Zoom lens and imaging apparatus

Abstract

To provide a zoom lens capable of suppressing various aberrations while being small-sized and lightweight.SOLUTION: A zoom lens comprises a positive first lens group L1 that does not move when zooming, an intermediate group including two or more lens groups that move when zooming, and a rear lens group that does not move when zooming. The intermediate group includes a negative second lens group L2 that moves when zooming. The first lens group includes, in order from an object side to an image side, a first partial group L1A that does not move when focusing, and a second partial group L1B and a third partial group L1C that move to the object side when focusing from an infinite object to a close object. The first partial group has, in order from the object side, one negative lens and one or more positive lenses. An Abbe number ν1B based on d line of an aspherical lens in the second partial group satisfies a condition, 81≤ν1B≤100.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a zoom lens suitable for an image pickup apparatus. [Background technology]

[0002] Some zoom lenses use a front focus system in which focusing is performed by moving a focus lens group located closer to the object than the lens group that moves during zooming. In the front focus system, the amount of movement of the focus lens group during focusing is constant regardless of the zoom position, and there is no decrease in imaging magnification during focusing. Patent Document 1 discloses a zoom lens that has a substantial six-group configuration and focuses by moving all or a part of the first lens group that is closest to the object. Patent Document 2 discloses a zoom lens that has a first lens group that does not move during zooming, an intermediate group that includes two or more lens groups that move during zooming, and a rear lens group that does not move during zooming, and focuses by moving a part of the first lens group. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-071140 A [Patent Document 2] JP 2016-173529 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the zoom lenses disclosed in Patent Documents 1 and 2, when the focus lens group is made smaller and lighter, the refractive power of each lens constituting the focus lens group becomes stronger, resulting in the occurrence of higher-order aberrations such as spherical aberration and chromatic aberration.

[0005] The present invention provides a zoom lens that is small and lightweight yet capable of suppressing various aberrations. [Means for solving the problem]

[0006] A zoom lens according to one aspect of the present invention has a first lens group having positive refractive power and not moving during zooming, an intermediate group including two or more lens groups that move during zooming, and a rear lens group that does not move during zooming, which are arranged in order from the object side to the image side, and the interval between adjacent lens groups changes during zooming. The intermediate group is arranged closest to the object side among the intermediate groups and includes a second lens group having negative refractive power and moving during zooming. The first lens group has a first subgroup that does not move during focusing, and a second subgroup and a third subgroup that move toward the object side so that the interval between adjacent subgroups changes during focusing from an infinite object to a close object, which are arranged in order from the object side to the image side. The first subgroup has one negative lens and one or more positive lenses, which are arranged in order from the object side to the image side. The second subgroup includes an aspheric lens having an aspheric lens surface, and when the Abbe number of the aspheric lens based on the d-line is ν1B, 81≦ν1B≦100 The present invention is characterized in that the above conditions are satisfied. An image pickup apparatus including the above zoom lens also constitutes another aspect of the present invention. Effect of the Invention

[0007] According to the present invention, it is possible to provide a zoom lens that is small and lightweight yet capable of suppressing various aberrations. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a cross-sectional view of the zoom lens of the first embodiment at the wide-angle end. [Diagram 2] 5A to 5C are aberration diagrams of the zoom lens of the first embodiment. [Diagram 3] FIG. 11 is a cross-sectional view of a zoom lens at a wide-angle end according to a second embodiment. [Figure 4] 6A to 6C are aberration diagrams of the zoom lens of Example 2. [Diagram 5] FIG. 11 is a cross-sectional view of a zoom lens at a wide-angle end according to a third embodiment. [Figure 6] 11A to 11C are aberration diagrams of the zoom lens of Example 3. [Figure 7] FIG. 11 is a cross-sectional view of a zoom lens at a wide-angle end according to a fourth embodiment. [Figure 8] 11A to 11C are aberration diagrams of the zoom lens of Example 4. [Figure 9] FIG. 13 is a cross-sectional view of a zoom lens at a wide-angle end according to a fifth embodiment. [Figure 10] 13A to 13C are aberration diagrams of the zoom lens of Example 5. [Figure 11] FIG. 13 is a cross-sectional view of a zoom lens at a wide-angle end according to a sixth embodiment. [Figure 12] 13A to 13C are aberration diagrams of the zoom lens of Example 6. [Figure 13] FIG. 2 is a diagram showing an image pickup apparatus equipped with the zoom lens of each embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0010] 1, 3, 5, 7, 9 and 11 respectively show the optical configurations of the zoom lenses of Examples 1 to 6 at the wide-angle end and in a state where the lens is focused on an object at infinity (hereinafter referred to as an infinity focused state). Prior to describing specific Examples 1 to 6, matters common to the respective Examples will be described.

[0011] The zoom lens of each embodiment is used in various imaging devices such as digital still cameras, video cameras, television cameras, surveillance cameras, and film cameras.

[0012] In a zoom lens, a lens group is a group of one or more lenses that move together during zooming between the wide-angle end and the telephoto end. That is, the spacing between adjacent lens groups changes during zooming. The lens group may include an aperture stop. The wide-angle end and the telephoto end respectively indicate the zoom states of the maximum angle of view (shortest focal length) and the minimum angle of view (maximum focal length) when the lens group that moves during zooming is located at both ends of the range that it can move mechanically or controllably on the optical axis.

[0013] The zoom lens of each embodiment has a first lens group L1 with positive refractive power that does not move during zooming, an intermediate group including two or more lens groups that move during zooming, and a rear lens group that does not move during zooming, which are arranged in order from the object side to the image side. The intermediate group is arranged closest to the object side and includes a second lens group L2 with negative refractive power that moves during zooming. In each figure, the movement locus of the lens group that moves during zooming from the wide-angle end to the telephoto end is indicated by an arrow. SP is an aperture stop, and I is an image plane. The imaging surface (light receiving surface) of the image sensor and the film surface (photosensitive surface) of the silver halide film are arranged on the image plane I.

[0014] In each embodiment, the first lens group L1 includes a first subgroup L1A that does not move during focusing, and a second subgroup L1B and a third subgroup L1C that move during focusing, arranged in order from the object side to the image side. The subgroup (sub lens group) here is a group of one or more lenses that move during focusing. In other words, the spacing between adjacent lens groups changes during focusing. The second subgroup L1B and the third subgroup L1C move toward the object side as shown by the arrows in each figure when focusing from an object at infinity to a close object.

[0015] The first sub-group L1 includes one negative lens and one or more positive lenses arranged in order from the object side to the image side. The second sub-group L1B includes an aspheric surface, and satisfies the condition of the following formula (1) when the Abbe number of the lens having the aspheric surface with respect to the d-line is ν1B. The definition of the Abbe number with respect to the d-line will be described later.

[0016] 81≦ν1B≦100 (1) In the zoom lens of each embodiment, the first lens group L1, which is the most object side, is configured with a plurality (three) of partial lens groups for focusing, the first to third partial lens groups L1A to L1C. In this case, the first lens group L1 includes a large number of lenses for aberration correction, and tends to be large in size. Therefore, in each embodiment, in order to prevent the first lens group from becoming large, it is configured as described above and satisfies the condition of formula (1).

