JP6540857B2 - Variable power optical system, optical device, manufacturing method of variable power optical system - Google Patents

Description

  The present invention relates to a variable magnification optical system, an optical device, and a method of manufacturing the variable magnification optical system.

  Heretofore, many variable magnification optical systems suitable for interchangeable lenses for cameras, digital cameras, video cameras and the like have been proposed in which the lens group on the most object side has positive refractive power (for example, Patent Document 1) reference.).

Unexamined-Japanese-Patent No. 2007-292994

  However, the conventional variable magnification optical system as described above has a problem that it is difficult to obtain sufficiently high optical performance if it is attempted to miniaturize it while maintaining a high magnification ratio.

  The present invention has been made in view of the above problems, and provides a variable magnification optical system having a high magnification ratio, a small size, and high optical performance, an optical device, and a method of manufacturing the variable magnification optical system. The purpose is

In order to solve the above problems, the present invention is
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 fourth lens having a positive refractive power The lens unit and the fifth lens unit substantially consist of five lens units ,
An aperture stop is provided on the object side of the third lens group,
During zooming , the distance between the first lens group and the second lens group, the distance between the second lens group and the third lens group, the distance between the third lens group and the fourth lens group, The distance between the fourth lens group and the fifth lens group changes, and the aperture stop and the fourth lens group move integrally.
A variable magnification optical system characterized by satisfying the following conditional expressions (1) and (2A) is provided.
(1) 0.650 <(-f2) / fw <1.240
(2A) 0.410 <f3 / f4 < 0.880
However,
fw: focal length f2 of the variable magnification optical system in the wide-angle end state: focal length f3 of the second lens group: focal length f3 of the third lens group: focal length of the fourth lens group
Also, the present invention is
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 fourth lens having a positive refractive power The lens unit and the fifth lens unit substantially consist of five lens units,
An aperture stop is provided on the object side of the third lens group,
During zooming from the wide-angle end state to the telephoto end state, the distance between the first lens group and the second lens group, the distance between the second lens group and the third lens group, and the third lens group The distance between the fourth lens group changes, the distance between the fourth lens group and the fifth lens group increases, and the aperture stop and the fourth lens group move integrally.
A variable magnification optical system characterized by satisfying the following conditional expressions (1) and (2) is provided.
(1) 0.650 <(-f2) / fw <1.240
(2) 0.410 <f3 / f4 <1.000
However,
fw: focal length of the variable magnification optical system in the wide-angle end state
f2: focal length of the second lens group
f3: focal length of the third lens group
f4: focal length of the fourth lens group
Also, the present invention is
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 fourth lens having a positive refractive power The lens unit and the fifth lens unit substantially consist of five lens units,
An aperture stop is provided on the object side of the third lens group,
During zooming, the distance between the first lens group and the second lens group, the distance between the second lens group and the third lens group, the distance between the third lens group and the fourth lens group, The distance between the fourth lens group and the fifth lens group changes, the aperture stop and the fourth lens group move integrally, and the position of the fifth lens group is fixed.
A variable magnification optical system characterized by satisfying the following conditional expressions (1) and (2) is provided.
(1) 0.650 <(-f2) / fw <1.240
(2) 0.410 <f3 / f4 <1.000
However,
fw: focal length of the variable magnification optical system in the wide-angle end state
f2: focal length of the second lens group
f3: focal length of the third lens group
f4: focal length of the fourth lens group

The present invention
An optical apparatus comprising the variable magnification optical system is provided.

  According to the present invention, it is possible to provide a variable magnification optical system having a high zoom ratio, small size, and high optical performance, an optical device, and a method of manufacturing the variable magnification optical system.

(A), (b), (c), (d), and (e) respectively show the wide-angle end state, the first intermediate focal length state, and the second intermediate state of the variable magnification optical system according to the first embodiment of the present application. It is sectional drawing in a focal distance state, a 3rd intermediate | middle focal distance state, and a telephoto end state. (A), (b), and (c) show an infinite distance object in the wide-angle end state, the first intermediate focal length state, and the second intermediate focal length state of the variable magnification optical system according to the first embodiment of the present application, respectively. FIG. 7 shows various aberrations that occurred during focusing. FIGS. 7A and 7B are aberration diagrams at the time of focusing on an infinite distance object in the third intermediate focal length state and the telephoto end state, respectively, of the zoom optical system according to the first embodiment of the present application. FIGS. (A), (b), (c), (d) and (e) respectively show the wide-angle end state, the first intermediate focal length state, and the second intermediate state of the variable magnification optical system according to the second embodiment of the present invention. It is sectional drawing in a focal distance state, a 3rd intermediate | middle focal distance state, and a telephoto end state. (A), (b), and (c) show an infinite distance object in the wide-angle end state, the first intermediate focal length state, and the second intermediate focal length state of the variable magnification optical system according to the second embodiment of the present application, respectively. FIG. 7 shows various aberrations that occurred during focusing. FIGS. 7A and 7B are aberration diagrams at the time of focusing on an infinity object in the third intermediate focal length state and the telephoto end state, respectively, of the zoom lens system according to Example 2 of the present application. FIGS. (A), (b), (c), (d) and (e) respectively show the wide-angle end state, the first intermediate focal length state, and the second intermediate state of the variable magnification optical system according to the third example of the present application. It is sectional drawing in a focal distance state, a 3rd intermediate | middle focal distance state, and a telephoto end state. (A), (b), and (c) show an infinite distance object in the wide-angle end state, the first intermediate focal length state, and the second intermediate focal length state of the variable magnification optical system according to the third embodiment of the present application, respectively. FIG. 7 shows various aberrations that occurred during focusing. FIGS. 7A and 7B are aberration diagrams respectively at the time of focusing on an infinite distance object in the third intermediate focal length state and the telephoto end state of the variable magnification optical system according to the third example of the present application. FIGS. (A), (b), (c), (d) and (e) are respectively the wide-angle end state, the first intermediate focal length state, and the second intermediate state of the variable magnification optical system according to the fourth example of the present application. It is sectional drawing in a focal distance state, a 3rd intermediate | middle focal distance state, and a telephoto end state. (A), (b) and (c) show the infinite distance object in the wide-angle end state, the first intermediate focal length state and the second intermediate focal length state of the variable magnification optical system according to the fourth example of the present application, respectively. FIG. 7 shows various aberrations that occurred during focusing. FIGS. 7A and 7B are aberration diagrams respectively at the time of focusing on an infinity object in the third intermediate focal length state and the telephoto end state of the variable magnification optical system according to the fourth example of the present application. FIGS. It is a figure which shows the structure of the camera provided with the variable magnification optical system of this application. It is a figure which shows the outline of the manufacturing method of the variable magnification optical system of this application.

Hereinafter, the variable magnification optical system, the optical apparatus, and the method of manufacturing the variable magnification optical system according to the present application will be described.
The variable magnification optical system of the present application comprises, in order from the object side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a positive lens. A fourth lens group having a refractive power of the first lens group and a fifth lens group, and a distance between the first lens group and the second lens group at the time of zooming from the wide-angle end state to the telephoto end state; A distance between the second lens group and the third lens group, a distance between the third lens group and the fourth lens group, and a distance between the fourth lens group and the fifth lens group are changed. There is. With this configuration, the variable magnification optical system according to the present application realizes zooming from the wide-angle end state to the telephoto end state, and can suppress variations in distortion aberration, astigmatism, and spherical aberration accompanying zooming. .

