KR100237889B1 - Vibration absorbing device for disc drive - Google Patents

Abstract

The present invention relates to a vibration absorbing device that eliminates vibration and noise caused by the rotation of the disk.

The vibration absorbing device of the disk driver according to the present invention includes at least one mechanism base on which the spindle motor and the optical pickup are mounted, and one side of the mechanism base to suppress vibration of the mechanism base regardless of the rotational speed of the disk at a mass m2. Mass correction means;

The vibration absorber of the disk driver of the present invention has an advantage of suppressing vibration and noise by making the center of gravity and the rotational center coincide.

Description

Vibration Absorber of Disk Driver

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc recording / reproducing apparatus, and more particularly, to a vibration absorbing apparatus that eliminates vibration and noise caused by rotation of a disc.

)의 제곱에 비례하므로 디스크의 회전속도가 커질수록 진동은 심각한 문제를 일으키게 된다. 기록매체의 제조공정에서 질량 불균형 (Mass unbalance)을 완전히 제거하기는 불가능하고, 또한 기록매체가 디스크 드라이버에 장착될 때의 편차 등으로 인하여 불가피하게 디스크의 회전에 따른 질량 불균형(Mass unbalance)의 문제를 발생한다. 개인용 컴퓨터(Personal Computer)에 사용되는 디스크의 기록/재생 장치의 경우, 인접한 주변기기의 진동이 디스크의 기록/재생 장치에 진동을 일으킬 수 있다. 이러한 외부의 가진원에 의한 영향은 휴대용(Portable)기기와 자동차용 기기에서 개발되는 디스크의 기록/재생 장치에 있어서는 더욱 심각한 문제가 되고 있다.Recently, a compact disc (hereinafter referred to as "CD") recording medium and a digital versatile disk (hereinafter referred to as "DVD") which have been spotlighted with superior recording density compared to CD. The recording / reproducing apparatus of the recording medium is required to increase the transmission speed. As a result, the rotational speed of the disk is increased in proportion to the transmission speed. At this time, if the center of rotation and the center of mass do not coincide, the disk driver deck inevitably causes vibration and noise problems, especially in the high frequency mode. High-speed rotation of the disc that does not coincide with the center of rotation causes the centrifugal force caused by mass unbalance to cause the support of the rotor to vibrate. This centrifugal force is the speed of rotation (

As the rotational speed of the disk increases, vibration causes serious problems. It is impossible to completely remove mass unbalance in the manufacturing process of the recording medium, and inevitably, there is a problem of mass unbalance due to the rotation of the disk due to the deviation when the recording medium is mounted in the disk driver. Occurs. In the case of a disc recording / reproducing apparatus used in a personal computer, vibration of adjacent peripheral devices may cause vibration of the disc recording / reproducing apparatus. The influence of such an external excitation source becomes a more serious problem in the disc recording / reproducing apparatus developed in portable devices and automotive devices.

Conventional disc recording / reproducing apparatus is provided with an anti-vibration rubber between an arbitrary fixing part of a driver set and a mechanism base to suppress the vibration of the mechanism base against an excitation circle from the outside.

Hereinafter, a vibration absorbing apparatus of a conventional disk driver will be described with reference to FIGS. 1 and 2.

Referring to the first (a), (b) and (c), the vibration absorbing device of the conventional disk driver includes a mechanism base 10 to which the spindle motor 2 and the optical pickup 4 are assembled, and a mechanism base. It is provided between the 10 and the fixing part 8 of a driver set, and is equipped with the anti-vibration rubber 6 which suppressed the vibration of the mechanism base 10 from an external excitation source.

