JPH09213029A - Rotary type information recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an information recording disk from being excited for vibration through a base by a magnet-yoke assembly vibrating by receiving the carriage driving reactive force at the time of positioning the head of a rotary type information recording/reproducing device. SOLUTION: The magnet-yoke assembly consisting of an upper side yoke 9A adhering a permanent magnet 10A and a lower side yoke 9B adhering a permanent magnet 10B is held between slip guiding members 11A, 11C and preloading viscoelastic members 12A, 12C. Then, the magnet-yoke assembly is attenuatedly supported by a cylindrical screw 13B for holding the viscoelastic members for minutely displacing in the direction within the surface of the base 8A. The magnet-yoke assembly is thereby prevented from displacing in the vertical direction of the base 8A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary information recording / reproducing apparatus which moves a head for recording / reproducing information to a predetermined position on an information recording disk for positioning.

[0002]

2. Description of the Related Art As an example of a conventional rotary information recording / reproducing apparatus, a magnetic disk apparatus disclosed in US Pat. No. 5,027,242 will be described. The laminated information recording discs are rotationally driven at a constant rotational speed by a disc rotational drive motor fixed to the base. The carriage supports the head via a head support spring, and the head floats above the disk with a minute gap therebetween to record / reproduce information. High-speed and high-accuracy positioning of the head is performed by rotationally driving the carriage with a voice coil motor. The carriage is supported by a ball bearing arranged between the carriage and a rotating shaft fixed on the base, and rotates about the rotating shaft. The voice coil motor that drives the carriage is
It is composed of a voice coil (also referred to as “driving coil”), a permanent magnet, and a yoke. Of these, a voice coil is attached to the carriage, and the remaining permanent magnets and yokes (these are referred to as "magnet / yoke assembly") are fixed on the base. Since the voice coil sandwiched by the magnetic circuit is subjected to the magnetic field action, the voice coil can be driven by energizing the voice coil.
A housing is composed of the base and the cover.

When the voice coil is energized to generate a driving force, the magnet / yoke assembly receiving the reaction force vibrates the base. The vibrating force excites the disk rotation drive motor and vibrates the disk. As a result, relative displacement occurs during positioning between the head supported by the carriage and the disk. As a result, off-track occurs and the positioning settling time becomes long, which hinders the positioning performance. The magnetic disk device is often attached to the external housing with screws or the like, and since the external housing is generally made of sheet metal or the like, the entire device including the external housing vibrates and is positioned by the above-mentioned vibration force. Adversely affect. In order to perform high-speed and high-accuracy positioning, it is necessary to reduce structural vibration due to the reaction force of the voice coil motor.

As a means for solving the above problems, for example, there is a technique disclosed in Japanese Patent Laid-Open No. 59-210573. In this example, the carriage holding the voice coil and the magnet / yoke assembly are configured to be independently rotatable around the rotation axis. The magnet / yoke assembly is engaged with a cushioning material arranged on the base via a plate at one end thereof. When the voice coil supported by the coil frame of the carriage is energized and the carriage is driven to rotate, the reaction force causes the magnet / yoke assembly to be slightly rotationally displaced about the rotation axis in the direction opposite to the direction of the carriage. The minute rotational vibration of the magnet / yoke assembly is transmitted to the cushioning material via the plate and is attenuated. Thereby, it is possible to reduce the reaction force transmission to the base due to the movement of the carriage.

As an example of improving the vibration characteristics of the structure using a viscoelastic body, there is a technique disclosed in JP-A-59-198567. In this example, the magnet assembly is attached to the housing via a rubber viscoelastic body to prevent the resonance frequency of the housing from decreasing.

[0006]

Problems to be Solved by the Invention JP-A-59-2105
In the above-mentioned prior art disclosed in Japanese Patent Publication No. 73-73, the carriage holding the voice coil and the magnet / yoke assembly need to be independently rotatable around the rotation axis. Therefore, the device size, particularly the thickness size, is reduced. There is a problem that it becomes large and it is difficult to reduce the thickness. In a magnetic disk device, a standard device size (length, width, height) called a form factor is defined, and the device must be accommodated within this size. Further, since one end of the magnet / yoke assembly is damped and supported, there is a problem that a sufficient vibration reduction effect cannot be obtained.

