Lens device and imaging device

Abstract

The objective is to provide a compact, large-aperture, medium-telephoto lens device that can effectively correct chromatic aberration and field curvature. [Solution] The lens device consists of a first lens group, a second lens group, and a third lens group, all with positive refractive power, arranged sequentially from the object side to the image side, and the spacing between adjacent lens groups changes during focusing. During focusing, the second lens group moves, and the first lens group has two consecutive meniscus positive lenses with a convex surface on the object side, arranged sequentially from the object side to the image side, and the first lens group has a first negative lens with negative refractive power. The refractive index of the first negative lens at the d line, the Abbe number of the first negative lens at the d line, the partial dispersion ratio of the first negative lens with respect to the g line, the distance on the optical axis from the lens surface closest to the image to the image plane, and the focal length at infinity focus are appropriately set.

Description

Technical Field

[0001] The present invention relates to a lens device and an imaging device.

Background Art

[0002] In recent years, lens devices used in imaging devices are required to have various aberrations well corrected along with the high performance of image sensors. Particularly in a large-aperture medium telephoto lens, chromatic aberration and field curvature are likely to occur, and it is necessary to suppress them. As a lens device that satisfies these requirements, a lens device including, in order from the object side to the image side, a first lens group with a positive refractive power, a focus group with a positive refractive power, and a third lens group with a positive or negative refractive power is disclosed. Patent Document 1 discloses a lens device aiming at miniaturization and weight reduction while correcting various aberrations such as chromatic aberration.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the lens device described in Patent Document 1, since the optical material used for the negative lens of the first lens group has relatively high refractive index and high dispersion, more lenses are required to suppress chromatic aberration and field curvature. An object of the present invention is to provide a large-aperture medium telephoto lens device that is small-sized and can well correct chromatic aberration and field curvature.

Means for Solving the Problems

[0005] In order to achieve the above object, a lens device according to one aspect of the present invention includes a first lens group having a positive refractive power, a second lens group having a positive refractive power, and a third lens group, which are arranged in order from the object side to the image side. During focusing, the distance between adjacent lens groups changes, and the second lens group moves during focusing. The first lens group has, in order from the object side to the image side, two consecutive meniscus positive lenses having convex surfaces on the object side. The first lens group has a first negative lens having a negative refractive power. Let the refractive index of the first negative lens at the d-line be ndb1n, the Abbe number of the first negative lens at the d-line be νdb1n, the partial dispersion ratio of the first negative lens with respect to the g-line be θgFb1n, the distance on the optical axis from the most image-side lens surface to the image plane be Bf, and the focal length at infinity focus be f. Then, 1.50 < ndb1n ndb1n + 0.015 × νdb1n < 2.35 26.0 < νdb1n < 60.0 -0.100 < θgFb1n - (-9.529×10

[0006] ×νdb1n 3 +3.694×10 -5 ×νdb1n 2 -4.�17×10 -3 ×νdb1n +7.139×10 -1 ) < 0.000 0.03 < Bf / f < 0.40 It is characterized by satisfying the following conditions.

[0006] <00?0102>A lens device according to another aspect of the present invention includes a first lens group having a positive refractive power, a second lens group having a positive refractive power, and a third lens group, which are arranged in order from the object side to the image side. It is a lens device in which the distance between adjacent lens groups changes during focusing, and the second lens group moves during focusing. The first lens group is characterized by having a negative meniscus lens with a convex surface facing the object side.

Advantages of the Invention

[0007] According to the present invention, it is possible to provide a compact, large-aperture, medium-telephoto lens device that can effectively correct chromatic aberration and field curvature. [Brief explanation of the drawing]

[0008] [Figure 1] This is a cross-sectional view of the lens device of Example 1 when it is focused at infinity. [Figure 2] This is an aberration diagram of the lens device of Example 1 when it is focused at infinity. [Figure 3] This is a cross-sectional view of the lens device of Example 2 when it is focused at infinity. [Figure 4] This is an aberration diagram of the lens device of Example 2 when it is focused at infinity. [Figure 5] This is a cross-sectional view of the lens device of Example 3 when it is focused at infinity. [Figure 6] This is an aberration diagram of the lens device of Example 3 when it is focused at infinity. [Figure 7] This is a cross-sectional view of the lens device of Example 4 when it is focused at infinity. [Figure 8] This is an aberration diagram of the lens device of Example 4 when it is focused at infinity. [Figure 9] This is a cross-sectional view of the lens device of Example 5 when it is focused at infinity. [Figure 10] This is an aberration diagram of the lens device of Example 5 when it is focused at infinity. [Figure 11] This is a cross-sectional view of the lens device of Example 6 when it is focused at infinity. [Figure 12] This is an aberration diagram of the lens device of Example 6 when it is focused at infinity. [Figure 13] This is a cross-sectional view of the lens device of Example 7 when it is focused at infinity. [Figure 14] This is an aberration diagram of the lens device of Example 7 when it is focused at infinity. [Figure 15] This is a cross-sectional view of the lens device of Example 8 when it is focused at infinity. [Figure 16] This is an aberration diagram of the lens device of Example 8 when it is focused at infinity. [Figure 17] This is a cross-sectional view of the lens device of Example 9 when it is focused at infinity. [Figure 18] This is an aberration diagram of the lens device of Example 9 when it is focused at infinity. [Figure 19] This is a cross-sectional view of the lens device of Example 10 when it is in focus at infinity. [Figure 20] This is an aberration diagram of the lens device of Example 10 when it is focused at infinity. [Figure 21] This is a cross-sectional view of the lens device of Example 11 when it is focused at infinity. [Figure 22] This is an aberration diagram of the lens device of Example 11 when it is focused at infinity. [Figure 23] This is a cross-sectional view of the lens device of Example 12 when it is focused at infinity. [Figure 24] This is an aberration diagram of the lens device of Example 12 when it is focused at infinity. [Figure 25] This is a cross-sectional view of the lens device of Example 13 when it is focused at infinity. [Figure 26] This is an aberration diagram of the lens device of Example 13 when it is focused at infinity. [Figure 27] This is a cross-sectional view of the lens device of Example 14 when it is focused at infinity. [Figure 28] This is an aberration diagram of the lens device of Example 14 when it is focused at infinity. [Figure 29] This is a schematic diagram of the imaging device of the present invention. [Modes for carrying out the invention]

[0009] The lens device of the present invention will be described in detail below with reference to the attached drawings. In each figure, the same reference numeral is used for identical components, and redundant explanations are omitted.

[0010] Figures 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, and 27 are cross-sectional views of the lens devices of Examples 1 to 14 when focused at infinity. The lens devices of each example are used in imaging devices such as digital video cameras, digital still cameras, broadcast cameras, silver halide film cameras, and surveillance cameras.

[0011] In each cross-sectional view, the left side is the object side and the right side is the image side. The lens apparatus of each embodiment is composed of multiple lens groups. In this specification, a lens group is a collection of lenses that move or remain stationary as a whole during focusing. That is, in the lens apparatus of each embodiment, the distance between adjacent lens groups changes during focusing. Each lens group may consist of one lens or multiple lenses.

[0012] The lens apparatus of each embodiment consists of a first lens group U1 with positive refractive power, a second lens group U2 with positive refractive power, and a third lens group U3 with positive or negative refractive power, arranged in order from the object side to the image side.

[0013] SP is the aperture diaphragm. IP is the image plane, and when the lens device of each embodiment is used as a shooting lens device for a digital still camera or digital video camera, the image plane of a solid-state image sensor (photoelectric conversion element) such as a CCD sensor or CMOS sensor is placed on it. When the lens device of each embodiment is used as a shooting lens device for a silver halide film camera, the image plane IMG has a photosensitive surface corresponding to the film plane.

[0014] The arrows shown in each cross-sectional view indicate the direction of movement of the lens group when focusing from infinity to the closest distance. In the lens apparatus of each embodiment, when focusing from infinity to the closest distance, the second lens group U2 moves toward the object, while the first lens group U1 and the third lens group U3 remain stationary.

[0015] Figures 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, and 28 are aberration diagrams of the lens devices of Examples 1 to 14 at infinity focus, respectively. In the spherical aberration diagram, Fno is the F number and indicates the amount of spherical aberration for the d line (wavelength 587.6 nm) and the g line (wavelength 435.8 nm). In the astigmatism diagram, S indicates the amount of astigmatism at the sagittal image plane, and M indicates the amount of astigmatism at the meridional image plane. The distortion diagram shows the amount of distortion for the d line. The chromatic aberration diagram shows the amount of chromatic aberration at the g line. ω is the half-angle of view (degrees) of the image.

[0016] Next, the characteristic configurations of the lens devices in each embodiment will be described. In the lens device of each embodiment, the first lens group U1 is arranged with two consecutive meniscus positive lenses having convex surfaces on the object side in order from the object side, and at least two negative lenses are arranged in the first lens group U1. In a large-aperture medium telephoto lens, chromatic aberration is particularly prominent. On the other hand, if a lens arrangement that focuses on correcting chromatic aberration is selected, the curvature of field correction will be insufficient. Therefore, an appropriate lens arrangement that balances both is necessary.

[0017] The lens device of each embodiment has a first negative lens with a negative refractive power in the first lens group. When the refractive index of the first negative lens at the d-line is ndb1n, the Abbe number of the first negative lens at the d-line is νdb1n, the partial dispersion ratio of the first negative lens with respect to the g-line is θgFb1n, the distance on the optical axis from the most image-side lens surface of the lens device to the image plane is Bf, and the focal length of the lens device when focused at infinity is f, 1.50 < ndb1n ···(1) ndb1n + 0.015 × νdb1n < 2.35 ···(2) 26.0 < νdb1n < 60.0 ···(3) -0.100 < θgFb1n - (-9.529×10 -8 ×νdb1n 3 +3.694×l0 -5 ×νdb1n 2 -4.717×10 -3 ×νdb1n +7.139×10 -1 ) < 0.000 ···(4) 0.03 < Bf / f < 0.40 ···(5) satisfies the following conditions.

[0018] The conditional expression (1) is a conditional expression that defines the refractive index of the first negative lens included in the first lens group U1. If it exceeds the lower limit of the conditional expression (1), the curvature of the first negative lens becomes too strong, making it difficult to suppress spherical aberration and coma aberration, which is not preferable. Conditional equation (2) is a conditional equation that defines the relationship between the refractive index and Abbe number of the first negative lens included in the first lens group U1. Exceeding the upper limit of conditional equation (2) is undesirable because it increases the Petzval sum of the lens device to the positive side, making it difficult to correct the field curvature.

[0019] Condition (3) is a condition that specifies the Abbe number of the first negative lens included in the first lens group U1. If the lower limit of condition (3) is exceeded, the dispersion due to the first negative lens becomes too strong, requiring many lenses to compensate for it, which is undesirable as it increases the size of the lens device. If the upper limit of condition (3) is exceeded, the dispersion of the first negative lens becomes too weak, making it difficult to correct chromatic aberration, which is also undesirable.

[0020] Conditional equation (4) is a conditional equation that defines the partial dispersion ratio of the first negative lens included in the first lens group U1. Exceeding the lower limit of conditional equation (4) is undesirable because it results in overcorrection of the chromatic aberration of the g line. Exceeding the upper limit of conditional equation (4) is also undesirable because it results in undercorrection of the chromatic aberration of the g line.

[0021] Condition (5) is a condition that defines the ratio of the back focus to the focal length of the lens device. Exceeding the lower limit of condition (5) is undesirable because the angle of incidence of light rays on the image plane becomes too strong, making it difficult for the image sensor to receive light. Exceeding the upper limit of condition (5) is also undesirable because it prevents the proper lens arrangement for correcting chromatic aberration in the high-image-height region, resulting in insufficient correction.

[0022] As shown in Table 1, in each embodiment, two first negative lenses L1n1 and L1n2 within the first lens group U1 satisfy conditions (1) to (4).

