Variable magnification optical system and imaging device

Abstract

The present invention provides a variable magnification optical system that achieves a high magnification ratio while effectively correcting aberrations across the entire magnification range, and an imaging device equipped with this variable magnification optical system. [Solution] The variable magnification optical system consists of a first lens group having positive refractive power, an intermediate group, and a subsequent group, arranged in order from the object side to the image side. The intermediate group consists of three or fewer lens groups, including the M1 lens group having negative refractive power, which is positioned closest to the object, and the Mr lens group having negative refractive power, which is positioned closest to the image. The R1 lens group having positive refractive power is positioned closest to the object in the subsequent group. The first lens group remains stationary during magnification. When the focal length of the M1 lens group is fM1 and the focal length of the first lens group is f1, the variable magnification optical system satisfies the condition expressed as 0.05 < (-fM1) / f1 < 0.8.

Description

[Technical Field]

[0001] The technology disclosed herein relates to a variable magnification optical system and an imaging device. [Background technology]

[0002] Conventionally, the optical system described in Patent Document 1 below has been proposed as an optical system applicable to imaging devices such as surveillance cameras and digital cameras. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2015-018155 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] There is a demand for variable magnification optical systems that achieve high magnification ratios while effectively correcting aberrations across the entire magnification range. These demands are increasing year by year.

[0005] This disclosure provides a variable magnification optical system that achieves a high magnification ratio while effectively correcting aberrations across the entire magnification range, and an imaging device equipped with this variable magnification optical system. [Means for solving the problem]

[0006] A variable magnification optical system according to one aspect of this disclosure comprises, in order from the object side to the image side, a first lens group having positive refractive power, an intermediate group, and a successor group, wherein the intermediate group has an M1 lens group having negative refractive power positioned closest to the object, and the intermediate group has an Mr lens group having negative refractive power positioned closest to the image, and the intermediate group consists of three or fewer lens groups having refractive power, including the M1 and Mr lens groups, and the successor group has an R1 lens group having positive refractive power positioned closest to the object, and during magnification, the first lens group is fixed with respect to the image plane, and the spacing between all adjacent lens groups changes. 0.05 < (-fM1) / f1 < 0.8 (1) The condition (1) expressed by is satisfied. Here, the focal length of the M1 lens group is denoted as fM1, and the focal length of the first lens group is denoted as f1.

[0007] When the focal length of the R1 lens group is fR1, the variable magnification optical system of the above embodiment is: 0.05 <fR1 / f1<0.85 (2) It is preferable that the condition (2) expressed by is satisfied.

[0008] When the focal length of the Mr lens group is fMr, the variable magnification optical system of the above configuration is: 0.8 <fMr / fM1<7 (3) It is preferable that the condition expressed in equation (3) is satisfied.

[0009] If DG1 is the distance along the optical axis from the object-side surface of the first lens group to the image-side surface of the first lens group, and Dsum is the distance along the optical axis from the object-side surface of the first lens group to the image-side surface of the subsequent lens group when in focus on an object at infinity at the wide-angle end, then the variable magnification optical system of the above embodiment is: 0.012 <DG1 / Dsum<0.25 (4) It is preferable that the condition expressed in equation (4) is satisfied.

[0010] When the focal length of the entire variable magnification optical system is fw when it is in focus on an object at infinity at the wide-angle end, the variable magnification optical system of the above embodiment is: 0.08 <fw / f1<0.3 (5) It is preferable that the condition (5) expressed by is satisfied.

[0011] When the focal length of the entire variable magnification optical system is fw when it is in focus on an object at infinity at the wide-angle end, the variable magnification optical system of the above embodiment is: -3 <fw / fM1<-0.2 (6) It is preferable that the condition expressed in equation (6) is satisfied.

[0012] When the focal length of the entire zoom optical system in the state of focusing on an infinite object at the wide-angle end is fw and the focal length of the R1 lens group is fR1, the zoom optical system of the above aspect satisfies: 0.1 < fw / fR1 < 1.4 (7) It is preferable to satisfy the conditional expression (7) represented by the above.

[0013] When the focal length of the entire zoom optical system in the state of focusing on an infinite object at the wide-angle end is fw and the focal length of the entire zoom optical system in the state of focusing on an infinite object at the telephoto end is ft, the zoom optical system of the above aspect satisfies: 0.6 < f1 / (fw × ft) 1 / 2 <4 (8) It is preferable to satisfy the conditional expression (8) represented by the above.

[0014] When the focal length of the entire zoom optical system in the state of focusing on an infinite object at the wide-angle end is fw and the focal length of the entire zoom optical system in the state of focusing on an infinite object at the telephoto end is ft, the zoom optical system of the above aspect satisfies: 9 < ft / fw < 60 (9) It is preferable to satisfy the conditional expression (9) represented by the above.

[0015] In a configuration where the subsequent group includes an anti-vibration group that moves in a direction intersecting the optical axis during image blur correction, when the focal length of the entire zoom optical system in the state of focusing on an infinite object at the wide-angle end is fw and the focal length of the anti-vibration group is fois, the zoom optical system of the above aspect satisfies: 0.1 < fw / |fois| < 1.5 (10) It is preferable to satisfy the conditional expression (10) represented by the above.

[0016] In a configuration where the subsequent group includes an anti-vibration group, when the focal length of the entire zoom optical system in the state of focusing on an infinite object at the telephoto end is ft, the maximum half angle of view at the wide-angle end in the state of focusing on an infinite object is ωw, and the maximum half angle of view at the telephoto end in the state of focusing on an infinite object is ωt, the zoom optical system of the above aspect satisfies: 0.6 < (fw × tan ωw) / (ft × tan ωt) < 0.98 (11) It is preferable to satisfy the conditional expression (11) represented by

[0017] When the refractive index with respect to the d line of the lens included in the zoom optical system is Nd and the Abbe number based on the d line of the lens included in the zoom optical system is νd, the zoom optical system of the above aspect is 2.435 < Nd + 0.01425 × νd < 2.75 (12) 15 < νd < 39 (13) It is preferable to include at least one specific lens that is a lens satisfying the conditional expressions (12) and (13) represented by

[0018] When the partial dispersion ratio between the g line and the F line of the lens included in the zoom optical system is θgF, the specific lens is 0.65 < θgF + 0.00316 × νd < 0.85 (14) It is preferable to satisfy the conditional expression (14) represented by

[0019] Among the specific lenses included in the zoom optical system, when the maximum effective diameter of the specific lens having the largest effective diameter is EDL, the focal length of the entire zoom optical system in a state of being focused on an infinite object at the telephoto end is ft, and the maximum half angle of view at the telephoto end in a state of being focused on an infinite object is ωt, the zoom optical system of the above aspect is 0.1 < EDL / (2 × ft × tan ωt) < 2 (15) It is preferable to satisfy the conditional expression (15) represented by

[0020] [[ID=3l]]The intermediate group preferably includes at least one specific lens.

[0021] The subsequent group preferably includes at least one specific lens.

[0022] In a configuration where the zoom optical system includes at least one cemented lens, at least one cemented lens of the zoom optical system preferably includes a specific lens.

[0023] The intermediate group may be configured to be composed of three lens groups.

[0024] The M1 lens group may be configured to include two or more positive lenses and three or more negative lenses.

[0025] Another aspect of the present disclosure is an imaging device equipped with the magnification optical system of the above aspect.

[0026] Furthermore, the terms "~consisting of" and "~consisting of" in this specification are intended to include, in addition to the listed components, lenses that substantially have no refractive power, optical elements other than lenses such as apertures, filters, and cover glass, and mechanical parts such as lens flanges, lens barrels, image sensors, and image stabilization mechanisms.

[0027] In this specification, "a group of lenses having positive refractive power" means that the group as a whole has positive refractive power. Similarly, "a group of lenses having negative refractive power" means that the group as a whole has negative refractive power. "A lens having positive refractive power" and "a positive lens" are synonymous. "A lens having negative refractive power" and "a negative lens" are synonymous. In this specification, "a lens group," "a lens group," "a vibration-damping group," and "a focusing group" are not limited to configurations consisting of multiple lenses, but may also consist of only one lens.

[0028] In this specification, the number of lenses refers to the number of constituent lenses. For example, in a cemented lens formed by joining multiple single lenses of different materials, the number of lenses is expressed as the number of single lenses that make up the cemented lens. However, a composite aspherical lens (a lens in which a lens (e.g., a spherical lens) and an aspherical film formed on that lens are integrally constructed and function as a single aspherical lens as a whole) is not considered a cemented lens and is treated as a single lens. Unless otherwise specified, the sign of the refractive power and the surface shape for lenses including aspherical surfaces are those of the paraxial region.

[0029] In this specification, the "focal length" used in the conditional equations refers to the paraxial focal length. Unless otherwise specified, the "distance on the optical axis" used in the conditional equations refers to the geometric distance. Unless otherwise specified, the values ​​used in the conditional equations are those obtained when the image is in focus on an object at infinity, with the d-line as the reference.

[0030] The terms "d-line," "C-line," "F-line," and "g-line" used herein are emission lines. The wavelength of the d-line is treated as 587.56 nm (nanometers), the wavelength of the C-line as 656.27 nm (nanometers), the wavelength of the F-line as 486.13 nm (nanometers), and the wavelength of the g-line as 435.84 nm (nanometers). [Effects of the Invention]

[0031] According to this disclosure, it is possible to provide a variable magnification optical system that achieves a high magnification ratio while good correction of aberrations across the entire magnification range, and an imaging device equipped with this variable magnification optical system. [Brief explanation of the drawing]

[0032] [Figure 1] This figure corresponds to the variable magnification optical system of Example 1 and shows a cross-sectional view and movement trajectory of the configuration of the variable magnification optical system according to one embodiment. [Figure 2] Figure 1 is a cross-sectional view of the configuration of the variable magnification optical system at its wide-angle end, and also serves to explain the notation in the conditional equation. [Figure 3] This is a diagram to explain the effective diameter. [Figure 4] These are aberration diagrams for the variable magnification optical system of Example 1. [Figure 5] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 2. [Figure 6] These are aberration diagrams for the variable magnification optical system of Example 2. [Figure 7] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 3. [Figure 8] These are aberration diagrams for the variable magnification optical system of Example 3. [Figure 9]This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 4. [Figure 10] These are aberration diagrams for the variable magnification optical system of Example 4. [Figure 11] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 5. [Figure 12] These are aberration diagrams for the variable magnification optical system of Example 5. [Figure 13] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 6. [Figure 14] These are aberration diagrams for the variable magnification optical system of Example 6. [Figure 15] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 7. [Figure 16] These are aberration diagrams for the variable magnification optical system of Example 7. [Figure 17] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 8. [Figure 18] These are aberration diagrams for the variable magnification optical system of Example 8. [Figure 19] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 9. [Figure 20] These are aberration diagrams for the variable magnification optical system of Example 9. [Figure 21] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 10. [Figure 22] These are aberration diagrams for the variable magnification optical system of Example 10. [Figure 23] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 11. [Figure 24] These are aberration diagrams for the variable magnification optical system of Example 11. [Figure 25] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 12. [Figure 26] These are aberration diagrams for the variable magnification optical system of Example 12. [Figure 27] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 13. [Figure 28] These are aberration diagrams for the variable magnification optical system of Example 13. [Figure 29] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 14. [Figure 30] These are aberration diagrams for the variable magnification optical system of Example 14. [Figure 31] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 15. [Figure 32] These are aberration diagrams for the variable magnification optical system of Example 15. [Figure 33] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 16. [Figure 34] These are aberration diagrams for the variable magnification optical system of Example 16. [Figure 35] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 17. [Figure 36] These are aberration diagrams for the variable magnification optical system of Example 17. [Figure 37] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 18. [Figure 38] These are aberration diagrams for the variable magnification optical system of Example 18. [Figure 39] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 19. [Figure 40] These are aberration diagrams for the variable magnification optical system of Example 19. [Figure 41] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 20. [Figure 42] These are aberration diagrams for the variable magnification optical system of Example 20. [Figure 43] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 21. [Figure 44] These are aberration diagrams for the variable magnification optical system of Example 21. [Figure 45] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 22. [Figure 46] These are aberration diagrams for the variable magnification optical system of Example 22. [Figure 47] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 23. [Figure 48] These are aberration diagrams for the variable magnification optical system of Example 23. [Figure 49] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 24. [Figure 50] These are aberration diagrams for the variable magnification optical system of Example 24. [Figure 51] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 25. [Figure 52] These are aberration diagrams for the variable magnification optical system of Example 25. [Figure 53] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 26. [Figure 54] These are aberration diagrams for the variable magnification optical system of Example 26. [Figure 55] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 27. [Figure 56] These are aberration diagrams for the variable magnification optical system of Example 27. [Figure 57] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 28. [Figure 58] These are aberration diagrams for the variable magnification optical system of Example 28. [Figure 59] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 29. [Figure 60] These are aberration diagrams for the variable magnification optical system of Example 29. [Figure 61] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 30. [Figure 62] These are aberration diagrams for the variable magnification optical system of Example 30. [Figure 63] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 31. [Figure 64] These are aberration diagrams for the variable magnification optical system of Example 31. [Figure 65] This figure shows a cross-sectional view and movement trajectory of the variable magnification optical system configuration of Example 32. [Figure 66] These are aberration diagrams for the variable magnification optical system of Example 32. [Figure 67]This is a schematic diagram of an imaging device according to one embodiment. [Modes for carrying out the invention]

[0033] Embodiments of this disclosure will be described below with reference to the drawings.

