Abstract:
A disk drive apparatus of the present invention, includes: a movable portion, a stationary portion disposed around the movable portion, and a damping portion disposed between the movable portion and the stationary portion, for connection therebetween, the movable portion, the stationary portion, and the damping portion being disposed substantially in a plane, wherein a head for performing at least one of recording or reproducing information with respect to a disk, a head drive portion for moving the head, and a rotation drive portion for driving a disk are provided on the movable portion.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a disk drive apparatus for performing at least one of recording information onto or reproducing information from a recording medium, for example, a disk. In particular, the present invention relates to a disk drive apparatus provided with a damping mechanism. 
     2. Description of the Related Art 
     FIG. 21 is a perspective exploded view showing a conventional damping mechanism in a disk drive apparatus. As shown in FIG. 21, a disk drive motor  1002  for driving a disk  1001  is fixed onto a base  1003 , and two guide axes  1005  are fixed onto the base  1003  so as to be parallel to each other. Furthermore, a recording/reproducing head  1004  for recording information onto or reproducing information from the disk  1001  is supported by the guide axes  1005  so as to move in a radial direction (represented by an arrow  1009 ) of the disk  1001 . The base  1003  is fixed onto a chassis  1008  via damping portions  1007  made of rubber resin disposed at four corners. The damping portions  1007  are fixed between the chassis  1008  and the base  1003  with screws (not shown) or the like. 
     The damping function in a conventional disk drive apparatus with the above-mentioned structure will be described. 
     The recording/reproducing head  1004  moves in the radial direction  1009  along the disk  1001  which rotates at a high speed, thereby recording information onto or reproducing information from the disk  1001 . At this time, the high-speed rotation of the disk  1001  and the high-speed movement of the recording/reproducing head  1004  in the radial direction  1009  cause mechanical vibrations. 
     Thus, in a disk drive apparatus requiring low noise and low vibrations, in order to prevent the above-mentioned mechanical vibrations from being propagated to outside the apparatus, attempts have been made to attenuate the mechanical vibrations by using the damping portions  1007 . 
     Attempts have also been made to attenuate the mechanical vibrations by using the damping portions  1007  for the purpose of enhancing vibration resistance and shock resistance of the disk drive apparatus, i.e., for the purpose of minimizing the propagation of the mechanical vibrations of the chassis  1008  (caused by shock and vibrations outside the apparatus) to the recording/reproducing head  1004 , and the like. 
     In a recording/reproducing apparatus for recording/reproducing information with respect to a hard disk, an optical disk, or the like, a higher density of information recorded on the disk, a larger amount of space of the disk, a higher data transfer speed involved in high-speed rotation of the disk, and a shorter access time are desired. Furthermore, recently, in order to adapt to a note-size personal computer, there has been a demand for a thinner disk drive apparatus with decreased power consumption and lower noise. 
     It is desired to substantially enhance tracking control precision of the recording/reproducing head, along with a higher density of information recorded on the disk and a higher capacity of the disk. However, by doing so, the mechanical vibrations caused by the high-speed rotation and high-speed access of the disk in the disk drive apparatus cause external disturbance vibrations, resulting in a decrease in tracking control precision. on the other hand, there has been a demand for a thinner disk drive apparatus with decreased power consumption and lower noise. 
     Therefore, in a disk drive apparatus, it is desired to provide a damping mechanism for efficiently suppressing internal vibrations and enhancing vibration resistance and shock resistance in a limited available space. 
     In the conventional damping mechanism shown in FIG. 21, the damping portions  1007  are fixed between the chassis  1008  and the base  1003  with screws (not shown) or the like. Therefore, it is difficult to render the disk drive apparatus thinner by incorporating such a conventional damping mechanism. Furthermore, the available space of the damping portions  1007  tends to be reduced, which makes it difficult to increase a design flexibility. Consequently, the effect of attenuating vibrations of the damping portions  1007  is degraded. 
     Furthermore, considering horizontal and vertical setting conditions of a disk drive apparatus, and that various conditions of the mechanical vibrations caused by the movement of the recording/reproducing head  1004  are concentrated in the radial direction  1009 , it is required to provide the vibration attenuating characteristics of the damping portions  1007  with anisotropy, by rendering an intrinsic vibration frequency of the damping portions  1007  in the radial direction  1009  different from that of the damping portions  1007  in a tangential direction (represented by an arrow  1014 ) orthogonal to the radial direction  1009 . However, in the case of using substantially spherical damping portions  1007  as shown in FIG. 21, it is difficult to realize anisotropy of the intrinsic vibration frequency between the radial direction  1009  and the tangential direction  1014 . Accordingly, a damping effect is not sufficient. 
     Furthermore, there is a limit to a space accommodating vibrations of the disk drive apparatus, so that the base  1003  should be disposed substantially horizontal. However, in general, the center of gravity of the base  1003  on which the disk drive motor  1002  and the recording/reproducing head  1004  are disposed is likely to be biased toward the disk drive motor  1002 . Therefore, in the conventional damping mechanism, the damping portions  1007  of which material or shape is varied depending upon the setting position, are disposed, whereby a horizontal posture of the base  1003  is realized. However, this increases the kinds of the damping portions  1007 . Furthermore, different kinds of damping portions  1007  may be mixed during assembly of the apparatus, which makes it necessary to classify them. 
     SUMMARY OF THE INVENTION 
     A disk drive apparatus of the present invention, includes: a movable portion, a stationary portion disposed around the movable portion, and a damping portion disposed between the movable portion and the stationary portion for connection therebetween, the movable portion, the stationary portion, and the damping portion being disposed substantially in a plane, wherein a head for performing at least one of recording or reproducing information with respect to a disk, a head drive portion for moving the head, and a rotation drive portion for driving a disk are provided on the movable portion. 
     In one embodiment of the present invention, the stationary portion is disposed so as to surround the movable portion, an annular gap in formed between the movable portion and the stationary portion, and the damping portion has an annular shape and is disposed in the annular gap. 
     In another embodiment of the present invention, the damping portion partially connects the movable portion to the stationary portion. 
