JP2002074707A - Objective lens driving device and optical disk unit equipped therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an objective lens driving device that has a superior tracking frequency characteristics by suppressing an objective lens shift in the tracking direction caused by gravity when the holder tilts and by suppressing effect on tracking correcting motion caused by holder vibration generating at high- speed access, and also to provide an optical disk unit equipped with this objective lens driving device. SOLUTION: The objective lens driving device drives the objective lens 1 by supporting the objective lens 1-equipped holder 2 in a translatable and rotatable manner by a driving mechanism that has two pairs each of magnets 5, yokes 4, 8, focus coils 6 and tracking coils 7, 7. With the purpose of supporting the holder 2 in a translatable and rotatable manner, elastic supporting members 10, 10 are provided in which a pair of V-structured and unparallelly arranged members are disposed in two sets so that the face formed by each V-structured member are parallel to each other. The elastic supporting members 10, 10 are each formed with inward projections 12, 12 at least in one place.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to an optical recording / reproducing apparatus such as an MD apparatus and a CD apparatus capable of optically recording, reproducing and erasing information by irradiating a recording medium with a light beam. The present invention relates to an objective lens driving device for driving an objective lens in an optical axis direction and a direction orthogonal to the optical axis, and an optical disc device including the same.

[0002]

2. Description of the Related Art In an optical pickup equipped in an optical information recording / reproducing apparatus using an optical disk as a recording medium, that is, an optical disk apparatus, a minute spot of a detection beam focused from an objective lens is accurately scanned on a recording surface of the optical disk. There is provided a correction driving device for performing correction so as to perform the correction.

In this correction driving device, a holder holding an objective lens is supported so as to be operable in an optical axis direction of the objective lens and in a direction orthogonal to the optical axis, and uses a magnet and a coil. The holder is driven in each of the above directions using the driving mechanism described above.

[0004] When the objective lens is driven in the direction of the optical axis, focusing correction for making the focus of the beam spot coincide with the recording surface of the optical disk is performed, and the objective lens is driven in a direction perpendicular to the optical axis. Accordingly, tracking correction for causing the beam spot to follow the track on the recording surface of the optical disk is performed.

More specifically, in an objective lens driving device generally used in an optical disk device such as an MD recording / reproducing device, for example, as shown in FIGS. The holder 72 is cantilevered by four elastic support members 73 arranged vertically and horizontally. Between the holder 72 and the fixed side, magnets 74 and 74, yokes 75 and 75, and the focus coil 7
6 and a tracking coil 77 are provided, and the driving force causes the respective elastic support members 73 to bend and deform, thereby driving the holder 72 in the focusing direction and the tracking direction. It has become.

By the way, usually, in a portable MD device,
The posture of the MD device takes various directions. In particular, when the device is used in a posture in which gravity is applied in the tracking correction direction, that is, when the device is used with the direction of the arrow ef being vertical in the drawing, the weight of the holder 72 acts in the tracking direction, and the tracking correction operation is performed. Is not performed correctly.

To solve this problem, for example, there is an objective lens driving device disclosed in Japanese Patent Application Laid-Open No. 64-33732.

As shown in FIG. 13, the support mechanism described in Japanese Patent Laid-Open Publication No. Sho 64-33732 disposes a holder 82 holding an objective lens 81 through a position of the center of gravity and parallel to the optical axis of the objective lens 81. V-shaped metal plate 8 around the axis
3 ... rotatably supported.

With the above configuration, the focus coil 8
7 and magnets 85 and 85 and yokes 86.8 for generating a magnetic field
6, a thrust is generated in the direction of arrow gh to perform a focusing correction operation, and two sets of tracking coils 84 and a magnet 85 for generating a magnetic field. 85 and yokes 86, 86 act on the magnetic circuit, and arrows ij shown in FIG.
The tracking correction operation is performed by generating a rotational force that becomes a couple in the direction.

[0010]

However, in the conventional objective lens driving device shown in FIG. 13, a phase change occurs in the tracking frequency characteristic due to the deformation mode of the support material.

Specifically, it can be seen from the analysis result of the tracking frequency characteristic of the objective lens actuator shown in FIG. 14 and the experimental result shown in FIG. 15 that a phase delay occurs. In FIG. 14, the upper graph shows the phase (°) with respect to the frequency (Hz), while the lower graph shows the gain (dB) with respect to the frequency (Hz). In the graph of FIG. 15, the gain (dB) and phase (P) on the vertical axis are displayed with respect to the frequency (kHz) on the horizontal axis.

That is, as can be seen from FIGS. 14 and 15, although the frequency absolute value is different, two phase changes due to deformation of the V-shaped metal plates 83, both of which are elastic support members, ie, arrows in FIG. It is confirmed that a phase delay occurs from the two downwardly convex phase changes shown in A and B.

These two phase changes occur due to the configuration of the objective lens driving device including the inclination of the principal axis of inertia of the holder 82. Among these two phase changes, the low frequency phase change, that is, the phase change indicated by the arrow A in FIG. 14 is the rotational motion mode of the holder 82 indicated by the arrow k in FIG. The phase change, that is, the phase change indicated by the arrow B in FIG. 14 is the translational motion mode of the holder 82 indicated by the arrow 1 in FIG.

Since the occurrence of these phase changes makes it difficult to control the correction operation, an objective lens driving device having a frequency characteristic with a small phase change is required.

