JP2002117559A - Optical pickup, optical disk device and actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical pickup, an optical disk device and an actuator capable of suppressing a secondary resonance phenomenon generating in a lens holder Lh by current flowing through a focus coil. SOLUTION: The optical pickup is provided with the lens holder Lh which holds an object lens 01, a first magnet Emg1 and a second magnet Emg2 for generating magnetic fields Mf1 and Mf2 in order to drive the lens holder Lh in the focusing direction or in the tracking direction, and the focus coil Cf1 and a tracking coil Ctr which generate driving force for driving the lens holder Lh in the focusing or tracking direction cooperating with the first magnet Emg1 and the second magnet Emg2 by making current flow. The intensity of the magnetic field of the permanent magnet Emg1 is larger than the intensity of the magnetic field of the permanent magnet Emg2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD OF THE INVENTION

[0002]

2. Description of the Related Art A conventional optical disk reproducing apparatus, an optical pickup, and actuator parts used therein will be described with reference to FIGS.

FIG. 7 is a circuit block diagram of a conventional optical disk reproducing apparatus.

[0004] The circuit of the optical disk reproducing apparatus of FIG.
A spindle motor Spm in which a turntable (not shown) is fitted to a rotating shaft, an optical pickup Pu for reading data recorded on an optical disk, an RF amplifier Rfa, a data slice circuit Dsl, an NRZI (Non Retu)
rn To Zero Inverted) demodulation circuit N
rd, Ecc processing circuit Ecc, demodulation circuit Dec, address extraction circuit Add, track jump circuit Trj, pickup motor Pum, tracking servo circuit Tr
s, a focus servo circuit Fos, and a spindle motor servo circuit Spms.

Next, the operation of the circuit will be described.

An optical disk Od is mounted on a turntable (not shown).

The turntable is fitted on the rotating shaft of the spindle motor Spm as described above, and rotates the mounted optical disc Od according to the rotation of the spindle motor Spm.

The spindle motor Spm is a spindle motor servo circuit Spms that outputs a motor drive signal in accordance with a command from a microprocessor (not shown).
Are connected via a signal line Mdr.

The spindle motor servo circuit Spms is
A drive signal is output to the spindle motor Spm via the signal line Mdr so that the spindle motor Spm rotates at a rotation speed according to a command output from the microprocessor.

Also, a spindle motor servo circuit Spm
In s, a rotation speed signal corresponding to the rotation speed of the spindle motor Spm is obtained in order to monitor the rotation speed of the spindle motor Spm.

The rotation speed signal is transmitted to the spindle motor Sp.
m and the spindle motor servo circuit Spms via a signal line Mfd connected between the spindle motor servo circuit Spms.

The spindle motor servo circuit Spm finely adjusts the drive signal according to the rotation speed signal so that the spindle motor Spm rotates at the set rotation speed in accordance with the command of the microprocessor.
pm is feedback controlled.

The optical pickup Pu detects data recorded from the rotating disk Od.

Then, the optical pickup Pu outputs an RF signal (high-frequency signal) corresponding to the read data to an RF amplifier Rfa connected to the subsequent stage.

The RF amplifier Rfa amplifies the RF signal with a predetermined gain, and then outputs the amplified signal to a data slice circuit Dsl connected to the subsequent stage.

The data slice circuit Dsl slices the amplified RF signal, converts it into a square wave signal corresponding to the data, and outputs it to the NRZI demodulation circuit Nrd connected at the subsequent stage.

The NRZI demodulation circuit Nrd demodulates the generated square wave signal as digital data based on the NRZI demodulation rule, and then connects the ECC circuit Ec connected to the subsequent stage.
Output to c.

The ECC circuit performs an error correction process on the digital data, and then outputs the digital data to a demodulation circuit Dec connected at a subsequent stage.

The demodulation circuit Dec performs a process of removing a margin bit added when data is recorded on the optical disk Od from the data in order to suppress a DC signal component.

Further, the demodulation circuit Dec outputs data to a data reproducing system (not shown) connected to the subsequent stage,
Similarly, data is output to an address extraction circuit Add connected at the subsequent stage.