The spindle motor 2 has a turntable 2a on which the disk is seated to rotate the disk 1 by the driving force of the motor. The optical pickup 4 includes an objective lens 4a for condensing the light beam from the laser diode light source on the information recording surface of the disk 1 and directing the light beam reflected from the information recording surface toward the photodetector, so as to receive the light beam from the information recording surface. Photoelectric conversion is reproduced or information is recorded on the information recording surface. The spindle motor 2 is fixed to the mechanism base 10, and the optical pickup 4 is mounted to the mechanism base 10 so as to be able to transfer in the radial direction of the disk. The objective lens 4a of the optical pickup 4 is driven vertically, horizontally, and by the Lorentz force generated in the magnetic circuit. The vertical direction to the flow of the objective lens 4a represents the focusing direction in which the light beam from the objective lens 4a falls within the depth of focus in the signal track of the disc 1, and the left and right directions are the light beams from the objective lens 4a. It refers to a tracking direction for following the signal track center of the disc 1. Accordingly, the conveyance direction of the optical pickup 4 is hereinafter referred to as "tracking direction" for convenience. In the disc driver, the centrifugal force F due to mass unbalance occurs in the radial direction of the disc 1. This centrifugal force is transmitted to the mechanism base 10 via the spindle motor 2. At this time, the centrifugal force due to the mass imbalance causes a discrepancy between the center of mass and the center of rotation of the disc, causing the mechanism base 10 to vibrate in the radial direction of the disc 1. In order to eliminate such vibration, there is a method of fixing the mechanism base 10 to the driver set 8. In this case, when vibration is applied to the driver set 8 by an excitation source that generates vibration of the driver deck external rotor, the vibration is transmitted to the mechanism base 10 as it is, and the optical pickup 4 located on the mechanism base 10 is provided. Will cause vibration. The objective lens 4a vibrates in the focusing or tracking direction as the optical pickup vibrates, causing the optical pickup 4 to incorrectly reproduce or record the signal recorded on the disc 1. In the case of a PC, vibration is inevitable due to the disk driver and other peripherals installed. In particular, in the development of automotive disk drivers and portable disk drivers, the excitation source from the outside acts on the driver set relatively larger.

To solve this problem, by installing a dustproof material between the mechanism base 10 and the fixing part of the driver set 8, the objective lens 4a vibrates by lowering the natural frequency against external vibration. It is essential to prevent that. Thus, the anti-vibration rubber 6 is located between the mechanism base 10 and the fixing part of the driver set 8.

t로 진동하는 진동체(스핀들 모터, 광픽업 등이 설치된 메카니즘 베이스)의 질량 m1의, 질량 불균형(mass unbalance)에 의한 m1의 변위 x1, 메카니즘 베이스(10)와 세트의 고정부(8) 사이에 위치한 방진고무(6)의 스프링 상수 k1, 뎀핑(damping; 이하 “감쇠”라 함)상수 c1으로 모델링된다. m1,x1,k1,c1은 진동계에서의 무차원화한 변수이다. 방진고무(6)는 진동계의 수학적 모델링에서 스프링 상수 k1, 감쇠상수 c1으로 표현된다. 메카니즘 베이스(10)의 질량 m1의 변위 x1은 디스크가 회전함에 따라 발생하는 원심력(F)에 의해 가진이 된다. 이 진동계의 고유 진동수를

이라고 하면, 그 해석의 결과는 수학식 1과 같다.Referring to FIG. 2, which shows a mathematical model thereof, mathematical modeling of a vibrometer according to a conventional disk driver has Fsin with a centrifugal force (F).

Displacement x1 of mass m1 of the vibrating body (mechanism base provided with spindle motor, optical pickup, etc.) oscillating at t, m1 due to mass unbalance, between mechanism base 10 and set fixing part 8 It is modeled as the spring constant k1 and the damping constant c1 of the anti-vibration rubber 6 located at. m1, x1, k1, c1 are dimensionless variables in the vibration system. The anti-vibration rubber 6 is represented by the spring constant k1 and the damping constant c1 in the mathematical modeling of the vibration system. The displacement x1 of the mass m1 of the mechanism base 10 is excited by the centrifugal force F generated as the disk rotates. The natural frequency of this vibrometer

If it is, the result of the analysis is the same as the equation (1).

[Equation 1]

)와 고유 진동수(

_n)의 비 r =

/

_n로 정의된다.Here, the magnitude of the damping factor ζ is ζ <1, and the rotational frequency of the disk (

) And natural frequency (

_n ) ratio r =

Of

_n is defined.

²이 된다. 이를 수학식 1에 대입하면, 수학식 2와 같다.In this case, if the mass unbalance is m _e and its position is e from the center of mass, then the centrifugal force F = m _e e

^{Becomes 2} Substituting this into Equation 1, it is the same as Equation 2.

[Equation 2]

)와 고유 진동수(

_n)의 비 r은 r 〉〉 1로 되어 수학식 2는

에 수렴한다. 이에 따라, 디스크의 회전주파수(

)가 높아지면 질량 불균형(mass unbalance)과 그 위치 e에 비례하여 메카니즘 베이스(10)의 질량 m1의 변위가 발생하게 된다. 또한, 메카니즘 베이스(10)가 외부에 전달하는 힘은 메카니즘 베이스(10)의 가속도에 비례하고, 이 가속도는

