JP2703947B2 - Recording and playback device - Google Patents

Description

The present invention relates to a recording / reproducing apparatus for recording / reproducing information on / from a disc-shaped information recording medium.

(Related Art) Recently, in a Winchester-type disk drive, a demand for a small-sized and large-capacity magnetic disk storage device has been increased. As a result of recent developments, it has become possible to increase the track density, and for this purpose, attempts have been made to provide a small actuator that can be accessed at a very high speed.

FIG. 6 shows a conventional technique used for such a purpose. Head slider with transducer
An arm assembly 31 for rotatably moving 30a, 30b,
It is composed of a pivot part 32 at the center of rotation of the arm assembly 31, suspensions 33a and 33b attaching the head sliders 30a and 30b to the arm assembly 31, and a voice coil motor 34 for driving the arm assembly 31 (US Patent No. 1,
342,495).

Each of the head sliders 30a and 30b is provided with two transducers. The transducer reads out a position signal written on the recording disk and feeds it back to the voice coil motor 34 to form a positioning servo system, thereby positioning the actuator. The pivot portion 32 is usually composed of a ball bearing and a steel shaft. For this reason, recording can be performed at a relatively high density and the access speed can be increased.However, since the size cannot be reduced to a certain value or more in order to secure the rigidity of the pivot portion 32, the actuator cannot be extremely reduced, and the rotating mass can be reduced. There is a limit, and there is a limit to faster access. In addition, it is difficult to increase the dynamic rigidity of the pivot portion 32 of the actuator, and the servo system tends to be unstable. Further, in order to use the ball bearing by applying a preload thereto, either of the inner and outer rings of the bearing can be slid in the actuator. Therefore, when the external temperature changes, slippage occurs due to thermal expansion, and the position of the transducer slightly changes. This is called thermal off-track.

Further, in the Winchester-type device, the head slider flies above the disk by an extremely small amount of air slider effect. For this reason, it is important to clean the internal air, and the internal air is constantly filtered by an air filter. For this reason, if oil or the like of the bearing scatters in the device, a head crash or the like occurs,
It is likely to cause a loss of reliability.

Another conventional example is shown in FIG. 7 (US Pat. No. 613,163).
This is because the mounting direction of the suspension 41 for fixing the head slider 40 is arranged substantially orthogonal to the above-mentioned conventional example, and the length of the arm 42 can be shortened. For this reason, the rotating mass can be reduced by the length of the arm 42 which is shorter than that of the conventional example, which is suitable for high speed access. However, since the pivot portion 43 of the ball bearing is provided as in the conventional example, the size of the entire actuator is hardly changed, and there is a limit in reducing the mass.

(Problems to be Solved by the Invention) As described above, in a recording / reproducing apparatus using a conventional rotary actuator, a pivot section using a ball bearing is generally used to rotatably support an arm, Because of this pivot, miniaturization is difficult,
Further, there is a problem that the servo system is unstable, heat off-track, head crash and the like are likely to occur.

The present invention solves the above-mentioned problems, and is suitable for a small and light-weight device with a simple configuration, capable of higher-speed access, has a stable servo system, has good positioning accuracy, and is suitable for high-density recording. It is an object of the present invention to provide a recording / reproducing apparatus and a highly reliable recording / reproducing apparatus which does not generate a thermal off-track and hardly causes a head crash or the like.

[Configuration of the invention]

(Means for Solving the Problems) In the recording / reproducing apparatus of the present invention, at least one transducer for reading / writing a record on / from a recording disk, an arm for supporting the transducer, and this arm One end is fixed to the arm for rotatably supporting the fixed part, and the other end is fixed to the fixed part, and each of the elastic beams is arranged to intersect with each other. And driving means.

Further, one of the elastic beams is arranged substantially parallel to the rotation direction of the arm.

Further, each of the elastic beams is arranged substantially orthogonally.

Further, the transducer is attached to one end of the arm, and the driving force of the driving means acts on the other end.

Further, the elastic beam has a small elasticity value in a rotating direction of the arm, and a large elasticity value in a direction orthogonal to the rotating direction.