[0034] Figure 1 shows the configuration and cross-sectional view of the light beam and the movement trajectory of a variable magnification optical system according to one embodiment of the present disclosure. In Figure 1, the upper section labeled "Wide" shows the wide-angle end state, and the lower section labeled "Tele" shows the telephoto end state. In Figure 1, the light beams shown are the on-axial light beam and the light beam with the maximum half-angle of view ωw at the wide-angle end, and the on-axial light beam and the light beam with the maximum half-angle of view ωt at the telephoto end. Figure 2 shows a cross-sectional view of the configuration of the variable magnification optical system of Figure 1 at the wide-angle end. In Figures 1 and 2, the left side is the object side and the right side is the image side, showing the state when focused on an object at infinity. The examples shown in Figures 1 and 2 correspond to the variable magnification optical system of Embodiment 1 described later. The following explanation will mainly refer to Figure 1, and to Figure 2 as necessary.

[0035] The variable magnification optical system of this disclosure consists of a first lens group G1 having positive refractive power, an intermediate group GM, and a subsequent group GR, arranged in order from the object side to the image side along the optical axis Z. The M1 lens group GM1 having negative refractive power is positioned at the object side of the intermediate group GM. The Mr lens group GMr having negative refractive power is positioned at the image side of the intermediate group GM. The intermediate group GM consists of three or fewer lens groups having refractive power, including the M1 lens group GM1 and the Mr lens group GMr. That is, the intermediate group GM consists of two or three lens groups having refractive power. The R1 lens group GR1 having positive refractive power is positioned at the object side of the subsequent group GR. During magnification, the first lens group is fixed with respect to the image plane Sim, and the spacing between all adjacent lens groups changes. The above configuration is advantageous for achieving a high magnification ratio while effectively correcting aberrations across the entire magnification range.

[0036] By making the refractive power of the first lens group closest to the object positive, miniaturization is advantageous, and the height of the light rays incident on the intermediate group GM can be reduced, which is advantageous in suppressing aberration fluctuations during magnification. Including two lens groups with negative refractive powers in the intermediate group GM is advantageous in achieving both good aberration correction across the entire magnification range and a high magnification ratio. Making the refractive power of the lens group closest to the object in the subsequent group GR positive is advantageous in miniaturization. Keeping the first lens group closest to the object immobile during magnification is advantageous in suppressing fluctuations in the center of gravity during magnification.

[0037] In this specification, a group of lenses whose distance in the optical axis direction changes when magnification is varied is defined as one lens group. Within a single lens group, the distance between adjacent lenses does not change when magnification is varied. That is, a "lens group" is a component of a variable magnification optical system that includes at least one lens, separated by the air gap that changes when magnification is varied. When magnification is varied, each lens group is moved or fixed. A "lens group" may include components other than lenses that do not have refractive power, such as an aperture diaphragm St.

[0038] As an example, each group of the variable magnification optical system in Figure 1 is configured as follows, as shown in detail in Figure 2. The first lens group G1 consists of five lenses, L11 to L15, in order from the object side to the image side. The intermediate group GM consists of two lens groups, M1 lens group GM1 and Mr lens group GMr, in order from the object side to the image side. M1 lens group GM1 consists of six lenses, L21 to L26, in order from the object side to the image side. Mr lens group GMr consists of two lenses, L31 to L32, in order from the object side to the image side. The subsequent group GR consists of one lens group called R1 lens group GR1. R1 lens group GR1 consists of lens L41, aperture diaphragm St, lenses L42 to L55, optical element PP, and lenses L56 to L58, in order from the object side to the image side. The aperture diaphragm St shown in Figures 1 and 2 indicates its position in the optical axis direction, not its size or shape. The optical element PP is a parallel plate-shaped member with no refractive power, intended for use as various filters, etc. In the variable magnification optical system of this disclosure, it is also possible to have a configuration that does not include the optical element PP.

[0039] In the example in Figure 1, during magnification, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the M1 lens group GM1 and the Mr lens group GMr move along the optical axis Z, changing their relative distance from each other. In Figure 1, between the upper and lower diagrams, the approximate movement trajectories of each lens group during magnification, from the wide-angle end to the telephoto end, are shown by solid arrows.

[0040] The first lens group G1 may be configured to include two cemented lenses, each consisting of a negative lens and a positive lens joined together. This configuration is advantageous for correcting chromatic aberration. In addition to the two cemented lenses, the first lens group G1 may also be configured to include one more positive lens. This configuration is advantageous for correcting spherical aberration.

[0041] The M1 lens group GM1 preferably includes two or more positive lenses and three or more negative lenses. This configuration is advantageous in suppressing aberration fluctuations during magnification.

[0042] The Mr lens group GMr may be configured to consist of a cemented lens formed by joining a negative lens and a positive lens. This configuration is advantageous in suppressing fluctuations in chromatic aberration during magnification.

[0043] It is preferable that the lens surface closest to the object and the lens surface closest to the image of the subsequent lens group GR are fixed to the image plane Sim during magnification. This is advantageous for simplifying the mechanism.

[0044] The subsequent group GR may be configured to include an aperture diaphragm St. This configuration is advantageous for miniaturizing the subsequent group GR.

[0045] The subsequent group GR preferably includes an anti-vibration group that moves in a direction intersecting the optical axis Z during image blur correction. By placing the anti-vibration group in the subsequent group GR, it becomes easier to suppress the diameter of the anti-vibration group, which is advantageous for miniaturization. In this specification, "image blur correction" is also referred to as "vibration isolation".

[0046] As an example, the vibration isolation group of the variable magnification optical system in Figure 1 consists of lenses L45 to L48 shown in Figure 2. In the lower part of Figure 1, brackets with downward-pointing arrows are placed below the lenses that make up the vibration isolation group. Although the vibration isolation group functions throughout the entire magnification range, including the wide-angle end, the brackets and arrows are only shown in the lower part of Figure 1 to avoid making the diagram too complex. The same method of illustrating the vibration isolation group is used in the diagrams of other embodiments.

[0047] The variable magnification optical system may be configured to include a focusing group that moves along the optical axis Z when focusing. In the example in Figure 1, the subsequent group GR includes the focusing group. By placing the focusing group in the subsequent group GR, it becomes easier to suppress the diameter of the focusing group, which is advantageous for miniaturization.

[0048] As an example, the focusing group of the variable magnification optical system in Figure 1 consists of lenses L52 to L55 shown in Figure 2. In the lower part of Figure 1, brackets with left-right arrows are placed below the lenses that make up the focusing group. These left-right arrows indicate the direction in which the focusing group moves when focusing from an object at infinity to the nearest object. The focusing group functions throughout the entire variable magnification range, including the wide-angle end, but in Figure 1, to avoid complexity, the brackets and arrows are only included in the lower part of the diagram. The same method of illustrating the focusing group is used in the diagrams of other embodiments.

[0049] Next, preferred configurations of the variable magnification optical system of this disclosure with respect to the conditional formulas will be described. In the following explanation of the conditional formulas, the same symbols will be used for the same definitions, and redundant explanations of symbols will be omitted to avoid redundancy. Also, to avoid redundancy, "the variable magnification optical system of this disclosure" will also be simply referred to as "the variable magnification optical system" below.

[0050] The variable magnification optical system preferably satisfies the following condition (1). Here, the focal length of the M1 lens group GM1 is denoted as fM1. The focal length of the first lens group G1 is denoted as f1. By ensuring that the corresponding value in condition (1) does not fall below the lower limit, the refractive power of the first lens group G1 can be increased, which is advantageous for shortening the overall optical length. By ensuring that the corresponding value in condition (1) does not exceed the upper limit, it is advantageous for maintaining the variable magnification effect of the M1 lens group GM1, which is advantageous for achieving a high magnification ratio. Furthermore, by ensuring that the corresponding value in condition (1) does not exceed the upper limit, it is advantageous for shortening the amount of movement of the M1 lens group GM1 during magnification, which is advantageous for miniaturization. 0.05 < (-fM1) / f1 < 0.8 (1)

[0051] To obtain better characteristics, the lower limit of conditional equation (1) is more preferably 0.08, even more preferably 0.1, even more preferably 0.12, even more preferably 0.14, even more preferably 0.16, even more preferably 0.18, even more preferably 0.2, even more preferably 0.21, and even more preferably 0.22. To obtain better characteristics, the upper limit of conditional equation (1) is more preferably 0.75, even more preferably 0.7, even more preferably 0.65, even more preferably 0.6, even more preferably 0.55, even more preferably 0.5, even more preferably 0.45, even more preferably 0.4, and even more preferably 0.35.

[0052] When the focal length of the R1 lens group GR1 is fR1, it is preferable that the variable magnification optical system satisfies the following condition (2). By ensuring that the corresponding value in condition (2) does not fall below the lower limit, the refractive power of the first lens group G1 does not become too weak, which is advantageous for shortening the overall optical length. By ensuring that the corresponding value in condition (2) does not exceed the upper limit, the refractive power of the first lens group G1 does not become too strong, which is advantageous for suppressing aberration fluctuations during magnification. 0.05 <fR1 / f1<0.85 (2)

[0053] To obtain better characteristics, the lower limit of conditional equation (2) is more preferably 0.07, even more preferably 0.09, even more preferably 0.11, even more preferably 0.13, even more preferably 0.15, even more preferably 0.16, even more preferably 0.17, even more preferably 0.18, and even more preferably 0.185. To obtain better characteristics, the upper limit of conditional equation (2) is more preferably 0.8, even more preferably 0.75, even more preferably 0.7, even more preferably 0.65, even more preferably 0.6, even more preferably 0.55, even more preferably 0.45, even more preferably 0.4, and even more preferably 0.35.

[0054] When the focal length of the Mr lens group GMR is fMr, it is preferable that the variable magnification optical system satisfies the following condition (3). By ensuring that the corresponding value in condition (3) does not fall below the lower limit, the refractive power of the M1 lens group GM1 does not become too weak, making it easier to shorten the amount of movement of the M1 lens group GM1 during magnification, which is advantageous for shortening the overall optical length. By ensuring that the corresponding value in condition (3) does not exceed the upper limit, the refractive power of the M1 lens group GM1 does not become too strong, which suppresses excessive correction of spherical aberration at the telephoto end, and is advantageous for obtaining high optical performance. 0.8 <fMr / fM1<7 (3)

[0055] To obtain better characteristics, the lower limit of conditional equation (3) is more preferably 0.95, even more preferably 1.1, even more preferably 1.25, even more preferably 1.4, even more preferably 1.55, even more preferably 1.7, even more preferably 1.8, even more preferably 1.9, and even more preferably 2. To obtain better characteristics, the upper limit of conditional equation (3) is more preferably 6, even more preferably 5.5, even more preferably 5, even more preferably 4.5, even more preferably 4.25, even more preferably 4, even more preferably 3.75, even more preferably 3.5, and even more preferably 3.25.

[0056] The variable magnification optical system preferably satisfies the following condition (4). Here, DG1 is the distance along the optical axis from the object-side surface of the first lens group to the image-side surface of the first lens group. Dsum is the distance along the optical axis from the object-side surface of the first lens group G1 to the image-side surface of the subsequent group GR when in focus on an object at infinity at the wide-angle end. As an example, Figure 2 shows the above distances DG1 and Dsum. Distance DG1 corresponds to the optical axis thickness of the first lens group G1. By ensuring that the corresponding value of condition (4) does not fall below the lower limit, the first lens group G1 does not become too thin, which is advantageous for correcting chromatic aberration and astigmatism. By ensuring that the corresponding value of condition (4) does not exceed the upper limit, the weight of the first lens group G1 can be prevented from becoming excessive, thus preventing the overall weight of the optical system from becoming excessive. 0.012 <DG1 / Dsum<0.25 (4)

[0057] To obtain better characteristics, the lower limit of conditional equation (4) is more preferably 0.014, even more preferably 0.016, even more preferably 0.018, even more preferably 0.02, even more preferably 0.022, even more preferably 0.024, even more preferably 0.026, even more preferably 0.028, and even more preferably 0.03. To obtain better characteristics, the upper limit of conditional equation (4) is more preferably 0.24, even more preferably 0.23, even more preferably 0.22, even more preferably 0.21, even more preferably 0.2, even more preferably 0.19, even more preferably 0.18, even more preferably 0.17, and even more preferably 0.16.

