Imaging lens and imaging device

Abstract

To provide a telephoto image capturing lens which is compact and light-weight and offers good optical performance, and an image capturing device having the same.SOLUTION: An image capturing lens is provided, consisting of a first lens group having positive refractive power, an aperture stop, a second lens group having positive refractive power, and a third lens group having negative refractive power arranged in order from the object side. When focusing, the first and third lens groups are stationary relative to the image plane while the second lens group moves along an optical axis. The image capturing lens satisfies predefined conditional expressions.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The technology of the present disclosure relates to an imaging lens and an imaging device.

Background Art

[0002] Conventionally, as an imaging lens applicable to imaging devices such as digital cameras and video cameras, for example, lens systems described in Patent Document 1, Patent Document 2, Patent Document 3, and Patent Document 4 below are known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, there has been a demand for a telephoto imaging lens that is small and lightweight and has good optical performance.

[0005] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a telephoto imaging lens that is small and lightweight and has good optical performance, and an imaging device including this imaging lens.

Means for Solving the Problems

[0006] The imaging lens according to one aspect of the present disclosure includes, in order from the object side to the image side, a first lens group having a positive refractive power, an aperture stop, a second lens group having a positive refractive power, and a third lens group having a negative refractive power. When focusing, the first lens group and the third lens group are fixed with respect to the image plane, the second lens group moves along the optical axis, and the distance on the optical axis from the most object-side lens surface of the first lens group to the most image-side lens surface of the third lens group and the total system back focus in terms of air equivalent distance are summed as TL, the focal length of the entire system in the state of focusing on an infinite object is f, the focal length of the first lens group is f1, the maximum half angle of view in the state of focusing on an infinite object is ω, and when the unit of ω is degrees, 0 < TL / f < 0.64 (1) 1.5 < f / f1 < 5 (2) 0 < ω < 4 (3) It satisfies the conditional expressions (1), (2), and (3) represented by

[0007] The first lens group preferably includes a diffractive optical surface. When the distance on the optical axis from the diffractive optical surface to the aperture stop is dDOE, the imaging lens of the above aspect 0.1 < dDOE / TL < 0.5 (4) Preferably satisfies the conditional expression (4) represented by

[0008] Preferably, two or more positive lenses are arranged continuously in order from the most object side of the first lens group.

[0009] When the focal length of the second lens group is f2, the imaging lens of the above aspect 0 < f / f2 < 6 (5) Preferably satisfies the conditional expression (5) represented by

[0010] When the focal length of the third lens group is f3, the imaging lens of the above aspect -30 < f / f3 < 0 (6) Preferably satisfies the conditional expression (6) represented by

[0011] When the distance on the optical axis between the object-side surface of the positive lens having the strongest refractive power among the positive lenses arranged on the image side of the aperture and the object-side surface of the negative lens having the strongest refractive power among the negative lenses arranged on the image side of the aperture is Δd, the imaging lens of the above aspect is 0 < Δd / TL < 0.3 (7) preferably satisfies the conditional expression (7) represented by 0 < Δd / TL < 0.25 (7-1) more preferably satisfies the conditional expression (7-1) represented by

[0012] When the distance on the optical axis from the aperture to the object-side surface of the positive lens having the strongest refractive power among the positive lenses arranged on the image side of the aperture is dSpmax, the imaging lens of the above aspect is 0.05 < dSpmax / TL < 0.6 (8) preferably satisfies the conditional expression (8) represented by

[0013] When the longest air interval on the optical axis within the first lens group is dair, the imaging lens of the above aspect is 0.01 < dair / TL < 0.25 (9) preferably satisfies the conditional expression (9) represented by

[0014] The first lens group may be configured to include, in order from the object side to the image side, a first A lens group having a positive refractive power and a first B lens group having a negative refractive power separated from the first A lens group by the longest air interval on the optical axis within the first lens group. In this configuration, when the focal length of the first A lens group is f1A and the focal length of the first B lens group is f1B, the imaging lens of the above aspect is -2.5 < f1A / f1B < 0 (10) preferably satisfies the conditional expression (10) represented by

[0015] In the configuration where the first lens group consists of the above-mentioned first A lens group and first B lens group, it is preferable that the first B lens group includes a first lens pair composed of a positive lens and a negative lens adjacent to each other. When the Abbe number of the positive lens of the first lens pair based on the d-line is ν1Bp, the imaging lens of the above aspect is 40 < ν1Bp < 100 (11) It is preferable to satisfy the conditional expression (11) represented by

[0016] The third lens group may be configured to include, in order from the object side to the image side, a third A lens group and a third B lens group separated from the third A lens group by the longest air interval on the optical axis within the third lens group. In this configuration, it is preferable that the third A lens group includes two or more negative lenses and two or more positive lenses. Also, when the focal length of the third A lens group is f3A and the focal length of the third B lens group is f3B, the imaging lens of the above aspect is -0.3 < f3A / f3B < 4 (12) It is preferable to satisfy the conditional expression (12) represented by

[0017] The third lens group preferably includes an anti-vibration group that moves in a direction intersecting the optical axis during image blur correction. When the focal length of the anti-vibration group is fis, the imaging lens of the above aspect is 2.5 < f / |fis| < 30 (13) It is preferable to satisfy the conditional expression (13) represented by

[0018] The third lens group preferably includes a rear group having a positive refractive power on the image side of the anti-vibration group. When the focal length of the rear group is fr, the imaging lens of the above aspect is 2.5 < f / fr < 25 (14) It is preferable to satisfy the conditional expression (14) represented by

[0019] When one lens component is a single lens or a cemented lens, it is preferable that a lens component having a negative refractive power is disposed between the second lens group and the vibration-proof group. When the refractive index of the negative lens included in the lens component having a negative refractive power with respect to the d-line is N3Cn, the imaging lens of the above aspect is 1.75 < N3Cn < 2.2 (15) It is preferable to satisfy the conditional expression (15) represented by

[0020] The vibration-proof group preferably includes a second lens pair composed of a positive lens and a negative lens adjacent to each other. And when the refractive index of the positive lens of the second lens pair with respect to the d-line is N3p, the refractive index of the negative lens of the second lens pair with respect to the d-line is N3n, the Abbe number of the positive lens of the second lens pair based on the d-line is ν3p, the Abbe number of the negative lens of the second lens pair based on the d-line is ν3n, the partial dispersion ratio between the g-line and the F-line of the positive lens of the second lens pair is θ3p, and the partial dispersion ratio between the g-line and the F-line of the negative lens of the second lens pair is θ3n, the imaging lens of the above aspect is -0.15 < N3p - N3n < 0.5 (16) -40 < ν3p - ν3n < -5 (17) 0 < θ3p - θ3n < 0.1 (18) It is preferable to satisfy the conditional expressions (16), (17), and (18) represented by

[0021] The second lens group preferably includes a third lens pair composed of a positive lens and a negative lens adjacent to each other. In this configuration, when the refractive index of the positive lens of the third lens pair with respect to the d-line is N2p, the refractive index of the negative lens of the third lens pair with respect to the d-line is N2n, the Abbe number of the positive lens of the third lens pair based on the d-line is ν2p, the Abbe number of the negative lens of the third lens pair based on the d-line is ν2n, the partial dispersion ratio between the g-line and the F-line of the positive lens of the third lens pair is θ2p, and the partial dispersion ratio between the g-line and the F-line of the negative lens of the third lens pair is θ2n, the imaging lens of the above aspect is -0.6 < N2p - N2n < 0 (19) -10 < ν2p - ν2n < 30 (20) -0.15 < θ2p - θ2n < 0.1 (21) It is preferable to satisfy the conditional expressions (19), (20), and (21) represented by

[0022] When the back focus of the entire system at the air equivalent distance is Bf, the imaging lens of the above aspect 1.5 < Bf / (f × tanω) < 10 (22) It is preferable to satisfy the conditional expression (22) represented by

[0023] An imaging device according to another aspect of the present disclosure includes the imaging lens of the above aspect.

[0024] Note that the phrases "comprising" and "consisting of" in this specification are intended to mean that, in addition to the recited components, lenses having substantially no refractive power, optical elements other than lenses such as diaphragms, filters, and cover glasses, and mechanical parts such as lens flanges, lens barrels, imaging elements, and shake correction mechanisms may be included.

[0025] In this specification, the phrase "a group having a positive refractive power" means that the group as a whole has a positive refractive power, and the phrase "a group having a negative refractive power" means that the group as a whole has a negative refractive power. Similarly, the phrase "a lens component having a positive refractive power" means that the lens component as a whole has a positive refractive power, and the phrase "a lens component having a negative refractive power" means that the lens component as a whole has a negative refractive power.

[0026] The "first lens group", "second lens group", "third lens group", "vibration prevention group", and "rear group" are not limited to configurations consisting of a plurality of lenses, and may also be configurations consisting of only one lens. Note that the "first lens group", "second lens group", and "third lens group" in this specification each refer to a part of the imaging lens that includes at least one lens separated by an air interval that changes during focusing. During focusing, each lens group is moved or fixed as a unit, and the mutual distance between the lenses within each lens group does not change.

[0027] "Single lens" means a single lens that is not joined. However, a compound aspherical lens (a lens in which a spherical lens and an aspherical film formed on the spherical lens are integrally formed and function as a single aspherical lens as a whole) is not regarded as a joined lens but is treated as a single lens. Regarding the sign of the refractive power and the surface shape of a lens including an aspherical surface, those in the paraxial region are used unless otherwise specified.

[0028] In this specification, "entire system" means the imaging lens. "Back focus at air-equivalent distance" is the air-equivalent distance on the optical axis from the most image-side lens surface of the entire system to the image plane. The "focal length" used in the conditional expression is the paraxial focal length. The values used in the conditional expression are values based on the d-line when focused on an infinite object unless otherwise specified.

