Abstract:
A magnetic head capable of increasing the data transfer rate during recording and/or reproduction, while improving the accuracy of tracking control is provided. The magnetic head for magnetically recording and/or reproducing data from magnetic disk media is constructed by: a head slider for approaching or contacting the magnetic disk media; rails or pads formed on the head slider; and head elements provided on the rails or the pads; wherein a plurality of head elements are provided on one of the rails or the pads at intervals along the track arrangement direction of the magnetic disk media.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a magnetic head for magnetically recording and/or reproducing data from magnetic disk media, such as a magnetic disk cartridge. 
     2. Description of the Related Art 
     Conventional magnetic disk cartridges are provided comprising: a flexible magnetic disk medium formed by a discoid substrate formed of a flexible polyester sheet or the like having magnetic layers formed on both sides thereof; and a case having a window for insertion of a magnetic head. The magnetic disk media is rotatably housed within the case. This type of magnetic disk cartridge is mainly used as recording media for computers, due to its advantages regarding ease of use and low cost. 
     A drive apparatus for driving a magnetic disk cartridge of the aforementioned construction generally comprises: a rotating drive means for rotating the magnetic disk medium; a magnetic head for performing recording and/or reproduction of signals from the magnetic disk medium; and a magnetic head arm on which the magnetic head is mounted, for moving the magnetic head in the radial direction of the magnetic disk medium. With regard to a drive apparatus of this structure, data is recorded onto and reproduced from concentric tracks of the magnetic disk medium by the relative movement between the magnetic head and the magnetic disk medium in the circumferential direction thereof, as well as movement of the magnetic head in the radial direction of the magnetic disk medium by the movement of the magnetic head arm. 
     Note that the aforementioned magnetic head basically comprises: a head slider that approaches or contacts the magnetic disk medium; rails or pads formed on the head slider; and head elements provided on the rails or pads. 
     Regarding the conventional magnetic head of the basic structure described above, a single or a plurality of rails or pads are formed on the head slider. A head element is formed on one of the rails or the pads. Note that there are provided magnetic heads having a head element formed on each of a pair of rails or pads. However, even magnetic heads of this construction, only one head element on one of the rails or pads is actually utilized for magnetic recording and/or reproduction. That is, these magnetic heads are constructed in this manner due to magnetic heads for facing both sides of a magnetic disk medium being produced in a common step. 
     Recently, there is a widespread demand for miniaturization of magnetic disk cartridges, so that they can be used as low cost removable media for portable equipment. A problem of reduced data transfer rate arises along with a decrease in the diameter of magnetic disk media. If the data transfer rate becomes slow, recording/reproduction of data in real time becomes impossible in a video camera that processes motion pictures, for example. 
     In addition, in the case that the diameter of magnetic disk media is decreased, the recording density is increased, in order not to decrease recording capacity thereof. That is, it is often the case that the tracks are made narrower. However, if the tracks are made narrower, tracking control, by which the magnetic head follows the tracks, becomes difficult. That is, as the tracks become narrower, servo signals which are used for tracking control become more likely to be influenced by signal dropouts and the like, thereby causing failures in the tracking control. 
     SUMMARY OF THE INVENTION 
     The present invention has been developed in view of the above circumstances, and it is an object of the present invention to provide a magnetic head that enables high speed data transfer, while improving the accuracy of tracking control. 
     The magnetic head according to the present invention is a magnetic head for magnetically recording and/or reproducing data from magnetic disk media comprising: 
     a head slider for approaching or contacting the magnetic disk media; 
     rails or pads formed on the head slider; and 
     head elements provided on the rails or the pads; wherein 
     a plurality of head elements are provided on one of the rails or the pads at intervals along the track arrangement direction of the magnetic disk media. 
     Note that regarding the structure described above, it is desirable that each of the head elements comprises a combined head element containing an inductive one and a MR (magneto resistive effect) one, formed by a thin film process. 
     The magnetic head according to the present invention comprises a plurality of head elements provided on one of the rails or the pads at intervals along the track arrangement direction of the magnetic disk media. Therefore, the plurality of head elements are employed to simultaneously record data to or reproduce data from multiple locations of the magnetic disk media, thereby increasing the data transfer rate during recording or reproduction. 
     In addition, servo signals can also be read from multiple locations of the magnetic disk media by employing the plurality of head elements as described above. Therefore, even if there is a missing servo signal at one location of the magnetic disk media due to signal drop out or the like, servo signals from other locations become usable, thereby improving the accuracy of tracking control. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing a magnetic head according to a first embodiment of the present invention. 
         FIG. 2  is a side view showing the magnetic head of  FIG. 1  in use. 
         FIG. 3  is a plan view showing the magnetic head of  FIG. 1  mounted on an arm. 
         FIG. 4  is a magnified plan view of a portion of the magnetic head of  FIG. 1 . 
         FIG. 5  is a plan view showing a modified version of the magnetic head of  FIG. 1 . 
         FIG. 6  is a plan view showing a magnetic head according to a second embodiment of the present invention. 
         FIG. 7  is a perspective view showing a magnetic head according to a third embodiment of the present invention. 
         FIG. 8  is a perspective view showing a magnetic head according to a fourth embodiment of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, the embodiments of the present invention will be described in detail with reference to the attached drawings. 
