JP2022024121A5 - - Google Patents

Claims (10)

From the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a subsequent lens group having a positive refractive power. It consists of
The subsequent lens group has a fourth lens group and a fifth lens group having a negative refractive power in order from the object side.
At the time of scaling, the distance between the first lens group and the second lens group changes, the distance between the second lens group and the third lens group changes, and the third lens group and the subsequent lens group change. The distance between the lens and the lens changes, and the distance between adjacent lens groups of the subsequent lens group changes.
At the time of scaling, the first lens group moves,
The in- focus lens group that moves during in-focus is included in the subsequent lens group, and is included in the subsequent lens group .
A variable magnification optical system that satisfies the following conditional expression.
0.040 <βFw <0.800
0.100 <BFw / fw <1.00
however,
βFw: Lateral magnification of the in-focus lens group in the wide-angle end state BFw: Back focus of the variable magnification optical system in the wide-angle end state fw: Focal length of the variable magnification optical system in the wide-angle end state The variable magnification optical system according to claim 1, which satisfies the following conditional expression.
-3.00 <f5 / f3 <-0.500
however,
f3: Focal length of the third lens group
f5: Focal length of the fifth lens group The subsequent lens group includes the fourth lens group, the fifth lens group, and the sixth lens group in order from the object side.
The variable magnification optical system according to claim 1 or 2, wherein the sixth lens group does not move at the time of magnification change. The variable magnification optical system according to any one of claims 1 to 3, wherein the in-focus lens group is a lens of the fourth lens group or a part of the fourth lens group. The variable magnification optical system according to any one of claims 1 to 4, wherein the third lens group includes a positive meniscus lens having a convex surface facing the object side on the most object side. The variable magnification optical system according to any one of claims 1 to 5, which satisfies the following conditional expression.
4.000 <f1 / f1Rw <9000
however,
f1: Focal length of the first lens group
f1Rw: Combined focal length in the wide-angle end state of the lens group arranged on the image plane side of the first lens group. The variable magnification optical system according to any one of claims 1 to 6, which satisfies the following conditional expression.
0.500 <1 / βRw <1,000
however,
βRw: Lateral magnification of the lens group placed closest to the image plane in the wide-angle end state The variable magnification optical system according to any one of claims 1 to 7, which satisfies the following conditional expression.
0.500 <f2fn / f2 <1.10
however,
f2fn: Focal length of the lens component on the most object side in the second lens group
f2: Focal length of the second lens group The variable magnification optical system according to any one of claims 1 to 8, which satisfies the following conditional expression.
0.300 <fF / ft <1.400
however,
fF: Focal length of the focusing lens group
ft: Focal length of the variable magnification optical system in the telephoto end state The variable magnification optical system according to any one of claims 1 to 9, which satisfies the following conditional expression.
40.00 ° <ωw <85.00 °
however,
ωw: Half angle of view of the variable magnification optical system in the wide-angle end state