CN113267875A

CN113267875A - Imaging lens and imaging device

Info

Publication number: CN113267875A
Application number: CN202110114338.XA
Authority: CN
Inventors: 河村大树; 长伦生
Original assignee: Fujifilm Corp
Current assignee: Fujifilm Corp
Priority date: 2020-01-29
Filing date: 2021-01-27
Publication date: 2021-08-17
Also published as: JP7203811B2; JP2021117492A

Abstract

The invention provides an imaging lens with small F value and good correction of each aberration and an imaging device with the imaging lens. The imaging lens includes, as lens groups, a positive 1 st lens group and a positive 2 nd lens group in this order from the most object side. Upon focusing, the interval between the 1 st lens group and the 2 nd lens group changes. The diaphragm is disposed on the image side of the 2 nd lens from the object side. The combined refractive power of all lenses on the object side of the diaphragm is positive. The imaging lens includes a LA positive lens and a LB positive lens which satisfy a predetermined conditional expression on the object side of the diaphragm. The abbe number of the LB positive lens is largest among the abbe numbers of all positive lenses on the object side from the diaphragm.

Description

Imaging lens and imaging device

Technical Field

The present invention relates to an imaging lens and an imaging apparatus.

Background

Conventionally, as an imaging lens that can be used in an imaging device such as a digital camera, imaging lenses described in patent document 1 and patent document 2 below are known.

Patent document 1: japanese patent laid-open publication No. 2015-141384

Patent document 2: japanese patent laid-open publication No. 2016-173398

In recent years, an appropriate imaging lens having a small F value and excellent correction of each aberration has been demanded.

Disclosure of Invention

The present invention has been made in view of the above circumstances, and an object thereof is to provide an imaging lens having a small F value and suitable for correcting aberrations well, and an imaging apparatus including the imaging lens.

An imaging lens of the present invention includes, as lens groups, a 1 st lens group having a positive refractive power and a 2 nd lens group having a refractive power in order from the most object side to the image side, wherein, in focusing, an interval between the 1 st lens group and the 2 nd lens group changes, and intervals between all lenses in the 1 st lens group and intervals between all lenses in the 2 nd lens group are constant, a diaphragm is disposed on the image side of the 2 nd lens from the object side, a combined refractive power of all lenses on the object side of the diaphragm is positive, at least one LA lens and at least one LB lens are included on the object side of the diaphragm, a d-line-based abbe number of the LB lens is largest among d-line-based abbe numbers of all positive lenses on the object side of the diaphragm, a refractive index of the LA positive lens with respect to d-line is NdA, and a d-line-based abbe number of the LA lens is vddA, When the d-line reference abbe number of the LB positive lens is set to v dB, the imaging lens satisfies the following conditional expressions (1), (2) and (3).

1.86＜NdA＜2.2 (1)

10＜v dA＜35 (2)

57＜v dB＜105 (3)

Preferably, the imaging lens of the present invention satisfies at least one of the following conditional expressions (1-1), (2-1), and (3-1).

1.88＜NdA＜2.15 (1-1)

13.5＜ν dA＜31 (2-1)

62＜ν dB＜92 (3-1)

Preferably, the 1 st lens group includes at least two positive lenses and at least two negative lenses.

Preferably, the 2 nd lens group includes at least two positive lenses and at least two negative lenses.

Preferably, in focusing, the 1 st lens group is fixed with respect to the image plane, and the 2 nd lens group is moved.

Preferably, there is only one lens group that moves in focus. In this case, it is preferable that only the 2 nd lens group is a lens group which moves in focusing.

Preferably, the 1 st lens group includes at least two negative lenses, and the imaging lens of the present invention satisfies the following conditional expression (4), more preferably the following conditional expression (4-1), when an average value of d-line-based abbe numbers of the two negative lenses selected in order of increasing d-line-based abbe numbers among the negative lenses included in the 1 st lens group is v dn 1.

15＜ν dn1＜28 (4)

16＜ν dn1＜25 (4-1)

Preferably, the 1 st lens group is fixed with respect to an image plane in focusing, and the 1 st lens group includes at least one LA positive lens.

Preferably, the imaging lens of the present invention satisfies the following conditional expression (5) when TL is the sum of the distance on the optical axis from the most object-side lens surface to the most image-side lens surface in the state of focusing on an infinity object and the back focal length in terms of an air-converted distance, FNo is the F value of the imaging lens in the state of focusing on an infinity object, and F is the focal length of the imaging lens in the state of focusing on an infinity object.

1.5＜TL×FNo/f＜5 (5)

Preferably, the imaging lens of the present invention includes, as lens groups, in order from the object side to the image side, only two lens groups including a 1 st lens group fixed to the image surface in focusing and a 2 nd lens group moving in focusing, or includes, in order from the object side to the image side, only three lens groups including a 1 st lens group fixed to the image surface in focusing, a 2 nd lens group moving in focusing and a 3 rd lens group composed of two or less lenses fixed to the image surface in focusing.

The 2 nd lens group may be configured as a lens group having positive refractive power.

Preferably, the 1 st lens group includes at least three negative lenses.

Preferably, the 2 nd lens group includes at least two positive lenses and at least three negative lenses.

In the imaging lens of the present invention, when one lens component is a single lens or a single cemented lens, one lens component of the most object-side lens component and the 2 nd lens component from the object side has a negative refractive power and the other lens component has a positive refractive power, and in a state of focusing on an object at infinity, an on-axis light flux emitted from the most image-side lens surface of the one lens component having a negative refractive power toward the image side may be divergent light.

Preferably, at least one of the most object-side lens and the 2 nd lens from the object side is a negative lens having a concave lens surface on the object side.

Preferably, the most object side lens is a negative lens.

Preferably, the imaging lens of the present invention includes, in order from the most object side, a single lens having a negative refractive power, a single lens having a positive refractive power, and a single lens having a positive refractive power.

Preferably, the object side lens surface of the most object side lens is concave.

Preferably, the imaging lens of the present invention includes at least one LC positive lens on the object side from the diaphragm, the LC positive lens being a positive lens having a maximum or 2 nd-largest d-line-reference abbe number among all positive lenses on the object side from the diaphragm, and the following conditional expression (6) is satisfied where the d-line-reference abbe number of the LC positive lens is denoted by v dC.

57＜v dC＜102 (6)

Preferably, the imaging lens of the present invention satisfies the following conditional expression (7) when the minimum value of the refractive index of all positive lenses on the object side with respect to the d-line with respect to the diaphragm is Ndfm.

1.46＜Ndfm＜1.72 (7)

Preferably, the diaphragm is disposed in a lens group fixed with respect to the image plane at the time of focusing, or disposed between the lens group and the lens group.

Preferably, the stop is disposed between the 1 st lens group and the 2 nd lens group, and the 1 st lens group and the stop are fixed with respect to the image plane and the 2 nd lens group is moved during focusing.

Preferably, the 2 nd lens group moves in focusing, and the number of lenses included in the 2 nd lens group is 7 or less, more preferably 6 or less, and further preferably 5 or less.

The number of lenses disposed on the object side of the diaphragm is preferably 8 or less, and more preferably 7 or less.

Preferably, the imaging lens of the present invention includes 13 or less lenses, and more preferably 12 or less lenses.

Preferably, the imaging lens of the present invention includes at least two positive lenses on the image side of the aperture stop, and the following conditional expression (8) is satisfied when an average value of refractive indices of all the positive lenses on the image side of the aperture stop with respect to the d-line is Ndpr.

1.77＜Ndpr＜2.15 (8)

Preferably, the 2 Nd lens group moves in focusing, the 2 Nd lens group includes at least one positive lens, and the imaging lens of the present invention satisfies the following conditional expression (9) when an average value of refractive indexes of all the positive lenses in the 2 Nd lens group with respect to the d-line is Nd2 p.

1.7＜Nd2p＜2.2 (9)

Preferably, the 2 nd lens group moves upon focusing, and the 2 nd lens group includes at least two cemented lenses.

Preferably, three positive lenses are arranged in series in the 1 st lens group. More preferably, 4 positive lenses are arranged continuously in the 1 st lens group.

Preferably, the imaging lens of the present invention satisfies the following conditional expression (10) with f1 as the focal length of the 1 st lens group and f as the focal length of the imaging lens in a state of focusing on an object at infinity.

0.5＜f1/f＜3.5 (10)

Preferably, the imaging lens of the present invention satisfies the following conditional expression (11) when ω max is a maximum half angle of view of the imaging lens in a state focused on an infinitely distant object, and FNo is an F value of the imaging lens in a state focused on an infinitely distant object.

1.8＜1/{tan(ωmax)×FNo}＜4.5 (11)

Preferably, the 2 nd lens group moves at the time of focusing, and when a focal length of the 2 nd lens group is f2 and a focal length of the imaging lens in a state of focusing on an object at infinity is f, the imaging lens of the present invention satisfies the following conditional expression (12).

0.3＜|f2|/f＜2.2 (12)

Preferably, the imaging lens of the present invention satisfies the following conditional expression (13) when the focal length of the 1 st lens group is f1 and the focal length of the 2 nd lens group is f 2.

1＜f1/f2＜5 (13)

Preferably, the 2 nd lens group is moved at the time of focusing, and when a lateral magnification of the 2 nd lens group in a state of focusing on an object at infinity is β 2, a combined lateral magnification of all lenses on the image side of the 2 nd lens group in a state of focusing on an object at infinity when lenses are arranged on the image side of the 2 nd lens group is β r, and β r is not 1 when lenses are arranged on the image side of the 2 nd lens group, the imaging lens of the present invention satisfies the following conditional expression (14).

0.3＜|(1-β2²)×βr²|＜1.5 (14)

Preferably, the imaging lens of the present invention satisfies the following conditional expression (15) when Tf is an optical-axis distance from a most object-side lens surface to a stop in a state of focusing on an object at infinity, and TL is a sum of an optical-axis distance from the most object-side lens surface to a most image-side lens surface in a state of focusing on an object at infinity and a back focal length in terms of an air-converted distance.

0.2＜Tf/TL＜0.65 (15)

Preferably, the 1 st lens group includes, in order from the most object side, a 1 st unit having a negative refractive power and a 2 nd unit having a positive refractive power which is separated from the 1 st unit by a maximum air space on the optical axis in the 1 st lens group, the 2 nd unit includes one single lens or one cemented lens, and the imaging lens of the present invention satisfies the following conditional expression (16) when a focal length of the imaging lens in a state focused on an infinity object is f and a combined focal length of all lenses on the image side of the 2 nd unit in the imaging lens in a state focused on an infinity object is fm.

0.7＜f/fm＜0.98 (16)

Preferably, when the 1 st lens group includes the 1 st unit and the 2 nd unit, the 1 st unit includes one negative lens and the 2 nd unit includes one positive lens.

Preferably, the imaging lens of the present invention satisfies the following conditional expression (17) when the partial dispersion ratio between the g-line and the F-line of the LA positive lens is θ gFA.

0.01＜θgFA+0.00162×v dA-0.64159＜0.06 (17)

Preferably, the imaging lens of the present invention satisfies the following conditional expression (18) with the partial dispersion ratio between the g-line and the F-line of the LB positive lens set to θ gFB.

0.01＜θgFB+0.00162×v dB-0.64159＜0.05 (18)

Preferably, the 1 st lens group includes at least two negative lenses, and the imaging lens of the present invention satisfies the following conditional expression (19) when an average value of d-line reference abbe numbers of the two negative lenses selected in order of decreasing d-line reference abbe numbers among the negative lenses included in the 1 st lens group is denoted by v dn1, and an average value of partial dispersion ratios between g-line and F-line of the two negative lenses selected in order of decreasing d-line reference abbe numbers among the negative lenses included in the 1 st lens group is denoted by θ gFn 1.

0.01＜θgFn1+0.00162×v dn1-0.64159＜0.05 (19)

The imaging device of the present invention includes the imaging lens of the present invention.

In addition, the term "including" or "including" in the present specification means that the optical elements other than a lens having substantially no refractive power and a lens such as a diaphragm, a filter, and a cover glass, and mechanical parts such as a lens flange, a lens barrel, an imaging element, and a hand-shake correction mechanism, and the like, may be included in addition to the components described above.

In the present specification, "group having positive refractive power" means that the entire group has positive refractive power. Similarly, "group having negative refractive power" means that the group as a whole has negative refractive power. "lens having positive refractive power", "positive lens" and "positive lens" mean the same. "lens having negative refractive power", "negative lens" and "negative lens" mean the same. "singlet" means an unbonded piece of lens.

The "lens group" is not limited to a configuration including a plurality of lenses, and may be a configuration including only one lens. A compound aspherical lens (a lens in which a spherical lens and an aspherical film formed on the spherical lens are integrally formed to function as one aspherical lens as a whole) is used as one lens and is not regarded as a cemented lens. Unless otherwise specified, the sign of the refractive power of the lens including the aspherical surface, the surface shape of the lens surface, and the radius of curvature are considered in the paraxial region. The sign of the curvature radius is positive for the surface of the shape with the convex surface facing the object side, and negative for the surface of the shape with the convex surface facing the image side.

In this specification, "the entire system" means "an imaging lens". In this specification, "the most object side of the entire system" is also simply referred to as "the most object side". The "order from the object side to the image side" relating to the arrangement order is also simply referred to as "order from the object side". The "focal length" used in the conditional expression is a paraxial focal length. The value of "FNo" used in the conditional expression is the value of the open F value. The "back focal length" is the distance on the optical axis from the lens surface closest to the image side focal position of the imaging lens. The value used in the conditional expression is a value when the d-line is used as a reference in a state of focusing on an object at infinity. When the refractive indices of a lens with respect to g, F and C lines are Ng, NF and NC, respectively, the partial dispersion ratio θ gF between the g and F lines of the lens is defined by θ gF ═ Ng (Ng-NF)/(NF-NC). The "d line", "C line", "F line" and "g line" described in the present specification are open lines, the wavelength of the d line is 587.56nm (nm), the wavelength of the C line is 656.27nm (nm), the wavelength of the F line is 486.13nm (nm), and the wavelength of the g line is 435.84nm (nm).

Effects of the invention

According to the present invention, it is possible to provide an appropriate imaging lens having a small F value and in which aberrations are well corrected, and an imaging apparatus including the imaging lens.

Drawings

Fig. 1 is a cross-sectional view showing a structure and a light flux of an imaging lens (imaging lens of example 1) according to an embodiment.

Fig. 2 is a spherical aberration diagram, an astigmatism diagram, a distortion aberration diagram, and a magnification chromatic aberration diagram of the imaging lens according to embodiment 1.

Fig. 3 is a lateral aberration diagram of the imaging lens of embodiment 1.

Fig. 4 is a sectional view showing the structure and light beams of the imaging lens of embodiment 2.

Fig. 5 is a spherical aberration diagram, an astigmatism diagram, a distortion aberration diagram, and a magnification chromatic aberration diagram of the imaging lens of example 2.

Fig. 6 is a lateral aberration diagram of the imaging lens of embodiment 2.

Fig. 7 is a sectional view showing the structure and light beams of an imaging lens of embodiment 3.

Fig. 8 is a spherical aberration diagram, an astigmatism diagram, a distortion aberration diagram, and a magnification chromatic aberration diagram of the imaging lens according to example 3.

Fig. 9 is a lateral aberration diagram of the imaging lens of embodiment 3.

Fig. 10 is a sectional view showing the structure and light beam of an imaging lens of embodiment 4.

Fig. 11 is a spherical aberration diagram, an astigmatism diagram, a distortion aberration diagram, and a magnification chromatic aberration diagram of the imaging lens of example 4.

Fig. 12 is a lateral aberration diagram of the imaging lens of embodiment 4.

Fig. 13 is a sectional view showing the structure and light beams of an imaging lens of embodiment 5.

Fig. 14 is a spherical aberration diagram, an astigmatism diagram, a distortion aberration diagram, and a magnification chromatic aberration diagram of the imaging lens of example 5.

Fig. 15 is a lateral aberration diagram of the imaging lens of embodiment 5.

Fig. 16 is a sectional view showing the structure and light beam of an imaging lens of embodiment 6.

Fig. 17 is a spherical aberration diagram, an astigmatism diagram, a distortion aberration diagram, and a magnification chromatic aberration diagram of the imaging lens of example 6.

Fig. 18 is a lateral aberration diagram of the imaging lens of embodiment 6.

Fig. 19 is a sectional view showing the structure and light beam of an imaging lens of embodiment 7.

Fig. 20 is a spherical aberration diagram, an astigmatism diagram, a distortion aberration diagram, and a magnification chromatic aberration diagram of the imaging lens of example 7.

Fig. 21 is a lateral aberration diagram of the imaging lens of embodiment 7.

Fig. 22 is a sectional view showing the structure and light beam of an imaging lens of embodiment 8.

Fig. 23 is a spherical aberration diagram, an astigmatism diagram, a distortion aberration diagram, and a magnification chromatic aberration diagram of the imaging lens according to example 8.

Fig. 24 is a lateral aberration diagram of the imaging lens of embodiment 8.

Fig. 25 is a sectional view showing the structure and light beams of an imaging lens of embodiment 9.

Fig. 26 is a spherical aberration diagram, an astigmatism diagram, a distortion aberration diagram, and a chromatic aberration of magnification diagram of the imaging lens according to example 9.

Fig. 27 is a lateral aberration diagram of the imaging lens of embodiment 9.

Fig. 28 is a sectional view showing the structure and light beams of the imaging lens of embodiment 10.

Fig. 29 is a spherical aberration diagram, an astigmatism diagram, a distortion aberration diagram, and a chromatic aberration of magnification diagram of the imaging lens according to example 10.

Fig. 30 is a lateral aberration diagram of the imaging lens of embodiment 10.

Fig. 31 is a sectional view showing the structure and light beam of an imaging lens of embodiment 11.

Fig. 32 is a spherical aberration diagram, an astigmatism diagram, a distortion aberration diagram, and a chromatic aberration of magnification diagram of the imaging lens according to example 11.

Fig. 33 is a lateral aberration diagram of the imaging lens of embodiment 11.

Fig. 34 is a sectional view showing the structure and light beam of an imaging lens of embodiment 12.

Fig. 35 is a spherical aberration diagram, an astigmatism diagram, a distortion aberration diagram, and a chromatic aberration of magnification diagram of the imaging lens according to example 12.

Fig. 36 is a lateral aberration diagram of the imaging lens of embodiment 12.

Fig. 37 is a sectional view showing the structure and light beams of an imaging lens of embodiment 13.

Fig. 38 is a spherical aberration diagram, an astigmatism diagram, a distortion aberration diagram, and a chromatic aberration of magnification diagram of the imaging lens according to example 13.

Fig. 39 is a lateral aberration diagram of the imaging lens of embodiment 13.

Fig. 40 is a sectional view showing the structure and light beam of an imaging lens of embodiment 14.

Fig. 41 is a spherical aberration diagram, an astigmatism diagram, a distortion aberration diagram, and a chromatic aberration of magnification diagram of the imaging lens according to example 14.

Fig. 42 is a lateral aberration diagram of the imaging lens of embodiment 14.

Fig. 43 is a sectional view showing the structure and light beams of an imaging lens of embodiment 15.

Fig. 44 is a spherical aberration diagram, an astigmatism diagram, a distortion aberration diagram, and a chromatic aberration of magnification diagram of the imaging lens according to example 15.

Fig. 45 is a lateral aberration diagram of the imaging lens of embodiment 15.

Fig. 46 is a sectional view showing the structure and light beams of an imaging lens of embodiment 16.

Fig. 47 is a spherical aberration diagram, an astigmatism diagram, a distortion aberration diagram, and a chromatic aberration of magnification diagram of the imaging lens according to example 16.

Fig. 48 is a lateral aberration diagram of the imaging lens of embodiment 16.

Fig. 49 is a sectional view showing the structure and light beams of an imaging lens of embodiment 17.

Fig. 50 is a spherical aberration diagram, an astigmatism diagram, a distortion aberration diagram, and a chromatic aberration of magnification diagram of the imaging lens according to example 17.

Fig. 51 is a lateral aberration diagram of an imaging lens of embodiment 17.

Fig. 52 is a sectional view showing the structure and light beam of an imaging lens of example 18.

Fig. 53 is a spherical aberration diagram, an astigmatism diagram, a distortion aberration diagram, and a chromatic aberration of magnification diagram of the imaging lens according to example 18.

Fig. 54 is a lateral aberration diagram of an imaging lens of embodiment 18.

Fig. 55 is a sectional view showing a structure and a light beam of an imaging lens of embodiment 19.

Fig. 56 is a spherical aberration diagram, an astigmatism diagram, a distortion aberration diagram, and a chromatic aberration of magnification diagram of the imaging lens according to example 19.

Fig. 57 is a lateral aberration diagram of an imaging lens of embodiment 19.

Fig. 58 is a sectional view showing the structure and light beams of an imaging lens of embodiment 20.

Fig. 59 is a spherical aberration diagram, an astigmatism diagram, a distortion aberration diagram, and a chromatic aberration of magnification diagram of the imaging lens according to example 20.

Fig. 60 is a lateral aberration diagram of the imaging lens of embodiment 20.

Fig. 61 is a front perspective view of the imaging device according to the embodiment.

Fig. 62 is a perspective view of the back side of the imaging device according to the embodiment.

Detailed Description

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Fig. 1 is a diagram showing a configuration of a cross section including an optical axis Z of an imaging lens according to an embodiment of the present invention. The example shown in fig. 1 corresponds to an imaging lens of embodiment 1 described later. In fig. 1, the left side is an object side, and the right side is an image side, showing a state of focusing on an object at infinity, and also showing an on-axis light beam 2 and a light beam 3 at the maximum angle of view.

Fig. 1 shows an example in which an imaging lens is applied to an imaging apparatus, and a parallel flat plate-shaped optical member PP is disposed between the imaging lens and an image plane Sim. The optical member PP is a member assumed to be various filters, cover glass, or the like. Examples of the various filters include a low-pass filter, an infrared cut filter, and a filter for cutting off a specific wavelength region. The optical member PP has no optical power, and may be omitted.

