JPH0562226A - Objective lens driving device - Google Patents

Abstract

PURPOSE:To continue write and read of an information signal without moving an objective lens even at the time of application of oscillation, shock, etc., from the external. CONSTITUTION:A lens bobbin 17 to which an objective lens 19 is attached and a balancer member 20 are attached to both end parts of a supporting arm 7 through displacing parts 12 and 15. The arm 7 is turnably supported in a centroid position 6 and movably supports the objective lens 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an objective lens driving device constituting an optical pickup device used in an optical disk player device or the like.

[0002]

2. Description of the Related Art Conventionally, optical writing and / or writing of information signals
Alternatively, optical discs configured for reading have been proposed. As such an optical disc, for example, there is one that has a disc substrate made of a transparent synthetic resin such as polycarbonate and a metal thin film such as aluminum adhered to the disc substrate. In this optical disc, fine irregularities corresponding to information signals, so-called pits, are formed on the disc substrate by means such as injection molding. Then, the metal thin film is formed in a fine concavo-convex shape corresponding to the information signal, following the pit, to form a signal recording surface.

A disc player device is used to record and / or reproduce information signals on such an optical disc. This disc player device is configured to have a rotation operation device for rotating the optical disc and an optical pickup device for writing and / or reading an information signal on the optical disc. That is, in this disc player device, the optical disc is rotated by the rotation operating device, and
Writing and / or reading of an information signal is performed with the signal recording surface facing the objective lens of the optical pickup device.

The optical pickup device includes a light source such as a laser diode, a predetermined optical device for guiding a light beam emitted from the light source, an objective lens for condensing the light beam on the signal recording surface of the optical disc, and the signal recording surface. It is configured to have a photodetector or the like for detecting the reflected light flux. This optical pickup device is configured by incorporating the light source, the optical device, the photodetector, and the like in an optical block section, and supporting the objective lens via an objective lens driving device attached to the optical block section. ing. This objective lens driving device causes the objective lens to follow the so-called surface wobbling and eccentricity of the optical disc that is rotated by the rotation operating device, and the light flux emitted from the objective lens is on the signal recording surface of the optical disc. It is a device for always collecting light.

As shown in FIG. 5, this objective lens driving device has a base 126. This base 126
A pair of support pins 124 and 125 are erected on the top. The support portion 110 of the displacement member is fitted and attached to the support pins 124 and 125. The displacement member is integrally formed of a flexible material such as synthetic resin. This displacement member has a pair of parallel arm portions 111 and 112 whose base ends are supported by the support portion 110 via a pair of first displacement portions 113 and 114. The first displacement portions 113, 114 are thinned in a hinge shape so that the parallel arm portions 11 can be formed.
1, 112 are rotatably connected to the support portion 110.

A relay section 117 is connected to the tip ends of the parallel arm sections 111 and 112 through second displacement sections 116 and 115. The second displacement parts 116, 1
15 is formed in the same manner as each of the first displacing portions 113 and 114, and the relay portion 117 is provided to the parallel arm portions 111 and 112 with respect to each of the first displacing portions 113 and 11.
It can be rotated in the same direction as 4. That is, as shown by the arrow f in FIG. 5, the relay part 117 maintains the posture with respect to the support part 110 while maintaining the posture thereof.
Can be displaced with respect to. At this time, the parallel arm portions 111 and 112 maintain the parallel state.

A bobbin mounting portion 119 is connected to the relay portion 117 via a third displacement portion 118. The third displacing portion 118 includes the first and second displacing portions.
The displacement portions 113, 114, 116 and 115 are formed in a hinge shape. The third displacing portion 118 is configured such that the bobbin mounting portion 119 is provided with respect to the relay portion 117.
The first and second displacement parts 113, 114, 116, 1
It is connected so as to be rotatable in a direction orthogonal to 15. That is, the bobbin mounting portion 119 is rotatable about the third displacing portion 118 as an axis, as indicated by an arrow t in FIG. The rotatable direction of the bobbin mounting part 119 is determined by the support part 110 of the relay part 117.
The direction is orthogonal to the displaceable direction with respect to.

