Patent ID: 7213253

Claim:
An optical recording medium having an information signal area on which an information signal can be recorded and/or reproduced, said medium comprising: a disc substrate layer having a flat annular shape, a first opening in a center and a first outer diameter; and a light transmitting layer having a flat annular shape, a second opening in a center and a second outer diameter; wherein, said information area is formed on said disc substrate layer, said light transmitting layer transmits a laser beam for recording and/or reproducing the information signal; said information signal is formed within said information signal area, a clamp reference plane is arranged on said light transmitting layer; said light transmitting layer comprises a light transmitting sheet, an adhesive layer through which said light transmitting sheet is adhered to the major surface of said disc substrate layer; and a protective layer formed on a side opposite to a side on which said adhesive layer of said light transmitting sheet is formed; said adhesive layer is made of a pressure sensitive adhesive through which said laser beam can be transmitted; a diameter of said second opening is larger than a diameter of said first opening and smaller than an inner circumference diameter of a clamp region in said disc substrate layer; the second outer diameter of the light transmitting sheet is smaller than the first outer diameter of the disc substrate layer.