Further, two pairs of the elastic beams arranged substantially orthogonally are arranged at an upper portion and a lower portion in a stacking direction of the recording disks.

A straight line obtained by extending a virtual intersection point of the elastic beams arranged substantially orthogonally in the laminating direction of the recording disk passes near the outer periphery of the recording disk or inside the recording disk.

(Operation) The operation of the present invention will be described. The recording apparatus of the present invention is characterized in that the center part of the arm main body having the transducer at one end and the drive motor part at the other end is supported by two intersecting elastic beams. In this configuration, the center of rotation is approximately on the line connecting the intersections of the two beams. The rotational elasticity around the rotation center can be made negligibly small when moving the arm body. Also, the elasticity in directions other than around the rotation center can be made sufficiently large so that vibrations in other directions can be substantially ignored. Thereby, the resonance frequency of the elastic beam itself can be increased to a negligible level. Also, increase the number of transducers (provide many arms)
When the length of the arm body in the up-down direction is long, the center of rotation is further stabilized by arranging the intersecting elastic beams at two places above and below the arm body, so that a better actuator can be obtained. Since most of the mass of the actuator is occupied by the transducer and the drive motor section, by arranging the two at both ends of the arm body, the center of rotational inertia of the arm body can be arranged at the center of the actuator. Therefore, the rotating mass can be reduced, and the arm body can be rotationally moved by the driving motor at a higher speed.

Normally, in a magnetic disk drive, a positioning servo system having a gain intersection point of about 400 Hz is configured. Therefore, when there is a low resonance mode in the rotation direction as in the present invention, a necessary positioning servo system can be configured by setting the resonance frequency to 40 Hz or less. The actuator is preferably a rigid body, but actually has various resonances. This higher resonance frequency is 2k
If it is set to Hz or more, a stable servo system can be constructed. Even if the elastic beam is supported by the elastic beam as in the present invention, by arranging the two elastic beams crossing each other, the elastic value of the elastic beam can be increased and the resonance frequency can be set to 2 kHz or more.

The elastic beam has resonance of the beam alone. Even if this frequency is 2 kHz or more, there is almost no damping, and a very large peak occurs, possibly deteriorating servo stability. In such a case, in the present invention, since the damping member is added to the beam portion, it is possible to configure a servo system which does not have a very large peak and is always stable.

By fixing one end of the elastic beam portion to the stationary portion and fixing the other end to the arm body, bending stress of the beam portion caused by rotation of the arm body can be reduced. Therefore, the reliability can be improved without breaking the beam for a long time.

In the present invention, since there is no part constituting the pivot part in the actuator only because there is a rotation center where the elastic beam part intersects, the actuator can be extremely reduced in size and weight, and the rotating mass can be reduced. Also, the center of rotation can be arranged on the recording disk. This is the most important point of the present invention in that the conventional ball bearings and shafts can be used to arrange the center of rotation only outside the disk plate. The radius of rotation of the transducer has a positive correlation with the distance between the center of rotation of the disk and the center of rotation of the arm body. If the center of rotation of the arm body is placed on the disk, the radius of rotation of the transducer can be reduced and the size of the actuator is very small. Can be. Since the rotating mass is approximately proportional to the square of the magnitude, the rotating mass rapidly decreases as the arm body becomes smaller. If the rotating mass is small, a large acceleration can be performed, so that the access speed can be increased and the energy consumption can be reduced. or,
Since there is no large pivot portion, it is possible to use a large voice coil motor capable of obtaining a large driving force corresponding to the space, and it is possible to further increase the access speed.

In the case of using a ball bearing, in order to apply a preload, either the inner or outer ring can be slid. Therefore, when the external temperature changes, slip occurs and the position of the transducer slightly changes, resulting in a positioning error called thermal off-track. In the present invention, since there is no slide portion, basically, there is no heat off track. Also, since no bearing containing oil is used, there is no fear of contaminating the atmosphere inside the device, and the reliability is improved.

In the conventional configuration, since there is no urging force in the rotation direction of the actuator, it is customary to separately add a spring for urging in order to urge and fix the arm body in a fixed direction at the time of stop.
In the present invention, since the actuator support itself has elasticity and always stops at the neutral position when stopped, there is no need to separately add a biasing spring, thereby improving reliability and reducing the structural cost.

