Substrate for magnetic recording medium, magnetic recording medium, and magnetic recording and reproducing apparatus

Abstract

In an example magnetic recording medium substrate, a plurality of recording tracks are formed on a substrate, each recording track being formed of a magnetic material. Non-recording sections are formed on the substrate, each non-recording section separating adjacent recording tracks. Each recording track includes a plurality of recording sections and connecting sections for connecting the recording sections adjacent thereto in a track longitudinal direction, and each connecting section has a cross-sectional area in a track width direction that is smaller than a cross-sectional area in a track width direction of adjacent recording sections.

1 . A magnetic recording medium substrate comprising:
 a plurality of protruded portions formed on a substrate, each protruded portion being in a track shape; and   depressed portions formed on the substrate, each depressed portion separating adjacent protruded portions,   each protruded portion including a plurality of first portions and second portions for connecting the first portions adjacent thereto in a track longitudinal direction, and each second portion having a cross-sectional area in a track width direction that is smaller than a cross-sectional area in a track width direction of adjacent first portions.   
     
     
         2 . The magnetic recording medium substrate according to  claim 1 , wherein the cross-sectional area in the track width direction of each second portion has a smallest value. 
     
     
         3 . The magnetic recording medium substrate according to  claim 2 , wherein the cross-sectional area in the track width direction of each second portion decreases as a distance from one of the two adjacent first portions increases until the cross-sectional area reaches the smallest value, and then increases as a distance to the other first portion decreases. 
     
     
         4 . The magnetic recording medium substrate according to  claim 1 , wherein pairs each including one first portion and one second portion are periodically arranged in a track longitudinal direction. 
     
     
         5 . The magnetic recording medium substrate according to  claim 1 , wherein a size in the track width direction of the second portion is smaller than a size in the track width direction of the first portion. 
     
     
         6 . The magnetic recording medium substrate according to  claim 1 , wherein a height of the second portion is smaller than a height of the first portion. 
     
     
         7 . The magnetic recording medium substrate according to  claim 1 , wherein a smallest cross-sectional area in the track width direction of the second portion is greater than 0. 
     
     
         8 . A magnetic recording medium comprising:
 a magnetic recording medium substrate according to  claim 1 ; and   a magnetic film formed on the magnetic recording medium substrate.