# US 2017/0254993 A1 · Zoom lens, optical apparatus and method for manufacturing the zoom lens

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- Number: US 2017/0254993 A1
- Document ID: US20170254993A1
- Status: Published application
- Kind: A1
- Application number: 15/462,811
- Filed: 2017-03-18
- Published: 2017-09-07
- Earliest claimed: 2014-09-24
- Assignees: Nikon Corporation
- Applicants: Nikon Corporation
- Inventors: Atsushi SUZUKI; Kenji ISHIDA; Saburo MASUGI
- Web page: https://patentgrep.com/patent/US20170254993A1

## CPC

- G02B 15/16: with interdependent non-linearly related movements between one lens or lens group, and another lens or lens group (G02B15/22 takes precedence)
- G02B 5/208: {for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation}
- G02B 15/145105: {arranged +-+--}
- G02B 15/145117: {arranged +---+}
- G02B 15/145121: {arranged +-+-+}
- G02B 15/145129: {arranged +-+++}
- G02B 15/1461: {the first group being positive}
- G02B 15/20: having an additional movable lens or lens group for varying the objective focal length
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

## Abstract

A first lens group (G1) having positive refractive power, a second lens group (G2) having negative refractive power, a third lens group (G3) having positive refractive power, a fourth lens group (G4) having negative refractive power, and a fifth lens group (G5) having positive refractive power are arranged in order from an object, and zooming is performed by changing distances between each lens group, and the first lens group (G1) is composed of three or more lenses, the fourth lens group (G4) is composed of two or less lenses, and the fifth lens group (G5) is composed of two or less lenses and moves to an image surface side upon zooming from a wide angle end state to a telephoto end state, and the following conditional expression (1) is satisfied. 8.40<f1/(−f2) (1) where, f1 denotes a focal length of the first lens group (G1), and f2 denotes a focal length of the second lens group (G2).

## Claims

### Claim 1

A zoom lens comprising, in order from an object, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having negative refractive power, and a fifth lens group having positive refractive power, and zooming being performed by changing distances between each lens group, and
the first lens group being composed of three or more lenses,
the fourth lens group being composed of two or less lenses, and
the fifth lens group being composed of two or less lenses and moving to an image surface side upon zooming from a wide angle end state to a telephoto end state, and
the following conditional expression being satisfied.
8.40<f1/(−f2)
where,
f1 denotes a focal length of the first lens group, and
f2 denotes a focal length of the second lens group.

### Claim 2

A zoom lens comprising, in order from an object, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having negative refractive power, and a fifth lens group having positive refractive power, and zooming being performed by changing distances between each lens group, and
the first lens group being composed of three or more lenses,
the fourth lens group being composed of two or less lenses, and
the fifth lens group being composed of two or less lenses and moving to an image surface side upon zooming from a wide angle end state to a telephoto end state, and
the following conditional expression being satisfied.
5.80<Dt12/(−f2)
where,
Dt12 denotes a distance on an optical axis from an image side surface of the first lens group in a telephoto end state to an object side surface of the second lens group, and
f2 denotes a focal length of the second lens group.

### Claim 3

A zoom lens comprising, in order from an object, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having negative refractive power, and a fifth lens group having positive refractive power, and zooming being performed by changing distances between each lens groups, and
the first lens group being composed of three or more lenses,
the fourth lens group being composed of two or less lenses, and
the fifth lens group being composed of two or less lenses and moves to an image surface side upon zooming from a wide angle end state to a telephoto end state, and
the following conditional expressions being satisfied.
0.01<D1/ft<0.15
0.70<Zidwt/Fnwt<1.10
where,
D1 denotes a distance on an optical axis from an object side surface of the first lens group to an image side surface,
ft denotes a focal length of a whole system in a telephoto end state,
βt4 denotes magnification of the fourth lens group in the telephoto end state,
βt5 denotes magnification of the fifth lens group in the telephoto end state,
βw4 denotes magnification of the fourth lens group in the wide angle end state,
βw5 denotes magnification of the fifth lens group in the wide angle end state,
Fnt denotes an f number in the telephoto end state, and
Fnw denotes an f number in the wide angle end state.
Note that the following definitions are applicable.
Zidwt={(1−βt4̂2)*βt5̂2}/{(1−βw4̂2)*βw5̂2}
Fnwt=Fnt/Fnw

### Claim 4 (depends on 1)

A zoom lens according to claim 1, wherein the following conditional expression is satisfied.
5.80<Dt12/(−f2)
where,
Dt12 denotes a distance on an optical axis from the image side surface of the first lens group in the telephoto end state to the object side surface of the second lens group.

