JPH08321060A - Manufacture of objective lens driving device - Google Patents

Abstract

PURPOSE: To enable everybody to process coil end parts of a focus coil and a tracking coil by simple work without causing lowering of an output. CONSTITUTION: An objective lens is driven in the focusing direction and the tracking direction. Respective coil end parts 2a, 2b, 3a and 4a of a driving coil consisting of the focus coil 2 and the tracking coils 3 and 4 are held by resins 21 and 22 at positions approximately corresponding to respective terminals provided on a bobbin, and this driving coil is incorporated in the bobbin.

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 objective lens driving device for writing and reading an information signal to and from an optical disk, and more particularly to a coil terminal processing technique for a driving coil.

[0002]

2. Description of the Related Art A recording and / or reproducing apparatus for reading out music information and image information written on a recording disk such as an optical disk or a magneto-optical disk has a built-in objective lens driving device which is a light beam positioning actuator. Has been done.

In an objective lens driving device used in this type of device, a movable part incorporating the objective lens is supported by a suspension made of a thin wire or a thin metal plate with respect to a fixed part, and an electromagnetic effect is utilized. A so-called biaxial actuator is used, which controls the facing distance of the objective lens to the recording disk and the radial position of the recording disk by energizing the drive coil in the movable part.

In order to drive the objective lens, a focus coil is driven to move the objective lens toward and away from the recording disc, that is, in the focus direction, and the objective lens is driven in the radial direction of the recording disc, that is, the tracking direction. A drive coil consisting of a tracking coil is used.

Each of the focus coil and the tracking coil is formed by winding a copper wire or the like into a predetermined shape, and is incorporated in a bobbin constituting a movable part. The focus coil and the tracking coil are configured such that the coil ends of the respective coils are soldered to the respective terminal portions provided on the bobbin.

By the way, in order to incorporate the drive coil into the bobbin, the focus coil and the tracking coil are grasped with tweezers or the like, and these are incorporated into the bobbin. Then, the coil ends of the respective coils that have become dangling are picked up with tweezers, and these are solder-connected to the terminal portions provided on the bobbin.

However, since the coil end after the coil is wound is in a dangling state, it is difficult for a skilled worker to solder the coil end to the terminal portion. Moreover, since the diameter of the copper wire is as thin as about 100 μm or less, it is easy to cut when the coil end is left as a free end.

As described above, since the position of the coil terminal is uncertain, it is difficult to mechanize the coil terminal processing. In addition, there is a problem that it is difficult to use an electrical connection method other than soldering.

As a method for solving this, the following method has been proposed by the applicant. First, as shown in FIG. 9, one center pole 101 of the two center poles 101 and 102 of the coil winding machine (not shown) is drawn from a virtual coil winding start surface 103 indicated by diagonal lines. , The thickness ΔT of the coil to be wound is projected in the pole projecting direction indicated by arrow X in the figure.

These center poles 101 and 102 are
It serves as a core for winding the coil,
Since the tracking coil is wound in a rectangular shape, it is formed as an elongated bar having a rectangular cross section.

Next, as shown in FIG. 10, the coil terminal holder 104 for temporarily fixing the coil terminal of the wound coil is projected in the pole projecting direction by a jig (not shown), and once the virtual coil winding is performed. It is provided at the same position as the starting surface 103 and slightly protruding. The coil terminal holder 104 has a coil winding section 105 for winding the tracking coil and a coil terminal processing section 106 for temporarily fixing the coil terminal. In the coil winding portion 105, rectangular through holes 107 and 108 through which the center poles 101 and 102 are inserted are formed.

Then, as shown in FIG. 11, the coil terminal 109a, which is the beginning of coil winding, is connected to the coil terminal processing unit 10.
Fix at 6. The coil terminal 109a can be fixed by fixing it with heat such as a hot melt sheet or by applying an ultraviolet curable resin and irradiating it with ultraviolet rays.

Next, the coil end holder 104 is slightly displaced from the virtual coil winding start surface 103 in the direction opposite to the pole projecting direction. Then, the tracking coil is wound around the center pole 101 protruding from the through hole 107. When the tracking coil 109 is completely wound, the other center pole 102 is projected and the coil winding portion 1
05 through the other through hole 108.

