| 发明名称 | Wide-angle lens system, image sensing optical device and digital apparatus | ||
| 摘要 | A wide-angle lens system is formed, sequentially from an object side, with a first group having a positive power, a second group having a negative power and a third group having a positive power, and at the time of focusing, only the second group is moved on an optical axis. The lens system satisfies conditional formulas of 0.3<BH1/T1<0.7 and 0.9<f3/f<1.8 (where BH1 is a distance from the final surface of the first group to a principal point position on the back side of the first group, T1 is a distance on the optical axis from a lens element surface of the first group closest to the side of the object to a lens element surface closest to the side of the image, f3 is the focal length of the third group and f is the focal length of the entire system). | ||
| 申请公布号 | US9247134(B2) | 申请公布日期 | 2016.01.26 |
| 申请号 | US201313916112 | 申请日期 | 2013.06.12 |
| 申请人 | KONICA MINOLTA, INC. | 发明人 | Souma Yoshihito |
| 分类号 | G02B13/04;H04N5/232;G02B9/14;G02B3/04;G02B9/62 | 主分类号 | G02B13/04 |
| 代理机构 | Cozen O'Connor | 代理人 | Cozen O'Connor |
| 主权项 | 1. A wide-angle lens system which is formed, sequentially from a side of an object, with a first group having a positive optical power, a second group having a negative optical power and a third group having a positive optical power and in which at a time of focusing, only the second group is moved on an optical axis, wherein the wide-angle lens system satisfies conditional formulas (1) and (2) below: 0.3<BH1/T1<0.7 (1)0.9<f3/f<1.8 (2) where BH1 is a distance from a final surface of the first group to a principal point position on a back side of the first group (a direction extending from the side of the object to an image surface is positive), T1 is a distance on the optical axis from a lens element surface of the first group closest to the side of the object to a lens element surface closest to the side of the image, f3 is a focal length of the third group and f is a focal length of the entire system. | ||
| 地址 | Tokyo JP | ||