The imaging lens of the present invention is a fixed focus lens, and includes, as lens groups, a 1 st lens group G1 having positive refractive power and a 2 nd lens group G2 having refractive power in this order from the most object side to the image side along an optical axis Z. The aperture stop St is disposed on the image side of the 2 nd lens from the object side. By setting the refractive power of the 1 st lens group G1 positive, it is advantageous to shorten the total lens length.

The imaging lens of the present invention may further include a lens group on the image side of the 2 nd lens group G2. In addition, the "lens group" in the present specification refers to a constituent part of an imaging lens, which includes at least one lens separated by an air space that changes upon focusing. Upon focusing, the lens groups are moved or fixed in units of lens groups, and the mutual interval of the lenses within one lens group is constant.

As an example, the imaging lens shown in fig. 1 includes, in order from the object side, a 1 St lens group G1, an aperture stop St, a 2 nd lens group G2, and a 3 rd lens group G3. The aperture stop St shown in fig. 1 indicates a position on the optical axis, and does not indicate a shape. In the imaging lens of fig. 1, as an example, the 1 st lens group G1 includes 7 lenses of lenses L1a to L1G in order from the object side, the 2 nd lens group G2 includes 5 lenses of lenses L2a to L2e in order from the object side, and the 3 rd lens group G3 includes one lens of lens L3 a. However, in the imaging lens of the present invention, the number of lenses constituting each lens group may be different from the example shown in fig. 1.

In the imaging lens of the present invention, the imaging lens is configured such that: upon focusing from an infinity object to a close object, the interval between the 1 st lens group G1 and the 2 nd lens group G2 varies, and the mutual interval of all lenses in the 1 st lens group and the mutual interval of all lenses in the 2 nd lens group are constant. The phrase "in focus to constant distance from each other" as used herein means that the distance from each other is constant during focusing. By configuring the interval between the lens groups to change during focusing, it is possible to suppress the variation of the field curvature during focusing, compared to a configuration in which the entire imaging lens is moved integrally to focus. The term "integrally move" as used herein means to simultaneously move in the same direction by the same amount.

In the imaging lens of fig. 1, for example, when focusing from an infinity object to a closest object, the 1 st lens group G1 and the 3 rd lens group G3 are fixed to the image plane Sim, and the 2 nd lens group G2 moves to the object side along the optical axis Z. That is, in the imaging lens of fig. 1, a lens group that moves upon focusing (hereinafter, referred to as a focusing lens group) includes the 2 nd lens group G2. The horizontal left arrow on the lower side of the 2 nd lens group G2 in fig. 1 indicates that the 2 nd lens group G2 moves to the object side when focusing from an infinity object to a closest object.

The imaging lens is configured such that the combined refractive power of all lenses on the object side of the aperture stop St is positive. The imaging lens is configured to include at least one LA positive lens LA and at least one LB lens LB on the object side of the aperture stop St. LA lens LA is a positive lens as follows: the objective lens is disposed on the object side of the aperture stop St, and satisfies the following conditional expressions (1) and (2) when the refractive index of the LA positive lens LA with respect to the d-line is NdA and the d-line-based abbe number of the LA positive lens LA is vda.

1.86＜NdA＜2.2 (1)

10＜v dA＜35 (2)

The LB lens LB is a positive lens as follows: the d-line reference Abbe number is the largest among the d-line reference Abbe numbers of all positive lenses arranged on the object side of the aperture stop St, and the following conditional expression (3) is satisfied. Here, the d-line reference dispersion coefficient of the LB positive lens LB is set to v dB.

57＜v dB＜105 (3)

In the example of fig. 1, the lens L1c corresponds to the LA lens LA, and the lens L1b corresponds to the LB lens LB.

By not being equal to or less than the lower limit of conditional expression (1), the absolute value of the radius of curvature of the lens does not become excessively small, and therefore generation of spherical aberration can be suppressed. By not being equal to or more than the upper limit of conditional expression (1), the specific gravity of the lens does not become excessively large, which is advantageous for weight reduction.

Setting the lower limit of conditional expression (2) or less is advantageous for correcting the primary chromatic aberration favorably. The secondary chromatic aberration is favorably corrected by not being equal to or more than the upper limit of conditional expression (2). Satisfying the conditional expression (2) is advantageous for correcting the primary chromatic aberration and the secondary chromatic aberration well.

By not being lower than the lower limit of conditional expression (3), chromatic aberration, particularly on-axis chromatic aberration, can be favorably corrected. The refractive index of the LB positive lens LB can be prevented from becoming too low by not being equal to or more than the upper limit of the conditional expression (3). When the positive lens is made of a material having a low refractive index, spherical aberration and coma aberration are likely to occur, but the upper limit of conditional expression (3) or more is not set, and the occurrence of spherical aberration and coma aberration can be suppressed.

In the imaging lens of the present invention, a high-refractive-index and high-dispersion LA lens LA satisfying the conditional expressions (1) and (2) is disposed on the object side of the aperture stop St, and a low-dispersion LB positive lens LB satisfying the conditional expression (3) is disposed. The plurality of lenses arranged on the object side of the aperture stop St have a positive refractive power as a whole, and among these, by arranging the LA positive lens LA made of a material satisfying the conditional expressions (1) and (2), a correction effect of secondary chromatic aberration can be obtained. By controlling the amount of chromatic aberration generated by the LA lens LA and the LB positive lens LB, a balance between the primary chromatic aberration and the secondary chromatic aberration can be maintained. Further, by disposing the positive lenses made of a high refractive index material satisfying the conditional expression (1), the absolute value of the radius of curvature of each positive lens can be prevented from becoming excessively small. This makes it easy to correct monochromatic aberrations such as chromatic aberration, spherical aberration, and coma aberration in a well-balanced manner.

In order to obtain more favorable characteristics, the LA lens LA preferably satisfies at least one of the following conditional expressions (1-1), (1-2), (2-1), (2-2), and (2-3).

1.88＜NdA＜2.15 (1-1)

1.91＜NdA＜2.15 (1-2)

13.5＜v dA＜31 (2-1)

14＜ν dA＜28 (2-2)

14.5＜v dA＜22 (2-3)

In order to obtain more favorable characteristics, the LB positive lens preferably satisfies the following conditional expression (3-1), and more preferably satisfies the following conditional expression (3-2).

62＜v dB＜92 (3-1)

66＜v dB＜88 (3-2)

When the d-line reference dispersion coefficient of the LA lens LA is represented by v dA and the partial dispersion ratio between the g-line and the F-line of the LA lens LA is represented by θ gFA, the following conditional expression (17) is preferably satisfied. By not being lower than the lower limit of conditional expression (17), insufficient correction of the secondary chromatic aberration can be suppressed. By not being equal to or more than the upper limit of conditional expression (17), excessive correction of the secondary chromatic aberration can be suppressed. In order to obtain more favorable characteristics, the following conditional formula (17-1) is more preferably satisfied.

0.01＜θgFA+0.00162×v dA-0.64159＜0.06 (17)

0.015＜θgFA+0.00162×v dA-0.64159＜0.055 (17-1)

Conditional expression (17) θ gFA +0.00162 × v dA-0.64159 is Δ θ gFA represented by the following formula.

ΔθgFA＝θgFA-(-0.00162×v dA+0.64159)

Δ θ gFA is a value representing the anomalous dispersion of the material used for LA positive lens LA, and the greater the value, the higher the anomalous dispersion. The anomalous dispersion can be considered using an orthogonal coordinate system having the dispersion coefficient v d with the d-line as the horizontal axis and the partial dispersion ratio θ gF between the g-line and the F-line as the vertical axis. In the orthogonal coordinate system, a straight line passing through two points of (v d, θ gF) ═ 60.49, 0.5436 and (v d, θ gF) ═ 36.26, 0.5828 is used as a reference line. The deviation from the reference line indicates the degree of abnormal dispersibility. Δ θ gF a represents the deviation of the partial dispersion ratio from the reference line. In addition, the definition of the above-mentioned deviation is based on the definition of the abnormal dispersibility of OHARA inc.

Similarly, when the partial dispersion ratio between the g-line and the F-line of the LB lens LB is θ gFB, the following conditional expression (18) is preferably satisfied. θ gFB +0.00162 × v dA-0.64159 in conditional expression (18) is a value representing the anomalous dispersion of the material for the LB positive lens LB, and the greater the value, the higher the anomalous dispersion. By not being lower than the lower limit of conditional expression (18), chromatic aberration, particularly on-axis chromatic aberration, can be easily corrected. By not being equal to or more than the upper limit of conditional expression (18), a material other than the low refractive index material can be selected, and therefore the absolute value of the radius of curvature of the lens can be prevented from becoming excessively small. This makes it easy to correct spherical aberration and coma aberration. By satisfying the conditional expression (18), chromatic aberration, spherical aberration, and coma are easily corrected in a balanced manner. In order to obtain more favorable characteristics, the following conditional formula (18-1) is more preferably satisfied.

0.01＜θgFB+0.00162×ν dB-0.64159＜0.05 (18)

0.012＜θgFB+0.00162×v dB-0.64159＜0.035 (18-1)

Other preferable configurations and realizable configurations of the imaging lens of the present invention will be described below. Preferably, the 1 st lens group G1 is fixed with respect to the image plane Sim during focusing, and the 1 st lens group G1 includes at least one LA positive lens LA. The reason for this is as follows. When the LA positive lens LA made of a material having a high refractive index and high dispersion is disposed in the focusing lens group, the variation in chromatic aberration and the variation in spherical aberration are likely to increase during focusing, and therefore, it is preferable to dispose the LA positive lens LA in the 1 st lens group that does not move during focusing. Alternatively, when the LA lens LA is disposed in the focus lens group, a negative lens needs to be further disposed in the focus lens group in order to cancel out the aberration generated by the LA positive lens LA, which leads to an increase in the size of the focus lens group. In view of the above, it is more preferable that the 1 st lens group G1 is fixed with respect to the image plane Sim and the 1 st lens group G1 includes all LA lenses LA in focusing.

Preferably, the imaging lens includes at least one LC lens LC on the object side than the aperture stop St. The LC lens LC is a positive lens as follows: the positive lenses disposed on the object side of the aperture stop St have the maximum or 2 nd-line-greater dispersion coefficient of the d-line reference among all the positive lenses disposed on the object side of the aperture stop St, and satisfy the following conditional expression (6). Here, the d-line reference abbe number of the LC positive lens LC is vdC.

57＜v dC＜102 (6)

Fig. 1 shows an example in which the lens L1d corresponds to the LC positive lens LC.

By setting the lower limit of conditional expression (6) or less, chromatic aberration, particularly on-axis chromatic aberration, can be corrected well. By not being equal to or more than the upper limit of conditional expression (6), the refractive index of the LC positive lens LC does not become too low, and therefore generation of spherical aberration and coma aberration can be suppressed. By providing the imaging lens with the LB lens L B made of a low dispersion material satisfying the conditional expression (3) on the object side of the aperture stop St and the LC positive lens LC made of a low dispersion material satisfying the conditional expression (6), chromatic aberration and spherical aberration can be corrected favorably. In the structure having the LB positive lens LB and the LC positive lens LC, the refractive power of the LB positive lens LB can be reduced, compared to the structure in which the positive lens made of a low dispersion material is only the LB positive lens LB. Thus, the absolute value of the curvature radius of the LB lens LB is not excessively small, and thus generation of spherical aberration can be suppressed. Further, the refractive index of the LC lens LC can be made higher than that of the LB lens LB by the refractive index characteristics and the abbe number characteristics of the optical material. Therefore, in the case where the imaging lens has two positive lenses made of a low dispersion material on the object side of the aperture stop St, the absolute value of the radii of curvature of the two positive lenses can be increased in the configuration in which one LB positive lens LB and one LC positive lens LC are provided, compared to the configuration in which both of the two positive lenses are provided as LB lenses LB, which is advantageous for suppressing the occurrence of spherical aberration.

In order to obtain more favorable characteristics, the LC positive lens LC preferably satisfies the following conditional expression (6-1), and more preferably satisfies the following conditional expression (6-2).

62＜ν dC＜88 (6-1)

66＜v dC＜80 (6-2)

When the minimum value of the refractive index of all positive lenses on the object side of the aperture stop St with respect to the d-line is Ndfm, the following conditional expression (7) is preferably satisfied. By not being equal to or less than the lower limit of conditional expression (7), the absolute value of the radius of curvature of the lens does not become excessively small, and therefore generation of spherical aberration can be suppressed. Further, the positive lens arranged in the 1 st lens group G1 having a large lens diameter does not become excessively thick, and therefore, is advantageous for downsizing of the lens system. By not being equal to or more than the upper limit of equation (7), a low dispersion material can be selected, which is advantageous for chromatic aberration correction. In order to obtain more favorable characteristics, the following conditional formula (7-1) is more preferably satisfied.

1.46＜Ndfm＜1.72 (7)

1.52＜Ndfm＜1.68 (7-1)

Preferably, the imaging lens includes at least two positive lenses on the image side of the aperture stop St, and the following conditional expression (8) is satisfied when an average value of refractive indices of all the positive lenses on the image side of the aperture stop St with respect to the d-line is Ndpr. By disposing two or more positive lenses on the image side of the aperture stop St, astigmatism and field curvature can be corrected well. By not being equal to or less than the lower limit of conditional expression (8), the absolute value of the radius of curvature of the lens is not excessively small, and thus astigmatism and field curvature are easily corrected well. By not being equal to or more than the upper limit of conditional expression (8), it is possible to select a material other than the high-dispersion material, which is advantageous for correction of chromatic aberration. In order to obtain more favorable characteristics, the following conditional expression (8-1) is more preferably satisfied, and the following conditional expression (8-2) is further preferably satisfied.

1.77＜Ndpr＜2.15 (8)

1.81＜Ndpr＜2.1 (8-1)

1.87＜Ndpr＜2.05 (8-2)

Preferably, the 1 st lens group G1 includes at least two positive lenses and at least two negative lenses. In this case, spherical aberration, coma aberration, and axial chromatic aberration can be corrected well, and variation in aberration accompanying variation in the interval between the 1 st lens group G1 and the 2 nd lens group G2 at the time of focusing can be reduced easily.

Preferably, three positive lenses are arranged in series in the 1 st lens group. In this case, since the height of the edge ray on the axis can be gradually reduced by three positive lenses arranged in series, the occurrence of spherical aberration can be suppressed. In order to further favorably suppress the generation of spherical aberration, it is preferable to arrange 4 positive lenses in series in the 1 st lens group.

Preferably, the 1 st lens group G1 includes at least two negative lenses, and the following conditional expression (4) is satisfied when the average value of the d-line reference abbe numbers of the two negative lenses selected in order of the d-line reference abbe numbers from small to large among the negative lenses included in the 1 st lens group G1 is made v dn 1. In addition, the "two negative lenses selected in the order of smaller abbe number to larger abbe number" may have the same abbe number. Specifically, when there are two or more negative lenses having the minimum value of the abbe numbers of all the negative lenses in the 1 st lens group, the minimum value is v dn 1. In the case where the negative lens having the minimum value of the abbe numbers of all the negative lenses in the 1 st lens group is only one, the average value of the minimum value and the 2 nd smallest value of the abbe numbers of all the negative lenses in the 1 st lens group is v dn 1. In order to avoid redundant description, the "d-line reference dispersion coefficient" is simply referred to as "dispersion coefficient" in the above description. Setting the lower limit of conditional expression (4) or less is advantageous for correcting the secondary chromatic aberration favorably. The upper limit of conditional expression (4) is not exceeded, which is advantageous for correcting the primary chromatic aberration well. By satisfying the conditional expression (4), it is advantageous to uniformly correct the primary chromatic aberration and the secondary chromatic aberration. In order to obtain more favorable characteristics, the following conditional formula (4-1) is more preferably satisfied.

15＜v dn1＜28 (4)

16＜v dn1＜25 (4-1)

Preferably, the 1 st lens group G1 includes at least two negative lenses, and satisfies the following conditional expression (19) when the average value of the d-line reference dispersion coefficients of the two negative lenses selected in the order of decreasing d-line reference dispersion coefficients among the negative lenses included in the 1 st lens group G1 is v dn1, and the average value of the partial dispersion ratios between G-line and F-line of the two negative lenses selected in the order of decreasing d-line reference dispersion coefficients among the negative lenses included in the 1 st lens group G1 is θ gFn 1. In the same manner as in conditional expression (4), in conditional expression (19), "two negative lenses selected in the order of smaller dispersion coefficient to larger dispersion coefficient" may be the same. Similarly to θ gFA +0.00162 × v dA-0.64159 of conditional expression (17), θ gFn1+0.00162 × v dn1-0.64159 of conditional expression (19) is a value representing an average value of the anomalous dispersion of two negative lenses selected in order of the dispersion coefficient from small to large among the negative lenses arranged in the 1 st lens group G1, and the larger the value, the higher the anomalous dispersion. By setting the lower limit of conditional expression (19) or less, the primary chromatic aberration can be corrected easily and satisfactorily. By setting the upper limit of conditional expression (19) or more, the secondary chromatic aberration can be corrected easily. By satisfying the conditional expression (19), the primary chromatic aberration and the secondary chromatic aberration are easily corrected in a balanced manner. In order to obtain more favorable characteristics, the following conditional formula (19-1) is more preferably satisfied.

0.01＜θgFn1+0.00162×v dn1-0.64159＜0.05 (19)

0.016＜θgFn1+0.00162×v dn1-0.64159＜0.042 (19-1)

Preferably, the 1 st lens group G1 includes at least three negative lenses. In this case, chromatic aberration is easily corrected well, and it is also advantageous to correct image plane curvature.

When the focal length of the 1 st lens group G1 is f1 and the focal length of the imaging lens in a state of focusing on an object at infinity is f, the following conditional expression (10) is preferably satisfied. By not being equal to or less than the lower limit of conditional expression (10), the refractive power of the 1 st lens group G1 does not become excessively strong, and hence it is advantageous to correct each aberration, particularly spherical aberration, favorably. The refractive power of the 1 st lens group G1 is not excessively weak by not being equal to or more than the upper limit of the conditional expression (10), and therefore the total lens length is advantageously shortened. In order to obtain more favorable characteristics, the following conditional expression (10-1) is more preferably satisfied, the following conditional expression (10-2) is still more preferably satisfied, and the following conditional expression (10-3) is still more preferably satisfied.

0.5＜f1/f＜3.5 (10)

0.7＜f1/f＜3.3 (10-1)

1.4＜f1/f＜3.2 (10-2)

1.8＜f1/f＜2.9 (10-3)

The 1 st lens group G1 may be configured as follows: the 1 st unit Gs1 having a negative refractive power and the 2 nd unit Gs2 having a positive refractive power separated from the 1 st unit Gs1 by the maximum air space on the optical axis in the 1 st lens group are successively included in order from the most object side. The 1 st cell Gs1 is a cell including at least one lens, and the 2 nd cell Gs2 is a cell including one single lens or one cemented lens. In this case, a structure like a wide-angle conversion lens can be formed by the 1 st cell Gs1 and the 2 nd cell Gs2, and sagittal coma aberration is easily suppressed while widening the angle of view. In the example of fig. 1, the 1 st cell Gs1 includes lens L1a, and the 2 nd cell Gs2 includes lens L1 b.

In the configuration in which the 1 st lens group G1 includes the 1 st cell Gs1 and the 2 nd cell Gs2 described above, it is preferable that the following conditional expression (16) is satisfied when the focal length of the imaging lens in a state focused on an object at infinity is f and the combined focal length of all lenses on the image side of the 2 nd cell Gs2 in the imaging lens in a state focused on an object at infinity is fm. By not being equal to or less than the lower limit of the conditional expression (16), it is advantageous to suppress coma aberration generated by the 1 st cell Gs1 and the 2 nd cell Gs 2. By not being equal to or more than the upper limit of conditional expression (16), it is advantageous to suppress aberrations, particularly coma aberration, generated by the lens on the image side of unit 2 Gs 2. In order to obtain more favorable characteristics, the following conditional formula (16-1) is more preferably satisfied.

0.7＜f/fm＜0.98 (16)

0.75＜f/fm＜0.95 (16-1)

Preferably, in the case where the 1 st lens group G1 has the 1 st cell Gs1 and the 2 nd cell Gs2 described above, the 1 st cell Gs1 includes one piece of negative lens and the 2 nd cell Gs2 includes one piece of positive lens. In this case, the number of lenses of the 1 st cell Gs1 and the 2 nd cell Gs2 having large lens diameters becomes small, and therefore, it is advantageous for the miniaturization and weight reduction of the imaging lens.

Preferably, one of the most object-side lens component and the 2 nd lens component of the entire system has a negative refractive power, and the other lens component has a positive refractive power, and in a state of focusing on an object at infinity, an on-axis light flux 2 emitted from the most image-side lens surface of the one lens component having a negative refractive power toward the image side is divergent light. In addition, one lens component means one single lens or one cemented lens. In the example of fig. 1, lens L1a, which is the most object-side lens component of the entire system, has negative refractive power, and lens L1b, which is the 2 nd lens component from the object side of the entire system, has positive refractive power. As shown in fig. 1, the on-axis light flux 2 emitted from the lens L1a to the image side between the lens L1a and the lens L1b has a larger beam diameter moving farther to the image side, and becomes divergent light.

As described above, by disposing the lens component having negative refractive power at a position closer to the object, the angle of the principal ray of the maximum angle of view emitted from the lens component having negative refractive power to the image side with respect to the optical axis Z can be reduced, and hence sagittal coma aberration can be easily suppressed. Further, by disposing a lens component having a negative refractive power in the 1 st lens group, the 1 st lens group G1 can be prevented from having an excessively strong positive refractive power, and generation of spherical aberration and field curvature can be prevented. However, if the negative refractive power is continuously arranged so that both the lens component closest to the object side and the 2 nd lens component from the object side have negative refractive power, the entire lens system becomes large in size. Therefore, it is preferable that one of the two lens components has a negative refractive power and the other lens component has a positive refractive power. Further, by making the on-axis light flux 2 emitted from the above-mentioned one lens component having negative refractive power a divergent light, the 1 st lens group G1 having positive refractive power can adopt a configuration in which the light flux is once expanded and then converged again, which is advantageous for suppressing sagittal coma.

