JP2020134806A - Zoom optical system, optical device, and method of manufacturing zoom optical system - Google Patents

Abstract

To provide a zoom optical system which is compact, has a wide view angle, and offers superior optical performance, an optical device having the same, and a method of manufacturing the zoom optical system.SOLUTION: A zoom optical system ZL used for optical devices such as cameras 1 is provided, the zoom optical system comprising a first lens group G1 having negative refractive power, a second lens group G2 having positive refractive power, and a third lens group G3 having positive refractive power in order from the object side, and being configured such that distances between adjacent lens groups change while zooming. A distance between the first lens group G1 and the second lens group G2 decreases when zooming from the wide-angle end to the telephoto end, and the second lens group G2 moves toward the image side when shifting focus from an object at infinity to a nearby object. The first lens group G1 has a negative meniscus lens having a convex surface on the object side. The zoom optical system satisfies predetermined conditional expression.SELECTED DRAWING: Figure 1

Description

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

Conventionally, a variable magnification optical system that realizes a small size and a wide angle of view has been proposed (see, for example, Patent Document 1). However, further improvement in optical performance is required.

Japanese Unexamined Patent Publication No. 2018-013685

The variable magnification optical system according to the first aspect of the present invention has a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a positive refractive power in order from the object side. It has a third lens group, and the distance between adjacent lens groups changes when scaling, and the distance between the first lens group and the second lens group when changing from the wide-angle end state to the telescopic end state. The second lens group moves to the image side when focusing from an infinity object to a short-range object, and the first lens group has a negative meniscus lens with a convex surface facing the object side most. It has and satisfies the condition of the following equation.
N1n ≤ 3
100.00 ° <2ωw
However,
N1n: Number of negative lenses included in the first lens group 2ωw: Total angle of view of the variable magnification optical system at the wide-angle end state

The variable magnification optical system according to the second aspect of the present invention has a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a positive refractive power in order from the object side. It has a third lens group, and the distance between adjacent lens groups changes when scaling, and the distance between the first lens group and the second lens group when changing from the wide-angle end state to the telescopic end state. The second lens group moves to the image side when focusing from an infinity object to a short-range object, and the first lens group has a negative meniscus lens with a convex surface facing the object side most. It has and satisfies the condition of the following equation.
nL1 <1.70
However,
nL1: Refractive index of the lens on the most object side of the first lens group with respect to the d line of the medium

The variable magnification optical system according to the third aspect of the present invention has a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a positive refractive power in order from the object side. It has a third lens group, and the distance between adjacent lens groups changes when scaling, and the distance between the first lens group and the second lens group when changing from the wide-angle end state to the telescopic end state. The second lens group moves to the image side when focusing from an infinity object to a short-range object, and the first lens group has a negative meniscus lens with a convex surface facing the object side most. It has and satisfies the condition of the following equation.
59.00 <(Σν1n) / N1n
N1n ≤ 3
However,
N1n: Number of negative lenses included in the first lens group Σν1n: Abbe number of negative lenses included in the first lens group with respect to the d-line of the medium

In the method for manufacturing a variable magnification optical system according to the first aspect of the present invention, in order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, and positive refraction It is a method of manufacturing a variable magnification optical system having a third lens group having power, and when the magnification is changed, the distance between adjacent lens groups changes, and when the magnification is changed from the wide-angle end state to the telescopic end state, The first lens group is arranged so that the distance between the first lens group and the second lens group is reduced, and the second lens group is arranged so as to move toward the image side when focusing from an infinity object to a short-range object. A negative meniscus lens with a convex surface facing the object side is arranged on the most object side of the lens group so as to satisfy the condition of the following equation.
N1n ≤ 3
100.00 ° <2ωw
However,
N1n: Number of negative lenses included in the first lens group 2ωw: Total angle of view in the wide-angle end state of the variable magnification optical system

It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 1st Example. It is a diagram of various aberrations at the time of focusing an object at infinity of the variable magnification optical system according to the first embodiment, (a) shows a wide-angle end state, and (b) shows a telephoto end state. It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 2nd Example. It is a diagram of various aberrations at the time of focusing an object at infinity of the variable magnification optical system according to the second embodiment, (a) shows a wide-angle end state, and (b) shows a telephoto end state. It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 3rd Example. It is a diagram of various aberrations at the time of focusing an object at infinity of the variable magnification optical system according to the third embodiment, (a) shows a wide-angle end state, and (b) shows a telephoto end state. It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 4th Example. It is a diagram of various aberrations at the time of focusing an object at infinity of the variable magnification optical system according to the fourth embodiment, (a) shows a wide-angle end state, and (b) shows a telephoto end state. It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 5th Example. It is a diagram of various aberrations at the time of focusing an object at infinity of the variable magnification optical system according to the fifth embodiment, (a) shows a wide-angle end state, and (b) shows a telephoto end state. It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 6th Example. It is a diagram of various aberrations at the time of focusing an object at infinity of the variable magnification optical system according to the sixth embodiment, (a) shows a wide-angle end state, and (b) shows a telephoto end state. It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 7th Example. It is a diagram of various aberrations at the time of focusing on an infinity object of the variable magnification optical system according to the seventh embodiment, (a) shows a wide-angle end state, and (b) shows a telephoto end state. It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 8th Example. 8 is a diagram of various aberrations at the time of focusing an object at infinity of the variable magnification optical system according to the eighth embodiment, where (a) shows a wide-angle end state and (b) shows a telephoto end state. It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 9th Example. 9 is a diagram of various aberrations of the variable magnification optical system at the time of focusing on an infinity object according to a ninth embodiment, in which FIG. 9A shows a wide-angle end state and FIG. 9B shows a telephoto end state. It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 10th Example. It is a diagram of various aberrations at the time of focusing on an infinity object of the variable magnification optical system according to the tenth embodiment, (a) shows a wide-angle end state, and (b) shows a telephoto end state. A cross-sectional view of a camera equipped with the above variable magnification optical system is shown. It is a flowchart for demonstrating the manufacturing method of the variable magnification optical system.

Hereinafter, preferred embodiments will be described with reference to the drawings.

[First Embodiment]
As shown in FIG. 1, the variable magnification optical system ZL according to the first embodiment has a first lens group G1 having a negative refractive power and having at least two lenses, and the first lens group G1. It is composed of a rear group GR having at least one lens group arranged on the image side. Further, in the variable magnification optical system ZL according to the first embodiment, when the magnification is changed, the adjacent lens groups change. With this configuration, it is possible to secure a scaling ratio that satisfies the present embodiment.

Further, it is desirable that the variable magnification optical system ZL according to the first embodiment satisfies the conditional expression (1) shown below.

80.00 <ν1n (1)
However,
ν1n: Abbe number of at least one medium of the negative lens included in the first lens group G1 with respect to the d-line.

The conditional expression (1) defines the Abbe number of at least one medium of the negative lens included in the first lens group G1 with respect to the d-line (hereinafter, the conditional expression (1) of the first lens group G1 is used. A satisfying negative lens is called a "specific negative lens"). By satisfying this conditional expression (1), it is possible to reduce the weight by reducing the number of lenses in the first lens group G1 while satisfactorily correcting the occurrence of various aberrations such as chromatic aberration of magnification. The medium (glass material) of the lens constituting the first lens group G1 can be appropriately selected. In order to ensure the effect of the conditional expression (1), the lower limit of the conditional expression (1) is set to 82.00, 85.00, 88.00, 90.00, 93.00, and 95. It is more desirable to set it to .00.

Further, it is desirable that the variable magnification optical system ZL according to the first embodiment satisfies the conditional expression (2) shown below.

1.05 <nL2 / nL1 (2)
However,
nL1: Refractive index of the lens of the first lens group G1 on the most object side with respect to the d line of the medium nL2: Refractive index of the second lens of the first lens group G1 from the object side with respect to the d line of the medium

The conditional expression (2) defines the ratio of the refractive index of each medium of the lens closest to the object side and the lens second from the object side to the d line in the first lens group G1. By satisfying this conditional expression (2), the weight can be reduced by reducing the number of lenses in the first lens group G1 while satisfactorily correcting the occurrence of various aberrations such as curvature of field and astigmatism. In addition, the medium (glass material) of the lens constituting the first lens group G1 can be appropriately selected. In order to ensure the effect of the conditional expression (2), the lower limit of the conditional expression (2) is set to 1.08, 1.10, 1.11, 1.13, 1.14, and further. It is more desirable to set it to 1.15.

Further, it is desirable that the variable magnification optical system ZL according to the first embodiment satisfies the conditional expression (3) shown below.

N1n ≤ 4 (3)
However,
N1n: Number of negative lenses included in the first lens group G1

The conditional expression (3) defines the number of negative lenses included in the first lens group G1. By satisfying this conditional expression (3), it is possible to reduce the weight by reducing the number of negative lenses in the first lens group G1. In addition, it is possible to reduce aberration fluctuations during focusing and scaling. In order to ensure the effect of the conditional expression (3), it is desirable that the upper limit value of the conditional expression (3) is 3. Further, in order to ensure the effect of the conditional expression (3), the lower limit value of the conditional expression (3) is set to 1 (1 <N1n), that is, the first lens group G1 has at least one lens. It is desirable to have a negative lens.

Further, it is desirable that the variable magnification optical system ZL according to the first embodiment satisfies the conditional expression (4) shown below.

100.00 ° <2ωw (4)
However,
2ωw: Total angle of view of the variable magnification optical system ZL at the wide-angle end state

The conditional expression (4) defines the total angle of view of the variable magnification optical system ZL in the wide-angle end state. By satisfying this conditional expression (4), the present variable magnification optical system ZL can be a bright ultra-wide-angle zoom lens. In order to ensure the effect of the conditional expression (4), the lower limit values of the conditional expression (4) are set to 105.00 °, 110.00 °, 112.00 °, and further 114.00 °. Is more desirable.

Further, it is desirable that the variable magnification optical system ZL according to the first embodiment satisfies the conditional expression (5) shown below.

nL1 <1.70 (5)
However,
nL1: Refractive index of the lens on the most object side of the first lens group G1 with respect to the d line of the medium.

The conditional expression (5) defines the refractive index of the lens on the most object side of the first lens group G1 with respect to the d-line of the medium. By satisfying this conditional expression (5), the lens of the medium (glass material) having a low refractive index is arranged on the most object side of the first lens group G1, so that the Petzval sum can be satisfactorily corrected. In addition, it is possible to reduce aberration fluctuations during focusing and scaling. In order to ensure the effect of the conditional expression (5), the upper limit of the conditional expression (5) is set to 1.69, 1.68, 1.66, 1.65, 1.64, and further 1. It is more desirable to set it to .63.

[Second Embodiment]
As shown in FIG. 1, the variable magnification optical system ZL according to the second embodiment includes a first lens group G1 having a negative refractive power and at least one arranged on the image side of the first lens group G1. It is composed of a rear group GR having a lens group. Further, in the variable magnification optical system ZL according to the second embodiment, the distance between adjacent lens groups changes at the time of magnification change. With this configuration, it is possible to secure a scaling ratio that satisfies the present embodiment.

Further, it is desirable that the variable magnification optical system ZL according to the second embodiment satisfies the conditional expression (6) shown below.

85.00mm ² <fw × (-f1) / Fnow <165.00mm ²
(6)
However,
fw: Focal length of the variable magnification optical system ZL in the wide-angle end state f1: Focal length of the first lens group G1 Fnow: Open F number at the time of focusing an object at infinity in the wide-angle end state of the variable magnification optical system ZL

The conditional expression (6) defines an appropriate refractive power (power) of the first lens group G1 with respect to the open F number of the variable magnification optical system ZL. By satisfying this conditional expression (6), it is possible to achieve both weight reduction by reducing the number of lenses in the first lens group G1 and high performance by appropriate refractive power (power) of the first lens group G1. it can. In addition, the variable magnification optical system ZL can be made compatible with a bright ultra-wide-angle zoom lens. In order to ensure the effect of the conditional expression (6), the upper limit values of the conditional expression (6) are set to 160.00 mm ² , 155.00 mm ² , 150.00 mm ² , 145.00 mm ² , 140. ^{00mm 2, 135.00mm 2, 130.00mm 2} , 125.00mm 2, 120.00mm 2, further it is more preferable to 115.00mm ^2. Further, in order to ensure the effect of the conditional expression (6), the lower limit of the conditional expression (6) is set to 90.00 mm ² , 95.00 mm ² , 100.00 mm ² , 102.00 mm ² , 103. 300 mm ^2, further more preferably set to 104.00mm ^2.

Further, it is desirable that the variable magnification optical system ZL according to the second embodiment satisfies the conditional expression (3A) shown below.

N1n ≤ 3 (3A)
However,
N1n: Number of negative lenses included in the first lens group G1

The explanation of this conditional expression (3A) is the same as that of the above-mentioned conditional expression (3).

Further, it is desirable that the variable magnification optical system ZL according to the second embodiment satisfies the conditional expression (4) shown below.

100.00 ° <2ωw (4)
However,
2ωw: Total angle of view of the variable magnification optical system ZL at the wide-angle end state

The description of this conditional expression (4) is as described above.

Further, it is desirable that the variable magnification optical system ZL according to the second embodiment satisfies the conditional expression (5) shown below.

nL1 <1.70 (5)
However,
nL1: Refractive index of the lens on the most object side of the first lens group G1 with respect to the d line of the medium.

The description of this conditional expression (5) is as described above.

[Third Embodiment]
As shown in FIG. 1, the variable magnification optical system ZL according to the third embodiment includes a first lens group G1 having a negative refractive power and at least one arranged on the image side of the first lens group G1. It is composed of a rear group GR having a lens group. Further, in the variable magnification optical system ZL according to the present embodiment, the distance between adjacent lens groups changes at the time of magnification change. With this configuration, it is possible to secure a scaling ratio that satisfies the present embodiment.

Further, it is desirable that the variable magnification optical system ZL according to the third embodiment satisfies the conditional expression (7) shown below.

-4.00 <(L1r2 + L1r1) / (L1r2-L1r1) <-0.50
(7)
However,
L1r1: Radius of curvature of the lens surface on the object side of the lens on the most object side of the first lens group G1 L1r2: Radius of curvature of the lens surface on the image side of the lens on the most object side of the first lens group G1

The conditional expression (7) defines the shape of the lens on the most object side of the first lens group G1. By satisfying this conditional expression (7), the lens on the most object side of the first lens group G1 becomes a negative meniscus lens with a convex surface facing the object side, so that both miniaturization and good aberration correction can be achieved at the same time. Can be done. In addition, it is possible to reduce aberration fluctuations during focusing and scaling. In addition, the variable magnification optical system ZL can be made compatible with a bright ultra-wide-angle zoom lens. Exceeding the upper limit of the conditional expression (7) is not preferable because the distortion aberration increases and the manufacturability decreases. In order to ensure the effect of the conditional expression (7), the upper limit of the conditional expression (7) is set to -0.60, -0.70, -0.80, -0.85, -0. It is more desirable to set it to .90, -0.95, -0.98, -1.00, and further -1.05. Further, if it is less than the lower limit of the conditional expression (7), the radius of curvature of the lens surface on the object side becomes short, and the variable magnification optical system ZL becomes large and heavy, which is not preferable. In order to ensure the effect of the conditional expression (7), the lower limit values of the conditional expression (7) are set to -3.50, -3.00, -2.50, -2.25, -2. It is more desirable to set it to .00, -1.80, -1.65, and further -1.55.

Further, it is desirable that the variable magnification optical system ZL according to the third embodiment satisfies the conditional expression (4) shown below.

100.00 ° <2ωw (4)
However,
2ωw: Total angle of view of the variable magnification optical system ZL at the wide-angle end state

The description of this conditional expression (4) is as described above.

Further, it is desirable that the variable magnification optical system ZL according to the third embodiment satisfies the conditional expression (3) shown below.

N1n ≤ 4 (3)
However,
N1n: Number of negative lenses included in the first lens group G1

The description of this conditional expression (3) is as described above.

Further, it is desirable that the variable magnification optical system ZL according to the third embodiment satisfies the conditional expression (5) shown below.

nL1 <1.70 (5)
However,
nL1: Refractive index of the lens on the most object side of the first lens group G1 with respect to the d line of the medium.

The description of this conditional expression (5) is as described above.

[Fourth Embodiment]
As shown in FIG. 1, the variable magnification optical system ZL according to the fourth embodiment has a first lens group G1 having a negative refractive power, a second lens group G2 having a positive refractive power, and a positive refraction. It has a third lens group G3 having power. Further, in the variable magnification optical system ZL according to the fourth embodiment, the distance between adjacent lens groups changes during magnification change, and the first lens group changes from the wide-angle end state to the telephoto end state. It is desirable that the distance between G1 and the second lens group G2 is reduced. With this configuration, it is possible to secure a scaling ratio that satisfies the present embodiment. Further, in the variable magnification optical system ZL according to the fourth embodiment, it is desirable that the second lens group G2 moves to the image side when focusing from an infinity object to a short-distance object. With this configuration, it is possible to reduce the aberration fluctuation during focusing.

Further, in the variable magnification optical system ZL according to the fourth embodiment, it is desirable that the first lens group G1 has a negative meniscus lens having a convex surface facing the object side on the most object side. With such a configuration, both miniaturization and good aberration correction can be achieved at the same time. In addition, it is possible to reduce aberration fluctuations during focusing and scaling. In addition, the variable magnification optical system ZL can be made compatible with a bright ultra-wide-angle zoom lens.

Further, it is desirable that the variable magnification optical system ZL according to the second embodiment satisfies the conditional expression (3A) shown below.

N1n ≤ 3 (3A)
However,
N1n: Number of negative lenses included in the first lens group G1

The explanation of this conditional expression (3A) is the same as that of the above-mentioned conditional expression (3).

Further, it is desirable that the variable magnification optical system ZL according to the second embodiment satisfies the conditional expression (4) shown below.

100.00 ° <2ωw (4)
However,
2ωw: Total angle of view of the variable magnification optical system ZL at the wide-angle end state

The description of this conditional expression (4) is as described above.

[Fifth Embodiment]
As shown in FIG. 1, the variable magnification optical system ZL according to the fifth embodiment has a first lens group G1 having a negative refractive power, a second lens group G2 having a positive refractive power, and a positive refraction. It has a third lens group G3 having power. Further, in the variable magnification optical system ZL according to the fifth embodiment, the distance between adjacent lens groups changes during magnification change, and the first lens group changes from the wide-angle end state to the telephoto end state. It is desirable that the distance between G1 and the second lens group G2 is reduced. With this configuration, it is possible to secure a scaling ratio that satisfies the present embodiment. Further, in the variable magnification optical system ZL according to the fourth embodiment, it is desirable that the second lens group G2 moves to the image side when focusing from an infinity object to a short-distance object. With this configuration, it is possible to reduce the aberration fluctuation during focusing.

Further, in the variable magnification optical system ZL according to the fifth embodiment, it is desirable that the first lens group G1 has a negative meniscus lens having a convex surface facing the object side on the most object side. With such a configuration, both miniaturization and good aberration correction can be achieved at the same time. In addition, it is possible to reduce aberration fluctuations during focusing and scaling. In addition, the variable magnification optical system ZL can be made compatible with a bright ultra-wide-angle zoom lens.

Further, it is desirable that the variable magnification optical system ZL according to the fifth embodiment satisfies the conditional expression (5) shown below.

nL1 <1.70 (5)
However,
nL1: Refractive index of the lens on the most object side of the first lens group G1 with respect to the d line of the medium.

The description of this conditional expression (5) is as described above.

[Sixth Embodiment]
As shown in FIG. 1, the variable magnification optical system ZL according to the sixth embodiment has a first lens group G1 having a negative refractive power, a second lens group G2 having a positive refractive power, and a positive refraction. It has a third lens group G3 having power. Further, in the variable magnification optical system ZL according to the sixth embodiment, the distance between adjacent lens groups changes when the magnification is changed, and when the magnification is changed from the wide-angle end state to the telephoto end state, the first lens group It is desirable that the distance between G1 and the second lens group G2 is reduced. With this configuration, it is possible to secure a scaling ratio that satisfies the present embodiment. Further, in the variable magnification optical system ZL according to the fourth embodiment, it is desirable that the second lens group G2 moves to the image side when focusing from an infinity object to a short-distance object. With this configuration, it is possible to reduce the aberration fluctuation during focusing.

