Zoom lens and imaging device

Abstract

There is a demand for a compact zoom lens with a wide angle of view and high zoom magnification. [Solution] The zoom lens is composed of a first lens group with positive refractive power that does not move for zooming, three or more movable lens groups that move for zooming, and a final lens group with positive refractive power that does not move for zooming. The three or more movable lens groups include a P lens group with positive refractive power, an N lens group with negative refractive power, and one or more V lens groups, arranged in order from the image side. When the focal length of the first lens group is f1, the focal length of the i-th movable lens group among the one or more V lens groups is fVi, the ratio of the focal lengths of the telephoto end and wide-angle end of the zoom lens when in focus at infinity is Z, and the ratio of the combined horizontal magnification at the telephoto end and wide-angle end of the one or more V lens groups when in focus at infinity is ZV, then -1.0 ≤ Σ(f1 / fVi) ≤ -0.4, 0

Description

Technical Field

[0001] The present invention relates to a zoom lens suitable for imaging.

Background Art

[0002] Zoom lenses are required to be small in size while having a wide angle of view and high optical performance. Patent Document 1 discloses a zoom lens composed of a first lens group having a positive refractive power that does not move for zooming, a plurality of lens groups that move for zooming, and a rear lens group having a positive refractive power that does not move for zooming, which are arranged in order from the object side to the image side.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] A small zoom lens with a wider angle of view and a higher zoom ratio than conventional ones is desired.

Means for Solving the Problems

[0005] One aspect of the present invention is a zoom lens which includes a plurality of lens groups. The plurality of lens groups consist of a first lens group with positive refractive power that does not move for zooming and is arranged in order from the object side to the image side, three or more movable lens groups that move for zooming, and a final lens group with positive refractive power that does not move for zooming, and the spacing between adjacent lens groups changes when zooming. The three or more movable lens groups include a P lens group with positive refractive power, an N lens group with negative refractive power, and one or more V lens groups which are arranged in order from the image side to the object side. Let f1 be the focal length of the first lens group, and fVi be the focal length of the i-th moving lens group from the object side among one or more V lens groups. Let Σ(f1 / fVi) be the sum of f1 / fVi. Let Z be the ratio of the focal length at the telephoto end of the zoom lens when focused on an object at infinity to the focal length at the wide-angle end of the zoom lens when focused on an object at infinity. Let ZV be the ratio of the combined horizontal magnification at the telephoto end of one or more V lens groups when focused on an object at infinity to the combined horizontal magnification at the wide-angle end. -1.0 ≤ Σ(f1 / fVi) ≤ -0.4 0 <Z / ZV≦1.0 3.0 ≤ Z ≤ 10.0 It is characterized by satisfying the following conditions. Furthermore, an imaging device equipped with the above-mentioned zoom lens also constitutes another aspect of the present invention. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a zoom lens that is compact yet has a wide angle of view and high zoom magnification. [Brief explanation of the drawing]

[0007] [Figure 1] Cross-sectional view of the zoom lens of Example 1 at its wide-angle end. [Figure 2] Aberration diagrams of the zoom lens of Example 1 at the (A) wide-angle end and (B) telephoto end. [Figure 3] Cross-sectional view of the zoom lens of Example 2 at its wide-angle end. [Figure 4] Aberration diagrams of the zoom lens of Example 2 at the (A) wide-angle end and (B) telephoto end. [Figure 5] Cross-sectional view of the zoom lens of Example 3 at its wide-angle end. [Figure 6] Aberration diagrams of the zoom lens of Example 3 at the (A) wide-angle end and (B) telephoto end. [Figure 7] Cross-sectional view of the zoom lens of Example 4 at its wide-angle end. [Figure 8] Aberration diagrams of the zoom lens of Example 4 at the (A) wide-angle end and (B) telephoto end. [Figure 9] Cross-sectional view of the zoom lens of Example 5 at its wide-angle end. [Figure 10] Aberration diagrams of the zoom lens of Example 5 at the (A) wide-angle end and (B) telephoto end. [Figure 11] Cross-sectional view of the zoom lens of Example 6 at its wide-angle end. [Figure 12] Aberration diagrams of the zoom lens of Example 6 at the (A) wide-angle end and (B) telephoto end. [Figure 13] A diagram showing an imaging device using a zoom lens in each embodiment. [Modes for carrying out the invention]

[0008] The embodiments of the present invention will be described below with reference to the drawings. First, before describing the specific embodiments 1 to 6, we will explain the matters common to each embodiment.