[0058] The variable magnification optical system preferably satisfies the following condition (5). Here, fw is the focal length of the variable magnification optical system when it is in focus on an object at infinity at the wide-angle end. Ensuring that the corresponding value in condition (5) does not fall below the lower limit is advantageous for shortening the overall optical length. Ensuring that the corresponding value in condition (5) does not exceed the upper limit is advantageous for securing the angle of view at the wide-angle end. 0.08 <fw / f1<0.3 (5)

[0059] To obtain better characteristics, the lower limit of conditional equation (5) is more preferably 0.085, even more preferably 0.09, even more preferably 0.095, even more preferably 0.1, even more preferably 0.105, and even more preferably 0.11. To obtain better characteristics, the upper limit of conditional equation (5) is more preferably 0.22, even more preferably 0.2, even more preferably 0.18, even more preferably 0.17, even more preferably 0.16, and even more preferably 0.15.

[0060] The variable magnification optical system preferably satisfies the following condition (6). By ensuring that the corresponding value in condition (6) does not fall below the lower limit, the negative refractive power of the M1 lens group GM1 does not become too strong, thereby suppressing the increase in the diameter of the light beam incident on the intermediate group GM and the group closer to the image than the intermediate group GM, which is advantageous for miniaturization. By ensuring that the corresponding value in condition (6) does not exceed the upper limit, the negative refractive power of the M1 lens group GM1 does not become too weak, which is advantageous for achieving a high magnification ratio. -3 <fw / fM1<-0.2 (6)

[0061] To obtain better characteristics, the lower limit of conditional equation (6) is more preferably -2.5, even more preferably -2, even more preferably -1.8, even more preferably -1.6, even more preferably -1.4, even more preferably -1.3, even more preferably -1.2, even more preferably -1.1, and even more preferably -1.05. To obtain better characteristics, the upper limit of conditional equation (6) is more preferably -0.3, even more preferably -0.4, even more preferably -0.45, even more preferably -0.5, even more preferably -0.6, even more preferably -0.64, even more preferably -0.67, even more preferably -0.7, and even more preferably -0.73.

[0062] The variable magnification optical system preferably satisfies the following condition (7). By ensuring that the corresponding value in condition (7) does not fall below the lower limit, it is advantageous to suppress fluctuations in spherical aberration during magnification. By ensuring that the corresponding value in condition (7) does not exceed the upper limit, it is possible to suppress excessive correction of spherical aberration, especially at the wide-angle end. 0.1 <fw / fR1<1.4 (7)

[0063] To obtain better characteristics, the lower limit of conditional equation (7) is more preferably 0.2, even more preferably 0.25, even more preferably 0.3, even more preferably 0.35, even more preferably 0.37, even more preferably 0.39, even more preferably 0.41, even more preferably 0.43, and even more preferably 0.45. To obtain better characteristics, the upper limit of conditional equation (7) is more preferably 1.3, even more preferably 1.2, even more preferably 1.1, even more preferably 1, even more preferably 0.95, even more preferably 0.9, even more preferably 0.85, even more preferably 0.83, and even more preferably 0.81.

[0064] The variable magnification optical system preferably satisfies the following condition (8). Here, ft is the focal length of the entire variable magnification optical system when in focus on an object at infinity at the telephoto end. By ensuring that the corresponding value in condition (8) does not fall below the lower limit, the refractive power of the first lens group G1 does not become too strong, which is advantageous in suppressing aberration fluctuations during magnification. By ensuring that the corresponding value in condition (8) does not exceed the upper limit, the refractive power of the first lens group G1 does not become too weak, which is advantageous in shortening the overall optical length. 0.6 <f1 / (fw×ft) 1 / 2 <4 (8)

[0065] To obtain better characteristics, the lower limit of conditional equation (8) is more preferably 0.9, even more preferably 1.2, even more preferably 1.4, even more preferably 1.55, even more preferably 1.65, and even more preferably 1.75. To obtain better characteristics, the upper limit of conditional equation (8) is more preferably 3.5, even more preferably 3, even more preferably 2.9, even more preferably 2.8, even more preferably 2.5, and even more preferably 2.3.

[0066] It is preferable that the variable magnification optical system satisfies the following condition (9). By ensuring that the corresponding value in condition (9) does not fall below the lower limit, the magnification ratio does not become too low, allowing the variable magnification optical system to fully demonstrate its value. By ensuring that the corresponding value in condition (9) does not exceed the upper limit, the magnification ratio does not become too high, preventing excessive movement of the lens group, which is advantageous for miniaturizing the entire optical system. 9 <ft / fw<60 (9)

[0067] To obtain better characteristics, the lower limit of conditional expression (9) is more preferably 11, even more preferably 13, even more preferably 15, even more preferably 17, even more preferably 18, and even more preferably 19. To obtain better characteristics, the upper limit of conditional expression (9) is more preferably 50, even more preferably 40, even more preferably 30, even more preferably 25, even more preferably 22, and even more preferably 20.

[0068] In a configuration in which the subsequent group GR includes an anti-vibration group that moves in a direction intersecting the optical axis Z during image blur correction, it is preferable that the variable magnification optical system satisfies the following conditional equation (10). Here, the focal length of the anti-vibration group is denoted as fois. By ensuring that the corresponding value of conditional equation (10) does not fall below the lower limit, the amount of movement of the anti-vibration group during image blur correction can be suppressed, thereby reducing the overall size of the variable magnification optical system and the size of the anti-vibration unit (i.e., the anti-vibration group and the mechanism that moves this anti-vibration group). By ensuring that the corresponding value of conditional equation (10) does not exceed the upper limit, the refractive power of the anti-vibration group does not become too strong, thereby suppressing aberration fluctuations during image blur correction. 0.1 <fw / |fois|<1.5 (10)

[0069] To obtain better characteristics, the lower limit of conditional expression (10) is more preferably 0.2, even more preferably 0.3, even more preferably 0.4, even more preferably 0.5, even more preferably 0.6, and even more preferably 0.7. To obtain better characteristics, the upper limit of conditional expression (10) is more preferably 1.1, even more preferably 1, even more preferably 0.95, even more preferably 0.9, even more preferably 0.85, and even more preferably 0.8.

[0070] In a configuration where the subsequent group GR includes the above-mentioned image stabilization group, it is preferable that the variable magnification optical system satisfies the following conditional equation (11). Here, ωw is the maximum half-angle of view when in focus on an object at infinity at the wide-angle end. ωt is the maximum half-angle of view when in focus on an object at infinity at the telephoto end. As an example, Figure 1 shows the above-mentioned maximum half-angle of view ωw and maximum half-angle of view ωt. Conditional equation (11) is an equation that takes into account moving the image sensor placed on the image plane Sim in a direction perpendicular to the optical axis Z for image stabilization (i.e., image blur correction). In conditional equation (11), (fw × tanωw) / (ft × tanωt) corresponds to the ratio of the size of the image circle at the wide-angle end to the size of the image circle at the telephoto end. Since it is preferable that the image stabilization correction angle is approximately constant throughout the entire variable magnification range, it is preferable to change the size of the image circle between the wide-angle end and the telephoto end as in conditional equation (11). The amount of movement required to move the image sensor perpendicular to the optical axis Z for image stabilization increases proportionally to the focal length of the variable magnification optical system, assuming a constant image stabilization correction angle. By ensuring that the corresponding value in conditional equation (11) does not exceed the upper limit, the image circle at the telephoto end can be made larger than the image circle at the wide-angle end, making it easier to secure the required amount of movement of the image sensor within the image circle during image stabilization, especially at the telephoto end. By ensuring that the corresponding value in conditional equation (11) does not fall below the lower limit, it is possible to prevent the image sensor from becoming too large. 0.6 < (fw × tanωw) / (ft × tanωt) < 0.98 (11)

[0071] To obtain better characteristics, the lower limit of conditional equation (11) is more preferably 0.65, even more preferably 0.68, and even more preferably 0.7. To obtain better characteristics, the upper limit of conditional equation (11) is more preferably 0.91, even more preferably 0.85, and even more preferably 0.8.

[0072] The variable magnification optical system preferably satisfies the following condition (16). Here, ν1pave is defined as the average value of the Abbe numbers of all positive lenses in the first lens group G1, with respect to the d line. Ensuring that the corresponding value in condition (16) does not fall below the lower limit is advantageous for correcting axial chromatic aberration, especially at the telephoto end. Ensuring that the corresponding value in condition (16) does not exceed the upper limit is advantageous for correcting aberrations other than chromatic aberration. 70<ν1pave<97 (16)

[0073] To obtain better characteristics, the lower limit of conditional equation (16) is more preferably 78, and even more preferably 86. To obtain better characteristics, the upper limit of conditional equation (16) is more preferably 95, and even more preferably 93.

[0074] The variable magnification optical system preferably satisfies the following condition (20). By ensuring that the corresponding value in condition (20) does not fall below the lower limit, it is possible to suppress the incident angle of the off-axis principal rays on the image plane Sim from becoming excessively large, and it is also advantageous in suppressing aberration fluctuations during magnification. By ensuring that the corresponding value in condition (20) does not exceed the upper limit, it is advantageous in suppressing spherical aberration at the telephoto end. 0.1 < (-fMr) / fR1 < 5 (20)

[0075] To obtain better characteristics, the lower limit of conditional expression (20) is more preferably 0.3, even more preferably 0.5, even more preferably 0.7, even more preferably 0.9, even more preferably 1.1, and even more preferably 1.3. To obtain better characteristics, the upper limit of conditional expression (20) is more preferably 4, even more preferably 3, even more preferably 2.5, even more preferably 2.1, even more preferably 1.8, and even more preferably 1.5.

[0076] The variable magnification optical system preferably includes at least one of the specific lenses described below. The specific lens is defined as a lens that satisfies the following conditions (12) and (13). Here, Nd is the refractive index of the lens included in the variable magnification optical system with respect to the d line. νd is the d-line-referenced Abbe number of the lens included in the variable magnification optical system. 2.435 <Nd+0.01425×νd<2.75 (12) 15<νd<39 (13) The material for a specific lens may be glass, for example. Pages 40-42 of the proceedings of the 49th Optical Symposium (held June 20-21, 2024, organized by the Optical Society of Japan) describe optical glass that satisfies conditions (12) and (13) and a method for manufacturing it.

[0077] By ensuring that the corresponding value in conditional equation (12) does not fall below the lower limit, it becomes advantageous to perform good correction of spherical aberration and chromatic aberration. By ensuring that the corresponding value in conditional equation (12) does not exceed the upper limit, it is possible to suppress the difficulty of correcting field curvature.

[0078] To obtain better characteristics, the lower limit of conditional expression (12) is more preferably 2.445, even more preferably 2.455, even more preferably 2.468, even more preferably 2.48, even more preferably 2.49, even more preferably 2.5, even more preferably 2.51, and even more preferably 2.52. To obtain better characteristics, the upper limit of conditional expression (12) is more preferably 2.74, even more preferably 2.73, even more preferably 2.72, even more preferably 2.71, even more preferably 2.7, even more preferably 2.69, even more preferably 2.68, and even more preferably 2.67.

[0079] By ensuring that the corresponding value in conditional equation (13) does not fall below the lower limit, in addition to correcting the first-order aberration, the second-order spectrum can be corrected effectively. By ensuring that the corresponding value in conditional equation (13) does not exceed the upper limit, the second-order spectrum can be corrected more reliably and effectively.

[0080] To obtain better characteristics, the lower limit of conditional expression (13) is more preferably 15.5, even more preferably 16, even more preferably 16.5, even more preferably 16.8, even more preferably 17.1, and even more preferably 17.3. To obtain better characteristics, the upper limit of conditional expression (13) is more preferably 37, even more preferably 35, even more preferably 33, even more preferably 32, even more preferably 31, and even more preferably 30.

[0081] When the partial dispersion ratio between the g-line and F-line of the lens included in the variable magnification optical system is θgF, it is preferable that the specific lens satisfies the following condition (14). 0.65<θgF+0.00316×νd<0.85 (14)

[0082] Furthermore, if the refractive indices of a lens for the g-line, F-line, and C-line are Ng, NF, and NC, respectively, and the partial dispersion ratio between the g-line and F-line of that lens is θgF, then θgF is defined by the following formula. θgF = (Ng - NF) / (NF - NC)

[0083] By ensuring that the corresponding value in conditional equation (14) does not fall below the lower limit, in addition to correcting the first-order aberration, the second-order spectrum can be corrected effectively. By ensuring that the corresponding value in conditional equation (14) does not exceed the upper limit, the second-order spectrum can be corrected more reliably and effectively.

[0084] To obtain better characteristics, the lower limit of conditional equation (14) is more preferably 0.67, even more preferably 0.675, even more preferably 0.68, even more preferably 0.683, even more preferably 0.689, and even more preferably 0.692. To obtain better characteristics, the upper limit of conditional equation (14) is more preferably 0.8, even more preferably 0.78, even more preferably 0.76, even more preferably 0.74, even more preferably 0.73, and even more preferably 0.725.