[0023] It is preferable that the condition is satisfied when the lower limit of condition (1) is changed to 1.52. It is even more preferable that the condition is satisfied when the lower limit of condition (1) is changed to 1.55, 1.59, 1.61, or 1.63. It is preferable that the upper limit of condition (2) be changed to 2.34 and that the condition is satisfied. Furthermore, it is even more preferable that the upper limit of condition (2) be changed to 2.33, 2.32, or 2.30 and that the condition is satisfied.

[0024] It is preferable that the lower limit of condition (3) be changed to 26.5 and that the condition is satisfied. It is even more preferable that the lower limit be changed to 27.0, 28.0, 28.5, or 29.0 and that the condition is satisfied. It is preferable that the upper limit of condition (3) be changed to 55.0 and that the condition is satisfied. It is even more preferable that the upper limit be changed to 50.0, 45.0, 40.0, or 38.0 and that the condition is satisfied.

[0025] It is preferable that the lower limit of condition (4) be changed to -0.030 and the condition is satisfied. It is even more preferable that the lower limit of condition (4) be changed to -0.010, -0.0095, and -0.009 and the condition is satisfied. It is preferable that the upper limit of condition (4) be changed to -0.002 and the condition is satisfied. It is even more preferable that the upper limit of condition (4) be changed to -0.003, -0.004, and -0.005 and the condition is satisfied.

[0026] It is preferable that the lower limit of condition (5) be changed to 0.05 and that the condition is satisfied. It is even more preferable that the lower limit of condition (5) be changed to 0.08, 0.01, 0.12, 0.13, and 0.15 and that the condition is satisfied. It is preferable that the upper limit of condition (5) be changed to 0.35 and that the condition is satisfied. It is even more preferable that the upper limit of condition (5) be changed to 0.30, 0.25, and 0.20 and that the condition is satisfied.

[0027] Next, we will describe the configurations that are preferable to satisfy in the lens device of each embodiment. In the first lens group U1, it is preferable that the third lens positioned from the object side is a meniscus lens with a convex surface facing the object. In large-aperture medium telephoto lenses, the refractive power of the lens system as a whole is relatively weak, and if an extremely powerful lens is placed within it, it becomes difficult to correct aberrations. Therefore, it is desirable to gently refract the light rays with a meniscus lens that has a convex surface facing the object. For the same reason, in the first lens group U1, it is preferable that the fourth lens positioned from the object side is a meniscus lens with a convex surface facing the object. Similarly, in the first lens group U1, it is preferable that the fifth lens positioned from the object side is a meniscus lens with a convex surface facing the object. Furthermore, it is preferable that the first lens group U1 includes a negative meniscus lens with its convex surface facing the object.

[0028] In the second lens group U2, it is preferable to have at least three lenses. The second lens group U2 is the moving group during focusing, but in order to reduce the distance variation due to the focusing position, such as spherical aberration, field curvature, and angle of view variation of the lens device, aberrations must be corrected within the moving group. By arranging three or more lenses in the second lens group U2, distance variations such as spherical aberration and coma aberration in the lens device can be suppressed to a minimum.

[0029] In the second lens group U2, it is preferable to include at least one aspherical lens within the group. In large-aperture medium telephoto lenses, placing an aspherical lens in the central part of the lens device effectively suppresses aberrations such as spherical aberration and coma aberration, as well as distance variation.

[0030] In the second lens group U2, it is preferable that the lens closest to the object has a negative refractive power. This facilitates the suppression of the Petzval sum and the correction of axial chromatic aberration.

[0031] Furthermore, it is preferable that the aperture in the lens device of each embodiment be positioned between the first lens group U1 and the second lens group U2. This makes it possible to suppress the distance variation of various aberrations such as field curvature and coma aberration of the lens device depending on the focus position.

[0032] Next, we will describe the conditions that the lens device of each embodiment preferably satisfies. The lens device of each embodiment preferably satisfies at least one of the following conditional formulas (6) to (35).

[0033] 1.00 <f1 / f<5.00 ···(6) 0.300 <f2 / f<1.50 ···(7) -2.00 <f / f3<1.00 ···(8) 0.10 <f2 / f1<0.70 ···(9) -1.0 <f2 / f3<0.50 ···(10) 1.60 <nd1<2.50 ···(11) 13.0 < νd1 < 50.0 ···(12) 0.15 <fg2 / fg1<1.50 ···(13) 0.50<(b3FR+b2LR) / (b3FR-b2LR)<2.50...(14) 15.0 < νdb3L1 < 90.0 ···(15) -0.005<θgFb3L1-(-9.529×10 -8 ×νdb3L1 3 +3.694 × 10 -5 ×νdb3L1 2 -4.717 × 10 -3 ×νdb3L1 +7.139 × 10 -1 )<0.025 ···(16) 20.0 < νdb3L2 < 90.0 ···(17) -0.005<θgFb3L2-(-9.529×10 -8 ×νdb3L2 3 +3.694 × 10 -5 ×νdb3L2 2-4.717×10 -3 ×νdb3L2 +7.139×10 -1 )<0.025 ···(18) 0.20<|Rmin| / f<0.60 ···(19) 0.0<(tan(ObjD_inf) / tan(ObjD_mod)-1)×100 <10.0 ···(20) 26.0<νdb1n_ave<60.0 ···(21) 0.90 <ndgn2 / ndgn1<1.30 ···(22) -0.30 <M2 / f<-0.03 ···(23) -1.00 <fno×f2 / f3<0.30 ···(24) -0.100<θgFb2n-(-9.529×10 -8 ×νdb2n 3 +3.694×10 -5 ×νdb2n 2 -4.717×10 -3 ×νdb2n +7.139×10 -1 )<0.000 ···(25) 0.20<β2<0.70 ···(26) 0.70<β3<1.70 ···(27) 0.45<(1-β2 2 )×β3 2 <2.00 ···(28) 5.00 <f1 / Bf<30.00 ···(29) 1.00 <f2 / Bf<10.00 ···(30) -0.30 <Bf / f3<0.10 ···(31) 0.200 <Lb23 / f<0.500 ···(32) 1.20 <fP1 / f<5.00 ···(33) 0.50 <fP2 / f<1.10 ···(34) 0.10 <fP2 / fP1<0.80 ···(35)

[0034] However, the focal length of the first lens group U1 is f1, the focal length of the second lens group U2 is f2, and the focal length of the third lens group U3 is f3. The refractive index and Abbe number for the d line of the lens in the first lens group U1 that is closest to the object are nd1 and νd1, respectively. The focal length of the lens in the first lens group U1 that is closest to the object is fg1, and the focal length of the lens in the first lens group U1 that is second closest to the object is fg2. The radius of curvature of the lens surface closest to the image in the second lens group U2 is b2LR, and the radius of curvature of the lens surface closest to the object in the third lens group U3 is b3FR.

[0035] The third lens group U3 has a negative refractive power third R negative lens L3nR positioned closest to the image, with the Abbe number of the third R negative lens L3nR with respect to the d line being νdb3L1, and the partial dispersion ratio of the third R negative lens with respect to the g line being θgFb3L1. The third lens group U3 also has a negative refractive power third F negative lens L3nF positioned second from the image side, with the Abbe number of the third F negative lens L3nF with respect to the d line being νdb3L2, and the partial dispersion ratio of the third F negative lens L3nF with respect to the g line being θgFb3L2. Rmin is the radius of curvature with the smallest absolute value among the optical surfaces included in the first lens group U1 and the third lens group U3.

[0036] In the lens device, ObjD_inf is the angle of the incident light ray from the object that passes through the center of the aperture diaphragm and forms an image at 90% of the maximum image height when focused at infinity, and ObjD_mod is the angle of the incident light ray from the object that passes through the center of the aperture diaphragm and forms an image at 90% of the maximum image height when focused at the closest distance. νdb1n_ave is the average value of the Abbe numbers of all negative lenses arranged in the first lens group U1. ndgn1 is the refractive index of one of the negative lenses in the first lens group U1, and ndgn2 is the refractive index of the negative lens located on the image side of that negative lens. When the direction of movement from the object side to the image side is considered positive, M2 is the relative movement of the second lens group U2 with respect to the image plane during focusing from infinity to the closest distance.

[0037] Let fno be the F-number of the lens assembly. Let νdb2n be the Abbe number and θgFb2n be the partial dispersion ratio of at least one negative lens located in the second lens group U2. Let β2 be the lateral magnification of the second lens group U2 when focused at infinity. Let β3 be the lateral magnification of the third lens group U3 when focused at infinity. Let Lb23 be the distance along the optical axis from the image-side surface of the first lens group U1 to the object-side surface of the second lens group U2 when focused at infinity. Let fP1 be the combined focal length of the lenses located on the object side of the aperture diaphragm in the lens assembly. Let fP2 be the combined focal length of the lenses located on the image side of the aperture diaphragm in the lens assembly.

[0038] Conditional equation (6) specifies the ratio of the focal length of the first lens group U1 to the focal length of the entire lens system. Exceeding the lower limit of conditional equation (6) is undesirable because the power of the first lens group U1 is too strong, making it difficult to correct spherical aberration, coma aberration, and axial chromatic aberration. Conversely, exceeding the upper limit of conditional equation (6) is also undesirable because the power of the first lens group U1 is too weak, making it difficult to correct spherical aberration, coma aberration, and axial chromatic aberration.

[0039] It is preferable that the lower limit of condition (6) be changed to 1.20 and that the condition is satisfied. It is even more preferable that the lower limit of condition (6) be changed to 1.30, 1.40, 1.50, or 1.60 and that the condition is satisfied. It is preferable that the upper limit of condition (6) be changed to 4.50 and that the condition is satisfied. It is even more preferable that the upper limit of condition (6) be changed to 4.00, 3.50, 3.00, or 2.50 and that the condition is satisfied.

[0040] Condition (7) specifies the ratio of the focal length of the second lens group U2 to the focal length of the entire lens system. Exceeding the lower limit of condition (7) is undesirable because the power of the second lens group U2 is too strong, resulting in large variations in spherical aberration, coma aberration, and field curvature. Exceeding the upper limit of condition (7) is also undesirable because the power of the second lens group U2 is too weak, resulting in excessive movement of the second lens group U2 during focusing, which extends the overall optical length.

[0041] It is preferable that the lower limit of condition (7) be changed to 0.35 and that the condition is satisfied. It is even more preferable that the lower limit of condition (7) be changed to 0.40, 0.45, or 0.50 and that the condition is satisfied. It is preferable that the upper limit of condition (7) be changed to 1.30 and that the condition is satisfied. It is even more preferable that the upper limit of condition (7) be changed to 1.20, 1.10, 1.00, 0.85, or 0.70 and that the condition is satisfied.

[0042] Conditional equation (8) specifies the ratio of the focal length of the third lens group U3 to the focal length of the entire lens system. Exceeding the lower limit of conditional equation (8) is undesirable because the power of the third lens group U3 is too strong, making it difficult to correct distortion and chromatic aberration, and also increasing the angle of incidence of light rays on the image plane. Exceeding the upper limit of conditional equation (8) is also undesirable because the power of the third lens group U3 is too strong, making it difficult to correct coma aberration, chromatic aberration, and Petzval sum.

[0043] It is preferable that the lower limit of condition (8) be changed to -1.70 and that the condition is satisfied. It is even more preferable that the lower limit of condition (8) be changed to -1.50, -1.30, -1.10, and -0.90 and that the condition is satisfied. It is preferable that the upper limit of condition (8) be changed to 0.50 and that the condition is satisfied. It is even more preferable that the upper limit of condition (8) be changed to 0.30, 0.10, -0.10, and -0.30 and that the condition is satisfied.

[0044] Conditional equation (9) specifies the ratio of the focal lengths of the first lens group U1 and the second lens group U2. Exceeding the lower limit of conditional equation (9) is undesirable because the power of the first lens group U1 is too weak, making it difficult to correct spherical aberration, coma aberration, and axial chromatic aberration. Exceeding the upper limit of conditional equation (9) is also undesirable because the power of the second lens group U2 is too weak, causing the amount of movement of the second lens group U2 during focusing to become too large, thus extending the overall optical length.

