Invention Grant
- Patent Title: Zoom lens
- Patent Title (中): 变焦镜头
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Application No.: US13010100Application Date: 2011-01-20
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Publication No.: US08395847B2Publication Date: 2013-03-12
- Inventor: Lai Wei
- Applicant: Lai Wei
- Applicant Address: JP Saitama-shi
- Assignee: Tamron Co., Ltd.
- Current Assignee: Tamron Co., Ltd.
- Current Assignee Address: JP Saitama-shi
- Agency: Foley & Lardner LLP
- Priority: JP2010-040456 20100225
- Main IPC: G02B15/14
- IPC: G02B15/14

Abstract:
A zoom lens includes sequentially from an object side a first lens group having a negative refractive power; a diaphragm; and a second lens group having a positive refractive power. Zoom from a wide angle edge to a telephoto edge is performed by displacement of the second lens group along an optical axis, toward the object side. Correction of imaging plane variation accompanying the zoom, is performed by displacement of the first lens group along the optical axis. The second lens group includes sequentially from the object side, a positive first lens having at least on aspheric surface and a positive second lens. Furthermore, a first condition υd21>63 and a second condition υd22>70 are satisfied, υd21 being the Abbe number for a d-line in the first lens of the second lens group and υd22 being the Abbe number for a d-line in the second lens of the second lens group.
Public/Granted literature
- US20110205638A1 ZOOM LENS Public/Granted day:2011-08-25
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