JPH11306560A - Two-axis actuator and optical device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify components by arranging the same number of holding parts as that of suspension members to be engaged therewith at the respective ends, twisting both ends of coil members around them, and electrically and directly connecting each coil end with the suspension members. SOLUTION: Holding parts 29 are arranged for engaging tip parts of wires (suspension members) 24 therewith at the longitudinal end parts on both of the top and bottom surfaces of a lens holder 23. The holding part 29 consists of main projection 29a and a sub-projections 20b, 29c arranged in the shape of a letter U, and has a gap between the main projections 29a and a sub- projections 29b, 29c for inserting a wire 24 therein. A coil end part 27a of a focus coil 27 (or tracking coil 28) is twisted around a winding part 29a2 of the main projection 29a several times before it is twisted around a wire 24 several times. And, the focus coil 27 is electrically connected with the wire 24 by soldering 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biaxial actuator used in an optical pickup for recording (writing) and / or reproducing (reading) an information signal using an optical recording medium such as an optical disk or a magneto-optical disk. And an optical device such as an optical recording / reproducing device using an optical pickup using the biaxial actuator.

[0002]

2. Description of the Related Art Conventionally, as a biaxial actuator of a wire supporting type in which a movable portion having an objective lens is elastically supported by four wires, for example, Japanese Unexamined Patent Publication No.
A structure as shown in FIG. 6 of JP-A-225960 is known. The biaxial actuator of FIG. 6 is shown as FIG. 5 of the present application.

The two-axis actuator 1 shown in FIG.
A lens holder 3 having the objective lens 2; four wires 4 and 4 for elastically supporting the lens holder 3; a support member 5 for supporting the base ends of the four wires 4 and 4; 5 is provided with a base member 6 and the like to which the fixing member 5 is fixed.
A focus coil 7 is wound around the outer periphery of the rectangular lens holder 3 so that the center of the coil is parallel to the optical axis of the objective lens 2. This focus coil 7
A tracking coil 8 wound in a track shape is provided on two sides facing each other in a direction parallel to the direction in which the wire 4 extends.
Are pasted side by side.

The focus coil 7 and the tracking coil 8 are connected to an outer yoke 9 erected on the base member 6,
The magnet 9 is inserted between the magnets 10 adhered to the inner surface of the magnet 9, respectively. The inner yokes 11, 11 provided continuously with the outer yokes 9, 9 are loosely inserted into the through holes 12, 12 provided in the lens holder 3. The four wires 4 have a function of supporting the lens holder 3 and a function of electrically connecting the printed wiring board arranged on the lens holder 3 and the printed wiring board arranged on the base member 6. ing.

[0005] For this reason, each end of the four wires 4 and the wiring pattern of the holder-side printed wiring board are connected via lead wires to which both ends are soldered. Furthermore, the wiring pattern of this printed wiring board includes
Both ends of the focus coil 7 and the tracking coil 8 are connected by soldering. By supplying a current to the focus coil 7 and the tracking coil 8 through the four wires 4, a magnetic circuit that generates a magnetic flux so as to intersect each coil at right angles causes the objective lens 2 to move in the focus direction. And in the tracking direction.

[0006]

However, in the conventional two-axis actuator as described above, the coil ends of the focus coil 7 and the tracking coil 8 and the tips of the four wires 4 are connected to the lens holder 3. However, there is a problem that the number of soldering steps is large and the productivity is low because the printed circuit boards are soldered individually to each other and electrically connected independently.

As another conventional biaxial actuator, a conductor such as a metal pin is embedded in a lens holder or the like, and a coil end is wound around the conductor and soldered. In this case, Since additional parts such as conductors are required, the number of parts increases, the structure becomes complicated, and if the accessories are not sufficiently fastened, resonance may be caused or other characteristics may be affected. There was a problem of becoming.

The present invention has been made in view of such a conventional problem, and has as its object to solve the above-mentioned problem by directly connecting a suspension member supporting a movable portion and a focus coil or a tracking coil. I have.