[0045] It is preferable that the lower limit of condition (9) be changed to 0.13 and the condition is satisfied. It is even more preferable that the lower limit of condition (9) be changed to 0.15 and 0.17 and the condition is satisfied. It is preferable that the upper limit of condition (9) be changed to 0.60 and the condition is satisfied. It is even more preferable that the upper limit of condition (9) be changed to 0.50, 0.40 and 0.35 and the condition is satisfied.

[0046] Conditional equation (10) specifies the ratio of the focal lengths of the second lens group U2 and the third lens group U3. Exceeding the lower limit of conditional equation (10) is undesirable because the power of the third lens group U3 becomes too negative, making it difficult to correct distortion and chromatic aberration, and also increasing the angle of incidence of light rays on the image plane. Exceeding the upper limit of conditional equation (10) is also undesirable because the power of the third lens group U3 becomes too positive, making it difficult to correct coma aberration, chromatic aberration, and Petzval sum.

[0047] It is preferable that the lower limit of condition (10) be changed to -0.70 and that the condition is satisfied. It is even more preferable that the lower limit of condition (10) be changed to -0.60, -0.50, and -0.40 and that the condition is satisfied. It is preferable that the upper limit of condition (10) be changed to 0.40 and that the condition is satisfied. It is even more preferable that the upper limit of condition (10) be changed to 0.30, 0.20, and 0.10 and that the condition is satisfied.

[0048] Conditional equations (11) and (12) specify the refractive index and Abbe number of the lens in the first lens group U1 that is positioned closest to the object. Exceeding the lower limit of conditional equation (11) is undesirable because the curvature of the lens in the first lens group U1 that is positioned closest to the object becomes too strong, making it difficult to correct spherical aberration and axial chromatic aberration. Exceeding the upper limit of conditional equation (11) is undesirable because the refractive power of the lens in the first lens group U1 that is positioned closest to the object becomes too strong, making it difficult to correct spherical aberration and coma aberration. Exceeding the lower limit of conditional equation (12) is undesirable because the dispersion of the lens in the first lens group U1 that is positioned closest to the object becomes too strong, making it difficult to correct axial chromatic aberration and lateral chromatic aberration. Exceeding the upper limit of conditional equation (12) is undesirable because the dispersion of the lens in the first lens group U1 that is positioned closest to the object becomes too weak, resulting in insufficient correction of axial chromatic aberration and lateral chromatic aberration.

[0049] It is preferable that the lower limit of condition (11) be changed to 1.65 and that the condition is satisfied. It is even more preferable that the lower limit of condition (11) be changed to 1.70, 1.75, or 1.80 and that the condition is satisfied. It is preferable that the upper limit of condition (11) be changed to 2.40 and that the condition is satisfied. It is even more preferable that the upper limit of condition (11) be changed to 2.15, 2.05, 1.95, or 1.90 and that the condition is satisfied.

[0050] It is preferable that the lower limit of condition (12) be changed to 15.0 and that the condition is satisfied. It is even more preferable that the lower limit of condition (12) be changed to 17.0, 19.0, 20.0, or 21.0 and that the condition is satisfied. It is preferable that the upper limit of condition (12) be changed to 45.0 and that the condition is satisfied. It is even more preferable that the upper limit of condition (12) be changed to 40.0, 35.0, 30.0, or 25.0 and that the condition is satisfied.

[0051] Conditional equation (13) specifies the ratio of the focal length of the lens closest to the object in the first lens group U1 to the focal length of the lens second closest to the object. Exceeding the lower limit of conditional equation (13) is undesirable because the power of the lens closest to the object in the first lens group U1 becomes too weak, making it difficult to correct spherical aberration and axial chromatic aberration. Exceeding the upper limit of conditional equation (13) is also undesirable because the refractive power of the lens closest to the object in the first lens group U1 becomes too strong, making it difficult to correct spherical aberration and coma aberration.

[0052] It is preferable that the lower limit of condition (13) be changed to 0.20 and the condition is satisfied. It is even more preferable that the lower limit of condition (13) be changed to 0.25 and 0.30 and the condition is satisfied. It is preferable that the upper limit of condition (13) be changed to 1.30 and the condition is satisfied. It is even more preferable that the upper limit of condition (13) be changed to 1.10, 0.90, 0.70 and 0.50 and the condition is satisfied.

[0053] Conditional equation (14) defines the shape factors of the radius of curvature of the lens surface closest to the image in the second lens group U2 and the radius of curvature of the lens surface closest to the object in the third lens group U3. Exceeding the lower limit of conditional equation (14) is undesirable because the radius of curvature of the lens surface closest to the object in the third lens group U3 becomes too strong, causing large variations in the distance of field curvature, coma aberration, and chromatic aberration of the lens device. Exceeding the upper limit of conditional equation (14) is undesirable because the radius of curvature of the lens surface closest to the image in the second lens group U2 becomes too strong, causing large variations in the distance of field curvature, coma aberration, and chromatic aberration of the lens device.

[0054] It is preferable that the lower limit of condition (14) be changed to 0.70 and that the condition is satisfied. It is even more preferable that the lower limit of condition (14) be changed to 0.80, 0.90, and 1.00 and that the condition is satisfied. It is preferable that the upper limit of condition (14) be changed to 2.20 and that the condition is satisfied. It is even more preferable that the upper limit of condition (14) be changed to 2.00, 1.80, 1.70, and 1.60 and that the condition is satisfied.

[0055] Conditional equations (15) and (16) specify the Abbe number and partial dispersion ratio of the lens (third R negative lens) located closest to the image in the third lens group U3. Exceeding the lower limit of conditional equation (15) is undesirable because it becomes difficult to correct chromatic aberration and field curvature. Exceeding the upper limit of conditional equation (15) is undesirable because it results in overcorrection of chromatic aberration and field curvature. Exceeding the lower limit of conditional equation (16) is undesirable because it results in overcorrection of chromatic aberration on the g line. Exceeding the upper limit of conditional equation (16) is undesirable because it results in undercorrection of chromatic aberration on the g line.

[0056] It is preferable that the lower limit of condition (15) be changed to 17.0 and that the condition is satisfied. It is even more preferable that the lower limit of condition (15) be changed to 20.0, 25.0, 27.0, or 30.0 and that the condition is satisfied. It is preferable that the upper limit of condition (15) be changed to 80.0 and that the condition is satisfied. It is even more preferable that the upper limit of condition (15) be changed to 65.0, 60.0, 55.0, or 50.0 and that the condition is satisfied.

[0057] It is preferable that the lower limit of condition (16) be -0.002. It is even more preferable that the condition is satisfied when the lower limit of condition (16) is changed to 0.000, 0.002, or 0.003. It is preferable that the upper limit of condition (16) be 0.015. It is even more preferable that the condition is satisfied when the upper limit of condition (16) is changed to 0.010, 0.008, or 0.007.

[0058] Conditional equations (17) and (18) specify the Abbe number and partial dispersion ratio of the second lens from the image side (third F negative lens) in the third lens group U3. Exceeding the lower limit of conditional equation (17) is undesirable because it becomes difficult to correct chromatic aberration and field curvature. Exceeding the upper limit of conditional equation (17) is undesirable because chromatic aberration and field curvature become overcorrected. Exceeding the lower limit of conditional equation (18) is undesirable because chromatic aberration of the g line becomes overcorrected. Exceeding the upper limit of conditional equation (18) is undesirable because chromatic aberration of the g line becomes undercorrected.

[0059] It is preferable that the lower limit of condition (17) be changed to 22.0 and that the condition is satisfied. It is even more preferable that the lower limit of condition (17) be changed to 25.0, 27.0, or 30.0 and that the condition is satisfied. It is preferable that the upper limit of condition (17) be changed to 80.0 and that the condition is satisfied. It is even more preferable that the upper limit of condition (17) be changed to 65.0, 60.0, 55.0, or 50.0 and that the condition is satisfied.

[0060] It is preferable that the lower limit of condition (18) be changed to -0.002 and that the condition is satisfied. It is even more preferable that the lower limit of condition (18) be changed to 0.000, 0.002, and 0.003 and that the condition is satisfied. It is preferable that the upper limit of condition (18) be changed to 0.015 and that the condition is satisfied. It is even more preferable that the upper limit of condition (18) be changed to 0.010, 0.008, and 0.007 and that the condition is satisfied.

[0061] Conditional equation (19) specifies the radius of curvature with the smallest absolute value among the optical surfaces included in the first lens group U1 and the third lens group U3. In order to correct field curvature and coma aberration while minimizing the number of lenses in the lens device, a surface with strong curvature is required at lens positions where the height of off-axis rays is high. Exceeding the lower limit of conditional equation (19) is undesirable because the radius of curvature becomes too strong, worsening spherical aberration and axial chromatic aberration. Exceeding the upper limit of conditional equation (19) is undesirable because the curvature becomes too weak, resulting in insufficient correction of field curvature and coma aberration.

[0062] It is preferable that the lower limit of condition (19) be changed to 0.23 and that the condition is satisfied. It is even more preferable that the lower limit of condition (19) be changed to 0.25, 0.26, 0.27, or 0.28 and that the condition is satisfied. It is preferable that the upper limit of condition (19) be changed to 0.50 and that the condition is satisfied. It is even more preferable that the upper limit of condition (19) be changed to 0.45, 0.40, or 0.35 and that the condition is satisfied.

[0063] Conditional equation (20) defines the angle of view variation from infinity to close focus in the lens device. Exceeding the lower limit of conditional equation (20) is undesirable because it raises concerns that the angle of view variation during focusing will become more noticeable and vibrate. Exceeding the lower limit of conditional equation (20) is undesirable because it is highly likely that the angle of view variation during focusing will cause discomfort to the user.

[0064] It is preferable that the lower limit of condition (20) be changed to 1.0 and the condition is satisfied. It is even more preferable that the lower limit of condition (20) be changed to 2.0 and 3.0 and the condition is satisfied. It is preferable that the upper limit of condition (20) be changed to 9.0 and the condition is satisfied. It is even more preferable that the upper limit of condition (20) be changed to 8.0, 7.0, 6.0 and 5.0 and the condition is satisfied.

[0065] Condition (21) specifies the average Abbe number of the negative lenses arranged in the first lens group U1. Exceeding the lower limit of condition (21) is undesirable because the dispersion per negative lens becomes too strong, requiring many lenses to compensate for it and resulting in a larger lens device. Exceeding the upper limit of condition (21) is also undesirable because the dispersion per negative lens becomes too weak, making it difficult to correct chromatic aberration.

[0066] It is preferable that the lower limit of condition (21) be changed to 26.5 and that the condition is satisfied. It is even more preferable that the lower limit of condition (21) be changed to 27.0, 28.0, 28.5, or 29.0 and that the condition is satisfied. It is preferable that the upper limit of condition (21) be changed to 55.0 and that the condition is satisfied. It is even more preferable that the upper limit of condition (21) be changed to 50.0, 45.0, 40.0, or 38.0 and that the condition is satisfied.

[0067] Conditional equation (22) specifies the refractive index of one of the negative lenses arranged in the first lens group U1 and the refractive index of the negative lenses arranged closer to the image. The negative lenses in the first lens group U1 have a significant influence on axial chromatic aberration and lateral chromatic aberration, and it is necessary to have a configuration that balances these two. In order to correct axial chromatic aberration without adversely affecting lateral chromatic aberration, it is desirable to arrange the negative lenses on the image side, which have lower off-axis ray heights, so that their refractive indices are equivalent to or higher than those of the negative lenses on the object side. Exceeding the lower limit of conditional equation (22) is undesirable because it worsens lateral chromatic aberration. Exceeding the upper limit of conditional equation (22) is undesirable because it worsens axial chromatic aberration.

[0068] It is preferable that the lower limit of condition (22) be changed to 0.92 and that the condition is satisfied. It is even more preferable that the lower limit of condition (22) be changed to 0.94, 0.96, 0.98, and 1.00 and that the condition is satisfied. It is preferable that the upper limit of condition (22) be changed to 1.25 and that the condition is satisfied. It is even more preferable that the upper limit of condition (22) be changed to 1.20, 1.15, and 1.10 and that the condition is satisfied.

