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US 8,797,655 B2Granted
Zoom lens and image pickup apparatus having the same
AssigneeCanon Kabushiki Kaisha
InventorShigenobu Sugita
Life of this patent
Estimating the term…
Abstract
A zoom lens includes a lens unit Ln having negative refractive power including two or less lenses moving during focusing and zooming, a lens unit Lp1 having positive refractive power disposed adjacent to an object side thereof, and a lens unit Lp2 having positive refractive power disposed adjacent to an image side thereof. The lens units Lp1 and Lp2 move during zooming. A distance Tlw between a lens surface nearest to the object side in the entire zoom lens and an image plane at a wide-angle end, a distance Dnw between the lens surface nearest to the image side of the lens unit Ln and the image plane at the wide-angle end, a back focus bfw at the wide-angle end, and a maximum amount of movement Mnz during focusing of the lens unit Ln at a telephoto end are appropriately set.
Claims30
A zoom lens comprising:
- a lens unit Ln having negative refractive power;
- a lens unit Lp1 having positive refractive power;
- and
- a lens unit Lp2 having positive refractive power,
- wherein the lens unit Ln includes two or less lenses and moves during focusing and zooming, the lens unit Lp1 is disposed adjacent to an object side of the lens unit Ln, the lens unit Lp2 is disposed adjacent to an image side of the lens unit Ln, and the lens unit Lp1 and the lens unit Lp2 move together during zooming, and
- wherein the zoom lens satisfies the following conditions:
- 0.2<(Dnw−bfw)/(Tlw−bfw)<0.8
- 0.3<−Mnz/Mfnt<1.0
- where Tlw denotes a distance between a lens surface of the entire zoom lens nearest to the object side and an image plane at a wide-angle end, Dnw denotes a distance between a lens surface of the lens unit Ln nearest to the image side and the image plane at the wide-angle end, bfw denotes a back focus at the wide-angle end, Mfnt denotes a maximum amount of focusing movement of the lens unit Ln at a telephoto end by assuming movement from the object side to the image side to be positive during focusing from infinite distance to close distance, and Mnz denotes an amount of change in distance between the lens unit Ln and the lens unit Lp1 during zooming from the wide-angle end to the telephoto end by assuming an increase in the distance to be positive.
6 more elements
An image pickup apparatus comprising a zoom lens, wherein the zoom lens comprises:
- a lens unit Ln having negative refractive power;
- a lens unit Lp1 having positive refractive power;
- and
- a lens unit Lp2 having positive refractive power,
- wherein the lens unit Ln includes two or less lenses and moves during focusing and zooming, the lens unit Lp1 is disposed adjacent to an object side of the lens unit Ln, the lens unit Lp2 is disposed adjacent to an image side of the lens unit Ln, and the lens unit Lp1 and the lens unit Lp2 move together during zooming, and
- wherein the zoom lens satisfies the following conditions:
- 0.2<(Dnw−bfw)/(Tlw−bfw)<0.8
- 0.3<−Mnz/Mfnt<1.0
- where Tlw denotes a distance between a lens surface of the entire zoom lens nearest to the object side and an image plane at a wide-angle end, Dnw denotes a distance between a lens surface of the lens unit Ln nearest to the image side and the image plane at the wide-angle end, bfw denotes a back focus at the wide-angle end, Mfnt denotes a maximum amount of focusing movement of the lens unit Ln at a telephoto end by assuming movement from the object side to the image side to be positive during focusing from infinite distance to close distance, and Mnz denotes an amount of change in distance between the lens unit Ln and the lens unit Lp1 during zooming from the wide-angle end to the telephoto end by assuming an increase in the distance to be positive.
6 more elements
A zoom lens comprising:
- a lens unit Lp having positive refractive power;
- a lens unit Ln1 having negative refractive power;
- and
- a lens unit Ln2 having negative refractive power,
- wherein the lens unit Lp includes two or less lenses and moves during focusing and zooming, the lens unit Ln1 is disposed adjacent to an object side of the lens unit Lp, the lens unit Ln2 is disposed adjacent to an image side of the lens unit Lp, and the lens unit Ln1 and the lens unit Ln2 move together during zooming, and
- wherein the zoom lens satisfies the following conditions:
- 0.2<(Dn2w−bfw)/(Tlw−bfw)<0.8
- 0.3<−Mpz/Mfpt<1.0
- where Tlw denotes a distance between a lens surface of the entire zoom lens nearest to the object side and an image plane at a wide-angle end, Dn2w denotes a distance between a lens surface of the lens unit Ln2 nearest to the image side and the image plane at the wide-angle end, bfw denotes a back focus at the wide-angle end, Mfpt denotes a maximum amount of focusing movement of the lens unit Lp at a telephoto end by assuming movement from the object side to the image side to be positive during focusing from infinite distance to close distance, and Mpz denotes an amount of change in distance between the lens unit Lp and the lens unit Ln2 during zooming from the wide-angle end to the telephoto end by assuming a decrease in the distance to be positive.
6 more elements
An image pickup apparatus comprising a zoom lens, wherein the zoom lens comprises:
- a lens unit Lp having positive refractive power;
- a lens unit Ln1 having negative refractive power;
- and
- a lens unit Ln2 having negative refractive power,
- wherein the lens unit Lp includes two or less lenses and moves during focusing and zooming, the lens unit Ln1 is disposed adjacent to an object side of the lens unit Lp, the lens unit Ln2 is disposed adjacent to an image side of the lens unit Lp, and the lens unit Ln1 and the lens unit Ln2 move together during zooming, and
- wherein the zoom lens satisfies the following conditions:
- 0.2<(Dn2w−bfw)/(Tlw−bfw)<0.8
- 0.3<−Mpz/Mfpt<1.0
- where Tlw denotes a distance between a lens surface of the entire zoom lens nearest to the object side and an image plane at a wide-angle end, Dn2w denotes a distance between a lens surface of the lens unit Ln2 nearest to the image side and the image plane at the wide-angle end, bfw denotes a back focus at the wide-angle end, Mfpt denotes a maximum amount of focusing movement of the lens unit Lp at a telephoto end by assuming movement from the object side to the image side to be positive during focusing from infinite distance to close distance, and Mpz denotes an amount of change in distance between the lens unit Lp and the lens unit Ln2 during zooming from the wide-angle end to the telephoto end by assuming a decrease in the distance to be positive.
