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

Abstract

The invention provides an optical system, an optical apparatus, and a method for manufacturing the optical system, which can obtain bright and good optical performance while realizing miniaturization. An optical system (OL) for an optical device such as a camera (1) is configured from, in order from the object side, a front group (Gf) having a positive refractive power, an intermediate group (Gi), and a rear group (Gr) having a negative refractive power, the intermediate group (Gi) being configured from a first focusing group (GF1) and a second focusing group (GF2) that move along different trajectories during focusing. The front group (Gf) has a negative lens component (Ln1), a negative lens component (Ln2), and a positive lens component (Lp) in this order from the object-most side, the rear group (G4) has a negative lens component (LnL) on the image-most side, and the optical system (OL) satisfies a condition based on a predetermined conditional expression.

Description

Technical Field

[0001] The invention relates to an optical system, an optical device and a method for manufacturing the optical system. Background Art

[0002] Conventionally, an optical system suitable for a photographic camera, an electronic still camera, a video camera, etc. has been proposed (for example, see Patent Document 1). In such an optical system, it is difficult to obtain a bright and good optical performance while miniaturizing the system.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-211489 Summary of the invention

[0006] The optical system of the first aspect of the present invention is composed of a front group having positive optical power, an intermediate group, and a rear group having negative optical power in order from the object side, the intermediate group is composed of a first focusing group and a second focusing group that move in different trajectories when focusing, the front group has a negative lens component, a negative lens component, and a positive lens component in order from the side closest to the object, and the rear group has a negative lens component on the side closest to the image plane, and the optical system satisfies the following conditions: 0.10<|fF1| / (-fr)<2.60 0.70<|fF2| / ff<2.00 in, fF1: focal length of the 1st focus group, fr: focal length of the rear group, fF2: focal length of the second focus group, ff: focal length of the front group.

[0007] The optical system of the second aspect of the present invention is composed of a front group having positive optical power, an intermediate group, and a rear group having negative optical power in order from the object side, the intermediate group is composed of a first focusing group and a second focusing group that move in different trajectories when focusing, the front group has a negative lens component, a negative lens component, and a positive lens component in order from the side closest to the object, and the rear group has a negative lens component on the side closest to the image plane, and the optical system satisfies the following conditions: 0.05<ff / (-fr)<0.90 -1.000<(r2+r1) / (r2-r1)<0.200 in, ff: focal length of the front group, fr: focal length of the rear group, r1: The curvature radius of the lens surface on the image side of the lens component arranged closest to the object side, r2: The curvature radius of the lens surface on the object side of the second lens component arranged from the object side.

[0008] A method for manufacturing an optical system according to a first aspect of the present invention, wherein the optical system is composed of a front group having positive optical power, an intermediate group, and a rear group having negative optical power in order from the object side, wherein the intermediate group is configured to be composed of a first focusing group and a second focusing group that move in different trajectories when focusing, the front group is configured to have a negative lens component, a negative lens component, and a positive lens component in order from the side closest to the object, and the rear group is configured to have a negative lens component on the side closest to the image plane, and the configuration satisfies the following conditions: 0.10<|fF1| / (-fr)<2.60 0.70<|fF2| / ff<2.00 in, fF1: focal length of the 1st focus group, fr: focal length of the rear group, fF2: focal length of the second focus group, ff: focal length of the front group.

[0009] A method for manufacturing an optical system according to a second aspect of the present invention, wherein the optical system is composed of a front group having positive optical power, an intermediate group, and a rear group having negative optical power in order from the object side, wherein the intermediate group is configured to be composed of a first focus group and a second focus group that move in different trajectories when focusing, the front group is configured to have a negative lens component, a negative lens component, and a positive lens component in order from the side closest to the object, and the rear group is configured to have a negative lens component on the side closest to the image plane, and the configuration satisfies the following conditions: 0.05<ff / (-fr)<0.90 -1.000<(r2+r1) / (r2-r1)<0.200 in, ff: focal length of the front group, fr: focal length of the rear group, r1: The curvature radius of the lens surface on the image side of the lens component arranged closest to the object side, r2: The curvature radius of the lens surface on the object side of the second lens component arranged from the object side. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a cross-sectional view showing the lens structure of the optical system according to the first embodiment when focusing on an object at infinity.

[0011] Figure 2 1 and 10 are diagrams showing various aberrations of the optical system of Example 1. (a) shows when an object at infinity is in focus, and (b) shows when an object at a close distance is in focus.

[0012] Figure 3 It is a cross-sectional view showing the lens structure of the optical system according to the second embodiment when focusing on an object at infinity.

[0013] Figure 4 1 and 10 are diagrams showing various aberrations of the optical system of Example 2. (a) shows when an object at infinity is in focus, and (b) shows when an object at a close distance is in focus.

[0014] Figure 5 It is a cross-sectional view showing the lens structure of the optical system according to the third embodiment when focusing on an object at infinity.

[0015] Figure 6 1 and 10 are diagrams showing various aberrations of the optical system of Example 3. (a) shows when an object at infinity is in focus, and (b) shows when an object at a close distance is in focus.

[0016] Figure 7 It is a cross-sectional view showing the lens structure of the optical system according to the fourth embodiment when focusing on an object at infinity.

[0017] Figure 8 1 and 10 are diagrams of various aberrations of the optical system of Example 4, wherein (a) represents when an object at infinity is in focus, and (b) represents when an object at a close distance is in focus.

[0018] Fig. 9 It is a cross-sectional view showing the lens structure of the optical system of Example 5 when focusing on an object at infinity.

[0019] Fig.10 1 and 12 are diagrams of various aberrations of the optical system of Example 5, wherein (a) represents when an object at infinity is in focus, and (b) represents when an object at a close distance is in focus.

[0020] Fig.11 It is a cross-sectional view showing the lens structure of the optical system of Example 6 when focusing on an object at infinity.

[0021] Fig.12 1 and 12 are diagrams of various aberrations of the optical system of Example 6, wherein (a) represents when an object at infinity is in focus, and (b) represents when an object at a close distance is in focus.

[0022] Fig.13 It is a cross-sectional view showing the lens structure of the optical system of Example 7 when focusing on an object at infinity.

[0023] Fig.14 1 and 12 are diagrams of various aberrations of the optical system of Example 7, wherein (a) represents when an object at infinity is in focus, and (b) represents when an object at a close distance is in focus.

[0024] Fig.15 It is a cross-sectional view showing the lens structure of the optical system of Example 8 when focusing on an object at infinity.

[0025] Fig.16 1 and 12 are diagrams of various aberrations of the optical system of Example 8, wherein (a) represents when an object at infinity is in focus, and (b) represents when an object at a close distance is in focus.

[0026] Fig.17 It is a cross-sectional view showing the lens structure of the optical system of Example 9 when focusing on an object at infinity.

[0027] Fig.18 1 and 10 are diagrams of various aberrations of the optical system of Example 9, wherein (a) represents when an object at infinity is in focus, and (b) represents when an object at a close distance is in focus.

[0028] Fig.19 It is a cross-sectional view showing the lens structure of the optical system of Example 10 when focusing on an object at infinity.

[0029] Fig. 20 10. These are various aberration diagrams of the optical system of Example 10, where (a) shows when an object at infinity is in focus, and (b) shows when an object at a close distance is in focus.

[0030] Fig.21 It is a cross-sectional view showing the lens structure of the optical system of Example 11 when focusing on an object at infinity.

[0031] Fig. 22 11. These are various aberration diagrams of the optical system of Example 11, where (a) shows when an object at infinity is in focus, and (b) shows when an object at a close distance is in focus.

[0032] Fig.23 It is a cross-sectional view of a camera equipped with the above-mentioned optical system.

[0033] Fig.24 It is a flowchart for explaining the manufacturing method of the above-mentioned optical system. DETAILED DESCRIPTION

[0034] Hereinafter, preferred embodiments will be described with reference to the drawings.

[0035] (First embodiment)

[0036] like Figure 1As shown, the optical system OL of the first embodiment is composed of a front group Gf having positive optical power, an intermediate group Gi, and a rear group Gr having negative optical power, in order from the object side. In addition, the intermediate group Gi is composed of a first focus group GF1 and a second focus group GF2 that move in different trajectories when focusing. In addition, the front group Gf has a negative lens component Ln1, a negative lens component Ln2, and a positive lens component Lp in order from the side closest to the object, and the rear group Gr has a negative lens component LnL on the side closest to the image plane. By configuring in this way, it is possible to achieve a compact optical system OL while achieving good optical performance in bright photography from an infinitely distant object to a close-up object.

[0037] In addition, the optical system OL of the first embodiment preferably satisfies the following conditional expression (1).

[0038] 0.10<|fF1| / (-fr)<2.60 (1) in, fF1: Focal length of the first focusing group GF1 fr: Focal length of rear group Gr

[0039] Conditional expression (1) specifies the ratio of the focal length of the first focusing group GF1 to the focal length of the rear group Gr. By satisfying the conditional expression (1), various aberrations, including coma, can be well corrected in photography from an object at infinity to an object at close range. When the upper limit value of the conditional expression (1) is exceeded, the focal length of the rear group Gr becomes too short, and it is difficult to correct coma and field curvature, and good optical performance cannot be obtained, so it is not preferred. In addition, in order to make the effect of the conditional expression (1) reliable, it is preferred to set the upper limit value of the conditional expression (1) to 2.50, 2.00, 1.75, 1.60, and further to 1.50. In addition, when it is lower than the lower limit value of the conditional expression (1), the focal length of the first focusing group GF1 becomes too short, and it is difficult to correct spherical aberration and coma when focusing on a close object, and good optical performance cannot be obtained, so it is not preferred. In order to ensure the effect of the conditional expression (1), the lower limit value of the conditional expression (1) is preferably set to 0.25, 0.40, 0.50, 0.60, 0.75, or further to 0.80.