[0017] In addition, the aspheric surface included in the second sub-group L1B is effective in reducing high-order aberrations (especially spherical aberration) and reducing the number of lenses in the first sub-group L1B that move for focusing. In addition, by setting the Abbe number of the material (glass material) of the aspheric lens within the range of formula (1), it is effective in reducing the axial chromatic aberration at the telephoto end and reducing the number of lenses in the second sub-group. If ν1B falls below the lower limit of formula (1), the axial chromatic aberration at the telephoto end increases, or the number of lenses in the second sub-group increases, making the first lens group larger, which is not preferable. If ν1B exceeds the upper limit of formula (1), it becomes difficult to select an appropriate material for the aspheric lens, or the axial chromatic aberration is overcorrected, which is not preferable.

[0018] It is more preferable that the numerical range of formula (1) is as follows:

[0019] 82≦ν1B≦99 (1a) Moreover, it is more preferable that the numerical range of the formula (1) is as follows:

[0020] 92≦ν1B≦97 (1b) It is preferable that the zoom lens of each embodiment satisfies at least one of the conditions of the following expressions (2) to (4).

[0021] The aspheric surface included in the second subgroup L1B has a shape in which the positive refractive power increases from the center to the periphery. When the aspheric amount at a position (end position) that is 100% of the effective diameter of the aspheric surface is ΔX10 and the focal length of the lens having the aspheric surface is fL, it is preferable that the condition of the following formula (2) is satisfied.

[0022] 5.0×10 -4 ≦|ΔX10 / fL|≦2.2×10 -3 (2) If |ΔX10 / fL| falls below the lower limit of formula (2), the effect of suppressing high-order aberrations is insufficient, which deteriorates the optical performance, which is not preferable. Also, if |ΔX10 / fL| exceeds the upper limit of formula (2), the high-order aberrations are overcorrected, which also deteriorates the optical performance, which is not preferable.

[0023] It is more preferable that the numerical range of the formula (2) is as follows:

[0024] 7.0×10 -4 ≦|ΔX10 / fL|≦2.0×10 -3 (2a) Moreover, it is more preferable that the numerical range of the formula (2) is as follows:

[0025] 7.5×10 -4 ≦|ΔX10 / fL|≦1.0×10 -3 (2b) Furthermore, when the focal length of the negative lens included in the first partial group L1A is f1An and the focal length of the first lens group L1 in an infinity focused state is f1, it is preferable to satisfy the following condition (3).

[0026] 1.0≦|f1An / f1|≦3.0 (3) By increasing the refractive power of the negative lens in the first sub-group L1A so as to satisfy the condition of formula (3), the refractive power of the positive lens in the second sub-group L1B can also be increased. This allows the image-side principal point of the first lens group L1 to be pushed toward the image side, which is effective in reducing the size of the zoom lens. In addition, by increasing the refractive power of the negative lens in the first sub-group L1A, high-order aberrations occur, but in each embodiment, the high-order aberrations are suppressed by the aspheric surface in the second sub-group L1B. If |f1An / f1| falls below the lower limit of formula (3), the refractive power of the negative lens becomes too strong and the aberrations cannot be suppressed completely, which is not preferable. Also, if |f1An / f1| exceeds the upper limit of formula (3), the effect of pushing out the image-side principal point of the first lens group L1 is reduced, which is not preferable because the zoom lens becomes large.

[0027] It is more preferable that the numerical range of the formula (3) is as follows:

[0028] 1.1≦|f1An / f1|≦2.8 (3a) Moreover, it is more preferable that the numerical range of the formula (3) is as follows:

[0029] 1.2≦|f1An / f1|≦2.6 (3b) The radius of curvature of the image-side surface of the negative lens included in the first subgroup L1A is G1R2, and the radius of curvature of the object-side surface of the positive lens adjacent to the negative lens among the one or more positive lenses included in the first subgroup L1A is G2R1. In this case, it is preferable to satisfy the condition of the following formula (4).

[0030] 1.5≦(G2R1+G1R2) / (G2R1-G1R2)≦30.0 (4) In addition, when the image side surface of the negative lens or the object side surface of the positive lens is aspheric, the radius of curvature (reference radius of curvature) of the sphere passing through the point on the optical axis (surface vertex) of that surface and the end position at the effective diameter is used. The condition of formula (4) indicates the appropriate range of the shape factor of the air lens between the image side surface of the negative lens of the first subgroup L1A and the object side surface of the adjacent positive lens. Since negative refractive power is generated by these two surfaces, the above-mentioned effect of pushing out the image side principal point of the first lens group L1 can be further strengthened, and the zoom lens can be made more compact. In addition, by appropriately selecting the Abbe number of the material (glass material) of the negative lens and the positive lens, it is possible to further suppress chromatic aberration. If the shape factor is below the lower limit of formula (4), the difference in refractive power between the two surfaces becomes too large, which is undesirable because it causes high-order aberrations or the suppression effect of chromatic aberration becomes excessive. Moreover, if the shape factor exceeds the upper limit of the formula (4), the difference in refractive power between the two surfaces becomes too small, which undesirably increases the size of the zoom lens.

[0031] It is more preferable that the numerical range of the formula (4) is as follows:

[0032] 2.0≦(G2R1+G1R2) / (G2R1-G1R2)≦28.5 (4a) Moreover, it is more preferable that the numerical range of the formula (4) is as follows:

[0033] 2.5≦(G2R1+G1R2) / (G2R1-G1R2)≦10.0 (4b) Furthermore, it is preferable that the zoom lens of each embodiment has at least one of the following configurations.

[0034] The first sub-group L1A is preferably composed of a negative lens, a positive lens, and a positive lens arranged in this order from the object side to the image side. By arranging the negative lens on the object side and the positive lens on the image side, the image side principal point position of the first sub-group L1A can be pushed toward the image side, and the diameter of the lens closest to the object side of the first lens group L1 (i.e., the zoom lens) can be reduced, thereby making the zoom lens more compact. In addition, in order to suppress aberrations occurring in the negative lens, it is necessary to place the positive lens close to the negative lens, but two positive lenses are arranged to give the negative lens sufficient refractive power.

[0035] In addition, it is preferable to form an anti-reflection film having a fine structure (concave-convex structure) with an average pitch of 400 nm or less on the image side surface of the negative lens included in the first sub-group L1A or the object side surface of the positive lens adjacent to the negative lens. In this fine structure, convex portions and holes are formed so that the density decreases continuously from the lens side to the air side. This makes the effective refractive index 1.30 or less. An anti-reflection film having such a fine structure with an average pitch of 400 nm or less has high reflection suppression performance. In each embodiment, since the curvature of the image side surface of the negative lens included in the first sub-group L1A and the object side surface of the positive lens adjacent thereto are close to each other, the incidence angle of the ghost light generated by reflection on these two surfaces to each surface becomes acute. When the incidence angle of the ghost light becomes acute, the reflectance becomes high. In response to this, by providing an anti-reflection film with a fine structure, it becomes possible to suppress the generation of the ghost light.

