JPH11224426A - Manufacture of driving device for objective lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the manufacturing method of the driving device for an objective lens capable of accurately positioning a focusing drive coil and a tracking drive coil so that the objective lens does not incline when the focusing and tracking operations are executed. SOLUTION: When an operating part 3 for moving the lens is positioned in the focusing direction, the tracking drive coil 23 is driven to operate a lens holder part 14 for driving in the tracking direction. By this procedure, the inclination of the objective lens obtained in accordance with the detection result of a reflected light of a photodetector 72 in an inclination detector 70 is minimized by the movement of the lens movement operating part 3 in the focusing direction, then this operating part 3 for moving the lens is positioned on a base part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an objective lens drive for driving an objective lens for focusing and irradiating a light beam emitted from a light source on a disk-shaped recording medium in a focusing direction and a tracking direction in an optical pickup device or the like. More specifically, the present invention relates to a method for manufacturing an objective lens driving apparatus for driving an objective lens in a focusing direction and a tracking direction, and more particularly to a method for manufacturing an objective lens driving apparatus for positioning the objective lens.

[0002]

2. Description of the Related Art Hitherto, disk-shaped recording media such as optical disks and magneto-optical disks have been proposed, and optical pickup devices for writing and reading information signals on and from these disk-shaped recording media have been proposed.

The disk-shaped recording medium has a transparent substrate made of synthetic resin or glass, and a signal recording surface made of a magnetic material or a metal material formed on the main surface of the transparent substrate. ing.

In the optical pickup device, a light source composed of a semiconductor laser or the like and a laser beam emitted from the light source pass through the transparent substrate of the disk-shaped recording medium and converge on a signal recording surface of the disk-shaped recording medium. And an optical detector for detecting light reflected by the signal recording surface of the light beam condensed on the signal recording surface.

In the disk-shaped recording medium, the signal recording is performed by condensing and irradiating the light beam onto the signal recording surface, or by using the irradiation of the light beam together with the application of an external magnetic field. An information signal is written on the surface. In addition, in this disc-shaped recording medium, reading of the information signal written on the signal recording surface is performed by detecting a change in the amount of reflected light of the light beam applied to the signal recording surface or a change in the polarization direction. Is performed.

In the optical pickup device, the light source and the photodetector are positioned and held by the same frame serving as a base. This frame is formed of a material having sufficient rigidity such as a metal or a synthetic resin material.

In the above-described optical pickup device, it is necessary to always converge a light beam transmitted through the objective lens at a position where an information signal is written on the disc-shaped recording medium.

[0008] For example, in an optical disk as the above-mentioned disk-shaped recording medium, for example, an information signal is formed along a recording track formed in a substantially concentric spiral shape on a signal recording surface of the optical disk. Written. In response to the optical disk having such a signal recording form, the optical pickup device is moved in the radial direction of the optical disk while being opposed to the optical disk that is rotated while being held at the center portion. The information signal is written or read to or from the recording track while being moved along the recording track. In this optical pickup device, the position where the light beam is condensed by the objective lens must follow the displacement of the position of the recording track due to surface deflection and eccentricity of the optical disk.

Therefore, in the optical pickup device, the objective lens is moved in the optical axis direction of the objective lens (that is,
Focusing direction) and a direction perpendicular to the optical axis and the tangent to the recording track (ie, tracking direction).
And a lens driving mechanism, for example, a two-axis actuator for driving operation.

[0010] For example, as shown in FIG. 15, the lens driving mechanism is an objective lens 10 for converging and irradiating a laser beam emitted from a light source onto a signal recording surface of an optical disk.
2 and a lens holder 103 that is a part for holding the objective lens 102 and is supported by an elastic member or the like.

The lens driving mechanism 101 includes a pair of magnets 104 constituting a magnetic circuit for generating a magnetic field as a part for driving the lens holder 103, and a focusing for driving the lens holder 103 in the focusing direction. Drive coil 108 and tracking drive coil 10 for driving operation in the tracking direction
9.

The objective lens 102 is mounted on a lens mounting portion 103a at the front of the lens holder 103. The objective lens 102 focuses a laser beam emitted from a light source (not shown) on a signal recording surface of an optical disc and irradiates it.

The lens holder 103 has the objective lens 102 at a front portion and the focusing drive coil 108 and the tracking drive coil 1 at a rear portion.
09. The lens holder section 103 is supported by a base section by an elastic member (not shown) or the like, and is movable at least in a focusing direction and a tracking direction.

A focusing drive coil 108 provided at a rear portion of the lens holder 103 has a hollow portion 112 and is formed in a substantially rectangular cylindrical shape. For example, the focusing drive coil 108 is configured to be wound around a bobbin. As shown in FIG. 16 (a view taken from the direction of arrow K in the NN section shown in FIG. 15), the focusing drive coil 108
The axis O ₂ parallel to the optical axis direction of the objective lens 102, that is, the focusing direction (the direction of the arrow F shown in FIG. 16) coincides with the configuration.

The tracking drive coil 109 is mounted on the outer side surface of the focusing drive coil 108 in the direction in which the objective lens 102 is arranged. The tracking drive coil 109 is
It comprises a first coil 110 and a second coil 111. The first coil 110 and the second coil 1
11 are adjacent to each other, and their central axes are parallel to each other. Here, the first coil 110 and the second coil 1
11 the central axis of, as shown in FIG. 17 (M-M cross section shown in FIG. 15), in a direction perpendicular to an axis parallel O ₂ in the optical axis direction, the tangential direction of the recording track of the optical disk (Tracking direction, that is, the direction of arrow T shown in FIG. 17).
Each of the first coil 110 and the second coil 111 has a substantially rectangular cylindrical shape. Then, the first coil 110 and the second coil 111
Are wound around respective bobbin portions provided on the side surfaces of the bobbin around which the focusing drive coil 108 is wound.

As shown in FIG. 15, in the front portion of the tracking drive coil 107 configured as described above,
An open through-hole portion 113 is provided. For example, the through-hole portion 113 is formed to have a size substantially equal to the inside size of the focusing drive coil 108.

The magnet 104 is composed of a pair of magnets, a first magnet 105 and a second magnet 106, thereby constituting a magnetic circuit for forming a magnetic field. These magnets 105, 10
Numerals 6 are, for example, both formed in a rectangular plate shape, and are attached to, for example, a yoke (not shown). here,
The main surfaces of the magnets 105 and 106 facing each other serve as gap forming surfaces for forming a magnetic field.