     In another embodiment of the present invention, the damping portion includes a first damping portion connected to the movable portion, a second damping portion connected to the stationary portion, and an intermediate movable portion connecting the first damping portion to the second damping portion. 
     In another embodiment of the present invention, the damping portion is made of rubber resin or silicon resin. 
     In another embodiment of the present invention, the damping portion is made of a thermoplastic elastomer. 
     In another embodiment of the present invention, the movable portion and the stationary portion are made of synthetic resin such as ABS resin and PBT resin. 
     In another embodiment of the present invention, the intermediate movable portion is made of synthetic resin such as ABS resin or PBT resin. 
     In another embodiment of the present invention, the damping portion includes a plurality of portions having intrinsic vibration frequencies which are different from each other. 
     A disk drive apparatus of the present invention, includes: a plurality of movable portions disposed separately, a stationary portion having a plurality of openings surrounding the respective movable portions, and a plurality of damping portions which are disposed between the movable portions and inner peripheries of the openings and connect the movable portions to the inner peripheries of the openings, each of the movable portions, each of the openings of the stationary portion, and each of the damping portions being disposed substantially in a plane, wherein a base is connected to each of the movable portions, and a head for performing at least one of recording or reproducing information with respect to a disk, a head drive portion for moving the head, and a rotation drive portion for driving the disk are provided on the base. 
     In one embodiment of the present invention, an annular gap is formed between each of the movable portions and the inner periphery of each opening of the stationary portion, and each of the damping portions has an annular shape and is disposed in each of the annular gaps. 
     In another embodiment of the present invention, each of the damping portions partially connects each of the movable portions to the inner periphery of each of the openings of the stationary portion. 
     In another embodiment of the present invention, each of the damping portions includes a first damping portion connected to each of the movable portions, a second damping portion connected to the inner periphery of each of the openings of the stationary portion, and an intermediate movable portion for connecting the first damping portion to the second damping portion. 
     In another embodiment of the present invention, each of the damping portions is made of rubber resin or silicon resin. 
     In another embodiment of the present invention, each of the damping portions is made of a thermoplastic elastomer. 
     In another embodiment of the present invention, each of the movable portions and the stationary portion are made of synthetic resin such as ABS resin and PBT resin. 
     In another embodiment of the present invention, each of the intermediate movable portions is made of synthetic resin such as ABS resin and PBT resin. 
     In another embodiment of the present invention, each of the damping portions includes a plurality of portions having intrinsic vibration frequencies which are different from each other. 
     A disk drive apparatus of the present invention, includes: a movable portion, a stationary portion disposed around the movable portion, and a damping portion and a connecting portion which are disposed between the movable portion and the stationary portion for connection therebetween, the movable portion, the stationary portion, and the damping portion being disposed substantially in a plane, wherein a head for performing at least one of recording or reproducing information with respect to a disk, a head drive portion for moving the head in a predetermined direction, and a rotation drive portion for driving the disk are provided on the movable portion. 
     In one embodiment of the present invention, the connecting portion is disposed substantially in the plane together with the movable portion, the stationary portion, and the damping portion. 
     In another embodiment of the present invention, the connecting portion has a first intrinsic vibration frequency in a first direction and a second intrinsic vibration frequency in a second direction which is different from the first direction, wherein the first intrinsic vibration frequency is lower than the second intrinsic vibration frequency. 
     In another embodiment of the present invention, the first direction and the second direction are different from each other, and are either of a direction substantially parallel to the plans or a direction substantially orthogonal to the plane. 
     In another embodiment of the present invention, the first direction and the second direction are different from each other, and are either of a movement direction of the head, a thickness direction of the disk, or a direction substantially orthogonal to the movement direction of the head and the thickness direction of the disk. 
     In another embodiment of the present invention, the damping portion is made of thermosetting resin or thermoplastic resin. 
     In another embodiment of the present invention, the connecting portion includes a flat spring. 
     In another embodiment of the present invention, the connecting portion contains resin. 
     In another embodiment of the present invention, the connecting portion includes a first pivot portion which pivots with respect to the stationary portion, and a second pivot portion which pivots with respect to the movable portion. 
     In another embodiment of the present invention, the stationary portion, the movable portion, and the connecting portion are integrally formed with resin. 
     In another embodiment of the present invention, the connecting portion includes a first cross-sectional portion and a second cross-sectional portion, and the second cross-sectional portion is formed in such a manner that the first intrinsic vibration frequency is lower than the second intrinsic vibration frequency. 
     In another embodiment of the present invention, a cross-sectional area of the second cross-sectional portion is smaller than a cross-sectional area of the first cross-sectional portion. 
     In another embodiment of the present invention, the second cross-sectional portion is formed on both ends of the connecting portion. 
     In another embodiment of the present invention, the second cross-sectional portion is formed at a center of the connecting portion. 
     According to the structure of the present invention, a space in a height direction of a disk drive apparatus is sufficiently decreased, whereby the disk drive apparatus can be rendered planar. A design flexibility of a damping mechanism can be increased even in a thin disk drive apparatus. Furthermore, only by changing the thickness and width of the damping portion, an effect of attenuating vibrations with anisotropy can be realized. Even when a movable portion with a biased center of gravity is vibrated while being maintained horizontal, the space accommodating vibrations of the movable portion can be minimized without increasing the number of components of the damping portion. Thus, internal vibrations are efficiently suppressed, and vibration resistance and shook resistance can be sufficiently kept. 
     The disk drive apparatus of the present invention can sufficiently keep vibration resistance and shock resistance; therefore, it becomes possible to satisfactorily record/reproduce information with respect to a disk. 
     Thus, the invention described herein makes possible the advantage of: providing a disk drive apparatus which is capable of increasing a design flexibility of a damping mechanism in a thin disk drive apparatus, realizing an effect of attenuating vibrations with anisotropy, minimizing a space accommodating vibrations of a movable portion with a biased center of gravity without increasing the number of components in damping portions, and sufficiently keeping vibration resistance and shock resistance. 