[0040] In addition, the optical system OL of the first embodiment preferably satisfies the following conditional expression (2).

[0041] 0.70<|fF2| / ff<2.00 (2) in, fF2: Focal length of the second focusing group GF2 ff: Focal length of the front group Gf

[0042] Conditional expression (2) specifies the ratio of the focal length of the second focusing group GF2 to the focal length of the front group Gf. By satisfying this conditional expression (2), various aberrations, including coma, can be well corrected in photography from an object at infinity to an object at close range. When the upper limit value of conditional expression (2) is exceeded, the focal length of the front group Gf becomes too short, and it is difficult to correct spherical aberration, coma, and image curvature, and good optical performance cannot be obtained, so it is not preferred. In addition, in order to make the effect of this conditional expression (2) reliable, it is preferred to set the upper limit value of conditional expression (2) to 1.85, 1.75, 1.60, and further to 1.50. In addition, when it is lower than the lower limit value of conditional expression (2), the focal length of the second focusing group GF2 becomes too short, and it is difficult to correct coma and image curvature when focusing on a close object, and good optical performance cannot be obtained, so it is not preferred. In order to ensure the effect of the conditional expression (2), it is preferable to set the lower limit value of the conditional expression (2) to 0.85, 0.95, 1.00, or further to 1.10.

[0043] (Second embodiment)

[0044] like Figure 1 As shown, the optical system OL of the second embodiment is composed of a front group Gf having positive optical power, an intermediate group Gi, and a rear group Gr having negative optical power in order from the object side. In addition, the intermediate group Gi is composed of a first focus group GF1 and a second focus group GF2 that move in different trajectories when focusing. In addition, the front group Gf has a negative lens component Ln1, a negative lens component Ln2, and a positive lens component Lp in order from the side closest to the object, and the rear group Gr has a negative lens component LnL on the side closest to the image plane. By configuring in this way, it is possible to achieve a bright optical system OL that is compact and has good optical performance in photography from an infinitely distant object to a close-up object.

[0045] In addition, the optical system OL of the second embodiment preferably satisfies the following conditional expression (3).

[0046] 0.05<ff / (-fr)<0.90 (3) in, ff: Focal length of the front group Gf fr: Focal length of rear group Gr

[0047] Conditional formula (3) specifies the ratio of the focal length of the front group Gf to the focal length of the rear group Gr. By satisfying the conditional formula (3), various aberrations, headed by coma and field curvature, can be well corrected. When the upper limit value of the conditional formula (3) is exceeded, the focal length of the rear group Gr becomes too short, and it is difficult to correct the coma and field curvature, and good optical performance cannot be obtained, so it is not preferred. In addition, in order to make the effect of the conditional formula (3) reliable, it is preferred to set the upper limit value of the conditional formula (3) to 0.80, 0.75, 0.65, and further to 0.60. In addition, when it is lower than the lower limit value of the conditional formula (3), the focal length of the front group Gf becomes too short, and it is difficult to correct the spherical aberration, coma and field curvature, and good optical performance cannot be obtained, so it is not preferred. In order to ensure the effect of the conditional expression (3), the lower limit value of the conditional expression (3) is preferably set to 0.10, 0.25, 0.50, 0.75, 0.85, 1.00, or further to 1.10.

[0048] In addition, the optical system OL of the second embodiment preferably satisfies the following conditional expression (4).

[0049] -1.000<(r2+r1) / (r2-r1)<0.200 (4) in, r1: The curvature radius of the lens surface on the image plane side of the lens component Ln1 arranged closest to the object side r2: The curvature radius of the lens surface on the object side of the second lens component Ln2 arranged from the object side

[0050] Conditional formula (4) specifies the shape factors of the lens surface on the image side of the lens component Ln1 that is closest to the object side and the lens surface on the object side of the second lens component Ln2 that is closest to the object side. By satisfying this conditional formula (4), various aberrations headed by spherical aberration, coma and image curvature can be well corrected. When the upper limit value of conditional formula (4) is exceeded, it is difficult to correct spherical aberration, coma and image curvature, and good optical performance cannot be obtained, so it is not preferred. In addition, in order to make the effect of this conditional formula (4) reliable, it is preferred to set the upper limit value of conditional formula (4) to 0.180, 0.150, 0.100, 0.095, and further to 0.090. In addition, when it is lower than the lower limit value of conditional formula (4), it is difficult to correct spherical aberration, coma and image curvature, and good optical performance cannot be obtained, so it is not preferred. In order to ensure the effect of the conditional expression (4), it is preferable to set the lower limit value of the conditional expression (4) to -0.900, -0.750, -0.500, -0.350, or further to -0.250.

[0051] (Regarding the First Embodiment and the Second Embodiment)

[0052] In addition, the optical system OL of the first embodiment preferably satisfies the above-mentioned conditional expressions (3) and (4). The effects and the like obtained by satisfying the conditional expressions (3) and (4) are as described above.

[0053] In addition, the optical system OL of the first embodiment and the second embodiment (hereinafter referred to as "the present embodiment") preferably satisfies the following conditional expression (5).

[0054] 0.10<|fF2| / |fF1|<1.10 (5) in, fF1: Focal length of the first focusing group GF1 fF2: Focal length of the second focusing group GF2

[0055] Conditional expression (5) specifies the ratio of the focal length of the second focus group GF2 to the focal length of the first focus group GF1. By satisfying this conditional expression (5), various aberrations, including spherical aberration, coma and field curvature, can be well corrected in the photography from an infinitely distant object to a close-up object. In addition, it is possible to obtain bright optical performance in the photography from an infinitely distant object to a close-up object while realizing the miniaturization of the optical system OL. When the upper limit value of conditional expression (5) is exceeded, the focal length of the first focus group GF1 becomes too short, the spherical aberration, coma and field curvature generated in the first focus group GF1 become larger, and good optical performance cannot be obtained when focusing on a close-up object, so it is not preferred. In addition, in order to make the effect of this conditional expression (5) reliable, it is preferred to set the upper limit value of conditional expression (5) to 1.05, 1.00, 0.90, 0.85, 0.80, 0.75, 0.70, and further to 0.65. In addition, when the lower limit value of conditional expression (5) is lowered, the focal length of the second focus group GF2 becomes too short, the spherical aberration, coma and field curvature generated in the second focus group GF2 become larger, and good optical performance cannot be obtained when focusing on a close object, so it is not preferred. In addition, in order to make the effect of conditional expression (5) reliable, it is preferred to set the lower limit value of conditional expression (5) to 0.15, 0.20, and further to 0.25.

[0056] In addition, the optical system OL of the present embodiment preferably satisfies the following conditional expression (6).

[0057] 0.10<ff / |fF1|<0.65 (6) in, ff: Focal length of the front group Gf fF1: Focal length of the first focusing group GF1

[0058] Conditional expression (6) specifies the ratio of the focal length of the front group Gf to the focal length of the first focusing group GF1. By satisfying this conditional expression (6), various aberrations, including spherical aberration, coma and field curvature, can be well corrected in the photography from an infinitely distant object to a close-up object. In addition, it is possible to obtain bright optical performance in the photography from an infinitely distant object to a close-up object while realizing the miniaturization of the optical system OL. When the upper limit value of conditional expression (6) is exceeded, the focal length of the first focusing group GF1 becomes too short, the spherical aberration, coma and field curvature generated in the first focusing group GF1 become larger, and good optical performance cannot be obtained when focusing on a close-up object, so it is not preferred. In addition, in order to make the effect of this conditional expression (6) reliable, it is preferred to set the upper limit value of conditional expression (6) to 0.60, 0.55, 0.50, 0.45, and further to 0.42. In addition, when the value is lower than the lower limit of conditional expression (6), the focal length of the front group Gf becomes too short, the spherical aberration, coma and image curvature generated in the front group Gf become larger, and good optical performance cannot be obtained when focusing on close objects, so it is not preferred. In addition, in order to make the effect of conditional expression (6) reliable, it is preferred to set the lower limit of conditional expression (6) to 0.15, 0.18, and further to 0.20.

[0059] In addition, the optical system OL of the present embodiment preferably satisfies the following conditional expression (7).

[0060] 1.10<(-fr) / |fF2|<2.40 (7) in, fr: Focal length of rear group Gr fF2: Focal length of the second focusing group GF2

[0061] Conditional expression (7) specifies the ratio of the focal length of the rear group Gr to the focal length of the second focusing group GF2. By satisfying the conditional expression (7), various aberrations, including spherical aberration, coma and field curvature, can be well corrected. In addition, while miniaturizing the optical system OL, it is possible to obtain bright optical performance in photography from infinitely distant objects to close objects. When the upper limit value of the conditional expression (7) is exceeded, the focal length of the second focusing group GF2 becomes too short, and the spherical aberration, coma and field curvature generated in the second focusing group GF2 become larger, and good optical performance cannot be obtained when focusing on close objects, so it is not preferred. In addition, in order to make the effect of the conditional expression (7) reliable, it is preferred to set the upper limit value of the conditional expression (7) to 2.35, 2.25, and further to 2.21. In addition, when the lower limit value of conditional expression (7) is lowered, the focal length of the rear group Gr becomes too short, the spherical aberration, coma and field curvature generated in the rear group Gr become larger, and good optical performance cannot be obtained when focusing on close objects, so it is not preferred. In addition, in order to make the effect of conditional expression (7) reliable, it is preferred to set the lower limit value of conditional expression (7) to 1.15, 1.25, 1.30, 1.40, and further to 1.50.

[0062] In addition, it is preferable that the optical system OL of the present embodiment has a diaphragm (aperture stop S) between the first focus lens group GF1 and the second focus lens group GF2 and satisfies the following conditional expression (8).