[0069] Conditional equation (23) specifies the relative movement of the second lens group U2 with respect to the image plane when focusing from infinity to the closest distance. Exceeding the lower limit of conditional equation (23) is undesirable because the amount of movement of the second lens group U2 during focusing becomes too large, resulting in a larger lens device. Exceeding the upper limit of conditional equation (23) is also undesirable because the power of the second lens group U2 becomes too strong, leading to large variations in the performance of spherical aberration and field curvature of the lens device with respect to the subject distance.

[0070] It is preferable that the lower limit of condition (23) be changed to -0.25 and the condition is satisfied. It is even more preferable that the lower limit of condition (23) be changed to -0.22, -0.20, -0.17, -0.15, and -0.10 and the condition is satisfied. It is preferable that the upper limit of condition (23) be changed to -0.05 and the condition is satisfied. It is even more preferable that the upper limit of condition (23) be changed to -0.06 and -0.07 and the condition is satisfied.

[0071] Conditional equation (24) specifies the F-number of the lens device and the focal lengths of the second lens group U2 and the third lens group U3. Exceeding the lower limit of conditional equation (24) is undesirable because the focal length of the second lens group U2 becomes too long, increasing the amount of movement of the second lens group U2 during focusing and making it difficult to shorten the overall length of the lens. It is also undesirable because it becomes difficult to obtain the desired large aperture ratio. Exceeding the upper limit of conditional equation (24) is undesirable because the power of the second lens group U2 becomes too strong, causing large variations in the performance of spherical aberration and field curvature of the lens device with respect to the subject distance.

[0072] It is preferable that the lower limit of condition (24) be changed to -0.80 and the condition is satisfied. It is even more preferable that the lower limit of condition (24) be changed to -0.70, -0.60, -0.55, and -0.50 and the condition is satisfied. It is preferable that the upper limit of condition (25) be changed to 0.20 and the condition is satisfied. It is even more preferable that the upper limit of condition (24) be changed to 0.10, 0.05, 0.00, and -0.10 and the condition is satisfied.

[0073] Conditional equation (25) defines the partial dispersion ratio of the negative lenses arranged in the second lens group U2. Exceeding the lower limit of conditional equation (25) is undesirable because it results in overcorrection of the chromatic aberration of the g line. Exceeding the upper limit of conditional equation (25) is undesirable because it results in undercorrection of the chromatic aberration of the g line. The second lens group U2 in each embodiment of the present invention includes two negative lenses L2n1 and L2n2 that satisfy conditional equation (25).

[0074] It is preferable that the lower limit of condition (25) be changed to -0.009 and the condition is satisfied. It is even more preferable that the lower limit of condition (25) be changed to -0.008, -0.007, and -0.006 and the condition is satisfied. It is preferable that the upper limit of condition (25) be changed to -0.001 and the condition is satisfied. It is even more preferable that the upper limit of condition (25) be changed to -0.002, -0.003, and -0.004 and the condition is satisfied.

[0075] Conditional equation (26) specifies the lateral magnification of the image when the second lens group U2 is focused at infinity. Exceeding the lower limit of conditional equation (26) is undesirable because the power of the first lens group U1 becomes too weak, worsening spherical aberration and coma aberration. Exceeding the upper limit of conditional equation (26) is also undesirable because the power of the second lens group U2 becomes too weak relative to the first lens group U1, resulting in an excessively large amount of movement of the second lens group U2 during focusing, leading to an enlarged lens assembly.

[0076] It is preferable that the lower limit of condition (26) be changed to 0.25 and that the condition is satisfied. It is even more preferable that the lower limit of condition (26) be changed to 0.30, 0.32, and 0.34 and that the condition is satisfied. It is preferable that the upper limit of condition (26) be changed to 0.65 and that the condition is satisfied. It is even more preferable that the upper limit of condition (26) be changed to 0.60, 0.55, 0.50, and 0.45 and that the condition is satisfied.

[0077] Conditional equation (27) specifies the lateral magnification of the image when the third lens group U3 is focused at infinity. Exceeding the lower limit of conditional equation (27) is undesirable because the power of the third lens group U3 becomes too weak, worsening field curvature and chromatic aberration. Exceeding the upper limit of conditional equation (27) is undesirable because the power of the third lens group U3 becomes too strong, increasing the variation in spherical aberration and field curvature performance with respect to the subject distance of the lens device. It is also undesirable because it increases the angle of incidence of light rays on the image plane.

[0078] It is preferable that the lower limit of condition (27) be changed to 0.80 and that the condition is satisfied. It is even more preferable that the lower limit of condition (27) be changed to 0.90, 1.00, and 1.10 and that the condition is satisfied. It is preferable that the upper limit of condition (27) be changed to 1.50 and that the condition is satisfied. It is even more preferable that the upper limit of condition (27) be changed to 1.45, 1.40, and 1.35 and that the condition is satisfied.

[0079] Conditional equation (28) specifies the lateral magnification of the image when the second lens group U2 and the third lens group U3 are focused at infinity. Exceeding the lower limit of conditional equation (28) is undesirable because it increases the amount of movement of the second lens group U2 during focusing, making it difficult to shorten the overall length of the lens. Exceeding the upper limit of conditional equation (28) is undesirable because it increases the variation in spherical aberration and field curvature performance of the lens device with respect to the subject distance.

[0080] It is preferable that the lower limit of condition (28) be changed to 0.50 and that the condition is satisfied. It is even more preferable that the lower limit of condition (28) be changed to 0.60, 0.70, and 0.80 and that the condition is satisfied. It is preferable that the upper limit of condition (28) be changed to 1.90 and that the condition is satisfied. It is even more preferable that the upper limit be changed to 1.80, 1.70, 1.60, and 1.50 and that the condition is satisfied.

[0081] Conditional equation (29) specifies the ratio of the focal length of the first lens group U1 to the back focus of the lens device. Exceeding the lower limit of conditional equation (29) is undesirable because it worsens spherical aberration and coma aberration. Exceeding the upper limit of conditional equation (29) is also undesirable because it makes it difficult to correct chromatic aberration.

[0082] It is preferable that the lower limit of condition (29) be changed to 6.00 to satisfy the condition. Furthermore, it is even preferable that condition (29) be satisfied with the lower limit changed to 7.00, 8.00, or 9.00. It is preferable that the upper limit of condition (29) be changed to 27.00 to satisfy the condition. Furthermore, it is even preferable that condition (29) be satisfied with the upper limit changed to 25.00, 23.00, 20.00, or 18.00.

[0083] Conditional equation (30) specifies the ratio of the focal length of the second lens group U2 to the back focus of the lens device. Exceeding the lower limit of conditional equation (30) is undesirable because it becomes difficult to correct field curvature and coma aberration. Exceeding the upper limit of conditional equation (30) is also undesirable because the amount of movement of the second lens group U2 during focusing becomes too large, resulting in a larger lens device.

[0084] It is preferable that the lower limit of condition (30) be changed to 1.30 and that the condition is satisfied. It is even more preferable that the lower limit of condition (30) be changed to 1.50, 1.70, 1.90, or 2.00 and that the condition is satisfied. It is preferable that the upper limit of condition (30) be changed to 8.00 and that the condition is satisfied. It is even more preferable that the upper limit of condition (30) be changed to 7.00, 6.00, or 5.00 and that the condition is satisfied.

[0085] Conditional equation (31) specifies the ratio of the focal length of the third lens group U3 to the back focus of the lens device. Exceeding the lower limit of conditional equation (31) is undesirable because it increases the variation in spherical aberration and field curvature. It is also undesirable because it increases the angle of incidence of light rays on the image plane. Exceeding the upper limit of conditional equation (31) is undesirable because it worsens field curvature and chromatic aberration.

[0086] It is preferable that the lower limit of condition (31) be changed to -0.25 and that the condition is satisfied. It is even more preferable that the lower limit of condition (31) be changed to -0.20, -0.17, and -0.15 and that the condition is satisfied. It is preferable that the upper limit of condition (31) be changed to 0.08 and that the condition is satisfied. It is even more preferable that the upper limit of condition (31) be changed to 0.06, 0.04, 0.02, and 0.00 and that the condition is satisfied.

[0087] Conditional equation (32) defines the ratio of the distance on the optical axis from the image-side surface of the first lens group U1 to the object-side surface of the second lens group U2 to the focal length of the lens device. Exceeding the lower limit of conditional equation (32) is undesirable because the power of the second lens group U2 becomes too strong, leading to large variations in the performance of spherical aberration and field curvature of the lens device with respect to the subject distance. Exceeding the upper limit of conditional equation (32) is undesirable because the amount of movement of the second lens group U2 during focusing becomes too large, resulting in a larger lens device.

[0088] It is preferable that the lower limit of condition (32) be changed to 0.22 and the condition is satisfied. It is even more preferable that the lower limit of condition (32) be changed to 0.24 and 0.26 and the condition is satisfied. It is preferable that the upper limit of condition (32) be changed to 0.45 and the condition is satisfied. It is even more preferable that the upper limit be changed to 0.40, 0.35 and 0.32 and the condition is satisfied.

[0089] Conditional equation (33) specifies the ratio of the combined focal length of the lenses positioned before the aperture of the lens device to the focal length of the lens device. Exceeding the lower limit of conditional equation (33) is undesirable because the power of the lenses before the aperture is too strong, worsening spherical aberration and lateral chromatic aberration. Exceeding the upper limit of conditional equation (33) is also undesirable because the power of the lenses before the aperture is too weak, worsening field curvature and axial chromatic aberration.

[0090] It is preferable that the lower limit of condition (33) be changed to 1.40 and that the condition is satisfied. It is even more preferable that the lower limit of condition (33) be changed to 1.60, 1.80, or 2.00 and that the condition is satisfied. It is preferable that the upper limit of condition (33) be changed to 4.50 and that the condition is satisfied. It is even more preferable that the upper limit of condition (33) be changed to 4.20, 3.80, 3.40, or 3.00 and that the condition is satisfied.

[0091] Conditional equation (34) specifies the ratio of the combined focal length of the lenses positioned behind the aperture of the lens device to the focal length of the lens device itself. Exceeding the lower limit of conditional equation (34) is undesirable because the power of the lenses behind the aperture is too strong, worsening field curvature and coma aberration. Exceeding the upper limit of conditional equation (34) is also undesirable because the power of the lenses behind the aperture is too weak, worsening field curvature and chromatic aberration.

[0092] It is preferable that the lower limit of condition (34) be changed to 0.60 and the condition is satisfied. It is even more preferable that the lower limit of condition (34) be changed to 0.65 and 0.70 and the condition is satisfied. It is preferable that the upper limit of condition (34) be changed to 1.00 and the condition is satisfied. It is even more preferable that the upper limit of condition (34) be changed to 0.95, 0.90, 0.88 and 0.86 and the condition is satisfied.

[0093] Conditional equation (35) specifies the ratio of the combined focal length of the lenses positioned in front of the aperture of the lens device to the combined focal length of the lenses positioned behind the aperture of the lens device. Exceeding the lower limit of conditional equation (35) is undesirable because the power of the lenses behind the aperture becomes too strong, worsening field curvature and coma aberration. Exceeding the upper limit of conditional equation (35) is also undesirable because the power of the lenses in front of the aperture becomes too strong, worsening spherical aberration and chromatic aberration.

[0094] It is preferable that the lower limit of condition (35) be changed to 0.15 and that the condition is satisfied. It is even more preferable that the lower limit of condition (35) be changed to 0.20, 0.25, or 0.30 and that the condition is satisfied. It is preferable that the upper limit of condition (35) be changed to 0.70 and that the condition is satisfied. It is even more preferable that the upper limit of condition (35) be changed to 0.60, 0.50, or 0.45 and that the condition is satisfied.

