JP2001034973A - Driving device for objective lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a driving device which can be made thin and which can be manufactured at low costs and easily. SOLUTION: In a wire fixation member 2 at this device, four L-shaped metal plates 5, 6, 7, 8 are insert-molded, wire passage holes 11 are formed in end parts of the respective L-shaped metal plates 5 to 8, wires 22 are soldered here, and an FPC 19 is connected to other end parts of the L-shaped metal plates 5 to 8. A holding member 3 which is supported by the wire fixation member 2 is provided with a wire insertion and passage part 17 with a side-face hole 20, A damper agent can be injected from the side-face hole 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a compact disc (CD) and a digital versatile disc (DV).
D) An optical head for reproducing recorded data from various recording media such as a mini disk (MD) and a magneto-optical disk, or providing optical energy for recording, uses an objective lens for focus and tracking control. The present invention relates to an operating objective lens driving device.

[0002]

2. Description of the Related Art An optical pickup 51 as shown in FIG. 5, for example, is conventionally used for reproducing and recording on a recording medium using various kinds of light as described above. In the optical pickup 51, a support base 53 formed of polycarbonate or the like is fixed on a base 52 fixed on a base moving in the radial direction of the optical disk, and is integrally formed with the base 52 by bending. A substantially U-shaped yoke 54
Are provided, and the magnet 55 is supported by this.
A focus coil and a tracking coil (not shown) attached to the lens holder 59 are arranged around one magnet 55 so as to face each other. An objective lens 57 fixed to 59 is movable by a predetermined amount in the vertical direction (Z direction) and the horizontal direction (Y direction). The current flowing in the Y direction by the focus coil and the magnet 55
An electromagnetic force in the Z direction is generated by the magnetic field therebetween, whereby focus correction of the objective lens 57 held by the lens holder 59 is performed. In addition, a current flowing in the Z direction by the tracking coil generates an electromagnetic force in the Y direction, and thereby the tracking correction of the objective lens 57 is performed.

[0003] On both sides of a support base 53 fixed on a base 52, a wire insertion portion 58 penetrating in the X direction and having an elongated opening in the Z direction is formed.
A substrate 60 described later is fixed to the protruding portion formed on the back of the device. The board 60 has two on each of the left and right sides, for a total of 4
The base end of the wire 61 having elasticity is fixed by solder, and the end of each wire 61 is fixed to the left and right flanges 62 provided on the lens holder 59, so that the objective lens 57, the focus coil, and the tracking coil are fixed. The attached lens holder 59 is movably supported in the Y and Z directions.

As shown in FIG. 6, a flexible printed board (hereinafter referred to as "FPC") 64 having substantially the same shape as the board 60 is bonded and integrated on a metal reinforcing plate 63 as shown in FIG. A substrate fixing portion 6 protruding from the center of the back surface of the support base 53 as shown in FIG.
5, the central portion of the metal reinforcing plate 63 of the substrate 60 is attached and fixed. As a result, as shown in FIG. 8, the wire support portions 69 on both sides of the substrate 60 attached to the support base 53 face the back surfaces 67 of the wire insertion portion forming portions provided on both sides of the support base 53. Placed in The wire 61 penetrates through the wire insertion portion 58 of the support base 53,
Further, the opening 68 of the metal reinforcing plate 63 of the substrate 60 and the FPC 64
Project through the opening 70 to the rear surface of the substrate 60 to form a projection 71.

The projecting portion 71 of the wire 61 and the FPC 64
7 is soldered with a solder 73 as shown in FIG. 7, so that each wire 61 is connected to the FPC 64 with respect to the substrate 60 reinforced by the metal reinforcing plate 63 fixed to the support base 53. It is fixed in a conductive state. As a result, the lens holder 59 fixed to the tip of each wire 61 as described above is supported by the four wires 61, and the focus coil is fixed to the flange 62 of the lens holder 59 to which the tip of each wire 61 is fixed. By connecting the lead wire of the tracking coil and each wire 61, the current supplied from the external control device is
Power is supplied to each coil via the wire 64 and the wire 61.