A lens bobbin 102 is attached to the displacement member. This lens bobbin 102
Has a substantially flat plate shape, and a displacement member mounting recess 102a is formed from the rear side to the central portion. A front end portion of the displacement member mounting recess 102a, that is, a portion which is substantially the central portion of the lens bobbin 102 is mounted on the bobbin mounting portion 119 of the displacement member.
Therefore, due to the displacement of the displacement member, the lens bobbin 102 is, as shown by arrows f and t in FIG.
It is supported so as to be displaceable in two directions orthogonal to each other.

An objective lens 101 is attached to the front part of the lens bobbin 102. This objective lens 1
01 indicates that the first and second displacement parts 11 have the optical axis direction.
The movement direction of the lens bobbin 102 due to the displacement of 3, 114, 116, 115 is the same as the movement direction of the lens bobbin 102 due to the displacement of the third displacement portion 118. Installed. Further, in the rear portion of the lens bobbin 102, the objective lens 10 is provided in the displacement member mounting recess 102a.
The balancer member 103 for balancing the weight of the unit 1 is attached. The lens bobbin 102 is configured such that the center of gravity is located on the third displacement portion 118.

A pair of focus coils 104 and 105 and two pairs of tracking coils 106, 107, 108 and 109 are attached to both sides of the lens bobbin 102. On the other hand, on the base 126, the pair of magnetic yoke portions 12 are arranged so as to face the coils.
8, 131 are projected. These magnetic yoke parts 12
8 and 131 are made of a highly magnetically permeable material and have a plate shape, and magnets 130 and 133 are attached to them.
These magnetic yoke portions 128 and 131 are attached to the coils of the lens bobbin 102 and the magnets 130 and 133, respectively.
Are facing each other. In addition, the magnetic yoke portions 128 and 131
Inner yokes 129 and 132 are connected to each other. The inner yokes 129 and 132 are inserted in the focus coils 105 and 104, respectively.
The magnetic flux generated by the magnets 130 and 133 is generated by the magnetic yokes 128 and 131 and the inner yokes 129 and 13.
2, the coils 104, 105, 106,
It is linked to 107, 108, and 109.

In this objective lens driving device, a focus drive current is supplied to each of the focus coils 104 and 105, and each of the tracking coils 106 and 105 is supplied.
By supplying a tracking drive current to 107, 108, and 109, the objective lens 101 is moved in the optical axis direction indicated by arrow f in FIG.
It is driven and displaced in the direction orthogonal to the optical axis indicated by the middle arrow t, that is, in the tracking direction. In the objective lens 101, the focus drive current corresponds to the surface wobbling of the optical disc, and the tracking drive current corresponds to the eccentricity of the optical disc, whereby the surface wobbling and Drive displacement is performed so as to follow the eccentricity.

[0012]

By the way, in the above-mentioned objective lens driving device, when the base 126 has an acceleration due to vibration or shock propagating from the outside of the disc player device, Objective lens 101
However, it is easy to move in the focus direction. That is, in this objective lens driving device, the lens bobbin 10
Reference numeral 2 denotes the third rotation center in the tracking direction.
The center of gravity is made to coincide with the displacement portion 118 of the first displacement portion 113, 1 which is the center of rotation in the focus direction.
14 does not have the same center of gravity. Therefore, when the base 126 has an acceleration, the objective lens 101 is
It is difficult to move in the tracking direction, but it is easy to move together with the lens bobbin 102 in the focus direction.

When the objective lens 101 moves in the focus direction due to the acceleration of the base 126, the focal point of the light beam formed by the objective lens 101 deviates from the signal recording surface of the optical disc, It becomes impossible to continue writing and / or reading of information signals on the optical disc.

Therefore, the present invention has been proposed in view of the above situation, and the objective lens does not move or tilt even if acceleration due to vibration or shock propagating from the outside occurs. It is an object of the present invention to provide an objective lens driving device capable of continuously writing and / or reading an information signal to / from an optical disc by an optical pickup device.

