JP2001110080A - Optical head actuator and its production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical head actuator which can reduce the weight of its mobile member and also can decrease its unnecessary vibrations and also can be easily produced. SOLUTION: A plate-like member which constructs a support spring and a wiring member and drive coils are formed by an insertion molding and then the unnecessary parts of the plate-like member are cut. Thus, the inter-drive coil wiring is attained without attaching a new wiring member nor forming any wiring and accordingly the wiring processing is easily carried out in a procedure that is almost the same as the conventional one and without increasing the number of parts. In particular, the support spring doubles as a wiring member to an external circuit and the connection parts between the wiring member and every drive coil and also between the support spring and every drive coil are arranged on only one face side of a mobile member. In such a constitution, plural drive coils can be connected to each other and the support spring can be connected to every drive coil in the same process. As a result, the man-hour for wiring jobs can be decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical head actuator used for an optical disk device and the like, and a method for manufacturing the same.

2. Description of the Related Art Conventionally, for example, an optical head actuator of an optical disk apparatus has a lens holder as a movable member holding the objective lens in order to make the objective lens follow dynamic behavior due to surface deflection or eccentricity of a rotating optical disk. In the direction parallel to the rotation axis of the optical disc (focus direction) and the radial direction around the rotation axis (track direction)
The lens holder is provided with a drive coil for driving the lens holder. The focus direction drive coil and the track direction drive coil are independent of each other, and drive control of each coil is performed so that the lens holder can follow the dynamic behavior of the optical disk.

In such an optical head actuator, a support spring for holding a lens holder is made of a conductive material such as beryllium copper, and is moved from a coarsely moved base on the fixed side via the support spring. There is a structure for applying a current to a drive coil.

Here, conventionally, between the end of the support spring and the drive coil, the wire at the end of the coil is routed as a lead and connected to the end of the support spring with solder or the like, or the wiring is processed through a printed circuit board. It was a target.

[0004]

However, in the method in which the wire at the coil end is routed as a lead, an adhesive is used to fix the lead on the surface of the lens holder, so that the weight of the lens holder increases by the amount of the adhesive. In addition, the weight of the lens holder may fluctuate due to the amount of the adhesive applied or the work of drawing the end lines, or unnecessary resonance may occur due to the vibration of the floating lead, and the dynamic characteristics may be deteriorated.

In the method using a printed circuit board, not only is the weight of the entire lens holder increased due to the addition of the substrate to the lens holder, but also the size of the printed circuit board is limited. There is a problem in that the response and the like are reduced by increasing the size and weight of the lens holder.

Therefore, a method of embedding a conductive member for wiring in the lens holder or forming a wiring pattern on the surface of the lens holder has been devised. However, the number of parts and the number of assembly steps are increased, and a new manufacturing method is introduced. This raises a problem of cost increase, and has not yet replaced conventional wiring processing technology.

The present invention has been made in view of the above-mentioned problems of the prior art, and provides an optical head actuator which can reduce the weight of a movable member, reduce unnecessary vibrations, and is easy to manufacture, and a method of manufacturing the same. The purpose is to:

[0008]

It is an object of the present invention to provide a movable member for supporting an objective lens, which is spring-supported at a neutral position on a base member so as to be movable in a focus direction and a track direction, and is provided on the movable member. An optical head actuator driven in a focus direction and a track direction by a plurality of focus coils and a plurality of track coils, wherein a wiring member connecting the coils and the support spring are formed of the same plate-like member. After the plate member and the coils are insert-molded on the movable member, the wiring member and the support spring are cut so as to be electrically insulated from each other, so that the wiring member and the support spring are formed. Optical head actuator characterized by being, and a movable member supporting the objective lens,
An optical head which is spring-supported at a neutral position on a base member so as to be movable in a focus direction and a track direction, and is driven in a focus direction and a track direction by a plurality of focus coils and a plurality of track coils provided on the movable member. A method for manufacturing an actuator, wherein a wiring member for connecting the coils and the support spring are formed in an integrated state by processing the same plate-like member, and the wiring member and the support spring are formed. And a cutting method wherein the wiring member and the support spring are cut so as to be electrically insulated from each other after insert-molding the plate-like member integrated with the movable member. It is achieved by doing.
By insert molding the plate member and the drive coil that constitute the support spring and the wiring member, and then cutting unnecessary portions of the plate member, the number of parts does not increase in almost the same procedure as in the past. In addition, wiring processing can be easily performed. In particular, the support spring also serves as a wiring member for an external circuit, and a connection portion between the wiring member and each coil and a connection portion between the support spring and each coil are disposed only on one surface side of the movable member. Thus, the connection between the plurality of drive coils and the connection between the support spring and the drive coil can be performed in the same step, and the number of wiring operations can be reduced.