### Claim 5 (depends on 1)

A zoom lens according to claim 1, wherein the following conditional expression is satisfied.
0.01<D1/ft<0.15
where,
D1 denotes a distance on an optical axis from the object side surface of the first lens group to the image side surface, and
ft denotes a focal length of the whole system in the telephoto end state.

### Claim 6 (depends on 1)

A zoom lens according to claim 1, wherein the following conditional expression is satisfied.
0.70<Zidwt/Fnwt<1.10
Note that the following definitions are applicable.
Zidwt={(1−βt4̂2)*βt5̂2}/{(1−βw4̂2)*βw5̂2}
Fnwt=Fnt/Fnw
where,
βt4 denotes magnification of the fourth lens group in the telephoto end state,
βt5 denotes magnification of the fifth lens group in the telephoto end state,
βw4 denotes magnification of the fourth lens group in the wide angle end state,
βw5 denotes magnification of the fifth lens group in the wide angle end state,
Fnt denotes an f number in a telephoto end state, and
Fnw denotes an f number in the wide angle end state.

### Claim 7 (depends on 2)

A zoom lens according to claim 2, wherein the following conditional expression is satisfied.
8.40<f1/(−f2)
where,
f1 denote a focal length of the first lens group.

### Claim 8 (depends on 1)

A zoom lens according to claim 1, wherein the following conditional expression is satisfied.
2.70<βt3/βw3
where,
βt3 denotes magnification of the third lens group in the telephoto end state, and
βw3 denotes magnification of the third lens group in the wide angle end state.

### Claim 9 (depends on 1)

A zoom lens according to claim 1, wherein the following conditional expression is satisfied.
0.03<Mv2/ft
where,
Mv2 denotes amount of movement of the second lens group from the wide angle end state to the telephoto end state, and
ft denotes a focal length of a whole system in the telephoto end state.

### Claim 10 (depends on 1)

A zoom lens according to claim 1, wherein the fourth lens group is composed of two lenses, and these two lenses are cemented with each other.

### Claim 11 (depends on 1)

A zoom lens according to claim 1, wherein the fifth lens group is composed of two lenses, and these lenses are cemented with each other.

### Claim 12 (depends on 1)

A zoom lens according to claim 1, wherein the second lens group is composed of, in order from the object, a negative lens, a negative lens, a positive lens, and a negative lens.

### Claim 13 (depends on 1)

A zoom lens according to claim 1, wherein the third lens group comprises, in order from the image, a positive lens, a negative lens, a negative lens, and a positive lens.

### Claim 14 (depends on 1)

A zoom lens according to claim 1, wherein focusing is performed by moving the fourth lens group along an optical axis direction.

### Claim 15

A zoom lens comprising, in order from an object, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having negative refractive power, and a fifth lens group having positive refractive power, and zooming being performed by changing distances between each lens group, and
the first lens group being composed of three or more lenses, and
the fifth lens group moving to an image surface side upon zooming from a wide angle end state to a telephoto end state, and
the following conditional expression being satisfied.
0.020<(−f2)/ft<0.031
where,
f2 denotes a focal length of the second lens group in the telephoto end state, and
ft denotes a focal length of a whole system in the telephoto end state.

### Claim 16 (depends on 15)

A zoom lens according to claim 15, wherein the following conditional expressions are satisfied.
74.00<AVE1Grpvd<80.00
36.00<G1vd<48.00
where,
AVE1Grpvd denotes an average of an Abbe number on the basis of d-line of a lens in the first lens group, and
G1vd denotes the Abbe number on the basis of d-line of the lens arranged closest to an object side in the first lens group.

### Claim 17 (depends on 15)

A zoom lens according to claim 15, wherein the following conditional expression is satisfied.
100.00<D12t/D12w<140.00
where,
D12t denotes an air distance between the first lens group and the second lens group in the telephoto end state, and
D12w denotes an air distance between the first lens group and the second lens group in the wide angle end state.

### Claim 18 (depends on 15)

A zoom lens according to claim 15, wherein the following conditional expression is satisfied.
12.34<β2t/β2w<14.40
where,
β2t denote magnification of the second lens group in the telephoto end state, and
β2w denote magnification of the second lens group in the wide angle end state.