     These and other advantages of the present invention will become apparent to those skilled in the art upon reading and understanding the following detailed description with reference to the accompanying figures. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1A is a perspective view of Embodiment 1 of a disk drive apparatus according to the present invention. 
     FIG. 1B is a cross-sectional view of the disk drive apparatus in FIG.  1 A. 
     FIG. 2A in a perspective view of Embodiment 2 of a disk drive apparatus according to the present invention. 
     FIG. 2B is a cross-sectional view of the disk drive apparatus in FIG.  2 A. 
     FIG. 3 is a perspective view of Embodiment 3 of a disk drive apparatus according to the present invention. 
     FIG. 4 is a perspective view of Embodiment 4 of a disk drive apparatus according to the present invention. 
     FIG. 5A is a graph showing intrinsic vibration frequency characteristics of a damping portion. 
     FIG. 5B is a graph showing other intrinsic vibration frequency characteristics of a damping portion. 
     FIG. 6 is a perspective view of Embodiment 5 of a disk drive apparatus according to the present invention. 
     FIG. 7 is a perspective view of Embodiment 6 of a disk drive apparatus according to the present invention. 
     FIG. 8A is a perspective view of Embodiment 7 of an entire disk drive apparatus after assembly according to the present invention. 
     FIG. 8B is a perspective view of a chassis in the disk drive apparatus in FIG.  8 A. 
     FIG. 9A is a perspective view of Embodiment 8 of an entire disk drive apparatus after assembly according to the present invention. 
     FIG. 9B is a perspective view of a chassis in the disk drive apparatus in FIG.  9 A. 
     FIG. 10 is a perspective view of Embodiment 9 of a disk drive apparatus according to the present invention. 
     FIG. 11 is a plan view of Embodiment 10 of a disk drive apparatus according to the present invention. 
     FIG. 12 illustrates the steps of producing a stationary portion, a damping portion, and a movable portion in the disk drive apparatus in FIG.  11 . 
     FIG. 13 is a perspective view of Embodiment 11 of a disk drive apparatus according to the present invention. 
     FIG. 14 is a perspective view of Embodiment 12 of a disk drive apparatus according to the present invention. 
     FIG. 15 is a perspective view of Embodiment 13 of a disk drive apparatus according to the present invention. 
     FIG. 16A is a perspective view of Embodiment 14 of a disk drive apparatus according to the present invention. 
     FIG. 16B in a plan view showing main portions of the disk drive apparatus in FIG.  16 A. 
     FIG. 17 is a perspective view showing a modified example of the disk drive apparatus in FIG.  16 A. 
     FIG. 18 is a perspective view of Embodiment 15 of a disk drive apparatus according to the present invention. 
     FIG. 19 is a perspective view of Embodiment 16 of a disk drive apparatus according to the present invention. 
     FIG. 20 is a perspective view of Embodiment 17 of a disk drive apparatus according to the present invention. 
     FIG. 21 is a perspective exploded view of a damping mechanism in a conventional disk drive apparatus. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, the present invention will be described by way of illustrative embodiments with reference to the drawing. 
     Embodiment 1 
     FIG. 1A is a perspective view of Embodiment 1 of a disk drive apparatus  10  of the present invention. FIG. 1B is a cross-sectional view thereof. 
     Referring to FIGS. 1A and 1B, a disk drive motor  2  is fixed onto a base  3 , and two guide axes  5   a  and  5   b  are fixed onto the bass  3 . A recording/reproducing head  4  is supported by the guide axes  5   a  and  5   b  so as to move in a radial direction  9  of a disk  1 . The guide axis  5   b  is a screw, with which an and portion of the recording/reproducing head  4  is engaged. The recording/reproducing head  4  is moved by allowing the guide axis  5   b  to pivot by a movement drive portion  17 . 
     The bottom of the base  3  in fixed onto a movable portion  6  having a plate shape in plans, made of synthetic resin such as ABS resin and PBT resin. An annular damping portion  7  having a rectangular shape in plane, made of rubber resin or silicon resin is fixed around an outer periphery of the movable portion  6 . Furthermore, an annular chassis  8  having a rectangular shape in plans, made of synthetic resin is fixed around an outer periphery of the damping portion  7 . The chassis a in fixed onto an apparatus body, and the movable portion  6  is movable with respect to the chassis  8  via the damping portion  7 . 
     The movable portion  6 , the damping portion  7 , and the chassis  8  can be integrally molded with resin, and at least a part of the inner and outer peripheries should be fixed to each other. The movable portion  6 , the damping portion  7 , and the chassis  8  should be fixed to each other by appropriately selecting a method in accordance with the material of each portion. The movable portion  6 , the damping portion  7 , and the chassis  8  may be mechanically engaged with each other or may be fixed to each other with an adhesive. The base  3  and the movable portion  6  may be formed of the same material. 
     The damping function of Embodiment 1 of the disk drive apparatus as constructed above will be described. 
     The recording/reproducing head  4  for recording/reproducing information with respect to the disk  1  which is rotated at a high speed is moved at a high speed in the radial direction  9  by the movement drive portion  17 , thereby recording/reproducing information with respect to the disk  1 . At this time, the high-speed rotation of the disk  1  and the high-speed movement of the recording/reproducing head  4  in the radial direction  9  cause mechanical vibrations. 
     Therefore, the mechanical vibrations are attenuated by the damping portion  7  so as to minimize the propagation of the mechanical vibrations in the apparatus to outside the apparatus. Furthermore, in order to minimize the propagation of the mechanical vibrations of the chassis  8  caused by shock and vibrations outside the apparatus to inside the apparatus, the mechanical vibrations are attenuated by the damping portion  7 . 
     The above-mentioned damping function is similar to that of a conventional damping mechanism. However, the damping portion  7  substantially in an annular shape, the movable portion  6 , and the chassis  8  are integrated so as to be planar so that the disk drive apparatus can be rendered thin, and a design flexibility of the damping portion  7  can be increased. 
