Optical system, optical device, and method for manufacturing optical system

Abstract

The invention provides an optical system, an optical apparatus, and a method of manufacturing the optical system. An optical system used in an optical device such as a camera (1) is configured from, in order from the object side, a first lens group having a positive refractive power, a focusing group having a negative refractive power and moving along the optical axis during focusing, and a rear group having a positive refractive power and moving along the optical axis during focusing. The lens group disposed on the object side with the largest air gap (A) in the first lens group is set as the first 1A lens group, and the optical system satisfies the following conditional expressions: 1.00 lt, 1.00 lt, 1.00 lt, 1.00 lt, 1.00 lt, 1.00 lt, 1.00 lt, 1.00 lt, 1.00 lt, 1.00 lt; fNo * (TL / f) 2lt; 2.50 and 0.30 lt, 0.50 and 0.30 lt; dA / dG1lt; and 0.85%. Wherein FNo is the F value of the optical system during infinity focusing, TL is the optical full length of the optical system during infinity focusing, f is the focal length of the optical system during infinity focusing, dA is the distance on the optical axis of the air gap A, and dG1 is the distance on the optical axis of the first lens group.

Description

[0001] This application is a divisional application of the invention patent application filed on March 4, 2021, with international application number PCT / JP2021 / 008532, national application number 202180029750.X, and entitled "Optical System, Optical Device and Method of Manufacturing Optical System". Technical Field

[0002] This invention relates to optical systems, optical devices, and methods for manufacturing optical systems. Background Technology

[0003] Previously, optical systems used in photographic cameras, electronic still cameras, video cameras, etc., have been disclosed (see, for example, Patent Document 1).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2016-200685 Summary of the Invention

[0007] The optical system disclosed herein comprises, sequentially from the object side, a first lens group, a focusing group, and a rear group. The first lens group has positive optical power. The focusing group moves along the optical axis during focusing. The lens group disposed on the object side within the first lens group with the largest air gap A is designated as the first A lens group. The optical system satisfies all of the following conditions: 1.00 < FNo×(TL / f) 2 < 2.50 0.30 < dA / dG1 < 0.85 in, FNo: The F-number of the optical system when focusing at infinity. TL: The total optical length of the optical system when focusing at infinity. f: The focal length of the optical system when focusing at infinity. dA: The distance on the optical axis of the air gap A. dG1: The distance on the optical axis of the first lens group.

[0008] The optical system disclosed herein comprises, sequentially from the object side, a first lens group, a focusing group, and a rear group. The first lens group has positive optical power. The focusing group moves along the optical axis during focusing. The lens group disposed on the object side within the first lens group with the largest air gap A is designated as the first A lens group. The optical system satisfies all of the following conditions: 0.30 < TL / f < 0.80 0.30 < dA / dG1 < 0.85 in, TL: The total optical length of the optical system when focusing at infinity. f: The focal length of the optical system when focusing at infinity. dA: The distance on the optical axis of the air gap A. dG1: The distance on the optical axis of the first lens group.

[0009] The optical system disclosed herein is an optical system composed of multiple lenses, wherein the optical system has at least one positive lens component and a negative lens N sequentially from the object side, and the optical system satisfies all of the following conditions: 1.00 < FNo×(TL / f) 2 < 2.50 0.18 < dN / TL < 0.45 in, FNo: The F-number of the optical system when focusing at infinity. TL: The total optical length of the optical system when focusing at infinity. f: The focal length of the optical system when focusing at infinity. dN: The distance along the optical axis from the object-side surface of the optical system to the object-side surface of the negative lens N.

[0010] The optical system disclosed herein is an optical system composed of multiple lenses, wherein the optical system has a positive lens component on the object-side, and the optical system has a negative lens N on the object-side among the negative lenses disposed on the image side compared to the positive lens component, and the optical system satisfies all of the following conditions: 1.00 < FNo×(TL / f) 2 < 2.50 0.18 < dN / TL < 0.45 in, FNo: The F-number of the optical system when focusing at infinity. TL: The total optical length of the optical system when focusing at infinity. f: The focal length of the optical system when focusing at infinity. dN: The distance on the optical axis from the object-side surface of the optical system to the object-side surface of the negative lens N.

[0011] Regarding the manufacturing method of the optical system disclosed herein, the optical system comprises a plurality of lenses, wherein a first lens group, a focusing group, and a rear group are sequentially arranged from the object side, the first lens group having positive optical power, the focusing group moving along the optical axis during focusing, and a first A lens group arranged on the object side with the maximum air gap A within the first lens group, configured to satisfy all of the following conditions: 1.00 < FNo×(TL / f) 2 < 2.50 0.30 < dA / dG1 < 0.85 in, FNo: The F-number of the optical system when focusing at infinity. TL: The total optical length of the optical system when focusing at infinity. f: The focal length of the optical system when focusing at infinity. dA: The distance on the optical axis of the air gap A. dG1: The distance on the optical axis of the first lens group.

[0012] The method for manufacturing an optical system disclosed herein, the optical system comprising a plurality of lenses, wherein at least one positive lens component and a negative lens N are sequentially arranged from the object side, configured to satisfy all of the following conditions: 1.00 < FNo×(TL / f) 2 < 2.50 0.18 < dN / TL < 0.45 in, FNo: The F-number of the optical system when focusing at infinity. TL: The total optical length of the optical system when focusing at infinity. f: The focal length of the optical system when focusing at infinity. dN: The distance along the optical axis from the object-side surface of the optical system to the object-side surface of the negative lens N. Attached Figure Description

[0013] Figure 1A This is a cross-sectional view of the optical system of the first embodiment for focusing on an object at infinity.

[0014] Figure 1B This is a cross-sectional view of the optical system of the first embodiment when focusing on a close-up object.

[0015] Figure 2 This is a diagram of the aberrations of the optical system in the first embodiment when focusing on an object at infinity.

[0016] Figure 3AThis is a cross-sectional view of the optical system of the second embodiment when focusing on an object at infinity.

[0017] Figure 3B This is a cross-sectional view of the optical system of the second embodiment when focusing on a close-up object.

[0018] Figure 4 This is a diagram of the aberrations of the optical system in the second embodiment when focusing on an object at infinity.

[0019] Figure 5A This is a cross-sectional view of the optical system of the third embodiment when focusing on an object at infinity.

[0020] Figure 5B This is a cross-sectional view of the optical system of the third embodiment when focusing on a close-up object.

[0021] Figure 6 This is a diagram of the aberrations of the optical system in the third embodiment when focusing on an object at infinity.

[0022] Figure 7A This is a cross-sectional view of the optical system of the fourth embodiment when focusing on an object at infinity.

[0023] Figure 7B This is a cross-sectional view of the optical system of the fourth embodiment when focusing on a close-up object.

[0024] Figure 8 This is a diagram of the aberrations of the optical system in the fourth embodiment when focusing on an object at infinity.

[0025] Figure 9A This is a cross-sectional view of the optical system of the fifth embodiment when focusing on an object at infinity.

[0026] Figure 9B This is a cross-sectional view of the optical system of the fifth embodiment when focusing on a close-up object.

[0027] Figure 10 This is a diagram of the aberrations of the optical system in the fifth embodiment when focusing on an object at infinity.

[0028] Figure 11A This is a cross-sectional view of the optical system of the sixth embodiment when focusing on an object at infinity.

[0029] Figure 11B This is a cross-sectional view of the optical system of the sixth embodiment when focusing on a close-up object.

[0030] Figure 12 This is a diagram of the aberrations of the optical system in the sixth embodiment when focusing on an object at infinity.

[0031] Figure 13A This is a cross-sectional view of the optical system of the seventh embodiment when focusing on an object at infinity.

[0032] Figure 13B This is a cross-sectional view of the optical system of the seventh embodiment when focusing on a close-up object.

[0033] Figure 14 This is a diagram of the aberrations of the optical system in the seventh embodiment when focusing on an object at infinity.

[0034] Figure 15A This is a cross-sectional view of the optical system of the eighth embodiment when focusing on an object at infinity.

[0035] Figure 15B This is a cross-sectional view of the optical system of the eighth embodiment when focusing on a close-up object.

[0036] Figure 16 This is a diagram of the aberrations of the optical system in the eighth embodiment when focusing on an object at infinity.

[0037] Figure 17A This is a cross-sectional view of the optical system of the 9th embodiment when focusing on an object at infinity.

[0038] Figure 17B This is a cross-sectional view of the optical system of the 9th embodiment when focusing on a close-up object.

[0039] Figure 18 This is a diagram of the aberrations of the optical system in the 9th embodiment when focusing on an object at infinity.

[0040] Figure 19A This is a cross-sectional view of the optical system of the 10th embodiment when focusing on an object at infinity.

[0041] Figure 19B This is a cross-sectional view of the optical system of the 10th embodiment when focusing on a close-up object.

[0042] Figure 20 This is a diagram of the aberrations of the optical system in the 10th embodiment when focusing on an object at infinity.

[0043] Figure 21A This is a cross-sectional view of the optical system of the 11th embodiment when focusing on an object at infinity.

[0044] Figure 21B This is a cross-sectional view of the optical system of the 11th embodiment when focusing on a close-up object.

[0045] Figure 22 This is a diagram of the aberrations of the optical system in the 11th embodiment when focusing on an object at infinity.

[0046] Figure 23 This is a schematic diagram of a camera equipped with the optical system of this embodiment.

[0047] Figure 24 This is a first flowchart illustrating a general method for manufacturing the optical system according to this embodiment.

[0048] Figure 25 This is a second flowchart illustrating a general method for manufacturing the optical system according to this embodiment. Detailed Implementation

[0049] The optical system, optical device, and manufacturing method of the optical system according to the embodiments of this application will be described below.

[0050] The optical system of this embodiment consists of a first lens group, a focusing group, and a rear group in sequence from the object side. The first lens group has positive optical power. The focusing group moves along the optical axis when focusing. The lens group that is disposed on the object side within the first lens group with the largest air gap A is designated as the first A lens group. The optical system satisfies all of the following conditional expressions. (1) 1.00 < FNo×(TL / f) 2 < 2.50 (2) 0.30 < dA / dG1 < 0.85 in, FNo: The F-number of the optical system when focusing at infinity. TL: Total optical length of the optical system when focusing at infinity f: Focal length of the optical system when focusing at infinity dA: Distance on the optical axis of the air gap A dG1: Distance on the optical axis of the first lens group

[0051] The optical system of this embodiment, by correcting the lens on the image side compared to the first lens group A, can achieve an optical system that balances small size, lightweight design, and good optical performance. Furthermore, the optical system of this embodiment achieves miniaturization by satisfying conditional expression (1). Additionally, the optical system of this embodiment achieves lightweight design by satisfying conditional expression (2). The optical system of this embodiment achieves its effects more reliably by setting the upper limit of conditional expression (1) to 2.50. Furthermore, to more reliably achieve the effects of this embodiment, it is preferable to set the upper limit of conditional expression (1) to 2.45, 2.40, 2.35, 2.30, 2.25, 2.20, or more preferably 2.15.

[0052] Furthermore, by setting the lower limit value of conditional expression (1) to 1.00, the optical system of this embodiment can more reliably obtain the effects of this embodiment. In addition, in order to obtain the effects of this embodiment more reliably, it is preferable to set the lower limit value of conditional expression (1) to 1.10, 1.20, 1.25, 1.30, and more preferably 1.35.

[0053] The optical system of this embodiment can more reliably achieve the effect of this embodiment by setting the upper limit value of conditional expression (2) to 0.85. In addition, in order to more reliably achieve the effect of this embodiment, it is preferable to set the upper limit value of conditional expression (2) to 0.80, 0.76, 0.73, 0.70, and more preferably 0.68.

[0054] Furthermore, by setting the lower limit value of conditional expression (2) to 0.30, the optical system of this embodiment can more reliably achieve the effects of this embodiment. In addition, in order to more reliably achieve the effects of this embodiment, it is preferable to set the lower limit value of conditional expression (2) to 0.31, 0.33, or even 0.35.

[0055] Based on the above structure, a small, lightweight optical system with good imaging performance can be realized.

[0056] The optical system of this embodiment consists of a first lens group, a focusing group, and a rear group in sequence from the object side. The first lens group has positive optical power. The focusing group moves along the optical axis when focusing. The lens group that is disposed on the object side within the first lens group with the largest air gap A is designated as the first A lens group. The optical system satisfies all of the following conditional expressions. (3) 0.30 < TL / f < 0.80 (2) 0.30 < dA / dG1 < 0.85 in, TL: Total optical length of the optical system when focusing at infinity f: Focal length of the optical system when focusing at infinity dA: Distance on the optical axis of the air gap A dG1: Distance on the optical axis of the first lens group

[0057] The optical system of this embodiment, by using a lens on the image side compared to the first lens group A for correction, achieves an optical system that balances small size, lightweight design, and good optical performance. Furthermore, the optical system of this embodiment achieves miniaturization by satisfying condition (3). Additionally, the optical system of this embodiment achieves lightweight design by satisfying condition (2).

[0058] The optical system of this embodiment prevents the total length of the optical system from becoming excessively long by ensuring that the ratio of the total optical length to the focal length of the optical system is less than an upper limit. Furthermore, by setting the upper limit of conditional expression (3) to 0.80, the effects of this embodiment can be obtained more reliably. Moreover, to further ensure the effectiveness of this embodiment, it is preferable to set the upper limit of conditional expression (3) to 0.78, 0.76, 0.74, 0.72, and more preferably 0.70.

[0059] The optical system of this embodiment can effectively correct image plane curvature by making the ratio of the total optical length to the focal length of the optical system greater than a lower limit. Furthermore, by setting the lower limit of conditional expression (3) to 0.30, the effect of this embodiment can be obtained more reliably. Moreover, to obtain the effect of this embodiment more reliably, it is preferable to set the lower limit of conditional expression (3) to 0.33, 0.36, 0.40, 0.42, and more preferably 0.44.