Preferably, at least one of the most object-side lens and the 2 nd lens from the object side of the entire system is a negative lens having a concave lens surface on the object side. By disposing the negative lens at a position closer to the object in this manner, the angle of the principal ray of the maximum angle of view emitted from the negative lens to the image side with respect to the optical axis Z can be reduced, and hence sagittal coma aberration can be easily suppressed. Further, the concave surface on the object side of the negative lens is advantageous for correcting spherical aberration.

Preferably, the lens surface on the object side of the most object side lens of the entire system has a concave shape. In this case, it is advantageous to correct spherical aberration.

Preferably, the most object-side lens of the entire system is a negative lens. In this case, since the angle of the principal ray of the maximum angle of view emitted from the lens closest to the object side to the image side with respect to the optical axis Z can be reduced, sagittal coma aberration can be easily suppressed.

The imaging lens may be configured such that: the system comprises a single lens with negative refractive power, a single lens with positive refractive power and a single lens with positive refractive power in sequence from the most object side of the whole system. By setting the most object side lens to be a negative lens, sagittal coma is easily suppressed as described above. Further, the positive lens disposed in series with the lens closest to the object side can reduce the height of the marginal ray on the axis gradually, and thus can suppress the occurrence of spherical aberration. Further, by providing only one negative lens among the three lenses from the 1 st to the 3 rd from the most object side, it is possible to suppress an increase in size of the lens system.

The 2 nd lens group G2 may be configured as a lens group having positive refractive power. In this case, since the height of the peripheral ray on the axis can be gradually reduced from the 1 st lens group G1 where the light from the object is incident on the positive refractive power to the 2 nd lens group G2, the generation of spherical aberration can be suppressed even when the F value is small.

When the focal length of the 1 st lens group G1 is f1 and the focal length of the 2 nd lens group G2 is f2, the following conditional expression (13) is preferably satisfied. By setting the refractive power of the 1 st lens group G1 not to be equal to or less than the lower limit of conditional expression (13), the refractive power can be prevented from becoming excessively strong. By not being equal to or more than the upper limit of conditional expression (13), the refractive power of the 2 nd lens group G2 does not become excessively strong. By satisfying the conditional expression (13), it is easy to suppress each aberration generated by each of the 1 st lens group G1 and the 2 nd lens group G2. In order to obtain more favorable characteristics, the following conditional expression (13-1) is more preferably satisfied, the following conditional expression (13-2) is still more preferably satisfied, and the following conditional expression (13-3) is still more preferably satisfied.

1＜f1/f2＜5 (13)

1.2＜f1/f2＜4.4 (13-1)

2.3 < f1 Wide f2 < 4.2 (13-2)

2.5＜f1/f2＜4 (13-3)

Preferably, the 2 nd lens group G2 includes at least two positive lenses and at least two negative lenses. In this case, it is possible to favorably correct various aberrations, particularly field curvature, and to easily reduce aberration variation accompanying the change in the interval between the 1 st lens group G1 and the 2 nd lens group G2 in focusing.

Preferably, the 2 nd lens group G2 includes at least two positive lenses and at least three negative lenses. In this case, each aberration can be corrected favorably, and aberration variation at the time of focusing can be suppressed easily.

As the behavior of each lens group at the time of focusing, it is preferable that the 1 st lens group G1 is fixed with respect to the image plane Sim and the 2 nd lens group G2 is moved at the time of focusing. In a lens system having a large aperture ratio, the diameter of the lens on the most object side tends to be large, and thus the weight tends to be heavy. Therefore, if a structure is assumed in which the 1 st lens group G1 is moved in focusing, a plurality of inconveniences described below occur. First, a heavy lens has to be moved during focusing, and thus it is difficult to achieve high-speed autofocus. In addition, since a large motor with a high torque is required to move a heavy lens, the entire lens apparatus becomes large. Further, since the total length of the lens changes with the movement of the largest-diameter lens on the most object side, the position of the center of gravity of the imaging lens changes during shooting. For the above reasons, the inner focusing system or the rear focusing system is preferably employed. Further, the structure in which the 1 st lens group G1 does not move during focusing can also obtain a favorable point that the durability of the lens device is easily ensured.

Preferably, the aperture stop St is disposed between the lens groups, or within the lens group fixed with respect to the image plane Sim at the time of focusing. That is, it is preferable that the aperture stop St is not included in the focusing lens group. By not including the aperture stop unit in the focusing lens group, the focusing lens group can be made light and the autofocus can be made high-speed. Further, if the focus lens group can be made lightweight, a large high-torque motor is not necessary, which is advantageous for downsizing and weight saving of the entire lens system.

In view of the above, it is preferable that, when importance is attached to downsizing, weight reduction, or the like, the configuration is such that: the aperture stop St is disposed between the 1 St lens group G1 and the 2 nd lens group G2, and when focusing is performed, the 1 St lens group G1 and the aperture stop St are fixed with respect to the image plane Sim, and the 2 nd lens group G2 moves.

Preferably, there is only one lens group that moves in focus. By providing only one lens group that moves during focusing, the structure can be simplified, and the lens device can be made smaller and lighter. In a lens system having a large aperture ratio, the focal depth is extremely shallow, and the performance variation accompanying the lens tilt and/or the axial shift tends to become large. In particular, in the focusing lens group as the movable lens group, it is structurally impossible to completely zero the inclination and axial shift of the lens, and therefore the number of movable lens groups is preferably small.

As described above, it is preferable that the 1 st lens group G1 is fixed with respect to the image plane Sim during focusing, and that only one lens group is moved during focusing. In view of this, it is preferable that only the 2 nd lens group G2 be the lens group that moves in focus.

Preferably, when the 2 nd lens group G2 moves during focusing, the number of lenses included in the 2 nd lens group G2 is 7 or less. By suppressing the number of lenses of the 2 nd lens group G2 as a focusing lens group, the focusing lens group can be made lighter, and therefore, it is advantageous to increase the speed of autofocus. Further, if the focus lens group can be made lightweight, a large high-torque motor is not necessary, which is advantageous for downsizing and weight saving of the entire lens system. In view of this, in the configuration in which the 2 nd lens group G2 moves during focusing, the number of lenses included in the 2 nd lens group G2 is more preferably 6 or less, and still more preferably 5 or less.

Preferably, in a configuration in which the 2 Nd lens group G2 moves in focusing, the 2 Nd lens group G2 includes at least one positive lens, and the following conditional expression (9) is satisfied when an average value of refractive indexes of all the positive lenses in the 2 Nd lens group with respect to a d-line is Nd2 p. By setting the correction amount to not less than the lower limit of conditional expression (9), astigmatism and field curvature can be corrected easily and satisfactorily. By not being equal to or more than the upper limit of conditional expression (9), the specific gravity of the lens material does not become excessively large, and therefore, the weight of the focus lens group can be suppressed from becoming heavy. Further, since a material other than the high dispersion material can be selected, variation in chromatic aberration when the focus lens is moved can be suppressed. In order to obtain more favorable characteristics, the following conditional expression (9-1) is more preferably satisfied, the following conditional expression (9-2) is still more preferably satisfied, and the following conditional expression (9-3) is still more preferably satisfied.

1.7＜Nd2p＜2.2 (9)

1.77＜Nd2p＜2.15 (9-1)

1.81＜Nd2p＜2.1 (9-2)

1.87＜Nd2p＜2.05 (9-3)

Preferably, in the case where the 2 nd lens group G2 moves upon focusing, the 2 nd lens group G2 includes at least two cemented lenses. In this case, the fluctuation of chromatic aberration in focusing can be suppressed to be small.

Preferably, in the configuration in which the 2 nd lens group G2 moves during focusing, the following conditional expression (12) is satisfied where f2 is a focal length of the 2 nd lens group G2 and f is a focal length of the imaging lens in a state of focusing on an infinitely distant object. By setting the refractive power of the 2 nd lens group G2 to be not more than the lower limit of the conditional expression (12), the occurrence of each aberration generated in the 2 nd lens group G2 is easily suppressed. By not being equal to or more than the upper limit of conditional expression (12), the amount of movement of the 2 nd lens group G2 in focusing can be reduced, which is advantageous for downsizing the lens system. In order to obtain more favorable characteristics, the following conditional expression (12-1) is more preferably satisfied, the following conditional expression (12-2) is still more preferably satisfied, and the following conditional expression (12-3) is still more preferably satisfied.

0.3＜|f2|/f＜2.2 (12)

0.4＜|f2|/f＜1.9 (12-1)

0.45＜|f2|/f＜1.2 (12-2)

0.5＜|f2|/f＜1 (12-3)

Preferably, in the configuration in which the 2 nd lens group G2 moves during focusing, the following conditional expression (14) is satisfied when β 2 is a lateral magnification of the 2 nd lens group G2 in a state focused on an object at infinity, β r is a combined lateral magnification of all lenses on the image side of the 2 nd lens group G2 in a state focused on an object at infinity when lenses are disposed on the image side of the 2 nd lens group G2, and β r is not 1 when lenses are not disposed on the image side of the 2 nd lens group G2. [ 1-. beta.2 ] of conditional formula (14)²)×βr²| represents a moving amount of the image plane position in focus with respect to a moving amount of the 2 nd lens group G2, and represents so-called focus sensitivity. By setting not to satisfy conditional expression (14)The lower limit or less is advantageous in downsizing of the lens system because the moving amount of the 2 nd lens group G2 in focusing can be reduced. By not being equal to or more than the upper limit of conditional expression (14), it is possible to suppress the severity of the stop accuracy of the focus lens group during the focusing operation. Further, by setting the refractive power of the 2 nd lens group G2 not to be equal to or higher than the upper limit of the conditional expression (14), it is not necessary to intensify the refractive power for focusing sensitivity. Therefore, spherical aberration and coma aberration are easily corrected. In order to obtain more favorable characteristics, the following conditional expression (14-1) is more preferably satisfied, and the following conditional expression (14-2) is further preferably satisfied.

0.3＜|(1-β2²)×βr²|＜1.5 (14)

0.4＜|(1-β2²)×βr²|＜1.4 (14-1)

0.6＜|(1-β2²)×βr²|＜1 (14-2)

As illustrated in fig. 1, the imaging lens of the present invention preferably includes, as lens groups, in order from the object side to the image side, only three lens groups including a 1 st lens group G1 fixed with respect to the image plane Sim in focusing, a 2 nd lens group G2 moving in focusing, and a 3 rd lens group G3 including two or less lenses and fixed with respect to the image plane Sim in focusing. Alternatively, as exemplified in the embodiment described below, the imaging lens of the present invention preferably includes, as lens groups, only two lens groups including, in order from the object side to the image side, the 1 st lens group G1 fixed with respect to the image plane Sim at the time of focusing and the 2 nd lens group G2 moving at the time of focusing. In focusing, the 1 st lens group G1 is fixed with respect to the image plane Sim, and the 2 nd lens group G2 moves. When no lens is disposed on the image side of the 2 nd lens group G2, it is easy to secure the stroke of the 2 nd lens group G2 as a focusing lens group while suppressing the total length of the lens from becoming long. Alternatively, even when a lens is disposed on the image side of the 2 nd lens group G2, the total length of the lens can be suppressed from increasing and the stroke of the 2 nd lens group G2 as a focusing lens group can be easily ensured by setting the number of lenses to a small number of two or less. This makes it easy to increase the maximum imaging magnification. If a plurality of lenses are disposed on the image side of the 2 nd lens group G2 while maintaining the total lens length, the stroke of the 2 nd lens group G2 may be reduced, and the maximum imaging magnification may be reduced. Alternatively, if the refractive power of the 2 nd lens group G2 is increased in order to obtain the same maximum photographing magnification while maintaining the total lens length, various aberrations, particularly spherical aberration and field curvature, generated by the 2 nd lens group G2 become large.

Preferably, the number of lenses included in the imaging lens is 13 or less, and more preferably 12 or less. By constituting the imaging lens with a small number of lenses, miniaturization and weight reduction can be achieved.

The number of lenses disposed on the object side of the aperture stop St is preferably 8 or less, and more preferably 7 or less. Since the lens disposed on the object side of the aperture stop St tends to have a large outer diameter and a heavy weight, the number of lenses on the object side of the aperture stop St is preferably reduced.

Preferably, the following conditional expression (15) is satisfied where Tf is an optical axis distance from the most object-side lens surface to the aperture stop St in a state of focusing on an object at infinity, and TL is a sum of an optical axis distance from the most object-side lens surface to the most image-side lens surface in a state of focusing on an object at infinity and a back focal length in terms of an air-converted distance. Since the 1 St lens group G1 disposed on the most object side has positive refractive power, the height of the light beam in the lens disposed on the image side of the aperture stop St can be further reduced by not being equal to or less than the lower limit of the conditional expression (15), which is advantageous in suppressing the occurrence of each aberration in the lens disposed on the image side of the aperture stop St. Further, by not being equal to or less than the lower limit of conditional expression (15), it is easy to dispose the lenses, which are necessary for correction of spherical aberration, on-axis chromatic aberration, and the like, on the object side of aperture stop St. By not being equal to or more than the upper limit of conditional expression (15), it is possible to suppress an increase in the diameter of the lens disposed on the object side of aperture stop St, and therefore it is easy to reduce the size and weight of the entire lens system. In order to obtain more favorable characteristics, the following conditional expression (15-1) is more preferably satisfied, and the following conditional expression (15-2) is further preferably satisfied.

0.2＜Tf/TL＜0.65 (15)

0.4＜Tf/TL＜0.64 (15-1)

0.48＜Tf/TL＜0.61 (15-2)

Preferably, the following conditional expression (5) is satisfied where TL is the sum of the distance on the optical axis from the most object-side lens surface to the most image-side lens surface in the state of focusing on the infinity object and the back focal length in terms of the air-converted distance, FNo is the F value of the imaging lens in the state of focusing on the infinity object, and F is the focal length of the imaging lens in the state of focusing on the infinity object. By not being lower than the lower limit of conditional expression (5), it is advantageous to correct each aberration well. In more detail, it is easy to configure an optimum number of lenses for correcting each aberration, and therefore it is advantageous to obtain higher imaging performance. The upper limit of conditional expression (5) is not set to be higher than the upper limit, which is advantageous in suppressing an increase in size of the lens system. In order to obtain more favorable characteristics, the following conditional expression (5-1) is more preferably satisfied, and the following conditional expression (5-2) is further preferably satisfied.

1.5＜TL×FNo/f＜5 (5)

1.8＜TL×FNo/f＜3.5 (5-1)

2＜TL×FNo/f＜3.2 (5-2)

Preferably, the following conditional expression (11) is satisfied where ω max is a maximum half angle of the imaging lens in a state of focusing on the infinity object, and FNo is an F value of the imaging lens in a state of focusing on the infinity object. When conditional expression (11) is considered on the premise that a small F value is maintained, the smaller the value of 1/{ tan (ω max) × FNo } of conditional expression (11), the wider the lens system becomes, and the larger the value, the longer the lens system becomes. When the lower limit of conditional expression (11) or less is reached while maintaining a small F value, it becomes difficult to correct sagittal coma, and the number of lenses of the 1 st lens group G1 having a large outer diameter increases to correct sagittal coma, which may increase the lens system in size. On the other hand, if the F value is kept small and the upper limit of conditional expression (11) is reached or higher, the entrance pupil diameter increases and the diameter of the entire lens system increases, which may increase the size of the lens system. Alternatively, it may be necessary to lengthen the total lens length in order to correct the on-axis chromatic aberration that occurs as the lens system becomes a longer focal optical system. From this fact, satisfying conditional expression (11) is advantageous in achieving both a small F value and downsizing of the lens system. In order to obtain more favorable characteristics, the following conditional expression (11-1) is more preferably satisfied, and the following conditional expression (11-2) is further preferably satisfied.

1.8＜1/{tan(ωmax)×FNo}＜4.5 (11)

2.4＜1/{tan(ωmax)×FNo}＜4.2 (11-1)

2.8＜1/{tan(ωmax)×FNo}＜3.8 (11-2)

Next, description will be given of an example of a structure that can be realized by the imaging lens of the present invention. In the following 1 st to 15 th configuration examples, only the 2 nd lens group G2 moves along the optical axis Z during focusing. In the following description of the configuration examples, "1 st", "2 nd", and the like, which are attached to the cemented lens, are given for each configuration example. Therefore, for example, even in the case of the "1 st cemented lens", if the configuration example is different, the configuration of the lens included in the cemented lens may be different.

The imaging lens of configuration example 1 includes, in order from the object side, a 1 St lens group G1, an aperture stop St, a 2 nd lens group G2, and a 3 rd lens group G3. The 1 st lens group G1 includes, in order from the object side, a biconcave lens, a positive lens with a convex surface facing the image side, two positive meniscus lenses with a convex surface facing the object side, a 1 st cemented lens, and a negative meniscus lens with a convex surface facing the object side. The 1 st cemented lens is composed of a positive meniscus lens with a convex surface facing the object side and a negative meniscus lens with a convex surface facing the object side cemented together in this order from the object side. The 2 nd lens group G2 includes, in order from the object side, a negative meniscus lens with a concave surface facing the object side, a 2 nd cemented lens, and a 3 rd cemented lens. The 2 nd cemented lens is composed of a biconvex lens and a biconcave lens cemented together in order from the object side. The 3 rd cemented lens is composed of a biconvex lens and a negative lens with a concave surface facing the object side cemented together in this order from the object side. The 3 rd lens group G3 includes only a biconvex lens.

The imaging lens of the 2 nd configuration example includes, in order from the object side, a 1 St lens group G1, an aperture stop St, and a 2 nd lens group G2. The 1 st lens group G1 and the 2 nd lens group G2 of the 2 nd configuration example are the same as the 1 st lens group G1 and the 2 nd lens group G2 of the 1 st configuration example, respectively.

The imaging lens of the 3 rd configuration example includes, in order from the object side, a 1 St lens group G1, an aperture stop St, and a 2 nd lens group G2. The 1 st lens group G1 includes, in order from the object side, a biconcave lens, a positive meniscus lens with the convex surface facing the object side, a biconvex lens, a positive meniscus lens with the convex surface facing the object side, a 1 st cemented lens, and a negative meniscus lens with the convex surface facing the object side. The 1 st cemented lens is composed of a positive meniscus lens with a convex surface facing the object side and a negative meniscus lens with a convex surface facing the object side cemented together in this order from the object side. The 2 nd lens group G2 includes, in order from the object side, a 2 nd cemented lens, a negative meniscus lens with a concave surface facing the object side, and a 3 rd cemented lens. The 2 nd cemented lens is composed of a biconcave lens and a biconvex lens cemented together in this order from the object side. The 3 rd cemented lens is composed of a biconvex lens and a biconcave lens cemented together in order from the object side.

The imaging lens of the 4 th configuration example includes, in order from the object side, a 1 St lens group G1, an aperture stop St, and a 2 nd lens group G2. The 1 st lens group G1 includes, in order from the object side, a biconcave lens, a biconvex lens, three positive lenses with convex surfaces facing the object side, a 1 st cemented lens, and a negative meniscus lens with convex surfaces facing the object side. The 1 st cemented lens is composed of a biconvex lens and a biconcave lens cemented together in order from the object side. The 2 nd lens group G2 includes, in order from the object side, a 2 nd cemented lens, a biconcave lens, and a 3 rd cemented lens. The 2 nd cemented lens is composed of a biconcave lens and a biconvex lens cemented together in this order from the object side. The 3 rd cemented lens is composed of a biconvex lens and a negative meniscus lens having a concave surface facing the object side, which are cemented together in this order from the object side.

The imaging lens of the 5 th configuration example includes, in order from the object side, a 1 St lens group G1, an aperture stop St, and a 2 nd lens group G2. The 1 st lens group G1 includes, in order from the object side, a biconcave lens, a biconvex lens, three positive meniscus lenses with their convex surfaces facing the object side, and two negative meniscus lenses with their convex surfaces facing the object side. The 2 nd lens group G2 includes, in order from the object side, a negative meniscus lens with a concave surface facing the object side, a 1 st cemented lens, and a 2 nd cemented lens. The 1 st cemented lens is composed of a biconvex lens and a biconcave lens cemented together in order from the object side. The 3 rd cemented lens is composed of a biconvex lens and a negative meniscus lens having a concave surface facing the object side, which are cemented together in this order from the object side.

The imaging lens of the 6 th configuration example includes, in order from the object side, a 1 St lens group G1, an aperture stop St, a 2 nd lens group G2, and a 3 rd lens group G3. The 1 st lens group G1 includes, in order from the object side, three positive meniscus lenses with their convex surfaces facing the object side, a 1 st cemented lens, and a 2 nd cemented lens. The 1 st cemented lens is composed of a negative meniscus lens having a convex surface facing the object side and a double convex lens cemented together in this order from the object side. The 2 nd cemented lens is composed of a biconcave lens and a positive meniscus lens with the convex surface facing the object side cemented together in this order from the object side. The 2 nd lens group G2 includes, in order from the object side, a 3 rd cemented lens and a 4 th cemented lens. The 3 rd cemented lens is composed of a biconcave lens and a biconvex lens cemented together in this order from the object side. The 4 th cemented lens is composed of a positive meniscus lens having a concave surface facing the object side and a biconcave lens cemented together in this order from the object side. The 3 rd lens group G3 includes, in order from the object side, a biconvex lens, a 5 th cemented lens, a biconvex lens, and a biconcave lens. The 5 th cemented lens is composed of a positive lens and a biconcave lens cemented together with a convex surface facing the image side in this order from the object side.

The imaging lens of the 7 th configuration example includes, in order from the object side, a 1 St lens group G1, an aperture stop St, a 2 nd lens group G2, and a 3 rd lens group G3. The 1 st lens group G1 includes, in order from the object side, a biconcave lens, a biconvex lens, two positive meniscus lenses with the convex surface facing the object side, a 1 st cemented lens, and a 2 nd cemented lens. The 1 st cemented lens is composed of a negative meniscus lens having a convex surface facing the object side and a double convex lens cemented together in this order from the object side. The 2 nd cemented lens is composed of a biconcave lens and a positive lens with a convex surface facing the object side cemented together in this order from the object side. The 2 nd lens group G2 and the 3 rd lens group G3 of the 7 th configuration example are the same as the 2 nd lens group G2 and the 3 rd lens group G3 of the 6 th configuration example, respectively.