Therefore, for example, Japanese Patent Application Laid-Open No. 7-225961
In order to solve this problem, the objective lens driving device described in Japanese Patent Application Publication No.
1 are formed in a V-shape, and one end of each of the wires 92
, And the other ends of the wires 92 are fixed to the main body portions 94 to support the holder 91 so as to be able to translate and rotate. V-shaped wire 9
A mechanism as an adjustable dynamic balancer 96 for the purpose of balance adjustment is provided in the inner area of 2.92.

The damper block 95 is formed in a substantially rectangular shape.
At the portion where the wires 92 pass, the wires 92
So that the grooves 97 and 97 do not interfere with the damper block 95.
Are formed.

However, according to this configuration, the shape of the holder becomes large, and it is difficult to reduce the size of the objective lens driving device. In addition, since the mass of the holder 91 also increases, the current for driving the holder 91 increases and the driving sensitivity decreases, which causes a problem in reducing power consumption. Further, since the adjustment step is performed at the time of assembling, the workability of assembling is poor and the manufacturing cost is increased. In particular, when performing recording / reproducing on a recording medium contained in a cartridge case like an MD device, a dynamic balancer or the like is arranged due to dimensional restrictions such as a window size of the cartridge case, and the inclination of the main axis of inertia is reduced. Is difficult to correct.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to suppress the objective lens shift in the tracking direction due to its own weight when the holder is tilted, and to reduce the vibration of the holder generated during high-speed access. It is an object of the present invention to provide an objective lens driving device having good tracking frequency characteristics while suppressing the influence on the tracking correction operation due to the above, and an optical disc device including the same.

[0019]

In order to solve the above-mentioned problems, an objective lens driving device according to the present invention supports a holder provided with an objective lens in a translation and rotatable manner by a driving mechanism including a magnet, a yoke and a coil. In the objective lens driving device for driving the objective lens, each V-shaped member is provided in a non-parallel manner to form a pair of V-shaped members in order to support the holder so as to translate and rotate. Two sets of elastic support members are provided so that the surfaces are parallel to each other, and each of the elastic support members has a convex bent portion formed at least at one position.

According to the invention described above, the objective lens driving device drives the objective lens by supporting the holder provided with the objective lens in a translation and rotatable manner by the drive mechanism including the magnet, the yoke and the coil.

Here, in the present invention, in order to support the holder so as to be able to translate and rotate, a pair of non-parallel V-shaped members are arranged so that the surfaces formed by the respective V-shaped members are parallel to each other. Thus, two sets of elastic supporting members are provided.

For this reason, by forming the pair of elastic support members in a V-shape, the shift of the objective lens in the tracking direction due to the weight of the holder when the holder is tilted is suppressed, and the tracking correction due to the vibration of the holder generated at the time of high-speed access. The effect on the operation can be suppressed.

Also, the elastic support member is formed by at least one convex bent portion formed on the elastic support member.
It is possible to provide an objective lens driving device having good tracking frequency characteristics in the case of the letter configuration.

Further, since the phase change in the frequency characteristic can be reduced without increasing the number of parts and the number of assembling work steps, correction operation control becomes easy, and more stable recording / reproducing characteristics can be obtained.

According to another aspect of the present invention, there is provided an objective lens driving device, wherein the convex bending portions of the elastic support members are arranged in parallel to each other. It is characterized in that it is formed so as to protrude toward a V-shaped inner region formed by a pair of V-shaped elastic support members.

Therefore, it is possible to reliably suppress the objective lens shift in the tracking direction due to the weight of the holder when the holder is tilted, and to suppress the influence on the tracking correction operation due to the vibration of the holder generated at the time of high-speed access. It is possible to provide an objective lens driving device having an excellent tracking frequency characteristic.

[0027] In addition to the above-described operation of the objective lens driving device, the convex bending portion of the elastic support member is formed so as to protrude toward a V-shaped region formed by the elastic support member. Accordingly, the projection area from the upper surface of the objective lens driving device can be reduced, and the size of the entire device can be reduced.

In order to solve the above-mentioned problems, the objective lens driving device of the present invention supports a holder provided with an objective lens by a driving mechanism comprising a magnet, a yoke and a coil so as to translate and rotate. In an objective lens driving device for driving a lens, in order to support the holder in a translatable and rotatable manner, a pair of non-parallel V-shaped components are arranged so that the surfaces formed by the respective V-shaped components are mutually reciprocal. Two sets of elastic support members are provided so as to be parallel to each other, and each of the elastic support members extends from a connection end portion with the holder and extends substantially 90 degrees toward a V-shaped region formed by the elastic support members. It is characterized by being formed in a Z shape that bends at an angle of °.

According to the invention described above, the objective lens driving device drives the objective lens by supporting the holder provided with the objective lens in a translation and rotatable manner by the drive mechanism including the magnet, the yoke and the coil.

Further, in the present invention, in order to support the holder so as to be able to translate and rotate, a pair of non-parallel V-shaped members are arranged so that the surfaces formed by the respective V-shaped members are parallel to each other. Thus, two sets of elastic support members are provided.

Therefore, by forming the pair of elastic support members in a V-shape, the objective lens shift in the tracking direction due to the weight of the holder when the holder is inclined is suppressed, and the tracking correction due to the vibration of the holder generated at the time of high-speed access. The effect on the operation can be suppressed.

Each elastic support member is formed in a Z-shape extending from a connection end portion with the holder and bent at approximately 90 ° toward a V-shaped region formed by the elastic support member. In addition, it is possible to provide an objective lens driving device having good tracking frequency characteristics when the elastic support member has a V-shaped configuration.

