JP2900626B2 - Vibration suppression device for recording / reproducing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration suppressing device for a recording / reproducing apparatus for recording / reproducing information on / from an optical recording medium such as an optical disk.

[0002]

2. Description of the Related Art In recent years, optical discs have characteristics such as high recording density, non-contact recording / reproducing, so that the life of the medium is long, and random access is much faster than that of tape or other media. CD, VLP as
Many application proposals have been made such as image files, data files, and document files as recording / reproducing devices.

[0003] In the field of playback devices, a fairly large market has already been formed.
A very large market size is expected.

An example of the above-described conventional optical disk device will be described below with reference to the drawings.

FIG. 6 is a general configuration diagram of a conventional optical disk recording / reproducing apparatus. In FIG. 6, reference numeral 1 denotes an optical disk, which is mounted on a turntable 2 in a detachable manner,
The rotation is accurately controlled by the disk motor 3 at a predetermined rotation speed. Reference numeral 4 denotes a chassis, which is a pedestal for fixing the disk motor 3 and an optical head described below in a fixed relationship.

Reference numeral 5 denotes an optical head, on which optical elements such as a laser and a lens for recording and reproducing signals, a detector for detecting a signal, and a driving element for controlling the position of the lens are mounted. Reference numeral 6 denotes a linear motor for moving the optical head 5 in the radial direction of the disk so that the optical head can perform a recording / reproducing operation in a desired region on the disk. Although linear motors have been frequently used, there are also motors configured by a combination of a DC motor or a step motor and a feed screw. Reference numeral 7 denotes a guide rail, and 8 denotes a bearing. The optical head is supported via a guide rail 7 fixed to the chassis 4 so that the optical head can easily move in the radial direction of the disk and the distance between the disk and the optical head is kept constant. ing.

Reference numeral 9 denotes a lens position control circuit, which moves an objective lens on the optical head 5 and focuses a laser beam on the recording surface of the disk by following the surface deflection of the disk. It is a circuit for driving and controlling the linear motor 6 and the tracking control means for following the distortion of the pre-groove which forms the track recorded in advance and the eccentricity of the disk. Reference numeral 10 denotes a device control circuit, which is turned on and off by a microcomputer or the like to turn on and off the lens position control circuit 9 and the disk motor.
It controls the movement of the entire device such as FF.

Although not shown in the figure, an optical disk recording / reproducing apparatus including a signal recording circuit for modulating a recording signal and driving control of a laser, a reproducing circuit for reading a recorded signal, and the like are mounted. doing.

In such devices, recently, the optical head and chassis have been reduced in size and weight in order to increase the speed of access, including the size of the disk as a recording medium and the size of the device itself.

[0010]

However, as the size and weight of the device main body and the optical head have been reduced, the above-described configuration has a problem that vibrations from the outside and vibrations of the motor and the like generated inside cause a problem. As indicated by broken lines in the guide rail 7 of FIG. 6, the vibration amplitude of the optical head and the supporting portion supporting the optical head becomes large, which has a problem of affecting the reliability of signal recording and reproduction.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a recording / reproducing apparatus vibration suppressing apparatus which reduces the vibration amplitude due to disturbance of the optical head while reducing the weight of the optical head.

[0012]

According to the present invention, there is provided an optical head for recording and reproducing information, and a magnetic coupling means between an optical head and a chassis. The magnetic force is generated in a direction perpendicular to the
Record, reproduce, and move at high speed (hereinafter a
Access, etc.)
It is designed to be used as a brake during access .

[0013]

Further, a vibration detector or a position detector is provided on the optical head or the chassis, and according to the output of each detector,
It is configured to control the coupling force of the magnetic coupling means.

[0015]

According to the present invention, in the mode which does not require high-speed movement such as during recording and reproduction,
Strengthen the magnetic coupling between the optical head and the chassis, increase the rigidity between the chassis, and for low frequency vibration,
By making the vibration amount of the chassis and the optical head almost equal, the vibration is relatively reduced, and for high frequency vibration, the apparent mass is increased by the magnetic force that attracts or repels the optical head to the chassis, It acts to reduce the amplitude due to resonance or the like.

Further, by weakening or cutting off the magnetic coupling at the time of access, an apparent increase in load caused by friction between the bearing and the guide rail is eliminated, and the high-speed movement is enabled.

Further, by utilizing the magnetic coupling means as a brake at the time of stop in access, the decrease in acceleration caused by the increase in the mass of the linear motor due to the magnetic coupling means is canceled by adjusting the speed curve at the time of deceleration. So without sacrificing access time,
It works to realize stable recording and reproduction.

By using the output of a vibration detector or the like, the above-described operation can be realized without increasing the normal power consumption. Further, by controlling the distance between the optical head and the chassis to be constant using the output of the position detector, the vibration can be suppressed by a necessary force in a vertical direction of the vibration regardless of the gravitational acceleration.

[0019]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a recording / reproducing apparatus according to an embodiment of the present invention;

(Embodiment 1) FIG. 1 is a configuration diagram of a vibration suppressing device of a recording / reproducing apparatus according to a first embodiment of the present invention.