Further, in the variable magnification optical system ZL according to the sixth embodiment, it is desirable that the first lens group G1 has a negative meniscus lens having a convex surface facing the object side on the most object side. With such a configuration, both miniaturization and good aberration correction can be achieved at the same time. In addition, it is possible to reduce aberration fluctuations during focusing and scaling. In addition, the variable magnification optical system ZL can be made compatible with a bright ultra-wide-angle zoom lens.

Further, it is desirable that the variable magnification optical system ZL according to the sixth embodiment satisfies the conditional expression (8) shown below.

59.00 <(Σν1n) / N1n (8)
However,
N1n: Number of negative lenses included in the first lens group G1 Σν1n: Total Abbe number of the negative lens contained in the first lens group G1 with respect to the d-line

The conditional expression (8) defines the ratio of the total number of Abbe numbers to the number of negative lenses included in the first lens group G1. By satisfying this conditional expression (8), the number of lenses in the first lens group G1 is reduced to make it smaller and lighter, and the medium (glass material) of this lens is selected from those with low dispersion to reduce chromatic aberration over the entire zoom range. It can be corrected satisfactorily. In order to ensure the effect of the conditional expression (8), the lower limit of the conditional expression (8) is set to 60.00, 60.50, 61.00, 61.50, 61.80, and 62. It is more desirable to set it to .00.

Further, it is desirable that the variable magnification optical system ZL according to the sixth embodiment satisfies the conditional expression (9) shown below.

100.00 <(Σ (ν1n × f1n)) / (N1n × f1) (9)
However,
N1n: Number of negative lenses included in the first lens group G1 f1: Focal length of the first lens group G1 Σ (ν1n × f1n): Abbe number ν1n with respect to the d line of the medium of the negative lens included in the first lens group G1 Sum of the products of and the focal length f1n

The conditional expression (9) defines an appropriate relationship between the focal length of the first lens group G1 and the ratio of the total number of Abbe numbers to the number of negative lenses included in the first lens group G1. By satisfying this conditional expression (9), it is possible to obtain an appropriate refractive power (power) of the first lens group G1 while reducing the number of lenses in the first lens group G1 to make it smaller and lighter. By selecting the medium (glass material) from those with low dispersion, chromatic aberration can be satisfactorily corrected over the entire zoom range. In order to ensure the effect of the conditional expression (9), the lower limit of the conditional expression (9) is set to 105.00, 110.00, 115.00, 118.00, 120.00, 123. It is more desirable to set it to 00 and further to 125.00.

Further, it is desirable that the variable magnification optical system ZL according to the first to sixth embodiments satisfies the conditional expression (10) shown below.

1.20 <Bfw / fw <4.00 (10)
However,
fw: Focal length of the variable magnification optical system ZL in the wide-angle end state Bfw: Back focus of the variable magnification optical system ZL in the wide-angle end state

The conditional expression (10) defines the ratio of the back focus to the focal length of the entire system in the wide-angle end state. By satisfying this conditional expression (10), both miniaturization and good aberration correction can be achieved at the same time. If the upper limit of the conditional expression (10) is exceeded, the back focus becomes too long, which makes it difficult to miniaturize the variable magnification optical system ZL, which is not preferable. In order to ensure the effect of the conditional expression (10), the upper limit of the conditional expression (10) is set to 3.50, 3.30, 3.00, 2.90, 2.80, 2. It is more desirable to set it to 75, and further to 2.72. Further, if it is less than the lower limit of the conditional expression (10), the distance from the image plane to the exit pupil becomes too short, which is disadvantageous for correcting aberrations and securing the amount of peripheral light, which is not preferable. In order to ensure the effect of the conditional expression (10), the lower limit values of the conditional expression (10) are set to 1.25, 1.30, 1.35, 1.40, 1.45, 1. It is more desirable to set it to 50, 1.55, and further 1.60.

Further, it is desirable that the variable magnification optical system ZL according to the first to sixth embodiments satisfies the conditional expression (11) shown below.

0.40 <STLw / TLw <0.70 (11)
However,
TLw: Total optical length of the variable magnification optical system ZL in the wide-angle end state STRw: Distance on the optical axis from the lens surface to the aperture surface on the most object side in the wide-angle end state of the variable magnification optical system ZL

The conditional expression (11) defines the ratio between the total length and the aperture position in the wide-angle end state. By satisfying this conditional expression (11), both miniaturization and good aberration correction can be achieved at the same time. If it exceeds the upper limit of the conditional expression (11), the distance from the lens surface on the object side to the entrance pupil becomes long, and it becomes difficult to correct distortion and curvature of field, which is not preferable. In order to ensure the effect of the conditional expression (11), the upper limit of the conditional expression (11) is set to 0.68, 0.65, 0.64, 0.63, 0.62, 0. It is more desirable to set it to 61, further 0.58. Further, if it is less than the lower limit of the conditional expression (11), the distance from the image plane to the exit pupil becomes long and the total length is increased, which is not preferable. In order to ensure the effect of the conditional expression (11), the lower limit of the conditional expression (11) is set to 0.43, 0.45, 0.46, 0.47, 0.48, and further 0. It is more desirable to set it to .49.

Further, it is desirable that the variable magnification optical system ZL according to the first to sixth embodiments satisfies the conditional expression (12) shown below.

1.00 <(-f1) / fw <2.00 (12)
However,
fw: Focal length in the wide-angle end state of the variable magnification optical system ZL f1: Focal length of the first lens group G1

The conditional expression (12) defines the ratio of the focal length of the first lens group G1 to the focal length of the entire system in the wide-angle end state. By satisfying this conditional expression (12), the refractive power (power) of the first lens group G1 for achieving both miniaturization and high performance can be determined. If the upper limit of the conditional expression (12) is exceeded, the refractive power of the first lens group G1 becomes too weak and the lens becomes large, which is not preferable. In order to ensure the effect of the conditional expression (12), the upper limit of the conditional expression (12) is set to 1.90, 1.80, 1.70, 1.65, 1.63, 1. It is more desirable to set it to 60 and further 1.59. Further, if it is less than the lower limit value of the conditional expression (12), the refractive power of the first lens group G1 becomes too strong, and good aberration correction cannot be performed, which is not preferable. In order to ensure the effect of the conditional expression (12), the lower limit values of the conditional expression (12) are set to 1.10, 1.20, 1.25, 1.30, 1.35, 1. It is more desirable to set 38, 1.40, and further 1.42.

Further, it is desirable that the variable magnification optical system ZL according to the first to sixth embodiments satisfies the conditional expression (13) shown below.

0.65 <(-f1) / ft <1.20 (13)
However,
ft: Focal length in the telephoto end state of the variable magnification optical system ZL f1: Focal length of the first lens group G1

The conditional expression (13) defines the ratio of the focal length of the first lens group G1 to the focal length of the entire system in the telephoto end state. By satisfying this conditional expression (13), the refractive power (power) of the first lens group G1 for achieving both miniaturization and high performance can be determined. If the upper limit of the conditional expression (13) is exceeded, the refractive power of the first lens group G1 becomes too weak and the lens becomes large, which is not preferable. In order to ensure the effect of the conditional expression (13), the upper limit values of the conditional expression (13) are set to 1.15, 1.10, 1.08, 1.05, 1.03, and further 1. It is more desirable to set it to .00. Further, if it is less than the lower limit value of the conditional expression (13), the scaling ratio becomes too large, and good aberration correction cannot be performed, which is not preferable. In order to ensure the effect of the conditional expression (13), the lower limit of the conditional expression (13) is set to 0.70, 0.75, 0.78, 0.80, 0.83, 0. It is more desirable to set it to 85 and further to 0.87.

Further, it is desirable that the variable magnification optical system ZL according to the first to sixth embodiments satisfies the conditional expression (14) shown below.

1.00 <fL1 / f1 <2.00 (14)
However,
f1: Focal length of the first lens group G1 fL1: Focal length of the lens on the most object side of the first lens group G1

The conditional expression (14) defines the ratio of the focal lengths of the first lens group G1 and the lens on the most object side of the first lens group G1. By satisfying this conditional expression (14), both miniaturization and good aberration correction can be achieved at the same time. If the upper limit of the conditional expression (14) is exceeded, the refractive power (power) of the lens on the most object side of the first lens group G1 becomes too weak, which causes an increase in the size of the variable magnification optical system ZL and a decrease in the amount of peripheral light. Not preferable. In order to ensure the effect of the conditional expression (14), the upper limit of the conditional expression (14) is set to 1.90, 1.80, 1.75, 1.70, 1.65, 1. It is more desirable to set it to 60 and further 1.59. Further, if it is less than the lower limit of the conditional expression (14), the refractive power (power) of the lens on the most object side of the first lens group G1 becomes too strong, and it becomes difficult to correct coma aberration and curvature of field, which is preferable. Absent. In order to ensure the effect of the conditional expression (14), the lower limit values of the conditional expression (14) are set to 1.05, 1.10, 1.15, 1.20, 1.25, 1. It is more desirable to set it to 28 and further 1.30.

Further, it is desirable that the variable magnification optical system ZL according to the first to sixth embodiments satisfies the conditional expression (15) shown below.

1.00 <fL2 / f1 <4.00 (15)
However,
f1: Focal length of the first lens group G1 fL2: Focal length of the second lens from the object side of the first lens group G1

The conditional expression (15) defines the ratio of the focal lengths of the first lens group G1 and the second lens of the first lens group G1 from the object side. By satisfying this conditional expression (15), both miniaturization and good aberration correction can be achieved at the same time. If it exceeds the upper limit of the conditional expression (15), the refractive power of the second lens from the object side of the first lens group G1 becomes too weak and is not suitable for correction of curvature of field, which is not preferable. In order to ensure the effect of the conditional expression (15), the upper limit of the conditional expression (15) is set to 3.85, 3.60, 3.50, 3.45, 3.40, 3. It is more desirable to set it to 35 and further to 3.30. Further, if it is less than the lower limit of the conditional equation (15), the refractive power (power) of the second lens from the object side of the first lens group G1 becomes too strong, and it becomes difficult to correct spherical aberration and coma. Not preferable. In order to ensure the effect of the conditional expression (15), the lower limit of the conditional expression (15) is set to 1.10, 1.20, 1.50, 1.70, 1.80, 1.80. More preferably, it is 90, 2.00, and further 2.10.

Further, it is desirable that the variable magnification optical system ZL according to the first to sixth embodiments satisfies the conditional expression (16) shown below.

3.50 <TLw / Bfw <8.00 (16)
However,
Bfw: Back focus of the variable magnification optical system ZL in the wide-angle end state TLw: Optical total length of the variable magnification optical system ZL in the wide-angle end state

The conditional expression (16) defines the ratio of the back focus to the total length in the wide-angle end state. By satisfying this conditional expression (16), both miniaturization and good aberration correction can be achieved at the same time. If the upper limit of the conditional expression (16) is exceeded, the total length becomes too long or the back focus becomes too short, which is not preferable. In order to ensure the effect of the conditional expression (16), the upper limit values of the conditional expression (16) are set to 7.80, 7.50, 7.25, 7.00, 6.90, 6. More preferably, it is 80, 6.75, 6.70, 6.65, and further 6.50. On the other hand, if it is less than the lower limit of the conditional expression (16), the total length becomes too short and good aberration correction becomes difficult, which is not preferable. In order to ensure the effect of the conditional expression (16), the lower limit of the conditional expression (16) is set to 3.65, 3.75, 3.80, 3.85, 3.90, 3. It is more desirable to set it to 95 and further 4.00.

Further, in the variable magnification optical system ZL according to the first to third embodiments, it is desirable that the first lens group G1 has a negative meniscus lens having a convex surface facing the object side on the most object side. With such a configuration, both miniaturization and good aberration correction can be achieved at the same time. In addition, it is possible to reduce aberration fluctuations during focusing and scaling. In addition, the variable magnification optical system ZL can be made compatible with a bright ultra-wide-angle zoom lens.

Further, it is desirable that the variable magnification optical system ZL according to the first, second, fourth to sixth embodiments satisfies the conditional expression (7) shown below.

-4.00 <(L1r2 + L1r1) / (L1r2-L1r1) <-0.50
(7)
However,
L1r1: Radius of curvature of the lens surface on the object side of the lens on the most object side of the first lens group G1 L1r2: Radius of curvature of the lens surface on the image side of the lens on the most object side of the first lens group G1

The description of this conditional expression (7) is as described above.

Further, in the variable magnification optical system ZL according to the first to sixth embodiments, it is desirable that the first lens group G1 has at least two lenses, and it is desirable that the conditional expression (17) shown below is satisfied. ..

-4.00 <(L2r2 + L2r1) / (L2r2-L2r1) <-0.50
(17)
However,
L2r1: Radius of curvature of the lens surface of the second lens from the object side of the first lens group G1 on the object side L2r2: Radius of curvature of the lens surface on the image side of the second lens from the object side of the first lens group G1

The conditional expression (17) defines the shape of the second lens from the object side of the first lens group G1. By satisfying this conditional expression (17), the second lens from the object side of the first lens group G1 becomes a negative meniscus lens with a convex surface facing the object side, so that aberration correction can be performed satisfactorily. .. If it exceeds the upper limit of the conditional expression (17), it becomes difficult to correct the coma aberration, which is not preferable. In order to ensure the effect of the conditional expression (17), the upper limit of the conditional expression (17) is set to -0.60, -0.70, -0.75, -0.80, -0. It is more desirable to set it to .85, -0.90, -0.95, -1.00, and further -1.05. Further, if it is less than the lower limit value of the conditional expression (17), it becomes difficult to correct the curvature of field, which is not preferable. In order to ensure the effect of the conditional expression (17), the lower limit values of the conditional expression (17) are set to -3.90, -3.80, -3.70, -3.60, -3. It is more desirable to set it to .50, -3.40, -3.30, and further to -3.25.

Further, in the variable magnification optical system ZL according to the first to sixth embodiments, it is desirable that the first lens group G1 has at least three lenses, and it is desirable that the conditional expression (18) shown below is satisfied. ..

−0.80 <(L3r2 + L3r1) / (L3r2-L3r1) <0.80
(18)
However,
L3r1: Radius of curvature of the lens surface of the third lens from the object side of the first lens group G1 on the object side L3r2: Radius of curvature of the lens surface on the image side of the third lens from the object side of the first lens group G1

The conditional expression (18) defines the shape of the third lens from the object side of the first lens group G1. By satisfying this conditional expression (18), the third lens from the object side of the first lens group G1 becomes a biconcave negative lens, so that aberration correction can be performed satisfactorily. If it exceeds the upper limit of the conditional expression (18), it becomes difficult to correct the coma aberration, which is not preferable. In order to ensure the effect of the conditional expression (18), the upper limit of the conditional expression (18) is set to 0.70, 0.60, 0.50, 0.45, 0.40, 0. It is more desirable to set it to 35, 0.30, and further 0.28. Further, if it is less than the lower limit value of the conditional expression (18), it becomes difficult to correct the coma aberration, which is not preferable. In order to ensure the effect of the conditional expression (18), the lower limit of the conditional expression (18) is set to -0.70, -0.60, -0.50, -0.45, -0. It is more desirable to set it to .40, -0.35, -0.30, and further -0.28.

Further, in the variable magnification optical system ZL according to the first to sixth embodiments, it is desirable that the first lens group G1 moves in the optical axis direction at the time of magnification change. With such a configuration, it is possible to reduce the aberration fluctuation at the time of scaling.

Further, in the variable magnification optical system ZL according to the first to sixth embodiments, it is desirable that the first lens group G1 is composed of a negative lens, a negative lens, a negative lens, and a positive lens in this order from the object side. .. With this configuration, various aberrations, particularly distortion and curvature of field can be satisfactorily corrected. In the first lens group G1, each of these negative lenses, negative lenses, negative lenses, and positive lenses may be arranged as a single lens, or may be arranged as a bonded lens in which any of adjacent lenses is joined. Good.

Further, in the variable magnification optical system ZL according to the first to third embodiments, it is desirable that a part of the rear group GR moves to the image side when focusing from an infinity object to a short-distance object. With this configuration, it is possible to reduce the aberration fluctuation during focusing.

Further, in the variable magnification optical system ZL according to the first to third embodiments, the rear group GR has a second lens group G2 having a positive refractive power and a third lens group G3 having a negative refractive power. It is desirable that the second lens group G2 moves to the image side when focusing from an infinity object to a short-range object. With this configuration, it is possible to reduce the aberration fluctuation during focusing.

Further, it is desirable that the variable magnification optical system ZL according to the first to sixth embodiments has at least one lens group on the image side of the third lens group G3. With this configuration, it is possible to improve the correction of various aberrations such as coma at the time of scaling.

Further, in the variable magnification optical system ZL according to the first to sixth embodiments, it is desirable that the rear group GR (or the lens group after the second lens group G2) includes one or more aspherical surfaces. With this configuration, various aberrations, particularly curvature of field, can be satisfactorily corrected.

Further, in the variable magnification optical system ZL according to the first to sixth embodiments, the rear group GR (or the lens group after the second lens group G2) satisfies the following conditional expression (19) (this lens). Is referred to as a "specific lens").

66.50 <νr (19)
However,
νr: Abbe number with respect to the d-line of the lens medium of the rear group GR

The conditional expression (19) defines the Abbe number with respect to the d-line of the medium of the specific lens of the rear group GR (or the lens group of the second lens group G2 or later). When the rear group GR has one or more lenses (specific lenses) that satisfy the conditional expression (19), the chromatic aberration of magnification can be satisfactorily corrected. In order to ensure the effect of the conditional expression (19), the lower limit of the conditional expression (19) is set to 67.00, 67.50, 68.00, 70.00, 74.00, 78. More preferably, it is 00, 80.00, and further 81.00.

Further, it is desirable that the variable magnification optical system ZL according to the first to sixth embodiments satisfies the conditional expression (20) shown below.

Fnow <4.20 (20)
However,
Fnow: Open F-number when focusing an object at infinity in the wide-angle end state of the variable magnification optical system ZL

The conditional expression (20) defines an open F number when the variable magnification optical system ZL is in focus at an infinity object in the wide-angle end state. By satisfying this conditional expression (20), it is possible to secure a good resolution that satisfies the present embodiment in the wide-angle end state. In order to ensure the effect of the conditional expression (20), the lower limit of the conditional expression (20) is set to 4.05, 4.00, 3.80, 3.60, 3.40, 3. It is more desirable to set it to .20, 3.00, and further 2.95.

Further, it is desirable that the variable magnification optical system ZL according to the first to sixth embodiments satisfies the conditional expression (21) shown below.

Fnot <6.00 (21)
However,
Fnot: Open F number when focusing on an infinity object in the telephoto end state of the variable magnification optical system ZL

The conditional expression (21) defines an open F number when the infinity object is in focus in the telephoto end state of the variable magnification optical system ZL. By satisfying this conditional expression (21), it is possible to secure a good resolution that satisfies the present embodiment in the telephoto end state. In order to ensure the effect of the conditional expression (21), the lower limit of the conditional expression (21) is set to 5.50, 5.30, 5.00, 4.80, 4.50, 4 It is more desirable to set it to 0.05, 4.00, 3.80, 3.60, 3.40, 3.20, 3.00, and further 2.95.

Further, the variable magnification optical system ZL according to the first to sixth embodiments may have a filter on the object side of the first lens group G1. Even if the filter is arranged on the object side of the first lens group G1, the size of the filter does not increase, so that the entire variable magnification optical system ZL can be reduced in size.

Next, a camera which is an optical device provided with a variable magnification optical system ZL according to the first to sixth embodiments will be described with reference to FIG. This camera 1 is a so-called mirrorless camera of an interchangeable lens type provided with the variable magnification optical system ZL according to the present embodiment as a photographing lens 2. In the camera 1, the light from an object (subject) (not shown) is collected by the photographing lens 2 and passed through an OLPF (Optical low pass filter) (not shown) on the imaging surface of the imaging unit 3. Form a subject image. Then, the subject image is photoelectrically converted by the photoelectric conversion element provided in the imaging unit 3, and the image of the subject is generated. This image is displayed on the EVF (Electronic viewfinder) 4 provided in the camera 1. This allows the photographer to observe the subject via the EVF4.

When the photographer presses the release button (not shown), the photoelectrically converted image by the imaging unit 3 is stored in the (not shown) memory. In this way, the photographer can shoot the subject with the camera 1. In this embodiment, an example of a mirrorless camera has been described, but a single-lens reflex type camera having a quick return mirror in the camera body and observing a subject by a finder optical system is used as a variable magnification optical system ZL according to the present embodiment. Even when the camera 1 is mounted, the same effect as that of the camera 1 can be obtained.