The first magnet 105 is provided in the through hole 1.
13 and is disposed. The first magnet 105 is provided with a gap with respect to the inner surface of the through hole 113. That is, the first magnet 105 is disposed in front of the tracking drive coil 109.

The second magnet 106 is disposed so as to be inserted into a hollow portion 112 of the focusing drive coil 108. Then, the second magnet 106
Are provided with a gap to the inner surface of the focusing drive coil 108.

The first magnet 105 and the second magnet 106 are fixedly attached to the base supporting the lens holder 103 with an elastic member or the like. Therefore, the focusing drive coil 108 and the tracking drive coil 109 are in a state of being movable with respect to the first magnet 105 and the second magnet 106 fixed to the base.

Here, the focusing drive coil 108
The second magnet 106 is arranged such that when the lens holder 103 performs a tracking operation, the second magnet 106
8 so as not to come into contact with the inner surface. Specifically, the focusing drive is performed on the second magnet 106 so that the center of the second magnet 106 is located at the center of the focusing drive coil 108 when the lens holder 103 is at the neutral position in the tracking direction. The positioning of the coil 108 is performed. The positioning is performed, for example, such that equal gap intervals L ₃ and L ₄ are formed between the second magnet 106 and the focusing drive coil 108 in the tracking direction, respectively. Usually, the second magnet 106
The center in the optical axis direction is positioned so as to coincide with the center of the focusing drive coil 108.

The positional relationship between the tracking drive coil 109 and the magnets 105 and 106 is as follows: the center of the magnets 105 and 106 in the radial direction of the optical disk;
That is, the relationship is such that the intermediate position between the first coil 110 and the second coil 111 matches. That is, as shown in FIG. 17, the center of the magnets 105 and 106 and the intermediate position between the first coil 110 and the second coil 111 of the tracking drive coil 109 coincide with the axis O ₂ shown in the figure. ing.

The above-described lens drive mechanism 101 drives the focusing drive coil 108 and the tracking drive coil 109 by using the magnetic field formed by the magnets 105 and 106 constituting the magnetic circuit, thereby providing a lens holder. The unit 103 is driven in the focusing direction and the tracking direction.

Here, when driving the lens holder 103 in the focusing direction, the lens driving mechanism 101 supplies a current to the focusing driving coil 108,
The focusing drive coil 108 is connected to the magnet 10
5, 106 are driven in the focusing direction. Thus, the lens holder 103 is driven in the focusing direction.

When driving the lens holder 103 in the tracking direction, the lens driving mechanism 101 supplies a current to the tracking driving coil 109, and magnets 105 and 106 of the tracking driving coil 109.
Is driven in the tracking direction. As a result, the lens holder 103 is driven in the tracking direction.

As described above, the lens driving mechanism 101 can drive the lens holder 103 in the focusing direction and the tracking direction so that the objective lens 10 mounted on the lens holder 103 can be driven.
As described above, the focal position of the laser beam by the laser beam 2 can follow the displacement of the position of the recording track due to the surface deflection and eccentricity of the optical disk.

[0027]

By the way, conventionally,
The positioning of the lens holder 103 was performed visually. For example, the lens holder 103 is positioned and attached to the base, and at the time of attachment, the lens holder 103 is attached to the magnets 105 and 106 attached to the base. Focusing drive coil 108 and tracking drive coil 10
9 is positioned with respect to the base part by positioning. That is, for example, the gaps L ₃ and L ₄ are visually determined and the second magnet 106 is positioned in the focusing drive coil 108. Such visual positioning has a limitation in positioning accuracy.

In the conventional case where information signals are recorded and reproduced at a normal recording density, there is no problem simply by visual positioning as described above, but information signals are recorded and reproduced at a high recording density. In such a case, positioning accuracy is required. In the case of visual positioning, the positioning accuracy is low, which causes a problem that the information signal to be recorded and reproduced is deteriorated.

Specifically, when the positioning is performed visually, as shown in FIG. 18A, the focusing drive coil 108 is shifted in the tracking direction with respect to the second magnet 106 (FIG. 18A). Arrow X)
Direction) in some cases. FIG.
8A to 18C and FIG. 19A described later.
Arrows H that are perpendicular to the plane of the drawing shown in FIG. 19C indicate the direction of the magnetic field generated between the first magnet 105 and the second magnet 106.

When the focusing drive coil 108 is driven as it is from the state where the focusing drive coil 108 is displaced in the tracking direction with respect to the second magnet 106, as shown in FIG. driving force f ₁ of the focusing drive coil 108 is generated in the portion facing the major surface 106a of the second magnet 106. Further, the driving force is in the same direction as the driving force f _1, and the main surface portion 106 of the second magnet 106
also the driving force f ₂ is generated in the portion which is not opposed to a.
However, since the driving force f ₁ is larger than the driving force f ₂ , a rotational moment M ₁ is generated in the focusing drive coil 108.

That is, when the focusing drive coil 108 is driven from the state shifted in the tracking direction, a position that is not the position of the center of gravity of the focusing drive coil 108, that is, the position opposite to the tracking direction shifted from the position of the center of gravity. driving force f ₁ on the shift position is generated, the rotational moment M ₁ is generated for it.

When the rotational moment M ₁ is generated as described above, the focusing drive coil 108 is moved to the position shown in FIG.
As shown in (c), the second magnet 106 is inclined. Thereby, the objective lens 102
Is inclined with respect to the optical axis in the initial state.

Further, when the tracking operation is performed, a rotational moment may be generated in the tracking drive coil 109 in the same manner as described above. That is, for example,
As shown in FIG. 19A, the magnets 105 and 106
In this case, the tracking drive coil 109 is driven in a state where the tracking drive coil 109 is shifted in the focusing direction.

Specifically, as shown in FIG.
When the tracking drive coil 109 is directly driven from the state where the tracking drive coil 109 is shifted in the focusing direction with respect to the magnets 105 and 106, that is, for example, the first coil 110 and the second coil 110 are driven.
The arrow D ₁ shown in FIG.
D. Apply a current in the direction ₂ to drive the tracking drive coil 1
09 is driven, the tracking drive coil 109 is driven.
, A rotational moment M ₂ is generated.

