Imaging lens and imaging apparatus
AssigneeFUJIFILM Corporation
InventorsTaro Asami, Yu Kitahara
Life of this patent
Estimating the term…
Abstract
An imaging lens consists of, in order from the object side, a negative first lens, a positive second lens, a positive third lens, a negative fourth lens, a positive fifth lens, and a positive sixth lens. The imaging lens satisfies the condition expressions below: f1/f<−1.68 (1-2), −0.7<f4/f (2), −0.6<(R3+R4)/(R3−R4)<2.2 (11-2), and 0.5<f2/f3<4.0 (12), where f1 to f4 are focal lengths of the first to the fourth lenses, f is a focal length of the entire system, R3 is a radius of curvature of the object-side surface of the second lens, and R4 is a radius of curvature of the image-side surface of the second lens.
Claims20
An imaging lens consisting of, in order from an object side, a first lens having a negative power, a second lens having a positive power, a third lens having a positive power, a fourth lens having a negative power, a fifth lens having a positive power, and a sixth lens having a positive power, wherein the condition expressions below are satisfied:
- f1/f<−1.68 (1-2),
- −0.7<f4/f (2),
- 1<f12/f<25 (10),
- −0.6<(R3+R4)/(R3−R4)<2.2 (11-2), and
- 0.5<f2/f3<4.0 (12),
- 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, R3 is a radius of curvature of an object-side surface of the second lens, R4 is a radius of curvature of an image-side surface of the second lens, f is a focal length of the entire system, and f12 is a combined focal length of the first lens and the second lens.
An imaging lens consisting of, in order from an object side, a first lens having a negative power, a second lens having a positive power, a third lens having a positive power, a fourth lens having a negative power, a fifth lens having a positive power, and a sixth lens having a positive power, wherein the condition expressions below are satisfied:
- 2.4<f1/f4 (3),
- 0.0<f3/f<2.0 (4), and
- 3.2<νd6/νd4 (6),
- where f is a focal length of the entire system, f1 is a focal length of the first lens, f3 is a focal length of the third lens, f4 is a focal length of the fourth lens, νd4 is an Abbe number with respect to the d-line of a material forming the fourth lens, and νd6 is an Abbe number with respect to the d-line of a material forming the sixth lens.
An imaging lens consisting of, in order from an object side, a first lens having a negative power, a second lens having a positive power, a third lens having a positive power, a fourth lens having a negative power, a fifth lens having a positive power, and a sixth lens having a positive power, wherein the condition expression below is satisfied:
- 3.0<νd2/νd4 (5),
- where νd2 is an Abbe number with respect to the d-line of a material forming the second lens, and νd4 is an Abbe number with respect to the d-line of a material forming the fourth lens.
An imaging lens consisting of, in order from an object side, a first lens having a negative power, a second lens having a positive power, a third lens having a positive power, a fourth lens having a negative power, a fifth lens having a positive power, and a sixth lens having a positive power, wherein the second lens is made of a material having an Abbe number with respect to the d-line of 55 or more, and the condition expression below is satisfied:
- 3.2<νd6/νd4 (6),
- where νd4 is an Abbe number with respect to the d-line of a material forming the fourth lens, and νd6 is an Abbe number with respect to the d-line of a material forming the sixth lens.
An imaging lens consisting of, in order from an object side, a first lens having a negative power, a second lens having a positive power, a third lens having a positive power, a fourth lens having a negative power, a fifth lens having a positive power, and a sixth lens having a positive power, wherein the condition expressions below are satisfied:
- f1/f<−1.68 (1-2),
- −0.7<f4/f (2),
- 0.3<f23/f56<3.0 (15),
- −0.6<(R3+R4)/(R3−R4)<2.2 (11-2), and
- 0.5<f2/f3<4.0 (12),
- 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, R3 is a radius of curvature of an object-side surface of the second lens, R4 is a radius of curvature of an image-side surface of the second lens, f is a focal length of the entire system, f23 is a combined focal length of the second lens and the third lens, and f56 is a combined focal length of the fifth lens and the sixth lens.
Dependencies are inferred from the claim text.