As described above, the optical device according to the present embodiment is provided with the variable magnification optical system ZL having the above-described configuration, so that the optical apparatus has a small size and a wide angle of view, and has good aberration fluctuations during magnification change and focusing. It is possible to realize a suppressed optical device.

The contents described below can be appropriately adopted as long as the optical performance is not impaired.

In the present embodiment, the variable magnification optical system ZL having a configuration of 2 to 5 groups is shown, but the above configuration conditions and the like can be applied to other group configurations such as 6 groups and 7 groups. Further, a configuration in which a lens or a lens group is added on the most object side or a configuration in which a lens or a lens group is added on the most image side may be used. Further, the lens group refers to a portion having at least one lens separated by an air interval that changes at the time of scaling.

Further, a single or a plurality of lens groups or a partial lens group may be moved in the optical axis direction to form a focusing lens group for focusing from an infinity object to a short-distance object. In this case, the focusing lens group can also be applied to autofocus, and is also suitable for driving a motor (such as an ultrasonic motor) for autofocus. In particular, as described above, it is preferable that at least a part of the rear group GR (for example, the second lens group G2) is the focusing lens group.

In addition, the lens group or partial lens group is moved so as to have a component in the direction perpendicular to the optical axis, or is rotationally moved (oscillated) in the in-plane direction including the optical axis to correct image blur caused by camera shake. It may be a group of anti-vibration lenses. In particular, it is preferable that at least a part of the rear group GR (for example, the fourth lens group G4) is the anti-vibration lens group.

Further, the lens surface may be formed on a spherical surface or a flat surface, or may be formed on an aspherical surface. When the lens surface is spherical or flat, lens processing and assembly adjustment are facilitated, and deterioration of optical performance due to processing and assembly adjustment errors is prevented, which is preferable. Further, even if the image plane is deviated, the depiction performance is less deteriorated, which is preferable. When the lens surface is aspherical, the aspherical surface is an aspherical surface formed by grinding, a glass mold aspherical surface formed by forming glass into an aspherical shape, or a composite aspherical surface formed by forming resin on the glass surface into an aspherical shape. Any aspherical surface may be used. Further, the lens surface may be a diffraction surface, and the lens may be a refractive index distribution type lens (GRIN lens) or a plastic lens.

The aperture diaphragm S is preferably arranged in the rear group GR (for example, in the vicinity of the third lens group G3 (on the image side of the third lens group G3 or in the third lens group G3)), but the aperture diaphragm S is preferably arranged. The role may be substituted by the frame of the lens without providing the member as.

Further, each lens surface may be provided with an antireflection film having high transmittance in a wide wavelength range in order to reduce flare and ghost and achieve high optical performance with high contrast.

Further, the variable magnification optical system ZL of the present embodiment has a magnification ratio of about 1.2 to 3.0 times.

It should be noted that the configurations and conditions described above each exert the above-mentioned effects, and are not limited to those that satisfy all the configurations and conditions, and any of the configurations or conditions, or any of them. It is possible to obtain the above-mentioned effect even if it satisfies the above-mentioned configuration or combination of conditions.

The outline of the method for manufacturing the variable magnification optical system ZL according to the first to sixth embodiments will be described below with reference to FIG. 22. First, each lens is arranged to prepare a first lens group G1 having a negative refractive power and a rear group GR having at least one lens group (step S100), and these lens groups are arranged (step S200). .. In this step S200, the first lens group G1 and the rear group GR are arranged so that the distance between adjacent lens groups changes when the magnification is changed. At this time, when the rear group GR has a second lens group G2 having a positive refractive power and a third lens group G3 having a positive refractive power, the distance between the first lens group G1 and the second lens group G2 Is arranged so that the second lens group G2 moves to the image side when focusing from an infinity object to a short-range object, and the second lens group G1 is arranged so as to move to the image side, and the object side is the closest to the object side of the first lens group G1. Place a negative meniscus lens with a convex surface facing. Furthermore, it is arranged so as to satisfy the condition according to the above-mentioned conditional expression (step S300).

With the above configuration, it is possible to provide a variable magnification optical system having a small size, a wide angle of view and high optical performance, an optical device having this variable magnification optical system, and a method for manufacturing the variable magnification optical system.

Hereinafter, each embodiment of the present application will be described with reference to the drawings. In addition, FIG. 1, FIG. 3, FIG. 5, FIG. 7, FIG. 9, FIG. 11, FIG. 13, FIG. 15, FIG. 17 and FIG. 19 show the variable magnification optical system ZL according to the first to tenth embodiments. It is sectional drawing which shows the structure of ZL1 to ZL10) and the refractive power distribution. Further, in the lower part of the cross-sectional view of these variable magnification optical systems ZL1 to ZL10, the light of each lens group G1 to G3, G4 or G5 when the magnification is changed from the wide-angle end state (W) to the telephoto end state (T). The direction of movement along the axis is indicated by an arrow.

In each embodiment, the height of the aspherical surface in the direction perpendicular to the optical axis is y, and the distance (sag amount) along the optical axis from the tangent plane of the apex of each aspherical surface to each aspherical surface at the height y. Is S (y), the radius of curvature (near-axis radius of curvature) of the reference sphere is r, the conical constant is K, and the nth-order aspherical coefficient is An, it is expressed by the following equation (b). .. In the following examples, " ^En " indicates " ^{x10 -n} ".

S (y) = (y ² / r) / {1+ (1-K × y ² / r ² ) ^1/2 }
＋ A4 × y ⁴ ＋ A6 × y ⁶ ＋ A8 × y ⁸ ＋ A10 × y ¹⁰ ＋ A12 × y ¹² ＋ A14 × y ¹⁴ (a)

In each embodiment, the second-order aspherical coefficient A2 is 0. Further, in the table of each embodiment, the aspherical surface is marked with * on the right side of the surface number.

[First Example]
FIG. 1 is a diagram showing a configuration of a variable magnification optical system ZL1 according to the first embodiment. The variable magnification optical system ZL1 is composed of a first lens group G1 having a negative refractive power and a rear group GR having a positive refractive power in order from the object side. Further, the rear group GR includes a second lens group G2 having a positive refractive power, a third lens group G3 having a positive refractive power, and a fourth lens group G4 having a negative refractive power in order from the object side. It is composed of a fifth lens group G5 having a positive refractive power.

In this variable magnification optical system ZL1, the first lens group G1 has a negative meniscus lens shape in which the lens surface on the object side and the lens surface on the image side are formed in an aspherical shape in order from the object side, and the convex surface is directed toward the object side. Aspherical negative lens L11, an aspherical negative lens L12 having a negative meniscus lens shape in which the lens surface on the image side is formed in an aspherical shape and a convex surface facing the object side, a biconcave negative lens L13, and a biconvex positive lens L14. It is composed of. Further, the second lens group G2 is a junction lens in which a positive meniscus lens L21 having a convex surface facing the object side, a negative meniscus lens L22 having a convex surface facing the object side, and a biconvex positive lens L23 are joined in order from the object side. It is composed of. Further, the third lens group G3 is composed of a junction lens in which a negative meniscus lens L31 having a convex surface facing the object side and a biconvex positive lens L32 are joined in order from the object side. Further, the fourth lens group G4 is composed of a junction lens in which a biconcave negative lens L41 and a positive meniscus lens L42 having a convex surface facing the object side are joined in order from the object side, and a biconvex positive lens L43. Further, the fifth lens group G5 includes a junction lens in which a biconvex positive lens L51 and a negative meniscus lens L52 having a concave surface facing the object side are joined in order from the object side, and a negative meniscus lens L53 having a convex surface facing the object side. It is composed of a bonded lens in which the biconvex positive lens L54 is joined, and an aspherical negative lens L55 having a negative meniscus lens shape in which the lens surface on the image side is formed in an aspherical shape and the concave surface is directed toward the object side. A filter FL is arranged between the fifth lens group G5 and the image plane I.

Further, in the variable magnification optical system ZL1, the distance between the first lens group G1 and the second lens group G2 decreases when the magnification is changed from the wide-angle end state to the telescopic end state, and the second lens group G2 and the third lens group The distance from the G3 increases, the distance between the third lens group G3 and the fourth lens group G4 increases, the distance between the fourth lens group G4 and the fifth lens group G5 decreases, and the distance from the fifth lens group G5 The first lens group G1 moves to the image side so that the distance (back focus) from the image plane I increases, and the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 moves to the object side. The aperture diaphragm S is arranged between the third lens group G3 and the fourth lens group G4, and moves together with the fourth lens group G4 at the time of scaling.

Further, the variable magnification optical system ZL1 is configured to focus from an infinity object to a short-distance object by moving the second lens group G2 to the image side.

Table 1 below lists the specifications of the variable magnification optical system ZL1. In Table 1, f in the overall specifications represents the focal length of the entire system, FNO represents the F number, 2ω represents the total angle of view, Ymax represents the maximum image height, TL represents the total length, and Bf represents the back focus. Here, the total length TL represents the distance on the optical axis from the first surface of the lens surface to the image surface I when the infinite object is in focus. Further, the back focus Bf indicates the distance on the optical axis from the lens surface (the 32nd surface in FIG. 1) on the image side to the image surface I. Further, in the lens data, the first column m is the order (plane number) of the lens surfaces from the object side along the traveling direction of the light beam, and the second column r is the radius of curvature of each lens surface in the third column. d is the distance (plane spacing) on the optical axis from each optical surface to the next optical surface, and the fourth column nd and the fifth column νd are the refractive index and Abbe number with respect to the d line (λ = 587.6 nm). Is shown. The radius of curvature of 0.0000 indicates a plane, and the refractive index of air of 1.000000 is omitted. The lens group focal length indicates the start surface and focal length of each of the first to fifth lens groups G1 to G5.

Here, "mm" is generally used as the unit of the focal length f, the radius of curvature r, the surface spacing d, and other lengths listed in all the following specification values, but the optical system is proportionally expanded or proportional. It is not limited to this because the same optical performance can be obtained even if the reduction is performed. Further, the description of these codes and the description of the specification table are the same in the following examples.

In Table 1, the 18th surface shows the aperture stop S, and the 9th, 24th, and 33rd surfaces show virtual surfaces. Further, a secondary diaphragm can be arranged on the 24th surface.

When the filter is arranged on the object side of the variable magnification optical system ZL1, it is arranged at a position 6.10 mm away from the first surface on the object side.

(Table 1) First Example [Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f = 14.400 ~ 18.000 ~ 20.000 ~ 23.300
FNO = 2.91 ~ 2.91 ~ 2.91 ~ 2.91
2ω (°) = 114.737 ~ 100.340 ~ 93.766 ~ 84.519
Ymax = 21.600 ~ 21.600 ~ 21.600 ~ 21.600
TL (air equivalent length) = 161.247 ~ 157.019 ~ 156.182 ~ 155.795
Bf (air equivalent length) = 38.106 ~ 43.995 ~ 47.450 ~ 53.389

[Lens data]
m r d nd ν d
Physical surface ∞
1 * 220.0000 3.2000 1.588870 61.13
2 * 17.8900 12.8517
3 129.4201 2.0000 1.820980 42.50
4 * 32.1806 10.9734
5 -45.0029 1.7000 1.433848 95.23
6 53.1259 1.1806
7 46.0796 5.3284 1.834000 37.18
8 -278.7554 d8
9 0.0000 d9
10 40.5745 2.8000 1.698950 30.13
11 289.5688 0.2000
12 85.2105 1.1000 1.963000 24.11
13 19.6402 5.0000 1.688930 31.16
14 -402.4157 d14
15 136.9524 1.1000 1.834810 42.73
16 39.2521 5.0000 1.516800 64.13
17 -33.8194 d17
18 0.0000 4.3181 Aperture aperture S
19 -29.4115 1.1000 1.953750 32.33
20 26.8911 3.7000 1.846660 23.80
21 28206.6500 0.2000
22 60.6032 2.7000 1.846660 23.80
23 -199.9962 1.5000
24 0.0000 d24
25 27.2496 8.6000 1.497820 82.57
26 -22.2560 1.2000 1.834000 37.18
27 -31.7894 0.2000
28 304.4905 1.2000 1.834000 37.18
29 22.3340 6.9000 1.497820 82.57
30 -74.7302 1.1469
31 -66.1084 1.6000 1.860999 37.10
32 * -70.6675 d32
33 0.0000 35.2000
34 0.0000 2.0000 1.516800 64.13
35 0.0000 1.2329
Image plane ∞

[Lens group focal length]
Lens group Start surface Focal length 1st lens group 1 -21.147
2nd lens group 10 68.510
Third lens group 15 87.743
4th lens group 19 -76.490
5th lens group 25 46.500

In this variable magnification optical system ZL1, each lens surface of the first surface, the second surface, the fourth surface, and the 32nd surface is formed in an aspherical shape. Table 2 below shows the aspherical data for each surface, that is, the values of the conical constant K and the aspherical constants A4 to A12.

(Table 2)
[Aspherical data]
First side K = 1.000
A4 = 1.21050E-05 A6 = -1.90441E-08 A8 = 2.08981E-11
A10 ＝ -1.26480E-14 A12 ＝ 3.59780E-18 A14 ＝ 0.00000E + 00
Second side K = 0.0000
A4 = 5.30134E-06 A6 = 1.33691E-08 A8 = -2.53693E-11
A10 ＝ -2.12112E-13 A12 ＝ 3.35890E-16 A14 ＝ 0.00000E + 00
Side 4 K = 2.000
A4 = 1.46984E-05 A6 = 6.92202E-09 A8 = -3.91814E-11
A10 = 7.84867E-13 A12 = -1.29570E-15 A14 = 0.00000E + 00
Side 32 K = 1.000
A4 = 1.34572E-05 A6 = 1.92171E-08 A8 = 1.11927E-10
A10 = -3.98100E-13 A12 = 1.67540E-15 A14 = 0.00000E + 00

In this variable magnification optical system ZL1, the axial air spacing d8 and d9 between the first lens group G1 and the second lens group G2, and the axial air spacing d14 and third between the second lens group G2 and the third lens group G3. The on-axis air gap d17 between the lens group G3 and the fourth lens group G4, the on-axis air distance d24 between the fourth lens group G4 and the fifth lens group G5, and the on-axis of the fifth lens group G5 and the filter FL. The air spacing d32 changes upon scaling and focusing. Table 3 below shows the variable intervals at each focal length in the wide-angle end state, intermediate focal length state, and telephoto end state at the time of focusing on an infinity object, focusing on a short-range object, and focusing on the closest object, respectively. Indicates a value. In Table 3, f indicates the focal length, β indicates the magnification, and d0 indicates the distance from the first surface to the object. This description is the same in the following examples.

(Table 3)
[Variable interval data]
-When focusing on an infinite object-
Wide-angle end state Intermediate focal length state Telephoto end state f 14.400 18.000 20.000 23.300
d0 ∞ ∞ ∞ ∞
d8 23.7380 12.2188 7.5200 1.5000
d9 0.0000 0.0000 0.0000 0.0000
d14 4.7891 8.6308 9.6629 9.6567
d17 1.5000 2.9738 3.6783 4.4505
d24 6.3147 2.4012 1.0722 0.0000
d32 0.5000 6.3712 9.8216 15.7968

-When focusing on short-range objects-
Wide-angle end state Intermediate focal length state Telephoto end state β -0.025 -0.025 -0.025 -0.025
d0 543.6970 688.7637 769.2222 901.8471
d8 23.7380 12.2188 7.5200 1.5000
d9 0.8063 0.6504 0.5966 0.5323
d14 3.9828 7.9804 9.0662 9.1244
d17 1.5000 2.9738 3.6783 4.4505
d24 6.3147 2.4012 1.0722 0.0000
d32 0.5000 6.3712 9.8216 15.7968

-When the closest object is in focus-
Wide-angle end state Intermediate focal length state Telephoto end state β -0.104 -0.128 -0.141 -0.165
d0 111.9714 116.1994 117.0364 117.4232
d8 23.7380 12.2188 7.5200 1.5000
d9 3.2248 3.1636 3.2073 3.3250
d14 1.5643 5.4672 6.4555 6.3318
d17 1.5000 2.9738 3.6783 4.4505
d24 6.3147 2.4012 1.0722 0.0000
d32 0.5000 6.3712 9.8216 15.7968

Table 4 below shows the values corresponding to each conditional expression in the variable magnification optical system ZL1. In the variable magnification optical system ZL1, the specific negative lens is the biconcave negative lens L13, and the specific lenses are the biconvex positive lens L51 and the biconvex positive lens L54.

(Table 4)
Σν1n = 198.86
Σ (ν1n × f1n) =-9591.491
STLw = 82.461
fL1 = -33.265
fL2 = -52.658

[Conditional expression correspondence value]
(1) ν1n = 95.23
(2) nL2 / nL1 = 1.146
(3) N1n = 3
(4) 2ωw = 114.737 °
(5) nL1 = 1.589
(6) fw × (−f1) / Fnow = 106.475mm ²
(7) (L1r2 + L1r1) / (L1r2-L1r1) =-1.177
(8) (Σν1n) /N1n=66.287
(9) (Σ (ν1n × f1n)) / (N1n × f1) = 148.588
(10) Bfw / fw = 2.646
(11) STLw / TLw = 0.511
(12) (-f1) / fw = 1.494
(13) (-f1) /ft=0.923
(14) fL1 / f1 = 1.546
(15) fL2 / f1 = 2.447
(16) TLw / Bfw = 4.232
(17) (L2r2 + L2r1) / (L2r2-L2r1) =-1.662
(18) (L3r2 + L3r1) / (L3r2-L3r1) = 0.083
(19) νr = 82.57
(20) Fnow = 2.91
(21) Fnot = 2.91

As described above, the variable magnification optical system ZL1 satisfies all of the above conditional expressions (1) to (21).

FIG. 2 shows various aberration diagrams in the wide-angle end state and the telephoto end state when the variable magnification optical system ZL1 is in focus at an infinity object. In each aberration diagram, FNO indicates an F number and Y indicates an image height. The spherical aberration diagram shows the value of the F number corresponding to the maximum aperture, the astigmatism diagram and the distortion diagram show the maximum image height, and the transverse aberration diagram shows the value of each image height. d represents the d line (λ = 587.6 nm), and g represents the g line (λ = 435.8 nm). In the astigmatism diagram, the solid line shows the sagittal image plane and the broken line shows the meridional image plane. In addition, in the aberration diagram of each example shown below, the same reference numerals as those of this example are used. From these various aberration diagrams, it can be seen that the variable magnification optical system ZL1 satisfactorily corrects various aberrations from the wide-angle end state to the telephoto end state and has excellent imaging performance.

[Second Example]
FIG. 3 is a diagram showing a configuration of the variable magnification optical system ZL2 according to the second embodiment. The variable magnification optical system ZL2 is composed of a first lens group G1 having a negative refractive power and a rear group GR having a positive refractive power in order from the object side. Further, the rear group GR includes a second lens group G2 having a positive refractive power, a third lens group G3 having a positive refractive power, and a fourth lens group G4 having a negative refractive power in order from the object side. It is composed of a fifth lens group G5 having a positive refractive power.

In this variable magnification optical system ZL2, the first lens group G1 has a negative meniscus lens shape in which the lens surface on the object side and the lens surface on the image side are formed in an aspherical shape in order from the object side, and the convex surface is directed toward the object side. Aspherical negative lens L11, an aspherical negative lens L12 having a negative meniscus lens shape in which the lens surface on the image side is formed in an aspherical shape and a convex surface facing the object side, a biconcave negative lens L13, and a biconvex positive lens L14. It is composed of. Further, the second lens group G2 is a junction lens in which a positive meniscus lens L21 having a convex surface facing the object side, a negative meniscus lens L22 having a convex surface facing the object side, and a biconvex positive lens L23 are joined in order from the object side. It is composed of. Further, the third lens group G3 is composed of a junction lens in which a negative meniscus lens L31 having a convex surface facing the object side and a biconvex positive lens L32 are joined in order from the object side. Further, the fourth lens group G4 is composed of a junction lens in which a biconcave negative lens L41 and a biconvex positive lens L42 are joined, and a biconvex positive lens L43 in order from the object side. Further, the fifth lens group G5 includes a junction lens in which a biconvex positive lens L51 and a negative meniscus lens L52 having a concave surface facing the object side are joined in order from the object side, and a negative meniscus lens L53 having a convex surface facing the object side. It is composed of a bonded lens in which the biconvex positive lens L54 is joined, and an aspherical negative lens L55 having a negative meniscus lens shape in which the lens surface on the image side is formed in an aspherical shape and the concave surface is directed toward the object side. A filter FL is arranged between the fifth lens group G5 and the image plane I.