Further, by forming each elastic support member into a Z shape extending from the connection end with the holder and bending at approximately 90 °, the elastic support member has a convex bent portion. Since the number of bent portions of the elastic support member is smaller than in the case of having the above, rigidity is improved, and plastic deformation is less likely to occur in response to an impact on the device. Further, since the shape is simple, the dimensional variation is small and the characteristics after assembly are stable.

Therefore, the phase change in the frequency characteristic can be reduced without increasing the number of parts and the number of assembling work steps, so that correction operation control is facilitated, and more stable recording / reproducing characteristics can be obtained.

Further, since the elastic support member is formed in a Z-shape that is bent at approximately 90 ° toward the region inside the V-shape, the projected area from the upper surface of the objective lens driving device can be reduced. In addition, it is possible to prevent the entire device from being enlarged.

In order to solve the above-mentioned problems, an optical disk apparatus according to the present invention is provided with the objective lens driving device described above.

According to the above-mentioned invention, the optical disc device is
The objective lens driving device described above is provided.

Therefore, the objective lens shift in the tracking direction due to its own weight when the holder is tilted is suppressed, and the influence on the tracking correction operation due to the vibration of the holder generated at the time of high-speed access is suppressed so that the objective lens has a good tracking frequency characteristic. An optical disk device including a driving device can be provided.

[0039]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [Embodiment 1] An embodiment of the present invention will be described with reference to FIGS.
It is as follows. In the present embodiment, a case will be described in which the objective lens driving device is mounted on, for example, an MD device as an optical disc device.
Either a case having both recording and reproduction functions or a case having only reproduction functions may be used. Therefore, the optical disk device is not necessarily limited to the MD device, but may be, for example, a CD device. In addition, the optical disk device includes a device that uses magnetism when recording, in addition to a device that performs recording and reproduction using only light. Further, the objective lens driving device is fixed to an optical pickup (not shown), and the optical pickup is incorporated in a mechanical chassis, and the mechanical chassis is connected to the MD device main body via a damping material.

FIG. 1A shows the objective lens driving device.
As shown in (b), the objective lens 1 is attached to an end of the holder 2.

That is, in the case of the MD device, a disc as an information recording medium is housed in a cartridge case (not shown), a shutter (not shown) of the cartridge case is opened at the time of recording and reproduction, and the objective lens 1 is moved to the window of the cartridge case. It is designed to get inside.

Accordingly, the holder 2 is formed in such a structure that the objective lens 1 projects in the direction of insertion into the window to enter the window of the cartridge case.

As a result, as shown in FIG. 1B, the main axis of inertia of the holder 2 on which the objective lens 1 is mounted is inclined from the horizontal and vertical directions.

The holder 2 comprises four elastic support members 10, 10, 10, 1 made of, for example, thin metal plates supported on a base plate 3 of an objective lens driving device.
0 and is movable with respect to the base plate 3. In addition, the elastic support members 10.10.1
In the present embodiment, the thin metal plate constituting 0.10 is
For example, it is formed by etching beryllium copper having a thickness of 50 μm to 100 μm, has conductivity, and has a rectangular cross section. However, the elastic support members 10, 10, 10, 10 need not necessarily be plate members. In addition, the elasticity means that the elastic supporting members 10, 10, 10, 10 as cantilever beams exhibit elasticity by bending or twisting.

That is, the support structure of the holder 2 is shown in FIG.
As shown in (a), a pair of V-shaped elastic support members 10 and 10 arranged non-parallel in one plane are provided vertically in two sets as shown in FIG. The plane on which the upper elastic support members 10 are provided and the plane on which the lower elastic support members 10 are provided are arranged so as to be mutually parallel.

As described above, the pair of elastic support members 10.1
By making 0 a V-shaped configuration, in the MD device,
The objective lens shift in the tracking direction due to the falling weight of the holder 2 can be suppressed, and the influence on the tracking correction operation due to the vibration of the holder 2 generated at the time of high-speed access can be suppressed.

Each of the above elastic support members 10 ・ 10 ・ 10 ・
More specifically, as shown in FIGS. 1 (a) and 1 (b), reference numeral 10 denotes one end of a holder connecting end portion 10a, 10a, 10a, 10a.
Are attached to the holder center-of-gravity vertical portions 2a on the upper surface or the lower surface near the vertical line at the position of the center of gravity of the holder 2. One elastic support member 10 is fixed to the fixed end portion 10 via an inwardly protruding portion 12 which is bent from the holder connection end portion 10a into a convex shape, and a subsequent fixed end side support member 10d.
b. The inwardly protruding portion 12 functions as a protruding bent portion of the present invention.
That is, the inwardly protruding portions 12 are formed in a convex shape toward the in-V region S formed by the pair of V-shaped elastic support members 10 non-parallel arranged in one plane. Have been.

On the other hand, the fixed end 1 of the elastic support member 10
0b is the substrate 1 bonded to the base plate 3 by bonding or the like.
1 and solder 14 are electrically and mechanically fixed.
Thereby, the focus coil 6 provided in the holder 2
In addition, power can be supplied to the tracking coils 7.

