Patent ID: 7438630
Filing Date: 2008-10-21
Classification: B24B,G11B

Abstract:
1. A method of manufacturing a glass substrate for a magnetic recording medium, the glass substrate being in the form of a circular disc having a circular hole in a center portion of the disc, wherein an inner peripheral end surface of the glass substrate is polished by following steps: supplying an abrasive liquid containing free abrasive grains to the inner peripheral end surface of the glass substrate; and rotating a polishing brush in contact with the inner peripheral end surface of said glass substrate to perform polishing, wherein said polishing brush is connected to a rotation shaft, wherein a plurality of glass substrates are stacked and polished so that the inner peripheral end surfaces of the plurality of glass substrates are simultaneously polished, wherein the polishing brush has bristles which are planted in a helical shape on a surface of the rotation shaft, and the rotation shaft is rotated in a direction in which the abrasive liquid is drawn into the circular hole portion of a plurality of stacked glass substrates, and wherein the abrasive liquid is supplied from above the stacked glass substrates and toward the inner peripheral end surface of the glass substrates.