[0036] Examples 1 to 6 will be specifically described below. Example 6 is followed by Numerical Examples 1 to 6 corresponding to Examples 1 to 6, respectively. Numerical values ​​in the Numerical Examples will be described later. EXAMPLES

[0037] 1 is composed of, arranged in order from the object side to the image side, a first lens group L1 with positive refractive power, a second lens group L2 with negative refractive power, a third lens group L3 with negative refractive power, a fourth lens group L4 with positive refractive power, an aperture stop SP, and a fifth lens group L5 with positive refractive power. The second to fourth lens groups L2 to L4 correspond to the middle group, and the fifth lens group L5 corresponds to the rear lens group.

[0038] During zooming from the wide-angle end to the telephoto end, the first lens unit L1 and the fifth lens unit L5 do not move, the second lens unit L2 moves toward the image side, and the third lens unit L3 and the fourth lens unit L4 move toward the object side and the image side.

[0039] The first lens group L1 includes a first subgroup L1A, which is composed of a negative lens, a positive lens, and a positive lens arranged in this order from the object side to the image side. The second subgroup L1B includes a positive aspherical lens having an aspherical surface on the image side, and the third subgroup L1C includes a positive meniscus lens having a convex surface on the object side. The configuration of the first lens group L1 is the same in the other embodiments described later. EXAMPLES

[0040] 3 is composed of, arranged in order from the object side to the image side, a first lens group L1 with positive refractive power, a second lens group L2 with negative refractive power, a third lens group L3 with positive refractive power, a fourth lens group L4 with negative refractive power, a fifth lens group L5 with positive refractive power, an aperture stop SP, and a sixth lens group L6 with positive refractive power. The second to fifth lens groups L2 to L5 correspond to the middle group, and the sixth lens group L6 corresponds to the rear lens group.

[0041] During zooming from the wide-angle end to the telephoto end, the first lens unit L1 and the sixth lens unit L6 do not move, the second lens unit L2 and the third lens unit L3 move toward the image side, and the fourth lens unit L4 and the fifth lens unit L5 move toward the object side and the image side. EXAMPLES

[0042] 5 is composed of, arranged in order from the object side to the image side, a first lens group L1 with positive refractive power, a second lens group L2 with negative refractive power, a third lens group L3 with negative refractive power, a fourth lens group L4 with negative refractive power, a fifth lens group L5 with positive refractive power, an aperture stop SP, and a sixth lens group L6 with positive refractive power. The second to fifth lens groups L2 to L5 correspond to the middle group, and the sixth lens group L6 corresponds to the rear lens group.

[0043] During zooming from the wide-angle end to the telephoto end, the first lens unit L1 and the sixth lens unit L6 do not move, the second lens unit L2 and the third lens unit L3 move toward the image side, and the fourth lens unit L4 and the fifth lens unit L5 move toward the object side and the image side. EXAMPLES

[0044] 7 is composed of, arranged in order from the object side to the image side, a first lens group L1 with positive refractive power, a second lens group L2 with negative refractive power, a third lens group L3 with positive refractive power, a fourth lens group L4 with negative refractive power, a fifth lens group L5 with positive refractive power including an aperture stop SP, and a sixth lens group L6 with positive refractive power. The second to fifth lens groups L2 to L5 correspond to the middle group, and the sixth lens group L6 corresponds to the rear lens group.

[0045] During zooming from the wide-angle end to the telephoto end, the first lens unit L1 and the sixth lens unit L6 do not move, the second lens unit L2 and the third lens unit L3 move toward the image side, and the fourth lens unit L4 and the fifth lens unit L5 move toward the object side and the image side. EXAMPLES

[0046] 9 is composed of a first lens group L1 with positive refractive power, a second lens group L2 with negative refractive power, a third lens group L3 with negative refractive power, an aperture stop SP, and a fourth lens group L4 with positive refractive power, arranged in this order from the object side to the image side. The second and third lens groups L2 and L3 correspond to the middle group, and the fourth lens group L4 corresponds to the rear lens group.

[0047] During zooming from the wide-angle end to the telephoto end, the first lens unit L1 and the fourth lens unit L4 do not move, the second lens unit L2 moves toward the image side, and the third lens unit L3 moves toward the object side and the image side. EXAMPLES

[0048] 11 is composed of, arranged in order from the object side to the image side, a first lens group L1 with positive refractive power, a second lens group L2 with negative refractive power, a third lens group L3 with negative refractive power, a fourth lens group L4 with negative refractive power, a fifth lens group L5 with positive refractive power, an aperture stop SP, and a sixth lens group L6 with positive refractive power. The second to fifth lens groups L2 to L5 correspond to the middle group, and the sixth lens group L6 corresponds to the rear lens group.

[0049] During zooming from the wide-angle end to the telephoto end, the first lens unit L1 and the sixth lens unit L6 do not move, the second lens unit L2 and the third lens unit L3 move toward the image side, and the fourth lens unit L4 and the fifth lens unit L5 move toward the object side and the image side.

[0050] Numerical examples 1 to 6 are shown below. In each numerical example, surface number i indicates the order of the surface counted from the object side. r indicates the radius of curvature of the i-th surface (mm), and d indicates the lens thickness or distance (air gap) (mm) on the optical axis between the i-th surface and the (i+1)-th surface. nd indicates the refractive index at the d-line of the optical material between the i-th surface and the (i+1)-th surface. νd is the Abbe number based on the d-line of the optical material between the i-th surface and the (i+1)-th surface. The Abbe number νd based on the d-line is given by the following when the refractive indices at the d-line (wavelength 587.6 nm), F-line (wavelength 486.1 nm), and C-line (wavelength 656.3 nm) of the Fraunhofer lines are Nd, NF, and NC, respectively: νd=(Nd-1) / (NF-NC) It is expressed as:

[0051] In each numerical example, the half angle of view (°) of the zoom lens is shown, and the maximum image height corresponding to the half angle of view is shown as "image height". Furthermore, the focal length of each lens group is shown as lens group data. The focal length in the numerical example is the focal length at e-line (wavelength 546.07 nm). "BF" is back focus (mm). The back focus is the distance on the optical axis from the image side surface (final surface) of the lens closest to the image side that has refractive power in the zoom lens to the paraxial image surface, expressed as an air-equivalent length. In addition, the "lens total length" is the length obtained by adding the back focus to the distance on the optical axis from the object side surface (front surface) of the lens closest to the object side that has refractive power in the zoom lens to the final surface.

[0052] An "*" next to a surface number means that the surface is aspheric. An aspheric shape is expressed by the following formula, where X is the displacement from the apex of the surface in the optical axis direction, H is the height from the optical axis in a direction perpendicular to the optical axis, the light traveling direction is positive, R is the paraxial radius of curvature, K is the conic constant, and A2 to A16 are aspheric coefficients. The conic constant and the aspheric coefficients "e±x" are ×10 ±x means.