[0015]

In order to solve the above problems and to achieve the above objects, an objective lens driving device according to the present invention comprises a support member in which a supported portion at an intermediate portion is rotatably supported. A lens support which has an objective lens and is attached to one end side of the support member via a first displacement portion and is supported by being rotatable at least in the optical axis direction of the objective lens by rotation of the support member. The body, the balancer member attached to the other end side of the support member via the second displacement portion, the midway portion is rotatably supported, and the one end side supports the lens via the third displacement portion. The lens support is attached to the body so that the optical axis of the objective lens moves in parallel when the other end is attached to the balancer member via the fourth displacement portion and the support member rotates. With the link for maintaining the parallel state For example, the support member has, on the supported portion, the lens support is made of a whole of the center of gravity of the balancer member and the support member.

[0016]

In the objective lens driving device according to the present invention,
The support member that rotatably supports the supported portion in the middle,
A lens support mounted on the supported portion at one end side of the support member via a first displacement portion, and a balancer member attached at the other end side of the support member via a second displacement portion. And since it has the center of gravity of the whole of this support member, even if acceleration is generated by vibration or shock propagating from the outside,
The acceleration does not cause the supported portion to be rotated.

Further, in this objective lens driving device, the parallel state maintaining link having the midway portion rotatably supported has one end attached to the lens support through the third displacement portion and the other end. Since the side is attached to the balancer member via the fourth displacement portion and supports the lens support so that the optical axis of the objective lens moves in parallel when the support member rotates, the objective lens The optical axis of is not tilted.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below with reference to the drawings. The objective lens driving device according to the present invention is used for the configuration of an optical pickup device for writing and / or reading an information signal to / from an optical disc, and is used for the optical disc that is rotated by a rotation operating device of the disc player device. This is a device for causing the objective lens to follow so-called surface wobbling and eccentricity so that the light beam emitted from the objective lens is always focused on the signal recording surface of the optical disc.

This objective lens driving device is shown in FIGS.
As shown in FIG. This base 1
Is fixedly mounted on an optical block portion (not shown) of the optical pickup device. The optical block unit is configured to include a light source such as a laser diode, an optical device that guides a light beam emitted from the light source, and a photodetector that detects the light beam reflected by the optical disk and returned to the optical block unit. Is. The base 1 is provided with a light flux passage hole 33 for passing the light flux emitted from the optical block section to the upper side of the base 1.

A displacement member 2 is arranged on the base 1. The displacement member 2 is integrally formed of a flexible material such as synthetic resin. This displacement member 2
Has a support portion 3 formed in a substantially rod shape. The support portion 3 is attached to a substantially central portion of the upper surface portion of the base 1 so as to be substantially vertical to the upper surface portion, with its base end portion fixed. A relay plate portion 5 is attached to the support portion 3 via a tracking displacement portion 4. The relay plate portion 5 is formed into a substantially rectangular plate shape. The tracking displacement portion 4 is a thin hinge-shaped portion formed along the side surface of the support portion 3. The tracking displacement portion 4 rotatably connects the side surface portion of the support portion 3 and the central portion of the main surface portion of the relay plate portion 5. That is, the relay plate portion 5 is supported in a posture substantially vertical to the base 1, the upper end portion and the lower end portion thereof are substantially parallel to the upper surface portion of the base 1, and the tracking The movable portion 4 is rotatable about the axis.

The displacement member 2 has a supporting arm portion 7 which serves as a supporting member. This support arm portion 7
Is formed in the shape of a rectangular plate and has a substantially central portion in the longitudinal direction.
The relay plate portion 5 is connected to and supported by the upper end portion of the relay plate portion 5 via a focusing displacement portion 6 serving as a supported portion. The focusing displacement portion 6 is formed like a thin hinge like the tracking displacement portion 4, and connects the support arm portion 7 to the upper end portion of the relay plate portion 5. The focusing displacement portion 6 is formed along the upper end portion of the relay plate portion 5. The support arm portion 7 is rotatable with respect to the relay plate portion 5 about the focus displacement portion 6 as an axis by the displacement of the focus displacement portion 6.

The displacement member 2 has a bobbin mounting portion 11 which is a part of the lens support. The bobbin mounting portion 11 is formed to have substantially the same size and shape as the relay plate portion 5, and the upper end portion thereof is provided at one end portion of the support arm portion 7 via the first displacement portion 12. It is lined up. The first displacement portion 12 has a hinge shape similar to the displacement portions 4 and 6, and is formed along one end of the support arm portion 7. The first displacement portion 12 is parallel to the focusing displacement portion 6. The bobbin mounting portion 11 is rotatable with respect to the support arm portion 7 about the first displacement portion 12 as an axis.
The bobbin mounting portion 11 is suspended from one end of the support arm portion 7 so as to be substantially perpendicular to the base 1.

That is, the bobbin mounting portion 11 is rotated relative to the base 1 as shown by an arrow F in FIG. 1 when the support arm portion 7 rotates about the focusing displacement portion 6. It is possible to move in the vertical direction while maintaining the vertical posture. Further, the bobbin mounting portion 11 is rotated with respect to the base 1 as shown by an arrow T in FIG. 1 when the relay plate portion 5 rotates about the tracking displacement portion 4. The movable portion 4 is rotatable around the center. The movable direction and the rotatable direction of the bobbin mounting portion 11 with respect to the base 1 are orthogonal to each other.

The displacement member 2 has a balancer mounting portion 14 which is a part of the balancer member. The balancer mounting portion 14 is formed to have substantially the same size and shape as the bobbin mounting portion 11, and the upper end portion thereof is disposed at the other end portion of the support arm portion 7 via the second displacement portion 15. Are connected in series. The second displacement portion 15 has a hinge shape like the first displacement portion 12, and is formed along the other end portion of the support arm portion 7. The second displacement portion 15 is parallel to the focusing displacement portion 6. The balancer attachment portion 14 is rotatable with respect to the support arm portion 7 about the second displacement portion 15 as an axis. And, this balancer mounting portion 14 is
It is suspended from the other end of the support arm portion 7 so as to be substantially perpendicular to the base 1.

That is, the balancer mounting portion 14 is
By rotating the support arm portion 7 about the focus displacement portion 6 as an axis, the support arm portion 7 can move in the vertical direction while maintaining a vertical posture with respect to the base 1. Further, the balancer mounting portion 14 is rotatable about the tracking displacement portion 4 with respect to the base 1 by the rotation of the relay plate portion 5 about the tracking displacement portion 4. Has been done.

The displacement member 2 also has a parallel state maintaining link portion 9. The parallel state maintaining link portion 9 is formed to have substantially the same size and shape as the supporting arm portion 7, and the center portion thereof is located at the lower end portion of the relay plate portion 5 like the focusing displacement portion 6. It is connected rotatably through a fifth displacement portion 8 formed on the. One end of the parallel state maintaining link portion 9 is connected to the lower end portion of the bobbin mounting portion 11 via the third displacement portion 13. The other end of the parallel state maintaining link portion 9 is connected to the lower end portion of the balancer mounting portion 14 via the fourth displacement portion 16. These third and fourth displacement parts 13 and 16 are the first and second displacement parts 12 and
Similar to 15, it is formed in a hinge shape. The parallel state maintaining link portion 9 is supported so as to be parallel to the support arm portion 7.

The parallel state maintaining link portion 9 is provided with a through hole 10 substantially at the center thereof in order to prevent the parallel state maintaining link portion 9 and the supporting portion 3 from coming into contact with each other. There is.

The bobbin mounting portion 11 and the balancer mounting portion 14 are supported by the support arm portion 7 and the parallel state maintaining link 6 at the upper end portion and the lower end portion, so that the bobbin mounting portion 11 and the balancer mounting portion 14 are supported with respect to the base 1. A vertical posture with respect to the base 1 is maintained when moving and rotating.

A lens bobbin 17 constituting a lens support is attached to the main surface portion on one side of the bobbin mounting portion 11, that is, the main surface portion on the outer side of the displacement member 2. The lens bobbin 17 is formed in a substantially rectangular parallelepiped shape. An objective lens 19 is attached to the lens bobbin 17. This lens bobbin 1
Reference numeral 7 designates arrows F and T in FIG. 1 due to the displacement of the focusing displacement portion 6, the first to fifth displacement portions 12, 15, 13, 16, 8 and the tracking displacement portion 4 of the displacement member 2. As shown, it can be displaced in two directions orthogonal to each other.

The objective lens 19 is arranged so that the focusing and first to fifth displacement portions 6 and 1 are arranged in the optical axis direction.
The lens bobbin 17 is attached in such a manner that the lens bobbin 17 is moved by the displacement of 2, 15, 13, 16, and 8. Further, in the objective lens 19, the direction orthogonal to the optical axis is the moving direction of the lens bobbin 17 due to the displacement of the tracking displacement portion 4.

The objective lens 19 is fitted and supported in the opening 18 formed through the lens bobbin 17 corresponding to the objective lens 19, and is directly above the light flux passage hole 33. Since it is positioned, the light beam emitted from the optical block unit of the optical pickup device (not shown) can enter.

The balancer mounting portion 14 has
A balancer 20 that constitutes a balancer member is attached. The balancer 20 is formed to have substantially the same size, shape and mass as the lens bobbin 17.

The lens bobbin 17 has a first focus coil 21 and a pair of tracking coils 23 and 2.
4 and are attached. Further, the balancer 20 includes a second focus coil 22 paired with the first focus coil 21 and a pair of tracking coils 2.
5 is attached. The first and second focus coils 21 and 22 and the tracking coils 23 and 2
4, 25 are attached so as to be symmetrical with respect to the tracking displacement portion 4.

On the other hand, at both ends of the base 1, corresponding to the coils 21, 22, 23, 24 and 25,
A pair of magnetic yokes 27, 30 is arranged. These magnetic yokes 27, 30 are formed by bending a plate-shaped high magnetic permeability material in a U-shape, and have an outer yoke portion and inner yoke portions 28, 31 facing the outer yoke portion. These magnetic yokes 27 and 30 are provided on the inner side of each outer yoke portion.
A pair of magnets 29 and 32 are attached correspondingly. These magnetic yokes 27 and 30 are used for the coils 2
1, 22, 23, 24, 25, the magnet 29,
32 are opposed to each other. In addition, each of the magnetic yokes 27,
In the reference numeral 30, the inner yoke portions 28 and 31 are inserted in the focus coils 21 and 22, respectively. The magnetic fluxes generated by the magnets 28 and 31 are guided to the magnetic yokes 29 and 30, respectively, and are linked to the coils 21, 22, 23, 24 and 25.

In this objective lens driving device constructed as described above, the focus coils 21 and 22 described above are used.
By supplying a focus drive current to the tracking coils 23, 24, and 25, the objective lens 19 moves in the optical axis direction indicated by arrow F in FIG. 1, that is, the focus direction. 1 is driven and displaced in a direction orthogonal to the optical axis indicated by arrow T in FIG. 1, that is, in the tracking direction. Then, in the objective lens 19, the focus drive current corresponds to the surface wobbling of the optical disc in the disc player device, and the tracking drive current corresponds to the eccentricity of the optical disc. Drive displacement is performed so as to follow the surface wobbling and the eccentricity.

By the way, in this objective lens driving device, the displacement member 2, the lens bobbin 17, the objective lens 19, the balancer 20, and the coils 21, 22, 23, 24 are combined. The position of the center of gravity is configured to be on the tracking displacement portion 4. Further, the position of the center of gravity of the support arm portion 7 of the displacement member 2, the lens bobbin 17, the objective lens 19, the balancer 20, and the coils 21, 22, 23, 24 is the focus. It is configured so as to be on the displacement portion 6 for use. That is, in this objective lens driving device, the members such as the displacement member 2 that are displaced in the tracking direction have their centers of gravity aligned with the tracking displacement portion 4 that is the rotation center in the tracking direction. Further, in this objective lens driving device, the members such as the support arm portion 7 which are displaced in the focus direction have their centers of gravity aligned with the focus displacement portion 6 which is the rotation center in the focus direction. ..

