Title:
光学系及びそれを有する光学機器
Document Type and Number:
Japanese Patent JP5424745
Kind Code:
B2
Abstract:
An optical system having a larger total lens length than a focal length includes lenses L and NL on at least one of a magnification conjugate side and a reduction conjugate side with respect to an aperture stop. The lens L satisfies conditional expressions as follows, −1.68×10−3·νL+0.590<θL<3.15×10−4·νL2−1.86×10−2·νL+0.878, and 5<νL<27, where νL and θL are an Abbe number and a gF-line partial dispersion ratio of the lens L. The refractive power of the lens L is positive when located at the magnification conjugate side, or negative when located at the reduction conjugate side.
Inventors:
Ken Wada
Arata Sato
Arata Sato
Application Number:
JP2009157739A
Publication Date:
February 26, 2014
Filing Date:
July 02, 2009
Export Citation:
Assignee:
Canon Inc
International Classes:
G02B15/20; G02B13/04; G02B13/18; G03B21/14; H04N5/225
Domestic Patent References:
| JP2008129403A | ||||
| JP2008122676A | ||||
| JP2007155836A | ||||
| JP2005062225A | ||||
| JP8248314A | ||||
| JP2008241794A | ||||
| JP2008129460A |
Attorney, Agent or Firm:
Yukio Takanashi