| 摘要 |
PROBLEM TO BE SOLVED: To prevent warpage and deformation in an optical recording medium and to attain high quality optical recording/reproducing with less aberration by sticking a thinner high rigidity substrate to a thin transparent substrate forming an optical recording layer, fixing to each other. SOLUTION: This optical recording medium is constituted of the transparent substrate 1 forming the optical recording layer 7 on its main surface and the high rigidity substrate with a Young's modulus larger than the same of the transparent substrate 1 and with a planar shape nearly equal to the transparent substrate 1 and fixed to the optical recording layer 3 side of the transparent substrate 1. Then, the thickness of the transparent substrate 1 is made 0.05mm or above and 1.0mm or below, and further, the thickness of the high rigidity substrate 9 is made 0.02mm or above and less than 0.3mm, and the Young's modulus is made 20GPa or above. Thus, the bend rigidity EI as the whole optical recording medium is improved, even though the whole thickness of the optical recording medium is reduced, the bend and the deformation are reduced. Further, since the thickness of the high rigidity substrate 9 is thin, a spacing d between a magnetic core 12 and the optical recording layer 3 is reduced, and it becomes advantageous for magnetic modulation recording also. |