Therefore, in this objective lens driving device, even if the base 1 has an acceleration due to vibration or shock propagating from the outside of the disc player device, this acceleration causes the acceleration to occur in the first and fifth parts. Displacement parts 14, 18
Is not displaced, and the objective lens 19 does not move in the focus direction and the tracking direction with respect to the base 1.

That is, in the optical pickup device having the objective lens driving device, even if the base 1 has an acceleration, the objective lens 19 moves in the focus direction and the direction relative to the base 1. Since it does not move in the tracking direction and the focal point of the light beam formed by the objective lens 19 does not deviate from the signal recording surface of the optical disc, writing and / or reading of the information signal on the optical disc is favorably performed. You can continue.

Further, in the optical pickup device having the objective lens driving device, the objective lens 19 is located at the center position of the movable range of the objective lens 19 in the non-use state. Therefore, in this optical pickup device, the distance to move the objective lens 19 at the start of writing or reading of the information signal to or from the optical disc is small, power consumption is reduced, and writing or reading of the information signal is started. Can be accelerated.

The objective lens driving device according to the present invention is not limited to the above-mentioned embodiment, and as shown in FIG. 3, one rod-shaped support member 43 and a pair of substantially rigid members are provided. Rod-like parallel state maintaining links 44, 45
May be used. This objective lens drive is
It is configured to have a base 40. On the base 40, there is provided a fixing plate 42 which is fixedly supported by the base 40 via a supporting member 41. This fixing plate 42 is
It is formed in a substantially triangular plate shape, and first to third support portions 46, 47, 48 are provided at the corners. These support parts 4
Reference numerals 6, 47 and 48 are formed as recesses formed by cutting out the fixing plate 42. In addition, these support portions 46, 4
The inside of 7, 48 has a so-called knife edge shape in which the thickness of the fixing plate 42 is thin.

The central portions of the support member 43 and the parallel state maintaining links 44, 45 are fitted in correspondence with the support portions 46, 47, 48, respectively. The support member 43 and the parallel state maintaining links 44 and 45
With respect to the fixed plate 42, each of the support portions 46, 4
It is possible to make a displacement that rotates about 7, 48. That is, the first support portion 46 supports the supported portion of the support member 43.

Then, the support member 43 and the parallel state maintaining links 44, 45 are connected to one end sides thereof near the ends of the support member 43 and the parallel state maintaining links 44, 45, respectively. A lens support plate 49 forming a lens support is attached. The lens support plate 49 is formed to have substantially the same size and shape as the fixed plate 42. The support member 43 can be displaced so as to be inclined with respect to the lens support plate 49, and is joined to the lens support plate 49. That is,
One end side of the support member 43 is a first displacement portion. Further, the parallel state maintaining links 44, 45 described above are also provided.
Can be displaced so as to be inclined with respect to the lens support plate 49, and is joined to the lens support plate 49.
That is, one end side of each of the parallel state maintaining links 44 and 45 serves as a third displacement portion.

The other ends of the support member 43 and the parallel state maintaining links 44 and 45 are connected to the ends of the support member 43 and the parallel state maintaining links 44 and 45, respectively. Then, a balancer support plate 50 that constitutes a balancer member is attached. The balancer support plate 50 is formed to have substantially the same size and shape as the fixed plate 42. The support member 43 can be displaced so as to be inclined with respect to the balancer support plate 50, and is joined to the balancer support plate 50. That is, the other end side of the support member 43 serves as a second displacement portion. Further, each of the parallel state maintaining links 44,
45 is joined to the balancer support plate 50 so that it can be displaced so as to be inclined with respect to the balancer support plate 50. That is, the parallel state maintaining links 44,
The other end side of 45 is a fourth displacement portion.