Further, the variable magnification optical system according to the present application is characterized by satisfying the following conditional expressions (1) and (2).
(1) 0.650 <(-f2) / fw <1.240
(2) 0.410 <f 3 / f 4 <1. 000
However,
fw: focal length f2 of the variable magnification optical system in the wide-angle end state: focal length f3 of the second lens group: focal length f3 of the third lens group: focal length of the fourth lens group

Conditional expression (1) defines the range of an appropriate focal length of the second lens unit. By satisfying the conditional expression (1), the variable magnification optical system of the present application can suppress the fluctuation of spherical aberration and the fluctuation of astigmatism at the time of zooming.
When the corresponding value of the conditional expression (1) of the variable magnification optical system of the present application falls below the lower limit value, it becomes difficult to suppress the variation of the spherical aberration and the variation of the astigmatism generated in the second lens unit during zooming. It will not be possible to realize high optical performance. In order to further ensure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (1) to 0.760.
On the other hand, when the corresponding value of the conditional expression (1) of the variable magnification optical system of the present application exceeds the upper limit value, the distance between the first lens group and the second lens group at the time of zooming in order to obtain a predetermined zooming ratio. It is necessary to increase the change amount of As a result, it becomes difficult to miniaturize, and the height from the optical axis of the off-axis luminous flux incident on the first lens group to the second lens group largely changes with the magnification change. For this reason, the variation of astigmatism becomes excessive at the time of zooming, and high optical performance can not be realized. In order to make the effect of the present invention more reliable, it is more preferable to set the upper limit value of the conditional expression (1) to 1.180. Moreover, in order to make the effect of this application more reliable, it is more preferable to set the upper limit of conditional expression (1) to 1.145.

Conditional expression (2) defines the range of an appropriate focal length ratio of the third lens unit and the fourth lens unit. By satisfying the conditional expression (2), the variable magnification optical system according to the present application can suppress the fluctuation of spherical aberration and the fluctuation of astigmatism at the time of zooming.
When the corresponding value of the conditional expression (2) of the variable magnification optical system of the present application falls below the lower limit value, it becomes difficult to suppress the variation of the spherical aberration and the variation of the astigmatism generated in the third lens unit at the time of zooming. It will not be possible to realize high optical performance. In order to make the effect of the present invention more reliable, it is more preferable to set the lower limit of conditional expression (2) to 0.550.
On the other hand, when the corresponding value of the conditional expression (2) of the variable magnification optical system of the present application exceeds the upper limit value, it is difficult to suppress the variation of the spherical aberration and the variation of the astigmatism generated in the fourth lens unit at the time of zooming. As a result, high optical performance can not be realized. In order to make the effect of the present invention more reliable, it is more preferable to set the upper limit of conditional expression (2) to 0.880.
With the above configuration, it is possible to realize a variable power optical system having a high zoom ratio, a small size, and high optical performance.

Further, it is desirable that the variable magnification optical system of the present application satisfy the following conditional expression (3).
(3)-0.050 <(d3t-d3w) / fw <0.750
However,
fw: focal length d3w of the variable magnification optical system in the wide-angle end state: distance from the lens surface closest to the image in the third lens group to the lens surface closest to the object in the fourth lens group in the wide-angle end d3t: distance from the lens surface closest to the image side in the third lens unit to the lens surface closest to the object in the fourth lens unit in the telephoto end state

The conditional expression (3) is the distance on the optical axis from the lens surface closest to the image side in the third lens unit to the lens surface closest to the object in the fourth lens unit, ie, the third lens unit and the fourth lens unit And defines the range of an appropriate amount of change during zooming. By satisfying the conditional expression (3), the variable magnification optical system of the present application can suppress the fluctuation of coma and the fluctuation of astigmatism at the time of zooming.
When the corresponding value of the conditional expression (3) of the variable magnification optical system of the present application falls below the lower limit value, it becomes difficult to suppress the fluctuation of astigmatism generated in the third lens unit at the time of zooming, and high optical performance is realized It can not be done. In order to make the effect of the present invention more reliable, it is more preferable to set the lower limit value of conditional expression (3) to 0.000.
On the other hand, when the corresponding value of the conditional expression (3) of the variable magnification optical system of the present application exceeds the upper limit, it becomes difficult to suppress the fluctuation of the coma aberration generated in the fourth lens unit at the time of zooming and high optical performance It can not be realized. In order to make the effect of the present invention more reliable, it is more preferable to set the upper limit of conditional expression (3) to 0.500.

  Further, in the variable magnification optical system of the present application, it is desirable that the first lens group move to the object side at the time of zooming from the wide angle end state to the telephoto end state. With this configuration, it is possible to suppress the change in height from the optical axis of the off-axis light beam passing through the first lens group at the time of zooming. As a result, not only the diameter of the first lens unit can be reduced, but also the fluctuation of astigmatism can be suppressed during zooming.

  Further, in the variable magnification optical system of the present application, it is desirable that the fifth lens group have a positive refractive power. With this configuration, the use magnification of the fifth lens group is smaller than equal magnification, and as a result, the combined focal length from the first lens group to the fourth lens group can be relatively increased. By this, it is possible to relatively suppress the influence of decentering comatic aberration and the like caused by the decentering of the lenses generated in the first lens group to the fourth lens group at the time of manufacture, and realize high optical performance. it can.

  Further, in the variable magnification optical system of the present application, it is desirable that the distance between the first lens group and the second lens group be increased at the time of zooming from the wide angle end state to the telephoto end state. With this configuration, it is possible to multiply the magnification of the second lens unit, and to realize a high zoom ratio efficiently, and to suppress variations in spherical aberration and astigmatism during zooming.

  Further, in the variable magnification optical system of the present application, it is desirable that the distance between the second lens group and the third lens group be reduced at the time of zooming from the wide-angle end state to the telephoto end state. With this configuration, it is possible to multiply the combined magnification of the third lens group and the fourth lens group, and to effectively realize a high zoom ratio while suppressing variations in spherical aberration and astigmatism during zooming. be able to.

  Further, in the variable magnification optical system of the present application, it is desirable that an interval between the fourth lens group and the fifth lens group be increased at the time of zooming from the wide angle end state to the telephoto end state. With this configuration, it is possible to multiply the combined magnification of the third lens group and the fourth lens group, and to effectively realize a high zoom ratio while suppressing variations in spherical aberration and astigmatism during zooming. be able to.

  Further, in the variable magnification optical system of the present application, it is desirable that the position of the fifth lens group be fixed at the time of zooming from the wide angle end state to the telephoto end state. With this configuration, it is possible to change the height from the optical axis of the marginal ray that enters the fourth lens unit to the fifth lens unit during zooming. Thereby, it is possible to better suppress the variation of astigmatism at the time of zooming.

  The optical apparatus of the present application is characterized by including the variable magnification optical system having the above-described configuration. As a result, it is possible to realize an optical apparatus having a high zoom ratio, a small size, and high optical performance.

