Dynamic information storage or retrieval – Storage or retrieval by simultaneous application of diverse... – Magnetic field and light beam
Reexamination Certificate
2001-09-18
2004-07-13
Psitos, Aristotelis M. (Department: 2653)
Dynamic information storage or retrieval
Storage or retrieval by simultaneous application of diverse...
Magnetic field and light beam
C369S013330, C369S112230, C359S719000
Reexamination Certificate
active
06762978
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optical head slider for use in an optical head for recording/reproducing information signals to/from a recording medium such as an optical disc, a method for manufacturing the optical head slider, and a recording and/or reproducing apparatus for recording/reproducing information signals to/from a recording medium by the use of an optical head having the optical head slider.
2. Description of the Related Art
Up to now, there have been proposed optical discs, such as a magneto-optical disc and phase change type optical disc, to/from which information signals are recorded/reproduced by irradiating a beam to the signal recording surface thereof. So as to record many information signals to an optical disc to the utmost, attempts to enlarge recording density thereof have been made enthusiastically.
Along with the attempts to enlarge recording density of an optical disc, attempts to improve recording density have been made as to an optical pick up which records/reproduces information signals to/from an optical disc. That is, the optical pick up has reduced its spot size of a beam to be irradiated to the signal recording surface of an optical disc.
Especially, recently, the techniques of a floating type head slider of a hard disc drive have been employed to configure an optical head slider by mounting an optical lens to a sliding member. That is, there is proposed an optical head slider which is floated by a predetermined clearance and slides on the signal recording surface of an optical disc and whose optical lens condenses a beam led by an optical fiber to irradiate the condensed beam to the signal recording surface of an optical disc.
In case such an optical head slider is used in an optical disc drive, the clearance between the optical lens and the signal recording surface of an optical disc can significantly be reduced compared with that which does not use the optical head slider and irradiates a beam from an optical head to the signal recording surface of an optical disc. Thus, a lens of a high NA (numerical aperture) can be used, and the spot size of a beam to be irradiated to the signal recording surface of an optical disc can be reduced.
In the above-described optical disc drive, the optical lens is required to be unitedly mounted to the optical head slider such that the bottom of the optical lens is located at the bottom of the optical head slider which faces the optical disc. The optical lens is fixed at an opening provided at the optical head slider by undergoing glass fusion or adhesion using UV (ultraviolet) curing type organic adhesive.
FIG. 1
shows a sectional view of a conventional optical head slider
100
. As shown, the optical head slider
100
has a sliding member
102
which is floated and slides on the signal recording surface of a magneto-optical disc
101
at the time of recording/reproducing information signals to/from the magneto-optical disc
101
, and an objective lens
103
which is fixed to the sliding member
102
. The sliding member
102
has an optical fiber
104
and a deflection mirror
105
built therein. A laser beam L led by the optical fiber
104
falls on the objective lens
103
via the deflection mirror
105
, and is condensed by the objective lens
103
, and then falls on a signal recording layer
101
a
of the magneto-optical disc
101
.
The sliding member
102
further has a thin-film coil
106
for applying a magnetic field to the magneto-optical disc
101
at the time of recording information signals, and a terminal
107
which is electrically connected to the thin-film coil
106
. The thin-film coil
106
is so located at the lower part of the sliding member
102
facing the magneto-optical disc
101
as to wind around the objective lens
103
to form a thin film. On the other hand, the terminal
107
is formed by filling conductive material into an opening
108
which penetrates the sliding member
102
along the thickness direction thereof such that the end thereof is shared with the end of the thin-film coil
106
.
The sliding member
102
is mounted to the end of a supporting arm
109
which is mounted to the optical disc drive. The laser beam L scans the signal recording surface of the rotated magneto-optical disc
101
when the supporting arm
109
is caused to pivot along the radial direction of the magneto-optical disc
101
.
Thus configured optical bead slider
100
receives an airflow generated due to the rotation of the magneto-optical disc
101
, and is floated by a predetermined clearance from the signal recording surface of the magneto-optical disc
101
, while irradiating the laser beam L condensed by the objective lens
103
to the signal recording layer
101
a
of the magneto-optical disc
101
to record/reproduce information signals to/from the magneto-optical disc
101
. When recording information signals, the thin-film coil
106
generates a magnetic field of a predetermined intensity, and applies the magnetic field to a portion of the signal recording layer
101
a
of the magneto-optical disc
101
to which the laser beam L is irradiated.
The optical head slider
100
is provided with an opening
113
which penetrates the sliding member
102
along the thickness direction thereof, and the objective lens
103
is fit into the opening
113
and fixed to the sliding member
102
by undergoing glass fusion or adhesion using UV (ultraviolet) curing type organic adhesive
110
.
The lower part of the optical head slider
100
is made up of the lower part of the sliding member
102
, objective lens
103
, thin-film coil
106
and adhesive
110
. So, at the time of polishing the bottom of the optical head slider
100
, there are generated micro-irregularities being of the order of 100 nm to 200 nm due to the hardness difference between their materials.
In case of irradiating a beam of a reduced spot size to the magneto-optical disc
101
by the use of the high NA lens to enlarge recording density, the clearance between the optical head slider
100
and the signal recording surface of the magneto-optical disc
101
becomes significantly small. So, when dust is attached to the micro-irregularities of the floating surface or the bottom of the optical head slider
100
, the magneto-optical disc
101
is caused to crash frequently due to the reduced clearance. Furthermore, the dust attached to the floating surface of the optical head slider
100
is burned, and such burned dust cannot be removed or cleaned up even though organic solvent is used.
OBJECT AND SUMMARY OF THE INVENTION
It is therefore an object of the present invention to overcome the above-mentioned drawbacks by providing an optical head slider of a high reliability which can appropriately record/reproduce information signals to/from a recording medium even though the clearance from the signal recording surface of the recording medium becomes significantly small and of a configuration which can facilitate the manufacturing thereof.
It is another object of the present invention to provide a method for manufacturing the optical head slider easily with high accuracy.
It is yet another object of the present invention to provide a recording and/or reproducing apparatus having an optical head using the optical head slider.
According to the present invention, there is provided an optical head slider including:
a sliding member which is floated and slides on a recording medium at the time of recording/reproducing signals to/from the recording medium;
an optical lens having a spherical surface and a flat surface, which is bonded to the sliding member; and
means for generating a magnetic field, which is mounted to the bottom of the sliding member which faces the recording medium;
wherein the sliding member is made of the same material as that of the optical lens, and the flat surface of the optical lens is bonded to the top surface of the sliding member, so that a sum of a thickness of the optical lens and that of a basal plate becomes the radius of curvature of the spherical surface of
Mishima Akio
Watanabe Kenjiro
Kananen Ronald P.
Psitos Aristotelis M.
Rader & Fishman & Grauer, PLLC
Sony Corporation
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