Flexible polymeric resinous magnetic head supporting device

A magnetic head supporting device which includes a supporter having a resilient spring portion and a rigid beam portion contiguous to the resilient spring portion a flexible member whose one end is attached to the supporter at a portion near its free end; a loading projection provided in the upper surface of the flexible member or in the lower surface of the supporter at a portion near its free end to thereby transmit a loading force from the free end of the supporter to the flexible member; and a magnetic head having a slider attached with reading/writing elements, the magnetic head being fixed to the lower surface of the flexible member, wherein the flexible member is composed of a plate of a polymeric resinous material having conductors for wiring; the conductors are electrically connected to electrodes for the reading/writing elements of the magnetic head, and the plate of a polymeric resinous material is extended on the supporter in its longitudinal direction.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a magnetic head supporting device. More 
particularly, it relates to a magnetic head supporting device of a type 
wherein flexible member is attached to a supporter at a portion near its 
free end; a loading projection is provided on the supporter to thereby 
transmit a loading force from the supporter to the flexible member, and a 
magnetic head having a slider attached with reading/writing elements is 
mounted on the lower surface of the flexible member. 
2. Discussion of Background 
In the magnetic head supporting device of this type, the following 
requirements have to be satisfied in order that the magnetic head can 
follow tracks formed in a surface of the magnetic disk with a 
predetermined small gap. Namely, a slider of the magnetic head holding 
reading/writing elements undergoes a pitching motion with respect to a 
first axis and a rolling motion with respect to a second axis which 
perpendicularly intersects the first axis to thereby remove uneven 
swinging motions. A magnetic head supporting device of this type is 
disclosed, for instance, in Japanese Examined Patent Publication No. 
22827/1983 and Japanese Utility Model Publication No. 93868/1986. 
FIG. 8 is a front view showing the relation beween the conventional 
magnetic head supporting device and a magnetic disk and FIG. 9 is a plane 
view of the supporting device and the magnetic disk. In the figures, 
reference numeral 1 designates a magnetic disk and numeral 2 designates a 
magnetic head supporting device. 
The magnetic disk 1 is driven in the direction of an arrow mark a by a 
driving unit (not shown). The magnetic head supporting device 2 is held by 
a positioning unit (not shown) so that it is driven linearly in the 
direction of an arrow mark b1 or b2, namely, in the radial direction along 
the diameter O.sub.1 of the rotating magnetic disk 1, and is positioned at 
a predetermined track so that writing operation to the magnetic disk 1 or 
reading operation from the disk 1 are carried out. 
The magnetic head supporting device 2 comprises a supporter 22 made of a 
flexible thin elongated plate of a material such as stainless steel, one 
end of which is fixed to a rigid arm 21, which is in turn attached to the 
positioning unit, by means of fastening means 211, 212 such as screws. The 
other end in the longitudinal direction of the supporter 22 which 
constitutes a free end is attached with a flexible member 23. A magnetic 
head 24 is attached to the lower surface of the flexible member 23. The 
supporter 22 comprises a resilient spring portion 221 which constitutes a 
portion connected to the rigid arm 21. A rigid beam portion 222 is formed 
integrally with the resilient spring portion 221. The rigid beam portion 
222 is provided at both sides with flanges 222a, 222b formed by bending 
both side portions of the rigid beam portion and this provides a loading 
force which pushes the magnetic head 24 toward the magnetic disk 1. 
FIG. 10 is an enlarged front view showing an important part of the 
conventional magnetic head supporting device and FIG. 11 is a side view of 
the same. The flexible member 23 is made of a resilient metallic plate of 
a material such as stainless steel. 
The flexible member 23 comprises a flexible flat plate portion, a pair of 
flexible outer frame portions 231, 232 formed integrally with both edges 
of the flat plate portion to extend substantially parallel to the axial 
line in the longitudinal direction of the supporter 22, a lateral frame 
233 connecting both ends of the pair of flexible outer frame portions 231 
and 232 at positions apart from the supporter 22, and a central tongue 
portion 234 which has an end connected to the intermediate portion of the 
lateral frame 233 and a free end extending toward the supporter, the free 
end extending between the pair of flexible outer frame portions 231, 232 
and substantially parallel to the same. One end of the flexible member 23 
which is opposite the lateral frame 233 is connected to the supporter 22 
at a portion near its free end by using bonding means such as an adhesive. 
