JP2003217150A - Optical pickup actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical pickup actuator which is movable in the tilting direction for the purpose of correcting the lens angle relative to the warpage of a disk, in a simple structure and at a low cost. <P>SOLUTION: In the optical pickup actuator, among a plurality of suspension wires 1-4, at least a pair of wires are each equipped with two suspension wire elements arranged side by side 1a, 1b, 2a, 2b, 3a, 3b, 4a, 4b. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup provided in an optical disk drive, and more particularly to an optical pickup actuator for displacing an objective lens vertically and horizontally.

[0002]

2. Description of the Related Art Conventionally, CD-ROM, CD-R / RW,
An optical pickup is used as a drive for reading from or writing to an optical recording medium (hereinafter referred to as an optical disk) such as a DVD-R / RW and a DVD-RAM. The optical pickup actuator shown in FIGS. 3 and 4 is used for such an optical pickup.

FIG. 3 is a perspective view showing an example of a conventional optical pickup actuator. FIG. 4 is a diagram showing another example of the conventional optical pickup actuator. 5A, 5B, and 5C are shown in FIG.
FIG. 5 is a front view, a bottom view, and a side view, respectively, of the optical pickup actuator of FIG.

The optical pickup actuator shown in FIGS. 3 and 4 has a similar structure except that the two yokes 36 'are integrally formed, and is different from the example shown in FIG. The conventional example of FIG. 4 will be described.

Referring to FIGS. 4 and 5, an optical pickup actuator 100 includes a movable portion 10 which constitutes a part of an optical head (optical pickup), and the movable portion 10 in the vertical direction (first direction) A. And left-right direction (second direction)
A fixed portion 20 that is movably supported by B and a drive device 30 provided on these are provided.

The movable portion 10 comprises an objective lens 11, a lens holder 12 for holding the objective lens 11, and a holding portion 13 for integrally holding and holding the lens holder 12. The holding portion 13 has a hole 13a at the center. The drive device 30 is provided in the hole 13a. The drive unit 30 is divided into a movable part and a fixed part.

The movable portion of the driving device 30 has first and second tracking coils 31 and 32, and a focus coil 33. The first and second tracking coils 31 and 32 are held by a holding unit 13, are respectively wound in a vertical direction, and are provided symmetrically with respect to the central axis of the holding unit 13. On the other hand, the focus coil 33 is held by the holding unit 13 adjacent to the first and second tracking coils 31 and 32 in the central axis direction, and is wound in the horizontal direction. The fixed portion of the drive unit 30 will be described later.

Also, two suspension wires 341, 342, 343 and 34, which are elastic rods or wire rods, are provided on each side of the holding portion 13.
4 are provided. One ends 341a to 344a of the first to fourth suspension wires 341 to 344 are respectively attached to the holding portion 13 and the first to fourth protrusions 131, 132, 133 and 1 protruding horizontally outward therefrom.
It is fixed at 34. On the other hand, the other ends 341b to 344 of the first to fourth suspension wires 341 to 344.
As will be described later, b is fixed to the damper base that constitutes the fixing portion 20.

The fixed portion 20 includes an actuator base 21.
And a damper base 22. The actuator base 21 is in the shape of a rectangular frame made of a magnetic metal material, and has a support block 211 that forms a receiving portion 21 a of the damper base 22 at one end thereof. That is, the damper base 22 is the support block 211.
It is fixedly supported on. The support block 211 is formed integrally with the actuator base 21.

The fixed portion of the drive portion 30 provided in the hole portion 13a of the holding portion 13 includes the first and second yokes 36 and 37 and the first and second magnets 38 and 3.
9 and. First and second yokes 36 and 37
Is composed of a part of the actuator base 21,
Stand up from the actuator base 21, and between them,
The first and second tracking coils 31 and 32 and the focus coil 33 described above are arranged. The first magnet 38 is the first tracking coil 31.
And the second magnet 39 is attached to the surface of the second yoke 37 facing the focus coil 33, and the second magnet 39 is attached to the surface of the second yoke 37 facing the focus coil 33. First yoke 36 and first magnet 3
8 together form a first fixed magnet section, and the second yoke 37 and the second magnet 39 together form a second fixed magnet section.