On the other hand, in the conventional technique disclosed in Japanese Patent Laid-Open No. 59-198567, the magnet assembly is only supported by the housing via the viscoelastic body made of rubber. If the magnet assembly can make a minute movement only in the in-plane direction of the arm by the driving reaction force, the vibration energy of the magnet assembly can be efficiently consumed. However, since the direction of minute movement of the magnet assembly is not regulated, when an external force is applied to the device, the magnet assembly vibrates not only in the in-plane direction of the arm but also in the out-plane direction, causing a gap between the permanent magnet and the drive coil. There was a problem that it was difficult to keep the gap between the two constant because of the relative displacement in the directions. Therefore, there is a problem that the thrust is likely to change, the gap may change over time due to the weight of the magnet assembly, and the permanent magnet may come into contact with the drive coil due to an external force.

It is an object of the present invention to prevent a magnet / yoke assembly, which vibrates due to a reaction force of a carriage drive when a head is positioned, from vibrating an information recording disk via a base, and has a small and thin rotation. To provide a shape information recording / reproducing apparatus.

[0009]

In order to achieve the above object, the rotary information recording / reproducing apparatus of the present invention holds a magnet / yoke assembly consisting of a permanent magnet and a yoke by a slide guide member and a viscoelastic member for preload. However, it is supported by damping so that it can be slightly displaced in the in-plane direction of the base.

In this rotary information recording / reproducing apparatus, it is preferable that the magnet / yoke assembly is dampedly supported on the housing by a viscoelastic member. For example, a cylindrical viscoelastic member is used, the cylindrical viscoelastic member is penetrated through the cylindrical viscoelastic member holding screw, and the outer surface of the cylindrical viscoelastic member is fitted into a hole provided in the base to form a cylindrical viscoelastic member. If the elastic member holding screw is connected to the yoke of the magnet / yoke assembly, a more preferable structure can be obtained by slightly displacing the magnet / yoke assembly in the in-plane direction of the base.

When the above construction is adopted, a washer made of a sliding bearing material is inserted between the cylindrical viscoelastic member and the cylindrical viscoelastic member holding screw, or the cylindrical viscoelastic member holding screw is inserted. It can be manufactured using plain bearing materials,
The portion of the cylindrical viscoelastic member retaining screw that engages with the cylindrical viscoelastic member may be coated with a plain bearing material.

To achieve the above object, the rotary information recording / reproducing apparatus of the present invention comprises a magnet / yoke assembly comprising a permanent magnet and a yoke, and a viscoelastic member comprising viscoelastic rubber or viscoelastic resin. The above-mentioned magnet / yoke assembly is coupled and integrated with the above-described yoke damping support member so that the magnet / yoke assembly is supported by damping so as to be capable of minute displacement in the in-plane direction of the base.

In this rotary information recording / reproducing apparatus, the yoke damping support member may be connected to the housing, or the yoke damping support member may be integrated with the rotation limit stopper portion of the carriage.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram of an embodiment of a rotary information recording / reproducing apparatus according to the present invention, and shows a state in which a part of a cover 8B and a part of an upper yoke 9A and the like are cut away. 2 is a cross-sectional view as seen from the direction A in FIG. The disks 6 stacked in the direction perpendicular to the paper surface of FIG. 1 are rotationally driven by a disk rotation drive motor 7 fixed to a base 8A. A head 1 for recording and reproducing information is attached to a carriage 3 via a head support spring 2. By fixing the pivot assembly containing the two rolling bearings 4A between the carriage rotation shaft 4 and the sleeve 4B to the carriage 3 and fixing the carriage rotation shaft 4 to the base 8A, the carriage 3 is fixed to the carriage rotation shaft 4. Support rotatably around.