[0095] The numerical values ​​corresponding to Examples 1 to 14 are shown below. In the surface data for each numerical example, r represents the radius of curvature of each optical surface, and d (mm) represents the on-axial spacing (distance along the optical axis) between the m-th surface and the (m+1)-th surface. Here, m is the surface number counted from the light incident side. Also, nd represents the refractive index of each optical element with respect to the d line, and νd represents the Abbe number of the optical element. Note that the Abbe number νd of a certain material is given by Nd, NF, and NC, respectively, when the refractive indices at the Fraunhofer lines d-line (587.6 nm), F-line (486.1 nm), and C-line (656.3 nm) are Nd, NF, and NC. νd = (Nd-1) / (NF-NC) It is represented as follows.

[0096] Furthermore, θgF represents the partial dispersion ratio of each optical component with respect to the g-line. The partial dispersion ratio θgF of a certain material is given by Nd, NF, NC, and Ng, respectively, when the refractive indices at the Fraunhofer lines d-line (587.6 nm), F-line (486.1 nm), C-line (656.3 nm), and g-line (435.8 nm). θgF = (Ng - NF) / (NF - NC) It is represented as follows.

[0097] In each numerical example, d, focal length (mm), F-number, and half-angle of view (°) are all values ​​when the lens device of each example is in focus on an object at infinity. Back focus BF is the distance along the optical axis from the final lens surface (the lens surface closest to the image) to the paraxial image plane, expressed in terms of air equivalent length. The total lens length is the distance along the optical axis from the first lens surface (the lens surface closest to the object) to the final lens surface plus the back focus. A lens group includes not only cases where it is composed of multiple lenses, but also cases where it is composed of a single lens.

[0098] Furthermore, if the optical surface is aspherical, the symbol * is added to the right of the surface number. (Aspherical shape) Here, x is the displacement from the vertex of the plane in the direction of the optical axis, h is the height from the optical axis in the direction perpendicular to the optical axis, and r is Paraxial radius of curvature, K is the cone constant, and A4, A6, A8, A10, A12 are the non-conical constants of each order. When using spherical coefficients,

number

[0099] [Numerical Example 1] Unit: mm Surface data Face number rd nd vd θgF 1 85.711 4.40 1.80810 22.8 2 172.688 0.30 3 44.670 9.22 1.59522 67.7 4 185.421 0.65 5 34.802 8.81 1.53775 74.7 6 145.052 1.60 1.77047 29.7 0.5951 7 25.075 7.82 8 509.541 1.40 1.77047 29.7 0.5951 9 99.203 5.72 10 (aperture) ∞ (variable) 11 -31.665 0.90 1.61340 44.3 0.5633 12 727.029 0.15 13* 82.051 6.15 1.80400 46.5 14* -74.067 1.39 15 201.950 1.08 1.65412 39.7 0.5737 16 40.155 9.43 1.59522 67.7 17 -37.387 (variable) 18 1492.403 1.20 1.72825 28.5 19 44.650 4.86 20 53.987 9.15 2.00100 29.1 21 -55.940 1.30 1.53172 48.8 0.5631 22 71.526 6.48 23 -51.974 1.30 1.63980 34.5 0.5922 24 -266.753 14.91 Image plane ∞ Aspherical data Page 13 K = 0.00000e+00 A 4=-3.93536e-06 A 6= 2.19775e-09 A 8=-9.74527e-11 A10= 3.31019e-13 A12=-8.98526e-16 Page 14 K = 0.00000e+00 A 4= 2.66866e-06 A 6= 1.89399e-09 A 8=-7.26017e-11 A10= 2.14452e-13 A12=-5.95719e-16 Various data Various data Focal length 82.60 F-number 1.44 Half-angle 14.68 Image height 21.63 Lens length: 117.52 BF 14.91 infinite close d10 16.44 6.97 d17 2.87 12.34 Group data Group starting plane focal length 1 1 196.15 2 11 51.80 3 18 -208.88

[0100] [Numerical Example 2] Unit: mm Surface data Face number rd nd vd θgF 1 81.194 4.07 1.84666 23.9 2 152.711 0.30 3 44.431 8.93 1.59522 67.7 4 160.167 0.65 5 33.692 8.85 1.53775 74.7 0.5951 6 120.211 1.60 1.77047 29.7 7 24.283 7.76 8 233.117 1.30 1.73037 32.2 0.5899 9 79.764 6.10 10 (aperture) ∞ (variable) 11 -30.458 1.00 1.61340 44.3 0.5633 12 240.098 0.15 13* 61.413 6.24 1.80400 46.5 14* -62.069 0.20 15 199.660 1.10 1.61340 44.3 0.5633 16 30.426 11.19 1.53775 74.7 17 -38.364 (variable) 18 1354.179 1.20 1.69895 30.1 19 41.062 3.71 20 52.689 9.61 2.00100 29.1 21 -49.669 1.30 1.60342 38.0 0.5835 22 80.999 6.18 23 -50.699 1.30 1.51742 52.4 0.5564 24 -266.891 14.91 Image plane ∞ Aspherical data Page 13 K = 0.00000e+00 A 4=-3.14948e-06 A 6= 9.81747e-09 A 8=-7.25479e-11 A10= 3.07580e-13 A12=-6.00601e-16 Page 14 K = 0.00000e+00 A 4= 3.47313e-06 A 6= 8.71345e-09 A 8=-6.46786e-11 A10= 2.90427e-13 A12=-5.77646e-16 Various data Focal length 82.50 F-number 1.44 Half-angle 14.69 Image height 21.63 Lens length: 117.52 BF 14.91 infinite close d10 17.00 7.20 d17 2.87 12.67 Group data Group starting plane focal length 1 1 197.46 2 11 52.89 3 18 -249.47

[0101] [Numerical Example 3] Unit: mm Surface data Face number rd nd vd θgF 1 69.299 3.94 2.00069 25.5 2 113.756 0.20 3 50.101 8.86 1.59522 67.7 4 208.028 0.50 5 35.512 9.48 1.59522 67.7 6 287.548 1.60 1.77047 29.7 0.5951 7 24.506 7.55 8 1586.902 1.30 1.77047 29.7 0.5951 9 111.660 4.07 10 (aperture) ∞ (variable) 11 -36.005 0.90 1.61340 44.3 0.5633 12 164.100 0.14 13* 65.349 6.70 1.80400 46.5 14* -49.373 6.98 15 -86.621 1.10 1.77047 29.7 0.5951 16 1520.575 4.84 1.75500 52.3 17 -48.619 (variable) 18 -195.078 5.56 1.91082 35.2 19 -35.528 1.20 1.77047 29.7 20 68.963 0.77 21 53.101 9.64 2.00100 29.1 22 -98.826 1.30 1.51823 58.9 0.5457 23 81.466 7.39 24 -41.851 1.30 1.80810 22.8 0.6307 25 -58.162 12.00 Image plane ∞ Aspherical data Page 13 K = 0.00000e+00 A 4=-3.10221e-06 A 6= 3.31924e-09 A 8=-3.36661e-11 A10= 1.62125e-13 A12=-4.65124e-16 Page 14 K = 0.00000e+00 A 4= 1.89421e-06 A 6= 3.29200e-09 A 8=-4.13312e-11 A10= 2.01462e-13 A12=-5.18869e-16 Various data Focal length 82.50 F-number 1.46 Half-angle 14.69 Image height 21.63 Lens length: 118.00 BF 12.00 infinite close d10 18.68 4.82 d17 2.00 15.86 Group data Group starting plane focal length 1 1 192.35 2 11 65.97 3 18 1035.38

[0102] [Numerical Example 4] Unit: mm Surface data Face number rd nd vd θgF 1 78.427 4.11 2.00069 25.5 2 154.526 0.20 3 47.936 5.83 1.59522 67.7 4 94.373 0.50 5 34.874 8.90 1.59522 67.7 6 110.225 0.20 7 85.587 1.60 1.77047 29.7 0.5951 8 25.121 7.76 9 223.708 4.21 1.59522 67.7 10 -77.386 1.40 1.73037 32.2 0.5899 11 118.661 5.20 12 (aperture) ∞ (variable) 13 -35.065 0.90 1.61340 44.3 0.5633 14 172.897 0.13 15* 67.168 6.07 1.80400 46.5 16* -44.994 5.99 17 -50.359 1.10 1.73037 32.2 0.5899 18 832.048 5.87 1.76385 48.5 19 -37.205 (variable) 20 -436.679 4.18 1.95375 32.3 21 -50.983 1.20 1.77047 29.7 22 49.016 1.65 23 47.967 7.74 2.00100 29.1 24 -109.101 1.30 1.51742 52.4 0.5564 25 70.346 6.57 26 -53.358 1.30 1.72825 28.5 0.6077 27 -91.583 11.99 Image plane ∞ Aspherical data Page 15 K = 0.00000e+00 A 4=-2.55131e-06 A 6=-1.87066e-09 A 8= 3.40325e-11 A10=-1.35512e-13 A12= 1.89277e-16 Page 16 K = 0.00000e+00 A 4= 3.91899e-06 A 6= 3.95520e-10 A 8= 2.90779e-12 A10= 3.38547e-14 A12=-1.11455e-16 Various data Focal length 82.49 F-number 1.46 Half-angle 14.70 Image height 21.63 Lens length: 117.51 BF 11.99 infinite close d12 19.62 6.18 d19 1.99 15.43 Group data Group starting plane focal length 1 1 167.45 2 13 62.40 3 20 -842.30

[0103] [Numerical Example 5] Unit: mm Surface data Face number rd nd vd θgF 1 75.809 4.02 1.84666 23.9 2 134.138 0.20 3 44.068 9.29 1.59522 67.7 4 178.758 1.05 5 37.480 9.17 1.49700 81.7 6 172.898 1.50 1.77047 29.7 0.5951 7 40.094 1.60 8 56.794 1.30 1.77047 29.7 0.5951 9 26.318 8.98 10 (aperture) ∞ (variable) 11 -32.079 1.00 1.61340 44.3 0.5633 12 141.594 0.20 13* 51.492 6.85 1.80400 46.5 14* -64.720 0.15 15 486.843 1.00 1.61340 44.3 0.5633 16 31.191 9.27 1.59522 67.7 17 -42.739 (variable) 18 -505.803 1.10 1.72342 38.0 19 25.457 5.38 1.48749 70.2 20 45.433 2.92 21 54.147 10.65 2.00100 29.1 22 -36.894 1.20 1.59270 35.3 0.5933 23 105.461 5.80 24 -47.150 1.30 1.59270 35.3 0.5933 25 -160.992 15.09 Image plane ∞ Aspherical data Page 13 K = 0.00000e+00 A 4=-4.34414e-06 A 6= 7.63666e-09 A 8=-7.45046e-11 A10= 3.32786e-13 A12=-7.64837e-16 Page 14 K = 0.00000e+00 A 4= 2.97381e-06 A 6= 6.88577e-09 A 8=-6.70959e-11 A10= 3.09798e-13 A12=-7.23048e-16 Various data Focal length 82.50 F-number 1.46 Half-angle 14.69 Image height 21.63 Lens length: 117.10 BF 15.09 infinite close d10 15.98 7.54 d17 2.10 10.54 Group data Group starting plane focal length 1 1 189.25 2 11 49.83 3 18 -203.98

