U.S. patent application number 09/340783 was filed with the patent office on 2002-03-07 for converter support structure.
Invention is credited to ENSHU, HISAYUKI, MIZUNO, OSAMU, MURAKAMI, YUTAKA, NAKAMURA, TOHRU.
Application Number | 20020027749 09/340783 |
Document ID | / |
Family ID | 16178591 |
Filed Date | 2002-03-07 |
United States Patent
Application |
20020027749 |
Kind Code |
A1 |
MIZUNO, OSAMU ; et
al. |
March 7, 2002 |
CONVERTER SUPPORT STRUCTURE
Abstract
A slider portion is provided with protrusion portions having a
spherical surface, contacting a recording medium. A center of a
magnetic pole is arranged on the line C1 connecting the vertices of
the protrusion portions. Line C1 is more or less aligned with the
gliding direction of the protrusion portions. Thereby, positional
variations between the magnetic pole and the surface of the
recording medium can be minimized even when the head slider is
tilted with respect to the surface of the recording medium. Thus, a
gliding converter support structure is provided whose conversion
efficiency does not decrease when it is tilted with respect to the
surface of the recording medium, which is easy to manufacture, has
little gliding resistance, and does not easily accumulate dust.
Inventors: |
MIZUNO, OSAMU; (OSAKA,
JP) ; MURAKAMI, YUTAKA; (OSAKA, JP) ; ENSHU,
HISAYUKI; (KYOTO, JP) ; NAKAMURA, TOHRU;
(OSAKA, JP) |
Correspondence
Address: |
MERCHANT & GOULD PC
P.O. BOX 2903
MINNEAPOLIS
MN
55402-0903
US
|
Family ID: |
16178591 |
Appl. No.: |
09/340783 |
Filed: |
June 28, 1999 |
Current U.S.
Class: |
360/246.1 ;
G9B/5.159; G9B/5.23 |
Current CPC
Class: |
G11B 5/6005 20130101;
G11B 5/49 20130101 |
Class at
Publication: |
360/246.1 |
International
Class: |
G11B 005/48 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 1, 1998 |
JP |
10-185885 |
Claims
What is claimed is:
1. A converter support structure for supporting a converter for
recording/reproducing while moving relative to a recording medium,
the converter support structure comprising at least two protrusion
portions for maintaining said converter in a predetermined position
with respect to the recording medium by contacting the recording
medium; wherein said protrusion portions are arranged substantially
in parallel to the direction in which said converter moves relative
to the recording medium; and a central portion of a region in which
said converter interacts with the recording medium is arranged
substantially on a line that passes through centers of regions
where said protrusion portions contact the recording medium.
2. The converter support structure according to claim 1, wherein
all of said protrusion portions are formed in a region that is on
one side of said converter with respect to the direction in which
said converter moves relative to the recording medium.
3. The converter support structure according to claim 1, wherein
said protrusion portions are two protrusion portions.
4. The converter support structure according to claim 1, wherein
said protrusion portions comprise a spherical surface.
5. The converter support structure according to claim 1, further
comprising, between both ends of the regions where said protrusion
portions contact the recording medium in the direction of the
relative movement, a weight application point for applying a weight
that forces the converter support structure toward the recording
medium, thereby contacting said protrusion portions with the
recording medium.
6. A converter support structure for supporting a converter for
recording/reproducing while moving relative to a recording medium,
comprising a protrusion portion for maintaining said converter in a
predetermined position with respect to the recording medium by
contacting the recording medium; wherein a long axis of a region of
contact between said protrusion portion and the recording medium is
arranged substantially in parallel to the direction in which said
converter moves relative to the recording medium; and a central
portion of a region in which said converter interacts with the
recording medium is arranged substantially on the long axis.
7. The converter support structure according to claim 1 or 6,
wherein said region where said protrusion portion contacts the
recording medium is substantially elliptical.
8. The converter support structure according to claim 1 or 6,
wherein the distance that said protrusion portion protrudes from a
surface of said converter is 30 to 60 .mu.m.