In the method of manufacturing a variable magnification optical system according to the present application, a first lens group having positive refractive power, a second lens group having negative refractive power, and a third lens group having positive refractive power are arranged in order from the object side And a fourth lens group having a positive refractive power, and a fifth lens group, wherein the second lens group, the third lens group, and the fourth lens group are provided. To satisfy the following conditional expressions (1) and (2), and at the time of zooming from the wide-angle end state to the telephoto end state, the distance between the first lens group and the second lens group; A distance between the second lens group and the third lens group, a distance between the third lens group and the fourth lens group, and a distance between the fourth lens group and the fifth lens group are changed. And As a result, it is possible to manufacture a variable magnification optical system having a high magnification ratio, a small size, and high optical performance.
(1) 0.650 <(-f2) / fw <1.240
(2) 0.410 <f 3 / f 4 <1. 000
However,
fw: focal length f2 of the variable magnification optical system in the wide-angle end state: focal length f3 of the second lens group: focal length f3 of the third lens group: focal length of the fourth lens group

  Hereinafter, a variable magnification optical system according to a numerical example of the present application will be described based on the attached drawings.

(First embodiment)
1 (a), 1 (b), 1 (c), 1 (d), and 1 (e) show the wide-angle end state of the variable magnification optical system according to the first embodiment of the present invention, respectively. FIG. 6 is a cross-sectional view in a first intermediate focal length state, a second intermediate focal length state, a third intermediate focal length state, and a telephoto end state.

  The variable magnification optical system according to the present embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens group having a positive refractive power. It comprises a lens group G3, a fourth lens group G4 having positive refractive power, and a fifth lens group G5 having positive refractive power.

The first lens group G1 includes, in order from the object side, a cemented lens of a negative meniscus lens L11 with a convex surface facing the object side and a biconvex positive lens L12, and a positive meniscus lens L13 with a convex surface facing the object side Become.
In the second lens group G2, in order from the object side, a negative meniscus lens L21 having a convex surface facing the object side, a biconcave negative lens L22, a biconvex positive lens L23, and a negative surface having a concave surface facing the object And a cemented lens with the meniscus lens L24. The negative meniscus lens L21 is a glass mold aspheric lens in which the lens surface on the object side is aspheric.

The third lens group G3 is composed of, in order from the object side, a cemented lens of a negative meniscus lens L31 having a convex surface facing the object side and a biconvex positive lens L32. An aperture stop S is provided on the object side of the third lens group G3.
The fourth lens group G4, in order from the object side, is a cemented lens of a biconvex positive lens L41 and a biconcave negative lens L42, and a negative meniscus with a biconvex positive lens L43 and a concave surface facing the object side A cemented lens with the lens L44, a cemented lens of a biconcave negative lens L45 and a biconvex positive lens L46, and a biconvex positive lens L47 with a negative meniscus lens L48 having a concave surface facing the object side It consists of a cemented lens. The negative meniscus lens L48 is a glass mold aspheric lens having an aspheric lens surface on the image side.

  The fifth lens group G5 is composed of, in order from the object side, a cemented lens of a positive meniscus lens L51 having a concave surface facing the object side and a negative meniscus lens L52 having a concave surface facing the object side. The negative meniscus lens L52 is a glass mold aspheric lens having an aspheric lens surface on the image side.

Under the above-described configuration, in the variable magnification optical system according to the present embodiment, an air gap between the first lens group G1 and the second lens group G2 and a second lens group at the time of zooming from the wide angle end state to the telephoto end state. The air spacing between G2 and the third lens group G3, the air spacing between the third lens group G3 and the fourth lens group G4, and the air spacing between the fourth lens group G4 and the fifth lens group G5 respectively change The first to fourth lens groups G1 to G4 move along the optical axis.
In detail, the first lens group G1, the third lens group G3 and the fourth lens group G4 move to the object side during zooming. The second lens group G2 moves to the object side from the wide angle end state to the third intermediate focal length state, and moves to the image side from the third intermediate focal length state to the telephoto end state. The position of the fifth lens group G5 in the optical axis direction is fixed at the time of zooming. The aperture stop S moves integrally with the fourth lens group G4 to the object side during zooming.

  As a result, the air gap between the first lens group G1 and the second lens group G2 increases during zooming, and the air gap between the second lens group G2 and the third lens group G3 decreases, and the fourth lens group G4 The air gap between the lens unit G5 and the fifth lens group G5 is increased. The air gap between the third lens group G3 and the fourth lens group G4 increases from the wide-angle end state to the first intermediate focal length state, and decreases from the first intermediate focal length state to the second intermediate focal length state. It increases from the intermediate focal length state to the telephoto end state. During zooming, the air gap between the aperture stop S and the third lens group G3 decreases from the wide-angle end state to the first intermediate focal length state, and increases from the first intermediate focal length state to the second intermediate focal length state. , Decrease from the second intermediate focal length state to the telephoto end state.

Table 1 below presents values of specifications of the variable magnification optical system according to the present example.
In Table 1, f is the focal length, and BF is the back focus (the distance between the most image side lens surface and the image plane I on the optical axis).
In [Surface Data], the surface number is the order of the optical surface counted from the object side, r is the radius of curvature, d is the surface distance (the distance between the nth surface (n is an integer) and the n + 1th surface), nd is The refractive index for the d-line (wavelength 587.6 nm) and ν d indicate the Abbe number for the d-line (wavelength 587.6 nm). The object plane indicates the object plane, the variable plane spacing is variable, the stop S indicates the aperture stop S, and the image plane indicates the image plane I. The radius of curvature r = ∞ indicates a plane. In the aspheric surface, the surface number is marked with *, and the value of the paraxial radius of curvature is shown in the column of radius of curvature r. The description of the refractive index nd = 1.000000 of air is omitted.

[Spherical surface data] shows the aspheric surface coefficient and the conical constant when the shape of the aspheric surface shown in [Surface data] is expressed by the following equation.
x = (h ² / r) / [1+ {1-κ (h / r) ² } ^1/2 ]
+ A ⁴ h ⁴ + A ⁶ h ⁶ + A ⁸ h ⁸ + A ¹⁰ h ¹⁰ + A ¹² h ¹²
Here, h is the height in the direction perpendicular to the optical axis, x is the distance along the optical axis direction from the tangent plane of the apex of the aspheric surface at height h to the aspheric surface (sag amount), and κ is the conical constant , A4, A6, A8, A10 and A12 are aspheric coefficients, and r is a radius of curvature (paraxial radius of curvature) of the reference spherical surface. Incidentally, "E-n" (n is an integer) indicates "× 10 ^-n", for example "1.234E-05" denotes "1.234 × 10 ^-5". The second-order aspheric coefficient A2 is 0, and the description is omitted.

In [Various data], FNO is F number, ω is half angle of view (unit: “°”), Y is image height, TL is total length of variable magnification optical system (image from first surface at infinity object focusing The distance on the optical axis to the surface I), dn represents a variable distance between the nth surface and the n + 1th surface, and φ represents the diameter of the aperture stop S. W indicates the wide-angle end state, M1 indicates the first intermediate focal length state, M2 indicates the second intermediate focal length state, M3 indicates the third intermediate focal length state, and T indicates the telephoto end state.
[Lens group data] indicates the starting surface of each lens group and the focal length.
In [Conditional Expression Correspondence Value], the correspondence values of the conditional expressions of the variable magnification optical system according to the present embodiment are shown.

Here, the unit of focal length f, radius of curvature r and other lengths listed in Table 1 is generally “mm”. However, the optical system is not limited to this because the same optical performance can be obtained by proportional enlargement or reduction.
In addition, the code | symbol of Table 1 described above shall be similarly used also in the table | surface of each Example mentioned later.

