JP2004273006A - Objective lens driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus related to an objective lens driving device of an optical pickup. <P>SOLUTION: The objective lens driving device supports an actuator movable section comprising a lens holder 2 for retaining an objective lens 1 so that the actuator movable section can be movably supported to a frame 9. In the objective lens driving device, a contacting section 2f is provided at the pickup movable section, an actuator frame 15 integrated with the frame 9 is arranged near both the outer sides of the pickup movable section, stoppers 17 are provided at the left/right upper sections of the actuator frame 15, and the contacting section 2f comes into contact with the stoppers 17, thus limiting the movement of the movable section in the direction of a disk exceeding a prescribed value. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an objective lens driving device for an optical pickup.
[0002]
[Prior art]
Optical heads for optically reading or writing signals to or from a signal recording medium such as a disk are usually made of a steel plate in a housing in which a semiconductor laser as a light emitting element and a photodetector as a light receiving element are incorporated. An actuator frame integrated with the frame is disposed along the vicinity of both side surfaces of the movable portion, and is molded below the frame so as to be attached to the housing.
[0003]
In addition, the lens holder of the movable part is provided with support parts on the upper and lower sides of the left and right side surfaces, and the support part is supported by a suspension wire, and a holding part for holding the suspension wire is provided at the other end of the suspension wire. The holding part is attached to the frame with screws. The lens holder supported by the suspension wire is molded in common with the coil bobbin, and a projection-shaped contact portion is provided on the upper surface of the coil bobbin.
[0004]
In the actuator frame, a steel plate cover that covers the entire movable part is provided on the upper part of the actuator frame disposed on the left and right sides by a plate spring having both upper ends of the cover bent, and in operation, the cover comes into contact with the inner surface of the cover. The movable portion is configured as a stopper mechanism for restricting an operation exceeding a specified value in the disk direction.
[0005]
[Patent Document 1]
JP 2000-251298 A
[Problems to be solved by the invention]
As described above, a normal objective lens driving device is a steel plate cover having a contact portion provided on an upper portion of a coil bobbin and a stopper function for covering an entire movable portion on an actuator frame disposed near both outer sides of a suspension wire. The stopper and the contact portion are configured to contact each other.However, in an ultra-thin optical pickup, the clearance between the disk and the pickup cover and the movement of the lens are secured while securing the amount of lens movement. The configuration of the stopper by arranging the pickup cover above the circuit was difficult.
[0007]
Limiting the movable range of the objective lens, which is configured with a cover that covers the entire pickup as a stopper, can lead to variations in the movable range due to the effects of lens attitude control and mounting variations. In the extreme case, when the external force (shock) is applied, the state of contact with the stopper becomes unbalanced right and left, which may lead to deformation of the suspension wire.
[0008]
An object of the present invention is to provide an objective lens driving device that solves such a problem.
[0009]
[Means for Solving the Problems]
A contact portion is provided on the movable portion of the pickup, an actuator frame integrated with the frame is disposed near both side surfaces of the movable portion of the pickup, and stoppers are respectively provided on the upper portions of the actuator frames. By contact, the movable portion restricts the operation in the direction of the disk beyond a specified value.
[0010]
【Example】
FIG. 1 is a perspective view showing an embodiment of an objective lens driving device according to the present invention, FIG. 2 is a perspective view showing a state in which a part of a main part of the objective lens driving device shown in FIG. 1 is removed, and FIG. FIG. 2 is a perspective view showing different directions of the objective lens driving device shown in FIG.
[0011]
The objective lens 1 is held by a lens holder 2 and a bobbin 2a is integrally formed at an end thereof. A focusing coil 3 is wound around the inner periphery of the bobbin 2a and mounted. Is wound at a predetermined position in contact with the focus coil 3 in the bobbin 2a.
[0012]
The left and right side surfaces of the lens holder 2 each have one end disposed above a suspension wire 6 serving as an elastic support member, two ends of which are parallel to each other, and a support portion integrally formed with the lens holder 2. 2b, an auxiliary support 2c is disposed on the lens holder 2 as an extension of the support 2b, and one end of a suspension wire 6 disposed below the support 2d is provided with a support 2d integrally molded with the lens holder 2; An auxiliary support portion 2e is supported at a position shorter than the auxiliary support portion 2c along an extension of the support portion 2d.
[0013]
The other end of each of the four suspension wires 6 is soldered to a holding member 7 and a printed board 8 attached to the holding member 7, and the printed board 8 and the holding member 7 are made of a steel plate frame. 9 is fixed by screws 10 and the objective lens driving section is elastically supported so as to be displaceable. Further, an abutting portion 2f projecting outward is integrally formed and provided between the supporting portions 2b and 2d disposed on both sides of the lens holder 2.