In the optical pickup 51 assembled as described above, the damper material is injected into the wire insertion portion 58 of the support base 53 from the first opening 74 located on the left side of FIG. . The damper material has ultraviolet curability, is initially injected into the wire insertion portion 58 in a state of having some fluidity, and becomes gel-like by irradiating ultraviolet light after the predetermined injection is completed. The properties of the gel can be freely set by arbitrarily selecting the material of the damper agent. The damper material injected from the first opening 74 partially flows out of the second opening 75 on the opposite side, and the metal reinforcing plate 63 of the substrate 60 and the back surface 6 of the support base 53 are removed.
7 also flows into the gap D, and in that state, is irradiated with ultraviolet rays to be cured, thereby forming a gel.

The above-mentioned damper agent directly contacts the outer periphery of the wire 61 at the wire insertion portion 58 in the support base 53, and acts on the substrate 60 between the substrate 60 and the back surface 67 of the support member 53. When the movement of the objective lens 57 in the focus direction and the movement in the tracking direction are performed while performing feedback control by supplying power to the focus coil and the tracking coil, an elastic support device for the objective lens 57 is provided. The wires 61 of this type vibrate in a higher order, and the substrate 60 that elastically supports the wires 61 due to this vibration is suppressed from undergoing sub-resonance.

[0008]

In the conventional objective lens driving device for the optical pickup 51, the substrate 60 for fixing the wires 61 needs to elastically support the wires 61, and is used for a long time. However, since it is necessary to prevent creep and the like from occurring, the metal reinforcing plate 63 having an appropriate material, thickness, and shape is used. Since the metal reinforcing plate 63 is conductive, the wire 61 comes into contact with the metal reinforcing plate 63 when the wire 61 passes through the opening 68 of the metal reinforcing plate 63 and is connected to the FPC 64 by soldering. I have to make sure there is no Therefore, the opening 68 of the metal reinforcing plate 63 is formed sufficiently larger than the opening 70 of the FPC 64 as shown in FIGS. 6 and 7 in consideration of a dimensional error of a part and an error at the time of assembly. .

As described above, it is necessary to form a sufficiently large opening 68 in the metal reinforcing plate 63, and there is a limit in reducing the height H of the metal reinforcing plate 63 so as to have a predetermined rigidity. Further, in order to securely solder the wire 61 to the land 72 of the FPC 64, the size of the land 72 cannot be reduced.
There is a limit in reducing the height of the optical pickup 51, and the entire device including the substrate 6 and the support base 53 is increased in size and becomes an expensive device. I was In addition, it is necessary to affix an expensive FPC 64 to substantially the entire surface of the metal reinforcing plate 63, which also causes an increase in cost.

Further, at the time of manufacturing the metal reinforcing plate 63,
The substrate 60 is manufactured by attaching the FPC 64 to the substrate 60 so as not to be displaced.
It is necessary that the wire 61 be passed through the opening 68 of the metal reinforcing plate 63 and the opening 70 of the FPC and be soldered to the land 72 of the FPC 64 accurately. However, a great deal of attention was required during production, and workability was poor.

Accordingly, it is a main object of the present invention to provide an objective lens driving device which can be reduced in thickness and which can be easily manufactured at low cost.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a lens holder having an objective lens mounted thereon and a plurality of conductive and elongated elastic members. A drive coil provided on the lens holder, to which current is supplied via the elastic member, and a magnet for generating a magnetic flux passing through the drive coil. An objective lens driving device that drives the lens holder in at least one of a focus direction and a tracking direction by an electromagnetic force generated by a current flowing through the magnet and a magnetic flux of the magnet, wherein the support portion includes a fixing member formed of a synthetic resin; A plurality of metal plates embedded in the fixing member with both ends protruding from the fixing member. The portion extends in a direction substantially perpendicular to the focus direction, and a base end of the elastic member is soldered to the first end, and a current supplied from a second end of each metal plate is applied to the elastic member. The objective lens driving device is transmitted to the driving coil via the first lens.

