Optical disc having a substrate with micro-embossments for tracking guides

Abstract

An optical disc includes a substrate having micro-embossments, in which flat portions referred to as lands, and track guides, referred to as hills, and which protrude from the surfaces of the flat portions are formed. A reflective layer is formed on the substrate, a dielectric layer is formed on the reflective layer, a recording layer is formed on the dielectric layer, and a protective layer is formed on the recording layer. Thus, the lands and hills on the substrate of the optical disc enable disc fabrication to more easily facilitate manufacturing of the optical disc. Accordingly, tracks of the disc can be narrowed, to thereby enhance a recording density of the optical disc.

1 . A method of forming an optical disc which stores data, comprising: 
 stamping a substrate to have first protrusions extending from a first surface of the substrate, wherein the first protrusions are track guides for the data.    
     
     
         2 . The method of  claim 1 , further comprising: 
 forming a first reflective layer on the first surface and the first protrusions;    forming a first dielectric layer on the first reflective layer;    forming a first recording layer on the first dielectric layer; and    forming a first protective layer on the first recording layer.    
     
     
         3 . The method of  claim 2 , wherein the first protective layer is further from the first surface than peaks of the first protrusions.  
     
     
         4 . The method of  claim 1 , further comprising: 
 stamping the substrate to have second protrusions extending from a second surface of the substrate, wherein the second protrusions are track guides for the data.    
     
     
         5 . The method of  claim 2 , further comprising: 
 stamping the substrate to have second protrusions extending from a second surface of the substrate, wherein the second protrusions are track guides for the data;    forming a second reflective layer on the second surface and the second protrusions;    forming a second dielectric layer on the second reflective layer;    forming a second recording layer on the second dielectric layer; and    forming a second protective layer on the second recording layer.    
     
     
         6 . The method of  claim 5 , wherein the second protective layer is further from the second surface than peaks of the second protrusions.  
     
     
         7 . A method of recording data on an optical disc including a substrate having a surface with protrusions extending from the surface, wherein the protrusions are track guides for the data, a reflective layer formed on the surface and the protrusions, a dielectric layer formed on the reflective layer, a recording layer formed on the dielectric layer, and a protective layer formed on the recording layer, the method comprising: 
 moving an objective lens of a flying head to a distance of λ/10 to λ/5 from the protective layer; and    forming an optical spot at a bottom of the objective lens to generate a near field, thereby recording the data on the recording layer based upon the protrusions.    
     
     
         8 . A method of reproducing data from an optical disc including a substrate having a surface with protrusions extending from the surface, wherein the protrusions are track guides for the data, a reflective layer formed on the surface and the protrusions, a dielectric layer formed on the reflective layer, a recording layer formed on the dielectric layer and storing the data, and a protective layer formed on the recording layer, the method comprising: 
 moving an objective lens of a flying head to a distance of λ/10 to λ/5 from the protective layer; and    forming an optical spot at a bottom of the objective lens to generate a near field; and    reflecting the optical spot from the reflective layer after passing through the cording layer, using the protrusions, to reproduce the data.