That is, the drive unit 30 includes the first and second tracking coils 31 held by the movable section 10,
32 and the focus coil 33, the first and second yokes 36 and 37 provided on the fixed portion 20, and the first
And second magnets 38 and 39. The movable unit 10 is configured to be movable in the vertical direction A and the horizontal direction B with respect to the fixed unit 20 (actuator base 21) by the drive device 30.

In the drive unit 30, when the first and second tracking coils 31 and 32 and the focus coil 33 are energized through the first to fourth suspension wires 341 to 344, the first and second fixed magnets. The movable part 10 is fixed to the fixed part 20 by the action of the magnetic flux from the part.
It is driven so as to move relative to the (actuator base 21), and the focus and tracking are adjusted.

The damper base 22 has first to fourth suspension wires 341 to 344 at its four corners, respectively.
The first to fourth hollow portions 221 and 221 capable of communicating the other end side of the
22, 223 and 224, and these first to fourth
A damping material (not shown) for suppressing the vibration of the first to fourth suspension wires 341 to 344 is injected into the hollow portions 221 to 224. On the rear wall of the damper base 22, the first to fourth hollow portions 221 to 22 are formed.
4 to the first to fourth suspension wires 3 respectively
Holes (not shown) for passing the other ends 341b to 344b of 41 to 344 are formed. That is, the other ends 341b of the first to fourth suspension wires 341 to 344
The 344 b passes through the holes of the first to fourth hollow portions 221 to 224 of the damper base 22 and extends from the rear wall of the damper base 22.

The first to fourth suspension wires 341 to 341 are provided at the center of the rear wall of the damper base 22.
The board 23 for passing an electric current to 44 is fitted, and the screw 4
It is fixed at 1. From both sides of this board 23,
The first to fourth conductive plates 231 and 232, which are conductive one by one,
233 and 234 are separated from the rear wall of the damper base 22 and extend in the horizontal direction (left-right direction) B. The first to fourth conductive plates 231 to 234 have first to fourth suspension wires 341 to 341 at their tip portions, respectively.
Holes 231a, 2 for passing the other ends 341b to 344b of 344
32a, 233a and 234a are vacant. The other ends 341b to 344 of the first to fourth suspension wires 341 to 344 are formed by the holes 231a to 234a.
b is the first to fourth conductive plates 231 to 234, respectively.
It is fixed to the tip of by soldering. That is, one conductive plate is fixed to one suspension wire. Each of the first to fourth conductive plates 231-234,
For example, it is made of a copper plate.

[0015]

In the above-mentioned conventional optical pickup actuator, the conventional actuator structure has the movable direction only in the focus direction and the track direction.

Therefore, when reading a warped disc,
Alternatively, when writing is performed, the disc and the objective lens become non-parallel and the quality of the laser spot on the disc deteriorates, causing a read error and a write error.

Therefore, a technical object of the present invention is to provide an optical pickup actuator in which the movable direction of the actuator can be moved not only in the focus and track directions but also in the tilt direction for correcting the angle of the lens with respect to the warp of the disk. To provide.

Another technical problem of the present invention is
An object of the present invention is to provide the optical pickup actuator with a simple structure and at low cost.

[0019]

According to the present invention, a movable part (10) including a lens holder (12) for holding an objective lens (11), a damper base (22), and a fixed support for the damper base. Actuator Base (21)
And a plurality of suspension wire portions (1 to 4) fixed to the movable portion (10) at one end and extending from both sides of the movable portion (10) and the other end fixed to the damper base (22). The damper base (22) so that the movable part (10) can be displaced at least vertically and horizontally with respect to the damper base (22) via the plurality of suspension wire parts (1 to 4). In the optical pickup actuator (50) supported by (1), at least a pair of each of the plurality of suspension wire portions (1 to 4) has two suspension wire elements (1a, 1b, 2a, 2b) arranged side by side. , 3
a, 3b, and 4a, 4b) are obtained.