[0085] The intermediate group GM preferably includes at least one specific lens. This is advantageous in suppressing fluctuations in chromatic aberration during magnification. The specific lens included in the intermediate group GM preferably satisfies the above condition (14).

[0086] In particular, the Mr lens group GMr preferably includes at least one specific lens. This is advantageous in suppressing fluctuations in chromatic aberration during magnification. The specific lens included in the Mr lens group GMr preferably satisfies the above conditional equation (14).

[0087] The subsequent group GR preferably includes at least one specific lens. This is particularly advantageous for suppressing axial chromatic aberration. The specific lens included in the subsequent group GR preferably satisfies the above conditional equation (14).

[0088] The variable magnification optical system includes at least one cemented lens, and it is preferable that the at least one cemented lens of the variable magnification optical system includes a specific lens. By employing a specific lens as a component of the cemented lens, it is advantageous to suppress chromatic aberration. It is preferable that the specific lens included in the cemented lens satisfies the above condition formula (14).

[0089] In a configuration in which a variable magnification optical system includes a specific lens, it is preferable that the variable magnification optical system satisfies the following condition (15). Here, the EDL is defined as the maximum effective diameter of the specific lens having the largest effective diameter among the specific lenses included in the variable magnification optical system. That is, the EDL is defined as the larger of the effective diameter of the object-side surface and the effective diameter of the image-side surface of the specific lens having the largest effective diameter. By ensuring that the corresponding value of condition (15) does not fall below the lower limit, the diameter of the specific lens does not become too small, making it easier to correct chromatic aberration. By ensuring that the corresponding value of condition (15) does not exceed the upper limit, the diameter of the specific lens does not become too large, thus preventing the manufacturing of the specific lens from becoming too difficult. 0.1 <EDL / (2×ft×tanωt)<2 (15)

[0090] To obtain better characteristics, the lower limit of conditional expression (15) is more preferably 0.2, even more preferably 0.3, even more preferably 0.36, even more preferably 0.39, even more preferably 0.41, and even more preferably 0.43. To obtain better characteristics, the upper limit of conditional expression (15) is more preferably 1.8, even more preferably 1.6, even more preferably 1.4, even more preferably 1.2, even more preferably 1, and even more preferably 0.95.

[0091] Here, we will explain the "effective diameter" with reference to Figure 3. Figure 3 is an explanatory diagram showing the configuration in a cross-section including the optical axis Z. In Figure 3, the left side is the object side and the right side is the image side. Figure 3 shows the on-axis light beam Xa and off-axis light beam Xb passing through the lens Lx. In the example in Figure 3, the ray Xb1, which is the upper ray of the off-axis light beam Xb, is the outermost ray. Here, "outside" means radially outward with respect to the optical axis Z, that is, away from the optical axis Z. In this specification, the effective diameter ED is twice the distance from the position Px, the intersection point of this outermost ray with respect to the lens surface, to the optical axis Z. Note that in the example in Figure 3, the upper ray of the off-axis light beam Xb is the outermost ray, but which ray is the outermost ray will vary depending on the optical system.

[0092] The variable magnification optical system of this disclosure can be modified in various ways without departing from the spirit of the technology of this disclosure. For example, the number of lens groups included in the intermediate group GM and the number of lens groups included in the subsequent group GR may differ from the example in Figure 1. The number of lenses included in each lens group, the image stabilization group and the focusing group may also differ from the example in Figure 1. Furthermore, although Figure 1 shows an example where the variable magnification optical system is a zoom lens, the variable magnification optical system of this disclosure may also be a varifocal lens.

[0093] For example, the intermediate GM group may be configured to consist of three lens groups. This configuration is advantageous for suppressing aberration variations during magnification.

[0094] More specifically, the intermediate group GM may be configured to consist of, in order from the object side to the image side, an M1 lens group GM1 having negative refractive power, an M2p lens group having positive refractive power, and an Mr lens group GMr having negative refractive power. In the configuration in which the intermediate group GM consists of the above-mentioned M1 lens group GM1, M2p lens group, and Mr lens group GMr, it is preferable that the variable magnification optical system satisfies the following conditional equation (19). Here, the focal length of the M2p lens group is set to fM2p. Ensuring that the corresponding value of conditional equation (19) does not fall below the lower limit is advantageous in suppressing aberration fluctuations during magnification. Ensuring that the corresponding value of conditional equation (19) does not exceed the upper limit is advantageous in suppressing spherical aberration at the telephoto end. 0.3 <fM2p / (-fMr)<5 (19)

[0095] To obtain better characteristics, the lower limit of conditional expression (19) is more preferably 0.7, even more preferably 1, even more preferably 1.2, even more preferably 1.4, even more preferably 1.6, and even more preferably 1.8. To obtain better characteristics, the upper limit of conditional expression (19) is more preferably 4.5, even more preferably 4, even more preferably 3.8, even more preferably 3.6, even more preferably 3.4, and even more preferably 3.2.

[0096] Alternatively, the intermediate group GM may be configured to consist of, in order from the object side to the image side, an M1 lens group having negative refractive power, an M2n lens group having negative refractive power, and an Mr lens group GMr having negative refractive power. In the configuration in which the intermediate group GM consists of the above-mentioned M1 lens group GM1, M2n lens group, and Mr lens group GMr, it is preferable that the variable magnification optical system satisfies the following conditional equation (21). Here, the focal length of the M2n lens group is set to fM2n. By ensuring that the corresponding value of conditional equation (21) does not fall below the lower limit, the negative refractive power of the M1 lens group GM1 does not become too weak, which is advantageous for achieving a high magnification ratio. By ensuring that the corresponding value of conditional equation (21) does not exceed the upper limit, the negative refractive power of the M2n lens group does not become too weak, which allows for a balanced distribution of negative refractive power between the M1 lens group GM1 and the M2n lens group, which is advantageous for suppressing aberration fluctuations during magnification. 1 <fM2n / fM1<20 (21)

[0097] To obtain better characteristics, the lower limit of conditional expression (21) is more preferably 1.2, even more preferably 1.3, even more preferably 1.4, even more preferably 1.5, even more preferably 1.6, and even more preferably 1.7. To obtain better characteristics, the upper limit of conditional expression (21) is more preferably 10, even more preferably 7, even more preferably 4, even more preferably 3.5, even more preferably 3.3, and even more preferably 3.

[0098] The subsequent lens group GR may be configured to include at least one lens group having negative refractive power. In a configuration in which the subsequent lens group GR includes at least one lens group having negative refractive power, it is preferable that the variable magnification optical system satisfies the following conditional equation (17). Here, fRnf is the focal length of the lens group with negative refractive power closest to the object among the lens groups with negative refractive power included in the subsequent lens group GR. By ensuring that the corresponding value of conditional equation (17) does not fall below the lower limit, it is advantageous to suppress aberration fluctuations during magnification. By ensuring that the corresponding value of conditional equation (17) does not exceed the upper limit, it is advantageous to suppress spherical aberration at the telephoto end. 0.1 <fR1 / (-fRnf)<5 (17)

[0099] To obtain better characteristics, the lower limit of conditional expression (17) is more preferably 0.2, even more preferably 0.3, even more preferably 0.35, even more preferably 0.4, even more preferably 0.45, and even more preferably 0.5. To obtain better characteristics, the upper limit of conditional expression (17) is more preferably 4, even more preferably 3, even more preferably 2, even more preferably 1.5, even more preferably 1, and even more preferably 0.8.

[0100] The subsequent lens group GR may be configured to include at least two lens groups having negative refractive power. In a configuration in which the subsequent lens group GR includes at least two lens groups having negative refractive power, it is preferable that the variable magnification optical system satisfies the following conditional equation (18). Here, fRnr is the focal length of the lens group with the most negative refractive power on the image side among the negative refractive power lens groups included in the subsequent lens group GR. By ensuring that the corresponding value of conditional equation (18) does not fall below the lower limit, it is advantageous to prevent excessive correction of aberrations during magnification. By ensuring that the corresponding value of conditional equation (18) does not exceed the upper limit, it is possible to suppress the incidence angle of the off-axis principal rays onto the image plane Sim from becoming excessive. 0.01 <fR1 / (-fRnr)<0.5 (18)

[0101] To obtain better characteristics, the lower limit of conditional equation (18) is more preferably 0.012, even more preferably 0.014, even more preferably 0.016, even more preferably 0.018, even more preferably 0.02, and even more preferably 0.022. To obtain better characteristics, the upper limit of conditional equation (18) is more preferably 0.4, even more preferably 0.3, even more preferably 0.25, even more preferably 0.2, even more preferably 0.15, and even more preferably 0.1.

[0102] The preferred and possible configurations described above, including those relating to conditional expressions, can be combined in any way within the bounds of consistency, and are preferably selected selectively as appropriate according to the required specifications.

[0103] As an example, a preferred embodiment of the present disclosure is a variable magnification optical system comprising, in order from the object side to the image side, a first lens group G1 having positive refractive power, an intermediate group GM, and a subsequent group GR, wherein the intermediate group GM has a negative refractive power M1 lens group GM1 positioned closest to the object, and the intermediate group GM has a negative refractive power Mr lens group GMr positioned closest to the image, and the intermediate group GM consists of three or fewer lens groups having refractive powers, including the M1 lens group GM1 and the Mr lens group GMr, and the subsequent group GR has a positive refractive power R1 lens group GR1 positioned closest to the object, and during magnification, the first lens group G1 is fixed with respect to the image plane Sim, and the spacing between all adjacent lens groups changes, satisfying the above condition (1).

[0104] Next, embodiments of the variable magnification optical system of this disclosure will be described with reference to the drawings. Note that the reference numerals assigned to each group in the cross-sectional view of each embodiment are used independently for each embodiment to avoid complexity in the explanation and drawings due to the increasing number of digits in the reference numerals. Therefore, even if common reference numerals are assigned in the drawings of different embodiments, they do not necessarily represent common configurations.

[0105] [Example 1] The configuration and movement trajectory of the variable magnification optical system of Example 1 are shown in Figure 1, and the method of illustration and configuration are as described above, so some redundant explanations will be omitted here. The variable magnification optical system of Example 1 consists of a first lens group G1 having positive refractive power, an intermediate group GM, and a subsequent group GR, in order from the object side to the image side. The intermediate group GM consists of two lens groups, the M1 lens group GM1 having negative refractive power and the Mr lens group GMr having negative refractive power, in order from the object side to the image side. The subsequent group GR consists of one lens group, the R1 lens group GR1 having positive refractive power.

[0106] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 12th to 15th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves towards the image side.

[0107] For the variable magnification optical system of Example 1, the basic lens data is shown in Tables 1A and 1B, and the specifications and variable plane spacing are shown in Table 2. Here, to avoid making a single table too long, the basic lens data is shown in two separate tables.

[0108] The basic lens data table is described as follows: The "Sn" column shows the surface number, with the surface closest to the object being designated as the first surface and the number increasing by one as you move towards the image side. The "R" column shows the radius of curvature of each surface. The "D" column shows the interplanar spacing on the optical axis between each surface and the surface adjacent to it on the image side. The "Nd" column shows the refractive index of each component with respect to the d line. The "νd" column shows the Abbe number of each component based on the d line. The "θgF" column shows the partial dispersion ratio between the g line and the F line of each component. The "Material" column shows the material name of each component and the name of the manufacturer, separated by a period. Including the table of examples described later, the names of manufacturers are generally shown as follows: "HOYA" refers to HOYA Corporation. "OHARA" refers to Ohara Corporation. "HIKARI" refers to Hikari Glass Co., Ltd. "SCHOTT" refers to SCHOTT Company. "SUMITA" refers to Sumita Optical Glass Co., Ltd. "CDGM" stands for Chengdu Guangming Optoelectronics Co., Ltd. "NHG" stands for Hubei Xinhua Guang Information Materials Co., Ltd. The "ED" column shows the effective diameter of each face.

[0109] In the basic lens data table, the sign of the radius of curvature of a surface with a convex shape facing the object is positive, and the sign of the radius of curvature of a surface with a convex shape facing the image is negative. In the column for the surface number of the surface corresponding to the aperture diaphragm St, the surface number and the phrase (St) are entered. The value in the bottom column of column D in the table is the distance between the image-side surface in the table and the image plane Sim. For variable surface spacing during magnification, the symbol DD[ ] is used, and the object-side surface number for this spacing is placed inside the [ ] and entered in the surface spacing column.

[0110] Table 2 shows the magnification ratio Zr, focal length f, back focus Bf, maximum aperture F-number FNo., maximum angle of view 2ω, and variable plane spacing relative to the d line. If the variable magnification optical system is a zoom lens, the magnification ratio is synonymous with the zoom magnification. The [°] in the 2ω column indicates that the unit is degrees. In Table 2, the columns labeled "Wide," "Middle," and "Tele" show the values ​​for the wide-angle end, intermediate focal length, and telephoto end, respectively.