The address extraction circuit Add extracts the address of the data read by the optical pickup Pu from the data, and the track jump circuit Tjp connected to the subsequent stage.
Output to

The track jump circuit Tjp is used to access the data recorded on the optical disk Od by the optical pickup according to the command of the microprocessor (not shown) and the address of the recording position of the data to be accessed on the disk. A track jump signal is output to the pickup motor Pum.

The track jump signal is a drive signal for the pickup motor Pu.

The pickup motor Pu rotates based on the track jump signal, and moves to the vicinity of the data to be accessed by the optical pickup Pu in order to access the data specified by the command of the microprocessor.

After the movement of the optical pickup Pu by the track jump circuit Tjp, the tracking servo circuit Trs causes the light beam output from the optical pickup to
A tracking servo process is performed so as to trace a data track on the optical disk Od. Similarly, the focus servo circuit Fos makes the light beam output from the optical pickup properly transmit to the signal recording surface on which the data track is recorded. Focus servo processing is performed so as to focus.

Both the tracking servo circuit Trs and the focus servo circuit Fos are connected to the RF amplifier Rfa at the preceding stage, and generate a tracking servo signal and a focus servo signal based on the RF signal output from the RF amplifier Rfa. I do.

The tracking servo circuit Trs is connected to an actuator Act built in the optical pickup Pu via a signal line Str.

The focus servo circuit Fos is connected to an actuator Act built in the optical pickup Pu via a signal line Sfo.

The tracking servo circuit Trs outputs a tracking servo signal to the actuator Act via the signal line Str.

The focus servo circuit Fos outputs a focus servo signal to the actuator Act via the signal line Sfo.

As described above, the tracking servo circuit Tr
Both s and the focus servo circuit Fo perform negative feedback tracking servo processing and focus servo processing on the actuator Act based on the RF signal reproduced by the optical pickup Pu.

As described above, the optical pickup Pu reads data after the tracking servo processing and the focus servo processing are performed by the tracking servo circuit Trs functioning as the actuator control circuit and the focus servo circuit, respectively. .

The address extraction circuit Add extracts the address of the read data from the data read by the optical pickup Pu.

The extracted address is output to the track jump circuit Tjp as described above.

The track jump circuit Tjp includes an address obtained from the microprocessor and an address extraction circuit Ad.
The address is obtained from d. If the addresses match, it is determined that the track jump has been completed, and the process waits until the next data access command is output.

As described above, in the conventional optical disk reproducing apparatus, data is accessed.

Next, FIG. 8 is used to describe the structure of the actuator Actj for the optical pickup Pu used in the conventional optical disc reproducing apparatus.

FIG. 8 is a top view showing the structure of a conventional actuator Actj.

The actuator Actj holds an actuator base Atb, a wire holder Hld erected on the actuator base Atb, a yoke Yk also erected on the actuator base Atb, a permanent magnet Emg provided on the yoke Yk, and an objective lens Ol. In order to suspend the lens holder Lh and the lens holder Lh from the wire holder Hld, the lens holder Lh and the lens holder Lh
And a wire Wir attached to the wire.

The lens holder Lh is a wire holder Hld
Is suspended in the yoke Yk.

A center rib Cl is formed on the lens holder Lh, and a loop-shaped actuator coil Ci is provided around the center rib Cl.

The actuator coil Ci is connected to the yoke Y
It has a function of driving the lens holder Lh in the tracking direction and the focusing direction in cooperation with the permanent magnet Emg fixed to k.

Specifically, the lens holder Lh has a permanent magnet E
The direction and magnitude of the magnetic field exerted by mg and the coil Ci
1 is driven in a focusing direction and a tracking direction by a driving force generated according to the direction and amount of the current flowing through l.

The current flowing through the coil Cil is controlled by an actuator control circuit including the tracking servo circuit Trs and the focus servo circuit Fos.

As described above, the lens holder Lh is driven in the tracking or focus direction.

By moving the lens holder Lh in the tracking or focusing direction, the spot position or the focal position of the light beam condensed on the optical disk Od is positioned so that an ideal reproduction signal is always obtained. Can be.

Next, a track jump operation of the conventional optical disc reproducing apparatus will be described with reference to FIG.

FIG. 9 is a view for explaining a track jump operation of the conventional optical disk reproducing apparatus.

