JP2001118265A - Lens driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens driving device capable of effectively utilizing the magnetic flux of a magnet and also miniaturizing a coil substrate. SOLUTION: The lens driving device 150 is constituted such that a pair of L-shaped yokes 13 fixing a V-shaped magnet 11 or an inverse V-shaped magnet 12 for forming a magnetic field are oppositely arranged with a prescribed magnetic gap provided in-between and are fastened with plural screws 14 on a planar actuator base 10, a V-shaped driving coil 80, which is suspended with the four supporting wires 21 of a supporting base 20 fixed onto the actuator base 10 with the screws 14 and which is composed of a focus driving coil 40 and a tracking driving coil 60 on the side face in the jitter direction of a lens holder 30, is fixed on a movable part 100, as is an inverted V-shaped driving coil 90 for which the V-shaped driving coil 80 is rotated at an angle of 180 degrees; and that this movable part 100 with the driving coils 80, 90 fixed is arranged in the magnetic gap formed with the V-shaped magnet 11 and the inverse V-shaped magnet 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens driving apparatus for a disk player for recording information on a disk and reading the recorded information, and more particularly to the structure of a lens driving apparatus using a planar coil.

[0002]

2. Description of the Related Art An objective lens is driven in the direction of a lens optical axis (focusing direction) to focus a reading beam from a disk on which information is optically recorded on the disk surface, and an objective lens is used to follow the information track. 2. Related Art A lens driving device that drives a lens in a direction perpendicular to a lens optical axis direction is known. It is desirable that the movable portion constituting the lens driving device is small and lightweight.
As shown in FIG. 14A, instead of a coil bobbin type 5 in which a focus coil 3 and a tracking coil 4 are wound around a coil bobbin 2 incorporating an objective lens 1 as shown in FIG. 14A, a holder incorporating the objective lens 1 as shown in FIG. A printed coil type 8 is proposed in which a flat coil substrate 7 formed by patterning a focus coil 3 and a tracking coil 4 on both side surfaces of the substrate 6 and etching the same is fixed with an adhesive or the like (for example, Japanese Unexamined Patent Application Publication No. -203103 publication).

[0003]

SUMMARY OF THE INVENTION However, Japanese Patent Application Laid-Open No. Hei 8-2
When using the coil substrate 7 as disclosed in JP-A-03103,
As shown in FIG. 14C, the focus coil 3 obtains a driving force in the focus (arrow F in the drawing) direction by being disposed so as to extend between the N pole and the S pole of the magnet 9. Further, the tracking coil 4 composed of four is provided with the two tracking coils 4 on the N pole side of the magnet 9 and the other two.
One tracking coil 4 is arranged on the S pole side of the magnet 9, and only about half of each tracking coil 4 (direction of arrow T in the tracking diagram) is arranged so as to enter the magnetic field of the magnet 9. Have gained. Therefore, the coil substrate 7 of the print coil type 8 needs to be formed so as to protrude more to the left and right in the tracking direction than the outer shape of the magnet 9, so that the effective magnetic field of the magnet 9 with respect to the tracking coil 4 decreases and the magnet 9 There is a problem that the coil substrate 7 becomes larger in size than the external shape.

[0004] The present invention has been made in view of the above problems, and an object of the present invention is to provide a lens driving device capable of effectively utilizing magnetic flux of a magnet and reducing the size of a coil substrate.

[0005]

According to a first aspect of the present invention, there is provided a lens driving apparatus, comprising: a lens holder movably supported in a focus direction and a tracking direction; A focusing drive coil and a tracking drive coil, and a magnetic flux applying unit for applying a magnetic flux to the focus drive coil and the tracking drive coil, wherein the focus drive coil and the tracking drive coil are each arranged in the jitter direction. The magnetic flux applying means is configured to include a pair of planar coils formed in a plane perpendicular to the plane and having a coil axis parallel to the jitter direction. Also, for two regions divided by the inclined virtual straight line, the jitter The magnetic flux of the opposite grant each other along a virtual straight line of each pair of the planar coil is characterized by being arranged symmetrically with respect to a plane and including the optical axis parallel to the jitter direction.

According to a second aspect of the present invention, there is provided a lens driving device according to the first aspect, wherein the magnetic flux applying means includes a magnet facing the planar coil, The magnet is characterized in that the magnetic poles facing each of the two regions are different.

According to a third aspect of the present invention, there is provided a lens driving device according to the first aspect, wherein the magnetic flux applying means faces the planar coil and is perpendicular to the jitter direction. Including a magnet having a surface,
The magnetic pole surface is characterized in that the magnetic poles are different with respect to the virtual straight line.

A lens driving device according to a fourth aspect of the present invention is the lens driving device according to any one of the first to third aspects, wherein the pair of planar coils constituting the focus driving coil are Each of them is supplied with a drive current in the same direction, and a pair of planar coils constituting a tracking drive coil are supplied with drive currents in opposite directions.

A lens driving device according to a fifth aspect of the present invention is the lens driving device according to any one of the first to third aspects, wherein a pair of planar coils constituting a focus driving coil is provided. Are characterized in that drive currents in opposite directions are supplied to each other, and drive currents in the same direction are supplied to a pair of planar coils constituting a tracking drive coil.

A lens driving device according to a sixth aspect of the present invention is the lens driving device according to any one of the first to fifth aspects, further comprising a pair of planar coils forming a focus driving coil. The pair of planar coils constituting the tracking drive coil are characterized in that they have the same in-plane shape and are arranged in an overlapping manner along the jitter direction.

A lens driving device according to a seventh aspect of the present invention is the lens driving device according to any one of the first to sixth aspects, wherein the lens driving device includes a pair of planar coils forming a focus driving coil. A combination of the driving forces generated from each of them becomes a driving force in the focus direction, and a combination of the driving forces generated from each of the pair of planar coils constituting the tracking driving coil becomes a tracking driving force.

The lens driving device according to the present invention has a bearing hole which is fitted in a shaft extending in a focus direction, and is slidable and rotatable with respect to the shaft. A lens driving device comprising: a holder; a focus driving coil and a tracking driving coil attached to the lens holder; and a magnetic flux applying unit for applying a magnetic flux to the focus driving coil and the tracking driving coil. And the tracking drive coil is configured to include a pair of coils each having a coil axis perpendicular to the focus direction,
The magnetic flux applying means applies magnetic fluxes in mutually opposite directions to two regions divided by a virtual line inclined with respect to both the focus direction and the tracking direction of the coil, and the magnetic flux applying unit includes a pair of coils. Are symmetrically arranged with respect to a plane including the axis.