The first end of the metal plate has a narrow portion formed near a portion where the base end of the elastic member is to be soldered. An elastic member is inserted, and a holding member having an insertion portion filled with a damper agent is provided. The fixing member and the fixing member are so arranged that an end face of the insertion portion faces a first end of the metal plate via a gap. A holding member is connected, and the insertion portion of the holding member penetrates along the longitudinal direction of the elastic member and is also opened in a direction intersecting the longitudinal direction, Further, a step portion is formed on the upper surface of the fixing member, and a fitting groove that opens to the lower surface side is formed in the holding member, and the holding portion is fitted by fitting the step portion into the fitting groove. A member is attached to the fixing member.

[0014]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an objective lens driving device 1 according to the present invention.
2 is a partial perspective view of FIG.
FIG. 3 is an exploded perspective view showing a state before assembling a wire fixing member 2 and a holding member 3, which are main members constituting the electronic device, and FIG. 3 is a perspective view showing the vicinity of a wire fixing portion in an L-shaped metal plate of the wire fixing member 2. It is. Note that the objective lens driving device of the present invention has the same configuration as the conventional objective lens driving device shown in FIG. 5 except for a support structure for supporting the base end of the wire, and therefore detailed description is omitted. I do.

The wire fixing member 2 is made of a heat-resistant synthetic resin such as LCP or PPS, and four first to fourth L-shaped metal plates 5, 6, 7, and 8 are integrated therein by insert molding or the like. Buried. In the first L-shaped metal plate 5, the wire support end 10 as the first end in which the wire through hole 11 is formed protrudes from the side wall 9 of the wire fixing member 2 in the Y direction (tracking direction). The FPC connection end 12 as a second end protrudes from the lower surface of the wire fixing member 2 so as to be bent downward in the member 2 as shown by a broken line in the drawing. The second L-shaped metal plate 6 is arranged in parallel with the first L-shaped metal plate 5, and the wire support end 10 in which the wire through hole 11 is formed projects from the side wall 9, and the wire fixing member 2
The FPC connection end 12 protrudes from the lower surface of the wire fixing member 2. 1st L type metal plate 5 and 2nd L
A third L-shaped metal plate 7 and a fourth L-shaped metal plate 8 are arranged in a similar configuration symmetrically to the mold metal plate 6. Each of the L-shaped metal plates 5, 6, 7, and 8 is carried into a mold for forming the wire fixing member 2 in a state of being formed into a hoop by pressing a metal strip, and is inserted or formed by outsourcing. It is formed by cutting the first end and the second end after being integrated with the wire fixing member 2.

The first to fourth L-shaped metal plates are arranged on the same plane, so that the surfaces of the wire supporting ends 10 of the first and second L-shaped metal plates 5 and 6 are aligned with the drawing of the wire fixing member 2. Located on the same plane on the left side of the center,
The surfaces of the wire supporting ends 10 of the fourth L-shaped metal plates 7 and 8 are located on the same side on the right side of the wire fixing member 2 in the drawing. Further, the first to fourth L-shaped metal plates 5,
The surfaces of 6, 7, and 8 FPC connection end portions 12 are all located on the same plane below the lower surface of the wire fixing member 2. A step 15 is formed in front of the upper surface 14 of the wire fixing member 2 as shown in FIG.

The holding member 3 is made of a transparent resin such as polycarbonate, and a fitting groove 16 with which a wire fixing member 2 described later is engaged is formed above the center of the lower surface.
The space between the side walls 6 is set substantially equal to the width of the wire fixing member 2 so that they can be fitted together without play. Further, on both sides of the holding member 3, a wire insertion portion 17 extending upward from below is formed, and in the wire insertion portion 17 in a direction intersecting the longitudinal direction of the wire,
A side hole 20 for injecting a damper agent described later is opened.