[0014]
A pair of magnets 11 and 12 having the same magnetic pole surface (N pole) opposed to each other with the focus coil 3 and the tracking coils 4 and 5 interposed therebetween are provided on the frame 9 with opposing yokes 13 and 14 formed integrally with the frame 9. Installed. Further, the actuator frame 15 integrated with the frame 9 is disposed near the outer side of both sides of the suspension wire 6.
[0015]
A stopper 17 made of a steel plate is provided to be attached to the upper and lower ends of the actuator frame 15, and is attached to the actuator frame 15 by claws 17a and 17b having tension at the upper end and claws 17c and 17d at the lower end. At the same time, a flange is provided on the upper part of the stopper 17, and a contact surface 17e that comes into contact with the contact portion 2f is provided.
[0016]
The magnetic flux generated from the magnets 11 and 12 acts on the effective area of the focus coil 3 and each of the tracking coils 4 and 5, and supplies a focus error signal to the focus coil 3 so that the objective surface together with the lens holder 2 is provided on the signal surface of the disk. The focus control for driving the lens 1 to focus the light beam is performed, and the tracking control for causing the light beam to follow the signal track of the disk is performed by supplying a tracking error signal to each of the tracking coils 4 and 5. As a result, the objective lens 1 together with the lens holder 2 can trace drive signals recorded on the disk.
[0017]
In the objective lens driving device configured as described above, the contact surface 17e provided with the stopper 17 on the left and right actuator frames 15 integrated with the frame 9 comes into contact with the contact portion 2f provided on the movable portion. The position accuracy is high.
[0018]
【The invention's effect】
According to the present invention, a contact portion is provided on the pickup movable portion, an actuator frame integrated with the frame is disposed near the left and right side surfaces of the pickup movable portion, and stoppers are provided on the upper portions of the actuator frames, respectively. The movable part restricts the operation beyond the specified direction in the direction of the disk by contacting the stopper with the part.In ultra-thin pickup, the clearance between the entire pickup and the disk covers the entire upper part of the pickup. Although the clearance can be secured only a little in the configuration in which the cover is provided, according to the present invention, the clearance can be secured with a margin.
[0019]
Further, in the present invention, the conventional stopper is bent at both ends of the steel plate, the bent portion is a plate spring, and is attached to the frame so as to cover the tracking coil and the focusing coil. Although the contact state with the stopper was left and right unbalanced, in the present invention, since it is securely attached to the left and right designated positions, since the reference points to the left and right stoppers do not change, the contact positions are the same. This has the effect that there is no danger of causing wire stress due to the lifting of the cover.
[0020]
Also, when adjusting the lens posture in the tangential direction, since the lens is displaced integrally with the frame, a positional relationship always parallel to the stopper portion of the lens holder can be secured, and the effect of preventing the occurrence of wire deformation can be obtained. .
[0021]
The contact portion is integrally formed between the upper and lower support portions of the left and right side surfaces of the lens holder, so that the strength is excellent.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment of an objective lens driving device according to the present invention.
FIG. 2 is a perspective view of a main part of the objective lens driving device with some parts removed;
FIG. 3 is a perspective view of the objective lens driving device shown in FIG. 1 from different directions.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Objective lens 2 Lens holder 2f Contact part 2b, 2d Support part 2c, 2e Secondary support part 6 Suspension wire 9 Frame 15 Actuator frame 17 Stopper 17a, 17b Claw 17c, 17d Claw

Claims (4)

An objective lens driving device in which an actuator movable portion including a lens holder for holding an objective lens is supported so as to be displaceable with respect to a frame, wherein a contact portion is provided on the pickup movable portion, and the contact portion is provided near both outer sides of the pickup movable portion. An actuator frame integrated with the frame is arranged, stoppers are provided at upper right and left sides of the actuator frame, and the stopper abuts on the abutting portion, so that the movable portion restricts the operation of the movable portion in the disk direction beyond a specified amount. An objective lens driving device, characterized in that: 2. The objective lens driving device according to claim 1, wherein contact portions are provided on both left and right sides of a lens holder that supports the actuator movable portion with a linear suspension wire displaceable with respect to the frame. 3. The objective lens driving device according to claim 2, wherein the contact portions are integrally formed between upper and lower support portions on both left and right side surfaces of the lens holder. 2. The objective lens driving device according to claim 1, wherein the stopper is made of a steel plate, and a claw having a tension is provided, and the stopper is attached to the actuator frame by the claw.

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