In the reference numerals in the figure, Tbl is a turntable on which the optical disk Od is mounted.

As shown in FIG. 5A, a chucking ball Cb is provided on the turntable Tbl, and the optical disc Od placed by elastic force is fixed on the turntable Tbl.

The optical disk Od has a signal recording surface Sl
A plurality of data tracks Tr are formed on yr.

The optical pickup Pu focuses the beam Bm on the data track Int via the objective lens Ol.

At this time, when a track jump signal for moving the pickup Pu to the target data track Tgt on which data to be accessed is recorded is output from the track jump circuit Tjp, the pickup Pu is driven by the pickup motor Pum. Moves in the direction D of the arrow.

When the optical pickup Pu approaches the vicinity of the data track Tgt, a brake signal is output from the track jump circuit Tjp.

The optical pickup Pu stops moving in accordance with the brake signal.

At this time, the lens holder Lh suspended by the wire Wir in the optical pickup Pu.
Moves in the direction D due to the inertial force even after the optical pickup Pu stops.

At this time, the light beam condensed from the objective lens Ol largely deviates in the direction D from the target data track Tgt.

As shown in (b) of the figure, after the optical pickup Pu stops, the tracking servo circuit Trs
As a result, the target data track Tgt is
Tracking servo is executed so that the light beam Bm of the optical pickup Pu traces.

At this time, the lens holder Lh holding the objective lens Ol moves in the direction Trs opposite to the direction D so that the light beam Bm is focused on the data track Trg as the target from the state deviating in the direction D. .

After that, the lens holder Lh is controlled by tracking servo processing so that the light beam traces the data track Trg as the target.

In a conventional optical disk reproducing apparatus, double-speed reproduction for reproducing data at a higher speed than a normal reproduction speed is mainly used.

To realize double-speed reproduction, the access speed to data must be increased.

In order to increase the data access speed, the time required for the track jump operation should be shortened as much as possible.

In order to reduce the time required for the track jump operation, a high torque may be generated in the pickup motor Pu.

However, when the pickup motor Pu generates a high torque, a large inertial force is applied to the lens holder Lh immediately after the track jump operation, so that the light beam Bm is large and the target data track Tr is generated.
g.

Immediately after the track jump, the focus servo must be performed so that the light beam is quickly focused on the signal recording surface on which the data track Trg is recorded. The sub-resonance phenomenon occurring in the actuator of the optical pickup causes an obstacle to the above.

[0067]

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides an optical pickup capable of suppressing the occurrence of a sub-resonance phenomenon, an optical disk device having the optical pickup, and an actuator. The purpose is to do.

[0068]

SUMMARY OF THE INVENTION In order to solve the above problems, an optical pickup according to the present invention is an optical pickup used for recording or reproducing data on an optical disk in an optical disk reproducing apparatus. An objective lens for condensing a light beam for recording or reproducing data, a lens holder for holding the objective lens, and driving the lens holder for recording or reproducing on a signal recording surface of the optical disc. ,
An actuator for moving a light beam condensed on the signal recording surface in a focus direction and a tracking direction of the optical disc to generate a magnetic field for driving the lens holder in the focus direction or the tracking direction. A focus coil for generating a driving force for driving the lens holder in a focusing or tracking direction in cooperation with the first magnet and the second magnet by flowing an electric current and the first magnet and the second magnet; And a tracking coil, wherein the focus coil is provided so as to surround the second magnet. When a current is applied to the focus coil, the focus coil has a magnetic field of the first magnet and the magnetic field of the second magnet. And a focus magnetic field generated by the focus coil so as to cross the resultant magnetic field. And a current flows in the focus coil in a second direction opposite to the first direction in the focus coil so as to cross the magnetic field of the second magnet and the magnetic field of the second magnet. And an actuator in which the driving force in the opposite direction generated thereby is given at the same time, and the strength of the magnetic field of the first magnet is made larger than the strength of the magnetic field of the second magnet. It is characterized by the following.

