| 摘要 |
PURPOSE:To prevent generation of microchipping by enclosing the outside circumference of a disk with annular frames to a U shape so that mechanical impact is dispersed. CONSTITUTION:This optical disk is constructed by joining a front substrate 1 on which a recording layer 3 is formed and a rear substrate 2 on which a recording layer 4 is formed by an adhesive agent 5, adhering the 1st L-shaped annular frame 8 to the end face of the disk and adhering another L-shaped annular frame 9 thereto from the other side. The L-shaped annular frame 9 is formed to the outside diameter larger than the outside diameter of the L- shaped annular frame 8 in order to enclose the outside circumference of the disk with these two frames 8, 9 to the U shape in the sectional shape. The adhesion of the frame 8 to the disk substrate may be executed simultaneously at the time of joining the front substrate 1 and the rear substrate 2 by an adhesive layer 5. The outside circumference of such optical disk is enclosed with the annular frames to the U shape. The impact is thus dispersed by the annular frames and the generation of microchipping to cause cracking is prevented. |
