Abstract:
A disk drive device includes a protective case having an upper case and a lower case. The disk drive device has a form such that the disk drive device can be inserted into and removed from a PCMCIA port of a computer. The disk drive device has an output connector located at one end of the protective case so that the input/output connector can connect with a PCMCIA connector of the computer when the disk drive device is inserted in the PCMCIA port. Information from the computer can thus be stored on the disk drive device, or information from the disk drive device can be read into the computer.

Description:
This application claims the benefit of Provisional application No. 60/106,352, filed Oct. 30, 1998. 
    
    
     BACKGROUND OF THE INVENTION 
     This Application is a 371 of PCT/US99/05821 filed Mar. 18, 1999, which claims priority to Provisional Application No. 60/106,352 filed Oct. 30, 1998. 
     This invention is directed to a disk drive device; more specifically, it is directed to a disk drive device which has the characteristic that data can be sent and received to and from a computer through a PCMCIA port. 
     Various types of disk drive devices that read and write information on a rotating disk medium have been developed and used for some time as computer data storage devices. Widely used magnetic disk drive devices are generally available in two broad categories—removable and fixed. In particular, removable cartridge disk drives read and write information magnetically on a disk that is enclosed in a removable protective case. By contrast, fixed disk drives read and write information magnetically on a fixed disk that is permanently fixed in the data storage device. 
     Fixed disk drives are used as the principal data storage devices of computers, since they typically have data transmission speeds and storage capacities that are several orders of magnitude greater than removable disk drives. Obviously however, fixed disk drives have the drawback, as compared with removable disk drives, that the disk cannot be easily moved to another computer. As a result, it is ordinarily desirable to provide computers with both a removable disk drive along with a fixed disk drive and most desktop computers have both. 
     In recent years, however, mobile computers of very small sizes, such as handheld, notebook and lap-top computers, have become widely used. Because space in these computers is a premium, removable cartridge disk drives are attached externally or not at all. Furthermore, in such small computers, external removable cartridge drives are very inconvenient for mobile use. Hence, many of these types of computers do not have disk drives, but rather use IC card based storage media via a PCMCIA port on the computer. However, since IC cards use semiconductor memories, storage capacities are small, and costs are high. These drawbacks have made it difficult for such computers to use programs and data that have large storage requirements. 
     Therefore, there is a need to provide a disk drive device that is portable and that can be easily attached to and detached from computers in the manner of as IC card. 
     SUMMARY OF THE INVENTION 
     In order to meet the aforementioned need, this invention provides a disk drive device of the type that accepts a removable disk cartridge. The disk drive device comprises a spindle motor for rotating, a disk medium within the disk cartridge; a head arm; a read/write head coupled to the head arm for writing and reading information on the disk medium, a head moving means, which operates the head arm; and a control circuit board on which electronic parts are mounted; a protective case which is formed from an upper case and a lower case, the protective case having a form such that it can be inserted into and removed from the PCMCIA port of a computer; and an input/output connector placed on one end of the protective case in order to connect it with a PCMCIA connector when it is inserted into the aforementioned PCMCIA board. In the disk drive device, the spindle motor is coupled to the protective case. Preferably, the bearings of the spindle motor are also coupled to the protective case. 
     The protective case is preferably formed from a sheet material, preferably by pressing. An attachment hole is placed in the bottom surface of the protective case for attachment of the bearings. To that end, projecting parts with a length almost equal to the thickness of the protective case are formed in the bearings, and the projecting part is inserted into the attachment hole in order to fix the bearings to the protective case. The attachment hole may have a flange attached to the bottom surface of the protective case around the attachment hole. Preferably, the flange is formed by burring the protective case. 
     The bearings are preferably formed from an oil-containing sintered alloy. Moreover, the bearings are preferably fixed to the protective case by inserting them into the attachment hole under pressure. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing summary, as well as the following detailed description of the preferred embodiments, are better understood when they are read in conjunction with the appended drawings. The drawings illustrate preferred embodiments of the invention to illustrate aspects of the invention. However, the invention should not be considered to be limited to the specific embodiments that are illustrated and disclosed. In the drawings: 
     FIG. 1 is a perspective view of a disk drive device and a disk cartridge of this invention; 
     FIG. 2 is an exploded perspective view of the disk drive device of FIG. 1; 
     FIG. 3 is a cross-sectional view of the disk drive device of FIG. 1 with a cartridge mounted therein; 
     FIG. 4 is a cross-sectional view of an embodiment of a spindle for use in the disk drive device of FIG. 1; and 
     FIG. 5 is a cross-sectional view of a second embodiment of a spindle for use in the disk drive device of FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The invention provides a removable cartridge disk drive for use in a PCMCIA form factor. Throughout the description, the invention is described in connection with a removable media disk drive, and the drive is shown having a rotary actuator. Moreover, a disk cartridge is shown with particular dimensions and a particular shape. However, the particular disk drive and cartridge shown only illustrate the operation of the present invention and are not intended as limitations. The invention is equally applicable to other disk drives including linear actuator disk drives and removable media disk drives that accept differently sized and shaped cartridges. Accordingly, the invention should not be limited to the particular drive or cartridge embodiment shown as the invention contemplates the application to other drive and cartridge types and configurations. 
