Dynamic magnetic information storage or retrieval – Fluid bearing head support – Disk record
Reexamination Certificate
2000-03-08
2002-05-28
Renner, Craig A. (Department: 2652)
Dynamic magnetic information storage or retrieval
Fluid bearing head support
Disk record
C360S236800, C360S236500, C360S237000, C360S236900
Reexamination Certificate
active
06396662
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a magnetic head and magnetic head apparatus, and more particularly, to a magnetic head and magnetic head apparatus for recording and reproducing information to and from a flexible rotating recording medium in a state in which the magnetic head floats over the flexible rotating recording medium due to an air flow generated between the magnetic head and the flexible rotating recording medium.
2. Description of the Related Art
Generally, an ordinary magnetic disk drive that uses a flexible magnetic disk having a coercive force of 900 oersted (Oe) or less as a magnetic recording medium allows a relatively low rotational speed of for example 300 rpm to 720 rpm. In this case, magnetic recording and reproduction is performed by causing the magnetic head to be in direct sliding contact with the magnetic disk.
However, with recent advances in high-density recording on magnetic disks, the rotation speed of the magnetic disk has been increased to for example 3000 rpm, with the coercive force of the magnetic disk being increased to 1500 Oe or more. As a result, in order to accommodate such so-called high-capacity magnetic disks a magnetic disk drive has appeared in which the magnetic head is provided with a narrow gap. Hereinafter such a magnetic disk drive will be referred to as a high-capacity magnetic disk drive.
Since a high-capacity magnetic disk drive allows the magnetic disk to be rotated at high speeds, the magnetic disk and the magnetic head used therein may be easily damaged if the magnetic head were to be caused to be in direct contact with the magnetic disk, as is done in the conventional magnetic disk drive.
As a result, the high-capacity magnetic disk drive is designed so that the magnetic head floats in an elevated state over the surface of the high-capacity magnetic disk due to an elevating force arising as a result of an air flow caused by a relative speed between a slider surface of the magnetic head and the magnetic disk. Magnetic recording and reproduction is performed while a state of non-contact between the magnetic head and the magnetic disk is maintained.
FIGS. 1
,
2
,
3
,
4
and
5
show a magnetic head used in the conventional high-capacity magnetic disk drive.
As shown in
FIGS. 1 and 2
, the conventional high-capacity magnetic head
1
generally comprises a slider
2
and a magnetic head unit
3
. The slider
2
supports the magnetic head unit
3
and causes the magnetic head unit
3
to float over the magnetic disk
6
, as shown for example in FIG.
3
.
The top surface of the slider
2
forms an air bearing surface for forming an air bearing with respect to the magnetic disk
6
. Additionally, a central groove
2
a
is formed at a central position of the top surface of the slider
2
. As shown in
FIG. 1
, the central groove
2
a
divides the air bearing surface into a first air bearing surface
2
b
located to the right side of the central groove
2
a
and a second air bearing surface
5
located to the left side.
The magnetic head unit
3
and a pair of grooves or slots
4
are provided on the first air bearing surface
2
b.
The magnetic head unit
3
for performing magnetic recording and reproducing is formed by sandwiching a gap member between thin plates of magnetic cores.
The slots
4
extend in a tangential direction of the magnetic disk
6
, that is, in the direction of arrow X in
FIG. 1
, and provide a vent for an air flow produced between the magnetic disk
6
and the first air bearing surface
2
b.
By providing a vent to the air flow produced between the magnetic disk
6
and the first air bearing surface
2
b,
an elevating force exerted on the magnetic head
1
is reduced. Accordingly, by providing the slots
4
, the elevating force of the magnetic head
1
can be controlled.
As described above, the second air bearing surface
5
is formed to the left of the central groove
2
a
located on the top surface of the slider
2
as shown in FIG.
2
. Like the first air bearing surface
2
b,
the second air bearing surface
5
also produces a force for elevating the magnetic head
1
.
FIG. 3
is a lateral cross-sectional view of a conventional magnetic head as seen from a direction of disk approach thereto. As shown in the drawing, a pair of magnetic heads
1
are supported so as to be opposite each other within the magnetic disk drive. The elevating force generated by the second air bearing surface
5
described above exerts a force that pushes the magnetic disk
6
in the direction of the first air bearing surface
2
b,
that is, in the direction of the magnetic head unit
3
, of the opposite magnetic head
1
. Accordingly, the second air bearing surface
5
also functions as a pressure pad for pressing the magnetic disk
6
toward the opposite magnetic head
1
.
Additionally, as described above, slots
4
are formed in the first air bearing surface
2
b.
The slots
4
provide a vent for the air flow produced between the magnetic disk
6
and the first air bearing surface
2
b,
thus reducing the elevating force exerted on the magnetic head
1
. Accordingly, the magnetic disk
6
is deformed by a negative pressure generated in the slots
4
and a pressure generated at the second air bearing surface
5
due to a change in air flow so as to warp toward a gap
31
as the magnetic disk
6
rotates between the pair of magnetic heads
1
. With this construction, optimum recording and reproduction of information to and from the magnetic disk
6
is ensured even with floating magnetic heads
1
.
FIG. 6
is an oblique view of a second example of a conventional magnetic head, in which the magnetic head is provided with both a high-density R/W gap and a lowdensity R/W gap. The magnetic head la comprises a slider, a first magnetic head unit
3
a
and a second magnetic head unit
3
b.
A central groove
2
a
is formed at a central position of the top surface of the slider
2
. As shown in
FIG. 6
, the central groove
2
a
divides the top surface of the slider into two surfaces. A first air bearing surface
9
a
is located in the figure to the left side of the central groove
2
a,
with the high-density R/W gap being formed on the first air bearing surface
9
a.
A second air bearing surface
9
b
is formed parallel to the first air bearing surface
9
a
on a side of the central groove
2
a
opposite the side on which the first air bearing surface
9
a
is formed, with the low-density R/W gap being formed on the second air bearing surface
9
b.
A pair of grooves or slots
4
is formed so as to extend the length of the first air bearing surface
9
a.
The magnetic head
1
a
having the structure described above can be adapted to a 300 rpm low-density mode or a 3600 rpm high-density mode, depending on the type of recording medium.
A description will now be given of how the magnetic head
1
faces the magnetic disk
6
, with reference to FIG.
4
and
FIG. 5
FIGS. 4 and 5
show views of a state in which the magnetic head
1
is recording information to or reproducing information from a magnetic disk
6
, from a radial direction Y of the magnetic disk
6
.
FIG. 4
shows the magnetic disk
6
in a state of optimal approach to the magnetic head
1
.
As shown in
FIG. 4
, a pair of slots
4
are formed in the first air bearing surface
2
b
in which the first magnetic head unit
3
is provided. These slots
4
are formed along the entire length of the first air bearing surface, that is, from a leading edge
7
of the magnetic head
1
, that is, an edge side of the magnetic head
1
at which the magnetic disk
6
enters the magnetic head
1
, to a trailing edge
8
of the magnetic head
1
, that is, an edge side of the magnetic head
1
at which the magnetic disk
6
exits the magnetic head
1
. As a result, a reduction in the elevating force due to the presence of the slots
4
is generated over the entire extent of the length of the first air bearing surface
2
b.
Accordingly, even in a state of optimal approach a distance H between the magnetic disk
6
and the l
Kudo Norikazu
Osaka Tomohiko
Ladas & Parry
Mitsumi Electric Co. Ltd.
Renner Craig A.
LandOfFree
High/low density magnetic head slider with lateral incision does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with High/low density magnetic head slider with lateral incision, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High/low density magnetic head slider with lateral incision will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2851820