Further, in the variable magnification optical system ZL2, when the magnification is changed from the wide-angle end state to the telescopic end state, the distance between the first lens group G1 and the second lens group G2 is reduced, and the second lens group G2 and the third lens group are reduced. The distance from G3 changes, the distance between the third lens group G3 and the fourth lens group G4 increases, the distance between the fourth lens group G4 and the fifth lens group G5 decreases, and the distance from the fifth lens group G5 The first lens group G1 moves to the image side so that the distance (back focus) from the image plane I increases, and the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 moves to the object side. The aperture diaphragm S is arranged between the third lens group G3 and the fourth lens group G4, and moves together with the fourth lens group G4 at the time of scaling.

Further, the variable magnification optical system ZL2 is configured to focus from an infinity object to a short-distance object by moving the second lens group G2 to the image side.

Table 5 below lists the specifications of the variable magnification optical system ZL2.

In Table 5, the 18th surface shows the aperture stop S, and the 9th, 24th, and 33rd surfaces show virtual surfaces. Further, a secondary diaphragm can be arranged on the 24th surface.

When the filter is arranged on the object side of the variable magnification optical system ZL2, it is arranged at a position 6.10 mm away from the first surface on the object side.

(Table 5) Second Example [Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f = 14.400 ~ 18.000 ~ 20.000 ~ 23.300
FNO = 2.91 ~ 2.91 ~ 2.91 ~ 2.91
2ω (°) = 114.733 ~ 100.255 ~ 93.680 ~ 84.518
Ymax = 21.600 ~ 21.600 ~ 21.600 ~ 21.600
TL (air equivalent length) = 157.612 ~ 154.540 ~ 154.421 ~ 153.680
Bf (air equivalent length) = 38.098 ~ 43.918 ~ 47.289 ~ 53.515

[Lens data]
m r d nd ν d
Physical surface ∞
1 * 205.1729 3.1000 1.588870 61.13
2 * 17.5567 12.8326
3 114.0778 2.0000 1.851080 40.12
4 * 31.6290 10.7225
5 -46.1746 1.7000 1.433848 95.23
6 64.9422 0.2000
7 43.9857 4.9563 1.850260 32.35
8 -739.0819 d8
9 0.0000 d9
10 52.0829 2.4000 1.755200 27.57
11 298.7151 0.2000
12 68.9680 1.1000 1.963000 24.11
13 18.9881 4.7000 1.737999 32.33
14 -2022.5978 d14
15 286.5992 1.1000 1.950000 29.37
16 46.7172 4.6000 1.531720 48.78
17 -31.7120 d17
18 0.0000 4.4042 Aperture aperture S
19 -27.9959 1.1000 1.953750 32.33
20 28.8462 3.7000 1.846660 23.80
21 -557.2164 0.2000
22 68.8702 2.8000 1.963000 24.11
23 -141.5400 1.5000
24 0.0000 d24
25 27.3401 8.6000 1.497820 82.57
26 -22.2407 1.2000 1.834000 37.18
27 -31.9295 0.2000
28 392.1080 1.2000 1.834000 37.18
29 22.3559 7.0000 1.497820 82.57
30 -57.4736 1.0035
31 -58.3185 1.5000 1.860999 37.10
32 * -71.1156 d32
33 0.0000 35.2000
34 0.0000 2.0000 1.516800 64.13
35 0.0000 1.2329
Image plane ∞

[Lens group focal length]
Lens group Start surface Focal length 1st lens group 1 -21.147
2nd lens group 10 68.510
Third lens group 15 87.743
4th lens group 19 -76.490
5th lens group 25 46.500

In this variable magnification optical system ZL2, each lens surface of the first surface, the second surface, the fourth surface, and the 32nd surface is formed in an aspherical shape. Table 6 below shows the data of the surface number m and the aspherical surface, that is, the values of the conical constant K and the aspherical constants A4 to A12.

(Table 6)
[Aspherical data]
First side K = 1.000
A4 = 1.15717E-05 A6 = -1.66721E-08 A8 = 1.77522E-11
A10 ＝ -1.04794E-14 A12 ＝ 3.05490E-18 A14 ＝ 0.00000E + 00
Second side K = 0.0000
A4 = 4.54275E-06 A6 = 1.13567E-08 A8 = 1.93629E-11
A10 ＝ -3.22207E-13 A12 ＝ 4.31580E-16 A14 ＝ 0.00000E + 00
Side 4 K = 2.000
A4 = 1.46075E-05 A6 = 1.38300E-08 A8 = -7.82738E-11
A10 = 9.13879E-13 A12 = -1.45480E-15 A14 = 0.00000E + 00
Side 32 K = 1.000
A4 = 1.36004E-05 A6 = 2.06160E-08 A8 = 8.92060E-11
A10 ＝ -2.49786E-13 A12 ＝ 1.19380E-15 A14 ＝ 0.00000E + 00

In this variable magnification optical system ZL2, the axial air spacing d8 and d9 between the first lens group G1 and the second lens group G2, and the axial air spacing d14 and third between the second lens group G2 and the third lens group G3. The on-axis air gap d17 between the lens group G3 and the fourth lens group G4, the on-axis air distance d24 between the fourth lens group G4 and the fifth lens group G5, and the on-axis of the fifth lens group G5 and the filter FL. The air spacing d32 changes upon scaling and focusing. Table 7 below shows the variable intervals at the wide-angle end state, intermediate focal length state, and telephoto end state at the time of focusing on an infinity object, focusing on a short-range object, and focusing on the closest object, respectively. Indicates a value.

(Table 7)
[Variable interval data]
-When focusing on an infinite object-
Wide-angle end state Intermediate focal length state Telephoto end state f 14.400 18.000 20.000 23.300
d0 ∞ ∞ ∞ ∞
d8 22.8572 11.8896 7.4255 1.5000
d9 0.0000 0.0000 0.0000 0.0000
d14 4.7767 8.7786 10.0600 9.3930
d17 1.5000 3.6452 4.8753 5.2525
d24 6.3610 2.2891 0.7521 0.0000
d32 0.5000 6.2202 9.5924 15.8643

-When focusing on short-range objects-
Wide-angle end state Intermediate focal length state Telephoto end state β -0.025 -0.025 -0.025 -0.025
d0 543.9428 689.0016 769.4614 902.1315
d8 22.8572 11.8896 7.4255 1.5000
d9 0.7774 0.6310 0.5801 0.5199
d14 3.9994 8.1476 9.4799 8.8730
d17 1.5000 3.6452 4.8753 5.2525
d24 6.3610 2.2891 0.7521 0.0000
d32 0.5000 6.2202 9.5924 15.8643

-When the closest object is in focus-
Wide-angle end state Intermediate focal length state Telephoto end state β -0.102 -0.126 -0.140 -0.163
d0 115.6064 118.6787 118.7977 119.5385
d8 22.8572 11.8896 7.4255 1.5000
d9 3.0354 3.0213 3.0846 3.2044
d14 1.7414 5.7572 6.9754 6.1886
d17 1.5000 3.6452 4.8753 5.2525
d24 6.3610 2.2891 0.7521 0.0000
d32 0.5000 6.2202 9.5924 15.8643

Table 8 below shows the values corresponding to each conditional expression in the variable magnification optical system ZL2. In the variable magnification optical system ZL2, the specific negative lens is the biconcave negative lens L13, and the specific lenses are the biconvex positive lens L51 and the biconvex positive lens L54.

(Table 8)
Σν1n = 196.48
Σ (ν1n × f1n) =-9987.927
STLw = 78.745
fL1 = -32.805
fL2 = -52.000

[Conditional expression correspondence value]
(1) ν1n = 95.23
(2) nL2 / nL1 = 1.165
(3) N1n = 3
(4) 2ωw = 114.733 °
(5) nL1 = 1.589
(6) fw × (−f1) / Fnow = 104.645mm ²
(7) (L1r2 + L1r1) / (L1r2-L1r1) =-1.187
(8) (Σν1n) / N1n = 65.493
(9) (Σ (ν1n × f1n)) / (N1n × f1) = 157.436
(10) Bfw / fw = 2.646
(11) STLw / TLw = 0.500
(12) (-f1) / fw = 1.469
(13) (-f1) /ft=0.908
(14) fL1 / f1 = 1.551
(15) fL2 / f1 = 2.459
(16) TLw / Bfw = 4.137
(17) (L2r2 + L2r1) / (L2r2-L2r1) =-1.767
(18) (L3r2 + L3r1) / (L3r2-L3r1) = 0.169
(19) νr = 82.57
(20) Fnow = 2.91
(21) Fnot = 2.91

As described above, the variable magnification optical system ZL2 satisfies all of the above conditional expressions (1) to (21).

FIG. 4 shows various aberration diagrams in the wide-angle end state and the telephoto end state when the variable magnification optical system ZL2 is in focus at an infinity object. From these various aberration diagrams, it can be seen that the variable magnification optical system ZL2 satisfactorily corrects various aberrations from the wide-angle end state to the telephoto end state and has excellent imaging performance.

[Third Example]
FIG. 5 is a diagram showing a configuration of the variable magnification optical system ZL3 according to the third embodiment. The variable magnification optical system ZL3 is composed of a first lens group G1 having a negative refractive power and a rear group GR having a positive refractive power in order from the object side. Further, the rear group GR includes a second lens group G2 having a positive refractive power, a third lens group G3 having a positive refractive power, and a fourth lens group G4 having a negative refractive power in order from the object side. It is composed of a fifth lens group G5 having a positive refractive power.

In this variable magnification optical system ZL3, the first lens group G1 has a negative meniscus lens shape in which the lens surface on the object side and the lens surface on the image side are formed in an aspherical shape in order from the object side, and the convex surface is directed toward the object side. The aspherical negative lens L11, the aspherical negative lens L12 having a biconcave negative lens shape with the lens surface on the image side formed into an aspherical shape, the biconcave negative lens L13, and the biconvex positive lens L14. Further, the second lens group G2 includes a positive meniscus lens L21 having a convex surface facing the object side, a negative meniscus lens L22 having a convex surface facing the object side, and a positive meniscus lens L23 having a convex surface facing the object side in order from the object side. It is composed of a bonded lens that is bonded to. Further, the third lens group G3 is composed of a junction lens in which a negative meniscus lens L31 having a convex surface facing the object side and a biconvex positive lens L32 are joined in order from the object side. Further, the fourth lens group G4 is composed of a junction lens in which a biconcave negative lens L41 and a positive meniscus lens L42 having a convex surface facing the object side are joined in order from the object side, and a biconvex positive lens L43. Further, the fifth lens group G5 includes a junction lens in which a biconvex positive lens L51 and a negative meniscus lens L52 having a concave surface facing the object side are joined in order from the object side, and a negative meniscus lens L53 having a convex surface facing the object side. The biconvex regular lens L54 and the lens surface on the image side are formed in an aspherical shape, and the lens surface is formed by joining the aspherical positive lens L55 in the shape of a positive meniscus lens with the concave surface facing the object side. A filter FL is arranged between the fifth lens group G5 and the image plane I.

Further, in the variable magnification optical system ZL3, when the magnification is changed from the wide-angle end state to the telescopic end state, the distance between the first lens group G1 and the second lens group G2 is reduced, and the second lens group G2 and the third lens group are reduced. The distance from G3 changes, the distance between the third lens group G3 and the fourth lens group G4 increases, the distance between the fourth lens group G4 and the fifth lens group G5 decreases, and the distance from the fifth lens group G5 The first lens group G1 moves to the image side so that the distance (back focus) from the image plane I increases, and the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 moves to the object side. The aperture diaphragm S is arranged between the third lens group G3 and the fourth lens group G4, and moves together with the third lens group G3 at the time of scaling.

Further, the variable magnification optical system ZL3 is configured to focus from an infinity object to a short-distance object by moving the second lens group G2 to the image side.

Table 9 below lists the specifications of the variable magnification optical system ZL3.

In Table 9, the 18th plane shows the aperture stop S, and the 9th, 24th, and 32nd planes show virtual planes. Further, a secondary diaphragm can be arranged on the 24th surface.

When the filter is arranged on the object side of the variable magnification optical system ZL3, it is arranged at a position 6.10 mm away from the first surface on the object side.

(Table 9) Third Example [Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f = 14.400 ~ 18.000 ~ 20.000 ~ 23.300
FNO = 2.91 ~ 2.91 ~ 2.91 ~ 2.91
2ω (°) = 114.733 ~ 100.259 ~ 93.684 ~ 84.519
Ymax = 21.600 ~ 21.600 ~ 21.600 ~ 21.600
TL (air equivalent length) = 165.966 ~ 158.445 ~ 157.021 ~ 155.742
Bf (air equivalent length) = 38.086 ~ 43.089 ~ 46.279 ~ 52.057

[Lens data]
m r d nd ν d
Physical surface ∞
1 * 140.3310 3.1000 1.588870 61.13
2 * 16.1170 15.8352
3 -2522.8076 2.0000 1.773870 47.25
4 * 45.4385 8.5558
5 -66.8335 1.7000 1.433848 95.23
6 43.6375 1.7140
7 42.3398 5.9280 1.804400 39.61
8 -378.8325 d8
9 0.0000 d9
10 52.1540 2.4000 1.772500 49.62
11 265.8146 0.2000
12 59.4781 1.1000 1.963000 24.11
13 18.8996 4.8000 1.731275 27.55
14 232.8799 d14
15 82.9424 1.1000 1.953750 32.33
16 35.0373 5.0000 1.525765 50.70
17 -39.0273 1.5000
18 0.0000 d18 Aperture aperture S
19 -39.0466 1.1000 1.953750 32.33
20 27.5192 3.3000 1.808090 22.74
21 182.0962 0.2000
22 56.9782 2.7000 1.963000 24.11
23 -407.2260 1.5000
24 0.0000 d24
25 26.0879 8.5000 1.497820 82.57
26 -22.3629 1.2000 1.883000 40.66
27 -30.9657 0.2000
28 1576.0034 1.2000 1.834000 37.18
29 20.7858 6.8000 1.497820 82.57
30 -78.3274 1.8000 1.860999 37.10
31 * -75.8550 d31
32 0.0000 35.2000
33 0.0000 2.0000 1.516800 64.13
34 0.0000 1.0651
Image plane ∞

[Lens group focal length]
Lens group Start surface Focal length 1st lens group 1 -22.503
2nd lens group 10 76.247
Third lens group 15 78.275
4th lens group 19 -72.637
5th lens group 25 48.145

In this variable magnification optical system ZL3, each lens surface of the first surface, the second surface, the fourth surface, and the 31st surface is formed in an aspherical shape. Table 10 below shows the data of the surface number m and the aspherical surface, that is, the values of the conical constant K and the aspherical constants A4 to A12.

(Table 10)
[Aspherical data]
First side K = 1.000
A4 = 4.25491E-06 A6 = -4.84680E-09 A8 = 5.09007E-12
A10 ＝ -2.74937E-15 A12 ＝ 7.56860E-19 A14 ＝ 0.00000E + 00
Second side K = 0.0000
A4 = 2.95160E-06 A6 = 8.42874E-09 A8 = -1.70913E-11
A10 ＝ -2.10307E-14 A12 ＝ -1.26170E-17 A14 ＝ 0.00000E + 00
Side 4 K = 2.000
A4 = 1.31082E-05 A6 = -2.47332E-09 A8 = 9.40637E-11
A10 ＝ -1.72001E-13 A12 ＝ 3.42270E-16 A14 ＝ 0.00000E + 00
Side 31 K = 1.000
A4 = 1.28263E-05 A6 = 1.08911E-08 A8 = 2.06427E-10
A10 ＝ -8.83154E-13 A12 ＝ 2.93050E-15 A14 ＝ 0.00000E + 00

In this variable magnification optical system ZL3, the axial air spacing d8 and d9 between the first lens group G1 and the second lens group G2, and the axial air spacing d14 and the third lens group G2 between the second lens group G2 and the third lens group G3. The on-axis air gap d18 between the lens group G3 and the fourth lens group G4, the on-axis air distance d24 between the fourth lens group G4 and the fifth lens group G5, and the on-axis of the fifth lens group G5 and the filter FL. The air spacing d31 changes upon scaling and focusing. Table 11 below shows the variable intervals at the wide-angle end state, intermediate focal length state, and telephoto end state at the time of focusing on an infinity object, focusing on a short-range object, and focusing on the closest object, respectively. Indicates a value.

(Table 11)
[Variable interval data]
-When focusing on an infinite object-
Wide-angle end state Intermediate focal length state Telephoto end state f 14.400 18.000 20.000 23.300
d0 ∞ ∞ ∞ ∞
d8 25.0258 12.9539 7.9550 1.5000
d9 0.0000 0.0000 0.0000 0.0000
d14 5.9986 9.9520 10.6450 10.4616
d18 3.3743 6.3751 7.4841 8.2905
d24 7.0481 2.6418 1.2253 0.0000
d31 0.5000 5.4031 8.6154 14.3923

-When focusing on short-range objects-
Wide-angle end state Intermediate focal length state Telephoto end state β -0.025 -0.025 -0.025 -0.025
d0 543.4416 688.5066 768.9767 901.6419
d8 25.0258 12.9539 7.9550 1.5000
d9 0.8802 0.7142 0.6565 0.5876
d14 5.1183 9.2378 9.9885 9.8739
d18 3.3743 6.3751 7.4841 8.2905
d24 7.0481 2.6418 1.2253 0.0000
d31 0.5000 5.4031 8.6154 14.3923

-When the closest object is in focus-
Wide-angle end state Intermediate focal length state Telephoto end state β -0.106 -0.129 -0.142 -0.165
d0 110.2525 114.7733 116.1976 117.4763
d8 25.0258 12.9539 7.9550 1.5000
d9 3.5539 3.4989 3.5405 3.6597
d14 2.4447 6.4532 7.1046 6.8019
d18 3.3743 6.3751 7.4841 8.2905
d24 7.0481 2.6418 1.2253 0.0000
d31 0.5000 5.4031 8.6154 14.3923

Table 12 below shows the values corresponding to each conditional expression in the variable magnification optical system ZL3. In the variable magnification optical system ZL3, the specific negative lens is the biconcave negative lens L13, and the specific lenses are the biconvex positive lens L51 and the biconvex positive lens L54.

(Table 12)
Σν1n = 203.61
Σ (ν1n × f1n) =-10400.130
STLw = 85.957
fL1 = -31.209
fL2 = -57.658

[Conditional expression correspondence value]
(1) ν1n = 95.23
(2) nL2 / nL1 = 1.116
(3) N1n = 3
(4) 2ωw = 114.733 °
(5) nL1 = 1.589
(6) fw × (−f1) / Fnow = 111.353 mm ²
(7) (L1r2 + L1r1) / (L1r2-L1r1) =-1.260
(8) (Σν1n) / N1n = 67.870
(9) (Σ (ν1n × f1n)) / (N1n × f1) = 154.058
(10) Bfw / fw = 2.645
(11) STLw / TLw = 0.527
(12) (-f1) / fw = 1.563
(13) (-f1) / ft = 0.966
(14) fL1 / f1 = 1.387
(15) fL2 / f1 = 2.562
(16) TLw / Bfw = 4.279
(17) (L2r2 + L2r1) / (L2r2-L2r1) =-0.965
(18) (L3r2 + L3r1) / (L3r2-L3r1) = -0.210
(19) νr = 82.57
(20) Fnow = 2.91
(21) Fnot = 2.91

As described above, the variable magnification optical system ZL3 satisfies all of the above conditional expressions (1) to (21).

FIG. 6 shows various aberration diagrams in the wide-angle end state and the telephoto end state when the variable magnification optical system ZL3 is in focus at an infinity object. From these various aberration diagrams, it can be seen that the variable magnification optical system ZL3 satisfactorily corrects various aberrations from the wide-angle end state to the telephoto end state and has excellent imaging performance.

[Fourth Example]
FIG. 7 is a diagram showing a configuration of the variable magnification optical system ZL4 according to the fourth embodiment. The variable magnification optical system ZL4 is composed of a first lens group G1 having a negative refractive power and a rear group GR having a positive refractive power in order from the object side. Further, the rear group GR includes a second lens group G2 having a positive refractive power, a third lens group G3 having a positive refractive power, and a fourth lens group G4 having a negative refractive power in order from the object side. It is composed of a fifth lens group G5 having a positive refractive power.

