Micro photographic lens system |
Title： |
| Micro photographic lens system |
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Application Number： |
200410027754 |
Application Date： |
2004/06/16 |
Announcement Date： |
2005/12/21 |
Pub. Date： |
2007/06/27 |
Publication Number： |
1710456 |
Announcement Number： |
1323306 |
Grant Date： |
2007-6-27 |
Granted Pub. Date： |
2007-6-27 |
ApplicationType： |
Invention |
State/Country： |
11[China|beijing] |
IPC： |
G02B 9/04, G02B 13/18 |
Applicant(s)： |
Tsinghua Univ. |
Inventor(s)： |
Jin Guofan, Wang Minqiang, Wang Zhuo, Yan Yingbai, Zeng Jiyong |
Key Words： |
Micro, photographic lens system |
Abstract： |
The system includes following parts from object side to imaging plane: diaphragm, a first biconvex lens, and a crescent shaped second lens whose concave is bent to the object side. At least one surface in first and second lenses is an aspheric surface, and at least one lens is made from glass. The system also satisfies following two conditions: condition (1) is l < T/f <1.6, where T as distance from diaphragm to image plane, f as focal length of the taking lens; optimal condition (2) is d /R2 >1.6, where R2 as absolute value of curvature radius of first lens's surface near to image plane, d as thickness of first lens. Emergence angle of principal ray is controlled within certain range in the system. Considering low cost and yield, the system raises image quality. The system is applicable to product in high end with million pixels. |
Claim： |
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Priority： |
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PCT： |
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LegalStatus： |
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