JPH11259878A - Optical pickup and magnet mounting method for the optical pickup - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely and surely fit a magnet to the internal wall of a yoke without using adhesive. SOLUTION: The yoke 11 is equipped with a 1st flat plate part 14a and a 2nd flat plate part 14b which are formed by folding metallic plates and arranging them opposite at a certain interval and the 1st flat plate part 14a is provided with a restriction part 17 which projects toward the 2nd flat plate part 14b; and the magnet 13 is fitted to the 2nd flat plate part 14b and the restriction part 17 performs position restriction in parallel to the surface of the 1st flat plate part 14a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup suitable for an optical disk device such as a magneto-optical disk.

[0002]

2. Description of the Related Art An optical pickup is mounted on an optical disk device and irradiates a laser beam onto an optical disk through an objective lens for guiding light to record information on the disk surface or reproduce the recorded information. Or something.

FIG. 9 shows an optical pickup 1 of this type.
50 has the following configuration. Lens holder 151
Is an upright rectangular wall 156 made of a metal member.
And a substantially cylindrical receiving portion 15 integrally formed with the wall portion 156.
7 is comprised. At both end portions of the wall portion 156, vertically elongated thin portions 158 are formed. A substantially V-shaped groove 158 is provided outside the thick portion 158.
b are formed side by side. Elongated wires (not shown) are attached and fixed to the four grooves 158b so as to be parallel to each other. On the back side of the wall portion 156, the above-mentioned receiving portion 157 is attached integrally with the wall portion 156, and the receiving portion 157 has a circular opening penetrating in the vertical direction. At the periphery of the opening, four claw portions 159a are formed at equal intervals at positions facing each other.

A tablet-shaped objective lens 155
Is made of a glass or synthetic resin member and has a flange 15
5a, the outer wall of the flange 155a is in contact with the inner wall of the claw 159a of the lens holder 151, and the bottom of the flange 155a is in contact with the periphery of the opening, and is fixedly attached using an adhesive.

[0005] The yoke 152 is a metal magnetic material formed by bending a substantially rectangular metal plate into a U-shape, and includes a first flat plate portion 152a and a second flat plate portion 152b which are arranged to face each other. And a bottom plate 152c connecting the flat plates 152a and 152b. The rectangular magnet 154 is a permanent magnet, is disposed on the inner wall of the first flat plate portion 152a, and is attached and fixed via an anaerobic adhesive so as to cover the entire inner wall of the first flat plate portion 152a. I have. Anaerobic adhesives are those that solidify by blocking air. First flat plate portion 152a and second flat plate portion 1
A first projection 164a and a second projection 164b each having a rectangular shape are formed on the end of the bottom 52b opposite to the bottom plate 152c.

The back yoke 153 is a rectangular plate-shaped metal magnetic material, and has a rectangular hole 1
65 are respectively formed. Back yoke 153
Corresponds to the hole 1 of the back yoke 153 with respect to the yoke 152.
The first projection 164a and the second projection 164b of the yoke 152 are fitted and fixed so as to form one substantially cylindrical body. A substantially cylindrical coil (not shown) arranged so as to surround the first flat plate portion 152a is formed on the first flat plate portion 152a, and a current flows through the coil. The objective lens 155 can be moved by the magnetic field generated between the magnet 154 and the magnet 154 attached to the yoke 152. 2nd flat plate part 1
Reference numeral 52b is such that the outer wall surface of the second flat plate portion 152b is in contact with the wall portion 156 via an adhesive. Immediately below the objective lens 155, a flat lens or a beam splitter (not shown) that changes the direction of the incident laser light at a right angle and emits the laser light to the objective lens 155 is attached.
The optical pickup 150 is fixed to a carriage (not shown) by integrating a yoke 152 with a lens holder 151 so that the optical pickup 150 can move parallel to the optical disk surface.

