JP2856078B2 - Objective lens actuator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an objective lens actuator for recording on or reproducing from an optical disk-shaped recording / reproducing medium.

[0002]

2. Description of the Related Art In recent years, a device for recording and reproducing information (hereinafter, referred to as an optical disk device) using a disk-shaped optical recording / reproducing medium (hereinafter, referred to as a disk) has advantages of large capacity and high speed. Recognized and widely used for voice, image and data recording. Among the components incorporated in the optical disk device, the objective lens actuator is positioned as an important mechanical component that affects recording / reproducing performance.

Hereinafter, a conventional objective lens actuator will be described with reference to the drawings. 5 is an external perspective view of a conventional objective lens actuator, FIG. 6 is an exploded perspective view of the objective lens actuator, and FIG. 7 is a cross-sectional view of a main part showing a mounting portion of the electromagnetic coil. This example shows an objective lens actuator using four suspension wires for holding a lens holder, and is widely used at present.

In FIGS. 5 and 6, a lens holder 32 is shown.
In the figure, the objective lens 1 is fixed on the upper surface and the balance weight 34 is fixed on the lower surface, and the soldering substrate 35 for soldering and fixing the tip of the suspension wire 39 is fixed on both side surfaces, and the other side surfaces as shown in the figure. Are magnetized in the NS direction, and two magnets 3 are bonded and fixed. A support holder 37 is fixed to one end of the base 40, and a soldering board 38 for soldering and fixing the other end of the suspension wire 39 is bonded and fixed to the support holder 37.
The suspension wire 39 is obtained by cutting a linear spring material into a predetermined length. The suspension wire 39 has a small hole 43 of a soldering board 38 made of a printed board, a small hole 44 of the support holder 37 and a small hole 45 of the holder 32. 4 are arranged in parallel, and both ends thereof are connected to a soldering board 35 fixed to the lens holder 32 and a soldering board 38 fixed to the support holder 37 by soldering portions 41 and 42 in FIG. Soldered.

An electromagnetic coil 36 which is opposed to and separates from the magnet 3 and electromagnetically drives it is also fixed to a predetermined position on a base 40 via a printed circuit board 47, and details thereof are shown on a winding frame 36a in FIG. There are two types of windings, a winding 36b around an arrow X1-X2 and a winding 36c around an arrow Y1-Y2. Metal pin 3 planted on 36a
6d is wound around the root 36e and soldered 36f
Is done. Next, the pins 36d of the winding frame 36a are inserted into four holes 47a of the printed circuit board 47, fixed by soldering 47c, and electrically connected to the print pattern. The mounting hole 47b of the printed circuit board 47 is
No. 0 is screwed into the screw hole 40a via a spacer 48, pulled out by a lead wire (not shown) soldered to the printed pattern, and connected to an electric circuit (not shown). And the opening 46 from the assembled thing
The cover 46 having a is attached to the base 40 by a hook 46b.

The operation of the conventional objective lens actuator configured as described above will be described below.
Both ends of the suspension wire 39 are fixed, the lens holder 32 side is cantilevered with respect to the support holder 37, and the lens holder 32 is connected to the arrow X1-X2 and the arrow Y1.
It is possible to translate in the −Y2 direction.
When a current was applied to two types of windings of the electromagnetic coil 36 centering on the arrows X1-X2 and the arrow Y1-Y2, they were opposed to and separated from the windings and magnetized in the NS direction. Magnet 3
Arrow X on the magnet 3 due to the electromagnetic force generated between
1-X2, Y1-Y2 driving force is generated to move the lens holder 32 and therefore the objective lens 1 fixed thereto.
Are driven in the directions of arrows X1-X2, Y1-Y2.

As a result, it is possible to move the focal position of the laser beam condensed on the disk (not shown) located above the objective lens through the objective lens 1, such as the surface deflection in the surface direction of the disk and the eccentricity in the radial direction. Recording or reproducing operation of the information signal.

[0008]

However, in the above-described conventional configuration, the windings 36b and 36c of the electromagnetic coil 36 are not provided.
Of the coil 36a of the coil winding frame 36a.
d and soldered, and further soldered through a pin 36d into a hole 47a of the printed circuit board 47,
In addition, the printed circuit board 47 must be fixed to the base 40, and then lead wires must be drawn out by soldering, and there are many soldering points, and there is a problem that solder defects are likely to occur.

Further, since the coil winding frame 36a is once soldered to the printed circuit board 47 and the printed circuit board 47 is attached to the base 40, there are many places where positional errors occur, and it is necessary to perform a final positioning operation. There was a problem.