At substantially the central portion on the upper surface of the central 
tongue portion 234, a loading projection 235 having, for instance, a 
semi-spherical form is provided so that the loading projection 235 
transmits a loading force from the free end of the supporter 22 to the 
central tongue portion 234. The loading projection 235 may be attached to 
the lower surface of the supporter 22 at a portion near the free end. The 
magnetic head 24 is attached to the lower surface of the central tongue 
portion 23 by means of, for instance, an adhesive agent. 
The magnetic head 24 is provided with a slider 241 which constitutes a 
ceramic structure. A pair of rails 242, 243 are formed on a surface of the 
slider 241 with a length so as to face the magnetic disk 1. A pair of 
reading/writing elements 244, 245 such as thin film type magnetic head 
elements are attached to the end portions of the rails 242, 243. The 
surface of the reading/writing elements 244, 245 are covered by a 
protecting layer of a material such as a ceramic cover. Electrodes 246 and 
247 or 248 and 249 each connected to a thin film type conductor coil are 
attached to the surface of the protecting layer. A pair of lead wires 4 of 
a linear material are bonded at one end thereof to either one of the 
reading/writing elements 244, 245, e.g. the electrodes 248, 249 of the 
reading/writing element 245. The lead wires 4 are bent in a loop and one 
end of the lead wires is extended toward the rigid beam portion 222 and 
the resilient spring portion 221 along the upper surface of the supporter 
22. 
In the above-mentioned conventional magnetic head supporting device, stable 
floating characteristics can be obtained at an area of flying height of 
more than 0.3 .mu.m. However, the conventional device has the following 
problems. 
(a) In order to obtain magnetic recording of high density by determining a 
flying height to be less than 1/3 as the conventionally used flying 
height, i.e. less than 0.1 .mu.m to thereby reducing the spacing loss, it 
is necessary to reduce the surface area of the slider 241 opposing the 
magnetic disk so as to reduce a dynamic pressure for floating. In this 
case, since the flexible member 23 of the conventional supporting device 
is constituted by an resilient metallic plate of a material such as 
stainless steel, the elasticity of the flexible member 23 is too strong in 
comparison with a dynamic pressure for floating to the slider, with the 
result that it is difficult to balance the elasticity of the flexible 
member to the dynamic pressure, and stable control for the posture of the 
head can not be obtained. 
(b) In order to balance the elasticity of the flexible member 23 and the 
dynamic pressure for floating, the flexible member inevitably has a 
complicated shape and a structure as disclosed in the above-mentioned 
publications. Since the flexible member is formed by the resilient 
metallic plate of stainless steel, it is difficult to form the flexible 
member into a complex structure. Especially, when the slider 241 
constituting the magnetic head 24 is to be miniaturized to thereby 
accomplish a low flying height, it is necessary to reduce the size of the 
flexible member 23; this requires further difficult machining. 
(c) Connecting and wiring operations are required for the lead wires 4 of a 
linear material which are to be connected to the electrodes 246 and 247 or 
248 and 249 of either one of the reading/writing elements 244, 245. The 
wiring structure is complicated, and the wiring and assembling operations 
are troublesome. 
(d) The function of the flexible member 23 is influenced by the elasticity 
of the lead wire 4 to thereby impair stable floating characteristics. If 
the elasticity of the flexible member 23 and the dynamic pressure for 
floating on the magnetic head 24 are made small so as to attain a low 
flying height, the elasticity of the lead wire 4 strongly influences the 
flexible member and the floating characteristics of the floating member is 
apt to change. 
(e) It is necessary to form a large loop of the lead wire 4 in order to 
reduce the adverse effect of the elasticity of the lead wire. This results 
in possible contact of the looped lead wire 4 with the other elements. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a magnetic head 
supporting device having a reduced size and a simple wiring structure; 
accomplishing a low flying height and providing stable operation. 