     Embodiment 2 
     FIG. 2A is a perspective view of Embodiment 2 of a disk drive apparatus  20  according to the present invention. FIG. 2B is a cross-sectional view thereof. 
     The disk drive apparatus  20  in Embodiment 2 is different from that in Embodiment 1, in that a movable portion is composed of a first movable portion  16  and a second movable portion  13 , and a damping portion is composed of a first damping portion  11  and a second damping portion  12 . More specifically, the first damping portion  11  substantially in an annular shape is fixed around an outer periphery of the first movable portion  16  corresponding to the movable portion  6  in Embodiment 1, and the second movable portion  13  substantially in an annular shape is fixed around an outer periphery of the first damping portion  11 . Furthermore, the second damping portion  12  substantially in an annular shape is fixed around an outer periphery of the second movable portion  13 , and a chassis  8 A is fixed around an outer periphery of the second damping portion  12 . 
     The first movable portion  16 , the first damping portion  11 , the second movable portion  13 , and the second damping portion  12 . and the chassis  8 A are integrally molded with resin and formed so as to be planar. 
     The basic damping function of Embodiment 2 of the disk drive apparatus is substantially the same as that in Embodiment 1 except for the following. In Embodiment 2, the mechanical vibrations generated inside the disk drive apparatus are attenuated by the combination of the first damping portion  11  and the second damping portion  12 . 
     Furthermore, the shape of the first damping portion  11  is rendered different from that of the second damping portion  12  so as to obtain different intrinsic vibration frequencies. Thus, the mechanical vibrations can be attenuated by being dispersed to those with different frequencies. Furthermore, by rendering the shape of the first damping portion  11  different from that of the second damping portion  12 , the disk drive apparatus can be made thinner. 
     Embodiment 3 
     FIG. 3 is a perspective view of Embodiment 3 of a disk drive apparatus  30  according to the present invention. 
     The disk drive apparatus  30  in Embodiment 3 is different from that in Embodiment 2 in that a bass  3 A has only a recording/reproducing head  4 , guide axes  5   a  and  5   b , a movement drive portion  17 , and a disk drive motor  2  is disposed on a second movable portion  13 A. 
     Due to the above-mentioned structure in Embodiment 3, the mechanical vibrations of the disk drive motor  2  are generated in the second movable portion  13 A, and the mechanical vibrations caused by the movement of the recording/reproducing head  4  are generated in the first movable portion  16 A. 
     As described above, the mechanical vibrations are allowed to be generated separately in the first movable portion  16 A and the second movable portion  13 A, whereby the mechanical vibrations with respective frequencies can be attenuated by a first damping portion  11 A and a second damping portion  12 . Thus, the mechanical vibrations in the disk drive apparatus can be dispersed and efficiently attenuated by the combination of the first damping portion  11 A and the second damping portion  12 . 
     Embodiment 4 
     FIG. 4 is a perspective view of Embodiment 4 of a disk drive apparatus  40  according to the present invention. 
     The basic structure in Embodiment 4 is substantially the same as that in Embodiment 1 except that a cross-sectional shape (size and thickness) of a damping portion  7 A substantially in an annular shape is rendered different between the respective directions. More specifically, a size t 1  of the damping portion  7 A in a radial direction  9  of a disk  1  is rendered different from a size t 2  of the damping portion  7 A in a tangential direction  14 . 
     In Embodiment 4, the size t 1  in the radial direction  9  of the disk  1  is prescribed to be longer than the size t 2  (t 1 &gt;t 2 ) in the tangential direction  14 . The basic damping function of such a damping mechanism is substantially the same an that in Embodiment 1 except for the following. In Embodiment 4, considering the directivity of the mechanical vibrations generated inside the disk drive apparatus, the intrinsic vibration frequency of the damping portion  7 A in the radial direction  9  of the disk  1  and the intrinsic vibration frequency of the damping portion  7 A in the tangential direction  14  can be controlled by adjusting the sizes t 1  and t 2  of the damping portion  7 A. 
     In Embodiment 4, the longitudinal and transverse sizes of the damping portion  7 A may be adjusted. However, the intrinsic vibration frequency in a thickness direction (focus direction) of the disk  1  may be controlled by adjusting the thickness of the damping portion  7 A. 
     FIGS. 5A and 5B are graphs showing intrinsic vibration frequency characteristics of the damping portion  7 A. FIG. 5A shows the intrinsic vibration frequency characteristics of the damping portion  7 A in the tangential direction (tracking direction)  14 , and FIG. 5B shows the intrinsic vibration frequency characteristics of the damping portion  7 A in the thickness direction (focus direction) of the disk  1 . Mechanical vibration frequencies are different between the tracking direction and the focus direction. Therefore, if damping portions having the intrinsic vibration frequency characteristics in each direction are provided in accordance with the respective mechanical vibration frequencies, the mechanical vibrations can be effectively suppressed. 
     Embodiment 5 
     FIG. 6 is a perspective view of Embodiment 5 of a disk drive apparatus  50  according to the present invention. 
     The disk drive apparatus  50  in Embodiment 5 has substantially the same structure as that in Embodiment 2, except that each width of a first damping portion  11 B and a second damping portion  12 B both substantially in an annular shape are rendered different between the longitudinal direction and the transverse direction. More specifically, a size t 1  of the first damping portion  11 B in the radial direction  9  of a disk  1  is rendered different from a size t 2  of the first damping portion  11 B in a tangential direction  14  (t 1 &gt;t 2 ). Furthermore, a size t 3  of the second damping portion  12 B in the radial direction  9  of the disk  1  is rendered different from a size t 4  of the second damping portion  12 B in the tangential direction  14  (t 4 &gt;t 3 ). 
