JP2003272201A - Optical pickup device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical pickup device which does not cause breaking of a wire and a short circuit due to an external factor and has an improved yield. <P>SOLUTION: Coils (37, 39, 41) include a tracking coil (37) which collaborates with magnets (31, 32) during energization in applying a movement force to a lens holder (24) in a track direction, a focusing coil (39) which applies a movement force to the lens holder in a focusing direction, and a tilting coil (41) which collaborates with the magnet during the energization in applying a movement force to the lens holder in a tilt direction. The tracking coil, the focusing coil, and the tilting coil are formed in the multilayer substrate (26), and the multilayer substrate is held by the lens holder. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup device provided in an optical disk drive or the like, and more particularly to an optical pickup device in which an objective lens can be displaced.

[0002]

2. Description of the Related Art Recently, an optical disk drive is often mounted on an electronic device such as a personal computer. CD-R (compact disc recordable), CD-R as one of the recording media usable for the optical disc drive
W (compact disc rewritable) is known. CD
-R is a recording medium on which additional recording can be repeated and is a CD-
RW is a rewritable recording medium, but a CD-ROM
It is also compatible with audio CDs (CD-DA). CD
-R, CD-RW requires a dedicated device and writing application to write to CD-R, CD-R
Reading from W can be performed with a normal CD-ROM drive. CD-R, CD-RW, CD-ROM, audio CD, DVD-ROM, DVD-R, DVD-R
W, DVD + RW, DVD-RAM, etc. are collectively referred to as an optical disc here.

An optical pickup device is used to record and reproduce data on such an optical disc. The optical pickup device includes an objective lens arranged to face the optical disc. The objective lens is held by the lens holder.

In order to finely adjust the position of the objective lens in the focus direction along the optical axis of the objective lens and the track direction intersecting the focus direction, the lens holder is movably held by the base member by the holder support mechanism. There is.
Then, the lens holder is moved as necessary by an adjustment drive device that is a combination of a magnet and a coil.

The main part of the prior art optical pickup device will be described with reference to FIGS. 7 to 9 as well. The optical base 10 includes a fixed actuator base 21. A damper base 22 is fixed to the actuator base 21. The actuator base 21 and the damper base 22 are collectively referred to as a base member.

A lens holder 24 is movably supported on the damper base 22 by four suspension wires 23 having conductivity and elasticity extending in a predetermined direction A1. The lens holder 24 includes an objective lens 6 and a bobbin 6
1 is held. One end of each suspension wire 23 is supported by the damper base 22 via a cushion material, and the other end is supported by a projection 261 integrated with the lens holder 24 via a cushion material. In this way, each of the focus direction A2 parallel to the optical axis of the objective lens 6 substantially orthogonal to the predetermined direction A1, the track direction A3 orthogonal to the focus direction A2, and the tilt direction A4 around the predetermined axis extending in the predetermined direction A1. At, these suspension wires 23 movably support the lens holder 24. That is, the suspension wire 23 functions as a holder support mechanism.

The central space of the lens holder 24 is divided into first and second spaces 28a and 28b adjacent to each other in the predetermined direction A1 by a coil support member 27 integral with the lens holder 24. In the first space 28a, first and second magnets 31a and 31b are arranged side by side in the track direction A3 separately on both sides of a predetermined axis and fixed to the actuator base 21. The third is in the second void 28b
And the fourth magnets 32a and 32b move in the track direction A.
3 are arranged side by side on a predetermined axis and are fixed to the actuator base 21. The first magnet 31a is opposed to the third magnet 32a, and the second magnet 31b is the fourth magnet 3a.
It faces 2b.

First to fourth magnets 31a, 31
b, 32a, and 32b are all magnetized in the same direction in the predetermined direction A1. Then, the first magnet 31a uses the yoke 34 to form the third magnet 32a.
The second magnet 31b is magnetically coupled to the fourth magnet 32b using the yoke 35. The arrow 36 indicates the magnetic flux of the magnet.

