Zoom lens and imaging apparatus
First Claim
1. A zoom lens comprising, in order from an object side:
- a first lens group that has a positive refractive power and remains stationary with respect to an image plane during zooming;
a plurality of movable lens groups that move by changing distances between groups adjacent to each other in a direction of an optical axis during zooming; and
a final lens group that has a positive refractive power and remains stationary with respect to the image plane during zooming,wherein in the plurality of movable lens groups, at least one movable lens group has a negative refractive power,wherein the first lens group includes, in order from the object side, a first lens group front group that has a negative refractive power and remains stationary with respect to the image plane during focusing, a first lens group intermediate group that has a positive refractive power and moves in the direction of the optical axis during focusing, and a first lens group rear group that is set such that a distance in the direction of the optical axis between the first lens group rear group and the first lens group intermediate group changes during focusing and has a positive refractive power,wherein the first lens group front group has, successively in order from a position closest to the object side, a first negative lens which is a negative meniscus lens concave toward an image side, and a second negative lens which is a negative lens concave toward the object side, andwherein all Conditional Expressions (1) to (4) are satisfied,
−
0.5<
DD12/f1a<
−
0.2
(1),
50<
ν
n2<
68
(2),
0.634<
θ
gFn2+0.001625×
ν
n2<
0.675
(3), and
1<
DDG1/f1<
1.5
(4),where DD12 is a distance on the optical axis between the first negative lens and the second negative lens,f1a is a focal length of the first lens group front group,ν
n2 is an Abbe number of the second negative lens at the d line,θ
gFn2 is a partial dispersion ratio of the second negative lens between the g line and the F line,DDG1 is a distance on the optical axis from a lens surface closest to the object side in the first lens group to a lens surface closest to the image side in the first lens group in a state where an object at infinity is in focus, andf1 is a focal length of the first lens group in a state where the object at infinity is in focus.
1 Assignment
0 Petitions
Accused Products
Abstract
The zoom lens consists of, in order from the object side, a first lens group that has a positive refractive power and remains stationary during zooming, a plurality of movable lens groups that move during zooming, and a final lens group that has a positive refractive power and remains stationary during zooming. The first lens group consists of, in order from the object side, a first lens group front group that has a negative refractive power, a first lens group intermediate group that has a positive refractive power and moves during focusing, and a first lens group rear group that has a positive refractive power. The first lens group front group has, successively in order from a position closest to the object side, a negative meniscus lens concave toward an image side, and a negative lens concave toward the object side. The components of the zoom lens satisfy predetermined conditional expressions.
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Citations
20 Claims
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1. A zoom lens comprising, in order from an object side:
-
a first lens group that has a positive refractive power and remains stationary with respect to an image plane during zooming; a plurality of movable lens groups that move by changing distances between groups adjacent to each other in a direction of an optical axis during zooming; and a final lens group that has a positive refractive power and remains stationary with respect to the image plane during zooming, wherein in the plurality of movable lens groups, at least one movable lens group has a negative refractive power, wherein the first lens group includes, in order from the object side, a first lens group front group that has a negative refractive power and remains stationary with respect to the image plane during focusing, a first lens group intermediate group that has a positive refractive power and moves in the direction of the optical axis during focusing, and a first lens group rear group that is set such that a distance in the direction of the optical axis between the first lens group rear group and the first lens group intermediate group changes during focusing and has a positive refractive power, wherein the first lens group front group has, successively in order from a position closest to the object side, a first negative lens which is a negative meniscus lens concave toward an image side, and a second negative lens which is a negative lens concave toward the object side, and wherein all Conditional Expressions (1) to (4) are satisfied,
−
0.5<
DD12/f1a<
−
0.2
(1),
50<
ν
n2<
68
(2),
0.634<
θ
gFn2+0.001625×
ν
n2<
0.675
(3), and
1<
DDG1/f1<
1.5
(4),where DD12 is a distance on the optical axis between the first negative lens and the second negative lens, f1a is a focal length of the first lens group front group, ν
n2 is an Abbe number of the second negative lens at the d line,θ
gFn2 is a partial dispersion ratio of the second negative lens between the g line and the F line,DDG1 is a distance on the optical axis from a lens surface closest to the object side in the first lens group to a lens surface closest to the image side in the first lens group in a state where an object at infinity is in focus, and f1 is a focal length of the first lens group in a state where the object at infinity is in focus. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification