JPH03283173A - Dumping device in disk driving device - Google Patents

Abstract

PURPOSE:To reduce the influence of vibration by interposing a damping elastic body between a motor or a clamper and the other member. CONSTITUTION:A disk 6 such as an optical disk is installed on a turn table 5, and it is sandwiched and held between the turn table 5 and the clamper 7. The clamper 7 has a magnet, for example, and it is attracted to the turn table 5 through the disk 6. The damping elastic body 11 is installed on the clamper 7 and a restriction member 12 having constant mass (m) is installed on said body 11 in a free state. The damping elastic body 11 is manufactured by viscoelasticity material whose vibration resistance is high such as butyl rubber or the other elastic material, and the damping elastic body 11 is sandwiched between the clamper 7 and the restriction member 12. Then, both surfaces of the elastic body are adhered to the clamper 7 and the restriction member 12. Thus, the transmission of vibration whose amplitude is large for pickup can be prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a disk drive device that rotates an information recording disk such as an optical disk or a magnetic disk, and particularly relates to a disk drive device that rotates an information recording disk such as an optical disk or a magnetic disk. This invention relates to a vibration damping device that suppresses vibrations emitted from a system.

[Prior Art] FIG. 8 shows the structure of a disk drive device installed in an optical disk device, a magneto-optical disk device, etc.

A disk drive motor 2 is fixed to the chassis 1 with screws 3 or the like. A turntable 5 is fixed to the upper end of the rotating shaft 4 of the motor 2 as a disk support. A disk 6 is placed on this turntable 5 and fixed by a clamper 7. The disk 6 is rotationally driven by the rotational force of the motor 2.

Reference numeral 8 is an optical pickup. This pickup 8 is moved in the radial direction of the disk 6 by a guide mechanism and a feeding mechanism provided on the chassis 1. Although the pickup 8 is shown in a simplified manner in the figure, the pickup 8 includes an objective lens 8a that focuses the laser beam on the recording surface of the disk 6, and an elastic support member 8b that supports the objective lens 8a so as to be able to move slightly in the F direction. It also includes a magnetic drive mechanism for driving the objective lens 8a in the F direction, as well as a semiconductor laser, a light receiving element, and the like.

[Problems to be Solved by the Invention] In this type of disk drive device, when the motor 2 rotates the resolution disk, the motor 2, the rotating shaft 4, the turntable 5, the clamper 7, and the disk 6 supported by these constitutes a kind of forced vibration system, and this vibration system is forced to vibrate by the rotation of the motor and the rotation of the disk 6. This vibration system has a natural frequency f determined by a mode equivalent mass M consisting of the motor 2, the disk 6, etc., and a mode equivalent stiffness K consisting of all parts such as the rotating shaft 4 and the disk 6. (shown in Figure 9). The frequency f of vibrations generated in the system when the motor is driven is the natural frequency f. When , the system resonates and its amplitude increases. Fig. 9 shows the mode of the vibration system (vibration model of the structure shown in Fig. 7) and the natural frequency of this mode, and Fig. 10 shows fO/f on the horizontal axis and vibration amplitude ( dB). A resonance state occurs when fo/f becomes 1.

On the other hand, in the pickup 8, the objective lens 8a is supported by an elastic support member 8b so as to be able to move slightly in the F direction, but when the vibration system generates resonance, the vibration is transmitted to the pickup amplifier via the chassis 1. Conveyed. When the natural frequency (resonant frequency) fo that causes the resonance is within the frequency band of the servo operation of the pickup 8, the resonance vibration transmitted from the vibration system to the knob 8 is transmitted to the objective lens support mechanism in the pickup. This has the same effect as sub-resonance and impairs the accuracy of focus servo.

The present invention solves the above-mentioned conventional problem, and suppresses the vibration amplitude of a vibration system consisting of a motor, a disk, a clamper, etc., especially when it resonates, or allows the vibration of this vibration system to be transmitted through the chassis to a vibrator, knob, etc. It is an object of the present invention to provide a vibration damping device for a disk drive device that can reduce the influence of vibrations by preventing vibrations from being transmitted.

