发明名称 OPTICAL RECORDING MEDIUM, AND OPTICAL INFORMATION DEVICE
摘要 An optical recording medium and an optical information device that improve the quality of a servo signal and a reproduction signal. In the optical recording medium, when 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 nrα and a thickness trα (satisfying: 1≦̸α≦̸n (where α 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 tα (satisfying: 1≦̸α≦̸n (where α is a positive integer and n is an integer of 4 or more)) are equal to each other. Further, 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, and |(t1+t2)−(t3+t4)|≧1 μm.
申请公布号 US2012011524(A1) 申请公布日期 2012.01.12
申请号 US201113238060 申请日期 2011.09.21
申请人 KOMMA YOSHIAKI;ANZAI JOJI;TSUKUDA MASAHIKO;HINO YASUMORI 发明人 KOMMA YOSHIAKI;ANZAI JOJI;TSUKUDA MASAHIKO;HINO YASUMORI
分类号 G11B7/24;G11B7/135 主分类号 G11B7/24
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