As shown in FIG. 2, the magnet / yoke assembly comprising a yoke and a permanent magnet is an integrated assembly comprising an upper yoke 9A to which a permanent magnet 10A is adhered and a lower yoke 9B to which a permanent magnet 10B is adhered. . Returning to FIG. 1, the description will be continued. The carriage 3 is rotationally driven by the voice coil motor constituted by the magnet / yoke assembly and the drive coil 5 provided on the carriage 3, and the head 1 is positioned on a predetermined track of the disk 6 to record / reproduce information.

For example, when the thrust F is applied to the drive coil 5 in the direction of the arrow in the figure and the head 1 is rotated in the direction of the arrow S in the figure for positioning, the reaction force R of the thrust F is in the opposite direction to the thrust F. Occurs in the magnet / yoke assembly 9. In the conventional device, the magnet / yoke assembly is fixed to the base using screws or the like. Therefore, the disk 6 on the base is vibrated by the reaction force R, a relative displacement occurs between the head and the disk, and the positioning characteristics deteriorate. In this embodiment, the magnet / yoke assembly includes three slide guide members 11B.
(Sliding guide members 11A and 11C are not shown) and three preload viscoelastic members 12A and 12C (viscoelastic member 1).
2B is supported on the base 8A by a damping support mechanism using (not shown). As a result, vibration of the disk due to the reaction force R is suppressed, and structural vibration that adversely affects the positioning characteristics can be reduced. As shown in FIG. 2, the sliding guide members 11A and 11C are arranged on the base side corresponding to the viscoelastic members 12A and 12C, and the viscoelastic member 12B is arranged on the cover side corresponding to the sliding guide member 11B. ing.

A damping support method for a magnet / yoke assembly,
That is, a method of supporting the magnet / yoke assembly so as to damp the vibration will be described with reference to FIG. In the conventional device, the magnet / yoke assembly is fixed to the base with screws or the like, as described above. In this embodiment, the sliding guide members 11A and 11C are adhered onto the base 8A,
The lower yoke 9B is in contact therewith. Further, the preload viscoelastic members 12A and 12C are adhered onto the cover 8B so that the entire magnet / yoke assembly is held between the base and the cover. The magnet / yoke assembly can be displaced in the in-plane direction of the base with the slide guide member as a reference surface. Preload viscoelastic members 12A, 12C
Is for holding the magnet / yoke assembly by applying pressure in advance.The thickness dimension of the magnet / yoke assembly is made larger than the clearance dimension between the upper yoke and the cover after assembly, and compression is performed by assembling the cover. It is deformed to generate a preload. As a result, the magnet / yoke assembly can be brought into close contact with the slide guide member.

The material of the slide guide member is preferably a material suitable for use as a slide bearing such as tetrafluoroethylene (trade name: Teflon). Further, as the material of the viscoelastic member for preload, a viscoelastic resin such as sponge-like urethane or sponge-like viscoelastic rubber is desirable. The numbers of the slide guide member and the preload viscoelastic member are preferably three, respectively, but the number of parts is not limited to this.

Further, in this mechanism, in order to consume the kinetic energy of the magnet / yoke assembly which is displaced slightly within the base surface in response to the driving reaction force, the cylindrical viscoelastic member 14 is further added.
B and the cylindrical viscoelastic member holding screw 13B,
The yoke assembly was supported by damping. A screw hole is provided in the lower yoke 9B, and a base hole is provided on the same center line as this screw hole. The cylindrical viscoelastic member 14B is fitted into the cylindrical portion 13B-2 of the cylindrical viscoelastic member holding screw, and the notch 13B-4 is provided in the flange portion 13B-3 of the cylindrical viscoelastic member holding screw.
The magnet / yoke assembly can be dampedly supported on the base via the cylindrical viscoelastic member by pressing a screw on the tool and pressing the screw. In the figure, 13B-1
Is a screw part, and 13A and 14A are the same cylindrical viscoelastic member holding screw and cylindrical viscoelastic member as described above.

