JPH10228656A - Pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a device low in cost by embedding power supplying members to coils in the inside of a pickup holder to dispense with power feeding flexible printed circuits and also to enable the speeding up of the pickup holder by enhancing the elasticity of the holder to suppress high order resonances. SOLUTION: Lead frames of power feeding members with respect to driving coils 7, 8 are embedded so as not cross with each other at different positions in the axial line direction of a lens holder 3 and driving currents are made to flow through a driving coil for focusing 7 and a driving coil for tracking 8 via the lead frames. It is desirable that the power feeding members are conductive plate shaped members bent in prescribed shapes and the pickup holder 3 is a resin molded piece integrally molded together with the power feeding members. Thus, it is made possible to supply currents to the coils 7, 8 without using expensive flexible printed circuits. Moreover, since the modulus of elasticity of the lens holder 3 is enhanced by the embedded lead frames, high order resonances are suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a pickup device.

[0002]

2. Description of the Related Art An optical pickup device is incorporated in an optical disk device for playing back a digital recording medium such as an optical disk. In this optical pickup device,
A lens holder (pickup holder) holding an objective lens is supported on a support shaft (holder support member) so as to be rotatable and movable along the axial direction, so that tracking and focusing can be performed on the disk. Have been.

In order to perform this tracking and focusing, the optical pickup device has a coil on the outer peripheral side of a lens holder and a magnetic field forming means such as a magnet, which is disposed to face the coil and forms a magnetic field, for example. Have. A flexible board provided with wiring is mounted on the outer peripheral surface of the lens holder, the coil is mounted at a predetermined position on the flexible board, and the coil terminal and the wiring terminal are connected by, for example, soldering. Have been. When a predetermined drive current is passed through the coil, a thrust is generated in the tracking direction or the focusing direction by the drive current and the magnetic flux of the magnetic circuit formed by the magnetic field generating means, thereby performing tracking and focusing. It has become possible.

As another example of power supply to a coil, a coil is directly attached to the outer peripheral surface of a lens holder and wiring is performed, and connection to external wiring is performed through a flexible substrate. A method of supplying power is also known.

[0005]

As described above, in any of the above-described devices, mounting is performed via a flexible substrate. However, since the flexible substrate is expensive, the cost of the device is increased. There was a problem of doing.

Accordingly, the present invention can supply electric power to the coil without using a flexible substrate, can reduce the cost, and can further increase the elasticity of the pickup holder, thereby increasing the height of the pickup holder. It is an object of the present invention to provide a pickup device capable of preventing next resonance.

[0007]

According to a first aspect of the present invention, there is provided a pickup apparatus comprising: a pickup holder having a coil; magnetic field forming means arranged to face the coil to form a magnetic field; Wherein a power supply member for the coil is embedded inside the pickup holder.

In order to achieve the above object, a pickup device according to a second aspect of the present invention, in addition to the first aspect, further includes a pickup holder provided with a plurality of coils and a plurality of power supply members, respectively. It is characterized by being buried in different positions.

In order to achieve the above object, a pickup device according to a third aspect is characterized in that, in addition to the first or second aspect, the power supply member is a conductive plate-shaped member bent into a predetermined shape. I have.

In order to achieve the above object, a pickup device according to a fourth aspect is characterized in that, in addition to the first or second aspect, the power supply member is a wire member that can be supplied with power and is bent into a predetermined shape. I have.

In order to achieve the above object, a pickup device according to a fifth aspect of the present invention, in addition to any one of the first to fourth aspects, wherein the pickup holder is a resin molded product integrally formed with the power supply member. It is characterized by:

In order to achieve the above object, a pickup device according to a sixth aspect is characterized in that, in addition to any one of the first to fifth aspects, a power supply member embedded inside the pickup holder and an outer surface of the pickup holder. And a power supply member provided in

According to the pickup device of the present invention, since the power supply member for the coil is directly embedded in the pickup holder, the flexible substrate used in the prior art is not required, and The elasticity of the pickup holder is enhanced by the power supply member.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show an optical pickup device to which the present invention is applied. An optical pickup device 1 according to the present embodiment generally includes a lens holder (pickup holder) 3 for holding an objective lens 2 and this lens holder. And a supporting shaft (holder supporting member) 5 that rotatably and slidably supports the supporting member 3.

