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US 9,753,250 B2Granted
Wide angle lens and image pickup apparatus using the same
AssigneeOlympus Corporation
InventorsAkinori Nishio, Masahiro Imamura, Tomoyuki Satori, Koji Nakagawa
Life of this patent
Estimating the term…
Abstract
A wide angle lens includes in order from an object side, a front lens unit having a positive refractive power, one focusing lens having a negative refractive power, and a rear lens unit having a positive refractive power, and at the time of focusing, the focusing lens moves on an optical axis, and the following conditional expressions (1) and (2) are satisfied. 0.1<f1/SSD<0.5 (1) 3.0≦f23/f (2)
Claims14
A wide angle lens comprising in order from an object side:
- a front lens unit having a positive refractive power;
- one focusing lens having a negative refractive power;
- and
- a rear lens unit having a positive refractive power, wherein
- at the time of focusing, the focusing lens moves on an optical axis, and
- the following conditional expressions (1) and (2) are satisfied:
- 0.1<f1/SSD<0.5 (1)
- 3.0≦f23/f (2)
- where,
- f1 denotes a focal length of the front lens unit;
- SSD denotes a distance from a lens surface nearest to an object of the wide angle lens up to an imaging surface, at the time of infinite object point focusing;
- f23 denotes a focal length of a lens system in which, the focusing lens and the rear lens unit are combined, at the time of infinite object point focusing;
- and
- f denotes a focal length of an overall wide angle lens system.
11 more elements
A wide angle lens comprising in order from an object side:
- a front lens unit having a positive refractive power;
- one focusing lens having a negative refractive power;
- and
- a rear lens unit having a positive refractive power, wherein
- at the time of focusing, the focusing lens moves on an optical axis, and
- the following conditional expressions (3), (4), and (5) are satisfied:
- 0.8<f1/f<1.2 (3)
- |f1/f23|<0.5 (4)
- 0.03<Fno/(f×21.633/Y)<0.08 (5)
- where,
- f1 denotes a focal length of the front lens unit,
- f23 denotes a focal length of a lens system in which, the focusing lens and the rear lens unit are combined, at the time of infinite object point focusing,
- f denotes a focal length of an overall wide angle lens system,
- Fno denotes an F-number of the overall wide angle lens system, and
- Y denotes a maximum image height at an imaging surface of the wide angle lens.
12 more elements
Dependencies are inferred from the claim text.