[0060] The optical system of this embodiment can more reliably achieve the effect of this embodiment by setting the upper limit value of conditional expression (2) to 0.85. In addition, in order to more reliably achieve the effect of this embodiment, it is preferable to set the upper limit value of conditional expression (2) to 0.80, 0.76, 0.73, 0.70, and more preferably 0.68.

[0061] Furthermore, by setting the lower limit value of conditional expression (2) to 0.30, the optical system of this embodiment can more reliably achieve the effects of this embodiment. In addition, in order to more reliably achieve the effects of this embodiment, it is preferable to set the lower limit value of conditional expression (2) to 0.31, 0.33, or even 0.35.

[0062] Based on the above structure, a small, lightweight optical system with good imaging performance can be realized.

[0063] The optical system of this embodiment is an optical system composed of multiple lenses, having at least one positive lens component and a negative lens N sequentially from the object side, and the optical system satisfies all of the following conditional expressions. (1) 1.00 < FNo×(TL / f) 2 < 2.50 (4) 0.18 < dN / TL < 0.45 in, FNo: The F-number of the optical system when focusing at infinity. TL: Total optical length of the optical system when focusing at infinity f: Focal length of the optical system when focusing at infinity dN: The distance along the optical axis from the object-side surface of the optical system to the object-side surface of the negative lens N.

[0064] The optical system of this embodiment, by satisfying conditions (1) and (4), enables the object side of the optical system to be configured to be small and lightweight, and allows for correction of various aberrations on the image side of the optical system to obtain good imaging performance. Furthermore, in this specification, "lens component" refers to a single lens or a combined lens. The optical system of this embodiment achieves its effects more reliably by setting the upper limit of condition (1) to 2.50. Moreover, to more reliably achieve the effects of this embodiment, it is preferable to set the upper limit of condition (1) to 2.45, 2.40, 2.35, 2.30, 2.25, 2.20, or more preferably 2.15.

[0065] Furthermore, by setting the lower limit value of conditional expression (1) to 1.00, the optical system of this embodiment can more reliably obtain the effects of this embodiment. In addition, in order to obtain the effects of this embodiment more reliably, it is preferable to set the lower limit value of conditional expression (1) to 1.10, 1.20, 1.25, 1.30, and more preferably 1.35.

[0066] The optical system of this embodiment achieves the desired effect more reliably by setting the upper limit of conditional expression (4) to 0.45. Furthermore, to achieve the desired effect more reliably, it is preferable to set the upper limit of conditional expression (4) to 0.42, 0.40, 0.38, or more preferably 0.36.

[0067] Furthermore, by setting the lower limit value of conditional expression (4) to 0.18, the optical system of this embodiment can more reliably achieve the effects of this embodiment. In addition, in order to more reliably achieve the effects of this embodiment, it is preferable to set the lower limit value of conditional expression (4) to 0.19, 0.20, 0.21, and more preferably 0.22.

[0068] Based on the above structure, a small, lightweight optical system with good imaging performance can be realized.

[0069] The optical system of this embodiment is an optical system composed of multiple lenses, having a positive lens component on the object side and a negative lens N on the object side that is disposed in the negative lens on the image side compared to the positive lens component. This optical system satisfies all of the following conditional expressions. (1) 1.00 < FNo×(TL / f) 2 < 2.50 (4) 0.18 < dN / TL < 0.45 in, FNo: The F-number of the optical system when focusing at infinity. TL: Total optical length of the optical system when focusing at infinity f: Focal length of the optical system when focusing at infinity dN: The distance along the optical axis from the object-side surface of the optical system to the object-side surface of the negative lens N.

[0070] The optical system of this embodiment, by satisfying conditions (1) and (4), enables the object side of the optical system to be configured to be small and lightweight, and allows for correction of various aberrations on the image side of the optical system to obtain good imaging performance. The optical system of this embodiment achieves the desired effect more reliably by setting the upper limit of condition (1) to 2.50. Furthermore, to more reliably achieve the desired effect, it is preferable to set the upper limit of condition (1) to 2.45, 2.40, 2.35, 2.30, 2.25, 2.20, or more preferably 2.15.

[0071] Furthermore, by setting the lower limit value of conditional expression (1) to 1.00, the optical system of this embodiment can more reliably obtain the effects of this embodiment. In addition, in order to obtain the effects of this embodiment more reliably, it is preferable to set the lower limit value of conditional expression (1) to 1.10, 1.20, 1.25, 1.30, and more preferably 1.35.

[0072] The optical system of this embodiment achieves the desired effect more reliably by setting the upper limit of conditional expression (4) to 0.45. Furthermore, to achieve the desired effect more reliably, it is preferable to set the upper limit of conditional expression (4) to 0.42, 0.40, 0.38, or more preferably 0.36.

[0073] Furthermore, the optical system of this embodiment can more reliably achieve the effects of this embodiment by setting the lower limit value of conditional expression (4) to 0.18. In addition, in order to more reliably achieve the effects of this embodiment, it is preferable to set the lower limit value of conditional expression (4) to 0.19, 0.20, 0.21, and more preferably 0.22.

[0074] Based on the above structure, a small, lightweight optical system with good imaging performance can be realized.

[0075] Furthermore, the optical system of this embodiment is preferably composed of a first lens group, a focusing group and a rear group in sequence from the object side. The focusing group moves along the optical axis when focusing. The first lens group has a first A lens group disposed on the object side with the largest air gap A in the first lens group. The optical system satisfies the following conditional expression. (2) 0.30 < dA / dG1 < 0.85 in, dA: Distance on the optical axis of the air gap A dG1: Distance on the optical axis of the first lens group

[0076] The optical system of this embodiment can be made even lighter by satisfying condition (2). The optical system of this embodiment can achieve the effect of this embodiment more reliably by setting the upper limit of condition (2) to 0.85. Furthermore, to achieve the effect of this embodiment more reliably, it is preferable to set the upper limit of condition (2) to 0.80, 0.76, 0.73, 0.70, or more preferably 0.68.

[0077] Furthermore, by setting the lower limit value of conditional expression (2) to 0.30, the optical system of this embodiment can more reliably achieve the effects of this embodiment. In addition, in order to more reliably achieve the effects of this embodiment, it is preferable to set the lower limit value of conditional expression (2) to 0.31, 0.33, or even 0.35.

[0078] Furthermore, the optical system of this embodiment preferably satisfies the following conditional expression. (3) 0.30 < TL / f < 0.80

[0079] The optical system of this embodiment achieves both miniaturization and good image plane curvature correction by satisfying condition (3). The optical system of this embodiment prevents the overall length of the optical system from becoming excessively long by ensuring that the ratio of the total optical length to the focal length of the optical system is less than an upper limit. Furthermore, setting the upper limit of condition (3) to 0.80 allows for more reliable attainment of the effects of this embodiment. Moreover, to further ensure more reliable attainment of the effects of this embodiment, it is preferable to set the upper limit of condition (3) to 0.78, 0.76, 0.74, 0.72, and more preferably 0.70.

[0080] The optical system of this embodiment can effectively correct image plane curvature by making the ratio of the total optical length to the focal length of the optical system greater than a lower limit. Furthermore, by setting the lower limit of conditional expression (3) to 0.30, the effect of this embodiment can be obtained more reliably. Moreover, to obtain the effect of this embodiment more reliably, it is preferable to set the lower limit of conditional expression (3) to 0.33, 0.36, 0.40, 0.42, and more preferably 0.44.

[0081] Furthermore, in this embodiment, the optical system preferably has a first lens group having a positive lens component and a negative lens N.

[0082] Furthermore, in the optical system of this embodiment, it is preferable that the system consists of a first lens group, a focusing group, and a rear group in sequence from the object side. The focusing group moves along the optical axis when focusing. The first lens group has a first A lens group disposed on the object side with the largest air gap A in the first lens group and a first B lens group disposed on the image side. The optical system satisfies the following conditional expression. (5) -2.00 < f1A / f1B < 0.30 in, f1A: Focal length of the first lens group (f1A) f1B: Focal length of the first lens group (f1B)

[0083] The optical system of this embodiment can effectively correct various aberrations by satisfying conditional expression (5). The optical system of this embodiment can effectively correct spherical aberrations by ensuring that the ratio of the focal length of the first lens group to the focal length of the first lens group is less than an upper limit value, thus preventing the focal intensity of the first lens group from becoming excessively positive. Furthermore, by setting the upper limit value of conditional expression (5) to 0.30, the effects of this embodiment can be obtained more reliably. Moreover, to obtain the effects of this embodiment more reliably, it is preferable to set the upper limit value of conditional expression (5) to 0.25, 0.20, 0.15, 0.10, and more preferably 0.07.

[0084] In this embodiment of the optical system, by ensuring that the ratio of the focal length of the first lens group to the focal length of the first lens group is greater than a lower limit, the focal intensity of the first lens group is not excessively negatively strengthened, thus effectively correcting coma and other aberrations. Furthermore, by setting the lower limit of conditional expression (5) to -2.00, the effects of this embodiment can be obtained more reliably. Moreover, to further ensure the reliability of the effects of this embodiment, it is preferable to set the lower limit of conditional expression (5) to -1.60, -1.30, -1.00, -0.80, and more preferably -0.60.

[0085] Furthermore, the optical system of this embodiment is preferably composed of a first lens group, a focusing group and a rear group in sequence from the object side. The focusing group moves along the optical axis when focusing. The first lens group has a first A lens group disposed on the object side with the largest air gap A in the first lens group. The optical system satisfies the following conditional expression. (6) 0.10 < f1A / f < 0.60 in, f1A: Focal length of the first lens group (f1A)

[0086] The optical system of this embodiment achieves both lightweight design and good coma correction by satisfying conditional expression (6). In this embodiment, the ratio of the focal length of the first lens group (1A) to the focal length of the optical system is less than an upper limit value, ensuring that the focal strength of the first lens group (1A) does not weaken. This allows for a reduction in the diameter of the first lens group (excluding the first lens group (1A)) and thus enables lightweight design of the optical system. Furthermore, setting the upper limit value of conditional expression (6) to 0.60 provides a more reliable representation of the effects of this embodiment. Moreover, to further ensure reliable representation of the effects of this embodiment, it is preferable to set the upper limit value of conditional expression (6) to 0.57, 0.55, 0.52, 0.48, and more preferably 0.45.

[0087] In this embodiment of the optical system, by ensuring that the ratio of the focal length of the first lens group to the focal length of the optical system is greater than a lower limit, the focal strength of the first lens group does not increase, thus enabling effective correction of coma. Furthermore, by setting the lower limit of conditional expression (6) to 0.10, the effects of this embodiment can be obtained more reliably. Moreover, to further ensure the effectiveness of this embodiment, it is preferable to set the lower limit of conditional expression (6) to 0.13, 0.16, 0.20, 0.22, and more preferably 0.25.

[0088] Furthermore, the optical system of this embodiment is preferably composed of a first lens group, a focusing group and a rear group in sequence from the object side. The focusing group moves along the optical axis when focusing. The first lens group has a first lens group B disposed on the image side with the largest air gap A in the first lens group. The optical system satisfies the following conditional expression. (7) 0.40 < dB / dG1 < 0.85 in, dB: The distance along the optical axis from the object-side surface of the optical system to the object-side surface of the first B lens group. dG1: Distance on the optical axis of the first lens group

[0089] The optical system of this embodiment achieves both lightweight design and good spherical aberration correction by satisfying condition (7). The optical system of this embodiment can effectively correct spherical aberration by making the value of condition (7) less than the upper limit value. Furthermore, by setting the upper limit value of condition (7) to 0.85, the effect of this embodiment can be obtained more reliably. Moreover, to obtain the effect of this embodiment more reliably, it is preferable to set the upper limit value of condition (7) to 0.82, 0.80, 0.78, 0.76, and more preferably 0.74.

[0090] The optical system of this embodiment can reduce the diameter of the first lens group by making the value of conditional expression (7) greater than the lower limit value, thus enabling the optical system to be lightweight. Furthermore, by setting the lower limit value of conditional expression (7) to 0.40, the effects of this embodiment can be obtained more reliably. Moreover, to obtain the effects of this embodiment more reliably, it is preferable to set the lower limit value of conditional expression (7) to 0.44, 0.47, 0.50, 0.52, and more preferably 0.54.

[0091] Furthermore, in the optical system of this embodiment, it is preferable that the system consists of a first lens group, a focusing group, and a rear group in sequence from the object side. The focusing group moves along the optical axis when focusing. The first lens group has a first A lens group disposed on the object side with the largest air gap A in the first lens group. The first A lens group consists of two or fewer positive lenses.

[0092] The optical system of this embodiment is lightweight because it has this structure.

[0093] Furthermore, the optical system of this embodiment is preferably composed of a first lens group, a focusing group and a rear group in sequence from the object side. The focusing group moves along the optical axis when focusing. The first lens group has a first A lens group disposed on the object side with the largest air gap A in the first lens group. The optical system satisfies the following conditional expression. (8) 0.80 < fL1 / fL2 < 3.30 in, fL1: The focal length of the first lens located closest to the object within the first lens group A. fL2: The focal length of the second lens located on the object side within the first A lens group.

[0094] The optical system of this embodiment can effectively correct spherical aberration and coma by satisfying conditional expression (8). The optical system of this embodiment can effectively correct coma by ensuring that the ratio of the focal length of the first lens to the focal length of the second lens is less than an upper limit value, thus preventing the focal strength of the first lens from becoming too weak. Furthermore, by setting the upper limit value of conditional expression (8) to 3.30, the effect of this embodiment can be obtained more reliably. Moreover, to obtain the effect of this embodiment more reliably, it is preferable to set the upper limit value of conditional expression (8) to 3.20, 3.10, 3.00, 2.90, and more preferably 2.80.