²x1이 되므로 디스크의 회전속도의 제곱에 비례하여 드라이버 세트(8)를 가진하는 힘이 발생하게 된다. 이 힘에 의해서 드라이버 세트(8)가 진동하고 소음을 발생한다. 디스크의 회전속도가 정보의 전송속도에 비례하여 고속화됨에 따라, 디스크의 고속 회전에 따른 메카니즘 베이스(10)의 진동 억제가 디스크 드라이버의 성능과 신뢰도를 높이는 중요한 요건이 된다. 그러나 종래의 디스크 드라이버의 진동 흡수 장치는 외부의 가진원으로부터 메카니즘 베이스의 진동을 억제하는 방진고무를 고정부와 메카니즘 베이스사이에 위치하도록 하는 진동계를 구현하였음에도 불구하고 디스크의 고속회전에는 대응하지 못하는 문제점을 초래한다.In the recording / reproducing medium according to the rotation of the disc, the vibration of the optical pickup 4 can be reduced by lowering the natural frequency to the excitation source from the outside. In this case, the rotational frequency of the disc (

) And natural frequency (

_n ) ratio r is r>> 1

Converge on. Accordingly, the rotation frequency of the disc (

Increasing) causes a displacement of the mass m1 of the mechanism base 10 in proportion to mass unbalance and its position e. In addition, the force transmitted by the mechanism base 10 to the outside is proportional to the acceleration of the mechanism base 10, and this acceleration is

^{Since 2} x 1, a force with the driver set 8 is generated in proportion to the square of the rotational speed of the disk. This force causes the driver set 8 to vibrate and generate noise. As the rotational speed of the disk is increased in proportion to the transmission speed of information, the vibration suppression of the mechanism base 10 due to the high-speed rotation of the disk becomes an important requirement for improving the performance and reliability of the disk driver. However, the vibration absorbing device of the conventional disk driver does not cope with the high speed rotation of the disk despite the implementation of a vibration system that places the vibration-proof rubber between the fixed part and the mechanism base to suppress the vibration of the mechanism base from an external excitation source. Brings about.

Accordingly, it is an object of the present invention to provide a vibration absorbing device for a disk driver which can suppress vibration and noise by making the center of gravity and the rotational center coincide.

Another object of the present invention is to provide a vibration absorbing device of a disc driver capable of accurate recording / playback by suppressing the vibration of the optical pickup by matching the center of gravity and the rotational center.

1 is a schematic longitudinal sectional view and a plan view of a disk driver employing a conventional vibration absorbing device.

2 is a mathematical modeling diagram for explaining a vibrometer of a conventional disk driver.

3 is a schematic longitudinal sectional view and a plan view of a disk driver to which a vibration absorbing device according to an embodiment of the present invention is applied.

4 is a mathematical modeling diagram for explaining the vibration system of the disk driver of the present invention in FIG.

Figure 5 is a longitudinal sectional view and plan view for explaining the vibration absorbing apparatus according to an embodiment of the present invention.

Figure 6 is a longitudinal sectional view and plan view for explaining a vibration absorbing device according to another embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

1: disc 2: spindle motor

2a: turntable 4: optical pickup

4a: objective lens 6: dustproof rubber

8: fixing part of screwdriver set 10: mechanism base

22,32: mass balance compensator 24,34: elastic body

26: screw 26a, 28a: boss

26b, 28b: vertical fixing piece

In order to achieve the above object, a vibration absorber of a disk driver according to the present invention is a mechanism base on which a spindle motor and an optical pickup are mounted, and located at one side of the mechanism base, and having a mass m2 of the mechanism base irrespective of the rotational speed of the disk. At least one mass correction means for suppressing the vibration of the.

Other objects and advantages of the present invention in addition to the above object will be apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 3 to 6.

3 is a schematic plan view and side view showing a disk driver to which the vibration absorbing device according to the present invention is applied.

Referring to the third (a), (b), (c), the vibration absorber of the disk driver according to the present invention includes a mechanism base 10, in which the spindle motor 2 and the optical pickup 4 are assembled; Dustproof rubber 6 located between the mechanism base 10 and the fixing part of the driver set 10 to suppress the vibration of the mechanism base 10 from an external excitation circle, and any on the mechanism base 10. And a mass compensator 22 positioned so as not to be supported by any fixed part to suppress the vibration of the mechanism base 10 regardless of the rotational speed of the disc 1.

The spindle motor 2 and the optical pickup 4 are located in the mechanism base 10, and the mechanism base 10 is suppressed from the external excitation source by the vibration-proof high part 6, and the mass compensator 22 As a result, vibration is suppressed regardless of the rotational speed of the disk 1.

An elastic body 24 is provided on one side of the mass compensator 22 to be fixed on the mechanism base 10 with an arbitrary spring constant k2 and an elastic modulus c2.