Then, as shown in FIG. 12, a winding auxiliary plate 111 having a notch 110 for exposing the center pole 102 protruding from the through hole 108 to the outside.
Is attached to the coil winding portion 105 of the coil terminal holder 104. The winding auxiliary plate 111 is formed as a plate having a thickness equal to or thicker than the thickness ΔT of the coil to be wound. That is, ΔS ≧ ΔT.
Therefore, the coil winding portion 10 of the winding auxiliary plate 111 is
The surface 111a on the opposite side of the surface facing 5 is a new virtual coil winding start surface (the portion shown by the diagonal lines in FIG. 11).

Next, the coil is started to be wound on the center pole 102 protruding from the coil winding start surface 111a of the winding auxiliary plate 111 by the thickness ΔT of the coil to be wound.
Then, after winding the tracking coil 112, the winding auxiliary plate 111 is removed, and the tracking coil 112 is displaced in the direction opposite to the pole projecting direction using the center pole 102 as a guide.

Then, as shown in FIG. 13, the coil end terminal 112a is fixed to the coil terminal processing unit 106 of the coil terminal holder 104. Any of the above processing methods can be used for this terminal processing.

The tracking coils 109 and 112 shown in FIG. 14 are completed as described above. Then, the coil terminal holder 104 as a whole is removed from the winding machine. To remove the tracking coils 109 and 112 from the winding machine,
The coil terminal holder 104 is attached to the center poles 101, 10
It suffices to project the pole in the direction of the pole along 2.

Next, a focus coil is manufactured. First, as shown in FIG. 15, the center pole 115 is inserted into the rectangular through hole 114 provided in the coil terminal holder 113 for temporarily fixing the coil terminal of the wound coil.

The coil terminal holder 113 has a coil winding section 116 around which the tracking coil is wound, and coil terminal processing sections 117 and 118 for temporarily fixing the coil terminal. A hatched portion 113a of the coil terminal holder 113 is a coil winding start surface for winding the coil.

Next, the center pole 115 is projected from the coil winding start surface 113a by the thickness ΔT of the coil to be wound in the pole projecting direction indicated by X in the drawing. Next, the coil terminal 119a, which is the beginning of coil winding, is fixed to one coil terminal processing unit 117. Any of the above methods can be adopted for the coil terminal processing here.

Then, the coil is started to be wound on the center pole 115 protruding from the coil winding start surface 113a. After winding the focus coil 119, as shown in FIG. 16, the coil terminal 119b at the end of winding is fixed to the other coil terminal processing unit 118. The coil terminal processing here is also the same.

The assembly of the focus coil 119 and the tracking coils 109, 112 manufactured as described above is positioned by a jig not shown in the drawing, and is bonded and fixed by an ultraviolet curable resin, as shown in FIGS. That is, so that the tracking coils 109 and 112 face the side surface of the focus coil 119,
Adhesive and fixed with UV curable resin. This allows
The drive coil is completed.

The drive coil is mounted on a fixed bobbin 120 shown in FIG.
It is incorporated into a movable bobbin 123 that is movably supported via As a result, the objective lens driving device is completed. Focus coil 119 incorporated in movable bobbin 123
Magnets 124 and 125 provided on U-shaped yokes are provided at positions facing the center hole and the tracking coils 109 and 112, respectively.

The coil terminal holder 104 is shown in FIG.
It may be a flat plate having no bent portion as shown in FIG.
In this case, the coil winding portion 105 indicated by diagonal lines in the figure is the same as in FIG.
It overlaps with a so-called air gap in the magnetic circuit of the objective lens driving device shown in FIG. For this reason, it is preferable that the coil winding portion 105 be omitted if possible.
It is desirable to cut after assembling in 3. As for the coil terminal holder 113, as shown in FIG. 21, both coil terminal processing units 117 and 118 may be shaped so as to be lowered downward. This coil terminal holder 113
FIG. 22 shows the state in which the focus coil 119 is attached.

