JPS6316427A - Optical pickup feeder - Google Patents

Abstract

PURPOSE:To apply a 3-beam system which excels in the tracking characteristics for an optical pickup feeding device, by turning a swing motion into a linear motion to feed linearly the optical pickup in the disk radius direction. CONSTITUTION:An optical pickup 13 is fed linearly by the swing actions of a rotary electromagnetic drive means via a coupling part between a groove 15 of a projecting bar 14 and a shaft 27. In such a way, a feed mechanism is simplified and the pickup 13 is fed at a high speed compared with a case where the pickup main body is attached directly to an arm. Furthermore the feed function is secured with the moment produced by the Lorentz force due to the rotary electromagnetic drive and rotational force is turned into the linear feed motions via said coupling part. Thus a feed action is secured with small force. Then the pickup 13 is moved in the linear direction along guide shafts 11 and 11 after the swing motions are turned into the linear motions. Thus it is possible to attain a 3-beam system which excels in the tracking characteristics despite application of an electromagnetic drive means of a swing system.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Use
The present invention relates to an optical pickup feeding device applied to optical disk devices such as M@DRAW (-recordable) disks and MO (magnetic optical) disks.

Conventional technology and its problems As an optical disk drive device equipped in an optical disk device such as CI), the optical drive device and the Quanope feeder reduce the rotational driving force of the drive motor.
There are two main types: a motor drive method that decelerates the optical pickup via +R and sends the optical pickup, and an electromagnetic drive method that uses the Lorentz force generated by passing a current through a coil placed in a magnetic field to send the optical pickup. be done.

As the motor drive method, a screw feed method, a gouge & pinion method, etc. are adopted due to the configuration of the final stage of the reduction mechanism. This motor drive system allows the optical pickup to be fed without being affected by tilting of the optical disk device or external vibrations, etc. However, noise from the deceleration mechanism is generated during high-speed feeding. However, there was also a limit to the ability to increase the speed of optical pickups, such as the inability to achieve both high-speed movement and precise movement.

On the other hand, the electromagnetic drive method does not have a speed reduction mechanism, so it does not generate noise during high-speed movement, can achieve both high-speed movement and precision movement, and has excellent reliability and durability. However, in this method, the optical pickup is slidably 5M in the radial direction of the disk, and the optical pickup is moved by Lorentz force.Since the optical pickup is normally installed in a movable manner, it may be affected by the tilt of the optical disk device itself. Feed errors occur due to the influence of gravity on the optical pickup, the influence of external vibration, etc.

In addition, in the electromagnetic drive method, the magnetic circuit is formed in an arc shape,
There is a swing arm system in which the optical pickup is moved in a swing manner by a drive coil arranged in this magnetic circuit. Compared to the electromagnetic drive method that sends in a straight line, this method can exert a moment force, so the optical pickup can be moved with a smaller force. In addition, if the magnetic circuit is formed in a circumferential shape and the drive coils are arranged at several locations, the Lorentz force generated in each drive coil will act in the rotational direction, so that the optical pick amplifier will be affected by the tilt of the optical disk device. It is possible to create a structure that is less susceptible to the effects of gravity.

However, in this swing arm method, since the optical pinocqua and the knob are operated in a swinging manner, the optical axis of irradiation onto the disk medium is arranged in an arc between the innermost track and the outermost track in the disk radial direction. It is sent by tracing the trajectory of For this reason, it could only be applied to a 1-beam type optical pickup, and not to a 3-beam type with good tracking characteristics. Furthermore, it could not be applied to an actuator-separated type optical pickup in which the optical pickup main body is separated into a movable part and a fixed part, and the movable part is lightened and moved at high speed.

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical pickup feeding device that can feed an optical pickup at high speed and is less susceptible to the influence of gravity due to the tilting of an optical disk device.

Means for Solving the Problems The present invention connects an electromagnetic drive means that swings about one point and an optical pickup body that is slidably mounted in the radial direction of the disk through a connecting portion. Configured.

According to the present invention, the optical pickup main body is linearly fed in the radial direction of the disk via the connecting portion by the swing motion by the electromagnetic drive means.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of an optical pickup/lamp feeder according to the present invention, FIG. 2 is a side view thereof, and FIG. 3 is a plan view thereof.

A pair of guide shafts 11 are mounted on the chassis base 10.
．． 11 are arranged in parallel. Guide shaft 11.
An optical pickup 13 is slidably mounted on the bearing 11 via a bearing portion 12.12. optical pickup 13
is located opposite the disk D, and the optical pickup 13
Laser light F condensed from the objective lens is movable in a straight line along the guide shaft 11.11 corresponding to the radial direction R of the disk D.

On one side of the optical pickup 13, the optical pickup 13
A plate-shaped protrusion 14 is attached to protrude on one side perpendicular to the direction of movement of the plate. The protruding piece 14 is the optical pickup 13
It is formed in a bifurcated shape with a long notch groove 15 formed in a direction perpendicular to the direction of movement. A Teflon resin coating is applied to the entire surface of the projecting piece 14 or to the entire circumference of the inner edge of the cutout groove 15.

