Dynamic information storage or retrieval – With servo positioning of transducer assembly over track... – Optical servo system
Reexamination Certificate
2001-01-16
2004-03-16
To, Doris H. (Department: 2655)
Dynamic information storage or retrieval
With servo positioning of transducer assembly over track...
Optical servo system
C369S044160, C359S823000
Reexamination Certificate
active
06707771
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to an optical pickup device and to a method of manufacturing the same. More particularly, the present invention relates to a technique of supporting an objective lens of an optical pickup device.
An optical pickup device used for reproducing/recording information in an optical recording medium is described in, for example, Japanese Patent Publication No. 4-49174B2. As shown in
FIGS. 8 and 9
, the optical pickup device described in the publication has an objective lens
11
for converging a laser beam originating from a light source (not depicted) onto an optical recording medium (not depicted), and a lens holder
12
for sustaining the objective lens
11
. A drive coil
13
for focus-correction purpose (hereinafter called “focus-correction drive coil
13
”) is wound around the lens holder
12
. Further, a pair of drive coils
14
for tracking correction purpose (hereinafter called “tracking-correction drive coils
14
”) are bonded to each of opposed side faces of the lens holder
12
.
In the optical pickup device
10
, the lens holder
12
is elastically supported in a cantilever fashion by four metal wires
16
A,
16
B,
16
C, and
16
D. The four wires
16
A,
16
B,
16
C, and
16
D extend from a fixation member
110
and act as members for feeding power to the lens holder
12
. The wires
16
A to
16
D are coated with insulation material
15
such as a rubber tube or resin. In each of the wires
16
A to
16
D, a base end
161
is fixed to the fixation member
110
, and a leading end
162
passes through a hole
12
a
formed in opposed side faces of the lens holder
12
, wherein the holes
12
a
are formed in upper and lower areas of the side faces. The leading end
162
is soldered to a printed board
17
disposed on either lateral side face of the lens holder
12
.
The ends of the drive coil
13
and the ends of the drive coil
14
are soldered to the respective printed boards
17
. The focus-correction drive coil
13
and the tracking-correction drive coils
14
are electrically connected to the four wires
16
A through
16
D by way of copper foil patterns of the printed boards
17
.
The base end
161
of each of the wires
16
is soldered to a printed board
18
(i.e., the side of the printed board
18
on which is mounted the fixation member
110
). The printed board
18
is fixed to the side of the C-shaped fixation member
110
through use of a screw
19
. The fixation member
110
is formed from magnetic material, and two magnets
111
are bonded to the interior side of the fixation member
110
, thus constituting a magnetic circuit in conjunction with the focus-correction drive coil
13
and the tracking-correction drive coils
14
. Lead wires
112
are soldered to the printed board
18
and are electrically connected to the wires
16
A through
16
D by way of a copper foil pattern of the printed board
18
.
In the optical pickup device
10
having the foregoing construction, when power is fed to the lead wires
112
, power is fed to the focus-correction drive coil
13
or to the tracking-correction drive coils
14
by way of the wires
16
A through
16
D. By magnetic force developing between the focus-correction drive coil
13
or the tracking-correction drive coils
14
and the magnets
111
, the lens holder
12
is moved in a focusing or tracking direction so as to oppose the elastic force of the wires
16
A to
16
D while deforming the wires
16
A to
16
D. Consequently, the objective lens
11
is also moved in either the focusing or tracking direction. Accordingly, a laser beam originating from a light source (not depicted) is radiated onto a predetermined position on an optical recording medium by way of the objective lens
11
. If the light reflected from the recording medium is detected, information can be recorded onto and reproduced from the optical recording medium.
As shown in
FIG. 10A
, the four wires
16
A to
16
D are arranged in parallel to each other such that they overlap in sets of two when viewed in either the focusing direction (designated by arrow F) or the tracking direction (designated by arrow T). As shown in
FIG. 10B
, when viewed from the base ends of the four wires
16
A through
16
D, the wires
16
A through
16
D are arranged independently of each other within a rectangular-parallelepiped space (with the shorter sides of the rectangular-parallelepiped space extending in the focusing direction and the longer sides thereof extending in the tracking direction). Further, each of the wires
16
A to
16
D is formed from a wire having a uniformly-circular cross section.
Demands exists for a more compact and slim optical pickup device
10
. However, the optical pickup device
10
, in which the lens holder
12
is supported by the wires
16
A through
16
D as described by reference to
FIGS. 10A and 10B
, cannot satisfy such a demand in many cases. For instance, realization of a compact and slim optical pickup device
10
involves high-density layout of components. However, the wires
16
A through
16
D are placed in the corners of the rectangular-parallelepiped space, as shown in
FIGS. 10A and 10B
, and hence this space becomes dead space.
When the related optical pickup device
10
has been made compact and slim, difficulty is encountered in moving the lens holder
12
appropriately in the focusing direction or in the tracking direction. If the lens holder
12
is made compact and slim in association with the optical pickup device
10
having been made compact and slim, the wires
16
A through
16
D become closer to each other in both the focusing and tracking directions. Accordingly, the attitude of the lens holder
12
during movement of the lens holder
12
in either the focusing or tracking direction becomes difficult to control. If the wires
16
A to
16
D become closer to each other in the focusing direction as a result of the lens holder
12
being made slim, the wires
16
A through
16
D become likely to twist in the focusing direction. Hence, when moved in the tracking direction, the lens holder
12
becomes likely to tilt. If the wires
16
A through
16
D become closer to each other in the tracking direction as a result of a decrease in the width of the lens holder
12
, the wires
16
A through
16
D become likely to twist in the tracking direction. Accordingly, when moved in the focusing direction, the lens holder
12
becomes likely to tilt.
SUMMARY OF THE INVENTION
In the light of drawbacks of the related optical pickup device, the object of the present invention is to provide an optical pickup device which enables a reduction in dead space, even when adopting a construction of supporting a lens holder with four wires in view of effective feed of power.
Further, another object of the present invention is to provide an optical pickup device which enables a reduction in dead space and appropriate movement of a lens holder in both focusing and tracking directions, as well as to provide a method of manufacturing the optical pickup device.
In order to achieve the above objects, according to the present invention, there is provided an optical pickup device for an optical recording medium, comprising:
an objective lens for converging a laser beam onto the optical recording medium;
a lens holder for holding the objective lens;
fixation member;
four wires, first ends of which is supported by the fixation member, and second ends of which is connected to the lens holder; and
a lens driver for moving the objective lens in a focusing direction and a tracking direction of the optical recording medium, by elastically deforming the four wires through use of a magnetic force,
wherein the four wires are arranged so as to form two sets of wires and such that the two wires in each set overlap when viewed from at least one of the focusing direction and the tracking direction; and
wherein the two wires in at least one set of the two sets are integrally fixed together.
In terms of use of four wires for feeding power to a lens holder, there is a commonality between the present invention and th
Sugihara Hiroshi
Wade Tatsuki
Kabushiki Kaisha Sankyo Seiki Seisakusho
Ortiz-Criado Jorge
LandOfFree
Optical pickup device and method of manufacturing the same does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Optical pickup device and method of manufacturing the same, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical pickup device and method of manufacturing the same will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3225620