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Patent Searching and Data


Title:
INTERNAL FOCUSING LARGE-APERTURE MEDIUM TELEPHOTO LENS, IMAGE CAPTURE OPTICAL DEVICE, AND DIGITAL DEVICE
Document Type and Number:
WIPO Patent Application WO/2011/108428
Kind Code:
A1
Abstract:
The disclosed internal focusing large-aperture medium telephoto lens has as lens groups a positive first lens group, a positive second lens group, and a third lens group, in that order from the object side. When focusing on nearby objects, the first lens group and the third lens group have a fixed position relative to the image surface, and the second lens group displaces toward the object side. The second lens group has only one negative lens, and, in order from the object side, has at least a positive lens, a negative lens, and a positive lens. The following expression is fulfilled: -0.5 < (R1+R2)/(R1-R2) < -0.1 (wherein, R1: radius of curvature of the object side surface of the negative lens in the second lens group; R2: radius of curvature of the image side surface of the negative lens in the second lens group).

Inventors:
SOUMA Yoshihito (C/O Konica Minolta Opto, Inc. 2970, Ishikawa-Machi, Hachioji-Sh, Tokyo 05, 〒1928505, JP)
相馬 祥人 (〒05 東京都八王子市石川町2970 コニカミノルタオプト株式会社内 Tokyo, 〒1928505, JP)
Application Number:
JP2011/054084
Publication Date:
September 09, 2011
Filing Date:
February 24, 2011
Export Citation:
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Assignee:
Konica Minolta Opto, Inc. (2970, Ishikawa-Machi Hachioji-Sh, Tokyo 05, 〒1928505, JP)
コニカミノルタオプト株式会社 (〒05 東京都八王子市石川町2970 Tokyo, 〒1928505, JP)
NIKON CORPORATION (12-1, Yurakucho 1-chome Chiyoda-k, Tokyo 31, 〒1008331, JP)
株式会社ニコン (〒31 東京都千代田区有楽町一丁目12番1号 Tokyo, 〒1008331, JP)
International Classes:
G02B13/02; H04N5/225
Attorney, Agent or Firm:
SANO Shizuo (Tenmabashi-Yachiyo Bldg. Bekkan, 2-6 Tenmabashi-Kyomachi, Chuo-Ku, Osaka-Sh, Osaka 32, 〒5400032, JP)
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Claims: