WO2011013205A1

WO2011013205A1 - Objective lens drive device, optical pickup, and optical recording and playback device

Info

Publication number: WO2011013205A1
Application number: PCT/JP2009/063430
Authority: WO
Inventors: 武浩松田
Original assignee: パイオニア株式会社
Priority date: 2009-07-28
Filing date: 2009-07-28
Publication date: 2011-02-03

Abstract

An objective lens drive device and an optical pickup are reduced in size and weight. In the objective lens drive device, respective coil patterns of first and second focus coils (16a, 17a) and respective coil patterns of first and second track coils (18a, 19a) are formed and arranged side by side on a first printed coil board (13) and, at the same time, both the other coil pattern of each of the first and second focus coils, which patterns have a dual spiral form and are separated from each other a predetermined distance, and the other coil pattern of each of the first and second track coils are formed and arranged on a second printed coil board. In a lens holder (11), the width (W2) of a front face (11ba) of a front coil mounting section (11b) is substantially equal to the width of the first printed coil board (13) and, at the same time, the width (W1) of a rear face (11ca) of a rear coil mounting section (11c) is substantially equal to the width of the second printed coil board. The first printed coil board (13) is mounted to the front face (11ba) of the front coil mounting section (11b), and the second print coil board is mounted to the rear face of the rear coil mounting section (11c).

Description

Objective lens driving device, optical pickup and optical recording / reproducing device

The present invention relates to an objective lens driving device for driving an objective lens constituting an optical pickup for recording or reproducing information on an optical recording medium such as an optical disk in a focus direction and a radial direction (tracking direction), and the like. The present invention relates to an optical pickup provided and an optical recording / reproducing apparatus equipped with the optical pickup. Here, when the side on which the optical recording medium is disposed with respect to the objective lens driving device is the upper side, the vertical direction is the focus direction, and the direction along the radius of the optical recording medium is the radial direction.

Some conventional objective lens driving devices include a drive magnet disposed in the vicinity of a focus coil and a track coil attached to an objective lens holding member (lens holder) that holds the objective lens. The driving magnet is divided by a magnetization boundary line in the focus direction, a substantially L-shaped magnetization boundary line in the focus direction and in the radial direction, and a lens holder, and the substantially L-shaped magnetization boundary line has two sides. There is provided a magnetized area composed of a substantially rectangular area, a magnetization boundary line in the focus direction, and a substantially L-shaped area surrounded by a substantially L-shaped magnetization boundary line.

The focus coil is disposed at a position straddling one side extending in the radial direction of the substantially L-shaped magnetization boundary line and facing the substantially rectangular region and the substantially L-shaped region. On the other hand, the track coil is disposed at a position straddling the magnetization boundary line in the focus direction and a part of the track coil is opposed to the longest side portion in the focus direction of the substantially L-shaped region (for example, patent Reference 1). Hereinafter, this technique is referred to as a first conventional example.

In addition, the conventional objective lens driving device is arranged to face the tangential direction with respect to the lens holder that holds the objective lens, and is divided into the focus direction and the radial direction, respectively, and the magnetization direction is directed to the tangential direction. The first magnet having the first to fourth divided regions magnetized in this manner and the first magnet opposed to the first magnet in the tangential direction and reversely magnetized with respect to the first magnet Some have a second magnet. Here, the tangential direction with respect to the track of the optical disc perpendicular to both the focus direction and the radial direction is the tangential direction.

The lens holder is provided with a track coil, a focus coil, and first and second tilt coils. The track coil includes first and second divided regions adjacent in the radial direction of the first magnet, third and fourth divided regions adjacent in the radial direction of the first magnet, and second of the second magnet. Corresponding to the areas facing the first and second divided areas and the areas facing the third and fourth divided areas of the second magnet, respectively, are provided at four locations that generate the driving force in the radial direction. Yes.

The focus coil includes first and third divided regions adjacent to the first magnet in the focus direction, second and fourth divided regions adjacent to the first magnet in the focus direction, and second magnets of the second magnet. Corresponding to the areas facing the first and third divided areas and the areas facing the second and fourth divided areas of the second magnet, respectively, are provided at four locations that generate driving force in the focus direction. Yes.