[0063] 1.00<fsr / fsf<2.20 (8) in, fsr: The composite focal length of a lens that is located on the image side relative to the aperture stop (aperture stop S) when focusing on an object at infinity. fsf: The composite focal length of a lens that is located on the object side relative to the aperture stop (aperture stop S) when focusing on an object at infinity.

[0064] Conditional expression (8) specifies the ratio of the synthetic focal length of the lens arranged on the image side relative to the aperture to the synthetic focal length of the lens arranged on the object side relative to the aperture when focusing on an object at infinity. By satisfying this conditional expression (8), various aberrations headed by coma and field curvature can be well corrected. In addition, it is possible to obtain bright and good optical performance while realizing the miniaturization of the optical system OL. When the upper limit value of conditional expression (8) is exceeded, the synthetic focal length of the lens arranged on the object side relative to the aperture becomes too short, and it is difficult to correct spherical aberration, coma and field curvature, and good optical performance cannot be obtained, so it is not preferred. In addition, in order to make the effect of this conditional expression (8) reliable, it is preferred to set the upper limit value of conditional expression (8) to 2.15, 2.10, and further to 2.05. In addition, when it is lower than the lower limit value of conditional expression (8), the synthetic focal length of the lens arranged on the image side relative to the aperture becomes too short, and it is difficult to correct coma and field curvature, and good optical performance cannot be obtained, so it is not preferred. In order to ensure the effect of the conditional expression (8), it is preferable to set the lower limit value of the conditional expression (8) to 1.05, 1.10, 1.15, or further to 1.20.

[0065] In addition, the optical system OL of the present embodiment preferably satisfies the following conditional expression (9).

[0066] 0.80<y / Bfa<2.10 (9) in, y: image height of optical system OL Bfa: Back focal length of the optical system OL when focusing on an object at infinity (length in terms of air)

[0067] Conditional formula (9) specifies the ratio of the image height to the back focal length (air conversion length) of the optical system OL when focusing on an infinitely distant object. By satisfying this conditional formula (9), it is possible to obtain bright and good optical performance while realizing the miniaturization of the optical system OL. In addition, in order to make the effect of this conditional formula (9) reliable, it is preferred to set the upper limit value of the conditional formula (9) to 2.08, and further to 2.05. In addition, in order to make the effect of this conditional formula (9) reliable, it is preferred to set the lower limit value of the conditional formula (9) to 1.00, 1.25, 1.35, 1.50, and further to 1.75.

[0068] In addition, the optical system OL of the present embodiment preferably satisfies the following conditional expression (10).

[0069] 1.50<f / Bfa<5.00 (10) in, f: The focal length of the entire optical system OL when focusing on an object at infinity Bfa: Back focal length of the optical system OL when focusing on an object at infinity (length in terms of air)

[0070] Conditional formula (10) specifies the ratio of the focal length of the entire system to the back focal length (air-converted length) of the optical system OL when focusing on an infinitely distant object. By satisfying the conditional formula (10), it is possible to achieve bright and good optical performance while miniaturizing the optical system OL. In addition, in order to make the effect of the conditional formula (10) reliable, it is preferred to set the upper limit value of the conditional formula (10) to 4.50, 4.25, 4.00, 3.75, and further to 3.50. In addition, in order to make the effect of the conditional formula (10) reliable, it is preferred to set the lower limit value of the conditional formula (10) to 1.75, 2.00, 2.25, 2.50, 2.75, and further to 3.00.

[0071] In addition, the optical system OL of the present embodiment preferably satisfies the following conditional expression (11).

[0072] 1.50<TLa / f<3.50 (11) in, f: The focal length of the entire optical system OL when focusing on an object at infinity TLa: The total optical length of the optical system OL when focusing on an object at infinity (length in air terms)

[0073] Conditional formula (11) specifies the ratio of the total optical length (air-converted length) to the focal length of the entire system of the optical system OL when focusing on an infinitely distant object. By satisfying the conditional formula (11), it is possible to obtain bright and good optical performance while realizing the miniaturization of the optical system OL. In addition, in order to make the effect of the conditional formula (11) reliable, it is preferred to set the upper limit value of the conditional formula (11) to 3.45, 3.35, 3.25, 3.10, and further to 3.00. In addition, in order to make the effect of the conditional formula (11) reliable, it is preferred to set the lower limit value of the conditional formula (11) to 1.75, 2.00, 2.25, 2.50, and further to 2.75.

[0074] In the optical system OL of the present embodiment, the first focus group GF1 preferably has negative refractive power. With such a configuration, it is possible to achieve a bright optical system OL with good optical performance in photographing objects from infinity to close distances while miniaturizing the optical system OL.

[0075] In the optical system OL of the present embodiment, the second focus group GF2 preferably has positive refractive power. With such a configuration, it is possible to achieve a bright optical system OL with good optical performance in photographing objects from infinity to close distances while miniaturizing the optical system OL.

[0076] In addition, the conditions and structures described above each exert the above-mentioned effects, and are not limited to satisfying all the conditions and structures. The above-mentioned effects can be obtained even if any condition or structure, or any combination of conditions or structures, is satisfied.

[0077] Next, based on Fig.23 A camera as an optical device having an optical system OL according to the present embodiment is described. The camera 1 is a so-called mirrorless camera of a lens-interchangeable type having an optical system OL according to the present embodiment as a photographic lens 2. In the camera 1, light from an object (subject) not shown is condensed by the photographic lens 2, and a subject image is formed on a photographing surface of a photographing unit 3 via an OLPF (Optical Low Pass Filter) not shown. Then, the subject image is photoelectrically converted by a photoelectric conversion element (photographing element) provided on the photographing unit 3, and an image of the subject is generated. The image is displayed on an EVF (Electronic View Finder) 4 provided on the camera 1. Thus, the photographer can observe the subject via the EVF 4.

[0078] Furthermore, when the photographer presses a release button (not shown), an image photoelectrically converted by the imaging unit 3 is stored in a memory (not shown). In this way, the photographer can photograph a subject using the camera 1. In the present embodiment, an example of a mirrorless camera is described, but even if the optical system OL of the present embodiment is mounted on a single-lens reflex camera having a quick return mirror on the camera body and observing the subject through a viewfinder optical system, the same effect as that of the above-mentioned camera 1 can be achieved.

[0079] In addition, the contents described below can be appropriately adopted within a range not impairing the optical performance.

[0080] In this embodiment, an optical system OL of a 4-group structure is shown, but the above-mentioned composition conditions and the like can also be applied to other group structures such as 3-group or 5-group. Specifically, a structure in which a lens group whose position relative to the image plane is fixed when focusing is added to the side closest to the image plane is considered. In addition, the so-called lens group, unless the boundary is specially specified, means a part having at least one lens separated by an air gap that changes when focusing. In addition, a lens component refers to a single lens or a joint lens formed by joining multiple lenses.

[0081] In addition, a single lens group or a plurality of lens groups or a part of lens groups may be used as a focus group, and the focus group moves along the optical axis direction to focus from an infinitely distant object to a close object. In this case, the focus group may also be applied to autofocus, and is also suitable for motor drive (such as an ultrasonic motor) for autofocus. It is particularly preferred to use the first focus group GF1 and the second focus group GF2 of the intermediate group Gi as the focus group, and the positions of the other lenses relative to the image plane are fixed when focusing.

[0082] In addition, a lens group or part of a lens group may be used as an anti-shake group, which moves in a manner having a displacement component in a direction orthogonal to the optical axis or rotates (sways) in a plane direction including the optical axis to correct image blur caused by hand shake.

[0083] In addition, the lens surface can be formed by a spherical surface or a plane, or it can be formed by an aspherical surface. In the case where the lens surface is a spherical surface or a plane, lens processing and assembly adjustment become easy, and the degradation of optical performance caused by errors in processing and assembly adjustment can be prevented, so it is preferred. In addition, even in the case of deviation of the image plane, the degradation of the drawing performance is small, so it is preferred. In the case where the lens surface is an aspherical surface, the aspherical surface can be any of an aspherical surface based on grinding, a glass molded aspherical surface in which glass is formed into an aspherical shape with a mold, and a composite aspherical surface in which a resin is formed into an aspherical shape on the surface of the glass. In addition, the lens surface can be set as a diffraction surface, and the lens can be set as a refractive index distribution lens (GRIN lens) or a plastic lens.

[0084] The aperture stop S is preferably disposed between the first focus group GF1 and the second focus group GF2 in the intermediate group Gi, but a member serving as the aperture stop may be omitted and its function may be replaced by a lens frame.

[0085] Furthermore, in order to reduce glare and ghosting and realize high optical performance with high contrast, an antireflection coating having high transmittance in a wide wavelength range may be applied to each lens surface.

[0086] Below, refer to Fig.24The manufacturing method of the optical system OL of the present embodiment is described in outline. First, a front group Gf having positive optical power, an intermediate group Gi, and a rear group Gr having negative optical power are prepared in order from the object side (step S100). Next, the intermediate group Gi is configured to be composed of a first focus group GF1 and a second focus group GF2 that move in different trajectories when focusing (step S200), the front group Gf is configured to have a negative lens component Ln1, a negative lens component Ln2, and a positive lens component Lp in order from the closest to the object side (step S300), and the rear group Gr is configured to have a negative lens component LnL on the closest to the image plane side (step S400). Then, each group is configured to satisfy a predetermined condition (for example, if it is the first embodiment, it is the above-mentioned conditional expressions (1) and (2), and if it is the second embodiment, it is the conditional expressions (3) and (4)) (step S500).

[0087] Based on the above, it is possible to provide an optical system, an optical device, and a method for manufacturing an optical system that are compact, bright, and can obtain good optical performance in photographing objects from infinity to close distances.