[0009] The zoom lenses of each embodiment are used in various imaging devices such as cinema cameras, broadcast cameras, video cameras, surveillance cameras, digital still cameras, and silver halide film cameras. In a zoom lens, a lens group is a collection of one or more lenses that move together or remain stationary during zooming between the wide-angle and telephoto ends. That is, the distance between adjacent lens groups changes during zooming. The lens group may include an aperture diaphragm. The wide-angle and telephoto ends represent the zoom states at the maximum angle of view (shortest focal length) and minimum angle of view (longest focal length), respectively, when the lens group that moves during zooming is positioned at both ends of the range that is mechanically or controllly movable along the optical axis.

[0010] Figures 1, 3, 5, 7, 9, and 11 each show a cross-section at the wide-angle end of the zoom lens of Examples 1 to 6 in a state focused on an infinite object (hereinafter referred to as an infinite focus state). In each figure, the left side is the object side (front side), and the right side is the image side (rear side). OA indicates the optical axis of the zoom lens.

[0011] Li is the i-th lens group (i = 1, 2,...) counted from the object side, and L1m is the m-th sub-lens group (m = 1, 2,...) counted from the object side in the first lens group L1. A sub-lens group is a collection of one or more lenses that move together or do not move during focusing. SP is the aperture stop, and I is the image plane. On the image plane I, the imaging surface (light-receiving surface) of the imaging element in the imaging device or the film surface (photosensitive surface) of the silver halide film is arranged.

[0012] In each figure, under the lens group that moves during zooming, the movement trajectory of the lens group during zooming from the wide-angle end to the telephoto end is indicated by an arrow. Further, under the sub-lens group that moves during focusing in the first lens group L1, the movement direction of the sub-lens group during focusing from infinity to the closest distance is indicated by an arrow marked with FOCUS.

[0013] The zoom lens of each example includes a plurality of lens groups. The plurality of lens groups are arranged in order from the object side to the image side, including a first lens group L1 with a positive refractive power that does not move for zooming, three or more moving lens groups L2 to L4 (or L5) that move for zooming, and a final lens group L5 (or L6) with a positive refractive power that does not move for zooming. The three or more moving lens groups include a P lens group L4 (or L5) with a positive refractive power, an N lens group L3 (or L4) with a negative refractive power, and one or more V lens groups L2 (or L3, L2), which are arranged in order from the image side to the object side.

[0014] And the zoom lens of each example satisfies at least one of the following formulas (1) to (3).

[0015] -1.0 ≤ Σ(f1 / fVi) ≤ -0.4 (1) 0 <Z / ZV≦1.0 (2) 3.0 ≤ Z ≤ 10.0 (3) In equations (1) to (3), f1 is the focal length of the first lens group, fVi (i=1,2,…) is the focal length of the i-th lens group from the object side among one or more V lens groups, and Σ(f1 / fVi) is the sum of f1 / fVi. Z is the ratio of the focal length at the telephoto end of the zoom lens in the infinity focus state to the focal length at the wide-angle end of the zoom lens in the infinity focus state. ZV is the ratio of the combined lateral magnification at the telephoto end of one or more V lens groups in the infinity focus state to the combined lateral magnification at the wide-angle end of the same one or more V lens groups.

[0016] The conditions in equation (1) indicate an appropriate relationship between the combined focal length of the first lens group L1 and one or more V lens groups from the moving lens group that contribute significantly to achieving the zoom ratio. By satisfying the conditions in equation (1), it is possible to realize a refractive power arrangement that is advantageous for high zoom magnification while keeping the zoom lens small and lightweight. If Σ(f1 / fVi) exceeds the upper limit of equation (1), the combined refractive power of the V lens groups becomes too weak compared to the refractive power of the first lens group L1, making it difficult to achieve high zoom magnification in the zoom lens, which is undesirable. If Σ(f1 / fVi) falls below the lower limit of equation (1), the combined refractive power of the V lens groups becomes too strong, resulting in large aberration fluctuations during zooming, or making it difficult to make the zoom lens small and lightweight if aberration fluctuations are suppressed, which is also undesirable.

[0017] Furthermore, it is preferable to set the upper limit of equation (1) to -0.45 or -0.48.