The first tilt coil is wound with the focus direction as the winding axis direction, the first and second divided regions adjacent to each other in the radial direction of the first magnet, and the first and second divided portions of the second magnet. A driving force is generated in the tilt direction corresponding to the region facing the region. On the other hand, the second tilt coil corresponds to the third and fourth divided regions adjacent to each other in the radial direction of the first magnet and the region facing the third and fourth divided regions of the second magnet. Thus, a driving force is generated in the tilt direction (see, for example, Patent Document 2). Hereinafter, this technique is referred to as a second conventional example.

Furthermore, some conventional objective lens driving devices include a lens holder provided with a notch through which a light beam incident from a direction orthogonal to the optical axis of the objective lens is passed in a part of the side wall. A pair of coil substrates is bonded to the side wall of the lens holder with the objective lens interposed therebetween. Each coil substrate has a track coil, a focus coil, and a radial tilt coil inside. In this objective lens driving device, the focus coils in the pair of coil substrates are arranged diagonally on the side wall of the lens holder with the center of gravity of the movable part interposed therebetween (see, for example, Patent Document 3). Hereinafter, this technique is referred to as a third conventional example.

JP 2006-260712 A Japanese Patent No. 4148221 JP 2007-234112 A

In the first and second conventional examples described above, the external appearance of the lens holder that holds the objective lens and to which the focus coil and the track coil are attached has a substantially rectangular parallelepiped shape. Therefore, the length of the lens holder in the radial direction, in other words, the length in the direction perpendicular to the tangential direction (hereinafter referred to as “lens holder width”) is the entire length parallel to the tangential direction of the lens holder. It is almost the same.

As described above, the conventional lens holder has a substantially rectangular parallelepiped appearance, with a pair of surfaces on both sides orthogonal to the tangential direction of the lens holder (hereinafter referred to as “lens holder front and back”). This is because it is necessary to mount the focus coils in parallel. As described above, since the width of the lens holder is substantially the same from the front to the back of the lens holder, the movable part including the lens holder, the objective lens driving device including the movable part, and thus the objective lens driving device are provided. There has been a problem that it is difficult to reduce the size and weight of the optical pickup.

Further, in the above-described third conventional example, as can be seen from FIGS. 5 to 7 of Patent Document 3, of the pair of coil substrates, the one provided on the side where the notch of the lens holder is formed is , Protruding from the lens holder. Therefore, there is a problem that it is difficult to reduce the size of the optical pickup provided with the objective lens driving device.

The present invention has been made in view of the above-described circumstances, and is intended to solve the above-described problems as an example, and an objective lens driving device and a light that can solve these problems An object is to provide a pickup and an optical recording / reproducing apparatus.

In order to solve the above-mentioned problem, an objective lens driving device according to the invention of claim 1 is formed by laminating a lens holder on which an objective lens is mounted and a plurality of spiral coil patterns with an insulating member interposed therebetween. First and second printed coil substrates, each of which has a coil pattern on each of the pair of first and second focus coils for moving the objective lens in the focus direction. And one coil pattern of a pair of track coils for moving the objective lens in the radial direction are formed in parallel, and the second printed coil substrate has a double spiral shape separated by a predetermined distance. The other coil pattern of each of the first and second focus coils formed on the track coil and the other coil pattern of the track coil are arranged in parallel. In the lens holder, the width of one coil mounting portion facing the tangential direction orthogonal to the focus direction and the radial direction is substantially equal to the width of the first printed coil substrate, and the tangential direction The width of the other coil mounting part opposite to the second printed coil board is substantially equal to the width of the second printed coil board, and the first printed coil board is attached to the one coil mounting part of the lens holder. The second printed coil board is attached to the other coil attachment portion.

It is a perspective view which shows schematic structure of the movable part which is a part of objective lens drive device based on Embodiment 1 of this invention. It is a figure which shows schematic structure of the movable part shown in FIG. 1, (a) is a front view, (b) is a top view, (c) is a rear view. It is the schematic which showed an example of the coil pattern formed in the one surface side of the 2nd printed coil board | substrate which comprises the movable part shown in FIG. It is the schematic which showed an example of the coil pattern formed in the other surface side of the 2nd printed coil board | substrate which comprises the movable part shown in FIG. It is a perspective view which shows schematic structure of the movable part as a comparative example. It is a rear view which shows schematic structure of the movable part as a comparative example shown in FIG. It is a perspective view which shows schematic structure of the movable part which is a part of objective lens drive device based on Embodiment 2 of this invention. It is the perspective view which looked at schematic structure of the movable part shown in FIG. 7 from the angle different from FIG. It is the schematic which shows the structure of the optical recording / reproducing apparatus which concerns on Embodiment 3 of this invention.

