JP6136195B2 - Variable magnification optical system, optical device - Google Patents

Description

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

  Conventionally, as a variable power optical system suitable for an interchangeable lens for a camera, a digital camera, a video camera, and the like, many lenses having a positive refractive power in the most object side lens group have been proposed (for example, Patent Document 1). reference.).

JP 2007-292994 A

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

  Accordingly, the present invention has been made in view of the above problems, and provides a variable power optical system, an optical apparatus, and a variable power optical system manufacturing method having a high zoom ratio, a small size, and high optical performance. For the purpose.

In order to solve the above problems, the present invention provides:
In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, an aperture stop, a third lens group having a positive refractive power, a fourth lens group having a positive refractive power, It consists essentially of 5 lens groups with 5 lens groups,
At the time of 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, interval to vary between the fifth lens group and the fourth lens group, Ri distance invariant der between the fourth lens group and the aperture stop,
A variable magnification optical system characterized by satisfying the following conditional expression (3) is provided.
(3) 4.000 <(TLt−TLw) / fw <7.0000
However,
fw: the total focal length in the wide-angle end state of the variable magnification optical system,
TLw: distance on the optical axis from the lens surface closest to the object side to the image plane in the first lens unit of the zoom optical system in the wide-angle end state;
TLt: distance on the optical axis from the lens surface closest to the object side to the image plane of the first lens unit of the zoom optical system in the telephoto end state.
The present invention also provides:
In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, an aperture stop, a third lens group having a positive refractive power, a fourth lens group having a positive refractive power, It consists essentially of 5 lens groups with 5 lens groups,
At the time of 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 is changed, and the distance between the aperture stop and the fourth lens group is unchanged.
A variable magnification optical system characterized by satisfying the following conditional expression (4A) is provided.
(4A) 0.300 <f1 / ft <0.530
However,
ft: the total focal length in the telephoto end state of the variable magnification optical system,
f1: Focal length of the first lens group.
The present invention also provides:
In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, an aperture stop, a third lens group having a positive refractive power, a fourth lens group having a positive refractive power, It consists essentially of 5 lens groups with 5 lens groups,
At the time of 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 is changed, and the distance between the aperture stop and the fourth lens group is unchanged.
A variable magnification optical system characterized by satisfying the following conditional expression (1A) is provided.
(1A) 0.638 ≦ f3 / f4 <0.880
However,
f3: focal length of the third lens group,
f4: focal length of the fourth lens group.

  The present invention also provides an optical apparatus comprising the variable magnification optical system.

  According to the present invention, it is possible to provide a variable power optical system, an optical device, and a method for manufacturing a variable power optical system that have a high zoom ratio, are small, and have high optical performance.

(A), (b), (c), (d), and (e) are 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 example of the present application, respectively. 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) are objects at infinity 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 example of the present application, respectively. It is an aberration diagram at the time of focusing. FIGS. 7A and 7B are graphs showing various aberrations when the object at infinity is in focus in the third intermediate focal length state and the telephoto end state of the variable magnification optical system according to the first example of the present application, respectively. (A), (b), (c), (d), and (e) are 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 example of the present application, respectively. 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) are objects at infinity 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 example of the present application, respectively. It is an aberration diagram at the time of focusing. FIGS. 9A and 9B are graphs showing various aberrations when the object at infinity is in focus in the third intermediate focal length state and the telephoto end state of the variable magnification optical system according to the second example of the present application, respectively. (A), (b), (c), (d), and (e) are 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, respectively. 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) are objects at infinity 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 example of the present application, respectively. It is an aberration diagram at the time of focusing. FIGS. 7A and 7B are graphs showing various aberrations when the object at infinity is in focus 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, respectively. 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) are objects at infinity 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. It is an aberration diagram at the time of focusing. FIGS. 9A and 9B are graphs showing various aberrations when the object at infinity is in focus in the third intermediate focal length state and the telephoto end state of the zoom optical system according to the fourth example of the present application, respectively. 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, a variable magnification optical system, an optical apparatus, and a method for manufacturing the variable magnification optical system of the present application will be described.
The variable magnification optical system of the present application includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, an aperture stop, a third lens group having a positive refractive power, and a positive refractive power. The fourth lens group and the fifth lens group, 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, and the second lens group The distance between the third lens group, the distance between the third lens group and the fourth lens group, and the distance between the fourth lens group and the fifth lens group vary. With this configuration, the variable magnification optical system of the present application realizes variable magnification from the wide-angle end state to the telephoto end state, and can suppress each variation of distortion aberration, astigmatism, and spherical aberration associated with variable magnification. .

In addition, the distance between the aperture stop and the fourth lens group does not change when zooming from the wide-angle end state to the telephoto end state. With this configuration, it is possible to suppress a change in height from the optical axis of the off-axis light beam that passes through the fourth lens group. Thereby, it is possible to suppress fluctuations in astigmatism and distortion during zooming.
With the above configuration, a variable magnification optical system having a high zoom ratio, a small size, and high optical performance can be realized.