[0088] Example

[0089] Hereinafter, each embodiment will be described based on the accompanying drawings. Figure 1 , Figure 3 , Figure 5 , Figure 7 , Fig. 9 , Fig.11 , Fig.13 , Fig.15 , Fig.17 , Fig.19 and Fig.21 1 and 2 are cross-sectional views showing the structure and power distribution of the optical system OL (OL1 to OL11) of each embodiment. In addition, in the lower part of these cross-sectional views, arrows are used to indicate the direction from the infinitely distant object ( ) is the moving direction of the first focusing group GF1 and the second focusing group GF2 along the optical axis when focusing on a close object (close distance).

[0090] In each embodiment, the aspheric surface is represented by the following formula (a) when the height in the direction perpendicular to the optical axis is y, the distance along the optical axis from the tangent plane of the vertex of each aspheric surface at the height y to each aspheric surface (the amount of concavity) is S(y), the radius of curvature (paraxial radius of curvature) of the reference spherical surface is r, the conic constant is K, and the aspheric coefficient of the nth order is An. In the following embodiments, "En" represents "×10 -n ”.

[0091] S(y)=(y 2 / r) / {1+(1-K×y2 / r 2 ) 1 / 2}+A4×y 4 +A6×y 6 +A8×y 8 +A10×y 10 (a)

[0092] In each example, the second-order aspheric coefficient A2 is 0. In the table of each example, an aspheric surface is indicated by an * on the right side of the surface number.

[0093] [First embodiment]

[0094] Figure 1 The structure of the optical system OL1 of the first embodiment is shown. The optical system OL1 is composed of a front group Gf having positive optical power, an intermediate group Gi having positive optical power, and a rear group Gr having negative optical power in order from the object side. In addition, the intermediate group Gi is composed of a first focus group GF1 and a second focus group GF2, which move in different tracks when focusing, respectively, and the first focus group GF1 has negative optical power and the second focus group GF2 has positive optical power.

[0095] The front group Gf is composed, from the object side, in sequence: a meniscus-shaped negative lens L11 (negative lens component Ln1) with the convex surface toward the object side, a meniscus-shaped negative lens L12 (negative lens component Ln2) with the concave surface toward the object side, a meniscus-shaped positive lens L13 (positive lens component Lp) with the concave surface toward the object side, a biconvex positive lens L14, and a meniscus-shaped positive lens L15 with the convex surface toward the object side.

[0096] In addition, the first focusing group GF1 constituting the intermediate group Gi is composed of a negative lens L21 of a meniscus shape with a convex surface facing the object side. In addition, the second focusing group GF2 constituting the intermediate group Gi is composed of a negative lens L31 of a meniscus shape with a concave surface facing the object side, a positive lens L32 of a biconvex shape, and a positive lens L33 of a meniscus shape with an aspherical surface formed on the lens surface on the object side and with a concave surface facing the object side. In addition, the positive lens L33 is a composite lens in which a resin layer is provided on the surface on the object side of a glass lens body to form an aspherical surface.

[0097] In addition, the rear group Gr is composed of a meniscus-shaped negative lens L41 (negative lens component LnL) having a concave surface facing the object side.

[0098] In addition, an aperture stop S is disposed between the first focus group GF1 and the second focus group GF2 of the intermediate group Gi. In addition, between the rear group Gr and the image plane I, an optical filter FL is disposed.

[0099] In addition, when the optical system OL1 focuses from an infinitely distant object to a close object, the front group Gf and the rear group Gr are fixed relative to the image plane I, and the first focus group GF and the second focus group GF2 constituting the intermediate group Gi move along the optical axis direction. Specifically, the first focus group GF1 moves toward the image plane side, and the second focus group GF2 moves toward the object side. In addition, when focusing, the aperture stop S is fixed relative to the image plane I.

[0100] The values ​​of the parameters of the optical system OL1 are shown in the following Table 1. In this Table 1, the overall parameters shown as f are the focal length of the entire system, Fno is the F value, ω is the half field angle [°], Y is the maximum image height, TL is the total optical length, Bf is the back focal length, and the value when focusing at infinity is shown. Here, the back focal length Bf represents the distance on the optical axis from the lens surface closest to the image plane (the 22nd surface) to the image plane I and its air-converted length. In addition, the total optical length TL represents the length obtained by adding the back focal length and its air-converted length to the distance on the optical axis from the lens surface closest to the object side (the 1st surface) to the lens surface closest to the image plane (the 22nd surface). In addition, the first column m in the lens data indicates the order of the lens surfaces from the object side along the direction of light travel (surface number), the second column r indicates the radius of curvature of each lens surface, the third column d indicates the distance on the optical axis from each optical surface to the next optical surface (surface spacing), and the fourth column nd and the fifth column νd indicate the refractive index and Abbe number relative to the d line (λ=587.6nm). In addition, the radius of curvature ∞ indicates a plane, and the refractive index of air 1.0000 is omitted. In addition, the focal length of the lens group shows the number and focal length of the starting surface of each lens group.

[0101] Here, the focal length f, radius of curvature r, surface spacing d, and other lengths recorded in all the following parameter values ​​are generally expressed in "mm", but the optical system is not limited thereto because it can obtain the same optical performance even if the ratio is enlarged or reduced. In addition, the description of these symbols and the description of the parameter table are the same in the subsequent embodiments.

[0102] (Table 1) First embodiment

[0103] [Overall parameters]

[0104] [Lens data]

[0105] [Focal length of lens group]

[0106] In the optical system OL1, the 18th surface is formed into an aspherical shape. The following Table 2 shows data of the aspherical surface, that is, the values ​​of the cone constant K and the aspherical constants A4 to A10.

[0107] (Table 2)

[0108] [Aspherical surface data]

[0109] In addition, in the optical system OL1, the axial air interval D10 between the front group Gf and the first focusing group GF1, the axial air interval D12 between the first focusing group GF1 and the aperture stop S, the axial air interval D13 between the aperture stop S and the second focusing group GF2, and the axial air interval D20 between the second focusing group GF2 and the rear group Gr change when focusing. In the following Table 3, the variable intervals when focusing at infinity (infinity) and when focusing at a close object (close distance) are shown. In addition, f represents the focal length, β represents the photographic magnification, and D0 represents the distance from the lens surface (first surface) on the most object side of the optical system OL1 to the object. This description is also the same in the subsequent embodiments.

[0110] (Table 3)

[0111] [Variable interval data]

[0112] exist Figure 2 The spherical aberration diagram, astigmatism diagram, distortion diagram, chromatic aberration diagram and coma diagram of the optical system OL1 when focusing at infinity and at a close object are shown in the figure. In each aberration diagram, FNO represents F value, NA represents numerical aperture, and Y represents image height. In addition, the F value or the value of numerical aperture corresponding to the maximum aperture is shown in the spherical aberration diagram, the maximum value of image height is shown in the astigmatism diagram and the distortion diagram, and the value of each image height is shown in the coma diagram. d represents d line (λ=587.6nm), and g represents g line (λ=435.8nm). In the astigmatism diagram and the coma diagram, the solid line represents the sagittal image plane, and the dotted line represents the meridional image plane. In addition, the same symbols as those of the present embodiment are also used in the aberration diagrams of each embodiment shown later. It can be seen from these aberration diagrams that the optical system OL1 corrects each aberration well and has excellent imaging performance.

[0113] [Second embodiment]

[0114] Figure 3The structure of the optical system OL2 of the second embodiment is shown. The optical system OL2 is composed of a front group Gf having positive optical power, an intermediate group Gi having positive optical power, and a rear group Gr having negative optical power in order from the object side. In addition, the intermediate group Gi is composed of a first focus group GF1 and a second focus group GF2, which move in different tracks when focusing, respectively, and the first focus group GF1 has negative optical power and the second focus group GF2 has positive optical power.

[0115] The front group Gf is composed, from the object side, in sequence: a meniscus-shaped negative lens L11 (negative lens component Ln1) with the convex surface toward the object side, a meniscus-shaped negative lens L12 (negative lens component Ln2) with the concave surface toward the object side, a meniscus-shaped positive lens L13 (positive lens component Lp) with the concave surface toward the object side, a biconvex positive lens L14, and a meniscus-shaped positive lens L15 with the convex surface toward the object side.

[0116] In addition, the first focusing group GF1 constituting the intermediate group Gi is composed of a negative lens L21 of a meniscus shape with a convex surface facing the object side. In addition, the second focusing group GF2 constituting the intermediate group Gi is composed of a negative lens L31 of a meniscus shape with a concave surface facing the object side, a positive lens L32 of a biconvex shape, and a positive lens L33 of a meniscus shape with an aspherical surface formed on the lens surface on the object side and with a concave surface facing the object side. In addition, the positive lens L33 is a composite lens in which a resin layer is provided on the surface on the object side of a glass lens body to form an aspherical surface.

[0117] In addition, the rear group Gr is composed of a meniscus-shaped negative lens L41 (negative lens component LnL) having a concave surface facing the object side.

[0118] In addition, an aperture stop S is disposed between the first focus group GF1 and the second focus group GF2 of the intermediate group Gi. In addition, between the rear group Gr and the image plane I, an optical filter FL is disposed.

[0119] In addition, when the optical system OL2 focuses from an infinitely distant object to a close object, the front group Gf and the rear group Gr are fixed relative to the image plane I, and the first focus group GF and the second focus group GF2 constituting the intermediate group Gi move along the optical axis direction. Specifically, the first focus group GF1 moves toward the image plane side, and the second focus group GF2 moves toward the object side. In addition, when focusing, the aperture stop S is fixed relative to the image plane I.

[0120] In the following Table 4, the values ​​of the parameters of the optical system OL2 are described.

[0121] (Table 4) Second embodiment

[0122] [Overall parameters]

[0123] [Lens data]

[0124] [Focal length of lens group]

[0125] In the optical system OL2, the 18th surface is formed into an aspherical shape. The following Table 5 shows data of the aspherical surface, that is, the values ​​of the cone constant K and the aspherical constants A4 to A10.

