JPH07134833A - Objective lens driving device and optical head driving device - Google Patents

Abstract

(57) [Summary] [Object] According to the present invention, it is not necessary to use a connecting wire for supplying a control drive current to each control drive coil, the number of parts can be reduced, and higher-order resonance and the like can be achieved. It is an object of the present invention to provide a drive device that can drive an objective lens or an optical head without generating the light. A flexible printed wiring board having a wiring pattern formed on at least one side surface and a bobbin for supporting an objective lens are provided, and the bobbin is supported on one end side of the printed wiring board. In the objective lens driving device in which the end side is attached to a support base, the bobbin supporting means uses a conductor such as copper foil formed on the printed wiring board as a spring material. This can also be applied to the optical head driving device.

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 and an optical head driving device used in an optical information recording / reproducing apparatus for recording and / or reproducing an information signal on an optical recording medium such as an optical disk. It is a thing.

[0002]

2. Description of the Related Art Conventionally, a signal beam is irradiated onto a signal recording surface of an optical disk which is mounted on a disk rotation driving device and rotated, and an information signal recorded on the optical disk is read or a predetermined information signal is applied to the optical disk. An optical pickup device is used as a writing unit. The optical pickup device has a light source such as a semiconductor laser element, and a light beam emitted from the light source is passed through a predetermined optical device such as a collimator lens or a beam splitter and an objective lens to be a signal of an optical disc as an optical recording medium. Condensed on the recording surface and configured to detect an optical beam reflected by the signal recording surface by a photodetector and write and / or read an information signal on the signal recording surface Is proposed.

As described above, in the optical pickup device, the objective lens is driven to be displaced in the two axial directions of the optical axis direction (that is, the focus direction) and the direction orthogonal to the optical axis (that is, the tracking direction) by the electromagnetic driving force. The objective lens driving device is provided, and the light beam is focused on the signal recording surface of the optical disc to accurately scan the recording track.

In such an objective lens driving device,
As an objective lens supporting member that supports the objective lens so as to be displaceable in two axial directions, a supporting arm made of four round bar members as shown in Japanese Utility Model Laid-Open No. 1-252424, and Japanese Patent Application Laid-Open No.
There is known one in which a lens bobbin to which an objective lens is attached is drivably supported by a supporting arm formed by combining parallel leaf springs in a direction orthogonal to each other as shown in Japanese Patent No. 179932.

In the objective lens driving device having such a supporting arm, the objective lens is driven and displaced based on the output of the photodetector to perform so-called focus servo and tracking servo.

That is, in the focus servo, the light beam projected on the signal recording surface is always accurately focused on the signal recording surface even if so-called surface wobbling occurs when the optical disk is rotationally driven. It is what you do. Therefore, when the focus servo is operated, the objective lens is driven and displaced so that the distance from the optical disc is always kept at a predetermined value.

Further, the tracking servo is a recording in which a beam spot formed by condensing the light beam is formed on the signal recording surface even if so-called center deviation occurs when the optical disk is rotationally driven. It is designed to trace the track accurately.

As described above, in the conventional objective lens driving device, the supporting arm for supporting the lens bobbin includes a rod member or a parallel plate spring.

However, in the case of the four support arms made of the round bar material, it is necessary to attach each support arm to the lens bobbin for holding the objective lens, which is difficult to manufacture.

Further, in order to supply a drive current for control to the focus coil and the tracking coil provided on the lens bobbin which is a movable part, it is necessary to provide a connecting wire between the lens bobbin and the fixed part. For this connecting wire, it is necessary to use a wire material such as an extremely thin Litz wire that is sufficiently flexible and can be displaced following the lens bobbin without giving a large load to the movable portion of the objective lens. Since this litz wire is thin and has insufficient mechanical strength, connection work is difficult.

Therefore, there is one disclosed in the above-mentioned Japanese Patent Laid-Open No. 179932, which has a structure as shown in FIG. That is, as shown in FIG. 11, power is supplied to the focus coil and the tracking coil for driving the objective lens 31, and the printed wiring board 32 is provided on the surface of the support arm 33 formed by combining parallel leaf springs in the orthogonal direction. Is attached.

However, there is a problem that the resonance of the printed wiring board itself appears and the control system tends to be unstable, and the mechanism for fixing the printed wiring board to the support arm becomes complicated. In addition, there is a problem that the number of parts increases and assembly becomes difficult.

[0013]

As described above, in the conventional objective lens driving device, power is supplied to the focus coil and the tracking coil for driving the objective lens.
Since the printed wiring board is attached to the surface of the support consisting of parallel leaf springs, there is a problem that the resonance of the printed wiring board itself appears and the servo control system easily becomes unstable. There is a problem that the mechanism for fixing to the arm becomes complicated.