[0053]

number

[0054] Moreover, the values ​​of the above-mentioned formulas (1) to (6) in each numerical example are summarized in Table 1. Each numerical example satisfies all of the conditions of formulas (1) to (6).

[0055] 2, 4, 6, 8, 10, and 12 respectively show longitudinal aberrations (spherical aberration, astigmatism, distortion, and chromatic aberration) of the zoom lenses of Numerical Examples 1 to 6 at (a) the wide-angle end, (b) the intermediate zoom position, and (c) the telephoto end. In the spherical aberration diagrams, Fno indicates the F-number, the solid line indicates the spherical aberration for the d-line (wavelength 587.6 nm), and the two-dot chain line indicates the spherical aberration for the g-line (wavelength 435.8 nm). In the astigmatism diagrams, the solid line S indicates the astigmatism on the sagittal image plane, and the dashed line M indicates the astigmatism on the meridional image plane. The distortion diagrams show the distortion aberration at the d-line. The chromatic aberration diagrams show the chromatic aberration of magnification at the g-line. ω is the half angle of view (°).

[0056] [Numerical example 1] Unit: mm Surface Data Surface number rd nd νd Effective diameter 1 -231.015 2.70 1.74951 35.3 83.12 2 116.521 4.98 78.03 3 244.962 10.10 1.43387 95.1 77.89 4 -148.187 0.20 77.60 5 175.558 8.46 1.43387 95.1 73.63 6 -240.829 8.64 72.95 7 106.705 11.53 1.43875 94.7 71.07 8* -226.577 0.26 70.59 9 68.097 5.58 1.75500 52.3 65.48 10 131.182 (variable) 64.60 11* 82.877 0.80 2.05090 26.9 22.90 12 15.097 6.20 19.23 13 -29.850 0.60 2.00100 29.1 18.53 14 48.354 5.91 1.92286 18.9 18.75 15 -14.873 0.60 2.00100 29.1 18.90 16 566.873 0.18 19.51 17 60.181 4.98 1.76182 26.5 19.81 18 -19.605 0.60 2.00100 29.1 19.87 19 -46.500 (variable) 20.25 20 -54.631 0.75 1.88300 40.8 24.52 21 55.380 4.10 1.84666 23.8 25.81 22 -65.610 1.50 26.27 23 -37.021 0.75 1.88300 40.8 26.40 24 -102.457 (variable) 27.60 25* 87.503 5.72 1.75500 52.3 30.72 26 -49.044 0.20 31.34 27 97.233 1.00 1.85478 24.8 31.48 28 47.871 5.14 1.43875 94.7 31.18 29 -125.795 (variable) 31.22 30(Aperture) ∞ 0.69 30.43 31 29.186 8.37 1.64769 33.8 30.10 32 635.153 1.50 2.00100 29.1 27.95 33 34.508 36.58 26.32 34 -56.569 2.32 1.72825 28.5 28.64 35 -37.066 0.20 29.05 36 -230.969 1.00 1.88300 40.8 28.98 37 80.240 4.84 1.48749 70.2 29.11 38 -63.475 0.35 29.39 39 43.685 7.45 1.43875 94.7 29.41 40 -35.952 1.00 2.00100 29.1 29.01 41 -116.720 0.20 29.33 42 32.845 3.96 1.51742 52.4 29.09 43 140.416 4.00 28.62 44 ∞ 33.00 1.60859 46.4 40.00 45 ∞ 13.20 1.51633 64.1 40.00 46∞7.38 40.00 Image plane ∞ Aspheric Data Side 8 K = 0.00000e+000 A 4=-7.92530e-008 A 6=-1.08923e-011 A 8= 3.94939e-015 A10=-9.29079e-019 Page 11 K = 1.13468e+000 A 4= 4.35851e-006 A 6=-4.12206e-008 A 8= 4.64295e-010 A10=-1.68402e-012 A12=-4.27528e-014 A14= 4.68544e-016 A16=-1.38386e-018 Page 25 K =-2.00250e+000 A 4=-3.74810e-006 A 6= 3.91198e-009 A 8=-1.12574e-011 A10=2.58107e-014 A12=-2.20162e-017 Various data Zoom ratio 24.31 Wide Angle Mid-Telephoto Focal length 7.80 31.12 189.65 F-number 1.86 1.86 3.01 Half angle of view (°) 35.19 10.02 1.66 Image height 5.50 5.50 5.50 Lens total length 269.01 269.01 269.01 BF 40.60 40.60 40.60 d10 0.74 39.60 61.99 d19 65.76 9.51 2.07 d24 0.99 10.51 0.49 d29 0.96 8.83 3.90 Entrance pupil position 48.99 171.16 851.95 Exit pupil position 877.20 877.20 877.20 Front principal point position 56.86 203.38 1082.95 Back principal point position -0.42 -23.74 -182.27 Lens Group Data Group Starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 77.19 52.46 35.27 1.48 2 11 -13.48 19.88 0.63 -14.17 3 20 -51.99 7.10 1.29 -3.13 4 25 37.24 12.06 2.68 -5.04 5 30 54.80 118.67 58.28 -40.40 [Numerical example 2] Unit: mm Surface Data Surface number rd nd νd Effective diameter 1 -224.589 2.70 1.74951 35.3 83.13 2 115.075 5.05 78.12 3 242.373 10.09 1.43387 95.1 77.98 4 -149.259 0.20 77.68 5 176.816 8.64 1.43387 95.1 73.61 6 -222.729 8.72 72.89 7 108.463 11.55 1.43875 94.7 71.39 8* -224.823 0.21 70.91 9 67.744 5.66 1.75500 52.3 65.77 10 132.539 (variable) 64.93 11* 93.947 0.80 2.05090 26.9 23.17 12 16.081 5.41 19.61 13 -39.781 0.60 2.00100 29.1 