[0018] The conditions in equation (2) indicate an appropriate relationship between the overall zoom ratio of the zoom lens and the zoom ratio obtained by one or more V lens groups within the moving lens group that significantly contribute to achieving the zoom ratio. By satisfying equation (2), it is possible to realize a refractive force arrangement that is advantageous for high zoom magnification while keeping the zoom lens small and lightweight. If Z / ZV exceeds the upper limit of equation (2), the zoom ratio that can be achieved by the V lens group becomes too small, making it difficult to increase the zoom magnification and miniaturize the zoom lens, which is undesirable. If Z / ZV falls below the lower limit of equation (2), the aberration fluctuations during zooming become large, which is also undesirable.

[0019] Furthermore, it is preferable to set the upper limit of equation (2) to 0.95 or 0.93.

[0020] The conditions in equation (3) indicate an appropriate range for the overall zoom ratio of the zoom lens. If Z exceeds the upper limit of equation (3), the zoom ratio of the zoom lens becomes too large, making it difficult to achieve both miniaturization and high performance, which is undesirable. If Z falls below the lower limit of equation (3), it becomes difficult to achieve a sufficient zoom magnification, which is also undesirable.

[0021] Furthermore, it is more preferable to set the lower limit of formula (3) to 3.3 or 3.5, and the upper limit of formula (3) to 8.0, 7.0, or 6.0.

[0022] By satisfying the above configuration and conditions, it is possible to realize a zoom lens that is compact yet offers a wide angle, high zoom magnification, and high optical performance.

[0023] Furthermore, it is preferable that the zoom lens of each embodiment satisfies at least one of the following conditions (4) to (9).

[0024] 2.5 ≤ (f1 + bok1) / f1 ≤ 5.0 (4) -3.0 ≤ Σ(fP / fVi) ≤ -0.5 (5) 0 <Lm / L≦0.3 (6) -0.7 ≤ LV / fm < 0 (7) |βr|≦1.0 (8) 1.0 ≤ f1 / fw ≤ 5.0 (9) In equations (4) to (9), bok1 is the distance along the optical axis from the image-side surface of the first lens group L1 to the rear principal point of the first lens group L1, with the direction from the object side to the image side being considered positive. fP is the focal length of the P lens group. One or more V lens groups include one or more lens groups with negative refractive power, and Lm is the amount of movement from the object side to the image side during zooming from the wide-angle end to the telephoto end of the negative lens group with the largest negative refractive power among the one or more negative lens groups. The amount of movement of a lens group is the difference between the position of the lens group at the wide-angle end and the position of the lens group at the telephoto end, and does not include the amount of movement back and forth. It is considered positive when the lens group is located on the image side at the telephoto end compared to the wide-angle end. L is the length along the optical axis from the object-side surface of the first lens group L1 to the image-side surface of the final lens group.

[0025] Furthermore, LV is the length along the optical axis from the object-side surface to the image-side surface of the negative lens group with the largest negative refractive power among the one or more negative lens groups that make up the V lens group. fm is the focal length of the negative lens group with the largest negative refractive power among the one or more negative lens groups mentioned above. βr is the lateral magnification of the final lens group, and fw is the focal length of the entire zoom lens system at the wide-angle end.

[0026] The conditions in equation (4) indicate an appropriate range for the retrospective ratio of the first lens group L1 in order to obtain a wide-angle, compact, and lightweight zoom lens. Increasing the retrospective ratio is advantageous for a wide angle of view, but it also increases the diameter of the other lenses on the image side of the first lens group L1 and the number of lenses in the first lens group L1. If (f1+bok1) / f1 exceeds the upper limit of equation (4), the retrospective ratio of the first lens group L1 becomes too large, increasing the diameter of the other lenses on the image side of the first lens group L1 and the number of lenses in the first lens group L1. This is undesirable because it makes it difficult to obtain a compact and lightweight zoom lens. If (f1+bok1) / f1 falls below the lower limit of equation (4), the retrospective ratio of the first lens group L1 becomes too small, making it difficult to obtain a wide-angle zoom lens, which is also undesirable. Furthermore, the diameter of the lens on the object side of the first lens group L1 increases, which is undesirable because it makes it difficult to obtain a compact and lightweight zoom lens.

[0027] Furthermore, it is more preferable to set the lower limit of formula (4) to 2.6, 2.7, or 2.8, and the upper limit of formula (4) to 4.5, 4.2, or 4.0.