Further, as compared with a case where the elastic beams are arranged in parallel without crossing each other, there is an effect that the tilt of the arm body which is the moving object is not excited.

Furthermore, when the intersection of the elastic beams is aligned with the rotational inertia center of the arm body that is the object to be moved, the force that excites the arm body to tilt even when the arm body is shifted from the neutral position is basically It does not work.

(Example) Hereinafter, the present invention will be described with reference to the drawings.

1 to 3 show one embodiment of the present invention. FIG. 1 is a plan view of a recording / reproducing apparatus of the present invention, and FIG.
The figure is a sectional view of the main part (actuator part) of the present invention,
FIG. 3 is a perspective view of a main part of the present invention.

The magnetic disk 1 is mounted on a spindle motor 2 and rotated. In most cases, a plurality of magnetic disks 1 are mounted, and information is read and written on both front and back surfaces. In addition,
The spindle motor 2 is fixed to a frame 3, and the air inside the device is constantly purified by an air filter 5.

The head slider 6 is a magnetic head and is provided with an air bearing to slightly float from the surface of the magnetic disk 1 and is supported by a suspension 7 constituting a transducer. The suspension 7 is attached to an arm 8 and fixed to an arm body 9.

On the other hand, the arm body 9 is rotatably supported by a yoke 12 to be described later by thin elastic beams 10a, 10b, 10c and 10d.
Since the elastic beam portion 10 has a thin plate shape, as shown in the cross-sectional view of FIG.
They are arranged so as to obtain a strong elasticity in the vertical direction (the direction in which the magnetic disks 1 are stacked).

The elastic beam portion 10 includes two elastic beams 10a, 10b and 10c, 10d.
Consists of two pairs of upper and lower pairs each arranged substantially orthogonally,
The upper outer elastic beam 10a and the lower outer elastic beam 10d are arranged so as to be substantially parallel to a virtual straight line connecting the rotation center of the arm body 9 and the head slider 6. On the other hand, the upper inner elastic beam 10b and the lower inner elastic beam 10c
Are arranged substantially parallel to the rotation direction (the seek direction of the head slider 6) and substantially orthogonal to the elastic beams 10a and 10d. As described above, the elastic beam portion 10 composed of the upper and lower two pairs is
They are arranged symmetrically.

The magnetic circuit includes the yoke 12, the permanent magnets 13a and 13b, and the drive coil 11. The drive coil 11 is wound in an elongated shape in the vertical direction (the direction in which the magnetic disks 1 are stacked), and the permanent magnets 13a and 13b are arranged outside (13a) and inside (13b) of the rotation center with the drive coil 11 interposed therebetween. Have been. Also,
The drive coil 11 is arranged in parallel with the rotation direction of the arm body 9 and is fixed at two ends at both ends of the arm body 9. For this reason, the magnetic gap has an arc shape, but the rotating mass is small and suitable for high-speed access. The permanent magnets 13a, 13b
Rare earth magnets, iron, neodymium magnets, ferrite magnets and the like are suitable.

Further, the actuators are arranged substantially symmetrically about the center of the rotating mass in the vertical direction, and the elastic beam portions 10 are also arranged at symmetrical positions. This arrangement reduces the influence of the two degrees of rotational freedom on the servo system.

14 is a magnetic shield of a permalloy plate and a weak signal flows
FPC (flexible print coil) 15 and drive coil 1
1, the yoke 12 is separated. 15 is an FPC for passing a signal, and 16 is a head amplifier.

In the recording / reproducing apparatus configured as described above, when a drive current flows through the drive coil 11, a translational force acts on the arm body 9 to which the drive coil 11 is fixed at one end. This translational force acts in a direction to compress the elastic beams 10b, 10c, and the elastic beams 10a, 10b
Works in the direction of bending. As described above, a relatively large elastic value is obtained in the direction in which the elastic beams 10b and 10c are compressed (this coincides with the seek direction of the head slider 6). This is very useful, that is, it is necessary to increase the resonance frequency in the direction parallel to the seek direction of the head slider 6, and as described above, the elastic beams 10b and 10c arranged substantially orthogonally are provided.
Are arranged in parallel with the seek direction of the head slider 6, thereby achieving a high resonance frequency in the seek direction.

