JPH06215391A - Sliding shaft type actuator - Google Patents

Abstract

PURPOSE:To provide the control current conducting part of good assembling workability without impairing the operating stability in a sliding shaft type actuator for an optical disk device. CONSTITUTION:This actuator comprises a main body 2, an objective lens 14, coils 12, 13, a movable part 3 borne by the shaft 6 of the main body 2 and a control current continuing part 50 for sending the current from the main body 2 to the coils 12, 13. The control current continuing part 50 comprises a downward bending flexible printed board part 70 formed by bending a flexible printed board downward in almost a circular-arcuate shape and upward bending printed boards 71, 72 by bending them upward in almost a circular-arcuate shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a control current conducting portion of a shaft sliding type actuator of an optical disk device.

It is desirable that the control current conducting portion of the shaft sliding type actuator has a structure that does not adversely affect the operation of the actuator and that the assembly work is easy.

[0003]

2. Description of the Related Art A conventional shaft slide type actuator 1 comprises a main body 2 and a movable body 3, as shown in FIGS.

First, a general structure will be described.

The main body 2 has a magnetic circuit 5 and a shaft 6 on a base 4.
And are fixed configurations.

The movable body 3 includes an arm 10, a cylindrical bearing 11 at the center of the arm 10, and a bearing 11 below the arm 10.
A focusing coil 12 and a tracking coil 13, which are formed in a cylindrical shape to surround, an objective lens 14 on one end side of the arm 10, and a balancer 15 on the other end side of the arm 10.

In the movable body 3, the bearing 11 is fitted and supported by the shaft 6, and the cylindrical coils 12 and 13 are opposed to the magnetic circuit 5 so as to be rotatable in the arrow A direction and in the arrow Z direction. It is slidable.

As shown in FIG. 10, this actuator 1 is incorporated in an optical disk device.

The laser beam 21 emitted from the laser unit 20 is reflected by the mirror 22 to rise, is focused by the objective lens 14 of the actuator 1, is focused on the optical disk 23, and is recorded and reproduced.

When the tracking error signal is supplied to the tracking coil 13, the movable body 3 is rotated in the A direction,
The objective lens 14 is displaced in the track width direction of the optical disc 23, and tracking control is performed.

When the focus error signal is supplied to the focusing coil 12, the movable body 3 is displaced in the Z direction, the objective lens 14 is displaced in the optical axis direction, and focus control is performed.

Next, the structure of the control current conducting portion will be described.

Reference numerals 30 and 31 denote twisted lead wires for supplying the focus coil current, one end of which is a pad 32 on the main body 2.
33, and the other end is soldered to the pads 34, 35 on the side surface of the arm 10 and bent in a U shape.

Reference numerals 36 and 37 denote twisted lead wires for supplying the tracking coil current, and the twisted lead wires 30 and 3 described above.
As in the case of No. 1, it is bent into a U shape, and one end is soldered and attached to the pad on the main body 2 and the other end to the pad on the arm 10.

During the above tracking and focus control, the movable body 3 has the twisted lead wires 30, 31, 36, 37.
Displace while deforming.

The twisted lead wires 30, 31, 36,
37 is freely deformable.

For this reason, the movable body 3 has a twisted lead wire 30,
It is displaced smoothly without being affected by 31, 36 and 37, and the tracking control and the focus control are normally performed.

[0018]

[Problems to be Solved by the Invention] The above-mentioned twisted lead wire 3
0, 31, 36, and 37 were positioned one by one, soldered at both ends, and bent and formed into a U shape to be connected.

That is, positioning, soldering, and delicate forming are performed on each twisted lead wire 30, 31, 36, 37.
Had to be done for each one.

Therefore, the conventional shaft sliding type actuator 1
The control current conducting part of No. 3 was not easy to assemble.

Therefore, the inventor of the present invention has proposed a shaft sliding type actuator 1A in which a strip-shaped flexible printed board 40 is elastically curved in a substantially arc shape in the control current conducting portion as shown in FIG. I put it out.

According to this structure, one strip-shaped flexible printed board 40 on which four wiring patterns are formed.
Since it suffices to fix one end to the end of the arm 10 and the other end to the block 41 on the base 4A, the control current conducting portion can be assembled with good workability.

However, as a result of the experiment, it was found that the displacement of the movable body 3 in the Z direction becomes uncomfortable and the focus control becomes unstable.