In this variable magnification optical system ZL4, the first lens group G1 has a negative meniscus lens shape in which the lens surface on the object side and the lens surface on the image side are formed in an aspherical shape in order from the object side, and the convex surface is directed toward the object side. Aspherical negative lens L11, an aspherical negative lens L12 having a negative meniscus lens shape in which the lens surface on the image side is formed in an aspherical shape and a convex surface facing the object side, a biconcave negative lens L13, and a biconvex positive lens L14. It is composed of. Further, the second lens group G2 is a junction lens in which a positive meniscus lens L21 having a convex surface facing the object side, a negative meniscus lens L22 having a convex surface facing the object side, and a biconvex positive lens L23 are joined in order from the object side. It is composed of. Further, the third lens group G3 is composed of a junction lens in which a negative meniscus lens L31 having a convex surface facing the object side and a biconvex positive lens L32 are joined in order from the object side. Further, the fourth lens group G4 is composed of a junction lens in which a biconcave negative lens L41 and a biconvex positive lens L42 are joined in order from the object side, and a positive meniscus lens L43 having a convex surface facing the object side. Further, the fifth lens group G5 includes a junction lens in which a biconvex positive lens L51 and a negative meniscus lens L52 having a concave surface facing the object side are joined in order from the object side, and a negative meniscus lens L53 having a convex surface facing the object side. The biconvex regular lens L54 and the lens surface on the image side are formed in an aspherical shape, and the lens surface is formed by joining the aspherical positive lens L55 in the shape of a positive meniscus lens with the concave surface facing the object side. A filter FL is arranged between the fifth lens group G5 and the image plane I.

Further, in the variable magnification optical system ZL4, when the magnification is changed from the wide-angle end state to the telescopic end state, the distance between the first lens group G1 and the second lens group G2 is reduced, and the second lens group G2 and the third lens group are reduced. The distance from G3 changes, the distance between the third lens group G3 and the fourth lens group G4 increases, the distance between the fourth lens group G4 and the fifth lens group G5 decreases, and the distance from the fifth lens group G5 The first lens group G1 moves to the image side so that the distance (back focus) from the image plane I increases, and the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 moves to the object side. The aperture diaphragm S is arranged between the third lens group G3 and the fourth lens group G4, and moves together with the third lens group G3 at the time of scaling.

Further, the variable magnification optical system ZL4 is configured to focus from an infinity object to a short-distance object by moving the second lens group G2 to the image side.

Table 13 below lists the specifications of the variable magnification optical system ZL4.

In Table 13, the 18th surface shows the aperture stop S, and the 9th, 24th, and 32nd surfaces show virtual surfaces. Further, a secondary diaphragm can be arranged on the 24th surface.

When the filter is arranged on the object side of the variable magnification optical system ZL4, it is arranged at a position 6.10 mm away from the first surface on the object side.

(Table 13) Fourth Example [Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f = 14.400 ~ 18.000 ~ 20.000 ~ 23.300
FNO = 2.91 ~ 2.91 ~ 2.91 ~ 2.91
2ω (°) = 114.734 ~ 100.512 ~ 93.875 ~ 84.519
Ymax = 21.600 ~ 21.600 ~ 21.600 ~ 21.600
TL (air equivalent length) = 159.177 ~ 154.664 ~ 153.790 ~ 153.659
Bf (air equivalent length) = 38.070 ~ 43.957 ~ 47.366 ~ 53.184

[Lens data]
m r d nd ν d
Physical surface ∞
1 * 90.3166 3.1000 1.677980 54.89
2 * 17.5651 13.1700
3 174.6872 2.0000 1.882023 37.22
4 * 32.3261 10.9488
5 -40.1458 1.7000 1.433848 95.23
6 63.0439 0.2488
7 49.0293 5.3084 1.953750 32.33
8 -272.4542 d8
9 0.0000 d9
10 52.7250 3.4795 1.850000 27.03
11 905.8749 0.2000
12 63.2104 1.1000 1.963000 24.11
13 19.5101 5.0000 1.647690 33.72
14 -605.1149 d14
15 131.6961 1.1000 1.903660 31.27
16 41.1798 4.8000 1.516800 64.13
17 -33.5987 1.5000
18 0.0000 d18 Aperture aperture S
19 -33.4463 1.1000 1.953750 32.33
20 28.7483 3.7000 1.808090 22.74
21 -4455.8379 0.2000
22 56.8591 2.3000 1.963000 24.11
23 1989.0932 1.5000
24 0.0000 d24
25 27.9660 8.7000 1.497820 82.57
26 -21.3402 1.2000 1.883000 40.66
27 -29.4982 0.2000
28 833.0842 1.2000 1.834000 37.18
29 21.2365 6.7000 1.497820 82.57
30 -131.0269 1.8000 1.860999 37.10
31 * -81.9522 d31
32 0.0000 35.2000
33 0.0000 2.0000 1.516800 64.13
34 0.0000 1.3049
Image plane ∞

[Lens group focal length]
Lens group Start surface Focal length 1st lens group 1 -20.675
2nd lens group 10 64.283
Third lens group 15 77.240
4th lens group 19 -64.451
5th lens group 25 46.308

In this variable magnification optical system ZL4, each lens surface of the first surface, the second surface, the fourth surface, and the 31st surface is formed in an aspherical shape. Table 14 below shows the data of the surface number m and the aspherical surface, that is, the values of the conical constant K and the aspherical constants A4 to A12.

(Table 14)
[Aspherical data]
First side K = 1.000
A4 = 9.81343E-06 A6 = -2.00352E-08 A8 = 2.68089E-11
A10 ＝ -1.91082E-14 A12 ＝ 6.61500E-18 A14 ＝ 0.00000E + 00
Second side K = 0.0000
A4 = 9.32337E-06 A6 = 3.93185E-11 A8 = -4.76302E-11
A10 ＝ -1.21872E-13 A12 ＝ 2.94780E-16 A14 ＝ 0.00000E + 00
Side 4 K = 2.000
A4 = 1.36041E-05 A6 = 4.77634E-09 A8 = 6.06428E-11
A10 = 4.61232E-13 A12 = -1.15710E-15 A14 = 0.00000E + 00
Side 31 K = 1.000
A4 = 1.19337E-05 A6 = 1.13335E-08 A8 = 1.45175E-10
A10 ＝ -5.29199E-13 A12 ＝ 1.81530E-15 A14 ＝ 0.00000E + 00

In this variable magnification optical system ZL4, the axial air spacing d8 and d9 between the first lens group G1 and the second lens group G2, and the axial air spacing d14 and the third lens group G2 between the second lens group G2 and the third lens group G3. The on-axis air gap d18 between the lens group G3 and the fourth lens group G4, the on-axis air distance d24 between the fourth lens group G4 and the fifth lens group G5, and the on-axis of the fifth lens group G5 and the filter FL. The air spacing d31 changes upon scaling and focusing. Table 15 below shows the variable intervals at each focal length in the wide-angle end state, intermediate focal length state, and telephoto end state at the time of focusing on an infinity object, focusing on a short-range object, and focusing on the closest object, respectively. Indicates a value.

(Table 15)
[Variable interval data]
-When focusing on an infinite object-
Wide-angle end state Intermediate focal length state Telephoto end state f 14.400 18.000 20.000 23.300
d0 ∞ ∞ ∞ ∞
d8 22.4312 11.5043 7.0971 1.5000
d9 0.0000 0.0000 0.0000 0.0000
d14 6.4000 9.7974 10.2841 9.7673
d18 3.1355 4.8832 5.7872 6.9523
d24 6.8852 2.2657 1.0000 0.0000
d31 0.5000 6.3273 9.7040 15.5208

-When focusing on short-range objects-
Wide-angle end state Intermediate focal length state Telephoto end state β -0.025 -0.025 -0.025 -0.025
d0 543.9177 689.0584 769.5276 902.1634
d8 22.4312 11.5043 7.0971 1.5000
d9 0.7514 0.5958 0.5433 0.4811
d14 5.6486 9.2017 9.7408 9.2862
d18 3.1355 4.8832 5.7872 6.9523
d24 6.8852 2.2657 1.0000 0.0000
d31 0.5000 6.3273 9.7040 15.5208

-When the closest object is in focus-
Wide-angle end state Intermediate focal length state Telephoto end state β -0.103 -0.126 -0.139 -0.163
d0 114.0413 118.5550 119.4285 119.5597
d8 22.4312 11.5043 7.0971 1.5000
d9 2.9730 2.8628 2.8851 2.9744
d14 3.4270 6.9346 7.3990 6.7929
d18 3.1355 4.8832 5.7872 6.9523
d24 6.8852 2.2657 1.0000 0.0000
d31 0.5000 6.3273 9.7040 15.5208

Table 16 below shows the values corresponding to each conditional expression in the variable magnification optical system ZL4. In this variable magnification optical system ZL4, the specific negative lens is the biconcave negative lens L13, and the specific lenses are the biconvex positive lens L51 and the biconvex positive lens L54.

(Table 16)
Σν1n = 187.34
Σ (ν1n × f1n) =-8838.345
STLw = 82.487
fL1 = -32.727
fL2 = -45.270

[Conditional expression correspondence value]
(1) ν1n = 95.23
(2) nL2 / nL1 = 1.122
(3) N1n = 3
(4) 2ωw = 114.734 °
(5) nL1 = 1.678
(6) fw × (−f1) / Fnow = 102.308mm ²
(7) (L1r2 + L1r1) / (L1r2-L1r1) = -1.483
(8) (Σν1n) /N1n=62.447
(9) (Σ (ν1n × f1n)) / (N1n × f1) = 142.498
(10) Bfw / fw = 2.644
(11) STLw / TLw = 0.518
(12) (-f1) / fw = 1.436
(13) (-f1) / ft = 0.887
(14) fL1 / f1 = 1.583
(15) fL2 / f1 = 2.190
(16) TLw / Bfw = 4.181
(17) (L2r2 + L2r1) / (L2r2-L2r1) =-1.454
(18) (L3r2 + L3r1) / (L3r2-L3r1) = 0.222
(19) νr = 82.57
(20) Fnow = 2.91
(21) Fnot = 2.91

As described above, the variable magnification optical system ZL4 satisfies all of the above conditional expressions (1) to (21).

FIG. 8 shows various aberration diagrams in the wide-angle end state and the telephoto end state when the variable magnification optical system ZL4 is in focus at an infinity object. From these various aberration diagrams, it can be seen that the variable magnification optical system ZL4 satisfactorily corrects various aberrations from the wide-angle end state to the telephoto end state and has excellent imaging performance.

[Fifth Example]
FIG. 9 is a diagram showing the configuration of the variable magnification optical system ZL5 according to the fifth embodiment. The variable magnification optical system ZL5 is composed of a first lens group G1 having a negative refractive power and a rear group GR having a positive refractive power in order from the object side. Further, the rear group GR includes a second lens group G2 having a positive refractive power, a third lens group G3 having a positive refractive power, and a fourth lens group G4 having a negative refractive power in order from the object side. It is composed of a fifth lens group G5 having a positive refractive power.

In this variable magnification optical system ZL5, the first lens group G1 has a negative meniscus lens shape in which the lens surface on the object side and the lens surface on the image side are formed in an aspherical shape in order from the object side, and the convex surface is directed toward the object side. Aspherical negative lens L11, an aspherical negative lens L12 having a negative meniscus lens shape in which the lens surface on the image side is formed in an aspherical shape and a convex surface facing the object side, a biconcave negative lens L13, and a biconvex positive lens L14. It is composed of. Further, the second lens group G2 is a junction lens in which a positive meniscus lens L21 having a convex surface facing the object side, a negative meniscus lens L22 having a convex surface facing the object side, and a biconvex positive lens L23 are joined in order from the object side. It is composed of. Further, the third lens group G3 is composed of a junction lens in which a negative meniscus lens L31 having a convex surface facing the object side and a biconvex positive lens L32 are joined in order from the object side. Further, the fourth lens group G4 is composed of a junction lens in which a biconcave negative lens L41 and a biconvex positive lens L42 are joined in order from the object side, and a positive meniscus lens L43 having a convex surface facing the object side. Further, the fifth lens group G5 includes a junction lens in which a biconvex positive lens L51 and a negative meniscus lens L52 having a concave surface facing the object side are joined in order from the object side, and a plano-concave negative lens having a flat surface facing the object side. It is composed of a bonded lens in which the L53, the biconvex positive lens L54, and the lens surface on the image side are formed in an aspherical shape, and the aspherical positive lens L55 in the shape of a positive meniscus lens with the concave surface facing the object side is joined. A filter FL is arranged between the fifth lens group G5 and the image plane I.

Further, in the variable magnification optical system ZL5, when the magnification is changed from the wide-angle end state to the telescopic end state, the distance between the first lens group G1 and the second lens group G2 is reduced, and the second lens group G2 and the third lens group are reduced. The distance from G3 changes, the distance between the third lens group G3 and the fourth lens group G4 increases, the distance between the fourth lens group G4 and the fifth lens group G5 decreases, and the distance from the fifth lens group G5 The first lens group G1 moves to the image side so that the distance (back focus) from the image plane I increases, and the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 moves to the object side. The aperture diaphragm S is arranged between the third lens group G3 and the fourth lens group G4, and moves together with the third lens group G3 at the time of scaling.

Further, the variable magnification optical system ZL5 is configured to focus from an infinity object to a short-distance object by moving the second lens group G2 to the image side.

Table 17 below lists the specifications of the variable magnification optical system ZL5.

In Table 17, the 18th surface shows the aperture stop S, and the 9th, 24th, and 32nd surfaces show virtual surfaces. Further, a secondary diaphragm can be arranged on the 24th surface.

When the filter is arranged on the object side of the variable magnification optical system ZL5, it is arranged at a position 6.10 mm away from the first surface on the object side.

(Table 17) Fifth Example [Overall Specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f = 14.398 ~ 17.997 ~ 19.996 ~ 23.295
FNO = 2.91 ~ 2.91 ~ 2.91 ~ 2.91
2ω (°) = 114.745 ~ 100.443 ~ 93.827 ~ 84.532
Ymax = 21.600 ~ 21.600 ~ 21.600 ~ 21.600
TL (air conversion length) = 160.086 ~ 155.358 ~ 154.117 ~ 153.530
Bf (air equivalent length) = 38.011 ~ 43.671 ~ 47.032 ~ 52.761

[Lens data]
m r d nd ν d
Physical surface ∞
1 * 142.8958 3.1000 1.622910 58.30
2 * 17.5350 13.2834
3 132.6436 2.0000 1.882023 37.22
4 * 33.1818 10.8088
5 -41.0334 1.7000 1.433848 95.23
6 46.0617 0.7860
7 44.4748 5.7377 1.902650 35.72
8 -235.5192 d8
9 0.0000 d9
10 42.7013 2.6873 1.805180 25.45
11 522.0903 0.2000
12 83.2170 1.1000 1.963000 24.11
13 19.3467 5.0000 1.647690 33.72
14 -399.2039 d14
15 102.8869 1.1000 1.903660 31.27
16 40.4334 5.0000 1.516800 64.13
17 -34.8882 1.5000
18 0.0000 d18 Aperture aperture S
19 -34.1551 1.1000 1.953750 32.33
20 27.1687 3.7000 1.808090 22.74
21 -8566.3566 0.2000
22 56.2695 2.3000 1.963000 24.11
23 605.9610 1.5000
24 0.0000 d24
25 27.0443 8.6000 1.497820 82.57
26 -21.2587 1.2000 1.834810 42.73
27 -29.8675 0.2000
28 0.0000 1.2000 1.834000 37.18
29 21.0339 6.7000 1.497820 82.57
30 -117.6080 1.8000 1.860999 37.10
31 * -78.0322 d31
32 0.0000 35.2000
33 0.0000 2.0000 1.516800 64.13
34 0.0000 0.9924
Image plane ∞

[Lens group focal length]
Lens group Start surface Focal length 1st lens group 1 -21.334
2nd lens group 10 68.859
Third lens group 15 71.237
4th lens group 19 -61.116
5th lens group 25 46.502

In this variable magnification optical system ZL5, each lens surface of the first surface, the second surface, the fourth surface, and the 31st surface is formed in an aspherical shape. Table 18 below shows the data of the surface number m and the aspherical surface, that is, the values of the conical constant K and the aspherical constants A4 to A12.

(Table 18)
[Aspherical data]
First side K = 1.000
A4 = 1.15893E-05 A6 = -1.94243E-08 A8 = 2.17289E-11
A10 ＝ -1.31603E-14 A12 ＝ 3.82590E-18 A14 ＝ 0.00000E + 00
Second side K = 0.0000
A4 = 8.59688E-06 A6 = 1.24322E-08 A8 = -2.07525E-11
A10 ＝ -2.35847E-13 A12 ＝ 3.68790E-16 A14 ＝ 0.00000E + 00
Side 4 K = 2.000
A4 = 1.30779E-05 A6 = -3.01480E-10 A8 = 4.09540E-11
A10 = 4.27730E-13 A12 = -7.83650E-16 A14 = 0.00000E + 00
Side 31 K = 1.000
A4 = 1.23681E-05 A6 = 1.27283E-08 A8 = 1.60295E-10
A10 ＝ -6.40573E-13 A12 ＝ 2.30490E-15 A14 ＝ 0.00000E + 00

In this variable magnification optical system ZL5, the axial air spacing d8 and d9 between the first lens group G1 and the second lens group G2, and the axial air spacing d14 and third between the second lens group G2 and the third lens group G3. The on-axis air gap d18 between the lens group G3 and the fourth lens group G4, the on-axis air distance d24 between the fourth lens group G4 and the fifth lens group G5, and the on-axis of the fifth lens group G5 and the filter FL. The air spacing d31 changes upon scaling and focusing. Table 19 below shows the variable intervals at the wide-angle end state, intermediate focal length state, and telephoto end state at the time of focusing on an infinity object, focusing on a short-range object, and focusing on the closest object, respectively. Indicates a value.

(Table 19)
[Variable interval data]
-When focusing on an infinite object-
Wide-angle end state Intermediate focal length state Telephoto end state f 14.398 17.997 19.996 23.295
d0 ∞ ∞ ∞ ∞
d8 23.4594 12.0282 7.3795 1.5000
d9 0.0000 0.0000 0.0000 0.0000
d14 5.9621 10.0114 10.4817 10.0986
d18 3.2198 4.9501 5.7201 6.6670
d24 6.9306 2.1947 1.0000 0.0000
d31 0.5000 6.1010 9.5647 15.3030

-When focusing on short-range objects-
Wide-angle end state Intermediate focal length state Telephoto end state β -0.025 -0.025 -0.025 -0.025
d0 543.8708 688.9750 769.4422 902.0778
d8 23.4594 12.0282 7.3795 1.5000
d9 0.7957 0.6366 0.5823 0.5176
d14 5.1665 9.3748 9.8994 9.5810
d18 3.2198 4.9501 5.7201 6.6670
d24 6.9306 2.1947 1.0000 0.0000
d31 0.5000 6.1010 9.5647 15.3030

-When the closest object is in focus-
Wide-angle end state Intermediate focal length state Telephoto end state β -0.104 -0.126 -0.140 -0.163
d0 113.1249 117.8508 119.0910 119.6750
d8 23.4594 12.0282 7.3795 1.5000
d9 3.1636 3.0691 3.0949 3.1924
d14 2.7985 6.9423 7.3868 6.9061
d18 3.2198 4.9501 5.7201 6.6670
d24 6.9306 2.1947 1.0000 0.0000
d31 0.5000 6.1010 9.5647 15.3030

Table 20 below shows the values corresponding to each conditional expression in the variable magnification optical system ZL5. In the variable magnification optical system ZL5, the specific negative lens is the biconcave negative lens L13, and the specific lenses are the biconvex positive lens L51 and the biconvex positive lens L54.

