JP2932408B2 - Method for manufacturing optical head actuator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an optical head actuator for magneto-optical recording and reproduction of an optical disk, a CD (compact disk), a magneto-optical disk and the like.

[0002]

2. Description of the Related Art FIGS. 5 and 6 are external views showing respective examples of a conventional optical head actuator (hereinafter, referred to as an actuator). First, in FIG. 5, reference numeral 1 denotes an objective lens holding cylinder, and an objective lens 2 is provided with an adhesive 3 at a substantially central portion thereof.
And so on. Reference numeral 4 denotes a support elastic member for the objective lens holding cylinder 1 composed of four wire springs 4a.
One end of a is fixed to the base member 5, and the other end is fixed to the objective lens holding cylinder 1. Reference numeral 6 denotes a focus coil for moving the objective lens holding cylinder 1 in a focus direction perpendicular to an optical disc (not shown). Reference numeral 7 denotes a tracking coil for moving the objective lens holding tube 1 in the tracking direction. By supplying an electric current to 7, an electromagnetic force is generated, and the objective lens holding cylinder 1, and thus the objective lens 2, can be moved in the focus direction or the tracking direction.

A conventional actuator has the above-described configuration, and the method of manufacturing the actuator is assembled by using an objective lens holding cylinder 1, a base member 5, and a support elastic member 4, which are separate members. Therefore, an assembling jig was required to assemble each member at a precise dimensional relationship.

FIG. 6 shows another example of the optical actuator. The structure of the optical actuator is substantially the same as that of FIG. 5, except that the supporting elastic member 4 is constituted by four resin springs 4b. . Therefore, as in the case of FIG. 5, a jig is required for assembling.

[0005]

By the way, in order to prevent unnecessary vibration of the objective lens holding cylinder 1 itself from the viewpoint of performance, the actuator is provided with the objective lens holding cylinder 1,
The focus coil 6 or the tracking coil 7 for driving the center of gravity of each member so that the supporting elastic member 4, the focus coil 6, the tracking coil 7 and the like do not have unnecessary vibration modes in the focus direction and the tracking direction. It is necessary to assemble by assembling the force of the magnetic field generated by the above.

[0006] Therefore, the objective lens holding cylinder 1, which is a separate member,
In order to assemble the base member 5 and the support elastic member 4 with high accuracy at the time of assembly, the objective lens holding cylinder 1 and the support elastic member 4 are bonded to the base member 5 while being positioned and held using an assembling jig. It had to be left in that state until the adhesive 3 was completely cured.

The wire spring 4a itself has low rigidity, so that the objective lens holding cylinder 1 and the wire spring 4a
Then, the base member 5 becomes cantilevered, and stress is applied to the wire spring 4a at the time of work, and the wire spring 4a may be deformed, so that attention is required.

An object of the present invention is to provide a method of manufacturing an optical head actuator which has solved the above-mentioned problems in assembly.

[0009]

According to the present invention, an objective lens is provided.
Continuously around the objective lens holding cylinder and the objective lens
Having a base member formed so as to surround the light
A method for manufacturing a head actuator, comprising: a base member
Four thin portions formed in a continuous thinner line
Thus, a molding step of connecting the base member and the objective lens holding cylinder to form an integral body, and
A wire spring is wound between the lens holding cylinder and both ends are fixed.
The wire spring support step and four wires without stressing the wire spring
And a separating step of separating the thin portion.
Near the position where the wire spring is fixed to the objective lens holding barrel.
An optical head actuator characterized by being connected two by two.
It is a manufacturing method of an eta.

[0010]

According to the present invention, the relative position of the objective lens holding cylinder and the base member is invariably connected by the thin portion so that the dimensional position accuracy as a part at the time of assembling is a completely integrated product. Therefore, no jig is required to attach the support elastic member to the support elastic member, and the attachment of the support elastic member is stable. Finally, after attaching other necessary coils or the like as an actuator, the support elastic member is unnecessary. An optical head actuator in which the objective lens holding cylinder is accurately supported on the base member by the supporting elastic member is formed by separating both ends of the thin portion so as not to apply excessive stress.

[0011]

FIG. 1 is a top view of an actuator according to one embodiment of the present invention, which is an example of an actuator using a wire spring as a supporting elastic member, and has the same functions as those in FIGS. It is indicated by reference numerals.

In FIG. 1, an objective lens 2 is fixed to an objective lens holding tube 1 with an adhesive 3 or the like, and the objective lens holding tube 1 and a base member 5 surrounding the objective lens holding tube are high in resin. Integrally molded with rigid PPS (Polyphenylene Sulfide) or the like. At this time, several portions are formed in a thin portion 8 to form an integrally molded product 9 in which the objective lens holding cylinder 1 and the base member 5 are connected to each other. By using four wire springs 4a as the member 4, the objective lens holding cylinder 1 and the base member 5 are supported.