The foregoing and other objects of the present invention have been attained 
by providing a magnetic head supporting device which comprises a supporter 
having a resilient spring portion and a rigid beam portion contiguous to 
the resilient spring portion; a flexible member whose one end is attached 
to the supporter at a portion near its free end; a loading projection 
provided in the upper surface of the flexible member or in the lower 
surface of the supporter at a portion near its free end to thereby 
transmit a loading force from the free end of the supporter to the 
flexible member; and a magnetic head having a slider attached with 
reading/writing elements, the magnetic head being fixed to the lower 
surface of the flexible member, wherein the flexible member is composed of 
a plate of a polymeric resinous material having conductors for wiring; the 
conductors are electrically connected to electrodes for the 
reading/writing elements of the magnetic head, and the plate of a 
polymeric resinous material is extended on the supporter in its 
longitudinal direction.

DESCRIPTION OF PREFERRED EMBODIMENTS 
Several embodiments of the magnetic head supporting device of the present 
invention will now be described with reference to the drawings, wherein 
the same reference numerals designate the same or corresponding parts. 
A flexible member 23, which was conventionally made of a resilient metallic 
plate of a material such as stainless steel, is constituted by a plate of 
a polymeric resinous material. The plate of a polymeric resinous material 
is attached with conductors 236, 237 for wiring. Preferably, the flexible 
member 23 has such a construction that the conductors 236, 237 having a 
thickness of about several tens .mu.m are embedded as lines for wiring in 
a flexible plate-like material made of a polymeric resinous material 
having a thickness of about 125 .mu.m-250 .mu.m. 
Each end of the conductors 236, 237 is electrically connected to electrodes 
of either reading/writing element 244 or 245 of the magnetic head 24, for 
instance, to electrodes 248, 249 of the reading/writing element 245, and 
each other end is drawn outside. Beam lead conductors 25, 26 respectively 
connect the conductors 236, 237 to the electrodes 248, 249. 
In this embodiment, in the same manner as the conventional supporting 
device, the flexible member 23 comprises two flexible outer frame portions 
231, 232 extending substantially in parallel with the axial line in the 
longitudinal direction of the supporter 22, a lateral frame 233 connecting 
the flexible outer frame portions 231, 232 at the end far from the 
supporter 22 and a central tongue portion 234 extending substantially in 
parallel with the flexible outer frame portions 231, 232 from around the 
center of the lateral frame 233 and having its forward end as a free end. 
One end opposite the end with the lateral frame 233 is connected to a 
point near the free end of the supporter 22 by means of e.g. bonding. The 
conductors 236, 237 are embedded in the flexible outer frame portions 231, 
232 and the lateral frame 233. A loading projection 223 having, for 
instance, a semi-spherical shape is provided on the lower surface of the 
supporter 22 at a position near the free end so that a loading force is 
transmitted from the free end of the supporter 22 to the central tongue 
portion 234. The loading projection 223 may be provided on the upper 
surface of the flexible member 23 in the same manner as the conventional 
device. 
Thus, by forming the flexible member 23 with a polymeric resinous 
plate-like material 230, the flexible member 23 having a weak spring 
function and a high degree of freedom of twisting and elongation can be 
obtained in comparison with the conventional resilient metallic plate of a 
material such as stainless steel. The flexible member 23 having the 
above-mentioned structure assures a balance between the dynamic pressure 
for floating acting on the slider 241 and the elasticity of the flexible 
member 23, and stable posture of the magnetic head even when the magnetic 
head 24 is miniaturized to thereby reduce flying height and to increase 
the density of magnetic recording. Further, the flexible member 23 allows 
easy machining operations because it is formed by a polymeric resinous 
material. 
Since the flexible member 23 is so constructed that the conductors 236, 237 
for wiring which are electrically connected to the electrodes 248, 249 of 
the reading/writing element 245 of the magnetic head 24 are attached onto 
the polymeric resinous plate-like material 230, the conductors 236, 237 
can be utilized as lines to be connected to the magnetic head 24. The same 
effect is obtainable when the conductors 236, 237 for wiring are 
respectively connected to the electrodes 246, 247 of the reading/writing 
element 244. The construction of the magnetic head supporting device of 
the present invention simplifies the wiring structure connected to the 
magnetic head 24 and eliminates any adverse effect to the flexibility of 
the flexible member 23 unlike the conventional device having the outer 
lead wires. 
