JP3468653B2 - Optical pickup - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CD player, C
The present invention relates to an optical pickup used in a D-ROM device, an MD device and the like, and more particularly to an optical pickup in which a movable base having an objective lens mounted thereon is movably supported by an elastic support member.

[0002]

2. Description of the Related Art FIG. 5A is a plan view of a conventional optical pickup, and FIG. 5B is a side view thereof. In this optical pickup, a support base 1 is fixed on a moving base 9 that moves along the optical disc. A U-shaped yoke 2 is fixed to the moving base 9, and magnets 3a and 3b are supported by the yoke 2. A coil Cf for focus correction is embedded in the inner peripheral portion of the through hole 4a of the movable base 4, and a pair of coils Ct1 and Ct2 for tracking correction are bonded and fixed to the side surface of the focus coil Cf. The coils Cf, Ct1, and Ct2 are located between the magnets 3a and 3b to form a magnetic drive unit A. An electric force in the Z direction is generated by the current flowing in the Y direction in the focus coil Cf and the magnetic field between the magnets 3a and 3b, whereby the focus of the objective lens 5 held by the movable base 4 is corrected. . Further, an electromagnetic force in the Y direction is generated by the current flowing in the Z direction in the tracking coils Ct1 and Ct2, whereby the tracking correction of the objective lens 5 is performed.

On both sides of the support base 1 fixed on the moving base 9, there are formed recesses 1a, 1a penetrating in the X direction and having a slot-like opening area in the Z direction. A substrate 6 is provided. The elastic support material W that supports the movable base 4 is four elastic wire rods.
Are paired and inserted into the recessed portion 1a, and the base ends thereof are fixed to the conductor pattern portion of the substrate 6 with solder 7. On the side surface of the movable base 4, a set of two convex portions 8 is formed on one side. The protrusion 8 has an insertion hole 8a.
Are formed, and the tip of the elastic support material W is inserted and fixed. Movable base 4 holding an objective lens 5
Is elastically supported by the elastic support material W in a movable state in the Y direction and the Z direction.

In the example shown in FIG. 5, the elastic support material W is also used as a current-carrying path to the coil, and the wire rods L1 and L2 serving as both ends of the coil Cf are individually conducted to the elastic support material W. There is. In addition, the tracking correction coil Ct
1 and Ct2 are continuously wound by a common wire rod, and a wire rod extending between both coils Ct1 and Ct2 is indicated by L5. Wires L4 and L3 serving as terminals from the coils Ct1 and Ct2 are also individually conducted to the elastic support material W. That is, the wire rods L1, L2, L3, L4
Is individually conducted to each of the four elastic support members W,
The solder 7 is electrically connected to the conductor pattern on the circuit board 6 through the elastic support material W. The conductor pattern on the circuit board 6 is further connected to an external circuit.

[0005]

SUMMARY OF THE INVENTION In the above, the wire L
The connection between 1, L2, L3, L4 and the four elastic support members W is made via the relay boards 11a, 11b which are adhesively fixed to the side surfaces of the movable base 4 in the vicinity of the projections 8. At this time, as shown in FIG. 5, the hooking portions 12a and 12b provided on the X (−) side with the convex portions 8 and 8 interposed therebetween, and X
The hooking portions 13a and 13b provided on the (+) side are used auxiliary. The hooking portions 12a and 12b and the hooking portions 13a and 13b are integrally formed with the movable base 4 together with the convex portion 8 from synthetic resin.

As shown in FIG. 5 (B), the elastic support member W is fixed to the conductor pattern on the relay board 11a by the solders 14a1 and 14a2 while being inserted into the insertion hole 8a. On the other hand, the wire rods L1, L2, L3, L4, which are the ends of the windings of the coils Cf, Ct1, Ct2, are drawn out from the inside of the movable base 4 and pass through the bottom surface side (Z (−) side) of the movable base 4 respectively. Relay board 11a,
11b is pulled out to a position on 11b, and relay boards 11a and 11b
Is soldered to the conductor pattern.

As shown in FIGS. 5 (A) and 5 (B), for example, the wire L1 extending from the coil Cf is pulled out in the Z (+) direction on the outer peripheral surface of the movable base 4 and extends along the side surface of the hook portion 13b. And bent from the Z (+) direction to the X (-) direction at a substantially right angle. The tip of the wire L1 is connected to the relay board 11
It is fixed to the conductor pattern on b by solder 14b2. In the relay board 11b, the solder 14a2 and the solder 1
The connecting portion 4b2 is electrically connected by the conductor pattern, and as a result, the wire L1 is electrically connected to the elastic support material W located on the Z (-) side. The wire L3 extending from the coil Ct2 is pulled out in the Z (+) direction on the outer peripheral surface of the movable base 4, and extends from the Z (+) direction in the X (+) direction along the side surface of the hook 12b.
It can be bent at a right angle in the (+) direction. The tip of the wire L3 is fixed to the conductor pattern on the relay board 11b by the solder 14b1 so that the wire L3 is electrically connected to the elastic support W located on the Z (+) side. Similarly, the wire L2 extending from the coil Cf and the wire L4 extending from the coil Ct1 are bent by the hook portions 13a and 12a, respectively, and are conductively fixed by the solders 14a1 and 14a2 of the relay board 11a.

