Invention Grant
- Patent Title: Zoom lens and image-pickup apparatus
- Patent Title (中): 变焦镜头和摄像装置
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Application No.: US10589675Application Date: 2005-10-04
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Publication No.: US07706080B2Publication Date: 2010-04-27
- Inventor: Motoyuki Ohtake , Shinichi Arita
- Applicant: Motoyuki Ohtake , Shinichi Arita
- Applicant Address: JP Tokyo
- Assignee: Sony Corporation
- Current Assignee: Sony Corporation
- Current Assignee Address: JP Tokyo
- Agency: Rader, Fishman & Grauer PLLC
- Priority: JP2004-369632 20041221
- International Application: PCT/JP2005/018343 WO 20051004
- International Announcement: WO2006/067905 WO 20060629
- Main IPC: G02B15/14
- IPC: G02B15/14

Abstract:
To provide a zoom lens capable of achieving stable optical quality by inhibiting an effect of assemble errors during manufacturing. A zoom lens includes a positive first lens group G1, a negative second lens group G2, a positive third lens group G3, and a positive fourth lens group G4, which are arranged from an object side in that order, and during variation in lens position from a wide angle end state to a telescopic end state, G1 and G3 are fixed, G2 is moved toward an image side, G4 moves so as to compensate fluctuations in image-surface position due to the shift of G2, and an aperture diaphragm S is fixed adjacent to the object side of G3, etc. G2 includes a negative meniscus lens L21 with a concave surface opposing the image side and a cemented lens L22 of a biconcave lens and a positive lens with a convex surface opposing the object side, which are arranged from the object side in that order, and the negative meniscus lens is a compound lens of a glass lens and a resin lens PL formed adjacent to the image side of the glass lens, the lens surface adjacent to the image side of the resin lens is aspheric, and the conditional equation (1) below is satisfied: n2>1.75, (1) where n2 is the average refractive index of glass constituting G2.
Public/Granted literature
- US20090109545A1 Zoom Lens and Image-Pickup Apparatus Public/Granted day:2009-04-30
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