发明名称 |
Optical recording medium and disc cartridge |
摘要 |
An optical recording medium is provided which has a substrate and a signal recording layer provided on the substrate and in which an information signal is recorded in the form of microscopic pits. A light beam is focused on the signal recording layer and some change of the light beam carried by a return light from the signal recording layer is detected to read the information signal recorded on the signal recording layer. The optical recording medium has a diameter of 65 mm or less and a thickness of 0.4 to 0.7 mm. An information signal recording area extends outwardly from a radial position of 12.5 mm or less from the center of the medium. The ratio in area between the information signal recording area and non-signal recording area is 3.4 or more. The storage capacity of this medium is 2 gigabytes or more. The optical recording medium has formed at the center thereof a center hole around which an annular table-abutment convexing to one side of the medium is formed. A magnetic-clamping hub is installed in the center hole and thus the medium is magnetically clamped to a rotation driving mechanism of an optical recording and/or reproducing apparatus. The compactness and high density of recording of the optical recording medium will contribute greatly to a further compact structure of a recording and/or reproducing apparatus in which the medium is to be used. <IMAGE> |
申请公布号 |
EP1067519(A1) |
申请公布日期 |
2001.01.10 |
申请号 |
EP20000112911 |
申请日期 |
2000.06.19 |
申请人 |
SONY CORPORATION |
发明人 |
NETSU, NAOHIRO;AOKI, YOSHITAKA;WATANABE, TETSU;FUJIIE, KAZUHIKO;MAEDA, YASUAKI;KAERIYAMA, TAKUYA |
分类号 |
G11B7/007;G11B7/013;G11B7/24;G11B7/26;G11B11/105;G11B23/00;G11B23/03 |
主分类号 |
G11B7/007 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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