Zoom lens and image pick up apparatus including the same
A zoom lens includes, in order from an object side to an image side: a first lens unit having positive optical power; a second lens unit having negative optical power; a third lens unit having positive optical power and an aperture stop; a fourth lens unit having negative optical power; and a fifth lens unit having positive optical power, in which, during zooming from a wide-angle end to a telephoto end, the first lens unit stays, the second lens unit moves toward the image side, and the third lens unit moves together with the aperture stop.
1. A zoom lens, comprising, in order from an object side to an image side:
a first lens unit having positive optical power;
a second lens unit having negative optical power;
a third lens unit having positive optical power, the third lens unit including an aperture stop;
a fourth lens unit having negative optical power; and
a fifth lens unit having positive refractive power, wherein the first lens unit does not move for zooming, and during zooming from a wide-angle end to a telephoto end:
the second lens unit moves toward the image side; and
the third lens unit moves together with the aperture stop, wherein:
the fourth lens unit moves during the zooming; and
the fourth lens unit moves during focusing.
2. An image pick up apparatus, comprising:
a zoom lens according to claim 1 ; and
a solid-state image pick up element for receiving an image formed by the zoom lens.
3. A zoom lens according to claim 1 , wherein the third lens unit moves along a locus convex to the object side during the zooming from the wide-angle end to the telephoto end.
4. A zoom lens according to claim 1 , wherein at least one of three conditions
0.2 <|f 2 /fA|< 0.4
2.10 <e 4 T/fw< 4.35
0.7 <|f 3 /f 4|<1.3
is satisfied, where
fA=√{square root over (fw·ft)}
fw and ft represent a focal length of an entire system at the wide-angle end and a focal length thereof at the telephoto end, respectively, f 2 represents a focal length of the second lens unit, f 3 represents a focal length of the third lens unit, f 4 represents a focal length of the fourth lens unit, and e 4 T represents a principal point interval between the fourth lens unit and the fifth lens unit in a case where focusing is performed on an infinitely distant object at the telephoto end.
5. A zoom lens according to claim 1 , wherein the following condition is satisfied,
1.5 <M 2 /M 3<5.4,
where M 2 represents a movement amount of the second lens unit in a case where zooming is performed from the wide-angle end to the telephoto end and M 3 represents a distance on an optical axis between a position of the third lens unit in a case where the third lens unit is located at the most object side and a position thereof in the case where the third lens unit is located at the most image side.
6. A zoom lens according to claim 1 , wherein the second lens unit comprises an aspherical shape having an optical power that becomes weaker as a position in the second lens unit becomes farther from a lens center and closer to a lens circumference.
7. A zoom lens according to claim 1 , wherein the following condition is satisfied,
1.76<Nn<2.01,
where Nn represents an average refractive index of lens materials of the second lens unit.
8. A zoom lens according to claim 1 , wherein the following condition is satisfied,
0.46 <|R 22 /R 23|<0.79,
where R 2 i represents a curvature radius of an i-th lens surface of the second lens unit counted from the object side.
9. A zoom lens according to claim 1 , wherein the first lens unit includes at least one negative lens and a plurality of positive lenses, an average Abbe number of materials of the positive lenses is equal to or larger than 68, and an Abbe number of a material of at least one positive lens is equal to or larger than 70.
10. A zoom lens according to claim 1 , wherein the aperture stop is located on the object side of the third lens unit or between the lenses of the third lens unit.
11. A zoom lens according to claim 1 , wherein at least part of the third lens unit are shifted in a direction perpendicular to an optical axis or rotated about an axis orthogonal to the optical axis.
12. A zoom lens according to claim 11 , wherein the following condition is satisfied,
1.7×10 −3 <|(1 −βa )·β R|·EM/ft< 0.05,
where EM and βa represent a maximum movement amount and a photographing magnification of the at least part of the third lens unit at the telephoto end, respectively, ft represents a focal length of an entire system at the telephoto end, and βR represents a photographing magnification of a lens system located closer to the image side than the at least part of the third lens unit.
13. A zoom lens, comprising, in order from an object side to an image side:
a first lens unit having positive optical power;
a second lens unit having negative optical power;
a third lens unit having positive optical power, the third lens unit including an aperture stop;
a fourth lens unit having negative optical power; and
a fifth lens unit having positive refractive power, wherein the first lens unit does not move for zooming, and during zooming from a wide-angle end to a telephoto end:
the second lens unit moves toward the image side; and
the third lens unit moves together with the aperture stop, wherein at least one of three conditions
0.2 <|f 2 /fA|< 0.4
2.10 <e 4 T/fw< 4.35
0.7 <|f 3 /f 4|<1.3
is satisfied, where
fA=√{square root over (fw·ft)}
fw and ft represent a focal length of an entire system at the wide-angle end and a focal length thereof at the telephoto end, respectively, f 2 represents a focal length of the second lens unit, f 3 represents a focal length of the third lens unit, f 4 represents a focal length of the fourth lens unit, and e 4 T represents a principal point interval between the fourth lens unit and the fifth lens unit in a case where focusing is performed on an infinitely distant object at the telephoto end.