(Table 20)
Σν1n = 190.75
Σ (ν1n × f1n) = -8509.219
STLw = 83.425
fL1 = -32.395
fL2 = -50.648

[Conditional expression correspondence value]
(1) ν1n = 95.23
(2) nL2 / nL1 = 1.160
(3) N1n = 3
(4) 2ωw = 114.745 °
(5) nL1 = 1.623
(6) fw × (−f1) / Fnow = 105.570mm ²
(7) (L1r2 + L1r1) / (L1r2-L1r1) =-1.280
(8) (Σν1n) /N1n=63.583
(9) (Σ (ν1n × f1n)) / (N1n × f1) = 132.952
(10) Bfw / fw = 2.640
(11) STLw / TLw = 0.521
(12) (-f1) / fw = 1.482
(13) (-f1) /ft=0.916
(14) fL1 / f1 = 1.518
(15) fL2 / f1 = 2.374
(16) TLw / Bfw = 4.212
(17) (L2r2 + L2r1) / (L2r2-L2r1) =-1.667
(18) (L3r2 + L3r1) / (L3r2-L3r1) = 0.058
(19) νr = 82.57
(20) Fnow = 2.91
(21) Fnot = 2.91

As described above, the variable magnification optical system ZL5 satisfies all of the above conditional expressions (1) to (21).

FIG. 10 shows various aberration diagrams in the wide-angle end state and the telephoto end state when the variable magnification optical system ZL5 is in focus at an infinity object. From these various aberration diagrams, it can be seen that the variable magnification optical system ZL5 satisfactorily corrects various aberrations from the wide-angle end state to the telephoto end state and has excellent imaging performance.

[Sixth Example]
FIG. 11 is a diagram showing a configuration of the variable magnification optical system ZL6 according to the sixth embodiment. The variable magnification optical system ZL6 is composed of a first lens group G1 having a negative refractive power and a rear group GR having a positive refractive power in order from the object side. Further, the rear group GR includes a second lens group G2 having a positive refractive power, a third lens group G3 having a positive refractive power, and a fourth lens group G4 having a negative refractive power in order from the object side. It is composed of a fifth lens group G5 having a positive refractive power.

In this variable magnification optical system ZL6, the first lens group G1 has a negative meniscus lens shape in which the lens surface on the object side and the lens surface on the image side are formed in an aspherical shape in order from the object side, and the convex surface is directed toward the object side. Aspherical negative lens L11, the lens surface on the image side is formed in an aspherical shape, and the negative meniscus lens-shaped aspherical negative lens L12 with the convex surface facing the object side, the biconcave negative lens L13, and the convex surface on the object side. It is composed of a facing plano-convex regular lens L14. Further, the second lens group G2 is composed of a junction lens in which a negative meniscus lens L21 having a convex surface facing the object side and a biconvex positive lens L22 are joined in order from the object side. Further, the third lens group G3 is composed of a junction lens in which a negative meniscus lens L31 having a convex surface facing the object side and a biconvex positive lens L32 are joined in order from the object side. Further, the fourth lens group G4 is composed of a negative meniscus lens L41 having a concave surface facing the object side in order from the object side, and a junction lens in which a biconcave negative lens L42 and a biconvex positive lens L43 are joined. Further, the fifth lens group G5 includes a junction lens in which a biconvex positive lens L51 and a negative meniscus lens L52 having a concave surface facing the object side are joined in order from the object side, and a negative meniscus lens L53 having a convex surface facing the object side. It is composed of a bonded lens in which the biconvex positive lens L54 is joined, and an aspherical negative lens L55 having a negative meniscus lens shape in which the lens surface on the image side is formed in an aspherical shape and the concave surface is directed toward the object side. A filter FL is arranged between the fifth lens group G5 and the image plane I.

Further, in the variable magnification optical system ZL6, when the magnification is changed from the wide-angle end state to the telescopic end state, the distance between the first lens group G1 and the second lens group G2 is reduced, and the second lens group G2 and the third lens group are reduced. The distance from G3 changes, the distance between the third lens group G3 and the fourth lens group G4 increases, the distance between the fourth lens group G4 and the fifth lens group G5 decreases, and the distance from the fifth lens group G5 The first lens group G1 moves to the image side so that the distance (back focus) from the image plane I increases, and the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 moves to the object side. The aperture diaphragm S is arranged between the third lens group G3 and the fourth lens group G4, and moves together with the fourth lens group G4 at the time of scaling.

Further, the variable magnification optical system ZL6 is configured to focus from an infinity object to a short-distance object by moving the second lens group G2 to the image side.

Table 21 below lists the specifications of the variable magnification optical system ZL6.

In Table 21, the 16th surface shows the aperture stop S, and the 9th, 22nd, and 31st surfaces show virtual surfaces. Further, a secondary diaphragm can be arranged on the 22nd surface.

When the filter is arranged on the object side of the variable magnification optical system ZL6, it is arranged at a position 6.10 mm away from the first surface on the object side.

(Table 21) 6th Example [Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f = 14.400 ~ 18.000 ~ 20.000 ~ 23.300
FNO = 2.91 ~ 2.91 ~ 2.91 ~ 2.91
2ω (°) = 114.742 ~ 100.593 ~ 93.838 ~ 84.517
Ymax = 21.600 ~ 21.600 ~ 21.600 ~ 21.600
TL (air equivalent length) = 155.513 ~ 152.665 ~ 152.329 ~ 152.315
Bf (air equivalent length) = 38.123 ~ 43.258 ~ 46.065 ~ 51.259

[Lens data]
m r d nd ν d
Physical surface ∞
1 * 201.4901 3.1000 1.516800 64.13
2 * 15.2473 15.4015
3 603.8279 2.0000 1.795256 45.25
4 * 42.2007 8.2350
5 -63.7303 1.7000 1.497820 82.57
6 37.4616 0.2008
7 34.7568 5.6708 1.883000 40.66
8 0.0000 d8
9 0.0000 d9
10 44.7965 1.1000 1.963000 24.11
11 20.5527 4.6000 1.698950 30.13
12 -190.9319 d12
13 49.0558 1.1000 1.963000 24.11
14 29.9609 5.8000 1.516800 64.13
15 -38.9734 d15
16 0.0000 2.7000 Aperture aperture S
17 -51.6576 1.1000 1.883000 40.66
18 -116.3501 1.3131
19 -38.6822 1.1000 1.883000 40.66
20 25.7541 3.9000 1.963000 24.11
21 -180.3900 1.2000
22 0.0000 d22
23 31.7152 8.6000 1.497820 82.57
24-21.9588 1.2000 1.834810 42.73
25 -35.9397 0.2000
26 64.5388 1.2000 1.902650 35.72
27 23.4943 10.0000 1.497820 82.57
28 -24.5354 0.2000
29 -29.0690 1.2000 1.860999 37.10
30 * -47.9865 d30
31 0.0000 35.2000
32 0.0000 2.0000 1.516800 64.13
33 0.0000 1.0502
Image plane ∞

[Lens group focal length]
Lens group Start surface Focal length 1st lens group 1-21.025
2nd lens group 10 81.077
Third lens group 13 56.282
4th lens group 17 -42.270
5th lens group 23 37.527

In this variable magnification optical system ZL6, each lens surface of the first surface, the second surface, the fourth surface, and the thirty surface is formed in an aspherical shape. Table 22 below shows the data of the surface number m and the aspherical surface, that is, the values of the conical constant K and the aspherical constants A4 to A12.

(Table 22)
[Aspherical data]
First side K = 1.000
A4 = 5.05392E-06 A6 = -4.62096E-09 A8 = 4.79306E-12
A10 ＝ -2.76369E-15 A12 ＝ 8.66720E-19 A14 ＝ 0.00000E + 00
Second side K = 0.0000
A4 = 3.76598E-06 A6 = 8.88285E-09 A8 = -7.50984E-12
A10 ＝ -1.78288E-14 A12 ＝ -8.37710E-17 A14 ＝ 0.00000E + 00
Side 4 K = 2.000
A4 = 1.41674E-05 A6 = 2.34561E-09 A8 = 1.37528E-10
A10 ＝ -4.20057E-13 A12 ＝ 1.08030E-15 A14 ＝ 0.00000E + 00
Side 30 K = 1.000
A4 = 9.98516E-06 A6 = 4.68513E-09 A8 = 1.00957E-10
A10 ＝ -3.98485E-13 A12 ＝ 9.87550E-16 A14 ＝ 0.00000E + 00

In this variable magnification optical system ZL6, the axial air spacing d8 and d9 between the first lens group G1 and the second lens group G2, and the axial air spacing d12 and third between the second lens group G2 and the third lens group G3. The on-axis air spacing d15 between the lens group G3 and the fourth lens group G4, the on-axis air spacing d22 between the fourth lens group G4 and the fifth lens group G5, and the on-axis of the fifth lens group G5 and the filter FL. The air spacing d30 changes upon scaling and focusing. Table 23 below shows the variable intervals at each focal length in the wide-angle end state, intermediate focal length state, and telephoto end state at the time of focusing on an infinity object, focusing on a short-range object, and focusing on the nearest object, respectively. Indicates a value.

(Table 23)
[Variable interval data]
-When focusing on an infinite object-
Wide-angle end state Intermediate focal length state Telephoto end state f 14.400 18.000 20.000 23.300
d0 ∞ ∞ ∞ ∞
d8 20.6874 10.5726 6.5831 1.5000
d9 0.0000 0.0000 0.0000 0.0000
d12 6.6363 9.9733 10.6667 10.4559
d15 1.5000 3.6282 4.9450 6.2785
d22 5.7449 2.4116 1.2488 0.0000
d30 0.5000 5.5629 8.4375 13.6950

-When focusing on short-range objects-
Wide-angle end state Intermediate focal length state Telephoto end state β -0.025 -0.025 -0.025 -0.025
d0 544.5834 689.3773 769.7371 902.2544
d8 20.6874 10.5726 6.5831 1.5000
d9 0.7871 0.6675 0.6213 0.5623
d12 5.8493 9.3059 10.0454 9.8936
d15 1.5000 3.6282 4.9450 6.2785
d22 5.7449 2.4116 1.2488 0.0000
d30 0.5000 5.5629 8.4375 13.6950

-When the closest object is in focus-
Wide-angle end state Intermediate focal length state Telephoto end state β -0.101 -0.124 -0.138 -0.162
d0 117.7057 120.5537 120.8893 120.9039
d8 20.6874 10.5726 6.5831 1.5000
d9 3.0261 3.1485 3.2479 3.4206
d12 3.6103 6.8249 7.4188 7.0353
d15 1.5000 3.6282 4.9450 6.2785
d22 5.7449 2.4116 1.2488 0.0000
d30 0.5000 5.5629 8.4375 13.6950

Table 24 below shows the values corresponding to each conditional expression in the variable magnification optical system ZL6. In the variable magnification optical system ZL6, the specific negative lens is the biconcave negative lens L13, and the specific lenses are the biconvex positive lens L51 and the biconvex positive lens L54.

(Table 24)
Σν1n = 191.95
Σ (ν1n × f1n) =-8535.853
STLw = 77.732
fL1 = -32.101
fL2 = -57.143

[Conditional expression correspondence value]
(1) ν1n = 82.57
(2) nL2 / nL1 = 1.184
(3) N1n = 3
(4) 2ωw = 114.742 °
(5) nL1 = 1.517
(6) fw × (−f1) / Fnow = 104.042mm ²
(7) (L1r2 + L1r1) / (L1r2-L1r1) =-1.164
(8) (Σν1n) / N1n = 63.983
(9) (Σ (ν1n × f1n)) / (N1n × f1) = 135.328
(10) Bfw / fw = 2.647
(11) STLw / TLw = 0.500
(12) (-f1) / fw = 1.460
(13) (-f1) /ft=0.902
(14) fL1 / f1 = 1.527
(15) fL2 / f1 = 2.718
(16) TLw / Bfw = 4.079
(17) (L2r2 + L2r1) / (L2r2-L2r1) =-1.150
(18) (L3r2 + L3r1) / (L3r2-L3r1) = -0.260
(19) νr = 82.57
(20) Fnow = 2.91
(21) Fnot = 2.91

As described above, the variable magnification optical system ZL6 satisfies all of the above conditional expressions (1) to (21).

FIG. 12 shows various aberration diagrams in the wide-angle end state and the telephoto end state when the variable magnification optical system ZL6 is in focus at an infinity object. From these various aberration diagrams, it can be seen that the variable magnification optical system ZL6 satisfactorily corrects various aberrations from the wide-angle end state to the telephoto end state and has excellent imaging performance.

[7th Example]
FIG. 13 is a diagram showing a configuration of the variable magnification optical system ZL7 according to the seventh embodiment. The variable magnification optical system ZL7 is composed of a first lens group G1 having a negative refractive power and a rear group GR having a positive refractive power in order from the object side. Further, the rear group GR includes a second lens group G2 having a positive refractive power, a third lens group G3 having a positive refractive power, and a fourth lens group G4 having a negative refractive power in order from the object side. It is composed of a fifth lens group G5 having a positive refractive power.

In this variable magnification optical system ZL7, the first lens group G1 has a negative meniscus lens shape in which the lens surface on the object side and the lens surface on the image side are formed in an aspherical shape in order from the object side, and the convex surface is directed toward the object side. Aspherical negative lens L11, an aspherical negative lens L12 having a negative meniscus lens shape in which the lens surface on the image side is formed in an aspherical shape and a convex surface facing the object side, a biconcave negative lens L13, and a biconvex positive lens L14. It is composed of. Further, the second lens group G2 includes a junction lens in which a negative meniscus lens L21 having a convex surface facing the object side and a biconvex positive lens L22 are joined in order from the object side, and a negative meniscus lens L23 having a concave surface facing the object side. It is composed of. Further, the third lens group G3 is composed of a junction lens in which a negative meniscus lens L31 having a convex surface facing the object side and a biconvex positive lens L32 are joined in order from the object side. Further, the fourth lens group G4 is composed of a bonded lens in which a biconcave negative lens L41 and a biconvex positive lens L42 are joined in order from the object side. Further, the fifth lens group G5 includes a junction lens in which a negative meniscus lens L51 having a convex surface facing the object side and a biconvex positive lens L52 are joined in order from the object side, and a negative meniscus lens L53 having a convex surface facing the object side. The biconvex positive lens L54 and the lens surface on the image side are formed in an aspherical shape, and the lens surface is formed by joining the negative meniscus lens-shaped aspherical negative lens L55 with the concave surface facing the object side. A filter FL is arranged between the fifth lens group G5 and the image plane I.

Further, in the variable magnification optical system ZL7, when the magnification is changed from the wide-angle end state to the telescopic end state, the distance between the first lens group G1 and the second lens group G2 is reduced, and the third lens group G3 and the fourth lens group are reduced. The first is such that the distance from the G4 is increased, the distance between the fourth lens group G4 and the fifth lens group G5 is reduced, and the distance (back focus) between the fifth lens group G5 and the image plane I is increased. The lens group G1 moves to the image side, and the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 move to the object side. At the time of scaling, the second lens group G2 and the third lens group G3 move integrally. Further, the aperture diaphragm S is arranged between the third lens group G3 and the fourth lens group G4, and moves together with the fourth lens group G4 at the time of scaling.

Further, the variable magnification optical system ZL7 is configured to focus from an infinity object to a short-distance object by moving the second lens group G2 to the image side.

Table 25 below lists the specifications of the variable magnification optical system ZL7.

In Table 25, the 18th plane shows the aperture stop S, and the 9th, 22nd, and 30th planes show virtual planes. Further, a secondary diaphragm can be arranged on the 22nd surface.

When the filter is arranged on the object side of the variable magnification optical system ZL7, it is arranged at a position 6.10 mm away from the first surface on the object side.

(Table 25) Example 7 [Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f = 14.400 ~ 18.000 ~ 20.000 ~ 23.300
FNO = 2.91 ~ 2.91 ~ 2.91 ~ 2.91
2ω (°) = 114.733 ~ 100.450 ~ 93.835 ~ 84.548
Ymax = 21.600 ~ 21.600 ~ 21.600 ~ 21.600
TL (air equivalent length) = 162.664 ~ 155.206 ~ 153.078 ~ 151.580
Bf (air equivalent length) = 38.030 ~ 42.928 ~ 45.480 ~ 49.783

[Lens data]
m r d nd ν d
Physical surface ∞
1 * 115.7220 3.1000 1.622910 58.30
2 * 16.6323 14.8987
3 370.8034 2.0000 1.882023 37.22
4 * 41.1683 9.2575
5 -46.1330 1.6000 1.497820 82.57
6 80.3534 3.1175
7 55.6397 6.7000 1.637964 38.48
8 -73.0750 d8
9 0.0000 d9
10 40.8572 1.1000 1.953721 32.33
11 23.4797 6.2000 1.662956 32.26
12 -46.4852 1.4528
13 -42.2265 1.1000 1.953745 32.33
14 -128.2484 d14
15 38.1116 1.1000 1.963000 24.11
16 23.4511 6.5000 1.520273 68.04
17 -55.7009 d17
18 0.0000 3.8271 Aperture aperture S
19 -56.4383 1.1000 1.919778 33.15
20 23.9956 4.2000 1.808090 22.74
21 -281.4369 1.2000
22 0.0000 d22
23 26.3769 1.2000 1.615813 50.88
24 19.6278 7.5000 1.497820 82.57
25 -40.0111 0.2000
26 439.2276 1.2000 1.756739 39.10
27 20.1301 7.8000 1.497820 82.57
28 -66.7106 1.2000 1.882023 37.22
29 * -87.9719 d29
30 0.0000 35.2000
31 0.0000 2.0000 1.516800 64.13
32 0.0000 1.2022
Image plane ∞

[Lens group focal length]
Lens group Start surface Focal length 1st lens group 1 -22.762
2nd lens group 10 92.534
Third lens group 15 64.107
4th lens group 19 -55.689
5th lens group 23 45.190

In this variable magnification optical system ZL7, each lens surface of the first surface, the second surface, the fourth surface, and the 29th surface is formed in an aspherical shape. Table 26 below shows the data of the surface number m and the aspherical surface, that is, the values of the conical constant K and the aspherical constants A4 to A12.

(Table 26)
[Aspherical data]
First side K = 1.000
A4 = 4.80598E-06 A6 = -2.42564E-09 A8 = 1.78291E-12
A10 = -1.05251E-15 A12 = 6.26000E-19 A14 = 0.00000E + 00
Second side K = 0.0000
A4 = 3.68669E-06 A6 = 1.22584E-08 A8 = 6.05239E-12
A10 = 2.50928E-14 A12 = -1.70140E-16 A14 = 0.00000E + 00
Side 4 K = 1.000
A4 = 1.44539E-05 A6 = -5.00574E-10 A8 = 5.52057E-11
A10 ＝ -5.98876E-14 A12 ＝ 3.04350E-16 A14 ＝ 0.00000E + 00
Side 29 K = 1.000
A4 = 1.07870E-05 A6 = 7.32487E-09 A8 = 1.83159E-10
A10 ＝ -9.56431E-13 A12 ＝ 3.09390E-15 A14 ＝ 0.00000E + 00

In this variable magnification optical system ZL7, the axial air spacing d8 and d9 between the first lens group G1 and the second lens group G2, and the axial air spacing d14 and the third lens group G2 between the second lens group G2 and the third lens group G3. The on-axis air gap d17 between the lens group G3 and the fourth lens group G4, the on-axis air distance d22 between the fourth lens group G4 and the fifth lens group G5, and the on-axis of the fifth lens group G5 and the filter FL. The air spacing d29 changes upon scaling and focusing. Table 27 below shows the variable intervals at each focal length in the wide-angle end state, intermediate focal length state, and telephoto end state at the time of focusing on an infinity object, focusing on a short-range object, and focusing on the closest object, respectively. Indicates a value.

(Table 27)
[Variable interval data]
-When focusing on an infinite object-
Wide-angle end state Intermediate focal length state Telephoto end state f 14.400 18.000 20.000 23.300
d0 ∞ ∞ ∞ ∞
d8 24.3283 11.9508 7.2794 1.5000
d9 0.0000 0.0000 0.0000 0.0000
d14 5.4427 5.4427 5.4427 5.4427
d17 1.5000 3.8035 5.2139 7.3002
d22 5.8094 3.5281 2.1089 0.0000
d29 0.5000 5.2980 7.9112 12.2190

-When focusing on short-range objects-
Wide-angle end state Intermediate focal length state Telephoto end state β -0.025 -0.025 -0.025 -0.025
d0 544.5834 689.3773 770.0044 902.4751
d8 24.3283 11.9508 7.2794 1.5000
d9 0.9072 0.7587 0.7018 0.6289
d14 4.5355 4.6840 4.7409 4.8138
d17 1.5000 3.8035 5.2139 7.3002
d22 5.8094 3.5281 2.1089 0.0000
d29 0.5000 5.2980 7.9112 12.2190

-When the closest object is in focus-
Wide-angle end state Intermediate focal length state Telephoto end state β -0.106 -0.127 -0.139 -0.161
d0 110.5549 118.0123 120.1404 121.6387
d8 24.3283 11.9508 7.2794 1.5000
d9 3.6767 3.6540 3.7024 3.8252
d14 1.7660 1.7887 1.7403 1.6175
d17 1.5000 3.8035 5.2139 7.3002
d22 5.8094 3.5281 2.1089 0.0000
d29 0.5000 5.2980 7.9112 12.2190

Table 28 below shows the values corresponding to each conditional expression in the variable magnification optical system ZL7. In this variable magnification optical system ZL7, the specific negative lens is a biconcave negative lens L13, and the specific lens is a biconvex positive lens L51 and a biconvex positive lens L54.