This is also true in the optical head driving device.
There were similar problems.

It is an object of the present invention to solve the above-mentioned problems and to provide an objective lens driving device and an optical head driving device in which the number of parts can be reduced and higher-order resonance or the like does not occur. is there.

[0016]

In order to achieve the above object, the present invention provides a flexible printed wiring board having a wiring pattern of a conductor such as copper foil formed on at least one side surface, and an objective lens. And a bobbin for supporting the bobbin on one end side of the printed wiring board and for mounting the other end side of the printed wiring board on a support base. The supporting means uses a conductor such as a copper foil formed on the printed wiring board as a spring material.

The present invention is also characterized in that a printed wiring board is similarly used in an optical head driving device which performs at least one of recording and reproducing information from an optical recording medium.

Further, according to the present invention, in these objective lens driving device and optical head driving device, a wiring pattern is formed on at least one side surface of a film substrate as a printed wiring board, and a cover film is formed on this wiring pattern. In addition, a viscoelastic material may be used to bond the film substrate and the wiring pattern or the wiring pattern and the cover film.

Further, according to the present invention, in the above-mentioned objective lens driving device and optical head driving device, as a printed wiring board, the wiring pattern is widened in a portion other than the portion where the elastic displacement is required to have high rigidity. What was formed so that it can be used.

Further, according to the present invention, in the above-mentioned objective lens driving device and optical head driving device, as a printed wiring board, a wiring pattern is formed in a plurality of layers and the thickness of the wiring pattern which is outside the bent portion is set. It is possible to use a wiring pattern having a thickness larger than the thickness of the wiring pattern coming inside.

[0021]

According to the present invention, a bobbin for supporting an objective lens is supported by using a flexible printed wiring board having a wiring pattern of a conductor such as copper foil used as a spring material on at least one side surface. Therefore, in order to supply a drive current for control to the focus control drive coil and the tracking control drive coil attached to this bobbin, the litz wire and the new printed wiring board are connected between the bobbin and the fixed portion. It is not necessary to use such a connecting wire,
The number of parts can be reduced, the structure is simple and the assembly is easy, and the objective lens or the optical head can be driven with good responsiveness to the drive current for control without generating higher-order resonance.

Further, in the present invention, as a printed wiring board, a wiring pattern is formed on at least one side surface of a film substrate, a cover film is formed on the wiring pattern, and between the film substrate and the wiring pattern or By using a viscoelastic body bonded between the wiring pattern and the cover film, the peak at main resonance can be suppressed by the damping effect of the viscoelastic body as a bonding material, and higher-order resonance etc. are generated. It is possible to drive the objective lens or the optical head with high responsiveness to the control drive current.

Further, in the present invention, by using a printed wiring board in which the pattern width of the portion other than the portion where the elastic displacement is required is wide as the printed wiring board, the elastic displacement can be caused by driving the objective lens or the optical head. The rigidity of portions other than the necessary portions can be increased, and by preventing excessive displacement from occurring, it is possible to perform strict drive control of the objective lens or the optical head.

Further, in the present invention, a printed wiring board in which the wiring patterns are formed in a plurality of layers and the thickness of the wiring patterns outside the bent portion is larger than the thickness of the wiring patterns inside the bent portion is preferable. By using this, especially when the objective lens support member or the optical head support member is formed by integral bending, it is possible to prevent the portion of the wiring pattern which is subjected to a large bending deformation from coming outside, and at the same time, to bend the bent portion. Can stabilize the shape of
The operation reliability can be kept high.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the objective lens driving device according to the present invention includes a plurality of wiring patterns 2a, 2b, which are used as spring materials, on one side surface of a flexible synthetic resin film substrate 1. 2c and 2d are formed on the wiring patterns 2a, 2b, 2c and 2d, except for a plurality of land portions 4a and 4b indicated by inclined portions which are coil soldering points arranged on both ends of the wiring patterns 2a, 2b, 2c and 2d. Using the flexible printed wiring board 5 on which the insulating cover film 3 made of synthetic resin having flexibility is formed, the lens bobbin 7 having the objective lens 6 shown in FIGS. 2 and 3 is arranged in two axial directions orthogonal to each other. It is movably supported.