4 shows mathematical modeling of a vibration absorbing device of a disk driver according to the present invention.

t로 진동하는 진동체(스핀들 모터, 광픽업 등이 설치된 메카니즘 베이스)의 질량 m1과, 질량 불균형(mass unbalance)에 의한 변위 x1과, m1과 고정부 사이에 위치한 방진고무(6)의 스프링 상수 k1 및 감쇠상수 c1과, 스프링 상수 k2 및 c2으로 m1에 직렬 접속된 질량 보정체(22)의 질량 m2로 모델링된다. m1,x1,k1,c1,m2,x2,k2,c2는 진동계에서의 무차원화한 변수이다.Referring to FIG. 4, mathematical modeling of the vibration absorbing device of the disk driver according to the present invention has a centrifugal force (F) with Fsin.

spring constant of the vibration m vibrating at t (mechanism base on which a spindle motor, optical pickup, etc. is installed), the displacement x1 due to mass unbalance, and the vibration-proof rubber (6) located between m1 and the fixing part The mass m2 of the mass compensator 22 connected in series with m1 by k1 and the damping constant c1 and the spring constants k2 and c2 is modeled. m1, x1, k1, c1, m2, x2, k2, c2 are dimensionless variables in the vibration system.

의 회전 속도로 회전함에 따라 발생하는 원심력(F)에 의해 가진이 된다. 이러한 진동계를 수학적으로 해석하면, 수학식 3과 같다.The displacement x1 of the mass m1 of the mechanism base 10 indicates that the disk

Excitation is caused by the centrifugal force (F) generated by rotating at the rotational speed of. Mathematical analysis of such a vibration system is given by Equation (3).

[Equation 3]

Here, if the damping constant c2 = 0, Equation 3 is equal to Equation 4.

[Equation 4]

²m2=0인 경우라면, x1=0이 된다. 즉,

²=k2/m2이면 디스크 드라이버에는 회전속도에 관계없이 진동이 발생하지 않는다. 질량 보정체(22)가 없는 종래의 진동 흡수 장치에 있어서, 메카니즘 베이스(10)의 변위 x1은 고유 진동수보다 디스크의 회전 주파수가 충분히 크면

에 수렴하고, 드라이버 세트(8)에 전달되는 가진력(가속도)은

²x1으로 디스크의 회전 속도의 제곱에 비례하여 커지므로 고속으로 디스크를 회전시키는 경우에는 진동, 소음의 문제를 야기시킨다. 반면에, 본 발명에 따른 진동 흡수 장치는 질량 보정체(22)를 메카니즘 베이스(10) 상의 임의의 일측에 설치함으로서 디스크의 회전속도에 무관하게 진동이 발생하지 않는다.In Equation 4, k2-

^{If 2} m2 = 0, x1 = 0. In other words,

^{When 2} = k2 / m2, the disk driver does not generate vibration regardless of the rotation speed. In the conventional vibration absorbing device without the mass compensator 22, if the displacement x1 of the mechanism base 10 is sufficiently larger than the natural frequency, the rotation frequency of the disk is sufficiently large.

Convergence, and the excitation force (acceleration) transmitted to the driver set 8

² x 1 increases in proportion to the square of the rotational speed of the disk, causing the vibration and noise problems when rotating the disk at high speed. On the other hand, the vibration absorbing device according to the present invention does not generate vibration regardless of the rotational speed of the disc by installing the mass compensator 22 on any one side on the mechanism base 10.

Background Art In recent years, a disc driver using an optical disc as a recording medium has generally been rotated at a constant speed in order to increase the data transfer speed. When the disk rotates at the set speed, the vibration system due to the vibration absorbing device according to the present invention does not need to install a separate device to match the center of gravity and the center of rotation. In addition, the vibration absorbing device of the disk driver according to the present invention does not transmit the vibration due to the rotation of the disk to the outside does not generate vibration and noise. In addition, if the vibration absorbing device according to the present invention is applied to a recording / reproducing apparatus, since the mechanism base does not vibrate to the vibration caused by the rotation of the disk, it is possible to stably record / play back the optical pickup located on the mechanism base. This will be described in detail with reference to the attached FIGS. 5 and 6 according to an embodiment of the present invention.

5 is a schematic longitudinal cross-sectional view and side view of a vibration absorbing device of a disk driver according to an embodiment of the present invention.

Referring to FIGS. 5 (a) and 5 (b), the vibration absorbing device of the disk driver according to the present invention includes a boss 26a extending to a certain height at an arbitrary point on the mechanism base 10, and a cylindrical shape. The elastic body 24 and the cylindrical mass correction body 22 which are located in the outer peripheral surface of the elastic body 24, and the elastic body 24 fit in an inner diameter are provided.