The coil support member 27 holds first and second tracking coils 37 and 38. That is, the first and second tracking coils 37 and 38 are
The first and second magnets 31a and 31b and the third and fourth magnets 32a and 32b are inserted and arranged at respective intervals. The first and second tracking coils 37 and 38 are capable of being energized in a direction intersecting the magnetic flux 36 through the suspension wire 23. The first and second tracking coils 37 and 38 are provided for the first to fourth magnets 31a, 31b, 32a, and
The lens holder 24 works in the track direction A3 in cooperation with 32b.
It gives the movement power of. Therefore, the position of the objective lens 6 can be finely adjusted in the track direction A1 by controlling the energization of the first and second tracking coils 37 and 38.

A focusing coil 39 is held on the lens holder 24. Focusing coil 39
Is also enabled to pass through the suspension wire 23 in a direction intersecting the magnetic flux 36. However, the current of the focusing coil 39 is equal to the tracking coils 37 and 38.
Shall be orthogonal to the direction of the current. The focusing coil 39 cooperates with the first to fourth magnets 31a, 31b, 32a, 32b to apply a moving force in the focus direction A2 to the lens holder 24 when a direct current is applied. Therefore, the position of the objective lens 6 can be finely adjusted in the focus direction A2 by controlling the energization of the focusing coil 39.

The lens holder 24 also has first and second tilting coils 41, which are wound in opposite phases.
42 is retained. The first and second tilting coils 41 and 42 are located below the focusing coil 39.

First and second tilting coils 41,
42 is capable of conducting electricity in a direction intersecting with the magnetic flux 36 through a conducting wire 43 provided in parallel with the suspension wire 23. This energizing wire 43 also has one end supported by the damper base 22 and the other end supported by the lens holder 24. In the first and second tilting coils 41 and 42, currents flow in opposite directions when a direct current is applied, and therefore the first to fourth magnets 31 a and 31.
In cooperation with b, 32a, and 32b, the lens holder 24 is given a turning force in the tilt direction A4. Therefore, by controlling the energization of the first and second tilting coils 41 and 42, the orientation of the objective lens 6 can be finely adjusted in the tilt direction A4.

In the above optical pickup device,
A total of four magnets 31a, 31b, 32a, 32b are arranged in two places spaced apart in the predetermined direction A1.

Therefore, there is no problem that the magnetic flux density decreases when fine adjustment of the objective lens 6 in the tilt direction A4 is possible. The first to fourth magnets 31
a, 31b, 32a, 32b, first and second tracking coils 37, 38, and focusing coil 39
And the first and second tilting coils 41 and 42 together form an adjustment drive device.

[0015]

In the above-described optical pickup device, the first and second tracking coils 37 and 38 for driving the objective lens 6 for focusing, tracking and radial tilt, the focusing coil 39, and the 1st and 2nd tilting coil 4
1 and 42, a copper wire having a protective film is wound around a bobbin made of a resin material, or an air-core coil made of a fused copper wire is attached to a lens holder 24 for assembly. Since the copper wire is exposed to the outer shape, there is a problem that the copper wire is likely to be broken or short-circuited due to external factors.

Further, since the copper wire is used as a winding wire or an air-core coil, the characteristics of the coil (resistance value, etc.) vary widely, resulting in a variation in the actuator characteristics.

Further, there is a problem that the bobbin 61 and the lens holder 24 must be held by an assembly process.

Therefore, an object of the present invention is to provide an optical pickup device in which disconnection or short circuit failure due to external factors does not occur, and as a result, the yield can be improved.

Another object of the present invention is to provide an optical pickup device which can make the characteristics of the optical pickup uniform.