The material of the plurality of wiring patterns 2a, 2b, 2c, 2d used as the spring material is a conductor such as copper, beryllium copper, phosphor bronze or the like. The film substrate 1 and the insulating cover film 3 are made of a synthetic resin film having heat resistance and not so high rigidity as a base material. For example, synthetic resins such as polyimide, polyamide-imide, aromatic polyamide (heat resistant nylon), fluororesin such as polytetrafluoroethylene, polyester resin such as polyparabanic acid and polyethylene terephthalate are used.

The objective lens driving device is shown in FIGS.
, The objective lens 6 supported by the lens bobbin 7, the flexible printed wiring board 5 supporting the objective lens 6 in a swingable manner, and the drive coils 8, 9 attached to the lens bobbin 7. The magnet 10 arranged to face the drive coil, and the magnet 10
And a magnetic yoke 11 for supporting.

That is, the lens bobbin 7 is supported by the flexible printed wiring board 5 in the magnetic yoke 11 formed as a frame so as to face the magnet 10 mounted in the magnetic yoke 11.

A focus coil 8 and a tracking coil 9 are attached to the lens bobbin 7 as coils for driving the objective lens 6 in the two axial directions. A magnetic circuit can be formed between the magnet bobbin 7 and the magnet 10 attached to the magnetic yoke 11 at a position facing the lens bobbin 7. Therefore, the objective lens 6 can be driven in the biaxial directions within the magnetic yoke 11.

Next, as shown in FIG. 1, the flexible printed wiring board 5 supporting the objective lens 6 so as to be swingable in two orthogonal directions is a rectangular frame-shaped flexible printed wiring board 5. It is formed by bending.

As shown in FIG. 1, the flexible printed wiring board 5 formed in the bent rectangular frame shape has a pair of connecting portions 20, 20 so that the pair of supporting arm portions 21, 21 are parallel to each other. It is formed by bending 90 degrees at right angles to. The support arms 21 and 21 function as a leaf spring in the longitudinal direction and can be elastically displaced in the thickness direction by using a conductor such as copper foil as a spring material. Further, the connecting portions 20 and 20 are made of a conductor such as copper foil as a spring material, so that the supporting arm portions 21 and
It is possible to elastically displace only in the thickness direction of the connecting portions 20, 20 in a direction orthogonal to the displacement of the connecting portion 20 in the thickness direction.

As shown in FIGS. 2 and 3, a part of the connecting portions 20, 20 is fixed to the lens bobbin 7 and the supporting member 12 for holding the objective lens 6 by a fixing member 22, respectively. This fixing means may be any means as long as it firmly positions and fixes the flexible printed wiring board 5 to the lens bobbin 7 and the supporting member 12, such as using a screw or using an adhesive.

The support member 12 is for supporting the flexible printed wiring board 5. That is, the support member 12 is attached to the magnetic yoke 11 so that the flexible printed wiring board 5 can be manufactured.
I support you. In this embodiment, the flexible printed wiring boards 5 are attached to both sides of the lens bobbin 7 to support the objective lens 6. At this time, the focus coil 8 and the tracking coil 9 arranged on the lens bobbin 7 supported by the flexible printed wiring board 5 are arranged to face the magnet 10 in the magnetic yoke 11. There is. Then, the focus coil 8, the tracking coil 9, the magnet 10 and the magnetic yoke 11 are provided.
Constitutes a magnetic circuit.

Therefore, in the magnetic yoke 11, the objective lens 6 supported by the flexible printed wiring board 5 so as to be swingable in two axial directions is supplied with a predetermined focus drive current to the focus coil 8. As a result, the lens bobbin 7 is driven and displaced in the optical axis direction of the objective lens 6 indicated by the arrow f in FIG. 2, that is, in the focus direction. Further, by supplying a predetermined tracking drive current to the tracking coil 9, the lens bobbin 7 is driven in a direction orthogonal to the optical axis of the objective lens 6 shown by an arrow t in FIG. 2, that is, a tracking direction. Is displaced.

Here, the supply of the drive current to the focus coil 8 and the tracking coil 9 is extended from the plurality of lands 4a provided on the flexible printed wiring board 5 and the coils 8 and 9. The ends of the coils are connected by soldering or the like, while the plurality of lands 4a received by the flexible printed wiring board 5 and external connection wires for supplying a control current are connected by soldering or the like. .

As described above, the flexible printed wiring board 5 formed in the bent rectangular frame body has a pair of connecting portions so that the pair of supporting arm portions 21 and 21 are parallel to each other, as shown in FIG. The objective lens supporting member can be elastically displaced in two axial directions simply by forming a 90-degree bend at a right angle to 20, so that the objective lens supporting member has an extremely simple structure.

