Title:
PROJECTION OPTICAL SYSTEM AND PROJECTOR
Document Type and Number:
WIPO Patent Application WO/2016/199393
Kind Code:
A1
Abstract:
The purpose of the present invention is to provide: a projection optical system capable of covering a broad variable magnification range using focus lens groups having a reduced number of component lenses; and a projector provided with said projection optical system. First and second lens groups 42, which are focus lens groups, include: a lens group F1 comprising one positive lens; a lens group F2 comprising one positive lens and one negative lens; and a lens group F3 comprising one negative lens. At least lens group F2 is moved during the focusing which accompanies a change in magnification.
Inventors:
MINEFUJI NOBUTAKA (JP)
Application Number:
PCT/JP2016/002721
Publication Date:
December 15, 2016
Filing Date:
June 06, 2016
Export Citation:
Assignee:
SEIKO EPSON CORP (JP)
International Classes:
G02B17/08; G03B21/00; G03B21/14
Foreign References:
| JP2008250296A | 2008-10-16 | |||
| JP2008134350A | 2008-06-12 |
Other References:
See also references of EP 3309597A4
Attorney, Agent or Firm:
WATANABE, Kazuaki et al. (JP)
Kazuaki Watanabe (JP)
Kazuaki Watanabe (JP)
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