[0104] [Numerical Example 6] Unit: mm Surface data Face number rd nd vd θgF 1 97.228 3.17 1.80810 22.8 2 168.826 0.20 3 41.379 10.84 1.59282 68.6 4 200.784 1.00 5 40.219 8.03 1.53775 74.7 6 198.669 1.50 1.66565 35.6 0.5820 7 49.362 1.90 8 84.177 1.30 1.77047 29.7 0.5951 9 27.576 10.15 10 (aperture) ∞ (variable) 11 -31.134 1.29 1.61340 44.3 0.5633 12 96.564 0.25 13* 49.942 8.35 1.80400 46.5 14* -64.735 1.22 15 117.139 1.00 1.62205 41.1 0.5690 16 54.207 7.32 1.59282 68.6 17 -39.455 (variable) 18 -166.269 1.10 1.76634 35.8 19 24.940 5.44 1.49700 81.7 20 43.276 3.66 21 61.692 12.72 2.00100 29.1 22 -31.249 1.20 1.59270 35.3 0.5933 23 219.792 4.40 24 -52.388 1.30 1.59270 35.3 0.5933 25 -865.095 14.89 Image plane ∞ Aspherical data Page 13 K = 0.00000e+00 A 4=-4.83963e-06 A 6= 8.39015e-10 A 8=-4.48994e-11 A10= 2.42331e-13 A12=-6.32257e-16 Page 14 K = 0.00000e+00 A 4= 4.38692e-06 A 6= 2.60397e-09 A 8=-4.57563e-11 A10= 2.44643e-13 A12=-5.88968e-16 Various data Focal length 83.05 F-number 1.46 Half-angle 14.60 Image height 21.63 Lens length: 118.14 BF 14.89 infinite close d10 13.76 7.44 d17 2.15 8.47 Zoom lens group data Group starting plane focal length 1 1 168.72 2 11 41.81 3 18 -113.14

[0105] [Numerical Example 7] Unit: mm Surface data Face number rd nd vd θgF 1 96.026 5.00 1.90366 31.3 2 168.366 4.54 3 45.025 14.83 1.57144 71.6 4 209.436 1.34 5 40.362 7.92 1.49700 81.7 6 189.800 2.90 1.67300 38.3 0.5757 7 59.902 1.61 8 95.509 1.30 1.77047 29.7 0.5951 9 26.901 9.89 10 (aperture) ∞ (variable) 11 -30.768 1.00 1.61340 44.3 0.5633 12 111.087 0.20 13* 51.970 7.23 1.80400 46.5 14* -68.052 0.15 15 132.562 1.10 1.66565 35.6 0.5820 16 36.038 8.42 1.59522 67.7 17 -41.053 (variable) 18 -201.329 1.10 1.80420 46.5 19 26.394 5.76 1.48749 70.2 20 52.618 3.17 21 59.558 11.04 2.00100 29.1 22 -34.464 1.20 1.59270 35.3 0.5933 23 176.938 4.69 24 -50.588 1.30 1.59270 35.3 0.5933 25 -258.856 14.86 Image plane ∞ Aspherical data 13th surface K = 0.00000e+00 A 4=-3.20525e-06 A 6= 9.04389e-10 A 8=-4.69907e-11 A10= 2.62624e-13 A12=-6.22599e-16 14th surface K = 0.00000e+00 A 4= 3.84427e-06 A 6= 1.52484e-09 A 8=-3.24113e-11 A10= 1.89133e-13 A12=-4.88668e-16 Various data Focal length 98.20 F-number 1.46 Half angle of view 12.42 Image height 21.63 Overall length of lens 130.02 BF 14.86 Infinity to closest d10 17.33 7.46 d17 2.15 12.02 Group data Group starting plane focal length 1 1 170.96 2 11 48.24 3 18 -133.88

[0106] [Numerical Example 8] Unit: mm Surface data Face number rd nd vd θgF 1 99.589 3.47 1.84666 23.9 2 173.493 0.20 3 42.371 10.54 1.59522 67.7 4 210.582 1.06 5 38.837 8.09 1.49700 81.7 6 159.379 2.57 1.66565 35.6 0.5820 7 50.805 1.73 8 85.565 1.30 1.77047 29.7 0.5951 9 26.613 8.89 10 (aperture) ∞ (variable) 11 -30.290 1.00 1.61340 44.3 0.5633 12 104.164 0.20 13* 51.450 7.34 1.80400 46.5 14* -63.581 0.15 15 115.144 1.30 1.66565 35.6 0.5820 16 43.099 8.39 1.59522 67.7 17 -39.969 (variable) 18 -252.835 1.10 1.76200 40.1 19 24.975 5.80 1.49700 81.7 20 46.998 3.67 21 60.576 11.06 2.00100 29.1 22 -33.415 1.20 1.59270 35.3 0.5933 23 166.902 4.82 24 -48.682 1.30 1.59270 35.3 0.5933 25 -357.203 14.91 Image plane ∞ Aspherical data Surface 13 K = 0.00000e+00 A 4=-4.71780e-06 A 6= 2.46819e-... Surface 14 K = 0.00000e+00 A 4= 3.63620e-06 A 6= 2.86896e-... Various data Focal length 83.14 F-number 1.46 Half angle of view 14.58 Image height 21.63 Overall length of lens 116.76 BF 14.91 Infinity - closest d10 14.52 7.52 d17 2.15 9.15 Group data Group Starting surface Focal length 1 1 175.86 2 11 44.29 3 18 -129.57

[0107] [Numerical Example 9] Unit: mm Surface data Face number rd nd vd θgF 1 67.105 3.46 1.92286 20.9 2 116.947 0.10 3 55.455 5.74 1.59522 67.7 4 176.537 9.98 5 445.843 1.26 1.73037 32.2 0.5899 6 80.483 3.55 1.59522 67.7 7 1051.320 0.10 8 107.455 1.16 1.77047 29.7 0.5951 9 23.696 7.05 1.57144 71.6 10 65.102 4.95 11 (aperture) ∞ (variable) 12 -35.560 0.90 1.61340 44.3 0.5633 13 131.508 0.15 14 54.776 6.01 1.88300 40.8 15 -54.060 2.40 16 -52.643 1.00 1.73037 32.2 0.5899 17 64.403 1.17 18* 59.603 6.64 1.80400 46.5 19* -54.841 (variable) 20 -247.709 5.76 1.61997 63.9 21 -32.116 1.20 1.59270 35.3 22 49.936 2.84 23 61.515 9.92 2.05090 26.9 24 -47.578 1.30 1.59270 35.3 0.5933 25 94.429 7.85 26 -35.088 1.30 1.59270 35.3 0.5933 27 -68.429 12.22 Image plane ∞ Aspherical data Side 18 K = 0.00000e+00 A 4=-2.81841e-06 A 6=-2.49797e-09 A 8= 1.54912e-11 A10=-5.66952e-14 Page 19 K = 0.00000e+00 A 4= 2.47387e-06 A 6=-3.48143e-09 A 8= 2.29005e-11 A10=-6.83295e-14 Various data Focal length 75.00 F-number 1.46 Half-angle 16.09 Image height 21.63 Lens length: 118.20 BF 12.22 infinite close d11 18.21 6.16 d19 2.00 14.05 Group data Group starting plane focal length 1 1 159.10 2 12 68.21 3 20 -1331327.58

[0108] [Numerical Example 10] Unit: mm Surface data Face number rd nd vd θgF 1 96.036 3.94 1.92286 20.9 2 165.145 1.74 3 43.871 7.45 1.59282 68.6 4 199.452 1.20 5 41.105 8.58 1.57144 71.6 6 205.159 1.50 1.67300 38.3 0.5757 7 45.660 1.87 8 89.820 1.30 1.77047 29.7 0.5951 9 27.064 8.04 10 (aperture) ∞ (variable) 11 -30.872 1.00 1.61340 44.3 0.5633 12 104.842 0.60 13* 58.317 6.67 1.80400 46.5 14* -70.157 0.15 15 104.647 1.50 1.66565 35.6 0.5820 16 32.721 9.98 1.59282 68.6 17 -40.480 (variable) 18 -610.276 1.10 1.66565 35.6 19 24.924 7.51 1.51742 52.4 20 53.590 2.74 21 56.249 10.87 2.00100 29.1 22 -40.472 1.20 1.59270 35.3 0.5933 23 126.313 8.18 24 -46.547 1.30 1.59270 35.3 0.5933 25 -245.357 14.15 Image plane ∞ Aspherical data Page 13 K = 0.00000e+00 A 4=-3.26921e-06 A 6= 1.45128e-09 A 8=-1.87179e-11 A10= 8.17637e-14 A12=-3.63818e-16 Page 14 K = 0.00000e+00 A 4= 2.84441e-06 A 6= 2.38339e-09 A 8=-1.47714e-11 A10= 7.16272e-14 A12=-3.29602e-16 Various data Focal length 71.96 F-number 1.49 Half-angle 16.73 Image height 21.63 Lens length: 120.00 BF 14.15 infinite close d10 15.28 7.40 d17 2.15 10.03 Group data Group starting plane focal length 1 1 259.06 2 11 49.49 3 18 -452.01

[0109] [Numerical Example 11] Unit: mm Surface data Face number rd nd vd θgF 1 80.476 3.30 2.00272 19.3 2 136.737 0.42 3 42.622 9.98 1.53775 74.7 4 188.580 2.21 5 61.387 2.00 1.66565 35.6 0.5820 6 27.345 1.42 7 29.388 10.67 1.49700 81.5 8 -349.827 2.00 1.90110 27.1 0.6072 9 51.140 8.98 10 (aperture) ∞ (variable) 11 -38.926 1.18 1.62205 41.1 0.5690 12 106.556 0.20 13 63.727 4.51 1.95375 32.3 14* -71.338 2.62 15 -77.137 1.17 1.66565 35.6 0.5820 16 39.878 7.69 1.65160 58.5 17 -38.330 (variable) 18 -682.105 2.18 1.95375 32.3 19 -99.194 1.17 1.75211 25.0 20 65.974 6.01 21 56.104 7.44 2.00100 29.1 22 -65.877 0.90 1.54072 47.2 0.5651 23 51.489 8.92 24 -33.649 2.69 1.51742 52.4 0.5564 25 -63.183 12.06 Image plane ∞ Aspherical data Page 14 K = 0.00000e+00 A 4= 5.26742e-06 A 6=-4.71748e-09 A 8= 5.30510e-11 A10=-2.19645e-13 A12= 3.36431e-16 Various data Focal length 82.50 F-number 1.46 Half-angle 14.69 Image height 21.63 Lens length: 117.80 BF 12.06 infinite close d10 16.07 3.60 d17 2.00 14.47 Group data Group starting plane focal length 1 1 169.04 2 11 64.90 3 18 -449.50

[0110] [Numerical Example 12] Unit: mm Surface data Face number rd nd vd θgF 1 85.221 3.86 1.79631 22.6 2 159.037 0.30 3 43.764 9.39 1.59282 68.6 4 166.271 1.10 5 34.819 8.31 1.49700 81.7 6 107.467 1.50 1.77047 29.7 0.5951 7 39.513 1.90 8 55.972 1.30 1.77047 29.7 0.5951 9 25.750 9.39 10 (aperture) ∞ (variable) 11 -30.437 1.00 1.61340 44.3 0.5633 12 174.473 0.20 13* 51.841 7.50 1.80400 46.5 14* -59.960 0.15 15 401.421 1.00 1.61340 44.3 0.5633 16 25.502 8.45 1.59282 68.6 17 -45.229 (variable) 18 -960.535 1.10 1.72342 38.0 19 25.478 4.63 1.51742 52.4 20 43.377 4.03 21 55.508 10.15 2.00100 29.1 22 -40.068 1.20 1.59270 35.3 0.5933 23 92.796 7.60 24 -46.751 1.30 1.59270 35.3 0.5933 25 -129.983 14.16 Image plane ∞ Aspherical data Page 13 K = 0.00000e+00 A 4=-3.52516e-06 A 6= 5.21660e-09 A 8=-8.42824e-12 A10= 2.96841e-14 A12= 2.42859e-17 Side 14 K = 0.00000e+00 A 4= 3.41076e-06 A 6= 5.23989e-09 A 8=-1.34642e-11 A10= 5.58489e-14 A12=-5.82497e-18 Various data Focal length 82.50 F-number 1.46 Half-angle 14.69 Image height 21.63 Lens length: 118.00 BF 14.16 infinite close d10 16.49 8.28 d17 2.00 10.21 Group data Group starting plane focal length 1 1 191.96 2 11 49.71 3 18 -181.57