The flexible printed wiring board 5 is made by bending a conductor made of a uniform material such as copper foil as a spring material, and is made of the same material in both axial directions. Since it is configured, the resonance frequency becomes constant as a whole, and it is possible to prevent the occurrence of partial harmful resonance.

Further, the flexible printed wiring board 5 includes the supporting arms 21, 21 and the connecting portion 2.
Since the displacement directions of 0 and 20 are displaced only in the directions orthogonal to the other, twisting and distortion can be prevented when the objective lens 6 is driven, and the responsiveness can be improved.

Therefore, by supplying a predetermined drive current to the drive coil, it is possible to drive the lens bobbin 7 to a predetermined position and reliably perform focus servo and tracking servo.

Therefore, according to the above-described embodiment, the objective lens is supported by using the flexible printed wiring board having the conductive wiring pattern such as the copper foil used as the spring material on at least one side surface. Since the bobbin is supported, a litz wire and a new wire are provided between the bobbin and the fixed part in order to supply a control drive current to the focus control drive coil and the tracking control drive coil attached to the bobbin. It is not necessary to use a connecting wire such as a printed wiring board, the number of parts can be reduced, the structure is simple, and the assembly is easy.

Further, the flexible printed wiring board formed in the bent rectangular frame shape is bent 90 degrees at right angles to the pair of connecting portions so that the pair of supporting arm portions are parallel to each other. The objective lens support member can be elastically displaceable in two axial directions, and the objective lens support member can have a simple structure.

Further, the flexible printed wiring board is
A conductive material such as a copper foil made of a uniform material is used as a spring material and is bent and formed by the same member in both axial directions, so that the resonance frequency is constant as a whole. Therefore, it is possible to prevent partial harmful resonance from occurring.

Furthermore, since the flexible printed wiring board is displaced only in the directions in which the support arm portion and the connecting portion are displaced in the directions orthogonal to the other, twisting and distortion can be prevented when the objective lens is driven, and the response characteristics are improved. It is possible to improve.

Therefore, by supplying a predetermined drive current to the drive coil, it is possible to drive the lens bobbin to a predetermined position and reliably perform focus servo and tracking servo.

Next, as a preferred embodiment of the present invention, an example of an optical head driving device will be described with reference to the drawings.

1 of the optical head driving device according to the present embodiment
As an example, a recording and / or reproducing optical head biaxial actuator has a plurality of wiring patterns 42a used as spring materials on both surfaces of a flexible synthetic resin film substrate 41 as shown in FIGS. , 42b, 42c, 4
2d, 42e, ... Are formed, and the wiring patterns 42a,
42b, 42c, 42d, 42e, ... A plurality of land portions 44a, 44b, 44c, 44d, 44 indicated by inclined portions provided at both ends of each of which are coil soldering points.
, and the flexible printed wiring board 45 on which an insulating cover film 43 made of a synthetic resin having flexibility is formed, and the objective lens 46, the semiconductor laser element, and the objective lens 46 shown in FIGS. A collimator lens, a beam splitter, a prism, a hologram optical element (not shown), a photodetector (not shown), etc. are provided inside the integrated optical head unit 47 for recording and / or reproducing information symbols. It is movably supported in two axial directions orthogonal to each other.

A plurality of the wiring patterns 42a, 42b, 42c, 42d, 42 used as the spring material.
Conductors such as copper, beryllium copper, and phosphor bronze are used as materials for e, .... Further, as the film substrate 41 and the insulating cover film 43, those having a base material of a synthetic resin film having heat resistance and not so high in rigidity are used. For example, synthetic resins such as polyimide, polyamide-imide, aromatic polyamide (heat resistant nylon), fluororesin such as polytetrafluoroethylene, polyester resin such as polyparabanic acid and polyethylene terephthalate are used.

The recording and / or reproducing optical head biaxial actuator is, as shown in FIGS. 6 and 7, an objective lens 46, a semiconductor laser element, a collimator lens, a beam splitter, a prism, a hologram optical element, a photodetector and the like. An integrated optical head unit 47 (not shown) for recording and / or reproducing an information signal and an integrated optical head unit 4 for recording and / or reproducing the information signal.
Flexible printed wiring board 45 for supporting 7 in a swingable manner, and drive coil 4 attached to integrated optical head section 47 for recording and / or reproducing the information signal.
8, 49, a magnet 410 arranged to face the driving coil, and a magnetic yoke 411 supporting the magnet 410.

That is, the integrated optical head portion 47 for recording and / or reproducing the information signal is provided in the magnetic yoke 411 formed as a frame body.
It is supported by the flexible printed wiring board 45 so as to face the magnet 410 mounted inside the magnet 11.

