Optical recording medium, and manufacturing method and manufacturing device thereof

A manufacturing device of an optical recording medium, comprising:

• a cutting device for forming a circular cut in a light transmitting layer of a semifinished product of an optical recording medium, the optical recording medium including a disc-like shaped substrate having an information recording face at least on one side and the light transmitting layer thinner than the substrate on the information recording face;
• and
• a punching device for punching out at least a part of an area inside the circular cut by a punching tool to divide the light transmitting layer at the circular cut and form both center holes in the light transmitting layer and the substrate after the circular cut is formed in the light transmitting layer by the cutting device, wherein
• the cutting device forms the circular cut at a larger diameter than an inner diameter of the center hole in the substrate, and
• the punching device pressurizes the area inside the circular cut in a thickness direction to divide the light transmitting layer at the circular cut and to punch the light transmitting layer and the substrate, thereby forming the center hole at a larger inner diameter than that of the center hole in the substrate in the light transmitting layer.

A method for manufacturing an optical recording medium, comprising:

• a molding step of molding a disc-like shaped substrate including an information recording face at least on one side;
• a light transmitting layer formation step of forming a light transmitting layer thinner than the substrate on the information recording face;
• a cutting step of forming a circular cut in the light transmitting layer;
• and
• a punching step of punching out at least a part of an area inside the circular cut by a punching tool to form center holes in the light transmitting layer and the substrate, wherein
• the circular cut in the light transmitting layer is formed at a larger diameter than an inner diameter of the center hole in the substrate, and
• the area inside the circular cut is pressurized in a thickness direction by the punching tool to divide the light transmitting layer at the circular cut and to punch the light transmitting layer and the substrate, thereby forming the center hole at a larger inner diameter than that of the center hole in the substrate in the light transmitting layer.

A manufacturing device of an optical recording medium, comprising:

• a cutting device for forming a circular cut in a light transmitting layer of a semifinished product of an optical recording medium, the optical recording medium including a disc-like shaped substrate having an information recording face at least on one side and the light transmitting layer thinner than the substrate on the information recording face;
• and
• a punching device for punching out at least a part of an area inside the circular cut by a punching tool to form center holes in the light transmitting layer and the substrate, wherein
• the cutting device forms the circular cut at a larger diameter than an inner diameter of the center hole in the substrate, and
• the punching device pressurizes the area inside the circular cut in a thickness direction to divide the light transmitting layer at the circular cut and to punch the light transmitting layer and the substrate, thereby forming the center hole at a larger inner diameter than that of the center hole in the substrate in the light transmitting layer.