[0009]

Means for Solving the Problems In order to solve the above-mentioned problems and the like, and to achieve the above-mentioned object, a first aspect of the present invention is described.
In the biaxial actuator according to the present invention, the movable portion is provided with a hold portion in which one end of the suspension member is respectively engaged with the same number as the number of the suspension members, and both ends of the coil member are wound around these hold portions, respectively. The coil end and the suspension member are electrically connected to each other.

[0010] The biaxial actuator according to a second aspect of the present invention is characterized in that the holding portion is a projection provided integrally with a lens holder having an objective lens.

According to a third aspect of the present invention, in the two-axis actuator, the holding portion is a projection made of a separate member implanted in a lens holder having an objective lens.

In the biaxial actuator according to a fourth aspect of the present invention, the holding portion includes a member receiving portion into which the suspension member is loosely inserted, and a coil winding having both sides of the opening of the member receiving portion projecting outward. The suspension member is elastically supported by a member receiving portion via a cushioning material, and the coil member is wound around the coil winding portion to restrict the suspension member from jumping out. .

In the biaxial actuator according to a fifth aspect of the present invention, the coil member comprises a focus coil for driving the objective lens in the focus direction and a tracking coil for driving the objective lens in the tracking direction. It is characterized by four metal wires that support the lens holder at four locations on the upper and lower sides.

According to a sixth aspect of the present invention, in the optical device, the biaxial actuator includes a movable portion having an objective lens facing the information recording surface and a coil member for driving the objective lens in at least one of the focus direction and the tracking direction. Two or more conductive suspension members for supporting the movable portion, and the movable portion is provided with hold portions in which one end of each of the suspension members is engaged with the same number as the number of the suspension members. In addition, both ends of the coil member are wound, and each coil end and the suspension member are electrically connected.

With the above-described structure, in the biaxial actuator according to the first aspect of the present invention, the end of the coil member and the suspension are directly electrically connected via the holding portion. Can be simplified, the mounting accuracy of the suspension member can be improved, and the possibility of occurrence of resonance due to mounting backlash of another member can be eliminated.

In the two-axis actuator according to the second aspect of the present invention, the holding portion can be formed very simply, the manufacturing is easy, and the cost can be reduced.

In the biaxial actuator according to the third aspect of the present invention, the holding portion can be formed by using a separate member, so that the manufacturing is easy and the cost can be reduced.

In the biaxial actuator according to the fourth aspect of the present invention, the suspension member can be supported without soldering, and the suspension member can be prevented from dropping from the holding portion.

In the biaxial actuator according to a fifth aspect of the present invention, there is provided a biaxial actuator in which both ends of a focus coil are connected to two suspension members and both ends of a tracking coil are connected to two suspension members. can get.

In the optical device according to the sixth aspect of the present invention, the components are simplified, the mounting accuracy of the suspension member is high, and there is no fear of occurrence of resonance due to the looseness of the mounting of another member. can get.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 4 show an embodiment of the present invention, in which only an information signal is reproduced (read) or recorded (written) using an optical recording medium such as a CD (compact disk) or MD (mini disk). CD player or M as an optical device capable of performing both
The present invention is applied to a wire supporting type biaxial actuator used in an optical pickup suitable for use in a D player or the like. That is, FIG. 1 is a perspective view showing a wire supporting type biaxial actuator according to the optical pickup of the present invention,
2 is an enlarged perspective view showing a main part of FIG. 1, FIG. 3 is an exploded perspective view of FIG. 1, and FIG. 4 is an explanatory view showing a main part of a hold unit according to the present invention.

As shown in FIGS. 1 to 3, the biaxial actuator unit 21 includes four lens holders 23 each having an objective lens 22 and a suspension member for elastically supporting the lens holder 23. The printed wiring board 25 includes metal wires 24, 24, a printed wiring board 25 that supports the base ends of the four wires 24, and a base member 26 to which the printed wiring board 25 is fixed. At the center of the upper surface of the quadrangular lens holder 23, the objective lens 22 is integrally provided with the optical axis directed vertically.