That is, when the first coil 110 and the second coil 111 are formed in a substantially rectangular cylindrical shape as described above, when a current is supplied to the first coil 110 and the second coil 111, As shown in FIG. 19B, each wire bundle portion 11 forming the first coil 110
0a, 110b, 110c, the driving force _{f 11, f 12, f 13} , f 14 in 110d is generated, the second coil 111
, The bundle portions 111a, 111b, 111c,
Each driving force _{f 21, f 22, f 23} , f 24 is generated in the 111d. As described above, since the tracking drive coil 109 is displaced in the focusing direction with respect to the second magnet 106, the flux bundle portion 110a facing the main surface portion 106a of the second magnet 106
Generated in the main surface portion 1 of the flux portion 110c (magnet 106 in which the driving force f ₁₁ is opposed to the flux portion 110a
It becomes larger than the driving force f ₁₂ generated in the flux portion) which is located at the edge portion of the 06a. On the other hand, the first coil 11
0 and the bundle portion adjacent to the second coil 111, that is, the bundle portion 110b of the first coil 110
Driving force f ₁₂ to the tracking direction is generated in the flux portion 111d of the second coil 111 which is opposite to the first coil 110 of Toko.

As described above, the rotational moment M ₂ is generated in the tracking drive coil 109 mainly due to the generation of the driving forces f ₁₁ and f ₁₂ .

As described above, when the rotation moment M ₂ is generated, the tracking drive coil 109 is moved to the position shown in FIG.
As shown in (c), the state is inclined with respect to the magnets 105 and 106. Therefore, the objective lens 102 is inclined with respect to the optical axis in the initial state.

As described above, the magnets 105 and 106
On the other hand, when the focusing drive coil 108 and the tracking drive coil 109 are driven while the focusing drive coil 108 and the tracking drive coil 109 are shifted, the focusing drive coil 108 and the tracking drive coil 109 are attached to the magnets 105 and 106. Accordingly, the objective lens 102 is inclined with respect to the optical axis in the initial state.

As described above, the objective lens 102 with respect to the optical axis
If it is inclined, the desired focusing operation and tracking operation cannot be performed, and even if the information signal is recorded and reproduced on the optical disc, the recorded and reproduced information signal is deteriorated. It will be something.

Therefore, the present invention has been made in view of the above-mentioned circumstances, and a focusing drive coil and a tracking drive coil are provided so that an objective lens does not tilt when performing a focusing operation and a tracking operation. It is an object of the present invention to provide a method of manufacturing an objective lens driving device capable of accurately positioning.

[0041]

According to the present invention, there is provided a method of manufacturing an objective lens driving device, the method comprising:
A movable section having an objective lens and a drive coil for condensing a light beam from a light source on a signal recording surface of an optical recording medium, and moving the movable section in a tracking direction and a focusing direction perpendicular to the tracking direction via an elastic member. A method for manufacturing an objective lens driving device in which a lens moving operation unit having a fixed member that is supported so as to be positioned and attached to a base having a magnetic circuit that forms a magnetic field used for driving a driving coil is mounted.

The method of manufacturing the objective lens driving device includes the steps of: reflecting a mirror attached to the objective lens; a light source for irradiating the objective lens with light; and a light from the light source transmitted through the objective lens and reflected by the reflection mirror. The lens movement operation unit is positioned with respect to the base by using an objective lens inclination detecting means including a reflected light detecting means for detecting the reflected light.

That is, in the manufacturing method of the objective lens driving device, the driving coil is driven to drive the movable portion in the tracking direction, so that the objective lens tilt detecting device detects the reflected light by the reflected light detecting device. The tilt of the obtained objective lens is minimized by moving the lens moving operation unit in the focusing direction, and the reflected light is detected by the objective lens tilt detection unit by driving the drive coil to drive the movable unit in the focusing direction. The tilt of the objective lens obtained based on the detection result of the reflected light of the means is minimized by moving the lens movement operation unit in the tracking direction, and the lens movement operation unit is positioned with respect to the base.

Accordingly, when the lens moving operation unit is displaced in the focusing direction with respect to the base, the lens moving operation unit is moved in the focusing direction based on the detection of the inclination of the objective lens obtained by driving the movable unit in the tracking direction. If the lens moving operation unit is shifted in the tracking direction with respect to the base, the lens moving operation unit is moved based on the detection of the inclination of the objective lens obtained by driving the movable unit in the focusing direction. Correct the deviation in the tracking direction.

According to the method of manufacturing the objective lens driving device, there is provided an objective lens driving device in which the objective lens does not tilt when the objective lens is driven in the tracking direction and the focusing direction.

[0046]

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, a method of manufacturing an objective lens driving device according to the present invention is applied to a lens driving mechanism manufactured by positioning a lens moving operation unit that movably supports an objective lens.

The lens drive mechanism is mounted on an optical pickup device for writing and reading information signals to and from an optical disk which is a disc-shaped recording medium, and causes a laser beam irradiated on the optical disk to follow the optical disk. It is.

Here, the optical pickup device is provided in a disk drive device or the like, and irradiates a laser beam to the optical disk mounted on the disk drive device to write and read information signals to and from the optical disk. As the optical disk, a so-called magneto-optical disk capable of writing and reading information signals and a type capable of reading information signals only are used.

The optical pickup device irradiates the optical disk with a laser beam emitted from a light source through an objective lens to write and read information signals on a signal recording surface of the optical disk. Therefore, the optical pickup device includes a lens driving mechanism that follows the objective lens with respect to the signal recording surface of the optical disc, that is, performs focusing and tracking.

As shown in FIG. 1, the lens driving mechanism 1
An objective lens 2 for condensing a light beam emitted from a light source (not shown) on a signal recording surface of an optical disk and irradiating the light beam; a lens moving operation unit 3 for moving the objective lens 2 in a focusing direction and a tracking direction; Yoke 5 for driving drive coils 23 and 26 of section 3
2 and 53 and a substrate part 4 having a magnet 5 and constituting a base part.

In the lens driving mechanism 1, the objective lens 2 and the driving coils 23 and 26 constitute a lens holder 14 which is a movable part.
Are leaf spring members 15, 16, 17, 18 which are elastic members.
Thus, it is movably supported by the base.

In the lens driving mechanism 1, the yokes 52, 53 and the magnet 5 constitute a magnetic circuit for generating a magnetic field for driving the driving coils 23, 26. In the magnetic circuit, the main surface of the magnet 5 opposed to the magnetic circuit is a gap forming surface for forming a magnetic field.

