Glass Substrate for Information Recording Medium and Method for Producing the Same

Abstract

A glass substrate for an information recording medium is manufactured by polishing the surface of a raw material glass plate. The polishing of the raw material glass plate is divided into a step for performing a first polishing process to roughly polish the surface of the raw material glass plate to be smooth and a step for performing a second polishing process to finely polish the surface of the roughly polished raw material glass plate to be smoother. The first polishing process uses a polishing pad made of a synthetic resin foam and slides the polishing pad on the raw material glass plate surface while supplying a polishing agent to roughly polish the surface. A pad dressing process is performed on the polishing pad before being used in the first polishing process. The pad dressing process polishes the surface of the polishing pad by sliding the polishing pad on a pad dresser including abrasive grains.

1 - 12 . (canceled) 
   
   
       13 . A polishing device for manufacturing a glass substrate for an information recording medium by polishing the surface of a raw material glass plate using a polishing agent, the device comprising:
 a carrier for moving the raw material glass plate about a center of axis; and   a polishing pad formed from a synthetic resin foam, and a pad dresser including abrasive grains, wherein the polishing pad slides on the raw material glass plate when moved by the carrier for roughly polishing the surface of the raw material glass plate while supplying the surface of the raw material glass plate with a polishing agent, and a pad dresser slides on the surface of the polishing pad to polish the polishing pad.   
   
   
       14 . The device for manufacturing a glass substrate for an information recording medium according to  claim 13 , wherein the pad dresser has a circular-plate shape, and the diameter and thickness are substantially the same as the diameter and the thickness of the raw material glass plate.