In the supporting assembly in this case, the wire spring 4a is positioned on the integrally molded article 9, and is bonded with an adhesive or the like. Further, a magnet 10 and a yoke 11 for driving the objective lens holding cylinder 1 in the focus direction or the tracking direction are incorporated in the base member 5 conforming to the shape, and are fixed by an adhesive. Then, after the components constituting a part of the actuator are incorporated, the connecting portion formed by the thin portion 8 is cut off with a laser beam or the like, and finally the gap between the objective lens holding cylinder 1 and the base member 5 as shown in FIG. An actuator supported by the wire spring 4a is formed.

The light of the present invention manufactured as described above
First, the head actuator is as shown in FIGS.
The base member is formed so as to surround the lens holding cylinder.
The base member itself has high rigidity
It has become. Next, the thin part is thinner than the base member
Since it is formed in a continuous linear shape, it can be cooled during molding.
There is no risk of stress being concentrated and deforming or breaking.
No. In addition, the four thin parts hold the wire spring with the objective lens
Since two were connected near the position fixed to the cylinder,
In addition to improving the positioning accuracy of the objective lens holding barrel,
Also prevent the lens holding cylinder from tilting with respect to the base member.
Can be. 3 and 4 are top views showing another embodiment of the present invention, in which the supporting elastic member 4 is formed of a resin spring, FIG. 3 shows a state before cutting the thin portion, and FIG. Shows after cutting.

[0015] The above mentioned FIG. 1, in place of the FIG. 2 with wire spring 4a, this arrangement resin spring 4b, differ only in the configuration obtained by supporting the objective lens holding cylinder 1 to the base member 5,
Since other structures are identical, the manufacturing method is omitted the detailed description. The resin spring 4b may use the thin portion 8 at the time of forming the integrally molded article 9 in which the objective lens holding cylinder 1 and the base member 5 are connected to each other, or may be newly formed of resin. A thin hinge portion 4b 'is formed in the portion, and the objective lens 2 is changed in the focus or tracking direction using the thin hinge portion 4b' . From the above description of the manufacturing method, the above-described wire spring 4a
Has the same effect as the example using
Support steps can be omitted, reducing manufacturing costs
Can be.

[0016]

As described above, the method of manufacturing an actuator according to the present invention comprises the following steps.
Since the two members of the base member of the fixed portion are integrally formed via the thin resin portion, the objective lens, magnet, yoke,
Alternatively, when a support elastic member or the like is incorporated, when the support elastic member is a wire spring, the objective lens holding cylinder and the base member are always fixed via a thin portion. Can be reduced.

Further, when the supporting member is a resin spring formed by a thin hinge portion, the objective lens holding cylinder, the base member and the resin spring can be integrally molded, so that the number of parts is reduced and the workability of assembly is improved. As a result, the balance of the center of gravity that determines the performance of the actuator, the positional accuracy, or the mounting accuracy of the support springs are influenced only by the accuracy of a single product before assembly, and the manufacturing accuracy is stabilized.

[Brief description of the drawings]

FIG. 1 is a top view showing a state before a thin portion is cut in an embodiment of the present invention.

FIG. 2 is a top view showing the thin portion of FIG. 1 after being cut off.

FIG. 3 is a top view showing a thin portion before it is cut in another embodiment of the present invention.

FIG. 4 is a top view showing the thin portion of FIG. 3 after being cut off.

FIG. 5 is an external view showing an example of a conventional optical actuator.

FIG. 6 is an external view showing another example of a conventional optical actuator.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Objective lens holding cylinder, 2 ... Objective lens, 3 ... Adhesive, 4 ... Support elastic member, 4a ... Wire spring, 4b ... Resin spring, 4b '... Thin hinge part, 5 ... Base member, 6
... Focus coil, 7 ... Tracking coil, 8
... Thin section, 9 ... Integrally molded product, 10 ... Magnet, 11
…yoke.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-308434 (JP, A) JP-A-1-290132 (JP, A) JP-A-1-208736 (JP, A) (58) Field (Int.Cl. ⁶ , DB name) G11B 7/22 G11B 7/09

Claims (2)

(57) [Claims] 1. An objective lens holding cylinder for holding an objective lens.
And continuously surround the objective lens.
Optical head actuator having base member formed
4. The method according to claim 1, wherein the base member is formed in a continuous linear shape thinner than the base member.
The base member and the objective lens
Forming step to connect with the holding cylinder to form integrally
And a wire spring supporting step of fixing a wire spring between the base member and the objective lens holding cylinder to fix both ends, and separating the four thin portions without applying stress to the wire spring.
The four thin portions hold the wire spring to the objective lens.
A method of manufacturing an optical head actuator, comprising connecting two heads each near a position fixed to a cylinder . 2. An objective lens holding cylinder for holding an objective lens.
And continuously surround the objective lens.
Optical head actuator having a base member formed
2. The method according to claim 1, wherein the base member is formed into a continuous linear shape thinner than the base member.
The base member is formed by two thin portions and two resin springs.
And the objective lens holding cylinder are connected to each other to form
And a separating step of separating the two thin portions without applying stress to the wire spring. The two thin portions hold the resin spring to the objective lens.
A method of manufacturing an optical head actuator, wherein the optical head actuator is connected one by one near a position where the optical head actuator is integrally formed with a holding cylinder .