JPH1011776A - Optical pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the access speed by driving and controlling an objective lens in the radial direction of an optical disk and holding it at a prescribed position according to the directions of currents of two coils to suppress the vibration of the objective lens. SOLUTION: At the time of driving an objective lens 2, directions of currents made to flow through independent coils 6, 7 and 8, 9 wound around respective cores 5 are made to be the same. When an optical pickup device 1 is moved to a target data position on the recording surface of an optical disk, directions of current made to flow through the coils 6, 7 and 8, 9 are made to be of directions reverse with each other. Consequently, when a coercive force is larger than the inertial force accompanied by the movement of the device 1, the lens is made to be held at the position without generating a vibration in the objective lens 2 in the moving and after the stoppage of the device 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an optical pickup device used for an optical disk device and reproducing or recording information by light.

[0002]

2. Description of the Related Art A conventional optical pickup device will be described below with reference to the drawings. Radial direction (track direction) of the optical disk in the conventional optical pickup device 1
As shown in FIG. 5, the drive mechanism of the objective lens 2 is such that coils 10 and 11 are attached to a support member 3 that supports the objective lens 2, and two permanent magnets 4 are sandwiched between the coils 10 and 11. A ferromagnetic core 5 having a substantially U-shaped cross-section sandwiching the coils 10 and 11 and having the permanent magnet 4 bonded to the side sandwiching the coils 10 and 11 is arranged. is there. The support member 3 is held by a suspension base (not shown) so as to be able to move up, down, left and right by a suspension wire (not shown).

In the optical pickup device 1, when the position of the objective lens 2 is moved to converge a laser beam to a target data position on the recording surface of the optical disk, the poles of the permanent magnet 4 are arranged as shown in FIG. If it is, coil 1
When an electric current is caused to flow through arrows 0 and 11 in the direction of arrow B in the figure, an electromagnetic force is generated from the relationship between the magnetic field and the current, and the support member 3 and the objective lens 2 are driven rightward in the figure. In addition, as shown in FIG.
The support member 3 and the objective lens 2 are driven leftward in the drawing by reversing the direction.

Next, another conventional optical pickup device will be described with reference to FIGS. This FIG.
In the optical pickup device 1 shown in FIG. 1, the permanent magnets 4 are arranged at positions symmetrical with respect to the objective lens 2 of the support member 3 and symmetrical in the radial direction of the optical disk.
The cores 5 are arranged in parallel with each other, and the coils 10 and 11 are wound around each of the cores 5. The support member 3 is held on a suspension base (not shown) by suspension wires (not shown), as in the case of FIG.

In this optical pickup device 1, when the position of the objective lens 2 is moved in order to focus the laser beam on a target data position on the recording surface of the optical disk, the poles of the permanent magnet 4 are arranged as shown in FIG. If it is, coil 1
When an electric current is caused to flow through arrows 0 and 11 in the direction of arrow D in the figure, an electromagnetic force is generated from the relationship between the magnetic field and the current, and the support member 3 and the objective lens 2 are driven rightward in the figure. In addition, as shown in FIG. 10, by reversing the direction of the current flowing through the coils 10 and 11 in the direction E in the figure, the support member 3 and the objective lens 2 are driven leftward in the figure.

[0006]

In an optical disk device, a higher access speed is required. For this purpose, the optical pickup device 1 is moved to a target data position on the optical disk,
It is effective to reduce the time for matching the data to the target data position.

However, in the structure of the conventional optical pickup device 1 as described above, as the optical pickup device 1 is moved to a target data position at a higher speed, the inertial force acting with the movement of the optical pickup device 1 supports the optical pickup device 1. The member 4 and the objective lens 2 are greatly inclined in the direction opposite to the moving direction of the optical pickup device 1 to generate vibration having a large amplitude, and it takes time for the vibration to stop due to the damping effect of the suspension wire supporting the support member 4. Since the position error of the objective lens 2 due to vibration increases, the objective lens 2
However, there is a problem that the time required to adjust the position of the target data position to the target data position cannot be shortened, and the access speed is delayed.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide an optical pickup device capable of suppressing a vibration of an objective lens and achieving a large increase in access speed.

[0009]

In the optical pickup device of the present invention, the direction of the current flowing through two coils each having a winding wound around two magnetic members provided in series with the optical pickup device is provided. The objective lens can be driven and controlled in the radial direction of the optical disk by applying current in the same manner as each other, and the objective lens can be held at a predetermined position to prevent vibration of the objective lens by applying power in opposite directions. Things. According to the present invention, the objective lens can be reliably driven to the target data position simultaneously with the stop of the movement of the optical pickup device, the moving speed of the optical pickup device can be increased, and the access to data can be made faster. Can be done.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical pickup device for reproducing or recording an optical disk, comprising: an objective lens for condensing a laser beam; and an optical pickup device surrounding the circumference of the objective lens for supporting the objective lens. A supporting member, two permanent magnets attached to both sides of the supporting member that are symmetrical with respect to the objective lens and symmetrical with respect to the radial direction of the optical disc; It has two pairs of cores in which two magnetic members are connected in series so that the length is longer in the radial direction of the optical disc than the permanent magnet, and a coil in which a winding is wound around each magnetic member. The direction of the current flowing through the two coils wound around the two magnetic members connected in series is set to the same direction, so that the supporting member and the objective lens on which the permanent magnets are disposed can be optically driven. The center position of the objective lens is set to a predetermined position by driving in the radial direction of the disc and applying a current in the opposite direction to the current flowing through the two coils wound around the two magnetic members connected in series. The objective lens can be adjusted to the target data position at the same time when the movement of the optical pickup device is stopped, and the optical pickup device can be moved at high speed, and the data access speed can be further increased. It is.

