JPH01236435A - Objective lens actuator - Google Patents

Abstract

PURPOSE:To improve both the durability and the assembling workability of an objective lens actuator by connecting the terminal lead wires of the focusing and tracking coils to the upper surface part of an objective lens holder set on a flexible printed board. CONSTITUTION:A flexible printed board 14 provides a part 14a which is stuck on the upper surface of an objective lens holder 2 and a cable type part 14b extending along a hinge type plate spring 10 in an one body. Then the terminal lead wires 3A and 4A of focusing coil 3 and a tracking coil 4 are soldered to the part 14a of the board 14. At the same time, a control signal line 15 led from an external control circuit is soldered to a part 14c on the back of a fixed part 11 and connected to both coils 3 and 4. Thus the part connected to the part 11 serves as the part 14b of the board 14. As a result, both the durability and the assembling workability are improved for an objective lens actuator.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an objective lens actuator for an optical head that optically reproduces information or records and reproduces information, and particularly relates to a terminal processing means for a focusing coil and a tracking coil. Regarding.

[Prior Art] FIG. 2 shows a conventional objective lens actuator. This objective lens actuator moves an objective lens holder 2 to which an objective lens 1 is attached in the tracking direction (X direction) via a tracking hinge part 9. A hinged parallel plate spring 10 that is displaceable and has hinge parts 10a at both ends.
A focusing coil 3 is attached to both sides of the objective lens holder 2 in the tracking direction, a tracking coil 4 is attached to the front surface of the objective lens holder 2, and the focusing coil 3 is attached to the front surface of the objective lens holder 2. The focusing drive magnet 5 is arranged opposite to the tracking coil 4, and the tracking drive magnet 7 is arranged opposite to the tracking coil 4.

In the conventional objective lens actuator described above, as shown in the figure, each terminal lead wire 3A of the focusing coil 3 and the tracking coil 4.

3B, 4A, and 4B are guided to a fixing part 11 at the proximal end of the hinged parallel plate spring 10 to the base 12, and this fixing part 11
It was directly connected by soldering to the printed circuit board shown attached to the back of the . A control signal line 15 from the external control circuit is connected to the printed circuit board.

Problems to be Solved by the Invention] In the above conventional coil terminal processing method, the terminal lead wire 3A
, 3B, 4A, and 4B are long, and the terminal lead wire itself vibrates due to the wind generated from the rotation of the optical disk.
Depending on long-term use, there is a risk of wire breakage, which poses problems in terms of durability. In addition, thin and long terminal lead wires 3A, 3B
, 4A, and 4B are complicated to handle and have poor assembly workability.

The present invention has been made to eliminate the above-mentioned conventional drawbacks, and an object of the present invention is to provide an objective lens actuator that is durable and has good assembly workability.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a flexible lens that integrally has a portion attached to the upper surface of the objective lens holder and a free cable-like portion extending along a hinge type parallel plate spring. A printed circuit board was provided, and terminal lead wires of the focusing coil and tracking coil were connected to the upper surface of the objective lens holder of this flexible printed circuit board.

[Function] In the above configuration, the terminal lead wires of the focusing coil and the tracking coil only require a length up to the top surface of the objective lens holder, and can be extremely short.

[Example] An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 is a perspective view of an objective lens actuator according to an embodiment of the present invention. In this embodiment, in order to reduce the thickness, the hinge type parallel leaf spring is shaped convexly inward. In Figure 0, which is applied to a structure in which a magnetic circuit that also serves as a drive is arranged on the left and right sides of an objective lens, 1 is an objective lens, 2 is an objective lens holder, and the front side of this objective lens holder 2 is An opening 2a is formed to provide a horizontal optical path.

The left and right sides of this objective lens holder 2 (tracking direction (X
Focusing coils 3 are respectively fixed in the direction )), and two tracking coils 4 are attached to the right or left outer surface of each focusing coil 3, respectively. 5 is a magnet that serves both as a focusing drive and a tracking drive, and this magnet 5 is attached to a yoke 6.
a, and the opposing yoke 6b is provided inside the focusing coil 3. 9 is objective lens holder 2
10 is a hinged parallel leaf spring that has hinge parts 10a at both ends and supports the objective lens holder 2 so as to be movable in the focusing direction (two directions). The parallel plate spring 10 has a hinge portion 10a formed by an inwardly directed V-side, and has an inwardly convex shape. A fixed portion 11 at the proximal end of the hinged parallel plate spring 10 is fixed to a column 13 vertically disposed on a base 12.

