Invention Grant
- Patent Title: Projection optical system and projector
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Application No.: US15580584Application Date: 2016-06-10
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Publication No.: US10534252B2Publication Date: 2020-01-14
- Inventor: Nobutaka Minefuji
- Applicant: SEIKO EPSON CORPORATION
- Applicant Address: JP Tokyo
- Assignee: SEIKO EPSON CORPORATION
- Current Assignee: SEIKO EPSON CORPORATION
- Current Assignee Address: JP Tokyo
- Agency: Oliff PLC
- Priority: JP2015-119003 20150612; JP2016-077075 20160407
- International Application: PCT/JP2016/002803 WO 20160610
- International Announcement: WO2016/199426 WO 20161215
- Main IPC: G03B21/53
- IPC: G03B21/53 ; G02B13/18 ; G02B13/16 ; G03B21/28

Abstract:
A projection optical system and that includes a relatively small number of lenses and are able to cover a wide zooming range and a projector. A 1-2 lens group which is a focus lens group is constituted with a lens which includes a single positive lens having a convex surface to the reduction side, a lens which includes a single negative meniscus lens having a convex surface to an enlargement side, and a lens which includes a single negative lens, and the 1-2 lens group is moved at the time of focusing accompanying magnification change.
Public/Granted literature
- US20180173088A1 PROJECTION OPTICAL SYSTEM AND PROJECTOR Public/Granted day:2018-06-21
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