Dynamic magnetic information storage or retrieval – Automatic control of a recorder mechanism – Controlling the head
Reexamination Certificate
1998-11-09
2001-08-21
Hudspeth, David (Department: 2651)
Dynamic magnetic information storage or retrieval
Automatic control of a recorder mechanism
Controlling the head
C360S254200, C360S256200
Reexamination Certificate
active
06278570
ABSTRACT:
BACKGROUN OF THE INVENTION
1. Field of the Invention
The present invention relates to a hard disk drive storage device and more particularly to a method for controlling the hard disk drive device to improve the durability of a surface of a landing zone of a data recording hard disk in the disk drive storage device when a head/slider assembly of an actuator arm lands on the surface of the landing zone.
2. Description of Related Art
In the hard disk drive device, a contact start/stop (CSS) scheme causes the head/slider assembly to rest on the surface of the landing zone of the data recording hard disk when a read/write operation is terminated. In the CSS scheme, the head/slider assembly is slidably moved on the surface of the data recording hard disk, so that the surface of the data recording hard disk is worn. To decrease the wear of the surface of the data recording hard disk, fine grooves referred to as mechanical texture are formed in a circumference direction of the data recording hard disk. The
FIG. 1
shows the mechanical texture
1
formed on the data recording hard disk
2
. The surface of the data recording hard disk is divided into the landing zone
3
and a data recording zone
4
. The mechanical texture
1
is formed on the landing zone
3
and data recording zone
4
, since it is difficult to define a clear boundary
5
between the landing zone
3
and the data recording zone
4
, as shown in the FIG.
2
(A). Defining a clear boundary is difficult because the mechanical process for forming the mechanical texture
1
, i.e. the fine grooves, is not precisely controlled, so that a transition zone
6
as shown in the FIG.
2
(B) is necessarily formed in the data recording zone
4
, and thus the area of the data recording zone
4
reserved for data is decreased.
The
FIG. 3
shows a typical structure of the hard disk drive device. The data recording hard disk
2
is rotated by a spindle motor (not shown). An actuator arm
7
is pivotally mounted on a pivot point
12
, and is rotated around the pivot point
12
by a voice coil motor (VCM)
9
, so that a head/slider assembly
8
is moved along a radial direction of the data recording hard disk
2
. An inner actuator lock
11
is provided to stop the movement of the head/slider assembly
8
at the landing zone
3
. The detail structure of the inner actuator lock
11
is shown in the
FIG. 6
, wherein the inner actuator lock
11
is moved between a first position, i.e. an inner most position or a left side position in the
FIG. 6
, and a second position, i.e. an outer most position or a right side position in the
FIG. 6
, as described latter to absorb any shock when the actuator arm
7
engages with the inner actuator lock
11
. An outer actuator lock
10
is provided to stop the movement of the head/slider assembly
8
at an outer most data recording track in the data recording zone
4
. The outer actuator lock
10
is also moved between a first position and a second position, as in the case of the inner actuator lock
11
. Referring back to
FIG. 3
, one end of a flexible cable
16
is connected to the actuator arm
7
to supply the data signals to the read/write head and receives the data signals from the read/write head. The other end of the flexible cable
16
is mounted to a frame
28
of the hard disk drive device. In the hard disk drive device using the data recording hard disk with the mechanical texture, it is required to oscillatingly move the head/slider assembly
8
in a radial direction
13
within the landing zone
3
to minimize the wear and the damage of the mechanical texture
1
, i.e. the fine grooves, when the head/slider assembly
8
lands on or takes off the surface of the landing zone
3
.
A flying height of the head/slider assembly
8
above the surface of the data recording hard disk
2
has been decreased to increase a data recording capacity of the hard disk
2
. A laser texture has been used in place of the mechanical texture to improve the durability of the surface of the landing zone
3
and to use a zone texture technology in which the texture is formed only in the landing zone, when the low flying height of the head/slider assembly
8
is used. The laser texture realizes the low flying height and the large data capacity since it is possible to precisely control a height, a density and a roughness of the laser texture.
FIGS. 4A and 4B
show the laser texture
14
formed in the landing zone
3
. The laser texture
14
is constituted by a plurality of discrete bumps
15
formed by a laser process. The bumps
15
are regularly arranged, and the height and the diameter of the bumps
15
and the space between the bumps
15
are precisely controlled. The height of the bump
15
is 10 nm through 50 nm, preferably 20 nm through 30 nm, the width or diameter of the bump
15
is 5 nm through 30 nm, preferably 10 nm. The space between the adjacent bumps is 20 nm through 200 nm, preferably 50 nm through 100 nm.
In has been noted, however, that the movement of the head/slider assembly
8
in the radial direction
13
of the hard disk
2
during the landing operation of the head/slider assembly
8
remarkably damages the bumps
15
of the laser texture
14
of the landing zone
3
and thus decreases the durability of the surface of the landing zone
3
. Correspondingly, the number of times of the CSS operation is decreased and the life cycle of the hard disk drive device is shortened. More particularly, the following problems have been found with the above described approach: (1) if the actuator arm
7
supporting the head/slider assembly
8
is oscillatingly moved between the first position and the second position of the inner actuator lock
11
during the landing operation as performed for the hard disk with the mechanical texture
1
, the laser dimples are damaged by the head/slider assembly
8
; (2) if the actuator arm
7
supporting the head/slider assembly
8
is moved between the first position and the second position of the inner actuator lock
11
during the landing operation due to an application of a leakage current to the VCM
9
which is induced by a counterelectromotive force of a spindle motor coil, the laser dimples are damaged by the head/slider assembly
8
; (3) if the actuator arm
7
supporting the head/slider assembly
8
is moved between the first position and the second position of the inner actuator lock
11
during the landing operation due to a bias force applied by the flexible cable
16
, the laser dimples are damaged by the head/slider assembly
8
; and (4) if the actuator arm
7
supporting the head/slider assembly
8
is moved between the first position and the second position of the inner actuator lock
11
during the landing operation due to a restore force of the actuator lock
11
, the laser bumps are damaged by the head/slider assembly
8
.
In summary, it has been found that the undesired damage of the laser bumps is caused by the fact that the head/slider assembly
8
is landed on the landing zone
3
before that the inner actuator lock
11
engaged with the actuator arm
7
is not fixed at the first or second position of the inner actuator lock
11
. Accordingly, it can be seen that there is a need in the art to provide an improved method and apparatus for moving a head arm assembly to the landing zone in a disk drive storage device.
SUMMARY OF THE INVENTION
To overcome the shortcomings of the prior art described above, it is the object of the present invention is to provide a method and apparatus for moving a head arm assembly to a landing zone in a disk drive storage device.
It is a further object of the present invention to provide a method and apparatus for landing the head arm assembly in the landing zone that minimizes damage to the bumps of laser texture in the landing zone of a rotating data storage disk.
Briefly stated, a disk drive storage device that achieves the above described objects in accordance with the present invention comprises: a rotating data recording disk having a data recording zone and a landing zone; a head/slider assembly flying above the
Akiyama Hiroyuki
Kanamaru Masayuki
Morita Akira
Tsuda Shingo
Davidson Dan I.
Hudspeth David
International Business Machines - Corporation
Krall Noreen A.
Martin Robert B.
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