# US 12,222,482 B2 · Zoom lens, optical apparatus and method for manufacturing the zoom lens

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- Number: US 12,222,482 B2
- Document ID: US12222482B2
- Status: Granted
- Kind: B2
- Application number: 17/367,306
- Filed: 2021-07-02
- Published: 2021-10-28
- Granted: 2025-02-11
- Earliest claimed: 2015-12-09
- Assignees: Nikon Corporation
- Applicants: Nikon Corporation
- Inventors: Saburo Masugi
- Web page: https://patentgrep.com/patent/US12222482B2

## CPC

- G02B 15/20: having an additional movable lens or lens group for varying the objective focal length
- G02B 13/02: Telephoto objectives, i.e. systems of the type + - in which the distance from the front vertex to the image plane is less than the equivalent focal length
- G02B 15/145121: {arranged +-+-+}
- G02B 15/173: arranged +-+
- G02B 13/0045: {having five or more lenses}
- G02B 13/18: with lenses having one or more non-spherical faces, e.g. for reducing geometrical aberration {(G02B13/002 takes precedence)}
- G02B 15/14: by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective
- G02B 27/646: {compensating for small deviations, e.g. due to vibration or shake (movement of one or more optical elements for control of motion blur in cameras, projectors or printers G03B2205/0007; image stabilisation in cameras peculiar to the presence or use of an electronic image sensor H04N23/68)}
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

## Abstract

A zoom lens, comprises: in order from an object, 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, wherein, upon zooming from a wide-angle end state to a telephoto end state, a distance between each of lens groups and a lens group adjacent thereto changes to satisfy the following conditional expression: 2.90<|MV5/MV2|<11.50 where, MV5 denotes, upon zooming from a wide-angle end state to a telephoto end state, a moving amount of the fifth lens group with an image surface as a reference; and MV2 denotes, upon zooming from the wide-angle end state to the telephoto end state, a moving amount of the second lens group with the image surface as the reference.

## 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; an aperture stop; 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, wherein
a lens closest to the object in the third lens group is a single lens having positive refractive power,
upon zooming from a wide-angle end state to a telephoto end state,
the fourth lens group moves toward the object monotonically,
a distance between each of lens groups and a lens group adjacent thereto changes to satisfy the following conditional expression:
3.50<|MV5/MV2|<11.50
where
MV5 denotes, upon zooming from the wide-angle end state to the telephoto end state, a moving amount of the fifth lens group with an image surface as a reference; and
MV2 denotes, upon zooming from the wide-angle end state to the telephoto end state, a moving amount of the second lens group with the image surface as a reference,
wherein the zoom lens satisfies the following conditional expression:
5.0<ωt<25.0
where
ωt denotes a half angle of view (unit: degree) of the zoom lens as a whole in the telephoto end state.

### Claim 2 (depends on 1)

The zoom lens according to claim 1, which satisfies the following conditional expression:
28.0<ωw<65.0
where
ωw denotes a half angle of view (unit: degree) of the zoom lens as a whole in the wide-angle end state.

### Claim 3 (depends on 1)

The zoom lens according to claim 1, which satisfies the following conditional expression:
6.00<|MV4/MV2|<15.00
where
MV4 denotes, upon zooming from the wide-angle end state to the telephoto end state, a moving amount of the fourth lens group with the image surface as a reference.

### Claim 4 (depends on 1)

The zoom lens according to claim 1, which satisfies the following conditional expression:
1.20<β2t/β2w<2.50
where
β2t denotes a magnification of the second lens group in the telephoto end state; and
β2w denotes a magnification of the second lens group in the wide-angle end state.

### Claim 5 (depends on 1)

The zoom lens according to claim 1, which satisfies the following conditional expression:
0.10<(β2t×β4w)/(β2w×β4t)<2.40
where
β2t denotes a magnification of the second lens group in the telephoto end state;
β2w denotes a magnification of the second lens group in the wide-angle end state;
β4t denotes a magnification of the fourth lens group in the telephoto end state; and
β4w denotes a magnification of the fourth lens group in the wide-angle end state.

### Claim 6 (depends on 1)

The zoom lens according to claim 1, which satisfies the following conditional expression:
1.50<TLt/ft<5.00
where
TLt denotes a total length of the zoom lens as a whole on an optical axis from a lens surface closest to the object in the first lens group to the image surface, in the telephoto end state; and
ft denotes a focal length of the zoom lens as a whole in the telephoto end state.

### Claim 7 (depends on 1)

The zoom lens according to claim 1, wherein, upon zooming from the wide-angle end state to the telephoto end state, the first lens group moves toward the object.

### Claim 8 (depends on 1)

An optical apparatus, comprising the zoom lens according to claim 1.

### Claim 9

A method for manufacturing a zoom lens comprising:
providing a lens barrel; and
arranging a plurality of lens groups in the lens barrel, the plurality of lens groups including, in order from an object, a first lens group having positive refractive power; a second lens group having negative refractive power; an aperture stop; 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,
a lens closest to the object in the third lens group being a single lens having positive refractive power,
the method further comprising:
arranging the first to the fifth lens groups in the lens barrel so as to be movable relative to each other and so that:
the fourth lens group moves toward the object monotonically,
upon zooming from a wide-angle end state to a telephoto end state, a distance between each of lens groups and a lens group adjacent thereto changes to satisfy the following conditional expression:
3.50<|MV5/MV2|<11.50
where
MV5 denotes, upon zooming from the wide-angle end state to the telephoto end state, a moving amount of the fifth lens group with an image surface as a reference; and
MV2 denotes, upon zooming from the wide-angle end state to the telephoto end state, a moving amount of the second lens group with the image surface as a reference, and
satisfying the following conditional expression:
5.0<ωt<25.0
where
ωt denotes a half angle of view (unit: degree) of the zoom lens as a whole in the telephoto end state.