The elastic support member 10 has a cantilever 13 branching from the inwardly protruding portion 12 at a branch fixed end 13a located on the shoulder of the inwardly protruding portion 12 on the side of the fixed end 10b. ing. The cantilever 13 extends in the direction of the fixed end 10 b of the elastic support member 10 after branching off from the inwardly protruding portion 12. Further, a cantilever free end portion 13b of the cantilever portion 13 has a tip end formed with a cantilever free end portion 13c.
The fixed end 10b is formed with a fixed end projection 10c corresponding to 3c. The above-mentioned cantilever tip concave portion 13
A gap is formed between c and the fixed end protrusion 10c. Thereby, the cantilever portion 13 is connected to the branch fixed end 1.
It is a cantilever having a fixed end 3a and a free end 13b of the cantilever free end.

The upper cantilever beam concave portion 13c and the fixed end convex portion 10c are connected on their lower surfaces in a semi-fixed state with a damping material 15 which is an impact buffer such as an ultraviolet curable resin material. ing. Specifically, they are in contact. In addition, as shown in FIG. 1B, the elastic support member 10 including the lower cantilever tip concave portion 13c and the fixed end convex portion 10c is in contact with the damping material 15 on the upper surface thereof.

The damping material 15 is used for the elastic support member 1.
0, that is, a portion extending from the holder connecting end portion 10a to the fixed end portion 10b via the convex inwardly directed convex portion 12 and the subsequent fixed end side support member 10d when the portion is bent. , While suppressing the amount of deformation,
It is provided for the purpose of damping vibration.

Such an elastic support member 10.10
The holder 2 is supported by the holder 2
Can be rotated in the directions of arrows cd shown in FIG. 3A around an axis parallel to the optical axis of the objective lens 1 passing through the center of gravity of the objective lens 1.

In the present embodiment, the inwardly protruding portion 12 is provided only at one place on the elastic support member 10, but the present invention is not limited to this, and two, three or more places are provided. May be a plurality of locations. In other words, at least one location is sufficient.

On the other hand, the objective lens driving device according to the present embodiment is for driving the holder 2 in cooperation with the magnetic circuit composed of the yokes 4 and 8 and the magnet 5 for generating a magnetic field. And two drive mechanisms each including a focus coil 6 and tracking coils 7, 7 as the above-mentioned coils are disposed symmetrically on both left and right sides (vertical direction in FIG. 3A). The above-mentioned focus coil 6 is wound around an axis parallel to the optical axis of the objective lens 1, while the tracking coils 7 are wound around an axis orthogonal to the optical axis of the objective lens 1. It is adhered to the side surface of the focus coil 6.

The two tracking coils 7, 7 are:
In the tracking frequency characteristic, mainly the elastic support member 1
In order to correct the phase change due to the rotational motion mode deformation of 0.10.10,10, it is arranged so as to be substantially in line with the inclination of the inertia main axis based on the analysis result.

In the above-described objective lens driving device, a magnetic circuit composed of two sets of focus coils 6.6 and a magnet 5 for generating a magnetic field and yokes 4.8 is used, as shown in FIG. Alternatively, a thrust is generated in the direction of arrow b to perform the focusing correction operation.

On the other hand, four sets of tracking coils 7.7,
And a magnetic circuit constituted by the magnets 5 and the yokes 4 and 8 which generate a magnetic field, as shown in FIG.
A tracking correction operation is performed in which the light passes through the center of gravity of the holder 2 and rotates about an axis parallel to the optical axis of the objective lens 1.

FIG. 2 shows an analysis result of the tracking frequency characteristic in the objective lens driving device having the above-described configuration. Also,
The result of the experiment is shown in FIG.

In FIG. 2, the upper graph shows the relationship between phase (°) and frequency (Hz), and the lower graph shows the relationship between gain (dB) and frequency (Hz). .

The graph of FIG. 3 shows the relationship between gain (dB) and phase (°) and frequency (Hz).

As can be determined from the figure, there is no large phase change due to the rotational motion mode and the translational motion mode of the objective lens holder 2 and it can be confirmed that the frequency characteristics are good.

As described above, in the objective lens driving device of the present embodiment, the holder 2 provided with the objective lens 1 is driven by the driving mechanism including the magnet 5, the yokes 4.8, the focus coil 6 and the tracking coils 7.7. The objective lens 1 is driven while being supported for translation and rotation.

Here, in this embodiment, in order to support the holder 2 so as to be able to translate and rotate, a pair of V-shaped members arranged non-parallel to each other has a surface formed by each V-shaped member. Two elastic support members 10 arranged in parallel with each other;
10.10.10.

For this reason, the V-shaped elastic support member 10.
With the use of 10.10.10, the objective lens shift in the tracking direction due to the weight of the holder 2 when the holder 2 is tilted can be suppressed, and the influence on the tracking correction operation due to the vibration of the holder 2 generated at the time of high-speed access can be suppressed.

Further, the elastic supporting members 10.10.10.1
0 at least one inwardly protruding portion 12.
The elastic support member 1 having the V-shaped configuration
It is possible to provide an objective lens driving device having good tracking frequency characteristics at 0.10.10. Note that the inwardly facing convex portion of the present embodiment has a configuration in which the convex portion returns to a state without bending from the branch fixed end 13a as compared with the case where the convex portion is bent in a Z shape described in the third embodiment. It is considered that an operation effect without a large phase change occurs.

Further, since the phase change can be reduced in the frequency characteristic without increasing the number of parts and the number of assembly work steps, the correction operation control becomes easy, and more stable recording / reproducing characteristics can be obtained.