[0126] (Table 5)

[0127] [Aspherical surface data]

[0128] In addition, in the optical system OL2, the on-axis air interval D10 between the front group Gf and the first focus group GF1, the on-axis air interval D12 between the first focus group GF1 and the aperture stop S, the on-axis air interval D13 between the aperture stop S and the second focus group GF2, and the on-axis air interval D20 between the second focus group GF2 and the rear group Gr are changed when focusing. The following Table 6 shows the variable intervals when focusing at infinity (infinity) and when focusing on a close object (close distance).

[0129] (Table 6)

[0130] [Variable interval data]

[0131] exist Figure 4 , spherical aberration diagrams, astigmatism diagrams, distortion diagrams, lateral chromatic aberration diagrams, and coma diagrams of the optical system OL2 when focusing at infinity and at close objects are shown in FIG. From these aberration diagrams, it can be seen that the optical system OL2 corrects various aberrations well and has excellent imaging performance.

[0132] [Third embodiment]

[0133] Figure 5 The structure of the optical system OL3 of the third embodiment is shown. The optical system OL3 is composed of a front group Gf having positive optical power, an intermediate group Gi having positive optical power, and a rear group Gr having negative optical power in order from the object side. In addition, the intermediate group Gi is composed of a first focus group GF1 and a second focus group GF2, which move in different tracks when focusing, respectively, and the first focus group GF1 has negative optical power and the second focus group GF2 has positive optical power.

[0134] The front group Gf is composed, from the object side, in sequence: a meniscus-shaped negative lens L11 (negative lens component Ln1) with the convex surface toward the object side, a meniscus-shaped negative lens L12 (negative lens component Ln2) with the concave surface toward the object side, a meniscus-shaped positive lens L13 (positive lens component Lp) with the concave surface toward the object side, a biconvex positive lens L14, and a meniscus-shaped positive lens L15 with the convex surface toward the object side.

[0135] In addition, the first focusing group GF1 constituting the intermediate group Gi is composed of a negative lens L21 of a meniscus shape with a convex surface facing the object side. In addition, the second focusing group GF2 constituting the intermediate group Gi is composed of a negative lens L31 of a meniscus shape with a concave surface facing the object side, a positive lens L32 of a biconvex shape, and a positive lens L33 of a meniscus shape with an aspherical surface formed on the lens surface on the object side and with a concave surface facing the object side. In addition, the positive lens L33 is a composite lens in which a resin layer is provided on the surface on the object side of a glass lens body to form an aspherical surface.

[0136] In addition, the rear group Gr is composed of a meniscus-shaped negative lens L41 (negative lens component LnL) having a concave surface facing the object side.

[0137] In addition, an aperture stop S is disposed between the first focus group GF1 and the second focus group GF2 of the intermediate group Gi. In addition, between the rear group Gr and the image plane I, an optical filter FL is disposed.

[0138] In addition, when the optical system OL3 focuses from an infinitely distant object to a close object, the front group Gf and the rear group Gr are fixed relative to the image plane I, and the first focus group GF and the second focus group GF2 constituting the intermediate group Gi move along the optical axis direction. Specifically, the first focus group GF1 moves toward the image plane side, and the second focus group GF2 moves toward the object side. In addition, when focusing, the aperture stop S is fixed relative to the image plane I.

[0139] In the following Table 7, the values ​​of the parameters of the optical system OL3 are described.

[0140] (Table 7) Example 3

[0141] [Overall parameters]

[0142] [Lens data]

[0143] [Focal length of lens group]

[0144] In the optical system OL3, the 18th surface is formed into an aspherical shape. The following Table 8 shows the data of the aspherical surface, that is, the values ​​of the cone constant K and the aspherical constants A4 to A10.

[0145] (Table 8)

[0146] [Aspherical surface data]

[0147] In addition, in the optical system OL3, the on-axis air interval D10 between the front group Gf and the first focus group GF1, the on-axis air interval D12 between the first focus group GF1 and the aperture stop S, the on-axis air interval D13 between the aperture stop S and the second focus group GF2, and the on-axis air interval D20 between the second focus group GF2 and the rear group Gr are changed when focusing. The following Table 9 shows the variable intervals when focusing at infinity (infinity) and when focusing on a close object (close distance).

[0148] (Table 9)

[0149] [Variable interval data]

[0150] exist Figure 6 , spherical aberration diagrams, astigmatism diagrams, distortion diagrams, lateral chromatic aberration diagrams, and coma diagrams of the optical system OL3 when focusing at infinity and at a close object are shown in FIG. From these aberration diagrams, it can be seen that the optical system OL3 corrects various aberrations well and has excellent imaging performance.

[0151] [Fourth embodiment]

[0152] Figure 7 The structure of the optical system OL4 of the fourth embodiment is shown. The optical system OL4 is composed of a front group Gf having positive optical power, an intermediate group Gi having positive optical power, and a rear group Gr having negative optical power in order from the object side. In addition, the intermediate group Gi is composed of a first focus group GF1 and a second focus group GF2 which move in different tracks when focusing, the first focus group GF1 having negative optical power, and the second focus group GF2 having positive optical power.

[0153] The front group Gf is composed, from the object side, in sequence: a meniscus-shaped negative lens L11 (negative lens component Ln1) with the convex surface toward the object side, a meniscus-shaped negative lens L12 (negative lens component Ln2) with the concave surface toward the object side, a meniscus-shaped positive lens L13 (positive lens component Lp) with the concave surface toward the object side, a biconvex positive lens L14, and a meniscus-shaped positive lens L15 with the convex surface toward the object side.

[0154] In addition, the first focusing group GF1 constituting the intermediate group Gi is composed of a negative lens L21 of a meniscus shape with a convex surface facing the object side. In addition, the second focusing group GF2 constituting the intermediate group Gi is composed of a negative lens L31 of a meniscus shape with a concave surface facing the object side, a positive lens L32 of a biconvex shape, and a positive lens L33 of a meniscus shape with an aspherical surface formed on the lens surface on the object side and with a concave surface facing the object side. In addition, the positive lens L33 is a composite lens in which a resin layer is provided on the surface on the object side of a glass lens body to form an aspherical surface.

[0155] In addition, the rear group Gr is composed of a meniscus-shaped negative lens L41 (negative lens component LnL) having a concave surface facing the object side.

[0156] In addition, an aperture stop S is disposed between the first focus group GF1 and the second focus group GF2 of the intermediate group Gi. In addition, between the rear group Gr and the image plane I, an optical filter FL is disposed.

[0157] In addition, when the optical system OL4 focuses from an infinitely distant object to a close object, the front group Gf and the rear group Gr are fixed relative to the image plane I, and the first focus group GF and the second focus group GF2 constituting the intermediate group Gi move along the optical axis direction. Specifically, the first focus group GF1 moves toward the image plane side, and the second focus group GF2 moves toward the object side. In addition, when focusing, the aperture stop S is fixed relative to the image plane I.

[0158] In the following Table 10, the values ​​of the parameters of the optical system OL4 are described.

[0159] (Table 10) Example 4

[0160] [Overall parameters]

[0161] [Lens data]

[0162] [Focal length of lens group]

[0163] In the optical system OL4, the 18th surface is formed into an aspherical shape. The following Table 11 shows the data of the aspherical surface, that is, the values ​​of the cone constant K and the aspherical constants A4 to A10.

[0164] (Table 11)

[0165] [Aspherical surface data]

[0166] In addition, in the optical system OL4, the on-axis air interval D10 between the front group Gf and the first focus group GF1, the on-axis air interval D12 between the first focus group GF1 and the aperture stop S, the on-axis air interval D13 between the aperture stop S and the second focus group GF2, and the on-axis air interval D20 between the second focus group GF2 and the rear group Gr are changed when focusing. The following Table 12 shows the variable intervals when focusing at infinity (infinity) and when focusing on a close object (close distance).

[0167] (Table 12)

[0168] [Variable interval data]

[0169] exist Figure 8 , spherical aberration diagrams, astigmatism diagrams, distortion diagrams, lateral chromatic aberration diagrams, and coma diagrams of the optical system OL4 when focusing at infinity and at close objects are shown in FIG. From these aberration diagrams, it can be seen that the optical system OL4 corrects various aberrations well and has excellent imaging performance.

[0170] [Fifth embodiment]

[0171] Fig. 9 The structure of the optical system OL5 of the fifth embodiment is shown. The optical system OL5 is composed of a front group Gf having positive optical power, an intermediate group Gi having positive optical power, and a rear group Gr having negative optical power in order from the object side. In addition, the intermediate group Gi is composed of a first focus group GF1 and a second focus group GF2, which move in different tracks when focusing, respectively, and the first focus group GF1 has negative optical power and the second focus group GF2 has positive optical power.

[0172] The front group Gf is composed, from the object side, in sequence: a meniscus-shaped negative lens L11 (negative lens component Ln1) with the convex surface toward the object side, a meniscus-shaped negative lens L12 (negative lens component Ln2) with the concave surface toward the object side, a meniscus-shaped positive lens L13 (positive lens component Lp) with the concave surface toward the object side, a biconvex positive lens L14, and a meniscus-shaped positive lens L15 with the convex surface toward the object side.

[0173] In addition, the first focusing group GF1 constituting the intermediate group Gi is composed of a negative lens L21 of a meniscus shape with a convex surface facing the object side. In addition, the second focusing group GF2 constituting the intermediate group Gi is composed of a negative lens L31 of a meniscus shape with a concave surface facing the object side, a positive lens L32 of a biconvex shape, and a positive lens L33 of a meniscus shape with an aspherical surface formed on the lens surface on the object side and with a concave surface facing the object side. In addition, the positive lens L33 is a composite lens in which a resin layer is provided on the surface on the object side of a glass lens body to form an aspherical surface.

[0174] In addition, the rear group Gr is composed of a meniscus-shaped negative lens L41 (negative lens component LnL) having a concave surface facing the object side.

