Patent ID: 8156515
Filing Date: 2012-04-10
Classification: G11B

Abstract:
1. An optical recording medium, comprising a plurality of laminated recording layers, wherein a spacing is provided between each respective recording layer of the plurality of recording layers and each other recording layer of the plurality of recording layers, as a spacing between each respective pair of recording layers, the spacing between each respective pair of recording layers of all recording layer pair combinations selected from the plurality of recording layers is different from the spacing between each other recording layer pair combination of all recording layer combinations selected from the plurality of recording layers, the plurality of recording layers includes five or more recording layers, the optical recording medium further comprises four or more intermediate layers arranged between recording layers of the plurality of recording layers, three or more of the four or more intermediate layers, excluding a foremost intermediate layer or a rearmost intermediate layer, are composed of a plurality of alternating odd-numbered intermediate layers and one or more alternating even-numbered intermediate layers, out of the three or more of the four or more intermediate layers, excluding the foremost intermediate layer or the rearmost intermediate layer from a perspective of light incident side, a minimum thickness of the even-numbered intermediate layers from the perspective of the light incident side is larger than a maximum thickness of the odd-numbered intermediate layers or a minimum thickness of the odd-numbered intermediate layers is larger than a maximum thickness of the even-numbered intermediate layers, and the odd-numbered intermediate layers and the even-numbered intermediate layers are arranged to successively become thicker or thinner from the light incident side.