(Table 1) First embodiment
[Plane data]
Face number r d nd d d
Object ∞

1 165.4019 1.6350 1.902650 35.73
2 41.88.93 9.2560 1.497820 82.57
3 -178.4364 0.1000
4 42.8430 5.1140 1.729160 54.61
5 515.0653 Variable

* 6 500.0000 1.0000 1.851350 40.10
7 9.0059 4.2479
8-16.6413 1.0000 1.883000 40.66
9 50.8442 0.7538
10 32. 1419 3.0566 1.808090 22.74
11 -18.1056 1.0000 1.883000 40.66
12-29.3627 Variable

13 (stop S) ∞ variable

14 27.1583 1.0000 1.883000 40.66
15 14.3033 3.4259 1.593190 67.90
16-43.0421 Variable

17 12.5000 8.2427 1.670030 47.14
18 -79.2339 1.0000 1.883000 40.66
19 11.4345 2.0000
20 18.9834 3.3397 1.518600 69.89
21 -12.4126 1.0000 1.850260 32.35
22-22.7118 1.5000
23-46.2616 1.0000 1.902650 35.73
24 11.4391 3.5033 1.581440 40.98
25-30.7870 0.1000
26 28.7953 5.0986 1.581440 40.98
27 -8.8012 1.0000 1.820800 42.71
* 28 -35.2149 Variable

29 -40.0000 1.6432 1.497820 82.57
30-19.4318 1.0000 1.834410 37.28
* 31-22.7996 BF

Image plane ∞

[Aspheric surface data]
Sixth face 11. 11.00000
A4 3.95289E-05
A6 -2.04622E-07
A8 -4.81392E-09
A10 9.83575E-11
A12 -5.88880E-13

The 28th face 1. 1.0000
A4 -5.59168E-05
A6-2.20298E-07
A8 3.87818E-10
A10 1.16318E-11
A12 0.00000

The 31st face 1. 1.00000
A4 2.65930E-05
A6 7.69228E-08
A8-1.34346E-09
A10 0.00000
A12 0.00000

[Various data]
Magnification ratio 14.14

W T
f 9.47 to 133.87
FNO 4.12 to 5.78
ω 41.95 to 3.27 °
Y 8.00 to 8.00
TL 112.25-165.65

W M1 M2 M3 T
f 9.47002 17.83631 60.50026 90.50043 133.87072
ω 41.95497 23.18274 7.18 201 4.82759 3.26779
FNO 4.12 5.24 5.77 5.77 5.78
φ 8.52 8.52 9.55 10.30 11.04
d5 2.10000 12.15693 36.10717 41.77210 46.27797
d12 24.77744 16.39929 5.66327 3.74451 2.20000
d13 5.18928 3.23115 4.53928 3.63928 1.80000
d16 2.25000 4.20813 2.90000 3.80000 5.63928
d28 1.86861 12.02032 28.59900 32.29005 33.66620
BF 14.04947 14.04956 14.04989 14.04993 14.05005

[Lens group data]
Group front f
1 1 68.08250
2 6-9.98760
3 14 38.80284
4 17 60.78065
5 29 129.99998

[Conditional expression corresponding value]
(1) (-f2) / fw = 1.055
(2) f3 / f4 = 0.638
(3) (d3t-d3w) / fw = 0.358

FIGS. 2A, 2B, and 2C respectively show the wide-angle end state, the first intermediate focal length state, and the second intermediate focus of the variable magnification optical system according to the first embodiment of the present application. FIG. 7 shows various aberrations that occurred when an infinity object was in focus in the distance state.
FIGS. 3A and 3B show various aberrations of the variable magnification optical system according to the first embodiment of the present invention at the time of focusing on an infinity object at the third intermediate focal length and at the telephoto end, respectively. It is.

  In each of the aberration diagrams, FNO denotes an F number, and A denotes a light beam incident angle, that is, a half angle of view (unit: "°"). d indicates the aberration at the d-line (wavelength 587.6 nm), g indicates the aberration at the g-line (wavelength 435.8 nm), and those without d and g indicate the aberration at the d-line. In astigmatism diagrams, a solid line indicates a sagittal image plane, and a broken line indicates a meridional image plane. The same reference numerals as in this example are used also in the aberration charts of the examples which will be described later.

  From the aberration diagrams, it is understood that in the variable magnification optical system according to the present example, various aberrations are well corrected from the wide-angle end state to the telephoto end state, and have high optical performance.

Second Embodiment
FIGS. 4 (a), 4 (b), 4 (c), 4 (d), and 4 (e) respectively show the wide-angle end state of the variable magnification optical system according to the second embodiment of the present invention; FIG. 6 is a cross-sectional view in a first intermediate focal length state, a second intermediate focal length state, a third intermediate focal length state, and a telephoto end state.
The variable magnification optical system according to the present embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens group having a positive refractive power. It comprises a lens group G3, a fourth lens group G4 having positive refractive power, and a fifth lens group G5 having positive refractive power.

The first lens group G1 includes, in order from the object side, a cemented lens of a negative meniscus lens L11 with a convex surface facing the object side and a biconvex positive lens L12, and a positive meniscus lens L13 with a convex surface facing the object side Become.
The second lens group G2 includes, in order from the object side, a negative meniscus lens L21 having a convex surface facing the object, a biconcave negative lens L22, a biconvex positive lens L23, and a biconcave negative lens L24. And a cemented lens. The negative meniscus lens L21 is a glass mold aspheric lens in which the lens surface on the object side is aspheric.

The third lens group G3 is composed of, in order from the object side, a cemented lens of a negative meniscus lens L31 having a convex surface facing the object side and a biconvex positive lens L32. An aperture stop S is provided on the object side of the third lens group G3.
The fourth lens group G4 includes, in order from the object side, a cemented lens of a positive meniscus lens L41 with a convex surface facing the object side and a negative meniscus lens L42 with a convex surface facing the object side, a biconvex positive lens L43, and an object A cemented lens with a negative meniscus lens L44 concave on the side, a cemented lens with a biconcave negative lens L45 and a biconvex positive lens L46, a biconvex positive lens L47 and a concave surface on the object side And a cemented lens with a negative meniscus lens L48 directed. The negative meniscus lens L48 is a glass mold aspheric lens having an aspheric lens surface on the image side.

  The fifth lens group G5 is composed of, in order from the object side, a cemented lens of a positive meniscus lens L51 having a concave surface facing the object side and a negative meniscus lens L52 having a concave surface facing the object side. The negative meniscus lens L52 is a glass mold aspheric lens having an aspheric lens surface on the image side.

Under the above-described configuration, in the variable magnification optical system according to the present embodiment, an air gap between the first lens group G1 and the second lens group G2 and a second lens group at the time of zooming from the wide angle end state to the telephoto end state. The air spacing between G2 and the third lens group G3, the air spacing between the third lens group G3 and the fourth lens group G4, and the air spacing between the fourth lens group G4 and the fifth lens group G5 respectively change The first to fourth lens groups G1 to G4 move along the optical axis.
In detail, the first lens group G1, the third lens group G3 and the fourth lens group G4 move to the object side during zooming. The second lens group G2 moves to the object side from the wide angle end state to the third intermediate focal length state, and moves to the image side from the third intermediate focal length state to the telephoto end state. The position of the fifth lens group G5 in the optical axis direction is fixed at the time of zooming. The aperture stop S moves integrally with the fourth lens group G4 to the object side during zooming.