6 more elements
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 negative refractive power;
- and
- a rear group that includes one or more lens units and has positive refractive power as a whole, wherein the lens units move during zooming and the fourth lens unit moves during focusing, and
- wherein the zoom lens satisfies the following conditions:
- |ft/f123t|<0.6, and
- −0.269≦|β4w|<1.0,
- where ft denotes a focal length of the entire zoom lens at a telephoto end and f123t denotes a composite focal length ranging from the first lens unit to the third lens unit at the telephoto end, and β4w denotes a lateral magnification of the fourth lens unit at the wide-angle end.
7 more elements
An image pickup apparatus comprising a zoom lens, wherein the zoom lens comprises, 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 negative refractive power;
- and
- a rear group that includes one or more lens units and has positive refractive power as a whole, wherein the lens units move during zooming and the fourth lens unit moves during focusing, and
- wherein the zoom lens satisfies the following conditions:
- |ft/f123t|<0.6
- −0.269 ≦|β4w|<1.0
- where ft denotes a focal length of the entire zoom lens at a telephoto end and f123t denotes a composite focal length ranging from the first lens unit to the third lens unit at the telephoto end, and β4w denotes a lateral magnification of the fourth lens unit at the wide-angle end.
7 more elements
A zoom lens comprising:
- a lens unit Ln having negative refractive power;
- a lens unit Lp1 having positive refractive power;
- and
- a lens unit Lp2 having positive refractive power,
- wherein the lens unit Ln includes two or less lenses and moves during focusing and zooming, the lens unit Lp1 is disposed adjacent to an object side of the lens unit Ln, the lens unit Lp2 is disposed adjacent to an image side of the lens unit Ln, and the lens unit Lp1 and the lens unit Lp2 move during zooming, and
- wherein the zoom lens satisfies the following conditions:
- 0.2<(Dnw−bfw)/(Tlw−bfw)<0.8
- 0.3<−Mnz/Mfnt<1.0
- |(okw−okp2)/fp2|<0.3
- where Tlw denotes a distance between a lens surface of the entire zoom lens nearest to the object side and an image plane at a wide-angle end, Dnw denotes a distance between a lens surface of the lens unit Ln nearest to the image side and the image plane at the wide-angle end, bfw denotes a back focus at the wide-angle end, Mfnt denotes a maximum amount of focusing movement of the lens unit Ln at a telephoto end by assuming movement from the object side to the image side to be positive during focusing from infinite distance to close distance, Mnz denotes an amount of change in distance between the lens unit Ln and the lens unit Lp1 during zooming from the wide-angle end to the telephoto end by assuming an increase in the distance to be positive, okw denotes a rear principal point position of a composite lens unit including the lens unit Lp1, lens unit Ln, and the lens unit Lp2 at the wide-angle end, okp2 denotes a rear principal point position of the lens unit Lp2, and fp2 denotes a focal length of the lens unit Lp2.
7 more elements
A zoom lens comprising:
- a lens unit Lp having positive refractive power;
- a lens unit Ln1 having negative refractive power;
- and
- a lens unit Ln2 having negative refractive power,
- wherein the lens unit Lp includes two or less lenses and moves during focusing and zooming, the lens unit Ln1 is disposed adjacent to an object side of the lens unit Lp, the lens unit Ln2 is disposed adjacent to an image side of the lens unit Lp, and the lens unit Ln1 and the lens unit Ln2 move during zooming, and
- wherein the zoom lens satisfies the following conditions:
- 0.2<(Dn2w−bfw)/(Tlw−bfw)<0.8
- 0.3<−Mpz/Mfpt<1.0
- |(o1w−o1n1)/fn1|<0.3
- where Tlw denotes a distance between a lens surface of the entire zoom lens nearest to the object side and an image plane at a wide-angle end, Dn2w denotes a distance between a lens surface of the lens unit Ln2 nearest to the image side and the image plane at the wide-angle end, bfw denotes a back focus at the wide-angle end, Mfpt denotes a maximum amount of focusing movement of the lens unit Lp at a telephoto end by assuming movement from the object side to the image side to be positive during focusing from infinite distance to close distance, Mpz denotes an amount of change in distance between the lens unit Lp and the lens unit Ln2 during zooming from the wide-angle end to the telephoto end by assuming a decrease in the distance to be positive, o1w denotes a front principal point position of a composite lens unit including the lens unit Ln1, lens unit Lp, and the lens unit Ln2 at the wide-angle end, o1n1 denotes a front principal point position of the lens unit Ln1, and fn1 denotes a focal length of the lens unit Ln1.
7 more elements
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 negative refractive power;
- a fifth lens unit having positive refractive power;
- and
- a sixth lens unit having positive refractive power, wherein the lens units move during zooming and the fourth lens unit moves during focusing, and
- wherein the zoom lens satisfies the following condition:
- |ft/f123t|<0.6
- where ft denotes a focal length of the entire zoom lens at a telephoto end, and f123t denotes a composite focal length ranging from the first lens unit to the third lens unit at the telephoto end.
7 more elements
Dependencies are inferred from the claim text.