[0028] The conditions in equation (5) indicate an appropriate relationship between the focal lengths of the P lens group and one or more V lens groups, which greatly contribute to achieving the zoom ratio. By satisfying the conditions in equation (5), miniaturization of the zoom lens can be achieved. If Σ(fP / fVi) exceeds the upper limit of equation (5), the refractive power of one or more V lens groups weakens, and their displacement increases, making it difficult to miniaturize the zoom lens. This is undesirable. If Σ(fP / fVi) falls below the lower limit of equation (5), the refractive power of the P lens group weakens too much, the lens diameter of the final lens group increases, and it becomes difficult to miniaturize the zoom lens. This is also undesirable.

[0029] Furthermore, it is more preferable to set the lower limit of equation (5) to -2.5, -2.2, or -2.0, and the upper limit of equation (5) to -1.0, -1.3, or -1.5.

[0030] The conditions in equation (6) indicate an appropriate relationship between the amount of movement of the negative lens group, which has the largest negative refractive power among the V lens group that greatly contributes to achieving the zoom ratio, during zooming, and the length from the object-side surface to the image-side surface of the zoom lens. If Lm / L exceeds the upper limit of equation (6), the amount of movement of the negative lens group during zooming becomes too large, making it difficult to miniaturize the zoom lens, which is undesirable. If Lm / L falls below the lower limit of equation (6), the amount of movement of the negative lens group during zooming becomes too small, making it difficult to increase the zoom ratio, which is also undesirable.

[0031] Furthermore, it is more preferable to set the upper limit of equation (6) to 0.25, 0.22, or 0.2.

[0032] The conditions in equation (7) indicate an appropriate relationship between the thickness of the negative lens group with the greatest negative refractive power among the V lens group and its focal length. If LV / fm exceeds the upper limit of equation (7), the refractive power of the negative lens group becomes too weak, increasing the amount of movement of the negative lens group and making it difficult to miniaturize the zoom lens. This is undesirable. If LV / fm falls below the lower limit of equation (7), the thickness of the negative lens group becomes too large, making it difficult to miniaturize the zoom lens. This is also undesirable.

[0033] Furthermore, it is preferable to set the lower limit of equation (7) to -0.6 or -0.5.

[0034] The conditions in equation (8) indicate an appropriate range for the lateral magnification of the final lens group, which is a fixed group, during zooming. If |βr| exceeds the upper limit of equation (8), the aberrations occurring up to the final lens group become large, making it difficult to improve the performance of the zoom lens. Therefore, this is undesirable.

[0035] Furthermore, it is more preferable to set the upper limit of equation (8) to 0.8, 0.7, or 0.6.

[0036] The conditions in equation (9) indicate an appropriate relationship between the focal length of the first lens group L1 and the focal length of the entire zoom lens system at the wide-angle end, in order to obtain a compact zoom lens with a wide angle of view, a high zoom ratio, and high optical performance. If f1 / fw exceeds the upper limit of equation (9), the lens diameter of the first lens group L1 becomes large, making it difficult to obtain a compact zoom lens, which is undesirable. If f1 / fw falls below the lower limit of equation (9), it becomes difficult to obtain a zoom lens with a wide angle of view and a high zoom ratio, or it becomes difficult to keep aberrations at the wide-angle end within an acceptable range, which is also undesirable.

[0037] Furthermore, it is more preferable to set the lower limit of formula (9) to 1.5, 2.0, or 2.2, and the upper limit of formula (9) to 4.0, 3.5, or 3.3.

[0038] Furthermore, the zoom lens of each embodiment preferably has the following configuration. The first lens group L1 preferably includes a first sub-lens group L11 with negative refractive power that does not move for focusing and is positioned on the object side of the focus group that moves during focusing, a second sub-lens group L12 with positive refractive power as the focus group, and a third sub-lens group L13 with positive refractive power that does not move for focusing and is positioned on the image side of the focus group. This configuration makes it possible to suppress aberration fluctuations due to focusing.

[0039] The zoom lenses for each embodiment will be described in detail below. Furthermore, numerical examples 1 to 6 corresponding to each of the embodiments (Embodiment 1 to 6) will be shown after Embodiment 6. [Examples]

[0040] The zoom lens of Embodiment 1 (Numerical Example 1) shown in Figure 1 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, a fourth lens group L4 with positive refractive power, an aperture diaphragm SP, and a fifth lens group L5 with positive refractive power, arranged in order from the object side to the image side. The first lens group L1 does not move for zooming. The second lens group L2, the third lens group L3, and the fourth lens group L4 constitute three or more movable lens groups that move for zooming. The fifth lens group L5 is the final lens group for image formation and does not move for zooming.