As a result, the air gap between the first lens group G1 and the second lens group G2 increases during zooming, and the air gap between the second lens group G2 and the third lens group G3 decreases, and the fourth lens group G4 And the fifth lens unit G5 has an increased air gap. The air gap between the third lens group G3 and the fourth lens group G4 increases from the wide-angle end state to the first intermediate focal length state, and decreases from the first intermediate focal length state to the second intermediate focal length state. It increases from the intermediate focal length state to the telephoto end state. During zooming, the air gap between the aperture stop S and the third lens group G3 decreases from the wide-angle end state to the first intermediate focal length state, and increases from the first intermediate focal length state to the second intermediate focal length state. , Decrease from the second intermediate focal length state to the telephoto end state.
Table 2 below presents values of specifications of the variable magnification optical system according to the present example.

(Table 2) Second embodiment
[Plane data]
Face number r d nd d d
Object ∞

1 149.1393 1.6350 1.902650 35.73
2 39.3210 9.1912 1.497820 82.57
3-200.0000 0.1000
4 41.9637 5.4484 1.729160 54.61
5 1039.4250 Variable

* 6 500.0000 1.0000 1.851350 40.10
7 9.7424 3.8435
8-27.3991 1.0000 1.883000 40.66
9 89.0051 0.2895
10 21.6984 3.7554 1.808090 22.74
11-15.0205 1.0000 1.883000 40.66
12 103.6128 Variable

13 (stop S) ∞ variable

14 26.3876 1.0000 1.883000 40.66
15 13. 2001 3.5030 1.593190 67.90
16-39.4805 Variable

17 12.5000 8.2088 1.743200 49.26
18 25.6321 1.0000 1.834000 37.18
19 9.6066 2.0000
20 17.4828 3.0696 1.516800 63.88
21 -13.7429 1.0000 1.850260 32.35
22-25.6259 1.5000
23-19.7745 1.0000 1.850260 32.35
24 12.4270 3.9453 1.620040 36.40
25-17.2177 0.3559
26 44.5160 5.3272 1.581440 40.98
27 -8.1562 1.0000 1.820800 42.71
* 28-28.1926 Variable

29-40.0000 1.7646 1.497820 82.57
30-18.8409 1.0000 1.834410 37.28
* 31-25.0038 BF

Image plane ∞

[Aspheric surface data]
Sixth aspect 10. 10.29120
A4 1.05982E-05
A6 1.47868E-07
A8 -6.64708E-09
A10 8.77431E-11
A12 -4.23990E-13

The 28th face 1. 1.0000
A4 -7.26393E-05
A6-3.38257E-07
A8 1.26743E-09
A10-2.83030E-11
A12 0.00000

The 31st face 1. 1.00000
A4 2.68564E-05
A6 7.91224E-08
A8 -8.06538E-10
A10 0.00000
A12 0.00000

[Various data]
Magnification ratio 14.13

W T
f 10.30 to 145.50
FNO 4.08 to 5.71
ω 39.62 to 3.01 °
Y 8.00 to 8.00
TL 112.60 to 162.60

W M1 M2 M3 T
f 10.30001 18.00395 60.50530 89.50052 145.50102
ω 39.61 866 23.08393 7.20247 4.88583 3.000545
FNO 4.08 4.79 5.49 5.75 5.72
φ 9.01 9.02 9.02 9.26 10.08
d5 2.10000 11.86757 33.84673 38.94667 43.98780
d12 24.38938 17.21960 5.86923 4.42463 2.20000
d13 2.46923 1.80000 4.59702 3.69702 1.80000
d16 5.02779 5.69702 2.90000 3.80000 5.69702
d28 1.6624 10.35671 26.30176 30.05048 31.92800
BF 14.04946 14.04953 14.04979 14.04990 14.05006

[Lens group data]
Group front f
1 1 64.91265
2 6-9.00 339
3 14 38.07719
4 17 46.69911
5 29 260.10501

[Conditional expression corresponding value]
(1) (-f2) / fw = 0.874
(2) f3 / f4 = 0.815
(3) (d3t-d3w) / fw = 0.065

FIGS. 5 (a), 5 (b) and 5 (c) respectively show the wide-angle end state, the first intermediate focal length state, and the second intermediate focus of the variable magnification optical system according to the second embodiment of the present invention. FIG. 7 shows various aberrations that occurred when an infinity object was in focus in the distance state.
FIGS. 6A and 6B show various aberrations of the variable magnification optical system according to the second embodiment of the present invention at the time of focusing on an infinity object at the third intermediate focal length and at the telephoto end, respectively. It is.

  From the aberration diagrams, it is understood that in the variable magnification optical system according to the present example, various aberrations are well corrected from the wide-angle end state to the telephoto end state, and have high optical performance.

Third Embodiment
7 (a), 7 (b), 7 (c), 7 (d), and 7 (e) show the wide-angle end state of the variable magnification optical system according to the third embodiment of the present invention, respectively. FIG. 6 is a cross-sectional view in a first intermediate focal length state, a second intermediate focal length state, a third intermediate focal length state, and a telephoto end state.
The variable magnification optical system according to the present embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens group having a positive refractive power. It comprises a lens group G3, a fourth lens group G4 having positive refractive power, and a fifth lens group G5 having positive refractive power.

The first lens group G1 includes, in order from the object side, a cemented lens of a negative meniscus lens L11 with a convex surface facing the object side and a biconvex positive lens L12, and a positive meniscus lens L13 with a convex surface facing the object side Become.
In the second lens group G2, in order from the object side, a negative meniscus lens L21 having a convex surface facing the object side, a biconcave negative lens L22, a biconvex positive lens L23, and a negative surface having a concave surface facing the object And a cemented lens with the meniscus lens L24. The negative meniscus lens L21 is a glass mold aspheric lens in which the lens surface on the object side is aspheric.

The third lens group G3 is composed of, in order from the object side, a cemented lens of a negative meniscus lens L31 having a convex surface facing the object side and a biconvex positive lens L32. An aperture stop S is provided on the object side of the third lens group G3.
The fourth lens group G4, in order from the object side, is a cemented lens of a biconvex positive lens L41 and a biconcave negative lens L42, and a negative meniscus with a biconvex positive lens L43 and a concave surface facing the object side A cemented lens with the lens L44, a cemented lens of a biconcave negative lens L45 and a biconvex positive lens L46, and a biconvex positive lens L47 with a negative meniscus lens L48 having a concave surface facing the object side It consists of a cemented lens. The negative meniscus lens L48 is a glass mold aspheric lens having an aspheric lens surface on the image side.

  The fifth lens group G5 is composed of, in order from the object side, a cemented lens of a positive meniscus lens L51 having a concave surface facing the object side and a negative meniscus lens L52 having a concave surface facing the object side. The negative meniscus lens L52 is a glass mold aspheric lens having an aspheric lens surface on the image side.

  Under the above-described configuration, in the variable magnification optical system according to the present embodiment, an air gap between the first lens group G1 and the second lens group G2 and a second lens group at the time of zooming from the wide angle end state to the telephoto end state. The air spacing between G2 and the third lens group G3, the air spacing between the third lens group G3 and the fourth lens group G4, and the air spacing between the fourth lens group G4 and the fifth lens group G5 respectively change The first to fourth lens groups G1 to G4 move to the object side along the optical axis. The position of the fifth lens group G5 in the optical axis direction is fixed at the time of zooming. The aperture stop S moves integrally with the fourth lens group G4 to the object side during zooming.