[0029] The "d-line", "C-line", "F-line", and "g-line" described in this specification are spectral lines. In this specification, the wavelength of the d-line is treated as 587.56 nm (nanometers), the wavelength of the C-line is 656.27 nm (nanometers), the wavelength of the F-line is 486.13 nm (nanometers), and the wavelength of the g-line is 435.84 nm (nanometers). The partial dispersion ratio θgF between the g-line and F-line of a certain lens is defined as θgF = (Ng - NF) / (NF - NC), where Ng, NF, and NC are the refractive indices of the lens for the g-line, F-line, and C-line, respectively.

Effects of the Invention

[0030] According to the present disclosure, it is possible to provide a telephoto imaging lens that is small and lightweight and has good optical performance, and an imaging device including this imaging lens.

Brief Description of the Drawings

[0031]

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Embodiments for Carrying Out the Invention

[0032] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0033] FIG. 1 shows a cross-sectional view of the configuration of an imaging lens according to an embodiment of the present disclosure in a state of being focused on an infinite object. FIG. 2 shows a cross-sectional view of the configuration and light beam in each focusing state of the imaging lens of FIG. 1. In FIG. 2, the upper part marked with "infinity" shows the state of being focused on an infinite object, and the lower part marked with "closest" shows the state of being focused on the closest object with a distance of 2.2 m (meter) from the image plane Sim. In this specification, an object at an infinite distance is referred to as an infinite object, and an object at the closest distance is referred to as a closest object. In FIG. 2, as the light beams, the upper part shows the on-axis light beam 2 and the light beam 3 with the maximum angle of view, and the lower part shows the on-axis light beam 4 and the light beam 5 with the maximum angle of view. The examples shown in FIGS. 1 and 2 correspond to the imaging lens of Example 1 described later. In FIGS. 1 and 2, the left side is the object side, and the right side is the image side. Hereinafter, the description will mainly refer to FIG. 1.

[0034] In FIG. 1, an example is shown in which a parallel plate-shaped optical member PP is arranged between the imaging lens and the image plane Sim assuming that the imaging lens is applied to an imaging device. The optical member PP is a member assuming various filters and / or cover glass, etc. The various filters are a low-pass filter, an infrared cut filter, and / or a filter that cuts a specific wavelength range, etc. The optical member PP is a member having no refractive power. It is also possible to configure the imaging device by omitting the optical member PP.

[0035] The imaging lens of the present disclosure includes, in order from the object side to the image side along the optical axis Z, a first lens group G1 having a positive refractive power, an aperture stop St, a second lens group G2 having a positive refractive power, and a third lens group G3 having a negative refractive power. By making the lens group closest to the object side a lens group having a positive refractive power, it becomes easier to reduce the diameter of the lens group on the image side of this lens group, which is advantageous for reducing the weight of the entire lens system.

[0036] In addition, in the imaging lens of the present disclosure, when focusing from an infinite object to the closest object, the first lens group G1 and the third lens group G3 are fixed with respect to the image plane Sim, and the second lens group G2 is configured to move along the optical axis Z. In this specification, a group that moves during focusing is referred to as a "focus group". Focusing is performed by the movement of the focus group. In the imaging lens of the present disclosure, the focus group consists of the second lens group G2.

[0037] In the imaging lens of the present disclosure, a lens group configuration in which positive, aperture stop St, positive, and negative are arranged in order from the object side to the image side is adopted, and by setting the behavior of each lens group during focusing as described above, it becomes easy to reduce the diameter of the focus group. In addition, since it becomes easy to increase the backlash magnification of the focus group, it is advantageous for reducing the movement amount of the focus group during focusing, and thereby it is advantageous for shortening the overall length of the lens system. Here, the backlash magnification refers to the ratio of the movement amount of the image plane position to the unit movement amount of the focus group.

[0038] As an example, the imaging lens of FIG. 1 is configured as follows. The first lens group G1 consists of six lenses L11 to L16 in order from the object side to the image side. The second lens group G2 consists of two lenses L21 to L22. The third lens group G3 consists of seven lenses L31 to L37 in order from the object side to the image side. Note that the aperture stop St in FIG. 1 does not indicate the size and shape, but indicates the position in the optical axis direction.

[0039] In the example of FIG. 1, during focusing, the entire second lens group moves integrally, and the other lens groups are fixed with respect to the image plane Sim. Here, "moving integrally" means moving simultaneously in the same direction by the same amount. The leftward arrow below the second lens group G2 in FIG. 1 indicates that the second lens group G2 is a focus group that moves toward the object side during focusing from an infinite object to the closest object.

[0040] Next, the preferred configuration and possible configurations of the imaging lens of the present disclosure will be described. In the following description of the preferred configuration and possible configurations, for the sake of avoiding redundancy, the "imaging lens of the present disclosure" is also simply referred to as the "imaging lens".

[0041] Regarding the overall length of the lens system, it is preferable that the imaging lens satisfies the following conditional expression (1). Here, TL is the sum of the distance on the optical axis from the most object-side lens surface of the first lens group G1 to the most image-side lens surface of the third lens group G3 and the back focus of the entire system in terms of air equivalent distance. Also, f is the focal length of the entire system in the state of focusing on an infinite object. By satisfying the conditional expression (1), it is advantageous for miniaturization. In order to obtain better characteristics, it is more preferable that the imaging lens satisfies the following conditional expression (1-1), and it is even more preferable that the imaging lens satisfies the following conditional expression (1-2). 0 < TL / f < 0.64 (1) 0 < TL / f < 0.63 (1-1) 0 < TL / f < 0.62 (1-2)

[0042] When the focal length of the entire system in the state of focusing on an infinite object is f and the focal length of the first lens group G1 is f1, it is preferable that the imaging lens satisfies the following conditional expression (2). By preventing the corresponding value of the conditional expression (2) from falling below the lower limit, it is advantageous for reducing the diameter of the aperture stop St and the lenses on the image side of the aperture stop St. By preventing the corresponding value of the conditional expression (2) from exceeding the upper limit, it is advantageous for suppressing spherical aberration. In order to obtain better characteristics, it is more preferable that the imaging lens satisfies the following conditional expression (2-1), and it is even more preferable that the imaging lens satisfies the following conditional expression (2-2). 1.5 < f / f1 < 5 (2) 1.6 < f / f1 < 4.5 (2-1) 1.7 < f / f1 < 3.5 (2-2)

[0043] Let ω be the maximum half-angle of view in the state of focusing on an infinitely distant object, and when the unit of ω is degrees, it is preferable that the imaging lens satisfies the following conditional expression (3). As an example, ω is shown in FIG. 2. By satisfying the conditional expression (3), a lens system suitable for a telephoto system is obtained, and thus the effects of miniaturization and weight reduction of the imaging lens according to the present disclosure can be made remarkable. In order to obtain better characteristics, it is more preferable that the imaging lens satisfies the following conditional expression (3-1), and it is even more preferable that the imaging lens satisfies the following conditional expression (3-2). 0 < ω < 4 (3) 0 < ω < 3 (3-1) 0 < ω < 2 (3-2)

[0044] The first lens group G1 may be configured to include a diffractive optical surface. By including the diffractive optical surface, it is advantageous for correcting axial chromatic aberration. When the first lens group G1 includes a diffractive optical surface, it is preferable that the imaging lens satisfies the following conditional expression (4). Here, the distance on the optical axis from the diffractive optical surface to the aperture stop St is denoted as dDOE. Also, TL used here is the same as TL in the conditional expression (1). By preventing the corresponding value of the conditional expression (4) from falling below the lower limit, it is advantageous for correcting axial chromatic aberration. By preventing the corresponding value of the conditional expression (4) from exceeding the upper limit, it is advantageous for shortening the overall length of the lens system. In order to obtain better characteristics, it is more preferable that the imaging lens satisfies the following conditional expression (4-1), and it is even more preferable that the imaging lens satisfies the following conditional expression (4-2). 0.1 < dDOE / TL < 0.5 (4) 0.15 < dDOE / TL < 0.4 (4-1) 0.2 < dDOE / TL < 0.35 (4-2)

[0045] When the focal length of the second lens group G2 is f2, it is preferable that the imaging lens satisfies the following conditional expression (5). Here, f used is the same as f in conditional expression (1). By preventing the corresponding value of conditional expression (5) from falling below the lower limit, it is advantageous for reducing the movement amount of the focus group during focusing. By preventing the corresponding value of conditional expression (5) from exceeding the upper limit, it is possible to suppress the tightening of the stop accuracy during focusing. In order to obtain better characteristics, it is more preferable that the imaging lens satisfies the following conditional expression (5-1), and even more preferable that it satisfies the following conditional expression (5-2). 0 < f / f2 < 6 (5) 2 < f / f2 < 5 (5-1) 2.5 < f / f2 < 4 (5-2)

[0046] When the focal length of the third lens group G3 is f3, it is preferable that the imaging lens satisfies the following conditional expression (6). Here, f used is the same as f in conditional expression (1). By preventing the corresponding value of conditional expression (6) from falling below the lower limit, it is advantageous for shortening the overall length of the lens system. By preventing the corresponding value of conditional expression (6) from exceeding the upper limit, it is advantageous for suppressing field curvature. In order to obtain better characteristics, it is more preferable that the imaging lens satisfies the following conditional expression (6-1), and even more preferable that it satisfies the following conditional expression (6-2). -30 < f / f3 < 0 (6) -25 < f / f3 < -2.5 (6-1) -20 < f / f3 < -5 (6-2)