A focus coil 48 and a tracking coil 49 are attached to the integrated optical head portion 47 for recording and / or reproducing the information signal as a coil for driving in two axial directions. A magnetic circuit can be formed between the magnet 410 and the magnet 410 attached to the magnetic yoke 411 at a position facing the integrated optical head portion 47 for recording and / or reproducing the information signal. Therefore, the integrated optical head unit 47 that records and / or reproduces the information signal in the magnetic yoke 411 can be driven in two axial directions.

Next, the flexible printed wiring board 4 which supports the integrated optical head portion 47 for recording and / or reproducing the information signal so as to be swingable in two orthogonal directions.
5 is formed by bending the one rectangular frame-shaped flexible printed wiring board having the structure shown in FIG. 5 as shown in FIG. As shown in FIG. 4, the flexible printed wiring board 45 formed in the bent rectangular frame shape has a pair of support arms 421 and 421 that are parallel to each other with respect to the pair of connecting portions 420 and 420. It is formed by bending 90 degrees at a right angle. The support arms 421, 421 function as a leaf spring in the longitudinal direction by using a conductor such as copper foil as a spring material, and are elastically displaceable in the thickness direction. In addition, the connecting portion 42
Reference numerals 0 and 420 are directions orthogonal to the displacement of the support arm portions 421 and 421 in the thickness direction by using a conductor such as copper foil as a spring material, and the connecting portions 420 and 420.
Is elastically displaceable only in the thickness direction.

Further, in the flexible printed wiring board 45, the width of the wiring pattern at the intermediate portion in the longitudinal direction of the connecting portion 420 and the supporting arm portion 421, which is the portion to be elastically deformed, is narrowed, and the other portions are formed. The rigidity is increased by widening the part.

As shown in FIG. 6 and FIG. 7, a part of the connecting portions 420, 420 has a fixing member 422 for recording and / or reproducing the information signal, and an integrated optical head portion 47 and a supporting member 412, respectively. Fixed to. This fixing means is used for recording the information signal and / or for recording the information signal on the flexible printed wiring board 45 by screwing or using an adhesive.
Alternatively, the integrated optical head portion 47 and the supporting member 4 for reproducing
Any means may be used as long as it can firmly position and fix it on the 12.

Further, in FIG. 8, at least one of the integrated optical head portion 47 for recording and / or reproducing the information signal and the supporting member 412 is made of an engineering plastic material having high rigidity and low linear expansion coefficient. There is another embodiment in which a part of the connecting portions 420, 420 is firmly integrally molded and fixed by injection molding.

The support member 412 is for supporting the flexible printed wiring board 45. That is, the support member 412 supports the flexible printed wiring board 45 by being attached to the magnetic yoke 411. In this embodiment, the flexible printed wiring boards 45 are attached to both sides of the integrated optical head section 47 for recording and / or reproducing the information signal, thereby recording and / or reproducing the information signal. The integrated optical head unit 47 is supported. Then, at this time, the focus coil 48 and the tracking coil 49 arranged in the integrated optical head portion 47 for recording and / or reproducing the information signal supported by the flexible printed wiring board 45 are the magnetic yokes. The magnet 411 faces the magnet 410. The focus coil 48, the tracking coil 49, the magnet 410 and the magnetic yoke 411 form a magnetic circuit.

Therefore, in the magnetic yoke 411, the flexible printed wiring board 45 prevents
The integrated optical head unit 47 that records and / or reproduces the information signal that is swingably supported in the axial direction is supplied with a predetermined focus drive current to the focus coil 48, so that the information signal The integrated optical head unit 47 for recording and / or reproducing is driven and displaced in the optical axis direction of the objective lens 46 indicated by an arrow f in FIG. 6, that is, in the focus direction. In addition, the tracking coil 49
An integral optical head unit 47 that records and / or reproduces the information signal by supplying a predetermined tracking drive current to is indicated by an arrow t in FIG. It is driven and displaced in the direction orthogonal to the optical axis of the objective lens 46, that is, in the tracking direction.

Here, the drive current is supplied to the focus coil 48 and the tracking coil 49 by the plurality of lands 44a, 44b, 44c, 44d, 44 provided on the flexible printed wiring board 45.
., by connecting the coil ends extended from the coils 48 and 49 to the external connection wires for supplying the control current by soldering or the like.