Further, it is desirable that the variable magnification optical system of the present application satisfies the following conditional expression (1).
(1) 0.410 <f3 / f4 <1.00
However,
f3: focal length of the third lens group,
f4: focal length of the fourth lens group.

Conditional expression (1) defines an appropriate focal length ratio range of the third lens group and the fourth lens group. The zooming optical system of the present application satisfies the conditional expression (1), and thus can suppress fluctuations in spherical aberration and astigmatism during zooming.
If the corresponding value of conditional expression (1) of the variable magnification optical system of the present application is below the lower limit value, it becomes difficult to suppress fluctuations in spherical aberration and astigmatism that occur in the third lens group at the time of variable magnification, and high optical performance. Can not be realized. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (1) to 0.550.
On the other hand, if the corresponding value of conditional expression (1) of the variable magnification optical system of the present application exceeds the upper limit value, it becomes difficult to suppress fluctuations in spherical aberration and astigmatism that occur in the fourth lens group at the time of zooming. Optical performance cannot be realized. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (1) to 0.880.

Moreover, it is desirable that the variable magnification optical system of the present application satisfies the following conditional expression (2).
(2) -0.010 <(d3t-d3w) / ft <0.130
However,
ft: the total focal length in the telephoto end state of the variable magnification optical system,
d3w: the distance on the optical axis from the most image side lens surface of the third lens group to the most object side lens surface of the fourth lens group in the wide-angle end state;
d3t: Distance on the optical axis from the most image side lens surface of the third lens group to the most object side lens surface of the fourth lens group in the telephoto end state.

Conditional expression (2) is obtained on the optical axis from the most image side lens surface of the third lens group to the most object side lens surface of the fourth lens group at the time of zooming from the wide-angle end state to the telephoto end state. It defines an appropriate range of distance. The zooming optical system according to the present application can suppress fluctuations in coma and astigmatism during zooming by satisfying conditional expression (2).
If the corresponding value of conditional expression (2) of the variable magnification optical system of the present application is below the lower limit value, it becomes difficult to suppress fluctuations in astigmatism that occurs in the third lens group during zooming, and high optical performance can be realized. It will disappear. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (2) to 0.000.
On the other hand, if the corresponding value of conditional expression (2) of the variable magnification optical system of the present application exceeds the upper limit value, it becomes difficult to suppress fluctuations in coma aberration generated in the fourth lens group at the time of zooming, and high optical performance is realized. It becomes impossible. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (2) to 0.065. In order to further secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (2) to 0.035.

In the zoom optical system according to the present application, it is preferable that the following conditional expression (3) is satisfied.
(3) 4.000 <(TLt−TLw) / fw <7.0000
However,
fw: the total focal length in the wide-angle end state of the variable magnification optical system,
TLw: distance on the optical axis from the lens surface closest to the object side to the image plane in the first lens unit of the zoom optical system in the wide-angle end state;
TLt: distance on the optical axis from the lens surface closest to the object side to the image plane of the first lens unit of the zoom optical system in the telephoto end state.

Conditional expression (3) is an appropriate range of the distance on the optical axis from the lens surface closest to the object side of the first lens group to the image plane at the time of zooming from the wide-angle end state to the telephoto end state, that is, the optical total length It defines the appropriate range. By satisfying conditional expression (3), the variable magnification optical system of the present application can not only reduce the diameter of the first lens group, but also can suppress fluctuations in astigmatism during zooming.
If the corresponding value of conditional expression (3) of the variable magnification optical system of the present application is below the lower limit value, the height from the optical axis of the off-axis light beam passing through the first lens group in the wide-angle end state becomes large and it is difficult to reduce the size. In addition, since the height from the optical axis of the off-axis light beam passing through the first lens group changes greatly with zooming, the fluctuation of astigmatism becomes excessive and high optical performance cannot be realized. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (3) to 4.200.
On the other hand, if the corresponding value of conditional expression (3) of the variable magnification optical system of the present application exceeds the upper limit value, the height from the optical axis of the off-axis light beam passing through the first lens group in the telephoto end state becomes large, and it is difficult to reduce the size. Become. In addition, since the height from the optical axis of the off-axis light beam passing through the first lens group changes greatly with zooming, the fluctuation of astigmatism becomes excessive and high optical performance cannot be realized. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (3) to 5.900.

In the variable magnification optical system of the present application, it is preferable that the following conditional expression (4) is satisfied.
(4) 0.300 <f1 / ft <0.555
However,
f1: Focal length of the first lens group.
ft: the total focal length in the telephoto end state of the variable magnification optical system,

Conditional expression (4) defines an appropriate focal length range of the first lens group. The zooming optical system according to the present application can satisfy the conditional expression (4), thereby suppressing variations in spherical aberration and astigmatism during zooming.
If the corresponding value of conditional expression (4) of the variable magnification optical system of the present application is below the lower limit value, it becomes difficult to suppress fluctuations in spherical aberration and astigmatism that occur in the first lens group at the time of variable magnification, and high optical performance. Cannot be realized. In order to secure the effect of the present application, it is preferable to set the lower limit of conditional expression (4) to 0.421.
On the other hand, when the corresponding value of conditional expression (4) of the zoom optical system of the present application exceeds the upper limit value, the first zoom ratio from the wide-angle end state to the telephoto end state is obtained in order to obtain a predetermined zoom ratio. It is necessary to increase the amount of change in the distance between the lens group and the second lens group. This not only makes it difficult to reduce the size, but also changes the ratio of the axial light beam diameter incident on the first lens group and the axial light beam diameter incident on the second lens group greatly with zooming. For this reason, the variation of the spherical aberration becomes excessive at the time of zooming, and high optical performance cannot be realized. In order to secure the effect of the present application, it is preferable to set the upper limit of conditional expression (4) to 0.530.

