发明名称 |
Close focusing zoom lens |
摘要 |
A zoom lens having capability of focusing to a magnification of 1:2 through movement of only the front focusing group. The power of the focusing group is chosen in relation to the power of the lens at its long focal length to accomplish close focusing with minimal axial travel while providing good aberration correction.
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申请公布号 |
US4307943(A) |
申请公布日期 |
1981.12.29 |
申请号 |
US19800178529 |
申请日期 |
1980.08.15 |
申请人 |
VIVITAR CORPORATION |
发明人 |
BETENSKY, ELLIS I.;KREITZER, MELVYN H. |
分类号 |
G02B15/22;(IPC1-7):G02B15/18 |
主分类号 |
G02B15/22 |
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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