The imaging lens of the 8 th configuration example includes, in order from the object side, a 1 st lens group G1 and a 2 nd lens group G2. The 1 st lens group G1 includes, in order from the object side, a biconcave lens, a 1 st cemented lens, a biconvex lens, a 2 nd cemented lens, a biconvex lens, and a positive meniscus lens with the convex surface facing the object side. The 1 st cemented lens is composed of a biconcave lens and a biconvex lens cemented together in this order from the object side. The 2 nd cemented lens is composed of a biconvex lens and a negative meniscus lens having a concave surface facing the object side, which are cemented together in this order from the object side. The 2 nd lens group G2 includes, in order from the object side, a positive meniscus lens with a convex surface facing the object side, a 3 rd cemented lens, an aperture stop St, a negative meniscus lens with a concave surface facing the object side, and a 4 th cemented lens. The 3 rd cemented lens is composed of a biconvex lens and a biconcave lens cemented together in order from the object side. The 4 th cemented lens is composed of a biconvex lens, a biconcave lens, and a biconvex lens cemented together in this order from the object side.

The imaging lens of the 9 th configuration example includes, in order from the object side, a 1 st lens group G1 and a 2 nd lens group G2. The 1 st lens group G1 includes, in order from the object side, a positive lens with a convex surface facing the image side, a biconcave lens, a 1 st cemented lens, a 2 nd cemented lens, a biconvex lens, and a positive meniscus lens with a convex surface facing the object side. The 1 st cemented lens is composed of a biconcave lens and a biconvex lens cemented together in this order from the object side. The 2 nd cemented lens is composed of a biconvex lens and a negative meniscus lens having a concave surface facing the object side, which are cemented together in this order from the object side. The 2 nd lens group G2 includes, in order from the object side, a positive meniscus lens with a convex surface facing the object side, a 3 rd cemented lens, an aperture stop St, a 4 th cemented lens, and a biconvex lens. The 3 rd cemented lens is composed of a biconvex lens and a biconcave lens cemented together in order from the object side. The 4 th cemented lens is composed of a negative meniscus lens having a concave surface facing the object side and a positive meniscus lens having a concave surface facing the object side cemented together in this order from the object side.

The imaging lens of the 10 th configuration example includes, in order from the object side, a 1 st lens group G1 and a 2 nd lens group G2. The 1 st lens group G1 of the 10 th configuration example is the same as the 1 st lens group G1 of the 9 th configuration example. The 2 nd lens group G2 of the 10 th configuration example includes, in order from the object side, a positive meniscus lens with a convex surface facing the object side, a 3 rd cemented lens, an aperture stop St, a negative meniscus lens with a concave surface facing the object side, a positive meniscus lens with a concave surface facing the object side, and a 4 th cemented lens. The 3 rd cemented lens is composed of a biconvex lens and a biconcave lens cemented together in order from the object side. The 4 th cemented lens is composed of a biconvex lens and a biconcave lens cemented together in order from the object side.

The imaging lens of the 11 th configuration example includes, in order from the object side, a 1 st lens group G1, a 2 nd lens group G2, and a 3 rd lens group G3. The 1 st lens group G1 includes, in order from the object side, a positive meniscus lens, a biconcave lens, a biconvex lens, a 1 st cemented lens, and a 2 nd cemented lens, with the convex surface facing the image side. The 1 st cemented lens is composed of a biconcave lens and a biconvex lens cemented together in this order from the object side. The 2 nd cemented lens is composed of a biconvex lens and a negative meniscus lens having a concave surface facing the object side, which are cemented together in this order from the object side. The 2 nd lens group G2 includes, in order from the object side, a positive meniscus lens with a convex surface facing the object side, a 3 rd cemented lens, an aperture stop St, a 4 th cemented lens, and a biconvex lens. The 3 rd cemented lens is composed of a biconvex lens and a biconcave lens cemented together in order from the object side. The 4 th cemented lens is composed of a biconcave lens and a biconvex lens cemented together in this order from the object side. The 3 rd lens group G3 includes a cemented lens in which a positive meniscus lens having a concave surface facing the object side and a negative meniscus lens having a concave surface facing the object side are cemented together in this order from the object side.

The imaging lens of the 12 th configuration example includes, in order from the object side, a 1 st lens group G1 and a 2 nd lens group G2. The 1 st lens group G1 includes, in order from the object side, a biconcave lens, a 1 st junction lens, a biconvex lens, a 2 nd junction lens, a 3 rd junction lens, and a biconvex lens. The 1 st cemented lens is composed of a biconcave lens and a biconvex lens cemented together in this order from the object side. The 2 nd cemented lens is composed of a biconcave lens and a positive meniscus lens with the convex surface facing the object side cemented together in this order from the object side. The 3 rd cemented lens is composed of a biconvex lens and a negative meniscus lens having a concave surface facing the object side, which are cemented together in this order from the object side. The 2 nd lens group G2 includes, in order from the object side, a positive meniscus lens with a convex surface facing the object side, a 4 th cemented lens, an aperture stop St, a biconcave lens, and a 5 th cemented lens. The 4 th cemented lens is composed of a biconvex lens and a biconcave lens cemented together in order from the object side. The 5 th cemented lens is composed of a biconvex lens, a biconcave lens, and a biconvex lens cemented together in this order from the object side.

The imaging lens of the 13 th configuration example includes, in order from the object side, a 1 St lens group G1, an aperture stop St, a 2 nd lens group G2, and a 3 rd lens group G3. The 1 st lens group G1 includes, in order from the object side, a biconcave lens, a 1 st cemented lens, a biconvex lens, a 2 nd cemented lens, a 3 rd cemented lens, two positive meniscus lenses with the convex surface facing the object side, a 4 th cemented lens, and a negative meniscus lens with the convex surface facing the object side. The 1 st cemented lens is composed of a biconcave lens and a biconvex lens cemented together in this order from the object side. The 2 nd cemented lens is composed of a positive meniscus lens having a concave surface facing the object side and a biconcave lens cemented together in this order from the object side. The 3 rd cemented lens is composed of a biconvex lens and a negative meniscus lens having a concave surface facing the object side, which are cemented together in this order from the object side. The 4 th cemented lens is composed of a biconvex lens and a biconcave lens cemented together in order from the object side. The 2 nd lens group G2 includes, in order from the object side, a negative meniscus lens with a concave surface toward the object side and a 5 th cemented lens. The 5 th cemented lens is composed of a biconvex lens, a biconcave lens, and a biconvex lens cemented together in this order from the object side. The 3 rd lens group G3 includes only a plano-concave lens with a concave surface facing the object side.

The imaging lens of the 14 th configuration example includes, in order from the object side, a 1 St lens group G1, an aperture stop St, and a 2 nd lens group G2. The 1 st lens group G1 includes, in order from the object side, a biconcave lens, a 1 st cemented lens, a biconvex lens, a biconcave lens, a 2 nd cemented lens, a biconvex lens, a positive meniscus lens with the convex surface facing the object side, a 3 rd cemented lens, and a negative meniscus lens with the convex surface facing the object side. The 1 st cemented lens is composed of a biconcave lens and a biconvex lens cemented together in this order from the object side. The 2 nd cemented lens is composed of a biconvex lens and a negative meniscus lens having a concave surface facing the object side, which are cemented together in this order from the object side. The 3 rd cemented lens is composed of a biconvex lens and a biconcave lens cemented together in order from the object side. The 2 nd lens group G2 includes, in order from the object side, a biconcave lens, a 4 th cemented lens, and a biconvex lens. The 4 th cemented lens is composed of a biconvex lens and a biconcave lens cemented together in order from the object side.

The imaging lens of the 15 th configuration example includes, in order from the object side, a 1 St lens group G1, an aperture stop St, a 2 nd lens group G2, and a 3 rd lens group G3. The 1 st lens group G1 includes, in order from the object side, a biconcave lens, a 1 st cemented lens, a biconvex lens, a 2 nd cemented lens, a 3 rd cemented lens, a biconvex lens, two positive meniscus lenses with the convex surface facing the object side, a 4 th cemented lens, and a negative meniscus lens with the convex surface facing the object side. The 1 st cemented lens is composed of a biconcave lens and a biconvex lens cemented together in this order from the object side. The 2 nd cemented lens is composed of a positive meniscus lens having a concave surface facing the object side and a biconcave lens cemented together in this order from the object side. The 3 rd cemented lens is composed of a biconvex lens and a negative meniscus lens having a concave surface facing the object side, which are cemented together in this order from the object side. The 4 th cemented lens is composed of a biconvex lens and a biconcave lens cemented together in order from the object side. The 2 nd lens group G2 includes, in order from the object side, a negative meniscus lens with a concave surface toward the object side and a 5 th cemented lens. The 5 th cemented lens is composed of a biconvex lens, a negative meniscus lens with a concave surface facing the object side, and a positive meniscus lens with a concave surface facing the object side, cemented together in this order from the object side. The 3 rd lens group G3 includes a plano-convex lens with the convex surface facing the object side.

The above-described preferred configurations and realizable configurations can be arbitrarily combined and preferably selectively employed as appropriate in accordance with the required specifications. According to the technique of the present invention, an appropriate imaging lens having a small F value and with aberrations being well corrected can be realized.

Next, a numerical example of the imaging lens of the present invention will be explained.

[ example 1]

The sectional structure of the imaging lens of embodiment 1 is shown in fig. 1, and the method and structure for its illustration are as described above, and therefore, a repetitive description thereof will be omitted here. The imaging lens of embodiment 1 includes, in order from the object side, a 1 St lens group G1 having positive refractive power, an aperture stop St, a 2 nd lens group G2 having positive refractive power, and a 3 rd lens group G3 having positive refractive power. When focusing from an infinity object to a closest object, the 1 st lens group G1 and the 3 rd lens group G3 are fixed to the image plane Sim, and the 2 nd lens group G2 moves to the object side along the optical axis Z. The 1 st lens group G1 includes 7 lenses, i.e., lenses L1a to L1G, in order from the object side. The 2 nd lens group G2 includes 5 lenses, i.e., lenses L2a to L2e, in order from the object side. The 3 rd lens group G3 includes one lens of lens L3 a.

With respect to the imaging lens of example 1, the basic lens data, the specifications, the variable surface intervals, and the aspherical surface coefficients are shown in table 1, table 2, table 3, and table 4, respectively. In table 1, the column Sn shows the surface number when the surface closest to the object side is the 1 st surface and the numbers are increased one by one toward the image side, the column R shows the radius of curvature of each surface, and the column D shows the surface interval on the optical axis between each surface and the surface adjacent to the image side. The refractive index of each component element with respect to the d-line is shown in the column Nd, the d-line-based dispersion coefficient of each component element is shown in the column v d, and the partial dispersion ratio between the g-line and the F-line of each component element is shown in the column θ gF.

In table 1, the sign of the radius of curvature of the surface of the shape in which the convex surface faces the object side is positive, and the sign of the radius of curvature of the surface of the shape in which the convex surface faces the image side is negative. Table 1 also shows the aperture stop St and the optical member PP, and the term of the surface number (St) is described in the column of the surface number corresponding to the surface of the aperture stop St. The value in the lowermost column of D in table 1 is the distance between the image plane Sim and the surface closest to the image side in the table. In table 1, the variable surface interval in which the focus time interval changes is denoted by DD [ ], and the object-side surface number of the interval is denoted by [ ]andis shown in the column D.

The values of the focal length F, F value fno, and maximum full-view angle 2 ω max of the imaging lens are shown in table 2. FNo is the same as FNo used in the above conditional expression. The unit of 2 ω max is degrees. The values shown in table 2 are values based on the d-line in a state of focusing on an object at infinity.

In table 3, the values of the variable surface interval in the state of focusing on an object at infinity and the values of the variable surface interval in the state of focusing on an object having a distance of 0.7m (meter) from the object to the image plane Sim are shown in the columns labeled "infinity" and "0.7 m", respectively.

In table 1, the aspheric surface is denoted by a symbol, and the column of the curvature radius of the aspheric surface shows the numerical value of the paraxial curvature radius. In table 4, the column Sn shows the surface number of the aspherical surface, and the columns K A and Am (m is an integer of 3 or more and varies from surface to surface) show the numerical values of the aspherical surface coefficients of the respective aspherical surfaces. Of aspherical coefficients of Table 4"E. + -. n" (n: integer) of the numerical values means ". times.10^±n". KA and Am are aspheric coefficients in an aspheric expression represented by the following expression.

Zd＝C×h²/{1+(1-KA×C²×h²)^1/2}+∑Am×h^m

Wherein,

and (d) is as follows: aspheric depth (length of a perpendicular line that depends from a point on the aspheric surface of height h to a plane tangent to the aspheric vertex and perpendicular to the optical axis);

h: height (distance from the optical axis to the lens surface);

c: the reciprocal of the paraxial radius of curvature;

KA. Am, and (2): the coefficient of the aspherical surface is,

the aspherical Σ represents a sum associated with m.

In the data of each table, degrees are used as a unit of angle, mm (millimeter) is used as a unit of length, and the optical system can be used in an enlarged scale or in a reduced scale. In each table shown below, numerical values rounded to a predetermined number of digits are shown.

[ Table 1]

Example 1

Sn	R	D	Nd	v d	θgF
						1	-202.46222	2.400	1.61750	36.25	0.58409
2	84.17703	10.655
						3	116.82988	10.000	1.45860	90.19	0.53516
4	-99.70316	1.010
						5	58.97589	6.168	2.00272	19.32	0.64514
6	157.48112	0.200
						7	39.80574	10.250	1.59282	68.62	0.54414
8	93.85195	0.200
						9	32.50135	7.910	1.53945	63.48	0.53990
10	113.27635	1.500	1.85896	22.73	0.62844
						11	30.08960	2.350
12	48.57213	1.500	1.98613	16.48	0.66558
						13	23.70172	7.000
14(St)	∞	DD[14]
						*15	-16.62654	1.800	1.68948	31.02	0.59874
*16	-20.47694	0.200
						17	46.52462	7.524	1.95375	32.32	0.59015
18	-24.94567	1.110	1.78555	25.72	0.61045
						19	32.92450	1.205
20	53.58123	8.896	1.95375	32.32	0.59015
						21	-21.67977	1.210	1.63849	34.39	0.58799
22	121.65386	DD[22]
						23	350.00000	2.000	1.90602	23.33	0.62075
24	-350.00000	12.401
						25	∞	2.850	1.51680	64.20	0.53430
26	∞	1.000

[ Table 2]

Example 1

f	51.529
		FNo.	1.03
2ωmax	30.6

[ Table 3]

Example 1

	Infinity	0.7m
			DD[14]	11.000	5.227
DD[22]	1.004	6.777

[ Table 4]

Example 1

Sn	15	16
			KA	1.0000000E+00	1.0000000E+00
A3	0.0000000E+00	0.0000000E+00
			A4	1.4134736E-05	1.5709981E-05
A5	2.6259559E-05	2.5965284E-05
			A6	-3.3907589E-06	-4.2475360E-06
A7	-2.4053109E-07	-1.2459177E-08
			A8	1.0812258E-07	1.0406812E-07
A9	-2.4866912E-09	-8.5930892E-09
			A10	-1.7843185E-09	-1.0929846E-09
A11	1.2258615E-10	1.6907154E-10
			A12	1.6697433E-11	4.3662373E-12
A13	-1.8317390E-12	-1.5987613E-12
			A14	-7.6120774E-14	1.5986683E-14
A15	1.4012767E-14	8.3615812E-15
			A16	2.5265457E-17	-2.3879418E-16
A17	-5.5017957E-17	-2.3215598E-17
			A18	1.1014057E-18	9.2450531E-19
A19	8.7746514E-20	2.6760815E-20
			A20	-2.9531051E-21	-1.2643529E-21

Fig. 2 and 3 show aberration diagrams of the imaging lens according to embodiment 1. Fig. 2 shows a spherical aberration diagram, an astigmatism diagram, a distortion aberration diagram, and a magnification chromatic aberration diagram in this order from the left. In fig. 2, the upper stage labeled "infinity" shows the respective aberration diagrams in a state of focusing on an object at infinity, and the lower stage labeled "0.7 m" shows the respective aberration diagrams in a state of focusing on an object at a distance of 0.7m (meter) from the object to the image plane Sim. In the spherical aberration diagram, aberrations in the d-line, C-line, F-line, and g-line are shown by a solid line, a long dashed line, a short dashed line, and a one-dot chain line, respectively. In the astigmatism diagrams, the aberration in the sagittal direction at d is shown by the solid line, and the aberration in the meridional direction at d is shown by the short dashed line. In the distortion aberration diagram, the aberration under the d-line is shown with a solid line. In the chromatic aberration of magnification diagram, aberrations in the C-line, F-line, and g-line are shown by the long dashed line, short dashed line, and one-dot chain line, respectively. Fno of the spherical aberration diagram indicates the F value, and ω of the other aberration diagrams indicates the half angle of view. In fig. 2, values of fno and ω corresponding to the upper ends of the vertical axes of the respective graphs are shown beside "═ a".

Fig. 3 shows a lateral aberration diagram in a state of focusing on an infinite object. For each angle of view, aberrations in the meridional direction are shown in the left column, and aberrations in the sagittal direction are shown in the right column. ω of fig. 3 represents a half view angle. In the lateral aberration diagram, aberrations in the d-line, C-line, F-line, and g-line are shown by a solid line, a long dashed line, a short dashed line, and a one-dot chain line, respectively.

Unless otherwise specified, the symbols, meanings, description methods, and illustration methods of the respective data relating to the above-described example 1 are the same in the following examples, and therefore, a part of the overlapping description is omitted below.

[ example 2]

Fig. 4 shows a sectional structure of an imaging lens of embodiment 2. The imaging lens of embodiment 2 includes, in order from the object side, a 1 St lens group G1 having positive refractive power, an aperture stop St, and a 2 nd lens group G2 having positive refractive power. In focusing from an infinity object to a closest object, the 1 st lens group G1 is fixed with respect to the image plane Sim, and the 2 nd lens group G2 moves to the object side along the optical axis Z. The 1 st lens group G1 includes 7 lenses, i.e., lenses L1a to L1G, in order from the object side. The 2 nd lens group G2 includes 5 lenses, i.e., lenses L2a to L2e, in order from the object side.

With respect to the imaging lens of example 2, the basic lens data, the specifications, the variable surface intervals, the aspherical coefficients and the respective aberrations are shown in table 5, table 6, table 7, table 8 and fig. 5 and 6, respectively. In fig. 5, the upper stage shows the respective aberration diagrams in a state of focusing on an object at infinity, and the lower stage shows the respective aberration diagrams in a state of focusing on an object having a distance of 0.75m (meter) from the object to the image plane Sim. In fig. 6, a lateral aberration diagram in a state of focusing on an infinite object is shown.

[ Table 5]

Example 2

Sn	R	D	Nd	v d	θgF
						1	-147.83201	2.400	1.56607	42.61	0.57194
2	86.55844	13.196
						3	-1112.59959	10.000	1.49700	81.61	0.53887
4	-74.96995	1.010
						5	56.10284	7.350	1.92286	20.88	0.63900
6	168.76278	0.200
						7	39.99940	10.364	1.49700	81.61	0.53887
8	153.92109	0.200
						9	33.63361	9.003	1.58350	61.79	0.54178
10	143.73093	1.500	1.89286	20.36	0.63944
						11	32.94000	2.350
12	58.54173	1.500	1.98613	16.48	0.66558
						13	26.84925	7.000
14(St)	∞	DD[14]
						*15	-16.34007	2.374	1.68948	31.02	0.59874
*16	-20.92321	0.200
						17	46.16889	5.601	2.00100	29.13	0.59952
18	-34.75772	1.110	1.82933	23.53	0.61772
						19	36.00359	1.259
20	65.48463	7.692	2.00100	29.13	0.59952
						21	-21.60337	1.210	1.72399	28.80	0.60142
22	-221.70851	DD[22]
						23	∞	2.850	1.51680	64.20	0.53430
24	∞	1.000

[ Table 6]

Example 2

f	48.912
		FNo.	1.03
2ωmax	32.2

[ Table 7]

Example 2

	Infinity	0.75m
			DD[14]	11.000	6.974
DD[22]	15.398	19.418

[ Table 8]

Example 2

Sn	15	16
			KA	1.0000000E+00	1.0000000E+00
A3	0.0000000E+00	0.0000000E+00
			A4	1.1642920E-05	1.4474213E-05
A5	2.1306014E-05	2.0258437E-05
			A6	-3.3814546E-06	-4.0400080E-05
A7	-1.9812243E-07	4.7913832E-08
			A8	1.0663262E-07	9.6017868E-08
A9	1.5803952E-09	-8.4598138E-09
			A10	-1.8092896E-09	-9.9449719E-10
A11	9.0694353E-11	1.5710711E-10
			A12	1.8185970E-11	4.0001956E-12
A13	-1.4218748E-12	-1.4517868E-12
			A14	-9.8519189E-14	1.3061204E-14
A15	1.1294372E-14	7.4850181E-15
			A16	1.8703189E-16	-2.0136740E-16
A17	-4.5775183E-17	-2.0557864E-17
			A18	5.1939904E-19	7.6973691E-19
A19	7.4994186E-20	2.3482464E-20
			A20	-2.1146255E-21	-1.0301864E-21

[ example 3]

Fig. 7 shows a sectional structure of an imaging lens of embodiment 3. The imaging lens of embodiment 3 includes, in order from the object side, a 1 St lens group G1 having positive refractive power, an aperture stop St, and a 2 nd lens group G2 having positive refractive power. In focusing from an infinity object to a closest object, the 1 st lens group G1 is fixed with respect to the image plane Sim, and the 2 nd lens group G2 moves to the object side along the optical axis Z. The 1 st lens group G1 includes 7 lenses, i.e., lenses L1a to L1G, in order from the object side. The 2 nd lens group G2 includes 5 lenses, i.e., lenses L2a to L2e, in order from the object side.