Since the number of parts is large, the operation of winding a lead wire around the pin 36d and the hole 47
There is also a problem that the number of work steps is large, such as the work of passing the pins 36d of the coil frame 36a through a, and the production cost is increased.

The present invention solves the above-mentioned conventional problems. The present invention has a small number of soldering points, is unlikely to cause soldering defects, has a small number of parts, is easy to position, is easy to assemble, and has excellent productivity. An object of the present invention is to provide an objective lens actuator.

[0012]

In order to achieve the above object, an objective lens actuator according to the present invention is provided with a winding portion for winding coils having different directions in two axes in two layers, and connected to the winding portion. A coating portion provided on the coating portion, a plurality of wire processing grooves for winding lead wires at the start and end of winding of the coil, and the wire processing groove in a part of the wire processing groove. With a configuration having a coil frame having a solder processing portion provided on a lead wire wound around
In the solder processing part, the depth of the wire processing groove is partially reduced.
And the corresponding conductive foil is applied to the soldering part.
A flexible printed circuit board
I do.

[0013]

According to another aspect of the present invention, there is provided a lens holding member for holding an objective lens, a plurality of linear spring members for supporting the lens holding member, and a fixing member for fixing the linear spring member. And two different coils in two axial directions
A coil frame connected to a winding portion wound around the layer and having a positioning fixing portion with respect to the fixing member, wherein a pair of magnets are fixed to the lens holding member by bonding or molding. Can be used. The coil frame can have a protrusion or an extension for locking the lens holding member, and the coil frame having the extension, a frame-shaped fixing member, and the lens holding portion form a substantially box-like structure. be able to.

[0015]

According to the objective lens actuator of the present invention, the lead wires at the beginning and end of winding of the coil wound around the winding portion are wound around the wire processing groove of the covering portion of the coil frame by the above-described structure. For example, soldering may be performed in a soldering portion at an end portion thereof, and a flexible printed board having a conductive foil corresponding to the soldering portion may be contacted and soldered.

The soldering portion may be located not only on the end face of the coating portion but also on the flat portion of the coating portion, and according to the configuration in which the depth of the wire processing groove is partially reduced in the soldering portion, Since the parts are raised on the surface, the reliability of soldering is increased, and when the coil frame is formed of a synthetic resin material, if a material having heat resistance higher than the solder melting temperature is used, the shape is broken by soldering Never.

[0017]

Further, the coil frame can be locked by the projection or the extended portion so that the lens holding member does not swing excessively. Also, the coil frame having the extended portion, the frame-shaped fixing member, and the lens holding portion can be fixed. , And has a substantially box-like shape, so that dust and the like hardly enter the interior surrounded by these portions.

[0019]

An embodiment of the present invention will be described below with reference to the drawings. 1 is an external perspective view of an objective lens actuator according to one embodiment of the present invention, FIG. 2 is an exploded perspective view of the objective lens actuator, FIG. 3 is an enlarged perspective view of a coil frame, and FIG. 4 is an electrical connection to the coil frame. It is an assembly drawing showing a method. In FIGS. 1 and 2, an objective lens 1 is adhered and fixed to a lens holder 2 which is a lens holding member formed of a synthetic resin on the upper surface and an optical plate 4 is adhered to a lower surface. The tip of a suspension wire 8 which is a linear spring member of phosphor bronze or stainless steel of about 100 microns is molded and fixed by molding.
As shown in the figure, two magnets 3 magnetized in the NS direction are fixed to the protrusion 2a and the other two side surfaces at the positions of 90 degrees by bonding or molding. The other end of the suspension wire 8 is molded and fixed at one of four fixing points 8a to 8d on one side wall 10a of the frame-shaped housing 10 which is a fixing member formed of a synthetic resin. A hole 11 for attachment is provided as appropriate.

The coil frame 5 made of a synthetic resin has a winding portion 5a at the center, which is connected to both upper ends thereof, and a coating portion 5b having a projection 5c at one end. Have two wire winding grooves 5e and 5f, and have positioning fixed holes 5g on both lower surfaces for firmly fitting and fixing to positioning fixing pins 10b projecting from four corners of the housing 10. . In the winding part 5a, the electromagnetic coil 6 is wound around the winding 6a centered on the arrow Y1-Y2 and the winding 6b centered on the arrow X1-X2. The lead wire 6c at the beginning and end of each winding is wound around the wire processing grooves 5e and 5f several times, respectively.
The outer edge portion 6d of each wound wire is fixed by soldering. The printed pattern 12 is made of copper foil on the flexible printed circuit board 12 to be in contact with this portion.
a is formed, and the terminal is a terminal pattern 12b having an enlarged area, and a through-hole processing part 12e electrically connected to the terminal pattern part 12b is provided in the concave part 12d of the cross section 12c as necessary.