[0111] In the data in each table, degrees are used as the unit for angles and millimeters as the unit for lengths. However, since optical systems can be used with proportional magnification or reduction, other appropriate units can also be used. Furthermore, the values ​​in the tables below are rounded to a predetermined number of decimal places.

[0112] [Table 1A]

[0113] [Table 1B]

[0114] [Table 2]

[0115] Figure 4 shows the aberration diagrams of the variable magnification optical system of Example 1 when focused on an object at infinity. In Figure 4, from left to right, the diagrams show spherical aberration, astigmatism, distortion, and chromatic aberration. In Figure 4, the upper section labeled "Wide" shows the aberrations at the wide-angle end, the middle section labeled "Middle" shows the aberrations at intermediate focal lengths, and the lower section labeled "Tele" shows the aberrations at the telephoto end. In the spherical aberration diagram, the aberrations along the d, C, F, and g lines are shown as solid lines, long dashed lines, short dashed lines, and dashed lines, respectively. In the astigmatism diagram, the aberration along the d line in the sagittal direction is shown as a solid line, and the aberration along the d line in the tangential direction is shown as a short dashed line. In the distortion diagram, the aberration along the d line is shown as a solid line. In the chromatic aberration diagram, the aberrations along the C, F, and g lines are shown by long dashed lines, short dashed lines, and dashed lines, respectively. In the spherical aberration diagram, the value of the wide-open F number is shown after FNo.=. In other aberration diagrams, the value of the maximum half-angle of view is shown after ω=.

[0116] The symbols, meanings, methods of description, and methods of illustration for each data point in Example 1 described above are basically the same in the following examples unless otherwise specified, so redundant explanations will be omitted below.

[0117] [Example 2] Figure 5 shows the configuration and movement trajectory of the variable magnification optical system of Example 2. The variable magnification optical system of Example 2 consists of a first lens group G1 with positive refractive power, an intermediate group GM, and a subsequent group GR, arranged in order from the object side to the image side. The intermediate group GM consists of two lens groups, the M1 lens group GM1 with negative refractive power and the Mr lens group GMr with negative refractive power, arranged in order from the object side to the image side. The subsequent group GR consists of one lens group, the R1 lens group GR1 with positive refractive power.

[0118] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 7th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 10th to 13th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves towards the image side.

[0119] For the variable magnification optical system of Example 2, the basic lens data is shown in Tables 3A and 3B, the specifications and variable plane spacing are shown in Table 4, the aspherical coefficient is shown in Table 5, and the aberration diagrams are shown in Figure 6.

[0120] In the basic lens data table, the aspherical surface numbers are marked with an asterisk (*), and the column for the radius of curvature of the aspherical surface lists the value of the paraxial radius of curvature. In Table 5, the row labeled Sn shows the aspherical surface number, and the rows labeled KA and Am show the numerical value of the aspherical coefficient for each aspherical surface. Note that m in Am is an integer greater than or equal to 3 and varies depending on the surface. For example, for surface 45 in Example 2, m = 4, 6, 8, 10, 12, 14, 16, 18, 20. The numerical value of the aspherical coefficient in Table 5, "E±n" (n: integer), is "×10 ±n This means "[...]. KA and Am are the aspheric coefficients in the aspheric equation expressed by the following formula. Zd = C × h 2 / {1+(1-KA×C 2 ×h 2 ) 1 / 2}+ΣAm×h m however, Zd: Aspherical depth (length of the perpendicular line drawn from a point on the aspherical surface at height h to a plane perpendicular to the optical axis Z to which the aspherical surface tangent is located). h: Height (distance from the optical axis Z to the lens surface) C: Reciprocal of the radius of paraxial curvature KA, Am: Aspherical coefficients Therefore, the Σ in the aspherical formula represents the summation with respect to m. The method of describing aspherical surfaces described above is basically the same in the following examples unless otherwise specified.

[0121] [Table 3A]

[0122] [Table 3B]

[0123] [Table 4]

[0124] [Table 5]

[0125] [Example 3] Figure 7 shows the configuration and movement trajectory of the variable magnification optical system of Example 3. The variable magnification optical system of Example 3 consists of a first lens group G1 having positive refractive power, an intermediate group GM, and a subsequent group GR, in order from the object side to the image side. The intermediate group GM consists of two lens groups, the M1 lens group GM1 having negative refractive power and the Mr lens group GMr having negative refractive power, in order from the object side to the image side. The subsequent group GR consists of one lens group, the R1 lens group GR1 having positive refractive power.

[0126] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 7th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 10th to 13th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves towards the image side.

[0127] For the variable magnification optical system of Example 3, the basic lens data is shown in Tables 6A and 6B, the specifications and variable plane spacing are shown in Table 7, and the aberration diagrams are shown in Figure 8.

[0128] [Table 6A]

[0129] [Table 6B]

[0130] [Table 7] [Example 4] Figure 9 shows the configuration and movement trajectory of the variable magnification optical system of Example 4. The variable magnification optical system of Example 4 consists of a first lens group G1 having positive refractive power, an intermediate group GM, and a subsequent group GR, in order from the object side to the image side. The intermediate group GM consists of two lens groups, the M1 lens group GM1 having negative refractive power and the Mr lens group GMr having negative refractive power, in order from the object side to the image side. The subsequent group GR consists of one lens group, the R1 lens group GR1 having positive refractive power.

[0131] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 12th to 14th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves toward the image side.

[0132] For the variable magnification optical system of Example 4, the basic lens data is shown in Tables 8A and 8B, the specifications and variable plane spacing are shown in Table 9, the aspherical coefficient is shown in Table 10, and the aberration diagrams are shown in Figure 10.

[0133] [Table 8A]

[0134] [Table 8B]

[0135] [Table 9]

[0136] [Table 10]

[0137] [Example 5] Figure 11 shows the configuration and movement trajectory of the variable magnification optical system of Example 5. The variable magnification optical system of Example 5 consists of a first lens group G1 having positive refractive power, an intermediate group GM, and a subsequent group GR, in order from the object side to the image side. The intermediate group GM consists of two lens groups, the M1 lens group GM1 having negative refractive power and the Mr lens group GMr having negative refractive power, in order from the object side to the image side. The subsequent group GR consists of one lens group, the R1 lens group GR1 having positive refractive power.

[0138] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 12th to 14th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves toward the image side.

[0139] For the variable magnification optical system of Example 5, the basic lens data is shown in Tables 11A and 11B, the specifications and variable plane spacing are shown in Table 12, the aspherical coefficient is shown in Table 13, and the aberration diagrams are shown in Figure 12.

[0140] [Table 11A]

[0141] [Table 11B]

[0142] [Table 12]

[0143] [Table 13]

[0144] [Example 6] Figure 13 shows the configuration and movement trajectory of the variable magnification optical system of Example 6. The variable magnification optical system of Example 6 consists of a first lens group G1 having positive refractive power, an intermediate group GM, and a subsequent group GR, in order from the object side to the image side. The intermediate group GM consists of two lens groups, the M1 lens group GM1 having negative refractive power and the Mr lens group GMr having negative refractive power, in order from the object side to the image side. The subsequent group GR consists of one lens group, the R1 lens group GR1 having positive refractive power.

[0145] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 12th to 14th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves toward the image side.

[0146] For the variable magnification optical system of Example 6, the basic lens data is shown in Tables 14A and 14B, the specifications and variable plane spacing are shown in Table 15, the aspherical coefficient is shown in Table 16, and the aberration diagrams are shown in Figure 14.

[0147] [Table 14A]

[0148] [Table 14B]

[0149] [Table 15]

[0150] [Table 16]

[0151] [Example 7] Figure 15 shows the configuration and movement trajectory of the variable magnification optical system of Example 7. The variable magnification optical system of Example 7 consists of a first lens group G1 with positive refractive power, an intermediate group GM, and a subsequent group GR, arranged in order from the object side to the image side. The intermediate group GM consists of two lens groups, the M1 lens group GM1 with negative refractive power and the Mr lens group GMr with negative refractive power, arranged in order from the object side to the image side. The subsequent group GR consists of one lens group, the R1 lens group GR1 with positive refractive power.

[0152] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 12th to 14th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves toward the image side.

[0153] For the variable magnification optical system of Example 7, the basic lens data is shown in Tables 17A and 17B, the specifications and variable plane spacing are shown in Table 18, the aspherical coefficient is shown in Table 19, and the aberration diagrams are shown in Figure 16.

[0154] [Table 17A]

[0155] [Table 17B]

[0156] [Table 18]

[0157] [Table 19]

[0158] [Example 8] Figure 17 shows the configuration and movement trajectory of the variable magnification optical system of Example 8. The variable magnification optical system of Example 8 consists of a first lens group G1 with positive refractive power, an intermediate group GM, and a subsequent group GR, arranged in order from the object side to the image side. The intermediate group GM consists of two lens groups, the M1 lens group GM1 with negative refractive power and the Mr lens group GMr with negative refractive power, arranged in order from the object side to the image side. The subsequent group GR consists of one lens group, the R1 lens group GR1 with positive refractive power.

[0159] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 12th to 14th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves toward the image side.

[0160] For the variable magnification optical system of Example 8, the basic lens data is shown in Tables 20A and 20B, the specifications and variable plane spacing are shown in Table 21, the aspherical coefficient is shown in Table 22, and the aberration diagrams are shown in Figure 18.

[0161] [Table 20A]

[0162] [Table 20B]

[0163] [Table 21]

[0164] [Table 22]

[0165] [Example 9] Figure 19 shows the configuration and movement trajectory of the variable magnification optical system of Example 9. The variable magnification optical system of Example 9 consists of a first lens group G1 with positive refractive power, an intermediate group GM, and a subsequent group GR, arranged in order from the object side to the image side. The intermediate group GM consists of two lens groups, the M1 lens group GM1 with negative refractive power and the Mr lens group GMr with negative refractive power, arranged in order from the object side to the image side. The subsequent group GR consists of one lens group, the R1 lens group GR1 with positive refractive power.

[0166] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 12th to 14th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves toward the image side.

[0167] For the variable magnification optical system of Example 9, the basic lens data is shown in Tables 23A and 23B, the specifications and variable plane spacing are shown in Table 24, the aspherical coefficient is shown in Table 25, and the aberration diagrams are shown in Figure 20.

[0168] [Table 23A]

[0169] [Table 23B]

[0170] [Table 24]

[0171] [Table 25]

[0172] [Example 10] Figure 21 shows the configuration and movement trajectory of the variable magnification optical system of Example 10. The variable magnification optical system of Example 10 consists of a first lens group G1 having positive refractive power, an intermediate group GM, and a subsequent group GR, in order from the object side to the image side. The intermediate group GM consists of two lens groups, the M1 lens group GM1 having negative refractive power and the Mr lens group GMr having negative refractive power, in order from the object side to the image side. The subsequent group GR consists of one lens group, the R1 lens group GR1 having positive refractive power.

[0173] When zooming from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed with respect to the image plane Sim, and the other lens groups move along the optical axis Z by changing the distance between adjacent lens groups. The anti-vibration group consists of four lenses, the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of three lenses, the 12th to 14th lenses from the object side of the R1 lens group GR1. When focusing from an infinite object to the closest object, the focusing group moves toward the image side.

[0174] Regarding the zoom optical system of Example 10, the basic lens data is shown in Tables 26A and 26B, the specifications and variable surface intervals are shown in Table 27, the aspherical coefficients are shown in Table 28, and each aberration diagram is shown in FIG. 22.

[0175] The zoom optical system of Example 10 includes specific lenses. Lenses with any of "N231.Glass", "N216.Glass", and "N200.Glass" described in the material column of the basic lens data table are specific lenses. The notation method for specific lenses in this basic lens data table is the same in the examples described later.

[0176] As "N231.Glass", "N216.Glass", and "N200.Glass", the glasses described in the lecture proceedings of the 49th Optical Symposium (Session: June 20 - 21, Reiwa 6, Organizer: The Optical Society of Japan) on pages 40 - 42 can be used.

[0177]

Table 26A

[0178]

Table 26B

[0179]

Table 27

[0180]

Table 28

[0181] [Example 11] Figure 23 shows the configuration and movement trajectory of the variable magnification optical system of Example 11. The variable magnification optical system of Example 11 consists of a first lens group G1 having positive refractive power, an intermediate group GM, and a subsequent group GR, in order from the object side to the image side. The intermediate group GM consists of two lens groups, the M1 lens group GM1 having negative refractive power and the Mr lens group GMr having negative refractive power, in order from the object side to the image side. The subsequent group GR consists of one lens group, the R1 lens group GR1 having positive refractive power.

[0182] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 12th to 14th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves toward the image side.

[0183] For the variable magnification optical system of Example 11, the basic lens data is shown in Tables 29A and 29B, the specifications and variable plane spacing are shown in Table 30, the aspherical coefficient is shown in Table 31, and the aberration diagrams are shown in Figure 24.

