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US 8,576,499 B2Granted
Imaging lens and imaging apparatus
AssigneeSony Corporation
InventorHideaki Okano
Life of this patent
Estimating the term…
Abstract
An imaging lens includes: an aperture stop; a first lens having a positive refractive power; a second lens having a negative refractive power which is formed in a concave shape on both sides thereof; a third lens having a positive refractive power which is formed in a meniscus shape in which a concave surface is directed toward the side of an object; and a fourth lens having a negative refractive power in which a convex surface is directed toward the object side, which are sequentially disposed from the object side to the image side, wherein the imaging lens satisfies the following conditional expressions (1), (2), (3) and (4): 0.40<f1/|f2|<0.80 (1) 0.10<f/f3<0.80 (2) 0.20<f/|f4|<1.00 (3) vd1−vd2>25. (4)
Claims12
An imaging lens comprising:
- an aperture stop:
- a first lens having a positive refractive power:
- a second lens having a negative refractive power which is formed in a concave shape on both sides thereof;
- a third lens having a positive refractive power which is formed in a meniscus shape in which a concave surface is directed toward the side of an object;
- and
- a fourth lens having a negative refractive power in which a convex surface is directed toward the object side, which are sequentially disposed from the object side to the image side,
- wherein the imaging lens satisfies the following conditional expressions (1), (2), (3) and (4):
- 0.40<f1/|f2|<.80 (1)
- 0.10<f/f3<080 (2)
- 0.20<f/|f4|<1.00 (3)
- vd1−vd2>25 (4)
- where f1 is a focal length of the first lens, f2 is a focal length of the second lens, f3 is a focal length of the third lens, f4 is a focal length of the fourth lens, f is a focal length of an entire lens system, vd1 is an Abbe number of the first lens, and vd2 is an Abbe number of the second lens, and
- wherein the imaging lens satisfies the following conditional expression (5):
- 1.50<R6/R7<4.00 (5)
- where R6 is a paraxial curvature radius of the surface on the object side of the third lens, and R7 is a paraxial curvature radius of a surface on the image side of the third lens.
12 more elements
An imaging apparatus comprising:
- an imaging lens;
- and
- an imaging device which converts an optical image formed by the imaging lens into an electrical signal,
- wherein the imaging lens includes an aperture stop, a first lens having a positive refractive power, a second lens having a negative refractive power which is formed in a concave shape on both sides thereof, a third lens having a positive refractive power which is formed in a meniscus shape in which a concave surface is directed toward the side of an object, and a fourth lens having a negative refractive power in which a convex surface is directed toward the object side, which are sequentially disposed from the object side to the image side, and
- wherein the imaging lens satisfies the following conditional expressions (1), (2), (3) and (4):
- 0.40<f1/|f2|<0.80 (1)
- 0.10<f/f3<0.80 (2)
- 0.20<f/|f4|<1.00 (3)
- vd1−vd2>25 (4)
- where f1 is a focal length of the first lens, f2 is a focal length of the second lens, f3 is a focal length of the third lens, f4 is a focal length of the fourth lens, f is a focal length of an entire lens system, vd1 is an Abbe number of the first lens, and vd2 is the Abbe number of the second lens, and
- wherein the imaging lens satisfies the following conditional expression (5):
- 1.50<R6/R7<4.00 (5)
- where R6 is a paraxial curvature radius of the surface on the object side of the third lens, and R7 is a paraxial curvature radius of a surface on the image side of the third lens.
10 more elements
An imaging lens comprising:
- an aperture stop;
- a first lens having a positive refractive power;
- a second lens having a negative refractive power which is formed in a concave shape on both sides thereof;
- a third lens having a positive refractive power which is formed in a meniscus shape in which a concave surface is directed toward the side of an object;
- and
- a fourth lens having a negative refractive power in which a convex surface is directed toward the object side, which are sequentially disposed from the object side to the image side,
- wherein the imaging lens satisfies the following conditional expressions (1), (2), (3) and (4):
- 0.40<f1/|f2|<0.80 (1)
- 0.10<f/f3<0.80 (2)
- 0.20<f/|f4|<1.00 (3)
- vd1−vd2>25 (4)
- where f1 is a focal length of the first lens, f2 is a focal length of the second lens, f3 is a focal length of the third lens, f4 is a focal length of the fourth lens, f is a focal length of an entire lens system, vd1 is an Abbe number of the first lens, and vd2 is an Abbe number of the second lens, and
- wherein the value of the F-number of the entire lens system is 2.1 to 2.6.
10 more elements
An imaging lens comprising:
- an aperture stop;
- a first lens having a positive refractive power;
- a second lens having a negative refractive power which is formed in a concave shape on both sides thereof;
- a third lens having a positive refractive power which is formed in a meniscus shape in which a concave surface is directed toward the side of an object;
- and
- a fourth lens having a negative refractive power in which a convex surface is directed toward the object side, which are sequentially disposed from the object side to the image side,
- wherein the imaging lens satisfies the following conditional expressions (1), (2), (3) and (4):
- 0.40<f1/|f2|<0.80 (1)
- 0.10<f/f3<0.80 (2)
- 0.20<f/|f4|<1.00 (3)
- vd1−vd2>25 (4)
- where is a focal length of the first lens, f2 is a focal length of the second lens, f3 is a focal length of the third lens, f4 is a focal length of the fourth lens, f is a focal length of an entire lens system, vd1 is an Abbe number of the first lens, and vd2 is an Abbe number of the second lens, and
- wherein the total optical length with respect to a diagonal length of the imaging lens is 1.4 to 2.0, the diagonal length being a length from a center of the imaging lens to an opposing angle.
10 more elements
An imaging lens comprising:
- an aperture stop;
- a first lens having a positive refractive power;
- a second lens having a negative refractive power which is formed in a concave shape on both sides thereof;
- a third lens having a positive refractive power which is formed in a meniscus shape in which a concave surface is directed toward the side of an object;
- and
- a fourth lens having a negative refractive power in which a convex surface is directed toward the object side, which are sequentially disposed from the object side to the image side,
- wherein the imaging lens satisfies the following conditional expressions (1), (2), (3) and (4):
- 0.40<f1/|f2|<0.80 (1)
- 0.10<f/f3<0.80 (2)
- 0.20<f/|f4|<1.00 (3)
- vd1−vd2>25 (4)
- where f1 is a focal length of the first lens, f2 is a focal length of the second lens, f3 is a focal length of the third lens, f4 is a focal length of the fourth lens, f is a focal length of an entire lens system, vd1 is an Abbe number of the first lens, and vd2 is an Abbe number of the second lens, and
- wherein the value of the paraxial curvature radius R6 on the surface of the object side of the third lens is −12.424 mm to −3.254 mm.
10 more elements
Dependencies are inferred from the claim text.