19.04 14 45.764 6.21 1.92286 18.9 18.95 15 -13.898 0.60 2.00100 29.1 18.91 16 253.213 (variable) 19.13 17 61.962 4.41 1.76182 26.5 19.77 18 -22.101 0.60 2.00100 29.1 19.73 19 -77.942 (variable) 20.41 20 -68.320 0.75 1.88300 40.8 25.21 21 50.251 4.13 1.84666 23.8 26.37 22 -79.761 1.50 26.78 23 -35.084 0.75 1.88300 40.8 26.77 24 -98.486 (variable) 28.10 25* 92.943 5.67 1.75500 52.3 31.42 26 -51.574 0.20 32.09 27 74.957 1.00 1.85478 24.8 32.54 28 45.036 5.76 1.43875 94.7 32.21 29 -101.199 (variable) 32.25 30(Aperture) ∞ 0.69 30.85 31 28.888 6.93 1.64769 33.8 30.33 32 158.724 1.50 2.00100 29.1 28.60 33 31.537 36.58 26.82 34 -52.897 2.33 1.72825 28.5 28.81 35 -36.277 0.20 29.25 36 -1387.087 1.00 1.88300 40.8 29.20 37 82.176 4.67 1.48749 70.2 29.20 38 -70.782 0.35 29.38 39 41.887 7.23 1.43875 94.7 29.11 40 -39.404 1.00 2.00100 29.1 28.60 41 -264.050 0.20 28.72 42 35.008 4.06 1.51742 52.4 28.59 43 239.178 4.00 28.14 44 ∞ 33.00 1.60859 46.4 40.00 45 ∞ 13.20 1.51633 64.1 40.00 46∞7.40 40.00 Image plane ∞ Aspheric Data Side 8 K = 0.00000e+00 A 4=-8.75737e-08 A 6=-1.25122e-11 A 8= 4.68660e-15 A10=-1.25976e-18 Page 11 K = 5.10296e-01 A 4= 4.93713e-06 A 6=-3.11763e-08 A 8= 1.63591e-10 A10= 3.78481e-12 A12=-8.78287e-14 A14= 6.34293e-16 A16=-1.57286e-18 Page 25 K =-2.00384e+00 A 4=-3.66371e-06 A 6= 3.62693e-09 A 8=-8.36802e-12 A10= 1.42654e-14 A12=-5.74460e-18 Various data Zoom ratio 24.36 Wide Angle Mid-Telephoto Focal length 7.80 31.36 189.98 F-number 1.87 1.87 3.02 Half angle of view (°) 35.19 9.95 1.66 Image height 5.50 5.50 5.50 Lens total length 268.98 268.98 268.98 BF 40.57 40.57 40.57 d10 0.79 39.31 61.50 d16 3.00 1.98 2.64 d19 65.48 9.57 2.31 d24 0.49 10.17 0.47 d29 0.69 9.43 3.54 Entrance pupil position 49.00 170.52 865.75 Exit pupil position -5282.92 -5282.92 -5282.92 Front principal point position 56.79 201.70 1048.91 Back principal point position -0.40 -23.96 -182.58 Lens Group Data Group Starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 76.35 52.82 35.60 1.87 2 11 -9.58 13.62 2.71 -6.05 3 17 69.46 5.01 0.63 -2.19 4 20 -51.56 7.13 1.79 -2.62 5 25 35.20 12.64 2.94 -5.20 6 30 55.82 116.94 55.24 -37.72 [Numerical example 3] Unit: mm Surface Data Surface number rd nd νd Effective diameter 1 -232.442 2.70 1.74951 35.3 83.12 2 116.347 5.13 77.52 3 257.544 9.79 1.43387 95.1 77.21 4 -147.475 0.20 76.76 5 173.424 8.28 1.43387 95.1 72.29 6 -239.152 8.64 71.59 7 106.271 11.63 1.43875 94.7 71.09 8* -222.474 0.26 70.60 9 67.778 5.56 1.75500 52.3 65.42 10 129.283 (variable) 64.54 11* 98.541 0.80 2.05090 26.9 22.90 12 15.447 (variable) 19.27 13 -28.485 0.60 2.00100 29.1 18.09 14 57.049 5.80 1.92286 18.9 18.30 15 -14.505 0.60 2.00100 29.1 18.46 16 423.945 0.18 19.04 17 62.657 5.58 1.76182 26.5 19.32 18 -16.596 0.60 2.00100 29.1 19.41 19 -39.567 (variable) 20.23 20 -63.919 0.75 1.88300 40.8 25.22 21 61.066 4.14 1.84666 23.8 26.35 22 -72.217 1.50 26.85 23 -38.487 0.75 1.88300 40.8 26.95 24 -108.597 (variable) 28.11 25* 82.267 5.36 1.75500 52.3 30.94 26 -60.379 0.20 31.50 27 82.887 1.00 1.85478 24.8 31.84 28 47.520 5.51 1.43875 94.7 31.55 29 -112.034 (variable) 31.60 30(Aperture) ∞ 0.70 30.66 31 30.266 6.94 1.64769 33.8 30.28 32 99.334 1.50 2.00100 29.1 28.39 33 32.432 36.58 26.86 34 -54.653 2.42 1.72825 28.5 28.69 35 -37.611 0.20 29.17 36 1121.088 1.00 1.88300 40.8 29.16 37 58.510 5.13 1.48749 70.2 29.12 38 -80.910 0.35 29.35 39 39.835 7.42 1.43875 94.7 29.35 40 -40.841 1.00 2.00100 29.1 28.88 41 -228.000 0.20 29.03 42 37.087 4.19 1.51742 52.4 28.92 43 427.643 4.00 28.46 44 ∞ 33.00 1.60859 46.4 40.00 45 ∞ 13.20 1.51633 64.1 40.00 46∞7.82 40.00 Image plane ∞ Aspheric Data Side 8 K = 0.00000e+00 A 4=-8.25537e-08 A 6=-8.40262e-12 A 8= 2.14457e-15 A10=-4.11570e-19 Page 11 K = 2.00113e+00 A 4= 6.27753e-06 A 6=-3.42120e-08 A 8= 2.73017e-10 A10= 2.21978e-13 A12=-4.76993e-14 A14= 4.45695e-16 A16=-1.26851e-18 Page 25 K =-1.48547e+00 A 4=-3.43020e-06 A 6= 3.12673e-09 A 8=-8.38241e-12 A10= 1.93236e-14 A12=-1.73874e-17 Various data Zoom ratio 24.31 Wide Angle Mid-Telephoto Focal length 7.80 31.11 189.65 F-number 1.86 0.00 0.00 Half angle of view (°) 35.19 0.00 0.00 Image height 5.50 5.50 5.50 Lens total length 269.01 