A lens driving device according to the present invention includes a lens holder supported movably in a focus direction and a tracking direction, a focus drive coil and a tracking drive coil attached to the lens holder, and a focus drive coil and a tracking drive coil. A focus driving coil and a tracking driving coil, each of which is formed in a plane perpendicular to the jitter direction and has a coil axis parallel to the jitter direction. And a pair of planar coils having the following. The magnetic flux applying means applies magnetic fluxes in opposite directions along the jitter direction to two regions divided by a virtual straight line inclined in both the focus direction and the tracking direction of the planar coil. , The virtual straight line of each of the pair of planar coils is
Since they are arranged in parallel with the jitter direction and symmetrically with respect to the plane including the optical axis, when a drive current in the same direction is supplied to each of a pair of planar coils constituting the focus drive coil, the coils are driven in the focus direction and tracking is performed. When drive currents in opposite directions are supplied to a pair of planar coils constituting the drive coil, the coils are driven in the tracking direction.

[0014]

FIG. 1 is an external view of a main part of a lens driving device 150 according to a first embodiment of the present invention. FIG. 2 shows the positional relationship between the V-shaped magnet 11 and the V-shaped driving coil 80 constituting the lens driving device 150 according to the embodiment of the present invention, and the relationship between the inverted V-magnet 12 and the inverted V-shaped driving coil 90. It is the perspective view which showed the positional relationship typically. The configuration of the lens driving device 150 will be described below with reference to FIGS. FIG. 1A shows the lens driving device 15.
1 is a top view, and FIG. 1B is a side view of the lens driving device 150.

In the lens driving device 150 according to the first embodiment of the present invention, a pair of L-shaped yokes 13 having a V-shaped magnet 11 or an inverted V-magnet 12 for forming a magnetic field fixed on a plate-shaped actuator base 10 are provided. A movable section 100 that is opposed to the apparatus with a predetermined magnetic gap, fixed by a plurality of screws 14, and suspended by four support wires 21 of a support base 20 fixed on the actuator base 10 by the screws 14. Are disposed between the V-shaped magnet 11 and the inverted V-magnet 12.

The V-shaped magnet 11 is, for example, a three-division multipole magnet in which a magnetic pole surface is formed in a rectangular shape by an N-pole surface of a right-angled triangle magnet and S-pole surfaces of two right-angled triangle magnets. Are arranged in a V-shape, and have a structure in which S pole faces are disposed on the left and right of the N pole face. That is, the V-shaped magnet 11
The magnetic poles are divided by a virtual straight line (details will be described later) inclined with respect to both the focus direction and the tracking direction, and generate magnetic fluxes in opposite directions along the jitter direction. Also, a reverse V magnet 12
Is a three-division multipole magnet formed in a rectangular shape by a right triangular S pole surface and two right triangular magnet N pole surfaces, and an S pole surface is disposed in the center in an inverted V-shape. Have a structure in which N pole faces are arranged on the left and right sides of the.

The movable section 100 has a substantially rectangular lens holder 30 containing an objective lens 31 therein, and an adhesive or the like on the side of the lens holder 30 facing the V-shaped magnet 11 in the jitter (arrow J in the figure) direction. The V-shaped drive coil 80 fixed by the above, and the V-shaped drive coil 80 fixed by an adhesive or the like on the side surface of the lens holder 30 facing the inverted V magnet 12 in the jitter direction, which is rotated 180 degrees, Focusing is achieved by supporting four holding portions 32a and 32b formed of a driving coil 90 and protruding in the tracking (arrow T direction in the figure) direction of the lens holder 30 with four support wires 21. It is suspended so as to be movable in a middle arrow F) direction and a tracking direction.

The support wire 21 is formed of a conductive rod-shaped or plate-shaped elastic member, and one end of the support wire 21 is expanded by rolling.
2a are formed, and a part of the support wire 21 is integrally formed by outsert molding or the like when the support base 20 is formed. Similarly, the other end of the support wire 21 is rolled and expanded to form a connection portion 22b, and is fixed to four holding portions 32a and 32b provided on the lens holder 30 with an adhesive or the like.

The lens driving device 150 according to the first embodiment of the present invention is characterized by the structure of the V-shaped driving coil 80 described above. Therefore, referring to FIG.
An outline of the structure will be described. FIG. 3A is a plan view of the V-shaped drive coil 80, and FIG.
It is the figure which showed the side surface of 0 typically. As shown in FIG. 3A, the V-shaped drive coil 80 is patterned and etched in the same shape on the double-sided copper foil of the focusing substrate 41 which is a double-sided copper-clad laminated printed board made of, for example, a glass epoxy material. Focus drive coil 40 having two focus coils 43 on the front side and two on the back side
And a tracking drive coil 60 in which four tracking coils 63 are formed on a tracking substrate 61, which is a double-sided copper-clad laminated printed circuit board, as described above, as shown in FIG. Stack
The focus driving coil 40 and the tracking driving coil 60 are connected by using a plurality of jumper wires J1 to J4. In addition, the inverted V-shaped drive coil 90 is
The V-shaped drive coil 80 is rotated by 180 degrees.
Therefore, the structure of the V-shaped drive coil 80 and the structure of the inverted V-shaped drive coil 90 will be described by sequentially describing the structures of the focus drive coil 40 and the tracking drive coil 60 constituting the V-shaped drive coil 80. I do.

First, the structure of the focus drive coil 40 constituting the V-shaped drive coil 80 will be described below with reference to FIG. 4A is a plan view of the front side of the focus drive coil 40, FIG. 4B is a plan view of the focus drive coil 40 seen through the back side, and FIG. A sectional view of the coil 40 is shown.