As shown in FIG. 13, the restoring force to the linear state indicated by the chain double-dashed line stored in the strip-shaped flexible printed board 40 itself is the force F in the direction indicated by the arrow at the end of the arm 10. ₁ , a clockwise moment acts on the movable body 3, and as shown in an exaggerated manner in the figure, the upper and lower end portions 11a and 11b of the cylindrical bearing 11 are locally supported by the shaft 6a.
It is believed that this is due to the strong contact with the.

Further, the optical axis 14a of the objective lens 14 is tilted, which causes aberration.

Therefore, an object of the present invention is to provide a shaft sliding type actuator in which the shape of the flexible printed board is devised so as to improve the assembling property without deteriorating the stability of the operation of the actuator. .

[0027]

According to a first aspect of the present invention, there is provided a main body having a magnetic circuit and a shaft, a bearing, a focusing coil, a tracking coil and an objective lens, and the bearing is supported by the shaft. A movable body rotatably and slidably provided, which is flexible, is connected to the main body and the movable body, and is provided between the movable body and the main body, and a control current is applied to the focusing coil and the tracking coil. In a shaft slide type actuator having a control current conducting part for energizing the movable body, the control current conducting part is curved in a substantially arc shape in one direction with respect to a movable body rotating surface on which the movable body rotates. And a unidirectionally curved flexible printed board portion having a belt shape and a unidirectionally curved flexible printed board portion having a belt shape which is curved substantially in an arc shape in the other direction with respect to the movable body rotating surface. Existence It is obtained by the configuration that.

According to a second aspect of the present invention, the one-way curved flexible printed board portion and the other-direction curved flexible printed board portion are adjacent strip portions of the flat flexible printed board having slits formed by the slits. Are curved in opposite directions with respect to the surface of the flat flexible printed board.

According to a third aspect of the present invention, there is provided a main body having a magnetic circuit and a shaft, a bearing, a focusing coil, a tracking coil and an objective lens, and the bearing is rotatably and slidably supported on the shaft. A movable body which is provided so that it is flexible, and a control current conducting section which is connected to the main body and the movable body and is provided between the movable body and the flexible body, and which supplies a control current to the focusing coil and the tracking coil. In the shaft sliding type actuator having a configuration, the control current conducting portion is curved in a substantially arcuate shape in one direction with respect to a movable body rotating surface on which the movable body rotates, and has a strip shape. The one-way curved flexible printed board portion and the other-direction curved flexible printed board portion which is curved in a substantially arc shape in the other direction with respect to the movable body rotating surface and the movable body rotating surface. versus Te is a vertical, in which a structure having an arm portion which is strip-shaped in the longitudinal direction of the control current supply unit.

According to a fourth aspect of the present invention, the one-way curved flexible printed board portion and the other-direction curved flexible printed board portion are adjacent strip portions of the flat flexible printed board on which slits are formed and are separated by the slits. Is formed by curving in a direction opposite to each other with respect to the surface of the flat flexible printed board, and the arm portion is formed by bending an extending portion of the flat flexible printed board. .

[0031]

According to the first aspect of the invention, the one-way curved flexible printed board portion and the other-direction curved flexible printed board portion act so that the direction of the force applied to the movable body is within the rotation surface of the movable body.

According to the slit of the second aspect, a part of one flat flexible printed board forms a curved flexible printed board portion. The arm portion of claim 3 acts so as to bend in a direction perpendicular to the surface when the movable body rotates. The extension part of Claim 4 is bent and acts so that an arm part may be formed.

[0033]

1 and 2 show a shaft sliding type actuator 1B according to a first embodiment of the present invention.

In each of the drawings, parts corresponding to those shown in FIGS. 10 to 13 are designated by the same reference numerals, and their description will be omitted.

Reference numeral 50 denotes a control current conducting portion, which has a shape taken out and shown in FIG. 3. The base 55 _-4 side is fixed on the block 52 on the base 4, and the tip 55 _-5 side is the arm 1.
It is fixed at the end of 0.

The control current supply portion 50 is formed by bending the flat flexible printed board 55 shown in FIGS. 4 and 5.