[0020]

According to the present invention, a base member (21, 22), a lens holder (24), and a holder support mechanism (23) movably supporting the lens holder on the base member. A pair of magnets (31, 32) held by the base member and including an objective lens (6) held by the lens holder, and a plurality of coils held by the lens holder and cooperating with the magnets. (37, 39, 41), wherein the coil cooperates with the magnet to apply a moving force in the track direction to the lens holder when energized.
A focusing coil (39) that cooperates with the magnet to apply a moving force in the focus direction to the lens holder when energized; and a focusing coil (39) that cooperates with the magnet to energize the lens holder when energized. A tilting coil (41) that gives a moving force in a tilt direction around a predetermined axis extending in a direction orthogonal to the direction, and the tracking coil, the focusing coil, and the tilting coil are provided on a multilayer substrate (26). And the multi-layer substrate is held by the lens holder.

The multilayer substrate may be held by the lens holder by insert molding.

The magnets may be arranged at intervals in a direction parallel to the predetermined axis.

The holder support mechanism includes a plurality of suspension wires (23), one end of which is held by the base member and the other end of which is held by the lens holder, and each of the suspension wires has elasticity. May be.

The reference numerals in the above parentheses are given for easy understanding and are merely examples, and the present invention is not limited to these.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An outline of an optical pickup device according to an embodiment of the present invention will be described with reference to FIG. The illustrated optical pickup device can be used for an optical disk driver mounted on an electronic device such as a personal computer, and uses a laser diode 1 which is a semiconductor laser for generating a laser beam as a light emitting element. The laser beam emitted from the laser diode 1 is branched by the beam splitter 2, and a part of the laser beam is incident on the monitor device 3. The other part of the laser beam irradiates the optical disk 7 through the collimator lens 4, the raising mirror 5, and the objective lens 6. The monitor device 3 detects the intensity of the laser beam. The detected intensity is used to control the driving of the laser diode 1. In this way, data can be recorded on the optical disk 7 using the laser beam emitted from the laser diode 1.

The reflected light from the optical disk 7 enters a photodiode 8 as a light receiving element via the objective lens 6, the rising mirror 5, the collimating lens 4, the beam splitter 2 and the like. In this way, the optical disk 7 is produced by using the laser beam emitted from the laser diode 1.
You can play the data from.

The optical pickup device will be described in detail with reference to FIG. 2 in addition to FIG. A beam splitter 2, a collimator lens 4, which is arranged in the path of the laser beam,
Various optical elements such as the rising mirror 5 and the objective lens 6 are collectively referred to as an optical system here. This optical system, laser diode 1, monitor device 3, and photodiode 8
Are held by the optical base 10, which is the device housing. The optical base 10 is movably mounted on the optical disk drive using the guide hole 11. The laser diode 1 is fixed to the diode mounting portion 12 of the optical base 10.

Main portions of the optical pickup device shown in FIG. 2 will be described with reference to FIGS. The same parts as those described in the prior art are designated by the same reference numerals, and the description of the partial configuration is omitted.

The optical base 10 includes a fixed actuator base 21. A damper base 22 is fixed to the actuator base 21. Here, the actuator base 21 and the damper base 22 are collectively referred to as a base member.

A lens holder 24 is movably supported on the damper base 22 by four suspension wires 23 having conductivity and elasticity extending in a predetermined direction A1. The objective lens 6 is fixedly held in the lens holder 24.

One end of each suspension wire 23 is supported by the damper base 22 via a cushion material 221, and the other end is supported by both ends of a multilayer substrate 26 integrally provided with the lens holder 24. Multilayer substrate 26
Is a plate-like body that is long in the track direction A3. Thus
In each of a focus direction A2 parallel to the optical axis of the objective lens 6 substantially orthogonal to the predetermined direction A1, a track direction A3 orthogonal to the focus direction A2, and a tilt direction A4 around a predetermined axis extending in the predetermined direction A1. The suspension wire 23 movably supports the lens holder 24. That is, the suspension wire 23 functions as a holder support mechanism.