Here, as shown in FIGS. 6 and 7, two or more flexible printed wiring boards having a wiring pattern of a conductor such as a copper foil formed on at least one side surface are used symmetrically as shown in FIGS. 6 and 7. The signal line from the detector and the drive current line for supplying the drive current for controlling the drive coil and the semiconductor laser element are separately connected to the two left and right flexible printed wiring boards 45, which are different from each other, and are connected to each other to form the drive current line. The noise from is not adversely affecting the signal line from the photodetector.

The left and right flexible printed wiring boards 45 are preferably the same so that good focusing vibration characteristics and tracking vibration characteristics can be obtained.

As described above, the flexible printed wiring board 45 formed in the bent rectangular frame shape has a pair of connecting portions so that the pair of supporting arm portions 421 and 421 are parallel to each other, as shown in FIG. An integrated optical head support for recording and / or reproducing an information signal having a very simple structure, which can be elastically displaced in two axial directions simply by bending 90 degrees at a right angle to 420, 420. It can be a member.

The flexible printed wiring board 45 is formed by bending a conductor made of a uniform material such as copper foil as a spring material and bending it. Since it is configured, the resonance frequency becomes constant as a whole, and it is possible to prevent the occurrence of partial harmful resonance.

Further, in the flexible printed wiring board 45, the width of the wiring pattern in the longitudinal middle portion of each of the connecting portion 420 and the supporting arm portion 421, which is a portion to be elastically deformed, is narrowed, and other portions are formed. Since the rigidity is increased by widening the portion, the integrated optical head portion 47 can be easily displaced, and sufficient rigidity can be maintained.

Further, since the flexible printed wiring board 45 is displaced only in the directions in which the displacement directions of the support arms 421 and 421 and the connecting portions 420 and 420 are orthogonal to the other, the recording of the information signal is performed. And / or twisting and distortion can be prevented when driving the integrated optical head portion 47 for reproducing, and the response characteristics can be improved.

Therefore, by supplying a predetermined drive current to the drive coil, the integrated optical head portion 47 for recording and / or reproducing the information signal is driven to a predetermined position to ensure focus servo and tracking servo. Can be done.

Therefore, according to the above-described embodiment, recording and recording of information signals is performed by using a flexible printed wiring board having a wiring pattern of a conductor such as a copper foil used as a spring material formed on at least one side surface. Since it supports an integrated optical head for recording and / or reproducing, a control drive is provided for a focus control drive coil and a tracking control drive coil attached to the integrated optical head for recording and / or reproducing this information signal. Since a current is supplied, there is no need to use a connecting line such as a litz wire and a new printed wiring board between the fixed optical disk and the integrated optical head that records and / or reproduces the information signal. The reduction is achieved, the structure is simple, and the assembly is easy.

Further, two or more flexible printed wiring boards having a wiring pattern of a conductor such as a copper foil formed on at least one side surface are used symmetrically, and the signal line from the photodetector and the drive coil are used. And the drive current line for supplying the drive current for controlling the semiconductor laser device is separately connected to two different left and right flexible printed wiring boards, and noise from the drive current line is transferred to the signal line from the photodetector. I try not to have a bad influence.

By using the same flexible printed wiring boards as the left and right flexible printed wiring boards, good focusing vibration characteristics and tracking vibration characteristics can be obtained.

Further, the flexible printed wiring board formed in the bent rectangular frame shape is bent 90 degrees at right angles to the pair of connecting portions so that the pair of supporting arm portions are parallel to each other. It can be elastically displaceable in two axial directions, and can be an integrated optical head support member for recording and / or reproducing information signals having an extremely simple structure.

The flexible printed wiring board is
A conductive material such as a copper foil made of a uniform material is used as a spring material and is bent and formed by the same member in both axial directions, so that the resonance frequency is constant as a whole. Therefore, it is possible to prevent partial harmful resonance from occurring.

Further, since the flexible printed wiring board is displaced only in the direction in which the supporting arm portion and the connecting portion are displaced in a direction orthogonal to the other, the flexible printed wiring board of the integrated optical head for recording and / or reproducing information signals is formed. Twisting and distortion can be prevented during driving, and response characteristics can be improved.

Therefore, by supplying a predetermined drive current to the drive coil, the integrated optical head for recording and / or reproducing the information signal can be driven to a predetermined position to reliably perform the focus servo and the tracking servo. it can.

Although the integrated optical head unit 7 has been described in the above embodiment, it is also applicable to a separation optical system in which the objective lens 6, the rising mirror and the like are separated from the semiconductor laser device, the photodetector and the like. Is.