[0025]

The focus coil 119 and the tracking coil 1 manufactured as described above.
09 and 112 are coil terminals 109a and 11 respectively.
9a, 119b, 112a are coil terminal processing units 106,
Since it is temporarily fixed to 117 and 118, the movable bobbin 1
Anyone can easily perform the soldering process after assembling into 23 regardless of a skilled worker. In addition, there is no inconvenience that the coil terminal is cut off when it is handled.

However, in order to manufacture the focus coil 119 and the tracking coils 109 and 112, dedicated coil terminal holders 104 and 113 are required, respectively, so that the number of parts is large and the cost increase cannot be avoided. Further, since the coil terminal holders 104 and 113 are incorporated into the movable bobbin 123, the coil terminal holders 104 and 113 may overlap the air gap of the magnetic circuit section, which may cause a reduction in output.

Therefore, in order to solve the above-mentioned technical problems of the present invention, the objective lens in which anyone can perform the coil terminal processing of the focus coil and the tracking coil by a simple operation, and the output does not decrease. It is an object of the present invention to provide a method for manufacturing a drive device.

[0028]

In order to solve the above-mentioned problems, the present invention provides a method for manufacturing an objective lens driving device in which an objective lens is driven in a focus direction and a tracking direction, a focus coil and a tracking coil. Each of the coil ends of the drive coil consisting of is configured to be incorporated into the bobbin in a state in which the coil terminal holding member holds the coil terminals at positions substantially corresponding to the terminals provided on the bobbin. To do.

As the coil end holding member, adhesive paper having an adhesive layer or resin is used. As the resin, a hot melt resin or an ultraviolet curable resin is preferable.

[0030]

In the present invention, the respective coil terminals of the drive coil composed of the focus coil and the tracking coil are placed at positions substantially corresponding to the respective terminals provided on the bobbin.
Since the drive coil is incorporated in the bobbin while being held by the coil end holding member, anyone can easily connect the coil end to each terminal provided on the bobbin.

Particularly, when adhesive paper having an adhesive layer or resin is used as the coil end holding member, after the coil end is completely connected to each terminal provided on the bobbin,
If these adhesive paper and resin are removed, the output does not fall in the air gap of the magnetic circuit section and does not decrease.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments to which the present invention is applied will be described in detail below with reference to the drawings.

First, the structure of the objective lens driving device will be described. The objective lens driving device is a biaxial actuator including a movable part in which an objective lens and a drive coil are incorporated, and a fixed part that movably supports the movable part by a suspension. A movable bobbin holding the coil,
The fixed bobbin holding the movable bobbin is formed by insert molding.

As shown in FIGS. 1 and 2, the objective lens driving device includes a first movable bobbin 1 which mainly holds an objective lens (not shown), a focus coil 2 and a pair of tracking coils. A second movable bobbin 5 that holds a drive coil composed of 3, 4 and a first fixed bobbin 10 that supports the first movable bobbin 1 and the second movable bobbin 5 with suspensions 6, 7, 8, 9. And the second fixed bobbin 11.

First movable bobbin 1 and first fixed bobbin 1
0 indicates a pair of suspensions 6, 7 as shown in FIG.
It is designed to be connected by. Similarly, the second movable bobbin 5 and the second fixed bobbin 11 are also connected by the pair of suspensions 8 and 9. In addition, the first movable bobbin 1 and the second movable bobbin 5 are joined and integrated to form a movable portion, and the first fixed bobbin 10 and the second fixed bobbin 11 are also joined and integrated to form the fixed portion. It is designed to be configured.

The first movable bobbin 1 has an objective lens mounting portion 12 in which an objective lens is incorporated, and drive coil holding portions 13 and 14 for holding the focus coil 2 and the tracking coils 3 and 4. The objective lens mounting portion 12 is formed as a disc-shaped holding portion having a size large enough to hold the objective lens, and has a circular shape at its center for allowing laser light or return light from the recording disk to enter the objective lens. It has a light beam transmission 15 formed. Positioning protrusions 16 are provided at three positions on the peripheral edge of the opening of the light beam transmission 15 in contact with the outer peripheral edge of the objective lens for positioning.

