Patent ID: 7194751

Claim:
An optical information medium comprising a pair of discs which have center holes, an optical recording layer provided on at least one of the discs, a reflecting layer formed on an upper side of the optical recording layer and an adhesive layer provided on the reflecting layer for bonding the pair of discs, wherein each of the discs has a tracking guide provided therein, is made of a polycarbonate resin and has an outer diameter of 120 mm and a thickness of 0.6 mm, the discs are bonded to each other at surfaces extending from the center holes to the outermost peripheries of the discs, a non-bonding area is provided at peripheries of the center holes where no adhesive is provided and the diameter of the center hole of one disc is larger than the diameter of the center hole of the other disc and is also larger than the diameter of the non-bonding area.