As shown in FIG. 4, the focus drive coil 40 is composed of one focus coil 43a and four focus coils 43d having the same shape and a substantially elliptical shape on the copper foil on the surface side of the focus substrate 41. The two focus coils 43b and three focus coils 4 of the same shape as described above are formed on the copper foil on the back side in parallel with the jitter direction and symmetrically with respect to the plane including the optical axis (C line in the figure).
3c is formed at the same position as above, and one focus coil 43a and two focus coils 43b arranged on the right side with respect to the optical axis are connected by two through holes 44 and 45, and on the left side with respect to the optical axis. The three focus coils 43c and the four focus coils 43d are connected by two through holes 48, 49, and a pair of left and right focus coils 43a, 43b, 43 is formed by using the external wiring 51.
This is a planar coil formed by connecting c and 43d in series.

The through holes 44, 45, 48, 4
9 is to form a silver paste by injecting a silver paste into a hole penetrating the copper foil on the front side and the back side and baking the silver paste or to form an inner surface of the hole penetrating the copper foil on the front side and the back side. The copper foil on the front side and the copper foil on the back side were connected by copper plating, and the through-hole portion was indicated by a double circle in the figure.

The elliptical focus coil 43 constituting the focus drive coil 40 is arranged so that its two long sides are crotched between the N pole and the S pole of the V-shaped magnet 11 magnetized into three parts. The focus coils 43a and 43b are formed at a position rotated clockwise by approximately 45 degrees with respect to the optical axis, and the focus coils 3c, 43c and 43d are formed at approximately 45 degrees with respect to the optical axis. It is formed at the position rotated left. With this arrangement, the focus drive coil 40 can generate a focus drive force to be described later equally in the vertical direction of the optical axis.

Next, a method of connecting the focus drive coil 40 will be described. One end of one focus coil 43a formed on the front surface side of the focus substrate 41 is connected to a focus terminal (A) 42 formed on the outer peripheral portion of the front surface side of the focus substrate 41. One focus coil 43a connected to the focus terminal (A) 42
Is formed in a spiral form from the outer circumference to the inner circumference by clockwise rotation, and the other end is connected to one through hole 44. The one through hole 44 is electrically connected to the two focus coils 43b on the rear surface side. 2 focus coils 4 on the back side
3b is formed in a spiral form from the inner circumference to the outer circumference by clockwise rotation.
Connected to the through hole 45. Through hole 4 for 2
5 is connected to a focus terminal (B) 46 via a copper foil formed on the front surface side. Therefore, one focus coil 43a and two focus coils 43b are
Are connected in series between the focus terminal (A) 42 and the focus terminal (B) 46 via through holes 44 and 45 for use.

On the other hand, a focus terminal (C) 47 formed on the front side of the focus substrate 41 is connected to a through hole 48 for three via a copper foil. The through hole 48 for 3 is connected to the 3 focus coils 43c on the back side, and is formed in a spiral form from the outer circumference to the inner circumference by clockwise rotation.
Is connected to the through hole 49. Through hole 4 for 4
Reference numeral 9 denotes four focus coils 43d formed on the surface side
Connected to. The fourth focus coil 43 d is formed in a spiral shape from the inner circumference to the outer circumference by right rotation, and is connected to a focus terminal (D) 50 formed on the front surface side of the focus substrate 41. Therefore, the three focus coils 43c and 4
Is connected in series between a focus terminal (C) 47 and a focus terminal (D) 50 via through holes 48 and 49 for 3 and 4. Then, the focus terminal (B) 46 and the focus terminal (C)
The focus drive coil 40 in which the four focus coils 43a to 43d are connected in series between the focus terminal (A) 42 and the focus terminal (D) 50 is formed by connecting 47 with the external wiring 51. The focus driving coil 40 is formed in a plane perpendicular to the jitter direction and forms a pair of planar coils having a coil axis parallel to the jitter direction.
When a focus driving current is supplied between the focus terminal (A) 42 and the focus terminal (D) 50, a driving force in the focus direction is generated.

As shown in FIG. 4, two focus coils 43 and 4 are provided on the front side of the focus substrate 41.
Focus terminals (A) 42, (B) 50, (C) 4
6, (D) 47, and a tracking substrate 6 described later.
1 and four tracking coils 63a to 63
d, four tracking terminals (E) 52, (F) 53, (G) 54,
(H) 55 are provided, and connection holes 52a, 53a, 54a, and 55a are formed at substantially the center of the copper foil portion, respectively.
These tracking terminals (E) 52, (F) 53,
When connecting the focus substrate 41 and the tracking substrate 61, the (G) 54 and the (H) 55 are connected to the tracking terminals (E) 52, (F) 53, and (F) 53, as shown in FIG.
(G) 54, (H) 55 jumper wires J1
J4 is soldered, and the jumper wires J1 to J4 are drawn out toward the tracking substrate 61 through the connection holes 52a, 53a, 54a, and 55a.

Next, the configuration of the tracking drive coil 60 will be described with reference to FIGS. FIG. 5A is a plan view of the back surface side of the tracking drive coil 60, and FIG.
FIG. 5B is a plan view of the tracking drive coil 60 in a see-through state, and FIG. 5C is a cross-sectional view of the tracking drive coil 60.

As shown in FIG. 5, the tracking drive coil 60 is composed of two tracking coils 63b and four tracking coils 63d having the same shape and substantially elliptical shape on the copper foil on the back side of the tracking substrate 61.
The tracking coils 63a and 3 having the same shape as those described above are formed on the copper foil on the surface side in parallel with the jitter direction 1 and symmetrically with respect to the plane including the optical axis (line C in the figure). 63c is formed at the same position as above, and one tracking coil 63 disposed on the right side with respect to the optical axis.
a and two tracking coils 63b are connected by two through holes 64 and 65, and three tracking coils 63c and four tracking coils 63d disposed on the left side with respect to the optical axis are connected by two through holes 68 and 69. And a planar coil formed by connecting a pair of left and right tracking coils 63a to 63d in series by using the external wiring 56.

The elliptical tracking coil 63 constituting the tracking drive coil 60 has two long sides 3
Since the V-shaped magnet 11 divided and magnetized is arranged so as to extend between the N pole and the S pole, one tracking coil 63a is provided.
And 2 tracking coils 63b are approximately 4
The tracking coil of No. 3 and 63c and the tracking coil 63d of 4 are formed at a position rotated clockwise approximately 45 degrees to the left with respect to the optical axis. With this arrangement, the tracking drive coil 60 can generate a tracking drive force, which will be described later, equally in the left-right direction of the optical axis.