The drive coil holding portions 13 and 14 are provided as a pair of parallel arms having one end as a free end with respect to the objective lens mounting portion 12, and hold the focus coil 2 and the tracking coils 3 and 4 therebetween. It has become. The drive coil holding portions 13 and 14 here hold the upper end portion of the focus coil 2 with an adhesive or the like.

The focus coil 2 is for driving the movable portion in a direction perpendicular to the recording disk so as to move toward and away from the recording disk, that is, in the focus direction, and has a rectangular hole in the center of which the yoke faces when the coil is wound. It is formed as a rectangular parallelepiped. On the other hand, the tracking coils 3 and 4 are for driving the movable portion in the radial direction of the recording disk, that is, the tracking direction, and are formed as rectangular flat coils and attached to one side surface of the focus coil 2. ing.

The second movable bobbin 5 holds the focus coil 2 and the tracking coils 3 and 4 in the center, and has a substantially rectangular plane shape having a magnetic circuit accommodating portion 17 formed as a through hole facing the magnet and the yoke. It is formed as a frame body having a shape. The magnetic circuit housing 17 includes a focus coil holder 17 that holds the focus coil 2.
a and a magnet arranging portion 17b facing a magnet (not shown) arranged to face the tracking coils 3 and 4 attached to the focus coil 2 held by the focus coil holding portion 17a. ing.

The second movable bobbin 5 is formed with a circular engagement hole 18 for positioning the first movable bobbin 1 when the second movable bobbin 5 and the first movable bobbin 1 are integrated with each other. On the other hand, the first movable bobbin 1 is provided with an engagement pin 19 that engages with the engagement hole 18.

The first fixed bobbin 10 functions to movably support the first movable bobbin 1 by the pair of suspensions 6 and 7. Similarly, the second fixed bobbin 1
1 also functions to movably support the second movable bobbin 5 by the pair of suspensions 8 and 9.

Then, in the second fixed bobbin 11,
A columnar engagement pin 20 is provided for positioning these when integrated with the first fixed bobbin 10. On the other hand, the first fixed bobbin 10
Is provided with an engagement hole (not shown) that engages with the engagement pin 20.

The objective lens driving device including the above-mentioned components is assembled as follows. The first movable bobbin 1 and the second movable bobbin 5 are joined and integrated, and the first fixed bobbin 10 and the second fixed bobbin 11 are also joined and integrated. Then, the objective lens is attached to the objective lens attachment portion 12 of the first movable bobbin 1, and
The focus coil 2 in which the tracking coils 3 and 4 are integrated is held by the drive coil holders 13 and 14 of the first movable bobbin 1 and the focus coil holder 17a of the second movable bobbin 5.

Then, the coil ends of the tracking coils 3 and 4 are soldered to the terminal portions 6a and 7a which are one end portions of the suspensions 6 and 7 which are exposed to the outside of the first movable bobbin 1. Similarly, the coil end of the focus coil 2 is also solder-connected to the terminal portions 8a and 9a of the suspensions 8 and 9 which are exposed to the outside of the second movable bobbin 5. These suspensions 6, 7, 8 and 9 also function as a wiring circuit that supplies a drive current to the focus coil 2 and the tracking coils 3 and 4.

As a result, the objective lens driving device is completed, and the movable part incorporating the objective lens and the driving coil is
It is movably supported by suspensions 6, 7, 8, 9 with respect to the fixed portion. Then, by energizing the drive coil, the objective lens is driven in the tracking direction and the focus direction.

By the way, the focus coil 2 and the tracking coils 3 and 4 are easily cut when the coil ends are placed at their free ends. Therefore, the coil ends are temporarily fixed and assembled into the movable bobbin. That is, as shown in FIG. 3, after the focus coil 2 and the tracking coils 3 and 4 are wound into a predetermined shape, the tracking coils 3 and 4 are attached to one side surface of the focus coil 2. Then, the coil terminals 2a and 2b of the focus coil 2 are provided at positions substantially corresponding to the terminal portions 8a and 9a of the suspensions 8 and 9 which are exposed to the outside of the second movable bobbin 5. Similarly, the suspensions 6, 7 in which the coil terminals 3a, 4a of the tracking coils 3, 4 are exposed to the outside of the first movable bobbin 1.
It is provided at a position substantially corresponding to the terminal portions 6a and 7a.