9. The converter support structure according to claim 1 or 6,
wherein a curvature radius of said protrusion portion is at least
10 mm.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates mainly to a converter support
structure gliding in contact over a recording medium. More
specifically, the present invention relates to a gliding converter
support structure for a magnetic recording device or an
optomagnetic recording and reproducing device used as an external
storage device for a computer, or as a recording and reproducing
device for music or video signals or other information.
[0003] 2. Description of the Prior Art
[0004] A common example of a conventional gliding converter support
structure is a magnetic core support structure for magnetic
recording. Magnetic tape and flexible disks used to be the main
media using such a structure, but recently minidisks (referred to
as "MDs" in the following) are becoming increasingly popular as
optomagnetic recording media for recording music. A prerequisite
for MDs is the use of a gliding magnetic head slider for
optomagnetic overwriting using a modulated magnetic field, and the
disk has a gliding film for gliding. The following is a discussion
of a magnetic head slider for MDs serving as a converter support
structure.
[0005] A conventional gliding magnetic head slider for optomagnetic
recording, particularly for MDs, is disclosed in Publication of
Unexamined Japanese Patent Application No. Hei 6-195851. Its
overall structure is shown in FIG. 4(a).
[0006] In FIG. 4(a), numeral 101 denotes a slider means serving as
a converter support structure, on which a magnetic core 102 serving
as a converter, and a coil (not shown in the drawings) are
installed. Publication of Unexamined Japanese Patent Application
No. Hei 7-129902 discloses details concerning the slider means 101,
which are illustrated in FIG. 4(b). A cylindrical surface 101a is
formed as a gliding surface on a surface of the slider means that
opposes the disk. Numeral 102a denotes the magnetic pole of a
magnetic core 102 that is exposed toward the side of the disk.
[0007] Publication of Unexamined Japanese Patent Application No.
Hei 6-195851 discloses the relation between the cylindrical surface
101a and the magnetic pole 102a, as shown in FIG. 5. FIG. 5 is a
drawing of the slider means 101 taken from the opposite side of the
surface opposing the disk.
[0008] In FIG. 5, A denotes the tangent line to the disk track of
the center point of the magnetic pole 102a, and B denotes the disk
radius through the magnetic pole 102a.
[0009] Contact region 101b is the region of the cylindrical surface
101a contacting the disk's gliding film. The contact line C101 is
defined as the line passing along the center of the contact region
101b. The contact line C101 is arranged so that it defines a
certain angle .phi. with the tangent A through the center of the
magnetic core 102a during regular contact with the disk. With such
a tilted arrangement, the contact line C101 can be arranged
substantially parallel to the tangent direction of the disk track
in the contact region 101b, which reduces the gliding width (that
is, the width of the contact region 101b in the direction
perpendicular to the gliding direction). In FIG. 5, the magnetic
pole 102a is shown as if all parts on the side opposing the disk
are transparent.
[0010] The slider means 101, which includes the cylindrical surface
101a, is made of a resin material that is resistant against
abrasion with the disk surface and very smooth, so that it prevents
damage due to abrasion between the slider and the disk.
[0011] The pressing force of a spring portion 104, which serves as
a loading means, causes the contact region 101b of the cylindrical
surface 101a to glide in contact with the gliding film of the disk,
so that the magnetic pole 102a is positioned near the disk's
recording film. The disk may be tilted due to surface warps and
distortions, causing positional misalignments but, contact can be
maintained because the gimbal 103 is deformed with respect to
tilting around an axis orthogonal to the contact line C101 in FIG.
5, and the contact region shifts with respect to tilting around an
axis parallel to the contact line C101 (rolling motion). In this
situation, thermomagnetic recording is performed by applying to the
recording film, which has been heated with focussed laser light, a
modulation magnetic field with a coil (not shown in the drawings)
from the magnetic pole 102a.
[0012] Together with the optical head, the slider means 101 can
move over the disk in the radial direction B in FIG. 5, so that a
recording magnetic field can be applied to any portion of the
disk.
[0013] However, a conventional magnetic head as described above
poses the following problems.
[0014] If C102 is the line segment that passes through the center
of the magnetic pole 102a in parallel to the contact line C101,
then C101 and C102 are separated by the distance d. The value of d
varies with shifts of the contact region 101b, but it is preferable
that it is zero during regular operation.
