Invention Grant
- Patent Title: Zoom lens, imaging device, and personal digital assistant
- Patent Title (中): 变焦镜头,成像设备和个人数字助理
-
Application No.: US11873078Application Date: 2007-10-16
-
Publication No.: US07663808B2Publication Date: 2010-02-16
- Inventor: Kazuyasu Ohashi
- Applicant: Kazuyasu Ohashi
- Applicant Address: JP Tokyo
- Assignee: Ricoh Company, Ltd.
- Current Assignee: Ricoh Company, Ltd.
- Current Assignee Address: JP Tokyo
- Agency: Oblon,Spivak, McClelland, Maier & Neustadt, L.L.P.
- Priority: JP2006-281814 20061016
- Main IPC: G02B15/14
- IPC: G02B15/14

Abstract:
The invention provides a zoom lens including at least a first lens group having a positive refracting power, a second lens group having a negative refracting power, a third lens group having a positive refracting power, in order from an object side, and an aperture stop between the second lens group and the third lens group, wherein, in changing magnification from a wide angle end toward a telephoto end, at least the first lens group and the third lens group move toward the object side so as to increase a spacing between the first lens group and the second lens group, and to decrease a spacing between the second lens group and the third lens group.
Public/Granted literature
- US20090091841A1 ZOOM LENS, IMAGING DEVICE, AND PERSONAL DIGITAL ASSISTANT Public/Granted day:2009-04-09
Information query