To assemble such an optical pickup 150, first, a metal magnetic material is punched out by a press, and
A flat metal plate is formed in the shape of the projection 164a and the second projection 164b. Place the flat metal plate on the base, address the punch to the center of the flat metal plate,
Pressed and bent into a U-shape, opposing first flat plate portion 1
52a, a second flat plate portion 152b, and a bottom plate portion 152c
Is formed. In FIG.
The jig 80 includes a metal plate 80a made of brass and the metal plate 80a.
Is formed of a hook portion 80b formed by cutting out a part of the hook. The magnet 154 extends along the edge where the hook 80b is provided.
And the jig 80 is inserted in parallel with the bottom plate portion 152c of the yoke 152. One of the surfaces of the magnet 154 is previously coated with an anaerobic adhesive. By operating the jig 80, the surface of the magnet 154 is brought into close contact with the inner wall surface of the first flat plate portion 152a. Since the anaerobic adhesive is solidified, the magnet 154 is attached and fixed to the first flat plate portion 152a.

Next, a substantially cylindrical coil (not shown) is inserted into the first coil.
Of the first protruding portion 164a around the flat plate portion 152a, and is mounted at a predetermined position. Further, the back yoke 153 is covered from above the ends of the first flat plate portion 152a and the second flat plate portion 152b of the yoke 152, and the mounting holes of the back yoke 153 are formed in the first protrusion 164a and the second protrusion 164b. 165 are fitted and fixed. Next, an adhesive is applied to the inner outer wall surface of the second flat plate portion 152b, and the side surface of the wall portion 156 and the second flat plate portion 152 are applied.
b. The side surfaces are brought into contact with each other and attached and fixed with this adhesive. Next, the receiving portion 157 of the lens holder 151 includes
The objective lens 155 is placed. This is the objective lens 15
The fifth flange portion 155a is attached and fixed to the inner wall of the claw portion 159a with an adhesive. Finally, the groove 158 of the wall 156
An elongated wire (not shown) is attached to b, and a lens holder 151 to which an objective lens 155 is attached and fixed.
In addition, a yoke 152 integrated with the lens holder 151 is flexibly held by the carriage.

The optical pickup 150 mounted on the optical disk drive supplies an electric current to the coil so as to follow the rotational eccentricity of the optical disk, and the magnetic pickup generated between the coil and the magnet 154 mounted on the yoke 152 causes the objective lens 15 to rotate.
5 can be moved in a focus direction (a direction approaching and separating from the optical disk surface) and a tracking direction (a radial direction of the optical disk), and the laser light emitted from the semiconductor laser element is vertically emitted by a plane lens or a beam slitter. Is changed so that the light is focused by the objective lens and is incident on a predetermined optical disk surface.

[0010]

By the way, the magnet 154
Is fixed to the inner wall of the first flat plate portion 152a of the yoke 152 using an adhesive, and the magnet 154 is moved from a predetermined mounting position to the direction along the bonding surface of the magnet 154 before the adhesive is hardened. There was a risk that it would shift. This is due to the action of the magnet's own weight and external force. Therefore, it was difficult to accurately position the magnet 154 with respect to the yoke 152. If the magnet 154 is displaced from a predetermined position, the magnetic field generated between the coil and the magnet 154 attached to the yoke 152 becomes non-uniform, thereby stabilizing the balance characteristics and resonance characteristics of the objective lens that is driven and controlled. Could be disturbed. Also, when an adhesive is used, if the other adhesive is stuck to an unnecessary part (a part such as a wire that is held with flexibility), the objective lens 155 will not move accurately and will follow the optical disk surface. There was a fear that it would not be possible.

In view of the above problems, an object of the present invention is to provide an optical pickup in which a magnet is accurately and reliably mounted on a yoke without using an adhesive, and a method of mounting a magnet in the optical pickup. It is in.

[0012]

Means for Solving the Problems In order to achieve the above object, as a first means for solving the above problems,
The yoke includes a first flat plate portion and a second flat plate portion which are formed by bending a metal plate and opposed to each other at a predetermined interval, and the first flat plate portion has a restriction protruding toward the second flat plate portion. And a magnet is attached to the regulating portion, and the regulating portion regulates the position of the magnet in a direction parallel to the surface of the first flat plate portion.

[0013] As a second solution, the restricting portion comprises a cut-and-raised portion obtained by cutting and raising a part of the first flat plate portion.

