| 摘要 |
PURPOSE:To improve the adhering strength between a disc base and a protection base by providing an information medium layer to a face having a track pit of the disc base one face of which the track pit is formed and adhering the protection base of the same shape as the said base while opposing the track pit. CONSTITUTION:The track pit 2 for guiding laser beam is formed incorporatedly to one face of the disc base 1. The recording medium layer 3 is provided to the face of the track pit 2 of the base 1. The protection base 6 to protect the medium layer 3 is adhered to the base 1 via an adhesive 7. Entirely the same base as the base 1 is used for the base 6, an adhesive 7 is bonded directly to the track pit 8 formed incorporatedly with the base 6 and the bonding force is improved by the ruggedness of the track pit 8. Thus, the adhering strength between the disc base 1 and the protection base 6 is improved. |