With respect to the imaging lens of example 3, the basic lens data, the specifications, the variable surface intervals, the aspherical coefficients and the respective aberrations are shown in table 9, table 10, table 11, table 12 and fig. 8 and 9, respectively. Fig. 8 shows, in the upper stage, the respective aberration diagrams in a state of focusing on an object at infinity, and in the lower stage, the respective aberration diagrams in a state of focusing on an object having a distance of 0.7m (meter) from the object to the image plane Sim. Fig. 9 shows a lateral aberration diagram in a state of focusing on an object at infinity.

[ Table 9]

Example 3

Sn	R	D	Nd	v d	θgF
						1	-138.62827	2.400	1.54072	47.23	0.56780
2	58.55723	10.030
						3	75.89616	11.800	1.59282	68.62	0.54414
4	-105.01257	0.200
						5	45.45982	10.800	1.59282	68.62	0.54414
6	399.21443	0.600
						7	44.95362	4.320	1.95906	17.47	0.65993
8	63.84817	0.600
						9	36.12697	5.270	1.78800	47.52	0.55545
10	60.17700	1.800	1.89286	20.36	0.63944
						11	31.65635	4.565
12	177.12407	1.520	1.80809	22.76	0.63073
						13	27.86122	6.406
14(St)	∞	DD[14]
						*15	-14.64464	2.550	1.68863	31.20	0.60109
*16	-18.73058	0.200
						17	49.66071	6.450	1.88300	39.22	0.57295
18	-32.52200	1.210	1.69895	30.05	0.60174
						19	32.52200	0.820
20	42.22428	8.800	1.88300	39.22	0.57295
						21	-28.75400	1.210	1.62005	36.35	0.58602
22	-178.14293	DD[22]
						23	∞	2.850	1.51680	64.20	0.53430
24	∞	1.000

[ Table 10]

Example 3

f	49.549
		FNo.	1.03
2ωmax	31.4

[ Table 11]

Example 3

	Infinity	0.7m
			DD[14]	11.466	7.025
DD[22]	14.401	18.842

[ Table 12]

Example 3

Sn	15	16
			KA	1.0000000E+00	1.0000000E+00
A3	0.0000000E+00	0.0000000E+00
			A4	5.0823068E-05	3.9661172E-05
A5	5.6696216E-06	7.3155985E-06
			A6	-1.1665918E-06	-1.9241870E-06
A7	2.3011235E-07	2.0632606E-07
			A8	-8.5462646E-09	2.7709406E-08
A9	-3.9871990E-09	-6.9926396E-09
			A10	5.8946218E-10	-2.2702122E-11
A11	6.8551648E-12	9.8429055E-11
			A12	-7.4371184E-12	-3.5432557E-12
A13	3.9451971E-13	-7.7218349E-13
			A14	3.7621265E-14	4.3918443E-14
A15	-4.2785117E-15	3.5209637E-15
			A16	-2.5668735E-17	-2.5005394E-16
A17	1.8252095E-17	-8.7077803E-18
			A18	-4.3536351E-19	7.1579377E-19
A19	-2.9072588E-20	9.0040531E-21
			A20	1.1528202E-21	-8.3059544E-22

[ example 4]

Fig. 10 shows a sectional structure of an imaging lens of embodiment 4. The imaging lens of embodiment 4 includes, in order from the object side, the 1 St lens group G1 having positive refractive power, an aperture stop St, and the 2 nd lens group G2 having positive refractive power. In focusing from an infinity object to a closest object, the 1 st lens group G1 is fixed with respect to the image plane sim, and the 2 nd lens group G2 moves to the object side along the optical axis Z. The 1 st lens group G1 includes 7 lenses, i.e., lenses L1a to L1G, in order from the object side. The 2 nd lens group G2 includes 5 lenses, i.e., lenses L2a to L2e, in order from the object side.

With respect to the imaging lens of example 4, the basic lens data, the specifications, the variable surface intervals, the aspherical coefficients and the respective aberrations are shown in table 13, table 14, table 15, table 16 and fig. 11 and 12, respectively. In fig. 11, the upper stage shows the respective aberration diagrams in a state of focusing on an object at infinity, and the lower stage shows the respective aberration diagrams in a state of focusing on an object having a distance of 0.6m (meter) from the object to the image plane Sim. Fig. 12 shows a lateral aberration diagram in a state of focusing on an infinite object.

[ Table 13]

Example 4

Sn	R	D	Nd	v d	θgF
						1	-184.15927	2.400	1.80000	29.84	0.60178
2	62.61647	4.878
						3	98.51388	6.313	1.98613	16.48	0.66558
4	4034.13252	1.100
						5	63.34975	10.200	1.59282	68.62	0.54414
6	-296.07052	0.200
						7	44.03004	10.250	1.59282	68.62	0.54414
8	795.08982	0.200
						9	34.85519	7.910	1.87070	40.73	0.56825
10	121.35104	1.500	1.89286	20.36	0.63944
						11	41.54155	2.500
12	103.47070	1.500	1.85896	22.73	0.62844
						13	22.43821	7.000
14(St)	∞	DD[14]
						15	-23.29314	1.110	1.59270	35.31	0.59336
16	23.13973	7.642	1.88300	39.22	0.57295
						17	-49.13842	0.500
*18	-31.45625	2.200	1.68948	31.02	0.59874
						*19	-35.44240	0.100
20	57.70265	8.669	1.88300	39.22	0.57295
						21	-29.44571	1.210	1.59270	35.31	0.59336
22	455.30805	DD[22]
						23	∞	2.850	1.51680	64.20	0.53430
24	∞	1.000

[ Table 14]

Example 4

f	48.495
		FNo.	1.03
2ωmax	32.4

[ Table 15]

Example 4

	Infinity	0.6m
			DD[14]	10.100	5.021
DD[22]	14.402	19.481

[ Table 16]

Example 4

Sn	18	19
			KA	1.0000000E+00	1.0000000E+00
A3	0.0000000E+00	0.0000000E+00
			A4	-4.1880254E-05	-1.8080969E-05
A5	2.2277957E-05	1.7658879E-05
			A6	-1.0486644E-06	-1.2728716E-06
A7	-6.0774700E-07	-2.8821944E-07
			A8	6.5534778E-08	3.8775713E-08
A9	9.8049532E-09	3.2995970E-09
			A10	-1.3866580E-09	-5.0968526E-10
A11	-9.2054942E-11	-2.6981943E-11
			A12	1.6184890E-11	3.7414083E-12
A13	4.5994752E-13	1.6196819E-13
			A14	-1.1024413E-13	-1.4531348E-14
A15	-7.7379704E-16	-6.8886559E-16
			A16	4.2085620E-16	1.7953337E-17
A17	-2.3252064E-18	1.8140969E-18
			A18	-7.7399797E-19	5.5970230E-20
A19	8.4567070E-21	-2.1514981E-21
			A20	4.0991440E-22	-1.5749796E-22

[ example 5]

Fig. 13 shows a sectional structure of an imaging lens of example 5. The imaging lens of embodiment 5 includes, in order from the object side, the 1 St lens group G1 having positive refractive power, an aperture stop St, and the 2 nd lens group G2 having positive refractive power. In focusing from an infinity object to a closest object, the 1 st lens group G1 is fixed with respect to the image plane Sim, and the 2 nd lens group G2 moves to the object side along the optical axis Z. The 1 st lens group G1 includes 7 lenses, i.e., lenses L1a to L1G, in order from the object side. The 2 nd lens group G2 includes 5 lenses, i.e., lenses L2a to L2e, in order from the object side.

With respect to the imaging lens of example 5, the basic lens data, the specifications, the variable surface intervals, the aspherical coefficients and the respective aberrations are shown in table 17, table 18, table 19, table 20 and fig. 14 and 15, respectively. In fig. 14, the upper stage shows the respective aberration diagrams in a state of focusing on an object at infinity, and the lower stage shows the respective aberration diagrams in a state of focusing on an object having a distance of 0.6m (meter) from the object to the image plane Sim. Fig. 15 shows a lateral aberration diagram in a state of focusing on an infinite object.

[ Table 17]

Example 5

Sn	R	D	Nd	v d	θgF
						1	-165.93122	2.400	1.56037	43.68	0.57006
2	76.27518	8.339
						3	203.54358	10.000	1.59522	67.73	0.54426
4	-111.87010	1.010
						5	56.74170	5.365	1.89286	20.36	0.63944
6	102.45084	0.200
						7	44.31471	10.250	1.59522	67.73	0.54426
8	292.61942	0.200
						9	32.85510	8.595	1.69253	56.87	0.54266
10	115.66155	1.500	1.78472	25.68	0.61052
						11	31.63618	2.819
12	63.52660	1.500	1.89286	20.36	0.63944
						13	23.88347	7.000
14(St)	∞	DD[14]
						*15	-16.34570	2.837	1.68948	31.02	0.59874
*16	-22.88973	0.200
						17	45.14005	6.141	1.90043	37.37	0.57720
18	-33.79047	1.110	1.70834	29.58	0.59931
						19	33.20670	1.120
20	51.98052	8.500	1.90043	37.37	0.57720
						21	-22.44701	1.210	1.60763	37.24	0.58209
22	-201.05993	DD[22]
						23	∞	2.850	1.54763	54.98	0.55247
24	∞	1.000

[ Table 18]

Example 5

f	50.617
		FNo.	1.03
2ωmax	31.4

[ Table 19]

Example 5

	Infinity	0.6m
			DD[14]	11.000	5.612
DD[22]	15.436	20.824

[ Table 20]

Example 5

Sn	15	16
			KA	1.0000000E+00	1.0000000E+00
A3	0.0000000E+00	0.0000000E+00
			A4	3.1181867E-05	2.6530803E-05
A5	1.4794096E-05	1.5226995E-05
			A6	-2.8122797E-06	-3.5186055E-06
A7	8.9003214E-08	2.0389209E-07
			A8	6.9213577E-08	7.3115649E-08
A9	-8.7233682E-09	-1.1688257E-08
			A10	-8.1799110E-10	-5.0238456E-10
A11	1.9725575E-10	1.9915512E-10
			A12	3.0890969E-12	-2.4972651E-12
A13	-2.3953381E-12	-1.7930323E-12
			A14	4.0298515E-14	6.6348784E-14
A15	1.6625829E-14	9.1585232E-15
			A16	-5.7273231E-16	-4.6481540E-16
A17	-6.1842548E-17	-2.5090883E-17
			A18	2.7969524E-18	1.4869080E-18
A19	9.5479576E-20	2.8685321E-20
			A20	-4.9925629E-21	-1.8543937E-21

[ example 6]

Fig. 16 shows a sectional structure of an imaging lens of example 6. The imaging lens of embodiment 6 includes, in order from the object side, the 1 St lens group G1 having positive refractive power, an aperture stop St, and the 2 nd lens group G2 having positive refractive power. In focusing from an infinity object to a closest object, the 1 st lens group G1 is fixed with respect to the image plane Sim, and the 2 nd lens group G2 moves to the object side along the optical axis Z. The 1 st lens group G1 includes 8 lenses, i.e., lenses L1a to L1h, in order from the object side. The 2 nd lens group G2 includes 5 lenses, i.e., lenses L2a to L2e, in order from the object side.

With respect to the imaging lens of example 6, the basic lens data, the specifications, the variable surface intervals, the aspherical coefficients and the aberrations are shown in table 21, table 22, table 23, table 24 and fig. 17 and 18, respectively. Fig. 17 shows, in the upper stage, aberration diagrams in a state of focusing on an object at infinity, and in the lower stage, aberration diagrams in a state of focusing on an object at a distance of 0.6m (meter) from the object to the image plane Sim. Fig. 18 shows a lateral aberration diagram in a state of focusing on an infinite object.

[ Table 21]

Example 6

Sn	R	D	Nd	v d	θgF
						1	-247.95976	2.800	1.77791	26.10	0.61461
2	75.89689	11.010
						3	114.39503	7.000	1.92286	18.90	0.64960
4	-837.42367	0.100
						5	69.26549	11.000	1.58525	61.72	0.54210
6	196.03197	0.100
						7	84.81564	7.038	1.53775	74.70	0.53936
8	1034.21503	0.100
						9	91.91092	5.000	1.53775	74.70	0.53936
10	177.41757	0.100
						11	33.30279	12.000	1.88300	39.22	0.57295
12	-424.49645	1.510	1.72186	28.91	0.60113
						13	61.07419	1.500
14	98.63832	1.500	1.91717	19.14	0.63501
						15	21.08130	7.000
16(St)	∞	DD[16]
						17	-22.42941	1.100	1.58780	39.22	0.57813
18	23.14403	7.400	1.88300	39.22	0.57295
						19	-31.61388	1.000
*20	-33.94641	1.800	1.61724	36.28	0.58403
						*21	173.48601	0.100
22	47.71113	7.271	1.81834	46.17	0.55821
						23	-26.72012	1.210	1.69584	30.30	0.60324
24	-56.34422	DD[24]
						25	∞	2.850	1.51680	64.20	0.53430
26	∞	1.000

[ Table 22]

Example 6

f	48.498
		FNo.	1.03
2ωmax	32.6

[ Table 23]

Example 6

	Infinity	0.6m
			DD[16]	10.100	4.816
DD[24]	14.400	19.684

[ Table 24]

Example 6

Sn	20	21
			KA	1.0000000E+00	1.0000000E+00
A3	0.0000000E+00	0.0000000E+00
			A4	-2.3773046E-05	3.0929722E-06
A5	5.6674484E-06	4.8487684E-06
			A6	5.6970844E-08	-5.0456910E-07
A7	-1.9176909E-07	1.5258010E-08
			A8	1.9626233E-08	6.7914018E-09
A9	2.9049337E-09	-1.5524880E-09
			A10	-6.6057808E-10	-1.1339723E-11
A11	-1.9889473E-11	2.4115890E-11
			A12	1.0577029E-11	-4.6114184E-13
A13	7.5098137E-15	-1.8660180E-13
			A14	-9.7929627E-14	3.8327989E-15
A15	7.5328476E-16	7.9224149E-16
			A16	5.3398130E-16	-7.7601860E-18
A17	-4.2992770E-18	-1.7504256E-18
			A18	-1.5949215E-18	-2.1972718E-20
A19	7.7287369E-21	1.5807498E-21
			A20	2.0144963E-21	7.7734912E-23

[ example 7]

Fig. 19 shows a sectional structure of an imaging lens of example 7. The imaging lens of embodiment 7 includes, in order from the object side, the 1 St lens group G1 having positive refractive power, an aperture stop St, and the 2 nd lens group G2 having positive refractive power. In focusing from an infinity object to a closest object, the 1 st lens group G1 is fixed with respect to the image plane Sim, and the 2 nd lens group G2 moves to the object side along the optical axis Z. The 1 st lens group G1 includes 8 lenses, i.e., lenses L1a to L1h, in order from the object side. The 2 nd lens group G2 includes 5 lenses, i.e., lenses L2a to L2e, in order from the object side.

With respect to the imaging lens of example 7, the basic lens data, the specifications, the variable surface intervals, the aspherical coefficients and the respective aberrations are shown in table 25, table 26, table 27, table 28 and fig. 20 and 21, respectively. In fig. 20, the upper stage shows the respective aberration diagrams in a state of focusing on an object at infinity, and the lower stage shows the respective aberration diagrams in a state of focusing on an object having a distance of 0.6m (meter) from the object to the image plane Sim. Fig. 21 shows a lateral aberration diagram in a state of focusing on an object at infinity.

[ Table 25]

Example 7

Sn	R	D	Nd	v d	θgF
						1	-204.30501	2.800	1.81294	24.35	0.61887
2	81.96794	13.010
						3	137.60012	7.000	2.10420	17.02	0.66311
4	-656.31103	3.750
						5	69.54614	12.000	1.57265	62.21	0.54137
6	267.60481	0.193
						7	88.85695	9.422	1.43875	94.66	0.53402
8	-2937.87944	0.100
						9	96.07701	5.000	1.43875	94.66	0.53402
10	181.83582	0.100
						11	33.17157	12.000	1.88300	39.22	0.57295
12	-374.98026	1.510	1.76530	26.82	0.60713
						13	66.58003	1.500
14	97.44593	1.500	1.96720	17.42	0.64384
						15	21.58463	7.000
16(St)	∞	DD[16]
						17	-22.85203	1.100	1.56026	43.70	0.57003
18	22.46642	7.400	1.88300	39.22	0.57295
						19	-31.83440	1.000
*20	-30.58326	1.800	1.66113	32.78	0.59162
						*21	340.35421	0.100
22	55.88143	6.486	1.81271	42.14	0.56732
						23	-26.29030	1.210	1.70642	29.68	0.60465
24	-49.33676	DD[24]
						25	∞	2.850	1.51680	64.20	0.53430
26	∞	1.000

[ Table 26]

Example 7

f	48.220
		FNo.	1.04
2ωmax	32.8

[ Table 27]

Example 7

	Infinity	0.6m
			DD[16]	10.100	4.858
DD[24]	14.973	20.215

[ Table 28]

Example 7

Sn	20	21
			KA	1.0000000E+00	1.0000000E+00
A3	0.0000000E+00	0.0000000E+00
			A4	-2.1813953E-05	5.6632078E-06
A5	5.5899615E-06	4.4402595E-06
			A6	8.3363623E-08	-4.7071845E-07
A7	-1.9184059E-07	1.5982530E-08
			A8	1.9586298E-08	6.7572477E-09
A9	2.8981856E-09	-1.5590421E-09
			A10	-6.6105638E-10	-1.1726148E-11
A11	-1.9888631E-11	2.4116692E-11
			A12	1.0581175E-11	-4.5950671E-13
A13	8.0018964E-15	-1.8648724E-13
			A14	-9.7926487E-14	3.8358049E-15
A15	7.5055780E-16	7.9215688E-16
			A16	5.3398130E-16	-7.7662214E-18
A17	-4.2992770E-18	-1.7496474E-18
			A18	-1.5949215E-18	-2.1852378E-20
A19	7.7287369E-21	1.5557319E-21
			A20	2.0144963E-21	7.8155637E-23

[ example 8]

Fig. 22 shows a sectional structure of an imaging lens of example 8. The imaging lens of embodiment 8 includes, in order from the object side, the 1 St lens group G1 having positive refractive power, an aperture stop St, and the 2 nd lens group G2 having positive refractive power. In focusing from an infinity object to a closest object, the 1 st lens group G1 is fixed with respect to the image plane Sim, and the 2 nd lens group G2 moves to the object side along the optical axis Z. The 1 st lens group G1 includes 7 lenses, i.e., lenses L1a to L1G, in order from the object side. The 2 nd lens group G2 includes 5 lenses, i.e., lenses L2a to L2e, in order from the object side.

With respect to the imaging lens of example 8, the basic lens data, the specifications, the variable surface intervals, the aspherical coefficients and the respective aberrations are shown in table 29, table 30, table 31, table 32 and fig. 23 and 24, respectively. Fig. 23 shows, in the upper stage, aberration diagrams in a state of focusing on an object at infinity, and in the lower stage, aberration diagrams in a state of focusing on an object at a distance of 0.6m (meter) from the object to the image plane Sim. Fig. 24 shows a lateral aberration diagram in a state of focusing on an object at infinity.

[ Table 29]

Example 8

Sn	R	D	Nd	v d	θgF
						1	-1250.00000	2.400	1.50911	53.29	0.55329
2	58.56667	12.004
						3	63.53662	10.300	1.55032	75.50	0.54001
4	-324.18577	1.010
						5	91.24308	4.145	1.55032	75.50	0.54001
6	237.79601	0.200
						7	41.36102	10.250	1.59282	68.62	0.54414
8	108.29456	0.200
						9	35.06677	7.900	2.00069	25.46	0.61364
10	76.31696	0.806
						11	90.22442	1.500	1.78880	28.43	0.60092
12	28.87926	2.968
						13	53.65263	1.500	1.89286	20.36	0.63944
14	23.13445	7.000
						15(St)	∞	DD[15]
*16	-16.70584	1.943	1.68948	31.02	0.59874
						*17	-24.50468	0.200
18	44.48608	6.995	1.88300	39.22	0.57295
						19	-26.79392	1.110	1.71036	29.48	0.59958
20	33.02652	1.005
						21	48.60027	9.237	1.85150	40.78	0.56958
22	-19.88726	1.210	1. 56738	42.37	0.57237
						23	-131.23867	DD[23]
24	∞	2.850	1.51680	64.20	0.53430
						25	∞	1.000

[ Table 30]

Example 8

f	51.521
		FNo.	1.03
2ωmax	31.0

[ Table 31]

Example 8

	Infinity	0.6m
			DD[15]	11.000	5.534
DD[23]	15.401	20.867

[ Table 32]

Example 8

Sn	16	17
			KA	1.0000000E+00	1.0000000E+00
A3	0.0000000E+00	0.0000000E+00
			A4	7.0570380E-05	6.6014243E-05
A5	1.9198543E-05	1.9606733E-05
			A6	-3.3289534E-06	-4.2582967E-06
A7	-9.0333134E-08	1.4153915E-07
			A8	9.0099971E-08	9.0936965E-08
A9	-4.1396511E-09	-1.1106603E-08
			A10	-1.4390577E-09	-8.1411034E-10
A11	1.2641084E-10	1.9638299E-10
			A12	1.3445189E-11	1.0722851E-12
A13	-1.7282916E-12	-1.7929595E-12
			A14	-6.2059351E-14	3.9257132E-14
A15	1.2881202E-14	9.2275563E-15
			A16	2.3758855E-17	-3.3269509E-16
A17	-5.0325955E-17	-2.5409216E-17
			A18	9.0421501E-19	1.1130994E-18
A19	8.0548323E-20	2.9170042E-20
			A20	-2.4717980E-21	-1.3898997E-21

[ example 9]

Fig. 25 shows a sectional structure of an imaging lens of example 9. The imaging lens of example 9 includes, in order from the object side, the 1 St lens group G1 having positive refractive power, an aperture stop St, and the 2 nd lens group G2 having positive refractive power. In focusing from an infinity object to a closest object, the 1 st lens group G1 is fixed with respect to the image plane sim, and the 2 nd lens group G2 moves to the object side along the optical axis Z. The 1 st lens group G1 includes 7 lenses, i.e., lenses L1a to L1G, in order from the object side. The 2 nd lens group G2 includes 5 lenses, i.e., lenses L2a to L2e, in order from the object side.