     The basic damping function of the disk drive apparatus  50  in Embodiment 5 is substantially the same as that in Embodiment 4 except for the following. In Embodiment 5, considering the directivity of the mechanical vibrations generated inside the disk drive apparatus  50 , the intrinsic vibration frequency of the first damping portion  11 B in the radial direction  9  of the disk  1  and the intrinsic vibration frequency of the first damping portion  11 B in the tangential direction  14  can be controlled by adjusting the sizes t 1  and t 2  of the first damping portion  11 B. In addition, considering the directivity of the mechanical vibrations applied to a chassis  8 A as external disturbance vibrations from outside the disk drive apparatus  50 , the intrinsic vibration frequency of the second damping portion  12 B in the radial direction  9  of the disk  1  and the intrinsic vibration frequency of the second damping portion  12 B in the tangential direction  14  can be controlled by adjusting the sizes t 3  and t 4  of the second damping portion  12 B. 
     More specifically, due to the above-mentioned structure in Embodiment 5, the propagation of the mechanical vibrations with bi-directivity (i.e., internal vibrations and external disturbance vibrations) in the disk drive apparatus  50  can be efficiently attenuated. 
     Embodiment 6 
     FIG. 7 is a perspective view of Embodiment 6 of a disk drive apparatus  60  according to the present invention. 
     The basic structure in Embodiment 7 is substantially the same as that in Embodiment 1, except that a part of a damping portion  7 B substantially in an annular shape is omitted to provide gaps  15 . 
     The basic damping function of the disk drive apparatus  60  in Embodiment 6 is substantially the same as that in Embodiment 1, except that a design flexibility for setting the intrinsic vibration frequency of the damping portion  7 B is remarkably enlarged. In Embodiment 6, each part of four sizes of the damping portion  7 B is omitted, which is effective for setting the intrinsic vibration frequency of the damping portion  7 B particularly at about 100 Hz or less. 
     Embodiment 7 
     FIGS. 8A and 8B are perspective views of Embodiment 7 of a disk drive apparatus  70  according to the present invention. FIG. 8A is a perspective view of the entire disk drive apparatus  70  after assembly, and FIG. 8B is a perspective view of a chassis. 
     The basic structure of a base  3  in Embodiment 7 is substantially the same as that in Embodiment 1, except that a plurality of stationary cylinders  46  are provided on the base  3  (in Embodiment 7, each corner of the base  3  has a stationary cylinder  46 ), and a damping mechanism is provided to each stationary cylinder  46 . More specifically, each stationary cylinder  46  is fixed on a disk-shaped movable portion  36 , and a damping portion  37  substantially in an annular shape is fixed around an outer periphery of each movable portion  36 . Furthermore, the outer periphery of each damping portion  37  is fixed into each stationary hole  38   a  provided in a chassis  38 . 
     The basic damping function of the disk drive apparatus  70  in Embodiment 7 is substantially the same as that in Embodiment 1, except that a planar available space of the damping portions  37  in the disk drive apparatus  70  is limited, which is effective in the case where the curvature of the damping portion  37  substantially in an annular shape cannot be increased. 
     Furthermore, a plurality of damping portions  37  substantially in an annular shape may be provided with different diameters and thicknesses, whereby the intrinsic vibration frequency of each damping portion  37  can be arbitrarily set. As a result, even when the center of gravity of the base  3  is biased toward the disk drive motor  2 , a space accommodating vibrations of the base  3  maintained in a horizontal posture can be equally disposed and minimized, which is suitable for rendering the disk drive apparatus  70  thinner. 
     Embodiment 8 
     FIGS. 9A and 9B are perspective views of Embodiment 8 of a disk drive apparatus  80  according to the present invention. FIG. 9A is a perspective view showing the entire disk drive apparatus  80  after assembly, and FIG. 9B is a perspective view of a chassis. 
     The basic structure of the disk drive apparatus  80  in Embodiment 8 is substantially the same as that in Embodiment 7, except that a damping portion includes a first damping portion  41  and a second damping portion  42 . More specifically, a stationary cylinder  46  is fixed on each first movable portion  39  in a disk shape, and a first damping portion  41 , a second movable portion  43 , and a second damping portion  42  are successively provided around an outer periphery of the first movable portion  39 . The outer periphery of the second damping portion  42  is fixed into each stationary hole  38   a  provided in a chassis  38 . 
     The basic damping function of the disk drive apparatus  80  in Embodiment 8 is substantially the same as that in Embodiment 7 except for the following. In embodiment 8, the shapes of the first damping portion  41  and the second damping portion  42  are rendered different for each stationary cylinder  46  so as to obtain different intrinsic vibration frequencies, whereby the internal vibrations in the disk drive apparatus  80  can be attenuated by being dispersed in frequency regions. 
     Embodiment 9 
     FIG. 10 is a perspective view of Embodiment 9 of a disk drive apparatus  90  according to the present invention. 
     The basic structure of the disk drive apparatus  90  in Embodiment 9 is substantially the same as those in Embodiments 1 and 4, except that sizes t 5  and t 6  of a damping portion  57  substantially in an annular shape provided around an outer periphery of a disk-shaped movable portion  56  are partially rendered different. More specifically, the size t 5  of the damping portion  57  on a disk drive motor  2  side is rendered different from the size t 6  on a recording/reproducing head  4  (t 6 &gt;t 5 ) in a radial direction  9  of a disk  1 . 
     The basic damping function of the damping mechanism in Embodiment 9 in substantially the same as that in Embodiment 7. As a result, even when the center of gravity of the base  3  is biased toward the disk drive motor  2 , a space accommodating vibrations of the base  3  maintained in a horizontal posture can be equally disposed and minimized. 
     Embodiment 10 
     FIG. 11 is a plan view of Embodiment 10 of a disk drive apparatus  100  according to the present invention. 
     As shown in FIG. 11, a disk drive motor  62  in fixed onto a base  63 , and two guide axes  65   a  and  65   b  are fixed onto the base  63 . A recording/reproducing head  64  is supported by the guide axes  65   a  and  65   b  so as to move in a radial direction  69  of a disk. The guide axis  65   b  is a screw with which the recording/reproducing head  64  is engaged. The recording/reproducing head  64  is moved by allowing the guide axis  65   b  to pivot by a movement drive portion  77 . 