The central space of the lens holder 24 is divided into first and second spaces 28a and 28b adjacent to each other in the predetermined direction A1 by a coil support member 27 integral with the lens holder 24. A first magnet 31 is arranged in the track direction A3 and fixed to the actuator base 21 in the first space 28a. A second magnet 32 is arranged in the track direction A3 and fixed to the actuator base 21 in the second space 28b. The first
The magnet 31a faces the third magnet 32a, and the first magnet 31 faces the second magnet 32.

The first and second magnets 31, 32 are
Both are magnetized in the same direction in the predetermined direction A1. Then, the first magnet 31 is magnetically coupled to the second magnet 32 by using the yoke 34 shown in FIG. 7. The arrow 36 shown in FIG. 5 indicates the direction of the magnetic flux (N, S) of the magnet.

FIG. 6A shows an arrangement of print patterns on the multilayer substrate 26. As shown in FIG. 6, the multi-layer substrate 26 is formed by stacking the first layer, the second layer, the third layer, the fourth layer and the substrate in a multi-layer structure.

In FIG. 6B, X shown on the multilayer substrate 26 is the direction in which the magnetic flux travels from the second magnet 32 to the first magnet 31, and Y is the magnetic flux from the first magnet 31 to the second magnet 31. The direction of movement to the magnet 32 is shown.

The multi-layer substrate 26 includes a tracking coil (T
Track-, Track +) 37, focus coil (Focus-, Focus +) 39, and tilting coil (Tili-, Tili +) 41 are formed on one multi-layer substrate 26 by screen printing or etching, and the multi-layer substrate 26 is used as a driving coil. There is. The multilayer substrate 26 is mounted on the actuator base 21 by insert molding the lens holder 24.

The tracking coil 37 has a form in which it is inserted and arranged in the respective gaps between the first magnet 31 and the second magnet 32, and enables energization in a direction intersecting with the magnetic flux 36 through the suspension wire 23. ing. The tracking coil 37 cooperates with the first and second magnets 31 and 32 to apply a moving force to the lens holder 24 in the track direction A3 when a direct current is applied. Therefore, by controlling the energization of the tracking coil 37, the position of the objective lens 6 is changed to the track direction A.
Fine adjustment is possible with 1.

The focusing coil 39 can be energized in a direction intersecting the magnetic flux 36 through the suspension wire 23. However, focusing coil 3
The current of 9 is orthogonal to the direction of the current of the tracking coll 37. The focusing coil 39 cooperates with the first and second magnets 31 and 32 to apply a moving force in the focus direction A2 to the lens holder 24 when a direct current is applied. Therefore, the focusing coil 3
By controlling the energization of 9, the position of the objective lens 6 can be finely adjusted in the focus direction A2.

In the tilting coil 41, as shown by the arrow in FIG. 6, the first layer and the second layer are wound in the same phase. The tilting coil 41 passes the magnetic flux 3 through the conducting wire 43 provided in parallel with the suspension wire 23.
It is possible to energize in a direction intersecting with 6. One end of the current-carrying wire 43 is also supported by the damper base 22,
The other end is supported by the lens holder 24. Since currents flow in the tilting coil 41 in opposite directions when a direct current is applied, the first and second magnets 31 and 3 are
In cooperation with 2, the lens holder 24 is given a turning force in the tilt direction A4. Therefore, the direction of the objective lens 6 can be finely adjusted in the tilt direction A4 by controlling the energization of the tilting coil 41.

In the optical pickup device described above,
Since the two magnets 31 and 32 are arranged, there is no problem of reduction in magnetic flux density when fine adjustment of the objective lens 6 in the tilt direction A4 is possible. The first
Also, the second magnets 31, 32, the tracking coil 37, the focusing coil 39, and the tilting coil 41 together constitute an adjustment drive device.

In the above description, two magnets are used, but the present invention is not limited to this, and a total of N (N is an odd number of 2 or more) magnets are used as the base member and the lens holder 24.
One of them should be held in at least two places.