  In the variable magnification optical system of the present application, it is desirable that the fifth lens group has a positive refractive power. With this configuration, the use magnification of the fifth lens group becomes smaller than the same magnification, and as a result, the combined focal length from the first lens group to the fourth lens group can be relatively increased. As a result, the influence of decentration coma aberration and the like caused by the decentration of the lenses occurring in the first lens group to the fourth lens group during manufacturing can be relatively reduced, and high optical performance can be realized. it can.

  In the zoom optical system of the present application, it is desirable that the distance between the first lens group and the second lens group is increased when zooming from the wide-angle end state to the telephoto end state. With this configuration, it is possible to increase the magnification of the second lens group, and it is possible to suppress fluctuations in spherical aberration and astigmatism during zooming while efficiently realizing a high zoom ratio.

  In the zoom optical system of the present application, it is preferable that the distance between the second lens group and the third lens group is reduced when zooming from the wide-angle end state to the telephoto end state. With this configuration, the combined magnification of the third lens group and the fourth lens group can be increased, and the variation of spherical aberration and astigmatism are suppressed during zooming while efficiently realizing a high zoom ratio. be able to.

  In the zoom optical system of the present application, it is desirable that the distance between the fourth lens group and the fifth lens group is increased when zooming from the wide-angle end state to the telephoto end state. With this configuration, the combined magnification of the third lens group and the fourth lens group can be increased, and the variation of spherical aberration and astigmatism are suppressed during zooming while efficiently realizing a high zoom ratio. be able to.

  In the zoom optical system of the present application, it is desirable that the position of the fifth lens group is fixed when zooming from the wide-angle end state to the telephoto end state. With this configuration, the height from the optical axis of the peripheral rays incident on the fifth lens group from the fourth lens group at the time of zooming can be changed, and astigmatism fluctuations at the time of zooming can be suppressed better. Can do.

  The optical device of the present application is characterized by having the variable magnification optical system having the above-described configuration. Thereby, an optical device having a high zoom ratio, a small size, and high optical performance can be realized.

  The variable magnification optical system manufacturing method of the present application includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, an aperture stop, and a third lens group having a positive refractive power. A method of manufacturing a variable magnification optical system having a fourth lens group having positive refractive power and a fifth lens group, wherein the first lens group and the second lens group are zoomed from the wide-angle end state to the telephoto end state. The distance between the 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, and the distance between the fourth lens group and the fifth lens group. Is changed so that the distance between the aperture stop and the fourth lens group is unchanged.

Hereinafter, a variable magnification optical system according to numerical examples of the present application will be described with reference to the accompanying drawings.
(First embodiment)
1 (a), FIG. 1 (b), FIG. 1 (c), FIG. 1 (d), and FIG. 1 (e) are respectively the wide-angle end state of the variable magnification optical system according to the first example of the present application, It is sectional drawing in a 1st intermediate | middle focal distance state, a 2nd intermediate | middle focal distance state, a 3rd intermediate | middle focal distance state, and a telephoto end state.
The variable magnification optical system according to the present example 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, an aperture stop S, and a positive refraction. The lens unit includes a third lens group G3 having power, 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 having a convex surface facing the object side and a biconvex positive lens L12, and a positive meniscus lens L13 having 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 directed toward the object side, a biconcave negative lens L22, a biconvex positive lens L23, and a negative surface having a concave surface directed toward the object side. It consists of a cemented lens with a meniscus lens L24. The negative meniscus lens L21 is a glass mold aspheric lens having an aspheric lens surface on the object side.

The third lens group G3 is composed of a cemented lens of a negative meniscus lens L31 having a convex surface directed toward the object side and a biconvex positive lens L32 in order from the object side. 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 biconvex positive lens L41 and a biconcave negative lens L42, and a negative meniscus with a biconvex positive lens L43 and a concave meniscus facing the object side. A cemented lens with a lens L44, a cemented lens with a biconcave negative lens L45 and a biconvex positive lens L46, a biconvex positive lens L47, and a negative meniscus lens L48 with 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 includes, in order from the object side, a cemented lens including 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.

With the above-described configuration, in the zoom optical system according to the present embodiment, the air gap between the first lens group G1 and the second lens group G2 and the second lens group at the time of zooming from the wide-angle end state to the telephoto end state. The air gap between G2 and the third lens group G3, the air gap between the third lens group G3 and the fourth lens group G4, and the air gap between the fourth lens group G4 and the fifth lens group G5 are changed. The first lens group G1 to the fourth lens group G4 move along the optical axis.
Specifically, 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 toward the object side from the wide-angle end state to the third intermediate focal length state, and moves toward 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 during zooming. The aperture stop S moves integrally with the fourth lens group G4 toward the object side so that the distance from the fourth lens group G4 remains unchanged during zooming.