     FIG. 1 is a perspective drawing of a disk drive device  10  and a disk cartridge  20 . Disk drive device  10  has a protective case  13 , consisting of an upper case  11  and a lower case  12 , which form an interior space for accepting disk cartridge  20 . Upper case  11  and lower case  12  are formed, preferably by pressing or stamping, from sheet material, preferably metal material. Lower case  12  has a bottom surface and side surfaces, and upper case  11  is formed so that it covers the top of lower case  12 . 
     Upper case  11  has a raised surface  11   a , which projects upward across a width W of the upper case  11 . Width W of this raised surface  11   a  is between about 48 mm and 51 mm. Furthermore, lower case  12  also has a raised surface (not shown) similar to raised surface  11   a  of upper case  11 . Here, however, the raised surface projects downward. Together the raised surfaces in upper and lower cases  11  and  12  form an interior space in the protective case  13 . Accordingly, space is available within case  13  to accommodate a disk cartridge  20  as well as a disk drive mechanism and electronics. 
     A plastic frame  14  is placed on the left and right sides of the protective case  13  such that it is sandwiched between upper and lower cases  11  and  12  (see also FIG.  2 ). Preferably, plastic frame  14  is molded to become integrated with the lower case  12  such as by outsert molding. Moreover, the plastic frame  14  is directly exposed at the four corners of the protective case  13  and protects the edges of the upper and lower cases  11  and  12  from impacts and the like. 
     A connector  15  (shown in phantom) is provided in one end of protective case  13 . The external dimensions of the protective case  13  are in a form which conforms to the PCMCIA Type II standard. According the standard, the form factor should conform to a length of about 85.6 mm, a width of about 54 mm, and a thickness of about 5 mm. By conforming to this standard, drive device  10  can be inserted into a PCMCIA port, such as the type commonly found in computers (not shown). Furthermore, when disk drive device  10  is inserted into a PCMCIA port of a computer in the direction shown by the arrow A, connector  15  connects to a corresponding connector within the PCMCIA port such that current source and electrical signals can be transmitted and received between disk drive device  10  and the computer. 
     A disk opening  16  for accepting disk cartridge  20  is formed in the other end of the protective case  13  from the connector  15 . 
     Disk cartridge  20  comprises an outer shell in which a flexible disk  21  is rotatably disposed. A disk access opening  22  is formed in a front portion of disk cartridge  20  to provide access to flexible disk  21 . A shutter  23  is rotatably disposed in cartridge  20  to selectively cover and expose disk access opening  22 . Shutter  23  rotates in a circumferential direction (arrow C) with the center of rotation  24  proximate the center of flexible disk  21 . Disk cartridge  20  is inserted into disk drive device  10  through the disk opening  16 . During insertion, shutter  23  is opened by a shutter opening and closing mechanism, not shown in the drawing, exposing flexible disk  21  for access by a pair of read/write heads, discussed in further detail below. 
     FIG. 2 illustrates the internal structure of the disk drive device  10 . A control circuit board  16 , containing the disk drive electronics, is firmly adhered to lower case  12 . Connector  15  is fixed to the control circuit board  16  by conventional means such as soldering a lead terminal  15   a  of connector  15  to circuit board  16 . Two openings  16   a ,  16   b  are formed in control circuit board  16 . Opening  16   a  is formed to provide access to the lower case  12  for attachment of a spindle motor, which comprises a rotor  40  and a stator coil  41 . Similarly, opening  16   b  is formed in order to provide access to lower case  12  for attachment of head arm assembly  30 . Head arm assembly  30  comprises a rotating shaft  31 , two head arms  32 , and a voice coil  33 . A magnetic head (not shown) is fixed to the end of each of the two head arms  32 . Moreover, voice coil  33  is formed on head assembly  30  opposite the head arms  32 . In combination with a magnet (not shown) voice coil  33  constitutes a voice coil motor for rotating the head arm assembly over the flexible disk  21  during drive  10  operation. 
