Hitachi Maxell, Limited

Toshio Higashihara

Toshinori Sugiyama

Masahiro Suzuki

Seiichi Matsushima

Mitsuru Shimizu

Ken Yoshizawa

An optical recording disc comprises a first bonding recess formed near an outside surface of an optical recording disc in a bonding boundary portion between a cylindrical hub and a transparent disc substrate, a disc member bonded with said transparent disc substrate through said cylindrical hub, and a second bonding recess formed near the outside surface of said optical recording disc in a bonding boundary portion between said cylindrical hub and said disc member. Accordingly, said optical recording disc can prevent remainder of a bonding material for bonding a pair of said transparent disc substrates or said transparent disc substrate and said disc member together from pushing out of the outside surface of the optical recording disc, resulting in that focusing for reading and writing an information signal can be properly performed.

Growing community of inventors

Ibaragi, Japan

Toshio Higashihara