(Table 28)
Σν1n = 178.09
Σ (ν1n × f1n) =-8640.434
STLw = 83.398
fL1 = -31.562
fL2 = -52.654

[Conditional expression correspondence value]
(1) ν1n = 82.57
(2) nL2 / nL1 = 1.160
(3) N1n = 3
(4) 2ωw = 114.733 °
(5) nL1 = 1.623
(6) fw × (−f1) / Fnow = 112.637mm ²
(7) (L1r2 + L1r1) / (L1r2-L1r1) =-1.336
(8) (Σν1n) /N1n=59.363
(9) (Σ (ν1n × f1n)) / (N1n × f1) = 126.533
(10) Bfw / fw = 2.641
(11) STLw / TLw = 0.550
(12) (-f1) /fp=1.581
(13) (-f1) / ft = 0.977
(14) fL1 / f1 = 1.387
(15) fL2 / f1 = 2.313
(16) TLw / Bfw = 4.277
(17) (L2r2 + L2r1) / (L2r2-L2r1) =-1.250
(18) (L3r2 + L3r1) / (L3r2-L3r1) = 0.271
(19) νr = 82.57
(20) Fnow = 2.91
(21) Fnot = 2.91

As described above, the variable magnification optical system ZL7 satisfies all of the above conditional expressions (1) to (21).

FIG. 14 shows various aberration diagrams of the variable magnification optical system ZL7 in the wide-angle end state and the telephoto end state when the object is in focus at infinity. From these various aberration diagrams, it can be seen that the variable magnification optical system ZL7 satisfactorily corrects various aberrations from the wide-angle end state to the telephoto end state and has excellent imaging performance.

[8th Example]
FIG. 15 is a diagram showing the configuration of the variable magnification optical system ZL8 according to the eighth embodiment. The variable magnification optical system ZL8 is composed of a first lens group G1 having a negative refractive power and a rear group GR having a positive refractive power in order from the object side. Further, the rear group GR is composed of a second lens group G2 having a positive refractive power and a third lens group G3 having a positive refractive power in order from the object side.

In this variable magnification optical system ZL8, the first lens group G1 has a negative meniscus lens shape in which the lens surface on the object side and the lens surface on the image side are formed in an aspherical shape in order from the object side, and the convex surface is directed toward the object side. Aspherical negative lens L11, an aspherical negative lens L12 having a negative meniscus lens shape in which the lens surface on the image side is formed in an aspherical shape and a convex surface facing the object side, a biconcave negative lens L13, and a biconvex positive lens L14. It is composed of. Further, the second lens group G2 is composed of a bonded lens in which a negative meniscus lens L21 having a convex surface facing the object side and a positive meniscus lens L22 having a convex surface facing the object side are joined in order from the object side. Further, the third lens group G3 includes a junction lens in which a negative meniscus lens L31 having a convex surface facing the object side and a biconvex positive lens L32 are joined in order from the object side, a biconcave negative lens L33 and a biconvex positive lens L34. A junction lens, a biconvex positive lens L35, a junction lens in which a negative meniscus lens L36 with a convex surface facing the object side and a positive meniscus lens L37 with a convex surface facing the object side are joined, a biconvex positive lens L38 and a biconcave It is composed of a bonded lens in which a negative lens L39 is joined, and an aspherical positive lens L310 having a positive meniscus lens shape in which a lens surface on the object side is formed in an aspherical shape and a concave surface is directed to the object side. A filter FL is arranged between the third lens group G3 and the image plane I.

Further, in the variable magnification optical system ZL8, when the magnification is changed from the wide-angle end state to the telescopic end state, the distance between the first lens group G1 and the second lens group G2 is reduced, and the second lens group G2 and the third lens group are reduced. The first lens group G1 moves to the image side so that the distance from the G3 decreases and the distance (back focus) between the third lens group G3 and the image plane I increases, and the second lens group G2 and the third lens group G2 and the third lens group G1 move. The lens group G3 moves to the object side. Further, the aperture diaphragm S is located in the third lens group G3 (between the junction lens in which the negative meniscus lens L31 and the biconvex positive lens L32 are bonded and the junction lens in which the biconcave negative lens L33 and the biconvex positive lens L34 are bonded. ), And moves with the third lens group G3 when scaling.

Further, the variable magnification optical system ZL8 is configured to focus from an infinity object to a short-distance object by moving the second lens group G2 to the image side.

Table 29 below lists the specifications of the variable magnification optical system ZL8.

In Table 29, the 16th surface shows the aperture stop S, and the 9th and 20th surfaces show virtual surfaces. Further, a secondary diaphragm can be arranged on the 20th surface.

When the filter is arranged on the object side of the variable magnification optical system ZL8, it is arranged at a position 6.10 mm away from the first surface on the object side.

(Table 29) Example 8 [Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f = 14.400 ~ 16.000 ~ 18.000 ~ 23.300
FNO = 2.91 ~ 2.91 ~ 2.91 ~ 2.91
2ω (°) = 115.176 ~ 108.256 ~ 100.691 ~ 84.861
Ymax = 21.600 ~ 21.600 ~ 21.600 ~ 21.600
TL (air equivalent length) = 137.332 ~ 134.390 ~ 131.934 ~ 129.823
Bf (air equivalent length) = 22.585 ~ 24.937 ~ 27.848 ~ 35.493

[Lens data]
m r d nd ν d
Physical surface ∞
1 * 342.7914 3.0000 1.588870 61.13
2 * 16.1106 11.6048
3 49.2913 2.0000 1.820980 42.50
4 * 25.8983 11.3832
5 -45.4837 1.5000 1.497820 82.57
6 54.3748 0.5376
7 38.8825 6.6444 1.635257 33.41
8 -91.9824 d8
9 0.0000 0.0000
10 33.1746 1.1000 1.963000 24.11
11 19.3866 4.3000 1.654152 32.42
12 119.3997 d12
13 24.1338 1.1000 1.846660 23.80
14 17.5000 6.2000 1.511153 65.39
15 -363.4978 1.5000
16 0.0000 2.8214 Aperture aperture S
17 -41.4313 1.1000 1.953750 32.33
18 27.1802 5.4000 1.846660 23.80
19 -54.0998 0.3995
20 0.0000 -0.3000
21 24.5452 6.0000 1.497820 82.57
22 -55.5602 0.2000
23 51.0776 1.1000 1.834810 42.73
24 17.5706 5.0000 1.497820 82.57
25 163.6668 0.2000
26 37.0379 7.0000 1.497820 82.57
27 -18.4013 1.1000 1.834810 42.73
28 86.5739 3.9979
29 * -60.3503 2.0000 1.860999 37.10
30 -50.2613 d30
31 0.0000 1.6000 1.516800 64.13
32 0.0000 1.0688
Image plane ∞

[Lens group focal length]
Lens group Start surface Focal length 1st lens group 1 -21.915
2nd lens group 9 122.590
Third lens group 13 39.056

In this variable magnification optical system ZL8, each lens surface of the first surface, the second surface, the fourth surface, and the 29th surface is formed in an aspherical shape. Table 30 below shows the data of the surface number m and the aspherical surface, that is, the values of the conical constant K and the aspherical constants A4 to A12.

(Table 30)
[Aspherical data]
First side K = 1.000
A4 = 1.19707E-05 A6 = -1.77697E-08 A8 = 1.6943E-11
A10 ＝ -8.85755E-15 A12 ＝ 1.9766E-18 A14 ＝ 0.00000E + 00
Second side K = 0.0000
A4 = 7.01276E-06 A6 = 2.77908E-08 A8 = 3.97015E-11
A10 = -5.16043E-13 A12 = 6.2126E-16 A14 = 0.00000E + 00
4th side K = 1.3632
A4 = 1.34780E-05 A6 = -1.71246E-09 A8 = 5.11129E-11
A10 = 3.88045E-13 A12 = 1.1914E-18 A14 = 0.00000E + 00
Side 29 K = 1.000
A4 = -2.04742E-05 A6 = -5.88742E-08 A8 = 2.99693E-10
A10 ＝ -3.41851E-12 A12 ＝ 7.3793E-15 A14 ＝ 0.00000E + 00

In this variable magnification optical system ZL8, the axial air gap d8 between the first lens group G1 and the second lens group G2, the axial air gap d12 between the second lens group G2 and the third lens group G3, and the third lens group G3. The axial air gap d30 between the lens group G3 and the filter FL changes during magnification and focusing. Table 31 below shows the variable intervals at the wide-angle end state, intermediate focal length state, and telephoto end state at the time of focusing on an infinity object, focusing on a short-range object, and focusing on the closest object, respectively. Indicates a value.

(Table 31)
[Variable interval data]
-When focusing on an infinite object-
Wide-angle end state Intermediate focal length state Telephoto end state f 14.400 16.000 18.000 23.300
d0 ∞ ∞ ∞ ∞
d8 19.3279 14.5264 9.8351 1.5000
d12 8.5296 8.0374 7.3623 5.9410
d30 20.4803 22.8718 25.7862 33.4872

-When focusing on short-range objects-
Wide-angle end state Intermediate focal length state Telephoto end state β -0.025 -0.025 -0.025 -0.025
d0 547.1797 611.4703 691.7918 904.4881
d8 20.3497 15.4876 10.7327 2.2703
d12 7.5079 7.0762 6.4647 5.1707
d30 20.4803 22.8718 25.7862 33.4872

-When the closest object is in focus-
Wide-angle end state Intermediate focal length state Telephoto end state β -0.091 -0.099 -0.110 -0.142
d0 136.0234 138.9653 141.4208 143.5318
d8 22.8593 18.1510 13.5843 5.5992
d12 4.9982 4.4129 3.6131 1.8418
d30 20.4803 22.8718 25.7862 33.4872

Table 32 below shows the values corresponding to each conditional expression in the variable magnification optical system ZL8. In this variable magnification optical system ZL8, the specific negative lens is a biconcave negative lens L13, and the specific lenses are a biconvex positive lens L35, a positive meniscus lens L37, and a biconvex positive lens L38.

(Table 32)
Σν1n = 186.20
Σ (ν1n × f1n) =-8786.587
STLw = 78.728
fL1 = -28.806
fL2 = -69.134

[Conditional expression correspondence value]
(1) ν1n = 82.57
(2) nL2 / nL1 = 1.146
(3) N1n = 3
(4) 2ωw = 115.176 °
(5) nL1 = 1.589
(6) fw × (−f1) / Fnow = 108.445mm ²
(7) (L1r2 + L1r1) / (L1r2-L1r1) = -1.099
(8) (Σν1n) / N1n = 62.067
(9) (Σ (ν1n × f1n)) / (N1n × f1) = 133.647
(10) Bfw / fw = 1.568
(11) STLw / TLw = 0.573
(12) (-f1) / fw = 1.522
(13) (-f1) / ft = 0.941
(14) fL1 / f1 = 1.314
(15) fL2 / f1 = 3.155
(16) TLw / Bfw = 6.081
(17) (L2r2 + L2r1) / (L2r2-L2r1) =-3.214
(18) (L3r2 + L3r1) / (L3r2-L3r1) = 0.089
(19) νr = 82.57
(20) Fnow = 2.91
(21) Fnot = 2.91

As described above, the variable magnification optical system ZL8 satisfies all of the above conditional expressions (1) to (21).

FIG. 16 shows various aberration diagrams in the wide-angle end state and the telephoto end state when the variable magnification optical system ZL8 is in focus at an infinity object. From these various aberration diagrams, it can be seen that the variable magnification optical system ZL8 satisfactorily corrects various aberrations from the wide-angle end state to the telephoto end state and has excellent imaging performance.

[9th Example]
FIG. 17 is a diagram showing the configuration of the variable magnification optical system ZL9 according to the ninth embodiment. The variable magnification optical system ZL9 is composed of a first lens group G1 having a negative refractive power and a rear group GR having a positive refractive power in order from the object side. Further, the rear group GR includes a second lens group G2 having a positive refractive power, a third lens group G3 having a positive refractive power, and a fourth lens group G4 having a negative refractive power in order from the object side. It is composed of.

In this variable magnification optical system ZL9, the first lens group G1 has a negative meniscus lens shape in which the lens surface on the object side and the lens surface on the image side are formed in an aspherical shape in order from the object side, and the convex surface is directed toward the object side. Aspherical negative lens L11, an aspherical negative lens L12 having a negative meniscus lens shape in which the lens surface on the image side is formed in an aspherical shape and a convex surface facing the object side, a biconcave negative lens L13, and a biconvex positive lens L14. It is composed of. Further, the second lens group G2 is composed of a bonded lens in which a negative meniscus lens L21 having a convex surface facing the object side and a positive meniscus lens L22 having a convex surface facing the object side are joined in order from the object side. Further, the third lens group G3 includes a junction lens L33 in which a negative meniscus lens L31 having a convex surface facing the object side and a positive meniscus lens L32 having a convex surface facing the object side are joined in order from the object side, and a biconcave negative lens L33. It is composed of a bonded lens in which a biconvex positive lens L34 is bonded, a biconvex positive lens L35, and a bonded lens in which a negative meniscus lens L36 with a convex surface facing the object side and a biconvex positive lens L37 are joined. Further, in the fourth lens group G4, in order from the object side, a bonded lens in which a biconvex positive lens L41 and a biconcave negative lens L42 are joined, and a lens surface on the object side are formed in an aspherical shape, and a concave surface on the object side. It is composed of an aspherical positive lens L43 having a positive meniscus lens shape. A filter FL is arranged between the fourth lens group G4 and the image plane I.

Further, in the variable magnification optical system ZL9, when the magnification is changed from the wide-angle end state to the telescopic end state, the distance between the first lens group G1 and the second lens group G2 is reduced, and the second lens group G2 and the third lens group are reduced. The first is such that the distance from G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 increases, and the distance (back focus) between the fourth lens group G4 and the image plane I increases. The lens group G1 moves to the image side, and the second lens group G2, the third lens group G3, and the fourth lens group G4 move to the object side. Further, the aperture diaphragm S is located in the third lens group G3 (between the junction lens in which the negative meniscus lens L31 and the biconvex positive lens L32 are bonded and the junction lens in which the biconcave negative lens L33 and the biconvex positive lens L34 are bonded. ), And moves with the third lens group G3 when scaling.

Further, the variable magnification optical system ZL9 is configured to focus from an infinity object to a short-distance object by moving the second lens group G2 to the image side.

Table 33 below lists the specifications of the variable magnification optical system ZL9.

In Table 33, the 16th surface shows the aperture stop S, and the 9th and 20th surfaces show virtual surfaces. Further, a secondary diaphragm can be arranged on the 20th surface.

When the filter is arranged on the object side of the variable magnification optical system ZL9, it is arranged at a position 6.10 mm away from the first surface on the object side.

(Table 33) Ninth Example [Overall Specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f = 14.400 ~ 16.000 ~ 18.000 ~ 23.300
FNO = 2.91 ~ 2.91 ~ 2.91 ~ 2.91
2ω (°) = 115.123 ~ 107.999 ~ 100.301 ~ 84.436
Ymax = 21.600 ~ 21.600 ~ 21.600 ~ 21.600
TL (air equivalent length) = 137.421 ~ 134.414 ~ 131.760 ~ 129.485
Bf (air equivalent length) = 21.808 ~ 24.029 ~ 26.719 ~ 34.219

[Lens data]
m r d nd ν d
Physical surface ∞
1 * 211.8265 3.0000 1.588870 61.13
2 * 15.9992 11.6180
3 48.6821 2.0000 1.820980 42.50
4 * 25.7140 11.5301
5 -43.5876 1.5000 1.497820 82.57
6 54.1333 0.5681
7 40.3289 6.6069 1.625844 34.24
8 -86.6000 d8
9 0.0000 0.0000
10 36.9813 1.1000 1.963000 24.11
11 19.6099 4.3000 1.680196 30.69
12 1248.2429 d12
13 26.0906 1.1000 1.846660 23.80
14 17.5000 6.2000 1.489456 69.86
15 1516.2872 1.5382
16 0.0000 2.6920 Aperture aperture S
17 -46.0077 1.1000 1.953750 32.33
18 26.5003 5.4000 1.846660 23.80
19 -55.7140 0.3744
20 0.0000 -0.3000
21 25.7684 6.0000 1.497820 82.57
22 -51.7236 0.2000
23 53.1758 1.1000 1.834810 42.73
24 17.7067 5.0000 1.497820 82.57
25 -115.0285 d25
26 57.4820 7.0000 1.497820 82.57
27 -18.9711 1.1000 1.834810 42.73
28 69.6403 3.9109
29 * -41.3607 2.0000 1.860999 37.10
30 -35.5329 d30
31 0.0000 1.6000 1.516800 64.13
32 0.0000 0.9492
Image plane ∞

[Lens group focal length]
Lens group Start surface Focal length 1st lens group 1 -21.475
2nd lens group 10 88.427
3rd lens group 13 32.839
4th lens group 26 -65.349

In this variable magnification optical system ZL9, each lens surface of the first surface, the second surface, the fourth surface, and the 29th surface is formed in an aspherical shape. Table 34 below shows the data of the surface number m and the aspherical surface, that is, the values of the conical constant K and the aspherical constants A4 to A12.

(Table 34)
[Aspherical data]
First side K = 1.000
A4 = 1.09229E-05 A6 = -1.69825E-08 A8 = 1.67481E-11
A10 ＝ -8.86570E-15 A12 ＝ 1.92870E-18 A14 ＝ 0.00000E + 00
Second side K = 0.0000
A4 = 9.21479E-06 A6 = 2.30867E-08 A8 = 1.30262E-11
A10 ＝ -4.06315E-13 A12 ＝ 4.84400E-16 A14 ＝ 0.00000E + 00
Side 4 K = 1.3178
A4 = 1.27593E-05 A6 = -2.12909E-09 A8 = 9.99165E-11
A10 = 8.39923E-14 A12 = 6.41400E-16 A14 = 0.00000E + 00
Side 29 K = 1.000
A4 ＝ -1.773924E-05 A6 ＝ -5.17645E-08 A8 ＝ 1.21697E-10
A10 ＝ -2.24340E-12 A12 ＝ 2.49200E-15 A14 ＝ 0.00000E + 00

In this variable magnification optical system ZL9, the axial air gap d8 between the first lens group G1 and the second lens group G2, the axial air gap d12 between the second lens group G2 and the third lens group G3, and the third lens group. The on-axis air spacing d24 between the G3 and the fourth lens group G4 and the on-axis air spacing d30 between the fourth lens group G4 and the filter FL change during scaling and focusing. Table 35 below shows the variable intervals at each focal length in the wide-angle end state, intermediate focal length state, and telephoto end state at the time of focusing on an infinity object, focusing on a short-range object, and focusing on the closest object, respectively. Indicates a value.

(Table 35)
[Variable interval data]
-When focusing on an infinite object-
Wide-angle end state Intermediate focal length state Telephoto end state f 14.400 16.000 18.000 23.300
d0 ∞ ∞ ∞ ∞
d8 19.8415 14.9293 10.0773 1.6769
d12 7.6288 7.1950 6.5331 5.0307
d25 1.5037 1.6216 1.7924 1.9194
d30 19.7474 21.9244 24.6266 32.2154

-When focusing on short-range objects-
Wide-angle end state Intermediate focal length state Telephoto end state β -0.025 -0.025 -0.025 -0.025
d0 547.1797 611.4703 691.7918 904.4881
d8 20.6724 15.6966 10.7821 2.2646
d12 6.7979 6.4278 5.8283 4.4429
d25 1.5037 1.6216 1.7924 1.9194
d30 19.7474 21.9244 24.6266 32.2154

-When the closest object is in focus-
Wide-angle end state Intermediate focal length state Telephoto end state β -0.091 -0.099 -0.110 -0.142
d0 136.0234 138.9653 141.4208 143.5318
d8 22.7133 17.8241 13.0223 4.8109
d12 4.7570 4.3002 3.5882 1.8967
d25 1.5037 1.6216 1.7924 1.9194
d30 19.7474 21.9244 24.6266 32.2154

Table 36 below shows the values corresponding to each conditional expression in the variable magnification optical system ZL9. In this variable magnification optical system ZL9, the specific negative lens is a biconcave negative lens L13, and the specific lenses are a biconvex positive lens L35, a biconvex positive lens L37, and a biconvex positive lens L41.