[0111] [Numerical Example 13] Unit: mm Surface data Face number rd nd vd θgF 1 90.873 4.75 1.84666 23.8 2 144.992 0.20 3 42.388 9.56 1.59522 67.7 4 196.547 0.70 5 37.986 8.03 1.53775 74.7 6 139.935 1.50 1.62205 41.1 0.5690 7 48.642 1.77 8 80.781 1.30 1.77047 29.7 0.5951 9 25.735 9.24 10 (aperture) ∞ (variable) 11 -32.508 1.00 1.61340 44.3 0.5633 12 114.767 0.48 13* 55.829 6.97 1.80400 46.5 14* -69.035 0.15 15 115.905 1.05 1.62205 41.1 0.5690 16 27.212 10.28 1.59522 67.7 17 -43.076 (variable) 18 -224.752 1.10 1.72000 46.0 19 25.725 5.32 1.51633 64.1 20 45.990 4.15 21 57.383 13.85 1.95375 32.3 22 -35.435 2.00 1.59270 35.3 0.5933 23 116.204 10.29 24 -39.516 1.38 1.59270 35.3 0.5933 25 -88.283 7.95 Image plane ∞ Aspherical data Page 13 K = 0.00000e+00 A 4=-3.32857e-06 A 6= 2.05846e-10 A 8=-2.68855e-11 A10= 1.54565e-13 A12=-5.10548e-16 Side 14 K = 0.00000e+00 A 4= 3.06068e-06 A 6= 1.73611e-09 A 8=-3.11197e-11 A10= 1.70198e-13 A12=-5.04008e-16 Various data Various data Focal length 79.95 F-number 1.46 Half-angle 15.14 Image height 21.63 Lens length: 120.00 BF 7.95 infinite close d10 14.82 7.53 d17 2.15 9.44 Group data Group starting plane focal length 1 1 184.57 2 11 46.80 3 18 -137.44

[0112] [Numerical Example 14] Unit: mm Surface data Face number rd nd vd θgF 1 91.681 3.32 2.00272 19.3 2 126.718 0.20 3 41.875 9.47 1.59522 67.7 4 210.215 0.70 5 39.472 8.28 1.49700 81.7 6 203.536 1.67 1.62205 41.1 0.5690 7 52.590 1.72 8 92.811 1.30 1.77047 29.7 0.5951 9 26.803 8.83 10 (aperture) ∞ (variable) 11 -30.189 1.00 1.61340 44.3 0.5633 12 93.151 0.54 13* 52.739 7.55 1.80400 46.5 14* -65.607 0.15 15 202.328 1.00 1.66565 35.6 0.5820 16 38.038 10.00 1.61997 63.9 17 -39.980 (variable) 18 -311.870 1.10 1.69600 36.3 19 26.088 5.24 1.49700 81.7 20 46.928 2.11 21 54.202 10.04 2.00100 29.1 22 -38.703 1.20 1.59270 35.3 0.5933 23 355.913 2.97 24 -69.982 1.20 1.59270 35.3 0.5933 25 227.201 23.37 Image plane ∞ Aspherical data Page 13 K = 0.00000e+00 A 4=-4.21523e-06 A 6= 1.54639e-09 A 8=-3.77992e-11 A10= 1.96151e-13 A12=-5.60818e-16 Side 14 K = 0.00000e+00 A 4= 3.26258e-06 A 6= 1.70302e-09 A 8=-2.79184e-11 A10= 1.51825e-13 A12=-4.57870e-16 Various data Focal length 77.89 F-number 1.46 Half-angle 15.52 Image height 21.63 Lens length: 120.30 BF 23.37 infinite close d10 15.33 7.43 d17 2.00 9.90 Group data Group starting plane focal length 1 1 221.91 2 11 49.24 3 18 -346.41

[0113] The numerical values ​​corresponding to conditional expressions (1) to (35) in each embodiment are shown in Tables 1 and 2 below.

[0114] [Table 1]

[0115] [Table 2]

[0116] [Imaging device] Next, an embodiment of a digital still camera (imaging device) 200 using the lens device of the present invention will be described with reference to Figure 29. In Figure 29, 201 is the camera body, and 202 is one of the lens devices described in Examples 1 to 14. 203 is a solid-state image sensor (photoelectric conversion element) such as a CCD sensor or CMOS sensor, which is built into the camera body and receives the optical image formed by the lens device 202 and converts it into photoelectric energy. Non-power optical components such as optical low-pass filters or ND filters may be placed in front of the solid-state image sensor. The camera body 201 may be a so-called single-lens reflex camera with a quick-turn mirror, or a so-called mirrorless camera without a quick-turn mirror. Thus, by applying the lens device 202 of the present invention to an imaging device such as a digital still camera, it becomes possible to provide a compact imaging device equipped with a large-aperture medium telephoto lens device that can effectively correct chromatic aberration and field curvature. Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various combinations, modifications, and changes are possible within the scope of its essence.

[0117] This embodiment includes the following configuration. (Composition 1) A lens device consisting of a first lens group, a second lens group, and a third lens group, all with positive refractive power, arranged sequentially from the object side to the image side, wherein the spacing between adjacent lens groups changes during focusing, and the second lens group moves during focusing. The first lens group comprises two consecutive meniscus positive lenses, each having a convex surface toward the object, in order from the object side to the image side. The first lens group has a first negative lens with negative refractive power, When the refractive index of the first negative lens at the d line is ndb1n, the Abbe number at the d line of the first negative lens is νdb1n, the partial dispersion ratio of the first negative lens with respect to the g line is θgFb1n, the distance on the optical axis from the lens surface closest to the image to the image plane is Bf, and the focal length at infinity is f, 1.50 <ndb1n<2.35-0.015×νdb1n 26.0 < νdb1n < 60.0 -0.100<θgFb1n-(-9.529×10 -8 ×νdb1n 3 +3.694 × 10 -5 ×νdb1n 2 -4.717 × 10 -3 ×νdb1n +7.139 × 10 -1 )<0.000 0.03 <Bf / f<0.40 A lens device characterized by satisfying the following conditions. (Configuration 2) When the focal length of the first lens group is f1, 1.00 <f1 / f<5.00 The lens device according to configuration 1, characterized by satisfying the following conditions. (Composition 3) When the focal length of the second lens group is f2, 0.300 <f2 / f<1.50 The lens device according to configuration 1, characterized by satisfying the following conditions. (Composition 4) When the focal length of the third lens group is set to f3, -2.00 <f / f3<1.00 The lens device according to configuration 1, characterized by satisfying the following conditions. (Composition 5) When the focal length of the first lens group is f1 and the focal length of the second lens group is f2, 0.10 <f2 / f1<0.70 The lens device according to configuration 1, characterized by satisfying the following conditions. (Composition 6) When the focal length of the second lens group is f2 and the focal length of the third lens group is f3, -1.0 <f2 / f3<0.50 The lens device according to configuration 1, characterized by satisfying the following conditions. (Composition 7) When the refractive index with respect to the d line of the lens positioned closest to the object in the first lens group is nd1 and the Abbe number with respect to the d line is νd1, 1.60 <nd1<2.50 13.0 < νd1 < 50.0 The lens device according to configuration 1, characterized by satisfying the following conditions. (Composition 8) In the first lens group, when the focal length of the lens positioned closest to the object is fg1, and the focal length of the lens positioned second closest to the object is fg2, 0.15 <fg2 / fg1<1.50 The lens device according to configuration 1, characterized by satisfying the following conditions. (Composition 9) When the radius of curvature of the lens surface closest to the image in the second lens group is b2LR, and the radius of curvature of the lens surface closest to the object in the third lens group is b3FR, 0.50<(b3FR+b2LR) / (b3FR-b2LR)<2.50 The lens device according to configuration 1, characterized by satisfying the following conditions. (Composition 10) The third lens group has a third R negative lens with negative refractive power positioned closest to the image, and when the Abbe number of the third R negative lens with respect to the d line is νdb3L1 and the partial dispersion ratio of the third R negative lens with respect to the g line is θgFb3L1, 15.0 < νdb3L1 < 90.0 -0.005<θgFb3L1-(-9.529×10 -8 ×νdb3L1 3 +3.694 × 10 -5 ×νdb3L1 2 -4.717 × 10 -3 ×νdb3L1 +7.139 × 10 -1 )<0.025 The lens device according to configuration 1, characterized by satisfying the following conditions. (Composition 11) The third lens group has a negative refractive power 3F negative lens positioned second from the image side, and when the Abbe number of the 3F negative lens with respect to the d line is νdb3L2 and the partial dispersion ratio of the 3F negative lens with respect to the g line is θgFb3L2, 20.0 < νdb3L2 < 90.0 -0.005<θgFb3L2-(-9.529×10-8 ×νdb3L2 3 +3.694 × 10 -5 ×νdb3L2 2 -4.717 × 10 -3 ×νdb3L2 +7.139 × 10 -1 )<0.025 The lens device according to configuration 1, characterized by satisfying the following conditions. (Composition 12) The lens device according to configuration 1, characterized in that the third lens positioned from the object side in the first lens group is a meniscus lens having a convex surface on the object side. (Composition 13) The lens device according to configuration 1, characterized in that the fourth lens positioned from the object side in the first lens group is a meniscus lens having a convex surface toward the object side. (Composition 14) The lens device according to configuration 1, characterized in that the fifth lens positioned from the object side in the first lens group is a meniscus lens having a convex surface toward the object side. (Composition 15) When Rmin is the radius of curvature with the smallest absolute value among the optical surfaces included in the first lens group and the third lens group, 0.20 < |Rmin| / f < 0.60 The lens device according to configuration 1, characterized by satisfying the following conditions. (Composition 16) It has an aperture diaphragm positioned between the first lens group and the second lens group, When the aperture diaphragm is focused at infinity, the angle of the incident light ray from the object that passes through the center and forms an image at 90% of the maximum image height is ObjD_inf. When the aperture diaphragm is focused at the closest distance, the angle of the incident light ray from the object that passes through the center and forms an image at 90% of the maximum image height is ObjD_mod. 0.0<(tan(ObjD_inf) / tan(ObjD_mod)-1) ×100 < 10.0 The lens device according to configuration 1, characterized by satisfying the following conditions. (Composition 17) When the average value of the Abbe numbers of all negative lenses arranged in the first lens group is denoted as νdb1n_ave, 26.0 < νdb1n_ave < 60.0 The lens device according to configuration 1, characterized by satisfying the following conditions. (Composition 18) When the refractive index of one of the negative lenses arranged in the first lens group is ndgn1, and the refractive index of the negative lens located on the image side of the said negative lens is ndgn2, 0.90 <ndgn2 / ndgn1<1.30 The lens device according to configuration 1, characterized by satisfying the following conditions. (Composition 19) The lens device according to configuration 1, characterized in that the second lens group has at least three lenses. (Composition 20) When the direction of movement from the object side to the image side is defined as positive, and the relative movement of the second lens group with respect to the image plane during focusing from infinity to the closest distance is denoted as M2, -0.30 <M2 / f<-0.03 The lens device according to configuration 1, characterized by satisfying the following conditions. (Composition 21) When the focal length of the second lens group is f2, the focal length of the third lens group is f3, and the F-number is fno, -1.00 <fno×f2 / f3 <0.30 The lens device according to configuration 1, characterized by satisfying the following conditions. (Composition 22) The lens apparatus according to configuration 1, characterized in that the lens closest to the object in the second lens group has a negative refractive power. (Composition 23) When the Abbe number of at least one negative lens arranged in the second lens group is νdb2n and the partial dispersion ratio is θgFb2n, -0.100<θgFb2n-(-9.529×10 -8 ×νdb2n 3 +3.694 × 10 -5 ×νdb2n2 -4.717 × 10 -3 ×νdb2n +7.139 × 10 -1 )<0.000 The lens device according to configuration 1, characterized by satisfying the following conditions. (Composition 24) When the image lateral magnification of the second lens group at infinity focus is β2, 0.20 < β2 < 0.70 The lens device according to configuration 1, characterized by satisfying the following conditions. (Composition 25) When the image lateral magnification of the third lens group at infinity focus is β3, 0.70 < β3 < 1.70 The lens device according to configuration 1, characterized by satisfying the following conditions. (Composition 26) When the lateral magnification of the second lens group at infinity focus is β2, and the lateral magnification of the third lens group at infinity focus is β3, 0.45<(1-β2 2 )×β3 2 <2.00 The lens device according to configuration 1, characterized by satisfying the following conditions. (Composition 27) The lens device according to configuration 1, characterized in that the second lens group has at least one aspherical lens. (Composition 28) When the focal length of the first lens group is f1, 5.00 <f1 / Bf<30.00 The lens device according to configuration 1, characterized by satisfying the following conditions. (Composition 29) When the focal length of the second lens group is f2, 1.00 <f2 / Bf<10.00 The lens device according to configuration 1, characterized by satisfying the following conditions. (Composition 30) When the focal length of the third lens group is set to f3, -0.30 <Bf / f3<0.10 The lens device according to configuration 1, characterized by satisfying the following conditions. (Composition 31) When Lb23 is the distance along the optical axis from the image-side surface of the first lens group to the object-side surface of the second lens group at infinity focus, 0.200 <Lb23 / f<0.500 The lens device according to configuration 1, characterized by satisfying the following conditions. (Composition 32) The lens device according to configuration 1, characterized by having an aperture diaphragm positioned between the first lens group and the second lens group. (Composition 33) When the combined focal length of the lens positioned on the object side of the aperture diaphragm is denoted as fP1, 1.20 <fP1 / f<5.00 The lens device according to configuration 32, characterized by satisfying the following conditions. (Composition 34) When the combined focal length of the lens positioned on the image side of the aperture diaphragm is denoted as fP2, 0.50 <fP2 / f<1.10 The lens device according to configuration 32 or 33, characterized by satisfying the following conditions. (Composition 35) When the combined focal length of the lens positioned on the object side of the aperture diaphragm is fP1, and the combined focal length of the lens positioned on the image side of the aperture diaphragm is fP2, 0.10 <fP2 / fP1<0.80 A lens device according to any one of configurations 32 to 34, characterized by satisfying the following conditions. (Composition 36) A lens device consisting of a first lens group, a second lens group, and a third lens group, all with positive refractive power, arranged sequentially from the object side to the image side, wherein the spacing between adjacent lens groups changes during focusing. During focusing, the second lens group moves, The lens device is characterized in that the first lens group has a negative meniscus lens with a convex surface facing the object side. (Composition 37) An imaging device characterized by having a lens device as described in any of configurations 1 to 36, and an image sensor for capturing an image formed by the lens device. [Explanation of symbols]

