Invention Grant
- Patent Title: Ultra-wide angle objective lens
- Patent Title (中): 超广角物镜
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Application No.: US12293711Application Date: 2007-11-15
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Publication No.: US07929221B2Publication Date: 2011-04-19
- Inventor: Alex Ning
- Applicant: Alex Ning
- International Application: PCT/US2007/001106 WO 20071115
- International Announcement: WO2007/120370 WO 20071025
- Main IPC: G02B13/04
- IPC: G02B13/04 ; G02B13/18

Abstract:
A ultra-wide angle objective lens comprising a first group having a first lens element having a convex object surface facing the object and a concave image surface facing the image plane, and a second aspheric lens element, the second aspheric lens element having a varying power that is negative at its vertex; and that increases positively with radial distance from the vertex. A second group has at least one lens element and a positive power. A third group has at least a first and a second lens element and a positive power. The ratio of the total track to the focal length satisfies the condition that TT/fo= f*θ, where h(θ) is the image height formed by an off-axis chief ray having a field angle θ, and f is the effective focal length of the lens.
Public/Granted literature
- US20090219631A1 ultra-wide angle objective lens Public/Granted day:2009-09-03
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