Zoom lens, and image pickup apparatus having the same
AssigneeCanon Kabushiki Kaisha
InventorJunya Ichimura
Life of this patent
Estimating the term…
Abstract
A zoom lens includes, in order from an object side to an image side, a first lens unit having positive refractive power, a second lens unit having negative refractive power, a third lens unit having positive refractive power, a fourth lens unit having positive refractive power, and a fifth lens unit having negative refractive power. During zooming from a wide-angle end to a telephoto end, a distance between adjacent lens units changes, the first lens unit and the third lens unit are fixed, and the second lens unit and the fourth lens unit move. The third lens unit includes a negative lens and a positive lens. A predetermined condition is satisfied.
Claims17
A zoom lens comprising, in order from an object side to an image side, a first lens unit having positive refractive power, a second lens unit having negative refractive power, a third lens unit having positive refractive power, a fourth lens unit having positive refractive power, and a fifth lens unit having negative refractive power,
- wherein during zooming from a wide-angle end to a telephoto end, a distance between adjacent lens units changes, the first lens unit and the third lens unit are fixed, and the second lens unit and the fourth lens unit move,
- wherein the third lens unit includes a negative lens and a positive lens, and
- wherein the following inequalities are satisfied:
- −3.50<β3w/β3t<−0.10
- −10.0<f1/f2<−4.0
- 1.2<f3/f4<2.0
- −6.0<M2/M4<−1.5
- 0.8<M2/D1<2.0
- where β3w is a lateral magnification of the third lens unit at the wide-angle end, β3t is a lateral magnification of the third lens unit at the telephoto end, f1 is a focal length of the first lens unit, f2 is a focal length of the second lens unit, f3 is a focal length of the third lens unit, f4 is a focal length of the fourth lens unit, M2 is a moving amount of the second lens unit during zooming from the wide-angle end to the telephoto end, M4 is a moving amount of the fourth lens unit during zooming from the wide-angle end to the telephoto end, and D1 is a distance on an optical axis from a lens surface closest to an object in the first lens unit to a lens surface closest to an image plane in the first lens unit.
An image pickup apparatus comprising:
- a zoom lens;
- and
- an image sensor configured to receive an image formed by the zoom lens,
- wherein the zoom lens includes, in order from an object side to an image side, a first lens unit having positive refractive power, a second lens unit having negative refractive power, a third lens unit having positive refractive power, a fourth lens unit having positive refractive power, and a fifth lens unit having negative refractive power,
- wherein during zooming from a wide-angle end to a telephoto end, a distance between adjacent lens units changes, the first lens unit and the third lens unit are fixed, and the second lens unit and the fourth lens unit move,
- wherein the third lens unit includes a negative lens and a positive lens, and
- wherein the following inequalities are satisfied:
- −3.50<β3w/β3t<−0.10
- −10.0<f1/f2<−4.0
- 1.2<f3/f4<2.0
- −6.0<M2/M4<−1.5
- 0.8<M2/D1<2.0
- where β3w is a lateral magnification of the third lens unit at the wide-angle end, β3t is a lateral magnification of the third lens unit at the telephoto end, f1 is a focal length of the first lens unit, f2 is a focal length of the second lens unit, f3 is a focal length of the third lens unit, f4 is a focal length of the fourth lens unit, M2 is a moving amount of the second lens unit during zooming from the wide-angle end to the telephoto end, M4 is a moving amount of the fourth lens unit during zooming from the wide-angle end to the telephoto end, and D1 is a distance on an optical axis from a lens surface closest to an object in the first lens unit to a lens surface closest to an image plane in the first lens unit.
Dependencies are inferred from the claim text.