Embodiment 1 FIG.
FIG. 1 is a perspective view showing a schematic configuration of a movable unit 1 that is a part of the objective lens driving apparatus according to Embodiment 1 of the present invention, and FIG. 2 is a diagram showing a schematic configuration of the movable unit 1 shown in FIG. (A) is a front view, (b) is a plan view, and (c) is a rear view. The movable part 1 according to the first embodiment is generally configured by a lens holder 11, an objective lens 12, a first printed coil board 13, a second printed coil board 14, and printed

boards

15a and 15b. .

The lens holder 11 is integrally formed by injection molding or extrusion molding using a lightweight and highly rigid synthetic resin as a raw material. Examples of the synthetic resin include liquid crystal polymer (LCP) and polyphenylene sulfide (PPS). The lens holder 11 may be made of the above synthetic resin whose glass fiber or carbon is used to enhance the rigidity.

The lens holder 11 has a substantially T-shaped planar shape as shown in FIGS. 1 and 2 (b), and a substantially U-shaped front surface as shown in FIGS. 1 and 2 (a). The lower part is open and hollow. The lens holder 11 is configured by integrally forming a lens mounting portion 11a, a front coil attachment portion 11b, and a rear coil attachment portion 11c. The objective lens 12 is fixed to the periphery of the through-hole 11aa formed in the approximate center of the lens mounting portion 11a with, for example, an adhesive.

The objective lens 12 condenses the parallel light beam from the preceding optical component constituting the optical pickup on the information recording surface of the optical disc and converts the reflected light beam from the optical disc into a parallel light beam. The objective lens 12 is integrally formed by injection molding or extrusion molding using synthetic resin such as olefin resin (for example, cycloolefin), acrylic resin (for example, PMMA), and methacrylic resin as a raw material. The objective lens 12 has a substantially disk shape as a whole, and the lower surface thereof is a spherical or aspheric convex curved surface forming a lens surface.

As shown in FIGS. 1 and 2, the first printed coil substrate 13 is fixed to the front surface 11ba perpendicular to the tangential direction (T direction) of the front coil mounting portion 11b by, for example, an adhesive. On the other hand, the second printed coil substrate 14 is fixed to the back surface 11ca orthogonal to the tangential direction (T direction) of the rear coil mounting portion 11c with, for example, an adhesive. The width of the front coil mounting portion 11 b is substantially equal to the width of the first printed coil substrate 13, and the width of the rear coil mounting portion 11 c is approximately equal to the width of the second printed coil substrate 14.

The first and second printed

coil boards

13 and 14 are formed by forming a plurality of spiral coil patterns on the printed board in a layered manner with an insulating member interposed therebetween. On the first printed coil board 13, coil patterns of a first focus coil 16a, a second focus coil 17a, a first track coil 18a and a second track coil 19a are formed in parallel. On the other hand, each of the first focus coil 16b and the second focus coil 17b, the first track coil 18b, and the second track coil 19b formed in a double spiral shape at a predetermined distance on the second printed coil substrate 14 is provided. Coil patterns are arranged in parallel.

FIG. 3 is a schematic view showing an example of a coil pattern formed on one surface side of the second printed coil substrate 14, and FIG. 4 shows an example of a coil pattern formed on the other surface side of the second printed coil substrate 14. FIG. The first focus coil 16b starts to form a coil pattern from the start point 16ba and is formed in a spiral shape toward the center in the clockwise direction in FIG. 3. When the first focus coil 16b reaches approximately the center, the other side of the first focus coil 16b passes through the through hole 16bb. It is connected to the coil pattern formed in. On the other surface side of the second printed coil board 14, the first focus coil 16b starts to form a coil pattern from the through hole 16bb, and is formed in a spiral shape outward in the clockwise direction in FIG. The lower right end point 16bc is reached.

On the other hand, the second focus coil 17b is formed spirally from the start point 17ba toward the center in FIG. 3 in the clockwise direction with respect to the first focus coil 16b, for example, with an interval of about 45 μm. Is connected to a coil pattern formed on the other surface side. On the other surface side of the second printed coil substrate 14, the second focus coil 17b faces the first focus coil 16b outward from the through hole 17bb in the clockwise direction in FIG. It is formed in a spiral shape and reaches the lower right end point 17bc in FIG.