[0047] The imaging lens preferably satisfies the following conditional expression (7). Here, TL used is the same as TL in conditional expression (1). Also, here, the distance on the optical axis between the object-side surface of the positive lens having the strongest refractive power among the positive lenses arranged on the image side of the aperture stop St and the object-side surface of the negative lens having the strongest refractive power among the negative lenses arranged on the image side of the aperture stop St is defined as Δd. As an example, Δd is shown in FIG. 2. In the example of FIG. 1, the positive lens having the strongest refractive power among the positive lenses arranged on the image side of the aperture stop St is lens L33, and the negative lens having the strongest refractive power among the negative lenses arranged on the image side of the aperture stop St is lens L34. Regarding the lower limit of conditional expression (7), since Δd > 0 and TL > 0 always hold, 0 < Δd / TL is obtained. By ensuring that the corresponding value of conditional expression (7) does not exceed the upper limit, it is advantageous for aberration correction. To obtain better characteristics, it is more preferable that the imaging lens satisfies the following conditional expression (7-1), and it is even more preferable that it satisfies the following conditional expression (7-2). 0 < Δd / TL < 0.3 (7) 0 < Δd / TL < 0.25 (7-1) 0 < Δd / TL < 0.2 (7-2)

[0048] The imaging lens preferably satisfies the following conditional expression (8). Here, TL used is the same as TL in conditional expression (1). Also, here, the distance on the optical axis from the aperture stop St to the object-side surface of the positive lens having the strongest refractive power among the positive lenses arranged on the image side of the aperture stop St is defined as dSpmax. As an example, dSpmax is shown in FIG. 2. By ensuring that the corresponding value of conditional expression (8) does not fall below the lower limit, it is advantageous for spherical aberration correction. By ensuring that the corresponding value of conditional expression (8) does not exceed the upper limit, it is advantageous for field curvature correction. To obtain better characteristics, it is more preferable that the imaging lens satisfies the following conditional expression (8-1), and it is even more preferable that it satisfies the following conditional expression (8-2). 0.05 < dSpmax / TL < 0.6 (8) 0.1 < dSpmax / TL < 0.5 (8-1) 0.13 < dSpmax / TL < 0.4 (8-2)

[0049] The imaging lens preferably satisfies the following conditional expression (9). Here, TL used is the same as TL in conditional expression (1). Also, here, the longest air interval on the optical axis within the first lens group is defined as dair. As an example, dair is shown in FIG. 2. By preventing the corresponding value of conditional expression (9) from falling below the lower limit, it is advantageous for weight reduction. By preventing the corresponding value of conditional expression (9) from exceeding the upper limit, it is advantageous for correcting spherical aberration. In order to obtain better characteristics, it is more preferable for the imaging lens to satisfy the following conditional expression (9-1), and even more preferable for it to satisfy the following conditional expression (9-2). 0.01 < dair / TL < 0.25 (9) 0.015 < dair / TL < 0.2 (9-1) 0.02 < dair / TL < 0.15 (9-2)

[0050] The first lens group G1 may be configured to be composed of a first A lens group G1A having a positive refractive power and a first B lens group G1B having a negative refractive power separated from the first A lens group G1A by the longest air interval on the optical axis within the first lens group, in order from the object side to the image side. As an example, in the example of FIG. 1, the first A lens group G1A consists of lenses L11 to L12, and the first B lens group G1B consists of lenses L13 to L16.

[0051] In the configuration where the first lens group G1 consists of the above-mentioned first A lens group G1A and the first B lens group G1B, when the focal length of the first A lens group G1A is f1A and the focal length of the first B lens group G1B is f1B, it is preferable that the imaging lens satisfies the following conditional expression (10). By preventing the corresponding value of the conditional expression (10) from falling below the lower limit, the spread of the light beam can be suppressed, which is advantageous for reducing the diameter of the aperture of the aperture stop St. Regarding the upper limit of the conditional expression (10), since f1A > 0 and f1B < 0, f1A / f1B < 0. To obtain better characteristics, it is more preferable that the imaging lens satisfies the following conditional expression (10-1), and it is even more preferable that the imaging lens satisfies the following conditional expression (10-2). -2.5 < f1A / f1B < 0 (10) -2 < f1A / f1B < 0 (10-1) -1.5 < f1A / f1B < 0 (10-2)

[0052] In the configuration where the first lens group G1 consists of the above-mentioned first A lens group G1A and the first B lens group G1B, it is preferable that the first B lens group G1B includes a lens pair consisting of a positive lens and a negative lens adjacent to each other. In this case, it is advantageous for correcting axial chromatic aberration.

[0053] Note that the "lens pair consisting of a positive lens and a negative lens adjacent to each other" in this specification may be arranged such that the positive lens and the negative lens are adjacent to each other with an air gap therebetween, or the positive lens and the negative lens may be joined. Also, the positive lens and the negative lens may be arranged in order from the object side to the image side, or the negative lens and the positive lens may be arranged in order from the object side to the image side.

[0054] For convenience of explanation, the "lens pair consisting of a positive lens and a negative lens adjacent to each other" included in the 1Bth lens group G1B will be referred to as the "first lens pair" hereinafter. In the configuration where the 1Bth lens group G1B includes the first lens pair, when the Abbe number of the positive lens of the first lens pair based on the d-line is ν1Bp, it is preferable that the imaging lens satisfies the following conditional expression (11). By satisfying the conditional expression (11), it becomes more advantageous for correcting axial chromatic aberration. In order to obtain better characteristics, it is more preferable that the imaging lens satisfies the following conditional expression (11-1), and it is even more preferable that the imaging lens satisfies the following conditional expression (11-2). 40 < ν1Bp < 100 (11) 50 < ν1Bp < 100 (11-1) 60 < ν1Bp < 100 (11-2)

[0055] The 3rd lens group G3 consists of a 3Ath lens group G3A and a 3Bth lens group G3B separated from the 3Ath lens group G3A by the longest air interval on the optical axis within the 3rd lens group, in order from the object side to the image side. In this configuration, it is preferable that the 3Ath lens group G3A includes two or more negative lenses and two or more positive lenses. In this case, it becomes advantageous for correcting spherical aberration.

[0056] In the configuration where the 3rd lens group G3 consists of the above-mentioned 3Ath lens group G3A and 3Bth lens group G3B, when the focal length of the 3Ath lens group G3A is f3A and the focal length of the 3Bth lens group G3B is f3B, it is preferable that the imaging lens satisfies the following conditional expression (12). By satisfying the conditional expression (12), it becomes advantageous for keeping a good balance between the correction of field curvature and the correction of spherical aberration. As an example, in the example of FIG. 1, the 3Ath lens group G3A consists of lenses L31 to L35, and the 3Bth lens group G3B consists of lenses L36 to L37. In order to obtain better characteristics, it is more preferable that the imaging lens satisfies the following conditional expression (12-1), and it is even more preferable that the imaging lens satisfies the following conditional expression (12-2). -0.3 < f3A / f3B < 4 (12) -0.2 < f3A / f3B < 3.5 (12-1) -0.1 < f3A / f3B < 2.5 (12 - 2)

[0057] It is preferable that the third lens group G3 includes an anti - shake group that moves in a direction intersecting the optical axis Z during image blur correction. In this case, anti - shake performance can be achieved. In the example of FIG. 1, the anti - shake group consists of lenses L33 to L34. The downward arrows below the lenses L33 to L34 in FIG. 1 indicate that the lenses L33 to L34 are the anti - shake group.

[0058] In a configuration where the third lens group G3 includes an anti - shake group, it is preferable that the imaging lens satisfies the following conditional expression (13). Here, the f used is the same as the f in conditional expression (1). Also, here, the focal length of the anti - shake group is set as fis. By preventing the corresponding value of conditional expression (13) from falling below the lower limit, it is advantageous for reducing the movement amount of the anti - shake group during image blur correction. By preventing the corresponding value of conditional expression (13) from exceeding the upper limit, it is advantageous for suppressing the variation of various aberrations during image blur correction. To obtain better characteristics, it is more preferable that the imaging lens satisfies the following conditional expression (13 - 1), and even more preferable that it satisfies the following conditional expression (13 - 2). 2.5 < f / |fis| < 30 (13) 5 < f / |fis| < 20 (13 - 1) 9 < f / |fis| < 18 (13 - 2)

[0059] The third lens group G3 preferably includes a rear group Gr having a positive refractive power on the image side with respect to the anti-shake group. In this case, it is advantageous for reducing the movement amount of the anti-shake group during image blur correction. In a configuration where the third lens group G3 includes the rear group Gr, the imaging lens preferably satisfies the following conditional expression (14). Here, f used is the same as f in the conditional expression (1). Also, here, the focal length of the rear group Gr is denoted as fr. By preventing the corresponding value of the conditional expression (14) from falling below the lower limit, it becomes more advantageous for reducing the movement amount of the anti-shake group during image blur correction. By preventing the corresponding value of the conditional expression (14) from exceeding the upper limit, it is advantageous for ensuring good anti-shake performance. In order to obtain better characteristics, it is more preferable for the imaging lens to satisfy the following conditional expression (14-1), and even more preferable to satisfy the following conditional expression (14-2). 2.5 < f / fr < 25 (14) 3 < f / fr < 20 (14-1) 5 < f / fr < 15 (14-2)

[0060] The rear group Gr may be a group consisting of one lens or a group consisting of a plurality of lenses. The anti-shake group and the rear group Gr may be arranged continuously or discontinuously. As an example, in the example of FIG. 1, the rear group Gr consists only of the lens L35.

[0061] The most image-side lens surface of the third lens group G3 is preferably a concave surface. In this case, it is advantageous for correcting field curvature.

[0062] It is preferable that a lens component having a negative refractive power is disposed between the second lens group G2 and the anti-vibration group. In this case, it is advantageous for suppressing fluctuations in anti-vibration performance during focusing. In this specification, one lens component is regarded as one single lens or one cemented lens. In a configuration where a lens component having a negative refractive power is disposed between the second lens group G2 and the anti-vibration group, when the refractive index of the negative lens included in this lens component having a negative refractive power with respect to the d-line is N3Cn, the imaging lens preferably satisfies the following conditional expression (15). By satisfying the conditional expression (15), it is advantageous for correcting field curvature. In order to obtain better characteristics, it is more preferable that the imaging lens satisfies the following conditional expression (15-1), and it is even more preferable that the imaging lens satisfies the following conditional expression (15-2). 1.75 < N3Cn < 2.2 (15) 1.8 < N3Cn < 2.2 (15-1) 1.85 < N3Cn < 2.1 (15-2)

[0063] In a configuration where a lens component having a negative refractive power is disposed between the second lens group G2 and the anti-vibration group, it is preferable that a positive lens is disposed closer to the image side than the negative lens included in this lens component having a negative refractive power. In this case, it is advantageous for suppressing fluctuations in anti-vibration performance during focusing.