According to the invention, in the optical pickup actuator (50), the movable part (1)
In addition to the vertical and horizontal directions, 0) is configured so that it can be displaced in the tilt directions in which the vertical and horizontal directions move in mutually opposite directions, so that an optical pickup actuator (50) can be obtained.

Further, according to the present invention, in the optical pickup actuator (50), the suspension wire elements (1a, 1b, 2a, 2b, 3a, 3b, 4a,) of the plurality of suspension wire portions (1-4) are provided.
Optical pickup actuators (50) are characterized in that 4 b) are arranged in a pair symmetrically in pairs on the left and right sides of the movable part (10) in a pair of 2 pairs and in a plane intersecting with the facing direction. Is obtained.

According to the invention, in the optical pickup actuator (50), the movable part (1)
The respective displacements of 0) are the coils provided corresponding to the respective displacements provided in the movable part (10), and the magnets (38a, 3a provided in the actuator base (22).
8b, 39a, 39b) and an electromagnetic force with the optical pickup actuator (50)
Is obtained.

According to the present invention, in the optical pickup actuator (50), the suspension wire elements (1a, 1b, 2a, 2b, 3a, 3b, 3b, 3b) of the suspension wire portions (1-4) are provided.
4a, 4b) has an energizing function to the coil, and an optical pickup actuator (5
0) is obtained.

It should be noted that the reference numerals in the above parentheses are given for facilitating understanding and are merely examples, and it goes without saying that the present invention is not limited to these.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view of an optical pickup actuator according to an embodiment of the present invention. FIG. 2 is a partial perspective view mainly showing a suspension wire of the optical pickup actuator of FIG.

Referring to FIG. 1, the optical pickup actuator comprises a movable portion 10 which constitutes a part of an optical head (optical pickup), a movable portion 10 which is vertically (first direction) A and horizontally (first). 2) B, and a tilting direction C (direction of rotation around an axis perpendicular to A and B) C, and a drive unit 30 provided on these.

The movable portion 10 comprises an objective lens 11, a lens holder 12 for holding the objective lens 11, and a holding portion 13 for integrally holding the lens holder 12 in a fixed manner. The holding portion 13 has a hole 13a at the center. The drive device 30 is provided in the hole 13a. The drive unit 30 is divided into a movable part and a fixed part.

The movable portion of the driving device 30 has first and second tracking coils 31a and 31b, a focus coil (not shown), and two tilt coils provided on the left and right of the focus coil (not shown). The first and second tracking coils 31a and 31b are held by the holding unit 13, are respectively wound in the vertical direction, and are provided symmetrically with respect to the central axis of the holding unit 13. On the other hand, the focus coil is held by the holding unit 13 adjacent to the first and second tracking coils 31a and 31b in the central axis direction, and is wound in the horizontal direction. Further, a pair of tilt coils is provided below the focus coil symmetrically with respect to the central axis, and is similarly held by the holding portion 13 and wound in the horizontal direction. The fixed portion of the drive unit 30 will be described later.

Further, on both sides of the holding portion 13, first to fourth suspension wire portions 1, 2, 3 and 4 made of elastic rods or wire rods are provided on the upper and lower sides.

Each of the first to fourth suspension wire parts 1, 2, 3, 4 is a suspension wire element 1a made of two elastic rods or wire rods which are vertically arranged and insulated from each other. 1b, 2a, 2b, 3
a, 3b, and 4a, 4b, respectively.

One end of each suspension wire element 1a, 1b of the first suspension wire portion 1 is fixed to the holding portion 13 by a first protrusion 131 protruding horizontally outward therefrom. On the other hand, the other ends of the respective suspension wire elements 1a and 1b of the first suspension wire portion 1 are fixed to a damper base forming the fixing portion 20, as described later.

Similarly, each suspension wire element 2 of the second to fourth suspension wire portions 2-4
One ends of a, 2b, 3a, 3b, 4a, and 4b are also fixed to the holding portion 13 by second to fourth protrusions 132, 133, and 134 protruding outward in the horizontal direction, respectively. On the other hand, the suspension wire elements 2a, 2 of the second to fourth suspension wires 2-4
The other ends of b, 3a, 3b, 4a, 4b are also fixed to the damper base that constitutes the fixing portion 20, as described later.