The elastic body 24 is fitted to the outer circumferential surface of the boss 26a of the mechanism base 10, and is vertically fixed in a cylindrical shape to support the elastic body 24 and the lower end face of the mass compensator 22 so as not to be separated and flowed in the vertical direction. Piece 26b is located. A screw 26 is fitted through the inner diameter of the vertical fixing piece 26b and the inner diameter of the boss 26a to fix the elastic body 24, the mass corrector 22, and the vertical fixing piece 26b. Then, the mass compensator 22 is fixed in the vertical direction of the mechanism base 10, and the vibration of the mass compensator 22 is controlled by the elastic body 22 in the horizontal direction. By setting the rotational frequency of the disk, the elastic modulus of the elastic material and the mass of the mass compensator to appropriate values, the vibration in the horizontal direction can be suppressed regardless of the rotational frequency of the disk. The height in the vertical direction of the mass corrector 22 is set to be lower than the height of the elastic body 24. As such, the cylindrical mass compensator 22 and the elastic body 24 can be usefully applied to suppress vibrations in the radial direction of all disks.

6 is a schematic longitudinal section and side view of a vibration absorbing device of a disk driver according to another embodiment of the present invention.

Referring to FIG. 6, the vibration absorbing device of the disk driver according to the present invention is located on the outer circumferential surface of the boss 28a and the boss 28a, which extends to a certain height at an arbitrary point on the mechanism base 10, in particular in the tracking direction. The rod-shaped elastic body 34 located in both directions of the optical pickup direction and the outer circumferential surface of the elastic body 34 are positioned so that the elastic body 34 fits into the inner diameter and has a height lower in the vertical direction than the elastic body 34. The mass correction body 32 which has is provided.

The elastic body 34 is positioned on the outer circumferential surface of the boss 28a so as to face the tracking direction, and a cylindrical vertical fixing piece for supporting the elastic body 34 and the lower surface of the mass compensator 32 so as not to be separated and flowed in the vertical direction ( 28b) is located. A screw 28 is fitted through the inner diameter of the vertical fixing piece 28b and the inner diameter of the boss 26a to fix the elastic body 34, the mass compensating body 32, and the vertical fixing piece 28b. Then, the mass compensator 22 is fixed in the vertical direction of the mechanism base 10, and the vibration of the mass compensator 22 is controlled by the elastic body 22 in the tracking direction. When the rotational frequency of the disk, the elastic modulus of the elastic material and the mass of the mass compensator are set to appropriate values, the vibration in the tracking direction can be suppressed regardless of the rotational frequency of the disk. As such, the configuration of the mass compensator 22 and the elastic member 24 positioned to face the tracking direction is relative to the direction of the transport movement of the optical pickup when the objective lens vibrates as the mechanism base 10 vibrates in the horizontal direction. It can be usefully applied for the purpose of effectively suppressing vibration.

As described above, the vibration absorbing apparatus of the disk driver of the present invention has an advantage of suppressing vibration and noise by matching the center of gravity and the center of rotation.

In addition, the vibration absorbing apparatus of the disk driver of the present invention has an advantage that accurate recording / playback can be achieved by suppressing the vibration of the optical pickup by matching the center of gravity and the rotation center.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (5)

A recording / reproducing apparatus having a spindle motor for rotating a disk, and an optical pickup for irradiating a light beam to the information recording surface of the disk and converting the light beam reflected from the information recording surface of the disk into an electrical signal. And a mechanism base on which the optical pickup is mounted, and at least one mass correction means positioned at one side of the mechanism base to suppress vibration of the mechanism base at a mass m2 irrespective of the rotational speed of the disk. Vibration absorber of the disk driver. The vibration absorber of claim 1, wherein the mass correction means has elastic means fixed to one side of the mechanism base with an arbitrary elastic modulus, and a mass body fixed to one side of the elastic means. Device. The method of claim 1, wherein the mass correction means for the rotational speed of the disk

² = k2 / m2 (

Is a rotational speed of the disk, k2 is a spring constant of the mass correction means, m2 is a mass of the mass correction means. The mass correction means according to claim 1, wherein the mass correction means includes a cylindrical first mass located on one side of the mechanism base and an inner diameter of the first mass so as to suppress vibration of the mechanism base in all radial directions of the disk. A vibration absorbing device for a disk driver, comprising: an elastic body. 2. The mass correction means according to claim 1, wherein the mass correction means is fitted with a second mass located on one side of the mechanism base and an inner diameter of the second mass to restrain the vibration of the mechanism base with respect to the transport direction of the optical pickup. And a second elastic body positioned to face the transfer direction of the pickup.

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