  Thereby, at the time of zooming, the air gap between the first lens group G1 and the second lens group G2 increases, 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 group G5 increase in air space. 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, decreases from the first intermediate focal length state to the second intermediate focal length state, and second 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. , And decreases from the second intermediate focal length state to the telephoto end state.

Table 1 below lists values of specifications of the variable magnification optical system according to the present example.
In Table 1, f indicates the focal length, and BF indicates the back focus (the distance on the optical axis between the lens surface closest to the image side and the image plane I).
In [Surface data], the surface number is the order of the optical surfaces counted from the object side, r is the radius of curvature, d is the surface interval (the interval between the nth surface (n is an integer) and the n + 1th surface), and nd is The refractive index for d-line (wavelength 587.6 nm) and νd indicate the Abbe number for d-line (wavelength 587.6 nm), respectively. In addition, the object plane indicates the object plane, the variable indicates the variable plane spacing, 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. For the aspherical surface, * is added to the surface number, and the value of the paraxial radius of curvature is indicated in the column of the radius of curvature r. The description of the refractive index of air nd = 1.00000 is omitted.

[Aspherical data] shows an aspherical coefficient and a conic constant when the shape of the aspherical surface shown in [Surface data] is expressed by the following equation.
x = (h ² / r) / [1+ {1−κ (h / r) ² } ^1/2 ]
+ A4h ⁴ + A6h ⁶ + A8h ⁸ + A10h ¹⁰ + A12h ¹²
Here, h is the height in the direction perpendicular to the optical axis, x is the distance (sag amount) from the tangent plane of the apex of the aspheric surface to the aspheric surface at the height h, and κ is the conic constant. , A4, A6, A8, A10, A12 are aspherical coefficients, and r is the radius of curvature of the reference sphere (paraxial radius of curvature). “E−n” (n is an integer) indicates “× 10 ⁻ⁿ ”, for example “1.234E-05” indicates “1.234 × 10 ⁻⁵ ”. The secondary aspherical coefficient A2 is 0 and is not shown.

In [Various data], FNO is the F number, ω is the half angle of view (unit is “°”), Y is the image height, TL is the total length of the variable magnification optical system (image from the first surface when focusing on an object at infinity) (Distance on the optical axis to the surface I), dn represents the variable distance between the nth surface and the (n + 1) th surface, and φ represents the diameter of the aperture stop S. W represents the wide-angle end state, M1 represents the first intermediate focal length state, M2 represents the second intermediate focal length state, M3 represents the third intermediate focal length state, and T represents the telephoto end state.
[Lens Group Data] indicates the start surface and focal length of each lens group.
[Conditional Expression Corresponding Value] shows the corresponding value of each conditional expression of the variable magnification optical system according to the present example.

Here, the focal length f, the radius of curvature r, and other length units listed in Table 1 are generally “mm”. However, the optical system is not limited to this because an equivalent optical performance can be obtained even when proportionally enlarged or proportionally reduced.
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 Example
[Surface data]
Surface number r d nd νd
Object ∞

1 165.4019 1.6350 1.902650 35.73
2 41.8893 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 (Aperture 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 ∞

[Aspherical data]
6th surface κ 11.00000
A4 3.95289E-05
A6 -2.04622E-07
A8 -4.81392E-09
A10 9.83575E-11
A12 -5.88880E-13

No. 28 κ 1.0000
A4 -5.59168E-05
A6 -2.20298E-07
A8 3.87818E-10
A10 1.16318E-11
A12 0.00000

31st surface κ 1.00000
A4 2.65930E-05
A6 7.69228E-08
A8 -1.34346E-09
A10 0.00000
A12 0.00000

[Various data]
Scaling ratio 14.14

W T
f 9.47 to 133.87
FNO 4.12 to 5.78
ω 41.95 〜 3.27 °
Y 8.00-8.00
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 7.18201 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 start surface f
1 1 68.08250
2 6 -9.98760
3 14 38.80284
4 17 60.78065
5 29 129.99998

[Conditional expression values]
(1) f3 / f4 = 0.638
(2) (d3t−d3w) /ft=0.025
(3) (TLt−TLw) /fw=5.639
(4) f1 / ft = 0.509

FIGS. 2A, 2B, and 2C are respectively a wide-angle end state, a first intermediate focal length state, and a second intermediate focus of the zoom optical system according to the first example of the present application. It is an aberration diagram at the time of focusing on an object at infinity in the distance state.
FIGS. 3A and 3B are graphs showing various aberrations when the object at infinity is in focus in the third intermediate focal length state and the telephoto end state of the variable magnification optical system according to the first example of the present application, respectively. It is.

  In each aberration diagram, FNO denotes an F number, and A denotes a light 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 the astigmatism diagram, the solid line indicates the sagittal image plane, and the broken line indicates the meridional image plane. Note that the same reference numerals as in this embodiment are used in the aberration diagrams of each embodiment described later.