On the front side of the tracking substrate 61, the tracking terminals (E) 52, (F) 53, (G) 54, and (H) 55 formed on the focusing substrate 41 described above.
Terminal 6 having a rectangular copper foil portion at a position corresponding to
2, 66, 67 and 70 are provided, and connection holes 62a, 66a, 67a and 70a are formed in the center of the copper foil portion. Therefore, the jumper wires J1 to J4 soldered to the copper foil portions of the tracking terminals (E) 52, (F) 53, (G) 54, and (H) 55 of the focus substrate 41 are connected to the connection holes 52a, 53a, The focusing substrate 4 is pulled out through the connecting holes 62a, 66a, 67a, 70a of the tracking substrate 61 and soldered to the copper foil portions of the relay terminals 62, 66, 67, 70, respectively.
1 and the tracking substrate 61 are connected.

Next, a method of connecting the tracking drive coil 60 will be described. Relay terminal 6 of tracking substrate 61
2 is a tracking terminal (E) of the focus substrate 41
52 and a jumper line J1. The one tracking coil 63a connected to the relay terminal 62 formed on the surface side of the tracking substrate 61 is formed in a spiral shape from the outer periphery to the inner periphery by clockwise rotation, and one through hole 64
Tracking coils 6 formed on the back side through the
3b. 2 tracking coil 63b
By turning clockwise, it is formed in a spiral form from the inner circumference to the outer circumference, and is connected to the relay terminal 66 via the through hole 65 for two. The relay terminal 66 is connected to the focusing board 41 by a jumper wire J2.
Are connected to the tracking terminal (F) 53. That is, one tracking coil 63a and two tracking coils 63b are connected to the tracking terminal (E) 52 and the tracking terminal (F) 53 formed on the focusing substrate 41 by the two through holes 64 and 65 and the jumper wires J1 and J2. Connected in series.

On the other hand, the relay terminal 67 of the tracking substrate 61 is connected to the tracking terminal (G) 54 of the focusing substrate 41 by a jumper wire J3. Relay terminal 6 formed on the surface side of tracking substrate 61
The three tracking coils 63c connected to 7 are formed in a spiral form from the outer circumference to the inner circumference by rotating counterclockwise, and are connected to the four tracking coils 63d formed on the back side through the three through holes 68. 4 tracking coils 63
d is formed in a spiral shape from the inside to the outside by turning left, and is connected to the relay terminal 70 via the through hole 69 for four.
The relay terminal 70 is connected to the tracking terminal (H) 55 of the focusing substrate 41 via a jumper wire J4.

That is, the three tracking coils 63c and the four tracking coils 63d are
The tracking terminals (G) 54 and the tracking (H) terminals 55 formed on the focusing substrate 41 are connected in series by 8, 69 and jumper lines J3 and J4.
Therefore, by connecting the tracking terminal (F) 53 and the tracking terminal (G) 54 with the external wiring 56, four tracking coils 63a to 63d are provided between the tracking terminal (E) 52 and the tracking terminal (H) 70. A tracking drive coil 60 connected in series is formed.
Since such a tracking drive coil 60 is formed in a plane perpendicular to the jitter direction and forms a pair of planar coils having a coil axis parallel to the jitter direction,
Opposing to the V-shaped magnet 11, a tracking driving current is supplied between the tracking terminal (E) 52 and the tracking terminal (H) 70 to generate a driving force in the tracking direction.

As described above, the focus drive coil 4
A V-shaped drive coil 80 composed of a tracking drive coil 60 and a zero-shaped drive coil 90 is fixed to one side surface of the lens holder 30 and an inverted V-shaped drive coil 90 obtained by rotating the V-shaped drive coil 80 by 180 degrees. Is fixed to the other side surface of the lens holder 30. Then, the V-shaped drive coil 80
And the focus drive coil 4 of the inverted V-shaped drive coil 90
0 are connected in series, and the V-shaped drive coil 80 and the tracking drive coils 60 of the inverted V-shaped drive coil 90 are connected in series. The ends of these windings are connected to the connection portions 22b of the support wires 21 bonded to the four holding portions 32a and 32b of the lens holder 30 by soldering or the like. A litz wire or the like (not shown) is connected to the lead portion 22 a of the support wire 21, and a drive current is supplied to the V-shaped drive coil 80 and the inverted V-shaped drive coil 90 from outside. When a drive current is supplied to the V-shaped drive coil 80 and the inverted V-shaped drive coil 90 via the support wire 21, the movable section 100 can freely move in the tracking direction and the focus direction according to the drive current in the magnetic gap. It is transferred to.

Next, the mechanism for driving the planar coil will be described with reference to FIG. 6A and 6B are explanatory diagrams of the operation in which the drive coil 56 schematically shown is opposed to the V-shaped magnet 11, and FIG. 6A is a plan view when a pair of square drive coils 56 are used, for example. FIG. 6 (b)
FIG. 6 is a plan view when a circular drive coil 56 is used, for example, and FIG. 6C shows a vector diagram of the total drive force.
It should be noted that the dot in the circle in the drawing indicates the direction of the magnetic flux penetrating from the back to the front of the paper, and the cross in the figure indicates the direction of the magnetic flux penetrating from the front to the back in the paper. The arrow inside the drive coil 58 indicates the direction of the current flowing through the drive coil 58, and the outlined arrow in the figure indicates the partial driving force of the drive coil 58.

As described above, the V-shaped magnet 11 serving as the magnetic flux applying means is a three-divided multipole magnet formed in a square shape by the N pole surface of a right triangle and the S pole surfaces of two right triangle magnets. The N pole face is arranged in a V-shape, and the S pole face is arranged on the left and right sides of the N pole face. Therefore, the boundary line between the central N pole surface and the left and right S pole surfaces (referred to as a virtual straight line L)
Are arranged at 45 degrees left and right with respect to the optical axis. The drive coil 58 has a square diagonal line arranged on the virtual straight line L as shown in FIG. That is, one region S1 of the drive coil 56 receiving the magnetic flux on the N-pole surface of the V-shaped magnet 11 and the other region S2 of the drive coil 56 receiving the magnetic flux on the S-pole surface of the V-shaped magnet 11 are the same. Accordingly, the drive coil 58 is provided with magnetic fluxes in opposite directions along the jitter direction in the two regions S1 and S2 divided by the virtual straight line L, and the pair of square drive coils 56 are arranged with respect to the optical axis. They are arranged symmetrically.