However, in the above-mentioned conventional connection method, it is necessary to separately provide the relay boards 11a and 11b on the outer peripheral surface of the movable base 4, and the number of parts is increased as compared with the movable base 4 alone. Therefore, there is a problem that the manufacturing process and manufacturing cost of the relay boards 11a and 11b increase. Further, the movable base 4 is not provided separately with the relay boards 11a and 11b.
It is conceivable that insert molding is performed to form the relay terminal when molding is performed, but in this case, the number of parts increases and the cost required for insert molding increases.

The present invention solves the above-mentioned problems of the prior art. It is possible to directly connect the elastic support material, which supports the movable base and also serves as the current-carrying path, and the terminal of each coil, without providing a relay board. It is an object of the present invention to provide an optical pickup capable of simplifying the manufacturing process and reducing the manufacturing cost.

[0010]

According to the present invention, there is provided a movable base on which an objective lens and a coil are mounted, a plurality of elastic supporting members for movably supporting the movable base, and a magnetic field generator for applying a magnetic field to the coil. the optical pickup is provided, the support portion is protruded to the movable base, the terminal of the coil is wound around the support portion, the terminal of the coil
Pre-solder is applied to the winding part of the
The tip portion is supported by the support portion, and the tip portion is the winding portion.
Is soldered through the preliminary solder to
By soldering the
It is characterized in that the moving base is fixed . Further, an insertion hole is formed in the support portion,
The elastic support member is inserted through the insertion hole, and its tip is in front.
It projects from the insertion hole, and the protruding tip part
It is soldered to the turning part.

Further, it is preferable that a portion of the support portion around which the end of the coil is wound is formed so as to be gradually narrowed toward a portion where the tip portion of the elastic support member is supported.

Further, the supporting portion can be formed integrally with the movable base.

Further, a metal film is formed around a portion of the surface of the support portion where the coil is wound and a portion where the elastic support material is fixed, and the metal film is formed on the end of the coil, the elastic support material and the metal film. A structure in which a conductive molten metal such as solder adheres may be provided.

In the optical pickup according to the present invention, the supporting portion provided so as to project from both sides of the movable base is elastic.
A support member is supported, and the elastic base member supports the movable base in an elastically movable state. The support part may be formed integrally with the movable base, or the support part may be separate from the movable base, and the support part may be fixed to the movable base. in this case,
The support may be made of metal or synthetic resin. The ends of the focus correction coil and the tracking correction coil provided on the movable base are wound around the support portion .

If the support portion is formed in a shape that gradually becomes thinner toward the portion where the elastic support member is supported, the winding is elastically supported by the elastic support member when the end of the winding is wound around the support portion. Inevitably approaches the part where is supported.

According to the present invention, a conductive molten metal such as solder is adhered to both the elastic support material and the winding, so that the elastic support material and the winding can be directly attached without providing a relay substrate. It can be conducted.

The bundle of wound wire rods has a predetermined width dimension. When preliminary soldering is applied to the bundle of wire rods, the wire rods are welded to each other, so that the winding region of the wire rods serves as a strong attachment region of the solder fillet. Therefore, the solder is surely brought into close contact between the tip of the elastic support member and the end of the winding, and the tip of the elastic support member can be reliably fixed by the solder.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. The same members as those in the conventional example described above are designated by the same reference numerals. 1A and 1B show an embodiment of an optical pickup according to the present invention. FIG. 1A is a plan view and FIG. 1B is FIG. 1A.
2 is a side view of FIG. 2, FIG. 2 is a perspective view of the movable base shown in FIG. 1,
FIG. 3 is an enlarged plan view of the supporting portion showing the coil end processing.

In the optical pickup shown in FIGS. 1A and 1B, the moving base 29 has a guide shaft (not shown).
Is movably supported in the Y-axis direction in the figure.
The Y-axis direction is set in the radial direction of the optical disc, and the optical pickup moves along the radial direction of the optical disc. A support base 21 and a yoke 22 having a U-shaped cross section for supporting the magnets 23a and 23b are fixed on the moving base 29.