On the other hand, the elastic beams 10a to 10d each have a thin plate shape, and a high elasticity value can be obtained also in the vertical direction.

The center of rotation of the arm body 9 (elastic beams 10a and 10b and
The orthogonal center of 10c and 10d) can be arranged near or on the magnetic disk 1.

In the embodiment of the sectional view shown in FIG. 2, the outermost peripheral position of the magnetic disk 1 and the rotation center position of the arm main body 9 substantially coincide with each other. The center position can be shifted. This is a magnetic disk 1
This is because the rotation center exists on the upper side and the lower side with respect to. This is the most important point of the present invention. In the case of using the conventional ball bearing and shaft, the rotation center can be arranged only outside the magnetic disk 1. The radius of rotation of the transducer has a positive correlation with the distance between the center of rotation of the magnetic disk 1 and the center of rotation of the arm body 9. If the center of rotation of the arm body 9 is arranged on or near the magnetic disk 1, the rotation of the transducer will occur. The radius can be reduced and the size of the arm body 9 can be made very small. Since the rotating mass is substantially proportional to the square of the size, the rotating mass rapidly decreases as the arm body 9 becomes smaller. If the rotating mass is small, a large acceleration can be performed, so that the access speed can be increased and the energy consumption can be reduced. Further, since there is no large pivot portion, a large voice coil motor capable of obtaining a large driving force corresponding to the space can be used, and the access speed can be further increased.

In the case of using a ball bearing, in order to apply a preload, either the inner or outer ring can be slid. Therefore, when the external temperature changes, slip occurs and the position of the transducer slightly changes, resulting in a positioning error called thermal off-track. In the present invention, since there is no slide portion, basically, there is no heat off track. Also, since no bearing containing oil is used, there is no fear of contaminating the atmosphere inside the device, and the reliability is improved.

In the conventional configuration, since there is no urging force in the rotation direction of the actuator, it is customary to separately add an urging spring in order to urge and fix the actuator in a fixed direction at the time of stop. In the present invention, since the actuator support itself has elasticity and always stops at the neutral position when stopped, there is no need to separately add a biasing spring, thereby improving reliability and reducing manufacturing costs. Further, since the mass of the actuator is mostly occupied by the transducer and the drive motor section, by arranging the two at both ends of the arm body 9, the center of rotational inertia of the arm body can be arranged at the center of the actuator. Therefore, the rotating mass can be reduced, and the actuator can be rotationally moved by the driving motor at a higher speed.

Further, as shown in FIG. 3, a damping member 18 made of, for example, silicon rubber may be attached to the elastic beams 10a to 10d to obtain good frequency characteristics.

The embodiments of the present invention are not limited to the above embodiments, and can be variously modified and used.

For example, the elastic beam portion 10 may be a single set without using two pairs of upper and lower members, and the shape of the elastic beam 10 is not limited to a thin plate shape, and may have any cross-sectional shape such as a rectangle, a circle, and an ellipse. .

Also, the shape of the magnetic circuit is not limited. More elastic beams
The arrangement of 10 is not limited to the above.

Further, in the above embodiment, each pair of elastic beams 10a
And 10b and 10c and 10d are almost orthogonal to each other,
The arrangement is not limited to the orthogonal arrangement, and any arrangement may be used as long as the arrangement is obliquely crossed.

Furthermore, in a field where the intersection of the intersecting elastic beams coincides with the rotational inertia center of the arm body 8, even when the arm body 8 is shifted from the neutral position, the force for exciting the tilt of the arm body 8 is fundamental. It does not work.

Next, FIGS. 4 and 5 show another embodiment of the present invention applied to an optical recording apparatus. FIG. 4 is a plan view and FIG. 5 is a side view.