For example, the drive coil 58 disposed on the right side
In one region S1 of a, a magnetic flux penetrating from the back surface to the front surface of the paper is given by the N-pole surface, and when a current is supplied to the drive coil 58a in the direction of the arrow, the portion A of the drive coil 58a moves vertically upward , A partial driving force is generated in the horizontal portion in the horizontal left direction. In the other region S2 of the drive coil 58a, the magnetic flux penetrating from the front surface of the paper to the back surface is given by the S pole surface.
When a current in the direction of the arrow is supplied to the drive coil 58a, a vertical driving force is generated in a portion C of the drive coil 58a, and
A partial driving force in the horizontal left direction is generated at the portion 8a. Accordingly, the drive coil 58a combines the partial driving force in the vertical upward direction of the part A and the part C and the partial driving force in the horizontal left direction of the part B and the part D, and is combined as shown in FIG. Generates an upward driving force. That is, a driving force in the left direction perpendicular to the virtual straight line L is generated.

The drive coil 58b disposed on the left side
Is located on the N pole face side,
Drive coil 58a disposed on the right side of drive coil 58b
When a current in the same direction is supplied, the portion A generates a vertical upward partial driving force, and the portion D generates a horizontal rightward partial driving force. The other area S2 of the drive coil 58b is
Since it is arranged on the N-pole surface side, the part B of the drive coil 58b generates a partial driving force in the horizontal right direction, and the part C generates a partial driving force in the vertical upward direction. Accordingly, the drive coil 58b disposed on the left side combines the vertical partial drive force of the portions A and C with the horizontal right partial drive force of the portion B and the portion D, as shown in FIG. As shown, a driving force is generated in the upward direction by 45 degrees to the right. The driving forces of the pair of left and right square driving coils 58a and 58b are combined to generate a total driving force in the vertical upward direction, that is, the focus direction (hatched arrow in the figure) as shown in FIG. 6C.

As shown in FIG. 6B, in the case of a circular drive coil 59, since the center line of the circular drive coil 59 is arranged on the virtual straight line L, the V-shaped magnet 11
Region S of drive coil 56 receiving the magnetic flux of the N pole surface
3 and the other area S4 of the drive coil 56 that receives the magnetic flux on the S pole face of the V-shaped magnet 11 are the same. In the circular drive coil 59, the drive force is generated radially from both the E portion and the F portion, but the partial drive force near the virtual straight line L is:
Since they have the same size in opposite directions, they are canceled out, for example, the driving coil 59a arranged on the right side generates a driving force in the upward direction of 45 degrees left as described above, and the driving coil 59b arranged on the left side. Generates a driving force in the upward direction of 45 degrees to the right, so that a pair of left and right circular driving coils 59a and 59b
Are combined to generate a total driving force in the vertical upward direction, that is, in the focus direction, as shown in FIG. 6C.

As described above, the drive coil 58 has two regions S 1 and S 2 on the virtual straight line L of the V-shaped magnet 11.
Are arranged so as to have the same area, and one region S1
Then, the magnetic fluxes in opposite directions are applied to the other area S2, so that the area S2 is accurately driven in the focus direction. Further, when currents in opposite directions are supplied to the pair of drive coils 58, a driving force in the tracking direction is obtained. That is, the drive coil 58 is not limited to the shape, but has a shape that is symmetrical with respect to the virtual straight line L, and has two left and right regions S.
If the areas of S1 and S2 are the same, the left and right drive coils 58
This shows that when the partial driving forces generated in the steps (1) and (2) are combined, an accurate focus driving force or tracking driving force can be obtained.

Next, the operation of the focus drive coil 40 will be described with reference to FIG. FIG. 7 is a schematic view of a focus drive coil 40 (one focus coil 4 on the front side).
FIG. 7A is an operation explanatory view showing a positional relationship between the V-shaped magnet 11 and the inverted V-magnet 12, and focuses constituting the V-shaped driving coil 80. FIG. 7B is a plan view showing the positional relationship between the drive coil 40 and the V-shaped magnet 11, and FIG. 7B shows the focus drive coil 40 (the focus drive coil 40 rotated by 180 degrees) constituting the inverted V-shaped drive coil 90. A plan view showing the positional relationship of the inverted V magnet 12 is shown in FIG.
FIG. 7C shows a vector diagram of the focus driving force by the focus driving coil 40.

As shown in FIG. 7A, two focus coils 43a and 43d of the focus drive coil 40 are provided.
The (a pair of planar coils) is arranged to face the V-shaped magnet 11 which is a magnetic flux applying means, and is arranged such that the long sides of the focus coil 43 extend between the N pole surface and the S pole surface. That is, the two virtual straight lines L of the V-shaped magnet 11 are arranged such that the area of one region S1 of the focus drive coil 40 and the area of the other region S2 are the same. When one of the focus coils 43a is supplied with a drive current in the direction shown in the figure and receives a magnetic flux in the direction shown in the figure from the V-shaped magnet 11, one focus coil 4a is formed.
The two regions S1 and S2 of 3a are located on the right side 4 with respect to the optical axis.
A driving force lower by 5 degrees (open arrow in the figure) is generated. Also,
Since the drive current in the same direction as the one focus coil 43a is supplied to the fourth focus coil 43d,
The two areas S1 and S2 of the fourth focus coil 43d both generate a driving force 45 degrees downward to the left with respect to the optical axis.
Therefore, the driving forces in the focus direction of the two focus coils 43a and 43d are combined, and a focus driving force in the downward direction of the optical axis (hatched arrow in the figure) is generated as shown in FIG. 7C.

The focus drive coil 40 rotated by 180 degrees is disposed to face the inverted V magnet 12 as shown in FIG. One focus coil 43a
When the drive current in the direction shown in the figure is supplied and the magnetic flux in the direction shown in the figure is applied from the reverse V magnet 12, the two regions S1 and S2 of one focus coil 43a are both on the right side with respect to the optical axis. Generates a 45 degree downward driving force. Also,
Since the drive current in the same direction as the one focus coil 43a is supplied to the fourth focus coil 43d,
The two areas S1 and S2 of the fourth focus coil 43d both generate a driving force 45 degrees downward to the left with respect to the optical axis.
Accordingly, the driving forces of the two focus coils 43a and 43d are combined, and a focus driving force in the downward direction of the optical axis is generated as shown in FIG. Also, when a drive current reverse to the direction shown in the drawing is supplied to the focus drive coil 40, the focus drive coil 40 generates a focus drive force in the direction above the optical axis.