[0118] U1 First Lens Group U2 Second Lens Group U3 Third Lens Group L1n1 First Negative Lens L1n2 First Negative Lens 202 Lens device

Claims

1. A lens device consisting of a first lens group, a second lens group, and a third lens group, all with positive refractive power, arranged sequentially from the object side to the image side, wherein the spacing between adjacent lens groups changes during focusing. During focusing, the second lens group moves, The first lens group comprises two consecutive meniscus positive lenses, each having a convex surface toward the object, in order from the object side to the image side. The first lens group has a first negative lens with negative refractive power, When the refractive index of the first negative lens at the d line is ndb1n, the Abbe number at the d line of the first negative lens is νdb1n, the partial dispersion ratio of the first negative lens with respect to the g line is θgFb1n, the distance on the optical axis from the lens surface closest to the image to the image plane is Bf, and the focal length at infinity is f, 1.50<ndb1n<2.35-0.015×νdb1n 26.0<νdb1n<60.0 -0.100<θgFb1n-(-9.529×10 －８ ×νdb1n ３ +3.694×10 －５ ×νdb1n ２ -4.717×10 －３ ×νdb1n ＋７．１３９×１０ －１ ）＜０．０００ 0.03<Bf / f<0.40 A lens device characterized by satisfying the following conditions.

2. When the focal length of the first lens group is f1, 1.00<f1 / f<5.00 The lens device according to claim 1, characterized in that it satisfies the following conditions.

3. When the focal length of the second lens group is f2, 0.300<f2 / f<1.50 The lens device according to claim 1, characterized in that it satisfies the following conditions.

4. When the focal length of the third lens group is f3, -2.00<f / f3<1.00 The lens device according to claim 1, characterized in that it satisfies the following conditions.

5. When the focal length of the first lens group is f1 and the focal length of the second lens group is f2, 0.10<f2 / f1<0.70 The lens device according to claim 1, characterized in that it satisfies the following conditions.

6. When the focal length of the second lens group is f2 and the focal length of the third lens group is f3, -1.0<f2 / f3<0.50 The lens device according to claim 1, characterized in that it satisfies the following conditions.

7. When the refractive index with respect to the d line of the lens positioned closest to the object in the first lens group is nd1 and the Abbe number with respect to the d line is νd1, 1.60<nd1<2.50 13.0<νd1<50.0 The lens device according to claim 1, characterized in that it satisfies the following conditions.

8. In the first lens group, when the focal length of the lens positioned closest to the object is fg1, and the focal length of the lens positioned second closest to the object is fg2, 0.15<fg2 / fg1<1.50 The lens device according to claim 1, characterized in that it satisfies the following conditions.

9. When the radius of curvature of the lens surface closest to the image in the second lens group is b2LR, and the radius of curvature of the lens surface closest to the object in the third lens group is b3FR, 0.50<(b3FR+b2LR) / (b3FR-b2LR)<2.50 The lens device according to claim 1, characterized in that it satisfies the following conditions.

10. The third lens group has a third R negative lens with negative refractive power positioned closest to the image, and when the Abbe number of the third R negative lens with respect to the d line is νdb3L1 and the partial dispersion ratio of the third R negative lens with respect to the g line is θgFb3L1, 15.0<νdb3L1<90.0 -0.005<θgFb3L1-(-9.529×10 －８ ×νdb3L1 ３ +3.694×10 －５ ×νdb3L1 ２ -4.717×10 －３ ×νdb3L1 ＋７．１３９×１０ －１ ）＜０．０２５ The lens device according to claim 1, characterized in that it satisfies the following conditions.

11. The third lens group has a negative refractive power third F negative lens positioned second from the image side, and when the Abbe number of the third F negative lens with respect to the d line is νdb3L2 and the partial dispersion ratio of the third F negative lens with respect to the g line is θgFb3L2, 20.0<νdb3L2<90.0 -0.005<θgFb3L2-(-9.529×10 －８ ×νdb3L2 ３ +3.694×10 －５ ×νdb3L2 ２ -4.717×10 －３ ×νdb3L2 ＋７．１３９×１０ －１ ）＜０．０２５ The lens device according to claim 1, characterized in that it satisfies the following conditions.

12. The lens device according to claim 1, characterized in that the third lens positioned from the object side in the first lens group is a meniscus lens having a convex surface toward the object side.

13. The lens device according to claim 1, characterized in that the fourth lens positioned from the object side in the first lens group is a meniscus lens having a convex surface toward the object side.

14. The lens device according to claim 1, characterized in that the fifth lens positioned from the object side in the first lens group is a meniscus lens having a convex surface toward the object side.

15. When Rmin is the radius of curvature with the smallest absolute value among the optical surfaces included in the first lens group and the third lens group, 0.20<|Rmin| / f<0.60 The lens device according to claim 1, characterized in that it satisfies the following conditions.

16. It has an aperture diaphragm positioned between the first lens group and the second lens group, When the aperture diaphragm is focused at infinity, the angle of the incident light ray from the object that passes through the center and forms an image at 90% of the maximum image height is denoted as ObjD_inf, and when the aperture diaphragm is focused at the closest distance, the angle of the incident light ray from the object that passes through the center and forms an image at 90% of the maximum image height is denoted as ObjD_mod. 0.0<(tan(ObjD_inf) / tan(ObjD_mod)-1) ×１００＜１０．０ The lens device according to claim 1, characterized in that it satisfies the following conditions.

17. When the average value of the Abbe numbers of all negative lenses arranged in the first lens group is denoted as νdb1n_ave, 26.0<νdb1n_ave<60.0 The lens device according to claim 1, characterized in that it satisfies the following conditions.

18. When the refractive index of one of the negative lenses arranged in the first lens group is ndgn1, and the refractive index of the negative lens located on the image side of the negative lens is ndgn2, 0.90<ndgn2 / ndgn1<1.30 The lens device according to claim 1, characterized in that it satisfies the following conditions.

19. The lens device according to claim 1, characterized in that the second lens group has at least three lenses.

20. When the direction of movement from the object side to the image side is defined as positive, and M2 is the relative movement of the second lens group with respect to the image plane during focusing from infinity to the closest distance, -0.30<M2 / f<-0.03 The lens device according to claim 1, characterized in that it satisfies the following conditions.

21. When the focal length of the second lens group is f2, the focal length of the third lens group is f3, and the F-number is fno, -1.00<fno×f2 / f3<0.30 The lens device according to claim 1, characterized in that it satisfies the following conditions.

22. The lens device according to claim 1, characterized in that the lens closest to the object in the second lens group has a negative refractive power.

23. When the Abbe number of at least one negative lens arranged in the second lens group is νdb²n and the partial dispersion ratio is θgFb²n, -0.100<θgFb2n-(-9.529×10 －８ ×νdb2n ３ +3.694×10 －５ ×νdb2n ２ -4.717×10 －３ ×νdb2n ＋７．１３９×１０ －１ ）＜０．０００ The lens device according to claim 1, characterized in that it satisfies the following conditions.

24. When the image lateral magnification of the second lens group at infinity focus is β2, ０．２０＜β２＜０．７０ The lens device according to claim 1, characterized in that it satisfies the following conditions.

25. When the image lateral magnification of the third lens group at infinity focus is β3, ０．７０＜β３＜１．７０ The lens device according to claim 1, characterized in that it satisfies the following conditions.

26. When the lateral magnification of the second lens group at infinity focus is β2, and the lateral magnification of the third lens group at infinity focus is β3, ０．４５＜（１－β２ ２ ）×β３ ２ ＜２．００ The lens device according to claim 1, characterized in that it satisfies the following conditions.

27. The lens device according to claim 1, characterized in that the second lens group has at least one aspherical lens.

28. When the focal length of the first lens group is f1, 5.00<f1 / Bf<30.00 The lens device according to claim 1, characterized in that it satisfies the following conditions.

29. When the focal length of the second lens group is f2, 1.00<f2 / Bf<10.00 The lens device according to claim 1, characterized in that it satisfies the following conditions.

30. When the focal length of the third lens group is f3, -0.30<Bf / f3<0.10 The lens device according to claim 1, characterized in that it satisfies the following conditions.

31. When Lb23 is the distance along the optical axis from the image-side surface of the first lens group to the object-side surface of the second lens group at infinity focus, 0.200<Lb23 / f<0.500 The lens device according to claim 1, characterized in that it satisfies the following conditions.

32. The lens device according to claim 1, characterized by having an aperture diaphragm positioned between the first lens group and the second lens group.

33. When the combined focal length of the lens positioned on the object side of the aperture diaphragm is denoted as fP1, 1.20<fP1 / f<5.00 The lens device according to claim 32, characterized in that it satisfies the following conditions.

34. When the combined focal length of the lens positioned on the image side of the aperture diaphragm is denoted as fP2, 0.50<fP2 / f<1.10 The lens device according to claim 32, characterized in that it satisfies the following conditions.

35. When the combined focal length of the lens positioned on the object side of the aperture diaphragm is fP1, and the combined focal length of the lens positioned on the image side of the aperture diaphragm is fP2, 0.10<fP2 / fP1<0.80 The lens device according to claim 32, characterized in that it satisfies the following conditions.

36. A lens device consisting of a first lens group, a second lens group, and a third lens group, all with positive refractive power, arranged sequentially from the object side to the image side, wherein the spacing between adjacent lens groups changes during focusing. During focusing, the second lens group moves, The lens device is characterized in that the first lens group has a negative meniscus lens with a convex surface facing the object side.

37. An imaging device characterized by having a lens device according to any one of claims 1 to 36 and an image sensor for capturing an image formed by the lens device.

Images