[0095] The optical system of this embodiment, by ensuring that the ratio of the focal length of the first lens to the focal length of the second lens is greater than a lower limit, prevents the focal intensity of the first lens from becoming excessively strong, thus enabling effective correction of spherical aberration. Furthermore, by setting the lower limit of conditional expression (8) to 0.80, the effects of this embodiment can be obtained more reliably. Moreover, to further ensure the effectiveness of this embodiment, it is preferable to set the lower limit of conditional expression (8) to 0.85, 0.90, 0.95, 1.00, and more preferably 1.05.

[0096] In addition, in the optical system of this embodiment, it is preferable that the first lens group, the focusing group and the rear group are arranged sequentially from the object side. The focusing group moves along the optical axis when focusing. The first lens group has a first A lens group disposed on the object side with the largest air gap A in the first lens group and a first B lens group disposed on the image side. The first B lens group has at least one positive lens Z that satisfies the following condition. (9) 60.00 < νd1Amax-νdLZ in, νd1Amax: The maximum Abbe number of the lenses contained in the 1A lens group, with reference to the d-line. νdLZ: Abbe number of the positive lens Z with reference to the d-line.

[0097] The optical system of this embodiment can effectively correct the second-order dispersion of axial chromatic aberration by making the value of conditional expression (9) greater than the lower limit value. Furthermore, by setting the lower limit value of conditional expression (9) to 60.00, the effect of this embodiment can be obtained more reliably. Moreover, to obtain the effect of this embodiment more reliably, it is preferable to set the lower limit value of conditional expression (9) to 62.00, 63.00, 64.00, 65.00, and more preferably 66.00.

[0098] Furthermore, the optical system of this embodiment is preferably composed of a first lens group, a focusing group and a rear group in sequence from the object side. The focusing group moves along the optical axis when focusing. The first lens group has a first A lens group disposed on the object side with the largest air gap A in the first lens group. The optical system satisfies the following conditional expression. (10)55.00 < νd1Aave in, νd1Aave: The average Abbe number of the lenses contained in the 1A lens group, with reference to the d-line.

[0099] The optical system of this embodiment can effectively correct axial chromatic aberration and magnification chromatic aberration by making the value of conditional expression (10) greater than the lower limit value. Furthermore, by setting the lower limit value of conditional expression (10) to 55.00, the effect of this embodiment can be obtained more reliably. Moreover, to obtain the effect of this embodiment more reliably, it is preferable to set the lower limit value of conditional expression (10) to 60.00, 65.00, 70.00, 75.00, and more preferably 80.00.

[0100] Furthermore, the optical system of this embodiment is preferably composed of a first lens group, a focusing group and a rear group in sequence from the object side. The focusing group moves along the optical axis when focusing. The first lens group has a first lens group B disposed on the image side with the largest air gap A in the first lens group. The first lens group B has at least one positive lens Z that satisfies all of the following conditions. (11)ndLZ+(0.01425×νdLZ) < 2.12 (12)νdLZ < 35.00 (13)0.702 < θgFLZ+(0.00316×νdLZ) in, ndLZ: The refractive index of the Z-line of a positive lens with respect to the d-line. νdLZ: Abbe number of the positive lens Z relative to the d-line. θgFLZ: The relative partial dispersion of a positive lens Z, defined by the following formula when the refractive index of the positive lens Z for the g line is ngLZ, the refractive index of the positive lens Z for the F line is nFLZ, and the refractive index of the positive lens Z for the C line is nCLZ. θgFLZ = (ngLZ-nFLZ) / (nFLZ-nCLZ)

[0101] The optical system of this embodiment, by having this structure, can effectively correct various aberrations. The optical system of this embodiment, by setting the value of conditional expression (11) to less than the upper limit value, prevents the Pittsvar sum from becoming too small, thus effectively correcting image plane curvature. Furthermore, by setting the upper limit value of conditional expression (11) to 2.12, the effects of this embodiment can be obtained more reliably. Moreover, to obtain the effects of this embodiment more reliably, it is preferable to set the upper limit value of conditional expression (11) to 2.10, 2.09, 2.08, 2.07, and more preferably 2.06.

[0102] The optical system of this embodiment can effectively correct the second-order dispersion of axial chromatic aberration by making the value of conditional expression (12) less than the upper limit value. Furthermore, by setting the upper limit value of conditional expression (12) to 35.00, the effect of this embodiment can be obtained more reliably. Moreover, to obtain the effect of this embodiment more reliably, it is preferable to set the upper limit value of conditional expression (12) to 33.00, 31.00, 30.50, 30.00, and more preferably 29.50.

[0103] The optical system of this embodiment can effectively correct the second-order dispersion of axial chromatic aberration by making the value of conditional expression (13) greater than the lower limit. Furthermore, by setting the upper limit of conditional expression (13) to 0.702, the effect of this embodiment can be obtained more reliably. Moreover, to obtain the effect of this embodiment more reliably, it is preferable to set the upper limit of conditional expression (13) to 0.704, 0.707, 0.710, 0.712, and more preferably 0.715.

[0104] Furthermore, the optical system of this embodiment is preferably composed of a first lens group, a focusing group and a rear group in sequence from the object side. The focusing group moves along the optical axis when focusing. The first lens group has a first A lens group disposed on the object side with the largest air gap A in the first lens group. The optical system satisfies the following conditional expression. (14)0.00 < (L1R2+L1R1) / (L1R2-L1R1) < 3.00 in, L1R1: The radius of curvature of the object-side surface of the first lens, which is positioned closest to the object. L1R2: Radius of curvature of the image-side surface of the first lens.

[0105] The optical system of this embodiment can effectively correct spherical aberration and coma by satisfying conditional expression (14). The optical system of this embodiment can effectively correct spherical aberration by making the value of conditional expression (14) less than the upper limit value. Furthermore, by setting the upper limit value of conditional expression (14) to 3.00, the effect of this embodiment can be obtained more reliably. Moreover, to obtain the effect of this embodiment more reliably, it is preferable to set the upper limit value of conditional expression (14) to 2.70, 2.50, 2.20, 2.00, and more preferably 1.80.

[0106] The optical system of this embodiment can effectively correct coma by making the value of conditional expression (14) greater than the lower limit value. Furthermore, by setting the lower limit value of conditional expression (14) to 0.00, the effect of this embodiment can be obtained more reliably. Moreover, to obtain the effect of this embodiment more reliably, it is preferable to set the lower limit value of conditional expression (14) to 0.20, 0.40, 0.50, 0.60, and more preferably 0.70.

[0107] Furthermore, the optical system of this embodiment is preferably composed of a first lens group, a focusing group and a rear group in sequence from the object side. The focusing group moves along the optical axis when focusing. The first lens group has a first A lens group disposed on the object side with the largest air gap A in the first lens group. The optical system satisfies the following conditional expression. (15)0.00 < (L2R2+L2R1) / (L2R2-L2R1) < 3.50 in, L2R1: The radius of curvature of the object-side surface of the second lens, which is the second lens positioned on the object side within the first A lens group. L2R2: Radius of curvature of the image-side surface of the second lens.

[0108] The optical system of this embodiment can effectively correct spherical aberration and coma by satisfying conditional expression (15). The optical system of this embodiment can effectively correct spherical aberration by making the value of conditional expression (15) less than the upper limit value. Furthermore, by setting the upper limit value of conditional expression (14) to 3.50, the effect of this embodiment can be obtained more reliably. Moreover, to obtain the effect of this embodiment more reliably, it is preferable to set the upper limit value of conditional expression (15) to 3.20, 3.00, 2.80, 2.60, and more preferably 2.40.

[0109] The optical system of this embodiment can effectively correct coma by making the value of conditional expression (15) greater than the lower limit value. Furthermore, by setting the lower limit value of conditional expression (15) to 0.00, the effect of this embodiment can be obtained more reliably. Moreover, to obtain the effect of this embodiment more reliably, it is preferable to set the lower limit value of conditional expression (15) to 0.20, 0.50, 0.80, 1.00, and more preferably 1.20.

[0110] Furthermore, the optical system of this embodiment is preferably composed of a first lens group, a focusing group, and a rear group in sequence from the object side. The focusing group moves along the optical axis when focusing, and the optical system satisfies the following conditional expression. (16) 0.10 < f1 / f < 0.60 in, f1: Focal length of the first lens group

[0111] The optical system of this embodiment achieves both miniaturization and good spherical aberration correction by satisfying conditional expression (16). The optical system of this embodiment achieves miniaturization by ensuring that the ratio of the focal length of the first lens group to the focal length of the optical system is less than an upper limit value, thus preventing the focal strength of the first lens group from becoming too weak. Furthermore, by setting the upper limit value of conditional expression (16) to 0.60, the effects of this embodiment can be obtained more reliably. Moreover, to obtain the effects of this embodiment more reliably, it is preferable to set the upper limit value of conditional expression (16) to 0.56, 0.53, 0.50, 0.48, and more preferably 0.45.

[0112] In this embodiment of the optical system, by ensuring that the value of conditional expression (16) is greater than the lower limit, the focal intensity of the first lens group does not become excessively strong, thus enabling effective correction of spherical aberration. Furthermore, by setting the lower limit of conditional expression (16) to 0.10, the effects of this embodiment can be obtained more reliably. Moreover, to further ensure the effectiveness of this embodiment, it is preferable to set the lower limit of conditional expression (16) to 0.14, 0.18, 0.22, 0.25, and more preferably 0.28.

[0113] Furthermore, the optical system of this embodiment is preferably composed of a first lens group, a focusing group, and a rear group in sequence from the object side. The focusing group moves along the optical axis when focusing, and the optical system satisfies the following conditional expression. (17) 0.20 < (-fF) / f1 < 0.85 in, fF: Focal length of the focus group f1: Focal length of the first lens group

[0114] The optical system of this embodiment, by satisfying conditional expression (17), can effectively correct spherical aberrations from infinity to near distance. The optical system of this embodiment, by ensuring that the ratio of the focal length of the focusing group to the focal length of the first lens group is less than an upper limit value, prevents the focal strength of the focusing group from becoming too weak, thus suppressing variations in image plane curvature. Furthermore, by setting the upper limit value of conditional expression (17) to 0.85, the effects of this embodiment can be obtained more reliably. Moreover, to obtain the effects of this embodiment more reliably, it is preferable to set the upper limit value of conditional expression (17) to 0.80, 0.77, 0.75, 0.72, and more preferably 0.65.

[0115] The optical system of this embodiment prevents the focal strength of the focusing group from becoming excessive by ensuring that the ratio of the focal length of the focusing group to the focal length of the first lens group is greater than a lower limit value, thereby suppressing variations in axial chromatic aberration. Furthermore, by setting the lower limit value of conditional expression (17) to 0.20, the effects of this embodiment can be obtained more reliably. Moreover, to obtain the effects of this embodiment more reliably, it is preferable to set the lower limit value of conditional expression (17) to 0.24, 0.28, 0.32, 0.36, and more preferably 0.40.

[0116] Furthermore, the optical system of this embodiment is preferably composed of a first lens group, a focusing group, and a rear group in sequence from the object side. The focusing group moves along the optical axis when focusing, and the optical system satisfies the following conditional expression. (18) -1.50 < (-fF) / fR < 0.60 in, fF: Focal length of the focus group fR: Focal length of the rear element

[0117] The optical system of this embodiment can effectively correct various aberrations by satisfying conditional expression (18). By ensuring that the value of conditional expression (18) is less than the upper limit, the optical system of this embodiment prevents the focal strength of the focus group from becoming too weak, thus effectively correcting image plane curvature. Furthermore, by setting the upper limit of conditional expression (18) to 0.60, the effects of this embodiment can be obtained more reliably. Moreover, to obtain the effects of this embodiment more reliably, it is preferable to set the upper limit of conditional expression (18) to 0.50, 0.40, 0.30, 0.20, and more preferably 0.10.

[0118] The optical system of this embodiment prevents the focal intensity of the focus group from becoming excessively strong by ensuring that the value of conditional expression (18) is greater than the lower limit, thus enabling good correction of magnification chromatic aberration. Furthermore, by setting the lower limit of conditional expression (18) to -1.50, the effect of this embodiment can be obtained more reliably. Moreover, to obtain the effect of this embodiment more reliably, it is preferable to set the lower limit of conditional expression (18) to -1.40, -1.30, -1.20, -1.10, and more preferably -1.00.

[0119] Furthermore, the optical system of this embodiment is preferably composed of a first lens group, a focusing group, and a rear group in sequence from the object side. The focusing group moves along the optical axis when focusing, and the optical system satisfies the following conditional expression. (19) 0.30 < dF / TL < 0.70 in, dF: The distance along the optical axis from the object-side surface of the optical system to the object-side surface of the focusing group.

[0120] The optical system of this embodiment, by satisfying condition (19), can simultaneously achieve high-speed focusing based on a lightweight focusing group and suppression of image plane curvature variations. In this embodiment, by setting the value of condition (19) to less than the upper limit, the focusing group is not positioned too far back, thus suppressing image plane curvature variations. Furthermore, by setting the upper limit of condition (19) to 0.70, the effects of this embodiment can be obtained more reliably. Moreover, to obtain the effects of this embodiment more reliably, it is preferable to set the upper limit of condition (19) to 0.67, 0.64, 0.61, 0.58, and more preferably 0.56.