[0184] [Table 29A]

[0185] [Table 29B]

[0186] [Table 30]

[0187] [Table 31]

[0188] [Example 12] The configuration and movement locus of the zoom optical system of Example 12 are shown in FIG. 25. The zoom optical system of Example 12 includes, in order from the object side to the image side, a first lens group G1 having a positive refractive power, an intermediate group GM, and a subsequent group GR. The intermediate group GM includes three lens groups: an M1 lens group GM1 having a negative refractive power, an M2 lens group GM2 having a positive refractive power, and an Mr lens group GMr having a negative refractive power, in order from the object side to the image side. The M2 lens group GM2 having a positive refractive power corresponds to the M2p lens group described above. The subsequent group GR consists of one lens group, an R1 lens group GR1 having a positive refractive power.

[0189] When zooming from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed with respect to the image plane Sim, and the other lens groups move along the optical axis Z by changing the interval between adjacent lens groups. The anti-shake group consists of four lenses from the 5th to the 8th lenses on the object side of the R1 lens group GR1. The focusing group consists of four lenses from the 12th to the 15th lenses on the object side of the R1 lens group GR1. When focusing from an infinite object to the closest object, the focusing group moves toward the image side. <{

[0190] Regarding the zoom optical system of Example 12, the basic lens data are shown in Tables 32A and 32B, the specifications and variable surface intervals are shown in Table 33, the aspherical coefficients are shown in Table 34, and each aberration diagram is shown in FIG. 26.

[0191]

Table 32A

[0192]

Table 32B

[0193]

Table 33

[0194] [Table 34]

[0195] [Example 13] Figure 27 shows the configuration and movement trajectory of the variable magnification optical system of Example 13. The variable magnification optical system of Example 13 consists of a first lens group G1 with positive refractive power, an intermediate group GM, and a successor group GR, in order from the object side to the image side. The intermediate group GM consists of three lens groups, in order from the object side to the image side: the M1 lens group GM1 with negative refractive power, the M2 lens group GM2 with positive refractive power, and the Mr lens group GMr with negative refractive power. The M2 lens group GM2 with positive refractive power corresponds to the M2p lens group described above. The successor group GR consists of one lens group, the R1 lens group GR1 with positive refractive power.

[0196] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 12th to 15th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves towards the image side.

[0197] For the variable magnification optical system of Example 13, the basic lens data is shown in Tables 35A and 35B, the specifications and variable plane spacing are shown in Table 36, the aspherical coefficient is shown in Table 37, and the aberration diagrams are shown in Figure 28.

[0198] [Table 35A]

[0199] [Table 35B]

[0200] [Table 36]

[0201] [Table 37]

[0202] [Example 14] Figure 29 shows the configuration and movement trajectory of the variable magnification optical system of Example 14. The variable magnification optical system of Example 14 consists of a first lens group G1 with positive refractive power, an intermediate group GM, and a subsequent group GR, in order from the object side to the image side. The intermediate group GM consists of three lens groups, in order from the object side to the image side: the M1 lens group GM1 with negative refractive power, the M2 lens group GM2 with positive refractive power, and the Mr lens group GMr with negative refractive power. The M2 lens group GM2 with positive refractive power corresponds to the M2p lens group described above. The subsequent group GR consists of one lens group, the R1 lens group GR1 with positive refractive power.

[0203] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 12th to 15th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves towards the image side.

[0204] For the variable magnification optical system of Example 14, the basic lens data is shown in Tables 38A and 38B, the specifications and variable plane spacing are shown in Table 39, the aspherical coefficient is shown in Table 40, and the aberration diagrams are shown in Figure 30.

[0205] [Table 38A]

[0206] [Table 38B]

[0207] [Table 39]

[0208] [Table 40]

[0209] [Example 15] Figure 31 shows the configuration and movement trajectory of the variable magnification optical system of Example 15. The variable magnification optical system of Example 15 consists of a first lens group G1 with positive refractive power, an intermediate group GM, and a subsequent group GR, in order from the object side to the image side. The intermediate group GM consists of three lens groups, in order from the object side to the image side: the M1 lens group GM1 with negative refractive power, the M2 lens group GM2 with negative refractive power, and the Mr lens group GMr with negative refractive power. The M2 lens group GM2 with negative refractive power corresponds to the M2n lens group described above. The subsequent group GR consists of one lens group, the R1 lens group GR1 with positive refractive power.

[0210] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 12th to 15th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves towards the image side.

[0211] For the variable magnification optical system of Example 15, the basic lens data is shown in Tables 41A and 41B, the specifications and variable plane spacing are shown in Table 42, and the aberration diagrams are shown in Figure 32.

[0212] [Table 41A]

[0213] [Table 41B]

[0214] [Table 42]

[0215] [Example 16] Figure 33 shows the configuration and movement trajectory of the variable magnification optical system of Example 16. The variable magnification optical system of Example 16 consists of a first lens group G1 with positive refractive power, an intermediate group GM, and a subsequent group GR, in order from the object side to the image side. The intermediate group GM consists of three lens groups, in order from the object side to the image side: the M1 lens group GM1 with negative refractive power, the M2 lens group GM2 with negative refractive power, and the Mr lens group GMr with negative refractive power. The M2 lens group GM2 with negative refractive power corresponds to the M2n lens group described above. The subsequent group GR consists of one lens group, the R1 lens group GR1 with positive refractive power.

[0216] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 12th to 15th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves towards the image side.

[0217] For the variable magnification optical system of Example 16, the basic lens data is shown in Tables 43A and 43B, the specifications and variable plane spacing are shown in Table 44, the aspherical coefficient is shown in Table 45, and the aberration diagrams are shown in Figure 34.

[0218] [Table 43A]

[0219] [Table 43B]

[0220] [Table 44]

[0221] [Table 45]

[0222] [Example 17] Figure 35 shows the configuration and movement trajectory of the variable magnification optical system of Example 17. The variable magnification optical system of Example 17 consists of a first lens group G1 with positive refractive power, an intermediate group GM, and a subsequent group GR, in order from the object side to the image side. The intermediate group GM consists of three lens groups, in order from the object side to the image side: the M1 lens group GM1 with negative refractive power, the M2 lens group GM2 with negative refractive power, and the Mr lens group GMr with negative refractive power. The M2 lens group GM2 with negative refractive power corresponds to the M2n lens group described above. The subsequent group GR consists of one lens group, the R1 lens group GR1 with positive refractive power.

[0223] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 12th to 15th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves towards the image side.

[0224] For the variable magnification optical system of Example 17, the basic lens data is shown in Tables 46A and 46B, the specifications and variable plane spacing are shown in Table 47, the aspherical coefficient is shown in Table 48, and the aberration diagrams are shown in Figure 36.

[0225] [Table 46A]

[0226] [Table 46B]

[0227] [Table 47]

[0228] [Table 48]

[0229] [Example 18] Figure 37 shows the configuration and movement trajectory of the variable magnification optical system of Example 18. The variable magnification optical system of Example 18 consists of a first lens group G1 with positive refractive power, an intermediate group GM, and a subsequent group GR, in order from the object side to the image side. The intermediate group GM consists of three lens groups, in order from the object side to the image side: the M1 lens group GM1 with negative refractive power, the M2 lens group GM2 with negative refractive power, and the Mr lens group GMr with negative refractive power. The M2 lens group GM2 with negative refractive power corresponds to the M2n lens group described above. The subsequent group GR consists of one lens group, the R1 lens group GR1 with positive refractive power.

[0230] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 12th to 15th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves towards the image side.

[0231] For the variable magnification optical system of Example 18, the basic lens data is shown in Tables 49A and 49B, the specifications and variable plane spacing are shown in Table 50, and the aberration diagrams are shown in Figure 38.

[0232] [Table 49A]

[0233] [Table 49B]

[0234] [Table 50]

[0235] [Example 19] Figure 39 shows the configuration and movement trajectory of the variable magnification optical system of Example 19. The variable magnification optical system of Example 19 consists of a first lens group G1 with positive refractive power, an intermediate group GM, and a successor group GR, in order from the object side to the image side. The intermediate group GM consists of three lens groups, in order from the object side to the image side: the M1 lens group GM1 with negative refractive power, the M2 lens group GM2 with negative refractive power, and the Mr lens group GMr with negative refractive power. The M2 lens group GM2 with negative refractive power corresponds to the M2n lens group described above. The successor group GR consists of one lens group, the R1 lens group GR1 with positive refractive power.

[0236] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 12th to 15th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves towards the image side.

[0237] For the variable magnification optical system of Example 19, the basic lens data is shown in Tables 51A and 51B, the specifications and variable plane spacing are shown in Table 52, the aspherical coefficient is shown in Table 53, and the aberration diagrams are shown in Figure 40.

[0238] [Table 51A]

[0239] [Table 51B]

[0240] [Table 52]

[0241] [Table 53]

[0242] [Example 20] Figure 41 shows the configuration and movement trajectory of the variable magnification optical system of Example 20. The variable magnification optical system of Example 20 consists of a first lens group G1 with positive refractive power, an intermediate group GM, and a successor group GR, in order from the object side to the image side. The intermediate group GM consists of three lens groups, in order from the object side to the image side: the M1 lens group GM1 with negative refractive power, the M2 lens group GM2 with negative refractive power, and the Mr lens group GMr with negative refractive power. The M2 lens group GM2 with negative refractive power corresponds to the M2n lens group described above. The successor group GR consists of one lens group, the R1 lens group GR1 with positive refractive power.

[0243] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 12th to 15th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves towards the image side.

[0244] For the variable magnification optical system of Example 20, the basic lens data is shown in Tables 54A and 54B, the specifications and variable plane spacing are shown in Table 55, the aspherical coefficient is shown in Table 56, and the aberration diagrams are shown in Figure 42.

[0245] [Table 54A]

[0246] [Table 54B]

[0247] [Table 55]

[0248] [Table 56]

[0249] [Example 21] Figure 43 shows the configuration and movement trajectory of the variable magnification optical system of Example 21. The variable magnification optical system of Example 21 consists of a first lens group G1 with positive refractive power, an intermediate group GM, and a subsequent group GR, in order from the object side to the image side. The intermediate group GM consists of three lens groups, in order from the object side to the image side: the M1 lens group GM1 with negative refractive power, the M2 lens group GM2 with negative refractive power, and the Mr lens group GMr with negative refractive power. The M2 lens group GM2 with negative refractive power corresponds to the M2n lens group described above. The subsequent group GR consists of one lens group, the R1 lens group GR1 with positive refractive power.

[0250] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 12th to 15th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves towards the image side.

[0251] For the variable magnification optical system of Example 21, the basic lens data is shown in Tables 57A and 57B, the specifications and variable plane spacing are shown in Table 58, the aspherical coefficient is shown in Table 59, and the aberration diagrams are shown in Figure 44.

[0252] [Table 57A]

[0253] [Table 57B]

[0254] [Table 58]

[0255] [Table 59]

[0256] [Example 22] Figure 45 shows the configuration and movement trajectory of the variable magnification optical system of Example 22. The variable magnification optical system of Example 22 consists of a first lens group G1 with positive refractive power, an intermediate group GM, and a subsequent group GR, in order from the object side to the image side. The intermediate group GM consists of three lens groups, in order from the object side to the image side: the M1 lens group GM1 with negative refractive power, the M2 lens group GM2 with negative refractive power, and the Mr lens group GMr with negative refractive power. The M2 lens group GM2 with negative refractive power corresponds to the M2n lens group described above. The subsequent group GR consists of one lens group, the R1 lens group GR1 with positive refractive power.

[0257] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 12th to 15th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves towards the image side.

[0258] For the variable magnification optical system of Example 22, the basic lens data is shown in Tables 60A and 60B, the specifications and variable plane spacing are shown in Table 61, and the aberration diagrams are shown in Figure 46.

[0259] [Table 60A]

[0260] [Table 60B]

[0261] [Table 61]

[0262] [Example 23] Figure 47 shows the configuration and movement trajectory of the variable magnification optical system of Example 23. The variable magnification optical system of Example 23 consists of a first lens group G1 with positive refractive power, an intermediate group GM, and a subsequent group GR, in order from the object side to the image side. The intermediate group GM consists of three lens groups, in order from the object side to the image side: the M1 lens group GM1 with negative refractive power, the M2 lens group GM2 with negative refractive power, and the Mr lens group GMr with negative refractive power. The M2 lens group GM2 with negative refractive power corresponds to the M2n lens group described above. The subsequent group GR consists of one lens group, the R1 lens group GR1 with positive refractive power.

[0263] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 12th to 15th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves towards the image side.

[0264] For the variable magnification optical system of Example 23, the basic lens data is shown in Tables 62A and 62B, the specifications and variable plane spacing are shown in Table 63, the aspherical coefficient is shown in Table 64, and the aberration diagrams are shown in Figure 48.