An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is an external view showing an optical pickup device according to an embodiment of the present invention, FIG. 2 is a diagram showing an internal configuration of an optical pickup device according to an embodiment of the present invention when an objective lens is driven, and FIG. FIG. 4 is a diagram showing an internal configuration of the optical pickup device according to the embodiment when the objective lens is prevented from vibrating. FIG. 4 is a table showing a relationship between an inertial force and a coercive force in the optical pickup device according to the embodiment of the present invention.

As shown in FIG. 1, in an optical pickup device according to an embodiment of the present invention, a support member 3 in which an objective lens 2 for condensing a laser beam is arranged so as to surround a circumference of the objective lens 2 is provided. On the side surface of the support member 3, two permanent magnets 4 are arranged at positions symmetrical with respect to the objective lens 2 and symmetrical with respect to the radial direction of the optical disk. The two cores 5a, 5b, 5c, and 5d are arranged as one set and connected in series via a predetermined gap t so as to protrude laterally beyond the end of the core 4. Each of the cores 5a, 5b and 5c, 5d is wound with two independent coils 6, 7, 8, 9 so as to be divided by the same center line.

Next, a driving operation and an anti-vibration operation of the objective lens 2 in the optical pickup device 1 according to the present embodiment will be described with reference to FIGS. When driving the objective lens 2, as shown in FIG. 2, the directions of currents flowing through two independent coils 6, 7, 8, and 9 wound on each core 5 are set to be the same direction. It becomes equal to the conventional structure shown in FIG.
Determines the driving direction.

When the optical pickup device 1 has moved to the target data position on the recording surface of the optical disk, as shown in FIG. 3, two independent coils 6, 7 wound around each core 5 and The directions of the currents flowing through 8 and 9 are opposite to each other as shown by arrow A in the figure. As a result, an N pole is generated at the end where the inertial force acts, and an S pole is generated at the other end. If the surface of the permanent magnet 4 on the core 5 side is the N pole, the N pole and the N pole repel and the N pole and the S pole attract each other, so that the objective lens 2 supported by the support member 3 to which the permanent magnet 4 is attached The coercive force is such that the center coincides with the center of the magnetic circuit. Therefore, if the coercive force generated by the present invention is larger than the inertial force accompanying the movement of the optical pickup device 1, the optical pickup device 1
During the movement and after the stop, the position of the objective lens 2 can be held without generating vibration.

FIG. 4 shows the relationship between the inertial force and the coercive force in the optical pickup device 1 according to the present embodiment. Even under the same conditions such as the weight and supply current of each component, a coercive force of about four times the inertial force can be obtained, so that the vibration of the objective lens 2 can be sufficiently prevented. Further, if the moving speed of the optical pickup device 1 is further increased, the inertia force also increases.
By increasing the current supplied to 7, 8, and 9 and improving the magnetic performance of the permanent magnet 4 and the core 5, it is possible to easily cope with the problem.

[0016]

As described above, according to the present invention, the direction of the current flowing through the two coils each having a winding wound around two magnetic members provided in series in the optical pickup device is determined.
The drive of the objective lens in the radial direction of the optical disk can be controlled by applying power in the same manner as each other, and the objective lens can be held at a predetermined position by applying power in the opposite direction, and vibration of the objective lens accompanying movement of the optical pickup device can be achieved. By stopping the movement of the optical pickup device, the objective lens can be driven to the target data position at the same time as stopping the movement of the optical pickup device, and the moving speed of the optical pickup device can be increased and the access time to data can be greatly reduced. Can be shortened to

[Brief description of the drawings]

FIG. 1 is an external view showing an optical pickup device according to an embodiment of the present invention.

FIG. 2 is a diagram showing an internal configuration of the optical pickup device according to the embodiment of the present invention when the objective lens is driven.

FIG. 3 is a diagram showing an internal configuration of the optical pickup device according to the embodiment of the present invention when vibration of an objective lens is prevented.

FIG. 4 is a table showing a relationship between an inertial force and a coercive force in the optical pickup device according to the embodiment of the present invention;

FIG. 5 is an external view showing a conventional optical pickup.

FIG. 6 is a diagram showing an internal configuration of the conventional optical pickup when an objective lens is driven.

FIG. 7 is a diagram showing an internal configuration when an objective lens is driven in a conventional optical pickup.

FIG. 8 is an external view showing another conventional optical pickup.

FIG. 9 is a diagram showing an internal configuration of another conventional optical pickup when an objective lens is driven.

FIG. 10 is a diagram showing an internal configuration when an objective lens is driven in another conventional optical pickup.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical pickup device 2 Objective lens 3 Support member 4 Permanent magnet 5 Core 5a, 5b Core 5c, 5d Core 6 Coil 7 Coil 8 Coil 9 Coil 10 Coil 11 Coil

Claims (1)

[Claims] 1. An optical pickup device for reproducing or recording an optical disk, comprising: an objective lens for condensing a laser beam; and a support disposed to surround a circumference of the objective lens and supporting the objective lens. A member, two permanent magnets mounted on both sides of the support member, which are symmetrical with respect to the objective lens and symmetrical with respect to the radial direction of the optical disc; The magnetic member comprises two pairs of cores in which two magnetic members are connected in series so as to have a longer length in the radial direction of the optical disc, and a coil formed by winding a coil around each of the magnetic members; The direction of the current flowing through the two coils wound around the two magnetic members connected in series is set to the same direction, so that the supporting member provided with the permanent magnet and the objective lens are mounted on the optical disk half. The center position of the objective lens is set at a predetermined position by driving the two coils wound in series in two directions and passing the currents flowing in the two directions wound in the two coils respectively in opposite directions. An optical pickup device characterized by being held.