US 2026/0202648 A1Published application

Variable magnification optical system and imaging apparatus

AssigneeFUJIFILM Corporation

InventorTakuya TANAKA

Life of this patent

Estimating the term…

Abstract

A variable magnification optical system consists of, in order from an object side to an image side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group, and a fourth lens group. The second lens group includes an aperture stop. A vibration-proof group is disposed adjacent to the aperture stop, and a focusing group is disposed closer to the image side than the aperture stop. The variable magnification optical system satisfies a predetermined conditional expression.

Claims20

Dependent claims

A variable magnification optical system consisting of, in order from an object side to an image side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group, and a fourth lens group,

wherein all spacings between adjacent lens groups change during changing magnification,
the second lens group includes an aperture stop,
a vibration-proof group that moves in a direction intersecting an optical axis during image shake correction is disposed adjacent to the aperture stop,
a focusing group that moves along the optical axis during focusing is disposed closer to the image side than the aperture stop, and
in a case where
a distance on the optical axis from a lens surface of the first lens group closest to the object side to a lens surface of the second lens group closest to the object side in a state where an infinite distance object is in focus at a wide angle end is denoted by DG1fG2f,
a focal length of the variable magnification optical system in a state where the infinite distance object is in focus at the wide angle end is denoted by fw,
a thickness of the first lens group on the optical axis is denoted by DG1,
a sum of a distance on the optical axis from the lens surface of the first lens group closest to the object side to a lens surface of the fourth lens group closest to the image side and a back focus of the variable magnification optical system in terms of an air conversion distance in a state where the infinite distance object is in focus at the wide angle end is denoted by TLw,
a maximum half angle of view in a state where the infinite distance object is in focus at the wide angle end is denoted by ωw, and
a back focus of the variable magnification optical system in terms of the air conversion distance at the wide angle end is denoted by Bfw,
Conditional Expressions (1), (2), (3), and (4) are satisfied, which are represented by
1
<
DG
⁢
1
⁢
fG
⁢
2
⁢
f
/
fw
<
5
,
(
1
)
0.4
<
DG
⁢
1
/
fw
<
2.5
,
(
2
)
2
<
TLw
/
(
fw
×
tan
⁢
ω
⁢
w
)
<
8
,
and
(
3
)
0.2
<
Bfw
/
(
fw
×
tan
⁢
ω
⁢
w
)
<
1.8
.
(
4
)

80 more elements

Dependencies are inferred from the claim text.

Facts

Application: 19/443,730Filed 8 Jan 2026
Priority: JP 2025-00551115 Jan 2025
Published: 16 Jul 2026
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

G02B 13/009
Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras: having zoom function
G02B 7/025
For lenses: using glue
G02B 13/0045
Having at least one aspherical surface: having five or more lenses
G02B 13/006
Employing a special optical element: at least one element being a compound optical element, e.g. cemented elements

Family

No related US applications are recorded in the indexed filing history.

Timeline

Citations

Open elsewhere

Building an agent or pulling many patents? Use the API or MCP server instead of scraping pages. Get an API key

patentgrep

Loading patent…

Abstract

wherein all spacings between adjacent lens groups change during changing magnification,
the second lens group includes an aperture stop,
a vibration-proof group that moves in a direction intersecting an optical axis during image shake correction is disposed adjacent to the aperture stop,
a focusing group that moves along the optical axis during focusing is disposed closer to the image side than the aperture stop, and
in a case where
a distance on the optical axis from a lens surface of the first lens group closest to the object side to a lens surface of the second lens group closest to the object side in a state where an infinite distance object is in focus at a wide angle end is denoted by DG1fG2f,
a focal length of the variable magnification optical system in a state where the infinite distance object is in focus at the wide angle end is denoted by fw,
a thickness of the first lens group on the optical axis is denoted by DG1,
a sum of a distance on the optical axis from the lens surface of the first lens group closest to the object side to a lens surface of the fourth lens group closest to the image side and a back focus of the variable magnification optical system in terms of an air conversion distance in a state where the infinite distance object is in focus at the wide angle end is denoted by TLw,
a maximum half angle of view in a state where the infinite distance object is in focus at the wide angle end is denoted by ωw, and
a back focus of the variable magnification optical system in terms of the air conversion distance at the wide angle end is denoted by Bfw,
Conditional Expressions (1), (2), (3), and (4) are satisfied, which are represented by
1
<
DG
⁢
1
⁢
fG
⁢
2
⁢
f
/
fw
<
5
,
(
1
)
0.4
<
DG
⁢
1
/
fw
<
2.5
,
(
2
)
2
<
TLw
/
(
fw
×
tan
⁢
ω
⁢
w
)
<
8
,
and
(
3
)
0.2
<
Bfw
/
(
fw
×
tan
⁢
ω
⁢
w
)
<
1.8
.
(
4
)

80 more elements

Facts

Application

19/443,730Filed 8 Jan 2026

Priority

JP 2025-00551115 Jan 2025

Published

16 Jul 2026

Term ends

Not estimatedThe source records don’t support an estimate.

Classification7 codes

G02B 13/009
Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras: having zoom function
G02B 7/025
For lenses: using glue
G02B 13/0045
Having at least one aspherical surface: having five or more lenses
G02B 13/006
Employing a special optical element: at least one element being a compound optical element, e.g. cemented elements