With the wire fixing member 2 and the holding member 3 configured as described above, the wire fixing member 2 is fitted into the fitting groove 16 of the holding member 3, and the step 15 of the wire fixing member 2 is It is fixed by an adhesive in a state of being in contact with the end face 29. As a result, the wire fixing member 2 and the holding member 3
And a support portion for supporting the lens holder 59 shown in FIG. 5 movably in the Z direction (focus direction) and the Y direction (tracking direction) via a plurality of wires 22 is configured. I have. By dividing and forming the wire fixing member 2 and the holding member 3 in this manner, the L-shaped metal plates 5, 6, 7, and 8 are insert-molded, and the wire insertion portion 17 and the side hole 20 of a complicated shape are formed. Can be formed. When a damper agent to be described later is injected and irradiated with ultraviolet rays, a transparent resin is selected as the holding member 3 for holding the damper agent, and the damper agent can be irradiated with ultraviolet rays through the holding member 3. For the wire fixing member 2, a resin suitable for the function of each member can be selected, such as selecting a heat-resistant resin that is easy to insert-mold the L-shaped metal plates 5, 6, 7, and 8.

In the wire fixing member 2 and the holding member 3 integrated as described above, the wire supporting end portions 10 of the L-shaped metal plates 5, 6, 7, 8 and the wire inserting end surface 2 of the holding member 3
A gap is formed between the two. The four wires 22 inserted through the wire insertion portions 17 of the holding member 3 respectively penetrate through the wire through holes 11 of the L-shaped metal plates 5, 6, 7, and 8 and project rearward, and the projection 23 and the wire The back surface of the support end 10 is fixed by solder 26. Further, each FPC of the L-shaped metal plates 5, 6, 7, and 8 protruding from the lower end surface of the wire fixing member 2
As shown in FIG. 1, each corresponding conductive portion at the end of the FPC 19 is connected to the connection end 12 by soldering.

The wire supporting ends 10 of the L-shaped metal plates 5, 6, 7, 8 are arranged on both left and right sides centered on the wire through hole 11, as shown in a partially enlarged view in FIG. U from the bottom
A character-shaped cut 25 is formed to form a narrow portion 39. Thus, when the protrusion 23 of the wire 22 protruding through the wire through hole 11 and the back surface of the wire support end 10 are fixed by the solder 26, the heat is not diffused to the entire L-shaped metal plate. The solder fillets are stably formed around the through holes 11. The narrow portion 39 may be provided only on one side of the wire hole 11. A tip 27 formed at an end of the L-shaped metal plate 5, 6, 7, 8 from the cut 25 is opposed to the wire insertion portion end face 21 of the holding member 3.

In the objective lens driving device 1 assembled in this manner, a damper agent is injected into the wire insertion portion 17 of the holding member 3 as in the above-described conventional example. Since this damper agent has a certain degree of fluidity at the time of injection, when the damper agent is injected into the wire insertion portion 17, L
It also enters the gap between the tip 27 and the wire insertion portion end face 21 in the mold metal plates 5, 6, 7, and 8. Alternatively, when a damper having a high viscosity is used, a damper is separately injected into a gap between the distal end portion 27 and the end face 21 of the wire insertion portion. When the damper agent is irradiated with ultraviolet light in this state, the damper agent is hardened and gels to a predetermined property. At this time, since the holding member 3 is formed of transparent polycarbonate or the like, the damper agent can be evenly irradiated with ultraviolet rays. As a result, the gelled damper agent contacts the outer periphery of the wire 22 extending into the wire insertion portion 17 to perform the vibration damping action of the wire 22, and the damper agent gelled in the gap portion causes Mold metal plate 5,6
7 and 8, the wire supporting end 10 has a vibration damping action for higher-order resonance.

When the damper agent is injected, the holding member 3
When a damper agent is injected from the side hole 20 provided in the side wall 18 of the wire by an injector, even a relatively high-viscosity damper agent can be injected evenly over the entire wire insertion portion 17. The selection range expands. In addition, since the damper agent can be injected from both the end face in the X direction of the wire insertion portion 17 and the side surface hole 20, the damper agent injection operation can be performed regardless of the posture of the objective lens driving device 1. Workability is improved.

In the objective lens driving device 1 as described above, the wires 22 can be directly soldered to the narrow L-shaped metal plates 5, 6, 7, and 8, and the wire through holes 11 can be formed.
Can be formed with a small diameter and high precision by press working, so that the wire 61 and the metal reinforcing plate 6 can be formed as in the above-mentioned conventional apparatus.
A large opening 68 is provided in the metal reinforcing plate 63 so as not to come into contact with
In order to solder to the land 72 of FIG. 4, there is no limitation on the dimension in the height direction due to the necessity of forming a sufficiently large land 72, and L is formed in a hoop shape by pressing. Since the mold metal plates 5, 6, 7, 8 can be arranged close to each other, it is possible to make the wires 22 approach each other in the height direction,
The entire device can be made thinner.