A movable base 24 is elastically supported by an elastic support member W between the magnets 23a and 23b. An objective lens 25 is mounted on the movable base 24,
The movable base 24 also functions as a bobbin for forming a coil. An upper flange 24d and a lower flange 24e are integrally formed on the movable base 24,
A bobbin is provided between them, and the focus coil Cf is wound and formed. Around the upper flange 24d, a latch plate 24 having an L-shaped cross section that projects in the X-axis direction in the figure.
Two a are provided side by side. Similarly, the lower flange 24
A latch plate 24b is also provided in parallel around e. The upper and lower hooking plates 24a and 24b form a pair of bobbins, and the tracking coil Ct is wound around the bobbins. Each tracking coil Ct is four coils connected in series, for example, Ct1 and Ct.
The windings are formed in the order of t2, Ct3, and Ct4.

A support portion 24f projecting in the Y-axis direction from the side surface of the movable base 24 which is parallel to the X axis is integrally formed, and the tip of the support portion 24f is an elastic support member W.
The fixed portion 24g for supporting the tip of the
g becomes a part of the supporting portion 24f. As shown in FIG. 1 (A), the support portion 24f is formed with a tapered surface 24f1 whose width gradually decreases from the root portion on the movable base 24 side toward the fixed portion 24g side. Further, the fixing portion 24g is provided with an insertion hole 24h penetrating in the X-axis direction in the drawing and tapering in the X-axis (-) direction. The support portion 24f and the fixed portion 2 at the tip thereof
4g is an upper flange 24d and a lower flange 24e.
There are two locations on each side, and a total of four locations. In this example, the movable base 24 is made of synthetic resin, and the support portions 24f and the fixed portions 24g are also integrally formed of synthetic resin.

Support base 2 fixed on the moving base 29
Recesses 21a, 21a penetrating in the X direction and having a slot-like opening area in the Z direction are formed on both sides of 1, and a substrate 26 is provided on the back thereof. This recess 21a,
Two base end portions of each elastic supporting member W extending in the X-axis direction in the drawing are inserted into each of 21a. Each elastic support material W
The base ends of are fixed to the substrate 26 with solder 27, respectively. The tip of the elastic support W is inserted into the insertion hole 24h formed in the support 24f of the movable base 24,
Since the insertion hole 24h has a tapered shape, it is possible to easily insert the elastic support material W into the insertion hole 24h in the X-axis (+) direction in the drawing. Then, the end surface 24 of the fixed portion 24g
The tip W0 of the elastic support material W projects from g1 in the X-axis (+) direction.

In FIG. 2, the wire Lt1 is the end of the winding of the coil Ct1 for tracking correction, and the wire Lt4 is the end of the winding of the coil Ct4. The wire Lf1 indicates one end of the focus correction coil Cf, and the wire of the other end is wired below the wire Lt4 on a side surface opposite to the wire Lf1 although not shown. 2,
As shown in FIG. 3, the wire Lt1 drawn from the coil Ct1 is bent at the corner of the upper flange 24d, guided in the X-axis (−) direction in the drawing, and passes below the support 24f to reach the support 24f. It is wound to form a winding portion (a). In the winding portion (a), the wire Lf1 is wound up to near the tip W0 of the elastic support material W, the winding end of the winding portion (a) and the tip W0 are extremely close to each other, and the gap dimension d is It is minute.

The support portion 24f has a tapered surface 24f1 formed from the movable base 24 side to the fixed portion 24g side.
It has a shape that gradually becomes thinner. Therefore, when the wire Lt1 is wound from the movable base 24 side toward the fixed portion 24g side, the winding radius becomes gradually smaller toward the fixed portion 24g. Therefore, for example, the wire rod of the winding portion (a) inevitably approaches the fixing portion 24g. Since the winding part (a) can be always brought close to the front end W0 of the elastic support member W, after the winding part (a) is formed, the winding end and the elasticity of the winding part (a) can be improved. It is possible to maintain the gap dimension d between the support member and the front end W0 to be minute. The gap dimension d between the winding end of the winding portion (a) and the tip portion W0 is preferably set to 0.3 mm or less. As described above, the solder 30 is attached over the winding end of the winding portion (a) and the tip portion W0 of the elastic support material W which are close to each other, but the gap dimension d is 0.3.
By setting the thickness to be equal to or less than mm, the solder 30 is surely attached and adhered between the winding end and the tip portion W0.

Further, as shown in FIG. 3, by winding the wire Lt1 in close contact with the supporting portion 24f in order, the winding can be tightly wound around the supporting portion 24f without any gap, and the winding portion (a) It is possible to form the surface of a) into a substantially uniform surface. The solder 30 can be firmly fixed by applying preliminary solder to the winding portion (a).
Thus, the tip W0 of the elastic support material W can be securely fixed. Further, by integrally forming the support portion 24f and the fixed portion 24g with the movable base 24, the end of each wire and the tip W0 of each elastic support W can be surely conducted without using a relay substrate as in the prior art. Can be made. In consideration of the weight balance of the movable base 24, the end surface 24g1 of the fixed portion 24g is fixed to the movable base 24 as shown in FIG.
The movable base 24 can be supported with a stable load balance by setting it on the GG line that is parallel to the Y axis passing through the center of gravity and the optical axis of the objective lens 25.

