the contrary, there is also a loading/unloading type disk drive unit in which the slider is retreated to a ramp formed outside a magnetic disk while the magnetic disk does not rotate.
3. Problems to be Solved by the Invention
The main technical issues of the HDD are improvement of the recording capacity per magnetic disk and faster reading/writing data from/on the magnetic disk. Faster reading/writing data from a magnetic disk can be realized by reducing the seek time with which the magnetic head moves to a target track on the magnetic disk. Because the head is driven by a VCM as described above, the VCM performance is improved so as to improve the seek time. And, in order to improve the VCM, it is just required to employ a permanent magnet of the VCM, having a stronger magnetic property or increasing the thickness of the permanent magnet so as to increase the magnetic field to be applied to the voice coil of the VCM.
Reading/writing of data can also be made faster by increasing the rotation speed of the magnetic disk. In this case, however, faster rotation of the magnetic disk causes particles to hit the slider (head) more often when the number of particles in the subject HDD is the same as that when the rotation of the magnetic disk is slow. Particles mean powder existing in the HDD. Collision of those particles against the surface of the magnetic disk often causes hardware errors, that is errors in reading/writing of data, resulting in a loss of reliability in the HDD. On the other hand, because the flying height of the slider (head) from the magnetic disk has been required to be reduced so as to cope with the higher capacities of magnetic disks, the peril of collision of even fine particles that have been neglected against the slider (head) has also risen more and more.
Under such circumstances, it is an object of the present invention to provide a slider and a disk drive unit that can reduce read/write errors caused by particles, as well as assure reliability.
SUMMARY OF THE INVENTION
In order to achieve the above object, the present inventor observed actions of particles against a slider. As a result, the inventor recognized that the number of read/write errors was varied among the shapes of the ABS on a kind of a slider and there occurred a difference among the particles deposition states according to the ABS shape. Concretely, when the number of deposited particles is reduced, it is also possible to reduce the number of data read/write errors.
More concretely, the present invention provides a slider disposed so as to face a disk-like recording medium and enabled to support a head for reading/writing data from/on the disk. The slider comprises a slider body provided with an air leading edge, an air trailing edge, and an air bearing surface formed between the leading edge and the trailing edge; a rail formed almost like a U-letter on the air bearing surface so that its tip is disposed at the trailing edge side; and a pair of landing pads formed between the tip of the rail and the trailing edge. One of the pair of landing pads is curved convexly at its side facing the rail of the landing pad which is disposed at the outer periphery side of the disk-like recording medium while the slider is disposed so as to face the medium.
The slider of the present invention has the landing pads. And, the present inventor et al recognized through the examinations as described above that particles were apt to deposit at one side of a landing pad, which faces the rail. Especially, particles are apt to deposit on one of the pair of landing pads, which is disposed at the outer periphery side of the disk-like recording medium while the slider is disposed so as to face the medium. Thus, the inventor et al changed the shape of the landing pad and knew that the amount of deposited particles was varied among the shapes of the landing pad. Concretely, when the side of a landing pad, which faces the rail, is curved convexly, the deposition of particles can be reduced. This is why the slider of the present invention has been proposed. In the case of the present invention, the leading edge is disposed at the upstream of the trailing edge in the rotational direction of the disk-like recording medium.
Each landing pad of the slider of the present invention can be curved convexly in the center of the width direction. As to be described later, this is because deposition of particles on the landing pad can be reduced more significantly when the center portion in the width direction is curved convexly such way.
Furthermore, in the case of the slider of the present invention, a pad for applying a positive pressure to the slider can be formed on the rail, at the leading edge side, and betw
Baba Sachiyo
Kanamaru Masayuki
Kawamoto Yasunori
Ohta Shunichiroh
Bracewell & Patterson L.L.P.
Hitachi Global Storage Technologies, Inc. Netherlands B.V
Martin Robert B.
Tupper Robert S.
LandOfFree
Slider, head assembly, and disk drive unit does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Slider, head assembly, and disk drive unit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Slider, head assembly, and disk drive unit will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3343416