JPH0452816Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is used to reproduce information recorded on optical recording disks and to be attached to the actuator of an optical pickup used for recording information on such disks. Regarding printed coils.

[Conventional technology]

Generally, in an optical pickup, a light source, an optical system such as a beam splitter, and a photodetector are attached to the optical pickup body, and an actuator with an objective lens is attached to the optical pickup body to direct the light from the light source through the objective lens. The light is then irradiated onto the disk in a spot-like manner, and the reflected light is received by a photodetector via an objective lens.

Various types of actuators have been proposed in the past for such optical pickups, but in general, a focusing coil and a tracking are attached to a movable member that holds an objective lens and supports it so that it can be displaced in the focusing and tracking directions. By attaching King coils and applying magnetic flux to these coils to supply a focusing error signal to the focusing coil and a tracking error signal to the tracking coil, the movable member and therefore the objective lens are moved in the focusing direction. and is driven in the tracking direction.

However, in conventional actuators, the focusing coil and tracking are generally constructed with windings of conductive wire. Therefore, there is a problem that the weight of the movable parts including the objective lens and the movable member becomes heavy, and the access speed becomes slow.

Recently, as a way to solve such problems,
It has been proposed that a driving coil for a focusing coil or a tracking coil be constructed using a printed coil in which a conductive pattern is formed into a coil shape by etching, plating, etc. on a flexible insulating sheet. These printed coils are extremely light in weight compared to coils made of conductor wire windings, so the weight of the moving parts can be reduced, allowing high-speed access, and the shape of the conductor pattern can be made into a variety of shapes. This has the advantage of increasing the degree of freedom in design.

[Problem that the invention attempts to solve]

The above-mentioned printed coil is formed by connecting a plurality of coil parts in series to an insulating sheet,
It is attached by adhesive or the like to the outer surface of the movable member that holds the objective lens. However, in the case of conventional printed coils, since the coil parts are connected by a straight connecting conductor pattern, it is not possible to cope with changes in length due to bending, etc. There is a problem in that the connecting conductor pattern may break due to bending when the coil is attached along the same direction, or that the coil portion cannot be accurately positioned at a predetermined position because it cannot accommodate variations in the external dimensions of the movable member.

This idea was created by focusing on these conventional problems, and it is designed to prevent the connection conductor pattern from cracking due to bending, and to easily accommodate variations in the dimensions of movable members. An object of the present invention is to provide a printed coil for an actuator having the following structure.

[Means for resolving issues in the summer]

In order to achieve the above object, in this invention, in a printed coil having a plurality of coil parts, at least two adjacent coil parts that are connected to each other are connected by a connecting conductor pattern that is longer than the distance between them.

[Effect]

In the above configuration, in the portion where adjacent coil parts are connected by a connecting conductor pattern that is longer than the distance between them, there is an allowance in the length of the connecting conductor pattern, so that the distance between the coil parts can be extended. Therefore, it is possible to effectively prevent the occurrence of cracks in the connecting conductor pattern due to bending, and it is also possible to easily accommodate variations in the dimensions of the movable member, allowing the coil section to be accurately positioned and installed at a predetermined position. .

〔Example〕

1 to 4 show first to fourth embodiments of this invention. The printed coil 1 shown in FIGS. 1 to 4 is for tracking, and includes four tracking coil parts 3a to 3d formed on a flexible insulating sheet 2 in a predetermined positional relationship. These coil portions 3a to 3d are arranged between land portions 4a and 4b formed at both ends of the insulating sheet 2 for supplying a tracking error signal, and between coil portions 3a and 3b and coil portions 3c and 3d which are spaced apart from each other. are connected in series via connecting conductor patterns 5a and 5b which are longer than the distance between them.