The fixed portion 20 has an actuator base 21.
And a damper base 22. The actuator base 21 has the shape of a rectangular frame made of a magnetic metal material, and has a support block on one end side thereof that forms a receiving portion for the damper base 22. That is,
The damper base 22 is fixed and supported on a support block formed integrally with the actuator base 21.

The fixed portion of the driving portion 30 provided in the hole portion 13a of the holding portion 13 has U-shaped first and second U-shaped yokes 36a and 36b provided side by side with each other, and a first portion. 1st and 2nd magnet 38a, 38b
And 39a, 39b. First and second U
The character-shaped yokes 36a and 36b are configured by screwing both ends of the actuator base 21. The first and second tracking coils 31a and 31b described above are arranged between them.

The one first magnet 38a is attached to the surface of the first U-shaped yoke 36a on the side facing the first tracking coil 31a. First of the other
The magnet 38b of the second tracking coil 31
It is attached to the surface of the second U-shaped yoke 36a on the side opposite to b.

One of the second magnets 39a is on the side facing the focus coil and the first tilt coil,
It is attached to the surface of the first U-shaped yoke 36a.
The other second magnet 39b is attached to the surface of the first U-shaped yoke 36b on the side facing the focus coil and the first tilt coil.

The first U-shaped yoke 36a and one of the first magnets 38a constitute a first fixed magnet portion, and a second fixed magnet portion is formed.
U-shaped yoke 36a and the other first magnet 38b
And constitute a second fixed magnet section.

The first U-shaped yoke 36a and one of the second magnets 39a constitute a third fixed magnet portion,
U-shaped yoke 36b and one second magnet 39b
And constitute a fourth fixed magnet section.

That is, the driving device 30 includes the first and second tracking coils 31 held by the movable portion 10.
a, 31b, the focus coil, the first and second tilt coils, the first and second U-shaped yokes 36a and 36b provided on the fixed portion 20, and the first and second magnets 38a and 38b. It is composed of 39a and 39b. The movable unit 10 is configured to be movable in the vertical direction A, the horizontal direction B, and the tilt direction C with respect to the fixed unit 20 (actuator base 21) by the drive device 30.

In this drive device 30, the first and second tracking coils 3 are provided via the tracking wire elements of the first to fourth suspension wire parts 1 to 4.
When current is applied to the 1a and 31b, the focus coil, and the first and second tilt coils, the movable portion 10 is fixed to the fixed portion 20 by the action of the magnetic flux from the first to fourth fixed magnet portions.
The actuator is driven so as to move relative to the (actuator base 21), the focus and tracking are adjusted, and the angle of the objective lens can be corrected with respect to the warp of the disk surface.

The damper base 22 has first to fourth hollow portions 221 'and 2'that can connect the other ends of the first to fourth suspension wire portions 1 to 4 to the four corners thereof.
23 ', and these first and second hollow portions 221',
A damping material (not shown) for suppressing the vibration of the first to fourth suspension wire parts 1 to 4 is injected into the inside of 223 '. On the rear wall of the damper base 22,
Holes (not shown) are formed in the first and second hollow portions 221 'and 223' for passing the respective suspension wire elements of the first to fourth suspension wire portions 1 to 4, respectively. That is, the other ends of the first to fourth suspension wire portions 1 to 4 are respectively connected to the damper base 22.
Through the holes of the first and second hollow portions 221 ′ and 223 ′, and extend from the rear wall of the damper base 22.

At the center of the rear wall of the damper base 22, the suspension wire elements 1a, 1b and 2 of the first to fourth suspension wire portions 1 to 4 are provided.
A board 23 for passing a current to a, 2b, 3a, 3b, 4a, and 4b is fitted and fixed with a screw 41. First to fourth conductive plates 231 and 23 having conductor patterns on the upper and lower surfaces of each of the two sides of the substrate 23.
2, 233 and 234 are separated from the rear wall of the damper base 22 and extend in the horizontal direction (left-right direction) B. The first to fourth conductive plates 231 to 234 have
Each of the first to fourth suspension wire parts 1
A hole is provided for passing the other end of ~ 4. With these holes, the first
To the other ends of the fourth suspension wire parts 1 to 4,
Each of the suspension wire elements is fixed by soldering to a pattern provided at the tip of the first to fourth conductive plates 231 to 234. That is, one conductive plate is fixed to one of the suspension wire portions. Each of the first to fourth conductive plates 231-234,
For example, it is composed of a metal plate or a wiring board on the surface of which a pattern layer is provided via an insulating layer.