The support shaft 5 is erected and fixed substantially at the center of the bottom of the outer yoke 9 and is inserted into a bearing hole of the lens holder 3. This support shaft 5 is made of SUS,
In order to enhance the slidability of the bearing hole with the bearing surface 3a, on the surface thereof, for example, a sliding resin in which PTFE is dispersed in polyamideimide or a sliding in which molybdenum is dispersed in a polymer of PTFE and acrylic is used. Resin is coated.

A balancer 6 is fixed to the lens holder 3 on the opposite side of the objective lens 2 about the support shaft 5. On the outer peripheral surface of the lens holder 3, a pair of focusing drive coils 7, 7 are positioned symmetrically with respect to the support shaft 5.
And a pair of tracking drive coils 8, 8 are fixed respectively.

The outer yoke 9 for fixing the support shaft 5 is raised so that the outer peripheral edge located at a symmetrical position with respect to the support shaft 5 is bent at a right angle and faces the drive coils 7 and 8, respectively. , In each of the rising parts,
A pair of magnets (magnetic field forming means) 10, 10 facing the drive coils 7, 8 are fixed, respectively. The magnet 10 includes a focusing magnet 10a facing the focusing drive coil 7 and a tracking magnet 10b facing the tracking drive coil 8. The focusing magnet 10a is polarized and magnetized so that the N and S poles are arranged in the direction of the support axis, while the tracking magnet 10b is polarized and magnetized so that the N and S poles are arranged in the circumferential direction.

An inner yoke 11 is mounted on the bottom of the outer yoke 9 so as to overlap the outer yoke 9.
An outer peripheral edge of the inner yoke 11 located at a symmetrical position with respect to the support shaft 5 and located inside the drive coils 7 and 8 is inserted into an opening provided in the lens holder 3. Are bent at right angles to stand up. As described above, in order from the inside, the inner yoke 11, the drive coils 7, 8, the magnet 1
The outer yoke 9 is disposed at a symmetrical position with respect to the support shaft 5 so that a substantially closed magnetic path passing therethrough is formed.

The portion of the inner yoke 11 that faces the tracking drive coil 8 may not be provided, and the inner yoke 11 itself may not be provided.

Next, the features of the present embodiment will be described. In the present embodiment, a lead frame as a conductive plate-like member bent into a predetermined shape is used as a power supply member for the drive coils 7 and 8, and the lead frame has a thin plate shape. As shown in FIG. 5 to FIG. 5, different positions in the axial direction of the lens holder 3 (three positions)
Buried in The lens holder 3 is a resin molded product integrally formed by, for example, insert molding using a resin such as PPS, epoxy resin, or LCP, and the lead frames 20 to 25 described above.

As shown in FIG. 5, a lead frame 2 for connecting one (upper) focusing drive coil 7 and an external terminal 30 is provided on the upper part of the lens holder 3.
2, the other (lower illustrated) focusing drive coil 7
A lead frame 20 for connecting the external drive terminal 33 and the lead frame 23 for connecting the tracking drive coil 8 on one side (upper side in the drawing) and the external terminal 31 are embedded.

In the center of the lens holder 3, FIG.
As shown in FIG. 3, a lead frame 24 for connecting one (upper illustration) tracking drive coil 8 and the other (lower illustration) tracking drive coil 8 is embedded.

As shown in FIG. 3, a lead frame for connecting one (upper shown) focusing drive coil 7 and the other (lower shown) focusing drive coil 7 is provided below the lens holder 3. A lead frame 25 for connecting the tracking drive coil 8 on the other side (the lower side in the figure) and the external terminal 32 is embedded.

As described above, the lead frames 20 to 25
Are embedded at different positions in the axial direction of the lens holder 3 to prevent the lead frames from intersecting with each other.