In order to solve the above-mentioned problem, an optical disk device according to the present invention is an optical disk device provided with an optical pickup used for recording or reproducing data on an optical disk, wherein the optical disk is mounted. A turntable for rotationally driving, an objective lens for condensing a light beam for recording or reproducing data on or from an optical disk, a lens holder for holding the objective lens, and An actuator for moving a light beam focused on the signal recording surface in a focus direction and a tracking direction of the optical disc for recording or reproduction on the signal recording surface of the optical disc, and moving the lens holder in the focus direction. Alternatively, a first magnetic field for generating a magnetic field for driving in the tracking direction is provided. A magnet and a second magnet, and a focus coil and a tracking coil that generate a driving force for driving the lens holder in a focusing or tracking direction in cooperation with the first magnet and the second magnet by flowing an electric current. The focus coil is provided so as to surround the second magnet, and the first focus coil is provided when a current is applied to the focus coil.
A combined magnetic field generated by the magnetic field of the second magnet and the magnetic field of the second magnet; a positive driving force and a magnetic field of the second magnet that are generated by a current flowing in the focus coil in the first direction so as to cross the combined magnetic field; A driving force in a reverse direction generated by a current flowing in a second direction opposite to the first direction in the focus coil so as to cross the magnetic field; An optical pickup provided with an actuator having a magnetic field strength of the magnet of which is increased as compared with the magnetic field strength of the second magnet, and a guide for guiding the optical pickup in a radial direction of the optical disc. And a member.

To solve the above problem, the actuator of the present invention is used for recording or reproducing data on an optical disk in an optical disk reproducing apparatus, and focuses a light beam for recording or reproducing data on an optical disk. Used for an optical pickup including an objective lens and a lens holder for holding the objective lens, the signal recording surface for driving or driving the lens holder to record or reproduce the signal on the signal recording surface of the optical disc. An actuator for moving a light beam converged on the optical disc in a focus direction and a tracking direction of the optical disc, and driving the lens holder to record or reproduce on a signal recording surface of the optical disc. The light beam focused on the signal recording surface is focused on the optical disk. And a first magnet and a second magnet for generating a magnetic field for driving the lens holder in the focusing direction or the tracking direction. A focus coil and a tracking coil that generate a driving force for driving the lens holder in a focus or tracking direction in cooperation with the first magnet and the second magnet, and the focus coil surrounds the second magnet. The focus coil includes a combined magnetic field generated by a magnetic field of the first magnet and the magnetic field of the second magnet when a current flows through the focus coil, and a combined magnetic field generated by the focus coil so as to cross the combined magnetic field. The positive driving force and the magnetic field of the second magnet that are exerted by the current flowing in the first direction , The first in the focusing coil so as to cross the magnetic field
And a driving force in the opposite direction generated by the flow of current in a second direction opposite to the direction of the second magnet. Characterized in that it is increased compared to the strength of the magnetic field.

[0071]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment based on an embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a top view of an optical disk device equipped with the optical pickup of the present invention.

In the figure, Od is an optical disk, D
rv is an optical disk device, and Tbl is a turntable for mounting and rotating the optical disk Od.

Further, Pu is mounted on the optical pickup, and Ol is mounted on the optical pickup Pu.
d, an objective lens for condensing the light beam on the signal recording surface, Rd
Is a guide rod, and Rdh1 is a guide rod receiver for receiving the guide rod Rd.

The optical pickup Pu is guided in the radial direction Dr of the optical disc by the guide rod Rd inserted into the guide rod receiver Rdh1.

The optical disc Od on the turntable Tbl rotates, and the optical pickup is guided by the guide rod Rd to the track on the optical disc Od, so that the track is recorded in a digital signal format from the track. Data can be read, or the data can be recorded in digital signal format.

Fpc is a signal line made of a flexible printed circuit board.
Is connected to a signal processing circuit (not shown) via a connector Cnc.

The digital signal format data reproduced by the optical pickup Pu is transmitted to a signal processing circuit via the flexible printed circuit board Fpc and processed by the signal processing circuit.

The optical pickup Pu records data on an optical disk by a command transmitted from the signal processing circuit via the flexible printed circuit board Fpc.

Next, FIG. 2 will be used to explain the details of the optical pickup Pu.

FIG. 2 is a top view of the optical pickup Pu.