The lens driving mechanism 1 is a part of the base unit, and the substrate unit 4 is mounted on a light source block on which a light source and the like are mounted. For example, the light source is a laser coupler,
The laser beam is emitted to the objective lens 2 supported by the lens moving operation unit 3 of the lens driving mechanism 1.

The objective lens 2 has a lens driving mechanism 1 such that the optical axis is perpendicular to the signal recording surface of the optical disk.
Supported by The objective lens 2 focuses and irradiates the incident laser beam from the light source onto the signal recording surface of the optical disc.

The lens moving operation section 3 supporting the objective lens 2 includes a fixed section 13 which is positioned and attached to the substrate section 4, a leaf spring member 15 which is an elastic member with respect to the fixed section 13, And a lens holder portion 14 movably supported by 16, 17, and 18.

The lens holder section 14 is formed in a substantially frame shape, and an objective lens attaching section 20 to which the objective lens 2 is attached is provided at a front portion. Further, a bobbin 19 around which a focusing drive coil 26 and a tracking drive coil 23 are wound is attached to a rear portion of the lens holder portion 14. Also,
The leaf spring members 15, 16, 17, 18 are attached to both side surfaces of the lens holder 14. For example, the lens holder 14 is formed of a synthetic resin material or the like.

The objective lens mounting section 20 is provided with a lens mounting hole 20a having an inner diameter equivalent to the outer diameter of the objective lens 2. That is, the objective lens mounting section 20 has an objective lens mounting hole 20a.
The objective lens 2 is fitted so as to fit.

The lens holder portion 14 is elastically attached to the fixed portion 13 via a pair of leaf spring members 15 and 16 and leaf spring members 17 and 18 which are elastic members attached to both side portions. Supported.

These leaf spring members 15, 16, 17, 18
Is made of a metal material having appropriate elasticity such as phosphor bronze,
It is integrally formed in a thin and elongated plate shape.

Each of the leaf spring members 15, 16, 17, 18
The distal end portion is connected to the lens holder portion 14, and the proximal end portion is connected to the fixing portion 13.

Each of the leaf spring members 15, 16, 17, 18
Are linear portions extending from the distal end portion to the proximal end portion, and the crank portions 15a, 16 at the proximal end portion.
a, 17a and 18a.

The linear portions of the leaf spring members 15, 16, 17, 18 are substantially parallel to each other, and support the lens holder 14 so as to be displaceable with respect to the base.

Each of the crank portions 15a, 16a, 17
a and 18a are formed to have two 90 ° bent portions in mutually opposite directions.

These leaf spring members 15, 16, 17, 18
In the above, the base end portion of the straight portion and the tip end portions of the crank portions 15a, 16a, 17a, 18a are connected to each other via a wide connecting plate portion.

Further, these leaf spring members 15, 16, 1
7 and 18, the crank portions 15a, 16
a, 17a, 18a so as to surround both sides of the base end side and the halfway part, and each of the displacement regulating pieces 15b, 16b, 17b,
18b is provided. Each of these displacement restricting pieces 15
b, 16b, 17b, 18b and each of the crank portions 15
In the natural state in which the crank portions 15a, 16a, 17a, and 18a are not displaced, the edges are separated from each other. Also,
Each of the crank portions 15a, 16a, 17a, 18a
Each of the leaf spring members 15, 16, 17, and 18 is formed to be thinner (narrower) than the linear portion.

The base portion of the leaf spring members 15, 16, 17, 18 is attached to the fixing portion 13, which elastically supports the lens holder portion 14 by the leaf spring members 15, 16, 17, 18. It comprises a block portion 22 and a fixing plate 21 on which the block portion 22 is placed and which is a portion to be attached to the substrate portion 4.

The block portion 22 is formed in a substantially rectangular box shape.
The leaf spring members 15, 16, 17, 18 are attached. The block portion 22 is formed of, for example, a synthetic resin material or the like.

The fixed plate 21 is formed in a substantially rectangular plate shape, and positioning mounting portions 21a and 21b integrated with the fixed plate 21 are provided upright on both side ends. The positioning mounting portions 21a, 21 of the fixing plate 21
b is a portion that is attached to the positioning attachment portions 54 and 55 that are erected integrally with the substrate portion 4 behind the substrate portion 4.

Specifically, the dimension between the outer side surfaces of the positioning mounting portion 21a and the positioning mounting portion 21b of the fixing plate 21 is determined by the positioning mounting portion 54 of the substrate portion 4.
And a dimension between the inner side surface of the positioning attachment portion 55. Thereby, when attaching the lens moving operation unit 3 to the substrate unit 4, the fixing plate 21 is inserted between the positioning attachment unit 54 and the positioning attachment unit 55 of the substrate unit 4, The lens moving operation unit 3 is placed on the camera. Here, as described above, the fixing plate 2
The distance between the outer side surfaces of the positioning mounting portions 21a and 21b of the first mounting portion is determined by the positioning mounting portions 54 and 55 of the substrate portion 4.
And a margin is provided between the outer side surfaces of the positioning attachment portions 21a and 21b of the fixed plate 21 and the inner side surfaces of the positioning attachment portions 54 and 55 of the substrate portion 4. The proper positioning of the lens movement operation unit 3 with respect to the substrate unit 4 becomes possible by that much. The fixing of the lens moving operation unit 3 to the substrate unit 4, that is, the fixing of the fixing unit 13 to the substrate unit 4 is performed by the fixing plate 21.
The positioning mounting portions 21a and 21b are bonded to the positioning mounting portions 21a and 21b of the substrate unit 4.

The positioning performed here is performed by applying the manufacturing method of the objective lens driving device according to the present invention, and will be specifically described later.

Incidentally, for example, the block portion 22 of the lens holder portion 14 and the fixing portion 13 and the leaf spring members 15, 16, 1
7 and 18 means that the tip side portions of the leaf spring members 15, 16, 17 and 18 are inside the lens holder portion 14 and the leaf spring members 15, 16 and 17 by so-called outsert molding. , 18 are connected to each other while being buried inside the fixed block 13.

The above-described leaf spring members 15, 16, 17, 18
The lens holder 14 elastically supported by
As described above, the bobbin 19 is attached.