The flexible printed circuit board 55 are elongated rectangular shape, Yes and four wiring patterns 56 _-1 to 56 _-4 formed in parallel, the wiring pattern 56 _-1 and 56 between _-2 slits 57 _{- 1,} the slits 57 _-2 is formed between the wiring pattern 56 _-3 and 56 _-4. Each wiring pattern 56 _{-1 to} 5
At both ends of 6 _-4 , terminal portions 56 _-1a , 56 _-1b , ... 56
_-4a and 56 _-4b are formed.

Slit 57_-1, 57_-2By flexi
Wiring pattern 56_-2, 56_-3
With width W₁Central belt 55_-1And the wiring pattern
56_-1With width W₂The first lateral band 55 which is_-2
And the wiring pattern 56_-FourWith width W₃Is the third
Lateral belt 55_-3And the terminal portion 56_-1a, 56_-2a, 56
_-3a, 56_-4aWith a base 58_-FourAnd the terminal part 5
6_-1b, 56_-2b, 56_-3b, 56_-4bHaving a tip
55_-FiveIt is divided into and.

The widths W ₁ , W ₂ , W ₃ are W ₂ = W ₃ and W
There is a relation of ₁ = W ₂ + W ₃ .

As shown in FIG. 5, the flexible printed board 55 has a polyimide base film 58 having a thickness t ₁ of 12 μm and a wiring pattern 56 ₋₁ of rolled copper having a thickness t ₂ of 18 μm. The structure has a cover film 59 made of polyimide having a thickness t ₃ of 12 μm and having 56 _-4 and covering the wiring patterns 56 _-1 to 56 _-4 . While pushing the tip portion 55 _-5 of the flexible printed board 55 toward the base portion 55 _-4 as indicated by the arrow 60, the central strip portion 55 _-1 is pushed downward as indicated by the arrow 61, The first and second lateral bands 55 _-2 and 55 _-3 are respectively indicated by arrows 6
Push upwards as shown at 2,63.

As a result, the central strip _55-1 is elastically deformed to form a downward curved printed board portion 70 as a unidirectional curved flexible printed board portion curved downward in a substantially arcuate shape. The lateral strip portions 55 _-2 and 55 _-3 of ₂ are elastically deformed, and the upward curving flexible printed board portion 7 as the other direction flexible printed board portion that is curved upwards together.
1, 72 are formed.

The tip portion 55 _-5 is bent upward as shown by an arrow 64.

A flat flexible printed board 55 can be obtained by the simple operation of pushing and bending as shown in FIG.
The three-dimensional control current conducting portion 50 shown in (3) is attached to the actuator 1B in this state.

Downward curving flexible printed board 70
The upward curved flexible printed board portions 71 and 72 are symmetrical with respect to the rotation surface 75 of the movable body 3.

The focus coil current is the wiring pattern 5
The focusing coil 12 is energized through 6 _-1 and 56 _-2 . The tracking coil current is the wiring pattern 56.
_The tracking coil 13 is energized through _-3 and _56-4 .

As a result, the movable body 3 is displaced in the Z direction and is rotated in the A direction while deforming the curved flexible printed board portions 70, 71, 72 in the direction perpendicular to the plane and in the torsional deformation. Control and tracking control are performed.

This is the curved flexible printed board 7
An elastic force that restores linearly is stored in 0, 71, and 72.

Next, the force applied by the control current conducting portion 50 to the movable body 3 will be described.

In FIG. 2 and FIG. 3, the curved flexible printed board portion 70 in the state where the base portion _55-4 is fixed.
Tip of generates a force F _1, the tip of the curved flexible printed circuit board unit 71 generates a respective force F _2, F _3.

A resultant force F ₄ of the forces F ₁ , F ₂ , F ₃ acts on the tip portion 55 _-5 .

Here, the directions of the forces F ₁ , F ₂ and F ₃ are oblique, but the forces F ₁ and F ₂ and F ₃ are symmetrical with respect to the rotating surface 75.

Since W ₂ and W ₃ are half of W ₁ ,
F ₁ = F ₂ + F ₃ .

Therefore, the force F ₄ is a force directed in the in-plane direction of the rotation angle 75.

This force F ₄ acts on the movable body 3.

This force F ₄ is perpendicular to the axis 6 and
The movable body 3 does not tilt, and the bearing 11 is in a state of being uniformly pressed against the shaft 6 over the entire length.

Therefore, the movable body 3 is smoothly rotated in the arrow A direction and is also smoothly displaced in the arrow Z direction.

The optical axis 14a of the objective lens 14 is kept vertical.

