Title:
IMAGE PICKUP LENS
Document Type and Number:
Japanese Patent JP3467155
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To obtain an image pickup lens having simple constitution and fine optical performance by arranging a brightness stop for restricting a beam in the vicinity of the object side face of a radial type GRIN lens having positive refractive power as a whole and satisfying specific conditions.
SOLUTION: The image pickup lens consists of the radial type GRIN lens G of which object side face is concave and image side face is flat and the brightness stop S is formed on the object side face of the lens G. The lens G is constituted so as to satisfy inequalities -1<&phiv s1<&phiv <0, -2<d.&phiv <0.5 and -0.015<1/V1<0.015. In the inequalities, &phiv s1 is the refractive power of the object side face of the radial type refractive index distribution lens, &phiv is the refractive power of the whole radial type refractive index distribution lens G, d is an optical axis direction distance from the lens object face of the stop S, and V1 is the Abbe number of a medium for the lens G. Since the image pickup lens is constituted of one radial type GRIN lens, simple constitution can be obtained, the influence of an assembling error can be reduced and fine optical performance can be obtained.
Inventors:
Hirofumi Tsuchida
Application Number:
JP30239996A
Publication Date:
November 17, 2003
Filing Date:
October 29, 1996
Export Citation:
Assignee:
Olympus Optical Co., Ltd.
International Classes:
G02B9/00; G02B13/00; (IPC1-7): G02B13/00
Domestic Patent References:
| JP60140307A | ||||
| JP2284107A | ||||
| JP615221A | ||||
| JP3267913A | ||||
| JP836130A | ||||
| JP1282514A |
Attorney, Agent or Firm:
Kanji Mukai