269.01 269.01 BF 41.04 41.04 41.04 d10 0.82 39.64 62.00 d12 6.89 5.57 6.13 d19 65.71 9.81 1.81 d24 0.49 10.92 0.50 d29 0.88 8.87 4.36 Entrance pupil position 48.84 170.35 857.13 Exit pupil position 3867.48 3867.48 3867.48 Front principal point position 56.66 201.71 1056.09 Back principal point position 0.02 -23.29 -181.83 Lens Group Data Group Starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 77.10 52.19 35.13 1.46 2 11 -17.52 0.80 0.46 0.07 3 13 -57.22 13.35 -5.89 -14.63 4 20 -56.87 7.14 1.51 -2.93 5 25 37.93 12.08 2.58 -5.21 6 30 55.02 117.81 55.80 -39.21 [Numerical example 4] Unit: mm Surface Data Surface number rd nd νd Effective diameter 1 -208.843 2.70 1.74951 35.3 83.14 2 117.439 4.78 78.28 3 232.405 10.29 1.43387 95.1 78.16 4 -148.515 0.20 77.88 5 183.462 8.59 1.43387 95.1 73.86 6 -219.674 8.62 73.15 7 109.456 11.57 1.43875 94.7 71.52 8* -218.798 0.21 71.07 9 67.210 5.76 1.75500 52.3 65.90 10 132.900 (variable) 65.06 11* 138.502 0.80 2.05090 26.9 23.78 12 16.844 5.30 20.16 13 -53.819 0.60 2.00100 29.1 19.52 14 48.172 6.55 1.92286 18.9 19.28 15 -13.501 0.60 2.00100 29.1 19.15 16 138.740 (variable) 19.13 17 52.999 4.95 1.76182 26.5 19.60 18 -19.306 0.60 2.00100 29.1 19.57 19 -92.866 (variable) 20.34 20 -63.153 0.75 1.88300 40.8 25.30 21 58.303 3.97 1.84666 23.8 26.49 22 -71.393 1.50 26.89 23 -35.412 0.75 1.88300 40.8 26.93 24 -104.075 (variable) 28.28 25* 104.927 5.58 1.75500 52.3 30.26 26 -45.914 0.20 30.94 27 63.282 1.00 1.85478 24.8 31.28 28 40.317 5.43 1.43875 94.7 30.87 29 -153.194 0.69 30.84 30(Aperture) ∞ 0.69 30.68 31 26.825 6.58 1.64769 33.8 30.09 32 71.101 1.50 2.00100 29.1 28.15 33 26.891 (variable) 26.24 34 -51.824 2.17 1.72825 28.5 28.85 35 -38.573 0.20 29.33 36 -480.667 1.00 1.88300 40.8 29.46 37 72.008 5.93 1.48749 70.2 29.60 38 -44.427 0.35 29.93 39 43.523 6.57 1.43875 94.7 29.50 40 -47.739 1.00 2.00100 29.1 29.03 41 -528.213 0.20 29.01 42 33.291 3.76 1.51742 52.4 28.76 43 127.817 4.00 28.29 44 ∞ 33.00 1.60859 46.4 40.00 45 ∞ 13.20 1.51633 64.1 40.00 46∞7.39 40.00 Image plane ∞ Aspheric Data Side 8 K = 0.00000e+00 A 4=-7.32986e-08 A 6=-1.47498e-11 A 8= 6.62028e-15 A10=-1.79711e-18 Page 11 K =-1.47884e+00 A 4= 7.99637e-06 A 6=-3.90920e-08 A 8= 4.26214e-10 A10= 2.16449e-14 A12=-5.45852e-14 A14= 4.67659e-16 A16=-1.21180e-18 Page 25 K =-2.00176e+00 A 4=-3.83639e-06 A 6= 3.83274e-09 A 8=-1.08581e-11 A10=2.59318e-14 A12=-2.55141e-17 Various data Zoom ratio 24.36 Wide Angle Mid-Telephoto Focal length 7.80 30.54 189.97 F-number 1.87 1.87 3.02 Half angle of view (°) 35.19 10.21 1.66 Image height 5.50 5.50 5.50 Lens total length 268.98 268.98 268.98 BF 40.56 40.56 40.56 d10 0.94 39.16 61.19 d16 3.00 2.18 2.98 d19 65.03 9.50 2.58 d24 0.48 10.37 0.48 d33 37.01 45.24 39.24 Entrance pupil position 49.09 168.06 842.17 Exit pupil position 2011.70 252.68 688.65 Front principal point position 56.92 202.40 1085.12 Back principal point position -0.41 -23.14 -182.58 Lens Group Data Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 76.00 52.73 35.46 1.94 2 11 -9.82 13.86 2.69 -6.04 3 17 77.13 5.55 -0.08 -3.19 4 20 -51.73 6.97 1.67 -2.66 5 25 33.11 21.68 -3.38 -13.94 6 34 47.86 71.38 7.40 -39.56 [Numerical example 5] Unit: mm Surface Data Surface number rd nd νd Effective diameter 1 -140.056 2.70 1.74951 35.3 83.13 2 105.226 3.10 80.74 3 136.554 15.54 1.43387 95.1 81.30 4 -113.679 0.20 81.53 5 248.311 9.49 1.43387 95.1 80.34 6 -182.875 7.39 80.09 7 118.408 12.67 1.49700 81.5 76.05 8* -192.009 0.26 74.94 9 59.695 5.46 1.76385 48.5 62.37 10 107.144 (variable) 61.26 11* 72.279 0.80 2.05090 26.9 25.87 12 15.011 6.47 21.27 13 -55.492 0.60 2.00100 29.1 20.72 14 -197.180 6.55 1.92286 18.9 20.66 15 -12.728 0.60 2.00100 29.1 20.57 16 178.662 0.18 20.86 17 40.960 5.36 1.76182 26.5 21.14 18 -21.465 0.60 2.00100 29.1 21.00 19 -91.977 (variable) 21.11 20 -42.963 0.75 1.88300 40.8 19.56 21 35.369 5.62 1.84666 23.8 20.72 22 -67.042 1.50 21.86 23 -32.863 0.75 1.88300 40.8 22.05 24 -89.312 (variable) 23.07 25* 203.613 4.14 1.75500 52.3 28.00 26 -59.034 0.20 28.79 27 43.547 1.00 1.85478 24.8 30.31 28 39.218 5.46 1.43875 94.7 30.08 29 -115.340 0.99 30.10 30(Aperture) ∞ 0.70 29.91 31 36.090 2.74 1.64769 33.8 