Each coil pattern is made of a highly conductive material such as aluminum (Al) or copper (Cu). Each coil pattern is a thin film multilayer using, for example, chemical vapor deposition (CVD), vacuum deposition, sputtering, ion plating, photolithography, etching, plating, etc. Formed in the structure. Each coil pattern has a thickness direction of the first and second printed coil substrates 13 and 14 (a tangential direction (T) when the first and second printed

coil substrates

13 and 14 are attached to the lens holder 11. It is formed in a spiral shape with the direction along the direction) as the central axis. For details of the printed coil substrate, refer to, for example, Japanese Patent Application Laid-Open No. 2007-80305 and Japanese Patent Application Laid-Open No. 2006-332099.

The length of the first focus coil 16a and the second focus coils 17a and 17b in the focus direction (optical axis direction) (F direction) is longer than the length in the radial direction (R direction). When the first printed coil board 13 is mounted on the front surface 11ba of the front coil mounting portion 11b, the first focus coil 16a is positioned on the front surface of the front coil mounting portion 11b as shown in FIGS. It is arrange | positioned at the one end part of the radial direction (R direction) of 11ba. On the other hand, when the first printed coil board 13 is mounted on the front surface 11ba of the front coil mounting portion 11b, the second focus coil 17a has a front coil mounting portion 11b as shown in FIGS. 1 and 2A. Is disposed at the other end of the front surface 11ba in the radial direction (R direction).

Further, the first focus coil 16b and the second focus coil 17b formed in a double spiral shape are shown in FIG. 2B when the second printed coil substrate 14 is attached to the back surface 11ca of the rear coil attachment portion 11c. And as shown to (c), it arrange | positions in the approximate center of the back surface 11ca of the rear part coil attachment part 11c. Although not shown, the first focus coil 16a and the first focus coil 16b are electrically connected, and the second focus coil 17a and the second focus coil 17b are electrically connected.

Furthermore, the

first track coils

18a and 18b and the second track coils 19a and 19b have substantially the same length in the focus direction (optical axis direction) (F direction) and radial direction (R direction). When the first printed coil board 13 is attached to the front surface 11ba of the front coil attachment portion 11b, the first track coil 18a and the second track coil 19a are arranged in the first focus coil 16a on the front surface 11ba of the front coil attachment portion 11b. And the second focus coil 17a are arranged in parallel in the radial direction (R direction). On the other hand, the first track coil 18b and the second track coil 19b are doubled on the upper end of the back surface 11ca of the rear coil mounting portion 11c when the second printed coil board 14 is mounted on the back surface 11ca of the rear coil mounting portion 11c. The first focus coil 16b and the second focus coil 17b that are formed in a spiral shape are disposed therebetween.

Thus, on the front surface 11ba of the front coil mounting portion 11b, as shown in FIGS. 1 and 2A, the first focus coil 16a, the first track coil 18a, the second track coil 19a, and the second focus coil 19a are arranged in parallel. On the other hand, on the back surface 11ca of the rear coil mounting portion 11c, as shown in FIGS. 1 and 2C, the first track coil 18b, the first focus coil 16b formed in a double spiral shape, and the second A focus coil 17b and a second track coil 19b are arranged in parallel.

Therefore, as shown in FIG. 1, the radial length of the rear coil mounting portion 11c, in other words, the length in the direction perpendicular to the tangential direction (hereinafter referred to as “the width of the rear coil mounting portion 11c”) W1. Is the radial length of the front coil mounting portion 11b, in other words, the length in the direction orthogonal to the tangential direction (hereinafter referred to as “the width of the front coil mounting portion 11b”) W2. The length corresponding to the width of the first focus coil 16b is small.

Printed

boards

15a and 15b are respectively attached to the back surfaces 11bb and 11bc orthogonal to the tangential direction (T direction) of the front coil attaching part 11b. Each printed

circuit board

15a and 15b is made of a conductive elastic body, and one end of each of the four suspension wires 20 having flexibility is soldered and fixed at a predetermined interval. On the other hand, each other end side of the suspension wire 20 is soldered and fixed to a printed circuit board (hereinafter referred to as “fixed part side printed circuit board”) attached to a wire base constituting the fixed part, although none is illustrated. Yes. Thereby, the movable part 1 is cantilevered by the wire base and the fixed part side printed circuit board via the suspension wire 20, and is elastically supported so as to be relatively displaceable with respect to the fixed part.

