发明名称 |
Imaging lens and imaging apparatus |
摘要 |
An imaging lens provided with a negative first lens group and a positive second lens group disposed in order from the object side. The first lens group is composed of a first group first lens which is a negative biconcave single lens, and the second lens group is composed of a positive second group first lens, an aperture stop, a positive second group second lens, and a negative second group third lens disposed in order from the object side. The second group second lens and second group third lens are cemented together to form a cemented lens. The imaging lens is configured to satisfy a conditional expression (3) 0.9<dt3/f<1.3, and further configured to satisfy conditional expression (1) 31<νd2<55 or (1′): 35<νd2 and a conditional expression (2): −10<νd1−νd2<25. |
申请公布号 |
US9036279(B2) |
申请公布日期 |
2015.05.19 |
申请号 |
US201414153299 |
申请日期 |
2014.01.13 |
申请人 |
FUJIFILM CORPORATION |
发明人 |
Tsutsumi Katsuhisa;Ishii Yoshiaki |
分类号 |
G02B13/00;G02B9/58;G02B9/34 |
主分类号 |
G02B13/00 |
代理机构 |
Young & Thompson |
代理人 |
Young & Thompson |
主权项 |
1. An imaging lens, substantially consisting of a first lens group having a negative and of power and a second lens group having a positive refractive power disposed in order from the object side, wherein:
the first lens group is composed of a first group firs lens which is a single lens having a biconcave shape and a negative refractive power; second lens group is composed of a second group first lens having a positive refractive power, an aperture stop, a second group second lens having a positive refractive power, and a second group third lens having a negative refractive power, disposed in order from the object side; the second group second lens and the second group third lens are cemented together to form a cemented lens; and the imaging lens satisfies conditional expressions (1) and (3) given below:
31<νd2<55 (1); and0.9<dt3/f<1.3 (3),where:
νd2: the Abbe number of the second group first lens with reference to the d-line; dt3: the thickness of the second group, first lens on the optical axis; and f: the focal length of the entire lens system. |
地址 |
Tokyo JP |