[0175] In addition, an aperture stop S is disposed between the first focus group GF1 and the second focus group GF2 of the intermediate group Gi. In addition, between the rear group Gr and the image plane I, an optical filter FL is disposed.

[0176] In addition, when the optical system OL5 focuses from an infinitely distant object to a close object, the front group Gf and the rear group Gr are fixed relative to the image plane I, and the first focus group GF and the second focus group GF2 constituting the intermediate group Gi move along the optical axis direction. Specifically, the first focus group GF1 moves toward the image plane side, and the second focus group GF2 moves toward the object side. In addition, when focusing, the aperture stop S is fixed relative to the image plane I.

[0177] Table 13 below describes the parameter values ​​of the optical system OL5.

[0178] (Table 13) Fifth embodiment

[0179] [Overall parameters]

[0180] [Lens data]

[0181] [Focal length of lens group]

[0182] In the optical system OL5, the 18th surface is formed into an aspherical shape. The following Table 14 shows the data of the aspherical surface, that is, the values ​​of the cone constant K and the aspherical constants A4 to A10.

[0183] (Table 14)

[0184] [Aspherical surface data]

[0185] In addition, in the optical system OL5, the axial air interval D10 between the front group Gf and the first focus group GF1, the axial air interval D12 between the first focus group GF1 and the aperture stop S, the axial air interval D13 between the aperture stop S and the second focus group GF2, and the axial air interval D20 between the second focus group GF2 and the rear group Gr are changed when focusing. The following Table 15 shows the variable intervals when focusing at infinity (infinity) and when focusing on a close object (close distance).

[0186] (Table 15)

[0187] [Variable interval data]

[0188] exist Fig.10 , spherical aberration diagrams, astigmatism diagrams, distortion diagrams, lateral chromatic aberration diagrams, and coma diagrams of the optical system OL5 when focusing at infinity and at a close object are shown in FIG. From these aberration diagrams, it can be seen that the optical system OL5 corrects various aberrations well and has excellent imaging performance.

[0189] [Sixth embodiment]

[0190] Fig.11 The structure of the optical system OL6 of the sixth embodiment is shown. The optical system OL6 is composed of a front group Gf having positive optical power, an intermediate group Gi having positive optical power, and a rear group Gr having negative optical power in order from the object side. In addition, the intermediate group Gi is composed of a first focus group GF1 and a second focus group GF2 which move in different tracks when focusing, the first focus group GF1 having negative optical power, and the second focus group GF2 having positive optical power.

[0191] The front group Gf is composed, from the object side, in sequence: a meniscus-shaped negative lens L11 (negative lens component Ln1) with the convex surface toward the object side, a meniscus-shaped negative lens L12 (negative lens component Ln2) with the concave surface toward the object side, a meniscus-shaped positive lens L13 (positive lens component Lp) with the concave surface toward the object side, a biconvex positive lens L14, and a meniscus-shaped positive lens L15 with the convex surface toward the object side.

[0192] In addition, the first focusing group GF1 constituting the intermediate group Gi is composed of a negative lens L21 of a meniscus shape with a convex surface facing the object side. In addition, the second focusing group GF2 constituting the intermediate group Gi is composed of a negative lens L31 of a meniscus shape with a concave surface facing the object side, a positive lens L32 of a biconvex shape, and a positive lens L33 of a meniscus shape with an aspherical surface formed on the lens surface on the object side and with a concave surface facing the object side. In addition, the positive lens L33 is a composite lens in which a resin layer is provided on the surface on the object side of a glass lens body to form an aspherical surface.

[0193] In addition, the rear group Gr is composed of a meniscus-shaped negative lens L41 (negative lens component LnL) having a concave surface facing the object side.

[0194] In addition, an aperture stop S is disposed between the first focus group GF1 and the second focus group GF2 of the intermediate group Gi. In addition, between the rear group Gr and the image plane I, an optical filter FL is disposed.

[0195] In addition, when the optical system OL6 focuses from an infinitely distant object to a close object, the front group Gf and the rear group Gr are fixed relative to the image plane I, and the first focus group GF and the second focus group GF2 constituting the intermediate group Gi move along the optical axis direction. Specifically, the first focus group GF1 moves toward the image plane side, and the second focus group GF2 moves toward the object side. In addition, when focusing, the aperture stop S is fixed relative to the image plane I.

[0196] In the following Table 16, the values ​​of the parameters of the optical system OL6 are described.

[0197] (Table 16) Example 6

[0198] [Overall parameters]

[0199] [Lens data]

[0200] [Focal length of lens group]

[0201] In the optical system OL6, the 18th surface is formed into an aspherical shape. The following Table 17 shows the data of the aspherical surface, that is, the values ​​of the cone constant K and the aspherical constants A4 to A10.

[0202] (Table 17)

[0203] [Aspherical surface data]

[0204] In addition, in the optical system OL6, the axial air interval D10 between the front group Gf and the first focus group GF1, the axial air interval D12 between the first focus group GF1 and the aperture stop S, the axial air interval D13 between the aperture stop S and the second focus group GF2, and the axial air interval D20 between the second focus group GF2 and the rear group Gr are changed when focusing. The following Table 18 shows the variable intervals when focusing at infinity (infinity) and when focusing on a close object (close distance).

[0205] (Table 18)

[0206] [Variable interval data]

[0207] exist Fig.12, spherical aberration diagrams, astigmatism diagrams, distortion diagrams, lateral chromatic aberration diagrams, and coma diagrams of the optical system OL6 when focusing at infinity and at close objects are shown in FIG. From these aberration diagrams, it can be seen that the optical system OL6 corrects various aberrations well and has excellent imaging performance.

[0208] [Seventh embodiment]

[0209] Fig.13 The structure of the optical system OL7 of the seventh embodiment is shown. The optical system OL7 is composed of a front group Gf having positive optical power, an intermediate group Gi having positive optical power, and a rear group Gr having negative optical power in order from the object side. In addition, the intermediate group Gi is composed of a first focus group GF1 and a second focus group GF2 which move in different tracks when focusing, the first focus group GF1 having negative optical power, and the second focus group GF2 having positive optical power.

[0210] The front group Gf is composed, from the object side, in sequence: a meniscus-shaped negative lens L11 (negative lens component Ln1) with the convex surface facing the object side, a biconcave negative lens L12 (negative lens component Ln2), a meniscus-shaped positive lens L13 (positive lens component Lp) with the concave surface facing the object side, a biconvex positive lens L14, and a meniscus-shaped positive lens L15 with the convex surface facing the object side.

[0211] In addition, the first focusing group GF1 constituting the intermediate group Gi is composed of a negative lens L21 of a meniscus shape with a convex surface facing the object side. In addition, the second focusing group GF2 constituting the intermediate group Gi is composed of a negative lens L31 of a meniscus shape with a concave surface facing the object side, a positive lens L32 of a biconvex shape, and a positive lens L33 of a meniscus shape with an aspherical surface formed on the lens surface on the object side and with a concave surface facing the object side. In addition, the positive lens L33 is a composite lens in which a resin layer is provided on the surface on the object side of a glass lens body to form an aspherical surface.

[0212] In addition, the rear group Gr is composed of a meniscus-shaped negative lens L41 (negative lens component LnL) having a concave surface facing the object side.

[0213] In addition, an aperture stop S is disposed between the first focus group GF1 and the second focus group GF2 of the intermediate group Gi. In addition, between the rear group Gr and the image plane I, an optical filter FL is disposed.

[0214] In addition, when the optical system OL7 focuses from an infinitely distant object to a close object, the front group Gf and the rear group Gr are fixed relative to the image plane I, and the first focus group GF and the second focus group GF2 constituting the intermediate group Gi move along the optical axis direction. Specifically, the first focus group GF1 moves toward the image plane side, and the second focus group GF2 moves toward the object side. In addition, when focusing, the aperture stop S is fixed relative to the image plane I.

[0215] In the following Table 19, the values ​​of the parameters of the optical system OL7 are described.

[0216] (Table 19) Embodiment 7

[0217] [Overall parameters]

[0218] [Lens data]

[0219] [Focal length of lens group]

[0220] In the optical system OL7, the 18th surface is formed into an aspherical shape. The following Table 20 shows the data of the aspherical surface, that is, the values ​​of the cone constant K and the aspherical constants A4 to A10.

[0221] (Table 20)

[0222] [Aspherical surface data]

[0223] In addition, in the optical system OL7, the on-axis air interval D10 between the front group Gf and the first focus group GF1, the on-axis air interval D12 between the first focus group GF1 and the aperture stop S, the on-axis air interval D13 between the aperture stop S and the second focus group GF2, and the on-axis air interval D20 between the second focus group GF2 and the rear group Gr are changed when focusing. The following Table 21 shows the variable intervals when focusing at infinity (infinity) and when focusing on a close object (close distance).

[0224] (Table 21)

[0225] [Variable interval data]

[0226] exist Fig.14 , spherical aberration diagrams, astigmatism diagrams, distortion diagrams, lateral chromatic aberration diagrams, and coma diagrams of the optical system OL7 when focusing at infinity and at close objects are shown in FIG. From these aberration diagrams, it can be seen that the optical system OL7 corrects various aberrations well and has excellent imaging performance.

[0227] [Eighth Embodiment]

[0228] Fig.15The structure of the optical system OL8 of the eighth embodiment is shown. The optical system OL8 is composed of a front group Gf having positive optical power, an intermediate group Gi having positive optical power, and a rear group Gr having negative optical power in order from the object side. In addition, the intermediate group Gi is composed of a first focus group GF1 and a second focus group GF2 which move in different tracks when focusing, the first focus group GF1 having negative optical power, and the second focus group GF2 having positive optical power.

