Dynamic magnetic information storage or retrieval – Head mounting – Disk record
Reexamination Certificate
2002-02-13
2004-06-15
Tupper, Robert S. (Department: 2652)
Dynamic magnetic information storage or retrieval
Head mounting
Disk record
C360S265900
Reexamination Certificate
active
06751064
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a head supporting device for levitating type head, and a disk drive using the same such as a magnetic disk drive, optical disk drive, magneto-optic disk drive, and the like.
BACKGROUND OF THE INVENTION
With reference to the accompanying drawing, described hereinafter pertains to a head supporting device of the prior art employed in a magnetic disk drive such as hard disk drive, as an example of the conventional head supporting device of a disk drive having a levitating type head.
FIG. 11
is a plan view showing a structure of a head supporting device of the prior art for a magnetic disk drive, and a relation between the head supporting device and a magnetic recording medium.
In
FIG. 11
, head supporting device
108
has such a structure that comprises suspension
102
of a comparatively low rigidity, plate spring
103
, and support arm
104
of a comparatively high rigidity, and that the suspension
102
is provided with slider
101
having a magnetic head (not show in the drawing) mounted to an underside surface at one end thereof.
In addition, magnetic recording medium
107
is so disposed that it is spun by spindle motor
109
. During writing and reading of the magnetic disk drive, the magnetic head mounted to the slider
101
receives a certain amount of levitation associated with a levitational force due to airflow generated by spinning of the magnetic recording medium and a thrusting force of the plate spring
103
which shifts the slider
101
toward the magnetic recording medium
107
.
This structure of the head supporting device
108
is such that it rotates about bearing unit
105
by an interaction of voice coil
106
disposed to the support arm
104
during writing and/or reading, so that the magnetic head mounted to the slider
101
is positioned to a desired track on the magnetic recording medium
107
and performs the writing and/or reading.
The magnetic disk drive shown in
FIG. 11
is a kind of magnetic disk drive, which is generally called a “contact start-stop mode” (hereinafter referred to as CSS mode), having a feature that the magnetic head mounted to the slider
101
levitates from the magnetic recording medium
107
during writing and/or reading, although it stays in contact with the magnetic recording medium
107
when the magnetic recording medium
107
is at a standstill.
In such a magnetic disk drive of the CSS mode, an area shown by a reference mark A of the magnetic recording medium
107
in
FIG. 11
is the area that is magnetically writable, and another area shown by a reference mark B is the area where the magnetic head is retracted during a stop, which is called a CSS zone. When the magnetic recording medium
107
is to stop spinning, the magnetic head is first moved to the area B while it is kept levitated. When spinning speed of the magnetic recording medium
107
is reduced thereafter, the levitational force decreases as the airflow between the magnetic recording medium
107
and the slider
101
decreases. The magnetic head finally comes in contact with the magnetic recording medium
107
, and it stops in that position.
Therefore, the magnetic recording medium
107
in the magnetic disk drive of the CSS mode is so formed that a surface of the area B is rougher than a surface of the area A, so as to prevent a problem that the magnetic head adheres to the magnetic recording medium
107
when coming to a stop, and damages the magnetic recording medium
107
mechanically and/or magnetically when it restarts again.
There are also other methods of the magnetic disk drive, of which one is a “load/unload mode” (hereinafter referred to as L/UL mode).
FIG. 12
shows a general perspective view representing a structure of a magnetic disk drive of the L/UL mode. In
FIG. 12
, head supporting device
108
has a structure which is generally similar to that of the CSS mode shown in FIG.
11
. However, the head supporting device
108
rotates about bearing unit
105
, and moves outside of magnetic recording medium
107
when the magnetic disk drive comes to a stop. In this structure, there is provided ramp
110
at an outside of the magnetic recording medium
107
, so as to prevent slider
101
and magnetic head from adhering to the magnetic recording medium
107
by letting the slider
101
supported on suspension
102
to ride up on a tapered portion provided on the ramp
110
.
Referring now to
FIG. 13
, the structure and function of the conventional head supporting device will be described in more detail.
FIG. 13
is a perspective view showing a main portion of the conventional head supporting device where a magnetic head is mounted.
The magnetic head (not shown in the figure) is mounted to a surface, which confronts magnetic recording medium
112
, of the slider
101
disposed to an underside surface at one end of the suspension
102
. The other end of the suspension
102
is bent, in a manner to function as plate spring
103
, and this plate spring
103
is connected to the support arm
104
. In the case of the CSS mode, the structure is such that the slider
101
is in contact with the magnetic recording medium
112
when the magnetic recording medium
112
is not spinning, and the slider
101
is thrust toward the magnetic recording medium
112
by a reactive force of the plate spring
103
against the magnetic recording medium
112
.
As a design condition required for a head supporting device of the magnetic disk drive, it is necessary to impress a predetermined amount of load on the slider in a direction of the magnetic recording medium.
The purpose of this is to levitate the slider steadily and to stabilize an output of the magnetic head mounted to the slider even if there is any shock from the outside or a vertical movement of a surface of the magnetic recording medium during writing and/or reading.
Moreover, it is also necessary for the head supporting device to be such a structure that the plate spring has flexibility in order to maintain a steady thrusting force to the slider even when the surface of the magnetic recording medium is caused to make a vertical movement.
On the other hand, the head supporting device is required to have a high rigidity in order to prevent an impediment to trackability of the magnetic head mounted to the slider and to avoid an off-track error due to an undesired vibration mode that can occur in the head supporting device.
Furthermore, it is also necessary to form the head supporting device thin in a direction perpendicular to the surface of the magnetic recording medium in order to achieve miniaturization, or low-profiling to be more specific, of the magnetic disk drive.
However, because the conventional head supporting device has the structure in which the suspension and the support arm are connected with the plate spring, as described above, it is necessary to satisfy some conflicting conditions in order to meet a variety of requirements for the head supporting device.
In other words, it is necessary that the plate spring, to be more specific, has a reactive force large enough to impress upon the slider with a load it requires so that the slider carrying the magnetic head is levitated with stability. For this reason, number of attempts have been made to change an angle of bending (i.e. forming) between the suspension and the plate spring, and a material of the suspension, to adjust its thickness, and so on.
Next, it is also necessary for the head supporting device to have a certain degree of flexibility in order to prevent the load of the slider to the magnetic recording medium from fluctuating due to vertical movement of the magnetic recording medium, a manufacturing deviation in distance between the slider and the magnetic recording medium from one magnetic disk drive to another in the mass-production and the like. For this reason, the conventional head supporting device has been designed in such a way that the plate spring has the flexibility by providing it with cutout opening
111
as shown in
FIG. 13
, so as to lower rigidity of the plate spring
Kuwajima Hideki
Miyamoto Makoto
Sakamoto Ken'ichi
Matsushita Electric - Industrial Co., Ltd.
RatnerPrestia
Tupper Robert S.
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