[0121] The optical system of this embodiment prevents the focusing group from being positioned too far forward by ensuring that the value of conditional expression (19) is greater than the lower limit, thus enabling the focusing group to be lightweight. Furthermore, by setting the lower limit of conditional expression (19) to 0.30, the effects of this embodiment can be obtained more reliably. Moreover, to further ensure the effectiveness of this embodiment, it is preferable to set the lower limit of conditional expression (19) to 0.32, 0.34, 0.36, 0.38, and more preferably 0.40.

[0122] Furthermore, the optical system of this embodiment is preferably composed of a first lens group, a focusing group, and a rear group in sequence from the object side. The focusing group moves along the optical axis when focusing, and the optical system satisfies the following conditional expression. (20)40.00 < νdFave in, νdFave: The average Abbe number of the lenses included in the focusing group, with reference to the d-line.

[0123] The optical system of this embodiment can effectively correct axial chromatic aberration from infinity to near distance by making the value of conditional expression (20) greater than the lower limit value. Furthermore, by setting the lower limit value of conditional expression (20) to 40.00, the effect of this embodiment can be obtained more reliably. Moreover, to obtain the effect of this embodiment more reliably, it is preferable to set the lower limit value of conditional expression (20) to 50.00, 55.00, 60.00, 65.00, and more preferably 70.00.

[0124] Furthermore, the optical system of this embodiment preferably satisfies the following conditional expression. (21) 1.00° < 2ω < 20.00° in, 2ω: The full field of view of the optical system

[0125] Condition (21) sets an appropriate value for the full field of view of the optical system in this embodiment. By satisfying condition (21), variations in various aberrations such as coma, image plane curvature, and distortion that accompany focusing can be suppressed. Furthermore, by setting the upper limit of condition (21) to 20.00°, the effects of this embodiment can be obtained more reliably. In addition, to obtain the effects of this embodiment more reliably, it is preferable to set the upper limit of condition (21) to 18.00°, 16.00°, 14.00°, 12.00°, and more preferably 10.00°.

[0126] Furthermore, by setting the lower limit of conditional expression (21) to 1.00°, the effects of this embodiment can be obtained more reliably. In addition, in order to obtain the effects of this embodiment more reliably, it is preferable to set the lower limit of conditional expression (21) to 1.50°, 2.00°, 2.20°, 2.50°, and more preferably 2.80°.

[0127] Furthermore, the optical system of this embodiment preferably satisfies the following conditional expression. (22) 0.075 < Bf / f < 0.185 in, Bf: Back focal length of the optical system

[0128] The optical system of this embodiment achieves both miniaturization and weight reduction by satisfying conditional expression (22). The optical system of this embodiment shortens the overall length by ensuring that the ratio of the back focal length to the focal length is less than an upper limit value, thus preventing the back focal length from becoming excessively long. Furthermore, by setting the upper limit value of conditional expression (22) to 0.185, the effects of this embodiment can be obtained more reliably. Moreover, to obtain the effects of this embodiment more reliably, it is preferable to set the upper limit value of conditional expression (22) to 0.180, 0.175, 0.170, 0.165, and more preferably 0.160.

[0129] The optical system of this embodiment achieves lightweighting by ensuring that the ratio of the back focal length to the focal length of the optical system is greater than a lower limit value. Furthermore, by setting the lower limit value of conditional expression (22) to 0.075, the effects of this embodiment can be obtained more reliably. Moreover, to obtain the effects of this embodiment more reliably, it is preferable to set the lower limit value of conditional expression (22) to 0.080, 0.082, 0.085, 0.088, and more preferably 0.090.

[0130] Furthermore, in the optical system of this embodiment, it is preferable that the system consists of a first lens group, a focusing group, and a rear group in sequence from the object side. The focusing group moves along the optical axis when focusing, and the rear group has an image stabilization lens group that can move in a manner having a component perpendicular to the optical axis in order to correct image shake.

[0131] The optical system of this embodiment, by having this structure, is able to effectively correct image jitter.

[0132] Based on the above structure, a small, lightweight optical system with good imaging performance can be realized.

[0133] The optical device of this embodiment has an optical system with the structure described above. Therefore, a small, lightweight optical device with excellent imaging performance can be realized.

[0134] The method for manufacturing an optical system according to this embodiment is a method for manufacturing an optical system composed of multiple lenses. A first lens group, a focusing group, and a rear group are arranged sequentially from the object side. The first lens group has positive optical power. The focusing group moves along the optical axis when focusing. A first A lens group is arranged on the object side with the largest air gap A in the first lens group. The optical system is configured to satisfy all of the following conditions. (1) 1.00 < FNo×(TL / f) 2 < 2.50 (2) 0.30 < dA / dG1 < 0.85 in, FNo: The F-number of the optical system when focusing at infinity. TL: Total optical length of the optical system when focusing at infinity f: Focal length of the optical system when focusing at infinity dA: Distance on the optical axis of the air gap A dG1: Distance on the optical axis of the first lens group

[0135] The method for manufacturing an optical system according to this embodiment is a method for manufacturing an optical system composed of multiple lenses, wherein at least one positive lens component and a negative lens N are sequentially arranged from the object side, and the arrangement satisfies all of the following conditional expressions. (1) 1.00 < FNo×(TL / f) 2 < 2.50 (4) 0.18 < dN / TL < 0.45 in, FNo: The F-number of the optical system when focusing at infinity. TL: Total optical length of the optical system when focusing at infinity f: Focal length of the optical system when focusing at infinity dN: The distance along the optical axis from the object-side surface of the optical system to the object-side surface of the negative lens N.

[0136] This method of manufacturing optical systems enables the production of small, lightweight optical systems with excellent imaging performance.

[0137] (Numerical Example)

[0138] Hereinafter, embodiments of the present application will be described with reference to the accompanying drawings.

[0139] (First Embodiment)

[0140] Figure 1A This is a cross-sectional view of the optical system of the first embodiment for focusing on an object at infinity. Figure 1B This is a cross-sectional view of the optical system of the first embodiment when focusing on a close-up object.

[0141] The optical system of this embodiment includes, sequentially from the object side, a first lens group G1 with positive optical power, a focusing group GF with negative optical power, and a rear group GR with negative optical power. An aperture stop S is disposed between the first lens group G1 and the focusing group GF. The first lens group G1 includes a first A lens group G1A with positive optical power disposed on the object side within the first lens group, separated by the largest air gap A, and a first B lens group G1B with negative optical power disposed on the image side.

[0142] Lens group G1A consists of, from the object side, a positive meniscus lens L1 with its convex surface facing the object side and a positive meniscus lens L2 with its convex surface facing the object side.

[0143] Lens group G1B, from the object side, consists of a negative lens consisting of a positive meniscus lens L3 (convex side facing the object) and a negative meniscus lens L4 (convex side facing the object), a positive meniscus lens L5 (convex side facing the object), and a positive lens consisting of a biconvex positive lens L6 and a biconcave negative lens L7.

[0144] The focusing group GF consists of a negative meniscus lens L8 with its convex surface facing the object side.

[0145] The rear group GR consists of, from the object side, a positive meniscus lens L9 with its convex surface facing the image side, a negative lens consisting of a biconvex positive lens L10 and a biconcave negative lens L11, a biconcave negative lens L12, a positive lens consisting of a biconvex positive lens L13 and a biconcave negative lens L14, a positive lens consisting of a negative meniscus lens L15 with its convex surface facing the object side and a biconvex positive lens L16, a negative lens consisting of a biconcave negative lens L17 and a positive meniscus lens L18 with its convex surface facing the object side, and a biconvex positive lens L19.

[0146] An imaging element (not shown) composed of a CCD or CMOS sensor is disposed on image plane I.

[0147] The optical system of this embodiment focuses by moving the focus group GF along the optical axis. When focusing on a close object from a state of infinity, the focus group GF moves from the object side to the image side.

[0148] In the optical system of this embodiment, the rear group GR has a lens group in which the positive lens L10 and the negative lens L11 are combined, and the negative lens L12 constitutes an image stabilization lens group. This image stabilization lens group can move in a manner with a component perpendicular to the optical axis in order to correct image jitter.

[0149] In the optical system of this embodiment, the positive meniscus lens L1 corresponds to the first lens, and the positive meniscus lens L2 corresponds to the second lens. Additionally, in the optical system of this embodiment, the negative meniscus lens L4 corresponds to the negative lens N, and the positive lens L6 corresponds to the positive lens Z.

[0150] In the optical system of this embodiment, dA is the distance on the optical axis between the image-side surface of the positive meniscus lens L2 and the object-side surface of the positive meniscus lens L3. dG1 is the distance on the optical axis between the object-side surface of the positive meniscus lens L1 and the image-side surface of the negative lens L7. dB is the distance on the optical axis between the object-side surface of the positive meniscus lens L1 and the object-side surface of the positive meniscus lens L3. dN is the distance on the optical axis between the object-side surface of the positive meniscus lens L1 and the object-side surface of the negative meniscus lens L4. Furthermore, in the cross-sectional views of the optical systems of other embodiments described later, the illustrations of dA, dG1, dB, and dN are omitted.

[0151] Table 1 below shows the parameter values ​​of the optical system in this embodiment. In Table 1, f represents the focal length of the optical system when focusing at infinity, Fno represents the F-number of the optical system when focusing at infinity, TL represents the total optical length of the optical system when focusing at infinity, and Bf represents the back focal length of the optical system.

[0152] In the [lens parameters], m represents the order of the optical surfaces from the object side, r represents the radius of curvature, d represents the surface spacing, nd represents the refractive index for the d-line (wavelength 587.6 nm), and νd represents the Abbe number for the d-line. Additionally, in the [lens parameters], a radius of curvature r = ∞ indicates a plane.

[0153] The focal length f, radius of curvature r, and other length units listed in Table 1 are in mm. However, the same optical performance can be obtained even by scaling up or down the optical system, so it is not limited to this.

[0154] The symbols used in Table 1 described above are also used in the tables of other embodiments described later.

[0155] (Table 1)

[0156] [Overall Parameters]

[0157] [Lens Parameters]

[0158] [Focal length data for each group]

[0159] [Variable Interval Data]

[0160] Figure 2 This is a diagram of the aberrations of the optical system in the first embodiment when focusing on an object at infinity.

[0161] In each aberration diagram, FNO represents the F-value, and Y represents the image height. Specifically, the spherical aberration diagram shows the F-value corresponding to the maximum aperture, the astigmatism and distortion diagrams show the maximum image height, and the coma diagram shows the values ​​of each image height. D represents the d-line, and g represents the g-line (wavelength 435.8 nm). In the astigmatism diagram, solid lines represent the sagittal image plane, and dashed lines represent the meridional image plane. The same symbols as in the aberration diagrams of this embodiment are used in the aberration diagrams of other embodiments described later.

[0162] As can be seen from the various aberration diagrams, the optical system of this embodiment effectively suppresses aberration variations during focusing and has high optical performance.

[0163] (Second Embodiment)

[0164] Figure 3A This is a cross-sectional view of the optical system of the second embodiment for focusing on an object at infinity. Figure 3BThis is a cross-sectional view of the optical system of the second embodiment when focusing on a close-up object.

[0165] The optical system of this embodiment includes, sequentially from the object side, a first lens group G1 with positive optical power, a focusing group GF with negative optical power, and a rear group GR with positive optical power. An aperture stop S is disposed between the first lens group G1 and the focusing group GF. The first lens group G1 includes a first A lens group G1A with positive optical power disposed on the object side within the first lens group, separated by the largest air gap A, and a first B lens group G1B with negative optical power disposed on the image side.

[0166] Lens group G1A consists of, from the object side, a positive meniscus lens L1 with its convex surface facing the object side and a positive meniscus lens L2 with its convex surface facing the object side.

[0167] Lens group G1B, from the object side, consists of a negative lens consisting of a biconvex positive lens L3 and a biconcave negative lens L4, a positive meniscus lens L5 with its convex surface facing the object side, and a positive lens consisting of a biconvex positive lens L6 and a biconcave negative lens L7.

[0168] The focusing group GF consists of a biconcave negative lens L8.

[0169] The rear group GR, from the object side, consists of, in sequence, a positive meniscus lens L9 with its convex surface facing the image side, a negative lens combining a biconvex positive lens L10 and a biconcave negative lens L11, a biconcave negative lens L12, a positive lens combining a biconvex positive lens L13 and a negative meniscus lens L14 with its convex surface facing the image side, a positive lens combining a negative meniscus lens L15 with its convex surface facing the object side and a positive meniscus lens L16 with its convex surface facing the object side, a negative lens combining a biconcave negative lens L17 and a positive meniscus lens L18 with its convex surface facing the object side, and a biconvex positive lens L19.

[0170] An imaging element (not shown) composed of a CCD or CMOS sensor is disposed on image plane I.

[0171] The optical system of this embodiment focuses by moving the focus group GF along the optical axis. When focusing on a close object from a state of infinity, the focus group GF moves from the object side to the image side.

[0172] In the optical system of this embodiment, the rear group GR has a lens group in which the positive lens L10 and the negative lens L11 are combined, and the negative lens L12 constitutes an image stabilization lens group. This image stabilization lens group can move in a manner with a component perpendicular to the optical axis in order to correct image jitter.

[0173] In the optical system of this embodiment, the positive meniscus lens L1 corresponds to the first lens, and the positive meniscus lens L2 corresponds to the second lens. Additionally, in the optical system of this embodiment, the negative lens L4 corresponds to the negative lens N, and the positive lens L6 corresponds to the positive lens Z.

[0174] In the optical system of this embodiment, dA is the distance on the optical axis between the image-side surface of the positive meniscus lens L2 and the object-side surface of the positive lens L3. dG1 is the distance on the optical axis between the object-side surface of the positive meniscus lens L1 and the image-side surface of the negative lens L7. dB is the distance on the optical axis between the object-side surface of the positive meniscus lens L1 and the object-side surface of the positive lens L3. dN is the distance on the optical axis between the object-side surface of the positive meniscus lens L1 and the object-side surface of the negative lens L4.