[0009]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG.
1 is a perspective view showing a configuration of an optical head actuator to which the present invention is applied, and FIG. 2 is a partially transparent perspective view of only a movable portion thereof. This optical head is a lens holder 1 as a movable part.
And a base member 2. Lens holder 1
Is a pair of left and right coil units including a resin holding member 3 as a base, an objective lens 4, a drive coil 6 for driving the objective lens 4 in the focus direction, and a drive coil 7 for driving the objective lens 4 in the track direction. 5 is held. A support spring 8 composed of four linear springs is provided between the lens holder 1 and the base member 2 in parallel with each other, and can move in the focus direction and the track direction while urging the lens holder 1 to the neutral position. I support it.

The resin holding member 3 uses a coil unit 5 composed of a drive coil 6 wound around a coil bobbin 5a and a drive coil 7 adhered to the coil unit 5 and a support spring 8 for elastically supporting a movable portion, as insert materials. Insert molding is performed by injection molding. The wiring members 9 for connecting the coils of the left and right coil units 5 are also insert-molded.

Here, the support spring 8 also serving as a wiring member from an external circuit (not shown) and the wiring member 9 are formed of the same plate-like member 11 as described later (shown in FIG. 4).
After the plate member 11 and the coil unit 5 are insert-molded into a resin holding member, the connecting portions 11a and 1a are connected so that the support spring 8 and the wiring member 9 are electrically insulated from each other.
By cutting 1b, 11c and 11d, the support spring 8 and the wiring member 9 are formed.

Since a resin injection mold generally used for insert molding has a very high dimensional accuracy, the coil unit 5, the support springs 8, the wiring members 9 By positioning the resin and molding the resin, the displacement of each part is reduced to, for example, 20 μm or less, and the positioning accuracy is greatly improved.

On the other hand, the fixed portion 8 is provided with a magnetic circuit member 10 composed of a permanent magnet and a yoke for generating a magnetic flux acting on the drive coils 6 and 7, and a part of the magnetic circuit member 10 is formed by an opening of the resin holding member 3. 3a and stands up and down. Then, the optical head is roughly moved by a drive mechanism (not shown) of the optical disk apparatus main body side, and the lens holder 1 is driven in the focus direction and the track direction by selectively energizing the drive coils 6 and 7. Become.

Next, the procedure for assembling the lens holder will be described in detail. First, as shown in FIG. 3, the focus direction driving coil 6 is wound around the coil bobbin 5a. An end wire of the focus coil is connected to a terminal provided on the coil bobbin. Subsequently, a track-direction driving coil 7 wound in advance
Is bonded to the coil bobbin 5a, and the end line of the track direction driving coil 7 is connected to the terminal of the coil bobbin 5a to form the coil unit 5.

On the other hand, as shown in FIG. 4, a portion forming the support spring 8 and the wiring member 9 and the connecting portions 11a, 11
A pair of conductive plate members 11 composed of b, 11c, and 11d and having a shape surrounding the resin holding member 3 are formed. Here, each connecting portion 11a, 11b, 11c, 11d
Connects the support spring 8 and the wiring member 9 and deforms both.
It serves to prevent damage and maintain its shape and to position the support spring 8 and the wiring member 9 in the molding die of the resin holding member 3.

Next, as shown in FIG. 5, the pair of coil units 5 and the pair of plate members 11 are set and positioned. The positioning of the plate-like member 11 is performed by the connecting portions 11b, 1
This is performed by the positioning hole 11e formed in 1d. At this time, the terminals of the coil bobbin 5a of the coil unit 5 and the corresponding ends of the portions forming the support spring 8 and the wiring member 9 are all arranged close to each other on the free end surface of the coil unit 5.

The coil unit 5 is formed by injection molding.
The resin holding member 3 is formed using the plate-like member 11 as an insert material (FIG. 6). At this time, the terminals of the coil bobbin 5 a of the coil unit 5 and the corresponding ends of the portions forming the support spring 8 and the wiring member 9 are exposed on the free end side surface of the coil unit 5.

Actually, by simultaneously forming a part 2a of the base member 2 holding the base end side of the support spring 8, the bonding process on the base member side can be simplified and the bonding becomes non-uniform. Can be prevented, and the weight can be further reduced by the amount of the adhesive.