The lens holder 2 including the objective lens 22
As the material 3, for example, a lens material “ARTON (trademark)” manufactured by Nippon Synthetic Rubber Co., Ltd. can be applied. This "ARTON" is an acrylic resin having a norbornene structure in the main chain, has light transmittance, refraction, heat resistance, hygroscopicity, and has the property of withstanding high humidity conditions.

A focus coil 27 is wound around the outer periphery of the lens holder 23 so that the center of the coil is parallel to the optical axis of the objective lens 22. The focus coil 27 is a specific example of a coil member, and is wound so as to have a predetermined width in the thickness direction of the lens holder 23. The start end and end 2 of the focus coil 27
After being wound around the holding portion as described later, the wires 7a are individually wound around the wires 24 and fixed by fixing means such as soldering.

The objective lens 22 of the lens holder 23
On both sides, a tracking coil 28 is wound from above the focus coil 27 so that the center of the coil is orthogonal to the optical axis of the objective lens 22. The tracking coil 28 is another specific example of the coil member, and is wound so as to have a predetermined width in the longitudinal direction of the lens holder 23. This tracking coil 28
Similarly, after being wound around the holding portion as described later, the starting end portion and the ending portion 28a are individually wound around the wire 24 and fixed by fixing means such as soldering.

At both upper and lower surfaces of the lens holder 23, at both ends in the longitudinal direction, hold portions 29 for engaging the distal end of the wire 24 are provided. The holding portion 29 has three protrusions 29a, 2 arranged in a U-shape.
9b and 29c, and the inner main projection 29a
A gap for inserting the wire 24 is formed between the outer protrusions and the two outer protrusions 29b and 29c. The main projection 29a has a head _29a1 provided at the tip and this head 29a1.
slightly thinner than _a1 and a winding portion 29 _a2 having a difference in level, beginning or end of the focus coil 27 or the tracking coils 28 to the winding portion 29 _a2 (coil ends)
27a (or 28a) is wound.

The coil end 27a (or 28a)
After wound several times the winding portion 29 _a2 of the main projection 29a, attached several times around the wire 24. Then, the focus coil 27 or the tracking coil 28 and the wire 24
And are electrically connected. This coil end 27a
(Or 28a) and the wires 24 are similarly connected at four locations corresponding to the number thereof. This gives 4
A movable portion supported by the wires 24 is configured.

As a material of the wire 24, for example,
Phosphor bronze is preferred, but of course other metals can be used. Further, as the suspension member, for example, various materials other than metal can be used, such as a plastic rod in which metal powder is mixed with plastic to impart conductivity.

The other ends of the four wires 24 are inserted into the through holes of the printed wiring board 2 and connected to the wiring patterns by soldering. The base of each wire 24 on the printed wiring board 2 side is elastically supported by four wire receiving portions 32 provided on the base member 26 via a silicon-based gel material 33. These wire receiving portions 32 are formed in a U-shape, and support the wires 24 with the viscosity of the silicon-based gel material 33 held therein to improve the control performance of focus servo and tracking servo.

The base member 26 has a frame 26a formed in a rectangular frame shape, and a support 26b formed continuously on one side of the frame 26a. A pair of yokes 34, 34 facing each other are formed by cutting up and raising the inside. Magnets 35 are fixed to the inner surfaces of the yokes 34 by fixing means such as an adhesive. A movable portion having the above-described configuration is interposed between the magnets 35, 35. The current drive of the coils 27, 28 causes the movable portion to move in the optical axis direction (focus direction) of the objective lens 22 and the movable portion. , Can be driven in a direction (tracking direction) crossing the optical axis.

The support portion 26b of the base member 26 is provided with two T-shaped portions projecting from both sides in a substantially direction, and each T-shaped portion is bent in a U-shape to be separated vertically. As a result, as shown in FIG.
2 are integrally formed. This base member 26
A fixed portion elastically supports the movable portion via the wires 24.