[0175] Table 2 below shows the values ​​of the parameters of the optical system in this embodiment.

[0176] (Table 2)

[0177] [Overall Parameters]

[0178] [Lens Parameters]

[0179] [Focal length data for each group]

[0180] [Variable Interval Data]

[0181] Figure 4 This is a diagram of the aberrations of the optical system in the second embodiment when focusing on an object at infinity.

[0182] As can be seen from the various aberration diagrams, the optical system of this embodiment effectively suppresses aberration variations during focusing and has high optical performance.

[0183] (Third Embodiment)

[0184] Figure 5A This is a cross-sectional view of the optical system of the third embodiment for focusing on an object at infinity. Figure 5B This is a cross-sectional view of the optical system of the third embodiment when focusing on a close-up object.

[0185] The optical system of this embodiment includes, sequentially from the object side, a first lens group G1 with positive optical power, a focusing group GF with negative optical power, and a rear group GR with negative optical power. An aperture stop S is disposed between the first lens group G1 and the focusing group GF. The first lens group G1 includes a first A lens group G1A with positive optical power disposed on the object side within the first lens group, separated by the largest air gap A, and a first B lens group G1B with negative optical power disposed on the image side.

[0186] Lens group G1A consists of, from the object side, a positive meniscus lens L1 with its convex surface facing the object side and a positive meniscus lens L2 with its convex surface facing the object side.

[0187] Lens group G1B, from the object side, consists of a negative lens consisting of a biconvex positive lens L3 and a biconcave negative lens L4, a positive meniscus lens L5 with its convex surface facing the object side, and a positive lens consisting of a biconvex positive lens L6 and a biconcave negative lens L7.

[0188] The focusing group GF consists of a biconcave negative lens L8.

[0189] The rear group GR comprises, from the object side, a positive meniscus lens L9 with its convex surface facing the image side, a negative lens consisting of a biconvex positive lens L10 and a biconcave negative lens L11, a biconcave negative lens L12, a positive lens consisting of a biconvex positive lens L13 and a negative meniscus lens L14 with its convex surface facing the image side, a negative lens consisting of a biconcave negative lens L15 and a biconvex positive lens L16, a negative lens consisting of a biconcave negative lens L17 and a biconvex positive lens L18, and a positive meniscus lens L19 with its convex surface facing the object side.

[0190] An imaging element (not shown) composed of a CCD or CMOS sensor is disposed on image plane I.

[0191] The optical system of this embodiment focuses by moving the focus group GF along the optical axis. When focusing on a close object from a state of infinity, the focus group GF moves from the object side to the image side.

[0192] In the optical system of this embodiment, the rear group GR has a lens group in which the positive lens L10 and the negative lens L11 are combined, and the negative lens L12 constitutes an image stabilization lens group. This image stabilization lens group can move in a manner with a component perpendicular to the optical axis in order to correct image jitter.

[0193] In the optical system of this embodiment, the positive meniscus lens L1 corresponds to the first lens, and the positive meniscus lens L2 corresponds to the second lens. Additionally, in the optical system of this embodiment, the negative lens L4 corresponds to the negative lens N, and the positive lens L6 corresponds to the positive lens Z.

[0194] In the optical system of this embodiment, dA is the distance on the optical axis between the image-side surface of the positive meniscus lens L2 and the object-side surface of the positive lens L3. dG1 is the distance on the optical axis between the object-side surface of the positive meniscus lens L1 and the image-side surface of the negative lens L7. dB is the distance on the optical axis between the object-side surface of the positive meniscus lens L1 and the object-side surface of the positive lens L3. dN is the distance on the optical axis between the object-side surface of the positive meniscus lens L1 and the object-side surface of the negative lens L4.

[0195] Table 3 below shows the values ​​of the parameters of the optical system in this embodiment.

[0196] (Table 3)

[0197] [Overall Parameters]

[0198] [Lens Parameters]

[0199] [Focal length data for each group]

[0200] [Variable Interval Data]

[0201] Figure 6 This is a diagram of the aberrations of the optical system in the third embodiment when focusing on an object at infinity.

[0202] As can be seen from the various aberration diagrams, the optical system of this embodiment effectively suppresses aberration variations during focusing and has high optical performance.

[0203] (Example 4)

[0204] Figure 7A This is a cross-sectional view of the optical system of the fourth embodiment when focusing on an object at infinity. Figure 7B This is a cross-sectional view of the optical system of the fourth embodiment when focusing on a close-up object.

[0205] The optical system of this embodiment includes, sequentially from the object side, a first lens group G1 with positive optical power, a focusing group GF with negative optical power, and a rear group GR with negative optical power. An aperture stop S is disposed between the first lens group G1 and the focusing group GF. The first lens group G1 includes a first A lens group G1A with positive optical power disposed on the object side within the first lens group, separated by the largest air gap A, and a first B lens group G1B with negative optical power disposed on the image side.

[0206] Lens group G1A consists of, from the object side, a positive meniscus lens L1 with its convex surface facing the object side and a positive meniscus lens L2 with its convex surface facing the object side.

[0207] Lens group G1B, from the object side, consists of a negative lens consisting of a positive meniscus lens L3 (convex side facing the object) and a negative meniscus lens L4 (convex side facing the object), a positive meniscus lens L5 (convex side facing the object), and a positive lens consisting of a biconvex positive lens L6 and a biconcave negative lens L7.

[0208] The focusing group GF consists of a negative meniscus lens L8 with its convex surface facing the object side.

[0209] The rear group GR, from the object side, consists of a positive meniscus lens L9 with its convex surface facing the image side, a negative lens combining a biconvex positive lens L10 and a biconcave negative lens L11, a biconcave negative lens L12, a positive lens combining a biconvex positive lens L13 and a biconcave negative lens L14, a negative meniscus lens L15 with its convex surface facing the object side and a biconvex positive lens L16, a negative lens combining a biconcave negative lens L17 and a biconvex positive lens L18, and a positive meniscus lens L19 with its convex surface facing the object side.

[0210] An imaging element (not shown) composed of a CCD or CMOS sensor is disposed on image plane I.

[0211] The optical system of this embodiment focuses by moving the focus group GF along the optical axis. When focusing on a close object from a state of infinity, the focus group GF moves from the object side to the image side.

[0212] In the optical system of this embodiment, the rear group GR has a lens group in which the positive lens L10 and the negative lens L11 are combined, and the negative lens L12 constitutes an image stabilization lens group. This image stabilization lens group can move in a manner with a component perpendicular to the optical axis in order to correct image jitter.

[0213] In the optical system of this embodiment, the positive meniscus lens L1 corresponds to the first lens, and the positive meniscus lens L2 corresponds to the second lens. Additionally, in the optical system of this embodiment, the negative meniscus lens L4 corresponds to the negative lens N, and the positive lens L6 corresponds to the positive lens Z.

[0214] In the optical system of this embodiment, dA is the distance on the optical axis between the image-side surface of the positive meniscus lens L2 and the object-side surface of the positive meniscus lens L3. Furthermore, dG1 is the distance on the optical axis between the object-side surface of the positive meniscus lens L1 and the image-side surface of the negative lens L7. Additionally, dB is the distance on the optical axis between the object-side surface of the positive meniscus lens L1 and the object-side surface of the positive meniscus lens L3. Finally, dN is the distance on the optical axis between the object-side surface of the positive meniscus lens L1 and the object-side surface of the negative meniscus lens L4.

[0215] Table 4 below shows the values ​​of the parameters of the optical system in this embodiment.

[0216] (Table 4)

[0217] [Overall Parameters]

[0218] [Lens Parameters]

[0219] [Focal length data for each group]

[0220] [Variable Interval Data]

[0221] Figure 8 This is a diagram of the aberrations of the optical system in the fourth embodiment when focusing on an object at infinity.

[0222] As can be seen from the various aberration diagrams, the optical system of this embodiment effectively suppresses aberration variations during focusing and has high optical performance.

[0223] (5th embodiment)

[0224] Figure 9A This is a cross-sectional view of the optical system of the fifth embodiment for focusing on an object at infinity. Figure 9B This is a cross-sectional view of the optical system of the fifth embodiment when focusing on a close-up object.

[0225] The optical system of this embodiment includes, sequentially from the object side, a first lens group G1 with positive optical power, a focusing group GF with negative optical power, and a rear group GR with negative optical power. An aperture stop S is disposed between the first lens group G1 and the focusing group GF. The first lens group G1 includes a first A lens group G1A with positive optical power disposed on the object side within the first lens group, separated by the largest air gap A, and a first B lens group G1B with negative optical power disposed on the image side.

[0226] Lens group 1A G1A consists of a biconvex positive lens L1 and a positive meniscus lens L2 with its convex surface facing the object side, arranged sequentially from the object side.

[0227] Lens group G1B, from the object side, consists of a combined positive lens consisting of a biconvex positive lens L3 and a biconcave negative lens L4, a combined negative lens consisting of a negative meniscus lens L5 with its convex surface facing the object side and a biconvex positive lens L6, and a combined positive lens consisting of a positive meniscus lens L7 with its convex surface facing the image side and a negative meniscus lens L8 with its convex surface facing the image side.

[0228] The focusing group GF consists of a negative meniscus lens L9 with its convex surface facing the object side.

[0229] The rear group GR, from the object side, consists of, in sequence, a positive meniscus lens L10 with its convex surface facing the image side, a negative lens combining a biconvex positive lens L11 and a biconcave negative lens L12, a biconcave negative lens L13, a positive lens combining a biconvex positive lens L14 and a negative meniscus lens L15 with its convex surface facing the image side, a positive lens combining a negative meniscus lens L16 with its convex surface facing the object side and a biconvex positive lens L17, a negative lens combining a biconcave negative lens L18 and a positive meniscus lens L19 with its convex surface facing the object side, and a positive meniscus lens L20 with its convex surface facing the object side.

[0230] An imaging element (not shown) composed of a CCD or CMOS sensor is disposed on image plane I.

[0231] The optical system of this embodiment focuses by moving the focus group GF along the optical axis. When focusing on a close object from a state of infinity, the focus group GF moves from the object side to the image side.

[0232] In the optical system of this embodiment, the rear group GR has a lens group in which the positive lens L11 and the negative lens L12 are combined, and the negative lens L13 constitutes an image stabilization lens group. This image stabilization lens group can move in a manner with a component perpendicular to the optical axis in order to correct image jitter.

[0233] In the optical system of this embodiment, the positive lens L1 corresponds to the first lens, and the positive meniscus lens L2 corresponds to the second lens. Additionally, in the optical system of this embodiment, the negative lens L4 corresponds to the negative lens N, and the positive meniscus lens L7 corresponds to the positive lens Z.

[0234] In the optical system of this embodiment, dA is the distance on the optical axis between the image-side surface of the positive meniscus lens L2 and the object-side surface of the positive lens L3. Furthermore, dG1 is the distance on the optical axis between the object-side surface of the positive lens L1 and the image-side surface of the negative meniscus lens L8. Additionally, dB is the distance on the optical axis between the object-side surface of the positive lens L1 and the object-side surface of the positive lens L3. Finally, dN is the distance on the optical axis between the object-side surface of the positive lens L1 and the object-side surface of the negative lens L4.

[0235] Table 5 below shows the values ​​of the parameters of the optical system in this embodiment.

[0236] (Table 5)

[0237] [Overall Parameters]

[0238] [Lens Parameters]

[0239] [Focal length data for each group]

[0240] [Variable Interval Data]

[0241] Figure 10 This is a diagram of the aberrations of the optical system in the fifth embodiment when focusing on an object at infinity.

[0242] As can be seen from the various aberration diagrams, the optical system of this embodiment effectively suppresses aberration variations during focusing and has high optical performance.

[0243] (Sixth Embodiment)

[0244] Figure 11A This is a cross-sectional view of the optical system of the sixth embodiment when focusing on an object at infinity. Figure 11B This is a cross-sectional view of the optical system of the sixth embodiment when focusing on a close-up object.

[0245] The optical system of this embodiment includes, sequentially from the object side, a first lens group G1 with positive optical power, a focusing group GF with negative optical power, and a rear group GR with negative optical power. An aperture stop S is disposed between the first lens group G1 and the focusing group GF. The first lens group G1 includes a first A lens group G1A with positive optical power disposed on the object side within the first lens group, separated by the largest air gap A, and a first B lens group G1B with negative optical power disposed on the image side.

[0246] Lens group G1A consists of, from the object side, a positive meniscus lens L1 with its convex surface facing the object side and a positive meniscus lens L2 with its convex surface facing the object side.

[0247] Lens group G1B, from the object side, consists of a negative lens consisting of a positive meniscus lens L3 (convex side facing the object) and a negative meniscus lens L4 (convex side facing the object), a positive meniscus lens L5 (convex side facing the object), and a positive lens consisting of a biconvex positive lens L6 and a biconcave negative lens L7.

[0248] The focusing group GF consists of a biconcave negative lens L8.

[0249] The rear group GR, from the object side, consists of the following components in sequence: a positive meniscus lens L9 with its convex surface facing the image side; a positive meniscus lens L10 with its convex surface facing the image side combined with a biconcave negative lens L11; a biconcave negative lens L12; a positive lens L13 with its biconvex shape combined with a biconcave negative lens L14; a negative lens L15 with its biconcave shape combined with a biconvex positive lens L16; a positive lens L17 with its biconvex shape combined with a negative meniscus lens L18 with its convex surface facing the image side; and a negative lens L19 with its biconvex shape combined with a positive lens L20 with a negative meniscus lens L21 with its convex surface facing the image side.