[0015] The reason for this is that if the disk is tilted around an
axis parallel to the contact line C101 for an angle .theta., the
contact line C101 shifts, and the distance d changes. When the
original of d is d0 and the shift portion is d', then the largest
possible change of the distance between the magnetic pole 102a and
the disk is (d'+d0)sin .theta..
[0016] This change of distance causes variations in the size of the
magnetic field generated by the magnetic pole 102a, and a field
that is too small may lead to recording errors. Therefore, it is
necessary to run an additional current through the coil to
compensate for the shift portion, which leads to an increase in the
consumed power.
[0017] Moreover, since the gliding surface 101a is a cylindrical
surface, the region of contact with the disk is large, and the
viscous resistance with the gliding film of the disk is large, so
that the load on the spindle motor increases and causes an increase
in the consumed power.
[0018] Moreover, the cylindrical surface 101a easily gathers dust,
and when dust has accumulated near the center of the contact region
101b for example, it causes a large positional change, changing the
distance between the disk and the magnetic pole 102a. Since the
contact region is large, the accumulation of dust occurs relatively
easily.
[0019] As long as the direction in which the slider means 101 moves
when accessing the disk in a radial direction is not orthogonal to
the contact line C101, it is impossible to consistently match the
direction of the contact line C101 with the direction tangential to
the track in the contact region. In other words, with this
configuration, when accessing the disk in a radial direction, in
almost all positions in radial direction of the disk, the contact
line C101 has a certain tilt with respect to the direction
tangential to the track. This means that the slide width of the
contact region 101b (that is, the width in the direction orthogonal
to the slide direction of the contact region 101b) is always larger
than the width of the contact region 101b in the direction
perpendicular to the contact line C101, which becomes a cause for a
large sliding resistance and the accumulation of dust.
SUMMARY OF THE INVENTION
[0020] It is an object of the invention to solve the above problems
of the prior art, and to provide a converter support structure with
a simple configuration, high efficiency, and low sliding
resistance, that does not easily accumulate dust.
[0021] The following describes a configuration of the present
invention that achieves these objects.
[0022] A converter support structure according to a first
configuration of the present invention supports a converter for
recording/reproducing while moving relative to a recording medium,
and includes at least two protrusion portions for maintaining the
converter in a predetermined position with respect to the recording
medium by contacting the recording medium. The protrusion portions
are arranged substantially in parallel to the direction in which
the converter moves relative to the recording medium, and a central
portion of a region in which the converter interacts with the
recording medium is arranged substantially on a line that passes
through centers of regions where the protrusion portions contact
the recording medium.
[0023] A converter support structure according to a second
configuration of the present invention supports a converter for
recording/reproducing while moving relative to a recording medium,
and includes a protrusion portion for maintaining the converter in
a predetermined position with respect to the recording medium by
contacting the recording medium. A long axis of a region of contact
between the protrusion portion and the recording medium is arranged
substantially in parallel to the direction in which the converter
moves relative to the recording medium, and a central portion of a
region in which the converter interacts with the recording medium
is arranged substantially on this long axis.
[0024] The converter support structures of the present invention
reduce variations in the relative distance between the converter
and the recording medium because at least two protrusion portions
are arranged substantially in parallel to the direction in which
the converter moves relative to the recording medium, and a central
portion of the regions in which the converter interacts with the
recording medium is arranged substantially on a line that passes
through centers of regions where the protrusion portions contact
the recording medium, or a long axis of a region of contact between
the protrusion portions and the recording medium is arranged
substantially in parallel to the direction in which the converter
moves relative to the recording medium, and a central portion of a
region in which the converter interacts with the recording medium
is arranged substantially on this long axis.
[0025] In the first configuration, it is preferable that the
protrusion portions are two protrusion portions. Moreover, it is
preferable that the protrusion portions include a spherical
surface. Moreover, in the first and in the second embodiment, it is
preferable that the region where the protrusion portion contacts
the recording medium is substantially elliptical. With these
configurations, the sliding resistance with the recording medium is
reduced and the accumulation of dust is reduced, because the region
of contact between the protrusion portion and the surface of the
recording medium is reduced and the sliding width is reduced.