[0229] The front group Gf is composed of, from the object side, a biconcave negative lens L11 (negative lens component Ln1), a biconcave negative lens L12 (negative lens component Ln2), a biconvex positive lens L13 (positive lens component Lp), a biconvex positive lens L14, and a meniscus positive lens L15 with the convex surface facing the object side.

[0230] In addition, the first focusing group GF1 constituting the intermediate group Gi is composed of a negative lens L21 of a meniscus shape with a convex surface facing the object side. In addition, the second focusing group GF2 constituting the intermediate group Gi is composed of a negative lens L31 of a meniscus shape with a concave surface facing the object side, a positive lens L32 of a biconvex shape, and a positive lens L33 of a meniscus shape with an aspherical surface formed on the lens surface on the object side and with a concave surface facing the object side. In addition, the positive lens L33 is a composite lens in which a resin layer is provided on the surface on the object side of a glass lens body to form an aspherical surface.

[0231] In addition, the rear group Gr is composed of a meniscus-shaped negative lens L41 (negative lens component LnL) having a concave surface facing the object side.

[0232] In addition, an aperture stop S is disposed between the first focus group GF1 and the second focus group GF2 of the intermediate group Gi. In addition, between the rear group Gr and the image plane I, an optical filter FL is disposed.

[0233] In addition, when the optical system OL8 focuses from an infinitely distant object to a close object, the front group Gf and the rear group Gr are fixed relative to the image plane I, and the first focus group GF and the second focus group GF2 constituting the intermediate group Gi move along the optical axis direction. Specifically, the first focus group GF1 moves toward the image plane side, and the second focus group GF2 moves toward the object side. In addition, when focusing, the aperture stop S is fixed relative to the image plane I.

[0234] In the following Table 22, the values ​​of the parameters of the optical system OL8 are recorded.

[0235] (Table 22) Embodiment 8

[0236] [Overall parameters]

[0237] [Lens data]

[0238] [Focal length of lens group]

[0239] In the optical system OL8, the 18th surface is formed into an aspherical shape. The following Table 23 shows the data of the aspherical surface, that is, the values ​​of the cone constant K and the aspherical constants A4 to A10.

[0240] (Table 23)

[0241] [Aspherical surface data]

[0242] In addition, in the optical system OL8, the on-axis air interval D10 between the front group Gf and the first focus group GF1, the on-axis air interval D12 between the first focus group GF1 and the aperture stop S, the on-axis air interval D13 between the aperture stop S and the second focus group GF2, and the on-axis air interval D20 between the second focus group GF2 and the rear group Gr are changed when focusing. The following Table 24 shows the variable intervals when focusing at infinity (infinity) and when focusing on a close object (close distance).

[0243] (Table 24)

[0244] [Variable interval data]

[0245] exist Fig.16 , spherical aberration diagrams, astigmatism diagrams, distortion diagrams, lateral chromatic aberration diagrams, and coma diagrams of the optical system OL8 when focusing at infinity and at close objects are shown in FIG. From these aberration diagrams, it can be seen that the optical system OL8 corrects various aberrations well and has excellent imaging performance.

[0246] [Ninth embodiment]

[0247] Fig.17 The structure of the optical system OL9 of the ninth embodiment is shown. The optical system OL9 is composed of a front group Gf having positive optical power, an intermediate group Gi having positive optical power, and a rear group Gr having negative optical power in order from the object side. In addition, the intermediate group Gi is composed of a first focus group GF1 and a second focus group GF2 which move in different tracks when focusing, the first focus group GF1 having negative optical power, and the second focus group GF2 having positive optical power.

[0248] The front group Gf is composed of, from the object side, a biconcave negative lens L11 (negative lens component Ln1), a biconcave negative lens L12 (negative lens component Ln2), a biconvex positive lens L13 (positive lens component Lp), a biconvex positive lens L14, and a meniscus positive lens L15 with the convex surface facing the object side.

[0249] In addition, the first focusing group GF1 constituting the intermediate group Gi is composed of a negative lens L21 of a meniscus shape with a convex surface facing the object side. In addition, the second focusing group GF2 constituting the intermediate group Gi is composed of a negative lens L31 of a meniscus shape with a concave surface facing the object side, a positive lens L32 of a biconvex shape, and a positive lens L33 of a meniscus shape with an aspherical surface formed on the lens surface on the object side and with a concave surface facing the object side. In addition, the positive lens L33 is a composite lens in which a resin layer is provided on the surface on the object side of a glass lens body to form an aspherical surface.

[0250] In addition, the rear group Gr is composed of a meniscus-shaped negative lens L41 (negative lens component LnL) having a concave surface facing the object side.

[0251] In addition, an aperture stop S is disposed between the first focus group GF1 and the second focus group GF2 of the intermediate group Gi. In addition, between the rear group Gr and the image plane I, an optical filter FL is disposed.

[0252] In addition, when the optical system OL9 focuses from an infinitely distant object to a close object, the front group Gf and the rear group Gr are fixed relative to the image plane I, and the first focus group GF and the second focus group GF2 constituting the intermediate group Gi move along the optical axis direction. Specifically, the first focus group GF1 moves toward the image plane side, and the second focus group GF2 moves toward the object side. In addition, when focusing, the aperture stop S is fixed relative to the image plane I.

[0253] In the following Table 25, the values ​​of the parameters of the optical system OL9 are recorded.

[0254] (Table 25) 9th embodiment

[0255] [Overall parameters]

[0256] [Lens data]

[0257] [Focal length of lens group]

[0258] In the optical system OL9, the 18th surface is formed into an aspherical shape. The following Table 26 shows the data of the aspherical surface, that is, the values ​​of the cone constant K and the aspherical constants A4 to A10.

[0259] (Table 26)

[0260] [Aspherical surface data]

[0261] In addition, in the optical system OL9, the on-axis air interval D10 between the front group Gf and the first focus group GF1, the on-axis air interval D12 between the first focus group GF1 and the aperture stop S, the on-axis air interval D13 between the aperture stop S and the second focus group GF2, and the on-axis air interval D20 between the second focus group GF2 and the rear group Gr are changed when focusing. The following Table 27 shows the variable intervals when focusing at infinity (infinity) and when focusing on a close object (close distance).

[0262] (Table 27)

[0263] [Variable interval data]

[0264] exist Fig.18 , spherical aberration diagrams, astigmatism diagrams, distortion diagrams, lateral chromatic aberration diagrams, and coma diagrams of the optical system OL9 when focusing at infinity and at close objects are shown in FIG. From these aberration diagrams, it can be seen that the optical system OL9 corrects various aberrations well and has excellent imaging performance.

[0265] [10th embodiment]

[0266] Fig.19 The structure of the optical system OL10 of the tenth embodiment is shown. The optical system OL10 is composed of a front group Gf having positive optical power, an intermediate group Gi having positive optical power, and a rear group Gr having negative optical power in order from the object side. In addition, the intermediate group Gi is composed of a first focus group GF1 and a second focus group GF2 which move in different tracks when focusing, the first focus group GF1 having negative optical power, and the second focus group GF2 having positive optical power.

[0267] The front group Gf is composed of, from the object side, a biconcave negative lens L11 (negative lens component Ln1), a biconcave negative lens L12 (negative lens component Ln2), a biconvex positive lens L13 (positive lens component Lp), a biconvex positive lens L14, and a meniscus positive lens L15 with the convex surface facing the object side.

[0268] In addition, the first focusing group GF1 constituting the intermediate group Gi is composed of a negative lens L21 of a meniscus shape with a convex surface facing the object side. In addition, the second focusing group GF2 constituting the intermediate group Gi is composed of a negative lens L31 of a meniscus shape with a concave surface facing the object side, a positive lens L32 of a biconvex shape, and a positive lens L33 of a meniscus shape with an aspherical surface formed on the lens surface on the object side and with a concave surface facing the object side. In addition, the positive lens L33 is a composite lens in which a resin layer is provided on the surface on the object side of a glass lens body to form an aspherical surface.

[0269] In addition, the rear group Gr is composed of a meniscus-shaped negative lens L41 (negative lens component LnL) having a concave surface facing the object side.

[0270] In addition, an aperture stop S is disposed between the first focus group GF1 and the second focus group GF2 of the intermediate group Gi. In addition, between the rear group Gr and the image plane I, an optical filter FL is disposed.

[0271] In addition, when the optical system OL10 focuses from an infinitely distant object to a close-up object, the front group Gf and the rear group Gr are fixed relative to the image plane I, and the first focus group GF and the second focus group GF2 constituting the intermediate group Gi move along the optical axis direction. Specifically, the first focus group GF1 moves toward the image plane side, and the second focus group GF2 moves toward the object side. In addition, when focusing, the aperture stop S is fixed relative to the image plane I.

[0272] Table 28 below describes the parameter values ​​of the optical system OL10.

[0273] (Table 28) Example 10

[0274] [Overall parameters]

[0275] [Lens data]

[0276] [Focal length of lens group]

[0277] In the optical system OL10, the 18th surface is formed into an aspherical shape. The following Table 29 shows the data of the aspherical surface, that is, the values ​​of the cone constant K and the aspherical constants A4 to A10.

[0278] (Table 29)

[0279] [Aspherical surface data]

[0280] In addition, in the optical system OL10, the axial air interval D10 between the front group Gf and the first focus group GF1, the axial air interval D12 between the first focus group GF1 and the aperture stop S, the axial air interval D13 between the aperture stop S and the second focus group GF2, and the axial air interval D20 between the second focus group GF2 and the rear group Gr are changed when focusing. The following table 30 shows the variable intervals when focusing at infinity (infinity) and when focusing on a close object (close distance).

[0281] (Table 30)

[0282] [Variable interval data]

[0283] exist Fig. 20 2 shows the spherical aberration diagram, astigmatism diagram, distortion diagram, lateral chromatic aberration diagram and coma diagram of the optical system OL10 when focusing at infinity and at a close object. It can be seen from these aberration diagrams that the optical system OL10 corrects various aberrations well and has excellent imaging performance.