Further, in the objective lens driving device according to the present embodiment, the inwardly protruding portions 12, 12, 12, 12 of the elastic support members 10, 10, 10, 10 are formed by a pair of non-parallelly arranged convex portions. V formed by V-shaped elastic support members 10
It is formed so as to be convex toward the in-character area S.

For this reason, the elastic support members 10
The projection area from the upper surface of the objective lens driving device is reduced by forming the inwardly protruding portions 12 in the convex shape toward the V-shaped region S formed by the elastic support members 10. The device can be made small, and the entire device can be downsized.

Further, the optical disc device of the present embodiment
The objective lens driving device described above is provided.

For this reason, the objective lens shift in the tracking direction due to its own weight when the holder 2 is tilted is suppressed, and the influence of the vibration of the holder 2 generated at the time of high-speed access on the tracking correction operation is suppressed, so that a good tracking frequency characteristic is obtained. An optical disk device having an objective lens driving device can be provided.

[Second Embodiment] The following will describe another embodiment of the present invention with reference to FIGS. For convenience of explanation, members having the same functions as those shown in the drawings of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. Further, the various features described in the first embodiment can be applied in combination with the present embodiment.

In the objective lens driving device of the present embodiment,
The inward convex portions 12, 12, 12, 12 of the convex shape formed on the elastic support members 10, 10, 10, 10 are opposite to each other.

That is, in the objective lens driving device of the present embodiment, as shown in FIG.
The convex-shaped bent portion formed at 20 is located at one point on the way from the holder connecting ends 20a of the holder center-of-gravity vertical portion 2a to the fixed ends 20b to the base plate 3 on the base plate 3; Outwardly facing convex portion 2 having a convex shape
2 and 22 are bent. Further, the elastic support member 20 of the present embodiment has a cantilever portion 23 branched from the outwardly protruding portion 22 at a branch fixed end 23a on the shoulder on the fixed end portion 20b side of the outwardly protruding portion 22. are doing.
The cantilever portion 23 branches from the outwardly facing convex portion 22 and then extends in the direction of the fixed end portion 20 b of the elastic support member 20 and contacts the damping material 15. The number of the outwardly facing convex portions 22 is not limited to one, but may be plural. The other configuration is the same as that of the first embodiment, and the description is omitted.

The tracking frequency characteristics of the objective lens driving device having the above-described configuration are substantially the same as those of FIGS. 2 and 3 shown in the first embodiment, both in terms of analysis results and experimental results. It turned out to be the result.

However, as shown in FIG. 5B, in the elastic support member 10 of the above embodiment, the holder connecting end 10
The length m on the a side, the length n on the convex portion, and the fixed end side support member 10d
And the elastic support member 10
Has a length q extending outward from the holder connection end 10a.

On the other hand, in order to obtain the same spring constant as that of the elastic support member 10 having the above-mentioned length (m + n + o) in the elastic support member 20 of the present embodiment, as shown in FIG. (M + n + o) is required.

In the elastic support member 20, in order to secure this length (m + n + o), the branch fixed end 23
A layout space for the cantilever portion 23 branching from a is required. For this reason, an overhang length p from the holder connecting end 20a to the outside is required, and the overhang length p is longer than the overhang length q. That is, the overhang length p> the overhang length q.

As a result, it becomes difficult to reduce the size of the objective lens driving device.

Therefore, when there is no particular restriction on the size of the objective lens driving device in the width direction, the first embodiment is used.
As well as the objective lens driving device described above.

As described above, in the objective lens driving device of the present embodiment, the holder 2 provided with the objective lens 1 is driven by the driving mechanism including the magnet 5, the yokes 4.8, the focus coil 6 and the tracking coils 7.7. The objective lens 1 is driven while being supported for translation and rotation.

Here, in the present embodiment, in order to support the holder 2 so as to be able to translate and rotate, a pair of V-shaped members arranged non-parallel to each other has a surface formed by each V-shaped member. Two sets of elastic support members 20 arranged in parallel with each other
20, 20, 20 are provided.

For this reason, the V-shaped elastic support member 20.
By setting the distance to 20, 20, and 20, the objective lens shift in the tracking direction due to the weight of the holder 2 when the holder 2 is tilted is suppressed, and the influence on the tracking correction operation due to the vibration of the holder 2 generated during high-speed access is suppressed. Can be.

Further, the elastic supporting members 20 ・ 20 ・ 20 ・ 2
0 at least one outwardly protruding portion 22.
22 ・ 22 ・ 22, the V-shaped elastic support member 2
It is possible to provide an objective lens driving device having good tracking frequency characteristics when 0, 20, 20, and 20 are set.

Further, since the phase change in the frequency characteristic can be reduced without increasing the number of parts and the number of assembly work steps, the correction operation control is facilitated and more stable recording / reproducing characteristics can be obtained.

Also, the optical disk device of the present embodiment
The objective lens driving device described above is provided.

For this reason, the objective lens shift in the tracking direction due to its own weight when the holder 2 is tilted is suppressed, and the influence on the tracking correction operation due to the vibration of the holder 2 generated at the time of high-speed access is suppressed, so that good tracking frequency characteristics are obtained. An optical disk device having an objective lens driving device can be provided.

Embodiment 3 Still another embodiment of the present invention will be described with reference to FIGS.
It is as follows. For convenience of explanation, members having the same functions as those shown in the drawings of the first and second embodiments are denoted by the same reference numerals, and description thereof is omitted. The various features described in the first and second embodiments can be applied in combination with the present embodiment.