As a third solution, the cut-and-raised portion comprises a first cut-and-raised portion and a second cut-and-raised portion which respectively hold one opposing side surface and the other opposing side surface of the rectangular magnet.
And a cut-and-raised portion.

[0015] As a fourth solution, an engaging portion is provided on the magnet, and the engaging portion is engaged with the regulating portion.

[0016] As a fifth solution, the restricting unit comprises
And two clearance portions are provided in the two restricting portions, into which a part of the punch is inserted when the yoke is bent in a U-shape.

According to a sixth aspect of the present invention, there is provided a magnet mounting method for mounting a magnet on a yoke constituting an optical pickup, the yoke constituting the optical pickup being provided with a restricting portion for restricting movement of the magnet in four directions. Then, the magnet is previously attracted to the jig, the magnet is inserted into the restricting portion in the attracted state and attracted to the yoke, and then the magnet is separated from the jig by pulling out the jig along the yoke.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. The optical pickup 1 described above
The same components as those of 50 are denoted by the same reference numerals, and detailed description is omitted. An optical pickup according to a first embodiment of the present invention has the following configuration. 1 and 2
, The yoke 11 is a metal magnetic material formed by bending a substantially rectangular metal plate into a U-shape, and the first flat plate portion 14a and the second flat plate portion 14
b, and a bottom plate portion 14c connecting the first flat plate portion 14a and the second flat plate portion 14b. On both sides of the first flat plate portion 14a, two restricting portions 17 protruding toward the second flat plate portion 14b, and cutout grooves 40 are formed at both ends of the restricting portion 17, respectively. This regulation part 1
Reference numeral 7 denotes a cut-and-raised portion formed by bending the cut-out groove 40 at a substantially right angle with respect to the bending reference and forming the cut-and-raised portion (first
Cut-and-raised portion) 17a and a second cut-and-raised portion 17b in which both ends of each cut-and-raised portion (first cut-and-raised portion) 17a are bent substantially inward toward each other at right angles.
Consists of A U-shaped cut-and-raised portion is formed by the first cut-and-raised portion 17a and the two second cut-and-raised portions 17b, and are arranged so as to face each other with a predetermined gap portion 20 provided therebetween. First flat plate portion 14a and second flat plate portion 1
A first projection 18a and a second projection 18b each having a rectangular shape are formed at an end of the side 4b opposite to the bottom plate 14c. On both side surfaces of the second flat plate portion 14b, arm portions 16 extending in parallel with the surface of the first flat plate portion 14a facing the second flat plate portion 14b.
Are formed.

The magnet 13 having a rectangular parallelepiped shape is a permanent magnet, and has a front surface portion 13a and a back surface portion 13b facing each other, one facing side surface portions 13c and 13d, and the other facing side surface portion 1c.
3e and 13f (see FIG. 2). The magnet 13 is the first
Are arranged on the inner surface of the flat plate portion 14a, and the side portions (13c to 13f) of the magnet 13 are first cut and raised portions 17a.
And, it is attached to the inside of the U-shaped regulating portion 17 (magnet storage portion) surrounded by both inner side walls of the second cut-and-raised portion 17b. More specifically, one side surface portion 13c, 13d abuts on the first cut-and-raised portion 17a, and the other side surface portion 13e, 1d.
3f is in contact with the inner wall of the second cut-and-raised portion 17b.

The back yoke 12 is a rectangular plate-shaped metal magnetic material, and has rectangular holes 21 penetrating at both ends. The back yoke 12 is a yoke 1
1, the hole 21 of the back yoke 12 and the first projection 18a and the second projection 18b of the yoke 11 are fitted and fixed so as to form one substantially cylindrical body. A substantially cylindrical coil (not shown) is formed on the first flat plate portion 14a so as to surround the first flat plate portion 14a. An electric current flows through this coil, and the objective lens of the lens holder integrated with the yoke 11 can be moved by a magnetic field generated between the coil and the magnet 13 attached to the yoke 11. Although the connection between the yoke 11 and the lens holder is not shown, the arm 16 of the second flat plate portion 14b makes the outer wall surface of the arm 16 abut against the wall of the lens holder, and It is fitted with the guide groove provided in the direction.