FIG. 3 shows an assembled state of the cylindrical viscoelastic member holding screw and the cylindrical viscoelastic member. The arrow in the figure indicates the direction of assembly. Since the cylindrical viscoelastic member holding screw 13B is pushed into the base hole with the cylindrical viscoelastic member 14B fitted, the outer surface of the cylindrical viscoelastic member holding screw is slippery with respect to the cylindrical viscoelastic member. It is desirable that this facilitates assembly. Therefore, the sliding washer 17 may be inserted between them. Further, a portion of the cylindrical viscoelastic member holding screw 13B in contact with the cylindrical viscoelastic member 14B may be coated with a plain bearing material. Further, the cylindrical viscoelastic member holding screw itself may be made of a slide bearing material.

In this embodiment, the magnet / yoke assembly is held by the slide guide member and the preload viscoelastic member, and the magnet / yoke assembly is slightly displaced in the in-plane direction of the base by using the cylindrical viscoelastic member and screws. Damped support so that you can. Therefore, it is possible to prevent the magnet / yoke assembly, which vibrates due to the reaction force of the carriage driving when the head is positioned, from vibrating the information recording disk via the base. When no force is applied to the magnet / yoke assembly, the magnet / yoke assembly returns to the supporting reference, ie, the neutral position. Further, even if vibration or shock is applied to the device from the outside, the magnet / yoke assembly is not displaced more than the specified value and the disk or the carriage is not damaged, and the shock resistance can be improved.

The effect of the present invention will be described with reference to FIG. FIG. 8A shows a residual vibration measurement result in the positioning direction of the tip of the carriage guide arm. Acceleration time 5ms,
The carriage was driven by a triangular velocity pattern with a deceleration time of 5 ms. The horizontal axis represents the elapsed time after the end of deceleration, and the vertical axis represents the envelope of the residual vibration waveform after the end of deceleration based on the acceleration during acceleration of the tip of the carriage guide arm. In the method of the present invention, the residual vibration amplitude is reduced and the residual vibration is attenuated faster than in the conventional method.

In the same manner, the residual vibration in the positioning direction of the spindle center (center of the disk rotation shaft) was measured. FIG. 8B shows the envelope of the residual vibration waveform at the center of the spindle after deceleration with reference to the acceleration at the time of acceleration of the carriage guide arm tip. The maximum value of the residual vibration is reduced by about 40%, and the residual vibration is rapidly attenuated. From the above results, it is understood that the present invention can reduce the residual vibration of the carriage guide arm and the spindle and also shorten the residual vibration settling time.

Next, another embodiment in which the method of damping and supporting the magnet / yoke assembly is simplified, the number of parts is reduced, and the assemblability is improved will be described with reference to FIGS. 4 and 5. FIG.
(A), (b) is the top view and side view of the assembly which combined the damping support member with the magnet / yoke assembly. Attenuating support members 15A, 1 at both ends of the magnet / yoke assembly
5B and is an integrated assembly as a whole. The structure on one side of the damping support member is shown in FIG.
The damping support member 15B is formed by integrally molding viscoelastic rubber or viscoelastic resin and has a slit 15B-4 at the center, so that the four yoke coupling portions 15B-3 can be deformed in the direction of opening to the outside. In addition, the upper and lower yoke contact flanges 1
5B-2. Damping support member 15A on the other side
Is the same.

As shown in FIG. 4, the yoke coupling portions 15A-3 and 15B-3 are provided on the upper yoke 9A and the lower yoke 9B.
A notch is provided in advance so that they will engage with each other. The yoke contact flange portions 15A-2, 15B-2 and the yoke coupling portion 15A so as to sandwich the upper yoke 9A and the lower yoke 9B.
-3, 15B-3 are closely attached to the upper yoke 9A and the lower yoke 9B, and the damping support members 15A, 1
Fit 5B. This component integrated with the magnet / yoke assembly is screwed into the base with screw holes 15A.
-1, 15B-1 to fix. Damping support member 15
Since A and 15B are soft and deformable by themselves, the magnet / yoke assembly can be supported by damping even if it is screwed to the base. In this embodiment, the damping support member is of a type that is fitted into the magnet / yoke assembly, but may be bonded or screwed, or may be integrally molded with the magnet / yoke assembly.

