Invention Grant
- Patent Title: Projection lens and projection display device using the same
- Patent Title (中): 投影镜头和投影显示装置使用相同
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Application No.: US12508868Application Date: 2009-07-24
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Publication No.: US07880973B2Publication Date: 2011-02-01
- Inventor: Masaru Amano
- Applicant: Masaru Amano
- Applicant Address: JP Saitama
- Assignee: Fujinon Corporation
- Current Assignee: Fujinon Corporation
- Current Assignee Address: JP Saitama
- Agency: Birch, Stewart, Kolasch & Birch, LLP
- Priority: JPP2008-218203 20080827
- Main IPC: G02B9/00
- IPC: G02B9/00 ; G02B9/12

Abstract:
Disclosed are a projection lens that is faster than F1.95 and has a simple inner focus structure, a high optical performance, and a small size, and a projection display device.A projection lens includes a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a positive refractive power arranged in this order from a magnification side. A fifth lens arranged closest to a reduction side in the first lens group is moved along an optical axis to adjust focus. The projection lens satisfies the following conditional expression: 0.2
Public/Granted literature
- US20100053764A1 PROJECTION LENS AND PROJECTION DISPLAY DEVICE USING THE SAME Public/Granted day:2010-03-04
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