The bobbin 19 is formed in a substantially square cylindrical shape having a hollow portion 33 whose upper side and lower side are open.
The bobbin 19 is fitted into a through hole provided substantially at the center of the lens holder 14, and is fixed to the lens holder 14 by, for example, an adhesive. The bobbin 19 is provided with bobbins 24 and 25 for the tracking drive coil 23 on the side surface in the forward direction.

The bobbin 19 is provided with a focusing drive coil 26 and a tracking drive coil 23 which serve as drive coils.

The focusing drive coil 26 is wound around the side surface (outer periphery) of the bobbin 19, and the center axis of the coil is parallel to the optical axis of the objective lens 21 in the initial state. .

The tracking drive coil 23 is
And a second coil 25 adjacent to the first coil part 24. Coil section 2
4 and 25 are wound around bobbins 31 and 32 for a tracking drive coil formed on the front side surface of the bobbin 19, respectively. In the first coil section 24 and the second coil section 25, the center axes of the coils are parallel to each other, and the center axes are orthogonal to the optical axis of the objective lens 2 in the initial state. It has been.

The focusing drive coil 26 and the tracking drive coil 23 are connected to a terminal portion (not shown) provided on the rear side of the bobbin 19 with the lead wire at the beginning and end of winding. These terminal portions are connected to connection terminals provided on a terminal plate embedded in the lens holder portion 14 by soldering or the like. Thereby, each driving current is supplied to the focusing drive coil 26 and the tracking drive coil 23 via the terminal plate.

As described above, the focusing drive coil 2
The bobbin 19 to which the tracking drive coil 6 and the tracking drive coil 23 are attached is fitted and attached to the lens holder 14 as described above. Here, the lens holder portion 14 is provided with a through-hole portion 34 between the lens mounting portion 20 and the bobbin 19. That is, the lens holder 14
Is provided with a through-hole portion 34 located in the front direction of the tracking drive coil 23 to which the bobbin 19 is attached.

A pair of front and rear yokes 52 and 53 formed in a substantially rectangular plate shape constituting a magnetic circuit are provided on the substrate portion 4.
Are erected integrally with the substrate portion 4.
Here, the substrate section 4 and the yokes 52 and 53 are formed of a magnetic material (high magnetic permeability material) such as iron. The yokes 52 and 53 of the substrate section 4 are provided with a pair of substantially square plate-shaped magnets 5 on the inner side surfaces facing each other. That is, the first magnet 11 and the second magnet 1 whose main surfaces are opposed to each other are provided on inner surfaces of the yokes 52 and 53 erected on the substrate portion 4 facing each other.
2 are installed.

The yokes 52, 53 thus arranged,
The magnets 11 and 12 form a magnetic circuit that generates a magnetic field. In this magnetic circuit, the opposing main surfaces 11a and 11b of the first magnet 11 and the second magnet 12 form a gap forming surface for forming a magnetic field.

The front yoke 52 is inserted from below into the through hole 34 provided at the center position of the lens holder 14 and is located on the front side of the bobbin 19, that is, each of the tracking drives. It is arranged on the front side of the coil 23. The rear yoke 53 is inserted into the hollow portion 33 of the bobbin 19 from below, and is disposed so as to be located substantially at the center of the tracking drive coil 26.

As described above, the yoke 52 is positioned in the through hole 34 of the lens holder 14 and the yoke 53
Is located in the hollow portion 33 in the bobbin 19, so that the first magnet 11 is arranged to face the tracking drive coil 24, and the second magnet 12 is arranged in the focusing drive coil 26. Will be done.

The focusing drive coil 26 and the tracking drive coil 23 thus arranged are located in the magnetic field formed by the magnetic circuit constituted by the yokes 52, 53 and the magnets 11, 12. That is, in the magnetic circuit, a part of the focusing drive coil 26 and the tracking are performed in a magnetic field formed between the opposing main surfaces of the first magnet 11 and the second magnet 12, that is, between the gap forming surfaces. A drive coil 23 is provided.

The substrate section 4 is mounted on the optical block to which the light source is attached as described above. The light source block is formed of a material having sufficient rigidity, such as, for example, aluminum die-cast or a composite material of glass fiber and a synthetic resin. The light source is positioned and held in the light source block. The optical pickup device emits a laser beam emitted from a light source held by the light source block toward an objective lens 2 supported by a lens driving mechanism 1 mounted on the light source block. Then, the optical pickup device 1 focuses the laser beam on the signal recording surface of the optical disc by the objective lens 2 and irradiates the laser beam.

The above is the description of the configuration of the lens driving device 1. In the lens driving mechanism 1, the objective lens 2 is orthogonal to the optical axis direction of the objective lens 2, that is, the tracking direction (arrow F direction shown in FIG. 1) and the tangent line of the optical axis and the recording track of the optical disk. In this case, it is movably supported in two directions, that is, a tracking direction (the direction of arrow T shown in FIG. 1). The objective lens 2 supported by the lens driving mechanism 1 so as to be movable in the two directions includes the driving coils 2
The magnets 3 and 26 are driven in the two directions by the magnetic force generated between the magnets 11 and 12.

The driving operation of the objective lens 2 by the lens driving mechanism 1 is an operation for causing the objective lens 2 to follow the displacement of the optical disk. Thereby, the optical pickup device can always focus the light beam transmitted through the objective lens 2 to the position where the information signal is written on the signal recording surface of the optical disk.

Here, for example, the optical disk is a so-called magneto-optical disk capable of writing and reading information signals and a type capable of reading information signals only.

The magneto-optical disk is made of polycarbonate (P
It has a disk-shaped transparent substrate made of a synthetic resin or glass as in C), and a signal recording surface made of a magnetic material adhered and formed on the main surface of the transparent substrate. In this magneto-optical disk, a laser beam is focused and irradiated on the signal recording surface to locally heat the magnetic material forming the signal recording surface to a Curie temperature or higher, and an external magnetic field is applied to the heated portion. By applying the information, an information signal is written. In the magneto-optical disk, the signal recording surface is irradiated with a laser beam, and the change in the polarization direction of the laser beam reflected by the signal recording surface is detected, whereby the signal is written on the signal recording surface. An information signal can be read.

An optical disk capable of only reading information signals has a disk-shaped transparent substrate made of a synthetic resin such as polycarbonate (PC), and is formed on the main surface (signal recording surface) of the transparent substrate. Information signals are recorded by pits, and a reflective film made of a metal material such as aluminum is formed on the main surface of the transparent substrate on which the pits are formed. In an optical disc, the reflection film serves as a signal recording surface. In an optical disc, the signal recording surface is irradiated with a laser beam, and the information signal written on the signal recording surface is read by detecting a change in the amount of light reflected by the signal recording surface of the laser beam. It can be carried out.