Furthermore, these improved configurations can be manufactured
without posing any new difficulties.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is a perspective drawing of a magnetic head slider
including a converter support structure according to a first
embodiment of the present invention.
[0027] FIG. 2(a) is a side view of the magnetic head slider in FIG.
1. FIG. 2(b) is a bottom view of the magnetic head slider in FIG.
1.
[0028] FIG. 3 is a perspective view of the shape of the protrusion
portions used in the magnetic head slider including the converter
support structure according to a second embodiment of the present
invention.
[0029] FIG. 4(a) is a perspective view of the entire configuration
of a conventional sliding magnetic head. FIG. 4(b) is a perspective
view showing the configuration of a slider means used in FIG.
4(a).
[0030] FIG. 5 is a plan view of the configuration of a conventional
slider means, taken from the side opposite from the disk.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] The following is a description of the preferred embodiments
of the present invention with reference to FIGS. 1 to 3.
[0032] First Embodiment
[0033] FIGS. 1 and 2 illustrate a magnetic head slider, that is a
converter support structure according to a first embodiment of the
present invention. FIG. 1 is a schematic perspective view, FIG.
2(a) is a side view, and FIG. 2(b) is a bottom view.
[0034] Numeral 1 denotes a housing portion housing a magnetic core
7 made of a ferrite for example, and a coil 8 made of copper,
wherein a magnetic pole 2 is arranged so that it is exposed on the
side of the housing that opposes the disk surface. Numeral 3 is a
slider portion, and two protruding portions 4 and 5 are arranged on
the side of the slider portion 3 that opposes the disk surface. The
surfaces of the protruding portions 4 and 5 are spherical. The
housing portion 1 and the slider portion 3 are made in one piece of
a gliding resin, preferably a liquid crystal polymer to which a
fluorine additive has been added.
[0035] As can be seen in FIG. 2(a), the protruding portions 4 and 5
protrude a distance .delta. from the surface 2a that includes the
magnetic pole 2. Numeral 9 is a fusion pin 9 for connecting by a
known means such as ultrasonic fusion to a structure similar to the
gimbal 103 of the conventional example (see FIG. 4). The fusion pin
is provided between the protruding portions 4 and 5. Of course,
depending on the system for attaching, this fusion pin 9 may be
unnecessary, but in any case, the portion that couples to the
gimbal 103 (the weight application point for applying a weight that
forces the magnetic head slider toward the disk) is provided
between the protruding portions 4 and 5.
[0036] Numerals 4a and 5a in FIG. 2(b) denote contact regions that
result when the protruding portions 4 and 5 glide over the gliding
film of the disk, which are basically small circles having the
vertices of the spherical protruding portions in their centers. The
line C1 through the centers of the contact regions 4a and 5a--that
is, the line through these vertices--is the line of contact with
the disk during regular operation. The protruding portions 4 and 5
are arranged so that this contact line C1 passes through the center
of the magnetic pole 2. A is the tangent line to the disk track in
the center point of the magnetic pole 2, and B is the disk radius
through the center of the magnetic pole 2.
[0037] As in the conventional example, the contact line C1 is
arranged so that it defines a certain angle .phi. with the disk
tangent A through the center of the magnetic pole 2, and the
contact line C1 forms small angles close to zero with the tangents
to the disk tracks in the protruding portions 4 and 5.
[0038] The following is an explanation of the operation of the
first embodiment of the present invention.
[0039] The pressing force of a loading means that is similar to the
one shown in the prior art example acts at the position of the
fusion pin 9 and causes the contact regions 4a and 5a of the
protruding portions 4 and 5 to glide in contact with the gliding
film of the disk, so that the magnetic pole 2 is positioned near
the disk's recording film. The operation against tilts and
displacements due to warps and twists in the disk surface is
basically the same as in the conventional example, but since the
contact line C1 passes through the center of the magnetic pole 2
during regular operation, the distance d0 that was explained for
the conventional example becomes 0, which considerably reduces
distance variations between the magnetic pole 2 and the disk and
particularly enhances the efficiency of the magnetic field per coil
current.