The support member 43 and the parallel state maintaining links 44 and 45 are supported in parallel with each other.

The objective lens 1 is mounted on the lens support plate 49.
The lens bobbin 52 to which 9 is fitted and attached is attached. A balancer 51 is attached to the balancer support plate 50. Further, on the base 40, a driving means (not shown) for rotating the support member 43 around the support portion 46 is provided.

In this objective lens driving device, the lens support plate 49 and the balancer support plate 50 are maintained in parallel with each other and in a positional relationship of facing each other about the fixed plate 42. As it is, it is movable with respect to the base 40. Further, the objective lens driving device includes the supporting member 43, the parallel state maintaining links 44 and 45, and the lens supporting plate 4.
9. The center of gravity of the lens bobbin 52, the objective lens 19, the balancer support plate 50, and the balancer 51 is located on the fixed plate 42. Therefore, also in this objective lens driving device, the objective lens 19 does not move with respect to the base 40 due to acceleration due to vibration or impact propagating from the outside.

Further, in the objective lens driving device according to the present invention, as shown in FIG. 4, one rod-shaped support member 64 and a pair of rod-shaped parallel state maintaining links 65, 65 formed as a substantially rigid body. And a so-called universal joint may be used as the first to fourth displacement portions.

This objective lens driving device has a base 40. On this base 40, a fixed body 6 fixedly supported by the base 40 via a support member 41.
0 is provided. The fixed body 60 is formed in a substantially spherical shape, and the first to third universal joints 61, 62, 63 are attached to the three sides. The universal joints 61, 62, 63 are supported by the fixed body 60 so as to be rotatable about their axes.

The support member 64 and the parallel state maintaining links 65 and 66 are supported at their central portions in correspondence with the universal joints 61, 62 and 63, respectively. The support member 64 and the parallel state maintaining links 65 and 66 are displaceable with respect to the fixed body 60 by rotating around the universal joints 61, 62 and 63. That is, the first
The universal joint 61 supports the supported portion of the support member 64.

Then, the support member 64 and the parallel state maintaining links 65 and 66 are connected to one end side of the support member 64 and the parallel state maintaining links 65 and 66 through fourth to sixth universal joints 67 and 71, respectively. Links 65, 66
A lens support plate 74 that constitutes a lens support is attached so as to extend between one ends of the. The support member 64 can be displaced so as to be inclined with respect to the lens support plate 74 by the fourth universal joint 67. That is, the fourth universal joint 67 is a first displacement portion. The parallel state maintaining links 65 and 66 can be displaced so as to be inclined with respect to the lens support plate 74 by the fourth and fifth universal joints 71. That is, the fourth and fifth universal joints 71 serve as a third displacement portion.

Further, on the other end side of the supporting member 64 and the parallel state maintaining links 65 and 66, seventh to ninth members are provided.
Via universal joints 68, 70, 72 of
The support member 64 and the parallel state maintaining links 65,
A balancer plate 73, which serves as a balancer member, is attached so as to extend between the other ends of 66. The balancer plate 73 is formed to have substantially the same size and shape as the lens support plate 74. The support member 64 is
The seventh universal joint 68 enables displacement so as to be inclined with respect to the balancer plate 73. That is, the seventh universal joint 6
Reference numeral 8 is a second displacement portion. The parallel state maintaining links 65 and 66 can be displaced so as to be inclined with respect to the balancer plate 73 by the eighth and ninth universal joints 70 and 72.
That is, the 8th and 9th universal joints 70 and 72 are the 4th displacement parts.

The support member 64 and the parallel state maintaining links 65 and 66 are supported in parallel with each other.

The objective lens 1 is mounted on the lens support plate 74.
A lens bobbin 75 to which 9 is fitted and attached is attached. Further, on the base 40, a drive means (not shown) for rotating the support member 64 about the first universal joint 61 is provided.

