Magnetic disk apparatus

Details Magnetic disk apparatus Magnetic disk apparatus

1998-05-14

2001-06-05

Klimowicz, William (Department: 2754)

Dynamic magnetic information storage or retrieval

Head mounting

Disk record

C360S264200

Reexamination Certificate

active

06243236

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a magnetic disk apparatus for high-density recording on a magnetic disk.
2. Description of the Related Art
A magnetic disk apparatus in recent years has a tendency of becoming smaller in size but larger in capacity. For this reason, there is made an attempt to improve a recording density of the magnetic disk, i.e., a track density and a bit density. For improving this bit density, in place of a conventional readable/writable inductive head, a magnetic reluctance head (MR head) capable of taking a larger level of a regenerative signal is utilized as a reading head. Hence, the magnetic head involves the use of two heads, i.e., the inductive head for writing and the MR head for reading.
Such two heads are different from each other in terms of their positions in a track direction, and, therefore, a problem is a decline of a follow-up capability along the tracks due to a skew of a shaft and an angle of rotation relative to a rotary actuator.
FIG. 57
is a view illustrating a construction of a magnetic disk apparatus in the prior art.
FIG. 58
is a characteristic diagram of a head position versus a yaw angle in the prior art.
FIGS. 59A
,
59
B,
59
C and
59
D are diagrams of assistance in explaining the yaw angle in the prior art.
As depicted in
FIG. 57
, an actuator
92
moves a magnetic head
93
in its radial direction with respect to a magnetic disk
90
rotating about a center-of-rotation
91
. This actuator
92
involves the use of a rotary actuator rotating about a center-of-rotation
94
, thereby attaining down-sizing of the apparatus.
An MR head capable of enhancing the bit density is used as a read head of this magnetic head
93
. As shown in
FIGS. 59B and 59D
, if this MR head is used as a read head
93
-
2
, it is required that a write head
93
-
1
be provided separately. For example, the inductive head is employed as the write head
93
-
1
. Thus, it follows that a gap position between the individual heads
93
-
1
and
93
-
2
of the magnetic head
93
differs.
This rotary actuator
92
rotates about the center-of-rotation
94
and thereby moves the magnetic head
93
in the radial direction of the magnetic disk
90
, and, hence, a locus thereof depicts a circular arc. Accordingly, an angle (head skew angle or yaw angle) with respect to the track (cylinder) direction of the magnetic head
93
is not 0°. Besides, a yaw angle on the inner side of the magnetic disk
90
becomes as shown in
FIGS. 59A and 59B
. On the other hand, a yaw angle on the outer side of the magnetic disk
90
turns to be an angle as illustrated in
FIGS. 59C and 59D
. Consequently, the yaw angle changes on the inner and outer sides of the magnetic disk
90
.
Take the construction of
FIG. 57A
for example, a distance Rcg from the center-of-rotation
94
of the actuator
92
up to the gap position of the magnetic head
93
is set 0.85 times as small as a distance Rsc from the center-of-rotation
94
of the actuator
92
up to the center-of-rotation
91
of the magnetic disk
90
. As illustrated in
FIG. 58
, the variation in the yaw angle at this time amounts to a value as large as 24°.
This yaw angle causes a deviation between the write head
93
-
1
and the read head
93
-
2
with respect to a cylinder locus. This results in a narrowed effective gap width of the read head
93
-
2
and, consequently, a decline in terms of a read characteristic. For this reason, it is desirable that both the yaw angle and the variation in the yaw angle be small.
As a method of reducing an absolute value of this yaw angle, Japanese Patent Laid-Open Publication No.4-232610 proposes a method of shifting the positions of the heads
93
-
1
,
93
-
2
. Further, there is proposed another method of decreasing the yaw angle by using an actuator having a fan-shaped bearing (see Japanese Patent Laid-Open Publication No.2-126497).
Also, there are some configurations of a conventional disk enclosure, wherein a base and a cover are separated up and down, and the base and the cover are separated right and left (see Japanese Patent Laid-Open Publication No. 4-232610).
The conventional apparatus which effects the read/write processes through the same element presents no problem because of causing no track deviation due to the yaw angle. As shown in
FIGS. 59B and 59D
, however, when the head is provided with the write inductive head
83
-
1
and the read MR head
93
-
2
, the gap position between the inductive head
93
-
1
and the MR head
93
-
2
differs. Hence, the variation in the yaw angle brings about especially a deviation of the track position of the MR head
93
-
2
. Thus, it follows that a degree of mixing of adjacent track signal components among reading signals fluctuates depending on the respective tracks. A resolution of read data is thereby decreased.
For preventing this decline, a read output level is reduced by decreasing the gap width of the MR head
93
so that the gaps of the MR head
93
-
2
extends over the adjacent track in any tracks. For this reason, there arises a problem in which an S/N ratio increases, correspondingly. Further, according to the conventional method using the fan-shaped bearing, the actuator is a special one. Therefore, its structure becomes complicated, and, besides, the costs also increase.
Further, in such a construction of the disk enclosure that the base and the cover are separated up and down in the prior art, it is possible to support both ends of shafts of a spindle motor and the rotary actuator, and, therefore, a rigidity is comparatively high. However, since a degree of deformation due to variations in temperatures of upper and lower members is different, the shaft of the rotary actuator is easy to skew, with the result that an off-track readily takes place.
Similarly, as disclosed in Japanese Patent Laid-Open Publication No.4-232610, in the construction where the base and the cover are separated right and left, the base is formed with two openings, and hence the rigidity of the enclosure is low. Accordingly, the shaft of the rotary actuator is easy to skew, and therefore the off-track is readily produced.
SUMMARY OF THE INVENTION
It is a primary object of the present invention to provide a magnetic disk apparatus capable of reducing, even when using separate a read and write head, a track deviation of the head and recording with a high density.
In keeping with one aspect of the present invention, a magnetic disk device includes at least one magnetic disk, rotating means for rotating the magnetic disk, and a magnetic head for writing and reading information to and from the magnetic disk. A rotary type actuator is provided for moving the magnetic head so that it traverses tracks of the magnetic disk by rotating about a rotary shaft. The rotary type actuator has at least one arm for the magnetic head at its front end.
A first flat cable has one end connected to the rotary type actuator, for making an electrical connection to the electronics in the disk device. A second flat cable is provided on the side surface of the arm, for electrically connecting the magnetic head to the first flat cable. The first cable includes a plurality of lands arranged along an extended direction of the arm. The second flat cable includes a first land group provided at one end of the second flat cable for electrically connecting to the magnetic head. the first land group has a plurality of land arranged along an extended direction of the arm. A second land group is provided at the other end of the second flat cable for electrically connecting to the first flat cable. the second land group has a plurality of lands arranged along the extended direction of the arm, disposed in face-to-face relationship with the lands of the first flat cable, and a lead pattern is provided for electrically connecting the first land group and the second land group. In this manner, the second flat cable overlaps with the first flat cable at the other end.


REFERENCES:
patent: 4295711 (1981-10-01), Tanaka et al.
patent: 4388655 (1983-

Affiliated with

Also associated with

Rating

Magnetic disk apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Magnetic disk apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetic disk apparatus will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2490613