Immediately below the objective lens, a flat lens or a beam splitter (not shown) that changes the direction of the incident laser light at right angles and emits the laser light to the objective lens is attached. The optical pickup is integrally fixed to a carriage (not shown) by integrating a yoke 11 with a lens holder so that the optical pickup can move parallel to the optical disk surface.

Referring to FIG. 3, the assembly of the optical pickup thus constructed will be described below. First, a metal magnetic material is punched out by a press to form a flat metal plate that models the first protrusion 18 a, the second protrusion 18 b, and the arm 16. Next, both sides of the first flat plate portion 14a are bent at substantially right angles from the surface with the notch grooves 40 as a bending reference to form the regulating portion 17, and both ends of the regulating portion 17 are substantially perpendicular to each other. To form a second cut-and-raised portion 17b. As shown in FIG. 3, the substantially rectangular pillar-shaped metal punch 90 is formed with a protruding portion 90 a protruding from one side surface of the punch 90 main body, and the L-shaped step is formed by the protruding portion 90 a and the punch 90 main body. A portion 90b is formed. Further, a base 95 is provided with a space corresponding to substantially the width of the punch 90 opened. After the flat metal plate is placed on the base 95, the punch 90 is pressed toward the center of the flat metal plate and pressed to be bent into a U-shape. At this time, the protruding portion 90a is bent and formed so as to be disposed in the gap portion 20 between the second cut-and-raised portions 17b and the portion corresponding to the bottom plate portion 14c. That is, the punch 90 is addressed to a portion corresponding to the bent portion of the bottom plate portion 14c and the first flat plate portion 14a near the center of the flat metal plate, and the protruding portion 90a is arranged to face the gap portion 20. When the punch 90 is pressed directly below, the metal plate is gradually bent with reference to the edge of the protruding portion 90a of the punch 90, and a part of the opposing side walls of the protruding portion 90a enters the gap portion 20, and 2
The second cut-and-raised portion 17b is arranged on the stepped portion 90b while being restricted by the butted surface of the cut-and-raised portion 17b, so that the plate-shaped metal plate is bent and formed in a U-shape, and the opposing first plate is formed. Plate portion 14a and second plate portion 14
b, and the bottom plate portion 1 connecting the flat plate portions 14a and 14b
A yoke 11 made of 4c is formed. As described above, the projecting portion 90a of the bending punch 90 enters the gap portion 20 provided between the second cut-and-raised portions 17b on the bottom plate portion 14c side, and the second cut-and-raised portion 1 is inserted into the step portion 90b of the punch 90.
7b, the second cut-and-raised portion 1b is provided between the second cut-and-raised portion 17b near the bottom plate portion 14c and the bottom plate portion 14c.
7b and the bottom plate portion 14c.
Thickness in the height direction can be reduced. If necessary, the second cut-and-raised portion 17b of the first flat plate portion 14a close to the bottom plate portion 14c can be bent and formed so as to contact the surface of the bottom plate portion 14c.

In FIG. 4, in order to attach the magnet 13 to the yoke 11, first, the magnet 13 is attached to the insertion jig 100 made of a brass metal plate by its own magnetic force. This is one in which either the front surface portion 13a or the back surface portion 13b of the magnet 13 is attached to the side surface of the insertion jig 100. The insertion jig 100 is parallel to the surfaces of both flat portions 14a, 14b of the yoke 11, and the first projections 18a of the flat portions 14a, 14b are
It is inserted from the side of the second protrusion 18b toward the bottom plate portion 14c, and further, the insertion jig 100 is operated to be inserted into the surface portion (magnet housing portion) of the first flat plate portion 14a surrounded by the restriction portion 17. The magnet 13 is fitted, and either the front surface portion 13a or the back surface portion 13b is brought into contact. After the magnet 13 is fitted, the second cut-and-raised portion 17b on the side of the projections 18a, 18b
Is used as a guide to insert the jig 100 into the first flat plate portion 14a.
Up along the surface of the insertion jig 10 from the magnet 13.
Separate 0. The magnet 13 is controlled by its own magnetic force to form the first flat plate portion 14a surrounded by the restricting portion 17, that is, the first cut and raised portion 17a and the second cut and raised portion 17b.
It is attached and fixed to the surface part (magnet storage part) of the.