In the figure, Dcb is a zinc die-cast base, and the base Dcb is provided with an opening OM. An actuator Act is built in the opening Om. Yk is a yoke which is a magnetic circuit component constituting the actuator Act. Ol is an objective lens driven to focus and track a light beam focused on the signal recording surface of the optical disc Od by the actuator Act.

The objective lens Ol receives a light beam having the first wavelength from the optical component unit Iou1 and a light beam having a second wavelength different from the first wavelength from the optical component unit Iou2. Is guided along the optical axis Lx via a beam splitter Dp having a dichroic film surface Dc and a collimator lens Clz.

The guide rod receivers Rd for inserting the guide rods Rd are provided on both sides of the base Dbc.
h1 and a pair of guide rod receivers Rdh2 are provided.

Next, FIG. 3 will be used to describe the actuator built in the optical pickup Pu.

FIG. 3 is a perspective view of the actuator Act.

In the figure, Lh is a lens holder for holding the objective lens Ol, Emg1 and Emg2 are permanent magnets,
Clf is a focus coil, Clt is a tracking coil, and Yk is a yoke Yk.

The permanent magnets Emg1 and Emg2 are connected to the yoke Y
k, and is mechanically connected to the main body k. The focus coil Clf and the tracking coil Clt are mechanically connected to the lens holder Lh.

Wir is a wire that has one end mechanically connected to the lens holder, and Wh is a wire holder that mechanically connects the other end of the wire Wir.

The permanent magnets Emg1, Emg2, the four-cassin coil Clf, and the tracking coil Clt,
The yoke Yk forms an actuator Act, and can drive the lens holder Lh in the focusing or tracking direction by the action of a magnetic field generated by the permanent magnets Emg1 and Emg2 and a current applied to the focus coil Clf or the tracking coil Clt.

FIGS. 4 to 6 are used to explain the operation of the actuator Act.

FIG. 4 is a top view of the actuator Act. FIG. 5 is a diagram for explaining the operation of the permanent magnet and the focus coil. FIG. 6 shows an actuator Ac
It is a Bode diagram of t.

As described above, the lens holder Lh can drive the lens holder Lh in the focus or tracking direction by the action of the magnetic field generated by the permanent magnets Emg1 and Emg2 and the current applied to the focus coil Clf or the tracking coil Clt. It is possible.

A tracking coil is provided between the permanent magnets Emg1 and Emg2 around the direction of the magnetic field between the permanent magnets Emg1 and Emg2. The focusing coil is a permanent magnet E
It is provided so as to surround mg2.

Therefore, the permanent magnet Emg1 and the permanent magnet Em
Due to the magnetic field Mf1 caused by g2 and the current flowing through the tracking coil Clt, a driving force acts in a tracking direction orthogonal to the direction of the magnetic field Mf1 and the direction in which the current flows, and the lens holder Lh is driven in the tracking direction.

Further, the permanent magnet Emg1 and the permanent magnet Emg
Due to the magnetic field Mf1 between the two and the current flowing through the focus coil Clf, a driving force acts in a focus direction orthogonal to the direction of the magnetic field and the direction in which the current flows, and the lens holder Lh is driven in the focus direction.

By the way, as shown, the focus coil Clf is applied to the focus coils Mf1 and Mf2.
It is also arranged to cross both sides. According to the framing left-hand rule, when a current crosses a magnetic field, that is, a coil crosses in a perpendicular direction, a force is generated in a direction orthogonal to both the magnetic fields Mf1 and Mf2 and the direction of the current.

In the optical pickup Pu, the permanent magnets Emg1 and Emg2 serving as magnetic field generating means are mounted on the base Dc.
Since it is mechanically connected to the b side, a relative force acts on the focus coil Clf, and a driving force for driving the lens holder Lh in the focus direction is generated.

Here, FIG. 5 will be used to explain the generation of the driving force and the generation of the sub-resonance in the focus direction that acts on the focus coil Clf.

The permanent magnets Emg1, Em shown in FIG.
g2, focus coil Clf and magnetic fields Mf1, Mf2
Are the same as those shown in the actuator Act of FIG.

Arrows M1 and M shown in FIG.
2 indicates the direction of the magnetic field, and arrows I1 and I2 indicate the directions of the current flowing through the focus coil Cfl. S / N described in the permanent magnets Emg1 and Emg2 indicates the polarity of the permanent magnet.