(Table 36)
Σν1n = 186.20
Σ (ν1n × f1n) =-8728.096
STLw = 78.532
fL1 = -29.557
fL2 = -69.099

[Conditional expression correspondence value]
(1) ν1n = 82.57
(2) nL2 / nL1 = 1.146
(3) N1n = 3
(4) 2ωw = 115.123 °
(5) nL1 = 1.589
(6) fw × (−f1) / Fnow = 106.270 mm ²
(7) (L1r2 + L1r1) / (L1r2-L1r1) =-1.163
(8) (Σν1n) / N1n = 62.067
(9) (Σ (ν1n × f1n)) / (N1n × f1) = 135.474
(10) Bfw / fw = 1.514
(11) STLw / TLw = 0.571
(12) (-f1) / fw = 1.491
(13) (-f1) /ft=0.922
(14) fL1 / f1 = 1.376
(15) fL2 / f1 = 3.218
(16) TLw / Bfw = 6.301
(17) (L2r2 + L2r1) / (L2r2-L2r1) =-3.239
(18) (L3r2 + L3r1) / (L3r2-L3r1) = 0.108
(19) νr = 82.57
(20) Fnow = 2.91
(21) Fnot = 2.91

As described above, the variable magnification optical system ZL9 satisfies all of the above conditional expressions (1) to (21).

FIG. 18 shows various aberration diagrams of the variable magnification optical system ZL9 in the wide-angle end state and the telephoto end state when the object is in focus at infinity. From these various aberration diagrams, it can be seen that the variable magnification optical system ZL9 satisfactorily corrects various aberrations from the wide-angle end state to the telephoto end state and has excellent imaging performance.

[10th Example]
FIG. 19 is a diagram showing a configuration of the variable magnification optical system ZL10 according to the tenth embodiment. The variable magnification optical system ZL10 is composed of a first lens group G1 having a negative refractive power and a rear group GR having a positive refractive power in order from the object side. Further, the rear group GR includes a second lens group G2 having a positive refractive power, a third lens group G3 having a positive refractive power, and a fourth lens group G4 having a positive refractive power in order from the object side. , It is composed of a fifth lens group G5 having a negative refractive power.

In this variable magnification optical system ZL10, the first lens group G1 has a negative meniscus lens shape in which the lens surface on the object side and the lens surface on the image side are formed in an aspherical shape in order from the object side, and the convex surface is directed toward the object side. Aspherical negative lens L11, an aspherical negative lens L12 having a negative meniscus lens shape in which the lens surface on the image side is formed in an aspherical shape and a convex surface facing the object side, and a biconcave negative lens L13 and a biconvex positive lens L14. It is composed of a bonded lens that is bonded to. Further, the second lens group G2 is composed of a biconvex positive lens L21 and a junction lens in which a biconvex positive lens L22 and a biconcave negative lens L23 are joined in order from the object side. Further, the third lens group G3 is composed of a bonded lens in which a negative meniscus lens L31 having a convex surface facing the object side and a positive meniscus lens L32 having a convex surface facing the object side are joined in order from the object side. Further, the fourth lens group G4 includes a junction lens in which a biconcave negative lens L41 and a biconvex positive lens L42 are joined, a biconvex positive lens L43, and a negative meniscus lens L44 with a convex surface facing the object side, in order from the object side. It is composed of a bonded lens in which a biconvex regular lens L45 is bonded. Further, in the fifth lens group G5, the bonded lens in which the biconcave negative lens L51 and the biconvex positive lens L52 are joined in order from the object side, and the lens surface on the image side are formed in an aspherical shape, and the concave surface on the object side. It is composed of an aspherical positive lens L53 having a positive meniscus lens shape. A filter FL is arranged between the fifth lens group G5 and the image plane I.

Further, in the variable magnification optical system ZL10, when the magnification is changed from the wide-angle end state to the telescopic end state, the distance between the first lens group G1 and the second lens group G2 is reduced, and the second lens group G2 and the third lens group are reduced. The distance between the third lens group G3 and the fourth lens group G4 decreases, the distance between the fourth lens group G4 and the fifth lens group G5 increases, and the distance between the third lens group G3 and the fourth lens group G5 increases. The first lens group G1 moves to the image side so that the distance (back focus) from the image plane I increases, and the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 moves to the object side. Further, the aperture diaphragm S is arranged between the third lens group G3 and the fourth lens group G4, and moves together with the fourth lens group G4 at the time of scaling.

Further, the variable magnification optical system ZL10 is configured to focus from an infinity object to a short-distance object by moving the second lens group G2 to the image side.

Table 37 below lists the specifications of the variable magnification optical system ZL10.

In Table 37, the 18th surface shows the aperture stop S, and the 8th, 14th, and 32nd surfaces show virtual surfaces. Further, a secondary diaphragm can be arranged on the 14th surface.

When the filter is arranged on the object side of the variable magnification optical system ZL10, it is arranged at a position 6.10 mm away from the first surface on the object side.

(Table 37) Example 10 [Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f = 14.400 ~ 18.000 ~ 20.000 ~ 23.300
FNO = 2.91 ~ 2.91 ~ 2.91 ~ 2.91
2ω (°) = 114.664 ~ 99.908 ~ 93.228 ~ 83.941
Ymax = 21.600 ~ 21.600 ~ 21.600 ~ 21.600
TL (air equivalent length) = 143.298 ~ 136.392 ~ 134.454 ~ 133.191
Bf (air equivalent length) = 21.176 ~ 26.098 ~ 28.849 ~ 33.508

[Lens data]
m r d nd ν d
Physical surface ∞
1 * 73.3719 3.2000 1.588870 61.13
2 * 14.5908 13.6216
3 63.8356 2.0000 1.860999 37.10
4 * 30.0096 10.9163
5 -50.1332 2.7239 1.433848 95.23
6 36.7661 5.9645 1.806100 33.34
7 -2583.8501 d7
8 0.0000 d8
9 98.9830 3.3713 1.728250 28.38
10 -69.3563 0.2000
11 45.8254 4.5650 1.698950 30.13
12 -44.1835 1.2000 1.963000 24.11
13 51.6189 d13
14 0.0000 0.0000
15 22.9396 1.2004 1.834000 37.18
16 16.5758 5.1257 1.487490 70.32
17 159.7987 d17
18 0.0000 3.8360 Aperture aperture S
19 -72.2635 1.2000 1.834810 42.73
20 32.7563 4.3411 1.497820 82.57
21 -55.5942 0.2082
22 37.2299 3.8685 1.749500 35.25
23 -97.4255 0.9285
24 29.0556 1.2430 1.834000 37.18
25 18.1863 5.7887 1.497820 82.57
26 -93.6887 d26
27 -61.0712 1.2008 1.953747 32.32
28 18.9225 5.7947 1.672700 32.18
29 -118.9626 2.9252
30 -46.6184 1.3000 1.860999 37.10
31 * -43.1724 d31
32 0.0000 18.4181
33 0.0000 1.6000 1.516800 64.13
34 0.0000 1.1070
Image plane ∞

[Lens group focal length]
Lens group Start surface Focal length 1st lens group 1 -20.602
2nd lens group 9 91.157
Third lens group 15 76.110
4th lens group 19 30.004
5th lens group 27 -45.641

In this variable magnification optical system ZL10, each lens surface of the first surface, the second surface, the fourth surface, and the 31st surface is formed in an aspherical shape. Table 38 below shows the data of the surface number m and the aspherical surface, that is, the values of the conical constant K and the aspherical constants A4 to A12.

(Table 38)
[Aspherical data]
First side K = 1.000
A4 = -8.22269E-06 A6 = 2.29849E-08 A8 = -3.24259E-11
A10 = 2.63839E-14 A12 = -1.1616E-17 A14 = 2.16740E-21
Second side K = 0.0000
A4 = -9.13167E-07 A6 = -9.42128E-09 A8 = 8.71937E-11
A10 = 1.90838E-13 A12 = -1.19570E-15 A14 = 1.26750E-18
Side 4 K = 2.000
A4 = 4.11958E-06 A6 = 9.92408E-09 A8 = 1.20069E-11
A10 ＝ -2.46956E-13 A12 ＝ 1.41440E-15 A14 ＝ -2.30990E-18
Side 31 K = 1.000
A4 = 1.54778E-05 A6 = -8.95438E-09 A8 = 3.82731E-10
A10 ＝ -2.13552E-12 A12 ＝ 4.78640E-15 A14 ＝ 0.00000E + 00

In this variable magnification optical system ZL10, the axial air spacing d7 and d8 between the first lens group G1 and the second lens group G2, and the axial air spacing d13 and the third between the second lens group G2 and the third lens group G3. The axial air gap d17 between the lens group G3 and the 4th lens group G4, the axial air gap d26 between the 4th lens group G4 and the 5th lens group G5, and the axial air gap d26 between the 5th lens group G5 and the filter FL. The air spacing d31 changes upon scaling and focusing. Table 39 below shows the variable intervals at each focal length in the wide-angle end state, intermediate focal length state, and telephoto end state at the time of focusing on an infinity object, focusing on a short-range object, and focusing on the closest object, respectively. Indicates a value.

(Table 39)
[Variable interval data]
-When focusing on an infinite object-
Wide-angle end state Intermediate focal length state Telephoto end state f 14.400 18.000 20.000 23.300
d0 ∞ ∞ ∞ ∞
d7 22.3946 11.1020 6.8926 1.5000
d8 0.0000 0.0000 0.0000 0.0000
d13 5.3794 5.6650 5.5441 5.7924
d17 4.7709 3.2409 2.6170 1.4986
d26 2.8531 3.5619 3.8286 4.1689
d31 0.5000 5.5016 8.0722 12.9278

-When focusing on short-range objects-
Wide-angle end state Intermediate focal length state Telephoto end state β -0.025 -0.025 -0.025 -0.025
d0 545.2923 690.1690 770.5760 903.1960
d7 22.3946 11.1020 6.8926 1.5000
d8 0.8103 0.7197 0.6824 0.6343
d13 4.5692 4.9453 4.8617 5.1581
d17 4.7709 3.2409 2.6170 1.4986
d26 2.8531 3.5619 3.8286 4.1689
d31 0.5000 5.5016 8.0722 12.9278

-When the closest object is in focus-
Wide-angle end state Intermediate focal length state Telephoto end state β -0.094 -0.112 -0.124 -0.144
d0 130.1097 137.0620 138.9961 140.1704
d7 22.3946 11.1020 6.8926 1.5000
d8 2.6235 2.9752 3.0674 3.3170
d13 2.7248 2.6934 2.4623 2.5422
d17 4.7709 3.2409 2.6170 1.4986
d26 2.8531 3.5619 3.8286 4.1689
d31 0.5000 5.5016 8.0722 12.9278

Table 40 below shows the values corresponding to each conditional expression in the variable magnification optical system ZL10. In the variable magnification optical system ZL10, the specific negative lens is the biconcave negative lens L13, and the specific lenses are the biconvex positive lens L42 and the biconvex positive lens L45.

(Table 36)
Σν1n = 193.46
Σ (ν1n × f1n) =-9050.378
STLw = 86.634
fL1 = -31.560
fL2 = -67.630

[Conditional expression correspondence value]
(1) ν1n = 95.23
(2) nL2 / nL1 = 1.171
(3) N1n = 3
(4) 2ωw = 114.664 °
(5) nL1 = 1.589
(6) fw × (−f1) / Fnow = 101.938mm ²
(7) (L1r2 + L1r1) / (L1r2-L1r1) = -1.496
(8) (Σν1n) / N1n = 64.487
(9) (Σ (ν1n × f1n)) / (N1n × f1) = 146.446
(10) Bfw / fw = 1.471
(11) STLw / TLw = 0.605
(12) (-f1) / fw = 1.431
(13) (-f1) / ft = 0.884
(14) fL1 / f1 = 1.532
(15) fL2 / f1 = 3.283
(16) TLw / Bfw = 6.767
(17) (L2r2 + L2r1) / (L2r2-L2r1) = -2.774
(18) (L3r2 + L3r1) / (L3r2-L3r1) =-0.154
(19) νr = 82.57
(20) Fnow = 2.91
(21) Fnot = 2.91

As described above, the variable magnification optical system ZL10 satisfies all of the above conditional expressions (1) to (21).

FIG. 20 shows various aberration diagrams in the wide-angle end state and the telephoto end state when the variable magnification optical system ZL10 is in focus at an infinity object. From these various aberration diagrams, it can be seen that the variable magnification optical system ZL10 satisfactorily corrects various aberrations from the wide-angle end state to the telephoto end state and has excellent imaging performance.

1 Camera (optical equipment) ZL (ZL1 to ZL10) Variable magnification optical system G1 1st lens group G2 2nd lens group G3 3rd lens group

Claims (22)

From the object side,
The first lens group with negative refractive power and
A second lens group with positive refractive power,
It has a third lens group having a positive refractive power, and
When changing the magnification, the distance between adjacent lens groups changes,
When scaling from the wide-angle end state to the telephoto end state, the distance between the first lens group and the second lens group decreases,
When focusing from an infinite object to a short-distance object, the second lens group moves to the image side,
The first lens group has a negative meniscus lens with a convex surface facing the object side on the most object side.
A variable magnification optical system that satisfies the conditions of the following equation.
N1n ≤ 3
100.00 ° <2ωw
However,
N1n: Number of negative lenses included in the first lens group 2ωw: Total angle of view of the variable magnification optical system at the wide-angle end state From the object side,
The first lens group with negative refractive power and
A second lens group with positive refractive power,
It has a third lens group having a positive refractive power, and
When changing the magnification, the distance between adjacent lens groups changes,
When scaling from the wide-angle end state to the telephoto end state, the distance between the first lens group and the second lens group decreases,
When focusing from an infinite object to a short-distance object, the second lens group moves to the image side,
The first lens group has a negative meniscus lens with a convex surface facing the object side on the most object side.
A variable magnification optical system that satisfies the conditions of the following equation.
nL1 <1.70
However,
nL1: Refractive index of the lens on the most object side of the first lens group with respect to the d line of the medium. From the object side,
The first lens group with negative refractive power and
A second lens group with positive refractive power,
It has a third lens group having a positive refractive power, and
When changing the magnification, the distance between adjacent lens groups changes,
When scaling from the wide-angle end state to the telephoto end state, the distance between the first lens group and the second lens group decreases,
When focusing from an infinite object to a short-distance object, the second lens group moves to the image side,
The first lens group has a negative meniscus lens with a convex surface facing the object side on the most object side.
A variable magnification optical system that satisfies the conditions of the following equation.
59.00 <(Σν1n) / N1n
N1n ≤ 3
However,
N1n: Number of negative lenses included in the first lens group Σν1n: Abbe number of negative lenses included in the first lens group with respect to the d-line of the medium The variable magnification optical system according to any one of claims 1 to 3, which satisfies the conditions of the following equation.
100.00 <(Σ (ν1n × f1n)) / (N1n × f1)
However,
N1n: Number of negative lenses included in the first lens group f1: Focal length Σ (ν1n × f1n) of the first lens group: Abbe number ν1n with respect to d-line of the medium of the negative lens included in the first lens group Sum of the products of and the focal length f1n The variable magnification optical system according to any one of claims 1 to 4, which satisfies the conditions of the following equation.
1.20 <Bfw / fw <4.00
However,
fw: Focal length in the wide-angle end state of the variable magnification optical system Bfw: Back focus in the wide-angle end state of the variable magnification optical system The variable magnification optical system according to any one of claims 1 to 5, which satisfies the conditions of the following equation.
0.40 <STRw / TLw <0.70
However,
TLw: Total optical length of the variable magnification optical system in the wide-angle end state STRw: Distance on the optical axis from the lens surface to the aperture surface on the most object side in the wide-angle end state of the variable magnification optical system The variable magnification optical system according to any one of claims 1 to 6, which satisfies the conditions of the following equation.
1.00 <(-f1) / fw <2.00
However,
fw: Focal length in the wide-angle end state of the variable magnification optical system f1: Focal length of the first lens group The variable magnification optical system according to any one of claims 1 to 7, which satisfies the conditions of the following equation.
0.65 <(-f1) / ft <1.20
However,
ft: Focal length in the telephoto end state of the variable magnification optical system f1: Focal length of the first lens group The variable magnification optical system according to any one of claims 1 to 8, which satisfies the conditions of the following equation.
1.00 <fL1 / f1 <2.00
However,
f1: Focal length of the first lens group fL1: Focal length of the lens on the most object side of the first lens group The variable magnification optical system according to any one of claims 1 to 9, which satisfies the conditions of the following equation.
1.00 <fL2 / f1 <4.00
However,
f1: Focal length of the first lens group fL2: Focal length of the second lens from the object side of the first lens group The variable magnification optical system according to any one of claims 1 to 10, which satisfies the conditions of the following equation.
3.50 <TLw / Bfw <8.00
However,
Bfw: Back focus of the variable magnification optical system in the wide-angle end state TLw: Optical total length of the variable magnification optical system in the wide-angle end state The variable magnification optical system according to any one of claims 1 to 11, which satisfies the conditions of the following equation.
-4.00 <(L1r2 + L1r1) / (L1r2-L1r1) <-0.50
However,
L1r1: Radius of curvature of the lens surface on the object side of the lens on the most object side of the first lens group L1r2: Radius of curvature of the lens surface on the image side of the lens on the most object side of the first lens group The first lens group has at least two lenses.
The variable magnification optical system according to any one of claims 1 to 12, which satisfies the conditions of the following equation.
-4.00 <(L2r2 + L2r1) / (L2r2-L2r1) <-0.50
However,
L2r1: Radius of curvature of the lens surface of the second lens from the object side of the first lens group on the object side L2r2: Radius of curvature of the lens surface on the image side of the second lens from the object side of the first lens group The first lens group has at least three lenses.
The variable magnification optical system according to any one of claims 1 to 13, which satisfies the conditions of the following equation.
−0.80 <(L3r2 + L3r1) / (L3r2-L3r1) <0.80
However,
L3r1: Radius of curvature of the lens surface of the third lens from the object side of the first lens group on the object side L3r2: Radius of curvature of the lens surface on the image side of the third lens from the object side of the first lens group The variable magnification optical system according to any one of claims 1 to 14, wherein the first lens group moves in the optical axis direction at the time of scaling. The variable magnification optical system according to any one of claims 1 to 15, wherein the first lens group is composed of a negative lens, a negative lens, a negative lens, and a positive lens in order from the object side. The variable magnification optical system according to any one of claims 1 to 16, which has at least one lens group on the image side of the third lens group. The variable magnification optical system according to any one of claims 1 to 17, which satisfies the conditions of the following equation.
Fnow <4.20
However,
Fnow: Open F number in the infinity focusing state in the wide-angle end state of the variable magnification optical system The variable magnification optical system according to any one of claims 1 to 18, which satisfies the conditions of the following equation.
Fnot <6.00
However,
Fnot: Open F number in the infinity in-focus state in the telephoto end state of the variable magnification optical system. The variable magnification optical system according to any one of claims 1 to 19, which has a filter on the object side of the first lens group. An optical device having the variable magnification optical system according to any one of claims 1 to 20. A method for manufacturing a variable magnification optical system having a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a positive refractive power in order from the object side. And
At the time of scaling, the distance between adjacent lens groups changes, and at the time of scaling from the wide-angle end state to the telephoto end state, the distance between the first lens group and the second lens group is reduced.
When focusing from an infinite object to a short-distance object, the second lens group is arranged so as to move toward the image side.
A negative meniscus lens with a convex surface facing the object side is arranged on the most object side of the first lens group.
A method for manufacturing a variable magnification optical system that is arranged so as to satisfy the conditions of the following equation.
N1n ≤ 3
100.00 ° <2ωw
However,
N1n: Number of negative lenses included in the first lens group 2ωw: Total angle of view of the variable magnification optical system at the wide-angle end state

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