[0040] Furthermore, because of the two contact points, the contact
region is smaller than that of the cylindrical surface 101a of the
prior art example, which reduces the viscous resistance and the
load of the spindle motor. Also, since contact is established in
two points only, the chances of accumulating dust are greatly
reduced. Because the contact regions 4a and 5a are substantially
circular, even when the contact line C1 does not match any disk
track tangent in the protruding portions 4 and 5, there is hardly
any variation of the contact width (that is, the width of the
contact region in the direction perpendicular to the disk gliding
direction), regardless of the value for .phi., which allows stable
gliding with a small load.
[0041] The smaller the curvature radius of the spherical surfaces
is, the smaller is the shift of the contact line C1 and thus the
distance variations between the magnetic pole 2 and the disk
surface when the disk is tilted, but the durability deteriorates.
As was ascertained experimentally, from the viewpoint of durability
a curvature radius of about R=10 mm is preferable, more preferable
is a curvature radius of 10 mm or greater.
[0042] The size .delta. of the protrusion portion should be as
small as possible because this increases the conversion efficiency,
but, as has already been pointed out for the prior art example,
since the slider portion 3 and the housing portion 1 are linked
with a certain obliqueness against the disk, portions other than
the regular gliding portions, for example the corner portions of
the housing portion 1, may come into contact with the disk,
depending on the radius R. Consequently, there is a minimum value
for the size .delta. of the protrusion portion, which depends on
the design. For a curvature radius of about 10 mm, the value of
.delta. should be about 30 to 60 .mu.m.
[0043] Second Embodiment
[0044] FIG. 3 is a perspective view illustrating the shape of the
protruding portion of the magnetic head slider in a converter
support structure according to a second embodiment of the present
invention. The overall configuration of the magnetic head slider in
this embodiment is the same as that of the first embodiment shown
in FIGS. 1 and 2, so that a detailed explanation has been omitted
here. In this embodiment, the spherical protruding portions 4 and 5
serving as the protruding portion of the slider portion 3 are
replaced by two protruding portions 6 as shown in FIG. 3, whose
long axes (x-axis direction) are aligned with the contact line C1.
According to this embodiment, the contact region between the
protruding portion 6 and the disk surface is substantially
elliptical, and its long axis is aligned with the contact line
C1.
[0045] The effect of this embodiment is basically the same as that
of the first embodiment, but by using the elliptical surface 6 and
aligning its long axis with the contact line C1, the contact
pressure can be reduced by enlarging the contact area without any
danger of enlarging the contact width (that is, the width of the
contact region in the direction perpendicular to the disk gliding
direction). As a result, the durability of both the slider and the
disk is increased, while suppressing the accumulation of dust. As
in the first embodiment, it is preferable that the curvature radius
of the protruding portion 6 of this embodiment is at least 10 mm
with respect to the direction perpendicular to the contact line C1
(y-axis direction), and also the same design values for the
protrusion portion amount can be used.
[0046] The second embodiment has been explained by way of an
example where two protruding portions 6 were formed in the slider
portion 3, but it is also possible if there is only one protruding
portion 6. This is because it is possible to hold the contact
pressure below a certain tolerance value even with only one
protruding portion, if, compared to the protruding portions 4 and 5
of the first embodiment, the contact region of one protruding
portion becomes comparatively large such as the protruding portion
6 of this embodiment.
[0047] The shape of the contact region is not limited to elliptical
shapes, but can also be for example rectangular with four arced
corner portions or of elongated shape with semi-circles at both
ends. It is also possible to vary the surface shape of the
protruding portion to achieve such a contact region.
[0048] The above embodiments have been explained by way of examples
where the converter is a magnetic head. However, the converter
support structure of the present invention is not limited to this,
and the converter can also be an optical head including elements
for sending and detecting light signals, or an objective lens.
Another possible configuration is to mount a complete
optomagnetical recording system including both magnetic head and
focusing means.
[0049] The invention may be embodied in other specific forms
without departing from the spirit or essential characteristics
thereof. The embodiments disclosed in this application are to be
considered in all respects as illustrative and not restrictive, the
scope of the invention being indicated by the appended claims
rather than by the foregoing description, all changes that come
within the meaning and range of equivalency of the claims are
intended to be embraced therein.
* * * * *