Imaging lens and imaging device
AssigneeFujinon Corporation
InventorTaro ASAMI
Life of this patent
Estimating the term…
Abstract
The imaging lens is provided and includes: in order from the object side, a negative first lens whose concave surface is directed toward the image side; a second lens of a planoconcave lens whose flat surface is directed toward the object side or a biconcave lens whose surface having a larger absolute value of radius of curvature is directed toward the object side; a third biconvex lens; a stop; a positive fourth lens whose surface having a smaller absolute value of radius of curvature is directed toward the image side; and a cemented lens of a positive fifth lens of biconvex shape and a negative sixth lens of meniscus shape, the cemented lens having a positive refractive power, and an Abbe number v3 at d-line of the third lens satisfies a conditional expression (1) v3<43.
Claims24
An imaging lens comprising:
- in order from an object side of the imaging lens,
- a first lens having a negative refractive power and having a concave surface directed toward an image side of the imaging lens;
- a second lens that is one of a planoconcave lens having a flat surface directed toward the object side and a biconcave lens whose surface having a larger absolute value of radius of curvature is directed toward the object side;
- a third biconvex lens;
- a stop;
- a fourth lens whose surface having a smaller absolute value of radius of curvature is directed toward the image side, the fourth lens having a positive refractive power;
- and
- a cemented lens having a positive refractive power, the cemented lens including a fifth lens and a sixth lens, the fifth lens having a positive refractive power and having a biconvex shape, the sixth lens having a negative refractive power and having a meniscus shape,
- the imaging lens satisfying a conditional expression:
- v3<43 (1)
- wherein v3 represents an Abbe number of the third lens at the d-line.
An imaging lens comprising:
- in order from an object side of the imaging lens,
- a first lens having a negative refractive power and having a concave surface directed toward an image side of the imaging lens;
- a second lens that is one of a planoconcave lens having a flat surface directed toward the object side and a biconcave lens whose surface having a larger absolute value of radius of curvature is directed toward the object side;
- a third biconvex lens;
- a stop;
- a fourth lens having a positive refractive power;
- and
- a cemented lens having a positive refractive power, the cemented lens including a fifth lens and a sixth lens, one of the fifth lens and the sixth lens having a positive refractive power and the other having a negative refractive power,
- the imaging lens satisfies conditional expressions:
- 25<v3<35 (2)
- 1.79<N3<1.87 (3)
- vn<25 (4)
- wherein v3 represents an Abbe number of the third lens at the d-line, N3 represents a refractive index of the third lens at the d-line, and vn represents an Abbe number of the negative lens constituting the cemented lens at the d-line.
Dependencies are inferred from the claim text.