Further, since it is not necessary to attach an expensive FPC to the entire surface of the wire connecting portion as in the conventional device, an inexpensive device can be obtained.

In addition to the above embodiment, the present invention can be applied to an objective lens driving device 30 shown in FIG. 4 as an exploded perspective view. That is, in this device, a groove-shaped step portion 33 is formed on the upper surface 32 of the wire fixing member 31, and the upper wall 36 of the holding member 35 is engaged in the step portion 33 so that the holding member Positioning is performed in the X direction of 35. Locking portions 3 are provided on both sides of the lower end of the holding member 35.
6 is provided, and the side wall 3 of the holding member 35 is inserted into the engagement hole of the base 52 shown in FIG.
The elasticity of the snap fastener 8 and the snap fixing portion 37 enables the snap engagement.

With such a configuration, when the wire fixing member 31 and the holding member 35 are connected to each other, the wire fixing member 31 is connected to the end surface 4 of the fitting groove 40 of the holding member 35.
1 and the step 3 of the wire fixing member 31.
3 is engaged with the upper wall 44 of the holding member 35,
Are held between the fitting wall surfaces 42 of the step portion 33,
The positioning of the two is ensured, the work at the time of manufacturing is facilitated, and the gap between the surface of the wire support portion of the L-shaped metal plate and the end surface 43 of the wire insertion portion of the holding member 35 is reliably kept constant. Thus, the damper agent filled in the gap becomes uniform, and the wire support performance can be stabilized.

In the embodiment shown in FIGS. 1 to 3, the wire fixing member 2 is fixed to the base 52 shown in FIG. 5, and the holding member 3 is connected to the base 52 via the wire fixing member 2. Although an example in which the wire fixing member and the holding member are fixed is shown, the wire fixing member and the holding member may be formed as one member without being formed as separate members. Furthermore, although a plurality of metal plates embedded in the wire fixing member are formed in an L-shape, metal plates of various shapes can be adopted, and the first end to which the metal plates are soldered can be used. The parts can be arranged in various directions provided that they are substantially perpendicular to the focus direction. Further, in the above-described embodiment, an example is shown in which a wire through hole for inserting a wire is formed as a portion for fixing the wire to each metal plate. In the above embodiment, a U-shaped notch is formed near the point where the wire is soldered at the first end of the metal plate. As long as the heat can be prevented from diffusing, a substantially narrow portion can be formed in various modes, such as by forming various shapes of cuts or various shapes of holes. In the above embodiment, a wire is shown as a member for elastically supporting the lens holder, but a conductive elongated metal plate or the like may be used.

[0028]

According to the invention of claim 1 of the present application, the elastic member can be made of a metal plate without using a substrate formed by attaching a metal reinforcing plate to an FPC as in a conventional device. Therefore, the entire objective lens driving device can be reduced in thickness. In addition, since it is not necessary to use an expensive FPC, an inexpensive device can be provided, and since the metal plate is buried in the fixing member, there is no need to perform an operation of bonding the two, thereby improving the assemblability.

According to a second aspect of the present invention, the first metal plate
At the end, a narrow portion is formed near the place where the base end of the elastic member is soldered, so that when the elastic member is soldered to the metal plate, heat is diffused to the entire metal plate. This can prevent the solder fillet from being stably formed. .

According to a third aspect of the present invention, there is provided a holding member having an insertion portion through which the elastic member is inserted and filled with a damper agent, wherein an end face of the insertion portion is the first surface of the metal plate.
Since the fixing member and the holding member are connected to be opposed to each other with an end portion and a gap therebetween, the fixing member and the holding member can be separate members, for example, the fixing member is made of a heat-resistant resin. For example, a material optimal for the function of each member can be selected, such as using a translucent resin for the holding member. Further, since the first end of the metal plate does not interfere with the end surface of the holding member, the elastic member can be reliably held elastically, and the gap between the end surface of the insertion portion and the metal plate can be damped. When the agent is filled, the vibration damping action on the elastic member is further improved.

