Method for manufacturing disk-shaped glass substrate, method for manufacturing thin glass substrate, method for manufacturing light-guiding plate, and disk-shaped glass substrate

A method for manufacturing a thin glass substrate, comprising:

• preparing a disk-shaped glass blank, which is a glass plate having two circular main surfaces;
• chamfering an outer edge portion of each of the two main surfaces of the disk-shaped glass blank;
• grinding the two main surfaces of the chamfered disk-shaped glass blank, using a double-side grinding apparatus;
• polishing the ground two main surfaces, using a double-side polishing apparatus;
• and
• cutting out a plurality of thin glass substrates from a disk-shaped glass substrate obtained through the polishing.

A method for manufacturing a light-guiding plate, comprising:

• preparing a disk-shaped glass blank, which is a glass plate having two circular main surfaces;
• chamfering an outer edge portion of each of the two main surfaces of the disk-shaped glass blank;
• grinding the two main surfaces of the chamfered disk-shaped glass blank, using a double-side grinding apparatus;
• polishing the ground two main surfaces, using a double-side polishing apparatus;
• and
• cutting out a plurality of thin glass substrates from a disk-shaped glass substrate obtained through the polishing.

A disk-shaped glass substrate for cutting out one or more thin glass substrates, the disk-shaped glass substrate comprising:

• two circular main surfaces;
• an outer circumferential edge surface;
• and
• chamfering surfaces that are respectively inclined between the two main surfaces and the outer circumferential edge surface and that respectively connect the two main surfaces and the outer circumferential edge surface,
• wherein a distance between the two main surfaces is 100 to 350 μm, and
• a parallelism between the two main surfaces is less than 1.0 μm.