Next, the operation of the tracking drive coil 60 will be described with reference to FIG. FIG. 8 shows a tracking drive coil 60 (one tracking coil 62a and one tracking coil 6a on the front side) schematically shown in FIG.
FIG. 8 is an operation explanatory diagram showing a positional relationship between the V-shaped magnet 11 and the inverted V-magnet 12 (only 3c is displayed), and FIG.
8A is a plan view showing the positional relationship between the tracking drive coil 60 and the V-shaped magnet 11 constituting the V-shaped drive coil 80, and FIG. 8B is a tracking drive coil constituting the inverted V-shaped drive coil 90. 60 (the tracking drive coil 60 is rotated 180 degrees) and the reverse V magnet 1
FIG. 8C is a plan view showing the positional relationship of FIG. 2, and FIG. 8C is a vector diagram of the tracking driving force by the tracking driving coil 60.

As shown in FIG. 8A, two tracking coils 63a and 63 of the tracking drive coil 60 are provided.
c (a pair of planar coils) is disposed to face the V-shaped magnet 11 which is a magnetic flux applying means,
The three long sides are arranged so as to extend between the N pole face and the S pole face. That is, the two virtual straight lines L of the V-shaped magnet 11
, One area S1 of the tracking drive coil 60
And the area of the other region S2 are arranged to be the same. When a drive current in the direction shown in the figure is supplied to the one tracking coil 63a and a magnetic flux in the direction shown in the figure is applied from the V-shaped magnet 11, both areas S1 and S2 of the one tracking coil 63a become light. A driving force is generated at a right angle of 45 degrees below the axis (open arrow in the figure). Further, since the driving current in the direction opposite to that of the one tracking coil 63a is supplied to the three tracking coils 63c, the two regions S1 and S2 of the three tracking coils 63c are both 45 degrees to the right with respect to the optical axis. Of driving force. Therefore, the two tracking coils 63
The driving forces a and 63c are combined to generate a tracking driving force (hatched arrow in the figure) in a direction perpendicular to the optical axis as shown in FIG. 8C.

The tracking drive coil 60 rotated by 180 degrees is disposed to face the inverted V magnet 12 as shown in FIG. One tracking coil 63
a, when a driving current in the direction shown in the figure is supplied and a magnetic flux in the direction shown in the figure is applied from the reverse V magnet 12, both areas S1 and S2 of one tracking coil 63a are both positioned with respect to the optical axis. It generates a driving force 45 degrees below the right side. Further, since the three tracking coils 63c are supplied with a drive current in the opposite direction to the one tracking coil 63a, the two regions S1 of the three tracking coils 63c,
Both S2 generate a driving force 45 degrees to the right with respect to the optical axis. Therefore, the two tracking coils 63a, 63
The driving force of c is combined, and a tracking driving force in the right-right direction with respect to the optical axis is generated as shown in FIG.

As described above, the tracking drive coil 6
0 are arranged on a virtual straight line L formed in parallel with the jitter direction and symmetrically with respect to the plane including the optical axis, so that the center of gravity (Gc () Is located substantially at the center of the tracking substrate 61. The center of gravity (Cc) of the two tracking coils 63a and 63c is located substantially at the center of each of the tracking coils 63a and 63c. Accordingly, when one tracking coil 63a generates a driving force 45 degrees below the optical axis and three tracking coils 63c generates a driving force 45 degrees above the optical axis, FIG. As shown, the tracking drive coil 60 is centered on the center of gravity (Gc) of the tracking substrate 61 (arrow (g) in the figure).
A rotational driving force in the direction is generated.

In the case of the tracking drive coil 60 disposed opposite to the reverse V magnet 12, one tracking coil 63a generates a driving force 45 degrees below the optical axis, and the third tracking coil 63c generates light. Although a driving force of 45 degrees above the axis is generated, the positions of the first and third tracking coils 63a and 63c are arranged at positions rotated by 180 degrees with respect to the position shown in FIG. 8A. As shown in FIG. 8B, a rotational driving force in the left direction (arrow (h) in the figure) is generated.

As described above, the inverted V-shaped drive coil 90
Is obtained by rotating the V-shaped drive coil 80 by 180 degrees. The V-shaped drive coil 80 is fixed to one side surface of the lens holder 30 in the jitter direction.
Is fixed to the other side surface of the lens holder 30 in the jitter direction. Therefore, the V-shaped drive coil 80 generates, for example, a rightward rotational driving force, and the inverted V-shaped drive coil 90.
For example, when a rotational driving force in the left direction is generated, the rotational driving force is offset by each other, and the movable unit 100 does not generate a rotational force in any of the left and right directions. That is, the lens driving device 150 of the present invention includes the inverted V-shaped driving coil 90 and the inverted V-magnet 12 in which the V-shaped driving coil 80 is rotated by 180 degrees to cancel the rotational driving force generated by the V-shaped driving coil 80. It is configured using

As described above, the V-shaped driving coil 80 used in the lens driving device 150 according to the first embodiment of the present invention has a pair of substantially elliptical shapes which are arranged on a printed circuit board at an angle of about 45 degrees. Are arranged symmetrically with respect to the optical axis, and four focus coils 43 are stacked.
And a focus drive coil 40 formed, arranged and laminated in the same manner as the focus drive coil 40.
A tracking drive coil 60 formed by two tracking coils 63 is stacked on a plane perpendicular to the jitter direction. Therefore, the V-shaped drive coil 80 can be formed to have substantially the same size as the outer shape of the V-shaped magnet 11 arranged oppositely, and the focus drive coil 40 and the tracking drive that constitute the V-shaped drive coil 80 can be formed. V-shaped magnet 1 for coil 60
1 is efficiently applied.