[0250] An imaging element (not shown) composed of a CCD or CMOS sensor is disposed on image plane I.

[0251] The optical system of this embodiment focuses by moving the focus group GF along the optical axis. When focusing on a close object from a state of infinity, the focus group GF moves from the object side to the image side.

[0252] In the optical system of this embodiment, the rear group GR has a lens group in which the positive meniscus lens L10 and the negative lens L11 are combined, and the negative lens L12 constitutes an image stabilization lens group. This image stabilization lens group can move in a manner with a component perpendicular to the optical axis in order to correct image jitter.

[0253] In the optical system of this embodiment, the positive meniscus lens L1 corresponds to the first lens, and the positive meniscus lens L2 corresponds to the second lens. Additionally, in the optical system of this embodiment, the negative meniscus lens L4 corresponds to the negative lens N, and the positive lens L6 corresponds to the positive lens Z.

[0254] In the optical system of this embodiment, dA is the distance on the optical axis between the image-side surface of the positive meniscus lens L2 and the object-side surface of the positive meniscus lens L3. Furthermore, dG1 is the distance on the optical axis between the object-side surface of the positive meniscus lens L1 and the image-side surface of the negative lens L7. Additionally, dB is the distance on the optical axis between the object-side surface of the positive meniscus lens L1 and the object-side surface of the positive meniscus lens L3. Finally, dN is the distance on the optical axis between the object-side surface of the positive meniscus lens L1 and the object-side surface of the negative meniscus lens L4.

[0255] Table 6 below shows the values ​​of the parameters of the optical system in this embodiment.

[0256] (Table 6)

[0257] [Overall Parameters]

[0258] [Lens Parameters]

[0259] [Focal length data for each group]

[0260] [Variable Interval Data]

[0261] Figure 12 This is a diagram of the aberrations of the optical system in the sixth embodiment when focusing on an object at infinity.

[0262] As can be seen from the various aberration diagrams, the optical system of this embodiment effectively suppresses aberration variations during focusing and has high optical performance.

[0263] (Seventh Embodiment)

[0264] Figure 13A This is a cross-sectional view of the optical system of the seventh embodiment when focusing on an object at infinity. Figure 13B This is a cross-sectional view of the optical system of the seventh embodiment when focusing on a close-up object.

[0265] The optical system of this embodiment includes, sequentially from the object side, a first lens group G1 with positive optical power, a focusing group GF with negative optical power, and a rear group GR with negative optical power. An aperture stop S is disposed between the first lens group G1 and the focusing group GF. The first lens group G1 includes a first A lens group G1A with positive optical power disposed on the object side within the first lens group, separated by the largest air gap A, and a first B lens group G1B with negative optical power disposed on the image side.

[0266] Lens group 1A G1A consists of a biconvex positive lens L1 and a positive meniscus lens L2 with its convex surface facing the object side, arranged sequentially from the object side.

[0267] Lens group G1B, from the object side, consists of a combined negative lens consisting of a biconvex positive lens L3 and a biconcave negative lens L4, a positive meniscus lens L5 with its convex surface facing the object side, and a combined negative lens consisting of a biconvex positive lens L6 and a biconcave negative lens L7.

[0268] The focusing group GF consists of a biconcave negative lens L8.

[0269] The rear group GR, from the object side, consists of, in sequence, a positive meniscus lens L9 with its convex surface facing the image side, a negative lens combining a biconvex positive lens L10 and a biconcave negative lens L11, a biconcave negative lens L12, a positive lens combining a biconvex positive lens L13 and a biconcave negative lens L14, a negative lens combining a biconcave negative lens L15 and a biconvex positive lens L16, a positive lens combining a biconvex positive lens L17 and a negative meniscus lens L18 with its convex surface facing the image side, and a negative lens combining a biconcave negative lens L19, a biconvex positive lens L20, and a negative lens L21 with its convex surface facing the image side.

[0270] An imaging element (not shown) composed of a CCD or CMOS sensor is disposed on image plane I.

[0271] The optical system of this embodiment focuses by moving the focus group GF along the optical axis. When focusing on a close object from a state of infinity, the focus group GF moves from the object side to the image side.

[0272] In the optical system of this embodiment, the rear group GR has a lens group in which the positive lens L10 and the negative lens L11 are combined, and the negative lens L12 constitutes an image stabilization lens group. This image stabilization lens group can move in a manner with a component perpendicular to the optical axis in order to correct image jitter.

[0273] In the optical system of this embodiment, the positive lens L1 corresponds to the first lens, and the positive meniscus lens L2 corresponds to the second lens. Additionally, in the optical system of this embodiment, the negative lens L4 corresponds to the negative lens N, and the positive lens L6 corresponds to the positive lens Z.

[0274] In the optical system of this embodiment, dA is the distance on the optical axis between the image-side surface of the positive meniscus lens L2 and the object-side surface of the positive lens L3. Furthermore, dG1 is the distance on the optical axis between the object-side surface of the positive lens L1 and the image-side surface of the negative lens L7. Additionally, dB is the distance on the optical axis between the object-side surface of the positive lens L1 and the object-side surface of the positive lens L3. Finally, dN is the distance on the optical axis between the object-side surface of the positive lens L1 and the object-side surface of the negative lens L4.

[0275] Table 7 below shows the values ​​of the parameters of the optical system in this embodiment.

[0276] (Table 7)

[0277] [Overall Parameters]

[0278] [Lens Parameters]

[0279] [Focal length data for each group]

[0280] [Variable Interval Data]

[0281] Figure 14 This is a diagram of the aberrations of the optical system in the seventh embodiment when focusing on an object at infinity.

[0282] As can be seen from the various aberration diagrams, the optical system of this embodiment effectively suppresses aberration variations during focusing and has high optical performance.

[0283] (Embodiment 8)

[0284] Figure 15A This is a cross-sectional view of the optical system of the eighth embodiment when focusing on an object at infinity. Figure 15B This is a cross-sectional view of the optical system of the eighth embodiment when focusing on a close-up object.

[0285] The optical system of this embodiment includes, sequentially from the object side, a first lens group G1 with positive optical power, a focusing group GF with negative optical power, and a rear group GR with negative optical power. An aperture stop S is disposed between the first lens group G1 and the focusing group GF. The first lens group G1 includes a first A lens group G1A with positive optical power disposed on the object side within the first lens group, separated by the largest air gap A, and a first B lens group G1B with negative optical power disposed on the image side.

[0286] Lens group 1A G1A consists of a biconvex positive lens L1 and a positive meniscus lens L2 with its convex surface facing the object side, arranged sequentially from the object side.

[0287] Lens group G1B, from the object side, consists of a negative lens consisting of a negative meniscus lens L3 with its convex surface facing the object side and a positive meniscus lens L4 with its convex surface facing the object side, a positive lens consisting of a biconvex positive lens L5 and a biconcave negative lens L6, and a negative lens consisting of a positive meniscus lens L7 with its convex surface facing the object side and a negative meniscus lens L8 with its convex surface facing the object side.

[0288] The focusing group GF consists of a negative meniscus lens L9 with its convex surface facing the object side.

[0289] The rear group GR, from the object side, consists of, in sequence, a positive meniscus lens L10 with its convex surface facing the image side, a positive meniscus lens L11 with its convex surface facing the image side combined with a biconcave negative lens L12, a biconcave negative lens L13, a positive lens L14 with its biconvex shape combined with a biconcave negative lens L15, a negative lens L16 with its biconcave shape combined with a biconvex positive lens L17, a positive lens L18 with its biconvex shape combined with a negative meniscus lens L19 with its convex surface facing the image side, and a negative lens L20 with its biconcave shape combined with a positive lens L21 with a negative meniscus lens L22 with its convex surface facing the image side.

[0290] An imaging element (not shown) composed of a CCD or CMOS sensor is disposed on image plane I.

[0291] The optical system of this embodiment focuses by moving the focus group GF along the optical axis. When focusing on a close object from a state of infinity, the focus group GF moves from the object side to the image side.

[0292] In the optical system of this embodiment, the rear group GR has a lens group in which the positive meniscus lens L11 and the negative lens L12 are combined, and the negative lens L13 constitutes an image stabilization lens group. This image stabilization lens group can move in a manner having a component in the direction perpendicular to the optical axis in order to correct image jitter.

[0293] In the optical system of this embodiment, the positive lens L1 corresponds to the first lens, and the positive meniscus lens L2 corresponds to the second lens. Additionally, in the optical system of this embodiment, the negative meniscus lens L3 corresponds to the negative lens N, and the positive meniscus lens L7 corresponds to the positive lens Z.

[0294] In the optical system of this embodiment, dA is the distance on the optical axis between the image-side surface of the positive meniscus lens L2 and the object-side surface of the negative meniscus lens L3. Furthermore, dG1 is the distance on the optical axis between the object-side surface of the positive lens L1 and the image-side surface of the negative meniscus lens L8. Additionally, dB is the distance on the optical axis between the object-side surface of the positive lens L1 and the object-side surface of the negative meniscus lens L3. Finally, dN is the distance on the optical axis between the object-side surface of the positive lens L1 and the object-side surface of the negative meniscus lens L3.

[0295] Table 8 below shows the values ​​of the parameters of the optical system in this embodiment.

[0296] (Table 8)

[0297] [Overall Parameters]

[0298] [Lens Parameters]

[0299] [Focal length data for each group]

[0300] [Variable Interval Data]

[0301] Figure 16 This is a diagram of the aberrations of the optical system in the eighth embodiment when focusing on an object at infinity.

[0302] As can be seen from the various aberration diagrams, the optical system of this embodiment effectively suppresses aberration variations during focusing and has high optical performance.

[0303] (Embodiment 9)

[0304] Figure 17A This is a cross-sectional view of the optical system of the 9th embodiment when focusing on an object at infinity. Figure 17B This is a cross-sectional view of the optical system of the 9th embodiment when focusing on a close-up object.

[0305] The optical system of this embodiment includes, sequentially from the object side, a first lens group G1 with positive optical power, a focusing group GF with negative optical power, and a rear group GR with negative optical power. An aperture stop S is disposed between the focusing group GF and the rear group GR. The first lens group G1 includes a first A lens group G1A with positive optical power disposed on the object side within the first lens group, separated by the largest air gap A, and a first B lens group G1B with negative optical power disposed on the image side.

[0306] Lens group G1A consists of, from the object side, a positive meniscus lens L1 with its convex surface facing the object side and a positive meniscus lens L2 with its convex surface facing the object side.

[0307] Lens group G1B, from the object side, consists of a negative lens consisting of a negative meniscus lens L3 with its convex surface facing the object side and a positive meniscus lens L4 with its convex surface facing the object side, a positive lens consisting of a biconvex positive lens L5 and a biconcave negative lens L6, and a negative lens consisting of a positive meniscus lens L7 with its convex surface facing the object side and a negative meniscus lens L8 with its convex surface facing the object side.

[0308] The focusing group GF forms a negative lens L9 with a biconcave shape.

[0309] The rear group GR, from the object side, consists of, in sequence, a positive meniscus lens L10 with its convex surface facing the image side, a negative lens combining a biconvex positive lens L11 and a biconcave negative lens L12, a biconcave negative lens L13, a positive lens combining a biconvex positive lens L14 and a biconcave negative lens L15, a negative meniscus lens L16 with its convex surface facing the object side and a biconvex positive lens L17, a positive lens combining a biconvex positive lens L18 and a biconcave negative lens L19, and a negative lens combining a biconcave negative lens L20, a biconvex positive lens L21, and a negative meniscus lens L22 with its convex surface facing the image side.

[0310] An imaging element (not shown) composed of a CCD or CMOS sensor is disposed on image plane I.

[0311] The optical system of this embodiment focuses by moving the focus group GF along the optical axis. When focusing on a close object from a state of infinity, the focus group GF moves from the object side to the image side.

[0312] In the optical system of this embodiment, the rear group GR has a lens group in which the positive lens L11 and the negative lens L12 are combined, and the negative lens L13 constitutes an image stabilization lens group. This image stabilization lens group can move in a manner with a component perpendicular to the optical axis in order to correct image jitter.

[0313] In the optical system of this embodiment, the positive meniscus lens L1 corresponds to the first lens, and the positive meniscus lens L2 corresponds to the second lens. Additionally, in the optical system of this embodiment, the negative meniscus lens L3 corresponds to the negative lens N, and the positive meniscus lens L7 corresponds to the positive lens Z.

[0314] In the optical system of this embodiment, dA is the distance on the optical axis between the image-side surface of the positive meniscus lens L2 and the object-side surface of the negative meniscus lens L3. Furthermore, dG1 is the distance on the optical axis between the object-side surface of the positive meniscus lens L1 and the image-side surface of the negative meniscus lens L8. Additionally, dB is the distance on the optical axis between the object-side surface of the positive meniscus lens L1 and the object-side surface of the negative meniscus lens L3. Finally, dN is the distance on the optical axis between the object-side surface of the positive meniscus lens L1 and the object-side surface of the negative meniscus lens L3.

[0315] Table 9 below shows the values ​​of the parameters of the optical system in this embodiment.

[0316] (Table 9)

[0317] [Overall Parameters]

[0318] [Lens Parameters]

[0319] [Focal length data for each group]

[0320] [Variable Interval Data]

[0321] Figure 18 This is a diagram of the aberrations of the optical system in the 9th embodiment when focusing on an object at infinity.

[0322] As can be seen from the various aberration diagrams, the optical system of this embodiment effectively suppresses aberration variations during focusing and has high optical performance.

[0323] (Embodiment 10)

[0324] Figure 19A This is a cross-sectional view of the optical system of the tenth embodiment when focusing on an object at infinity. Figure 19B This is a cross-sectional view of the optical system of the 10th embodiment when focusing on a close-up object.