As shown in FIG. 6, the objective lens driving device of the present embodiment has the same movable portion as the objective lens driving device of the first embodiment, and the inclination of the principal axis of inertia of the holder 2, which is the movable portion, is also reduced. The two pairs of a pair of V-shaped elastic support members 30 which are the same and are arranged in a non-parallel manner are formed as a pair, and the surfaces formed by the V-shaped members are arranged in parallel to each other. Have been.

The pair of elastic support members 30 and 3
The holder connecting end portions 30a are supported by a holder center-of-gravity vertical portion 2a so as to be rotatable around an axis parallel to the optical axis of the objective lens 1 through the position of the center of gravity of the holder 2.

Further, each of the elastic support members 30, 30, 30,.
Reference numeral 30 denotes the holder connection end portions 30a, 30a, 30a.
The Z-shaped inner Z-shaped protrusions 31 extend from the center 30a and bend at substantially 90 degrees into the V-shaped inner region S formed by the elastic support members 30.・ It has 31 ・ 31. That is, the elastic support member 30 is bent at approximately 90 degrees toward the inside of the V-shaped region S at the branch fixed end 33a in the middle, and further bent again in the original extending direction. As a result, the inner Z-shaped projecting portion 31 has a Z shape that is bent at substantially 90 °. In addition, in FIG.
1 describes that the bent portions are each at a right angle, but the present invention is not necessarily limited to this and may be literally a Z shape.

The inner Z-shaped projecting portion 31 extends as it is and reaches a fixed end portion 31b. The fixed end portion 31b is fixed to the substrate 14 by the solder 14.
The elastic support member 30 is fixed to the base plate 3 by bonding the substrate 14 to the base plate 3.

On the other hand, a cantilever portion 33 is also formed in the elastic support member 30. The cantilever portion 33 extends straight from the branch fixed end 33a in the extending direction and cantileverly. It reaches the free end 33b, and contacts the damping material 15 at this cantilever free end 33b. Also,
The fixed end 31b of the elastic support member 30 has a fixed end recess 3 corresponding to the tip shape of the cantilever free end 33b.
1c is formed with a gap corresponding to the tip of the cantilever free end 33b. And this fixed end 31b
The periphery of the fixed end recess 31c is also in contact with the damping material 15.

The other configuration is the same as that of the first embodiment, and the description is omitted.

FIG. 7 shows an analysis result of the tracking frequency characteristic in the objective lens driving device having the above-described configuration. Also,
FIG. 8 shows the results of the experiment.

In FIG. 7, the relationship between the phase (°) and the frequency (Hz) is displayed on the upper graph, and the relationship between the gain (dB) and the frequency (Hz) is displayed on the lower graph. .

FIG. 8 shows the relationship between gain (dB) and phase (°) and frequency (Hz).

As can be determined from FIGS. 7 and 8, although the frequency absolute value is different, it is confirmed that the analysis result and the experiment result substantially coincide with each other.
It was confirmed that although a phase advance was caused by the translational motion mode deformation of 30, 30, 30, the phase lag due to the rotational motion mode deformation could be suppressed.

In this configuration, the elastic support members 30, 30, 30, 30 have less bent portions than the configuration of the objective lens driving device shown in the first and second embodiments. As a result, the shape is stabilized, and the rigidity is improved.

As described above, in the objective lens driving device of the present embodiment, the holder 2 having the objective lens 1 is
The objective lens 1 is driven by being translated and rotatably supported by a drive mechanism including the yokes 4 and 8 and the focus coil 6 and the tracking coils 7.

Further, in this embodiment, in order to support the holder 2 so as to be able to translate and rotate, the holder 2 is provided in a non-parallel manner with a pair of V-shaped components. Elastic support members 30/3 arranged in parallel with each other
0, 30 and 30 are provided.

For this reason, the elastic support members 30, 30, 30
The V-shaped configuration of 30 suppresses the objective lens shift in the tracking direction due to the weight of the holder 2 when the holder 2 is inclined, and suppresses the influence on the tracking correction operation due to the vibration of the holder 2 generated at the time of high-speed access. be able to.

Further, each of the elastic support members 30, 30, 30,.
The inner Z-shaped protrusions 31 of the elastic support member 30 extend from the connection end with the holder 2.
90 toward the V-shaped region S formed by 30, 30, 30
By being formed in a Z shape that bends at an angle, it is possible to provide an objective lens driving device having good tracking frequency characteristics when the elastic support members 30, 30, 30, 30 have a V-shaped configuration. Become.

That is, in the elastic support member 30, although the phase delay due to the rotational motion mode deformation can be suppressed,
Phase advance occurs due to translational mode deformation.

Here, in controlling the focusing correction operation and the tracking correction operation, it is most preferable that there is no phase change in the frequency characteristic, but it is required that neither the phase advance nor the phase delay exist. is not. That is, the phase advance can be controlled by the phase change amount, and when the phase lag cannot be removed,
On the objective lens driving device side, a method of intentionally breaking the balance to obtain a phase lead characteristic has been adopted.

Therefore, as in the present embodiment, the objective lens driving device having the elastic supporting member 30 in which only the phase lead remains can be used.

