Invention Grant
US08508855B2 Projection lens and projection-type display apparatus using the lens
有权
使用透镜的投影透镜和投影型显示装置
- Patent Title: Projection lens and projection-type display apparatus using the lens
- Patent Title (中): 使用透镜的投影透镜和投影型显示装置
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Application No.: US13075594Application Date: 2011-03-30
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Publication No.: US08508855B2Publication Date: 2013-08-13
- Inventor: Chikara Yamamoto
- Applicant: Chikara Yamamoto
- Applicant Address: JP Tokyo
- Assignee: Fujifilm Corporation
- Current Assignee: Fujifilm Corporation
- Current Assignee Address: JP Tokyo
- Agency: Young & Thompson
- Priority: JP2010-078038 20100330
- Main IPC: G02B13/16
- IPC: G02B13/16 ; G02B13/22 ; G02B9/14

Abstract:
A projection lens is composed of a positive first lens group, a negative second lens group, and a positive third lens group, which are sequentially arranged from the magnification side of the projection lens, and the reduction side of the projection lens is telecentric. Further, the following formulas (1) and (2) are satisfied: 0.30≦d23/f3≦0.65 (1); and 10≦|D12/ff| (2), where d23: space in air between the second lens group and the third lens group, f3: focal length of the third lens group, D12: total length of the first lens group and the second lens group in the direction of an optical axis, and ff: length from the most magnification-side surface in the entire system of the projection lens to a magnification-side focus position of the entire system.
Public/Granted literature
- US20110242685A1 PROJECTION LENS AND PROJECTION-TYPE DISPLAY APPARATUS USING THE LENS Public/Granted day:2011-10-06
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