[0325] The optical system of this embodiment includes, sequentially from the object side, a first lens group G1 with positive optical power, a focusing group GF with negative optical power, and a rear group GR with negative optical power. An aperture stop S is disposed between the first lens group G1 and the focusing group GF. The first lens group G1 includes a first A lens group G1A with positive optical power disposed on the object side within the first lens group, separated by the largest air gap A, and a first B lens group G1B with negative optical power disposed on the image side.

[0326] Lens group 1A G1A consists of a biconvex positive lens L1 and a positive meniscus lens L2 with its convex surface facing the object side, arranged sequentially from the object side.

[0327] Lens group G1B, from the object side, consists of a negative lens consisting of a negative meniscus lens L3 with its convex surface facing the object side and a positive meniscus lens L4 with its convex surface facing the object side, a positive lens consisting of a biconvex positive lens L5 and a biconcave negative lens L6, and a negative lens consisting of a negative meniscus lens L7 with its convex surface facing the object side and a positive meniscus lens L8 with its convex surface facing the object side.

[0328] The focusing group GF forms a negative lens L9 with a biconcave shape.

[0329] The rear group GR, from the object side, consists of, in sequence, a positive meniscus lens L10 with its convex surface facing the image side, a positive meniscus lens L11 with its convex surface facing the image side combined with a biconcave negative lens L12, a biconcave negative lens L13, a positive lens L14 with its biconvex shape combined with a biconcave negative lens L15, a negative lens L16 with its biconcave shape combined with a biconvex positive lens L17, a positive lens L18 with its biconvex shape combined with a negative meniscus lens L19 with its convex surface facing the image side, and a negative lens L20 with its biconcave shape combined with a positive lens L21 with a negative meniscus lens L22 with its convex surface facing the image side.

[0330] An imaging element (not shown) composed of a CCD or CMOS sensor is disposed on image plane I.

[0331] The optical system of this embodiment focuses by moving the focus group GF along the optical axis. When focusing on a close object from a state of infinity, the focus group GF moves from the object side to the image side.

[0332] In the optical system of this embodiment, the rear group GR has a lens group in which the positive meniscus lens L11 and the negative lens L12 are combined, and the negative lens L13 constitutes an image stabilization lens group. This image stabilization lens group can move in a manner having a component in the direction perpendicular to the optical axis in order to correct image jitter.

[0333] In the optical system of this embodiment, the positive lens L1 corresponds to the first lens, and the positive meniscus lens L2 corresponds to the second lens. Additionally, in the optical system of this embodiment, the negative meniscus lens L3 corresponds to the negative lens N, and the positive meniscus lens L8 corresponds to the positive lens Z.

[0334] In the optical system of this embodiment, dA is the distance on the optical axis between the image-side surface of the positive meniscus lens L2 and the object-side surface of the negative meniscus lens L3. Furthermore, dG1 is the distance on the optical axis between the object-side surface of the positive lens L1 and the image-side surface of the positive meniscus lens L8. Additionally, dB is the distance on the optical axis between the object-side surface of the positive lens L1 and the object-side surface of the negative meniscus lens L3. Finally, dN is the distance on the optical axis between the object-side surface of the positive lens L1 and the object-side surface of the negative meniscus lens L3.

[0335] Table 10 below shows the values ​​of the parameters of the optical system in this embodiment.

[0336] (Table 10)

[0337] [Overall Parameters]

[0338] [Lens Parameters]

[0339] [Focal length data for each group]

[0340] [Variable Interval Data]

[0341] Figure 20 This is a diagram of the aberrations of the optical system in the 10th embodiment when focusing on an object at infinity.

[0342] As can be seen from the various aberration diagrams, the optical system of this embodiment effectively suppresses aberration variations during focusing and has high optical performance.

[0343] (Embodiment 11)

[0344] Figure 21A This is a cross-sectional view of the optical system of the 11th embodiment when focusing on an object at infinity. Figure 21B This is a cross-sectional view of the optical system of the 11th embodiment when focusing on a close-up object.

[0345] The optical system of this embodiment includes, sequentially from the object side, a first lens group G1 with positive optical power, a focusing group GF with negative optical power, and a rear group GR with negative optical power. An aperture stop S is disposed between the first lens group G1 and the focusing group GF. The first lens group G1 includes a first A lens group G1A with positive optical power disposed on the object side within the first lens group and separated by the largest air gap A, and a first B lens group G1B with positive optical power disposed on the image side.

[0346] Lens group 1A G1A consists of a positive meniscus lens L1 with its convex surface facing the object side.

[0347] Lens group G1B, from the object side, consists of a positive lens consisting of a negative meniscus lens L2 with its convex surface facing the object side and a positive meniscus lens L3 with its convex surface facing the object side, a negative lens consisting of a biconvex positive lens L4 and a biconcave negative lens L5, and a positive meniscus lens L6 with its convex surface facing the object side.

[0348] The focusing group GF consists of a biconcave negative lens L7.

[0349] The rear group GR, from the object side, consists of the following components in sequence: a positive meniscus lens L8 with its convex surface facing the image side; a positive meniscus lens L9 with its convex surface facing the image side and a negative lens L10 with a biconcave shape; a plano-concave negative lens L11 with its concave surface facing the image side; a positive lens L12 with a biconvex shape and a negative lens L13 with a biconcave shape; a negative lens L14 with its convex surface facing the object side and a positive lens L15 with a biconvex shape; a positive lens L16 with a biconvex shape and a negative lens L17 with a biconcave shape; and a negative lens L18 with a biconcave shape, a positive lens L19 with a positive lens L19 with a negative meniscus lens L20 with its convex surface facing the image side.

[0350] An imaging element (not shown) composed of a CCD or CMOS sensor is disposed on image plane I.

[0351] The optical system of this embodiment focuses by moving the focus group GF along the optical axis. When focusing on a close object from a state of infinity, the focus group GF moves from the object side to the image side.

[0352] In the optical system of this embodiment, the rear group GR has a lens group in which the positive meniscus lens L9 and the negative lens L10 are combined, and the negative lens L11 forms an image stabilization lens group. This image stabilization lens group can move in a manner with a component perpendicular to the optical axis in order to correct image jitter.

[0353] In the optical system of this embodiment, the positive meniscus lens L1 corresponds to the first lens. Additionally, in the optical system of this embodiment, the negative meniscus lens L2 corresponds to the negative lens N, and the positive meniscus lens L6 corresponds to the positive lens Z.

[0354] In the optical system of this embodiment, dA is the distance on the optical axis between the image-side surface of the positive meniscus lens L1 and the object-side surface of the negative meniscus lens L2. Furthermore, dG1 is the distance on the optical axis between the object-side surface of the positive meniscus lens L1 and the image-side surface of the positive meniscus lens L6. Additionally, dB is the distance on the optical axis between the object-side surface of the positive meniscus lens L1 and the object-side surface of the negative meniscus lens L2. Finally, dN is the distance on the optical axis between the object-side surface of the positive meniscus lens L1 and the object-side surface of the negative meniscus lens L2.

[0355] Table 11 below shows the values ​​of the parameters of the optical system in this embodiment.

[0356] (Table 11)

[0357] [Overall Parameters]

[0358] [Lens Parameters]

[0359] [Focal length data for each group]

[0360] [Variable Interval Data]

[0361] Figure 22 This is a diagram of the aberrations of the optical system in the 11th embodiment when focusing on an object at infinity.

[0362] As can be seen from the various aberration diagrams, the optical system of this embodiment effectively suppresses aberration variations during focusing and has high optical performance.

[0363] According to the above embodiments, a small, lightweight optical system with good imaging performance can be realized.

[0364] The following shows an overview of the conditional expressions and the corresponding values ​​of the conditional expressions in each embodiment.

[0365] FNo is the F-number of the optical system when focusing at infinity, TL is the total optical length of the optical system when focusing at infinity, and f is the focal length of the optical system when focusing at infinity. dA is the distance on the optical axis of the air gap A, and dG1 is the distance on the optical axis of the first lens group. dN is the distance on the optical axis from the object-side surface of the optical system to the object-side surface of the negative lens N. f1A is the focal length of the first lens group A, and f1B is the focal length of the first lens group B. dB is the distance on the optical axis from the object-side surface of the optical system to the object-side surface of the first lens group B. fL1 is the focal length of the first lens located on the object-side, and fL2 is the focal length of the second lens located on the object-side. νd1Amax is the maximum Abbe number of the lenses included in the first lens group A, with reference to the d-line, and νdLZ is the Abbe number of the positive lens Z, with reference to the d-line. νd1Aave is the average Abbe number of the lenses contained in the 1A lens group, with the d line as the reference.

[0366] ndLZ is the refractive index of the positive lens Z with respect to the d line, and θgFLZ is the relative partial dispersion of the positive lens Z. When the refractive index of the positive lens Z with respect to the g line is ngLZ, the refractive index of the positive lens Z with respect to the F line is nFLZ, and the refractive index of the positive lens Z with respect to the C line is nCLZ, it is defined by the following formula.

[0367] θgFLZ = (ngLZ-nFLZ) / (nFLZ-nCLZ)

[0368] L1R1 is the radius of curvature of the object-side surface of the first lens, which is located closest to the object. L1R2 is the radius of curvature of the image-side surface of the first lens. L2R1 is the radius of curvature of the object-side surface of the second lens, which is located second from the object side. L2R2 is the radius of curvature of the image-side surface of the second lens. f1 is the focal length of the first lens group. fF is the focal length of the focusing group. fR is the focal length of the rear group. dF is the distance along the optical axis from the object-side surface of the optical system to the object-side surface of the focusing group. νdFave is the average Abbe number of the lenses included in the focusing group, with reference to the d-line. 2ω is the full field of view of the optical system. BF is the back focal length of the optical system.

[0369] [List of Conditional Expressions]

[0370] (1) Fno*(TL / f) 2

[0371] (2) dA / dG1

[0372] (3) TL / f

[0373] (4) dN / TL

[0374] (5) f1A / f1B

[0375] (6) f1A / f

[0376] (7) dB / dG1

[0377] (8) fL1 / fL2

[0378] (9) νd1Amax-νdLZ

[0379] (10) νd1Aave

[0380] (11) ndLZ+(0.01425*νdLZ)

[0381] (12) νdLZ

[0382] (13) θgFLZ+(0.00316*νdLZ)

[0383] (14) (L1R2+L1R1) / (L1R2-L1R1)

[0384] (15) (L2R2+L2R1) / (L2R2-L2R1)

[0385] (16) f1 / f

[0386] (17) (-fF) / f1

[0387] (18) (-fF) / fR

[0388] (19) dF / TL

[0389] (20) νdFave

[0390] (21) 2ω

[0391] (22) Bf / f

[0392] [Conditional expression corresponding value]

[0393] The above embodiments illustrate specific examples of the present invention, and the present invention is not limited thereto. The following can be appropriately employed without impairing the optical performance of the optical system of the embodiments of this application.

[0394] Alternatively, an antireflective coating with high transmittance over a wide wavelength range can be applied to the lens surface of the lens constituting the optical system of the above embodiments. This reduces glare and ghosting, and enables high-contrast optical performance.

[0395] Next, according to Figure 23 A camera equipped with the optical system of this embodiment will be described.

[0396] Figure 23 This is a schematic diagram of a camera equipped with the optical system of this embodiment.

[0397] Camera 1 is a lens-interchangeable camera that uses the optical system described in the first embodiment as the photographic lens 2.

[0398] In camera 1, light from an object (not shown) is focused by lens 2 and imaged onto focal plate 4 via reflex mirror 3. The light imaged onto focal plate 4 is then reflected multiple times within pentaprism 5 and guided to eyepiece 6. Thus, a photographer with their eyes at eyepoint EP can observe the subject as an upright image.

[0399] Furthermore, when the photographer presses the release button (not shown), the quick-return mirror 3 retracts outward from the light path, allowing light from the subject (not shown) to reach the imaging element 7. Thus, the light from the subject is captured by the imaging element 7 and stored as an image of the subject in a memory (not shown). This enables the photographer to take photographs of the subject based on the camera 1.

[0400] Here, the optical system of the first embodiment, which is mounted as the photographic lens 2 on the camera 1, is a small, lightweight optical system with good imaging performance. Therefore, the camera 1 can achieve small size and good optical performance. In addition, even if a camera is configured with the optical system of the second to eleventh embodiments mounted as the photographic lens 2, it can achieve the same effect as the camera 1.

[0401] Finally, according to Figure 24 and Figure 25 A general description of the manufacturing method of the optical system of this embodiment will be given.

[0402] Figure 24 This is a first flowchart illustrating a general method for manufacturing the optical system according to this embodiment.

[0403] Figure 24 The manufacturing method of the optical system shown in this embodiment is a manufacturing method of an optical system composed of multiple lenses, including the following steps S11, S12 and S13.

[0404] Step S11: The first lens group, the focusing group, and the rear group with positive optical power are sequentially arranged from the object side. The focusing group moves along the optical axis when focusing.

[0405] Step S12: The first lens group is positioned on the object side with the largest air gap A in the first lens group.

[0406] Step S13: Make the optical system satisfy all the predetermined conditions. (1) 1.00 < FNo×(TL / f) 2 < 2.50 (2) 0.30 < dA / dG1 < 0.85 in, FNo: The F-number of the optical system when focusing at infinity. TL: Total optical length of the optical system when focusing at infinity f: Focal length of the optical system when focusing at infinity dA: Distance on the optical axis of the air gap A dG1: Distance on the optical axis of the first lens group

[0407] According to the manufacturing method of the optical system of this embodiment, it is possible to manufacture a small, lightweight optical system with good imaging performance.

[0408] Figure 25 This is a second flowchart illustrating a general method for manufacturing the optical system according to this embodiment.

