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Title:
PHOTOGRAPHIC LENS
Document Type and Number:
Japanese Patent JP2005284003
Kind Code:
A
Abstract:

To provide a photographic lens capable of obtaining sufficient brightness and high resolution in spite of simple and compact constitution, such as two-lens constitution, suitably mounted on a small-sized electronic equipment in particular.

The photographic lens is equipped with a diaphragm, a positive lens G1 whose surface on an image side is constituted as an aspherical surface convex to the image side near an optical axis and a negative lens G2 whose surface on the image side is constituted as an aspherical surface convex to the image side near the optical axis in order from an object side. The photographic lens satisfies following conditional expressions (1) to (3). Provided that T is a conjugate distance, f is the focal distance of an entire system, ν2 is the Abbe number of the negative lens G2, and D3 is space on the optical axis Z1 between the surface S3 on the image side of the positive lens G1 and the surface S4 on the object side of the negative lens G2. A conditional expression (1) is 1.41<T/f<1.66, a conditional expression (2) is ν2<29.5, and a conditional expression (3) is D3/f>0.05.


Inventors:
NODA TAKAYUKI
Application Number:
JP2004098422A
Publication Date:
October 13, 2005
Filing Date:
March 30, 2004
Export Citation:
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Assignee:
FUJINON CORP
International Classes:
G02B9/10; G02B13/18; (IPC1-7): G02B9/10; G02B13/18
Domestic Patent References:
JP2004004742A2004-01-08
JP2003329921A2003-11-19
JP2002031752A2002-01-31
JPH1130701A1999-02-02
JPH10186226A1998-07-14
JPH05196865A1993-08-06
JPS63187213A1988-08-02
Attorney, Agent or Firm:
Yasushi Santanzaki
Yoichiro Fujishima