The above basic configuration is the same in FIGS. 1 to 4, but in FIG. 1, the width of the insulating sheet 2 is made uniform and the connection conductor patterns 5a, 5b are formed in a sinusoidal shape, and in FIG. In this case, the width of the insulating sheet 2 between the coil parts 3a and 3b and the coil parts 3c and 3d is made small and formed in a sinusoidal shape, and the connecting conductor patterns 5a and 5b are formed in accordance with the shape.

In addition, in FIG. 3, the width of the insulating sheet 2 between the coil parts 3a and 3b and the coil parts 3c and 3d is made small and linear, and the connecting conductor patterns 5a and 5b are formed in a sinusoidal shape in these parts. Although the width of the insulating sheet 2 is uniform in FIG. 4, cuts 6 are formed alternately in the insulating sheet 2 between the coil parts 3a and 3b and between the coil parts 3c and 3d to connect these parts. conductor pattern 5
a and 5b are formed in a zigzag shape.

FIGS. 5 and 6 are perspective views respectively showing examples of mounting the printed coil according to this invention. In FIG. 5, the printed coil 1 shown in FIG. 3 is attached to the outer circumferential surface of a rectangular movable member 12 that holds an objective lens 11 by bending it at a portion having connection conductor patterns 5a and 5b. , also the sixth
The figure shows a printed coil 1 shown in FIG. 4 attached to the outer peripheral surface of a cylindrical movable member 17 that holds an objective lens 15 and is slidable along an axis 16 and rotatable around the axis 16. This is what I did.

If the printed coil 1 is bent and attached to the pot shown in FIG. 5 at the part having the connecting conductor patterns 5a, 5b, the connecting conductor patterns 5a, 5b will stretch at these parts, so there will be no cracking. , it is possible to effectively deal with variations in the external dimensions of the movable member 12, and to accurately position and mount the coil portions 3a to 3d at predetermined positions with respect to the movable member 12. Further, the same applies to FIG. 6, even if there is variation in dimensions of the movable member 17, it can be effectively absorbed by the notch 6 and the deformation of the connecting conductor patterns 5a, 5b, so that the connecting conductor pattern 5a , 5b, and the coil portions 3a to 3d can be accurately positioned and attached to the movable member 17 at predetermined positions.

Note that this invention is not limited to the above-mentioned embodiments, and can be modified or changed in many ways. For example, the coil portions 3a to 3d may be formed in multiple layers in the thickness direction of the insulating sheet 2 with an insulating film interposed therebetween. Also, a land portion 4a is used to supply a tracking error signal to the coil portions 3a to 3d.
4b can be formed on any part of the insulating sheet 2. Furthermore, this invention can be effectively applied not only to printed coils for tracking, but also to cases in which a driving coil for focusing is configured with a printed coil. Further, the conductor pattern connecting the coil parts may be longer than the distance between at least two coil parts connected to each other.

[Effect of idea]

As mentioned above, according to this invention, the connecting conductor pattern is formed to be longer than the distance between the coil parts to be connected, so even if this part is bent, the connecting conductor pattern will not crack. In addition, it is possible to effectively deal with variations in the dimensions of the movable member to which the printed coil is attached, and it is possible to accurately position the coil portion at a predetermined position with respect to the movable member. Therefore, even if the shapes of the movable members are different, it is possible to use the same parts with the same printed coil attached to the movable members.

[Brief explanation of the drawing]

1 to 4 are views showing first to fourth embodiments of this invention, respectively, and FIGS. 5 and 6 are perspective views showing examples of mounting a printed coil according to this invention, respectively. 1...Printed coil, 2...Insulating sheet, 3
a to 3d... Coil part, 4a, 4b... Land part, 5a, 5b... Connection conductor pattern, 6...
Notch, 11, 15...Objective lens, 12, 1
7...Movable member, 16...Axle.

Claims (1)

[Scope of utility model registration request] A printed coil attached to a movable member holding the objective lens in order to drive the objective lens in a predetermined direction, the printed coil having a plurality of coil parts and at least two adjacent coils connected to each other. A printed coil for actuators that connects parts with a connecting conductor pattern that is longer than the distance between them.