[0265] [Table 62A]

[0266] [Table 62B]

[0267] [Table 63]

[0268] [Table 64]

[0269] [Example 24] Figure 49 shows the configuration and movement trajectory of the variable magnification optical system of Example 24. The variable magnification optical system of Example 24 consists of a first lens group G1 with positive refractive power, an intermediate group GM, and a successor group GR, in order from the object side to the image side. The intermediate group GM consists of three lens groups, in order from the object side to the image side: the M1 lens group GM1 with negative refractive power, the M2 lens group GM2 with negative refractive power, and the Mr lens group GMr with negative refractive power. The M2 lens group GM2 with negative refractive power corresponds to the M2n lens group described above. The successor group GR consists of one lens group, the R1 lens group GR1 with positive refractive power.

[0270] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 12th to 15th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves towards the image side.

[0271] For the variable magnification optical system of Example 24, the basic lens data is shown in Tables 65A and 65B, the specifications and variable plane spacing are shown in Table 66, the aspherical coefficient is shown in Table 67, and the aberration diagrams are shown in Figure 50.

[0272] [Table 65A]

[0273] [Table 65B]

[0274] [Table 66]

[0275] [Table 67]

[0276] [Example 25] Figure 51 shows the configuration and movement trajectory of the variable magnification optical system of Example 25. The variable magnification optical system of Example 25 consists of a first lens group G1 with positive refractive power, an intermediate group GM, and a subsequent group GR, in order from the object side to the image side. The intermediate group GM consists of three lens groups, in order from the object side to the image side: the M1 lens group GM1 with negative refractive power, the M2 lens group GM2 with negative refractive power, and the Mr lens group GMr with negative refractive power. The M2 lens group GM2 with negative refractive power corresponds to the M2n lens group described above. The subsequent group GR consists of one lens group, the R1 lens group GR1 with positive refractive power.

[0277] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 4th to 7th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 11th to 14th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves towards the image side.

[0278] For the variable magnification optical system of Example 25, the basic lens data is shown in Tables 68A and 68B, the specifications and variable plane spacing are shown in Table 69, the aspherical coefficient is shown in Table 70, and the aberration diagrams are shown in Figure 52.

[0279] [Table 68A]

[0280] [Table 68B]

[0281] [Table 69]

[0282] [Table 70]

[0283] [Example 26] Figure 53 shows the configuration and movement trajectory of the variable magnification optical system of Example 26. The variable magnification optical system of Example 26 consists of a first lens group G1 with positive refractive power, an intermediate group GM, and a subsequent group GR, in order from the object side to the image side. The intermediate group GM consists of three lens groups, in order from the object side to the image side: the M1 lens group GM1 with negative refractive power, the M2 lens group GM2 with negative refractive power, and the Mr lens group GMr with negative refractive power. The M2 lens group GM2 with negative refractive power corresponds to the M2n lens group described above. The subsequent group GR consists of one lens group, the R1 lens group GR1 with positive refractive power.

[0284] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 12th to 15th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves towards the image side.

[0285] For the variable magnification optical system of Example 26, the basic lens data is shown in Tables 71A and 71B, the specifications and variable plane spacing are shown in Table 72, the aspherical coefficient is shown in Table 73, and the aberration diagrams are shown in Figure 54.

[0286] [Table 71A]

[0287] [Table 71B]

[0288] [Table 72]

[0289] [Table 73]

[0290] [Example 27] Figure 55 shows the configuration and movement trajectory of the variable magnification optical system of Example 27. The variable magnification optical system of Example 27 consists of a first lens group G1 with positive refractive power, an intermediate group GM, and a subsequent group GR, in order from the object side to the image side. The intermediate group GM consists of three lens groups, in order from the object side to the image side: the M1 lens group GM1 with negative refractive power, the M2 lens group GM2 with negative refractive power, and the Mr lens group GMr with negative refractive power. The M2 lens group GM2 with negative refractive power corresponds to the M2n lens group described above. The subsequent group GR consists of one lens group, the R1 lens group GR1 with positive refractive power.

[0291] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 12th to 15th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves towards the image side.

[0292] For the variable magnification optical system of Example 27, the basic lens data is shown in Tables 74A and 74B, the specifications and variable plane spacing are shown in Table 75, the aspherical coefficient is shown in Table 76, and the aberration diagrams are shown in Figure 56.

[0293] [Table 74A]

[0294] [Table 74B]

[0295] [Table 75]

[0296] [Table 76]

[0297] [Example 28] Figure 57 shows the configuration and movement trajectory of the variable magnification optical system of Example 28. The variable magnification optical system of Example 28 consists of a first lens group G1 with positive refractive power, an intermediate group GM, and a subsequent group GR, in order from the object side to the image side. The intermediate group GM consists of three lens groups, in order from the object side to the image side: the M1 lens group GM1 with negative refractive power, the M2 lens group GM2 with negative refractive power, and the Mr lens group GMr with negative refractive power. The M2 lens group GM2 with negative refractive power corresponds to the M2n lens group described above. The subsequent group GR consists of one lens group, the R1 lens group GR1 with positive refractive power.

[0298] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 12th to 15th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves towards the image side.

[0299] For the variable magnification optical system of Example 28, the basic lens data is shown in Tables 77A and 77B, the specifications and variable plane spacing are shown in Table 78, the aspherical coefficient is shown in Table 79, and the aberration diagrams are shown in Figure 58.

[0300] [Table 77A]

[0301] [Table 77B]

[0302] [Table 78]

[0303] [Table 79]

[0304] [Example 29] Figure 59 shows the configuration and movement trajectory of the variable magnification optical system of Example 29. The variable magnification optical system of Example 29 consists of a first lens group G1 with positive refractive power, an intermediate group GM, and a successor group GR, in order from the object side to the image side. The intermediate group GM consists of two lens groups, M1 lens group GM1 with negative refractive power and Mr lens group GMr, both with negative refractive power, in order from the object side to the image side. The successor group GR consists of three lens groups, R1 lens group GR1 with positive refractive power, R2 lens group GR2 with negative refractive power and R3 lens group GR3 with negative refractive power, in order from the object side to the image side.

[0305] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1, the R1 lens group GR1, and the R3 lens group GR3 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the R2 lens group GR2. When focusing from an object at infinity to the nearest object, the focusing group moves towards the image side.

[0306] For the variable magnification optical system of Example 29, the basic lens data is shown in Tables 80A and 80B, the specifications and variable plane spacing are shown in Table 81, the aspherical coefficient is shown in Table 82, and the aberration diagrams are shown in Figure 60.

[0307] [Table 80A]

[0308] [Table 80B]

[0309] [Table 81]

[0310] [Table 82]

[0311] [Example 30] Figure 61 shows the configuration and movement trajectory of the variable magnification optical system of Example 30. The variable magnification optical system of Example 30 consists of a first lens group G1 with positive refractive power, an intermediate group GM, and a successor group GR, in order from the object side to the image side. The intermediate group GM consists of three lens groups, in order from the object side to the image side: the M1 lens group GM1 with negative refractive power, the M2 lens group GM2 with negative refractive power, and the Mr lens group GMr with negative refractive power. The M2 lens group GM2 with negative refractive power corresponds to the M2n lens group described above. The successor group GR consists of three lens groups, in order from the object side to the image side: the R1 lens group GR1 with positive refractive power, the R2 lens group GR2 with negative refractive power, and the R3 lens group GR3 with positive refractive power.

[0312] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1, the R1 lens group GR1, and the R3 lens group GR3 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the R2 lens group GR2. When focusing from an object at infinity to the nearest object, the focusing group moves towards the image side.

[0313] For the variable magnification optical system of Example 30, the basic lens data is shown in Tables 83A and 83B, the specifications and variable plane spacing are shown in Table 84, the aspherical coefficient is shown in Table 85, and the aberration diagrams are shown in Figure 62.

[0314] [Table 83A]

[0315] [Table 83B]

[0316] [Table 84]

[0317] [Table 85]

[0318] [Example 31] Figure 63 shows the configuration and movement trajectory of the variable magnification optical system of Example 31. The variable magnification optical system of Example 31 consists of a first lens group G1 with positive refractive power, an intermediate group GM, and a successor group GR, in order from the object side to the image side. The intermediate group GM consists of three lens groups, in order from the object side to the image side: the M1 lens group GM1 with negative refractive power, the M2 lens group GM2 with positive refractive power, and the Mr lens group GMr with negative refractive power. The M2 lens group GM2 with positive refractive power corresponds to the M2p lens group described above. The successor group GR consists of three lens groups, in order from the object side to the image side: the R1 lens group GR1 with positive refractive power, the R2 lens group GR2 with negative refractive power, and the R3 lens group GR3 with negative refractive power.

[0319] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1, the R1 lens group GR1, and the R3 lens group GR3 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 5th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the R2 lens group GR2. When focusing from an object at infinity to the nearest object, the focusing group moves towards the image side.

[0320] For the variable magnification optical system of Example 31, the basic lens data is shown in Tables 86A and 86B, the specifications and variable plane spacing are shown in Table 87, the aspherical coefficient is shown in Table 88, and the aberration diagrams are shown in Figure 64.

[0321] [Table 86A]

[0322] [Table 86B]

[0323] [Table 87]

[0324] [Table 88]

[0325] [Example 32] Figure 65 shows the configuration and movement trajectory of the variable magnification optical system of Example 32. The variable magnification optical system of Example 32 consists of a first lens group G1 with positive refractive power, an intermediate group GM, and a subsequent group GR, arranged in order from the object side to the image side. The intermediate group GM consists of two lens groups, the M1 lens group GM1 with negative refractive power and the Mr lens group GMr with negative refractive power, arranged in order from the object side to the image side. The subsequent group GR consists of one lens group, the R1 lens group GR1 with positive refractive power. Figure 65 shows an example in which an optical element P1 is placed between the subsequent group GR and the image plane Sim. The optical element P1 is a parallel plate-shaped member with no refractive power, such as various filters and / or cover glass.

[0326] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the R1 lens group GR1 are fixed relative to the image plane Sim, while the other lens groups move along the optical axis Z by changing the spacing between adjacent lens groups. The image stabilization group consists of the 6th to 8th lenses from the object side of the R1 lens group GR1. The focusing group consists of the 12th to 14th lenses from the object side of the R1 lens group GR1. When focusing from an object at infinity to the nearest object, the focusing group moves toward the image side.

[0327] For the variable magnification optical system of Example 32, the basic lens data is shown in Tables 89A and 89B, the specifications and variable plane spacing are shown in Table 90, and the aberration diagrams are shown in Figure 66.

[0328] [Table 89A]

[0329] [Table 89B]

[0330] [Table 90]

[0331] Tables 91 to 97 show the corresponding values ​​for conditional equations (1) to (11) and (15) to (21) of the variable magnification optical systems in Examples 1 to 32. Table 98 shows the corresponding values ​​for conditional equations (12) to (14) for "N231. Glass", "N216. Glass", and "N200. Glass" used in the above examples. The corresponding values ​​for the examples shown in Tables 91 to 98 may be used as the upper or lower limits of the conditional equations to set a preferred range for the conditional equations.

[0332] [Table 91]

[0333] [Table 92]

[0334] [Table 93]

[0335] [Table 94]

[0336] [Table 95]

[0337] [Table 96]

[0338] [Table 97]

[0339] [Table 98]

[0340] The variable magnification optical systems of Examples 1 to 32 have a magnification ratio of 18 times or more, achieving a high magnification ratio. Furthermore, the variable magnification optical systems of Examples 1 to 32 maintain high optical performance with aberrations well corrected throughout the entire magnification range.

[0341] Next, an imaging device according to an embodiment of the present disclosure will be described. Figure 67 shows a schematic configuration diagram of an imaging device 500 according to one embodiment of the present disclosure. Examples of the imaging device 500 include surveillance cameras, film cameras, broadcast cameras, digital cameras, film cameras, video cameras, FA (Factory Automation) cameras, and MV (Machine Vision) cameras.

[0342] The imaging device 500 comprises a variable magnification optical system 1 according to one embodiment of the present disclosure, a filter 2 disposed on the image side of the variable magnification optical system 1, and an image sensor 3 disposed on the image side of the filter 2. Figure 67 schematically illustrates the multiple lenses provided by the variable magnification optical system 1.

[0343] The image sensor 3 converts the optical image formed by the variable magnification optical system 1 into an electrical signal, and can be, for example, a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor). The image sensor 3 is positioned so that its imaging surface coincides with the image plane of the variable magnification optical system 1.

[0344] The imaging device 500 also includes a signal processing unit 5, a display unit 6, a magnification control unit 7, a focus control unit 8, and a vibration damping control unit 9. The signal processing unit 5 performs calculations on the output signal from the image sensor 3. The display unit 6 displays the image formed by the signal processing unit 5. The magnification control unit 7 controls the magnification of the magnification optical system 1. The focus control unit 8 controls the focusing of the magnification optical system 1. The vibration damping control unit 9 controls the vibration damping of the magnification optical system 1. Although only one image sensor 3 is shown in Figure 67, the imaging device may also be a so-called three-chip system having three image sensors.

