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Patent Searching and Data


Title:
PROJECTION OPTICAL SYSTEM AND IMAGE PROJECTION DEVICE
Document Type and Number:
WIPO Patent Application WO/2019/082933
Kind Code:
A1
Abstract:
According to an embodiment, a projection optical system for an image projection device, that includes a plurality of lenses. The projection optical system satisfies conditional expression (1): where fw is a focal length of a lens having the weakest refractive power in the lenses and f is a focal length of the whole projection optical system.

Inventors:
KUBOTA TAKASHI (JP)
Application Number:
JP2018/039510
Publication Date:
May 02, 2019
Filing Date:
October 24, 2018
Export Citation:
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Assignee:
RICOH CO LTD (JP)
KUBOTA TAKASHI (JP)
International Classes:
G02B9/64; G02B13/16
Foreign References:
US20090109543A12009-04-30
JP5199148B22013-05-15
JPS5210196B11977-03-22
JP2011170309A2011-09-01
JP2010249946A2010-11-04
JP2714687B21998-02-16
JP2014021309A2014-02-03
Attorney, Agent or Firm:
SAKAI, Hiroaki (Sakai International Patent Office, Toranomon Mitsui Building 8-1, Kasumigaseki 3-chome, Chiyoda-k, Tokyo 13, 〒1000013, JP)
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