[0064] The anti-vibration group preferably includes a lens pair composed of a positive lens and a negative lens adjacent to each other. In this case, it is advantageous for correcting lateral chromatic aberration. For the sake of convenience of explanation, the "lens pair composed of a positive lens and a negative lens adjacent to each other" included in the anti-vibration group will be referred to as the "second lens pair" hereinafter.

[0065] In a configuration where the anti-vibration group includes a second lens pair, when the refractive index of the positive lens of the second lens pair with respect to the d-line is N3p and the refractive index of the negative lens of the second lens pair with respect to the d-line is N3n, the imaging lens preferably satisfies the following conditional expression (16). By satisfying the conditional expression (16), it becomes more advantageous for correcting lateral chromatic aberration. In order to obtain better characteristics, it is more preferable for the imaging lens to satisfy the following conditional expression (16-1), and it is even more preferable to satisfy the following conditional expression (16-2). -0.15 < N3p - N3n < 0.5 (16) -0.1 < N3p - N3n < 0.4 (16-1) -0.05 < N3p - N3n < 0.3 (16-2)

[0066] In a configuration where the anti-vibration group includes a second lens pair, when the Abbe number of the positive lens of the second lens pair based on the d-line is ν3p and the Abbe number of the negative lens of the second lens pair based on the d-line is ν3n, the imaging lens preferably satisfies the following conditional expression (17). By satisfying the conditional expression (17), it becomes more advantageous for correcting lateral chromatic aberration. In order to obtain better characteristics, it is more preferable for the imaging lens to satisfy the following conditional expression (17-1), and it is even more preferable to satisfy the following conditional expression (17-2). -40 < ν3p - ν3n < -5 (17) -35 < ν3p - ν3n < -10 (17-1) -30 < ν3p - ν3n < -15 (17-2)

[0067] In a configuration where the anti-vibration group includes a second lens pair, when the partial dispersion ratio between the g-line and the F-line of the positive lens of the second lens pair is θ3p and the partial dispersion ratio between the g-line and the F-line of the negative lens of the second lens pair is θ3n, the imaging lens preferably satisfies the following conditional expression (18). By satisfying the conditional expression (18), it becomes more advantageous for correcting lateral chromatic aberration. In order to obtain better characteristics, it is more preferable for the imaging lens to satisfy the following conditional expression (18-1), and it is even more preferable to satisfy the following conditional expression (18-2). 0 < θ3p - θ3n < 0.1 (18) 0.01 < θ3p - θ3n < 0.08 (18 - 1) 0.02 < θ3p - θ3n < 0.07 (18 - 2)

[0068] In a configuration where the vibration-proof group includes the second lens pair, it is more preferable that the imaging lens simultaneously satisfies conditional expressions (16), (17), and (18). In order to obtain better characteristics, it is even more preferable that the imaging lens simultaneously satisfies conditional expressions (16), (17), and (18), and further satisfies at least one of conditional expressions (16 - 1), (16 - 2), (17 - 1), (17 - 2), (18 - 1), and (18 - 2).

[0069] It is preferable that the second lens group G2 includes a lens pair composed of a positive lens and a negative lens adjacent to each other. In this case, it is advantageous for suppressing the variation of axial chromatic aberration when the distance between the object and the imaging lens varies. For the sake of convenience in explanation, the "lens pair composed of a positive lens and a negative lens adjacent to each other" included in the second lens group G2 will be referred to as the "third lens pair" hereinafter.

[0070] In a configuration where the second lens group G2 includes the third lens pair, when the refractive index of the positive lens of the third lens pair with respect to the d-line is N2p and the refractive index of the negative lens of the third lens pair with respect to the d-line is N2n, it is preferable that the imaging lens satisfies the following conditional expression (19). By satisfying conditional expression (19), it is advantageous for correcting axial chromatic aberration. In order to obtain better characteristics, it is more preferable that the imaging lens satisfies the following conditional expression (19 - 1), and even more preferable that it satisfies the following conditional expression (19 - 2). -0.6 < N2p - N2n < 0 (19) -0.5 < N2p - N2n < -0.05 (19 - 1) -0.4 < N2p - N2n < -0.1 (19 - 2)

[0071] In a configuration where the second lens group G2 includes a third lens pair, when the Abbe number of the positive lens of the third lens pair with respect to the d-line is ν2p and the Abbe number of the negative lens of the third lens pair with respect to the d-line is ν2n, it is preferable that the imaging lens satisfies the following conditional expression (20). By satisfying the conditional expression (20), it is advantageous for correcting axial chromatic aberration. In order to obtain better characteristics, it is more preferable that the imaging lens satisfies the following conditional expression (20-1), and it is even more preferable that the imaging lens satisfies the following conditional expression (20-2). -10 < ν2p - ν2n < 30 (20) -5 < ν2p - ν2n < 25 (20-1) -0.5 < ν2p - ν2n < 20 (20-2)

[0072] In a configuration where the second lens group G2 includes a third lens pair, when the partial dispersion ratio between the g-line and the F-line of the positive lens of the third lens pair is θ2p and the partial dispersion ratio between the g-line and the F-line of the negative lens of the third lens pair is θ2n, it is preferable that the imaging lens satisfies the following conditional expression (21). By satisfying the conditional expression (21), it is advantageous for correcting axial chromatic aberration. In order to obtain better characteristics, it is more preferable that the imaging lens satisfies the following conditional expression (21-1), and it is even more preferable that the imaging lens satisfies the following conditional expression (21-2). -0.15 < θ2p - θ2n < 0.1 (21) -0.1 < θ2p - θ2n < 0.05 (21-1) -0.03 < θ2p - θ2n < 0.01 (21-2)

[0073] In a configuration where the second lens group G2 includes a third lens pair, it is more preferable that the imaging lens simultaneously satisfies the conditional expressions (19), (20), and (21). In order to obtain better characteristics, it is even more preferable that the imaging lens simultaneously satisfies the conditional expressions (19), (20), and (21) and further satisfies at least one of the conditional expressions (19-1), (19-2), (20-1), (20-2), (21-1), and (21-2).

[0074] The number of lenses included in the second lens group G2 is preferably 2 or less. In this case, it is advantageous for weight reduction of the focus unit.

[0075] When the back focus of the entire system in terms of air equivalent distance is Bf, the imaging lens preferably satisfies the following conditional expression (22). Here, f and ω used are the same as f in conditional expression (1) and ω in conditional expression (3), respectively. Also, tan is the tangent. By ensuring that the corresponding value of conditional expression (22) does not fall below the lower limit, it is possible to suppress the back focus from becoming too short with respect to the size of the image circle, which is advantageous for reducing the diameter of the third lens group G3. By ensuring that the corresponding value of conditional expression (22) does not exceed the upper limit, it is possible to suppress the back focus from becoming too long with respect to the size of the image circle, which is advantageous for shortening the overall length of the lens system. To obtain better characteristics, it is more preferable for the imaging lens to satisfy the following conditional expression (22-1), and even more preferable to satisfy the following conditional expression (22-2). 1.5 < Bf / (f × tan ω) < 10 (22) 2 < Bf / (f × tan ω) < 7.5 (22-1) 2.5 < Bf / (f × tan ω) < 6 (22-2)

[0076] When the F-number of the entire system in the state of focusing on an infinite object is FNo, the imaging lens preferably satisfies the following conditional expression (23). When the aperture diameter of the aperture stop St is variable, FNo is the open F-number. Also, f used here is the same as f in conditional expression (1). By ensuring that the corresponding value of conditional expression (23) does not fall below the lower limit, the technology of the present disclosure can be applied to a lens system of appropriate size, so that the effect of weight reduction can be obtained. By ensuring that the corresponding value of conditional expression (23) does not exceed the upper limit, excessive enlargement of the lens system can be suppressed, enabling effective weight reduction. To obtain better characteristics, it is more preferable to satisfy the following conditional expression (23-1), and even more preferable to satisfy the following conditional expression (23-2). 45 < f / FNo < 80 (23) 50 < f / FNo < 75 (23 - 1) 55 < f / FNo < 60 (23 - 2)

[0077] It is preferable that a lens component having a positive refractive power and a positive lens are arranged in sequence from the object side to the image side of the first lens group G1 in the most continuous manner. In this case, it is advantageous for correcting spherical aberration.

[0078] When a lens component having a positive refractive power is arranged on the most object side of the first lens group G1, this lens component having a positive refractive power may be a cemented lens. In this case, it is advantageous for correcting axial chromatic aberration.