FIG. 4 is a plan view showing another embodiment of the supporting portion. In this example, the extended portion 24i of the support portion 24f is provided at the tip of the fixed portion 24g. This extension 2
4i also has a tapered surface 24i1 so that the fixing portion 24g side becomes thinner. The wire rod at the end of the coil is wound around the support portion 24f and then passes through the fixed portion 24g to extend the extension portion 2f.
4i is continuously wound to form a winding portion (b). Since the taper surface 24i1 is formed in the extension portion 24i, the winding portion (b) approaches the tip portion W0 of the elastic support member W, similar to the winding portion (a) of the supporting portion 24f described above. Can be made. The winding portions (a) and (b) can be concentrated on the tip portion W0 of the elastic support material W from both directions, and the winding portion (a), the tip portion W0 of the elastic support material W and the winding portion (b). Can be entirely soldered with the solder 32.
With this soldering structure, the ends of the coil and the elastic support W
It is possible to more securely fix the front end W0 of the.

If an annular rib 24g2 protruding in the X-axis (+) direction in the drawing is formed around the insertion hole 24h on the end face 24g1 of the fixed portion 24g, the wire rod is inserted into the insertion hole when winding the wire rod. It is possible to avoid blocking 24h. Terminal processing of coils, such as described above, the end end wire Lt4 coil Ct4, coils C for focus correction
The same applies to the one end wire Lf1 of f and the other end wire Lf.

The taper surface 24 of the supporting portion 24f is provided.
f1 is not limited to the one formed only on the X-axis (+) side as shown in the plan view of FIG.
Side, the Z-axis (+) or (-) side, or these surfaces may be provided in combination, or the conical support portion 2
It may be such a tapered surface when 4f is viewed in plan. Also, the end face 24g1 of the fixed portion 24g
And the tapered surface 24f1 of the supporting portion 24f, and further as shown in FIG.
By forming a metal film on the tapered surface 24i1 of the extended portion 24i by sputtering or the like, it is possible to increase the adhesive strength of the solder.

[0029]

According to the present invention described in detail above, the end of the coil and the elastic support material can be surely conducted without providing the support portion of the elastic support material and a separate relay substrate on the movable base. You can

Further, since the elastic supporting member can be fixed and the above-mentioned conduction can be realized by performing the soldering process once, the assembly process of the optical pickup can be simplified.

[Brief description of drawings]

1A and 1B show an embodiment of an optical pickup according to the present invention, FIG. 1A is a plan view, FIG. 1B is a side view of FIG.

2 is a perspective view of the movable base shown in FIG. 1, FIG.

FIG. 3 is an enlarged plan view of a supporting portion showing a coil end treatment;

FIG. 4 is a plan view showing another embodiment of the supporting portion,

FIG. 5A is a plan view of a conventional optical pickup,
(B) is a side view,

[Explanation of symbols]

24 movable base 24f support portions 24f1, 24i1 taper surface 24g fixed portion 24h insertion hole 24i extension portions 30, 32 solder Ct, Ct1, Ct2, Ct3, Ct4 tracking king coil Cf focus coil Lt1, Lt4, Lf1, Lf2 coil end W Elastic support material (a), (b) Winding part

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-8-147730 (JP, A) JP-A-5-342606 (JP, A) Fukui 2-132319 (JP, U) (58) Field (Int.Cl. ⁷ , DB name) G11B 7/135

Claims (4)

(57) [Claims] 1. An optical pickup comprising: a movable base on which an objective lens and a coil are mounted; a plurality of elastic supporting members for supporting the movable base in a movable state; and a magnetic field generator for applying a magnetic field to the coil. A supporting portion is provided so as to project from the movable base, the terminal of the coil is wound around the supporting portion, and the winding portion of the terminal of the coil is wound around the supporting portion.
Preliminary solder is applied, and the tip of the elastic support material is
Supported by a support part, the tip part is in front of the winding part.
It is soldered through the preliminary solder.
The front portion of the elastic support member and the movable base
An optical pickup characterized by being fixed . 2. An insertion hole is formed in the support portion,
The elastic support member is inserted into the insertion hole, and a tip portion thereof is inserted.
Is protruding from the insertion hole, and the protruding tip is
The optical pick according to claim 1, wherein the optical pick is soldered to the winding portion.
up. 3. A portion of the terminal is wound in a coil in said support portion, claim are gradually formed narrower toward the portion tip portion of the elastic support member is supported 1
Or the optical pickup described in 2 . 4. The optical pickup according to claim 1, wherein the support portion is formed integrally with the movable base.