Next, another embodiment of the present invention will be described with reference to FIG. The objective lens driving device of this embodiment is a flexible printed wiring board, and has wiring patterns 2a, 2b, 2c, 2 of conductors formed on the connecting portion 20 and the supporting arm portion 21 of the flexible wiring board 1 shown in FIG.
The shapes of d, ... Are made easy to be deformed by narrowing the pattern width of the intermediate portions 50, 51 in the longitudinal direction thereof, which are the portions that undergo elastic deformation particularly when the objective lens 6 and the lens bobbin 7 are drive-controlled, It is characterized in that the pattern width of the other portion is widened to increase the rigidity. The configuration of the other parts is the same as that of the embodiment shown in FIG.
The description is omitted by giving the same reference numerals to the common parts.

By changing the width of the wiring pattern in this way, especially the portion to be deformed is easily deformed by the electromagnetic force, while the rigidity of other portions can be kept high, and the focusing and tracking performances can be improved. It becomes possible to keep the overall strength high while maintaining.

Next, another embodiment of the present invention will be described with reference to FIG.
It will be described based on. The objective lens driving device of this embodiment is characterized by the structure of the flexible printed wiring board 5 shown in FIGS. 1 and 9, and as shown in FIG.
Conductor wiring patterns 2a, 2b, 2c, ... Are formed on at least one side surface (both side surfaces in this embodiment) of the base substrate 1, and a viscoelastic body 60 as a bonding material is further provided on these wiring patterns. This is a structure in which the insulating cover film 3 is formed. The viscoelastic body 60 is not a thermosetting epoxy adhesive that is conventionally used, but is made of a material such as silicon gel or silicon rubber that does not cure by heat and has a small change over time. .

If the flexible printed wiring board 5 is used for such a structure, the peak at the main resonance can be suppressed by the damping effect of the viscoelastic body 60, and higher-order resonance or the like can be prevented. The objective lens 6 and the lens bobbin 7 can be driven with good response to the control drive current.

The flexible printed wiring board 5 having the sectional structure shown in FIG. 10 can be used in place of the flexible printed wiring board 45 of the optical head driving device shown in FIG. 5, whereby the viscoelastic body 60 is used. The peak at the time of main resonance can be suppressed by the damping effect possessed by, and the integrated optical head 47 shown in FIGS. 6 and 7 can respond to the drive current for control without generating higher-order resonance. You will be able to drive with good performance.

Next, still another embodiment of the present invention will be described with reference to FIG. The objective lens driving device of this embodiment is characterized by the structure of the flexible printed wiring board 5, and the wiring pattern 2a on one side surface of the base substrate 1,
The thickness of the conductor forming 2b is thin, the thickness of the conductor forming the wiring patterns 2c, 2d on the other side surface of the base substrate 1 is thick, and the bonding material of the viscoelastic body 60 is provided outside them. The insulating cover film 3 is bonded via the insulating cover film 3, and the side where the thin wiring patterns 2a and 2b are formed is inside and the side where the thick wiring patterns 2c and 2d are formed is outside. The flexible printed wiring board 5 formed into a bent rectangular frame shape shown in FIG. 1 by the integral bending process is used.

By using the flexible printed wiring board 5 having such a structure, it is possible to prevent the portion of the wiring pattern which is subjected to a large bending deformation from coming outside, and at the same time to stabilize the shape of the bent portion. Can
The objective lens 6 and the head bobbin 7 shown in FIGS.
The reliability of the operation of can be kept high.

In this embodiment, the viscoelastic body 60 may not be used as a joining material, and the wiring pattern and the insulating cover film may be joined by a conventional thermosetting adhesive.

Further, the flexible printed wiring board 5 having the sectional structure shown in FIG. 11 can be used in place of the flexible printed wiring board 45 of the optical head driving apparatus shown in FIG. It is possible to prevent the portion of the receiving wiring pattern that comes to the outside from being torn, and at the same time to stabilize the shape of the bent portion, and to improve the reliability of the operation of the integrated optical head 47 shown in FIGS. 6 and 7. You will be able to keep high.

[0083]

According to the objective lens driving device and the optical head driving device of the present invention, the number of parts can be reduced, the structure is simple and the assembly is easy, and higher-order resonance and the like can occur. Absent.

[Brief description of drawings]

FIG. 1 is a perspective view of a flexible printed wiring board that is an objective lens supporting member according to an embodiment of the present invention.

FIG. 2 is a perspective view of an objective lens driving device according to an embodiment of the present invention.

FIG. 3 is an exploded perspective view of FIG.

FIG. 4 is a perspective view of a flexible printed wiring board that is an optical head supporting member according to an embodiment of the present invention.

5 is a partial cross-sectional configuration diagram of FIG.

FIG. 6 is a perspective view of an optical head biaxial actuator according to an embodiment of the present invention.