As can be seen from FIG. 1, the upper surface of the objective lens actuator occupies a large area by the lens holder 2, the electromagnetic coil 6, and the coil frame 5 wound therewith.
As shown in FIG. 3, if the coil frame 5 is provided with the extension 5h, the upper surface of the objective lens actuator is almost covered, so that dust and the like hardly enter the interior without providing a special cover. Braking material holding frame 7 made of transparent synthetic resin
Have positioning fixing holes 7a at both ends for firmly fitting and fixing the positioning fixing pins 10c protruding at two places below the housing 10, and two partition walls 7b inside thereof.
have.

The method of assembling the objective lens actuator of the present embodiment configured as described above will be described below. The other end of the suspension wire 8 molded and fixed to the projections 2a on both side surfaces of the lens holder 2 is molded and fixed to one side wall 10a of the housing 10, and the lens holder 2 is cantilevered by the four suspension wires 8. I have. The two coil frames 5 on which the coils 6 are wound from above the housing 10 are press-fitted symmetrically with respect to the objective lens 1 with the positioning fixing pins 10b of the housing 10 aligned with the positioning fixed holes 5g.

The lead wire 6c at the beginning and end of each winding 6a of the coil frame 5 is fixed to the edge portion 6d where the lead wire 6c is wound several times around the wire processing grooves 5e and 5f by soldering. The other end of the printed pattern 12a is soldered to the terminal pattern 12b of the terminal of the printed pattern 12a, the through-hole processing portion 12e, and the edge portion 6d by contacting the flexible printed circuit board 12 as shown in the figure. A signal current is applied to the electromagnetic coil 6 by being electrically connected to the printed pattern 12a of the flexible printed circuit board 12 connected to an electric circuit (not shown).
Therefore, when the coil frame 5 is formed of a synthetic resin, it is necessary to use a synthetic resin material having heat resistance higher than the solder melting temperature. FIG. 4B shows a partial change of the winding frame 5.
4A is a cross-sectional view of the line processing groove 5e or 5f in FIG. 4A, and the bottom of the groove is particularly shallow at the end.
i, the lead wire 6c wound
Surface slightly protrudes from the coil frame 5. Then, since the flexible printed circuit board 12 is thin, the electrical connection is sufficiently made by the raised solder 12f without providing the through-hole processing portion 12e.

Here, the wire processing groove 5 is formed at the end of the coil frame 5.
Although an example is shown in which e or 5f is made shallow, a protrusion is provided at the bottom of the line processing groove 5e or 5f on the upper surface 5d in FIG. Flexible printed circuit board 12
May be applied in parallel to the covering portion 5b from above to perform soldering. Although the soldering is illustrated at the end of the flexible printed circuit board 12, a hole may be provided in the flexible printed circuit board 12 and soldering may be performed.

Next, the brake material holding frame 7 is press-fitted from below into the positioning fixed hole 7a in accordance with the positioning fixing pin 10c of the housing 10. The braking member holding frame 7 and the partition wall 7b are fixed to the housing 10 at a fixed position.
The inner wall 10d and the covering portion 5b of the coil frame 5 form a space that surrounds two suspension wires 8 from five sides, so that this space has a liquid, for example, ultraviolet curability mainly containing silicon. A braking material 9 (not shown) is injected and gelled by irradiating ultraviolet rays from the lower surface of the transparent braking material holding frame 7, and an optimal braking effect is obtained when the suspension wire 8 vibrates while supporting the lens holder 2. To have This damping material may be a viscoelastic material such as rubber or elastomer other than the gel material.

Next, the operation of the objective lens actuator according to the embodiment constructed as described above will be described. The operation of the electromagnetic coil 6 around the arrow X1-X2 and the arrow Y1-Y
When currents are passed through the flexible printed circuit board 12 to the two windings and the two types of windings 6a and 6b, respectively,
A driving force in the directions of arrows X1-X2 and Y1-Y2 is generated on the magnet 3 fixed to the lens holder 2 by the electromagnetic force generated between the magnet 3 and the magnet 3 magnetized in the NS direction while being opposed to and separated from the magnet. Then, the lens holder 2 cantilevered by the suspension wire 8 and thus the objective lens 1 fixed thereto are driven in the directions of arrows X1-X2 and Y1-Y2. At this time, the braking material 9 provides an optimal braking effect to the suspension wire 8 that supports the lens holder 2 and vibrates.