  From the respective aberration diagrams, it can be seen that the variable magnification optical system according to the present example has high optical performance with various aberrations corrected well from the wide-angle end state to the telephoto end state.

(Second embodiment)
4 (a), FIG. 4 (b), FIG. 4 (c), FIG. 4 (d), and FIG. 4 (e) are respectively the wide-angle end state of the variable magnification optical system according to the second example of the present application, It is sectional drawing in a 1st intermediate | middle focal distance state, a 2nd intermediate | middle focal distance state, a 3rd intermediate | middle focal distance state, and a telephoto end state.
The variable magnification optical system according to the present example 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, an aperture stop S, and a positive refraction. The lens unit includes a third lens group G3 having power, 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 having a convex surface facing the object side and a biconvex positive lens L12, and a positive meniscus lens L13 having 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 directed toward the object side, a biconcave negative lens L22, a biconvex positive lens L23, and a biconcave negative lens L24. The cemented lens. The negative meniscus lens L21 is a glass mold aspheric lens having an aspheric lens surface on the object side.

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

With the above-described configuration, in the zoom optical system according to the present embodiment, the air gap between the first lens group G1 and the second lens group G2 and the second lens group at the time of zooming from the wide-angle end state to the telephoto end state. The air gap between G2 and the third lens group G3, the air gap between the third lens group G3 and the fourth lens group G4, and the air gap between the fourth lens group G4 and the fifth lens group G5 are changed. The first lens group G1 to the fourth lens group G4 move along the optical axis.
Specifically, 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 toward the object side from the wide-angle end state to the third intermediate focal length state, and moves toward 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 during zooming. The aperture stop S moves integrally with the fourth lens group G4 toward the object side so that the distance from the fourth lens group G4 remains unchanged during zooming.

Thereby, at the time of zooming, the air gap between the first lens group G1 and the second lens group G2 increases, 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 group G5 increase in air space. 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, decreases from the first intermediate focal length state to the second intermediate focal length state, and second Increase 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. , The second intermediate focal length state decreases to the telephoto end state.
Table 2 below provides values of specifications of the variable magnification optical system according to the present example.

(Table 2) Second Example
[Surface data]
Surface number r d nd νd
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 (Aperture 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 ∞

[Aspherical data]
6th surface κ 10.29120
A4 1.05982E-05
A6 1.47868E-07
A8 -6.64708E-09
A10 8.77431E-11
A12 -4.23990E-13

No. 28 κ 1.0000
A4 -7.26393E-05
A6 -3.38257E-07
A8 1.26743E-09
A10 -2.83030E-11
A12 0.00000

31st surface κ 1.00000
A4 2.68564E-05
A6 7.91224E-08
A8 -8.06538E-10
A10 0.00000
A12 0.00000

[Various data]
Scaling ratio 14.13

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

W M1 M2 M3 T
f 10.30001 18.00395 60.55030 89.50052 145.50102
ω 39.61866 23.08393 7.20247 4.88583 3.00545
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 1.62642 10.35671 26.30176 30.05048 31.92800
BF 14.04946 14.04953 14.04979 14.04990 14.05006

[Lens group data]
Group start surface f
1 1 64.91265
2 6 -9.00339
3 14 38.07719
4 17 46.69911
5 29 260.10501

[Conditional expression values]
(1) f3 / f4 = 0.815
(2) (d3t−d3w) /ft=0.005
(3) (TLt−TLw) /fw=4.854
(4) f1 / ft = 0.446

FIGS. 5A, 5B, and 5C are respectively a wide-angle end state, a first intermediate focal length state, and a second intermediate focus of the variable magnification optical system according to the second example of the present application. It is an aberration diagram at the time of focusing on an object at infinity in the distance state.
FIGS. 6A and 6B are graphs showing various aberrations when focusing on an object at infinity in the third intermediate focal length state and the telephoto end state of the variable magnification optical system according to the second example of the present application, respectively. It is.

  From the respective aberration diagrams, it can be seen that the variable magnification optical system according to the present example has high optical performance with various aberrations corrected well from the wide-angle end state to the telephoto end state.

(Third embodiment)
7 (a), FIG. 7 (b), FIG. 7 (c), FIG. 7 (d), and FIG. 7 (e) are respectively the wide-angle end state of the variable magnification optical system according to the third example of the present application, It is sectional drawing in a 1st intermediate | middle focal distance state, a 2nd intermediate | middle focal distance state, a 3rd intermediate | middle focal distance state, and a telephoto end state.
The variable magnification optical system according to the present example 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, an aperture stop S, and a positive refraction. The lens unit includes a third lens group G3 having power, 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 having a convex surface facing the object side and a biconvex positive lens L12, and a positive meniscus lens L13 having 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 directed toward the object side, a biconcave negative lens L22, a biconvex positive lens L23, and a negative surface having a concave surface directed toward the object side. It consists of a cemented lens with a meniscus lens L24. The negative meniscus lens L21 is a glass mold aspheric lens having an aspheric lens surface on the object side.