Also, one end of each of the first focus coils 16a and 16b, the second focus coils 17a and 17b, the

first track coils

18a and 18b, and the second track coils 19a and 19b is soldered to each end of the suspension wire 20. Are electrically connected. On the other hand, each other end of the suspension wire 20 is electrically connected to a lens driving circuit 48 (see FIG. 9) via a fixed portion side printed board. That is, the suspension wire 20 functions as an elastic body (support) for supporting the movable portion 1, the first focus coils 16 a and 16 b, the second focus coils 17 a and 17 b, the first track coils 18 a and 18 b, It also has a function as a lead wire for supplying power to the second track coils 19a and 19b. The suspension wire 20 may be another elastic body such as a leaf spring, a coil spring, or conductive rubber. The movable part 1 described above is irradiated with a light beam along the tangential direction from the front surface 11ba side of the front coil attachment part 11b of the lens holder 11, and the inside of the movable part 1 from the concave part 11bd of the front coil attachment part 11b. The light beam enters.

Here, for comparison with the first embodiment, each of the first focus coil 16b, the second focus coil 17b, the first track coil 18b, and the second track coil 19b is provided on the back surface of the rear coil mounting portion of the lens holder. A schematic configuration of the movable portion 21 when it is assumed that the second printed coil substrate 23 formed by arranging the coil patterns in parallel (hereinafter referred to as “comparative example”) will be described. FIG. 5 is a perspective view showing a schematic configuration of the movable portion 21 as a comparative example, and FIG. 6 is a rear view showing the schematic configuration of the movable portion 21 shown in FIG.

The movable part 21 shown in FIGS. 5 and 6 is different from the movable part 1 shown in FIGS. 1 and 2 in that a lens holder 22 is provided instead of the lens holder 11 and the second printed coil substrate 14 is provided. In other words, the second printed coil substrate 23 is provided. 5 and FIG. 6, the same reference numerals are given to the parts corresponding to the respective parts in FIG. 1 and FIG.

The lens holder 22 is formed by substantially the same manufacturing method using substantially the same raw material as the lens holder 11. As shown in FIGS. 5 and 6, the lens holder 22 has a substantially rectangular planar shape, a substantially U-shaped front surface, an open bottom, and is hollow. The lens holder 22 is configured by integrally forming a lens mounting portion 22a, a front coil attachment portion 22b, and a rear coil attachment portion 22c. The objective lens 12 is fixed to, for example, an adhesive or the like in a through hole 22aa that is formed in the approximate center of the lens mounting portion 22a.

As can be seen from FIGS. 5 and 6, in the movable portion 21 as a comparative example, the first focus coil 16 b, the second focus coil 17 b, and the first track coil 18 b are provided on the back surface 22 ca of the rear coil mounting portion 22 c of the lens holder 22. And in order to attach the 2nd printed coil board | substrate 23 formed by arranging each coil pattern of the 2nd track coil 19b in parallel, the lens holder 22 is exhibiting the substantially rectangular parallelepiped shape. In addition, in order to attach the suspension wire 20 to the lens holder 22, projecting

portions

22d and 22e having a substantially prismatic shape are integrally formed on both side surfaces 22ab and 22ac of the lens mounting portion 22a.

In Embodiment 1 of the present invention, as shown in FIGS. 1 and 2, the width W2 of the front surface 11ba perpendicular to the tangential direction (T direction) of the front coil mounting portion 11b of the lens holder 11 is the first print. It is approximately equal to the width of the coil substrate 13. On the other hand, the width W1 of the back surface 11ca perpendicular to the tangential direction (T direction) of the rear coil mounting portion 11c of the lens holder 11 is substantially equal to the width of the second printed coil substrate 14.

The first coil 11a, the second focus coil 17a, the first track coil 18a and the second track coil 19a are arranged in parallel on the front surface 11ba of the front coil mounting portion 11b. 1 printed coil board 13 is attached, and the coil patterns of the first focus coil 16b and the second focus coil 17b formed in a double spiral shape with a predetermined distance are provided on the back surface 11ca of the rear coil attachment portion 11c. A second printed coil substrate 14 formed by arranging the coil patterns of the first track coil 18b and the second track coil 19b in parallel is attached.

The four suspension wires 20 are fixed by soldering to the printed

circuit boards

15a and 15b attached to the back surfaces 11bb and 11bc of the front coil attachment portion 11b. Therefore, the width of the movable portion 1 is substantially equal to the width W2 of the front surface 11ba of the front coil mounting portion 11b of the lens holder 11.