When a current flows through the focus coil Cfl, a current flows in the direction of arrow I1 across the magnetic field Mf1. As described above, in the magnetic field Mf1 in which the current flows in the direction of the arrow I1, the focus coil Cfl is set so that the arrow M1 indicating the direction of the magnetic field Mf1 and the arrow I1 indicating the direction of the current are orthogonal to each other.
A driving force is generated.

On the other hand, in the magnetic field Mf2,
A current flows in the direction of arrow I2 across f2. The focus coil Cfl is provided in a loop shape so as to surround the permanent magnet Emg2.
Is opposite to the direction of arrow I1.

As described above, the arrow I in the opposite direction to the magnetic field Mf1
In the magnetic field Mf2 in which the current flows in the direction of No. 2. Magnetic field M
An arrow M2 indicating the direction of f2 and an arrow I indicating the direction of the current
2 generates a force for driving the focus coil Cfl in a direction perpendicular to the direction.

Therefore, when a current flows through the focus coil Cfl, a forward driving force and a reverse driving force are simultaneously generated in the focus coil Cfl.

When the driving force in both the forward and reverse directions is generated in the focus coil Cfl, a sub-resonance phenomenon occurs in the lens holder Lh. The sub-resonance phenomenon of the lens holder Lh causes a high-frequency signal superimposed on the focus error signal.

In the present invention, the strength of the magnetic field of the permanent magnets Emg1 and Emg2 is made different from each other in order to suppress the influence of sub-resonance when a current flows through the focus coil Cfl.

Specifically, by making the magnetic field strength of the permanent magnet Emg1 relatively large with respect to the magnetic field strength of the permanent magnet Emg2, when a current flows through the focus coil Cfl, the magnetic field Mf2 is affected. The effect of the sub-resonance phenomenon is suppressed by minimizing the generated reverse driving force.

Further, a permanent magnet Emg1 and a permanent magnet Em
Since g2 has the same holding force per unit volume, the magnitude of the magnetic field of the permanent magnet Emg1 is increased by increasing the volume of the permanent magnet Emg1 as compared with the volume of the permanent magnet Emg2. It is larger than it is.

Specifically, the magnetic force generated by the permanent magnet Emg2 is about 80% of the magnetic force of the permanent magnet Emg1.

Here, FIG. 6 is used to explain the effect of the present invention.
Is used. FIG. 6 shows a gain characteristic curve of a Bode diagram, in which the vertical axis indicates the magnitude of the gain, and the horizontal axis indicates the frequency.

As described above, the permanent magnets Emg1 and Emg2
By setting the strength of the magnetic field of, the occurrence of the sub-resonance could be suppressed at around 600 Hz as shown in FIG.

In the curves showing the characteristics in the figure, A indicates the frequency characteristics of the optical pickup Pu using the present invention, and B indicates the frequency characteristics.
Indicates the frequency characteristics of the conventional optical pickup.

As described above, by increasing the strength of the magnetic field of the permanent magnet Emg1 as compared with the strength of the magnetic field of the permanent magnet Emg2, and allowing a current to flow through the focus coil Cfl,
The sub-resonance phenomenon occurring in the lens holder Lh was able to be suppressed.

[0115]

As described above, by causing a current to flow through the focus coil to vary the strength of the magnetic field affecting the focus coil, the occurrence of the sub-resonance phenomenon occurring in the lens holder is suppressed. It is possible to provide an optical pickup capable of performing the above-described operation, an optical disk device including the optical pickup, and an actuator.

[Brief description of the drawings]

FIG. 1 is a top view of an optical disc device.

FIG. 2 is a top view of the optical pickup Pu.

FIG. 3 is a perspective view of an actuator Act.

FIG. 4 is a top view of the actuator Act.

FIG. 5 is a diagram for explaining the operation of a permanent magnet and a focus coil.

FIG. 6 is a Bode diagram of the actuator Act.

FIG. 7 is a circuit block diagram of a conventional optical disc reproducing apparatus.

FIG. 8 is a top view showing the structure of a conventional actuator Actj.

FIG. 9 is an explanatory view of a track jump operation of a conventional optical disc reproducing apparatus.