Next, as shown in FIG. 4, the coil terminals 2a and 2b of the focus coil 2 are held by the resin 21 which is a coil terminal holding member. The resin 21 is provided over the main body of the focus coil 2 and the coil terminals 2a and 2b. In this example, the resin 21 has a substantially T-shape in plan view. Further, the resin 21 is also provided on the portion of the focus coil 2 that is pulled out from the main body portion.

Similarly, the coil terminals 3a and 4a of the tracking coils 3 and 4 are also held by the resin 22.
That is, the resin 22 is provided so as to be substantially U-shaped in a plane across the main body of the focus coil 2 and the coil terminals 3a and 4a.

A hot melt resin or an ultraviolet curable resin is used for these resins 21 and 22. The hot-melt resin contains a thermoplastic resin as a main component and is solid at room temperature, but becomes a molten state by heating. Therefore,
This hot melt resin is applied to an adherend by heating, pressure-bonded, and then cooled and solidified before use. On the other hand, the ultraviolet curable resin has a property that it is in a paste state before being irradiated with ultraviolet rays and hardened by being irradiated with ultraviolet rays. Therefore, this ultraviolet curable resin is applied to an adherend and pressure-bonded, and then irradiated with ultraviolet rays to be solidified and used.

In this way, the coil terminals 2a, 2 of each coil are
If b, 3a, 4a are held in the movable bobbin while being held by the resins 21, 22, the coil terminals 2a, 2
Since the positions of b, 3a, and 4a are provided at positions substantially corresponding to the terminal portions 6a, 7a, 8a, and 9a of the suspensions 8 and 9, these coil terminals 2a, 7a 2b, 3a, 4a and the terminal portions 6a, 7a, 8a, 9a of the suspensions 8, 9 can be electrically connected. As the electrical connection, for example, a method such as soldering, ultrasonic welding, resistance welding or the like can be adopted. As described above, since the positions of the coil terminals 2a, 2b, 3a, 4a are provided in advance at positions substantially corresponding to the terminal portions 6a, 7a, 8a, 9a of the suspensions 8, 9, it is possible for a skilled worker to Instead, automatic processing using a robot can be realized.

When the connection of the coil terminals is completed,
All or part of the resins 21 and 22 are removed. As a result, the state is almost the same as when only the focus coil 2 and the tracking coils 3 and 4 are incorporated into the movable bobbin,
There is no obstruction in the magnetic circuit, and there is no reduction in output.

The shapes of the resins 21 and 22 are not particularly limited as long as they can hold the coil terminals 2a, 2b, 3a and 4a. For example, as shown in FIG. 5, only the coil terminals 2a and 2b of the focus coil 2 may be held. Alternatively, the coil terminals 3a and 4a of the tracking coils 3 and 4 may be held by the resin 22 having a substantially T-shaped plan.

Alternatively, as shown in FIG. 6, an adhesive paper 25 having an adhesive layer 24 on one main surface of the support 23 may be used as a coil terminal holding member. The adhesive layer 24 only needs to have adhesive strength enough to hold the coil terminals 2a, 2b, 3a, 4a. Support 23
For this, it is desirable to use a hard paper or the like having a certain strength.

Using this adhesive paper 25, the coil terminals 2a,
A state in which 2b, 3a, and 4a are held is shown in FIGS. Even in such a case, the coil terminals 2a, 2b, 3
Terminal portions 6a, 7a, 8a, 9a of the suspensions 6, 7, 8, 9 which expose a, 4a to the outside of the movable bobbins 1, 5
It is provided as a position substantially corresponding to.