On the other hand, in the comparative example shown in FIGS. 3 and 4, the width W2 of the front surface 22ba perpendicular to the tangential direction (T direction) of the front coil mounting portion 22b of the lens holder 22 and the rear coil mounting of the lens holder 22 The width W2 of the back surface 22ca orthogonal to the tangential direction (T direction) of the portion 22c is equal. And, on the front surface 22ba of the front coil mounting portion 22b, the coil patterns of the first focus coil 16a, the second focus coil 17a, the first track coil 18a and the second track coil 19a are arranged in parallel. The first printed coil board 13 is attached, and the coil patterns of the first focus coil 16b, the second focus coil 17b, the first track coil 18b, and the second track coil 19b are formed on the back surface 22ca of the rear coil attachment portion 22c. A second printed coil substrate 23 formed in parallel is attached. Further, four suspension wires 20 are fixed by soldering to

protrusions

22d and 22e formed integrally on both side surfaces 22ab and 22bb of the lens mounting portion 22a. Therefore, the width of the movable portion 21 is substantially equal to the distance W3 from the protruding portion 22d to the protruding portion 22e.

As described above, in Embodiment 1 of the present invention, the width W2 of the movable part 11 can be made smaller than the width W3 of the conventional movable part 21, so that the objective lens driving device including the movable part 11 and thus The optical pickup provided with this objective lens driving device can be reduced in size and weight. For this reason, the sensitivity of the optical pickup is increased and the performance is improved. Some optical disc standards record information in an area closer to the center of rotation of the optical disc than other optical disc standards. In the first embodiment of the present invention, such a standard is applied. Information can also be recorded and reproduced on an optical disk.

Spindle motors that rotate optical disks generally become more severe in terms of performance such as rotational torque, difficulty in design, and price as the size of the motor is reduced. However, according to the first embodiment of the present invention, since the width of the movable portion 11 can be made smaller than before, information can be recorded in an area close to the rotation center of the optical disk without downsizing the spindle motor. Information can be recorded and reproduced on an optical disc to which the standard is applied.

Furthermore, in the first embodiment of the present invention, a plurality of spiral coil patterns are formed on a printed circuit board in a layered manner with an insulating member interposed therebetween, not a coil configured by winding a wire rod. A printed coil board is used. The second printed coil substrate 14 is formed with a first focus coil 16b and a second focus coil 17b that are formed in a double spiral shape at an extremely narrow distance of about 45 μm.

Accordingly, each coil pattern of the first focus coil 16b and the second focus coil 17b is compared with a case where coils configured by winding a wire are stacked one above the other (hereinafter referred to as “winding coil example”). In other words, it can be considered that they are formed on substantially the same path.

In the case of the winding coil example, since the distance between the pair of first focus coils is different from the distance between the pair of second focus coils, when the same current flows through the first and second focus coils, Since the thrust based on the pair of first focus coils is different from the thrust based on the pair of second focus coils, the radial tilt adjustment cannot be performed with high accuracy. Therefore, in the winding coil example, fine adjustment of the thrust is required.

On the other hand, in the first embodiment of the present invention, the coil patterns of the first focus coil 16b and the second focus coil 17b can be regarded as being formed on substantially the same path. Fine adjustment of thrust as in the coil example is not necessary.

Embodiment 2. FIG.
FIG. 7 is a perspective view showing a schematic configuration of the movable portion 31 which is a part of the objective lens driving device according to Embodiment 2 of the present invention. 8 is a perspective view of the schematic configuration of the movable unit 31 shown in FIG. 7 viewed from an angle different from that in FIG. The movable portion 31 according to the second embodiment is generally configured by a lens holder 32, an objective lens 33, a first printed coil substrate 34, and a second printed coil substrate 35.

The lens holder 32 is formed by substantially the same manufacturing method using substantially the same raw material as the

lens holders

11 and 22. As shown in FIG. 7, the lens holder 32 has a notch 32a formed in a part of the lower part of the left side wall and a part of the lower part of the front side wall, and the lower part is open and hollow. The objective lens 33 is fixed to the through-hole 32b drilled in the upper part of the lens holder 32 with, for example, an adhesive. The objective lens 33 is formed in substantially the same shape by substantially the same manufacturing method using substantially the same raw material as the objective lens 12.