This makes it possible to move the focal position of the laser beam condensed on the disk (not shown) located above the drawing through the objective lens 1 with respect to the objective lens, and to obtain the surface deflection and radius in the surface direction of the disk. The recording and reproducing operation of the information signal is performed following the eccentricity of the direction.

The housing 10 and the coil frame 5 or the brake material holding frame 7 can be fixed to each other by exchanging the positioning fixing pins and the positioning fixing holes, instead of the illustrated method. After mutually providing the position regulating members, they may be fixed by bonding or ultrasonic welding.
Although not shown, a cover corresponding to the cover 46 of the conventional example shown in FIG. 6 may be used if necessary, but a considerable area is covered by the covering portion 5b and the protrusion 5c of the coil frame 5, and By providing the extension portion 5h, the covering area is further increased, and it is not always necessary to use a cover as in the conventional example.

The projection 5c or the extension 5h
In addition to the role as a cover, when a strong current flows through the electromagnetic coil 6 due to strong vibration or acceleration from the outside, or for some reason, the lens holder 2 attempts to largely shake, thereby limiting the range of movement. Also bring.

Each part of each of the above embodiments may be implemented independently, or may be implemented by combining the parts of each embodiment. Needless to say, the present invention may be implemented by adding a conventionally known example.

[0031]

As described above, according to the objective lens actuator of the present invention, the start and end of the winding of the coil of the winding part are wound on the covering part which is connected to the winding part of the coil frame and covers the inside. A plurality of line processing grooves for winding lead wires are provided, and a part of the line processing groove is made shallow, and this shallow groove is formed.
Since the soldering is performed with the lead wire of the broken part, and the flexible printed circuit board with the conductive foil corresponding to the solder processing part is configured to contact and solder
The number of soldering points is reduced, and soldering defects are reduced.

The coil frame has a positioning and fixing portion. The positioning and fixing portion is used as a fixing member for supporting the lens holding member at one end with a plurality of linear spring members and fixing the linear spring member at the other end. Positioning can be naturally performed simply by attaching to the coil, so that the coil frame, that is, the position of the coil, can be easily attached to the lens holding member that holds the magnet, that is, the magnet, in an accurate relative position in conjunction with the improvement in the soldering method. accurately line the electromagnetic drive of the objective lens
In addition, the coil frame can prevent engagement of the lens holding member and entry of dust.

Thus, the present invention reduces the number of parts,
It is a useful tool that can reduce man-hours and a defective rate by reducing the number of processing locations, increase productivity, and improve processing accuracy by improving the configuration.

[Brief description of the drawings]

FIG. 1 is an external perspective view of an objective lens actuator according to one embodiment of the present invention.

FIG. 2 is an exploded perspective view of the objective lens actuator.

FIG. 3 is an enlarged perspective view of the coil frame.

FIG. 4A is an assembled perspective view showing a method of electrically connecting the coil frame to the coil frame. FIG. 4B is a sectional view showing another method of electrically connecting the coil frame to the coil frame.

FIG. 5 is an external perspective view of a conventional objective lens actuator.

FIG. 6 is an exploded perspective view of the objective lens actuator.

FIG. 7 is a sectional view of a main part showing a mounting portion of the electromagnetic coil.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Objective lens 2 Lens holder (lens holding member) 3 Magnet 5 Coil frame 5a Winding part 5b Coating part 5c Projection part 5d Upper surface 5e, 5f Line processing groove 5g Positioning fixed hole (positioning fixing part) 5h Extension part 5i Shallow groove part Reference Signs List 6 electromagnetic coil 6c lead wire 6d edge 8 suspension wire (linear spring member) 10 housing (fixing member) 12 flexible printed board 12a print pattern 12b terminal pattern 12d edge portion 12e through hole processing section

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G11B 7/09-7/095 H01F 7/06-7/16 H01F 15/00-21/12

Claims (2)

(57) [Claims] 1. A lens holding member for holding an objective lens
And a plurality of linear spring members supporting the lens holding member
A fixing member for fixing the linear spring member, and an electromagnetic drive
And a coil frame around which a coil is wound.
Is a winding part that winds coils with different biaxial directions in two layers
And a covering part connected to the winding part and covering the inside.
Beginning and end of winding of the coil provided on the covering portion
Multiple wire processing for winding each of the leader lines
With a groove, a part of the coil frame is in the longitudinal direction of the linear spring
The lens holding member is at least larger than the winding width of the coil.
Function of the lens holding member and dust proofer against vertical movement of
It has a projection or extension that combines
Objective lens actuator. 2. The line processing groove according to claim 1, wherein the end face of the covering portion is provided.
In the solder processing part provided in the above, the depth of the wire processing groove
Objective lens actuated by partially reducing the depth
Eputer.