Specifically, at the time of zooming, the air gap between the first lens group G1 and the second lens group G2 increases, and the air gap between the second lens group G2 and the third lens group G3 decreases, and the fourth lens group The air gap between G4 and the fifth lens group G5 is increased. The air gap between the third lens group G3 and the fourth lens group G4 increases from the wide-angle end state to the first intermediate focal length state, and decreases from the first intermediate focal length state to the second intermediate focal length state. It increases from the intermediate focal length state to the telephoto end state. During zooming, the air gap between the aperture stop S and the third lens group G3 decreases from the wide-angle end state to the first intermediate focal length state, and increases from the first intermediate focal length state to the second intermediate focal length state. , Decrease from the second intermediate focal length state to the telephoto end state.
Table 3 below presents values of specifications of the variable magnification optical system according to the present example.

(Table 3) Third embodiment
[Plane data]
Face number r d nd d d
Object ∞

1 142.4935 1.6350 1.950000 29.37
2 42.2502 8.5971 1.497820 82.57
3-244.5599 0.1000
4 43.5280 4.7901 1.834810 42.73
5 290.5464 Variable

* 6 500.0000 1.0000 1.851350 40.10
7 9.0471 4.3168
8-20. 3544 1.0000 1.903660 31.27
9 42.4575 0.7313
10 28.0 881 4.0634 1.808090 22.74
11-12.5975 1.0000 1.883000 40.66
12-38.6924 Variable

13 (stop S) ∞ variable

14 31.6163 1.0000 1.883000 40.66
15 15.7262 3.3464 1.593190 67.90
16 -39.3012 Variable

17 13.5000 9.6782 1.717000 47.98
18-38.7323 1.0000 1.883000 40.66
19 11.8099 2.0000
20 19.9976 3.2554 1.516800 63.88
21-12.0110 1.0000 1.850260 32.35
22 -20.9691 1.5000
23-39.8308 1.0000 1.950000 29.37
24 10.4776 3.5701 1.672700 32.19
25-30.1182 0.5349
26 36.6513 5.1773 1.581440 40.98
27-8.5118 1.0000 1.820800 42.71
* 28-28.2741 variable

29-40.0000 1.9141 1.497820 82.57
30 -18.1052 1.0000 1.834410 37.28
* 31-22.6207 BF

Image plane ∞

[Aspheric surface data]
Sixth face--3.81950
A4 4.21558E-05
A6-2.17082E-07
A8 -2.45102E-09
A10 5.51411E-11
A12-2.85950 E-13

The 28th face 1. 1.0000
A4-6.70317E-05
A6-2.82990E-07
A8 5.39592E-10
A10 -1.47007E-11
A12 0.00000

The 31st face 1. 1.00000
A4 2.67692E-05
A6 2.52197E-08
A8-6.04092E-10
A10 0.00000
A12 0.00000

[Various data]
Magnification ratio 14.13

W T
f 9.27 to 130.95
FNO 4.11 to 5.71
ω 42.66 to 3.37 °
Y 8.00 to 8.00
TL 113.35-167.85

W M1 M2 M3 T
f 9.27001 17.98649 60.50024 89.50040 130.95047
ω 42.66459 22.98882 7.25983 4.93130 3.37079
FNO 4.11 5.12 5.73 5.75 5.71
φ 8.59 8.59 9.57 10.18 11.03
d5 2.10000 14.22823 35.96983 41.57489 45.070436
d12 24.57776 16.27840 5.38702 3.71762 20000
d13 5.01075 3.17327 4.36075 3.46075 1.80000
d16 2.25000 4.08748 2.90000 3.80000 5.46075
d28 1.15583 11.01481 29.01229 32.10086 34.42483
BF 14.04945 14.04946 14.04979 14.04987 14.04999

[Lens group data]
Group front f
1 1 67.49208
2 6-9.52181
3 14 41.09622
4 17 53.39457
5 29 147.67270

[Conditional expression corresponding value]
(1) (-f2) / fw = 1.027
(2) f3 / f4 = 0.770
(3) (d3t-d3w) / fw = 0.346

FIGS. 8A, 8B, and 8C respectively show the wide-angle end state, the first intermediate focal length state, and the second intermediate focus of the variable magnification optical system according to the third example of the present application. FIG. 7 shows various aberrations that occurred when an infinity object was in focus in the distance state.
FIGS. 9 (a) and 9 (b) show various aberrations of the variable magnification optical system according to the third embodiment of the present invention at the time of focusing on an infinity object at the third intermediate focal length and at the telephoto end, respectively. It is.

  From the aberration diagrams, it is understood that in the variable magnification optical system according to the present example, various aberrations are well corrected from the wide-angle end state to the telephoto end state, and have high optical performance.

Fourth Embodiment
10 (a), 10 (b), 10 (c), 10 (d) and 10 (e) respectively show the wide-angle end state of the variable magnification optical system according to the fourth embodiment of the present invention; FIG. 6 is a cross-sectional view in a first intermediate focal length state, a second intermediate focal length state, a third intermediate focal length state, and a telephoto end state.
The variable magnification optical system according to the present embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens group having a positive refractive power. It comprises a lens group G3, a fourth lens group G4 having positive refractive power, and a fifth lens group G5 having positive refractive power.

The first lens group G1 includes, in order from the object side, a cemented lens of a negative meniscus lens L11 with a convex surface facing the object side and a biconvex positive lens L12, and a positive meniscus lens L13 with a convex surface facing the object side Become.
The second lens group G2 includes, in order from the object side, a negative meniscus lens L21 having a convex surface facing the object, a biconcave negative lens L22, a biconvex positive lens L23, and a biconcave negative lens L24. And a cemented lens. The negative meniscus lens L21 is a glass mold aspheric lens in which the lens surface on the object side is aspheric.

The third lens group G3 is composed of, in order from the object side, a cemented lens of a negative meniscus lens L31 having a convex surface facing the object side and a biconvex positive lens L32. An aperture stop S is provided on the object side of the third lens group G3.
The fourth lens group G4 includes, in order from the object side, a cemented lens of a positive meniscus lens L41 with a convex surface facing the object side and a negative meniscus lens L42 with a convex surface facing the object side, a biconvex positive lens L43, and an object From a cemented lens with a negative meniscus lens L44 concave on the side, a biconcave negative lens L45, and a cemented lens with a biconvex positive lens L46 and a negative meniscus lens L47 concave on the object side Become. The negative lens L45 is a glass mold aspheric lens in which the lens surface on the object side is aspheric, and the negative meniscus lens L47 is a glass mold aspheric lens in which the lens surface on the image side is aspheric.

  The fifth lens group G5 is composed of, in order from the object side, a cemented lens of a positive meniscus lens L51 having a concave surface facing the object side and a negative meniscus lens L52 having a concave surface facing the object side. The negative meniscus lens L52 is a glass mold aspheric lens having an aspheric lens surface on the image side.

Under the above-described configuration, in the variable magnification optical system according to the present embodiment, an air gap between the first lens group G1 and the second lens group G2 and a second lens group at the time of zooming from the wide angle end state to the telephoto end state. The air spacing between G2 and the third lens group G3, the air spacing between the third lens group G3 and the fourth lens group G4, and the air spacing between the fourth lens group G4 and the fifth lens group G5 respectively change The first to fourth lens groups G1 to G4 move along the optical axis.
In detail, the first lens group G1, the third lens group G3 and the fourth lens group G4 move to the object side during zooming. The second lens group G2 moves to the object side from the wide-angle end state to the second intermediate focal length state, moves to the image side from the second intermediate focal length state to the third intermediate focal length state, and moves to the third intermediate focal length state Move to the object side from to the telephoto end state. The position of the fifth lens group G5 in the optical axis direction is fixed at the time of zooming. The aperture stop S moves integrally with the fourth lens group G4 to the object side during zooming.