As a result, tracking control and focus control are stably performed.

6 and 7 show a shaft sliding actuator 1C according to a second embodiment of the present invention.

1 and 2 except for the control current conducting portion 50A.
Since the configuration is the same as that shown in FIG.

8 and 9 show the control current conducting portion 50A.

[0062] control current conduction unit 50A, a pair of arms 80 on both sides of the base 55 _-4 control current conduction unit 50 shown in FIG. 3,
81 is additionally provided, and in FIGS. 8 and 9, parts corresponding to the parts shown in FIGS. 3 and 4 are designated by the same reference numerals, and description thereof will be omitted.

[0063] Tabular flexible printed board 55A shown in FIG. 9, projects from both sides of the base portion 55 _-4, having an extending portion 55A _-6 and 55A _-7 extending in the longitudinal direction of the flexible printed circuit board 55A .

The wiring patterns 56 _-1 , 56 _-2 have a base 55.
_It extends beyond _-4 to the first extending portion 55A _-6 . The wiring patterns 56 _-2 and 56 _-3 extend beyond the base 55 _-4 to another extension 55A _-7 .

The extending portions 55A _-6 and 55A _-7 are indicated by arrows 6.
The arms 8 are bent as shown in FIGS.
0, 81 are formed.

In the control current conducting portion 50A, as shown in FIGS. 6 and 7, the tips of the arms 80 and 81 are fixed to the side surfaces on both sides of the block 82, and the tips 55 _-5 are _attached to the arm 10.
It is fixed and attached to the end of.

The arms 80 and 81 are perpendicular to the rotating surface 75 of the movable body, and are free to move in the direction perpendicular to the surfaces of the arms 80 and 81 (direction of arrow B), that is, in the surface direction of the rotating surface 75. It can turn into.

As a result, when the movable body 3 is rotated in the direction of arrow A, the bending of the arm portions 80, 81 in the direction B is performed with almost no torsional deformation of the curved flexible printed board portions 70, 71, 72. Therefore, the operation is performed more smoothly than in the case of FIG.

Although each of the control current conducting portions 50 and 50A is formed by one flexible printed board, each curved flexible printed board portion is formed by one member, and a plurality of flexible printed boards are combined. It can also be configured.

[0070]

As described above, according to the first aspect of the invention, since the control current conducting portion is configured to have the flexible printed board portion, the work of attaching the control current conducting portion uses a twisted wire. Compared with the conventional one, it can be performed more easily, and since it has a one-way curved flexible printed board part and another-direction curved flexible printed board part, the direction of the force acting on the movable part is perpendicular to the axis. As a result, the movement of the movable portion can be prevented from becoming astringent, and the focus and tracking control operations can be performed stably.

According to the second aspect of the present invention, the control current conducting portion can be formed from one flat flexible printed board, and the control current conducting portion can be provided as compared with the structure in which a plurality of flexible printed boards are combined. It can be easily formed.

According to the third aspect of the present invention, since the control current conducting portion is configured to have the flexible printed board portion, the work of attaching the control current conducting portion is simpler than that of the conventional method using the twisted wire. In addition, since it has a one-way curved flexible printed board portion and the other-direction curved flexible printed board portion, the direction of the force acting on the movable portion can be made perpendicular to the axis, whereby
It is possible to prevent the movement of the movable portion from becoming astringent, and it is possible to perform stable focus and tracking control operations.

Moreover, since the arm is bent in the direction perpendicular to the surface, the movable body can be rotated more smoothly, and the tracking control operation can be performed more stably.

According to the fourth aspect of the present invention, the control current conducting portion can be formed from one flat flexible printed board, and the control current conducting portion can be provided more than the structure in which a plurality of flexible printed boards are combined. It can be easily formed.

[Brief description of drawings]

FIG. 1 is a perspective view of a first embodiment of a shaft sliding type actuator of the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

3 is a perspective view showing a control current conducting portion in FIG. 1. FIG.

FIG. 4 is a diagram showing a state in which a control current conducting portion of FIG. 3 is expanded.

5 is an enlarged cross-sectional view taken along the line VV in FIG.

FIG. 6 is a perspective view of a second embodiment of the shaft sliding type actuator of the present invention.

7 is a cross-sectional view taken along the line VII-VII in FIG.

FIG. 8 is a perspective view showing a control current conducting portion in FIG.