29.53 32 56.559 1.50 2.00100 29.1 28.94 33 35.953 36.58 27.90 34 -32.559 1.66 1.72825 28.5 28.82 35 -32.455 0.20 29.57 36 -157.002 1.00 1.88300 40.8 30.06 37 101.556 6.54 1.48749 70.2 30.56 38 -36.990 0.35 31.16 39 53.415 7.94 1.43875 94.7 31.27 40 -34.618 1.00 2.00100 29.1 30.93 41 -89.216 0.20 31.44 42 32.002 6.02 1.51742 52.4 31.21 43 102.737 4.00 30.00 44 ∞ 33.00 1.60859 46.4 40.00 45 ∞ 13.20 1.51633 64.1 40.00 46∞10.77 40.00 Image plane ∞ Aspheric Data Side 8 K = 0.00000e+00 A 4=-4.82080e-08 A 6=-2.24681e-11 A 8= 7.98458e-15 A10=-2.72330e-18 Page 11 K =-2.00109e+00 A 4= 9.27124e-06 A 6=-4.65669e-08 A 8= 4.18513e-10 A10= 7.52361e-13 A12=-4.12756e-14 A14= 2.66266e-16 A16=-5.47562e-19 Page 25 K =-1.30409e+00 A 4=-3.44754e-06 A 6= 4.00765e-09 A 8=-1.99149e-11 A10=5.10888e-14 A12=-5.57484e-17 Various data Zoom ratio 20.00 Wide Angle Mid-Telephoto Focal length 7.80 27.06 156.00 F-number 1.87 1.86 2.69 Half angle of view (°) 35.19 11.49 2.02 Image height 5.50 5.50 5.50 Lens total length 268.03 268.03 268.03 BF 43.94 43.94 43.94 d10 0.69 34.88 54.58 d19 53.56 15.48 3.83 d24 5.02 8.92 0.88 Entrance pupil position 48.96 153.36 650.26 Exit pupil position -61671.64 -61671.64 -61671.64 Front principal point position 56.76 180.41 805.87 Back principal point position 2.97 -16.30 -145.23 Lens Group Data Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 68.25 56.81 36.87 3.90 2 11 -14.88 21.16 0.91 -13.71 3 20 -38.00 8.62 1.35 -3.82 4 25 62.55 128.41 71.65 -139.81 [Numerical example 6] Unit: mm Surface Data Surface number rd nd νd Effective diameter 1 -148.142 2.70 1.74951 35.3 83.13 2 143.596 1.50 78.78 3 154.053 11.04 1.49700 81.5 78.69 4* -160.337 0.20 78.28 5 -3109.040 8.46 1.43387 95.1 76.14 6 -106.880 7.52 75.55 7 95.843 11.34 1.43875 94.7 69.10 8* -288.253 0.26 68.54 9 64.459 5.57 1.75500 52.3 63.44 10 124.400 (variable) 62.54 11* 77.867 0.80 2.05090 26.9 23.96 12 14.209 (variable) 19.65 13 -30.667 0.60 2.00100 29.1 18.35 14 75.230 6.17 1.92286 18.9 18.54 15 -13.508 0.60 2.00100 29.1 18.70 16 212.535 0.18 19.38 17 53.796 5.61 1.76182 26.5 19.73 18 -17.933 0.60 2.00100 29.1 19.83 19 -41.550 (variable) 20.71 20 -60.762 0.75 1.88300 40.8 25.37 21 69.693 4.11 1.84666 23.8 26.50 22 -65.537 1.50 27.00 23 -38.108 0.75 1.88300 40.8 27.12 24 -99.729 (variable) 28.25 25* 84.955 5.12 1.75500 52.3 31.22 26 -68.662 0.20 31.75 27 93.458 1.00 1.85478 24.8 32.13 28 50.387 5.85 1.43875 94.7 31.91 29 -82.925 (variable) 32.01 30(Aperture) ∞ 0.69 30.86 31 29.581 5.75 1.64769 33.8 30.45 32 58.834 1.50 2.00100 29.1 28.78 33 29.769 36.58 27.26 34 -65.476 2.56 1.72825 28.5 28.83 35 -40.879 0.20 29.27 36 135.009 1.00 1.88300 40.8 29.21 37 35.685 5.50 1.48749 70.2 28.84 38 -204.031 0.35 29.03 39 33.827 7.45 1.43875 94.7 29.33 40 -49.644 1.00 2.00100 29.1 28.86 41 -642.176 0.20 28.87 42 46.800 5.47 1.51742 52.4 28.78 43 -313.260 4.00 28.08 44 ∞ 33.00 1.60859 46.4 40.00 45 ∞ 13.20 1.51633 64.1 40.00 46∞7.39 40.00 Image plane ∞ Aspheric Data Side 4 K = 0.00000e+00 A 4= 3.31238e-07 A 6=-1.69084e-11 A 8= 2.34373e-15 A10=-1.04604e-18 Side 8 K = 0.00000e+00 A 4=-2.96196e-07 A 6= 7.56214e-11 A 8=-1.22018e-14 A10 = 1.44826e-18 Page 11 K = 2.00047e+00 A 4= 6.25766e-06 A 6=-1.11804e-08 A 8=-1.87458e-10 A10= 5.60868e-12 A12=-7.93914e-14 A14= 5.01522e-16 A16=-1.16396e-18 Page 25 K =-2.00403e+00 A 4=-2.99623e-06 A 6= 2.31523e-09 A 8=-4.69495e-12 A10=8.18306e-15 A12=-4.07679e-18 Various data Zoom ratio 24.34 Wide Angle Mid-Telephoto Focal length 7.80 30.86 189.82 F-number 1.86 1.86 3.01 Half angle of view (°) 35.19 10.11 1.66 Image height 5.50 5.50 5.50 Lens total length 269.01 269.01 269.01 BF 40.61 40.61 40.61 d10 0.70 36.25 56.73 d12 7.81 6.33 6.77 d19 67.79 11.57 1.95 d24 0.49 11.21 0.50 d29 0.92 12.35 11.77 Entrance pupil position 47.38 170.14 916.61 Exit pupil position -2736.41 -2736.41 -2736.41 Front principal point position 55.16 200.65 1093.30 Back principal point position -0.41 -23.46 -182.43 Lens Group Data Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 73.99 48.58 30.21 -1.06 2 11 -16.65 0.80 0.48 0.09 3 13 -63.35 13.75 -6.49 -15.54 4 20 -60.78 7.11 1.27 -3.16 5 25 39.69 12.18 2.81 -5.12 6 30 55.64 118.46 54.51 -39.76