Next, a coil (not shown) is connected to the first flat plate portion 1.
After mounting the back yoke 12 on the first flat plate portion 14a and the second flat plate portion 14
b, the first projection 1 of the yoke 11
The mounting holes 21 of the back yoke 12 are fitted into the second projections 8a and the second projections 18b, respectively. To incorporate the yoke 11 combined as described above into the lens holder, the arm 16 of the second flat plate portion 14b of the yoke 11 is inserted into the guide groove of the wall of the lens holder in the same manner as described above. It is inserted so that the side surface of the second flat plate portion 14b abuts, and attached and fixed with an adhesive. The objective lens is mounted on the receiving portion of the lens holder, and the flange of the objective lens is attached and fixed to the inner wall of the claw portion with an adhesive. An elongated wire is attached to the groove of the wall, and the lens holder having the objective lens and the yoke 11 are flexibly supported by the carriage to complete the optical pickup. The optical pickup mounted on the optical disk device moves the objective lens in the focus direction (to the optical disk surface) by a magnetic field generated between the coil and the magnet 13 accurately and reliably mounted on the yoke 11 so as to follow the rotational eccentricity of the optical disk. The laser beam emitted from the semiconductor laser element is changed from a parallel direction to a vertical direction by a plane lens or a beam slitter so that the laser beam can move in a direction in which the laser beam approaches and separates from the semiconductor device and a tracking direction (a radial direction of the optical disk). hand,
The light is condensed by an objective lens and is incident on a predetermined optical disk surface.

The present invention has the following structure as a second embodiment of the yoke portion of the optical pickup. FIG. 5A
5B, a U-shaped yoke 31 made of a metallic magnetic material has a first flat plate portion 32 a and a first flat plate portion 3.
2a, a second flat plate portion (not shown)
And a bottom plate portion 32c connecting the second flat plate portion. The first flat plate portion 32a is formed with a regulating portion 33 attached to a side surface of the first flat plate portion 32a at a position having a different height. The restricting portion 33 includes a first cut-and-raised portion 33a and the first cut-and-raised portion 33a.
Cut-and-raised portion 3 which is bent in a direction perpendicular to the plane
3b, and a cutout groove 35 is formed in advance between the restriction portion 33 and the first flat plate portion 32a. The first cut-and-raised portion 33a and the second cut-and-raised portion 33b are formed so as to sandwich two diagonal corners of the rectangular magnet 13 described above. In other words, one of the first cut-and-raised portions 33a and the second cut-and-raised portions 3
Reference numeral 4 denotes a first cut-and-raised portion 33a and a second cut-and-raised portion 34 on the other side 13d and the side 13e.
, Respectively, sandwiches the adjacent side portions 13c and 13f to regulate the position of the magnet in four directions.

In order to make the yoke 31, in FIG. 5B, a plate made of a metallic magnetic material is punched out by a press, and a first flat plate portion 32a, a second flat plate portion, and a bottom plate portion 32c are formed.
Is formed to form a metal piece X that is partially connected to the metal plate shaped like. Using a jig, this metal piece X is bent substantially perpendicularly to the surface with the dashed line shown in the figure as a bending reference, to form a regulating portion 33 that becomes the first cut-and-raised portion 33a.
Further, a second cut-and-raised portion 34 is formed on the surface of the metal piece X at a substantially right angle with the dotted line in the drawing as a bending reference.

