Imaging optical system
AssigneeNidec Instruments Corporation
InventorTakuya KASAHARA
Life of this patent
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Abstract
An imaging optical system includes: in order from an object side to an image side, a front group; a diaphragm; and a rear group. The front group includes a plurality of lenses including a first lens arranged closest to the object side. The rear group includes a plurality of lenses. The first lens has a negative power. When a total track of an entire lens system is d0, an effective radius of a lens surface of the first lens on the object side is sd11, and a maximum image height is IH, the following conditional expressions: 3. < d 0 / sd 11 < 4.5 ( 1 ) 2.5 < d 0 / IH < 5. 000 ( 2 ) are satisfied.
Claims20
An imaging optical system comprising:
- in order from an object side to an image side, a front group;
- a diaphragm;
- and
- a rear group, wherein
- the front group includes a plurality of lenses including a first lens arranged closest to the object side,
- the rear group includes a plurality of lenses,
- the first lens has a negative power, and,
- when a total track of an entire lens system is d0, an effective radius of a lens surface of the first lens on the object side is sd11, and a maximum image height is IH, the following conditional expressions are satisfied:
- 3.
- <
- d
-
- 0
- /
- sd
-
- 11
- <
- 4.5
- ;
- (
- 1
- )
- 2.5
- <
- d
-
- 0
- /
- IH
- <
- 5.
- .
- (
- 2
- )
Dependencies are inferred from the claim text.