At the center of these optical disks (including the above-mentioned magneto-optical disks), a chucking hole for positioning and holding the optical disks is provided.

This optical disk is mounted on a disk drive device of an optical pickup device and rotated. Hereinafter, an outline of the disk drive device will be described.

The disk drive device positions and holds an optical disk on a disk table constituting a rotary operation mechanism. The disk table is formed in a disk shape,
The central part is attached to the drive shaft of the spindle motor of the disk drive. A centering projection having a substantially frustoconical shape is provided at the center of the upper surface of the disk table. When the center portion of the optical disk is placed on the disk table, the disk table centers and holds the optical disk by fitting the centering protrusions into the chucking holes. Then, the disk drive device rotates the optical disk held on the disk table by the spindle motor.

The optical pickup device is opposed to an optical disk held on the disk table and rotated by the spindle motor, and is moved in a radial direction of the optical disk by a moving means, whereby the optical pickup device is moved. The information signal is written to and read from the recording track while being moved along the recording track as a relative position to the recording track. Therefore, the optical pickup device is provided with the objective lens 2
Must be made to follow the displacement of the position of the recording track due to surface deflection and eccentricity of the optical disk. For this purpose, the lens driving mechanism 1 drives the objective lens 2 in the focusing direction and the tracking direction.

The lens drive mechanism 1 drives the lens holder 14 in the focusing direction by supplying a focusing drive current to the focusing drive coil 26. Specifically, the lens drive mechanism 1 supplies a drive current to the focusing drive coil 26, and drives the lens holder 14 in the focusing direction by the interaction between the drive current and the magnetic field formed by the magnetic circuit. .

The lens driving mechanism 1 supplies the tracking drive current to the tracking drive coil 23 to drive the lens holder 14 in the tracking direction. Specifically, the lens drive mechanism 1 supplies a drive current to the tracking drive coil 23, and drives the lens holder 14 in the tracking direction by an interaction between the drive current and a magnetic field formed by the magnetic circuit. .

For example, the driving current for focusing and the driving current for tracking are error signals (a focusing error signal and a tracking error signal) indicating a shift amount between the focus position of the laser beam by the objective lens 2 and the recording track. The signal is supplied to the lens driving mechanism 1 based on the signal. Therefore, this lens driving mechanism 1
Means that the objective lens 21 is periodically driven in synchronization with the rotation cycle of the optical disk.

A method for positioning the lens moving operation unit 3 in the lens driving mechanism 1 with respect to the substrate unit 4 on the base unit by applying the manufacturing method of the objective lens driving device according to the present invention will be described below.

The lens moving operation unit 3 and the substrate unit 4 are arranged as shown in FIG.
As shown in FIG. 5 to FIG. The lens moving operation unit 3 thus separated is placed on the substrate unit 4 as shown in FIGS. At this time, the lens moving operation unit 3
The substrate 1 is placed on the substrate unit 4 so as to be inserted between the positioning attachment parts 54 and 55 of the substrate unit 4. In addition, this mounting allows the focusing drive coil 26
Inside, that is, inside the hollow portion 33 of the bobbin 19, the second magnet 12 is arranged, and the first magnet 11 is arranged inside the through-hole portion 34 provided in front of the tracking drive coil 23. .

The lens driving mechanism 1 with the lens moving operation unit 3 placed on the substrate unit 4 performs the positioning adjustment by the inclination detecting device 70 shown in FIG.

The tilt detecting device 70 is configured to converge and irradiate a laser beam onto the objective lens 2 attached to the lens driving mechanism 1 provided for the tilt detecting device 70. ing.

Further, in this state, a reflection mirror 71 is mounted on the objective lens 2. here,
The reflection mirror 71 is mounted on the objective lens 2 such that the laser beam is condensed by the tilt detection device 70 and is incident on the reflection mirror 71 via the objective lens 2. That is, the tilt detecting device 70 is disposed so that the reflection mirror 71 is located in a direction facing the objective lens 2.

With this configuration, the light beam condensed from the inclination detecting device 70 is incident on the reflection mirror 71 via the objective lens 2. Then, the laser beam that has entered the reflection mirror 71 passes through the objective lens 2 as a reflected light beam, and is received by the tilt detection device 70.

The inclination detecting device 70 reflects the laser beam emitted from the light emitting element 75 toward the objective lens 2 as a light emitting element 75 as a light source for emitting the laser beam.
A beam splitter 73 for transmitting a reflected light beam emitted from the inclination detecting device 70 and reflected by the reflection mirror 71 to a photodetector 72; and a beam splitter 7
The condenser lens unit 74 receives the laser beam from the light emitting element 75 via the light emitting element 3 and the photodetector 72 converts the incident light into an electric signal and outputs the electric signal.

Here, the condenser lens section 74 is composed of a first lens 74a and a second lens 74b.
The laser beam from the light emitting element 75 incident through the beam splitter 73 is condensed and irradiated on the objective lens 2.

The photodetector 72 has a light receiving section 76 composed of two light receiving areas 76a and 76b as shown in FIGS. 9 (a) to 9 (c) and FIG. I have. Then, the light receiving areas 76a and 76a of the light receiving section 76
6b indicates a tracking direction (arrow T shown in FIG. 10).
Direction). Note that FIG.
FIGS. 9A to 9C show the positional relationship between the light receiving areas 76a and 76b and the reflection mirror 71 that is optically expressed.

Then, the light receiving area 76a and the light receiving area 76b
The electric signals output from the above are connected to a light receiving amount comparing unit (not shown) that compares the electric signals to compare the light receiving amounts in the light receiving regions 76a and 76b.

Hereinafter, the lens moving operation unit 3 for the substrate unit 4 performed by using the tilt detecting device 70 configured as described above.
Will be described.

First, as shown in FIGS. 11 and 12, the lens moving operation unit 3 is mounted on the substrate unit 4. That is, the fixing plate 21 of the fixing unit 3 of the lens moving operation unit 3 is disposed between the positioning mounting unit 54 and the positioning mounting unit 55 of the substrate unit 4.

