Title:
IMAGING LENS AND IMAGE PICKUP DEVICE USING THE SAME
Document Type and Number:
WIPO Patent Application WO/2004/107008
Kind Code:
A1
Abstract:
An imaging lens consists of: a first lens (L1) of biconvex shape having positive power and having both convex surfaces which are aspheric surfaces; and a second lens (L2) of meniscus shape having a concave surface opposing to an object, having negative power, and having both surfaces which are aspheric surfaces. The first lens and the second lens are arranged in this order from the object side and the ratio of the lens back focus (bf) against the focal distance (f) of the entire lens system is regulated to a range from 0.6 to 0.8. Thus, it is possible to obtain sufficient back focus and reduce the lens optical length. Accordingly, it is possible to provide a compact imaging lens having a high performance.
Inventors:
NIO JUNICHI (JP)
Application Number:
PCT/JP2004/006648
Publication Date:
December 09, 2004
Filing Date:
May 18, 2004
Export Citation:
Assignee:
SEIKO PRECISION KK (JP)
NIO JUNICHI (JP)
NIO JUNICHI (JP)
International Classes:
G02B13/00; G02B13/18; (IPC1-7): G02B13/00; G02B13/18
Foreign References:
| JP2003075719A | 2003-03-12 | |||
| JP2003227999A | 2003-08-15 | |||
| JP2003329921A | 2003-11-19 | |||
| JP2004004742A | 2004-01-08 |
Attorney, Agent or Firm:
Katayama, Shuhei (6-1 Kyobashi 1-chome, Chuo-k, Tokyo 31, JP)
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