Hard disk drive for perpendicular recording with transducer having submicron gap between pole tips

Abstract

An information storage system includes a transducer having a loop of ferromagnetic material with pole tips separated by an nonferromagnetic gap located adjacent to a medium such as a rigid disk. During writing the separation between the pole tips and the media layer of the disk is a small fraction of the gap separation. Due to the small separation between the pole tips and the media layer, the magnetic field generated by the transducer and felt by the media has a larger perpendicular than longitudinal component, favoring perpendicular recording over longitudinal recording. The media may have an easy axis of magnetization oriented substantially along the perpendicular direction, so that perpendicular data storage is energetically favored. The transducer may also include a magnetoresistive sensor for reading magnetic information from the disk.

1 . An information storage system comprising: 
 a spinning, rigid disk having a surface and an associated media layer,    a slider contacting said surface, said slider including a microscopic transducer having a conductive coil inductively coupled to a core of ferromagnetic material shaped as a loop with pole tips separated by a submicron amagnetic gap, and    a beam mechanically coupled to said slider and having an elongate dimension oriented substantially along a direction of travel of a portion of said surface adjacent to said pole tips,    wherein a magnetic field from said pole tips writes upon said media layer with a strength oriented substantially perpendicular to said surface that is larger than a maximum strength oriented parallel to said surface.    
     
     
         2 . The system of  claim 1  wherein said transducer has an at least partially sliding relationship with said surface at a time of transmission of said magnetic signal.  
     
     
         3 . The system of  claim 1  wherein: 
 said pole tips are separated from each other by a first distance,  
 said pole tips are separated from said media layer by a second distance, and  
 said first distance is at least several times greater than said second distance when said magnetic field from said pole tips writes upon said media layer.  
 
     
     
         4 . The system of  claim 1  wherein an easy axis of magnetization of said media layer is substantially perpendicular to said surface.  
     
     
         5 . The system of  claim 1  wherein said pole tips are separated from each other by a distance less than one-fifth of a micron and at least 125 angstroms.  
     
     
         6 . The system of  claim 1  wherein said pole tips are separated from said media layer by less than thirty nanometers during transmission of said magnetic field.  
     
     
         7 . The system of  claim 1  wherein said second distance is at most one-fifth that of said first distance.  
     
     
         8 . The system of  claim 1  wherein at least one of said pole tips is exposed adjacent to said surface.  
     
     
         9 . The system of  claim 1  wherein said slider includes a magnetoresistive sensor.  
     
     
         10 . An information storage system comprising: 
 a rigid disk having a disk surface and an associated magnetic media layer with an easy axis of magnetization oriented substantially perpendicular to said disk surface, and    a slider having a disk-facing surface with a projection, said slider including a transducer with a conductive coil that is inductively coupled to a loop of magnetic material partly disposed in said projection and having a pair of pole tips that are separated by a submicron amagnetic gap,    wherein said pole tips are separated from each other by a distance at least several times greater than that between one of said pole tips and said media layer when writing a magnetic signal from said pole tip to the media layer.    
     
     
         11 . The system of  claim 10  wherein said magnetic signal has a maximum strength at said media layer directed transversely to said disk surface.  
     
     
         12 . The system of  claim 10  wherein said slider contacts said disk surface during said writing.  
     
     
         13 . The system of  claim 10  wherein said pole tips are separated from each other by a distance less than one-fifth of a micron and at least 125 angstroms.  
     
     
         14 . The system of  claim 10  wherein said pole tips are separated from said media layer by less than thirty nanometers during said writing of said magnetic signal.  
     
     
         15 . The system of  claim 10  wherein said slider includes a magnetoresistive sensor.  
     
     
         16 . An information storage system comprising: 
 a rigid disk having a disk surface and an associated magnetic media layer with an easy axis of magnetization oriented substantially perpendicular to said disk surface, and    a slider including a transducer with a conductive coil that is inductively coupled to a loop of magnetic material and having a pair of pole tips that are separated by a submicron nonferromagnetic gap, at least one of said pole tips being separated from said media layer by a distance less than one-fourth that between said pole tips and said media layer when writing a magnetic signal from said pole tip to the media layer, said slider including a magnetoresistive sensor to read said signal.    
     
     
         17 . The system of  claim 16  wherein: 
 said magnetic signal has a component directed perpendicular to said disk surface and a component directed parallel to said disk surface, and  
 at said media layer said component directed perpendicular to said disk surface has a strength greater than that of said component directed parallel to said disk surface.  
 
     
     
         18 . The system of  claim 16  wherein said slider contacts said disk surface during said writing.  
     
     
         19 . The system of  claim 16  wherein said pole tips are separated from each other by a distance less than one-fifth of a micron and at least 125 angstroms.  
     
     
         20 . The system of  claim 16  wherein said pole tips are separated from said media layer by less than thirty nanometers during said writing of said magnetic signal.