CPC G02B 13/0045 (2013.01) [G02B 3/005 (2013.01); G02B 3/02 (2013.01); G02B 13/08 (2013.01)] | 20 Claims |
1. A lens system comprising:
a plurality of lens elements arranged from an object side to an image plane side; and
a diaphragm arranged between the plurality of lens elements,
wherein the plurality of lens elements include a plurality of freeform lenses each having a freeform surface that is asymmetrical with respect to a first direction and a second direction which cross with each other,
at least one freeform lens is placed on the image plane side of the diaphragm, and
at least one freeform lens satisfying a conditional expression (1) given below is placed on the object side of the diaphragm;
0.3<T1/T2<0.76 (1)
where
T1: a lens thickness in the first direction at a maximum height of an axial ray that passes through the lens system along with an optical axis of the lens system, and
T2: a lens thickness in the second direction at the maximum height of the axial ray that passes through the lens system along with the optical axis of the lens system.
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