The base member 26 is fixed to a slide base (not shown) by a fixing means such as a screw to form an optical pickup having the biaxial actuator 21. By configuring an optical device such as a CD player or an MD player using the optical pickup having the biaxial actuator 21, a laser beam is applied to the optical recording medium via the objective lens 22 of the biaxial actuator 21. An information signal can be recorded on an information recording surface of a recording medium, and an information signal recorded in advance on the information recording surface can be reproduced.

Thus, according to this embodiment, the holding unit 2 provided on the lens holder 23 having the objective lens 22
9, the fixing of the lens holder 23 to the wire 24 and the focusing coil 27 to the lens holder 23
And the tracking coil 28 can be fixed at the same time. Therefore, the configuration of the biaxial actuator 21 can be simplified, and the wire 24
Are simultaneously performed, the accumulated tolerance at the time of assembly can be reduced, and the wire mounting accuracy can be improved. Further, since the wire 24 and the coils 27 and 28 are directly joined, it is possible to prevent the occurrence of mounting backlash by providing a separate member, and to prevent the occurrence of resonance due to the mounting backlash.

FIG. 4 shows a main part of a second embodiment of the present invention, in which the wire 24 can be fixed to the lens holder 23 without using soldering. Hold section 39 shown in the second embodiment
A member receiving portion 39a provided with a slit-shaped notch portion 40 into which the wire 24 is loosely inserted;
A coil winding portion 39b is provided which has both sides projecting outward so that the coil end can be wound. Coil winding part 39b
Is provided with a head 39c protruding laterally at the tip of
The head 39c prevents the coil end 27a (or 28a) from falling off.

The coil winding portion 39b of the holding portion 39
The coil end 27a (or 28a) wound an appropriate number of times
After the tip is wound around the wire 24 an appropriate number of times, it is joined by a fixing means such as soldering 30 to achieve electrical continuity. In FIG. 4, reference numeral 41 denotes a wire 24.
Is a cushioning material for elastically supporting the elastic member. As the cushioning material 41, a component having elasticity, for example, a silicon-based gel material can be used.

With this configuration, the same effect as in the above embodiment can be obtained. In particular, in this embodiment, since the wire 24 can be fixed to the lens holder 23 only by inserting the wire 24 into the member receiving portion 39a filled with the silicon-based gel material, the wire fixing means can be simplified. Thus, the assembling work can be facilitated. In addition, by using the elastic cushioning material 41 for the member receiving portion 39a, which is the attachment portion of the wire 24, the shape and dimensional tolerance of the member receiving portion 39a can be roughly set.

As described above, the present invention is not limited to the above-described embodiment. For example, in the above-described embodiment, four wires are used as a suspension member, and a focus coil and a tracking coil are used. Although an example in which each coil end is connected to a wire has been described, the present invention can be implemented as long as one coil and two suspension members are directly connected. Furthermore, the shapes, structures, and the like of the lens holder 23, the base member 26, and other components are not limited to those in the above-described embodiment.

Further, in the above-described embodiment, an example has been described in which the holding portions 29 and 39 are formed integrally with the lens holder 23. However, pins and screws or the like are formed as separate members, and these are implanted in the lens holder 23. Alternatively, a configuration in which a hold portion is formed may be adopted. The material of the separate member may be plastic as described above, or may be metal. Further, in the above-described embodiment, the description has been given of the case where the objective lens 22 and the lens holder 23 are integrally formed. However, a configuration in which only the objective lens is supported by two or more suspension members may be adopted. Further, instead of the soldering described in the above embodiment, various joining means such as brazing or joining with a conductive adhesive can be applied. Thus, the present invention can be variously modified without departing from the spirit thereof.

[0039]

As described above, according to the first aspect of the present invention,
According to the biaxial actuator according to the above, since the end of the coil member is directly electrically connected to the suspension via the holding portion, the components can be simplified, and the mounting accuracy of the suspension member can be improved. In addition, it is possible to provide a two-axis actuator which is free from occurrence of resonance due to mounting play or the like due to the use of another member.