In FIG. 1, components having the same functions as those of the conventional example are denoted by the same reference numerals, and detailed description thereof will be omitted.

1 is an optical disk, 2 is a turntable, 3
Is a disk motor, 4 is a chassis, 5 is an optical head, 6 is a linear motor, 7 is a guide rail, 8 is a bearing, 9
, A lens position control circuit; and 10, an apparatus control circuit.

Numeral 11 denotes a magnetic piece fixed to the bottom of the linear motor 6 or the optical head 5. Magnetic piece 11
May be a sheet metal such as iron or nickel, or may be a permanent magnet using ferrite or the like. Numeral 12 denotes a permanent magnet as a magnetic coupling means, which forms a magnetic coupling with the magnetic piece 11 fixed to the chassis 4.

With the above configuration, a suction force is generated between the linear motor 6 and the chassis 4 in the direction of arrow A, and the linear motor 6 including the optical head 5 is pressed against the guide rail 8 so that the natural resonance frequency of the guide rail 8 is increased. It operates in such a direction as to suppress the vibration amplitude in the above. Also, arrow B
In the case of a low frequency with respect to the vibration in the direction of, the chassis 4 and the linear motor 6 operate so as to move in the same direction by the magnetic coupling force. However, the same effect can be obtained as when the vibration amplitude is relatively reduced. In the case of high frequency, if the applied force is generally the same, it is inversely proportional to the square of the frequency. Also, due to the stiffness of each component, the vibration phase differs depending on the position, and the frequency response is high. It is absorbed by the lens control means.

In this embodiment, a permanent magnet has been described as an example of the magnetic coupling means 12. However, an electromagnet may be used, or a fixed magnet of a linear motor may be used together. Further, the positional relationship between the magnetic piece 11 and the magnetic coupling means 12 can be exchanged.

(Embodiment 2) Next, a second embodiment of the present invention will be described with reference to FIG.

In FIG. 2, 13 is an electromagnet, 14 is a magnetic piece, 15 is an electromagnet drive circuit, and ON / OFF is controlled by a device control circuit 10.

According to the vibration suppressing device configured as described above, it is possible to efficiently generate a magnetic field as close as possible between the electromagnet 13 and the magnetic piece 14. A similar effect can be obtained by a similar magnetic coupling force.

Further, by using the electromagnet 13 as the magnetic coupling means and controlling the ON / OFF operation by the device control circuit 10, the magnetic coupling means can be cut off at the time of high-speed movement such as at the time of access to reduce the load on the linear motor 6 as much as possible. By using the electromagnet 13 as a brake at the time of stopping in access, the electromagnet 1
3, the decrease in acceleration caused by the increase in the mass of the linear motor 6 is offset by adjusting the speed curve at the time of deceleration, so that it is possible to achieve both high-speed access and vibration suppression.

Also in this embodiment, it is possible to use a permanent magnet or an electromagnet for the magnetic piece 14 or to exchange the positional relationship between the magnetic piece 14 and the electromagnet 13. Can be changed by a solenoid or the like to change the magnetic coupling force with the magnetic piece 11.

(Embodiment 3) Next, a third embodiment of the present invention will be described with reference to FIG.

In FIG. 3, reference numeral 16 denotes a vibration detector which can use an acceleration sensor, a speed sensor, and the like. Reference numeral 17 denotes a vibration control circuit which has a comparison function such as a comparator and may be a circuit for turning on the electromagnet when the vibration exceeds a certain level, or a difference between the reference level and the reference level by a differential amplifier to suppress the vibration by the vibration level. A negative feedback loop may be configured so that the value can be changed.

FIG. 4 shows the waveform of each part in each mode when a comparator is used in the vibration control circuit in this embodiment.
Shown in

In FIG. 4, C is a vibration suppression device forced OF.
F, at the time of reproduction, at the time of access (forced vibration suppression device OFF),
A typical operation mode at the time of recording or the like is shown. D is an output waveform of the vibration detector 16, D0, D1, and D3 indicate that vibration is applied from the outside, and D2 indicates self-vibration generated when the optical head moves. E indicates a coupling force generated between the electromagnet 13 and the magnetic material piece 14, and normally maintains a weak coupling force at the E1 level. When vibrations such as D1 and D3 are applied, the comparator operates and the maximum value is obtained. A level coupling force E2 is generated. F is a measurement of the vibration of the guide rail 7, and when the vibration suppression device is forcibly turned off, a damped vibration F0 having a large amplitude is generated by self-resonance due to the external vibration D0. The vibration due to D1, D3, etc. is F1,
As in F3 and the like, the vibration is suppressed by the magnetic coupling force and the amplitude is sufficiently small.

F1 'is a vibration in the same direction as the gravitational acceleration, and the vibration is not sufficiently suppressed in the amplitude direction, but operates so that the damped vibration does not continue for a long time. F2 is a self-vibration at the time of access, and the self-resonance overlaps with a small deformation of the guide rail, a distortion of the bearing, a squealing noise, etc., resulting in a considerably large vibration. Has no effect.

