JP2000293872A - Object lens driving mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently perform the connection work to connect each winding end part of a driving coil to each fixed plate by soldering a land part provided in a holding part of each fixed plate together with each winding end part of the driving coil corresponding to the land part. SOLUTION: A lens holder 1 is provided with plural detention part 22a to 22d where respective winding end parts of winding start ends and winding terminal ends of driving coils 3a, 3b, and 4a to 4d are entwined and detained, and fixed plates 23 and 24 to which supporting wires 20 are fixed are attached to both sides of the lens holder 1. Each fixed plate has holding parts 23a (23b) and 24a (24b) between which prescribed detention parts are held, and each holding part has a land part, and these land parts are soldered to connect winding end parts of driving coils to fixed plates.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an objective lens driving device in which a lens holder on which an objective lens is mounted is elastically supported so as to be displaceable.

[0002]

2. Description of the Related Art In general, an objective lens driving device in an optical head for optically reading or writing a signal on or from a signal recording medium such as a disk is generally composed of a lens holder on which an objective lens is mounted and a lens holder other than the objective lens. An optical flux is supported displaceably with respect to an optical housing incorporating an optical element, and a drive coil such as a focusing coil and a tracking coil is mounted on the lens holder, and a predetermined portion of the drive coil is formed by an effective magnetic flux formed by a magnetic circuit. The objective lens is driven in accordance with a drive signal supplied to the drive coil by being disposed in the inside.

[0003] In an objective lens driving device, a configuration in which a plurality of support wires are used to elastically support a lens holder so that the lens holder can be displaced with respect to an optical housing is mainstream. It is designed to be fixed to the base and the lens holder.

By the way, since a driving signal is supplied to the focusing coil and the tracking coil mounted on the lens holder via each supporting wire, it is necessary to connect each supporting wire to each corresponding winding end. .

[0005]

Conventionally, a fixing plate serving as a fixing portion of a support wire in a lens holder is constituted by a printed wiring board, and the fixing plate is attached to both sides of the lens holder with the objective lens interposed therebetween, and each fixing plate is fixed. It has been practiced to connect one end of each support wire and each winding end of a drive coil to a board by connecting each support wire to each corresponding winding end.

In this case, conventionally, each winding end of each drive coil is pulled out and connected to a land portion provided on the fixed plate, so that each winding end is formed on the fixed plate corresponding to each winding end. The connection work to connect to each land was troublesome.

Further, the lens holder has a direction perpendicular to the optical axis of the objective lens when the lens holder is displaced in the tracking direction due to an imbalance in weight balance or a driving force generated by an invalid portion of the tracking coil. A harmful rotational force centered is generated.

In order to suppress this rotational force, the stiffness of the upper support wire supported on the upper side of the lens holder should be larger than the stiffness of the lower support wire supported on the lower side of the lens holder. Although effective, the workability was poor because the wire diameter of the support wire was changed in order to make the stiffness of the upper support wire and the lower support wire different.

[0009]

SUMMARY OF THE INVENTION According to the present invention, there are provided a plurality of locking portions each of which is entangled and locked with respect to each of a winding start end and a winding end of a drive coil. Is provided on the lens holder, and each fixing plate to which each support wire is fixed on each side of the lens holder by soldering is attached to both sides of the lens holder with the objective lens interposed therebetween. Each of the fixing plates has a holding portion for holding a predetermined locking portion, and each holding portion has a land portion. When soldering to these lands, the holding plate is held by the holding portions and the holding portion. The respective winding ends locked by the locking portions are soldered together. Thereby, each winding end of the drive coil is connected to each fixing plate.

In this case, the fixing range of each of the two support wires fixed to each fixing plate is set to be larger for the upper support wire than for the lower support wire, and the effective length of the upper support wire is set to be lower. The stiffness of the upper support wire is made larger than the stiffness of the lower support wire.