In the present invention, a flexible printed circuit board 14 is used. The flexible printed circuit board 14 of the embodiment includes an upper surface portion 14a of the objective lens holder, a free cable-like portion 14b extending from the objective lens upper surface portion 14a in parallel with the hinged parallel plate spring 10, and the fixed portion 1.
Part 14c attached to the back side of 1 (indicated by a broken line)
The terminal lead wires 3A, 3 of the focusing coil 3 and the tracking coil 4 are integrally formed.
B, 4A, and 4B are soldered to the objective lens holder upper surface portion 14a of the flexible printed circuit board 14 as shown. And WI# from external control circuit
The signal line 15 is connected to the focusing coil 3 and the tracking coil 4 by soldering to the portion 14c on the back surface of the fixed portion.

To explain an example of the manufacturing process of the objective lens actuator having the above configuration, the objective lens holder upper surface portion 14a of the flexible printed circuit board 14 is pasted on the upper surface of the objective lens holder 2, and the fixing part back part 14c is pasted on the back surface of the fixing part 11 in advance. . After attaching the objective lens 1, focusing coil 3, and tracking coil 4 to the objective lens boulder 2 (note, these can also be attached before the pasting), the terminal lead wires of the focusing coil 3 and tracking coil 4 are attached. 3A, 3
A, 4B, and 4B are the objective lens holder upper surface portion 14a.
Solder the pattern.

Next, the fixed part 11 is fixed to the support column 13, and then the control signal line 15 from the external control circuit is connected to the fixed part rear part 14c.
Solder and connect. The terminal processing of each coil 3.4 in this assembly work consists of a short terminal lead wire 3A,
3B, 4A, and 4B are soldered to the nearby part (objective lens holder upper surface part 14a), so the workability is good. Also, the part connecting from the objective lens holder 2 to the fixed part 11 is connected to the cable of the flexible printed circuit board 14. The shaped portion 14b has sufficient strength and is highly durable.

Note that the present invention is not limited to the structure of the embodiment, but can be applied to various structures in which the objective lens holder is supported by a hinge type parallel plate spring.

[Effects of the Invention] According to the present invention described above, a flexible printed circuit board having a portion attached to the upper surface of the objective lens holder and a free cable portion extending along the hinged parallel plate spring is provided, and the flexible printed circuit board Since the terminal lead wires of the focusing coil and tracking coil were connected to the upper surface of the objective lens holder,
The length of the terminal lead wires of the focusing coil and tracking coil, which are thin and easily broken, can be shortened. On the other hand, the wiring to the fixed part of the base end of the hinge type parallel plate spring is strong because it is a cable-like part of the flexible printed circuit board. Durability has been significantly improved. Additionally, the work required to lead and connect a long terminal lead wire to the back of the fixed part is no longer necessary, significantly improving assembly work efficiency.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an objective lens actuator according to an embodiment of the present invention, and FIG. 2 is a perspective view of a conventional objective lens actuator. 1... Objective lens, 2... Objective lens holder, 3...
...Focusing coil, 4...Tracking coil, 3A, 3B, 4A, 4B...Terminal lead wire, 10
...Hinged parallel plate spring, 11...Fixed part, 14.
...Flexible printed circuit board, 14a...Top part of objective lens holder, 14b...Cable part, 14c
...Fixed part back part.

Claims (1)

[Claims] 1. An objective lens actuator in which an objective lens holder to which an objective lens, a focusing coil, and a tracking coil are attached is supported so as to be displaceable in the focusing direction via a hinged parallel plate spring, wherein the objective lens holder A flexible printed circuit board is provided which integrally includes a portion to be attached to the upper surface and a free cable-shaped portion extending along the hinge type parallel plate spring, and a focusing coil and a tracking coil are mounted on the upper surface portion of the objective lens holder of the flexible printed circuit board. An objective lens actuator characterized in that each terminal lead wire is connected to the objective lens actuator. 2. In addition to the upper surface portion of the objective lens holder and the cable-shaped portion, the flexible printed circuit board includes a fixed portion back portion that is attached to the back surface of the fixed portion at the proximal end of the hinged parallel leaf spring, which is continuous to the cable-shaped portion. The objective lens actuator according to claim 1, wherein the objective lens actuator is integrally held.