[0079] On the most object side of the first lens group G1, a cemented lens composed of a negative lens and a positive lens and having a positive refractive power as a whole may be arranged. In this configuration where a cemented lens composed of a negative lens and a positive lens is arranged on the most object side of the first lens group G1, when the refractive index of the positive lens of this cemented lens with respect to the d-line is N1p and the refractive index of the negative lens of this cemented lens with respect to the d-line is N1n, it is preferable that the imaging lens satisfies the following conditional expression (24). By satisfying the conditional expression (24), it is advantageous for correcting axial chromatic aberration. In order to obtain better characteristics, it is more preferable that the imaging lens satisfies the following conditional expression (24 - 1), and it is even more preferable that the imaging lens satisfies the following conditional expression (24 - 2). -0.5 < N1p - N1n < 0.35 (24) -0.35 < N1p - N1n < 0.25 (24 - 1) -0.28 < N1p - N1n < 0.18 (24 - 2)

[0080] In a configuration where a cemented lens composed of a negative lens and a positive lens is disposed on the most object side of the first lens group G1, when the Abbe number of the positive lens of this cemented lens based on the d-line is ν1p and the Abbe number of the negative lens of this cemented lens based on the d-line is ν1n, it is preferable that the imaging lens satisfies the following conditional expression (25). By satisfying the conditional expression (25), it becomes advantageous for correcting axial chromatic aberration. In order to obtain better characteristics, it is more preferable that the imaging lens satisfies the following conditional expression (25-1), and it is even more preferable that the imaging lens satisfies the following conditional expression (25-2). -45 < ν1p - ν1n < 0 (25) -35 < ν1p - ν1n < 0 (25-1) -25 < ν1p - ν1n < 0 (25-2)

[0081] In a configuration where a cemented lens composed of a negative lens and a positive lens is disposed on the most object side of the first lens group G1, when the partial dispersion ratio between the g-line and the F-line of the positive lens of this cemented lens is θ1p and the partial dispersion ratio between the g-line and the F-line of the negative lens of this cemented lens is θ1n, it is preferable that the imaging lens satisfies the following conditional expression (26). By satisfying the conditional expression (26), it becomes advantageous for correcting axial chromatic aberration. In order to obtain better characteristics, it is more preferable that the imaging lens satisfies the following conditional expression (26-1), and it is even more preferable that the imaging lens satisfies the following conditional expression (26-2). 0 < θ1p - θ1n < 0.15 (26) 0 < θ1p - θ1n < 0.1 (26-1) 0 < θ1p - θ1n < 0.05 (26-2)

[0082] In a configuration where a cemented lens composed of a negative lens and a positive lens is disposed on the most object side of the first lens group G1, it is even more preferable that the imaging lens simultaneously satisfies the conditional expressions (24), (25), and (26). In order to obtain better characteristics, it is even more preferable that the imaging lens simultaneously satisfies the conditional expressions (24), (25), and (26) and further satisfies at least one of the conditional expressions (24-1), (24-2), (25-1), (25-2), (26-1), and (26-2).

[0083] In a configuration where a lens component having a positive refractive power and a positive lens are arranged in sequence from the object side to the image side of the first lens group G1 in a continuous manner, it is preferable that the imaging lens satisfies the following conditional expression (27). Here, the Abbe number based on the d-line of the positive lens arranged continuously on the image side of the lens component having the above positive refractive power is designated as ν1Sp. By satisfying the conditional expression (27), it is advantageous for correcting the magnification chromatic aberration. In order to obtain better characteristics, it is more preferable that the imaging lens satisfies the following conditional expression (27-1), and it is even more preferable that the imaging lens satisfies the following conditional expression (27-2). 70 < ν1Sp < 100 (27) 80 < ν1Sp < 100 (27-1) 90 < ν1Sp < 100 (27-2)

[0084] The first lens group G1 may be configured such that two or more positive lenses are arranged in sequence from the object side to the image side in a continuous manner. In this case, it is advantageous for reducing the weight of the optical system.

[0085] In a configuration where two or more positive lenses are arranged in sequence from the object side to the image side of the first lens group G1 in a continuous manner, it is preferable that the imaging lens satisfies the following conditional expression (28). Here, the Abbe number based on the d-line of at least one of the two or more positive lenses arranged continuously above is designated as ν1pp. By satisfying the conditional expression (28), it is advantageous for correcting the axial chromatic aberration. In order to obtain better characteristics, it is more preferable that the imaging lens satisfies the following conditional expression (28-1), and it is even more preferable that the imaging lens satisfies the following conditional expression (28-2). 70 < ν1pp < 100 (28) 80 < ν1pp < 100 (28-1) 90 < ν1pp < 100 (28-2)

[0086] In a configuration where two or more positive lenses are arranged in sequence from the object side to the image side of the first lens group G1, it is preferable that the imaging lens satisfies the following conditional expression (29). Here, the proportion of the positive lenses satisfying the conditional expression (28) among the two or more positive lenses continuously arranged as described above in the first lens group G1 is defined as Sg. By satisfying the conditional expression (29), it is advantageous for weight reduction of the optical system. In order to obtain better characteristics, it is more preferable that the imaging lens satisfies the following conditional expression (29-1), and it is even more preferable that it satisfies the following conditional expression (29-2). 0 < Sg < 5 (29) 0 < Sg < 4.5 (29-1) 0 < Sg < 4 (29-2)

[0087] For good correction of axial chromatic aberration, it is preferable that the first lens group G1 includes one or more cemented lenses, and more preferably two or more. However, for improvement of productivity and design freedom, it is preferable that the number of cemented lenses included in the first lens group G1 is five or less, more preferably four or less, and even more preferably three or less. From the above circumstances, the number of cemented lenses included in the first lens group G1 is preferably one or more and five or less, more preferably two or more and four or less, and even more preferably two or more and three or less.

[0088] The first lens group G1 may be configured to include a compound aspherical lens. Since the first lens group G1, which is relatively likely to have a large lens diameter, includes a compound aspherical lens, it is advantageous for weight reduction.

[0089] In the configuration where the first lens group G1 includes a compound aspherical lens, when the distance on the optical axis from the surface on which the aspherical surface of the compound aspherical lens is formed to the aperture stop St is defined as dHAS, it is preferable that the imaging lens satisfies the following conditional expression (30). Here, TL used is the same as TL in conditional expression (1). By preventing the corresponding value of conditional expression (30) from falling below the lower limit, it is advantageous for correcting spherical aberration. By preventing the corresponding value of conditional expression (30) from exceeding the upper limit, it is advantageous for weight reduction. In order to obtain better characteristics, it is more preferable that the imaging lens satisfies the following conditional expression (30-1), and even more preferable that it satisfies the following conditional expression (30-2). 0.05 < dHAS / TL < 0.4 (30) 0.1 < dHAS / TL < 0.3 (30-1) 0.15 < dHAS / TL < 0.2 (30-2)

[0090] Note that the example shown in FIG. 1 is an example of the imaging lens of the present disclosure. The number of lenses constituting each group of the imaging lens of the present disclosure can be different from the example shown in FIG. 1. Each group of the imaging lens can be configured as follows, for example.

[0091] The number of lenses included in the first lens group G1 may be 6, may be 7, or may be 4.

[0092] The number of lenses included in the second lens group G2 may be 2. The second lens group G2 may be configured to be composed of one cemented lens. In that case, the second lens group G2 may be configured to be composed of a cemented lens in which a positive lens and a negative lens are cemented. The second lens group G2 may be configured to be composed of a positive lens and a negative lens in order from the object side to the image side.

[0093] The number of lenses included in the third lens group G3 may be 7 or may be 9. When the third lens group G3 is composed of the above-described third A lens group G3A and the third B lens group, the third A lens group G3A may be configured to include an anti-vibration group.

[0094] The number of lenses included in the anti-vibration group may be two. The anti-vibration group may be configured to consist of one cemented lens. In that case, the anti-vibration group may be configured to consist of a cemented lens in which a positive lens and a negative lens are cemented together. The anti-vibration group may be configured to consist of a positive lens and a negative lens in order from the object side to the image side.

[0095] The preferred configurations and possible configurations described above, including the configuration regarding the conditional expressions, can be combined arbitrarily, and it is preferable to be selectively adopted appropriately according to the required specifications. Note that the conditional expressions that the imaging lens of the present disclosure preferably satisfies are not limited to the conditional expressions described in the form of equations, and include all conditional expressions obtained by arbitrarily combining the lower limit and the upper limit from the conditional expressions described as preferable, more preferable, and even more preferable.

[0096] As an example, a preferred aspect of the present disclosure includes, in order from the object side to the image side, a first lens group G1 having a positive refractive power, an aperture stop St, a second lens group G2 having a positive refractive power, and a third lens group G3 having a negative refractive power. During focusing, the first lens group G1 and the third lens group G3 are fixed with respect to the image plane Sim, the second lens group G2 moves along the optical axis Z, and it is an imaging lens that satisfies the above conditional expressions (1), (2), and (3).

[0097] Next, examples of the imaging lens of the present disclosure will be described with reference to the drawings. Note that the reference numerals attached to the lenses in the cross-sectional views of each example are used independently for each example in order to avoid explanations due to an increase in the number of digits of the reference numerals and complication of the drawings. Therefore, even if common reference numerals are attached in the drawings of different examples, they are not necessarily common configurations.

[0098] [Example 1] A cross-sectional view of the configuration of the imaging lens of Example 1 is shown in FIG. 1. Since the illustration method and configuration are as described above, redundant explanations are partially omitted here. The imaging lens of Example 1 includes, in order from the object side to the image side, a first lens group G1 having a positive refractive power, an aperture stop St, a second lens group G2 having a positive refractive power, and a third lens group G3 having a negative refractive power. When focusing from an infinite object to the closest object, the second lens group G2 moves toward the object side, and the first lens group G1 and the third lens group G3 are fixed with respect to the image plane Sim.

[0099] Regarding the imaging lens of Example 1, the basic lens data is shown in Table 1, the specifications and variable surface intervals are shown in Table 2, and the aspherical coefficients are shown in Table 3. Table 1 is described as follows. In the column of Sn, the surface numbers are shown when the surface closest to the object side is taken as the first surface and the numbers are incremented one by one toward the image side. In the column of R, the curvature radius of each surface is shown. The sign of the curvature radius of a surface with a convex surface facing the object side is positive, and the sign of the curvature radius of a surface with a convex surface facing the image side is negative. In the column of D, the axial surface interval between each surface and the surface adjacent to it on the image side is shown. The value in the bottom row of D is the interval between the surface closest to the image side in the table and the image plane Sim. In the column of Nd, the refractive index with respect to the d-line of each component is shown. In the column of νd, the Abbe number based on the d-line of each component is shown. In the column of θgF, the partial dispersion ratio between the g-line and the F-line of each component is shown. Table 1 also shows the aperture stop St and the optical member PP. In the column of the surface number corresponding to the aperture stop St, the surface number and the phrase (St) are described.