[0345] Although the technology of this disclosure has been described above with reference to embodiments and examples, the technology of this disclosure is not limited to the above embodiments and examples, and various modifications are possible. For example, the radius of curvature, interplanar spacing, refractive index, Abbe number, and aspheric coefficient of each lens are not limited to the values ​​shown in each of the above embodiments, but can take other values.

[0346] The following additional information is disclosed regarding the above embodiments and examples. [Note 1] It consists of a first lens group with positive refractive power, an intermediate group, and a subsequent group, arranged in order from the object side to the image side. The M1 lens group, which has a negative refractive power, is positioned at the object side of the aforementioned intermediate group. The Mr lens group, which has negative refractive power, is positioned at the image-side end of the aforementioned intermediate group. The aforementioned intermediate group consists of three or fewer lens groups having refractive power, including the M1 lens group and the Mr lens group. The R1 lens group, which has a positive refractive power, is positioned at the object side of the aforementioned successor group. During magnification, the first lens group is fixed relative to the image plane, and the spacing between all adjacent lens groups changes. The focal length of the aforementioned M1 lens group is fM1, When the focal length of the first lens group is set to f1, 0.05 < (-fM1) / f1 < 0.8 (1) A variable magnification optical system that satisfies the condition (1) expressed by . [Note 2] When the focal length of the R1 lens group is denoted as fR1, 0.05 <fR1 / f1<0.85 (2) A variable magnification optical system as described in Appendix 1 that satisfies the conditional equation (2) represented by . [Note 3] If the focal length of the aforementioned Mr lens group is denoted as fMr, 0.8 <fMr / fM1<7 (3) A variable magnification optical system according to Appendix 1 or Appendix 2 that satisfies the conditional expression (3) represented by . [Note 4] DG1 is the distance along the optical axis from the object-side surface of the first lens group to the image-side surface of the first lens group. When the lens group is in focus on an object at infinity at the wide-angle end, Dsum is the distance along the optical axis from the object-side surface of the first lens group to the image-side surface of the subsequent lens group. 0.012 <DG1 / Dsum<0.25 (4) A variable magnification optical system described in any one of the appendices 1 to 3 that satisfies the conditional equation (4) represented by . [Note 5] If fw is the focal length of the entire variable magnification optical system when it is in focus on an object at infinity at the wide-angle end, 0.08 <fw / f1<0.3 (5) A variable magnification optical system described in any one of the appendices 1 to 4 that satisfies the conditional equation (5) represented by . [Note 6] If fw is the focal length of the entire variable magnification optical system when it is in focus on an object at infinity at the wide-angle end, -3 <fw / fM1<-0.2 (6) A variable magnification optical system described in any one of the appendices 1 to 5 that satisfies the conditional equation (6) represented by . [Note 7] fw is the focal length of the entire variable magnification optical system when it is in focus on an object at infinity at the wide-angle end. When the focal length of the R1 lens group is denoted as fR1, 0.1 <fw / fR1<1.4 (7) A variable magnification optical system described in any one of the appendices 1 to 6 that satisfies the conditional equation (7) represented by . [Note 8] Let the focal length of the entire zoom optical system in the state of being focused on an infinite object at the wide-angle end be fw, when the focal length of the entire zoom optical system in the state of being focused on an infinite object at the telephoto end is ft, 0.6 < f1 / (fw × ft) 1 / 2 <4 (8) The zoom optical system according to any one of Appendices 1 to 7 that satisfies the conditional expression (8) represented by [Appendix 9] Let the focal length of the entire zoom optical system in the state of being focused on an infinite object at the wide-angle end be fw, when the focal length of the entire zoom optical system in the state of being focused on an infinite object at the telephoto end is ft, 9 < ft / fw < 60 (9) The zoom optical system according to any one of Appendices 1 to 8 that satisfies the conditional expression (9) represented by [Appendix 10] The subsequent group includes an anti-vibration group that moves in a direction intersecting the optical axis during image blur correction, Let the focal length of the entire zoom optical system in the state of being focused on an infinite object at the wide-angle end be fw, when the focal length of the anti-vibration group is fois, 0.1 < fw / |fois| < 1.5 (10) The zoom optical system according to any one of Appendices 1 to 9 that satisfies the conditional expression (10) represented by [Appendix 11] Let the focal length of the entire zoom optical system in the state of being focused on an infinite object at the telephoto end be ft, Let the maximum half-angle of view at the wide-angle end in the state of being focused on an infinite object be ωw, when the maximum half-angle of view at the telephoto end in the state of being focused on an infinite object is ωt, <00018​​​​​​​​If the Abbe number of the lens included in the variable magnification optical system is νd, 2.435 <Nd+0.01425×νd<2.75 (12) 15<νd<39 (13) A variable magnification optical system according to any one of the appendices 1 to 11, comprising at least one specific lens that satisfies the conditional equations (12) and (13) represented by . [Note 13] When the partial dispersion ratio between the g-line and the F-line of the lens included in the aforementioned variable magnification optical system is denoted as θgF, The aforementioned specific lens is 0.65<θgF+0.00316×νd<0.85 (14) A variable magnification optical system as described in Appendix 12 that satisfies the conditional equation (14) represented by . [Note 14] Among the specific lenses included in the variable magnification optical system, the maximum effective diameter of the specific lens having the largest effective diameter is defined as EDL. The focal length of the entire variable magnification optical system when it is in focus on an object at infinity at the telephoto end is ft. If ωt is the maximum half-angle of view when in focus on an object at infinity at the telephoto end, 0.1 <EDL / (2×ft×tanωt)<2 (15) A variable magnification optical system according to Appendix 12 or Appendix 13 that satisfies the conditional expression (15) represented by . [Note 15] The intermediate group is a variable magnification optical system according to any one of appendices 12 to 14, which includes at least one of the specified lenses. [Note 16] The subsequent group is a variable magnification optical system according to any one of appendices 12 to 15, which includes at least one of the specified lenses. [Note 17] The variable magnification optical system includes at least one cemented lens, The variable magnification optical system is the variable magnification optical system according to any one of appendices 12 to 16, wherein at least one of the cemented lenses of the variable magnification optical system includes the specified lens. [Note 18] The aforementioned intermediate group is a variable magnification optical system described in any one of the appendices 1 to 17, consisting of three lens groups. [Note 19] The M1 lens group is a variable magnification optical system as described in any one of the appendices 1 to 18, comprising two or more positive lenses and three or more negative lenses. [Note 20] An imaging device equipped with a variable magnification optical system as described in any one of the appendices 1 to 19. [Explanation of symbols]

[0347] 1. Variable magnification optical system 2 filters 3 Image sensor 5. Signal Processing Unit 6 Display section 7. Multiplication Control Unit 8. Focusing Control Unit 9. Vibration Isolation Control Unit 500 Imaging device DG1 distance Dsum distance ED Effective Diameter G1 First Lens Group GM intermediate group GM1 M1 lens group GM2 M2 lens group GMr Mr lens group GR follow-up group GR1 R1 lens group GR2 R2 lens group GR3 R3 lens group L11~L58 Lx lens P1 Optical component PP optical components Px position Sim image plane St aperture diaphragm Xa On-axis luminous flux Xb Off-axis luminous flux Xb1 ray Z optical axis ωt Maximum half-angle ωw Maximum half-angle

Claims

1. It consists of a first lens group with positive refractive power, an intermediate group, and a subsequent group, arranged in order from the object side to the image side. The M1 lens group, which has a negative refractive power, is positioned at the object-side end of the aforementioned intermediate group. An Mr lens group with negative refractive power is positioned at the image-side end of the aforementioned intermediate group. The aforementioned intermediate group consists of three or fewer lens groups having refractive power, including the M1 lens group and the Mr lens group. The R1 lens group, which has a positive refractive power, is positioned at the object-side end of the aforementioned successor group. During magnification, the first lens group is fixed relative to the image plane, and the spacing between all adjacent lens groups changes. The focal length of the M1 lens group is fM1, When the focal length of the first lens group is set to f1, 0.05<(-fM1) / f1<0.8 (1) A variable magnification optical system that satisfies the condition (1) represented by .

2. When the focal length of the R1 lens group is denoted as fR1, 0.05<fR1 / f1<0.85 (2) A variable magnification optical system according to claim 1 that satisfies the conditional expression (2) represented by .

3. When the focal length of the aforementioned Mr lens group is denoted as fMr, 0.8<fMr / fM1<7 (3) A variable magnification optical system according to claim 1 that satisfies the conditional expression (3) represented by .

4. DG1 is the distance along the optical axis from the object-side surface of the first lens group to the image-side surface of the first lens group. When the lens group is in focus on an object at infinity at the wide-angle end, Dsum is the distance along the optical axis from the object-side surface of the first lens group to the image-side surface of the subsequent lens group. 0.012<DG1 / Dsum<0.25 (4) A variable magnification optical system according to claim 1 that satisfies the conditional expression (4) represented by .

5. If fw is the focal length of the entire variable magnification optical system when it is in focus on an object at infinity at the wide-angle end, 0.08<fw / f1<0.3 (5) A variable magnification optical system according to claim 1 that satisfies the conditional expression (5) represented by .

6. If fw is the focal length of the entire variable magnification optical system when it is in focus on an object at infinity at the wide-angle end, -3<fw / fM1<-0.2 (6) A variable magnification optical system according to claim 1 that satisfies the conditional expression (6) represented by .

7. The focal length of the entire variable magnification optical system when in focus on an object at infinity at the wide-angle end is fw. When the focal length of the R1 lens group is denoted as fR1, 0.1<fw / fR1<1.4 (7) A variable magnification optical system according to claim 1 that satisfies the conditional expression (7) represented by .

8. The focal length of the entire variable magnification optical system when in focus on an object at infinity at the wide-angle end is fw. If the focal length of the entire variable magnification optical system when it is in focus on an object at infinity at the telephoto end is denoted as ft, 0.6<f1 / (fw×ft) １／２ <4 (8) A variable magnification optical system according to claim 1 that satisfies the conditional expression (8) represented by .

9. The focal length of the entire variable magnification optical system when in focus on an object at infinity at the wide-angle end is fw. If the focal length of the entire variable magnification optical system when it is in focus on an object at infinity at the telephoto end is denoted as ft, 9<ft / fw<60 (9) A variable magnification optical system according to claim 1 that satisfies the conditional expression (9) represented by .

10. The aforementioned successor group includes an anti-vibration group that moves in a direction intersecting the optical axis during image blur correction. The focal length of the entire variable magnification optical system when in focus on an object at infinity at the wide-angle end is fw. When the focal length of the vibration isolation group is fois, 0.1<fw / |fois|<1.5 (10) A variable magnification optical system according to claim 1 that satisfies the conditional expression (10) represented by .

11. The focal length of the entire variable magnification optical system when it is in focus on an object at infinity at the telephoto end is ft. The maximum half-angle when focusing on an object at infinity at the wide-angle end is ωw. If ωt is the maximum half-angle of view when in focus on an object at infinity at the telephoto end, 0.6 < (fw × tanωw) / (ft × tanωt) < 0.98 (11) A variable magnification optical system according to claim 10 that satisfies the conditional expression (11) represented by .

12. The refractive index of the lens included in the variable magnification optical system with respect to the d line is Nd. If the Abbe number of the lens included in the variable magnification optical system is νd, 2.435<Nd+0.01425×νd<2.75 (12) 15<νd<39 (13) The variable magnification optical system according to claim 1, comprising at least one specific lens that satisfies the conditional expressions (12) and (13) represented by .

13. When the partial dispersion ratio between the g-line and the F-line of the lens included in the aforementioned variable magnification optical system is denoted as θgF, The aforementioned specific lens is 0.65<θgF+0.00316×νd<0.85 (14) A variable magnification optical system according to claim 12 that satisfies the conditional expression (14) represented by .

14. Among the specific lenses included in the variable magnification optical system, the maximum effective diameter of the specific lens having the largest effective diameter is defined as EDL. The focal length of the entire variable magnification optical system when it is in focus on an object at infinity at the telephoto end is ft. If ωt is the maximum half-angle of view when in focus on an object at infinity at the telephoto end, 0.1<EDL / (2×ft×tanωt)<2 (15) A variable magnification optical system according to claim 12 that satisfies the conditional expression (15) represented by .

15. The variable magnification optical system according to claim 12, wherein the intermediate group includes at least one of the specified lenses.

16. The subsequent group includes at least one of the specified lenses in the variable magnification optical system according to claim 12.

17. The variable magnification optical system includes at least one cemented lens, The variable magnification optical system according to claim 12, wherein at least one of the cemented lenses of the variable magnification optical system includes the specific lens.

18. The intermediate group comprises three lens groups, as described in claim 1.

19. The M1 lens group includes two or more positive lenses and three or more negative lenses, according to claim 1. The variable magnification optical system described.

20. An imaging apparatus comprising a variable magnification optical system according to any one of claims 1 to 19.

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