### Claim 19 (depends on 15)

A zoom lens according to claim 15, wherein the following conditional expression is satisfied.
0.04<f3/ft<0.06
where,
f3 denotes a focal length of the third lens group in the telephoto end state.

### Claim 20 (depends on 15)

A zoom lens according to claim 15, wherein the third lens group is composed of, in order from the object, a positive lens, a negative lens, a negative lens, and a positive lens.

### Claim 21 (depends on 15)

A zoom lens according to claim 15, wherein the third lens group comprises at least one aspherical lens.

### Claim 22

A zoom lens comprising, in order from an object, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having negative refractive power, and a fifth lens group having positive refractive power, and
the following conditional expressions being satisfied.
33.00<ft/(−f2)<46.00
1.60<(Fnt·f1)/ft<2.30
43.00<β2t−β3t/(β2w·β3w)<65.00
where,
ft denotes a focal length of a whole system in a telephoto end state,
f2 denotes a focal length of the second lens group,
Fnt denotes an F value in the telephoto end state,
f1 denotes a focal length of the first lens group,
β2t denotes magnification of the second lens group in the telephoto end state,
β3t denotes magnification of the third lens group in the telephoto end state,
β2w denotes magnification of the second lens group in a wide angle end state, and
β3w denotes magnification of the third lens group in the wide angle end state.

### Claim 23 (depends on 22)

A zoom lens according to claim 22, wherein distances between each mutually adjacent lens group change upon zooming from the wide angle end state to the telephoto end state.

### Claim 24 (depends on 22)

A zoom lens according to claim 22, wherein the fifth lens group is composed of one positive lens, and one negative lens.

### Claim 25 (depends on 22)

A zoom lens according to claim 22, wherein the following conditional expression is satisfied.
15.00<ft/f3<19.00
where,
f3 denote a focal length of the third lens group.

### Claim 26 (depends on 22)

A zoom lens according to claim 22, the following conditional expression is satisfied.
15.00<β2t/β2w<25.00

### Claim 27 (depends on 22)

A zoom lens according to claim 22, wherein the following conditional expression is satisfied.
2.00<f3/(−f2)<2.70
where,
f3 denote a focal length of the third lens group.

### Claim 28 (depends on 22)

A zoom lens according to claim 22, wherein the following conditional expression is satisfied.
15.00<f1/fw<40.00
where,
fw denotes a focal length of a whole system in the wide angle end state.

### Claim 29 (depends on 22)

A zoom lens according to claim 22, wherein the following conditional expression is satisfied.
10.00<ft/x2<40.00
where,
x2 denotes a distance the second lens group moves against an imaging position in an image surface direction upon zooming from the wide angle end state to the telephoto end state.

### Claim 30 (depends on 22)

A zoom lens according to claim 22, wherein an aperture stop is provided between the second lens group and the fourth lens group.

### Claim 31 (depends on 22)

A zoom lens according to claim 22, wherein an aperture stop is provided between the second lens group and the third lens group.

### Claim 32 (depends on 30)

A zoom lens according to claim 30, wherein the aperture stop is moved in an optical axis direction upon zooming.

### Claim 33 (depends on 22)

A zoom lens according to claim 22, wherein the following conditional expression is satisfied.
0.10°<ωt<5.00°
where,
ωt denotes a half angle of view in the telephoto end state.

### Claim 34 (depends on 22)

A zoom lens according to claim 22, wherein the following conditional expression is satisfied.
25.00°<ωw<80.00°
where,
ωw denotes a half angle of view in the wide angle end state.

### Claim 35 (depends on 1)

A zoom lens according to claim 1, wherein all of the lens groups move upon zooming from the wide angle end state to the telephoto end state.

### Claim 36 (depends on 1)

An optical apparatus equipped with the zoom lens according to claim 1.

### Claim 37

A method for manufacturing a zoom lens comprising, in order from an object, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having negative refractive power, and a fifth lens group having positive refractive power, and zooming being performed by changing distances between each lens group, and
the first lens group being composed of three or more lenses,
the fourth lens group being composed of two or less lenses, and
the fifth lens group being composed of two or less lenses, and moving to an image surface side upon zooming from a wide angle end state to a telephoto end state, and
each lens being disposed within a lens barrel so that the following conditional expressions is satisfied.
8.40<f1/(−f2)
where,
f1 denotes a focal length of the first lens group, and
f2 denotes a focal length of the second lens group.