9 is a diagram showing the control current conducting portion of FIG. 8 in an expanded manner.

FIG. 10 is a perspective view of an example of a conventional shaft sliding type actuator.

11 is an exploded perspective view of the shaft sliding actuator of FIG.

FIG. 12 is a perspective view of a shaft sliding actuator previously devised by the present inventor.

FIG. 13 is a diagram illustrating a problem of the shaft sliding type actuator of FIG.

[Explanation of symbols]

1B, 1C Axis sliding type actuator 2 Main body 3 Movable body 4 Base 5 Magnetic circuit 6 Axis 10 Arm 11 Cylindrical bearing 12 Focusing coil 13 Tracking coil 14 Objective lens 15 Balancer 20 Laser unit 21 Laser light 22 Mirror 23 Optical disk 30 , 31, 36, 37 twisted lead wire 32, 33, 34, 35 pad 40 strip-shaped flexible printed circuit board 41, 41A block 50, 50A control current conducting part 52, 82 block 55, 55A flat flexible printed board 55 _-1 center Belt 55 _-2 First lateral belt 55 _-3 Second lateral belt 55 _-4 Base 55 _-5 Tip 55A _-6 , 55A _-7 Extension 56 _{-1 to} 56 _-4 Wiring pattern 56 _-1a, 56 _-1b, 56 _-4b terminal portion 57 _-1, 57 _-2 slit 58 base film 59 Kabafu Lum 60-66 down arrow 70 indicating the direction to apply a force direction bending the flexible printed circuit board portions 71 and 72 upward bending the flexible printed circuit board unit 75 movable member rotation surface 80, 81 arms

Claims (4)

[Claims] 1. A body (2) having a magnetic circuit (5) and a shaft (6), a bearing (11) and a focusing coil (1).
2), tracking coil (13) and objective lens (1
4), the bearing is supported by the shaft, and the movable body (3) is rotatably and slidably provided, and has flexibility, and the main body and the movable body. A shaft sliding type actuator, which is connected and provided between the two, and has a control current conducting portion (50) for supplying a control current to the focusing coil and the tracking coil, wherein the control current conducting portion (50) is provided. A unidirectionally curved flexible printed board portion (70) having a strip shape, which is curved substantially in an arc in one direction with respect to a movable body rotating surface (75) on which the movable body rotates. A shaft sliding type actuator characterized in that it is curved substantially in an arc shape in the other direction with respect to the rotating surface, and has a flexible printed board part (71, 72) having a strip shape which is curved in the other direction. . 2. The one-way curved flexible printed board portion and the other-direction curved flexible printed board portion are separated by the slit of a flat plate-like flexible printed board having slits (57 _-1 , 57 _-2 ). 2. Adjacent strip portions ( _55-1 , _55-2 , _55-3 ) are formed by curving in opposite directions to the surface of the flat flexible printed board. Shaft sliding type actuator. 3. A body (2) having a magnetic circuit (5) and a shaft (6), a bearing (11) and a focusing coil (1).
2), a tracking coil (13), and an objective lens, the bearing is supported by the shaft, and the movable body (3) is rotatably and slidably provided and has flexibility. A shaft sliding type actuator having a structure which is connected to the main body and the movable body and is provided between the main body and the movable body, and which has a control current conducting portion (50A) for supplying a control current to the focusing coil and the tracking coil, The control current conducting portion (50A) is curved in a substantially arcuate shape in one direction with respect to the movable body rotating surface (75) on which the movable body rotates, and has a strip shape. The part (70), the other direction curved flexible printed board part (71, 72) which is curved in a substantially arc shape in the other direction with respect to the movable body rotating surface, and has the movable body rotating surface. Perpendicular to the plane Arms are strip-shaped in the longitudinal direction of the control current supply unit (8
0, 81), and a shaft sliding type actuator. 4. The one-way curved flexible printed board
Part and the flexible printed board part that bends in the other direction
To (57_-1, 57_-2) Formed flat plate flexi
Adjacent strips separated by the slits in the printed circuit board
Division (55_-1, 55_-2, 55_-3) Is the flat flexi
Curved in opposite directions to the surface of the printed circuit board.
The above-mentioned arm is an extension of the above-mentioned flat plate-like flexible printed board.
Division (55A_-6, 55A _-7Formed by bending 9
4. A shaft sliding type actuator according to claim 3, wherein
Eta.