Dynamic information storage or retrieval – Dynamic mechanism subsystem – Specified detail of transducer assembly support structure
Reexamination Certificate
2002-02-22
2004-05-04
Letscher, George J. (Department: 2653)
Dynamic information storage or retrieval
Dynamic mechanism subsystem
Specified detail of transducer assembly support structure
Reexamination Certificate
active
06731587
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a structure for supporting a transducer for recording or reproducing information on or from a recording medium mainly by an interaction with the recording medium, specifically, by the action of light, heat, magnetic field, or the like.
BACKGROUND ART
As a conventional example of a transducer-supporting structure, for example, a structure for supporting a magnetic core for magnetic recording is cited. As a medium, a magnetic tape or a flexible disk has been used, and in recent years, a minidisk (hereinafter abbreviated to MD) has been widely used as a magneto-optical recording medium mainly for music. The MD is based on the use of a sliding-type magnetic head slider for magneto-optical field modulation overwrite.
Next, a magnetic head structure mainly for MD will be discussed as an example of a conventional transducer-supporting structure. This example has been disclosed in Japanese Patent Laid-Open No. 6-195851. FIG.
10
(
a
) shows an entire structure.
In FIG.
10
(
a
), reference numeral
101
denotes a slider serving as a transducer mounting section. In general, the main function of the transducer mounting section is to interface with a medium. In this example, the slider comes into slidable contact with the medium to maintain a distance between a transducer and the medium.
The slider for a fixed magnetic disk keeps the distance between the transducer and the medium by means of floating. For the magnetic tape, flexible disk, and the like, although the transducer itself comes into contact with the medium, the contact pressure between the medium and the transducer is decreased by the expansion of sliding face, by which the transducer is prevented from wearing.
The slider
101
is mounted with a magnetic core
102
having an E shape in cross section, formed of ferrite etc., and a coil
104
(described later), both of which serve as a transducer. Reference numeral
103
denotes a suspension formed of a metallic elastic material such as stainless steel, beryllium copper, and phosphor bronze. The slider
101
is connected to the distal end of the suspension
103
.
The details of the sliding face of the slider
101
, which have been disclosed in Japanese Patent Laid-Open No. 7-129902, are shown in FIG.
10
(
b
). On the face opposed to disk of the slider
101
, a cylindrical face
101
a
that comes into contact with a disk
10
(described later) is formed as a sliding face. Reference numeral
102
a
denotes a magnetic pole exposed on the disk side of the magnetic core
102
. The cylindrical face
101
a
projects by a predetermined amount toward the disk from the magnetic pole
102
a.
The slider
101
including the cylindrical face
101
a
uses a slidable resin material having high wear resistance and some degree of lubricity on the face opposed to disk, which has an effect of preventing the slider
101
and the disk
10
from wearing.
FIG. 11
shows an essential part of the distal end of a magnetic head structure. A tongue
103
c
is formed at the distal end of the suspension
103
, and is connected to the slider
101
.
When the slider
101
comes into slidable contact with the disk
10
, which is a recording medium, a spring portion
103
a
is deformed elastically to apply a predetermined load in the direction toward the disk to the slider
101
. Thereby, a gimbal portion
103
b
is deformed elastically to keep the relative posture of the slider
101
and the disk
10
with respect to the disk inclination, so that the magnetic pole
102
a
is brought close to a recording film of the disk
10
.
FIG. 12
shows a sliding state. The slider
101
serving as a transducer mounting section has a box portion. In the box portion, the aforementioned magnetic core
102
is housed and fixed, and also an inside bottom face S of the box portion, which is in contact with the lower end face of the magnetic core
102
, plays a role in determining the relative height of the magnetic core
102
. The disk
10
moves in the direction indicated by an arrow A.
In this state, a modulated magnetic field produced by the coil
104
is induced by the magnetic core
102
and is applied from the magnetic pole
102
a
to the recording film heated by a converged laser beam, by which thermomagnetic recording is performed.
However, the above-described conventional transducer-supporting structure has problems described below.
In order to enhance the performance of equipment, for example, in order to increase the transfer rate of recorded information, it is necessary to increase the modulation frequency of magnetic field. Also, in order to achieve a high density, it is necessary to increase the intensity of magnetic field. Power consumption in the magnetic core
102
and the coil
104
, serving as an electromagnetic transducer, is caused by an eddy current loss and a high frequency loss such as a skin effect in the former case and coil resistance etc. in the latter case.
The consumed electric power turns to heat, which raises the temperatures of both of the magnetic core
102
and the coil
104
. Since the slider
101
is made of a resin material, which is a kind of thermal insulator, it is difficult to dissipate the heat of the electromagnetic transducer within the slider
101
, so that slight generation of heat leads to a great increase in temperature.
On the other hand, a magnetic material used for the magnetic core etc. generally has a Curie point. When a high-frequency large current is caused to flow, a temperature rise exceeding the Curie point due to the generation of heat loses the magnetism and extremely decreases the impedance. Therefore, there occurs a thermorunaway phenomenon that a large current flows, resulting in a temperature rise, and finally the burning of coil and the destruction of driving circuit take place.
Also, for another transducer, for example, an electro-optical transducer such as laser, a shorter wavelength is important to high-density recording and reproduction. However, light with a short wavelength has high energy, so that heat is generated greatly. On the other hand, for a semiconductor laser, the operating temperature has a great influence on the service life, so that a shorter wavelength cannot be achieved easily.
That is, in various types of transducers, a temperature rise greatly restricts the enhancement of performance.
Also, in the conventional example, the magnetic core
102
is fixed to the slider
101
by means of bonding etc. However, a change in temperature occurs as described above, and the coefficient of thermal expansion differs greatly between the magnetic core
102
and the slider
101
. Also, the slider
101
has a poor adhesive property because of being made of a slidable resin. Therefore, if thermal expansion and contraction are repeated for a long period of time, there arises a problem of reliability in that adhesion is lost, and thus the magnetic core
102
floats from the slider
101
, so that a sufficient magnetic field cannot be given to the recording film.
DISCLOSURE OF THE INVENTION
The present invention has been achieved to solve the above problems, and accordingly an object thereof is to provide a highly reliable transducer-supporting structure in which a rise in temperature is reduced, whereby the performance can be enhanced easily.
One aspect of the present invention is a transducer-supporting structure, characterized in that said structure at least comprises:
a transducer for recording and reproducing information on and from a medium;
a transducer mounting section which is mounted with said transducer and comes into contact with said medium by means of mechanical action or keeps a fixed distance from said medium;
a suspension which supports said transducer mounting section and elastically positions said transducer in the direction such as to bring and separate said transducer close to and from said medium; and
a thermal coupling member formed of a part of said suspension for thermally coupling said transducer with said suspension in direct contact with said transducer, and
at least a part of heat genera
Aikoh Hideki
Enshu Hisayuki
Mizuno Osamu
Murakami Yutaka
Nakamura Tohru
Beacham C R
Letscher George J.
Matsushita Electric - Industrial Co., Ltd.
RatnerPrestia
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