Here, for example, as shown in FIG. 9 (a), the fixed plate 21 is moved so that the optical axis of the reflected light beam r reflected from the reflecting mirror 71 is located at the boundary between the light receiving areas 76a and 76b. It is arranged between the positioning mounting part 54 and the positioning mounting part 55.

In this state, the lens holder 14 of the lens moving operation unit 3 is driven in the tracking direction (the direction of arrow T shown in FIG. 6).

By the way, conventionally, the magnets 11, 1
When the tracking drive coil 23 is driven with the tracking drive coil 23 shifted in the focusing direction with respect to the tracking drive coil 2,
3 is inclined with respect to the magnets 11 and 12. As a result, the lens holder 4 is tilted, and the objective lens 2 is also tilted. Specifically, the tilt of the objective lens 2 is a tilt in the tracking direction with respect to the optical axis in the initial state.

Therefore, when the tracking drive coil 23 is driven with the tracking drive coil 23 deviated in the focusing direction with respect to the magnets 11 and 12, as shown in FIG. 9B or FIG. ,
The light beam r reflected from the reflection mirror 71 is transmitted to the light receiving area 76a,
The light is received with a bias toward any one of 76b. At this time, the comparison result output from the light receiving amount comparing means indicates a result of the reflected light flux r being received unbalanced in the light receiving areas 76a and 76b.

On the other hand, in a case where the tracking drive coil 23 is not displaced with respect to the magnets 11 and 12 in the focusing direction, when the tracking drive coil 23 is driven, as shown in FIG.
The light beam r reflected from the reflection mirror 71 is transmitted to the light receiving area 76a,
Light is received such that its optical axis is located at the boundary of 76b.

Therefore, by driving the tracking drive coil 23, the fixing plate 21 of the lens moving operation unit 3 is moved so that the optical axis of the reflected light beam r is positioned at the boundary between the light receiving regions 76a and 76b. By disposing between the positioning mounting part 54 and the positioning mounting part 55,
It is possible to prevent the tracking drive coil 23 from being positioned in the focusing direction with respect to the magnets 11 and 12. That is, when the tracking operation is performed by the lens holder unit 14, the inclination of the objective lens 2 due to the tracking operation can be prevented.

Specifically, the process up to the positioning is performed as shown in FIG. 11 based on the comparison result of the received light amount in the light receiving region 76 and the light receiving region 76b output from the received light amount comparing means. The position of the fixed plate 21 is shifted in the focusing direction between the mounting portion 54 and the positioning mounting portion 55, that is, the entire lens moving operation portion 3 is shifted in the focusing direction with respect to the substrate portion 4 to adjust the position. . As a result, the position can be appropriately adjusted while referring to the comparison result from the light reception amount comparison unit.

Further, in the same manner as above, the magnet 1
It is also possible to prevent the focusing drive coil 26 from being positioned with respect to 1 and 12 while being shifted in the tracking direction. That is, the magnets 11 and 1
By driving the focusing drive coil 26 while the focusing drive coil 26 is displaced in the tracking direction with respect to 2, the tilting of the objective lens 2 can also be prevented.

That is, conventionally, the magnets 11, 1
If the focusing drive coil 26 is driven in a state where the focusing drive coil 26 is displaced in the tracking direction with respect to 2, the focusing drive coil 26 is inclined with respect to the magnets 11 and 12. As a result, the lens holder 4 is tilted, and the objective lens 2 is also tilted.
Specifically, the tilt of the objective lens 2 is a tilt in the tracking direction with respect to the optical axis in the initial state.

Therefore, while the focusing drive coil 26 is shifted in the tracking direction with respect to the magnets 11 and 12, the focusing drive coil 26
Is driven, as shown in FIG. 9B or FIG. 9C (the light receiving state before the driving of the focusing drive coil 26 is the same as that at the time of positioning the tracking drive coil 23, as shown in FIG. (A). The light beam r reflected from the reflection mirror 71 is received with a bias toward one of the light receiving regions 76a and 76b.

On the other hand, in a case where the focusing drive coil 26 is not displaced with respect to the magnets 11 and 12 in the tracking direction, when the focusing drive coil 26 is driven, as shown in FIG. Is reflected by the light receiving area 76.
Light is received such that its optical axis is located at the boundary between a and b.

Therefore, by driving the focusing drive coil 26, the fixing plate 21 of the lens moving operation unit 3 is moved to the position of the substrate unit 4 so that the optical axis of the reflected light beam r is positioned at the boundary between the light receiving regions 76a and 76b. By disposing between the positioning mounting portion 54 and the positioning mounting portion 55, it is possible to prevent the focusing drive coil 26 from being displaced in the tracking direction with respect to the magnets 11 and 12 and positioned. . That is,
When the focusing operation is performed by the lens holder unit 14, it is possible to prevent the objective lens 2 from being tilted due to the focusing operation.

In the process up to the positioning, specifically, as in the case of the above-described positioning of the tracking drive coil 23, the comparison of the amount of light received in the light receiving region 76 and the light receiving region 76b output from the light receiving amount comparing means is performed. Based on the result, as shown in FIG.
The position of the fixed plate 21 is shifted in the tracking direction between the positioning unit 55 and the positioning attachment unit 55, that is, the position of the entire lens movement operation unit 3 is shifted in the tracking direction with respect to the substrate unit 4. As a result, the position can be appropriately adjusted while referring to the comparison result from the light reception amount comparison unit.

As described above, by positioning the lens moving operation unit 3 with respect to the substrate unit 4 using the tilt detection device 70, the objective lens 2 is prevented from tilting during focusing and tracking. Focusing drive coil 26 and tracking drive coil 2
3 can be accurately positioned.

After being positioned in this manner, as shown in FIGS. 13 and 14, the positioning mounting portions 21a and 21b of the fixing plate 21 of the lens moving operation portion 3 and the positioning mounting portions 54 and 55 of the substrate portion 4 are provided. Are bonded by an adhesive 80 or the like, so that only the lens holder 14 of the lens moving operation unit 3 is movably supported with respect to the substrate 4. That is, the fixing portion 13 of the lens moving operation portion 3 is fixed to the substrate portion 4, and the lens holder portion 14 elastically supported by the leaf spring members 15, 16, 17, 18 with respect to the fixing portion 13, The unit 4 is supported movably at least in the focusing direction and the tracking direction.

Therefore, with the focusing drive coil 26 and the tracking drive coil 23 deviated from the magnets 11 and 12, the lens movement operation unit 3
Can be prevented from being positioned with respect to the substrate unit 4.