     When the disk cartridge  20  is inserted into disk drive device  10 , flexible disk  21  couples with a chuck platform  44  which is provided on rotor  40  by the chucking mechanism explained below, and accordingly rotates together with the rotation of rotor  40 . Head arm assembly  30  is retracts during insertion or ejection of disk cartridge  20 . Head arm assembly  30  loads the read/write heads (not shown) after cartridge  10  is inserted and flexible disk  21  is rotating at an operational speed. 
     FIG. 3 illustrates the various components that are attached to lower case  12 . In the exemplary drive shown in FIG. 3, the components are primarily attached to the lower case  12 . Accordingly, the material thickness of the lower case  12  is preferably greater than that of the upper case  11 . However, the material thickness of the upper and lower case is about 0.2 mm. 
     A chuck platform  44  is fixed to the top center of the rotor  40 . A circular rotor magnet  46  is coupled to the inside side walls of rotor  40 . The center of chuck platform  44  is center about the center of spindle  43 . Rotor  40 , chuck platform  44 , and spindle  43  all rotate together as one unit. A stator coil  41  is arranged on the bottom surface  12   a  of the lower case  12  and opposite rotor magnet  46 . Spindle  43  is fixed to the bottom surface  12   a  of lower case  12  through a bearing  42 , so that spindle  43  is free to rotate. 
     A metal hub  25  is fixed to the center of flexible disk  21 , which is contained in disk cartridge  20 . A ring-shaped projection  25   a  is formed in the center of the hub  25  and such that it aligns concentrically with chuck platform  44 . A ring shaped concave groove  44   a  is defined in the top surface of chuck platform  44 . A chucking magnet  45  is disposed on the chuck platform to magnetically couple the chuck platform with hub  25 . Furthermore, when disk cartridge  20  is inserted into the disk drive device  10 , ring shaped projection  25   a  engages with the ring-shaped concave groove  44   a , and as a result, flexible disk  21  is positioned concentrically with spindle  23 . Positioning is performed in the circumferential direction by the magnetic attraction of the hub  25  by the chucking magnet  45  and the alignment of projection  25   a  with groove  44   a.    
     Control circuit board  16  is adhered to the bottom surface of lower case  12  through an extremely thin insulating film. Upper case flange  13   a  and lower case flange  13   b  are formed on the ends of the upper and lower cases  11  and  12 . Connector  15  is sandwiched between flanges  13   a ,  13   b . Upper and lower case flanges  13   a  and  13   b  are, respectively, on a lower level than the top surface of upper case  11  and a higher level than the bottom surface of the lower case  12 . Control circuit board  16  is contained in the lower level of lower case  13 . As noted above, connector  15  is connected to circuit board  16  via lead terminal  15   a.    
     FIGS. 4 and 5 illustrate the attachment of spindle  43  within disk drive device  10 . FIG. 4 shows a first embodiment of the attachment mechanism of spindle  43 , and FIG. 5 shows a second embodiment of the attachment mechanism of spindle  43 . Both embodiments are described below. 
     As shown in FIG. 4, a flange  12   b  is formed on the lower case  12 . Preferably the flange is formed by burring. A bushing  42 , which is preferably formed from an oil-containing sintered metal; is fixed to lower case  12  by pushing it into flange  12   b . A ball bearing  47  is fixed between spindle  43  and bushing  42  to allow spindle  43  to freely rotate. Ball bearing  47  comprises an outer liner  47   a , an inner liner  47   b , and balls  47   c . Spindle  43  is held in place by the force exerted in the thrust direction from the inner liner  47   b , the balls  47   c , and the outer liner  47   a , which are held by bushing  42 . 
     FIG. 5 shows a second embodiment of the spindle attachment mechanism. The difference between the attachment mechanism of the spindle  43  in the embodiment shown in FIG. 5 from the embodiment of FIG. 4 is that no flange  12   b  is formed in lower case  12 . Rather, a concave engaging part  42   a  is formed in bushing  42 . Bushing  42  is fixed in place on the lower case  12  by pressing it into an opening formed in lower case  12 . 
     Other variations on the embodiments discussed above are possible. For example, spindle  43  could be fixed, not to lower case  12 , but to a separate sub-chassis from the lower case  12  through a bushing. The sub-chassis could then be fixed to the lower case  12 . The sub-chassis and lower case  12  could be fixed together by welding. 
     The above description of preferred embodiments is not intended to impliedly limit the scope of protection of the following claims. Thus, for example, except where they are expressly so limited, the following claims are not limited to applications involving disk drive systems conforming to the PCMCIA standard.