The third lens group G3 is composed of a cemented lens of a negative meniscus lens L31 having a convex surface directed toward the object side and a biconvex positive lens L32 in order from the object side. 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 biconvex positive lens L41 and a biconcave negative lens L42, and a negative meniscus with a biconvex positive lens L43 and a concave meniscus facing the object side. A cemented lens with a lens L44, a cemented lens with a biconcave negative lens L45 and a biconvex positive lens L46, a biconvex positive lens L47, and a negative meniscus lens L48 with 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 includes, in order from the object side, a cemented lens including 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.

  With the above-described configuration, in the zoom optical system according to the present embodiment, the air gap between the first lens group G1 and the second lens group G2 and the second lens group at the time of zooming from the wide-angle end state to the telephoto end state. The air gap between G2 and the third lens group G3, the air gap between the third lens group G3 and the fourth lens group G4, and the air gap between the fourth lens group G4 and the fifth lens group G5 are changed. The first lens group G1 to the fourth lens group G4 move toward the object side along the optical axis. The position of the fifth lens group G5 in the optical axis direction is fixed during zooming. The aperture stop S moves integrally with the fourth lens group G4 toward the object side so that the distance from the fourth lens group G4 remains unchanged during zooming.

Specifically, during zooming, the air gap between the first lens group G1 and the second lens group G2 increases, the air gap between the second lens group G2 and the third lens group G3 decreases, and the fourth lens group. The air space between G4 and the fifth lens group G5 increases. 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, decreases from the first intermediate focal length state to the second intermediate focal length state, and second Increase 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. , The second intermediate focal length state decreases to the telephoto end state.
Table 3 below lists values of specifications of the variable magnification optical system according to the present example.

(Table 3) Third Example
[Surface data]
Surface number r d nd νd
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 28.0881 4.0634 1.808090 22.74
11 -12.5975 1.0000 1.883000 40.66
12 -38.6924 Variable

13 (Aperture 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 ∞

[Aspherical data]
6th surface κ -3.81950
A4 4.21558E-05
A6 -2.17082E-07
A8 -2.45102E-09
A10 5.51411E-11
A12 -2.85950E-13

No. 28 κ 1.0000
A4 -6.70317E-05
A6 -2.82990E-07
A8 5.39592E-10
A10 -1.47007E-11
A12 0.00000

31st surface κ 1.00000
A4 2.67692E-05
A6 2.52197E-08
A8 -6.04092E-10
A10 0.00000
A12 0.00000

[Various data]
Scaling ratio 14.13

W T
f 9.27 to 130.95
FNO 4.11 to 5.71
ω 42.66-3.37 °
Y 8.00-8.00
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 45.70436
d12 24.57776 16.27840 5.38702 3.71762 2.20000
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 start surface f
1 1 67.49208
2 6 -9.52181
3 14 41.09622
4 17 53.39457
5 29 147.67270

[Conditional expression values]
(1) f3 / f4 = 0.770
(2) (d3t−d3w) /ft=0.025
(3) (TLt-TLw) / fw = 5.879
(4) f1 / ft = 0.515

FIGS. 8A, 8B, and 8C are respectively a wide-angle end state, a first intermediate focal length state, and a second intermediate focus of the variable magnification optical system according to the third example of the present application. It is an aberration diagram at the time of focusing on an object at infinity in the distance state.
FIGS. 9A and 9B are graphs showing various aberrations when focusing on an object at infinity 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, respectively. It is.

  From the respective aberration diagrams, it can be seen that the variable magnification optical system according to the present example has high optical performance with various aberrations corrected well from the wide-angle end state to the telephoto end state.

(Fourth embodiment)
10 (a), 10 (b), 10 (c), 10 (d), and 10 (e) are respectively the wide-angle end state of the variable magnification optical system according to the fourth example of the present application, It is sectional drawing in a 1st intermediate | middle focal distance state, a 2nd intermediate | middle focal distance state, a 3rd intermediate | middle focal distance state, and a telephoto end state.
The variable magnification optical system according to the present example 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, an aperture stop S, and a positive refraction. The lens unit includes a third lens group G3 having power, 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 having a convex surface facing the object side and a biconvex positive lens L12, and a positive meniscus lens L13 having 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 directed toward the object side, a biconcave negative lens L22, a biconvex positive lens L23, and a biconcave negative lens L24. The cemented lens. The negative meniscus lens L21 is a glass mold aspheric lens having an aspheric lens surface on the object side.

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

  The fifth lens group G5 includes, in order from the object side, a cemented lens including 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.

With the above-described configuration, in the zoom optical system according to the present embodiment, the air gap between the first lens group G1 and the second lens group G2 and the second lens group at the time of zooming from the wide-angle end state to the telephoto end state. The air gap between G2 and the third lens group G3, the air gap between the third lens group G3 and the fourth lens group G4, and the air gap between the fourth lens group G4 and the fifth lens group G5 are changed. The first lens group G1 to the fourth lens group G4 move along the optical axis.
Specifically, 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 toward the object side from the wide-angle end state to the second intermediate focal length state, moves toward the image side from the second intermediate focal length state to the third intermediate focal length state, and is in 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 during zooming. The aperture stop S moves integrally with the fourth lens group G4 toward the object side so that the distance from the fourth lens group G4 remains unchanged during zooming.