The plate of polymeric resinous material 230 which constitutes the flexible 
member 23 has its rear end portion which is led from the lower surface of 
the supporter 22 to the upper surface through an opening 224 formed at the 
rigid beam portion 222, and is extended along the upper surface of the 
rigid beam portion 222 and the resilient spring portion 221. In the 
above-mentioned construction, the conductors 236, 237 for wiring provided 
on or in the plate of polymeric resinous material 230 can be used as lead 
wires for taking out signals from the magnetic head 24 to the outside, 
whereby the construction for drawing out leads can be simplified. 
It is preferable that the plate of polymeric resinous material 230 is made 
for surface-contact with and is fixed onto the upper surface of the rigid 
beam portion 222 and/or the resilient spring portion 221 by means of an 
adhesive or similar contact material. With such construction, the plate of 
polymeric resinous material 230 can be used as a damper, and accordingly 
the frequency characteristics of vibrations of the rigid beam portion 222 
can be improved. 
In this embodiment, an integrated circuit element 6 for reading/writing to 
the magnetic head 24 is attached to a surface of the plate of polymeric 
resinous material 230. Accordingly, the distance between the magnetic head 
24 and the integrated circuit element 6 for reading/writing for arranging 
lead wires can be shorten, so that a lead inductance is reduced. 
Accordingly, there is obtainable a high magnetic recording/reproducing 
device having a high noise resistance characteristics and free from 
reduction of an output due to the lead inductance even when speed of 
reading/writing is high to perform high frequency operations. Further, 
influence of noises due to lead wires can be reduced. A technique of 
reducing a lead inductance by directly attaching an integrated circuit 
element 6 for reading/writing to the magnetic head 24 is known (for 
instance, in Japanese Unexamined Patent Publication No. 118017/1983). 
However, there is tendency to miniaturize the size of the magnetic head 
24. It causes difficulty in a physical sense to mount the integrated 
circuit element 6 on the magnetic head 24. In accordance with the 
embodiment of the present invention wherein the integrated circuit element 
6 for reading/writing is attached to a surface of the plate of a polymeric 
resinous material 230 which is in turn mounted on the rigid beam portion 
222 of the supporter 22, sufficient functioning is obtainable even though 
the magnetic head 24 is miniaturized. 
FIG. 6 is a front view of another embodiment of the magnetic head 
supporting device according to the present invention, and FIG. 7 is a side 
view showing the magnetic head supporting device as shown in FIG. 6. 
In FIGS. 6 and 7, a flexible member 23 is formed by a single flat plate of 
a polymeric resinous material without providing flexible outer frame 
portions, a lateral frame portion and central tongue portion. In this 
embodiment, the shape and the structure of the flexible member 23 are 
simplified and machining and assembling works of the flexible member are 
made easy by utilizing the features of the plate of a polymeric resinous 
material having a high degree of freedom of twisting and elongation. 
Thus, in accordance with the present invention, the following effects can 
be obtained. 
(a) The flexible member made of the polymeric resinous material has a high 
degree of freedom of twisting and elongation. Accordingly, there is 
obtainable a magnetic head supporting device which assures balance between 
the dynamic pressure for floating on the slider and the elasticity of the 
flexible member and a stable posture of the magnetic head even when the 
magnetic head is miniaturized to thereby reduce flying height and to 
increase the density of magnetic recording. 
(b) Since the flexible member is formed by a polymeric resinous material, 
the flexible member can be easily machined and assembled. 
(c) The conductors for wiring are attached or embedded in a plate of a 
polymeric resinous material, and the conductors are electrically connected 
to the electrodes of the reading/writing elements and the polymeric 
resinous plate-like material is extended along the supporter in its 
longitudinal direction. Accordingly, the conductors can be utilized as 
wires for reading/writing signals. Accordingly, the structure of wiring 
can be simplified, and the flexibility of the flexible member is not 
adversely affected by the outer lead wires. 
(d) The plate of a polymeric resinous material having the conductors for 
wiring functions as a damper. Accordingly, a magnetic head supporting 
device having excellent frequency characteristics can be attained. 
Obviously, numerous modifications and variations of the present invention 
are possible in light of the above teachings. It is therefore to be 
understood that within the scope of the appended claims, the invention may 
be practiced otherwise than as specifically described herein.