JP2003346437A - Pickup feeding mechanism of disk drive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pickup feeding mechanism of a disk drive, in which the performance of positional control for the pickup is improved by reducing a fluctuation in load of a pickup feeding motor caused by the position of the pickup. <P>SOLUTION: The pickup feeding mechanism which transmits the movement of a driving source 5 to the pickup 2 through transmission mechanisms 6, 7, is constituted so that a feed rate of the pickup 2 with respect to the unit working amount of the driving source 5 is changed by the transmission mechanisms 6, 7 in accordance with the position of the pickup 2 and a fluctuation in driving force of the driving source 5 due to the change of the reaction of the pickup 2 in the driving direction is reduced. <P>COPYRIGHT: (C)2004,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pickup feed mechanism for a disk drive, and more particularly, to a pickup feed mechanism that suppresses fluctuations in the load of a drive source.

[0002]

2. Description of the Related Art A conventional pickup feed mechanism of a disk drive will be described with reference to FIG. Pickup 2 shown in FIG.
Is supported on the chassis 1 so as to be slidable in the direction of arrow X in the figure, and a pickup feed motor 5 supported on the chassis 1 reduces a pinion 9 rotatably supported on the chassis 1 by a gear train. It is rotationally driven through a mechanism. The pinion 9 is a rack 2 provided on the pickup 2
It is engaged with c.

Accordingly, the pickup 2 is fed by the pickup feed motor 5 so that the objective lens 2a moves in the radial direction of the optical disk held on the turntable 4. Thus, the pickup 2 is designed to have a constant feed amount with respect to the unit rotation angle of the pickup feed motor 5.

[0004] The speed reduction mechanism of the pickup feed mechanism and the backlash between the pinion 9 and the rack 2c are eliminated to improve the followability of the pickup 2 with respect to switching of the rotation direction of the pickup feed motor 5, and furthermore, the displacement of the pickup 2 due to external vibration. To prevent this, a tension coil spring 3 is applied between the chassis 1 and the pickup 2 to urge the pickup 2 in one direction. Some use lead screws instead of rack and pinion,
Also in this case, the feed amount is constant with respect to the unit rotation angle of the pickup feed motor.

[0005]

In the above-described conventional pickup feed mechanism, the pickup feed amount is constant with respect to the unit rotation angle of the pickup feed motor, but the load applied to the pickup rack or lead screw, that is, The reaction force changes according to the amount of deformation of the tension coil spring.

Accordingly, the starting load of the pickup feed motor 5 when feeding in the direction opposite to the direction in which the load acts at the position where the load is large is large, and the starting voltage is high. In this case, the initial movement amount may be larger than when the sheet is sent in a position where the load is small or in a direction in which the load acts, and may pass the target position.

At this time, the control device for driving the pickup feed motor 5 attempts to control the position by performing a reverse rotation operation based on the position information read by the pickup from the disk. However, the control device feeds the tension coil spring from the extending direction to the biasing direction of the spring. When the direction changes, the load becomes extremely small, so that the vehicle easily passes the target position.

[0008] Even if the position is controlled by reversing the position again, the load becomes large this time, and the above-described operation is repeated. In order to make the characteristics of the control device correspond to such a load variation, it is necessary to make the load of the pickup feed motor constant regardless of the position of the pickup.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide a pickup feeding mechanism of a disk device for reducing a load fluctuation of a pickup feeding motor depending on a position of a pickup. It is in.

[0010]

A pickup feed mechanism for a disk drive according to the present invention is a pickup feed mechanism for transmitting the movement of a drive source to a pickup via a transmission mechanism, wherein the transmission mechanism operates with respect to a unit operation amount of the drive source. The feed amount of the pickup is changed according to the position of the pickup, so that the fluctuation of the driving force of the driving source due to the fluctuation of the reaction force in the driving direction of the pickup is reduced.

In the pickup feed mechanism, the transmission mechanism includes a cam and a lever driven by the cam, and the feed amount of the pickup relative to a unit operation amount of the drive source is set by the shape of the cam. Things.

In the pickup feed mechanism,
The transmission mechanism includes a rotating member and a lever having a slit engaged with a shaft provided on the rotating member.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A pickup feed mechanism of a disk drive according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing a pickup feed mechanism of a disk drive according to a first embodiment of the present invention, and FIG. 2 is a bottom view showing a cam 6 of the pickup feed mechanism. The pickup 2 shown in FIG. 1 is slidably supported on the chassis 1 in the direction of arrow X in the figure.