Thereby, at the time of zooming, the air gap between the first lens group G1 and the second lens group G2 increases, 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 group G5 increase in air space. 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, decreases from the first intermediate focal length state to the second intermediate focal length state, and second Increase 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. , The second intermediate focal length state decreases to the telephoto end state.
Table 4 below lists values of specifications of the variable magnification optical system according to the present example.

(Table 4) Fourth Example
[Surface data]
Surface number r d nd νd
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 (Aperture 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 20.2242 1.0000 1.850260 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 ∞

[Aspherical data]
6th surface κ -9.00000
A4 1.14894E-05
A6 2.79933E-07
A8 -1.11589E-08
A10 1.42629E-10
A12 -6.44930E-13

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

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

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

[Various data]
Scaling ratio 14.13

W T
f 10.30 to 145.50
FNO 4.12 to 5.77
ω 39.65 to 3.02 °
Y 8.00-8.00
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 3.47054 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 14.04886

[Lens group data]
Group start surface f
1 1 62.23195
2 6 -9.03822
3 14 37.53030
4 17 49.24516
5 28 130.00164

[Conditional expression values]
(1) f3 / f4 = 0.762
(2) (d3t−d3w) /ft=0.015
(3) (TLt−TLw) /fw=4.854
(4) f1 / ft = 0.428

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 zoom optical system according to the fourth example of the present application. It is an aberration diagram at the time of focusing on an object at infinity in the distance state.
FIGS. 12A and 12B are graphs showing various aberrations when focusing on an object at infinity 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, respectively. It is.

  From the respective aberration diagrams, it can be seen that the variable magnification optical system according to the present example has high optical performance with various aberrations corrected well from the wide-angle end state to the telephoto end state.

According to each of the above embodiments, a variable power optical system having a high zoom ratio, a small size, and high optical performance can be realized.
In addition, each said Example has shown one specific example of this invention, and this invention is not limited to these. The following contents can be adopted as appropriate as long as the optical performance of the variable magnification optical system of the present application is not impaired.

  A numerical example of the variable magnification optical system of the present application is shown as having a five-group configuration, but the present application is not limited to this, and constitutes a variable magnification optical system of other group configurations (for example, six groups, seven groups, etc.). You can also. Specifically, a configuration in which a lens or a lens group is added to the most object side or the most image side of the variable magnification optical system of the present application may be used. The lens group refers to a portion having at least one lens separated by an air interval that changes during zooming.

  In addition, the variable magnification optical system of the present application uses a part of a lens group, an entire lens group, or a plurality of lens groups as a focusing lens group for focusing from an object at infinity to a near object. It is good also as a structure moved to an axial direction. In particular, it is preferable that at least part of the second lens group, at least part of the third lens group, at least part of the fourth lens group, or at least part of the fifth lens group be the focusing lens group. Such a focusing lens group can also be applied to autofocus, and is also suitable for driving by an autofocus motor, such as an ultrasonic motor.

  Further, in the variable magnification optical system of the present application, any lens group or a part thereof is moved as a vibration-proof lens group so as to include a component in a direction perpendicular to the optical axis, or a surface including the optical axis A configuration in which image blur caused by camera shake or the like is corrected by rotationally moving (swinging) inward is also possible. 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, at least a part of the fourth lens group, or at least a part of the fifth lens group be an anti-vibration lens group.

  The lens surface of the lens constituting the variable magnification optical system of the present application may be a spherical surface, a flat surface, or an aspheric surface. When the lens surface is a spherical surface or a flat surface, it is preferable because lens processing and assembly adjustment are easy, and deterioration of optical performance due to errors in lens processing and assembly adjustment can be prevented. Further, even when the image plane is deviated, it is preferable because there is little deterioration in drawing performance. When the lens surface is aspherical, any of aspherical surface by grinding, glass mold aspherical surface in which glass is molded into an aspherical shape, or composite aspherical surface in which resin provided on the glass surface is formed in an aspherical 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.

In the variable magnification optical system of the present application, the aperture stop is preferably arranged in the third lens group or in the vicinity of the third lens group, and the role of the aperture stop is replaced by a lens frame without providing a member. Also good.
Further, an antireflection film having a high transmittance in a wide wavelength range may be applied to the lens surface of the lens constituting the variable magnification optical system of the present application. Thereby, flare and ghost can be reduced, and high optical performance with high contrast can be achieved.

Next, a camera equipped with the variable magnification optical system of the present application will be described with reference to FIG.
FIG. 13 is a diagram illustrating a configuration of a camera including 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 that includes the variable magnification optical system according to the first example as the photographing lens 2.
In the camera 1, light from an object (subject) (not shown) is collected by the photographing lens 2 and is on the imaging surface of the imaging unit 3 via an OLPF (Optical low pass filter) (not shown). A subject image is formed on the screen. Then, the subject image is photoelectrically converted by the photoelectric conversion element provided in the imaging unit 3 to generate an image of the subject. This image is displayed on an EVF (Electronic view finder) 4 provided in the camera 1. Thus, the photographer can observe the subject via the EVF 4.
When the release button (not shown) is pressed by the photographer, the subject image generated by the imaging unit 3 is stored in a memory (not shown). In this way, the photographer can shoot the subject with the camera 1.