     The bottom of the bass  63  is fixed onto a movable portion  66  having a plate shape in plane, made of synthetic resin such as ABS resin and PBT resin. An annular chassis  68  having a rectangular shape in plane, made of synthetic resin is fixed outside the movable portion  66 . An annular gap is formed between the movable portion  66  and the chassis  68 , and three damping portions  67  made of resin are disposed in the gap. Each damping portion  67  has a plurality of branch portions  67   a  on both sides thereof. The branch portions  67   a  of each damping portion  67  enter the movable portion  66  and the chassis  68 , whereby the movable portion  66  is connected to the chassis  68 . 
     The movable portion  66  and the damping portion  67  may be integrated with mold, and at least a part of the inner and outer peripheries thereof should be fixed to each other. 
     Due to the above-mentioned structure, the recording/reproducing head  64  for recording or reproducing information with respect to the disk which is rotated at a high speed is moved in the radial direction  69  of the disk at a high speed by the movement drive portion  77 , thereby recording/reproducing information with respect to the disk at a high speed. At this time, the high-speed rotation of the disk and the high-speed movement of the recording/reproducing head  64  in the radial direction  69  of the disk cause mechanical vibrations. 
     Thus, in order to minimize the propagation of the above-mentioned mechanical vibrations generated inside the apparatus to outside the apparatus, the mechanical vibrations are attenuated by the damping portion  67 . Furthermore, in order to minimize the propagation of the mechanical vibrations of the chassis  68  caused by shock and vibrations outside the apparatus to inside the apparatus, the mechanical vibrations are attenuated by the damping portion  67 . 
     The damping function in Embodiment 10 is substantially the same as that in a conventional damping mechanism. However, the damping portion  67 , the movable portion  66 , and the chassis  68  are integrated so as to be planar; therefore, the disk drive apparatus can be rendered thinner, and a design flexibility of the damping portion  67  can be increased. 
     FIG. 12 shows a method for producing the stationary portion, the damping portion, and the movable portion in the apparatus shown in FIG.  11 . 
     The method shown in FIG. 12 is a molding method called a core rotation system using a first mold  71  and a second mold  72 . In the first step, the first mold  71  is combined with the second mold  72 , whereby a space for molding the movable portion  66  and the chassis  68  is formed in the first mold  71  and the second mold  72 . In this state, molten synthetic resin is injected into the first mold  71  and the second mold  72  through a first nozzle  73 , whereby the movable portion  66  and the chassis  68  are molded. 
     Thereafter, the second mold  72  is moved in the left direction to remove the second mold  72  from the first mold  71 . Furthermore, after the second mold  72  is rotated by 180°, the second mold  72  is moved in the right direction, whereby the first mold  71  is combined with the second mold  72 . Thus, a space for molding the damping portion  67  is formed in the first mold  71  and the second mold  72 . In this state, molten synthetic resin is injected into the first mold  71  and the second mold  72  through a second nozzle  74 , whereby the damping portion  67  is molded. 
     Finally, the second mold  72  is removed from the first mold  71 , and the integrated molding of the movable portion  66 , the chassis  68 , and the damping portion  67  are taken out. 
     Embodiment 11 
     FIG. 13 is a perspective view of Embodiment 11 of a disk drive apparatus  200  according to the present invention. 
     As shown in FIG. 13, a disk drive motor  102  is fixed onto a base  103 . A recording/reproducing head  104  is supported by two guide axes  105   a  and  105   b  fixed on the base  103  so as to move in a head movement direction  109 . 
     The guide axis  105   b  is provided with a screw, for example, with which the recording/reproducing head  104  is engaged, and a movement drive portion  119  is disposed at an end portion of the guide axis  105   b . The bottom or side of the base  103  is fixed to a movable portion  106  having a plate shape in plans, made of synthetic resin such as ABS resin and PBT resin. 
     The movable portion  106  is attached to a chassis  108  via a connecting portion  120  of a flat spring made of metal such as phosphor bronze. In order to prescribe the intrinsic vibration frequency of the connecting portion  120  in the head movement direction  109  to be lower than the intrinsic vibration frequency of the connecting portion  120  in a tangential direction  111  orthogonal to the head movement direction  109  and a disk thickness direction  110 , and to be lower than the intrinsic vibration frequency of the connecting portion  120  in the disk thickness direction  110 , the connecting portion  120  is attached to the movable portion  106  and the chassis  108  so as to bend in the head movement direction  109 . The connecting portion  120  is fixed to the movable portion  106  and the chassis  108  by fastening portions  121  such as screws. 
     A damping portion  107  in a plate shape, made of thermosetting resin such as rubber resin or thermoplastic resin such as elastomer resin is fixed to each outer side surface  106   a  of the movable portion  106 . 
     Each outer side of the damping portion  107  is fixed to a side surface  108   a  of the annular chassis  108  having a rectangular shape in plane, made of synthetic resin. The chassis  108  is fixed to a body (not shown) of the disk drive apparatus  200 . The movable portion  106  becomes movable with respect to the chassis  108  via the damping portion  107  and the connecting portion  120 . 
     The movable portion  106 , the damping portion  107 , and the chassis  108  are integrally molded by the same production steps as those in FIG.  12 . At least a part of the inner and outer peripheries of the movable portion  106 , the damping portion  107 , and the chassis  108  should be connected to each other. 
     The case where the movable portion  106 , the damping portion  107 , and the chassis  108  are integrally molded with resin has been described. However, the present invention is not limited thereto. The movable portion  106 , the damping portion  107 , and the chassis  108  may be mechanically engaged with each other, or may be bonded to each other with an adhesive. A fixing method should be appropriately selected in accordance with the material of each portion. Furthermore, the movable portion  106  may be formed of a part of the base  103  and the movable portion  106 . 
     The damping function of the disk drive apparatus  200  in Embodiment 11 thus constructed will be described. 
     A recording/reproducing head  104  for recording/reproducing information with respect to a disk  101  which is rotated at a high speed is moved at a high speed in a head movement direction  109  by the movement drive portion  119 , thereby recording or reproducing information with respect to the disk  101 . 