[0011]

FIG. 1 is a plan view showing an embodiment of an objective lens driving device according to the present invention, and FIG. 2 is an end view from the side of the objective lens driving device shown in FIG.

In FIG. 1, reference numeral 1 denotes a lens holder in which an objective lens 2 is mounted at the center, and the lens holder 1 is a straight line passing through the optical axis of the objective lens 2 on both sides of the position where the objective lens 2 is mounted. Positions that are symmetrical with respect to the first and second bobbin portions are a first bobbin portion and a second bobbin portion.
4b, the focus coil 3b and the tracking coils 4c, 4d are respectively wound around the second bobbin.

Therefore, the objective lens 2 of the lens holder 1
A space is provided below the central portion where the first bobbin portion is mounted between the first and second bobbin portions.

The focus coils 3a and 3b are wound in a substantially rectangular shape with one coil wire continuously wound around the first and second bobbins in the direction of the optical axis of the objective lens 2 in the optical axis direction. And are connected in series with each other.

Further, the tracking coils 4a, 4b and 4c, 4d are arranged so that one coil wire is continuously formed in two pairs with respect to one bobbin portion, and is orthogonal to the optical axis direction of the objective lens 2. It is wound in a substantially rectangular shape having a winding center axis, and is connected in series with each other.

Reference numerals 5 and 6 denote a first pair of permanent magnets which are arranged so that one magnetic pole surface (N pole) of the same magnetic pole faces each other with the first bobbin portion of the lens holder 1 interposed therebetween.
Reference numerals 7 and 8 denote a second pair of permanent magnets arranged such that one magnetic pole surface (N pole) of the same magnetic pole faces each other with the second bobbin portion of the lens holder 1 interposed therebetween.

The first permanent magnets 5 and 6 have external yokes 9 and 10 respectively on the other magnetic pole surface (S-pole).
Each of the second permanent magnets 7 and 8 has an external yoke 11 on its other magnetic pole surface (S-pole).
And 12 are attached.

Further, one magnetic pole surface (N pole) of each of the first permanent magnets 5 and 6 has a hole 13 formed in a central portion between the permanent magnets 5 and 6 of the lens holder 1. The first permanent magnets 5 and 6, the outer yokes 9 and 10, and the inner yoke 14 are opposed to each other.
4 and a first magnetic circuit portion that forms a magnetic gap between one of the magnetic pole surfaces of the permanent magnet 6 and the internal yoke 14.

Also, one magnetic pole surface (N pole) of each of the second permanent magnets 7 and 8 has a hole 15 formed in a central portion between the permanent magnets 7 and 8 of the lens holder 1. The arranged internal yokes 16 are opposed to each other, and the second permanent magnets 7 and 8, the external yokes 11 and 12, and the internal yoke 16 are located between one pole face of the permanent magnet 7 and the internal yoke 16, and A second magnetic circuit portion that forms a magnetic gap between one magnetic pole surface of the permanent magnet 8 and the internal yoke 16 is formed.

The outer yokes 9 and 10, the outer yokes 10 and 11, and the outer yokes 11 are provided around the lens holder 1.
And the outer yokes 12 and 9 are connected to each other to form frames 17a to 17d surrounding the lens holder 1. A mounting portion 18 is extended from the frame 17d, and the objective lens driving mechanism is connected to the objective lens driving mechanism by the mounting portion 18. It is attached to an optical housing (not shown) in which optical elements except 2 are incorporated.

A wiring board 19 is fixed to the mounting portion 18, and four support wires 20 each having one end soldered to the wiring board 19 are soldered to the lens holder 1 at the other end. The lens holder 1 is displaceably and elastically supported by the respective support wires 20.

Each of the support wires 20 is connected to a wiring board 19.
Are arranged in the grooves formed in the auxiliary member 21 fixed to the groove, respectively, and are damped by the dump agent filled in the grooves.

