Invention Grant
- Patent Title: Zoom lens, camera, and portable information terminal device
- Patent Title (中): 变焦镜头,相机和便携式信息终端设备
-
Application No.: US14617118Application Date: 2015-02-09
-
Publication No.: US09329367B2Publication Date: 2016-05-03
- Inventor: Yoshifumi Sudoh
- Applicant: Yoshifumi Sudoh
- Applicant Address: JP Tokyo
- Assignee: RICOH COMPANY, LTD.
- Current Assignee: RICOH COMPANY, LTD.
- Current Assignee Address: JP Tokyo
- Agency: Oblon, McClelland, Maier & Neustadt, L.L.P.
- Priority: JP2014-034346 20140225
- Main IPC: G02B15/14
- IPC: G02B15/14 ; G02B9/36 ; G02B13/14 ; G03B3/00 ; G02B15/173 ; G02B13/00 ; G02B9/34 ; G02B15/167 ; G02B15/20 ; G02B5/00

Abstract:
A zoom lens includes, in order from an object side to an image side, first, second, third, and fourth lens groups with positive, negative, negative, and positive refractive powers, respectively. When varying magnification from a short focal length end to a long focal length end, the second lens group is moved to the image side, the third lens group is moved, and the first and fourth lens groups are fixed. The fourth lens group is constituted of a lens group on the object side and a lens group on the image side with a largest distance in the fourth lens group between them. Each of a refractive index, Abbe number, a partial dispersion ratio, and the like of each of at least one positive lens of the lens group on the object side and two positive lenses of the first lens group is regulated to be in a predetermined range.
Public/Granted literature
- US20150241675A1 ZOOM LENS, CAMERA, AND PORTABLE INFORMATION TERMINAL DEVICE Public/Granted day:2015-08-27
Information query