14. An image pick up apparatus, comprising:
a zoom lens according to claim 13 ; and
a solid-state image pick up element for receiving an image formed by the zoom lens.
15. A zoom lens, comprising, in order from an object side to an image side:
a first lens unit having positive optical power;
a second lens unit having negative optical power;
a third lens unit having positive optical power, the third lens unit including an aperture stop;
a fourth lens unit having negative optical power; and
a fifth lens unit having positive refractive power,
wherein the first lens unit does not move for zooming, and
during zooming from a wide-angle end to a telephoto end:
the second lens unit moves toward the image side; and
the third lens unit moves together with the aperture stop,
wherein the following condition is satisfied,
1.5 <M 2 /M 3<5.4,
where M 2 represents a movement amount of the second lens unit in a case where zooming is performed from the wide-angle end to the telephoto end and M 3 represents a distance on an optical axis between a position of the third lens unit in a case where the third lens unit is located at the most object side and a position thereof in the case where the third lens unit is located at the most image side.
16. An image pick up apparatus, comprising:
a zoom lens according to claim 15 ; and
a solid-state image pick up element for receiving an image formed by the zoom lens.
17. A zoom lens, comprising, in order from an object side to an image side:
a first lens unit having positive optical power;
a second lens unit having negative optical power;
a third lens unit having positive optical power, the third lens unit including an aperture stop;
a fourth lens unit having negative optical power; and
a fifth lens unit having positive refractive power,
wherein the first lens unit does not move for zooming, and
during zooming from a wide-angle end to a telephoto end:
the second lens unit moves toward the image side; and
the third lens unit moves together with the aperture stop,
wherein the second lens unit comprises an aspherical shape having an optical power that becomes weaker as a position in the second lens unit becomes farther from a lens center and closer to a lens circumference.
18. An image pick up apparatus, comprising:
a zoom lens according to claim 17 ; and
a solid-state image pick up element for receiving an image formed by the zoom lens.
19. A zoom lens, comprising, in order from an object side to an image side:
a first lens unit having positive optical power;
a second lens unit having negative optical power;
a third lens unit having positive optical power, the third lens unit including an aperture stop;
a fourth lens unit having negative optical power; and
a fifth lens unit having positive refractive power,
wherein the first lens unit does not move for zooming, and
during zooming from a wide-angle end to a telephoto end:
the second lens unit moves toward the image side; and
the third lens unit moves together with the aperture stop,
wherein the following condition is satisfied,
1.76<Nn<2.01,
where Nn represents an average refractive index of lens materials of the second lens unit.
20. An image pick up apparatus, comprising:
a zoom lens according to claim 19 ; and
a solid-state image pick up element for receiving an image formed by the zoom lens.
21. A zoom lens, comprising, in order from an object side to an image side:
a first lens unit having positive optical power;
a second lens unit having negative optical power;
a third lens unit having positive optical power, the third lens unit including an aperture stop;
a fourth lens unit having negative optical power; and
a fifth lens unit having positive refractive power,
wherein the first lens unit does not move for zooming, and
during zooming from a wide-angle end to a telephoto end:
the second lens unit moves toward the image side; and
the third lens unit moves together with the aperture stop,
wherein the following condition is satisfied,
0.46 <|R 22 /R 23|<0.79,
where R 2 i represents a curvature radius of an i-th lens surface of the second lens unit counted from the object side.
22. An image pick up apparatus, comprising:
a zoom lens according to claim 21 ; and
a solid-state image pick up element for receiving an image formed by the zoom lens.
23. A zoom lens, comprising, in order from an object side to an image side:
a first lens unit having positive optical power;
a second lens unit having negative optical power;
a third lens unit having positive optical power, the third lens unit including an aperture stop;
a fourth lens unit having negative optical power; and
a fifth lens unit having positive refractive power,
wherein the first lens unit does not move for zooming, and
during zooming from a wide-angle end to a telephoto end:
the second lens unit moves toward the image side; and
the third lens unit moves together with the aperture stop,
wherein the first lens unit includes at least one negative lens and a plurality of positive lenses, an average Abbe number of materials of the positive lenses is equal to or larger than 68, and an Abbe number of a material of at least one positive lens is equal to or larger than 70.
24. An image pick up apparatus, comprising:
a zoom lens according to claim 23 ; and
a solid-state image pick up element for receiving an image formed by the zoom lens.
25. A zoom lens, comprising, in order from an object side to an image side:
a first lens unit having positive optical power;
a second lens unit having negative optical power;
a third lens unit having positive optical power, the third lens unit including an aperture stop;
a fourth lens unit having negative optical power; and
a fifth lens unit having positive refractive power,
wherein the first lens unit does not move for zooming, and
during zooming from a wide-angle end to a telephoto end:
the second lens unit moves toward the image side; and
the third lens unit moves together with the aperture stop,
wherein at least part of the third lens unit are shifted in a direction perpendicular to an optical axis or rotated about an axis orthogonal to the optical axis.
26. An image pick up apparatus, comprising:
a zoom lens according to claim 25 ; and
a solid-state image pick up element for receiving an image formed by the zoom lens.