As a result, the lens moving operation unit 3 can be optically positioned with respect to the substrate unit 4, that is, the positioning between the drive coil and the magnet constituting the magnetic circuit can be performed without visual observation. The accuracy of the positioning can be improved.

Therefore, according to the positioning to which the manufacturing method of the objective lens driving device according to the present invention is applied, it is possible to prevent the deterioration of the information signal to be recorded and reproduced by increasing the positioning accuracy.

[0127]

According to the method of manufacturing an objective lens driving device of the present invention, a movable portion having an objective lens and a drive coil for condensing a light beam from a light source on a signal recording surface of an optical recording medium, and an elastic member are provided. A lens moving operation unit including a fixed member that movably supports the movable unit in a tracking direction and a focusing direction perpendicular to the tracking direction via a base having a magnetic circuit that forms a magnetic field used for driving a drive coil. This is a method for manufacturing an objective lens driving device that is positioned and mounted with respect to the objective lens driving device.

In the method of manufacturing the objective lens driving device, the driving coil is driven to drive the movable part in the tracking direction, so that the objective lens tilt detecting means detects the reflected light by the reflected light detecting means. The tilt of the obtained objective lens is minimized by moving the lens moving operation unit in the focusing direction, and the reflected light is detected by the objective lens tilt detection unit by driving the driving coil to drive the movable unit in the focusing direction. The tilt of the objective lens obtained based on the detection result of the reflected light of the means is minimized by moving the lens movement operation unit in the tracking direction, and the lens movement operation unit is positioned with respect to the base.

Accordingly, when the lens moving operation unit is displaced in the focusing direction with respect to the base, the lens moving operation unit moves in the focusing direction based on the detection of the inclination of the objective lens obtained by driving the movable unit in the tracking direction. Can be corrected, and when the lens movement operation part is displaced in the tracking direction with respect to the base, the inclination of the objective lens obtained by driving the movable part in the focusing direction can be detected. Based on this, the deviation in the tracking direction can be corrected.

Therefore, the method for manufacturing an objective lens driving device can provide an objective lens driving device positioned so that the objective lens does not tilt when focusing and tracking are performed.

Further, according to the method of manufacturing the objective lens driving device, the positioning between the drive coil and the magnet constituting the magnetic circuit can be performed without visual observation, so that the accuracy of the positioning can be improved.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a lens driving mechanism adjusted by a method of manufacturing a lens driving mechanism according to an embodiment of the present invention.

FIG. 2 is a plan view showing a lens moving operation unit provided in the lens driving mechanism.

FIG. 3 is a side view showing a lens moving operation unit provided in the lens driving mechanism.

FIG. 4 is a plan view showing a substrate unit provided in the lens driving mechanism.

FIG. 5 is a side view showing a substrate unit provided in the lens driving mechanism.

FIG. 6 is a plan view showing a state where the lens moving operation unit is mounted on the substrate unit.

FIG. 7 is a side view showing a state where the lens moving operation unit is mounted on the substrate unit.

FIG. 8 is a side view showing a configuration of an inclination detecting device used for positioning the lens moving operation unit with respect to the substrate unit.

FIG. 9 is a side view showing a state in which a reflected light beam from a reflecting mirror is received by the inclination detecting device.

FIG. 10 is a plan view showing an arrangement state of a light receiving region of a light receiving unit that receives the reflected light flux.

FIG. 11 shows a state in which the lens drive unit is mounted on the substrate unit and the lens holder unit is driven in the tracking direction to position the tracking drive coil with respect to the magnet in the focusing direction. FIG.

FIG. 12 shows a state in which the lens drive unit is mounted on the substrate unit and the lens holder unit is driven in the focusing direction to position the focusing drive coil with respect to the magnet in the tracking direction. FIG.

FIG. 13 is a plan view showing a case where a fixing unit in the lens movement operation unit is fixed to the substrate unit after the positioning.

FIG. 14 is a side view showing a state in which a fixing unit in the lens movement operation unit is fixed to the substrate after the positioning.

FIG. 15 is a plan view of a conventional lens driving mechanism used for describing a conventional manufacturing method.

FIG. 16 is a front view showing a positional relationship between a focusing drive coil and a magnet in the conventional lens drive mechanism.

FIG. 17 is a front view showing a positional relationship between a tracking drive coil and a magnet in the conventional lens drive mechanism.

FIG. 18 is a front view showing the attitude of the focusing drive coil when the focusing drive coil is driven from a state in which the focusing drive coil is shifted from the magnet in the tracking method in the conventional lens drive mechanism. .

FIG. 19 is a front view showing the attitude of the tracking drive coil when the tracking drive coil is driven from a state where the tracking drive coil is shifted in the focusing direction with respect to the magnet in the conventional lens drive mechanism. .

[Explanation of symbols]

Reference Signs List 1 lens drive mechanism, 2 objective lens, 3 lens movement operation section, 4 substrate section, 13 fixing section, 14 lens holder section, 23 tracking drive coil, 26 focusing drive coil, 70 tilt detecting device, 71 reflection mirror

Claims (1)

[Claims] 1. A movable section having an objective lens and a drive coil for condensing a light beam from a light source on a signal recording surface of an optical recording medium, and the movable section is perpendicular to the tracking direction and the tracking direction via an elastic member. Manufacture of an objective lens driving device for positioning and mounting a lens moving operation unit having a fixing member movably supported in a focusing direction with respect to a base having a magnetic circuit for forming a magnetic field used for driving the driving coil A reflection mirror attached to the objective lens, a light source for irradiating the objective lens with light, and detecting reflected light of the light from the light source transmitted through the objective lens and reflected by the reflection mirror. Using the objective lens tilt detecting means, comprising: a reflected light detecting means that drives the driving coil to move the movable part in the tracking direction. By driving, the inclination of the objective lens obtained based on the detection result of the reflected light by the reflected light detection means in the objective lens inclination detection means is minimized by moving the lens moving operation unit in the focusing direction. By driving the driving coil to drive the movable portion in the focusing direction, the tilt of the objective lens obtained based on the result of detection of the reflected light by the reflected light detection means in the objective lens tilt detection means can be calculated. A method of manufacturing an objective lens driving device, characterized in that the lens movement operation unit is moved to a minimum in the tracking direction and the lens movement operation unit is positioned with respect to the base.