| 摘要 |
<P>PROBLEM TO BE SOLVED: To enhance a manufacturing process margin for reducing the price in a thin optical recording medium having two or more recording layers. <P>SOLUTION: A high reflectance metal layer 4 having a mirror surface is formed to correspond to a region where information is recorded or reproduced in at least a recording layer 2 on a deeper side of the recording layer 2. When a beam 6 is made incident in the thin optical recording medium from a substrate 1 side via a lens to perform recording or reproduction, if a distance from a recording surface S0 located on the deepest side when viewed from a beam incident surface of the PC substrate 1 to the beam incident surface of the PC substrate 1, a thickness of a TO spacer layer located between the high reflectance metal layer 4 and an S0 recording layer in front thereof and a thickness of the PC substrate 1 are defined as BLD, TOD and SD, respectively, SD=(BLD-2TOD) is satisfied. Thereby, the price of the thin optical recording medium is reduced as compared with conventional one. <P>COPYRIGHT: (C)2009,JPO&INPIT |