[0057] [Table 1]

[0058] The "EM" in the |ΔX10 / fL| value in Table 1 is × 10 -M means. [Imaging device] 13 shows a digital still camera as an imaging device using the zoom lens of each of the above-mentioned embodiments as an imaging optical system. Reference numeral 20 denotes a camera body, and 21 denotes an imaging optical system constituted by any of the zoom lenses of embodiments 1 to 6. Reference numeral 22 denotes a solid-state imaging element such as a CCD sensor or a CMOS sensor that is built into the camera body 20 and captures an optical image (subject image) formed by the imaging optical system 21. Reference numeral 23 denotes a recording section that records image data generated by processing an imaging signal from the imaging element 22, and 24 denotes a rear display that displays the image data.

[0059] By using the zoom lens of each embodiment, a camera that is small in size and has high optical performance can be obtained.

[0060] The camera may be a single-lens reflex camera having a quick-turn mirror, or a mirrorless camera having no quick-turn mirror.

[0061] The above embodiment includes the following configurations.

[0062] (Configuration 1) A zoom lens having a first lens group having positive refractive power that does not move during zooming, an intermediate group including two or more lens groups that move during zooming, and a rear lens group that does not move during zooming, which are arranged in this order from the object side to the image side, and in which the distance between adjacent lens groups changes during zooming, the intermediate group includes a second lens group having negative refractive power that is disposed closest to the object side among the intermediate group and moves during zooming, the first lens group includes a first subgroup which is fixed during focusing, and a second subgroup and a third subgroup which move toward the object side during focusing from an object at infinity to a close object such that an interval between each of the subgroups changes; the first sub-group includes one negative lens and one or more positive lenses, which are arranged in order from the object side to the image side; the second sub-group includes an aspherical lens having an aspherical lens surface, When the Abbe number of the aspheric lens based on the d-line is ν, 81≦ν1B≦〇〇 A zoom lens characterized by satisfying the following conditions. (Configuration 2) the aspheric lens surface has a shape in which the positive refractive power increases from the center toward the periphery, When the aspheric amount at 100% of the effective diameter of the lens surface of the aspheric shape is ΔX10 and the focal length of the aspheric lens is fL, 5.0×10 -3 ≦|ΔX10 / fL|≦2.2×10 -3 2. The zoom lens according to claim 1, wherein the following condition is satisfied: (Configuration 3) Let f1An be the focal length of the negative lens included in the first subgroup, and f1 be the focal length of the first lens group when focused on an object at infinity, 1.0≦|f1An / f1|≦3.0 3. The zoom lens according to configuration 1 or 2, which satisfies the following conditions: (Configuration 4) When the radius of curvature of the image side surface of the negative lens included in the first subgroup is G1R2, and the radius of curvature of the object side surface of a positive lens adjacent to the negative lens among the one or more positive lenses included in the first subgroup is G2R1, 1.5≦(G2R1+G1R2) / (G2R1-G1R2)≦30.0 4. The zoom lens according to any one of configurations 1 to 3, which satisfies the following condition: (Configuration 5) 5. The zoom lens according to any one of configurations 1 to 4, wherein the first subgroup is composed of a negative lens, a positive lens, and a positive lens, arranged in that order from the object side to the image side. (Configuration 6) The zoom lens according to any one of configurations 1 to 5, characterized in having, arranged in order from the object side to the image side, the first lens group, the second lens group that moves toward the image side during zooming from the wide-angle end to the telephoto end, a third lens group with negative refractive power that moves toward the image side during zooming from the wide-angle end to the telephoto end, a fourth lens group with positive refractive power that moves during zooming, and a fifth lens group with positive refractive power as the rear lens group. (Configuration 7) The zoom lens according to any one of configurations 1 to 5, characterized in having, arranged in order from the object side to the image side, the first lens group, the second lens group that moves toward the image side during zooming from the wide-angle end to the telephoto end, a third lens group with positive refractive power that moves toward the image side during zooming from the wide-angle end to the telephoto end, a fourth lens group with negative refractive power that moves during zooming, a fifth lens group with positive refractive power that moves during zooming, and a sixth lens group with positive refractive power as the rear lens group. (Configuration 8) The zoom lens according to any one of configurations 1 to 5, characterized in having, arranged in order from the object side to the image side, the first lens group, the second lens group that moves toward the image side during zooming from the wide-angle end to the telephoto end, a third lens group with negative refractive power that moves toward the image side during zooming from the wide-angle end to the telephoto end, a fourth lens group with negative refractive power that moves during zooming, a fifth lens group with positive refractive power that moves during zooming, and a sixth lens group with positive refractive power as the rear lens group. (Configuration 9) The zoom lens according to any one of configurations 1 to 5, characterized in having, arranged in order from the object side to the image side, the first lens group, the second lens group that moves toward the image side during zooming from the wide-angle end to the telephoto end, a third lens group with negative refractive power that moves toward the image side during zooming from the wide-angle end to the telephoto end, and a fourth lens group with positive refractive power as the rear lens group. (Configuration 10) The zoom lens described in configuration 4, characterized in that an anti-reflection coating having a microstructure with an average pitch of 400 nm or less is formed on the image-side surface of the negative lens included in the first subgroup or on the object-side surface of the positive lens adjacent to the negative lens. (Configuration 11) The zoom lens according to any one of configurations 1 to 10, and an image sensor for capturing an image of a subject through the zoom lens.

[0063] The embodiments described above are merely representative examples, and various modifications and alterations are possible for each embodiment when implementing the present invention. [Explanation of symbols]

[0064] L1 First lens group L2 Second lens group L3: Third lens group L4 4th lens group L5 Fifth lens group L6 6th lens group I image plane SP aperture stop

Claims

1. A zoom lens having a first lens group having positive refractive power that does not move during zooming, an intermediate group including two or more lens groups that move during zooming, and a rear lens group that does not move during zooming, which are arranged in this order from an object side to an image side, and in which a distance between adjacent lens groups changes during zooming, the intermediate group includes a second lens group having negative refractive power that is disposed closest to the object side among the intermediate group and moves during zooming, the first lens group includes a first subgroup which is fixed during focusing, and a second subgroup and a third subgroup which move toward the object side during focusing from an object at infinity to a close object such that an interval between each of the subgroups changes; the first sub-group includes one negative lens and one or more positive lenses, which are arranged in order from the object side to the image side; the second sub-group includes an aspheric lens having an aspheric lens surface, When the Abbe number of the aspherical lens based on the d-line is ν1B, 81≦ν1B≦100 A zoom lens characterized by satisfying the following conditions.

2. the aspheric lens surface has a shape in which the positive refractive power increases from the center toward the periphery, When the aspheric amount at 100% of the effective diameter of the lens surface of the aspheric shape is ΔX10 and the focal length of the aspheric lens is fL, 5.0×10 －４ ≦|ΔX10 / fL|≦2.2×10 －３ 2. The zoom lens according to claim 1, which satisfies the following condition:

3. When the focal length of the negative lens included in the first subgroup is f1An and the focal length of the first lens group when focused on an object at infinity is f1, 1.0≦|f1An / f1|≦3.0 2. The zoom lens according to claim 1, which satisfies the following condition:

4. When the radius of curvature of the image side surface of the negative lens included in the first subgroup is G1R2 and the radius of curvature of the object side surface of a positive lens adjacent to the negative lens among the one or more positive lenses included in the first subgroup is G2R1, 1.5≦(G2R1+G1R2) / (G2R1-G1R2)≦30.0 2. The zoom lens according to claim 1, which satisfies the following condition:

5. 2. The zoom lens according to claim 1, wherein the first sub-group is made up of, in order from the object side to the image side, a negative lens, a positive lens and a positive lens.

6. 2. The zoom lens according to claim 1, comprising, arranged in order from the object side to the image side, the first lens group, the second lens group that moves toward the image side during zooming from the wide-angle end to the telephoto end, a third lens group with negative refractive power that moves toward the image side during zooming from the wide-angle end to the telephoto end, a fourth lens group with positive refractive power that moves during zooming, and a fifth lens group with positive refractive power as the rear lens group.

7. 2. The zoom lens according to claim 1, comprising, arranged in order from the object side to the image side, the first lens group, the second lens group that moves toward the image side during zooming from the wide-angle end to the telephoto end, a third lens group with positive refractive power that moves toward the image side during zooming from the wide-angle end to the telephoto end, a fourth lens group with negative refractive power that moves during zooming, a fifth lens group with positive refractive power that moves during zooming, and a sixth lens group with positive refractive power as the rear lens group.

8. 2. The zoom lens according to claim 1, comprising, arranged in order from the object side to the image side, the first lens group, the second lens group that moves toward the image side during zooming from the wide-angle end to the telephoto end, a third lens group with negative refractive power that moves toward the image side during zooming from the wide-angle end to the telephoto end, a fourth lens group with negative refractive power that moves during zooming, a fifth lens group with positive refractive power that moves during zooming, and a sixth lens group with positive refractive power as the rear lens group.

9. 2. The zoom lens according to claim 1, comprising, arranged in order from the object side to the image side, the first lens group, the second lens group that moves toward the image side during zooming from the wide-angle end to the telephoto end, a third lens group with negative refractive power that moves toward the image side during zooming from the wide-angle end to the telephoto end, and a fourth lens group with positive refractive power as the rear lens group.

10. 5. The zoom lens according to claim 4, wherein an anti-reflection coating having a microstructure with an average pitch of 400 nm or less is formed on an image-side surface of the negative lens included in the first subgroup or on an object-side surface of the positive lens adjacent to the negative lens.

11. A zoom lens according to any one of claims 1 to 10; and an image sensor for capturing an image of a subject through the zoom lens.

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