Next, another embodiment of the damping support method for the magnet / yoke assembly will be described with reference to FIG. FIG. 6 (c)
As shown in FIG. 5, the damping support member 15B is integrally formed of viscoelastic rubber or viscoelastic resin as in the embodiment shown in FIG. However, in the present embodiment, the damping support member 1
5B is provided with a carriage rotation limit stopper portion 15B-5 in advance. Further, as shown in FIG. 6B, a carriage rotation stopper hole 9B-1 is previously formed in the lower yoke 9B. As shown in FIG. 6A, the carriage rotation limit stopper portion 15B-5 is inserted into the carriage rotation stopper hole, the damping support member 15B is further pushed in, and the yoke coupling portion 15B-3 is engaged with the end surface of the lower yoke 9B. To combine. As a result, the magnet / yoke assembly and the damping support member 15B become an integrated assembly. The same applies to the structure on the other side of the damping support member. With this configuration, the magnet / yoke assembly has both a damping support function and a carriage rotation limit stopping function at the same time.
In addition to reducing the number of parts, the number of assembling steps is also reduced, and the cost can be reduced.

Next, another embodiment of the damping support method for the magnet / yoke assembly will be described with reference to FIG. The outer surfaces of the upper yoke 9A and the lower yoke 9B are coated with viscoelastic rubber or viscoelastic resin to provide the coating layer 16.
Grooves are formed in the base and the cover according to the shape of the yoke, and the magnet / yoke assembly is assembled by being sandwiched by the base and the cover. This allows the magnet / yoke assembly to be supported by damping.

As described above, as in the embodiment shown in FIGS. 4 to 7, the yoke damping support member is made of a viscoelastic member made of viscoelastic rubber or viscoelastic resin, and the yoke damping support member is attached to the magnet / yoke assembly. Were combined by press-fitting or screwing or bonding to form an integrated assembly. Further, the yoke damping support member is integrally molded with the magnet / yoke assembly. The yoke damping support member integrally assembled with the magnet / yoke assembly was coupled to the housing, and the magnet / yoke assembly was dampingly supported so that it could be finely displaced in the in-plane direction of the base. In addition, the outer surface of the magnet / yoke assembly is coated with a viscoelastic material, and the magnet / yoke assembly is held in a housing that is composed of a base and a cover, and the magnet / yoke assembly is damped so that it can be slightly displaced in the in-plane direction. Supported.
Therefore, the structure of the magnet / yoke assembly is simplified,
The number of parts was reduced and the assemblability was improved.

Further, by adopting a structure in which the rotation stopper portion of the carriage is integrated with the yoke damping support member integrally assembled with the magnet / yoke assembly, the magnet / yoke assembly has a damping support function and a carriage rotation limit stopping function. Since both functions are provided at the same time, the number of parts is further reduced, the number of assembling steps is also reduced, and the cost can be reduced.

With the above various configurations, the magnet / yoke assembly is supported so that it can be displaced only minutely in the in-plane direction of the base, so that the vibration energy of the magnet / yoke assembly can be efficiently consumed. As a result, it is possible to prevent the information recording disk from being vibrated and to realize high-speed and high-accuracy positioning of the head.

When the residual vibration in the positioning direction of the tip of the carriage guide arm and the residual vibration in the positioning direction of the spindle center were measured for these examples, almost the same effect as the result shown in FIG. 8 was obtained. .

In the embodiment described above, the apparatus is placed horizontally, but since the magnet / yoke assembly is supported by using the viscoelastic member between the base and the cover, the apparatus is supported vertically. It is also possible to do so. The present invention also provides 1.3 ″, 1.8 ″, 2.5 ″, 3.5 ″, 5.2.
It satisfies the form factor size of a small magnetic disk device such as 5 ″.

[0033]

As described above, according to the present invention, the magnet / yoke assembly can be finely displaced only in the in-plane direction of the base, and the magnet / yoke assembly vibrates the information recording disk via the base. It is possible to provide a mechanism for preventing the occurrence of the above and satisfying the form factor dimension.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram including a partial cross section of an embodiment of a rotary information recording / reproducing apparatus of the present invention.