With respect to the imaging lens of example 9, the basic lens data, the specifications, the variable surface intervals, the aspherical coefficients and the respective aberrations are shown in table 33, table 34, table 35, table 36 and fig. 26 and 27, respectively. Fig. 26 shows, in the upper stage, aberration diagrams in a state of focusing on an object at infinity, and in the lower stage, aberration diagrams in a state of focusing on an object at a distance of 0.6m (meter) from the object to the image plane Sim. Fig. 27 shows a lateral aberration diagram in a state of focusing on an infinite object.

[ Table 33]

Example 9

Sn	R	D	Nd	v d	θgF
						1	-193.76114	2.400	1.54760	46.08	0.56589
2	75.97796	9.081
						3	189.01581	10.000	1.49700	81.61	0.53887
4	-105.13621	1.010
						5	56.49917	5.721	1.92119	23.96	0.62025
6	104.36406	0.200
						7	43.70727	10.385	1.49700	81.61	0.53887
8	340.80096	0.200
						9	32.58246	9.094	1.75819	43.78	0.56631
10	73.72282	1.500	1.78472	25.68	0.61052
						11	32.68245	2.542
12	61.75401	1.500	1.89286	20.36	0.63944
						13	22.41400	7.000
14(St)	∞	DD[14]
						*15	-16.41866	2.693	1.68948	31.02	0.59874
*16	-22.85517	0.200
						17	45.64284	6.105	1.88300	39.22	0.57295
18	-33.87303	1.110	1.68877	30.80	0.59625
						19	33.14697	1.132
20	52.16226	8.770	1.88300	39.22	0.57295
						21	-21.44050	1.210	1.59203	38.80	0.57897
22	-202.15701	DD[22]
						23	∞	2.850	1.51680	64.20	0.53430
24	∞	1.000

[ Table 34]

Example 9

f	51.018
		FNo.	1.03
2ωmax	31.2

[ Table 35]

Example 9

	Infinity	0.6m
			DD[14]	11.000	5.539
DD[22]	15.401	20.862

[ Table 36]

Example 9

Sn	15	16
			KA	1.0000000E+00	1.0000000E+00
A3	0.0000000E+00	0.0000000E+00
			A4	2.5050662E-05	2.1927553E-05
A5	1.6399123E-05	1.6962214E-05
			A6	-2.7037336E-06	-3.5614573E-06
A7	2.2716407E-08	1.6637583E-07
			A8	7.0481328E-08	7.6462842E-08
A9	-7.0934969E-09	-1.1129036E-08
			A10	-9.1743883E-10	-5.7804163E-10
A11	1.7293397E-10	1.9360903E-10
			A12	5.1834973E-12	-1.4806257E-12
A13	-2.1727289E-12	-1.7572338E-12
			A14	1.7187231E-14	5.7682678E-14
A15	1.5404695E-14	9.0145899E-15
			A16	-4.2947569E-16	-4.1936383E-16
A17	-5.8157492E-17	-2.4764768E-17
			A18	2.3258567E-18	1.3542989E-18
A19	9.0773374E-20	2.8368189E-20
			A20	-4.3526649E-21	-1.6904315E-21

[ example 10]

Fig. 28 shows a sectional structure of an imaging lens of example 10. The imaging lens of embodiment 10 includes, in order from the object side, the 1 St lens group G1 having positive refractive power, an aperture stop St, the 2 nd lens group G2 having negative refractive power, and the 3 rd lens group G3 having positive refractive power. When focusing from an infinity object to a closest object, the 1 st lens group G1 and the 3 rd lens group G3 are fixed to the image plane Sim, and the 2 nd lens group G2 moves to the image side along the optical axis Z. The 1 st lens group G1 includes 7 lenses, i.e., lenses L1a to L1G, in order from the object side. The 2 nd lens group G2 includes 4 lenses, i.e., lenses L2a to L2d, in order from the object side. The 3 rd lens group G3 includes 5 lenses, i.e., lenses L3a to L3e, in order from the object side.

With respect to the imaging lens of example 10, the basic lens data, the specifications, the variable surface intervals and the respective aberrations are shown in tables 37, 38, 39 and 30, respectively. Fig. 29 shows, in the upper stage, the respective aberration diagrams in a state of focusing on an object at infinity, and in the lower stage, the respective aberration diagrams in a state of focusing on an object having a distance of 0.7m (meter) from the object to the image plane Sim. Fig. 30 shows a lateral aberration diagram in a state of focusing on an object at infinity.

[ Table 37]

Example 10

Sn	R	D	Nd	v d	θgF
							1	272.44778	3.300	2.05090	26.94	0.60519
2	1081.40696	0.100
						3	89.65014	3.000	1.59282	68.62	0.54414
4	152.15669	0.100
						5	74.09242	6.000	1.59282	68.62	0.54414
6	263.34977	0.100
						7	107.02621	1.500	1.85896	22.73	0.62844
8	78.42749	10.010	1.76212	31.60	0.59550
						9	-175.82899	1.000
10	-144.21433	1.500	1.85896	22.73	0.62844
						11	80.87758	4.510	1.56883	56.36	0.54890
12	716.45491	5.217
						13(St)	∞	DD[13]
14	-38.44224	1.000	1.87904	40.10	0.56811
						15	130.29249	6.010	1.59410	60.47	0.55516
16	-33.25476	0.600
						17	-351.00941	4.000	2.00272	19.32	0.64514
18	-45.80501	1.500	1.64173	39.35	0.57903
						19	36.04598	DD[19]
20	43.30755	7.389	1.59522	67.73	0.54426
						21	-236.34955	0.100
22	90.49741	7.652	1.83481	42.72	0.56486
						23	-46.09199	1.360	1.67270	32.10	0.59891
24	27.92315	4.075
						25	30.74850	9.035	1.65463	48.36	0.56208
26	-201.70415	2.100
						27	-51.13607	1.350	1.48749	70.44	0.53062
28	76.12890	21.401
						29	∞	2.850	1.51680	64.20	0.53430
30	∞	1.000

[ Table 38]

Example 10

f	87.302
		FNo.	1.86
2ωmax	18.6

[ Table 39]

Example 10

	Infinity	0.7m
			DD[13]	5.000	16.962
DD[19]	15.702	3.740

[ example 11]

Fig. 31 shows a sectional structure of an imaging lens of example 11. The imaging lens of example 11 includes, in order from the object side, a 1 St lens group G1 having positive refractive power, an aperture stop St, a 2 nd lens group G2 having negative refractive power, and a 3 rd lens group G3 having positive refractive power. When focusing from an infinity object to a closest object, the 1 st lens group G1 and the 3 rd lens group G3 are fixed to the image plane Sim, and the 2 nd lens group G2 moves to the image side along the optical axis Z. The 1 st lens group G1 includes 8 lenses, i.e., lenses L1a to L1h, in order from the object side. The 2 nd lens group G2 includes 4 lenses, i.e., lenses L2a to L2d, in order from the object side. The 3 rd lens group G3 includes 5 lenses, i.e., lenses L3a to L3e, in order from the object side.

With respect to the imaging lens of example 11, the basic lens data, the specifications, the variable surface intervals and the respective aberrations are shown in table 40, table 41, table 42 and fig. 32 and 33, respectively. Fig. 32 shows, in the upper stage, aberration diagrams in a state of focusing on an object at infinity, and in the lower stage, aberration diagrams in a state of focusing on an object at a distance of 0.8m (meter) from the object to the image plane Sim. Fig. 33 shows a lateral aberration diagram in a state of focusing on an object at infinity.

[ Table 40]

Example 11

Sn	R	D	Nd	v d	θgF
						1	-386.94657	1.800	1.69680	55.53	0.54341
2	119.46581	2.500
						3	207.26394	4.000	1.95375	32.32	0.59015
4	-238.96341	0.100
						5	76.64894	4.500	1.59522	67.73	0.54426
6	248.42469	0.100
						7	63.92071	5.500	1.43875	94.66	0.53402
8	216.59149	0.100
						9	107.16236	1.500	1.85025	30.05	0.59797
10	85.24799	7.998	1.65412	39.68	0.57378
						11	-205.11243	1.000
12	-197.70982	1.500	1.92119	23.96	0.62025
						13	90.62875	4.510	1.45860	90.19	0.53516
14	-30275.61759	8.130
						15(St)	∞	DD[15]
16	-43.49420	1.000	1.89190	37.13	0.57813
						17	185.12129	6.010	1.77250	49.60	0.55212
18	-44.59399	0.600
						19	-428.71303	4.000	2.10420	17.02	0.66311
20	-76.05920	1.500	1.58144	40.75	0.57757
						21	37.00980	DD[21]
22	36.00466	5.851	1..59522	67.73	0.54426
						23	-124.44012	0.100
24	829.97224	5.140	1.90043	37.37	0.57720
						25	-51.93826	1.360	1.67270	32.10	0.59891
26	28.10820	3.300
						27	34.48127	9.174	1.77250	49.60	0.55212
28	-110.39811	2.231
						29	-38.11168	1.350	1.48749	70.44	0.53062
30	89.57871	21.429
						31	∞	2.850	1.51680	64.20	0.53430
32	∞	1.000

[ Table 41]

Example 11

f	79.213
		FNo.	1.65
2ωmax	20.2

[ Table 42]

Example 11

	Infinity	0.8m
			DD[15]	5.043	18.069
DD[21]	14.864	1.838

[ example 12]

Fig. 34 shows a sectional structure of an imaging lens of example 12. The imaging lens of example 12 includes, in order from the object side, a 1 St lens group G1 having positive refractive power, an aperture stop St, a 2 nd lens group G2 having negative refractive power, and a 3 rd lens group G3 having positive refractive power. When focusing from an infinity object to a closest object, the 1 st lens group G1 and the 3 rd lens group G3 are fixed to the image plane Sim, and the 2 nd lens group G2 moves to the image side along the optical axis Z. The 1 st lens group G1 includes 8 lenses, i.e., lenses L1a to L1h, in order from the object side. The 2 nd lens group G2 includes 4 lenses, i.e., lenses L2a to L2d, in order from the object side. The 3 rd lens group G3 includes 5 lenses, i.e., lenses L3a to L3e, in order from the object side.

With respect to the imaging lens of example 12, the basic lens data, the specifications, the variable surface intervals and the respective aberrations are shown in table 43, table 44, table 45 and fig. 35 and 36, respectively. Fig. 35 shows, in the upper stage, aberration diagrams in a state of focusing on an object at infinity, and in the lower stage, aberration diagrams in a state of focusing on an object at a distance of 0.7m (meter) from the object to the image plane Sim. Fig. 36 shows a lateral aberration diagram in a state of focusing on an infinite object.

[ Table 43]

Example 12

Sn	R	D	Nd	v d	θgF
						1	-291.68052	1.800	1.64769	33.79	0.59393
2	99.99894	2.500
						3	177.53930	4.000	1.92119	23.96	0.62025
4	-250.63993	0.100
						5	83.49241	3.500	1.59522	67.73	0.54426
6	315.24688	0.100
						7	65.26695	5.500	1.55032	75.50	0.54001
8	230.27246	0.100
						9	117.55484	1.500	2.00069	25.46	0.61364
10	89.18435	10.010	1.67300	38.26	0.57580
						11	-205.86865	1.000
12	-214.55358	1.500	1.85896	22.73	0.62844
						13	81.16463	4.510	1.62299	58.16	0.54589
14	301.17897	7.667
						15(St)	∞	DD[15]
16	-44.85924	1.000	1.89190	37.13	0.57813
						17	78.25190	6.010	1.72916	54.68	0.54451
18	-44.95132	0.600
						19	-344.73789	4.000	1.94595	17.98	0.65460
20	-48.43416	1.500	1.58144	40.75	0.57757
						21	36.97488	DD[21]
22	38.40711	5.751	1.59522	67.73	0.54426
						23	-82.40638	0.100
24	-707.34003	5.905	1.85150	40.78	0.56958
						25	-45.35298	1.360	1.67270	32.10	0.59891
26	27.74475	1.726
						27	31.49767	9.688	1.80400	46.53	0.55775
28	-172.72812	2.100
						29	-40.02478	1.350	1.48749	70.44	0.53062
30	129.32128	21.402
						31	∞	2.850	1.51680	64.20	0.53430
32	∞	1.000

[ Table 44]

Example 12

f	77.634
		FNo.	1.65
2ωmax	20.8

[ Table 45]

Example 12

	Infinity	0.7m
			DD[15]	5.000	19.027
DD[21]	14.908	0.881

[ example 13]

Fig. 37 shows a sectional structure of an imaging lens of example 13. The imaging lens of example 13 includes, in order from the object side, the 1 st lens group G1 having positive refractive power and the 2 nd lens group G2 having positive refractive power. In focusing from an infinity object to a closest object, the 1 st lens group G1 is fixed with respect to the image plane Sim, and the 2 nd lens group G2 moves to the object side along the optical axis Z. The 1 st lens group G1 includes 8 lenses, i.e., lenses L1a to L1h, in order from the object side. The 2 nd lens group G2 includes, in order from the object side, lenses L2a to L2c, an aperture stop St, and lenses L2d to L2G.

With respect to the imaging lens of example 13, the basic lens data, the specifications, the variable surface intervals, the aspherical coefficients and the respective aberrations are shown in table 46, table 47, table 48, table 49 and fig. 38 and 39, respectively. Fig. 38 shows, in the upper stage, aberration diagrams in a state of focusing on an object at infinity, and in the lower stage, aberration diagrams in a state of focusing on an object at a distance of 0.4m (meter) from the object to the image plane Sim. Fig. 39 shows a lateral aberration diagram in a state of focusing on an infinite object.

[ Table 46]

Example 13

Sn	R	D	Nd	v d	θgF
						1	-80.28635	2.000	1.48749	70.24	0.53007
2	42.98733	13.000
						3	-63.79046	1.860	1.62004	36.26	0.58800
4	51.39741	12.441	1.88299	40.78	0.56829
						5	-144.73231	0.100
6	176.27919	7.877	2.00069	25.46	0.61364
						7	-160.05852	0.100
8	24017.51177	11.145	1.49700	81.54	0.53748
						9	-53.46758	2.020	1.95906	17.47	0.65993
10	-141.76150	0.100
						11	73.80784	6.228	1.43875	94.66	0.53402
12	-6705.69476	0.100
						13	135.56611	4.200	1.49700	81.54	0.53748
14	188.15073	DD[14]
						15	48.95259	5.513	1.95906	17.47	0.65993
16	205.45635	0.253
						17	25.65935	8.918	1.59282	68.62	0.54414
18	-442.23226	1.200	1.80809	22.76	0.63073
						19	17.92257	5.504
20(St)	∞	5.000
						*21	-17.88285	1.500	1.68948	31.02	0.59874
*22	-49.72259	0.500
						23	213.02720	6.649	1.81600	46.62	0.55682
24	-19.33525	1.120	1.62004	36.26	0.58800
						25	47.67656	6.689	1.88299	40.78	0.56829
26	-31.38846	DD[26]
						27	∞	2.850	1.51680	64.20	0.53430
28	∞	1.000

[ Table 47]

Example 13

f	32.024
		FNo.	1.03
2ωmax	49.0

[ Table 48]

Example 13

	Infinity	0.4m
			DD[14]	5.524	1.833
DD[26]	14.098	17.789

[ Table 49]

Example 13

Sn	21	22
			KA	1.0000000E+00	1.0000000E+00
A3	0.0000000E+00	0.0000000E+00
			A4	1.7715606E-04	1.7642986E-04
A5	1.7074166E-05	1.6476812E-05
			A6	-5.3189612E-06	-4.6629565E-06
A7	-1.7052372E-07	-2.6282483E-07
			A8	1.0629596E-07	1.1534278E-07
A9	3.7804819E-10	-2.9531996E-10
			A10	-1.7627478E-09	-1.9368547E-09
A11	3.7456752E11	8.2583641E-11
			A12	2.1780336E11	1.9811305E-11
A13	-1.0619291E-12	-1.3990529E-12
			A14	-1.6070128E-13	-1.1461723E-13
A15	1.2952078E-14	1.1207794E-14
			A16	4.9200989E-16	2.9951674E-16
A17	-7.4222889E-17	-4.5040584E-17
			A18	6.6519028E-19	5.5182976E-20
A19	1.6312319E-19	7.2914615E-20
			A20	-5.4198359E-21	-1.3034388E-21

[ example 14]

Fig. 40 shows a sectional structure of an imaging lens of example 14. The imaging lens of example 14 includes, in order from the object side, a 1 st lens group G1 having positive refractive power and a 2 nd lens group G2 having positive refractive power. In focusing from an infinity object to a closest object, the 1 st lens group G1 is fixed with respect to the image plane Sim, and the 2 nd lens group G2 moves to the object side along the optical axis Z. The 1 st lens group G1 includes 8 lenses, i.e., lenses L1a to L1h, in order from the object side. The 2 nd lens group G2 includes, in order from the object side, lenses L2a to L2c, an aperture stop St, and lenses L2d to L2 f.

With respect to the imaging lens of example 14, the basic lens data, the specifications, the variable surface intervals, the aspherical coefficients and the aberrations are shown in table 50, table 51, table 52, table 53 and fig. 41 and 42, respectively. Fig. 41 shows, in the upper stage, aberration diagrams in a state of focusing on an object at infinity, and in the lower stage, aberration diagrams in a state of focusing on an object at a distance of 0.3m (meter) from the object to the image plane Sim. Fig. 42 shows a lateral aberration diagram in a state of focusing on an infinite object.

[ Table 50]

Example 14

Sn	R	D	Nd	v d	θgF
						1	-741.84965	4.557	2.00001	16.35	0.64993
2	133.27267	2.137
						3	-88.69549	2.000	1.51957	51.33	0.55675
4	30.12135	17.951
						5	-43.59777	1.860	1.72220	28.89	0.60118
6	50.07951	14.509	1.99166	26.42	0.61104
						7	-73.94447	0.200
8	102.81602	12.918	1.72183	55.41	0.54271
						9	-47.50103	2.020	1.96573	16.71	0.64633
10	-188.35959	0.100
						11	282.52887	4.513	1.43875	94.66	0.53402
12	-146.67361	0.010
						13	51.37757	3.531	1.59522	67.73	0.54426
14	63.46607	DD[14]
						15	49.82440	5.000	2.00001	15.00	0.65515
16	197.53926	0.250
						17	27.63615	9.109	1.59522	67.73	0.54426
18	-134.79322	1.550	1.85370	22.31	0.62213
						19	18.23355	5.500
20(St)	∞	5.487
						21	-18.30655	1.500	1.63029	39.17	0.57925
22	-48.92302	5.529	1.48984	65.39	0.53509
						23	-24.64229	0.100
*24	56.89240	6.000	1.79341	48.66	0.55129
						*25	-36.65031	DD[25]
26	∞	2.850	1.51680	64.20	0.53430
						27	∞	1.000

[ Table 51]

Example 14

f	29.079
		FNo.	1.03
2ωmax	53.2

[ Table 52]

Example 14

	Infinity	0.3m
			DD[14]	6.500	1.921
DD[25]	16.342	20.921

[ Table 53]

Example 14

Sn	24	25
			KA	1.0000000E+00	1.0000000E+00
A4	-1.6809135E-06	8.5774318E-06
			A6	-2.1517689E-07	-2.0857403E-07
A8	9.2942401E-09	6.7208947E-09
			A10	-2.1073323E-10	-1.2334691E-10
A12	2.8305897E-12	1.3706654E-12
			A14	-2.3236997E-14	-9.4138699E-15
A16	1.1475262E-16	3.9270429E-17
			A18	-3.1366558E-19	-9.1668061E-20
A20	3.6536989E-22	9.2574233E-23

[ example 15]

Fig. 43 shows a sectional structure of an imaging lens of example 15. The imaging lens of example 15 includes, in order from the object side, a 1 st lens group G1 having positive refractive power and a 2 nd lens group G2 having positive refractive power. In focusing from an infinity object to a closest object, the 1 st lens group G1 is fixed with respect to the image plane Sim, and the 2 nd lens group G2 moves to the object side along the optical axis Z. The 1 st lens group G1 includes 8 lenses, i.e., lenses L1a to L1h, in order from the object side. The 2 nd lens group G2 includes, in order from the object side, lenses L2a to L2c, an aperture stop St, and lenses L2d to L2G.

With respect to the imaging lens of example 15, the basic lens data, the specifications, the variable surface intervals, the aspherical coefficients and the respective aberrations are shown in table 54, table 55, table 56, table 57 and fig. 44 and 45, respectively. Fig. 44 shows, in the upper stage, aberration diagrams in a state of focusing on an object at infinity, and in the lower stage, aberration diagrams in a state of focusing on an object at a distance of 0.3m (meter) from the object to the image plane Sim. Fig. 45 shows a lateral aberration diagram in a state of focusing on an object at infinity.