[0042]

As described above, according to the optical pickup device of the present invention, the tracking coil, the focus coil and the tilting coil are formed on one multi-layer substrate, and the multi-layer substrate is used as the driving coil. By insert molding into the lens holder, the copper wire is not exposed in the outer shape unlike the prior art mounted on the actuator base, so disconnection and short-circuit defects due to external factors do not occur, resulting in yield Can be improved.

Further, since a pattern can be formed on the multilayer substrate by etching, variations in coil characteristics such as resistance value can be suppressed, and as a result, the characteristics of the optical pickup can be made uniform.

Further, since it is possible to purchase a part in which the coil and the lens holder are integrally formed, it is not necessary to assemble the winding and the coil as in the prior art and the assembly process of the bobbin and the lens holder, which is a great advantage. Man-hours can be reduced.

[Brief description of drawings]

FIG. 1 is an explanatory diagram for explaining an outline of an optical pickup device according to an embodiment of the present invention.

FIG. 2 is a perspective view specifically showing the optical pickup device of FIG.

3 is a perspective view of a main part of the optical pickup device of FIG. 2 viewed from one side.

FIG. 4 is a perspective view of the actuator of the optical pickup device of FIG. 2 viewed from one side.

5 is a perspective view showing a relationship between the magnet shown in FIG. 3 and a multilayer substrate.

6 (a) and 6 (b) are front views showing the multilayer substrate shown in FIG. 3 in an exploded manner.

FIG. 7 is a perspective view of an optical pickup device in the related art as seen from one side.

8 is a perspective view of the actuator of the optical pickup device shown in FIG. 7, viewed from one side.

9 is a perspective view of the actuator of the optical pickup device shown in FIG. 7 as viewed from the other side.

[Explanation of symbols]

1 laser diode 2 beam splitter 3 Monitor device 4 Collimating lens 5 Launch mirror 6 Objective lens 7 Optical disc 8 photodiodes 10 Optical base 11 Guide hole 12 Diode mounting part 21 Actuator base 22 Damper base 23 suspension wire 24 lens holder 26 Multi-layer board 31, 31a First magnet 32, 31b Second magnet 32a Third magnet 32b Fourth magnet 34,35 York 36 Magnetic flux of magnet 37 1st tracking coil (tracking coil) 38 Second tracking coil 39 Focusing coil 41 First tilting coil (tilting coil) 42 Second tilting coil 43 energizing wire A1 predetermined direction A2 focus direction A3 track direction A4 tilt direction

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroyuki Okuda             5 Tategawa 1-1059, Yamagata City, Yamagata Prefecture             Yamagata Mitsumi Co., Ltd. F-term (reference) 5D118 AA06 AA15 AA28 BA01 DC03                       EA02 EB17 EC07 EC10 ED05                       ED08 EF09 FA29 FB20

Claims (4)

[Claims] 1. A base member, a lens holder, a holder support mechanism that movably supports the lens holder on the base member, and an objective lens held by the lens holder, and the holder member is held by the base member. A pair of magnets, and a plurality of coils held by the lens holder and cooperating with the magnets, the coils cooperating with the magnets when energized to provide a tracking force to the lens holder in the track direction. A coil, a focusing coil that cooperates with the magnet to apply a moving force in the focus direction to the lens holder when energized, and a focusing coil and a track direction that cooperate with the magnet when energized to the lens holder. A chill that gives a moving force in a tilt direction around a predetermined axis extending in a direction orthogonal to An optical pickup device comprising: a tracking coil, the tracking coil, the focusing coil, and the tilting coil are formed on a multilayer substrate, and the multilayer substrate is held by the lens holder. 2. The optical pickup device according to claim 1, wherein the multilayer substrate is held by the lens holder by insert molding. 3. The optical pickup device according to claim 1, wherein the magnets are arranged at intervals in a direction parallel to the predetermined axis. 4. The holder support mechanism includes a plurality of suspension wires, one end of which is held by the base member and the other end of which is held by the lens holder, and each of the suspension wires has elasticity. The optical pickup device according to claim 1, wherein