[0055]

As is apparent from the above description, according to the manufacturing method of the present invention, the respective coil terminals of the drive coil composed of the focus coil and the tracking coil substantially correspond to the terminals provided on the bobbin. Since the drive coil is incorporated in the bobbin while being held by the coil end holding member at the position, the anyone can easily connect the coil end to each terminal provided on the bobbin. Further, after the coil terminals are connected, the adhesive paper or the resin, which is the coil terminal holding member, is removed so that there is no overlap with the air gap of the magnetic circuit section, and it is possible to prevent the output from decreasing.

[Brief description of drawings]

FIG. 1 is a perspective view of an objective lens driving device.

FIG. 2 is an exploded perspective view of an objective lens driving device.

FIG. 3 is a perspective view of a drive coil.

FIG. 4 is a perspective view showing a state in which a coil end of a drive coil is held by a resin.

FIG. 5 is a perspective view showing another example of a state in which a coil end of a drive coil is held by a resin.

FIG. 6 is an enlarged side view of an adhesive paper having an adhesive layer on one main surface of a support.

FIG. 7 is a perspective view showing a state in which a coil end of a drive coil is held by adhesive paper.

FIG. 8 is a perspective view showing another example of a state in which a coil end of a drive coil is held by adhesive paper.

FIG. 9 is a perspective view showing a coil winding start surface, which sequentially shows the steps of winding the tracking coil by a conventional manufacturing method.

FIG. 10 is a perspective view showing a step of winding a tracking coil by a conventional manufacturing method, showing a state in which a center pole is inserted into a coil terminal holder.

FIG. 11 is a perspective view sequentially showing a process of winding the tracking coil by a conventional manufacturing method, showing a state in which the tracking coil is wound around one center pole.

FIG. 12 is a perspective view sequentially showing a step of winding a tracking coil by a conventional manufacturing method, showing a state in which a winding auxiliary plate is attached to the other center pole.

FIG. 13 is a perspective view sequentially showing a process of winding the tracking coil by a conventional manufacturing method, showing a state in which the tracking coil is wound around the other center pole.

FIG. 14 is a perspective view sequentially showing a process of winding the tracking coil by a conventional manufacturing method, showing a state where the tracking coil is completely wound.

FIG. 15 is a perspective view showing a coil winding start surface, which sequentially shows the steps of winding the focus coil by a conventional manufacturing method.

FIG. 16 is a perspective view sequentially showing a step of winding the focus coil by a conventional manufacturing method, showing a state in which the focus coil is completely wound.

FIG. 17 is a perspective view showing an assembly state of a tracking coil and a focus coil.

FIG. 18 is a plan view showing an assembly state of a tracking coil and a focus coil.

FIG. 19 is a plan view showing a state where a drive coil is incorporated in a movable bobbin.

FIG. 20 is a perspective view showing another example of the coil terminal holder around which the tracking coil is wound.

FIG. 21 is a perspective view showing another example of the coil terminal holder around which the focus coil is wound.

22 is a perspective view showing a state in which a focus coil is attached to the coil terminal holder shown in FIG. 21.

[Explanation of symbols]

 2 Focus coil 2a, 2b Focus coil coil end 3,4 Tracking coil 3a, 4a Tracking coil coil end 21,22 Resin 23 Support 24 Adhesive layer 25 Adhesive layer 6a, 7a, 8a, 9a Terminal part of suspension

Claims (5)

[Claims] 1. A method of manufacturing an objective lens driving device in which an objective lens is driven in a focus direction and a tracking direction, wherein each coil terminal of a drive coil including a focus coil and a tracking coil is provided on a bobbin. A method of manufacturing an objective lens driving device, characterized in that the driving coil is incorporated in a bobbin while being held by a coil end holding member at a position substantially corresponding to the terminal. 2. The method for manufacturing an objective lens driving device according to claim 1, wherein the coil end holding member is an adhesive paper having an adhesive layer. 3. The method for manufacturing an objective lens driving device according to claim 1, wherein the coil end holding member is made of resin. 4. The method of manufacturing an objective lens driving device according to claim 3, wherein the resin is a hot melt resin. 5. The method of manufacturing an objective lens driving device according to claim 3, wherein the resin is an ultraviolet curable resin.