In the optical pickup device constructed as described above, a predetermined drive current is supplied to the focusing drive coils 7, 7 via the lead frames 20, 21, 22 so that the drive current and the magnetic circuit are controlled. Thrust is generated by the magnetic flux, and the lens holder 3 moves in the optical axis direction (along the support shaft 5) to perform a focusing operation. Further, the tracking drive coil is driven via the lead frames 23, 24, and 25. When a predetermined drive current is passed through 8, 8, a thrust is generated by the drive current and the magnetic flux in the magnetic circuit, and the lens holder 3 swings around the support shaft 5, that is, moves in the tracking direction to perform tracking. The operation is performed.

At this time, since the elasticity of the lens holder 3 is increased by the embedded lead frames 20 to 25, higher-order resonance is prevented.

As described above, the lead frames 20 to 25 serving as power supply members for the coils 7 and 8 are
Since it is embedded inside the lens holder 3, the flexible substrate used in the prior art is not required, and cost reduction is achieved.

Although the invention made by the inventor has been specifically described based on the embodiment, the invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the invention. Needless to say, for example, in the above-described embodiment, the lead frames 20 to 25 are embedded in the lens holder 3 as the power supply member. It may be bent into a shape and embedded in the lens holder 3.

Further, in the above embodiment, the power supply member is embedded at different positions (three positions) in the axial direction of the lens holder 3, but the present invention is not limited to the three positions. One wiring may be formed, and the other wiring may be formed on the outer surface such as the upper surface or the lower surface of the lens holder 3 by, for example, printing.

Further, a sensor for detecting predetermined information is attached to the lens holder 3, and the electric wiring for inputting / outputting to / from the sensor is the above-described conductive plate member, which is embedded in the lens holder 3. It is also possible. Thereby, the elasticity of the lens holder 3 can be further increased.

As described above, when the lens holder 3 is formed by resin molding, a highly elastic filler is added,
Although it is conceivable to further increase the elasticity of the lens holder 3, in this case, if a conductive filler is added, conduction between the power supply members will occur. Therefore, a non-conductive filler such as a glass filler must be added.

[0032]

As described above, in the pickup device of the present invention, the power supply member for the coil is directly embedded in the pickup holder, so that the flexible substrate used in the prior art is not required and the pickup holder is not required. Since the elasticity of the power supply member is increased by the power supply member, the cost can be reduced, and the higher-order resonance of the pickup holder can be prevented and the speed of the pickup holder can be increased. Become.

[Brief description of the drawings]

FIG. 1 is a plan view showing an optical pickup device to which the present invention is applied.

FIG. 2 is a sectional view taken along the line AA in FIG.

FIG. 3 is a sectional view taken along line BB in FIG. 2;

FIG. 4 is a sectional view taken along line CC in FIG. 2;

FIG. 5 is a sectional view taken along line DD in FIG. 2;

[Explanation of symbols]

 Reference Signs List 3 pickup holder 7, 8 coil 10 magnetic field forming means 20 to 25 power supply member

Claims (6)

[Claims] 1. A pickup device comprising: a pickup holder having a coil; and magnetic field forming means arranged to face the coil and forming a magnetic field, wherein a power supply member for the coil is provided inside the pickup holder. A pickup device characterized by being buried. 2. The pickup device according to claim 1, wherein the pickup holder includes a plurality of coils and a plurality of power supply members, and the power supply members are embedded at different positions in the axial direction of the pickup holder. 3. The pickup device according to claim 1, wherein the power supply member is a conductive plate-like member bent into a predetermined shape. 4. The pickup device according to claim 1, wherein the power supply member is a wire member that can be supplied with power and is bent into a predetermined shape. 5. The pickup device according to claim 1, wherein the pickup holder is a resin molded product formed integrally with the power supply member. 6. The power supply member according to claim 1, further comprising a power supply member embedded inside the pickup holder, and a power supply member provided on an outer surface of the pickup holder. Pickup device.