### Claim 38

A method for manufacturing the zoom lens comprising, in order from an object, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having negative refractive power, and a fifth lens group having positive refractive power, and zooming being performed by changing distances between each lens group, and
the first lens group being composed of three or more lenses,
the fourth lens group being composed of two or less lenses, and
the fifth lens group being composed of two or less lenses, and moving to an image surface side upon zooming from a wide angle end state to a telephoto end state, and
each lens being disposed within a lens barrel so that the following conditional expressions is satisfied.
5.80<Dt12/(−f2)
where,
Dt12 denotes a distance on an optical axis from an image side surface of the first lens group in the telephoto end state to an object side surface of the second lens group, and
f2 denotes a focal length of the second lens group.

### Claim 39

A method for manufacturing a zoom lens comprising, in order from an object, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having negative refractive power, and a fifth lens group having positive refractive power, and zooming being performed by changing distances between each lens group, and
the first lens group being composed of three or more lenses,
the fourth lens group being composed of two or less lenses, and
the fifth lens group being composed of two or less lenses, and moving to an image surface side upon zooming from a wide angle end state to a telephoto end state, and
each lens being disposed within a lens barrel so that the following conditional expressions are satisfied.
0.01<D1/ft<0.15
0.70<Zidwt/Fnwt<1.10
where,
D1 denotes a distance on an optical axis from an object side surface of the first lens group to an image side surface,
ft denotes a focal length of a whole system in the telephoto end state,
βt4 denotes magnification of the fourth lens group in the telephoto end state,
βt5 denotes magnification of the fifth lens group in the telephoto end state,
βw4 denotes magnification of the fourth lens group in the wide angle end state,
βw5 denotes magnification of the fifth lens group in the wide angle end state,
Fnt denotes an f number in the telephoto end state, and
Fnw denotes an f number in the wide angle end state.
Note that the following definitions are applicable.
Zidwt={(1—βt4̂2)*βt5̂2}/{(1−βw4̂2)*βw5̂2}
Fnwt=Fnt/Fnw

### Claim 40

A method for manufacturing a zoom lens comprising, in order from an object, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having negative refractive power, and a fifth lens group having positive refractive power, and zooming being performed by changing distances between each lens group, and
the first lens group being composed of three or more lenses, and
the fifth lens group moving to an image surface side upon zooming from a wide angle end state to a telephoto end state, and
each lens being disposed within a lens barrel so that the following conditional expression is satisfied.
0.020<(−f2)/ft<0.031
where,
f2 denotes a focal length of the second lens group in the telephoto end state, and
ft denotes a focal length of a whole system in the telephoto end state.

### Claim 41

A method for manufacturing a zoom lens comprising, in order from an object, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having negative refractive power, and a fifth lens group having positive refractive power, and
each lens being disposed within a lens barrel so that the following conditional expressions are satisfied.
33.00<ft/(−f2)<46.00
1.60<(Fnt·f1)/ft<2.30
43.00<β2t−β3t/(β2w·β3w)<65.00
where,
ft denotes a focal length of a whole system in the telephoto end state,
f2 denotes a focal length of the second lens group,
Fnt denotes an F value in the telephoto end state,
f1 denotes a focal length of the first lens group,
β2t denotes magnification of the second lens group in the telephoto end state,
β3t denotes magnification of the third lens group in the telephoto end state,
β2w denotes magnification of the second lens group in the wide angle end state, and
β3w denotes magnification of the third lens group in the wide angle end state.

### Claim 42 (depends on 2)

A zoom lens according to claim 2, wherein the following conditional expression is satisfied.
0.01<D1/ft<0.15
where,
D1 denotes a distance on an optical axis from the object side surface of the first lens group to the image side surface, and
ft denotes a focal length of the whole system in the telephoto end state.

### Claim 43 (depends on 2)

A zoom lens according to claim 2, wherein the following conditional expression is satisfied.
0.70<Zidwt/Fnwt<1.10
Note that the following definitions are applicable.
Zidwt={(1−βt4̂2)*βt5̂2}/{(1−βw4̂2)*βw5̂2}
Fnwt=Fnt/Fnw
where,
βt4 denotes magnification of the fourth lens group in the telephoto end state,
βt5 denotes magnification of the fifth lens group in the telephoto end state,
βw4 denotes magnification of the fourth lens group in the wide angle end state,
βw5 denotes magnification of the fifth lens group in the wide angle end state,
Fnt denotes an f number in a telephoto end state, and
Fnw denotes an f number in the wide angle end state.