     At this time, the high-speed rotation of the disk  101  and the high-speed movement of the recording/reproducing head  104  in the head movement direction  109  cause mechanical vibrations. The connecting portion  120  is attached to the movable portion  106  and the chassis  108  so as to band in the head movement direction  109 . Therefore, the movable portion  106  is vibrated in the head movement direction  109  by the generated mechanical vibrations. In order to minimize the propagation of the mechanical vibrations generated inside the apparatus to outside the apparatus, the mechanical vibrations are attenuated by the damping portion  107 . 
     According to the damping function, the above-mentioned damping effect in obtained. In addition, since the stiffness of the damping mechanism in the disk thickness direction  110  is enhanced by the connecting portion  120 , the movable portion  106  becomes unlikely to sink due to its weight. Therefore, the available space for the damping mechanism can be decreased. 
     The movable portion  106  is attached to the chassis  108  via the connecting portion  120 . Therefore, the movable portion  106  will not bump into the chassis  108  to be damaged due to shock in the limited available space. 
     Furthermore, even at a time of shock or load, the amount of movement in the movable portion  106  in suppressed by the connecting portion  120 , so that the damping portion  107  is not detached from the movable portion  106  or the chassis  108 , whereby high endurance can be kept. 
     In Embodiment 11, the case where the connecting portion  120  of a flat spring made of metal has been described. However, the present invention in not limited thereto. Even when the connecting portion  120  is a flat spring made of plastic, the same effect can be obtained. 
     Furthermore, in Embodiment 11, the case where the fastening portion  121  is used for fastening the connecting portion  120  has been described. However, the present invention is not limited thereto. The connecting portion  120 , the movable portion  106 , and the chassis  108  may be integrated with resin. In this case, a small number of components suffices, resulting in a low production cost. 
     Embodiment 12 
     FIG. 14 is a perspective view of Embodiment 12 of a disk drive apparatus  300  according to the present invention. 
     The structure of the disk drive apparatus  300  in Embodiment 12 is different from that in Embodiment 11, in that a pivot portion is provided at a part of each connecting portion  320 , which pivots with respect to a movable portion  306  and a stationary portion  308 . The connecting portion  320  has pivot axes  320   a  and  320   b  having axes substantially in the same direction as a disk thickness direction  110 . The pivot axis  320   a  is pivotally supported in a pivot hole  306   a  provided in the movable portion  306 , and the pivot axis  320   b  is pivotally supported in a pivot hole  308   b  provided in the chassis  308 . 
     The basic operation of the above-mentioned damping mechanism is substantially the same as that in Embodiment 11 except for the following. In Embodiment 12, a movement load of the movable portion  306  in a head movement direction  109  is reduced by the connecting portion  320  so that the movable portion  306  becomes likely to vibrate in the head movement direction  109 . Since the movable portion  306  becomes likely to vibrate in the head movement direction  109 , the mechanical vibrations inside the disk drive apparatus  300  can be efficiently attenuated by a damping portion  107  via the movable portion  306 . 
     In Embodiment 12, the connecting portion  320  has pivot axes. Even when the connecting portion  320  is provided with pivot holes, and pivot axes are provided in the movable portion  306  and the chassis  308 , the same effect can be obtained. 
     Embodiment 13 
     FIG. 15 in a perspective view of Embodiment 13 of a disk drive apparatus  400  according to the present invention. 
     The disk drive apparatus  400  in Embodiment 13 is different from that in Embodiment 11 in that a chassis  408  is integrated with a movable portion  422  and a connecting portion  423 . Due to this structure, the connecting portion  423  bends in a direction represented by an arrow  109  as a flat spring made of resin. Therefore, the movable portion  422  vibrates in a head movement direction  109  due to mechanical vibrations generated by the high-speed rotation of a disk  101  and the high-speed movement of a recording/reproducing head  104 . The vibrations of the movable portion  422  in the head movement direction  109  are attenuated by a damping portion  107 . Therefore, in addition to the effect of Embodiment 11, the number of components can be largely reduced. Needless to say, this is suitable for rendering the disk drive apparatus  400  thinner. 
     Embodiment 14 
     FIG. 16A is a perspective view of Embodiment 14 of a disk drive apparatus  500  according to the present invention. FIG. 16B is a plan view showing main portions of the disk drive apparatus  500  in Embodiment 14. 
     The structure of the disk drive apparatus  500  in Embodiment 14 is different from that in Embodiment 13 in that both ends of a connecting portion  523  are provided with hinge portions  523   a . More specifically, the thickness of the connecting portion  523  is rendered thinner at its ends. 
     The basic operation of the disk drive apparatus  500  is substantially the same as that in Embodiment 3 except for the following. In Embodiment 14, since a movement load of a movable portion  522  in a head movement direction  109  is small, the movable portion  522  largely vibrates in the head movement direction  109 , which allows a damping portion  107  to have a larger effect of attenuating vibrations. 
     In Embodiment 14, the damping portions  107  are provided at parts of the movable portion  522  and the chassis  508 . However, as in a disk drive apparatus  600  shown in FIG. 17, damping portions  107   a  and  107   b  may be provided in the entire surfaces where the movable portion  522  are opposed to the chassis  508 . In this case, an opening is blocked in a disk thickness direction  110 , which prevents dust and dirt from passing therethrough. Thus, it is possible to perform a dust-proofing design. More specifically, a disk drive apparatus can be provided, which is stably operated even in a bad environment exposed to a lot of dust and dirt. 
     Embodiment 15 
     FIG. 18 is a perspective view of Embodiment 15 of a disk drive apparatus  700  according to the present invention. 
     The basic structure of the disk drive apparatus  700  in Embodiment 15 is substantially the same as that in Embodiment 13 except that a cut-away portion  723   b  is provided in each connecting portion  723 . More specifically, the cut-away portion  723   b  is provided in such a manner that the thickness of the connecting portion  723  in a disk thickness direction  109  becomes partially thinner. 
     The basic operation of the disk drive apparatus  700  is substantially the same as that in Embodiment 13 except for the following. In Embodiment 15, due to the cut-away portion  723   b , a movable portion  722  can vibrate in a disk thickness direction  110 , and the mechanical vibrations generated in the disk thickness direction  110  can be attenuated by damping portions  107 . 