[0100] In the column of materials in Table 1, the material name of each component and the name of its manufacturing company are shown with a period in between. Including the tables of the examples described later, in the column of materials, the manufacturing company names are shown approximately as follows. "CDGM" indicates Chengdu Guangming Optoelectronic Co., Ltd. "OHARA" indicates Ohara Corporation. "HOYA" indicates HOYA Corporation. "HIKARI" indicates Hikari Glass Co., Ltd. "NHG" indicates Hubei Xinhua Optoelectronic Information Materials Co., Ltd. "SUMITA" indicates Sumita Optical Glass Co., Ltd. "SCHOTT" indicates SCHOTT.

[0101] Table 2 shows the focal length f of the entire system, the back focus Bf at the air-equivalent distance of the entire system, the F-number FNo., and the maximum full angle of view 2ω. The values shown in Table 2 are those based on the d-line. The FNo. used in the above conditional expression, the FNo. in Table 2, and the FNo. in the aberration diagram described later are the same. The (°) in the column of 2ω indicates that the unit is degrees. In Table 2, the column of "Infinity" shows the values in the state of focusing on an infinite object, and the column of "Closest" shows the values in the state of focusing on the closest object. In the imaging lens of Example 1, the distance on the optical axis between the object and the image plane Sim in the state of focusing on the closest object is 2.2 m (meter), and this point is the same in the data of the aberration diagram described later.

[0102] In the basic lens data, an asterisk is attached to the surface number of the aspherical surface, and the numerical value of the paraxial curvature radius is described in the column of the curvature radius of the aspherical surface. In Table 3, the row of Sn shows the surface number of the aspherical surface, and the rows of KA and Am show the numerical values of the aspherical coefficients for each aspherical surface. Note that m in Am is an integer from 3 to 20. The "E±n" (n: integer) of the numerical value of the aspherical coefficient in Table 3 means "×10 ±n ". KA and Am are the aspherical coefficients in the aspherical formula represented by the following formula. Zd = C × h 2 / {1 + (1 - KA × C 2 × h 2 ) 1 / 2}+ ΣAm × h m However, Zd: Aspherical depth (the length of the perpendicular line dropped from the point on the aspherical surface with height h to the plane perpendicular to the optical axis Z passing through the intersection of the aspherical surface and the optical axis Z) h: Height (the distance from the optical axis Z to the lens surface) C: Reciprocal of the paraxial curvature radius KA, Am: Aspherical coefficients where Σ in the aspherical formula means the sum with respect to m.

[0103] In the data of each table, degrees are used as the unit of angle and mm (millimeter) is used as the unit of length. However, since the optical system can be used even if it is proportionally enlarged or reduced, other appropriate units can also be used. In addition, the numerical values rounded to a predetermined number of digits are described in each of the tables shown below.

[0104]

Table 1

[0105]

Table 2

[0106]

Table 3

[0107] Fig. 3 shows aberration diagrams of the imaging lens of Example 1. In Fig. 3, from left to right, spherical aberration, astigmatism, distortion, and longitudinal chromatic aberration are shown. In Fig. 3, the upper part marked with "infinity" shows aberration diagrams in the state of focusing on an object at infinity, and the lower part marked with "closest" shows aberration diagrams in the state of focusing on the closest object. In the spherical aberration diagram, the aberrations in the d-line, C-line, F-line, and g-line are shown by solid line, long dashed line, short dashed line, and dotted-dashed line, respectively. In the astigmatism diagram, the aberration in the sagittal direction of the d-line is shown by a solid line, and the aberration in the tangential direction of the d-line is shown by a short dashed line. In the distortion diagram, the aberration in the d-line is shown by a solid line. In the longitudinal chromatic aberration diagram, the aberrations in the C-line, F-line, and g-line are shown by long dashed line, short dashed line, and dotted-dashed line, respectively. In the spherical aberration diagram, the value of the F-number is shown after "FNo.=". In the other aberration diagrams, the value of the maximum semi-aperture angle is shown after "ω=".

[0108] The symbols, meanings, description methods, and illustration methods of the data related to Example 1 above are the same in the following examples unless otherwise specified, so repeated explanations will be omitted below. In addition, in the cross-sectional views of the following examples, the illustration of the rear group Gr is omitted.

[0109] [Example 2] A cross-sectional view of the configuration of the imaging lens of Example 2 is shown in FIG. 4. The imaging lens of Example 2 includes, in order from the object side to the image side along the optical axis Z, a first lens group G1 having a positive refractive power, an aperture stop St, a second lens group G2 having a positive refractive power, and a third lens group G3 having a negative refractive power. When focusing from an infinite object to the closest object, the second lens group G2 moves toward the object side, and the first lens group G1 and the third lens group G3 are fixed with respect to the image plane Sim.

[0110] The first lens group G1 includes, in order from the object side to the image side, a first A lens group G1A and a first B lens group G1B. The first A lens group G1A includes lenses L11 to L12 in order from the object side to the image side. The first B lens group G1B includes lenses L13 to L16 in order from the object side to the image side. The second lens group G2 includes lenses L21 to L22 in order from the object side to the image side. The third lens group G3 includes, in order from the object side to the image side, a third A lens group G3A and a third B lens group G3B. The third A lens group G3A includes lenses L31 to L35 in order from the object side to the image side. The third B lens group G3B includes lenses L36 to L37 in order from the object side to the image side. The anti-vibration group includes lenses L33 to L34.

[0111] Regarding the imaging lens of Example 2, the basic lens data is shown in Table 4, the specifications and variable surface intervals are shown in Table 5, the aspherical coefficients are shown in Table 6, and each aberration diagram is shown in FIG. 5. In FIG. 5, the upper part shows each aberration diagram in the state of focusing on an infinite object, and the lower part shows each aberration diagram in the state of focusing on the closest object. In the imaging lens of Example 2, the distance on the optical axis between the object and the image plane Sim in the state of focusing on the closest object is 3.2 m (meter).

[0112] [Table 4]

[0113] [Table 5]

[0114]

Table 6

[0115] [Example 3] A cross-sectional view of the configuration of the imaging lens of Example 3 is shown in FIG. 6. The imaging lens of Example 3 includes, in order from the object side to the image side along the optical axis Z, a first lens group G1 having a positive refractive power, an aperture stop St, a second lens group G2 having a positive refractive power, and a third lens group G3 having a negative refractive power. When focusing from an infinite object to the closest object, the second lens group G2 moves toward the object side, and the first lens group G1 and the third lens group G3 are fixed with respect to the image plane Sim.

[0116] The first lens group G1 includes, in order from the object side to the image side, a first A lens group G1A and a first B lens group G1B. The first A lens group G1A includes lenses L11 to L13 in order from the object side to the image side. The first B lens group G1B includes lenses L14 to L17 in order from the object side to the image side. The second lens group G2 includes lenses L21 to L22 in order from the object side to the image side. The third lens group G3 includes, in order from the object side to the image side, a third A lens group G3A and a third B lens group G3B. The third A lens group G3A includes lenses L31 to L35 in order from the object side to the image side. The third B lens group G3B includes lenses L36 to L37 in order from the object side to the image side. The anti-vibration group includes lenses L33 to L34.

[0117] Regarding the imaging lens of Example 3, the basic lens data is shown in Table 7, the specifications and variable surface intervals are shown in Table 8, the aspherical coefficients are shown in Table 9, and each aberration diagram is shown in FIG. 7. In FIG. 7, the upper row shows each aberration diagram in the state of focusing on an infinite object, and the lower row shows each aberration diagram in the state of focusing on the closest object. In the imaging lens of Example 3, the distance on the optical axis between the object and the image plane Sim in the state of focusing on the closest object is 3.2 m (meter).

[0118]

Table 7

[0119]

Table 8

[0120]

Table 9

[0121] [Example 4] Fig. 8 shows a cross-sectional view of the configuration of the imaging lens of Example 4. The imaging lens of Example 4 includes, in order from the object side to the image side along the optical axis Z, a first lens group G1 having a positive refractive power, an aperture stop St, a second lens group G2 having a positive refractive power, and a third lens group G3 having a negative refractive power. When focusing from an infinite object to the closest object, the second lens group G2 moves toward the object side, and the first lens group G1 and the third lens group G3 are fixed with respect to the image plane Sim.

[0122] The first lens group G1 includes, in order from the object side to the image side, a first A lens group G1A and a first B lens group G1B. The first A lens group G1A includes lenses L11 to L13 in order from the object side to the image side. The first B lens group G1B includes lenses L14 to L17 in order from the object side to the image side. The second lens group G2 includes lenses L21 to L22 in order from the object side to the image side. The third lens group G3 includes, in order from the object side to the image side, a third A lens group G3A and a third B lens group G3B. The third A lens group G3A includes lenses L31 to L35 in order from the object side to the image side. The third B lens group G3B includes lenses L36 to L37 in order from the object side to the image side. The anti-vibration group includes lenses L33 to L34.

[0123] Regarding the imaging lens of Example 4, the basic lens data is shown in Table 10, the specifications and variable surface intervals are shown in Table 11, the aspherical coefficients are shown in Table 12, and each aberration diagram is shown in Fig. 9. In Fig. 9, the upper row shows each aberration diagram in the state of focusing on an infinite object, and the lower row shows each aberration diagram in the state of focusing on the closest object. In the imaging lens of Example 4, the distance on the optical axis between the object and the image plane Sim in the state of focusing on the closest object is 3.2 m (meter).

[0124]

Table 10

[0125]

Table 11

[0126]

Table 12

[0127] [Example 5] A cross-sectional view of the configuration of the imaging lens of Example 5 is shown in FIG. 10. The imaging lens of Example 5 includes, in order from the object side to the image side along the optical axis Z, a first lens group G1 having a positive refractive power, an aperture stop St, a second lens group G2 having a positive refractive power, and a third lens group G3 having a negative refractive power. When focusing from an infinite object to the closest object, the second lens group G2 moves toward the object side, and the first lens group G1 and the third lens group G3 are fixed with respect to the image plane Sim.