In this embodiment, each of the elastic support members 30, 30, 30, 30 is formed in a Z shape that extends from the connection end with the holder 2 and is bent at approximately 90 °. The elastic support member is more than the elastic support member 10, 10, 10, 10, or the elastic support member 20, 20, 20, 20, 20 described in the first or second embodiment, which has a convex bent portion. Since the number of bent portions is small, rigidity is improved, and plastic deformation hardly occurs in response to an impact to the device.
Also, since the shape is simple, dimensional variation is small,
Characteristics after assembly are stable.

Therefore, the phase change can be reduced in the frequency characteristic without increasing the number of parts and the number of assembly work steps, so that the correction operation control is facilitated and more stable recording / reproducing characteristics can be obtained.

Further, the elastic support members 30, 30, 30, 3
Z bent at approximately 90 ° toward the V-shaped region S formed by 0
By being formed in a shape, the projection area from the upper surface of the objective lens driving device can be configured to be small,
It is possible to prevent the entire apparatus from becoming large.

Further, the optical disc device of the present embodiment
The objective lens driving device described above is provided. For this reason, the objective lens driving device having good tracking frequency characteristics by suppressing the objective lens shift in the tracking direction due to its own weight when the holder 2 is tilted, and suppressing the influence on the tracking correction operation due to the holder vibration generated at the time of high-speed access. The optical disk device provided with the above can be provided.

[Comparative Embodiment] In the objective lens driving device of the third embodiment, the elastic support members 30, 30, 30, 30
Inner Z-shaped projections 31 31 31
Is the V formed by the pair of V-shaped elastic support members 30.
It protruded toward the inside of the in-character area S.

On the other hand, here, as a comparative form,
As shown in FIG. 9, the elastic support members 40, 40, 40, 4
The bent portion formed at 0 is formed toward the outside on the opposite side to the V-shaped region S formed by the pair of V-shaped elastic support members 40 arranged in a non-parallel manner in one plane. The outer Z-shaped portions 41 will be described.

Elastic support member 4 of the objective lens driving device
0 is extended from the holder connecting end 40a of the holder center-of-gravity vertical portion 2a, which is the mounting position of the holder 2, to the outside from the V-shaped region S formed by the pair of elastic support members 40. And has a Z shape that is bent at approximately 90 °. A cantilever portion 43 is formed from the branch fixed end 43a. The other configuration is the same as that of the first embodiment, and the description is omitted.

FIG. 10 shows an analysis result of the tracking frequency characteristic in the objective lens driving device having the above configuration. In addition, FIG. 11 shows the results of the experiment.

In FIG. 10, the relationship between phase (°) and frequency (Hz) is displayed in the upper graph, and the relationship between gain (dB) and frequency (Hz) is displayed in the lower graph. . In addition, the graph of FIG. 11 shows the relationship between the gain (dB) and phase (°) and the frequency (Hz).

As can be seen from FIGS. 10 and 11, although the absolute value of the frequency is different, it has been confirmed that the analysis result and the experimental result substantially coincide with each other. However, in all cases, the elastic support members 40, 40, 40, 40 It can be seen that the phase lag due to the rotational motion mode deformation can be suppressed, but the phase lag due to the translational motion mode deformation occurs.

Here, in controlling the focusing correction operation and the tracking correction operation, it is most desirable that there is no phase change in the frequency characteristic.
In the case of phase advance, control can be performed by the amount of phase change, and the configuration can be used in the objective lens driving device having the elastic support member 30 having the configuration of FIG. 6 shown in the third embodiment. .

However, in the elastic support member 40 shown in this comparative example, as described above, the phase delay remains and cannot be controlled, so that it cannot be used as an objective lens driving device.

[0118]

As described above, the objective lens driving device according to the present invention can support the holder so that it can translate and rotate.
A pair of V-shaped non-parallel members are provided, and two sets of elastic support members are provided such that the surfaces formed by the V-shaped members are parallel to each other. Has a convex bent portion formed at least at one position.

Therefore, by forming the pair of elastic support members in a V-shape, the objective lens shift in the tracking direction due to the weight of the holder when the holder is inclined is suppressed, and the tracking correction due to the vibration of the holder generated at the time of high-speed access. The effect that the influence on operation | movement can be suppressed is produced.

Further, at least one convex bent portion formed on the elastic support member allows the elastic support member to
In the case of the character configuration, it is possible to provide an objective lens driving device having good tracking frequency characteristics.

Further, since the phase change can be reduced in the frequency characteristic without increasing the number of parts and the number of assembling work steps, it is possible to easily perform the correction operation control and obtain more stable recording / reproducing characteristics.

Further, as described above, the objective lens driving device according to the present invention includes the objective lens driving device described above,
The convex bending portion of each elastic support member is formed so as to protrude toward a V-shaped region formed by a pair of V-shaped elastic support members arranged in parallel.

Therefore, in addition to the effects of the objective lens driving device described above, the projection area from the upper surface of the objective lens driving device can be made small, and the effect of reducing the size of the entire device can be obtained. .

As described above, the objective lens driving device according to the present invention employs a pair of V-shaped non-parallel arrangements for supporting the holder so as to be able to translate and rotate. Two sets of elastic support members are provided so that the surfaces formed by the constituent members are parallel to each other, and each of the elastic support members extends from a connection end portion with the holder and forms a V formed by the elastic support members. Z bent at approximately 90 ° toward the in-character area
It is formed in a shape.

Therefore, by forming the pair of elastic supporting members in a V-shape, the objective lens shift in the tracking direction due to the weight of the holder when the holder is tilted is suppressed, and the tracking correction due to the vibration of the holder generated at the time of high-speed access. The effect that the influence on operation | movement can be suppressed is produced.