As a result, the air gap between the first lens group G1 and the second lens group G2 increases during zooming, and the air gap between the second lens group G2 and the third lens group G3 decreases, and the fourth lens group G4 And the fifth lens unit G5 has an increased air gap. The air gap between the third lens group G3 and the fourth lens group G4 increases from the wide-angle end state to the first intermediate focal length state, and decreases from the first intermediate focal length state to the second intermediate focal length state. It increases from the intermediate focal length state to the telephoto end state. During zooming, the air gap between the aperture stop S and the third lens group G3 decreases from the wide-angle end state to the first intermediate focal length state, and increases from the first intermediate focal length state to the second intermediate focal length state. , Decrease from the second intermediate focal length state to the telephoto end state.
Table 4 below presents values of specifications of the variable magnification optical system according to the present example.

(Table 4) Fourth embodiment
[Plane data]
Face number r d nd d d
Object ∞

1 128.2103 1.6350 1.950000 29.37
2 42.8046 8.6432 1.497820 82.57
3-200.0000 0.1000
4 42.6819 4.9663 1.816000 46.59
5 290.0414 Variable

* 6 500.0000 1.0000 1.851350 40.10
7 9.6706 3.8612
8-31.6340 1.0000 1.883000 40.66
9 50.5774 0.3860
10 20.2802 4.0969 1.808090 22.74
11-12.7389 1.0000 1.902650 35.73
12 182.6358 Variable

13 (stop S) ∞ variable

14 22.0943 1.0000 1.883000 40.66
15 12.0211 3.4295 1.593190 67.90
16-54.4618 Variable

17 13.5315 7.0129 1.816000 46.59
18 20.22 24 1.0000 1.850 260 32.35
19 10.9126 2.0000
20 18.6799 3.1628 1.516800 63.88
21 -12.1205 1.0000 1.850260 32.35
22-21.9214 1.5000
* 23-2373.2040 1.0000 1.806100 40.71
24 15.4976 2.3426
25 18.1342 5.9256 1.567320 42.58
26-8.0000 1.0000 1.851350 40.10
* 27-22.6238 Variable

28 -75.6072 2.0606 1.497820 82.57
29-18.0744 1.0000 1.834410 37.28
* 30-25.8110 BF

Image plane ∞

[Aspheric surface data]
Sixth face κ -9.00000
A4 1.14894E-05
A6 2.79933E-07
A8 -1.11589E-08
A10 1.42629E-10
A12 -6.44930E-13

The 23rd side κ 1.00000
A4-3.10495E-05
A6 4.64001E-07
A8-2.52074E-09
A10 1.73753E-10
A12 0.00000

Plane 27 κ 1.0000
A4 -5.63578E-05
A6 -8.97938E-08
A8 1.47935E-09
A10 -1.36135E-11
A12 0.00000

The 30th κ 1.00000
A4 2.81743E-05
A6 -2.96842E-08
A8 -7.80468E-10
A10 0.00000
A12 0.00000

[Various data]
Magnification ratio 14.13

W T
f 10.30 to 145.50
FNO 4.12 to 5.77
ω 39.65 to 3.02 °
Y 8.00 to 8.00
TL 107.35-157.35

W M1 M2 M3 T
f 10.30004 17.99586 60.49785 100.49280 145.50011
ω 39.65487 23.02121 7.21558 4.36760 3.01679
FNO 4.12 4.94 5.67 5.75 5.77
φ 8.34 8.34 9.08 9.22 10.26
d5 2.10000 12.12447 32.02336 38.52508 41.21393
d12 22.23850 16.63220 7.10168 3.99200 2.20000
d13 3.91359 2.69844 3.58860 3.47051 1.80000
d16 3.65694 4.87210 3.98194 4.10000 5.77054
d27 1.26857 9.13237 25.54504 27.42933 32.19314
BF 14.04952 14.04918 14.04790 14.04914 14.04088

[Lens group data]
Group front f
1 1 62.23195
2 6-9.03822
3 14 37.53030
4 17 49.24516
5 28 130.0156

[Conditional expression corresponding value]
(1) (-f2) / fw = 0.877
(2) f3 / f4 = 0.762
(3) (d3t-d3w) / fw = 0.205

11 (a), 11 (b) and 11 (c) respectively show the wide-angle end state, the first intermediate focal length state, and the second intermediate focus of the variable magnification optical system according to the fourth example of the present application. It is various aberrations figure at the time of an infinite point object focus in a distance state.
FIGS. 12A and 12B show various aberrations of the zoom optical system according to the fourth embodiment of the present invention, at the time of focusing on an infinity object at the third intermediate focal length and at the telephoto end, respectively. It is.

  From the aberration diagrams, it is understood that in the variable magnification optical system according to the present example, various aberrations are well corrected from the wide-angle end state to the telephoto end state, and have high optical performance.

According to each of the above embodiments, it is possible to realize a variable power optical system having a high zoom ratio, a small size, and high optical performance.
The above-described embodiments show one specific example of the present invention, and the present invention is not limited thereto. The following contents can be suitably adopted within the range that does not impair the optical performance of the variable magnification optical system of the present application.

  Although a five-group configuration is shown as a numerical example of the variable-magnification optical system according to the present application, the present application is not limited to this, and forms a variable-magnification optical system of other group configurations (for example, six groups, seven groups, etc. It can also be done. Specifically, a lens or lens group may be added to the most object side or most image side of the variable magnification optical system of the present application. The lens group indicates a portion having at least one lens separated by an air gap that changes at the time of zooming.

  Further, in the variable magnification optical system according to the present invention, in order to focus from an infinite distance object to a close distance object, a part of the lens group, an entire lens group, or a plurality of lens groups is used as a focusing lens group. It may be configured to move in the axial direction. In particular, it is preferable to set at least a part of the second lens group, at least a part of the third lens group, or at least a part of the fourth lens group, or at least a part of the fifth lens group as a focusing lens group. Further, such a focusing lens group can also be applied to auto focusing, and is also suitable for driving by a motor for auto focusing such as an ultrasonic motor.

  Further, in the variable magnification optical system according to the present application, all or part of any lens group is moved as a vibration reduction lens group so as to include a component in a direction perpendicular to the optical axis, or a surface including the optical axis It is also possible to correct image blurring caused by camera shake or the like by rotating (swinging) inward. In particular, in the variable magnification optical system of the present application, it is preferable that at least a part of the third lens group or at least a part of the fourth lens group or at least a part of the fifth lens group be a vibration reduction lens group.

  Further, the lens surface of the lens constituting the variable magnification optical system of the present invention may be a spherical surface or a plane, or may be an aspheric surface. When the lens surface is spherical or flat, it is preferable because lens processing and assembly adjustment can be facilitated, and deterioration of optical performance due to lens processing and assembly adjustment errors can be prevented. In addition, even when the image plane shifts, it is preferable because the deterioration of the imaging performance is small. When the lens surface is aspheric, any of aspheric aspheric surfaces by grinding, a glass mold aspheric surface formed by shaping a glass into aspheric surface shape, or a composite aspheric surface formed by forming a resin on a glass surface into an aspheric surface shape Good. The lens surface may be a diffractive surface, and the lens may be a gradient index lens (GRIN lens) or a plastic lens.