The objective lens driving device thus configured supplies a focus control signal to the focusing coils 3a and 3b in series, thereby moving the objective lens 2 through the lens holder 1 in the focus direction according to the focus control signal. By supplying a tracking control signal in series to the tracking coils 4a to 4d, the objective lens 2 can be driven in the tracking direction via the lens holder 1 according to the tracking control signal.

Next, in the objective lens driving device having such a configuration, the main structure of the present invention is shown in FIGS.
Further details will be described with reference to FIG. 3 which is an exploded perspective view showing a lens holder portion.

Locking portions 22a to 22d are integrally formed on the lens holder 1 above and below a central portion of both side ends, respectively. These locking portions 22a to 22d include a winding start end of the focusing coils 3a and 3b, and The winding ends at the winding ends and the winding start ends and the winding ends at the winding ends of the tracking coils 4a to 4d are entangled and locked independently.

Here, the insulating coating of the coil wire is peeled off at each winding end locked by each of the locking portions 22a to 22d.

A fixing plate 23 having holding portions 23a and 23b for holding upper and lower locking portions 22a and 22b on one side surface is mounted on the lens holder 1 from one side of the lens holder 1, and the other side. Holding portions 24 for holding the upper and lower locking portions 22c and 22d on the side surfaces of the
A fixing plate 24 having a and 24b is mounted from the other side of the lens holder 1.

The fixing plate 23 includes holding portions 23a and 23a.
The fixing plate 24 is fitted and attached to the lens holder 1 by holding the locking portions 22a and 22b with the holding plate 22b, and the fixing plate 24 is held in a state of holding the locking portions 22c and 22d with the holding portions 24a and 24b. By doing so, the lens holder 1 is fitted and attached.

Each of the fixing plates 23 and 24 is
a, 23b and 24a, 24b each have a land portion, and when the land portion is attached to the lens holder 1, each of the land portions corresponds to a focusing coil 3 corresponding to the land portion.
a, 3b and the respective winding ends of the tracking coils 4a to 4d are soldered together with the respective winding ends to the corresponding lands, and at the same time, the fixing plates 23 and 24 are fixed to the lens holder 1. .

The upper and lower support wires 20 are disposed on both sides of the lens holder 1 with the objective lens 2 interposed therebetween, and the two support wires 20 disposed on each side of the lens holder 1 are fixed to the respective fixing plates 23. And 24 are soldered.

The soldering is carried out simultaneously with the soldering of the lands of the fixing plates 23 and 24 together with the winding ends corresponding to the lands, and is fixed to one of the fixing plates 23. The lower support wire of each of the two support wires 20 is directly soldered to the land provided on the holding portion 23b corresponding to the support wire, and the upper support wire is held by the holding wire corresponding to the support wire. 2 are fixed to the other fixing plate 24 by being soldered to an extended land portion 25 extended from a land portion provided in the portion 23a and connected to the land portion.
The lower support wire of the book support wire 20 is directly soldered to the land provided on the holding portion 24b corresponding to the support wire, and the upper support wire is connected to the holding portion 24a corresponding to the support wire. Is extended from the land portion provided at the first portion and soldered to the extended land portion 26 connected to the land portion.

As described above, the supporting wires 20 are fixed to the fixing plates 23 and 24 by soldering, so that the winding ends of the focusing coils 3a and 3b and the tracking coils 4a to 4d are respectively fixed to the predetermined supporting wires 20. Connected.

Therefore, the focus control signal and the tracking control signal supplied to the wiring board 19 are supplied to the focusing coils 3a and 3b and the tracking coils 4a to 4d via the predetermined support wires 20, respectively.

Further, the fixing range of the two support wires 20 fixed to each of the fixing plates 23 and 24 is set larger for the upper support wire than for the lower support wire. The length is shorter than the effective length of the lower support wire, so that when the lens holder 1 is driven in the tracking direction, the objective lens 2
The harmful rotational force generated about the direction orthogonal to the optical axis of the lens holder is suppressed, and the lens holder 1 can be driven stably in the tracking direction.