[ Table 54]

Example 15

Sn	R	D	Nd	v d	θgF
							1	642.95860	5.882	2.00001	16.89	0.64786
2	-164.66697	1.863
						3	-99.52183	2.000	1.61064	54.41	0.55296
4	33.83357	15.951
						5	-47.68180	1.860	1.70668	31.21	0.59581
6	51.06375	13.761	1.98542	25.79	0.61339
						7	-87.22549	0.200
8	126.67025	12.325	1.72259	55.37	0.54271
						9	-47.54495	2.020	1.97455	17.92	0.64243
10	-275.27420	0.100
						11	171.98328	5.821	1.43875	94.66	0.53402
12	-113.39789	0.010
						13	46.43027	5.041	1.59522	67.73	0.54426
14	84.61748	DD[14]
						15	55.77297	4.000	2.00000	15.00	0.65515
16	202.80478	0.605
						17	27.63715	8.988	1.58689	61.66	0.54186
18	-134.09655	1.550	1.85789	22.11	0.62292
						19	19.09448	5.638
20(St)	∞	5.927
						*21	-28.03700	1.500	1.89872	28.11	0.60520
*22	-44.46753	1.250
						23	-96.25411	6.671	1.74032	53.97	0.54394
24	-23.20962	0.500
						25	63.33337	6.000	1.90048	37.95	0.57345
26	-32.84508	1.310	1.47999	58.75	0.54320
						27	33.51612	DD[27]
28	∞	2.850	1.51680	64.20	0.53430
						29	∞	1.000

[ Table 55]

Example 15

f	29.906
		FNo.	1.03
2ωmax	51.4

[ Table 56]

Example 15

	Infinity	0.3m
			DD[14]	6.500	1.468
DD[27]	11.900	16.932

[ Table 57]

Example 15

Sn	21	22
			KA	1.0000000E+00	1.0000000E+00
A4	-5.0827829E-05	-2.1426467E-05
			A6	-1.1853379E-07	-4.7548185E-08
A8	9.4795512E-09	5.2403072E-09
			A10	-2.7750209E-10	-1.0968658E-10
A12	5.8490730E-12	2.0277440E-12
			A14	-7.6027021E-14	-2.5419242E-14
A16	5.7225628E-16	1.8641103E-16
			A18	-2.2972054E-18	-7.2476475E-19
A20	3.8030548E-21	1.1546366E-21

[ example 16]

Fig. 46 shows a sectional structure of an imaging lens of example 16. The imaging lens of example 16 includes, in order from the object side, a 1 st lens group G1 having positive refractive power, a 2 nd lens group G2 having positive refractive power, and a 3 rd lens group G3 having negative refractive power. When focusing from an infinity object to a closest object, the 1 st lens group G1 and the 3 rd lens group G3 are fixed to the image plane Sim, and the 2 nd lens group G2 moves to the object side along the optical axis Z. The 1 st lens group G1 includes 7 lenses, i.e., lenses L1a to L1G, in order from the object side. The 2 nd lens group G2 includes, in order from the object side, lenses L2a to L2c, an aperture stop St, and lenses L2d to L2 f. The 3 rd lens group G3 includes two lenses, lens L3a to L3b, in order from the object side.

With respect to the imaging lens of example 16, the basic lens data, the specifications, the variable surface intervals, the aspherical coefficients and the respective aberrations are shown in tables 58, 59, 60, 61 and 48, respectively. Fig. 47 shows, in the upper stage, aberration diagrams in a state of focusing on an object at infinity, and in the lower stage, aberration diagrams in a state of focusing on an object at a distance of 0.3m (meter) from the object to the image plane Sim. Fig. 48 shows a lateral aberration diagram in a state of focusing on an infinite object.

[ Table 58]

Example 16

Sn	R	D	Nd	v d	θgF
						1	-297.13714	7.166	1.87070	40.73	0.56825
2	-85.86719	1.000
						3	-73.16221	2.000	1.74077	27.79	0.60961
4	42.66024	7.413
						5	392.24356	6.462	1.87070	40.73	0.56825
6	-146.01920	4.000
						7	-66.16556	1.860	1.72825	28.46	0.60772
8	51.18899	11.866	2.10420	17.02	0.66311
						9	-245.64485	0.200
10	77.22649	15.828	1.88300	40.80	0.56557
						11	-47.49919	2.020	1.98613	16.48	0.66558
12	-198.94323	DD[12]
						13	55.79899	6.000	1.92286	20.88	0.63900
14	1076.94076	0.250
						15	30.39757	10.286	1.59410	60.47	0.55516
16	-49.75521	1.550	1.92286	20.88	0.63900
						17	20.04359	5.500
18(St)	∞	5.642
						19	-22.24985	1.510	1.59270	35.31	0.59336
20	30.44450	8.452	1.90043	37.37	0.57668
						21	-37.69952	0.270
*22	87.14518	3.500	1.83481	42.72	0.56486
						*23	-62.14252	DD[23]
24	-134.06447	3.010	1.64000	60.08	0.53704
						25	-34.88724	1.000	1.65412	39.68	0.57378
26	-129.28425	12.064
						27	∞	2.850	1.51680	64.20	0.53430
28	∞	1.000

[ Table 59]

Example 16

f	33.489
		FNo.	1.03
2ωmax	46.8

[ Table 60]

Example 16

	Infinity	0.3m
			DD[12]	6.714	0.856
DD[23]	2.000	7.858

[ Table 61]

Example 16

Sn	22	23
			KA	1.0000000E+00	1.0000000E+00
A4	-5.8591082E-06	2.8872810E-06
			A6	8.0450854E-09	-1.4218337E-08
A8	-1.8982768E-10	4.2017521E-11
			A10	6.8830323E-13	-2.5968320E-13
A12	-2.8216339E-15	-1.0662872E-15

[ example 17]

Fig. 49 shows a cross-sectional structure of an imaging lens of example 17. The imaging lens of example 17 includes, in order from the object side, a 1 st lens group G1 having positive refractive power and a 2 nd lens group G2 having positive refractive power. In focusing from an infinity object to a closest object, the 1 st lens group G1 is fixed with respect to the image plane Sim, and the 2 nd lens group G2 moves to the object side along the optical axis Z. The 1 st lens group G1 includes 9 lenses, i.e., lenses L1a to L1i, in order from the object side. The 2 nd lens group G2 includes, in order from the object side, lenses L2a to L2c, an aperture stop St, and lenses L2d to L2G.

With respect to the imaging lens of example 17, the basic lens data, the specifications, the variable surface intervals, the aspherical coefficients and the aberrations are shown in table 62, table 63, table 64, table 65 and fig. 50 and 51, respectively. Fig. 50 shows, in the upper stage, aberration diagrams in a state of focusing on an object at infinity, and in the lower stage, aberration diagrams in a state of focusing on an object at a distance of 0.4m (meter) from the object to the image plane Sim. Fig. 51 shows a lateral aberration diagram in a state of focusing on an object at infinity.

[ Table 62]

Example 17

Sn	R	D	Nd	v d	θgF
						1	-336.27458	2.200	1.48749	70.24	0.53007
2	38.98761	15.631
						3	-46.53554	2.210	1.59551	39.24	0.58043
4	249.77972	5.766	1.88300	39.22	0.57295
						5	-160.59902	0.800
6	276.62948	8.350	2.00069	25.46	0.61364
						7	-81.36890	3.916
8	-63.06549	2.210	1.69895	30.13	0.60298
						9	135.70322	3.841	1.88300	39.22	0.57295
10	422.33573	1.500
						11	102.34565	15.415	1.43875	94.66	0.53402
12	-44.71698	2.200	1.85896	22.73	0.62844
						13	-77.19256	0.100
14	101.83391	9.311	1.59282	68.62	0.54414
						15	-119.76934	DD[15]
16	69.07462	5.899	1.95906	17.47	0.65993
						17	449.86569	0.600
18	33.09295	10.662	1.59282	68.62	0.54414
						19	-150.72672	1.700	1.85896	22.73	0.62844
20	26.86774	6.577
						21(St)	∞	8.310
*22	-28.92910	1.800	1.68948	31.02	0.59874
						*23	419.15250	1.784
24	124.99078	6.834	1.88300	39.22	0.57295
						25	-19.93892	1.220	1.59270	35.31	0.59336
26	40.55156	6.493	1.87070	40.73	0.56825
						27	-53.64933	DD[27]
28	∞	2.850	1.51680	64.20	0.53430
						29	∞	1.000

[ Table 63]

Example 17

f	32.299
		FNo.	1.03
2ωmax	49.0

[ Table 64]

Example 17

	Infinity	0.4m
			DD[15]	5.583	1.508
DD[27]	14.463	18.538

[ Table 65]

Example 17

Sn	22	23
			KA	1.0000000E+00	1.0000000E+00
A3	0.0000000E+00	0.0000000E+00
			A4	3.5406543E-05	4.9366505E-05
A5	7.0264041E-06	7.9379491E-06
			A6	-1.1816569E-06	-1.4343119E-06
A7	-2.2756224E-07	-2.0060437E-07
			A8	3.4450831E-08	4.3102131E-08
A9	5.4529188E-09	3.4605387E-09
			A10	-8.2702494E-10	-9.3263727E-10
A11	-8.7833902E11	-3.7283303E-11
			A12	1.3514381E-11	1.3092859E-11
A13	8.9890230E-13	2.4405774E-13
			A14	-1.4076774E-13	-1.1755255E-13
A15	-5.5890568E-15	-9.1931741E-16
			A16	8.9135105E-16	6.5486383E-16
A17	1.9220049E-17	1.7211209E-18
			A18	-3.1226127E-18	-2.0673300E-18
A19	-2.7989666E-20	-1.0111723E-21
			A20	4.6368363E-21	2.8305920E-21

[ example 18]

Fig. 52 shows a sectional structure of an imaging lens of example 18. The imaging lens of example 18 includes, in order from the object side, the 1 St lens group G1 having positive refractive power, an aperture stop St, the 2 nd lens group G2 having positive refractive power, and the 3 rd lens group G3 having negative refractive power. When focusing from an infinity object to a closest object, the 1 st lens group G1 and the 3 rd lens group G3 are fixed to the image plane Sim, and the 2 nd lens group G2 moves to the object side along the optical axis Z. The 1 st lens group G1 includes 13 lenses, i.e., lenses L1a to L1m, in order from the object side. The 2 nd lens group G2 includes 4 lenses, i.e., lenses L2a to L2d, in order from the object side. The 3 rd lens group G3 includes one lens of lens L3 a.

With respect to the imaging lens of example 18, the basic lens data, the specifications, the variable surface intervals, the aspherical coefficients and the respective aberrations are shown in table 66, table 67, table 68, table 69 and fig. 53 and 54, respectively. Fig. 53 shows, in the upper stage, aberration diagrams in a state of focusing on an object at infinity, and in the lower stage, aberration diagrams in a state of focusing on an object at a distance of 0.4m (meter) from the object to the image plane Sim. Fig. 54 shows a lateral aberration diagram in a state of focusing on an object at infinity.

[ Table 66]

Example 18

Sn	R	D	Nd	v d	θgF
						1	-633.25261	2.000	1.59551	39.24	0.58043
2	38.00665	12.863
						3	-54.28519	1.850	1.80100	34.97	0.58642
4	95.00850	10.922	1.71300	53.87	0.54587
						5	-67.98194	0.100
6	95.72298	6.765	2.00272	19.32	0.64514
						7	-251.63874	1.000
8	-246.42407	6.991	1.80100	34.97	0.58642
						9	-53.58723	1.610	1.69895	30.13	0.60298
10	99.80167	0.909
						11	137.54054	10.681	1.62041	60.29	0.54266
12	-52.34651	2.010	1.60342	38.03	0.58356
						13	-414.75790	0.100
14	143.20008	3.225	1.69680	55.53	0.54341
						15	366.55185	0.462
16	51.74239	6.881	1.91082	35.25	0.58224
						17	180.97539	0.260
18	35.24471	11.944	1.81600	46.62	0.55682
						19	-93.14313	1.010	1.72825	28.46	0.60772
20	79.60733	0.642
						21	118.00563	1.300	1.85896	22.73	0.62844
22	22.08603	7.000
						23(St)	∞	DD[23]
*24	-18.33819	1.700	1.68948	31.02	0.59874
						*25	-31.12948	0.100
26	111.28451	5.800	1.87070	40.73	0.56825
						27	-25.06585	1. 220	1.69895	30.13	0.60298
28	182.89249	6.206	1.81600	46.62	0.55682
						29	-28.43888	DD[29]
30	-125.00563	1.300	1.51742	52.43	0.55649
						31	∞	11.118
32	∞	2.150	1.54763	54.98	0.55247
						33	∞	1.317
34	∞	0.700	1.49784	54.98	0.55000
						35	∞	1.000

[ Table 67]

Example 18

f	32.025
		FNo.	1.03
2ωmax	48.4

[ Table 68]

Example 18

	Infinity	0.4m
			DD[23]	10.027	6.297
DD[29]	1.500	5.230

[ Table 69]

Example 18

Sn	24	25
			KA	1.0000000E+00	1.0000000E+00
A4	7.6509788E-05	8.6420274E-05
			A6	-1.2736248E-06	-6.0388926E-07
A8	5.0778640E-08	1.1474585E-08
			A10	-1.3097284E-09	-7.5854198E-11
A12	2.0623870E-11	-1.6331770E-12
			A14	-2.0059301E-13	3.9524334E-14
A16	1.1722812E-15	-3.5644909E-16
			A18	-3.7566167E-18	1.5341315E-18
A20	5.0432936E-21	-2.6183645E-21

[ example 19]

Fig. 55 shows a sectional structure of an imaging lens of example 19. The imaging lens of example 19 includes, in order from the object side, the 1 St lens group G1 having positive refractive power, an aperture stop St, and the 2 nd lens group G2 having positive refractive power. In focusing from an infinity object to a closest object, the 1 st lens group G1 is fixed with respect to the image plane Sim, and the 2 nd lens group G2 moves to the object side along the optical axis Z. The 1 st lens group G1 includes 12 lenses, i.e., lenses L1a to L1L, in order from the object side. The 2 nd lens group G2 includes 4 lenses, i.e., lenses L2a to L2d, in order from the object side.

With respect to the imaging lens of example 19, the basic lens data, the specifications, the variable surface intervals, the aspherical coefficients and the respective aberrations are shown in table 70, table 71, table 72, table 73 and fig. 56 and 57, respectively. Fig. 56 shows, in the upper stage, aberration diagrams in a state of focusing on an object at infinity, and in the lower stage, aberration diagrams in a state of focusing on an object at a distance of 0.4m (meter) from the object to the image plane Sim. Fig. 57 shows a lateral aberration diagram in a state of focusing on an infinite object.

[ Table 70]

Example 19

Sn	R	D	Nd	v d	θgF
						1	-158.58566	2.000	1.56926	62.34	0.54137
2	45.50663	11.311
						3	-58.28419	1.860	1.82401	23.80	0.61679
4	41.90339	13.828	1.88018	21.34	0.62618
						5	-101.81510	0.100
6	98.28394	8.000	1.99999	15.00	0.65515
						7	-127.35841	0.100
8	-132.35649	1.600	1.85117	22.44	0.62166
						9	84.30253	1.535
10	137.70215	12.985	1.66628	58.19	0.54256
						11	-39.49589	2.000	1.86788	21.61	0.62483
12	-124.45426	0.100
						13	73.44245	7.449	1.82042	45.96	0.55588
14	-358.81915	0.000
						15	52.60700	4.584	1.71060	55.97	0.54269
16	93.76319	0.250
						17	35.01559	11.718	1.81600	46.62	0.55682
18	-112.02490	1.000	1.83429	23.29	0.61859
						19	45.38534	0.919
20	60.40304	1.300	1.80688	24.66	0.61389
						21	21.37711	7.000
22(St)	∞	DD[22]
						23	-24.07079	1.400	1.48001	58.75	0.54321
24	352.80309	0.100
						25	39.97798	8.898	1.94001	31.43	0.59353
26	-30.93442	1.210	1.76519	26.74	0.60732
						27	59.03069	1. 000
*28	53.18296	5.500	1.80610	40.73	0.56940
						*29	-44.23856	DD[29]
30	∞	2.150	1.54763	54.98	0.55247
						31	∞	1.320
32	∞	0.700	1.49784	54.98	0.55000
						33	∞	1.000

[ Table 71]

Example 19

f	32.017
		FNo.	1.03
2ωmax	49.0

[ Table 72]

Example 19

	Infinity	0.4m
			DD[22]	10.229	5.964
DD[29]	11.831	16.096

[ Table 73]

Example 19

[ example 20]

Fig. 58 shows a sectional structure of an imaging lens of example 20. The imaging lens of example 20 includes, in order from the object side, a 1 St lens group G1 having positive refractive power, an aperture stop St, a 2 nd lens group G2 having positive refractive power, and a 3 rd lens group G3 having positive refractive power. When focusing from an infinity object to a closest object, the 1 st lens group G1 and the 3 rd lens group G3 are fixed to the image plane Sim, and the 2 nd lens group G2 moves to the object side along the optical axis Z. The 1 st lens group G1 includes 14 lenses, i.e., lenses L1a to L1n, in order from the object side. The 2 nd lens group G2 includes 4 lenses, i.e., lenses L2a to L2d, in order from the object side. The 3 rd lens group G3 includes one lens of lens L3 a.

With respect to the imaging lens of example 20, the basic lens data, the specifications, the variable surface intervals, the aspherical coefficients and the respective aberrations are shown in table 74, table 75, table 76, table 77 and fig. 59 and 60, respectively. Fig. 59 shows, in the upper stage, aberration diagrams in a state of focusing on an object at infinity, and in the lower stage, aberration diagrams in a state of focusing on an object at a distance of 0.6m (meter) from the object to the image plane Sim. Fig. 60 shows a lateral aberration diagram in a state of focusing on an infinite object.

[ Table 74]

Example 20

Sn	R	D	Nd	v d	θgF
						1	-69.40351	2.000	1.58913	61.13	0.54067
2	47.39750	10.135
						3	-65.36696	1.860	1.85896	22.73	0.62844
4	898.20220	6.892	1.88300	39.22	0.57295
						5	-80.44512	0.100
6	97.48909	5.741	1.98613	16.48	0.66558
						7	-546.89782	2.000
8	-171.12562	5.073	1.88300	39.22	0.57295
						9	-63.25974	1.610	1.60342	38.03	0.58356
10	111.43989	1.962
						11	341.07330	13.611	1.62041	60.29	0.54266
12	-34.36799	2.010	1.59270	35.31	0.59336
						13	-113.99006	0.100
14	276.49914	3.956	1.59282	68.62	0.54414
						15	-272.14204	0.100
16	88.96039	4.616	1.59282	68.62	0.54414
						17	546.58221	0.100
18	109.73550	3.000	1.63854	55.38	0.54858
						19	235.51602	0.000
20	32.76798	13.753	1.75500	52.32	0.54737
						21	-86.78027	1.010	1.74000	28.30	0.60790
22	46.97326	0.897
						23	62.86769	1.300	1.80518	25.42	0.61616
24	24.63660	7.000
						25(St)	∞	DD[25]
*26	-14.19913	1.700	1.68948	31.02	0.59874
						*27	-19.92300	0.100
30	217.66762	5.000	1.87070	40.73	0.56825
						30	-32.97025	1.220	1.69895	30.13	0.60298
30	-98.98873	5.691	1.88300	39.22	0.57295
						31	-31.65160	DD[31]
32	300.00000	1.800	1.48749	70.24	0.53007
						33	∞	11.121
34	∞	2.150	1.54763	54.98	0.55247
						35	∞	1.315
36	∞	0.700	1.49784	54.98	0.55000
						37	∞	1.000

[ Table 75]

Example 20

f	32.027
		FNo.	1.03
2ωmax	49.4

[ Table 76]

Example 20

	Infinity	0.6m
			DD[25]	11.613	8.481
DD[31]	1.500	4.632

[ Table 77]

Example 20

Sn	26	27
			KA	1.0000000E+00	1.0000000E+00
A4	1.6825325E-04	1.4660302E-04
			A6	-2.4177276E-06	-1.2134963E-06
A8	9.3324700E-08	1.6766078E-08
			A10	-2.2900676E-09	1.0718903E-10
A12	3.4816388E-11	-8.2761040E-12
			A14	-3.2819139E-13	1.3329649E-13
A16	1.8701820E-15	-1.0468186E-15
			A18	-5.8954769E-18	4.1491271E-18
A20	7.8960041E-21	-6.6428045E-21

Tables 78 to 82 show the corresponding values of conditional expressions (1) to (19) of the imaging lenses of examples 1 to 20. The embodiment including a plurality of LA positive lenses LA shows the values of all LA positive lenses LA. Examples 1 to 20 use the d-line as the reference wavelength. The values under the d-line reference are shown in tables 78 to 82.Δ θ gFA, Δ θ gFB, and Δ θ gFn1 in tables 78 to 82 respectively represent the following values.

Δ θgFA＝θgFA+0.00162×v dA-0.64159

Δ θgFB＝θgFB+0.00162×v dB-0.64159

Δ θgFn1＝θgFn1+0.00162×ν dn1-0.64159

[ Table 78]

Formula number		Example 1	Example 2	Example 3	Example 4
						(1)	NdA	2.00272	1.92286	1.95906	1.98613
(2)	v dA	19.32	20.88	17.47	16.48
						(3)	v dB	90.19	81.61	68.62	68.62
(4)	v dn1	19.61	18.42	21.56	21.55
						(5)	TL×FNo/f	2.246	2.417	2.293	2.225
(6)	v dC	68.62	81.61	68.62	68.62
						(7)	Ndfm	1.45860	1.49700	1.59282	1.59282
(8)	Ndpr	1.93784	2.00100	1.88300	1.88300
						(9)	Nd2p	1.95375	2.00100	1.88300	1.88300
(10)	f1/f	2.568	2.372	2.311	2.184
						(11)	1/{tan(ωmax)×FNo}	3.555	3.375	3.448	3.330
(12)	\|f2\|/f	0.795	0.721	0.705	0.699
						(13)	f1/f2	3.231	3.288	3.281	3.122
(14)	\|(1-β2²)×βr²\|	0.692	0.822	0.813	0.790
						(15)	Tf/TL	0.544	0.576	0.547	0.534
(16)	f/fm	0.859	0.803	0.872	0.825
						(17)	Δ θgFA	0.03485	0.03124	0.04664	0.05069
(18)	Δ θgFB	0.03968	0.02949	0.01371	0.01371
						(19)	Δ θgFn1	0.03718	0.04076	0.02842	0.02725

[ Table 79]

Formula number		Example 5	Example 6	Example 7	Example 8
						(1)	NdA	1.89286	1.92286	2.10420	2.00069
(2)	v dA	20.36	18.90	17.02	25.46
						(3)	v dB	67.73	74.70	94.66	75.50
(4)	v dn1	23.02	22.62	20.89	24.40
						(5)	TL×FNo/f	2.230	2.443	2.660	2.262
(6)	v dC	67.73	74.70	94.66	75.50
						(7)	Ndfm	1.59522	1.53775	1.43875	1.55032
(8)	Ndpr	1.90043	1.85067	1.84786	1.86725
						(9)	Nd2p	1.90043	1.85067	1.84786	1.86725
(10)	f1/f	2.366	2.003	2.051	2.513
						(11)	1/{tan(ωmax)×FNo}	3.462	3.329	3.279	3.512
(12)	\|f2\|/f	0.684	0.715	0.730	0.661
						(13)	f1/f2	3.457	2.800	2.808	3.800
(14)	-(1-β2²)×βr²\|	0.821	0.751	0.762	0.842
						(15)	Tf/TL	0.540	0.589	0.620	0.550
(16)	f/fm	0.860	0.822	0.796	0.933
						(17)	Δ θgFA	0.03083	0.03863	0.04909	0.01330
(18)	Δ θgFB	0.01239	0.01878	0.04578	0.02073
						(19)	Δ θgFn1	0.02068	0.01986	0.02360	0.01811

[ Table 80]

Formula number		Example 9	Example 10	Example 11	Example 12
						(1)	NdA	1.92119	2.05090	1.95375	1.92119
(2)	v dA	23.96	26.94	32.32	23.96
						(3)	v dB	81.61	68.62	94.66	75.50
(4)	v dn1	23.02	22.73	27.01	24.10
						(5)	TL×FNo/f	2.244	2.709	2.685	2.740
(6)	v dC	81.61	68.62	90.19	67.73
						(7)	Ndfm	1.49700	1.56883	1.43875	1.55032
(8)	Ndpr	1.88300	1.73630	1.82897	1.78517
						(9)	Nd2p	1.88300	1.79841	1.93835	1.83756
(10)	f1/f	2.380	0.872	1.076	1.050
						(11)	1/{tan(ωmax)×FNo}	3.482	3.302	3.395	3.309
(12)	\|f2\|/f	0.679	0.583	0.851	0.786
						(13)	f1/f2	3.503	-	-	-
(14)	\|(1-β2²)×βr²\|	0.823	1.294	0.821	0.875
						(15)	Tf/TL	0.546	0.285	0.335	0.339
(16)	f/fm	0.856	-	0.925	0.955
						(17)	Δ θgFA	0.01748	0.00724	0.00092	0.01748
(18)	Δ θgFB	0.02949	0.01371	0.04578	0.02073
						(19)	Δ θgFn1	0.02068	0.02367	0.01127	0.01848

[ Table 81]

[ Table 82]

The imaging lenses of examples 1 to 20 had an F value of less than 2. In particular, the F value of the imaging lenses of embodiments 1 to 9 is less than 1.2. The imaging lenses of embodiments 1 to 20 have such a small F value, and achieve miniaturization, and each aberration is well corrected, thereby achieving high optical performance.

