| 发明名称 |
Check discs. |
| 摘要 |
<p>A check disc (1) has a single frequency signal recorded adjacent to the information signal tracks (TN), and simulated defects (2 to 4) are formed at predetermined track positions.</p> |
| 申请公布号 |
EP0402002(B1) |
申请公布日期 |
1995.05.17 |
| 申请号 |
EP19900305551 |
申请日期 |
1990.05.22 |
| 申请人 |
SONY CORPORATION |
发明人 |
ISHIMURA, NORIYUKI, C/O PATENTS DIVISION SONY CORP;YOKOYAMA, KATSUJI, C/O PATENTS DIVISION SONY CORP |
| 分类号 |
G11B20/18;(IPC1-7):G11B20/18;G11B7/24;G11B7/013 |
主分类号 |
G11B20/18 |
| 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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