Method of manufacturing recording medium, method of manufacturing recording medium manufacturing master, apparatus for manufacturing recording medium and apparatus for manufacturing recording medium manufacturing master technical field

Abstract

A recording medium manufacturing method comprises a process for forming a thermosensitive material layer 12 on a substrate comprising a recording medium or a recording medium manufacturing master, a process for forming a denatured portion 12 s of a pattern corresponding to target very small concavities and convexities on the thermosensitive material layer by irradiating laser light on the thermosensitive material layer with patterns corresponding to target very small concavities and convexities and a process for forming target very small concavities and convexities by patterning the thermosensitive material layer by developing the thermosensitive material layer 12 . In particular, in the laser light irradiation, there can be formed patterns independent of the length of the very small concavities and convexities by irradiation of laser light modulated by a frequency higher than a period of very small concavities and convexities.

1 - 19  (Canceled)  
     
     
         20 . In a recording medium manufacturing master manufacturing apparatus for manufacturing a recording medium having very small concavities and convexities which correspond to recording marks or grooves, said recording medium manufacturing master manufacturing apparatus comprising: 
 holding means for holding a substrate constituting a master in which a thermosensitive inorganic material layer is deposited on at least one major surface;    a laser light source;    modulating means for modulating laser light from said laser light source in response to patterns of said very small concavities and convexities and modulating said laser light to a frequency higher than a period of the patterns of said very small concavities and convexities;    an optical system including a condenser lens system for focusing said laser light on said thermosensitive inorganic material layer; and    moving-means for moving irradiation position of said laser light relative to said thermosensitive inorganic material layer.    
     
     
         21 . A recording medium manufacturing apparatus according to  claim 20 , wherein said modulating means is comprised of a high-speed modulator and a low-speed modulator.  
     
     
         22 . A recording medium manufacturing apparatus according to  claim 20 , wherein said laser light source is comprised of a semiconductor laser and said modulating means modulates a current supplied to said semiconductor laser.