       FIG. 1  is a perspective view of a magnetic head  10  according to a first embodiment of the present invention. The magnetic head  10  comprises a head slider  12 ; two rails  11 ,  11  provided on the head slider  12 ; and two head elements  13 ,  13  provided on each of the rails  11 . Each of the rails  11  is tapered so that the thicknesses thereof decrease toward one of the ends thereof The head elements  13  are provided at the end of the rails  11  opposite the tapered ends thereof. A combined head element formed by a thin film process comprising an inductive element and an MR (Magneto Resistive effect) element is utilized as the head element  13 . 
     This magnetic head  10 , as shown schematically in  FIG. 2 , is utilized for magnetic recording/reproduction by being made to approach a rotating magnetic disk medium  20  while held by a gimbal. The magnetic disk medium  20  rotates in the direction indicated by arrow A. Note that the head slider  12  is held inclined so that the front edge thereof is further away from the magnetic disk medium  20  than the rear edge thereof. By this positioning, the air flow, indicated by arrow B, generated by rotation of the magnetic disk media  20 , is caused to travel between the two rails  11 ,  11  toward the rear. 
     More specifically, the head slider  12  is held by the gimbal  14  which is mounted at the tip of a suspension member  16  of a magnetic head arm  15  so that the magnetic head element  13  is positioned at the opposite end of the head slider  12  from the magnetic head arm  15 , as shown in  FIG. 3 . The head slider  12  is movable between a recording/reproducing position wherein it faces the magnetic disk medium  20  as shown in  FIG. 2 , and a standby position wherein it retreats to a position outside the circumference of the magnetic disk media  20 , by movement of the magnetic head arm  15 . In addition, the head slider  12  is moved in the radial direction of the magnetic disk medium  20  to be placed in positions wherein it faces specific tracks by movement of the magnetic head arm  15  in the aforementioned recording/reproducing position. 
     The two head elements  13  are provided on one rail  11 , separated in the width direction thereof. Note that the arrangement of the head elements  13  on the rail  11  is shown in the magnified view of  FIG. 4 . Here, the width W of the rail  11  is, for example, approximately 300 μm. 
     Only the two head elements  13  provided on one of the rails  11  are actually utilized for recording/reproduction, and the two head elements  13  provided on the other rail  11  are not utilized. That is, the head slider  12  is of this construction because that which is placed on the upper side of the magnetic disk medium  20  as shown in  FIG. 2 , and that which is placed on the lower side of the magnetic disk medium  20  (not shown) are manufactured in a common step. With regard to the head slider  12  to be placed on the lower side of the magnetic disk medium  20 , the two head elements  13  provided on the aforementioned other rail  11  are utilized. 
     The width direction of the rail  11  is substantially perpendicular to the direction of relative movement between the magnetic head  10  and the magnetic disk medium  20  (refer to  FIG. 2 ), and a plurality of tracks are arranged in this width direction on the magnetic disk medium  20 . Accordingly, simultaneous recording or reproduction is enabled to be performed at two locations of the magnetic disk medium  20  by employing the two head elements  13 . Therefore, it becomes possible to increase the data transfer rate during recording/reproduction. 
     In addition, servo signals for tracking control can be read out from two locations of the magnetic disk medium  20  by employing the two head elements  13 . Therefore, even if servo signals are missing from one location of the magnetic disk medium  20  due to signal dropout or the like, servo signals from the other location become usable, thereby the accuracy of tracking control can be improved. 
     In addition, a combined head element comprising an inductive one and an MR one formed by a thin film process is used as the head element  13  in the present embodiment. Therefore, the two head elements  13  are enabled to be formed while accurately maintaining the distance therebetween. 
     Note that, as shown in  FIG. 5 , the two head elements  13  may alternatively be formed at intervals in the direction of relative movement between the magnetic head  10  and the magnetic disk medium  20  (the length direction of the rail  11 ). 
     The present invention is not limited to application to magnetic heads having a plurality of completely separated rails, as illustrated in the embodiment described above, but may also be applied to magnetic heads having rails which are linked at the front ends thereof.  FIG. 6  shows a magnetic head  30  formed in this manner, as a second embodiment of the present invention. Note that with regard to  FIG. 6 , the same elements as those shown in  FIGS. 1 through 5  are denoted with the same reference numerals, and further description of these elements are omitted insofar as it is not particularly necessary. 
     Two rails  31 ,  31  are formed on a head slider  32  in the magnetic head  30  shown in  FIG. 6 . The rails  31 ,  31  are linked to each other at the front ends thereof. Two head elements  13  are formed on each rail  31 , separated in the width direction thereof. The same effects as obtained in the first embodiment are exhibited by the present embodiment. 
     Next, a third embodiment of the present invention will be described with reference to  FIG. 7 . A magnetic head  40  according to the third embodiment has three rails  41  formed on a head slider  42 . Head elements  13  are formed only on one of the rails  41 . Here also, two head elements  13  are formed on the rail  41  separated in the width direction thereof, and the same effects as obtained in the first embodiment are exhibited by the present embodiment. 
     Next, a fourth embodiment of the present invention will be described with reference to  FIG. 8 . A magnetic head  50  according to the fourth embodiment has four floating pads  51  formed on a head slider  52 . Two head elements  13  are formed on one of the floating pads  51  separated in the width direction (the direction substantially perpendicular to the direction of relative movement between the magnetic head  50  and a magnetic disk medium not shown in the figure) thereof. The same effects as obtained in the first embodiment are exhibited by the present embodiment. 
     Note that with regard to the present invention, the number of rails or pads formed on a head slider is not limited to those given in the embodiments described above, and other numbers can be suitably applied. In addition, the number of head elements formed on one of the rails or pads is not limited to two, as given in the embodiments described above. Three or more head elements may be formed on the rails or pads.