With the above configuration, the current of the electromagnet 13 can be cut off when it is unnecessary, while obtaining the same effect of suppressing vibration and increasing the speed of access as in the second embodiment, thereby saving power.

(Embodiment 4) Next, a fourth embodiment of the present invention will be described with reference to FIG.

In FIG. 5, reference numeral 18 denotes an electromagnet, and 19 denotes a permanent magnet, which can generate a force in both directions of attraction and repulsion. Reference numeral 20 denotes a position detector, and reference numeral 21 denotes a vibration control circuit. Position detector 2
In this embodiment, 0 is a Hall element and a permanent magnet 1
An output that is inversely proportional to the square of the distance to 9 is obtained, but an output that detects optically or a change that detects a change in capacitance may be used. The vibration control circuit 21 forms a negative feedback loop so that the difference between the reference level and the reference level can be obtained by the differential amplifier and the vibration suppression can be changed depending on the vibration level.

With the above-described configuration, in the vibration suppressing device of this embodiment, the field back loop operates so that the distance between the permanent magnet 19 attached to the optical head 5 and the position detector 20 attached to the chassis 4 becomes constant. A good vibration suppressing effect can be obtained without considering the direction and amplitude of the vibration. Further, there is an effect that the positional relationship between the optical head and the chassis is always kept constant even in the outer space where there is no gravitational acceleration.

Also in this embodiment, it is within the scope of the present invention to reverse the arrangement of the electromagnet 18, the permanent magnet 19, and the position detector 20.

The structure of the magnetic coupling means may be not the bottom surface of the optical head but the side surface or the top surface, or may be used together.

Further, when the tracking or focus detection signal is divided by a filter and the DC or low-frequency AC level exceeds a certain level, the coupling force of the magnetic coupling means is reduced to reduce the steady-state load, and the AC or DC frequency of about 10 Hz or more is reduced.
On the other hand, when the level becomes higher than a certain level, the power consumption can be reduced and the vibration can be reduced by increasing the coupling force without using a vibration detector.

Although the embodiment has been described using an optical disk device, it is apparent that the present invention can be applied to an optical card or other device requiring a high-precision positional relationship between a head and a recording medium.

[0044]

According to the present invention, as apparent from the above embodiments, a vibration suppressing device for a recording / reproducing apparatus having the following effects can be provided.

(1) A magnetic coupling means is provided between the optical head and the chassis, and a magnetic force is generated in a direction perpendicular to the traveling direction of the optical head. If necessary, the coupling force of the magnetic coupling means is recorded. , Reproduction, high-speed movement, etc., and the amount of vibration, so that it is possible to improve the reliability of the device by suppressing external vibrations and to speed up access, and to use the magnetic coupling means in the access. When stopped
By using it as a brake for magnetic coupling
Since the increase in the mass of the optical head due to the step can be compensated,
Stable recording and playback without sacrificing access time
Can be realized .

[0046]

( 2 ) By utilizing the outputs of the vibration detector, the position detector, and the like, the above-mentioned effects can be realized with little increase in power consumption, and the positional relationship between the optical head, the chassis, and the optical disk. Can always be kept constant, and ideal recording and reproducing conditions can be created.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of a vibration suppressing device for a recording / reproducing apparatus according to the present invention.
Configuration diagram of the embodiment

FIG. 2 is a configuration diagram of the second embodiment.

FIG. 3 is a configuration diagram of the third embodiment.

FIG. 4 is a waveform chart of each part in each mode of the third embodiment.

FIG. 5 is a configuration diagram of the fourth embodiment.

FIG. 6 is a configuration diagram of a conventional optical disk device.

[Explanation of symbols]

 4 Chassis 5 Optical Head 10 Device Control Circuit 11 Magnetic Piece 12 Permanent Magnet 13 Electromagnet 14 Magnetic Piece 15 Electromagnet Drive Circuit 16 Vibration Detector 17 Vibration Control Circuit 18 Electromagnet 19 Permanent Magnet 20 Position Detector 21 Vibration Control Circuit

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G11B 7/085 G11B 21/00-21/02

Claims (3)

(57) [Claims] An optical head for recording and reproducing method according to claim 1] information, comprising a magnetic coupling means between the optical head and the chassis, wherein
The magnetic coupling means is in a direction perpendicular to the traveling direction of the optical head.
And a magnetic force generated by the magnetic coupling means.
Switch between modes such as recording, playback, and high-speed movement
It is possible to use it as a brake at the time of access
Characteristic vibration suppression device for recording / reproducing machine. 2. A comprising an optical head or chassis vibration detector, the vibration detector in accordance with the output of the vibration suppression of the recording and reproducing apparatus of the magnetic coupling means of claim 1, wherein which is adapted to control the coupling force apparatus. 3. A position detector for measuring a relative position between the optical head and the chassis, and according to an output of the position detector,
3. The apparatus according to claim 1, wherein a coupling force of said magnetic coupling means is controlled.