| 摘要 |
PURPOSE:To prevent the decrease in mechanical accuracy caused by sealing of bubbles by forming a plurality of grooves from an outer periphery and/or an inner periphery to the outer periphery through a region facing the inner region of a disk in an adhesive agent layer formed on one of a pair of disk substrates, bonding the adhesive agent layers, and forming a unitary body. CONSTITUTION:Protecting layers 4, intermediate layers 5, recording layers 6 as data holding parts, protecting layers 7 and protecting coats 8 are sequentially provided on a pair of disk substrates 2 and 2. The substrates 2 and 2 from a unitay body with an adhesive agent layer 9. A pair of the adhesive agent layers, i.e., the adhesive agent layer 9 for bonding disks and a bonding agent layer 99 for bonding the disk and the bonding agent sheet, are formed on both main surfaces of a base material 91. Thus the adhesive agent sheets are used on both main surface of the base material 91. At this time, a plurality of grooves are formed from the outer periphery and /or an inner periphery, to the outer periphery and/or the inner periphery by way of a region facing the inner region of the disk in the adhesive agent layer 9 for bonding the disks of the adhesive agent layer. Thus, the optical disk having the high mechanical accuracy wherein bubbles are not sealed is obtained. |