[Means for Solving the Problems] A vibration damping device according to the present invention includes a motor, a disk support section provided on the rotating shaft of the motor, and a clamper that clamps the disk between the disk support section and the disk support section. The disk drive device is characterized in that a damping elastic body is interposed between the motor or clamper and other members.

[Operation 1] In the above means, first, by interposing a damping elastic body between the motor or clamper and the restraint member, the amplitude of vibrations emitted from the vibration system consisting of the motor, clamper, disk, etc. when the motor is driven is suppressed. Ru. Alternatively, by interposing a vibration-damping elastic body between the chassis to which the motor is attached and the motor, it is possible to prevent the vibrations emitted from the vibration system when the motor is driven from being transmitted to the chassis, thereby causing vibrations to be transmitted to the pickup on the chassis, etc. is prevented from being transmitted.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a vibration damping device according to a first embodiment of the invention.

In FIG. 1, reference numeral 1 denotes a chassis, to which a motor 2 is directly fixed with screws 3. As shown in FIG. A turntable 5 is fixed to the upper end of the rotating shaft 4 of the motor 2 as a disk support. A disk 6 such as an optical disk is placed on a turntable 5, and is held between the turntable 5 and a clamper 7. The clamper 7 has a magnet, for example, and is attracted to the turntable 5 via the disk 6. A damping elastic body 11 is placed on top of the clamper 7, and a restraining member 12 having a constant mass m is placed thereon in a free state. The vibration damping elastic body 11 is made of a viscoelastic material with high vibration damping properties such as butyl rubber, or other elastic material. This damping elastic body 11 connects the clamper 7 and the restraint member 12.
Both surfaces of the elastic body are adhered to the clamper 7 and the restraining member 12.

FIG. 2 shows a vibration model of the above structure.

M is the mode equivalent mass of the vibration system consisting of the motor 2, rotating shaft 4, turntable 5, disk 6, and clamper 7, and K is the motor 2, rotating shaft 4, and turntable 5.
, shows the mode equivalent stiffness of the vibration system consisting of the disk 6 and the clamper 7. In FIG. 2, α indicates a vibration system comprised from the motor 2 to the clamper 7. Further, β indicates a vibration suppressing portion consisting of a vibration damping elastic body 11 and a restraining member 12. m is the mass of the restraint member 12, k is the rigidity of the vibration damping elastic body 11, and C is the viscous damping coefficient due to the vibration damping elastic body 11.

In the disk drive device shown in FIG. 1, the amplitude of the forced vibration emitted from the vibration system shown by α is attenuated by the viscous damping coefficient shown by C. FIG. 6 is a diagram showing this attenuation characteristic. The horizontal axis shows the aforementioned fo /f, and the vertical axis shows the vibration amplitude.

In FIG. 6, the solid line represents the damping state in the above embodiment, and the dotted line represents the vibration characteristics when no vibration damping device is provided, similar to that shown in FIG. As shown in this diagram, in the above embodiment, it can be seen that the amplitude is attenuated at each frequency when the motor is driven, and particularly the amplitude is greatly reduced during resonance (fo/f=1). This damping can prevent large amplitude vibrations from being transmitted to the pickup through the chassis 1.

FIG. 3 shows a modification of the first embodiment.

In this case, a damping elastic body 11 and a restraining member 12 in a free state having a constant mass m are attached to the lower surface of the motor 2. The damping effect shown in FIG. 3 can also achieve the same damping effect as the embodiment shown in FIG. 1. FIG. 4 shows a second embodiment of the present invention.

In this embodiment, the motor 2 is directly fixed to the chassis 1, but a fixed restraint plate 13 is provided on the lower side of the chassis 1 via a column 14.