A first printed coil substrate 34 having a substantially plate shape is attached to the front portion of the lens holder 32. On the first printed coil board 34, the coil patterns of the first focus coil 36a and the second focus coil 37a formed in a double spiral shape at a predetermined distance and the coil pattern of the track coil 38a are arranged in parallel. It is arranged and formed. On the other hand, a second printed coil substrate 35 having a substantially plate shape is attached to the rear portion of the lens holder 32. On the second printed coil board 35, coil patterns of the first focus coil 36b, the second focus coil 37b, and the track coil 38b are formed in parallel. The first and second printed

coil substrates

34 and 35 are formed by substantially the same manufacturing method using substantially the same raw material as the first and second printed

coil substrates

13 and 14.

At both ends of the lens holder 32, one end side of each of the four suspension wires 39 made of a conductive elastic body and having flexibility is fixed by soldering at a predetermined interval.

In the first embodiment described above, as shown in FIGS. 1 and 2, the movable portion 1 is irradiated with a light beam along the tangential direction from the front surface 11ba side of the front coil mounting portion 11b of the lens holder 11. The light beam enters the movable portion 1 from the concave portion 11bd of the front coil attachment portion 11b.

On the other hand, in Embodiment 2 of the present invention, the movable part 31 is irradiated with a light beam from a direction in which the tangential direction in front of the lens holder 32 and the radial direction form a predetermined angle. The light beam enters the movable part 31 from the notch part 32a formed in the front part. In the case of such a structure, conventionally, the first printed coil board 34 protrudes from the right end of the lens holder 32 as in the above-described third conventional example. However, in the second embodiment of the present invention, since the first focus coil 36a and the second focus coil 37a are formed in a double spiral coil pattern, the first printed coil substrate 34 is the lens holder 32. It does not protrude from the right end of Therefore, the optical pickup provided with the objective lens driving device having the movable portion 31 can be reduced in size, and fine adjustment of the thrust becomes unnecessary.

Embodiment 3 FIG.
FIG. 9 is a schematic diagram showing a configuration of an optical recording / reproducing apparatus according to Embodiment 3 of the present invention. This optical recording / reproducing apparatus includes an optical pickup 41, a spindle motor 42, a spindle motor drive circuit 43, a controller 44, a feed motor 45, a feed motor drive circuit 46, a laser drive circuit 47, and a lens drive circuit 48. It is roughly composed of

The optical pickup 41 includes an objective lens driving device having the movable part 1 according to the first embodiment or the movable part 31 according to the second embodiment. The optical pickup 41 condenses a light beam of a predetermined wavelength emitted from a semiconductor laser as a light source on the information recording surface of the optical disk 49 to record or read information, and also reflects a reflected light beam from the optical disk 49 as an electric signal. And photoelectrically convert it into a detection signal.

The spindle motor drive circuit 43 drives the spindle motor 42 under the control of the controller 44 to rotate the optical disc 49. The controller 44 controls the spindle motor drive circuit 43, the feed motor drive circuit 46, the laser drive circuit 47, and the lens drive circuit 48 based on the detection signal supplied from the optical pickup 41, respectively.

The feed motor drive circuit 46 drives the feed motor 45 under the control of the controller 44 to move the optical pickup 41 in the radial direction of the optical disk 49. The laser drive circuit 47 generates a laser drive signal for driving a semiconductor laser (not shown) constituting the optical pickup 41 under the control of the controller 44 and supplies the laser drive signal to the optical pickup 41. The lens driving circuit 48 generates a lens driving signal for controlling the focus, tracking, and radial tilt of the

objective lens

12 or 33 constituting the optical pickup 41 under the control of the controller 44, and supplies the lens driving signal to the optical pickup 41.

The controller 44 includes a focus servo tracking circuit 51, a tracking servo tracking circuit 52, a tilt adjustment circuit 53, a collimating lens adjustment circuit 54, and a laser control circuit 55. The focus servo tracking circuit 51 is emitted from the optical pickup 41 to the information recording surface of the rotating optical disk 49 based on a focus error signal (FE signal) generated by calculation from the detection signal supplied from the optical pickup 41. A focus servo signal for focusing the obtained light beam is generated and supplied to the lens driving circuit 48.

The tracking servo tracking circuit 52 performs the optical pickup 41 with respect to the eccentric signal track of the optical disk 49 based on a tracking error signal (TE signal) generated by calculation from the detection signal supplied from the optical pickup 41. A tracking servo signal for tracking the beam spot of the light beam emitted from the lens is generated and supplied to the lens driving circuit 48. The tilt adjustment circuit 53 is for tilting the

objective lens

12 or 33 constituting the optical pickup 41 in the radial direction based on the TE signal or other signal generated by calculation from the detection signal supplied from the optical pickup 41. A tilt adjustment signal is generated and supplied to the lens driving circuit 48.