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

Finally, the outline of the manufacturing method of the variable magnification optical system of this application is demonstrated based on FIG.
The variable power optical system manufacturing method shown in FIG. 14 includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, an aperture stop S, And a fourth lens group having a positive refractive power, and a fifth lens group, and a method for manufacturing a variable magnification optical system, including the following steps S1 and S2. .

  Step S1: A first lens group having a positive refractive power, a second lens group having a negative refractive power, an aperture stop S, a third lens group having a positive refractive power, and a positive refractive power The fourth lens group and the fifth lens group are arranged in order from the object side in the lens barrel.

  Step S2: By providing a known moving mechanism in the lens barrel, the distance between the first lens group and the second lens group, the second lens group and the second lens group at the time of zooming from the wide-angle end state to the telephoto end state. The distance between the third lens group, the distance between the third lens group and the fourth lens group, and the distance between the fourth lens group and the fifth lens group are changed, and the distance between the aperture stop and the fourth lens group is changed. Make it immutable.

  According to such a method for manufacturing a variable magnification optical system of the present application, a variable magnification optical system having a high zoom ratio, a small size, and high optical performance can be manufactured.

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 surface

Claims (12)

In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, an aperture stop, a third lens group having a positive refractive power, a fourth lens group having a positive refractive power, It consists essentially of 5 lens groups with 5 lens groups,
At the time of 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, interval to vary between the fifth lens group and the fourth lens group, Ri distance invariant der between the fourth lens group and the aperture stop,
A variable magnification optical system characterized by satisfying the following conditional expression (3):
(3) 4.000 <(TLt−TLw) / fw <7.0000
However,
fw: the total focal length in the wide-angle end state of the variable magnification optical system,
TLw: distance on the optical axis from the lens surface closest to the object side to the image plane in the first lens unit of the zoom optical system in the wide-angle end state;
TLt: distance on the optical axis from the lens surface closest to the object side to the image plane of the first lens unit of the zoom optical system in the telephoto end state. In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, an aperture stop, a third lens group having a positive refractive power, a fourth lens group having a positive refractive power, It consists essentially of 5 lens groups with 5 lens groups,
At the time of 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, interval to vary between the fifth lens group and the fourth lens group, Ri distance invariant der between the fourth lens group and the aperture stop,
A variable magnification optical system characterized by satisfying the following conditional expression (4A):
(4A) 0.300 <f1 / ft <0.530
However,
ft: the total focal length in the telephoto end state of the variable magnification optical system,
f1: Focal length of the first lens group. In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, an aperture stop, a third lens group having a positive refractive power, a fourth lens group having a positive refractive power, It consists essentially of 5 lens groups with 5 lens groups,
At the time of 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, interval to vary between the fifth lens group and the fourth lens group, Ri distance invariant der between the fourth lens group and the aperture stop,
A variable magnification optical system characterized by satisfying the following conditional expression (1A):
(1A) 0.638 ≦ f3 / f4 <0.880
However,
f3: focal length of the third lens group,
f4: focal length of the fourth lens group. Variable-power optical system according to claim 1 or 2, characterized by satisfying the following conditional expression.
0.410 <f3 / f4 <1.00
However,
f3: focal length of the third lens group,
f4: focal length of the fourth lens group. The zoom lens system according to claim 1 or 3 , wherein the following conditional expression is satisfied.
0.300 <f1 / ft <0.555
However,
ft: the total focal length in the telephoto end state of the variable magnification optical system,
f1: Focal length of the first lens group. The zoom lens system according to any one of claims 1 to 5, wherein the following conditional expression is satisfied.
−0.010 <(d3t−d3w) / ft <0.130
However,
ft: the total focal length in the telephoto end state of the variable magnification optical system,
d3w: the distance on the optical axis from the most image side lens surface of the third lens group to the most object side lens surface of the fourth lens group in the wide-angle end state;
d3t: Distance on the optical axis from the most image side lens surface of the third lens group to the most object side lens surface of the fourth lens group in the telephoto end state. The fifth lens group is variable power optical system according to any one of claims 1 to 6, characterized in that it has a positive refractive power. Upon zooming from the wide-angle end state to the telephoto end state, the variable magnification optical according to any one of claims 1 to 7, wherein the distance between the first lens group and the second lens group and wherein the increasing system. Upon zooming from the wide-angle end state to the telephoto end state, the variable magnification optical according to any one of claims 1 to 8, interval of the third lens group and the second lens group and said reducing system. Upon zooming from the wide-angle end state to the telephoto end state, the variable magnification optical according to any one of claims 1-9, wherein the distance between the fourth lens group and said fifth lens group and wherein the increasing system. Upon zooming, zooming optical system according to any one of claims 1 to 10, the position of the fifth lens group is equal to or is a fixed. Optical apparatus characterized by having a variable magnification optical system according to any one of claims 1 to 11.

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