Imaging lens
AssigneeTokyo Visionary Optics Co., Ltd.
InventorMasaya HASHIMOTO
Life of this patent
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Abstract
There is provided an imaging lens with excellent optical characteristics which satisfies demand of a low profile and a low F-number. An imaging lens comprises in order from an object side to an image side, a first lens with positive refractive power having an object-side surface being convex in a paraxial region; a second lens with negative refractive power having an object-side surface being convex in a paraxial region; a third lens with negative refractive power having an object-side surface being concave in a paraxial region; a fourth lens with negative refractive power in a paraxial region; and a fifth lens with positive refractive power having an image-side surface being convex in a paraxial region, and predetermined conditional expressions are satisfied.
Claims7
An imaging lens comprising in order from an object side to an image side,
- a first lens with positive refractive power having an object-side surface being convex in a paraxial region;
- a second lens with negative refractive power having an object-side surface being convex in a paraxial region;
- a third lens with negative refractive power having an object-side surface being concave in a paraxial region;
- a fourth lens with negative refractive power in a paraxial region;
- and
- a fifth lens with positive refractive power having an image-side surface being convex in a paraxial region,
- wherein the following conditional expression (1) is satisfied:
- 0.90<|r7|/f<4.00 (1)
- where
- r7:
- a paraxial curvature radius of an object-side surface of the fourth lens, and
- f:
- a focal length of the overall optical system of the imaging lens.
Dependencies are inferred from the claim text.