[0409] Figure 25 The manufacturing method of the optical system shown in this embodiment is a manufacturing method of an optical system composed of multiple lenses, including the following steps S21, S22 and S23.

[0410] Step S21: Prepare multiple lenses.

[0411] Step S22: Arrange at least one positive lens component and a negative lens N sequentially from the object side.

[0412] Step S23: Make the optical system satisfy all the predetermined conditions. (1) 1.00 < FNo×(TL / f) 2 < 2.50 (4) 0.18 < dN / TL < 0.45 in, FNo: The F-number of the optical system when focusing at infinity. TL: Total optical length of the optical system when focusing at infinity f: Focal length of the optical system when focusing at infinity dN: The distance along the optical axis from the object-side surface of the optical system to the object-side surface of the negative lens N.

[0413] According to the manufacturing method of the optical system of this embodiment, it is possible to manufacture a small, lightweight optical system with good imaging performance.

[0414] It should be understood that those skilled in the art can make various changes, substitutions and modifications to the present invention without departing from the spirit and scope of the invention.

[0415] Label Explanation

[0416] S-Aperture Stop

[0417] I Image

[0418] 1 camera

[0419] 2. Camera lens

[0420] 7. Imaging components

Claims

1. An optical system, wherein a first lens group having a positive refractive power, a focus group having a negative refractive power and moving along an optical axis at the time of focusing, and a rear group are sequentially arranged from an object side, a lens group arranged on the object side within the first lens group through a largest air interval A is set as a first A lens group, the optical system satisfies all of the following conditional expressions: 1.00 < FNo x (TL / f) 2 < 2.50 0.30 < dA / dG1 < 0.85 wherein FNo: an F value of the optical system at the time of focusing at infinity, TL: an optical total length of the optical system at the time of focusing at infinity, f: a focal length of the optical system at the time of focusing at infinity, dA: a distance on the optical axis of the air interval A, dG1: a distance on the optical axis of the first lens group.

2. An optical system, wherein a first lens group having a positive refractive power, a focus group having a negative refractive power and moving along an optical axis at the time of focusing, and a rear group are sequentially arranged from an object side, a lens group arranged on the object side within the first lens group through a largest air interval A is set as a first A lens group, the optical system satisfies all of the following conditional expressions: 0.30 < TL / f < 0.80 0.30 < dA / dG1 < 0.85 wherein TL: an optical total length of the optical system at the time of focusing at infinity, f: a focal length of the optical system at the time of focusing at infinity, dA: a distance on the optical axis of the air interval A, dG1: a distance on the optical axis of the first lens group.

3. An optical system composed of a plurality of lenses, wherein the optical system has at least one positive lens component and a negative lens N sequentially from an object side, a focus group has a negative refractive power, the optical system satisfies all of the following conditional expressions: 1.00 < FNo x (TL / f) 2 < 2.50 0.18 < dN / TL < 0.45 wherein FNo: an F value of the optical system at the time of focusing at infinity, TL: an optical total length of the optical system at the time of focusing at infinity, f: a focal length of the optical system at the time of focusing at infinity, dN: a distance on the optical axis from a surface of the optical system on the most object side to a surface of the negative lens N on the object side.

4. An optical system composed of a plurality of lenses, wherein the optical system has a positive lens component on the most object side, a focus group has a negative refractive power, the optical system has a negative lens N arranged on the most object side among negative lenses arranged on the image side compared to the positive lens component, the optical system satisfies all of the following conditional expressions: 1.00 < FNo x (TL / f) 2 < 2.50 0.18 < dN / TL < 0.45 wherein FNo: an F value of the optical system at the time of focusing at infinity, TL: an optical total length of the optical system at the time of focusing at infinity, f: a focal length of the optical system at the time of focusing at infinity, dN: a distance on the optical axis from a surface of the optical system on the most object side to a surface of the negative lens N on the object side.

5. The optical system according to claim 3 or 4, wherein The optical system is composed of a first lens group, a focusing group, and a rear group in this order from the object side, the focusing group moves along the optical axis when focusing is performed, The first lens group has a first A lens group disposed on the object side within the first lens group across the largest air interval A, The optical system satisfies the following conditional expression: 0.30 < dA / dG1 < 0.85 wherein, dA: the distance on the optical axis of the air interval A, dG1: the distance on the optical axis of the first lens group.

6. The optical system according to any one of claims 3 to 5, wherein The optical system has a first lens group on the most object side, and satisfies the following conditional expression: 0.30 < TL / f < 0.

80.

7. The optical system according to claim 5 or 6, wherein The first lens group has the positive lens component and the negative lens N.

8. The optical system according to any one of claims 1 to 7, wherein The optical system is composed of a first lens group, a focusing group, and a rear group in this order from the object side, the focusing group moves along the optical axis when focusing is performed, The first lens group has a first A lens group disposed on the object side within the first lens group across the largest air interval A, and a first B lens group disposed on the image side, The optical system satisfies the following conditional expression: -2.00 < f1A / f1B < 0.30 wherein, f1A: the focal length of the first A lens group, f1B: the focal length of the first B lens group.

9. The optical system according to any one of claims 1 to 8, wherein The optical system is composed of a first lens group, a focusing group, and a rear group in this order from the object side, the focusing group moves along the optical axis when focusing is performed, The first lens group has a first A lens group disposed on the object side within the first lens group across the largest air interval A, The optical system satisfies the following conditional expression: 0.10 < f1A / f < 0.60 wherein, f1A: the focal length of the first A lens group.

10. The optical system according to any one of claims 1 to 9, wherein The optical system is composed of a first lens group, a focusing group, and a rear group in this order from the object side, the focusing group moves along the optical axis when focusing is performed, The first lens group has a first B lens group disposed on the image side within the first lens group across the largest air interval A, The optical system satisfies the following conditional expression: 0.40 < dB / dG1 < 0.85 wherein, dB: the distance on the optical axis from the surface on the most object side of the optical system to the surface on the object side of the first B lens group, dG1: the distance on the optical axis of the first lens group.

11. The optical system according to any one of claims 1 to 10, wherein The optical system is composed of a first lens group, a focusing group, and a rear group in this order from the object side, the focusing group moves along the optical axis when focusing is performed, The first lens group has a first A lens group disposed on the object side within the first lens group across the largest air interval A, The first 1A lens group is composed of two or more positive lenses.

12. The optical system according to any one of claims 1 to 11, wherein The optical system is composed of a first lens group, a focus group, and a rear group in this order from an object side, the focus group moves along an optical axis at the time of focusing, the first lens group has a first 1A lens group disposed on the object side with a largest air interval A in the first lens group, and the optical system satisfies the following conditional expression: 0.80 < fLl / fL2 < 3.30 wherein fLl: focal length of a first lens disposed on the object side most in the first 1A lens group, fL2: focal length of a second lens disposed on the object side second in the first 1A lens group.

13. The optical system according to any one of claims 1 to 12, wherein The optical system is composed of a first lens group, a focus group, and a rear group in this order from an object side, the focus group moves along an optical axis at the time of focusing, The first lens group has a first 1A lens group disposed on the object side with a largest air interval A in the first lens group and a first 1B lens group disposed on the image side, The first 1B lens group has at least one positive lens Z satisfying the following conditional expressions: 60.00 < νd1Amax-νdLZ wherein νd1Amax: maximum value of Abbe number with respect to d-line of a lens included in the first 1A lens group, νdLZ: Abbe number with respect to d-line of the positive lens Z.

14. The optical system according to any one of claims 1 to 13, wherein The optical system is composed of a first lens group, a focus group, and a rear group in this order from an object side, the focus group moves along an optical axis at the time of focusing, The first lens group has a first 1A lens group disposed on the object side with a largest air interval A in the first lens group, The optical system satisfies the following conditional expression: 55.00 < νd1Aave wherein νd1Aave: average value of Abbe number with respect to d-line of a lens included in the first 1A lens group.

15. The optical system according to any one of claims 1 to 14, wherein The optical system is composed of a first lens group, a focus group, and a rear group in this order from an object side, the focus group moves along an optical axis at the time of focusing, The first lens group has a first 1B lens group disposed on the image side with a largest air interval A in the first lens group, The first 1B lens group has at least one positive lens Z satisfying the following all conditional expressions: ndLZ+ (0.01425 x νdLZ) < 2.12 νdLZ < 35.00 0.702 < θgFLZ+ (0.00316 x νdLZ) wherein ndLZ: refractive index with respect to d-line of the positive lens Z, νdLZ: Abbe number with respect to d-line of the positive lens Z, θgFLZ: relative partial dispersion of the positive lens Z, defined by the following formula when ngLZ is the refractive index of the positive lens Z for g-line, nFLZ is the refractive index of the positive lens Z for F-line, and nCLZ is the refractive index of the positive lens Z for C-line, i.e. θgFLZ = (ngLZ - nFLZ) / (nFLZ - nCLZ).

16. The optical system according to any one of claims 1 to 15, wherein the optical system is composed of a first lens group, a focusing group, and a rear group in this order from the object side, the focusing group moves along the optical axis when focusing is performed, the first lens group has a first A lens group disposed on the object side with the largest air interval A in the first lens group, and the optical system satisfies the following conditional expression: 0.00 < (L1R2 + L1R1) / (L1R2 - L1R1) < 3.00 wherein L1R1: radius of curvature of a surface on the object side of a first lens disposed on the object side most in the first A lens group, L1R2: radius of curvature of a surface on the image side of the first lens.

17. The optical system according to any one of claims 1 to 16, wherein the optical system is composed of a first lens group, a focusing group, and a rear group in this order from the object side, the focusing group moves along the optical axis when focusing is performed, the first lens group has a first A lens group disposed on the object side with the largest air interval A in the first lens group, and the optical system satisfies the following conditional expression: 0.00 < (L2R2 + L2R1) / (L2R2 - L2R1) < 3.00 wherein L2R1: radius of curvature of a surface on the object side of a second lens disposed on the object side second in the first A lens group, L2R2: radius of curvature of a surface on the image side of the second lens.

18. The optical system according to any one of claims 1 to 17, wherein the optical system is composed of a first lens group, a focusing group, and a rear group in this order from the object side, the focusing group moves along the optical axis when focusing is performed, and the optical system satisfies the following conditional expression: 0.10 < f1 / f < 0.60 wherein f1: focal length of the first lens group.

19. The optical system according to any one of claims 1 to 18, wherein the optical system is composed of a first lens group, a focusing group, and a rear group in this order from the object side, the focusing group moves along the optical axis when focusing is performed, and the optical system satisfies the following conditional expression: 0.20 < (-fF) / f1 < 0.85 wherein fF: focal length of the focusing group, f1: focal length of the first lens group.

20. The optical system according to any one of claims 1 to 19, wherein the optical system is composed of a first lens group, a focusing group, and a rear group in this order from the object side, the focusing group moves along the optical axis when focusing is performed, and the optical system satisfies the following conditional expression: -1.50 < (-fF) / fR < 0.60 wherein fF: focal length of the focusing group, fR: focal length of the rear group. fR: focal length of the rear group.

21. The optical system according to any one of claims 1 to 20, wherein the optical system is composed of a first lens group, a focus group, and a rear group in this order from the object side, the focus group moves along the optical axis when focusing is performed, the optical system satisfies the following conditional expression: 0.30 < dF / TL < 0.70 wherein dF: distance on the optical axis from the most object-ward surface of the optical system to the most object-ward surface of the focus group.

22. The optical system according to any one of claims 1 to 21, wherein the optical system is composed of a first lens group, a focus group, and a rear group in this order from the object side, the focus group moves along the optical axis when focusing is performed, the optical system satisfies the following conditional expression: 40.00 < νdFave wherein νdFave: average value of Abbe number with respect to the d-line of lenses included in the focus group.

23. The optical system according to any one of claims 1 to 22, wherein the optical system satisfies the following conditional expression: 1.00° < 2ω < 20.00° wherein 2ω: total field angle of the optical system.

24. The optical system according to any one of claims 1 to 23, wherein the optical system satisfies the following conditional expression: 0.075 < Bf / f < 0.185 wherein Bf: back focal length of the optical system.

25. The optical system according to any one of claims 1 to 24, wherein the optical system is composed of a first lens group, a focus group, and a rear group in this order from the object side, the focus group moves along the optical axis when focusing is performed, the rear group has an anti-shake lens group which is movable in a manner having a component in a direction perpendicular to the optical axis in order to correct image shake.

26. An optical apparatus having the optical system according to any one of claims 1 to 25.

27. A manufacturing method of an optical system composed of a plurality of lenses, wherein a first lens group having a positive power, a focus group having a negative power and moving along the optical axis when focusing is performed, and a rear group are disposed in this order from the object side, a first A lens group is disposed on the object side across a largest air interval A within the first lens group, all of the following conditional expressions are satisfied: 1.00 < FNo x (TL / f) 2 < 2.50 0.30 < dA / dG1 < 0.85 wherein FNo: F value of the optical system at the time of infinity focus, TL: optical total length of the optical system at the time of infinity focus, f: focal length of the optical system at the time of infinity focus, dA: distance on the optical axis of the air interval A, dG1: distance on the optical axis of the first lens group.

28. A manufacturing method of an optical system composed of a plurality of lenses, wherein at least one positive lens component and a negative lens N are disposed in this order from the object side, a focus group has a negative power, all of the following conditional expressions are satisfied: 1.00 < FNo x (TL / f) 2 < 2.50 0.18 < dN / TL < 0.45 wherein, FNo: F number of the optical system at infinity focus, TL: total optical length of the optical system at infinity focus, f: focal length of the optical system at infinity focus, dN: distance on the optical axis from the most object side surface of the optical system to the object side surface of the negative lens N.

Images