Further, in the variable magnification optical system of the present application, the aperture stop is preferably disposed in the third lens group or in the vicinity of the third lens group, and the lens frame substitutes its role without providing a member as the aperture stop. It is also good.
In addition, an anti-reflection film having high transmittance over a wide wavelength range may be provided on the lens surface of the lens constituting the variable magnification optical system of the present application. This can reduce flare and ghost and achieve high contrast and high optical performance.

Next, a camera provided with the variable magnification optical system of the present application will be described based on FIG.
FIG. 13 is a diagram showing a configuration of a camera provided with the variable magnification optical system of the present application.
As shown in FIG. 13, the camera 1 is a so-called mirrorless camera of an interchangeable lens type provided with the variable magnification optical system according to the first embodiment as the photographing lens 2.
In the present camera 1, light from an object (not shown) from the object (not shown) is collected by the photographing lens 2 and passes through an OLPF (Optical Low Pass Filter) (not shown) on the imaging surface of the imaging unit 3 Form an image of the subject. Then, the subject image is photoelectrically converted by the photoelectric conversion element provided in the imaging unit 3 to generate the image of the subject. This image is displayed on an EVF (Electronic view finder) 4 provided in the camera 1. Thereby, the photographer can observe the subject via the EVF 4.
When the photographer presses a release button (not shown), the image of the subject generated by the imaging unit 3 is stored in a memory (not shown). In this way, the photographer can shoot a subject with the main camera 1.

  Here, the variable magnification optical system according to the first embodiment mounted as the photographing lens 2 in the present camera 1 is a variable magnification optical system having a high magnification ratio, small size, and high optical performance. Therefore, the camera 1 can realize downsizing and high optical performance while having a high zoom ratio. Even if a camera mounted with the variable magnification optical system according to the second to fourth examples as the photographing lens 2 can be provided, the same effect as the camera 1 can be obtained. Even when the variable magnification optical system according to each of the above embodiments is mounted on a single-lens reflex camera having a quick return mirror and observing a subject by a finder optical system, the same effect as that of the camera 1 can be obtained. it can.

Finally, an outline of a method of manufacturing a variable magnification optical system according to the present application will be described based on FIG.
The manufacturing method of the variable magnification optical system of the present application shown in FIG. 14 has a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a positive refractive power in order from the object side. A manufacturing method of a variable power optical system including a third lens group, a fourth lens group having positive refractive power, and a fifth lens group, and includes the following steps S1 and S2.

Step S1: The second lens group, the third lens group, and the fourth lens group satisfy the following conditional expressions (1) and (2), and the first to fifth lens groups are arranged in the lens barrel: Arrange in order from the side.
(1) 0.650 <(-f2) / fw <1.240
(2) 0.410 <f 3 / f 4 <1. 000
However,
fw: Focal length f2 of the variable magnification optical system in the wide-angle end state: Focal length f2 of the second lens group: Focal length f3 of the third lens group f4: Focal length of the fourth lens group

  Step S2: The distance between the first lens group and the second lens group, the second lens group and the second lens group, and the like at the time of zooming from the wide-angle end state to the telephoto end state by providing a known moving mechanism in the lens barrel. The distance between the third lens unit, the distance between the third lens unit and the fourth lens unit, and the distance between the fourth lens unit and the fifth lens unit are changed.

  According to the manufacturing method of such a variable power optical system of the present application, it is possible to manufacture a variable power optical system having a high power ratio, a small size, and high optical performance.

G1 first lens group G2 second lens group G3 third lens group G4 fourth lens group G5 fifth lens group S aperture stop I image plane

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 fourth lens having a positive refractive power The lens unit and the fifth lens unit substantially consist of five lens units ,
An aperture stop is provided on the object side of the third lens group,
During zooming , the distance between the first lens group and the second lens group, the distance between the second lens group and the third lens group, the distance between the third lens group and the fourth lens group, The distance between the fourth lens group and the fifth lens group changes, and the aperture stop and the fourth lens group move integrally.
A variable magnification optical system characterized by satisfying the following conditional expressions (1) and (2A) .
(1) 0.650 <(-f2) / fw <1.240
(2A) 0.410 <f3 / f4 < 0.880
However,
fw: focal length f2 of the variable magnification optical system in the wide-angle end state: focal length f3 of the second lens group: focal length f3 of the third lens group: focal length of the fourth lens group 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 fourth lens having a positive refractive power The lens unit and the fifth lens unit substantially consist of five lens units ,
An aperture stop is provided on the object side of the third lens group,
When zooming from the wide-angle end state to the telephoto end state, the distance between the first lens group and the second lens group, the distance between the second lens group and the third lens group, the third lens group and the third lens group interval to vary between the fourth lens group increases the distance between the front Symbol said fifth lens group and the fourth lens group, and the aperture stop and the fourth lens unit move integrally,
A variable magnification optical system characterized by satisfying the following conditional expressions (1) and (2) .
(1) 0.650 <(-f2) / fw <1.240
(2) 0.410 <f 3 / f 4 <1. 000
However,
fw: focal length f2 of the variable magnification optical system in the wide-angle end state: focal length f3 of the second lens group: focal length f3 of the third lens group: focal length of the fourth lens group 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 fourth lens having a positive refractive power The lens unit and the fifth lens unit substantially consist of five lens units ,
An aperture stop is provided on the object side of the third lens group,
During zooming , the distance between the first lens group and the second lens group, the distance between the second lens group and the third lens group, the distance between the third lens group and the fourth lens group, The distance between the fourth lens group and the fifth lens group changes, the aperture stop and the fourth lens group move integrally, and the position of the fifth lens group is fixed.
A variable magnification optical system characterized by satisfying the following conditional expressions (1) and (2) .
(1) 0.650 <(-f2) / fw <1.240
(2) 0.410 <f 3 / f 4 <1. 000
However,
fw: focal length f2 of the variable magnification optical system in the wide-angle end state: focal length f3 of the second lens group: focal length f3 of the third lens group: focal length of the fourth lens group Upon zooming, zooming optical system according to claim 2 in which the position of the fifth lens group is equal to or is a fixed. The variable magnification optical system according to any one of claims 1 to 4, wherein the following conditional expression (3) is satisfied.
(3) -0.050 <(d3t-d3w) / fw <0.750
However,
fw: focal length d3w of the variable magnification optical system in the wide-angle end state: distance from the lens surface closest to the image in the third lens group to the lens surface closest to the object in the fourth lens group in the wide-angle end d3t: distance from the lens surface closest to the image side in the third lens unit to the lens surface closest to the object in the fourth lens unit in the telephoto end state The variable magnification optical system according to any one of claims 1 to 5 , wherein the first lens group moves to the object side at the time of zooming from the wide angle end state to the telephoto end state. The variable power optical system according to any one of claims 1 to 6 , wherein the fifth lens group has a positive refractive power. The distance between the first lens group and the second lens group is increased at the time of zooming from the wide-angle end state to the telephoto end state, according to any one of claims 1 to 7 , Variable magnification optical system. The distance between the second lens group and the third lens group is decreased at the time of zooming from the wide-angle end state to the telephoto end state, according to any one of claims 1 to 8 , Variable magnification optical system. An optical apparatus comprising the variable magnification optical system according to any one of claims 1 to 9 .

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