The collimating lens adjusting circuit 54 is a collimating lens for adjusting a collimating lens (not shown) constituting the optical pickup 41 based on the FE signal or the TE signal generated by calculation from the detection signal supplied from the optical pickup 41. An adjustment signal is generated and supplied to the lens driving circuit 48. The laser control circuit 55 generates an appropriate laser drive signal based on the recording condition setting information recorded on the optical disc 49 extracted from the detection signal supplied from the optical pickup 41.

The controller 44 may be configured by hardware such as a digital signal processor (DSP) and a sequencer, and the CPU (central processing unit) has the focus servo tracking circuit 51, the tracking servo tracking circuit 52, the tilt adjustment circuit 53, The processes performed by the collimating lens adjustment circuit 54 and the laser control circuit 55 may be executed based on a program.

As described above, according to the third embodiment of the present invention, an optical recording / reproducing apparatus is provided using the optical pickup 41 including the objective lens driving device having the

movable part

1 or 31 according to the first or second embodiment. It is composed. Therefore, this optical recording / reproducing apparatus can reduce the size and weight of the objective lens driving device including the

movable portion

1 or 31, and by extension, the optical pickup 41 provided with the objective lens driving device.

For this reason, the sensitivity of the optical pickup 41 is increased and the performance is improved. Also, information can be recorded and reproduced on the optical disc 49 to which a standard for recording information in an area closer to the center of rotation of the optical disc 49 is applied compared to other optical disc standards.

As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and the design can be changed without departing from the scope of the present invention. Is included in the present invention.
For example, in each of the above-described embodiments, the example in which the focus coils are stacked has been described. However, the present invention is not limited to this, and track coils may be stacked.

DESCRIPTION OF

SYMBOLS

1,31 ... Movable part, 11, 32 ... Lens holder, 11a ... Lens mounting part, 11aa ... Through-hole, 11b ... Front coil attachment part, 11ba ... Front, 11bb, 11bc ... Back, 11bd ... Recess, 11c ... Rear Coil mounting portion, 11ca ... back surface, 12, 33 ... objective lens, 13, 34 ... first printed coil substrate, 14, 35 ... second printed coil substrate, 15a, 15b ... printed substrate, 16a, 16b, 36a, 36b ... First focus coil, 16ba, 17ba ... start point, 16bb, 17bb ... through hole, 16bc, 17bc ... end point, 17a, 17b, 37a, 37b ... second focus coil, 18a, 18b ... first track coil, 19a, 19b ... second track coil, 20, 39 ... suspension wire, 32a ... notch, 3 b ... through hole, 38a, 38b ... track coil, 41 ... optical pickup, 42 ... spindle motor, 43 ... spindle motor drive circuit, 44 ... controller, 45 ... feed motor, 46 ... feed motor drive circuit, 47 ... laser drive circuit 48 ... Lens drive circuit, 49 ... Optical disk, 51 ... Focus servo tracking circuit, 52 ... Tracking servo tracking circuit, 53 ... Tilt adjustment circuit, 54 ... Collimate lens adjustment circuit, 55 ... Laser control circuit

Claims

A lens holder on which the objective lens is mounted, and first and second printed coil substrates formed by laminating a plurality of spiral coil patterns in layers with an insulating member interposed therebetween,
The first printed coil board includes a pair of coil patterns for moving the objective lens in the focus direction and a pair of first and second focus coils for moving the objective lens in the radial direction. Is formed in parallel with one coil pattern of the track coil,
On the second printed coil substrate, the other coil pattern of the first and second focus coils and the other coil pattern of the track coil, which are formed in a double spiral shape at a predetermined distance, are arranged in parallel. Arranged and formed,
In the lens holder, the width of one coil mounting portion facing the tangential direction orthogonal to the focus direction and the radial direction is substantially equal to the width of the first printed coil substrate, and the other facing the tangential direction. The width of the coil mounting portion is substantially equal to the width of the second printed coil substrate;
The first printed coil substrate is attached to the one coil attachment portion of the lens holder,
The second printed coil substrate is attached to the other coil attachment portion of the lens holder. Objective lens driving device, wherein:
An optical pickup comprising the objective lens driving device according to claim 1.
An optical recording / reproducing apparatus comprising the optical pickup according to claim 2.