[0128] The first lens group G1 includes, in order from the object side to the image side, a first A lens group G1A and a first B lens group G1B. The first A lens group G1A includes, in order from the object side to the image side, lenses L11 to L13. The first B lens group G1B includes, in order from the object side to the image side, lenses L14 to L17. The second lens group G2 includes, in order from the object side to the image side, lenses L21 to L22. The third lens group G3 includes, in order from the object side to the image side, a third A lens group G3A and a third B lens group G3B. The third A lens group G3A includes, in order from the object side to the image side, lenses L31 to L35. The third B lens group G3B includes, in order from the object side to the image side, lenses L36 to L37. The anti-vibration group includes lenses L33 to L34.

[0129] For the imaging lens of Example 5, the basic lens data is shown in Table 13, the specifications and variable surface intervals are shown in Table 14, the aspherical coefficients are shown in Table 15, and each aberration diagram is shown in FIG. 11. In FIG. 11, the upper row shows each aberration diagram in the state of focusing on an infinite object, and the lower row shows each aberration diagram in the state of focusing on the closest object. In the imaging lens of Example 5, the distance on the optical axis between the object and the image plane Sim in the state of focusing on the closest object is 3.3 m (meter).

[0130]

Table 13

[0131]

Table 14

[0132]

Table 15

[0133] [Example 6] A cross-sectional view of the configuration of the imaging lens of Example 6 is shown in FIG. 12. The imaging lens of Example 6 includes, in order from the object side to the image side along the optical axis Z, a first lens group G1 having a positive refractive power, an aperture stop St, a second lens group G2 having a positive refractive power, and a third lens group G3 having a negative refractive power. When focusing from an infinite object to the closest object, the second lens group G2 moves toward the object side, and the first lens group G1 and the third lens group G3 are fixed with respect to the image plane Sim.

[0134] The first lens group G1 consists of a first A lens group G1A and a first B lens group G1B in order from the object side to the image side. The first A lens group G1A consists of lenses L11 to L13 in order from the object side to the image side. The first B lens group G1B consists of lenses L14 to L16 in order from the object side to the image side. The lens L14 is a compound aspherical lens. The second lens group G2 consists of lenses L21 to L22 in order from the object side to the image side. The third lens group G3 consists of a third A lens group G3A and a third B lens group G3B in order from the object side to the image side. The third A lens group G3A consists of lenses L31 to L35 in order from the object side to the image side. The third B lens group G3B consists of lenses L36 to L37 in order from the object side to the image side. The anti-vibration group consists of lenses L33 to L34.

[0135] Regarding the imaging lens of Example 6, the basic lens data is shown in Table 16, the specifications and variable surface intervals are shown in Table 17, the aspherical coefficients are shown in Table 18, and each aberration diagram is shown in FIG. 13. In FIG. 13, the upper part shows each aberration diagram in the state of focusing on an infinite object, and the lower part shows each aberration diagram in the state of focusing on the closest object. In the imaging lens of Example 6, the distance on the optical axis between the object and the image plane Sim in the state of focusing on the closest object is 3.3 m (meters).

[0136] [Table 16]

[0137] [Table 17]

[0138] [Table 18]

[0139] [Example 7] A cross-sectional view of the configuration of the imaging lens according to Example 7 is shown in FIG. 14. The imaging lens according to Example 7 includes, in order from the object side to the image side along the optical axis Z, a first lens group G1 having a positive refractive power, an aperture stop St, a second lens group G2 having a positive refractive power, and a third lens group G3 having a negative refractive power. When focusing from an infinite object to the closest object, the second lens group G2 moves toward the object side, and the first lens group G1 and the third lens group G3 are fixed with respect to the image plane Sim.

[0140] The first lens group G1 includes, in order from the object side to the image side, a first A lens group G1A and a first B lens group G1B. The first A lens group G1A includes lenses L11 to L13 in order from the object side to the image side. The first B lens group G1B includes lenses L14 to L16 in order from the object side to the image side. The second lens group G2 includes lenses L21 to L22 in order from the object side to the image side. The third lens group G3 includes, in order from the object side to the image side, a third A lens group G3A and a third B lens group G3B. The third A lens group G3A includes lenses L31 to L35 in order from the object side to the image side. The third B lens group G3B includes lenses L36 to L37 in order from the object side to the image side. The lens L31 is a compound aspherical lens. The anti-vibration group includes lenses L33 to L34.

[0141] Regarding the imaging lens of Example 7, the basic lens data is shown in Table 19, the specifications and variable surface intervals are shown in Table 20, the aspherical coefficients are shown in Table 21, and each aberration diagram is shown in FIG. 15. In FIG. 15, the upper row shows each aberration diagram in the state of focusing on an infinite object, and the lower row shows each aberration diagram in the state of focusing on the closest object. In the imaging lens of Example 7, the distance on the optical axis between the object and the image plane Sim in the state of focusing on the closest object is 3.3 m (meter).

[0142]

Table 19

[0143]

Table 20

[0144]

Table 21

[0145] [Example 8] A cross-sectional view of the configuration of the imaging lens of Example 8 is shown in FIG. 16. The imaging lens of Example 8 includes, in order from the object side to the image side along the optical axis Z, a first lens group G1 having a positive refractive power, an aperture stop St, a second lens group G2 having a positive refractive power, and a third lens group G3 having a negative refractive power. When focusing from an infinite object to the closest object, the second lens group G2 moves toward the object side, and the first lens group G1 and the third lens group G3 are fixed with respect to the image plane Sim.

[0146] The first lens group G1 includes, in order from the object side to the image side, a first A lens group G1A and a first B lens group G1B. The first A lens group G1A includes lenses L11 to L13 in order from the object side to the image side. The first B lens group G1B includes lenses L14 to L16 in order from the object side to the image side. The second lens group G2 includes lenses L21 to L22 in order from the object side to the image side. The third lens group G3 includes, in order from the object side to the image side, a third A lens group G3A and a third B lens group G3B. The third A lens group G3A includes lenses L31 to L35 in order from the object side to the image side. The third B lens group G3B includes lenses L36 to L37 in order from the object side to the image side. The lens L31 is a compound aspherical lens. The anti-vibration group includes lenses L33 to L34.

[0147] Regarding the imaging lens of Example 8, the basic lens data is shown in Table 22, the specifications and variable surface intervals are shown in Table 23, the aspherical coefficients are shown in Table 24, and each aberration diagram is shown in FIG. 17. In FIG. 17, the upper row shows each aberration diagram in the state of focusing on an infinite object, and the lower row shows each aberration diagram in the state of focusing on the closest object. In the imaging lens of Example 8, the distance on the optical axis between the object and the image plane Sim in the state of focusing on the closest object is 4.8 m (meters).

[0148]

Table 22

[0149]

Table 23

[0150]

Table 24

[0151] [Example 9] A cross-sectional view of the configuration of the imaging lens of Example 9 is shown in FIG. 18. The imaging lens of Example 9 includes, in order from the object side to the image side along the optical axis Z, a first lens group G1 having a positive refractive power, an aperture stop St, a second lens group G2 having a positive refractive power, and a third lens group G3 having a negative refractive power. When focusing from an infinite object to the closest object, the second lens group G2 moves toward the object side, and the first lens group G1 and the third lens group G3 are fixed with respect to the image plane Sim.

[0152] The first lens group G1 includes, in order from the object side to the image side, a first A lens group G1A and a first B lens group G1B. The first A lens group G1A includes lenses L11 to L12 in order from the object side to the image side. The first A lens group G1A also includes a diffractive optical surface DOE. The first B lens group G1B consists of lenses L13 to L14 in order from the object side to the image side. The second lens group G2 consists of lenses L21 to L22 in order from the object side to the image side. The third lens group G3 includes, in order from the object side to the image side, a third A lens group G3A and a third B lens group G3B. The third A lens group G3A consists of lenses L31 to L35 in order from the object side to the image side. The third B lens group G3B consists of lenses L36 to L39 in order from the object side to the image side. The anti-vibration group consists of lenses L33 to L34.

[0153] For the imaging lens of Example 9, the basic lens data is shown in Table 25, the specifications and variable surface intervals are shown in Table 26, the aspherical coefficients are shown in Table 27, the phase difference coefficients are shown in Table 28, and each aberration diagram is shown in FIG. 19. In FIG. 19, the upper row shows each aberration diagram in the state of focusing on an infinite object, and the lower row shows each aberration diagram in the state of focusing on the closest object. In the imaging lens of Example 9, the distance on the optical axis between the object and the image plane Sim in the state of focusing on the closest object is 3.3 m (meter).

[0154] In Table 25, the surface numbers of the diffractive optical surface DOE are marked with a ♯. In Table 28, the column of Sn shows the surface numbers of the diffractive optical surface DOE, and the columns of B2, B4, B6, B8, and B10 show the numerical values of the phase difference coefficients of the diffractive optical surface DOE. The "E-n" (n: integer) of the numerical values of the phase difference coefficients in Table 28 means "×10 -n ". The shape of the diffractive optical surface DOE is determined by the following phase difference function Φ(h). B2, B4, B6, B8, and B10 are the phase difference coefficients in the following phase difference function Φ(h). The h in the following formula is the height from the optical axis Z. Φ(h)=B2×h 2 +B4×h 4 +B6×h 6 +B8×h 8 +B10×h 10

[0155]

Table 25

[0156]

Table 26

[0157]

Table 27

[0158]

Table 28

[0159] Tables 29 and 30 show the corresponding values of conditional expressions (1) to (30) of the imaging lenses of Examples 1 to 9.

[0160]

Table 29

[0161]

Table 30

[0162] The imaging lenses of Examples 1 to 9 are of a telephoto lens system, yet are configured to be small and lightweight, and further, various aberrations are well corrected to achieve high optical performance.

