发明名称 |
APPARATUS FOR CONTACT COPYING MAGNETIC RECORDS INCLUDING SHIELD FOR PREVENTING ERASURE OF THE MASTER RECORD |
摘要 |
An apparatus for copying a magnetic record from a magnetic master with the assistance of anhysteretic magnetic fields includes a medium for setting up countermagnetic fields which oppose the anhysteretic magnetic fields and prevent erasure of the magnetic record.
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申请公布号 |
US3641280(A) |
申请公布日期 |
1972.02.08 |
申请号 |
USD3641280 |
申请日期 |
1970.01.19 |
申请人 |
BELL & HOWELL CO. |
发明人 |
LEWIS B. BROWDER |
分类号 |
G11B5/86;(IPC1-7):G11B5/86 |
主分类号 |
G11B5/86 |
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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