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US 11,886,040 B2Granted
Imaging lens and imaging apparatus
AssigneeFUJIFILM Corporation
InventorTaro Asami
Life of this patent
Estimating the term…
Abstract
The imaging lens includes only eight lenses consisting of, in order from an object side, a negative first lens, a negative second lens, a positive third lens convex toward an image side, a positive fourth lens convex toward an object side, a negative fifth lens, a positive sixth lens convex toward the image side, a positive seventh lens convex toward the object side, and a negative eighth lens, as lenses having refractive powers, in which predetermined conditional expressions are satisfied.
Claims18
An imaging lens comprising:
- only eight lenses consisting of, in order from an object side to an image side,
- a first lens that has a negative refractive power,
- a second lens that has a negative refractive power,
- a third lens that has a positive refractive power and of which an image side surface is convex,
- a fourth lens that has a positive refractive power and of which an object side surface is convex,
- a fifth lens that has a negative refractive power,
- a sixth lens that has a positive refractive power and of which an image side surface is convex,
- a seventh lens that has a positive refractive power and of which an object side surface is convex, and
- an eighth lens that has a negative refractive power, as lenses having refractive powers,
- wherein in the sixth lens, an absolute value of a radius of curvature of the image side surface is smaller than an absolute value of a radius of curvature of an object side surface, and
- wherein assuming that an Abbe number of the fifth lens at a d line is νd5, Conditional Expression (1) is satisfied, which is represented by
- νd5<23 (1).
9 more elements
An imaging lens comprising:
- only eight lenses consisting of, in order from an object side to an image side,
- a first lens that has a negative refractive power,
- a second lens that has a negative refractive power,
- a third lens that has a positive refractive power and of which an image side surface is convex,
- a fourth lens that has a positive refractive power and of which an object side surface is convex,
- a fifth lens that has a negative refractive power,
- a sixth lens that has a positive refractive power and of which an image side surface is convex,
- a seventh lens that has a positive refractive power and of which an object side surface is convex, and
- an eighth lens that has a negative refractive power, as lenses having refractive powers,
- wherein in the sixth lens, an absolute value of a radius of curvature of the image side surface is smaller than an absolute value of a radius of curvature of an object side surface, and
- wherein assuming that a distance on an optical axis between the second lens and the third lens is Db23 and a focal length of the imaging lens is f, Conditional Expression (2) is satisfied, which is represented by
- 0.8<Db23/f<7 (2).
9 more elements
An imaging lens comprising:
- only eight lenses consisting of, in order from an object side to an image side,
- a first lens that has a negative refractive power,
- a second lens that has a negative refractive power,
- a third lens that has a positive refractive power and of which an image side surface is convex,
- a fourth lens that has a positive refractive power and of which an object side surface is convex,
- a fifth lens that has a negative refractive power,
- a sixth lens that has a positive refractive power and of which an image side surface is convex,
- a seventh lens that has a positive refractive power and of which an object side surface is convex, and
- an eighth lens that has a negative refractive power, as lenses having refractive powers,
- wherein in the sixth lens, an absolute value of a radius of curvature of the image side surface is smaller than an absolute value of a radius of curvature of an object side surface, and
- wherein assuming that a composite focal length of the fourth lens, the fifth lens, and the sixth lens is f456 and a focal length of the imaging lens is f, Conditional Expression (3a) is satisfied, which is represented by
- 4.5<f456/f<28 (3a).
9 more elements
Dependencies are inferred from the claim text.