[0163] Next, an imaging device according to an embodiment of the present disclosure will be described. FIGS. 20 and 21 show external views of a camera 30 which is an imaging device according to an embodiment of the present disclosure. FIG. 20 shows a perspective view of the camera 30 as seen from the front side, and FIG. 21 shows a perspective view of the camera 30 as seen from the back side. The camera 30 is a so-called mirrorless type digital camera, and an interchangeable lens 20 can be detachably attached thereto. The interchangeable lens 20 is configured to include an imaging lens 1 according to an embodiment of the present disclosure housed in a lens barrel.

[0164] The camera 30 includes a camera body 31, and a shutter button 32 and a power button 33 are provided on the upper surface of the camera body 31. Further, an operation unit 34, an operation unit 35, and a display unit 36 are provided on the back surface of the camera body 31. The display unit 36 can display an image taken and an image within the angle of view before being taken.

[0165] A photographing aperture through which light from a photographing object enters is provided at the center of the front surface of the camera body 31, and a mount 37 is provided at a position corresponding to the photographing aperture, and the interchangeable lens 20 is attached to the camera body 31 via the mount 37.

[0166] Inside the camera body 31, there are provided an imaging device such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) that outputs an imaging signal corresponding to the subject image formed by the interchangeable lens 20, a signal processing circuit that processes the imaging signal output from the imaging device to generate an image, and a recording medium for recording the generated image. In the camera 30, it is possible to take a still image or a moving image by pressing the shutter button 32, and the image data obtained by this shooting is recorded on the above recording medium.

[0167] As described above, the technology of the present disclosure has been described with reference to the embodiments and examples. However, the technology of the present disclosure is not limited to the above embodiments and examples, and various modifications are possible. For example, the radius of curvature, the spacing between surfaces, the refractive index, the Abbe number, and the aspherical coefficient of each lens are not limited to the values shown in the above examples, and other values can be taken.

[0168] Also, the imaging device according to the embodiment of the present disclosure is not limited to the above example. For example, it can be in various forms such as a camera other than the mirrorless type, a film camera, and a video camera.

Explanation of Reference Numerals

[0169] 1 Imaging lens 2 On-axis light beam 3 Light beam of the maximum angle of view 4 On-axis light beam 5 Light beam of the maximum angle of view 20 Interchangeable lens 30 Camera 31 Camera body 32 Shutter button 33 Power button 34 Operation unit 35 Operation unit 36 Display unit 37 Mount dair Air spacing dSpmax Distance DOE Diffractive optical surface G1 First lens group G1A Group 1A lens unit G1B Group 1B lens unit G2 Group 2 lens unit G3 Group 3 lens unit G3A Group 3A lens unit G3B Group 3B lens unit Gr Rear group L11~L39 Lenses PP Optical member Sim Image plane St Aperture stop Z Optical axis Δd Distance ω Maximum semi-aperture angle

Claims

1. It consists of a first lens group having a positive refractive power, an aperture stop, a second lens group having a positive refractive power, and a third lens group having a negative refractive power, in order from the object side to the image side. During focusing, the first lens group and the third lens group are fixed with respect to the image plane, and the second lens group moves along the optical axis. The third lens group consists of a third A lens group and a third B lens group, which is separated from the third A lens group by the longest air interval on the optical axis within the third lens group, in order from the object side to the image side. The third A lens group includes two or more negative lenses and two or more positive lenses. Let TL be the sum of the distance on the optical axis from the most object-side lens surface of the first lens group to the most image-side lens surface of the third lens group and the back focus of the entire system in terms of air-equivalent distance. Let f be the focal length of the entire system in the state of focusing on an infinite object. Let f1 be the focal length of the first lens group. Let ω be the maximum half-angle of view in the state of focusing on an infinite object. Let f3A be the focal length of the third A lens group. Let f3B be the focal length of the third B lens group. When the unit of ω is degrees, 0 < TL / f < 0.64 (1) 1.5 < f / f1 < 5 (2) 0 < ω < 4 (3) −0.3 < f3A / f3B < 4 (12) An imaging lens that satisfies the conditional expressions (1), (2), (3), and (12) represented by these.

2. The first lens group includes a diffractive optical surface. When the distance on the optical axis from the diffractive optical surface to the aperture stop is dDOE, 0.1 < dDOE / TL < 0.5 (4) The imaging lens according to Claim 1, which satisfies the conditional expression (4) represented by this.

3. The imaging lens according to Claim 1, in which two or more positive lenses are arranged continuously in order from the most object side of the first lens group.

4. When the focal length of the second lens group is f2, 0 < f / f2 < 6 (5) The imaging lens according to any one of Claims 1 to 3, which satisfies the conditional expression (5) represented by this.

5. When the focal length of the third lens group is f3, −30 < f / f3 < 0 (6) The imaging lens according to any one of Claims 1 to 4, which satisfies the conditional expression (6) represented by this.

6. When the distance on the optical axis between the object-side surface of the positive lens having the strongest refractive power among the positive lenses arranged on the image side of the aperture stop and the object-side surface of the negative lens having the strongest refractive power among the negative lenses arranged on the image side of the aperture stop is Δd, 0 < Δd / TL < 0.3 (7) The imaging lens according to any one of claims 1 to 5, which satisfies the conditional expression (7) represented by

7. When the distance on the optical axis from the aperture to the object-side surface of the positive lens having the strongest refractive power among the positive lenses disposed on the image side of the aperture is defined as dSpmax, 0.05 < dSpmax / TL < 0.6 (8) The imaging lens according to any one of claims 1 to 6, which satisfies the conditional expression (8) represented by

8. When the longest air gap on the optical axis within the first lens group is defined as dair, 0.01 < dair / TL < 0.25 (9) The imaging lens according to any one of claims 1 to 7, which satisfies the conditional expression (9) represented by

9. The first lens group includes, in order from the object side to the image side, a first A lens group having a positive refractive power, and is separated from the first A lens group by the longest air gap on the optical axis within the first lens group and consists of a first B lens group having a negative refractive power, When the focal length of the first A lens group is f1A, and the focal length of the first B lens group is f1B, -2.5 < f1A / f1B < 0 (10) The imaging lens according to claim 8, which satisfies the conditional expression (10) represented by

10. The first lens group includes, in order from the object side to the image side, a first A lens group having a positive refractive power, and is separated from the first A lens group by the longest air gap on the optical axis within the first lens group and consists of a first B lens group having a negative refractive power, The first B lens group includes a first lens pair consisting of a positive lens and a negative lens adjacent to each other, When the Abbe number based on the d line of the positive lens of the first lens pair is ν1Bp, 40 < ν1Bp < 100 (11) The imaging lens according to claim 8 or 9, which satisfies the conditional expression (11) represented by

11. The third lens group includes an anti-vibration group that moves in a direction intersecting the optical axis during image blur correction, When the focal length of the anti-vibration group is fis, 2.5 < f / |fis| < 30 (13) The imaging lens according to any one of claims 1 to 10, which satisfies the conditional expression (13) represented by

12. The third lens group includes a rear group having a positive refractive power on the image side of the anti-vibration group, When the focal length of the rear group is fr, 2.5 < f / fr < 25 (14) The imaging lens according to claim 11, which satisfies the conditional expression (14) represented by

13. When one lens component is a single lens or a cemented lens, a lens component having a negative refractive power is disposed between the second lens group and the anti-shake group. When the refractive index of the negative lens included in the lens component having a negative refractive power with respect to the d-line is N3Cn, 1.75 < N3Cn < 2.2 (15) The imaging lens according to claim 11 or 12, which satisfies the conditional expression (15) represented by

14. The anti-shake group includes a second lens pair including a positive lens and a negative lens adjacent to each other. The refractive index of the positive lens of the second lens pair with respect to the d-line is N3p, The refractive index of the negative lens of the second lens pair with respect to the d-line is N3n, The Abbe number of the positive lens of the second lens pair based on the d-line is ν3p, The Abbe number of the negative lens of the second lens pair based on the d-line is ν3n, The partial dispersion ratio between the g-line and the F-line of the positive lens of the second lens pair is θ3p, When the partial dispersion ratio between the g-line and the F-line of the negative lens of the second lens pair is θ3n, -0.15 < N3p - N3n < 0.5 (16) -40 < ν3p - ν3n < -5 (17) 0 < θ3p - θ3n < 0.1 (18) The imaging lens according to any one of claims 11 to 13, which satisfies the conditional expressions (16), (17), and (18) represented by

15. The second lens group includes a third lens pair including a positive lens and a negative lens adjacent to each other. The refractive index of the positive lens of the third lens pair with respect to the d-line is N2p, The refractive index of the negative lens of the third lens pair with respect to the d-line is N2n, The Abbe number of the positive lens of the third lens pair based on the d-line is ν2p, The Abbe number of the negative lens of the third lens pair based on the d-line is ν2n, The partial dispersion ratio between the g-line and the F-line of the positive lens of the third lens pair is θ2p, When the partial dispersion ratio between the g-line and the F-line of the negative lens of the third lens pair is θ2n, -0.6 < N2p - N2n < 0 (19) -10 < ν2p - ν2n < 30 (20) -0.15 < θ2p - θ2n < 0.1 (21) The imaging lens according to any one of claims 1 to 14, which satisfies the conditional expressions (19), (20), and (21) represented by

16. When the back focus of the entire system in terms of air equivalent distance is Bf, 1.5 < Bf / (f × tan ω) < 10 (22) The imaging lens according to any one of claims 1 to 15, which satisfies the conditional expression (22) represented by

17. When the distance on the optical axis between the object-side surface of the positive lens having the strongest refractive power among the positive lenses arranged on the image side of the aperture and the object-side surface of the negative lens having the strongest refractive power among the negative lenses arranged on the image side of the aperture is defined as Δd, 0 < Δd / TL < 0.25 (7-1) The imaging lens according to any one of claims 1 to 16, which satisfies the conditional expression (7-1) represented by the above.

18. An imaging device including the imaging lens according to any one of claims 1 to 17.

Images