     Because of the above-mentioned structure, the directivity of the intrinsic vibration frequency of the movable portion  722  is rendered different, whereby the mechanical vibrations can be attenuated by being dispersed in frequency regions. 
     Embodiment 16 
     FIG. 19 is a perspective view of Embodiment 16 of a disk drive apparatus  800  according to the present invention. 
     The basic structure of the disk drive apparatus  800  in Embodiment 16 is substantially the same as that in Embodiment 11 except for the following. In Embodiment 16, the intrinsic vibration frequency in a tangential direction  111  among the intrinsic vibration frequency of a connecting portion  820  is prescribed to be lower than those in a head movement direction  109  and a disk thickness direction  110 . More specifically, the thickness of the connecting portion  820  in the tangential direction  111  is designed so as to be smaller. The connecting portion  820  functions so as to bend in the tangential direction  111  as a flat spring. 
     The basic operation of the disk drive apparatus  800  is substantially the same as that in Embodiment 11, except that the connecting portion  820  largely vibrates in the tangential direction  111 . This is because the connecting portion  820  functions so as to bend in the tangential direction  111 . 
     The above-mentioned structure is particularly effective in the case where the bias of the center of gravity of a disk  101  is large. The vibrations generated by the rotation of a disk  101  are directed in the tangential direction  111  so as to be orthogonal to the movement direction (represented by an arrow  109 ) of a recording/reproducing head  104 . Thus, the vibrations by the rotation of the disk  101  are prevented from being overlapped with the vibrations by the high-speed movement of the recording/reproducing head  104 , whereby a stable recording or reproducing operation may be realized. 
     Embodiment 17 
     FIG. 20 is a perspective view of Embodiment 17 of a disk drive apparatus  900  according to the present invention. 
     The basic structure of the disk drive apparatus  900  in Embodiment 17 is substantially the same as that in Embodiment 11 except for the following. In Embodiment 17, the intrinsic vibration frequency in a direction (represented by an arrow  111 ) in which gravity is applied among the intrinsic vibration frequency of a connecting portion  120  is prescribed to be higher than those in directions (represented by arrows  109  and  110 ) orthogonal to the gravity direction. 
     The basic operation of the disk drive apparatus  900  is substantially the same as that in Embodiment 11, except that the movement amount (i.e., weight sinking) of the movable portion  106  with respect to the gravity direction  111  is suppressed. The available space of a damping mechanism in the disk drive apparatus  900  can be effectively utilized, so that a thin disk drive apparatus can be provided. 
     As described above, the present invention has a structure in which a damping portion is fixed around a movable portion having a disk drive motor (which is a source for vibrating a disk drive apparatus) and a recording/reproducing head, and a chassis is fixed around an outer periphery of the damping portion. Therefore, even in a thin disk drive apparatus, a design flexibility of the damping portion can be increased. As a result, a thin disk drive apparatus with low vibrations and low noise can be realized, in which the mechanical vibrations generated inside the disk drive apparatus can be efficiently attenuated. 
     Furthermore, by providing two damping portions having different intrinsic vibration frequencies around the movable portion, the mechanical vibrations generated inside the disk drive apparatus can be attenuated by being dispersed in different frequencies. 
     Furthermore, a damping portion for supporting a disk drive motor and a damping portion for supporting a recording/reproducing head may be independently provided. Therefore, a propagation path for the mechanical vibrations of the disk drive apparatus is divided, whereby the vibrations with a particular mechanical vibration frequency can be attenuated. 
     Furthermore, by prescribing the cross-sectional shape (size and thickness) of a damping portion to be different in different directions, the mechanical vibrations generated inside the disk drive apparatus can be attenuated by considering the directivity of the vibrations. 
     Furthermore, due to the structure in which two damping portions have different cross-sectional shapes in different directions, the effect of attenuating the bi-directional mechanical vibrations (i.e., internal vibrations and external disturbance vibrations) of the disk drive apparatus may be enhanced. 
     Furthermore, since a movable portion is connected to a chassis at a plurality of positions by a plurality of damping portions, the intrinsic vibration frequency of the damping portions can be set at about 100 Hz or less. 
     Furthermore, by supporting a base by a plurality of damping portions with different sizes, even in the case where the center of gravity of the bass is biased, the space for accommodating vibrations of the base can be equally disposed and minimized under the condition that the base is maintained in a horizontal posture. Thus, a thin disk drive apparatus can be realized. 
     Furthermore, according to the present invention, by connecting a movable portion to a stationary portion via a flat spring, the movable portion is prevented from sinking due to its weight even in a thin disk drive apparatus, and the movable portion is prevented from bumping into a chassis due to shock. Furthermore, a damping portion is not detached by the application of a load, and the mechanical vibrations generated inside the disk drive apparatus are efficiently attenuated. Thus, a thin disk drive apparatus with low vibrations, low noise, and high endurance can be realized. 
     Furthermore, by using a connecting portion having a rotary portion in place of a flat spring, the mechanical vibrations can be effectively attenuated while suppressing sink due to weight. 
     Furthermore, by integrating a stationary portion, a movable portion, and a connecting portion, the number of components may be reduced. The mechanical vibrations can be efficiently attenuated by prescribing both ends of the connecting portion to be in a hinge shape. 
     Furthermore, by allowing the cross-sectional shape of the connecting portion to have difference in different directions, the intrinsic vibration frequency of the connecting portion in rendered different in a plurality of directions, and the vibration characteristics of the movable portion are provided with anisotropy. Thus, considering the directivity of the mechanical vibrations generated inside the disk drive apparatus, the vibrations can be attenuated. 
     In the disk drive apparatus of the present invention, vibration resistance and shock resistance can be sufficiently kept, so that information can be satisfactorily recorded onto or reproduced from a disk. 
     Various other modifications will be apparent to and can be readily made by those skilled in the art without departing from the scope and spirit of this invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the description as set forth herein, but rather that the claims be broadly construed.