On the other hand, on one side of the protruding piece 14 of the optical pickup 13 and on the chassis base, a rotary set of electromagnetic driving means 20 is disposed. The electromagnetic driving means 20 is configured by forming a magnetic circuit 22 on the outer periphery of a disc-shaped bottom plate 21. The magnetic circuit 22 is formed by dividing it into three equal parts, and the three arc-shaped magnetic circuits 22, . . . are formed into a ring shape. Each magnetic circuit 22,...
In this case, an arc-shaped yoke body 223 is sandwiched from above and below by a pair of substantially U-shaped yoke bodies 222 and 222, each of which has an arc-shaped permanent magnet 221 attached to one side facing each other, and the intermediate yoke body 223 and the permanent magnet 22L 221 It is assembled with a fixed gap between the two. Bottom plate 21
A support shaft 23 is erected at the center. Support shaft 23
An arm 24 is rotatably attached to the. The arms 24 are formed in a 7-shape shape and are equally spaced on three sides from the support center. Three arms of arm 24 ffi>24a
, 24b, 24c are provided with support plates 25a, 25b, 26 extending slightly inward and downward from the inner peripheral side of the magnetic circuit 22.
c are formed respectively. A frame-shaped coil 26 is attached to the outer surface of the support plate 25. coil 2
6 is located in the gap between the permanent magnet 22L221 and the yoke body 223 and is incorporated into the magnetic circuit 22. Each coil 28a attached to the arm 24 in this way
s28b126c are the magnetic circuits 22a and 22, respectively.
b Incorporated in %22c. A shaft 27 is formed at the end of one arm portion 24a of the arm 24 so as to protrude upward. The circumferential surface of the shaft 27 is coated with Teflon resin.

The shaft 27 of the arm 24 of the electromagnetic drive means 20 is fitted into the cutout groove 15 of the protrusion 14 of the optical pickup 13 described above. By applying Teflon resin coating to the shaft 27 and the protruding piece 14, the optical pickup 13 and the electromagnetic driving means 22 are prevented from shaking and the shaft 27 can move smoothly relative to the groove 15 of the protruding piece. are connected.

The arrangement of the electromagnetic driving means 22 of the optical pickup 13 is as shown by the solid line in FIG. Optical axis F, axis 27 and support axis 2
The line connecting the center with 3 is located on a straight line perpendicular to the moving direction of the optical pickup 13.

Next, the feeding operation of the optical pickup 13 will be explained.

In performing the sending operation of the optical pickup 13, first, current is passed through the coils 26as, 26bt, and 26c. Then, a Lorentz force is generated in each coil 26a126b128C constituting the magnetic circuits 22a, 22b122c, depending on the magnitude and direction of the current. This Lorentz force applies a moment to rotate the arm 24 about the support shaft 23, and the arm 24 is rotated about the shaft 23 in one direction in which the optical pickup is sent.

Moreover, when a current in the opposite direction is passed through the coil 26a126b126c, a Lorentz force in the opposite direction to the above is generated, and the arm 2
4 is rotated in the other direction.

By changing the direction of the current flowing through the coils 26 as 26 b 126 c, the arm 24 is rotated left and right about the shaft 23, and a swinging motion is performed within the range of the magnetic circuit 22.

The swing motion of the arm 24 causes the shaft 27 to reciprocate in a circular arc in the direction of the arrow 100 in FIG. Then,
The projecting piece 14 is urged via the shaft 27. by this,
The optical pickup 13 is linearly sent back and forth along the guide shaft 11.11 in the straight direction indicated by the arrow 101 in FIG.

In this way, the optical pickup 13 is operated by the electromagnetic driving means 20.
The swing movement of the arm 24 caused by the drive of the connecting portion 14.
17 in the disk radial direction R along the guide shaft 11.11.

According to the above embodiment structure, the groove 15 of the projection piece 14 and the shaft 27
The electromagnetic drive means 20 of the rotary set is connected to
Since the optical pickup 13 is linearly fed by the swinging motion, the feeding mechanism is simple, and high-speed feeding is possible compared to the case where the pickup body is directly attached to the arm. In addition, the electromagnetic drive of the rotary set produces a feeding action using the moment generated by the Lorentz force, and the rotational force is converted into a linear feeding motion via the connecting portion, so that the feeding action can be performed with a small force. Furthermore, since the electromagnetic driving means 20 is adapted to apply force at three locations in the circumferential direction of the magnetic circuit, the optical pickup 13 itself is not affected by the effects of acceleration and gravity applied thereto due to the inclination of the optical disk device body, etc. The structure becomes difficult. Furthermore, since the swing motion of the optical pickup 13 is converted into a linear motion and the optical pickup 13 is moved in a linear direction along the guide shaft 11.11, even if a swing-type electric 6 drive means is adopted, the trafking characteristic will not be improved. A good 3-beam system can be constructed. Incidentally, the present invention can also be applied to an actuator-separated optical pickup having the same configuration as above.

As described in detail, according to the present invention, by utilizing the advantages of the swing arm type electromagnetic drive system, the swing motion can be converted into a σ-ray motion to linearly feed the optical pickup in the radial direction of the disk. , it becomes possible to adopt a 3-beam system with good tracking characteristics, and faster high-speed feed can be performed. Historically, the pickup structure is less susceptible to the effects of gravity due to the tilting of the player's hat.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a feeding device for an optical pickup according to the present invention, FIG. 2 is a left side view as seen from the forward pickup feeding direction, and FIG. 3 is a front view showing the feeding operation of the optical pickup. . DESCRIPTION OF SYMBOLS 13... Optical pickup, 14... Projection piece, 15... Groove, connection part, 27... Shaft, 20... Electromagnetic drive means, 22... Magnetic circuit, 24... Arm, 26...Coil, D...Disc.

Claims (2)

[Claims] (1) In a feeding device that sends the optical pickup body in the disk radial direction, an electromagnetic drive unit that swings about a point and an optical pickup body that is slidably mounted in the disk radial direction are connected via a connecting part. A feeding device for an optical pickup, characterized in that the optical pickup main body is linearly fed through the connecting portion by a swing operation by the electromagnetic driving means. (2) The optical pickup feeding device according to claim (1), wherein the connecting portion is coated with a resin such as Teflon resin.