In this objective lens driving device, the lens support plate 74 and the balancer plate 73 are maintained in parallel with each other, and the fixed body 60 is mutually opposed.
It is configured to be movable with respect to the base 40 while maintaining the positional relationship facing each other with respect to. In this objective lens driving device, the center of gravity of the whole of the support member 64, the parallel state maintaining links 65 and 66, the lens support plate 74, the lens bobbin 75, the objective lens 19 and the balancer plate 73 is adjusted. , Is arranged on the fixed body 60. Therefore, also in this objective lens driving device, the objective lens 19 is moved to the base 40 by the acceleration due to vibration or shock propagating from the outside.
Never move against.

[0055]

As described above, in the objective lens driving device according to the present invention, the support member rotatably supporting the supported portion at the midway portion is provided on the supported portion. It has a lens support attached to one end side through a first displacement portion, a balancer member attached to the other end side through a second displacement portion, and the center of gravity of the entire support member. ing.

Therefore, in this objective lens driving device, even if vibration or shock is propagated from the outside to generate acceleration, the support member is rotated about the supported portion by this acceleration. There is no.

Further, in this objective lens driving device, the parallel state maintaining link rotatably supported at the middle part has one end attached to the lens support through the third displacement part and the other end. The side is attached to the balancer member via a fourth displacement portion and supports the lens support so that the optical axis of the objective lens moves in parallel when the support member rotates.

Therefore, this objective lens driving device prevents the optical axis of the objective lens from tilting, and enables the optical pickup device to write and / or read the information signal in good condition.

That is, according to the present invention, even if acceleration occurs due to vibration or shock propagating from the outside, the objective lens does not move or tilt, and the optical pickup device writes and / or writes an information signal on the optical disc. It is possible to provide an objective lens driving device that enables continuous reading.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of an objective lens driving device according to the present invention.

FIG. 2 is an exploded perspective view showing a configuration of the objective lens driving device.

FIG. 3 is a perspective view showing another example of the configuration of the objective lens driving device according to the present invention.

FIG. 4 is a perspective view showing still another example of the configuration of the objective lens driving device according to the present invention.

FIG. 5 is an exploded perspective view showing a configuration of a conventional objective lens driving device.

[Explanation of symbols]

6 ... Displacement part for focus 7 ...・ ・ ・ ・ Support arm 9 ・ ・ ・ ・ ・ ・ ・ ・ Link for maintaining parallel condition 11 ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Bobbin mounting part 12 ・ ・ ・ ・ ・ ・ ・ ・ First displacement part 13 ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ 3rd displacement part 14・ Balancer mounting part 15 ・ ・ ・ Second displacement part 17,52,75 ・ ・ ・・ Lens bobbin 16 ・ ・ ・ 4th displacement part 19 ・ ・・ ・ ・ Objective lens 20,51 ・ ・ ・ Balancer 43, 64 ・ ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ Supporting members 44, 45, 65, 66 ・ ・ Links for maintaining parallel state 46 ・ ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ First support 49,74 ・ ・ ・ ・ Lens support plate 50 ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ ・ Balancer mounting plate 61 ・ ・ ・ ・ ・ ・ ・ ・ 1st universal joint 67 ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ ・ 4th universal joint 68 ・ ・ ・ ・ ・ ・ ・ ・Seventh universal joint 70 ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 8th universal joint 71 ・ ・ ・ ・ ・ ・ ・ ・ 5th universal joint 72 ... 9th universal joint 73 ... ... Balancer plate

Claims (1)

[Claims] 1. A support member, in which a supported portion at an intermediate portion is rotatably supported, and an objective lens, which is attached to one end side of the support member via a first displacement portion, and the support member is provided. And a balancer member attached to the other end side of the support member via a second displacement section, the lens support body being supported by being capable of displacing at least the objective lens in the optical axis direction. , The middle part is rotatably supported, and one end side is the third
Is attached to the lens supporter via the displacement part of the objective lens, and the other end side is attached to the balancer member via the fourth displacement part so that the optical axis of the objective lens is parallel when the support member rotates. A parallel state maintaining link that supports the lens support so as to move, the support member having the lens support, the balancer member, and the center of gravity of the entire support member on the supported portion. Objective lens driving device.