发明名称 |
Zoom lens system for minimal lens system length and minimal aberrations |
摘要 |
The present invention provides a compact zoom lens system comprising; a first lens group having a positive refractive power; a second lens group having a negative refractive power located at the image side of the first lens group with a first variable air space between the first and second lens groups; and a third lens group having a positive refractive power, located at the image side of the second lens group with a second variable air space between the second and third lens groups, including a positive front lens unit and a positive rear lens located at the image side of the front lens unit with a third variable air space between the front and rear lens units, and having at least one aspheric surface; wherein the first lens group and the front and rear lens units of the third lens group are shiftable to the object side in the zooming operation from the shortest focal length to the longest focal length with changing the first, second and third variable air spaces.
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申请公布号 |
US4871239(A) |
申请公布日期 |
1989.10.03 |
申请号 |
US19870095168 |
申请日期 |
1987.09.09 |
申请人 |
MINOLTA CAMERA KABUSHIKI KAISHA |
发明人 |
MASUMOTO, HISAYUKI;FUKUSHIMA, AKIRA |
分类号 |
G02B15/173 |
主分类号 |
G02B15/173 |
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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