[0035]

As described above, according to the present invention, the lands provided at the holding portions of the respective fixing plates are soldered together with the respective winding ends of the drive coils corresponding to the respective lands. In addition, the connection work for connecting each winding end of the drive coil to each fixing plate can be efficiently performed.

Also, the fixing plates can be installed on the lens holder by holding the corresponding locking portions from the sides of the lens holder with the holding portions, and each land portion corresponds to each land portion. The respective fixing plates are fixed to the lens holder by soldering together with the respective winding ends, thereby facilitating the work of attaching each fixing plate to the lens holder.

Further, since the effective length of the upper support wire is made shorter than the effective length of the lower support wire, the direction orthogonal to the optical axis of the objective lens when the lens holder is driven in the tracking direction. The harmful torque generated around the center is suppressed, and the lens holder can be driven stably in the tracking direction.

In this case, making the effective length of the upper support wire shorter than the effective length of the lower support wire devises a land area where the upper and lower support wires are soldered to the fixing plate. This is easily achieved by:

[Brief description of the drawings]

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

FIG. 2 is an end view from the side of the objective lens driving device shown in FIG. 1;

FIG. 3 is an exploded perspective view showing a lens holder portion which is a main configuration of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lens holder 3a, 3b Focusing coil 4a, 4b, 4c, 4d Tracking coil 20 Support wire 22a, 22b, 22c, 22d Locking part 23, 24 Fixing plate 23a, 23b, 24a, 24b Holding part 25, 26 Expansion land part

Claims (4)

[Claims] 1. A drive coil is mounted on a lens holder on which an objective lens is mounted, the drive coil is arranged in a magnetic field formed by a magnetic circuit, and a drive signal is supplied to the drive coil to drive the objective lens. A plurality of support wires for elastically supporting the lens holder so that the lens holder can be displaced, and a lens holder corresponding to each of a winding start end and a winding end of a drive coil. And a plurality of locking portions each of which is wound and locked at each of the winding ends, and attached to both sides of the lens holder with the objective lens interposed therebetween, and each supporting wire is attached to each side of the lens holder by soldering. Each fixing plate has a holding portion for holding a predetermined locking portion, and the holding portion has a land portion. Wherein each land is soldered together with each winding end corresponding to each land to connect each winding end of the drive coil to each fixing plate. Drive. 2. The fixing plate is mounted on the lens holder by clamping the corresponding locking portion by the clamping portion from each side of the lens holder, and the land portions are respectively mounted on the respective winding portions corresponding to the land portions. 2. The objective lens driving device according to claim 1, wherein each fixing plate is fixed to a lens holder by soldering together with a turning end. 3. A drive coil is mounted on a lens holder on which an objective lens is mounted, the drive coil is arranged in a magnetic field formed by a magnetic circuit, and a drive signal is supplied to the drive coil to drive the objective lens. An objective lens driving device, comprising: two support wires arranged on both sides of the lens holder with the objective lens interposed therebetween, and four support wires for elastically supporting the lens holder so as to be displaceable; And a fixing plate to which two support wires respectively fixed to each side of the lens holder are fixed by soldering, and the effective length of the upper support wire is set to the lower side. In order to shorten the effective length of the supporting wire, the fixing range of each of the two supporting wires fixed to each of the fixing plates is set to the lower supporting wire. An objective lens driving device characterized in that the upper support wire is larger than the support wire. 4. A lens holder, wherein a plurality of locking portions are provided on the lens holder, at which respective winding ends of a winding start end and a winding end of the driving coil are tangled and locked. And a land portion at each of the holding portions, and a lower supporting wire of the two supporting wires fixed to each of the fixing plates is attached to a holding portion corresponding to the supporting wire. The solder is directly soldered to the land provided, and the upper support wire is extended from the land provided at the holding portion corresponding to the support wire and soldered to the extended land connected to the land. 4. The objective lens driving device according to claim 3, wherein the objective lens driving device is attached.