[0284] [11th embodiment]

[0285] Fig.21 The structure of the optical system OL11 of the 11th embodiment is shown. The optical system OL11 is composed of a front group Gf having positive optical power, an intermediate group Gi having positive optical power, and a rear group Gr having negative optical power in order from the object side. In addition, the intermediate group Gi is composed of a first focus group GF1 and a second focus group GF2 which move in different tracks when focusing, the first focus group GF1 having negative optical power, and the second focus group GF2 having positive optical power.

[0286] The front group Gf is composed of, from the object side, a biconcave negative lens L11 (negative lens component Ln1), a biconcave negative lens L12 (negative lens component Ln2), a meniscus positive lens L13 (positive lens component Lp) with the concave surface facing the object side, a biconvex positive lens L14, and a meniscus positive lens L15 with the convex surface facing the object side.

[0287] In addition, the first focusing group GF1 constituting the intermediate group Gi is composed of a negative lens L21 of a meniscus shape with a convex surface facing the object side. In addition, the second focusing group GF2 constituting the intermediate group Gi is composed of a negative lens L31 of a meniscus shape with a concave surface facing the object side, a positive lens L32 of a biconvex shape, and a positive lens L33 of a meniscus shape with an aspherical surface formed on the lens surface on the object side and with a concave surface facing the object side. In addition, the positive lens L33 is a composite lens in which a resin layer is provided on the surface on the object side of a glass lens body to form an aspherical surface.

[0288] In addition, the rear group Gr is composed of a meniscus-shaped negative lens L41 (negative lens component LnL) having a concave surface facing the object side.

[0289] In addition, an aperture stop S is disposed between the first focus group GF1 and the second focus group GF2 of the intermediate group Gi. In addition, between the rear group Gr and the image plane I, an optical filter FL is disposed.

[0290] In addition, when the optical system OL11 focuses from an infinitely distant object to a close object, the front group Gf and the rear group Gr are fixed relative to the image plane I, and the first focus group GF and the second focus group GF2 constituting the intermediate group Gi move along the optical axis direction. Specifically, the first focus group GF1 moves toward the image plane side, and the second focus group GF2 moves toward the object side. In addition, when focusing, the aperture stop S is fixed relative to the image plane I.

[0291] Table 31 below describes the parameter values ​​of the optical system OL11.

[0292] (Table 31) Example 11

[0293] [Overall parameters]

[0294] [Lens data]

[0295] [Focal length of lens group]

[0296] In the optical system OL11, the 18th surface is formed into an aspherical shape. The following Table 32 shows the data of the aspherical surface, that is, the values ​​of the cone constant K and the aspherical constants A4 to A10.

[0297] (Table 32)

[0298] [Aspherical surface data]

[0299] In addition, in the optical system OL11, the on-axis air interval D10 between the front group Gf and the first focus group GF1, the on-axis air interval D12 between the first focus group GF1 and the aperture stop S, the on-axis air interval D13 between the aperture stop S and the second focus group GF2, and the on-axis air interval D20 between the second focus group GF2 and the rear group Gr are changed when focusing. The following Table 33 shows the variable intervals when focusing at infinity (infinity) and when focusing on a close object (close distance).

[0300] (Table 33)

[0301] [Variable interval data]

[0302] exist Fig. 22 2 shows the spherical aberration diagram, astigmatism diagram, distortion diagram, lateral chromatic aberration diagram and coma diagram of the optical system OL11 when focusing at infinity and at a close object. It can be seen from these aberration diagrams that the optical system OL11 corrects various aberrations well and has excellent imaging performance.

[0303] [Conditional value]

[0304] The following Table 34 shows the corresponding values ​​of conditional expressions (1) to (11) in the first to eleventh embodiments.

[0305] (Table 34) (1) |fF1| / (-fr) (2) |fF2| / ff (3) ff / (-fr) (4) (r2+r1) / (r2-r1) (5) |fF2| / |fF1| (6) ff / |fF1| (7) (-fr) / |fF2| (8) fsr / fsf (9) y / Bfa (10) f / Bfa (11) TLa / f

[0306] Description of symbols 1 Camera (optical equipment) OL (OL1~OL11) Optical system Gf Front group Gi Middle group GF1 1st focus group GF2 2nd focus group Gr rear group Ln1 Negative lens component Ln2 Negative lens component Lp positive lens component LnL negative lens component

Claims

1. An optical system, wherein: The optical system is composed of a front group with positive optical power, a middle group and a rear group with negative optical power in order from the object side. The intermediate group is composed of a first focus group and a second focus group which move along different tracks when focusing. The front group has, in order from the object side, a negative lens component, a negative lens component, and a positive lens component. The rear group has a negative lens component on the side closest to the image plane. The optical system satisfies the following conditions: 0.10<|fF1| / (-fr)<2.60 0.70<|fF2| / ff<2.00 in, fF1: focal length of the 1st focus group, fr: focal length of the rear group, fF2: focal length of the second focus group, ff: focal length of the front group.

2. An optical system, wherein: The optical system is composed of a front group with positive optical power, a middle group and a rear group with negative optical power in order from the object side. The intermediate group is composed of a first focus group and a second focus group which move along different tracks when focusing. The front group has, in order from the object side, a negative lens component, a negative lens component, and a positive lens component. The rear group has a negative lens component on the side closest to the image plane. The optical system satisfies the following conditions: 0.05<ff / (-fr)<0.90 -1.000＜(r2+r1) / (r2-r1)＜0.200 in, ff: focal length of the front group, fr: focal length of the rear group, r1: The curvature radius of the lens surface on the image side of the lens component arranged closest to the object side, r2: The curvature radius of the lens surface on the object side of the second lens component arranged from the object side.

3. The optical system according to claim 1, wherein: The optical system satisfies the following conditions: 0.10<ff / (-fr)<0.90 in, ff: focal length of the front group, fr: Focal length of the rear group.

4. The optical system according to claim 1 or 3, wherein: The optical system satisfies the following conditions: -1.000＜(r2+r1) / (r2-r1)＜0.200 in, r1: The curvature radius of the lens surface on the image side of the lens component arranged closest to the object side, r2: The curvature radius of the lens surface on the object side of the second lens component arranged from the object side.

5. The optical system according to any one of claims 1 to 4, wherein: The optical system satisfies the following conditions: 0.10<|fF2| / |fF1|<1.10 in, fF1: focal length of the 1st focus group, fF2: focal length of the second focus group.

6. The optical system according to any one of claims 1 to 5, wherein: The optical system satisfies the following conditions: 0.10<ff / |fF1|<0.65 in, ff: focal length of the front group, fF1: focal length of the first focus group.

7. The optical system according to any one of claims 1 to 6, wherein: The optical system satisfies the following conditions: 1.10<(-fr) / |fF2|<2.40 in, fr: focal length of the rear group, fF2: focal length of the second focus group.

8. The optical system according to any one of claims 1 to 7, wherein: The optical system has an aperture between the first focusing lens group and the second focusing lens group. The optical system satisfies the following conditions: 1.00<fsr / fsf<2.20 in, fsr: The synthetic focal length when focusing on an object at infinity with the lens having the aperture arranged on the image side. fsf: The composite focal length when an object at infinity is focused on by a lens that is arranged on the object side relative to the aperture.

9. The optical system according to any one of claims 1 to 8, wherein: The optical system satisfies the following conditions: 0.80<y / Bfa<2.10 in, y: image height of the optical system, Bfa: The back focal length (air equivalent length) of the optical system when focusing on an object at infinity.

10. The optical system according to any one of claims 1 to 9, wherein: The optical system satisfies the following conditions: 1.50<f / Bfa<5.00 in, f: the focal length of the entire optical system when the infinitely distant object is in focus, Bfa: The back focal length (air equivalent length) of the optical system when focusing on an object at infinity.

11. The optical system according to any one of claims 1 to 10, wherein: The optical system satisfies the following conditions: 1.50<TLa / f<3.50 in, f: the focal length of the entire optical system when the infinitely distant object is in focus, TLa: The total optical length (air equivalent length) of the optical system when an object at infinity is in focus.

12. The optical system according to any one of claims 1 to 11, wherein: The first focusing group has negative optical power.

13. The optical system according to any one of claims 1 to 12, wherein: The second focusing group has positive optical power. 14 . An optical device comprising the optical system according to claim 1 .

15. A method for manufacturing an optical system, wherein the optical system is composed of a front group having positive optical power, a middle group, and a rear group having negative optical power in order from the object side, wherein: The intermediate group is configured to consist of a first focus group and a second focus group which move along different tracks when focusing. The front group is configured to have a negative lens component, a negative lens component, and a positive lens component in order from the object side, The rear group is configured to have a negative lens component on the side closest to the image plane, Configured to meet the following conditions: 0.10<|fF1| / (-fr)<2.60 0.70<|fF2| / ff<2.00 in, fF1: focal length of the first focus group, fr: focal length of the rear group, fF2: focal length of the second focus group, ff: focal length of the front group.

16. A method for manufacturing an optical system, wherein the optical system is composed of a front group having positive optical power, a middle group, and a rear group having negative optical power in order from the object side, wherein: The intermediate group is configured to consist of a first focus group and a second focus group which move along different tracks when focusing. The front group is configured to have a negative lens component, a negative lens component, and a positive lens component in order from the object side, The rear group is configured to have a negative lens component on the side closest to the image plane, Configured to meet the following conditions: 0.05<ff / (-fr)<0.90 -1.000＜(r2+r1) / (r2-r1)＜0.200 in, ff: focal length of the front group, fr: focal length of the rear group, r1: The curvature radius of the lens surface on the image side of the lens component arranged closest to the object side, r2: The curvature radius of the lens surface on the object side of the second lens component arranged from the object side.

Images