FIG. 7 is an exploded perspective view of FIG.

FIG. 8 is a perspective view of an optical head biaxial actuator according to another embodiment of the present invention.

FIG. 9 is a perspective view of another example of a flexible printed wiring board that is an objective lens supporting member according to the embodiment of the present invention.

FIG. 10 is a sectional view showing the structure of a flexible printed wiring board which is an objective lens supporting member according to an embodiment of the present invention.

FIG. 11 is a cross-sectional view showing a structure of a flexible printed circuit board which is an objective lens supporting member according to an embodiment of the present invention.

FIG. 12 is a perspective view of a conventional objective lens driving device.

[Explanation of symbols]

1, 41 film substrates 12a, 2b, 2c, 2d, 42a, 42b, 42c, 4
2d, 42e Wiring pattern 3, 43 Insulation cover film 4a, 4b, 44a, 44b, 44c, 44d, 44e
Land part 5,45 Flexible printed wiring board 6,46 Objective lens 7 Lens bobbin 47 Optical head part 8,48 Focus coil 9,49 Tracking coil 10,410 Magnet 11,411 Magnetic yoke 12,412 Support member 20,420 Connection part 21, 421 Support arm portions 22, 422 Fixing member 30 Objective lens driving device 31 Objective lens 32 Printed wiring board 33 Support arm 34 Lens bobbin 35 Magnetic yoke 50, 51 ... Intermediate portion 60 ... Viscoelastic body

Claims (6)

[Claims] 1. An objective lens driving device for driving an objective lens for condensing light on an optical recording medium for recording and / or reproducing information from the optical recording medium, comprising: A pair of support arms formed by bending a flexible printed wiring board in the shape of a rectangular frame having a conductor wiring pattern formed on its side surfaces so as to be parallel to each other, and connected to both ends of these support arm portions. An objective lens support member for supporting the objective lens, and a drive coil for driving the objective lens supported by the objective lens support member. A lens bobbin that is attached and is supported so as to be displaceable in two axial directions of the thickness direction of the support arm section and the thickness direction of the connecting plate section, and a drive coil for this lens bobbin And a magnet arranged to face each other, the supporting arm portion of the objective lens supporting member is elastically displaceable only in a thickness direction of the printed wiring board, and the connecting portion is provided with a printed wiring of the connecting portion. An objective lens driving device, which is configured to be elastically displaceable only in a thickness direction of a substrate and in a direction orthogonal to a displacement of the support arm portion in a thickness direction of a printed wiring board. 2. As the printed wiring board, a wiring pattern is formed on at least one side surface of a film substrate so as to widen a pattern width of a portion other than a portion where the elastic displacement is necessary to increase rigidity. 2. A cover film is formed on a pattern, and a viscoelastic body is used to bond between the film substrate and the wiring pattern or between the wiring pattern and the cover film. Objective lens driving device. 3. The printed wiring board having a wiring pattern formed in a plurality of layers and having a thickness of a wiring pattern outside the bent portion larger than that of an inside wiring pattern is used. The objective lens driving device according to claim 2. 4. An optical head drive device for driving an optical head that performs at least one of recording and reproducing information from an optical recording medium, the rectangular frame having a conductor wiring pattern formed on at least one side surface. A pair of supporting arms formed by bending a flexible printed wiring board to be parallel to each other, and a pair of connecting parts connected to both ends of the supporting arms, the optical head An optical head supporting member for supporting the optical head, and an optical head supported by a connecting portion of the optical head supporting member so as to be displaceable in the thickness direction of the supporting arm portion and the biaxial direction of the thickness direction of the printed wiring board of the connecting portion. A magnet that is arranged to face a drive coil attached to a side surface, and a support arm portion of the optical head support member is arranged in a thickness direction of the printed wiring board. And the connecting portion is elastically displaceable only in the direction orthogonal to the thickness direction of the printed wiring board of the connecting portion and the displacement of the support arm portion in the thickness direction of the printed wiring board. An optical head drive device characterized by the above. 5. As the printed wiring board, a wiring pattern is formed on at least one side surface of a film substrate so as to increase the rigidity by increasing the pattern width of a portion other than the portion where elastic displacement is required. 5. A cover film is formed on the pattern, and a viscoelastic body is used to bond between the film substrate and the wiring pattern or between the wiring pattern and the cover film. Optical head drive device. 6. The printed wiring board having a wiring pattern formed in a plurality of layers and having a thickness of a wiring pattern outside the bent portion larger than that of an inside wiring pattern is used. The optical head drive device according to claim 5, wherein