Optical: systems and elements – Lens – With support
Reexamination Certificate
2000-11-22
2002-10-08
Epps, Georgia (Department: 2873)
Optical: systems and elements
Lens
With support
C359S823000
Reexamination Certificate
active
06462892
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a lens driving apparatus used for information recording (information writing) into an information recording medium or information reproducing (information reading) from the information recording medium, and an apparatus and method of manufacturing the lens driving apparatus.
In order to optically perform information recording or information reproducing to a disk-shaped information recording medium such as CD (Compact Disk), DVD (Digital Video Disk or Digital Versatile Disk) or MD (Mini Disk), it is necessary to accurately follow an objective lens to an information track of the information recording medium. For this purpose, a so-called pickup apparatus is provided with a lens driving apparatus for electromagnetically driving the objective lens in a focusing direction and a tracking direction to perform positioning control.
FIG. 10
is a perspective view showing a configuration of a conventional lens driving apparatus provided in a pickup apparatus. This lens driving apparatus comprises a lens holder
2
in which an objective lens
1
is mounted and a substrate
7
for cantilevering the lens holder
2
by four elastic wires
3
,
4
,
5
,
6
.
While one ends of the respective elastic wires
3
,
4
,
5
,
6
are coupled to four corners of the lens holder
2
, the other ends of the elastic wires
3
,
4
,
5
,
6
are coupled to the substrate
7
through gaps defined by depression stepped portions
8
,
9
,
10
,
11
provided in four corners of the substrate
7
and opposed pieces
12
,
13
, and further the gaps are filled with ultraviolet cure resins
14
,
15
,
16
,
17
acting as a damping material which damps mechanical vibrations.
Further, as shown in a schematic side view of
FIG. 11
, a magnet
18
and yokes
19
,
20
fixed in the substrate
7
and an electric circuit board
21
fixed in the lens holder
2
are provided between the lens holder
2
and the substrate
7
, and a focusing coil and a tracking coil (not shown) are formed on the electric circuit board
21
. Also, the electric circuit board
21
in which the focusing coil and the tracking coil are formed is provided between the yokes
19
and
20
at a certain distance.
Then, magnetic force is generated in a focusing direction &thgr;
F
by supplying a driving current to the focusing coil and focusing control is performed by finely adjusting a position of the focusing direction &thgr;
F
of the objective lens
1
and the lens holder
2
by means of this magnetic force. Also, magnetic force is generated in a tracking direction &thgr;
T
by supplying a driving current to the tracking coil and tracking control is performed by finely adjusting a position of the tracking direction &thgr;
T
of the objective lens
1
and the lens holder
2
by means of this magnetic force.
Here, the lens holder
2
is cantilevered to the substrate
7
through the four elastic wires
3
,
4
,
5
,
6
, so that the lens holder
2
becomes deformed freely in response to the magnetic force generated in the case of the focusing control and the tracking control. As a result of this, the objective lens
1
and the lens holder
2
are deviated in a desired direction with them floated and thus, information recording into an information recording medium DSC or information reproducing from the information recording medium DSC can be performed with high accuracy.
Also, the elastic wires
3
,
4
,
5
,
6
are fixed in the substrate
7
while being buried in a state surrounded by the ultraviolet cure resins
14
,
15
,
16
,
17
acting as a damping material, so that the ultraviolet cure resins
14
,
15
,
16
,
17
absorb vibrations occurring in the elastic wires
3
,
4
,
5
,
6
in the case of the focusing control and the tracking control, and it is constructed so as to achieve the focusing control and the tracking control with good responsiveness.
Incidentally, as shown in
FIG. 11
, the substrate
7
is mounted on a movable body
24
supported by a pair of guide shafts
22
,
23
provided in a chassis of a body of an information recording and reproducing apparatus. Then, by forward or backward moving the movable body
24
along a longitudinal direction of the guide shafts
22
,
23
, this lens driving apparatus is forward or backward moved in a radial direction of the information recording medium DSC (the same direction as the tracking direction &thgr;
T
) and further by making use in combination with the focusing control and the tracking control, it is intended to perform the information recording and information reproducing with high accuracy.
However, in the conventional lens driving apparatus described above, as shown in
FIG. 10
, liquid sagging occurs in case of simply filling the depression stepped portions
8
,
9
,
10
,
11
of the substrate
7
with the ultraviolet cure resins
14
,
15
,
16
,
17
, so that the opposed pieces
12
,
13
other than the substrate
7
were mounted so as to attach to the depression stepped portions
8
,
9
,
10
,
11
and thereby the gaps capable of preventing the liquid sagging were defined and their gaps were filled with the ultraviolet cure resins
14
,
15
,
16
,
17
. Because of this, there were problems that the number of manufacturing steps increases while the number of parts increases. These problems will be described in detail with reference to
FIGS. 12 and 13
below.
First, as shown in an exploded perspective view of
FIG. 12
, the substrate
7
and the opposed pieces
12
,
13
are respectively molded by individual members. Depression stepped portions
7
c
,
7
d
,
7
e
,
7
f
for inserting the elastic wires
3
,
4
,
5
,
6
are molded in the four corners of the substrate
7
, and fitting protrusions
7
g
,
7
h
are formed on the side end of a T-shaped projection
7
b
of the side of the depression stepped portions
7
e
,
7
f
and fitting protrusions (not shown) similar to the fitting protrusions
7
g
,
7
h
are formed on the side end of a T-shaped projection
7
a
of the side of the depression stepped portions
7
c
,
7
d.
A through hole
13
a
for fitting the fitting protrusions
7
g
,
7
h
is formed in the opposed piece
13
and a through hole
12
a
similar to the through hole
13
a
is formed in the opposed piece
12
.
Next, as shown in a plan view of
FIG. 13
, after inserting the elastic wires
3
,
4
,
5
,
6
into the depression stepped portions
7
c
,
7
d
,
7
e
,
7
f
, the elastic wires
3
,
4
,
5
,
6
were supported in the substrate
7
by fixing respective rear ends of the elastic wires
3
,
4
,
5
,
6
with adhesive and then, the opposed pieces
12
,
13
were fitted to the projections
7
a
,
7
b
and the gaps defined thereby were filled with the liquid ultraviolet cure resins
14
,
15
,
16
,
17
and the resins were cured.
In this manner, the opposed pieces
12
,
13
were mounted in order to prevent the ultraviolet cure resins
14
,
15
,
16
,
17
from flowing out of the depression stepped portions
7
c
,
7
d
,
7
e
,
7
f
in a state of liquid, so that there were problems that the number of manufacturing steps increases while the number of parts increases.
SUMMARY OF THE INVENTION
The invention is implemented to overcome the problems of the conventional art, and it is an object of the invention to provide a lens driving apparatus, an apparatus and method of manufacturing the lens driving apparatus capable of reducing the number of parts and simplifying manufacturing steps.
In order to achieve the object, a lens driving apparatus of the invention is characterized in that the lens driving apparatus has a lens holder for holding an objective lens, and a substrate which supports the lens holder through elastic members and is molded with resin, and the elastic members are integrally supported in the substrate in the case of the resin molding and are provided within gaps molded in the substrate with the gaps ranging to the integrally supported portions and are buried in a damping material with which the gaps are filled.
Also, the lens driving apparatus is characterized in that the gaps are
Pioneer Corporation
Seyrafi Saeed H
Sughrue & Mion, PLLC
LandOfFree
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