With the optical pickup actuator according to the embodiment of the present invention having such a structure, it is possible to read and write in the best condition even on an optical disk having a warp.

Further, since the tilt coil is added to the conventional structure, the structure can be easily changed, and the structure can be simplified.

Since the changes can be easily implemented as described above,
Since it is possible to deal with it by increasing the number of parts and the price of components to the minimum, it is possible to deal with it by increasing the number of components and the price of components to the minimum, so that it is possible to change at a low cost.

Further, in the embodiment of the present invention, since the structure can be simplified, it can be mounted not only in the thick type (H / H) but also in the thin type (slim).

Further, in the embodiment of the present invention,
By arranging two wires at the four corners of the eight suspension wires for the conventional four suspension wires, the same lens tilt characteristics as the four wire support structure of the conventional structure can be obtained, and the tilt coil can be used. Can also be energized.

[0049]

As is apparent from the above description, according to the present invention, the movable direction of the actuator can be moved not only in the focus and track directions but also in the tilt direction for correcting the angle of the lens with respect to the warp of the disk. Therefore, it is possible to provide an optical pickup actuator capable of preventing the reading error and the writing error of the disc.

Further, according to the present invention, it is possible to provide an optical pickup actuator having the above advantages with a simple structure and at a low cost.

[Brief description of drawings]

FIG. 1 is a perspective view of an optical pickup actuator according to an embodiment of the present invention.

FIG. 2 is a partially enlarged perspective view of the suspension wire of FIG.

FIG. 3 is a perspective view showing an example of a conventional optical pickup actuator.

FIG. 4 is a perspective view showing another example of the conventional optical pickup actuator.

5A and 5B are diagrams showing the optical pickup actuator shown in FIG. 4, in which FIG. 5A is a plan view, FIG. 5B is a front view, and FIG. 5C is a left side view.

[Explanation of symbols]

1-4 suspension wire parts 1a, 1b, 2a, 2b, 3a, 3b, 4a, 4b
Suspension wire element 10 Moving part 11 Objective lens 12 Lens holder 21 Actuator base 22 Damper base 23 Substrates 231-234 Conductive plates 341-344 Suspension wire

Claims (5)

[Claims] 1. A movable part including a lens holder for holding an objective lens, a damper base, an actuator base for fixedly supporting the damper base, and an end fixed to the movable part and extending from both sides of the movable part. A plurality of suspension wire portions, the other ends of which are fixed to the damper base, so that the movable portion can be displaced at least vertically and horizontally with respect to the damper base through the plurality of suspension wire portions. In the optical pickup actuator supported by the damper base, at least a pair of each of the plurality of suspension wire portions includes two suspension wire elements arranged side by side. 2. The optical pickup actuator according to claim 1, wherein the movable portion is configured to be capable of displacement in a tilt direction in which vertical and horizontal directions move in opposite directions in addition to the vertical and horizontal directions. An optical pickup actuator characterized by: 3. The optical pickup actuator according to claim 1, wherein the suspension wire elements of the plurality of suspension wire portions are symmetrically arranged in pairs of four pairs on each of the left and right sides of the movable portion, in a symmetrical manner. An optical pickup actuator, wherein the optical pickup actuators are arranged side by side in a plane. 4. The optical pickup actuator according to claim 2, wherein the displacement of each of the movable parts is provided in each of the coils provided in the movable part in correspondence with the displacement, and in each of the actuator bases. An optical pickup actuator characterized by being generated by an electromagnetic force with a magnet. 5. The optical pickup actuator according to claim 4, wherein each suspension wire element of the plurality of suspension wire portions has a function of energizing the coil.