JPH05259588A - Flexible printed circuit and objective lens driving equipment - Google Patents

Abstract

PURPOSE:To facilitate the bending work of an FPC(flexible prited circuit) and improve the accuracy of a bending position. CONSTITUTION:Dummy pattern parts 8b are formed on both sides of a bending line of an FPC 8, and bending work of the FPC 8 is performed by using the dummy pattern parts 8b as the guide. The FPC 8 is fixed on an objective retaining member 4. Thereby the bending is made easy and accurate, on account of the difference of hardness between the bending line and the dummy pattern parts 8b on both sides of the line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bending guide of a flexible printed circuit (hereinafter referred to as FPC) and an objective lens driving device for an optical disc equipped with this FPC.

[0002]

2. Description of the Related Art FIG. 3 shows, for example, Japanese Patent Laid-Open No. 62-154331.
FIG. 4 is a plan view showing a conventional objective driving lens device disclosed in Japanese Patent Publication No. JP-A-2003-264, and FIG. 4 is a sectional view taken along the line BB of FIG.
In the figure, 1 is a body frame of the objective lens driving device,
Reference numeral 2 is a support shaft provided on the main body frame 1, 3 is an objective lens for forming a light spot on a recording surface of an optical disk (not shown), 4 is an objective lens holding member having a sliding hole 4a, and its sliding The hole 4a is attached to the support shaft 2, and is configured to be capable of rotating around the axis and sliding along the axis. The objective lens holding member 4 holds the objective lens 3 such that its optical axis and the support axis 2 are parallel to each other. Reference numeral 5 is a cylindrical focus direction driving coil fixed to the lower part of the objective lens holding member 4, 6 is a focus direction driving magnetic circuit, and 7a and 7b are squares fixed to the side surface of the objective lens holding member 4. The relay FPC 8 is adhered to the objective lens holding member 4 in order to connect the winding end conductor 17a of 7a and the winding start conductor 17b of 7b. 8a is a relay F
The conductors 9a and 9b formed on the PC 8 are magnetic circuits for driving in the track direction.

Next, the operation of the objective lens driving device will be described. When the focus shift of the light spot is detected, a current corresponding to this shift amount flows in the focus direction driving coil 5 and the objective lens holding member 4 is supported by the magnetic flux of the focus driving magnetic circuit 6 by an electromagnetic action. The optical spot is brought into focus on the recording surface of the optical disk by sliding in the axial direction of 2 to correct the focus shift. Further, when the track deviation of the light spot is detected, a current corresponding to the deviation amount flows in the track direction driving coils 7a and 7b, and the objective lens is electromagnetically acted by the magnetic flux of the track direction driving magnetic circuits 9a and 9b. The holding member 4 is rotated around the support shaft 2 to correct the track deviation so that the light spot follows the track on the recording surface of the optical disc.

[0004]

The conventional objective lens driving device is configured as described above, and the relay FPC 8 is bent at two right angles and then bonded to the objective lens holding member 4. Therefore, if there are variations in the bending position as shown in FIGS. 5B and 5C, the reaction force of the relay FPC 8 may increase and peeling may occur. There is a problem that the coils 7a and 7b are affected to a considerable extent.

The present invention has been made in order to solve the above problems, and facilitates the bending work of the relay FPC, and an objective lens driving device equipped with the relay FPC in which the bending position is accurate. The purpose is to provide.

[0006]

FPC according to the present invention
Is to form dummy pattern portions on both sides of the bending position and perform the bending work using the dummy pattern portions as guides.

Further, the above FPC is used as a relay FPC attached to the objective lens holding member.

[0008]

In the present invention, the dummy pattern portions are provided on both sides of the bending position of the FPC, so that the bending becomes easy and accurate.

Further, by using this FPC for the objective lens holding member, the adhesion can be stabilized, and peeling and unnecessary resonance during operation can be suppressed.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing a state in which the FPC according to the present embodiment is attached to an objective lens driving device, and FIG. 2 is a perspective view for explaining a bending operation of the FPC. In the figure, 1 is a main body frame of an objective lens driving device, 2 is a support shaft, 3 is an objective lens, 4 is an objective lens holding member, and an objective lens holding member having a sliding hole 4a attached to the support shaft 2, 7a and b are track direction driving coils, 17a is a winding end conductor wire, 17b is a winding start conductor wire, 8 is a relay FPC, and 9a and b are track direction driving magnetic circuits, the details of which are the same as those of the conventional example. is there. In this embodiment, the conductor pattern portion 8a is made of copper foil or the like on the relay FPC 8, and the dummy pattern portions 8b are also made of copper foil or the like on both sides of the bending position.

Next, the operation of the above embodiment will be described. Generally FPC (flexible printed circuit)
Is also called a flexible printed wiring board, and an electric conductor is formed on one or both sides of a flexible insulating film (polyimide type, polyester type, etc.) by a method such as etching. In this embodiment, by forming a dummy pattern portion 8b such as a copper foil on the flexible FPC 8 for relay, the hardness of that portion is increased, and the position of the bending line (FPC) and both sides thereof are increased. A hardness difference is generated with the (dummy pattern portion 8b). When the relay FPC 8 is bent by utilizing this hardness difference, it can be bent accurately and easily at the position of the bending line, and peeling due to poor adhesion to the objective lens holding member 4 or occurrence of unnecessary resonance during operation. Can be prevented.

In the above embodiment, the dummy pattern portion 8
Although the example in which b is formed of copper foil or the like is shown, the same effect can be obtained by forming another metal or a material that enhances hardness. Further, although the example in which the FPC is applied to the relay of the objective lens driving device is shown, it can be applied to the case where the FPC is fixed to a movable part of another device, and the same effect as the above embodiment can be obtained. You can

[0013]

As described above, according to the present invention, the FPC
Since the dummy pattern parts are formed on both sides of the bending position of, the bending position becomes accurate without any variation.
The adhesive effect with the objective lens holding member or the like on which the PC is mounted is improved, and a highly reliable device without peeling or unnecessary resonance is obtained.

[Brief description of drawings]

FIG. 1 is a plan view showing an objective lens driving device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an FPC according to an embodiment of the present invention.

FIG. 3 is a plan view showing a conventional objective lens driving device.

FIG. 4 is a view showing a cross section taken along line BB of a conventional objective lens driving device.

FIG. 5 is a diagram showing a reaction force when a conventional relay FPC is bent.

[Explanation of symbols]

 1 Main Frame 2 Support Shaft 3 Objective Lens 4 Objective Lens Holding Member 4a Sliding Hole 7a, b Track Direction Driving Coil 8 Relay FPC 8a Conductor 8b Dummy Pattern 9a, b Track Direction Driving Magnetic Circuit 17a, b Tracking Coil end wire

Claims (2)

[Claims] 1. A flexible printed circuit that is bent and used for a product, in which dummy pattern portions are formed on both sides of a bending position and bending work is performed by using the dummy pattern portions as guides. 2. An objective lens holding member supported by a support shaft fixed to a main body frame, rotatable about the support shaft, and slidable in the axial direction of the support shaft, and the objective lens holding member. And a drive means for causing the objective lens holding member to perform the rotating and sliding movements, and a lead for driving. In the objective lens driving device in which a flexible printed circuit for relay used for drawing a wire is mounted on the objective lens holding member, the flexible printed circuit according to claim 1 is used as the flexible printed circuit for relay, and the flexible printed circuit is used. An objective lens driving device that is bent and attached to an objective lens holding member.