Each elastic support member is formed in a Z shape extending from a connection end portion with the holder and bent at substantially 90 ° toward a V-shaped region formed by the elastic support member. In addition, it is possible to provide an objective lens driving device having good tracking frequency characteristics when the elastic support member has a V-shaped configuration.

Further, by forming each elastic support member into a Z-shape extending from the connection end portion with the holder and bending at approximately 90 °, the elastic support member has a convex bent portion. Also, since the bent portion of the elastic support member is small, the rigidity is improved, and plastic deformation hardly occurs in response to an impact to the device. Furthermore, since the shape is simple, the dimensional variation is small, and the characteristics after assembly are stable. Therefore, without increasing the number of parts and the assembly work process,
Since the phase change can be reduced in the frequency characteristic, the correction operation control is facilitated, and an effect that more stable recording / reproducing characteristics can be obtained.

Further, since the elastic support member is formed in a Z-shape that is bent at substantially 90 ° toward the V-shaped region, the projected area from the upper surface of the objective lens driving device can be reduced. This has the effect of preventing the entire apparatus from being enlarged.

Further, an optical disk device according to the present invention is provided with the objective lens driving device described above in order to solve the above problems.

Therefore, the objective lens shift in the tracking direction due to its own weight when the holder is tilted is suppressed, and the influence on the tracking correction operation due to the vibration of the holder generated at the time of high-speed access is suppressed, so that the objective lens has a good tracking frequency characteristic. There is an effect that an optical disk device including a driving device can be provided.

[Brief description of the drawings]

FIGS. 1A and 1B show an embodiment of an objective lens driving device according to the present invention, wherein FIG. 1A is a plan view and FIG. 1B is a side view.

FIG. 2 is a graph showing an analysis result of tracking frequency characteristics in the objective lens driving device.

FIG. 3 is a graph showing experimental results of tracking frequency characteristics in the objective lens driving device.

FIG. 4 is a plan view showing another embodiment of the objective lens driving device according to the present invention.

5A and 5B are plan views showing the overhang length of the elastic support member in the objective lens driving device, wherein FIG. 5A shows the elastic support member of FIG. 4, and FIG. 5B shows the elastic support member of FIG. It is shown.

FIG. 6 is a plan view showing still another embodiment of the objective lens driving device according to the present invention.

FIG. 7 is a graph showing an analysis result of tracking frequency characteristics in the objective lens driving device.

FIG. 8 is a graph showing experimental results of tracking frequency characteristics in the objective lens driving device.

FIG. 9 is a plan view showing a comparative example of the objective lens driving device according to the present invention.

FIG. 10 is a graph showing an analysis result of tracking frequency characteristics in the objective lens driving device.

FIG. 11 is a graph showing experimental results of tracking frequency characteristics in the objective lens driving device.

12A and 12B show a conventional objective lens driving device, wherein FIG. 12A is a plan view and FIG. 12B is a side view.

FIG. 13 is a perspective view showing another conventional objective lens driving device.

FIG. 14 is a graph showing an analysis result of tracking frequency characteristics in the objective lens driving device.

FIG. 15 is a graph showing experimental results of tracking frequency characteristics in the objective lens driving device.

FIG. 16 is a plan view showing still another conventional objective lens driving device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Objective lens 2 Holder 2a Holder vertical center of gravity center 3 Base plate 4 Yoke 5 Magnet 6 Focus coil (coil) 7 Tracking coil (coil) 8 Yoke 10 Elastic support member 10a Holder connection end 10b Fixed end 10d Fixed end side support 11 Substrate 12 Inwardly protruding portion (convex bent portion) 13 Cantilever portion 13a Branch fixed end 14 Solder 15 Damping material 20 Elastic support member 20a Holder connecting end portion 20b Fixed end portion 22 Outwardly protruding portion (convex bent portion) 23) Cantilever 23a Branch fixed end 30 Elastic support member 30a Holder connecting end 30b Fixed end 31 Inner Z-shaped protrusion 33 Cantilever 33a Branch fixed end

Claims (4)

[Claims] 1. An objective lens driving device for driving a translation lens, wherein the holder having an objective lens is translated and rotatably supported by a driving mechanism including a magnet, a yoke, and a coil, wherein the holder is translatable and rotatable. In order to provide support, a pair of V-shaped components arranged non-parallel are provided, and two sets of elastic support members are provided such that the surfaces formed by the V-shaped components are parallel to each other. The objective lens driving device, wherein each of the elastic support members has a convex bent portion formed at at least one position. 2. A convex bent portion of each elastic support member is formed so as to project toward a V-shaped region formed by a pair of V-shaped elastic support members arranged in parallel. 2. The objective lens driving device according to claim 1, wherein: 3. An objective lens driving device for driving an objective lens by supporting a holder having an objective lens translationally and rotatably by a driving mechanism including a magnet, a yoke, and a coil, wherein the holder can be translated and rotated. In order to provide support, a pair of V-shaped components arranged non-parallel are provided, and two sets of elastic support members are provided such that the surfaces formed by the V-shaped components are parallel to each other. Each of the elastic support members extends from a connection end portion with the holder and extends approximately 90 ° toward a V-shaped region formed by the elastic support members.
An objective lens driving device characterized in that it is formed in a Z-shape that bends at an angle. 4. An optical disk device comprising the objective lens drive device according to claim 1, 2 or 3.