The present invention has the following configuration as a third embodiment. 6, a U-shaped yoke 41 made of a metallic magnetic material includes a first flat plate portion 42a, a second flat plate portion (not shown) facing the first flat plate portion 42a, and a first flat plate portion 42a. It is composed of a flat plate portion 42a and a bottom plate portion 42c connecting the second flat plate portion. First flat plate portion 42a
A first cut-and-raised portion 43a, which serves as an opposing regulating portion 43, which is attached to the side surface of the first flat plate portion 42a so as to project toward the second flat plate portion, and a first flat plate portion 42a.
And a second cut-and-raised portion 43b serving as a restricting portion 43 formed by cutting out the surface at a substantially right angle. Then, the first cut and raised portion 43a and the second cut and raised portion 43
b are arranged to face each other, and the above-described rectangular magnet 13 is attached and fixed to the surface portion of the enclosed first flat plate portion 42a. And the first
The cut-and-raised portion 43a regulates the position in the horizontal direction parallel to the surface of the first flat plate portion 42a of the magnet, and the second cut-and-raised portion 43b controls the vertical position parallel to the surface of the first flat plate portion 42a of the magnet. Each position is regulated.

The present invention has the following configuration as a fourth embodiment. In FIG. 7, a U-shaped yoke 51 made of a metallic magnetic material has a first flat plate portion 52a, a second flat plate portion (not shown) opposed to the first flat plate portion 52a, and a first flat plate portion 52a. And a bottom plate portion 52c connecting the second flat plate portion. First flat plate portion 52a
Are provided with two cut-and-raised portions 53 which are cut-off portions on both side surfaces of the first flat plate portion 52a and are bent at substantially right angles from the surface of the first flat plate portion 52a to be opposed to each other. I have. The magnet 54 is a permanent magnet, and the magnet 54 has an engaging portion 54 in which both rectangular side walls are cut out in a rectangular shape corresponding to the cut-and-raised portion 53 of the first flat plate portion 52a.
a is formed. The magnet 54 is in contact with the inner surface of the first flat plate portion 52a, and the engaging portion 54a of the magnet 54 is moved to the first position.
Is fixed to the cut-and-raised portion 53 of the flat plate portion 52a. Then, by engaging the engaging portion 54a of the magnet 54 with the cut-and-raised portion 53 serving as a regulating portion of the first flat plate portion 52a, the position of the magnet 54 in the four directions parallel to the surface of the first flat plate portion 52a. Regulations are in place.

The present invention has the following configuration as a fifth embodiment. 8A and 8B, a U-shaped yoke 61 made of a metallic magnetic material has a first flat plate portion 62a and a second flat plate portion (not shown) opposed to the first flat plate portion 62a. , The first flat plate portion 62a and the second
And a bottom plate portion 62c connecting the flat plate portions. The first flat plate portion 62a is a restricting portion in which the wall of the first flat plate portion 62a is cut out in an H shape, and the cut-out portion is bent substantially at right angles from the outer wall to the inner wall so as to face the restricting portion. Two cut and raised portions 63 are provided. Magnet 64
Is a permanent magnet, and the magnet 64 has a first flat plate portion 62
a corresponding to the cut-and-raised portion 63 of FIG.
Is formed with an insertion hole 64a serving as an engagement portion. Magnet 6
4 is in contact with the inner wall of the first flat plate portion 62a,
Cut-and-raised portion 6 of first flat plate portion 62a.
3 and fixed. Then, the first flat plate portion 6
The cut-and-raised portion 63 of FIG.
a of the first flat plate portion 62a of the magnet 64
The position is regulated in four directions parallel to the surface. Then, the cut-and-raised portion 6 serving as a regulating portion of the first flat plate portion 62a
The position of the magnet 64 in four directions parallel to the surface of the first flat plate portion 62 a is regulated by engaging the insertion hole 64 a of the magnet 64 with the magnet 3.

[0030]

According to the present invention, the yoke is provided with a first flat plate portion and a second flat plate portion which are formed by bending a metal plate and are opposed to each other at a predetermined interval. A regulating portion protruding toward the flat plate portion is provided, and a magnet is attached to the restricting portion. The regulating portion regulates a position in a direction parallel to the surface of the first flat plate portion of the magnet. Since the magnet is fixed at a predetermined position, it is possible to prevent the magnet from being displaced by an external force simply by attracting the magnet to the yoke with its own magnetic force without using an adhesive,
The resonance characteristics and balance characteristics of the optical pickup can be stabilized.

The cut-and-raised portion comprises a first cut-and-raised portion and a second cut-and-raised portion which respectively hold one opposing side surface and the other opposing side surface of the rectangular magnet. Because the magnet is fixed in place,
Even without using an adhesive, the magnet can be securely attracted to the yoke by its own magnetic force, and displacement of the mounting position of the magnet due to external force or the like can be reliably prevented.