FIG. 2 is a sectional view as seen from a direction A in FIG. 1;

3 is an engagement view of components of a damping support mechanism of the rotary information recording / reproducing apparatus shown in FIG.

FIG. 4 is a plan view and a side view of another embodiment of the rotary information recording / reproducing apparatus of the present invention.

5 is a perspective view of an attenuation support member of the rotary information recording / reproducing apparatus shown in FIG.

FIG. 6 is a partial perspective view of still another embodiment of the rotary information recording / reproducing apparatus of the present invention.

FIG. 7 is a partial perspective view of still another embodiment of the rotary information recording / reproducing apparatus of the present invention.

FIG. 8 is a diagram showing the effect of the present invention.

[Explanation of symbols]

 1 ... Head 2 ... Head Support Spring 3 ... Carriage 4 ... Carriage Rotation Shaft 4A ... Rolling Bearing 4B ... Sleeve 5 ... Drive Coil 6 ... Disk 7 ... Disk Rotation Drive Motor 8 ... Housing 8A ... Base 8B ... Cover 9 ... Magnet / Yoke Assembly 9A ... Upper yoke 9B ... Lower yoke 9B-1 ... Carriage rotation stopper hole 10A, 10B ... Permanent magnets 11A, 11B, 11C ... Sliding guide member 12A, 12B, 12C ... Preload viscoelastic member 13A, 13B ... Cylindrical shape Viscoelastic member holding screw 13B-1 ... Screw portion 13B-2 ... Cylindrical portion 13B-3 ... Flange portion 13B-4 ... Notch 14A, 14B ... Cylindrical viscoelastic member 15A, 15B ... Damping support member 15A-1, 15B -1 ... screw hole 15A-2, 15B-2 ... yoke adhesion flange part 15A-3, 15B-3 ... Yoke coupling part 15B-4 ... Slit 15B-5 ... Carriage rotation limit stopper part 16 ... Coating layer 17 ... Slip washer

Claims (5)

[Claims] 1. A disk for recording information, a rotation driving means for rotationally driving the disk, a carriage for supporting a head for recording and reproducing information on the disk, and positioning of the carriage in the radial direction of the disk. In order to achieve this, a carriage drive unit that applies a rotational torque to the carriage and a housing that is configured by a base and a cover that include the carriage drive unit are provided. The carriage drive unit includes a drive coil, a permanent magnet, and a yoke provided on the carriage. In the rotary information recording / reproducing apparatus including the magnet / yoke assembly, the magnet / yoke assembly is clamped by the slide guide member and the viscoelastic member for preload so that the magnet / yoke assembly can be slightly displaced in the in-plane direction of the base. Rotational information recording / reproducing apparatus characterized by a structure supported by damping . 2. The rotary information recording / reproducing apparatus according to claim 1, wherein the magnet / yoke assembly is supported by the viscoelastic member on the housing in a damped manner. 3. A disc for recording information, a rotation driving means for rotationally driving the disc, a carriage for supporting a head for recording and reproducing information on the disc, and a positioning of the carriage in the radial direction of the disc. In order to achieve this, a carriage drive unit that applies a rotational torque to the carriage and a housing that is configured by a base and a cover that include the carriage drive unit are provided. The carriage drive unit includes a drive coil, a permanent magnet, and a yoke provided on the carriage. In the rotary information recording / reproducing apparatus including a magnet / yoke assembly made of, the magnet / yoke assembly is combined with and integrated with a yoke damping support member made of a viscoelastic member, and the integrated magnet / yoke assembly is , A base that is supported by damping so that it can be slightly displaced in the in-plane direction of the base. Rotary information recording and reproducing apparatus according to claim. 4. The rotary information recording / reproducing apparatus according to claim 3, wherein the yoke damping support member is connected to the housing. 5. The rotary information recording / reproducing apparatus according to claim 3, wherein the yoke damping support member has a structure in which a rotation limit stopper portion of the carriage is integrated.