发明名称 OPTICAL RECORDING MEDIUM AND OPTICAL INFORMATION DEVICE
摘要 An object of the invention is to provide an optical recording medium and an optical information device that enable to improve the quality of a servo signal and a reproduction signal. In the case where shape-wise thicknesses tr1, tr2, tr3, and tr4 of a cover layer (42), a first intermediate layer (43), a second intermediate layer (44), and a third intermediate layer (45) are respectively converted into thicknesses t1, t2, t3, and t4 of the respective corresponding layers each having a predetermined refractive index "no", a defocus amount with respect to a layer having a refractive index nr± and a thickness tr± (satisfying: 1‰¦±‰¦n (where ± is a positive integer and n is an integer of 4 or more)), and a defocus amount with respect to a layer having the refractive index "no" and a thickness t ± (satisfying: 1 ‰¦5±‰¦n (where ± is a positive integer and n is an integer of 4 or more)) are equal to each other; and the thicknesses t1, t2, t3, and t4 satisfy |t1-(t2+t3+t4)|‰§1 µm, a difference between any two values of the thicknesses t1, t2, t3, and t4 is set to 1 µm or more in any case, and |(t1+t2)-(t3+t4)|‰§1 µm.
申请公布号 EP2367172(A1) 申请公布日期 2011.09.21
申请号 EP20090825900 申请日期 2009.11.11
申请人 PANASONIC CORPORATION 发明人 KOMMA, YOSHIAKI;ANZAI, JOJI;TSUKUDA, MASAHIKO;HINO, YASUMORI
分类号 G11B7/24;G11B7/085;G11B7/135 主分类号 G11B7/24
代理机构 代理人
主权项
地址