Further, two regulating portions are provided on the first flat plate portion, and a gap portion is provided between the two regulating portions so that a part of the punch is inserted when the yoke is bent in a U-shape. The punch can be addressed to the gap, and the yoke can be made thinner in the height direction.

The yoke constituting the optical pickup is provided with a restricting portion for restricting the movement of the magnet in all directions. To mount the magnet on the restricting portion, the magnet is previously attracted to a jig, The magnet is inserted into the restricting section and attracted to the yoke in the attracted state, and then the jig is pulled out along the yoke to separate the magnet from the jig. Can be prevented, and it can be easily and securely fitted into a predetermined magnet storage portion.

[Brief description of the drawings]

FIG. 1 is a perspective view of a yoke portion of an optical pickup of the present invention.

FIG. 2 is a partially exploded perspective view of a yoke portion of the optical pickup of FIG.

FIG. 3 is a perspective view illustrating a bending process of a yoke portion of the optical pickup of the present invention.

FIG. 4 is a perspective view illustrating a method of assembling a magnet to a yoke portion of the optical pickup according to the present invention.

FIG. 5 is a yoke part of an optical pickup showing a second embodiment of the present invention, and FIG. 5A is a partial perspective view showing a modification of a restricting portion and a cut-and-raised portion formed on the yoke. FIG. 5B is a partially enlarged perspective view showing a state before assembly of the restricting portion and the cut-and-raised portion of FIG. 5A.

FIG. 6 is a partial perspective view of a yoke portion of an optical pickup according to a third embodiment of the present invention.

FIG. 7 is a partial perspective view of a yoke portion of an optical pickup according to a fourth embodiment of the present invention.

8A and 8B show a yoke portion of an optical pickup according to a fifth embodiment of the present invention. FIG. 8A is a partial perspective view, and FIG. 8B is a partial sectional view.

FIG. 9 is a perspective view showing an optical pickup of this type.

FIG. 10 is a perspective view illustrating a method of assembling a magnet to a yoke portion of this type of optical pickup.

[Explanation of symbols]

11, 31, 41, 51, 61 Yoke 13, 54, 64 Magnets 14a, 32a, 42a, 52a, 62a First flat plate portion 14b Second flat plate portion 17, 33, 43, 53, 63 Regulator 17a, 33a , 43a Cut-and-raised part (first cut-and-raised part) 17b, 33b, 43b Cut-and-raised part (second cut-and-raised part) 20 Gap part 54a, 64a Engagement part 90 Punch 100 Jig

Claims (6)

[Claims] The yoke includes a first flat plate portion and a second flat plate portion which are formed by bending a metal plate and are opposed to each other at a predetermined interval, and wherein the first flat plate portion has the second flat plate portion. A regulating portion protruding toward the portion is provided, and a magnet is attached to the regulating portion, and the regulating portion regulates a position of the magnet in a direction parallel to a surface of the first flat plate portion. Optical pickup. 2. The optical pickup according to claim 1, wherein the restricting portion is formed by cutting and raising a part of the first flat plate portion. 3. The cut-and-raised portion comprises a first cut-and-raised portion and a second cut-and-raised portion which respectively hold one opposing side surface and the other opposing side surface of the rectangular magnet. 3. The optical pickup according to 1 or 2. 4. The optical pickup according to claim 1, wherein an engaging portion is provided on the magnet, and the engaging portion is engaged with the regulating portion. 5. A gap in which a part of a punch is inserted between the two restricting portions when the yoke is bent in a U-shape between the two restricting portions. The optical pickup according to claim 1, further comprising a unit. 6. A magnet mounting method for mounting a magnet on a yoke constituting an optical pickup, wherein the yoke constitutes an optical pickup, and the magnet is mounted on the yoke. The magnet is inserted into the restricting portion and is attracted to the yoke in the attracted state, and then the magnet is separated from the jig by pulling out the jig along the yoke. Characteristic mounting method of magnet in optical pickup.