The imaginary straight line L of the focus coil 43, the tracking coil 63, and the three-division multipole magnet constituting the V-shaped driving coil 80 used in the lens driving device 150 of the present invention is 45 ° from each other with respect to the optical axis. Although the example in which the tilt angle is formed is described, the angle is not limited to the tilt angle. For example, FIG. 9A shows a state when the inclination of the focus coil 43 is set to 45 degrees or more with respect to the optical axis.
The focus driving force is increased as compared with the case of 45 degrees (shown in FIG. 9B). FIG. 9C shows a state in which the inclination of the tracking coil 63 is set to 45 degrees or less with respect to the optical axis.
The degree is increased as compared with the case of degree (shown in FIG. 9D). That is, the tracking coil 63 is
3, the tracking driving force is reduced, and the focus coil 43
If the inclination is the same as that of 3, the focus driving force is reduced. Therefore, the focus coil 43 and the tracking coil 63 determine the optimum inclination with respect to the optical axis in consideration of the focus drive current, the tracking drive current, and the like.

The V-shaped magnet 11 or the inverted V-magnet 12 used in the lens driving device 150 of the present invention.
May be configured using a four-division multipole magnet shown in FIG. FIG. 10A shows a V-shaped magnet 15 in which two sets of two-part magnets formed in a rectangular shape by a right-angled triangular S-pole surface and N-pole surface are adjacent to each other with different poles, and FIG. Is obtained by rotating the V-shaped magnet 15 by 180 degrees.
When such a V-shaped magnet 15 is used, the connection of the focus drive coil 40 or the tracking drive coil 60 is changed, and the direction of the current flowing through the focus coil 43 or the tracking coil is changed. 8, the same focus driving force and tracking driving force as those shown in FIG.

Next, the structure of a lens driving device 200 according to a second embodiment of the present invention will be described with reference to FIG. still,
FIG. 11A is a top view of the lens driving device 200, and FIG.
FIG. 1B shows a side view of the lens driving device 200. The lens driving device 200 according to the second embodiment of the present invention is configured such that the back side of a pair of L-shaped yokes 13 in which a V-shaped magnet 11 or a reverse V magnet 12 for forming a magnetic field is fixed on a plate-shaped actuator base 10. The actuator base 10 is disposed adjacent to each other and fixed with a plurality of screws 14.
The opening 3 of the movable portion 100 suspended by the four support wires 21 of the support base 20 fixed by screws 14 is provided with a predetermined magnetic gap for the V-shaped magnet 11 and the inverted V-magnet 12. Has been inserted.

The movable section 110 houses the objective lens 36 and has a rectangular opening 35 formed substantially in the center, and is fixed to one side surface inside the opening 35 in the jitter direction with an adhesive or the like. V-shaped driving coil 80 and an inverted V-shaped driving coil 90 fixed to the other side surface,
The V-shaped drive coil 80 side of the opening 35 is disposed on the V-shaped magnet 11 side, and the inverted V-shaped drive coil 90 side of the opening 35 is disposed on the opposite V-magnet 12 side. The four holding portions 38a and 38b formed so as to be protruded are supported by the four support wires 21 of the support base 20, and thus are suspended so as to be movable in the focus direction and the tracking direction. The other operations are the same as those of the lens driving device 150 according to the first embodiment, and thus detailed description is omitted.

Next, the structure of a lens driving device 210 according to a third embodiment of the present invention will be described with reference to FIG. still,
FIG. 12A is a perspective view of the movable portion 120 that constitutes the lens driving device 210, and FIG.
FIG. 12C is a perspective view of the yoke base 126 to which the V-shaped magnet 128 constituting the “0” is fixed, and FIG. The lens driving device 210 shown in FIG.
The movable part 120 constituting 10 is formed in a substantially cylindrical shape. In the lens holder 121 of the movable portion 120, a bearing hole 122 is formed substantially at the center, and the objective lens 123 is disposed at a position eccentric from the bearing hole 122 in the jitter (J in the drawing) direction. In the lens holder 121, a focus drive coil 124 is fixed on one side surface in the tracking direction, and a tracking drive coil 125 is fixed on the other side surface in the tracking direction with an adhesive or the like.

The actuator base 126 which forms the lens driving device 210 has a pair of yokes 127 formed in an L shape on the left and right sides in the tracking direction, and a pair of curved V-shapes on one inner surface of the yoke 127 in the tracking direction. Each of the magnets 128 is fixed with an adhesive or the like, and the support shaft 1 is disposed substantially at the center of the pair of V-shaped magnets 128.
29 is fixed by press fitting or welding. Movable part 1
20 is supported rotatably and vertically movable by axially mounting a bearing hole 122 of a lens holder 121 on a support shaft 129 of an actuator base 126. Further, the focus drive coil 124 and the tracking drive coil 12
5 is a V-shaped magnet 12 provided with a predetermined magnetic gap.
8 and are arranged facing.

As described above, the lens driving devices 150 and 200 according to the first and second embodiments have respective movable portions 1.
Since the rotation driving forces 00 and 110 generate a rotational driving force, a V-shaped driving coil 80 formed by the focus driving coil 40 and the tracking driving coil 60 and an inverted V-shaped coil formed by rotating the V-shaped driving coil 80 by 180 degrees. Although the lens drive device 210 according to the third embodiment is configured using the letter-shaped drive coil 90, the above-described rotational drive force is not generated in the movable portion 120 due to the adoption of the shaft sliding type. Therefore, for example, a focus drive coil 124 including only the focus drive coil 40 of the V-shaped drive coil 80 is provided at a position facing the one V-shaped magnet 128, and at a position facing the other V-shaped magnet 128. For example, a tracking drive coil 125 composed of only the tracking drive coil 60 of the V-shaped drive coil 80 is provided.

For example, as shown in FIG. 12 (c), when a plane parallel to the tracking direction including the support shaft 129 constituting the lens driving device 210 is defined as X, the focus driving coil 40 and the tracking driving coil 125 are configured. Since the pair of planar coils are arranged symmetrically with respect to the X, when the driving force in the focus direction is generated as described with reference to FIGS. When sliding and a driving force in the tracking direction is generated, the movable unit 120 rotates left and right about the support shaft 129 as a rotation axis. As described above, the lens driving device 210 according to the third embodiment can be configured with a small number of driving coils, and can reduce the weight of the movable unit 120.