A pickup feed motor 5 supported by the chassis 1 drives a cam 6 rotatably supported by the chassis 1 via gears. A convex portion 7b protruding from the lever 7 is engaged with a cam groove 6a provided on the cam 6. The lever 7 is rotatably supported by the chassis 1 by a shaft 7a, and a slit 7c provided at the end opposite to the protrusion 7b allows the shaft 2b provided on the pickup 2 to pass therethrough.

Accordingly, the pickup 2 is fed by the pickup feed motor 5 so that the objective lens 2a moves in the radial direction of the optical disk held on the turntable 4. In order to remove the backlash of the transmission mechanism such as the cam 6 and the lever 7 of the pickup feed mechanism, a tension coil spring 3 is applied between the chassis 1 and the pickup 2 to urge the pickup 2 in one direction.

The feed amount of the pickup with respect to the unit rotation angle of the pickup feed motor 5 is represented by a cam 6 shown in detail in FIG.
Can be set by the curve of the cam groove 6a. In the case of this embodiment, the curve of the cam groove 6a is set so that the pickup feed amount per unit rotation angle of the pickup feed motor 5 is inversely proportional to the extension amount of the extension coil spring 3. Therefore, regardless of the position of the pickup 2, the torque of the pickup feed motor 5 for driving the pickup 2 is constant, and the control characteristics of the pickup feed can be set well.

FIG. 3 is a plan view showing a pickup feed mechanism of a disk drive according to a second embodiment of the present invention.
In this example, a rotating member 8 is rotatably supported by the chassis 1, and the rotating member 8 is driven to rotate by a fixed rotation angle with respect to a unit rotation angle of the pickup feeding motor. Omitted.

A shaft 8a standing on the rotating member 8 passes through a slit 2d of the pickup 2, and the pickup 2 is fed by a pickup feed motor as in the first embodiment. Other configurations are the same as those of the first embodiment, and a detailed description thereof will be omitted.

In the case of this embodiment, the feed amount of the pickup with respect to the unit rotation angle of the pickup feed motor is a sine function of the rotation angle of the rotary member 8.
When the extension of the tension coil spring 3 is maximum, the feed amount becomes maximum when the elongation of the pickup coil 2 is minimum, and the slit 2d of the pickup 2 and the shaft 8a of the rotary member 8 are minimized.
Is set. Accordingly, the fluctuation of the load of the pickup feed motor due to the position of the pickup is reduced.

Although the embodiment is constructed as described above, the invention is not limited to this. For example, the cam 6 or the rotating member 8 for feeding the pickup is used as a drive source for the disc loading mechanism in addition to the feeding of the pickup. be able to.
In this case, for example, the rotation angle of the cam 6 or the rotation member 8 is 0 to 1
80 ° is used for pick-up feed, and the rotation angle is 180 °
0 to 360 ° may be used for driving the disc loading mechanism.

[0021]

According to the pickup feeding mechanism of the disk device of the present invention, the fluctuation of the load of the driving source due to the position of the pickup is reduced, so that the characteristic of the position control of the pickup is improved.

[Brief description of the drawings]

FIG. 1 is a plan view showing a pickup feed mechanism of a disk device according to a first embodiment of the present invention.

FIG. 2 is a bottom view showing a cam of the pickup feed mechanism.

FIG. 3 is a plan view showing a pickup feed mechanism of a disk device according to a second embodiment of the present invention.

FIG. 4 is a plan view showing an example of a pickup feed mechanism of a conventional disk device.

[Explanation of symbols]

1 chassis 2 pickup, 2a objective lens, 2b axis, 2c
Rack 2d Slit 3 Tension coil spring 4 Turntable 5 Pick-up feed motor 6 Cam, 6a Cam groove curve 7 Lever, 7a shaft, 7b convex portion, 7c slit 8 Rotating member, 8a shaft 9 pinion

Claims (3)

[Claims] 1. A pickup feed mechanism for transmitting a movement of a drive source to a pickup via a transmission mechanism, wherein the transmission mechanism changes a feed amount of the pickup relative to a unit operation amount of the drive source according to a position of the pickup. A pickup feed mechanism for a disk drive configured to reduce fluctuations in the driving force of the driving source due to fluctuations in the driving direction reaction force. 2. The disk drive according to claim 1, wherein the transmission mechanism includes a cam and a lever driven by the cam, and a feed amount of the pickup relative to a unit operation amount of the drive source is set by a shape of the cam. Pickup feed mechanism. 3. The pickup feed mechanism of a disk drive according to claim 1, wherein said transmission mechanism includes a lever having a slit engaged with a rotating member and a shaft provided thereon.