Reference numeral 20 denotes an objective lens forming a transducer, reference numeral 21 denotes an arm main body, and reference numerals 22a to 22d denote elastic beams which are symmetrically positioned with respect to the arm main body 2. The elastic beam portion 22 is formed of a needle-shaped member having a circular cross section and not only creates a center of rotation, but also acts as a parallel beam in the vertical direction and also serves as a guide for moving the entire arm body 21 in the vertical direction for focusing. I have. 23a
Reference numerals 23d to 23d are stationary with yokes forming a magnetic circuit. Two
4 is a permanent magnet. The drive coil is disposed so as to surround the yoke 23d. However, when a current flows through a drive coil (not shown), the objective lens 20 is rotated to access information on an arbitrary track. The light path is indicated by arrows in the figure. Light from the objective lens 20 is reflected by a not-shown reflector 90
After being bent, the light enters the total reflection mirror 27, enters the stationary reflection mirror 28, is taken out of the actuator, and is taken in an optical processing system (not shown). Reference numerals 26a and 26b denote focusing coils for moving the entire actuator 21 up and down to focus the objective lens 20. 25a and 25b are magnetic circuits for focusing. The magnetic circuits 23 and 25 are fixed.

Since the objective lens 20 and the drive coil are disposed at both ends of the actuator, and the orthogonal elastic beam portion is disposed at the center,
In addition to being extremely compact and lightweight, it is equipped with a large driving motor that can provide a large driving force.

When the elastic beams 22b and 22c are arranged in parallel to the tracking direction of the arm body 21 even when applied to this optical recording / reproducing apparatus, a high elasticity value can be obtained in the tracking direction and the resonance frequency can be increased. .

〔The invention's effect〕

As described in detail above, according to the present invention, a compact and lightweight recording / reproducing device, high-speed access is possible, a servo system is stable, positioning accuracy is high, and a highly reliable recording / reproducing device which does not cause thermal off-track or the like. Is obtained.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment in which the recording / reproducing apparatus of the present invention is applied to a magnetic recording / reproducing apparatus, and FIGS.
4 and 5 are a plan view and a side view, respectively, showing main parts when the present invention is applied to an optical recording / reproducing apparatus, and FIGS. FIG. 7 is a perspective view and a plan view of main parts showing first and second conventional examples. DESCRIPTION OF SYMBOLS 1 ... Recording disk, 2 ... Spindle motor, 6 ... Head slider (transducer), 7 ... Suspension, 8 ... Arm, 9 ... Arm body, 10a, 10b, 10c, 10
d ... Elastic beam, 11 ... Drive coil (drive means), 12 ...
Yoke (drive means), 13a, 13b ... permanent magnet (drive means).

Claims (9)

(57) [Claims] At least one transducer for reading and writing records on a recording disk, an arm body for supporting the transducer,
A plurality of elastic beams, one end of which is fixed to the arm main body, the other end is fixed to the fixing portion, and each of which is intersected to rotatably support the arm main body with respect to the fixing portion; A recording / reproducing apparatus comprising: a driving unit for rotationally driving the transducer. 2. The recording / reproducing apparatus according to claim 1, wherein one of said elastic beams is disposed substantially parallel to a rotation direction of said arm body. 3. The recording / reproducing apparatus according to claim 1, wherein each of said elastic beams is arranged substantially orthogonally. 4. The recording / reproducing apparatus according to claim 1, wherein said transducer is attached to one end of said arm body, and a driving force of said driving means acts on the other end. 5. The recording / reproducing apparatus according to claim 1, wherein said elastic beam has a small elasticity value in a direction of rotation of said arm body and a large elasticity value in a direction perpendicular to said direction of rotation. . 6. The recording / reproducing apparatus according to claim 1, wherein two pairs of the intersecting elastic beams are arranged at an upper part and a lower part in a stacking direction of the recording disks. 7. A straight line obtained by extending a virtual intersection point of the elastic beams intersected in the laminating direction of the recording disk passes near the outer periphery of the recording disk or inside the recording disk. The recording / reproduction device according to claim 1. 8. The recording / reproducing apparatus according to claim 1, wherein a damping member is provided on an outer surface or inside the elastic beam. 9. The recording / reproducing apparatus according to claim 1, wherein a virtual intersection point of the elastic beams intersected substantially coincides with a rotational inertia center of the arm body.