JPH0963214A - Optical pickup driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transmit rotating drive force of a motor in a noncontact state at the time of driving an optical pickup and to reduce a mechanical noise by arranging S-poles and N-poles alternately on a cylindrical magnet fixed to the tip of a rotary shaft of the motor and making the structure of gear parts into a noncontact state in a high rotating speed transmission system. SOLUTION: A rotation transmitting member 3 for transmitting the rotating drive force of the motor is located between a rack 1a and the cylindrical magnet 4. A gear part 3a is formed at an upper end part of this member 3, and is meshed with the rack 1a of the optical pickup 1. Then, a large diameter part is formed at a lower end part of the rotation transmitting member 3 adjacently opposite to an outer circumferential part of the cylindrical magnet 4, and is magnetized with plural S-poles and N-poles alternately in the circumferential direction in a similar manner to this cylindrical magnet 4. When the cylindrical magnet 4 is rotated by the motor 4, the rotation drive force is transmitted to the rotation transmitting member 3 under the noncontact state by attracting force of the different poles to each other and repulsive force of the same poles from each other between the cylindrical magnet 4 and the rotation transmitting member 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving technique of an optical pickup for recording / reproducing an optical disc.

[0002]

2. Description of the Related Art In a conventional compact disc reproducing apparatus or the like, as shown in FIG. 2, an optical pickup 1 is linearly moved along a guide rail 2 from the inner circumference to the outer circumference of the disc in order to read information recorded on the disc. A gear 7 meshed with a gear 3c having a large outer diameter integrally formed with a gear 3a having a small outer diameter rotatably held by a shaft 6 for driving a rack 1a of a feeding mechanism to be moved is a motor. Rotating shaft 5
The drive force of the motor 5 was transmitted by engaging with the gear a and engaging the gears with each other.

[0003]

However, in the conventional optical pickup driving device, when the motor rotates at a high speed to move the optical pickup at the time of selecting a music, the gears of the transmission system and the tooth tips collide with each other to cause mechanical noise. Since the sound is generated outside the device, a person who listens to music quietly felt uncomfortable, even if it was a small sound. The present invention has been made in view of the above problems, and an object thereof is to obtain a quiet optical pickup drive device by making a high-speed rotating gear portion of a transmission system non-contact.

[0004]

According to the present invention, there is provided a cylindrical first magnet engaged with a rotating shaft of a motor and having a plurality of S poles and N poles alternately arranged, and a first magnet facing the first magnet. A cylindrical second magnet rotatably supported at an adjacent position and having a plurality of S poles and N poles alternately arranged, a gear connected to the second magnet for rotation, and a guide rail. And an optical pickup that is held so as to be movable in a linear direction, and a rack that meshes with the gear and that moves the optical pickup. The present invention also provides
The optical pickup driving device according to claim 1, wherein the outer diameter of the second magnet is larger than the outer diameter of the gear that meshes with the rack.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION A magnetic pole magnetized by a cylindrical magnet fixed to the tip of a rotary shaft of a motor is divided into a plurality of magnetic poles and S poles and N poles are alternately arranged. Similarly, a rotation transmitting member in which a plurality of magnetic poles are alternately arranged with S poles and N poles is rotatably attached at a position facing and adjacent to the cylindrical magnet, so that the different poles of each magnet attract each other, and Since the poles repel each other, the rotational force of the motor can be transmitted to the rack of the optical pickup at a fine feed pitch in a non-contact state.

[0006]

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a drive device for an optical pickup according to an embodiment of the present invention. The optical pickup 1 is a guide rail 2
A rack 1a is integrally formed of synthetic resin at a side end portion of the optical pickup 1 so as to be slidably attached and held along the rack.

Rotating shaft 5 protruding upward from the center of motor 5
The cylindrical magnet 4 is fixed to the tip of a. The cylindrical magnet 4 is magnetized so that a plurality of magnetic poles are arranged in the circumferential direction so that S poles and N poles are alternately arranged.

A rotation transmitting member 3 for transmitting the rotational driving force of the motor is rotatably held by a shaft 6 between the rack 1a and the cylindrical magnet 4. A gear 3 a is formed on the upper end of the rotation transmitting member 3 and meshes with the rack 1 a of the optical pickup 1. Further, the lower end portion of the rotation transmitting member 3 is formed with a large diameter adjacent to and facing the outer peripheral portion of the cylindrical magnet 4, and like the cylindrical magnet 4, a plurality of magnetic poles in the circumferential direction are S poles and N poles. The poles are magnetized alternately, and when the cylindrical magnet 4 is rotated by the motor 5, the cylindrical magnet 4 is rotated.
The rotation driving force is transmitted to the rotation transmitting member 3 in a non-contact state by a force of attracting different polarities of the rotation transmitting member 3 and a force of repulsing the same polarities.

When the optical pickup 1 is linearly moved at a high speed along the guide rail 2, the natural vibration of the motor 5 is not directly transmitted to the rotation transmitting member 3, and the rotation transmitting member 3 is supported by the shaft 6. The large-diameter cylindrical magnet 3b receives magnetic force from the cylindrical magnet 4 to prevent free rattling with the shaft 6, and also to prevent rattling and rattling of gears between the rack 1a and the gear 3a. It is possible to reduce the generation of noise. Optical pickup 1
When an external force is applied to the rack and the rack does not move, the cylindrical motors 3b and 4 are idly rotated to mesh with the gear 3a and the rack. .

[0010]

As described above, according to the optical pickup driving device of the present invention, since the first stage of the transmission system is non-contact, it is possible to significantly reduce mechanical noise during high-speed search.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part showing one embodiment of the present invention.

FIG. 2 is a perspective view showing a conventional example.

[Explanation of symbols]

 1 Optical Pickup 1a Rack 2 Guide Rail 3 Rotation Transmission Member 3a Gears 3b, 4 Cylindrical Magnet 5 Motor 5a Rotation Shaft 6 Shaft

Claims (2)

[Claims] 1. A plurality of south poles and N poles are engaged with a rotary shaft of a motor.
A cylindrical first magnet having poles alternately arranged, and a cylindrical second magnet rotatably supported at an adjacent position facing the first magnet and having a plurality of S poles and N poles alternately arranged. Magnet, a gear connected to the second magnet and driven to rotate, an optical pickup movably held in a linear direction along a guide rail, and a rack that meshes with the gear to move the optical pickup. An optical pickup drive device comprising: 2. The optical pickup driving device according to claim 1, wherein the outer diameter of the second magnet is larger than the outer diameter of the gear that meshes with the rack.