A damping elastic body 11 is installed on the lower surface of the motor 2. The vibration damping elastic body 11 is interposed between the motor 2 and the fixed restraining plate 13 and bonded to both. Fixed restraint plate 13
Although a plate made of the same material as the chassis 1 may be used, an increase in the number of parts can be prevented by using a circuit board on which various circuits are mounted also as a fixed restraint plate.

FIG. 5 shows a vibration model of the structure of this second embodiment. The mode equivalent mass M of the vibration system consisting of the motor 2, rotating shaft 4, turntable 5, disk 6, and clamper 7 is supported by the equivalent stiffness k formed by the mode equivalent stiffness of this vibration system and the stiffness of the damping elastic body 11. , and is elastically restrained by the viscous damping coefficient shown by C of the damping elastic body 11.

Therefore, this viscous damping coefficient C can suppress the amplitude of the vibration system consisting of the motor 2, rotating shaft 4, turntable 5, disk 6, and turntable 7 when the motor is driven.

In all of the embodiments shown in FIGS. 1 to 5 above, the motor 2 or clamper 7 in the vibration system is elastically restrained from the outside to suppress the vibration amplitude of the vibration system, especially the vibration amplitude during resonance. It is something. Therefore, in these embodiments, since the motor 2 can be directly fixed to the chassis 1, there is an advantage that the motor can be mounted with high accuracy.

FIG. 7 shows a third embodiment of the invention.

In this embodiment, a damping elastic body 11 is interposed between the motor 2 and the chassis 1 to attenuate the vibrations occurring in the vibration system, especially the amplitude of resonance vibrations, and transmit the damped vibrations to the chassis 1. . In other words, the transmission path of resonance vibration to the pickup 8 is intended to be blocked by the vibration damping elastic body 11 having high vibration damping properties.

In this third embodiment, the restraining member 1 shown in FIGS.
2 does not need to be attached outside the vibration system, an increase in the number of parts and mass can be prevented. Further, the fixed restraint plate 13 shown in FIG. 4 is also unnecessary, which has the advantage of simplifying the structure.

Although the illustrated embodiment shows an optical disk drive device, the present invention can be similarly implemented in a magnetic disk drive device such as a hard disk or floppy disk. In the case of a magnetic disk drive device, it is possible to prevent the head from wobbling due to vibrations generated by motor drive, and it becomes possible to achieve higher density recording tracks.

[Effects] As described above, according to the present invention, since the vibration-damping elastic body is interposed between the motor or clamper and other members, The vibration of the vibration system, especially the amplitude of vibration during resonance, can be suppressed, or the vibration can be prevented from being transmitted to the chassis.

[Brief explanation of the drawing]

FIG. 1 is a side view of a disk drive device showing a first embodiment of the present invention, FIG. 2 is an explanatory diagram showing its vibration mode, and FIG. 3 is a side view of a disk drive device showing a modification of the first embodiment. 4 is a side view showing a disk drive device according to a second embodiment of the present invention, and FIG. 5 is an explanatory diagram showing its vibration mode.
FIG. 6 is a line section showing the vibration amplitude damping effect of the disk drive device according to the first and second embodiments, FIG. 7 is a side view of the disk drive device according to the third embodiment of the present invention, and FIG. 8 is a conventional one. FIG. 9 is an explanatory diagram showing its vibration mode, and FIG. 10 is a diagram showing the vibration characteristics of the conventional disk drive. 1... Chassis, 2... Motor, 4... Rotating shaft,
5... Turntable, 6... Disc, 7...
Clamper, 11... Vibration damping elastic body, 12... Restraint member, 13... Fixed restraint plate. 1...5 Yasi Gran 1? 1 ・fJ loss l soul 1 Figure 2 Figure 3 Figure t//f Figure 4 Figure 6 Figure M...Mode number mass fo, Fixed beak adoption 0.5 f,/f

Claims (1)

[Claims] 1. In a disk drive device that is provided with a motor, a disk support section provided on the rotating shaft of the motor, and a clamper that clamps the disk between the disk support section, the motor or clamper and other members A vibration damping device characterized in that a vibration damping elastic body is interposed between