Next, an imaging device according to an embodiment of the present invention will be described. Fig. 61 and 62 show external views of a camera 30 as an imaging device according to an embodiment of the present invention. Fig. 61 is a perspective view of the camera 30 viewed from the front side, and fig. 62 is a perspective view of the camera 30 viewed from the rear side. The camera 30 is a so-called non-reflective digital camera, and the interchangeable lens 20 is detachably attached thereto. The interchangeable lens 20 includes the imaging lens 1 according to an embodiment of the present invention accommodated in the lens barrel.

The camera 30 includes a camera body 31, and a shutter button 32 and a power button 33 are provided on an upper surface of the camera body 31. 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 displays the captured image and the image existing in the angle of view before the capturing.

A shooting opening into which light from a subject enters is provided in the center of the front surface of the camera body 31, a mount 37 is provided at a position corresponding to the shooting opening, and the interchangeable lens 20 is attached to the camera body 31 via the mount 37.

The camera body 31 is provided with an imaging element such as a CCD (Charge Coupled Device) or a CMOS (complementary Metal Oxide Semiconductor) that outputs an imaging signal corresponding to a subject image formed by the interchangeable lens 20, a signal processing circuit that processes the imaging signal output from the imaging element to generate an image, a recording medium that records the generated image, and the like. In the camera 30, a still image or a moving image can be captured by pressing the shutter button 32, and image data obtained by the capturing can be recorded in the recording medium.

The technique of the present invention has been described above by referring to the embodiments and examples, but the technique of the present invention is not limited to the embodiments and examples described above, and various modifications are possible. For example, the curvature radius, surface interval, refractive index, dispersion coefficient, aspherical surface coefficient, and the like of each lens are not limited to the values shown in the numerical examples, and other values may be used.

The imaging device according to the embodiment of the present invention is not limited to the above example, and various embodiments such as a non-transreflective camera, a film camera, and a video camera may be used.

Description of the symbols

1-imaging lens, 2-on-axis light beam, 3-maximum viewing angle light beam, 20-interchangeable lens, 30-camera, 31-camera body, 32-shutter button, 33-power button, 34, 35-operation part, 36-display part, 37-bayonet, G1-1 St lens group, G2-2 nd lens group, G3-3 rd lens group, Gs 1-1 St unit, Gs 2-2 nd unit, L1 a-L1 n, L2 a-L2G, L3 a-L3 e-lens, LA-LA positive lens, LB-LB positive lens, LC-LC positive lens, PP-optical component, Sim-image plane, St-aperture diaphragm, and Z-optical axis.

Claims

1. An imaging lens comprising, as lens groups, a 1 st lens group having positive refractive power and a 2 nd lens group having refractive power in this order from the most object side toward the image side,

in focusing, the interval between the 1 st lens group and the 2 nd lens group is changed, and the interval between all lenses in the 1 st lens group and the interval between all lenses in the 2 nd lens group are constant,

the aperture is disposed on the image side of the 2 nd lens from the object side,

the combined refractive power of all lenses on the object side of the diaphragm is positive,

at least one LA positive lens and at least one LB positive lens are included on the object side of the diaphragm,

the d-line reference Abbe number of the LB positive lens is the largest among the d-line reference Abbe numbers of all positive lenses on the object side of the diaphragm,

the refractive index of the LA positive lens relative to the d line is NdA,

The d-line reference Abbe number of the LA positive lens is vdA,

When the d-line reference abbe number of the LB positive lens is vdB,

the imaging lens satisfies the following conditional expressions (1), (2) and (3),

1.86＜NdA＜2.2 (1)

10＜vdA＜35 (2)

57＜vdB＜105 (3)。

2. the imaging lens according to claim 1,

the 1 st lens group includes at least two positive lenses and at least two negative lenses.

3. The imaging lens according to claim 1 or 2,

the 2 nd lens group includes at least two positive lenses and at least two negative lenses.

4. The imaging lens according to claim 1 or 2,

in focusing, the 1 st lens group is fixed relative to an image surface, and the 2 nd lens group moves.

5. The imaging lens according to claim 1 or 2,

the number of lens groups moved in focusing is only one.

6. The imaging lens according to claim 5,

the lens group that moves in focusing is only the 2 nd lens group.

7. The imaging lens according to claim 1 or 2,

the 1 st lens group includes at least two negative lenses,

in the case where the average value of the d-line reference abbe numbers of the two negative lenses selected in the order of the d-line reference abbe numbers from small to large among the negative lenses included in the 1 st lens group is set as ν dn1,

the imaging lens satisfies the following conditional expression (4),

15＜ν dn1＜28 (4)。

8. the imaging lens according to claim 1 or 2,

in focusing, the 1 st lens group is fixed relative to an image surface,

the 1 st lens group includes at least one piece of the LA positive lens.

9. The imaging lens according to claim 1 or 2,

the sum of the distance on the optical axis from the lens surface closest to the object side to the lens surface closest to the image side in a state of focusing on an object at infinity and the back focal length in terms of air-converted distance is TL,

The F value of the imaging lens in a state of focusing on an object at infinity is set as FNo,

In the case where the focal length of the imaging lens in a state of focusing on an infinite object is set to f,

the imaging lens satisfies the following conditional expression (5),

1.5＜TL×FNo/f＜5 (5)。

10. the imaging lens according to claim 1 or 2,

the imaging lens includes, as lens groups, only two lens groups including the 1 st lens group fixed to an image surface in focusing and the 2 nd lens group moving in focusing in order from an object side to an image side, or

The imaging lens includes, as lens groups, only three lens groups including the 1 st lens group fixed to an image surface in focusing, the 2 nd lens group moving in focusing, and the 3 rd lens group fixed to the image surface in focusing, which is composed of two or less lenses, in order from an object side to an image side.

11. The imaging lens according to claim 1 or 2,

the 2 nd lens group is a lens group having positive refractive power.

12. The imaging lens according to claim 1 or 2,

the 1 st lens group comprises at least three negative lenses.

13. The imaging lens according to claim 1 or 2,

the 2 nd lens group includes at least two positive lenses and at least three negative lenses.

14. The imaging lens according to claim 1 or 2,

in the case where one lens component is provided as a single lens or a cemented lens,

one lens component of the most object side lens component and the 2 nd lens component from the object side has a negative refractive power, and the other lens component has a positive refractive power,

in a state of focusing on an object at infinity, an on-axis light flux emitted from the most image-side lens surface of the one lens component having a negative refractive power to the image side is divergent light.

15. The imaging lens according to claim 1 or 2,

at least one of the most object-side lens and the 2 nd lens from the object side is a negative lens having a concave lens surface on the object side.

16. The imaging lens according to claim 1 or 2,

the most object-side lens is a negative lens.

17. The imaging lens according to claim 1 or 2,

the imaging lens includes, in order from the most object side, a single lens having a negative refractive power, a single lens having a positive refractive power, and a single lens having a positive refractive power.

18. The imaging lens according to claim 1 or 2,

the lens surface of the most object side lens on the object side is concave.

19. The imaging lens according to claim 1 or 2,

the imaging lens includes at least one LC positive lens on an object side from the diaphragm,

the LC positive lens is a positive lens having a maximum or 2 nd-larger d-line reference in all positive lenses on the object side than the diaphragm,

in the case where the d-line reference abbe number of the LC positive lens is set to vdC,

the imaging lens satisfies the following conditional expression (6),

57＜vdC＜102 (6)。

20. the imaging lens according to claim 1 or 2,

when the minimum value of the refractive index of all positive lenses on the object side of the diaphragm with respect to the d-line is Ndfm,

the imaging lens satisfies the following conditional expression (7),

1.46＜Ndfm＜1.72 (7)。

21. the imaging lens according to claim 1 or 2,

the aperture is disposed in a lens group fixed with respect to an image surface at the time of focusing, or disposed between the lens group and the lens group.

22. The imaging lens according to claim 1 or 2,

the aperture stop is disposed between the 1 st lens group and the 2 nd lens group,

in focusing, the 1 st lens group and the diaphragm are fixed relative to an image plane, and the 2 nd lens group moves.

23. The imaging lens according to claim 1 or 2,

when focusing, the 2 nd lens group moves,

the number of lenses included in the 2 nd lens group is 7 or less.

24. The imaging lens according to claim 1 or 2,

when focusing, the 2 nd lens group moves,

the number of lenses included in the 2 nd lens group is 6 or less.

25. The imaging lens according to claim 1 or 2,

when focusing, the 2 nd lens group moves,

the number of lenses included in the 2 nd lens group is 5 or less.

26. The imaging lens according to claim 1 or 2,

the number of lenses disposed on the object side of the diaphragm is 8 or less.

27. The imaging lens according to claim 1 or 2,

the number of lenses disposed on the object side of the diaphragm is 7 or less.

28. The imaging lens according to claim 1 or 2,

the imaging lens includes 13 or fewer lenses.

29. The imaging lens according to claim 1 or 2,

the imaging lens comprises less than 12 lenses.

30. The imaging lens according to claim 1 or 2,

the imaging lens includes at least two positive lenses on an image side of the aperture,

when the average value of the refractive indices of all the positive lenses on the image side of the aperture with respect to the d-line is Ndpr,

the imaging lens satisfies the following conditional expression (8),

1.77＜Ndpr＜2.15 (8)。

31. the imaging lens according to claim 1 or 2,

when focusing, the 2 nd lens group moves,

the 2 nd lens group includes at least one positive lens,

in the case where the average value of the refractive indices of all the positive lenses in the 2 Nd lens group with respect to the d-line is set to Nd2p,

the imaging lens satisfies the following conditional expression (9),

1.7＜Nd2p＜2.2 (9)。

32. the imaging lens according to claim 1 or 2,

when focusing, the 2 nd lens group moves,

the 2 nd lens group includes at least two cemented lenses.

33. The imaging lens according to claim 1 or 2,

three positive lenses are continuously arranged in the 1 st lens group.

34. The imaging lens according to claim 1 or 2,

4 positive lenses are continuously arranged in the 1 st lens group.

35. The imaging lens according to claim 1 or 2,

the focal length of the 1 st lens group is f1,

the imaging lens satisfies the following conditional expression (10),

0.5＜f1/f＜3.5 (10)。

36. the imaging lens according to claim 1 or 2,

the maximum half angle of view of the imaging lens in a state of focusing on an object at infinity is ω max,

In the case where the F value of the imaging lens in a state of being focused on an infinite object is set to FNo,

the imaging lens satisfies the following conditional expression (11),

1.8＜1/{tan(ωmax)×FNo}＜4.5 (11)。

37. the imaging lens according to claim 1 or 2,

when focusing, the 2 nd lens group moves,

the focal length of the 2 nd lens group is f2,

the imaging lens satisfies the following conditional expression (12),

0.3＜|f2|/f＜2.2 (12)。

38. the imaging lens according to claim 1 or 2,

the focal length of the 1 st lens group is f1,

In the case where the focal length of the 2 nd lens group is set to f2,

the imaging lens satisfies the following conditional expression (13),

1＜f1/f2＜5 (13)。

39. the imaging lens according to claim 1 or 2,

when focusing, the 2 nd lens group moves,

the transverse magnification of the 2 nd lens group in a state of focusing on an object at infinity is set to be beta 2,

When the combined lateral magnification of all lenses on the image side of the 2 nd lens group in a state of focusing on an object at infinity when a lens is disposed on the image side of the 2 nd lens group and β r is 1 when no lens is disposed on the image side of the 2 nd lens group,

the imaging lens satisfies the following conditional expression (14),

0.3＜|(1-β2²)×βr²|＜1.5 (14)。

40. the imaging lens according to claim 1 or 2,

the distance on the optical axis between the lens surface closest to the object side and the diaphragm in the state of focusing on the object at infinity is Tf,

When TL is the sum of the distance on the optical axis from the lens surface closest to the object side to the lens surface closest to the image side in a state of focusing on an object at infinity and the back focal length in terms of air-converted distance,

the imaging lens satisfies the following conditional expression (15),

0.2＜Tf/TL＜0.65 (15)。

41. the imaging lens according to claim 1 or 2,

the 1 st lens group includes, in order from the most object side, a 1 st unit having a negative refractive power and a 2 nd unit having a positive refractive power spaced apart from the 1 st unit by a maximum air space on an optical axis within the 1 st lens group,

the 2 nd unit comprises a single lens or a cemented lens,

the focal length of the imaging lens in a state of focusing on an object at infinity is set to f,

When the combined focal length of all lenses on the image side of the 2 nd unit in the imaging lens in a state of focusing on an infinite object is fm,

the imaging lens satisfies the following conditional expression (16),

0.7＜f/fm＜0.98 (16)。

42. the imaging lens as claimed in claim 41,

the 1 st unit comprises a piece of negative lens,

the 2 nd unit comprises a piece of positive lens.

43. The imaging lens according to claim 1 or 2,

in the case where the partial dispersion ratio between the g-line and the F-line of the LA positive lens is set to θ gFA,

the imaging lens satisfies the following conditional expression (17),

0.01＜θgFA+0.00162×vdA-0.64159＜0.06 (17)。

44. the imaging lens according to claim 1 or 2,

in the case where the partial dispersion ratio between the g-line and the F-line of the LB positive lens is set to θ gFB,

the imaging lens satisfies the following conditional expression (18),

0.01＜θgFB+0.00162×vdB-0.64159＜0.05 (18)。

45. the imaging lens according to claim 1 or 2,

the 1 st lens group includes at least two negative lenses,

wherein vdn1 is the average value of the d-line reference Abbe coefficients of two negative lenses selected in the order of the smaller d-line reference Abbe coefficients of the negative lenses included in the 1 st lens group,

When the average value of the partial dispersion ratios between the g-line and the F-line of two negative lenses selected in the order of the smaller dispersion coefficient of the d-line reference among the negative lenses included in the 1 st lens group is θ gFn1,

the imaging lens satisfies the following conditional expression (19),

0.01＜θgFn1+0.00162×vdn1-0.64159＜0.05 (19)。

46. the imaging lens according to claim 1 or 2,

the imaging lens satisfies the following conditional expression (1-1),

1.88＜NdA＜2.15 (1-1)。

47. the imaging lens according to claim 1 or 2,

the imaging lens satisfies the following conditional expression (1-2),

1.91＜NdA＜2.15 (1-2)。

48. the imaging lens according to claim 1 or 2,

the imaging lens satisfies the following conditional expression (2-1),

13.5＜vdA＜31 (2-1)。

49. the imaging lens according to claim 1 or 2,

the imaging lens satisfies the following conditional expression (2-2),

14＜vdA＜28 (2-2)。

50. the imaging lens according to claim 1 or 2,

the imaging lens satisfies the following conditional expression (2-3),

14.5＜vdA＜22 (2-3)。

51. the imaging lens according to claim 1 or 2,

the imaging lens satisfies the following conditional expression (3-1),

62＜vdB＜92 (3-1)。

52. the imaging lens according to claim 1 or 2,

the imaging lens satisfies the following conditional expression (3-2),

66＜νdB＜88 (3-2)。

53. the imaging lens according to claim 7,

the imaging lens satisfies the following conditional expression (4-1),

16＜vdn1＜25 (4-1)。

54. the imaging lens according to claim 9,

the imaging lens satisfies the following conditional expression (5-1),

1.8＜TL×FNo/f＜3.5 (5-1)。

55. the imaging lens according to claim 9,

the imaging lens satisfies the following conditional expression (5-2),

2＜TL×FNo/f＜3.2 (5-2)。

56. the imaging lens as claimed in claim 19,

the imaging lens satisfies the following conditional expression (6-1),

62＜vdC＜88 (6-1)。

57. the imaging lens as claimed in claim 19,

the imaging lens satisfies the following conditional expression (6-2),

66＜vdC＜80 (6-2)。

58. the imaging lens as claimed in claim 20,

the imaging lens satisfies the following conditional expression (7-1),

1.52＜Ndfm＜1.68 (7-1)。

59. the imaging lens as claimed in claim 30,

the imaging lens satisfies the following conditional expression (8-1),

1.81＜Ndpr＜2.1 (8-1)。

60. the imaging lens as claimed in claim 30,

the imaging lens satisfies the following conditional expression (8-2),

1.87＜Ndpr＜2.05 (8-2)。

61. the imaging lens as claimed in claim 31,

the imaging lens satisfies the following conditional expression (9-1),

1.77＜Nd2p＜2.15 (9-1)。

62. the imaging lens as claimed in claim 31,

the imaging lens satisfies the following conditional expression (9-2),

1.81＜Nd2p＜2.1 (9-2)。

63. the imaging lens as claimed in claim 31,

the imaging lens satisfies the following conditional expression (9-3),

1.87＜Nd2p＜2.05 (9-3)。

64. the imaging lens as claimed in claim 35, wherein,

the imaging lens satisfies the following conditional expression (10-1),

0.7＜f1/f＜3.3 (10-1)。

65. the imaging lens as claimed in claim 35, wherein,

the imaging lens satisfies the following conditional expression (10-2),

1.4＜f1/f＜3.2 (10-2)。

66. the imaging lens as claimed in claim 35, wherein,

the imaging lens satisfies the following conditional expression (10-3),

1.8＜f1/f＜2.9 (10-3)。

67. the imaging lens as claimed in claim 36, wherein,

the imaging lens satisfies the following conditional expression (11-1),

2.4＜1/{tan(ωmax)×FNo}＜4.2 (11-1)。

68. the imaging lens as claimed in claim 36, wherein,

the imaging lens satisfies the following conditional expression (11-2),

2.8＜1/{tan(ωmax)×FNo}＜3.8 (11-2)。

69. the imaging lens as claimed in claim 37,

the imaging lens satisfies the following conditional expression (12-1),

0.4＜|f2|/f＜1.9 (12-1)。

70. the imaging lens as claimed in claim 37,

the imaging lens satisfies the following conditional expression (12-2),

0.45＜|f2|/f＜1.2 (12-2)。

71. the imaging lens as claimed in claim 37,

the imaging lens satisfies the following conditional expression (12-3),

0.5＜|f2|/f＜1 (12-3)。

72. the imaging lens as claimed in claim 38,

the imaging lens satisfies the following conditional expression (13-1),

1.2＜f1/f2＜4.4 (13-1)。

73. the imaging lens as claimed in claim 38,

the imaging lens satisfies the following conditional expression (13-2),

2.3＜f1/f2＜4.2 (13-2)。

74. the imaging lens as claimed in claim 38,

the imaging lens satisfies the following conditional expression (13-3),

2.5＜f1/f2＜4 (13-3)。

75. the imaging lens as claimed in claim 39,

the imaging lens satisfies the following conditional expression (14-1),

0.4＜|(1-β2²)×βr²|＜1.4 (14-1)。

76. the imaging lens as claimed in claim 39,

the imaging lens satisfies the following conditional expression (14-2),

0.6＜|(1-β2²)×βr²|＜1 (14-2)。

77. the imaging lens as claimed in claim 40,

the imaging lens satisfies the following conditional expression (15-1),

0.4＜Tf/TL＜0.64 (15-1)。

78. the imaging lens as claimed in claim 40,

the imaging lens satisfies the following conditional expression (15-2),

0.48＜Tf/TL＜0.61 (15-2)。

79. the imaging lens as claimed in claim 41,

the imaging lens satisfies the following conditional expression (16-1),

0.75＜f/fm＜0.95 (16-1)。

80. the imaging lens of claim 43,

the imaging lens satisfies the following conditional expression (17-1),

0.015＜θgFA+0.00162×vdA-0.64159＜0.055 (17-1)。

81. the imaging lens as claimed in claim 44, wherein,

the imaging lens satisfies the following conditional expression (18-1),

0.012＜θgFB+0.00162×vdB-0.64159＜0.035 (18-1)。

82. the imaging lens as claimed in claim 45,

the imaging lens satisfies the following conditional expression (19-1),

0.016＜θgFn1+0.00162×νdn1-0.64159＜0.042 (19-1)。

83. an imaging device provided with the imaging lens according to any one of claims 1 to 82.