Then, the terminal of the coil bobbin 5a of the coil unit 5 and the support spring 8 are connected at four places (indicated by the symbol A),
The corresponding end of the portion forming the wiring member 9 and four places, a total of 8
Each part is soldered (indicated by reference numeral B), and further, each connecting part 11a, 11b, 11c, 11d is cut (FIG. 7). At this time, since the soldering portions are concentrated on the free end surface of the coil unit 5, soldering can be performed from one direction, and the work is facilitated. afterwards,
The lens holder 1 is completed by fitting the objective lens 4.

[0020]

As is apparent from the above description, according to the optical head actuator and the method of manufacturing the same according to the present invention, the plate-like member constituting the supporting spring and the wiring member and the drive coil are insert-molded. By cutting unnecessary portions of the plate-like member, wiring between the drive coils can be performed without attaching a new wiring member or forming a wiring, and the number of parts does not increase in almost the same procedure as before. In addition, wiring processing can be easily performed. In particular, the support spring also serves as a wiring member for the external circuit, and the connection portion between the wiring member and each coil and the connection portion between the support spring and each coil are arranged only on one surface side of the movable member. The connection between them and the connection between the support spring and the drive coil can be performed in the same step, and the number of wiring operations can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of an optical head actuator to which the present invention is applied.

FIG. 2 is a partially transparent perspective view showing only a movable portion of FIG. 1;

FIG. 3 is a perspective view illustrating a configuration of a plate-shaped member that forms a support spring and a wiring member.

FIG. 4 is a perspective view showing a procedure for forming a coil unit in the optical head actuator of FIG. 1;

FIG. 5 is a perspective view showing a procedure for forming the optical head actuator of FIG. 1;

FIG. 6 is a perspective view showing a procedure for forming the optical head actuator of FIG. 1;

FIG. 7 is a perspective view showing a procedure for forming the optical head actuator of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lens holder 2 Base member 2a Part of base member 3 Resin holding member 3a Opening 4 Objective lens 5 Coil unit 5a Coil bobbin 6 Focus driving coil 7 Track driving coil 8 Support spring 9 Wiring member 10 Magnetic circuit member 11 Plate member 11a, 11b, 11c, 11d Connecting part 11e Positioning hole

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] November 16, 1999 (1999.11.
16)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction contents]

Next, the procedure for assembling the lens holder will be described in detail. First, as shown in FIG. 4 , the focus direction driving coil 6 is wound around the coil bobbin 5a. An end wire of the focus coil is connected to a terminal provided on the coil bobbin. Subsequently, a track-direction driving coil 7 wound in advance
Is bonded to the coil bobbin 5a, and the end line of the track direction driving coil 7 is connected to the terminal of the coil bobbin 5a to form the coil unit 5.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0015

[Correction method] Change

[Correction contents]

On the other hand, as shown in FIG. 3 , a portion forming the support spring 8 and the wiring member 9 and the connecting portions 11a and 11
A pair of conductive plate members 11 composed of b, 11c, and 11d and having a shape surrounding the resin holding member 3 are formed. Here, each connecting portion 11a, 11b, 11c, 11d
Connects the support spring 8 and the wiring member 9 and deforms both.
It serves to prevent damage and maintain its shape and to position the support spring 8 and the wiring member 9 in the molding die of the resin holding member 3.

Claims (3)

[Claims] 1. A movable member for supporting an objective lens is spring-supported at a neutral position on a base member so as to be movable in a focus direction and a track direction, and a plurality of focus coils and a plurality of tracks provided on the movable member. An optical head actuator driven in a focus direction and a track direction by a coil, wherein a wiring member for connecting the coils and the support spring are formed of the same plate-like member, and the plate-like member is a movable member. An optical head actuator, wherein the wiring member and the support spring are formed by cutting the wiring member and the support spring so as to be electrically insulated from each other after insert-molding the wiring member. And a connecting portion between the wiring member and each of the coils and a connecting portion between the supporting spring and each of the coils are on one side of the movable member. 2. The optical head actuator according to claim 1, wherein the optical head actuator is disposed only on the optical head actuator. 3. A movable member supporting the objective lens is spring-supported at a neutral position on a base member so as to be movable in a focus direction and a track direction, and a plurality of focus coils and a plurality of tracks provided on the movable member. A method of manufacturing an optical head actuator driven in a focus direction and a track direction by a coil, wherein the wiring member for connecting the coils and the support spring are integrally formed by processing the same plate-shaped member. The wiring member and the support spring are cut so that the wiring member and the support spring are electrically insulated from each other after insert-molding the plate-shaped member in which the wiring member and the support spring are integrated into the movable member. A method of manufacturing an optical head actuator.