[Explanation of symbols]

 Ol: Objective lens Lh: Lens holder Emg1, Emg2: Permanent magnet Mf1, Mf2: Magnetic field

Claims (3)

[Claims] 1. An optical pickup used for recording or reproducing data on an optical disk in an optical disk reproducing apparatus, comprising: an objective lens for condensing a light beam for recording or reproducing data on an optical disk; A lens holder for holding an objective lens; and driving the lens holder to focus a light beam focused on the signal recording surface of the optical disc for recording or reproduction on the signal recording surface of the optical disc. And a first magnet and a second magnet for generating a magnetic field for driving the lens holder in the focusing direction or the tracking direction. The lens holder is focused in cooperation with the first magnet and the second magnet Is provided with a focus coil and a tracking coil that generate a driving force for driving in the tracking direction, the focus coil is provided so as to surround the second magnet, and when a current is applied to the focus coil, , A combined magnetic field produced by the magnetic fields of the first and second magnets;
A positive driving force and a magnetic field of the second magnet, which are generated by a current flowing in the first direction in the focus coil so as to cross the combined magnetic field, and the first direction in the focus coil so as to cross the magnetic field. And a driving force in a reverse direction generated by a current flowing in a second direction, which is a reverse direction, is given simultaneously. The strength of the magnetic field of the first magnet is An optical pickup comprising: an actuator whose strength is increased compared to strength. 2. An optical disk device comprising an optical pickup used for recording or reproducing data on or from an optical disk, comprising: a turntable for mounting and rotating the optical disk; An objective lens for condensing a light beam for recording or reproduction; a lens holder for holding the objective lens; and driving the lens holder to record or reproduce the signal on or from a signal recording surface of the optical disc. An actuator for moving a light beam condensed on a signal recording surface in a focus direction and a tracking direction of the optical disc, and for generating a magnetic field for driving the lens holder in the focus direction or the tracking direction. The first magnet and the second magnet are connected to the first magnet by passing an electric current. A focus coil and a tracking coil that generate a driving force for driving the lens holder in a focus or tracking direction in cooperation with a second magnet, and the focus coil is provided so as to surround the second magnet; A synthetic magnetic field generated by a magnetic field of the first magnet and the magnetic field of the second magnet when a current flows through the focus coil;
A positive driving force and a magnetic field of the second magnet, which are generated by a current flowing in the first direction in the focus coil so as to cross the combined magnetic field, and the first direction in the focus coil so as to cross the magnetic field. And a driving force in a reverse direction generated by a current flowing in a second direction, which is a reverse direction, is given simultaneously. The strength of the magnetic field of the first magnet is An optical disc reproducing apparatus, comprising: an optical pickup including an actuator whose strength is increased as compared with strength; and a guide member for guiding the optical pickup in a radial direction of the optical disc. 3. An objective lens used for recording or reproducing data on an optical disk in an optical disk reproducing apparatus, for focusing a light beam for recording or reproducing data on the optical disk, and a lens holding the objective lens. Used for an optical pickup having a holder, and driving the lens holder, for recording or reproducing on the signal recording surface of the optical disc, the light beam focused on the signal recording surface, An actuator for moving in a focus direction and a tracking direction of an optical disk, wherein the light is focused on the signal recording surface of the optical disk for driving or recording on the signal recording surface of the optical disk by driving the lens holder. Actuator that moves the beam in the focus direction and tracking direction of the optical disk A first magnet and a second magnet for generating a magnetic field for driving the lens holder in a focusing direction or a tracking direction, and a first magnet and a second magnet by flowing a current. A focus coil and a tracking coil for generating a driving force for driving the lens holder in a focus or tracking direction in cooperation with a magnet, wherein the focus coil is provided so as to surround the second magnet; Is a combined magnetic field generated by the magnetic fields of the first magnet and the second magnet when a current flows through the focus coil;
A positive driving force and a magnetic field of the second magnet, which are generated by a current flowing in the first direction in the focus coil so as to cross the combined magnetic field, and the first direction in the focus coil so as to cross the magnetic field. And a driving force in a reverse direction generated by a current flowing in a second direction, which is a reverse direction, is given simultaneously. The strength of the magnetic field of the first magnet is An actuator characterized by having an increased strength compared to its strength.