According to the two-axis actuator of the second aspect of the present invention, it is possible to provide a two-axis actuator in which the holding portion can be formed very simply, the manufacturing is easy, and the cost can be reduced. The effect is obtained.

According to the biaxial actuator according to the third aspect of the present invention, the holding portion can be formed by using a separate member, and the biaxial actuator can be easily manufactured and cost can be reduced. The effect that an actuator can be provided is obtained.

According to the biaxial actuator according to the fourth aspect of the present invention, it is possible to provide a biaxial actuator which can support the suspension member without soldering and can prevent the suspension member from dropping out of the hold portion. Is obtained.

According to the biaxial actuator of the present invention, both ends of the focus coil are connected to the two suspension members, and both ends of the tracking coil are connected to the two suspension members. The effect that an actuator can be provided is obtained.

According to the optical device according to the sixth aspect of the present invention, the components are simplified, the mounting accuracy of the suspension member is high, and there is no fear of occurrence of resonance due to mounting play of another member. The effect that a device can be provided is acquired.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of a biaxial actuator of the present invention.

FIG. 2 is an enlarged perspective view showing a main part of the biaxial actuator shown in FIG. 1;

FIG. 3 is an exploded perspective view of the biaxial actuator shown in FIG.

FIG. 4 is a perspective view showing another embodiment of the hold unit according to the biaxial actuator of the present invention.

FIG. 5 is a perspective view showing a conventional biaxial actuator.

[Explanation of symbols]

21 biaxial actuator, 22 objective lens, 2
3 lens holder, 24 wires (suspension member), 26 base member, 27 focus coil, 28 tracking coil, 29, 39 hold portion, 29a main projection, 30 soldering, 39a
Member receiving part, 39b coil winding part, 41 cushioning material

Claims (6)

[Claims] 1. A movable section having an objective lens facing an optical recording medium, a coil member for driving the objective lens in at least one of a focus direction and a tracking direction, and two or more conductive suspensions supporting the movable section. In the biaxial actuator comprising: a movable member, the movable portion is provided with a hold portion in which one end of the suspension member is engaged with the same number as the number of the suspension members, and both ends of the coil member are provided in these hold portions. A biaxial actuator, wherein each of the windings is wound and each coil end is electrically connected to a suspension member. 2. The biaxial actuator according to claim 1, wherein the holding unit is a projection provided integrally with a lens holder having the objective lens. 3. The biaxial actuator according to claim 1, wherein the hold section is a projection made of a separate member implanted in a lens holder having the objective lens. 4. The biaxial actuator according to claim 1, wherein the hold portion includes a member receiving portion into which the suspension member is loosely inserted, and a coil winding having both sides of the opening of the member receiving portion projecting outward. Having a turning portion, and elastically supporting the suspension member via the cushioning material in the member receiving portion,
A biaxial actuator, wherein the coil member is wound around the coil winding portion to prevent the suspension member from jumping out. 5. The two-axis actuator according to claim 1, wherein the coil member includes a focus coil that drives the objective lens in a focus direction and a tracking coil that drives the objective lens in a tracking direction. Are four metal wires that support the lens holder at four locations on the upper and lower sides. 6. An optical recording medium is irradiated with a laser beam through an objective lens of a biaxial actuator, and an information signal is recorded on an information recording surface of the optical recording medium, or an information signal recorded on the information recording surface is recorded on the information recording surface. In the optical device configured to reproduce, the biaxial actuator includes an objective lens facing the information recording surface, a movable unit having a coil member that drives the objective lens in at least one of a focus direction and a tracking direction, and the movable unit. And two or more electrically conductive suspension members for supporting the movable member. The movable portion is provided with hold portions in which one end of each of the suspension members is engaged with the same number as the number of the suspension members. While winding both ends of the coil member, each coil end and the suspension member are electrically connected to each other. Optical apparatus characterized by continued was.