Patent ID: 7376069

Claim:
A double sided optical disc comprising: a first record carrier having a light transmitting base board, a first reflecting layer formed on the base board and a first protective layer formed on the first reflecting layer; and a second record carrier having a light transmitting cover, a second reflecting layer formed on the cover and a second protective layer formed on the second reflecting layer wherein the first record carrier is united to the second record carrier through an adhesive layer by which the first protective layer is united to the second protective layer, and total thickness of the first record carrier and the second record carrier united together is not more than 1.4 mm and thickness of the light transmitting base board of the first record carrier is not less than 1.1 mm; wherein a first printing layer is formed on one surface of the first protective layer and the reflecting layer has a high reflectance only for a laser beam having a first specific wavelength in the first record carrier, and a second printing layer is formed on one surface of the second protective layer and the second reflecting layer has a high reflectance only for a laser beam having a second specific wavelength in the second record carrier.