Information recording and/or reproducing apparatus, information recording and/or reproducing method, and phase-change recording medium for use in the apparatus and the methods

Abstract

An information recording apparatus for recording multi-leveled information in a phase-change recording medium by the application of a laser beam thereto by modifying a power level of the laser beam into two or more power levels so as to correspond to the multi-leveled information to be recorded, and setting a plurality of recording mark units including therein at least one recording mark to be formed, based on the modified power levels, so as to correspond to the multi-leveled information, an information reproducing apparatus for reproducing multi-leveled information recorded in the phase-change recording medium with the application of a laser beam thereto, and an information recording and reproducing apparatus, and an information recording method, an information reproducing method, and a phase-change recording medium for use in the above apparatus are disclosed.

1 - 21 . (canceled)  
   
   
       22 . A phase-change recording medium comprising a recording layer in which multi-leveled information can be recorded by an information recording method for recording multi-leveled information in a phase-change recording medium by the application of a laser beam thereto, comprising: 
 modifying a power level of said laser beam into two or more power levels so as to correspond to said multi-leveled information;    applying at least two laser beams having different power levels to form at least one recording mark;    varying a power level of one of the at least two laser beams to set a plurality of recording mark units including therein the at least one recording mark to be formed, based on said modified power levels, so as to correspond to said multi-leveled information.    
   
   
       23 . The phase-change recording medium as claimed in  claim 22 , wherein said recording layer comprises Sb and Te with a Sb/Te content ratio of 2 to 5 in terms of atomic %, and at least one element selected from the group consisting of Ag, In, Ge, Ga, B, Si, and Al.