Title:
OPTICAL SYSTEM AND IMAGING DEVICE USING SAME
Document Type and Number:
Japanese Patent JP2011175280
Kind Code:
A
Abstract:
To provide an optical system, which can reduce its thickness while having a high variable power ratio and reduces influence of eccentricity to prevent deterioration in performance, and to provide an imaging device using the optical system.
The optical system includes: a first lens group G1 having negative refractive power; a second lens group G2 having positive refractive power; and a cemented lens having positive refractive power as a whole and having cemented surfaces on the optical axis. Lenses constituting the cemented lens satisfy an expression (5): 40<νmax-νmin<80 and an expression (6): 23.7>νmin. In the expressions (5) and (6), νmax is a maximum Abbe number in the cemented lens, and νmin is a minimum Abbe number in the cemented lens.
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Inventors:
YANAI TETSUYA
Application Number:
JP2011090147A
Publication Date:
September 08, 2011
Filing Date:
April 14, 2011
Export Citation:
Assignee:
OLYMPUS IMAGING CORP
International Classes:
G02B15/16; G02B13/18
Domestic Patent References:
| JP2006323233A | 2006-11-30 | |||
| JP2004240398A | 2004-08-26 | |||
| JP2002014285A | 2002-01-18 |
Attorney, Agent or Firm:
Hiroshi Nagisawa
Ryukichi Abe
Hirukawa Masanobu
Norihiko Uchida
Hideo Sugai
Kenji Aoki
Akira Yonezawa
Ryukichi Abe
Hirukawa Masanobu
Norihiko Uchida
Hideo Sugai
Kenji Aoki
Akira Yonezawa