Disk medium

Abstract

A disk medium includes a substrate and a designed topography of individually magnetizable features formed on the surface of the substrate. At least a portion of the topography is formed from an etched layer of magnetizable material deposited on the surface of the substrate. An information handling system records information on the disk medium magnetically and reads the recorded information optically or magnetically.

What is claimed is:  
     
         1 . A method for handling information, comprising the steps of: 
 etching a designed topography in a disk;    forming individually magnetizable features on the disk, the features corresponding to the designed topography; and    storing information on the disk by selectively changing a magnetic state of individual ones of the features.    
     
     
         2 . The method as set forth in  claim 1 , comprising the further step of reading the stored information by detecting the magnetic state of the features.  
     
     
         3 . The method as set forth in  claim 2 , wherein the magnetic state of the features is detected by determining effects of the features upon a beam of light.  
     
     
         4 . The method as set forth in  claim 3 , wherein the magnetic state of the features is detected by determining whether the features alter a polarization angle of the beam of light.  
     
     
         5 . The method as set forth in  claim 3 , wherein the beam of light is a reflected beam.  
     
     
         6 . The method as set forth in  claim 3 , wherein the beam of light is transmitted through the features on the disk.  
     
     
         7 . The method as set forth in  claim 2 , wherein the magnetic state of the features is detected by a magnetic head.  
     
     
         8 . The method as set forth in  claim 1 , wherein, prior to etching, a pattern is transferred onto the disk by a contact method and is developed thereon.  
     
     
         9 . The method as set forth in  claim 1 , wherein, prior to etching, a pattern is transferred onto the disk by a projection method and is developed thereon.  
     
     
         10 . The method as set forth in  claim 1 , wherein the disk includes an exterior disk surface having a designed R a , the method comprising the further steps of forming an air bearing at the exterior disk surface by rotating the disk so that aerodynamic effects characteristic of the R a  are developed at the exterior disk surface, and suspending at least one of means for selectively magnetizing the features and means for detecting a magnetic state of the features at a distance from the exterior disk surface with the air bearing.  
     
     
         11 . The method as set forth in  claim 1 , wherein the disk includes an exterior disk surface, and magnetizing means for selectively magnetizing the features selectively change the magnetic state of individual ones of the features, and detecting means for detecting a magnetic state of the features detect a magnetic state of the features, the method comprising the further steps of stopping and starting rotation of the disk relative to a contacting means that contacts the exterior disk surface as rotation of the disk is started and stopped, the contacting means including at least one of the magnetizing means and the detecting means, and wherein the designed topography is etched to control a C f  between the exterior disk surface and the contacting means.  
     
     
         12 . The method as set forth in  claim 1 , wherein the features are formed by filling recesses etched in the disk with magnetizable material.  
     
     
         13 . The method as set forth in  claim 1 , wherein the features are formed by etching the desigened topography in magnetizable material on the disk.  
     
     
         14 . A disk medium, comprising: 
 an etched, designed topography in a disk; and    individually magnetizable features formed on the disk and corresponding to the designed topography.    
     
     
         15 . The disk medium as set forth in  claim 14 , wherein the features are separated from one another by non-magnetic material.  
     
     
         16 . The disk medium as set forth in  claim 14 , wherein the features reflect light.  
     
     
         17 . The disk medium as set forth in  claim 14 , wherein the features transmit light.  
     
     
         18 . The disk medium as set forth in  claim 14 , wherein the disk includes a substrate, the substrate including at least one material selected from the group consisting of ceramic, polycarbonate, silicon, glass, and carbon materials.  
     
     
         19 . The disk medium as set forth in  claim 14 , wherein the features include magnetizable material, the magnetizable material including a layer of chromium and a layer of material selected from the group consisting of NiCoCr, PtCoCr, Fe, and Co deposited over the layer of chromium.  
     
     
         20 . The disk medium as set forth in  claim 14 , wherein the features include magnetizable material, the magnetizable material including a layer of material selected from the group consisting of NiCoCr, PtCoCr, Fe, and Co.  
     
     
         21 . The disk medium as set forth in  claim 14 , further comprising means for facilitating data retrieval.  
     
     
         22 . The disk medium as set forth in  claim 21 , wherein the data retrieval facilitating means include additional designed features formed on the disk.  
     
     
         23 . The disk medium as set forth in  claim 22 , wherein the additional designed features include track identification features.  
     
     
         24 . The disk medium as set forth in  claim 14 , further comprising an exterior disk surface having a designed R a .  
     
     
         25 . The disk medium as set forth in  claim 24 , wherein the designed R a  is characteristic of the designed topography.  
     
     
         26 . The disk medium as set forth in  claim 14 , wherein the designed topography includes recesses etched in the disk and the features include magnetizable material filled in the recesses.  
     
     
         27 . The disk medium as set forth in  claim 14 , wherein the features include magnetizable material etched to form the designed topography.  
     
     
         28 . A memory system. comprising: 
 a disk medium including an etched, designed topography in a disk and individually magnetizable features formed on the disk and corresponding to the designed topography;    means for magnetizing individual ones of the features; and    means for detecting the magnetic state of the features.    
     
     
         29 . The memory system as set forth in  claim 28 , wherein the magnetizing means includes a magnetic head assembly.  
     
     
         30 . The memory system as set forth in  claim 28 , wherein the detecting means includes a magnetic head assembly.  
     
     
         31 . The memory system as set forth in  claim 28 , wherein the detecting means includes an optical head assembly.  
     
     
         32 . The memory system as set forth in  claim 31 , wherein the optical head assembly includes means for determining effects of the features on a beam of light.  
     
     
         33 . The memory system as set forth in  claim 32 , wherein the effects determining means determine effects of the features on polarity of the beam of light.  
     
     
         34 . The memory system as set forth in  claim 28 , further comprising means for rotating the disk medium.  
     
     
         35 . The memory system as set forth in  claim 34 , wherein the disk medium has an exterior disk surface having a designed R a .  
     
     
         36 . The memory system as set forth in  claim 35 , wherein the designed R a  is characteristic of the designed topography.  
     
     
         37 . The memory system as set forth in  claim 35 , wherein rotation of the disk medium by the rotating means causes an air bearing to form at the exterior disk surface that is characteristic of the designed R a .  
     
     
         38 . The memory system as set forth in  claim 37 , wherein the air bearing suspends at least one of the magnetizing means and the detecting means at a distance above the exterior disk surface that is characteristic of the designed R a .  
     
     
         39 . The memory system as set forth in  claim 34 , wherein, during starting and stopping of rotation of the disk medium, an exterior disk surface of the disk medium is contacted by contacting means including at least one of the magnetizing means and the detecting means, and wherein the disk exterior surface and the contacting means have a designed C f .  
     
     
         40 . The memory system as set forth in  claim 39 , wherein the designed C f  is characteristic of the designed topography.  
     
     
         41 . A method for making a disk medium, comprising the steps of: 
 etching a designed topography in a disk; and    forming individually magnetizable features on the disk, the features corresponding to the designed topography.    
     
     
         42 . The method as set forth in  claim 41 , wherein the features are formed by filling recesses etched in the disk with magnetizable material.  
     
     
         43 . The method as set forth in  claim 41 , wherein the features are formed by etching the designed topography in magnetizable material on the disk.  
     
     
         44 . The method as set forth in  claim 41 , comprising the further step of forming a designed R a  on an exterior surface of the disk by controlling the etching of the designed topography.