### Claim 44 (depends on 2)

A zoom lens according to claim 2, wherein the following conditional expression is satisfied.
2.70<βt3/βw3
where,
βt3 denotes magnification of the third lens group in the telephoto end state, and
βw3 denotes magnification of the third lens group in the wide angle end state.

### Claim 45 (depends on 2)

A zoom lens according to claim 2, wherein the following conditional expression is satisfied.
0.03<Mv2/ft
where,
Mv2 denotes amount of movement of the second lens group from the wide angle end state to the telephoto end state, and
ft denotes a focal length of a whole system in the telephoto end state.

### Claim 46 (depends on 2)

A zoom lens according to claim 2, wherein the fourth lens group is composed of two lenses, and these two lenses are cemented with each other.

### Claim 47 (depends on 2)

A zoom lens according to claim 2, wherein the fifth lens group is composed of two lenses, and these lenses are cemented with each other.

### Claim 48 (depends on 2)

A zoom lens according to claim 2, wherein the second lens group is composed of, in order from the object, a negative lens, a negative lens, a positive lens, and a negative lens.

### Claim 49 (depends on 2)

A zoom lens according to claim 2, wherein the third lens group comprises, in order from the image, a positive lens, a negative lens, a negative lens, and a positive lens.

### Claim 50 (depends on 2)

A zoom lens according to claim 2, wherein focusing is performed by moving the fourth lens group along an optical axis direction.

### Claim 51 (depends on 2)

A zoom lens according to claim 2, wherein all of the lens groups move upon zooming from the wide angle end state to the telephoto end state.

### Claim 52 (depends on 2)

An optical apparatus equipped with the zoom lens according to claim 2.

### Claim 53 (depends on 3)

A zoom lens according to claim 3, wherein the following conditional expression is satisfied.
5.80<Dt12/(−f2)
where,
Dt12 denotes a distance on an optical axis from the image side surface of the first lens group in the telephoto end state to the object side surface of the second lens group.

### Claim 54 (depends on 3)

A zoom lens according to claim 3, wherein the following conditional expression is satisfied.
8.40<f1/(−f2)
where,
f1 denote a focal length of the first lens group.

### Claim 55 (depends on 3)

A zoom lens according to claim 3, wherein the following conditional expression is satisfied.
2.70<βt3/βw3
where,
βt3 denotes magnification of the third lens group in the telephoto end state, and
βw3 denotes magnification of the third lens group in the wide angle end state.

### Claim 56 (depends on 3)

A zoom lens according to claim 3, wherein the following conditional expression is satisfied.
0.03<Mv2/ft
where,
Mv2 denotes amount of movement of the second lens group from the wide angle end state to the telephoto end state, and
ft denotes a focal length of a whole system in the telephoto end state.

### Claim 57 (depends on 3)

A zoom lens according to claim 3, wherein the fourth lens group is composed of two lenses, and these two lenses are cemented with each other.

### Claim 58 (depends on 3)

A zoom lens according to claim 3, wherein the fifth lens group is composed of two lenses, and these lenses are cemented with each other.

### Claim 59 (depends on 3)

A zoom lens according to claim 3, wherein the second lens group is composed of, in order from the object, a negative lens, a negative lens, a positive lens, and a negative lens.

### Claim 60 (depends on 3)

A zoom lens according to claim 3, wherein the third lens group comprises, in order from the image, a positive lens, a negative lens, a negative lens, and a positive lens.

### Claim 61 (depends on 3)

A zoom lens according to claim 3, wherein focusing is performed by moving the fourth lens group along an optical axis direction.

### Claim 62 (depends on 3)

A zoom lens according to claim 3, wherein all of the lens groups move upon zooming from the wide angle end state to the telephoto end state.

### Claim 63 (depends on 3)

An optical apparatus equipped with the zoom lens according to claim 3.

### Claim 64 (depends on 15)

A zoom lens according to claim 15, wherein all of the lens groups move upon zooming from the wide angle end state to the telephoto end state.

### Claim 65 (depends on 15)

An optical apparatus equipped with the zoom lens according to claim 15.

### Claim 66 (depends on 22)

A zoom lens according to claim 22, wherein all of the lens groups move upon zooming from the wide angle end state to the telephoto end state.

### Claim 67 (depends on 22)

optical apparatus equipped with the zoom lens according to claim 22.