As a lens driving device 220 according to another embodiment of the present invention, a structure shown in FIG. 13 can be considered. The lens driving device 220 shown in FIG.
A drive coil 130 in which a focus drive coil 124 and a tracking drive coil 125 are stacked on one side of the drive coil 130
And a yoke 127 is provided on one side surface of the actuator base 126, and a curved V-shaped magnet 128 is disposed on the inner surface thereof. Drive coil 130
May be configured using the V-shaped drive coil 80 described above. With this configuration, the number of components can be further reduced, and the size and weight can be reduced.

The lens driving device 2 according to the third embodiment
10 is configured using the focus drive coil 124 and the tracking drive coil 125, but the V-shaped drive coil 80 and the V-shaped magnet 11, used in the lens drive devices 150 and 200 of the first and second embodiments, It is needless to say that the same effect can be obtained even if it is constituted by the V-shaped drive coil 90 and the inverted V magnet 12.

[0061]

According to the present invention, the lens driving device 150 is used.
In this example, a pair of substantially elliptical planar coils arranged at an inclination of about 45 degrees on a printed circuit board are arranged in line symmetry with a V-shaped driving coil 80 constituting the lens driving device 150, and these are laminated. A focus drive coil 40 formed by four focus coils 43 and a tracking drive coil 60 formed by four tracking coils 63 formed, arranged, and laminated in the same manner as the focus drive coil 40
Are stacked in a plane perpendicular to the jitter direction. Therefore, the V-shaped drive coil 80 can be formed to have substantially the same size as the outer shape of the V-shaped magnet 11 disposed to face, and the magnetic flux of the magnet can be effectively used, and the V-shaped drive coil 80 The size can be reduced.

[Brief description of the drawings]

FIG. 1 shows a lens driving device 1 according to a first embodiment of the present invention.
FIG.

FIG. 2 is a lens driving device 1 according to the first embodiment of the present invention.
FIG. 3 is a perspective view schematically showing a positional relationship between a V-shaped magnet 11 and a V-shaped drive coil 80 and the like constituting 50.

FIG. 3 is a lens driving device 1 according to the first embodiment of the present invention.
FIG. 2 is a schematic configuration diagram of a V-shaped drive coil 80 constituting 50.

FIG. 4 is a connection diagram of a focus drive coil constituting a V-shaped drive coil of the lens drive device according to the first embodiment of the present invention.

FIG. 5 is a connection diagram of a tracking drive coil constituting a V-shaped drive coil of the lens drive device according to the first embodiment of the present invention.

FIG. 6 is a view used to explain a mechanism for driving a planar coil.

FIG. 7 is a diagram used to explain the driving force in the focus direction of the lens driving device according to the first embodiment of the present invention.

FIG. 8 is a diagram used to explain the driving force in the tracking direction of the lens driving device according to the first embodiment of the present invention.

FIG. 9 is a diagram used to explain the relationship between the inclination and the driving force of the focus coil and the tracking coil of the lens driving device according to the first embodiment of the present invention.

FIG. 10 is a view showing different structures of a V-shaped magnet and an inverted V magnet.

FIG. 11 is an external view of a main part of a lens driving device according to a second embodiment of the present invention.

FIG. 12 is an external view of a main part of a lens driving device according to a third embodiment of the present invention.

FIG. 13 is an external view of a main part of a lens driving device according to another embodiment of the present invention.

FIG. 14 is a diagram showing a relationship between a planar coil and a magnet in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Actuator base 11 ... V-shaped magnet 11 12 ... Reverse V magnet 12 13 ... Yoke 14 ... Screw 20 ... Support base 21 ... Support wire 30 ... Lens holder 80: V-shaped drive coil 90: inverted V-shaped drive coil

Claims (8)

[Claims] 1. A lens holder movably supported in a focus direction and a tracking direction, a focus drive coil and a tracking drive coil attached to the lens holder, and a magnetic flux applied to the focus drive coil and the tracking drive coil. Magnetic flux applying means,
Wherein the focus drive coil and the tracking drive coil each include a pair of planar coils formed in a plane perpendicular to the jitter direction and having a coil axis parallel to the jitter direction. The magnetic flux applying means is configured along the jitter direction for two regions divided by a virtual line inclined with respect to both the focus direction and the tracking direction of the planar coil. A lens driving device for applying magnetic fluxes in opposite directions to each other, wherein the virtual lines of each of the pair of planar coils are arranged in parallel with the jitter direction and symmetrically with respect to a plane including the optical axis. . 2. The magnetic recording medium according to claim 1, wherein the magnetic flux applying means includes a magnet facing the planar coil, and the magnet has different magnetic poles facing each of the two regions. The lens drive device according to claim 1. 3. The magnetic flux applying means includes a magnet facing the planar coil and having a magnetic pole surface perpendicular to the jitter direction, wherein the magnetic pole surfaces have different magnetic poles with respect to the virtual line. The lens driving device according to claim 1. 4. The pair of planar coils forming the focus driving coil are supplied with a driving current in the same direction, and the pair of planar coils forming the tracking driving coil are supplied in opposite directions. The lens driving device according to claim 1, wherein the driving current is supplied. 5. A pair of planar coils forming the focus driving coil are supplied with driving currents in opposite directions, and a pair of planar coils forming the tracking driving coil are supplied with driving currents in the same direction. The lens driving device according to any one of claims 1 to 3, wherein is supplied. 6. A pair of planar coils constituting the focus drive coil and a pair of planar coils constituting the tracking drive coil are formed to have the same in-plane shape and along the jitter direction. The lens driving device according to any one of claims 1 to 5, wherein the lens driving device is arranged so as to be overlapped. 7. A combination of the driving force generated from each of the pair of planar coils forming the focus driving coil becomes a driving force in a focus direction, and a combination of the driving force generated from each of the pair of planar coils forming the tracking driving coil. The lens driving device according to claim 1, wherein a combination of the generated driving force is a tracking driving force. 8. A lens holder having a bearing hole fitted in a shaft extending in a focus direction, and slidably and rotatable with respect to the shaft, a focus driving coil attached to the lens holder, and A tracking drive coil,
A magnetic flux applying unit that applies a magnetic flux to the focus drive coil and the tracking drive coil, wherein the focus drive coil and the tracking drive coil each have a coil axis perpendicular to a focus direction. The magnetic flux applying means is configured to include two coils divided by imaginary lines inclined with respect to both the focus direction and the tracking direction of the coil. Wherein the imaginary lines of each of the pair of coils are arranged symmetrically with respect to a plane including the axis.