According to a fourth aspect of the present invention, the insertion portion of the holding member penetrates along the longitudinal direction of the elastic member and opens in a direction intersecting the longitudinal direction. The damper agent can be injected into the insertion portion regardless of the posture of the whole, and the damper agent can be injected evenly into the wire insertion portion inside the opening from the opening. The vibration action can be kept constant, and a damper agent having a relatively high viscosity can be selected, so that the reliability of the objective lens driving device can be improved.

According to a fifth aspect of the present invention, a step is formed on the upper surface of the fixing member, and a fitting groove which is open on the lower surface side is formed in the holding member. Since the holding member is attached to the fixing member by being fitted in the groove, when the wire fixing member and the holding member are combined and integrated, it is possible to prevent a deviation between the two, and to perform a manufacturing operation. And the accuracy of the device after manufacture can be improved.

[Brief description of the drawings]

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

FIG. 2 is an exploded perspective view showing a state before assembling a wire fixing member and a holding member of the device.

FIG. 3 is a perspective view showing the vicinity of a wire fixing portion of the device.

FIG. 4 is an exploded perspective view showing a state before assembling a wire fixing member and a holding member according to another embodiment of the present invention.

FIG. 5 is a perspective view showing an entire objective lens driving device to which the related art is applied.

FIG. 6 is a perspective view showing a state before joining an FPC and a metal reinforcing plate on a substrate supporting a wire in the device.

FIG. 7 is a sectional view of the vicinity of a wire supporting portion of the device.

FIG. 8 is an exploded perspective view of the same device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Objective lens driving device 2 Wire fixing member 3 Holding member 5, 6, 7, 8 L-shaped metal plate 10 Wire support end 11 Wire through hole 12 FPC connection end 15 Step 17 Wire insertion portion 18 Side surface 19 FPC 20 Side surface Hole 22 Wire 25 Cut 26 Solder 39 Narrow part

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kenji Uehara 1-8-1, Nishigotanda, Shinagawa-ku, Tokyo Alpine, Inc. F-term (reference) 5D118 AA02 AA04 AA06 AA23 DC03 FA29 FB06 FB12 FB13 5D119 AA38 MA04 NA07

Claims (5)

[Claims] 1. A lens holder to which an objective lens is attached, a support portion movably supporting the lens holder via a plurality of conductive and elongated elastic members, and a support portion provided on the lens holder. A driving coil to which a current is supplied via the elastic member, and a magnet for generating a magnetic flux passing through the driving coil, wherein the electromagnetic force generated by the current flowing through the driving coil and the magnetic flux of the magnet causes In an objective lens driving device for driving a lens holder in at least one of a focus direction and a tracking direction, the supporting portion includes a fixing member formed of a synthetic resin, and both ends of the fixing member projecting from the fixing member. A plurality of metal plates embedded in the fixing member are provided, and a first end of each metal plate extends in a direction substantially orthogonal to the focus direction. At the same time, the base end of the elastic member is soldered to the first end, and the current supplied from the second end of each metal plate is transmitted to the drive coil via the elastic member. Objective lens driving device. 2. The objective lens driving device according to claim 1, wherein a narrow portion is formed at a first end of the metal plate near a portion where a base end of the elastic member is soldered. 3. The supporting portion includes a holding member having an insertion portion through which the elastic member is inserted and filled with a damper agent, and an end surface of the insertion portion is formed to have a gap with a first end of the metal plate. 2. The objective lens driving device according to claim 1, wherein the fixing member and the holding member are connected so as to face each other. 4. The objective lens driving device according to claim 3, wherein the insertion portion of the holding member penetrates along a longitudinal direction of the elastic member and opens in a direction intersecting the longitudinal direction. 5. A step portion is formed on an upper surface of the fixing member, and a fitting groove which is open on a lower surface side is formed in the holding member, and the step portion is fitted into the fitting groove. The objective lens driving device according to claim 3, wherein the holding member is attached to the fixed member by means of (a).