[0041] The first lens group L1 consists of a first sub-lens group L11 with negative refractive power, a second sub-lens group L12 with positive refractive power, and a third sub-lens group L13 with positive refractive power, arranged in order from the object side to the image side. The second sub-lens group L12 is a focusing group that moves towards the image side when focusing from infinity to close.

[0042] The second lens group L2 is a variator group (V lens group) that moves toward the image side when zooming from the wide-angle end to the telephoto end. The third lens group (N lens group) L3 and the fourth lens group (P lens group) L4 also move toward the image side when zooming from the wide-angle end to the telephoto end. An optical unit such as an extender lens for focal length conversion may be inserted into the fifth lens group L5.

[0043] Figure 2(A) shows the longitudinal aberrations (spherical aberration, astigmatism, distortion, and chromatic aberration) of the zoom lens of numerical example 1 at infinity focus and the wide-angle end. Figure 2(B) shows the longitudinal aberrations of the zoom lens of numerical example 1 at infinity focus and the telephoto end.

[0044] In the spherical aberration diagram, Fno indicates the F number, the solid line shows the spherical aberration for the d line (wavelength 587.6 nm), and the dashed line shows the spherical aberration for the g line (wavelength 435.8 nm). The dashed line shows the spherical aberration for the C line (wavelength 656.3 nm), and the long dashed line shows the spherical aberration for the F line (wavelength 486.1 nm). In the astigmatism diagram, the solid line S shows astigmatism on the sagittal image plane, and the dashed line M shows astigmatism on the meridional image plane. The distortion diagram shows distortion on the d line. The chromatic aberration diagram shows lateral chromatic aberration on the g, C, and F lines. The astigmatism and chromatic aberration diagrams show the amount of aberration when the central ray of the light beam at the aperture position is considered the principal ray. ω is the paraxial half-angle of view (°). Spherical aberration is depicted on a scale of 0.2 mm, astigmatism on 0.2 mm, distortion on 5%, and chromatic aberration on 0.05 mm. The explanation for the above aberration diagrams is the same for aberration diagrams of other numerical examples. [Examples]

[0045] The zoom lens of Embodiment 2 (Numerical Example 2) shown in Figure 3 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, a fourth lens group L4 with positive refractive power including the aperture diaphragm SP, and a fifth lens group L5 with positive refractive power, arranged in order from the object side to the image side. The first lens group L1 does not move for zooming. The second lens group L2, the third lens group L3, and the fourth lens group L4 constitute three or more movable lens groups that move for zooming. The fifth lens group L5 is the final lens group for image formation and does not move for zooming.

[0046] The first lens group L1 consists of a first sub-lens group L11 with negative refractive power, a second sub-lens group L12 with positive refractive power, and a third sub-lens group L13 with positive refractive power, arranged in order from the object side to the image side. The second sub-lens group L12 is a focusing group that moves towards the image side when focusing from infinity to close.

[0047] The second lens group L2 is a variator group (V lens group) that moves toward the image side when zooming from the wide-angle end to the telephoto end. The third lens group (N lens group) L3 and the fourth lens group (P lens group) L4 also move toward the image side when zooming from the wide-angle end to the telephoto end. The aperture diaphragm SP moves together with the fourth lens group L4 when zooming. An optical unit such as an extender lens for focal length conversion may be inserted into the fifth lens group L5.

[0048] Figure 4(A) shows the longitudinal aberration at the wide-angle end and in focus at infinity for the zoom lens of numerical example 2. Figure 4(B) shows the longitudinal aberration at the telephoto end and in focus at infinity for the zoom lens of numerical example 2. [Examples]

[0049] The zoom lens of Embodiment 3 (Numerical Example 3) shown in Figure 5 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, a fourth lens group L4 with positive refractive power including the aperture diaphragm SP, and a fifth lens group L5 with positive refractive power, arranged in order from the object side to the image side. The first lens group L1 does not move for zooming. The second lens group L2, the third lens group L3, and the fourth lens group L4 constitute three or more movable lens groups that move for zooming. The fifth lens group L5 is the final lens group for image formation and does not move for zooming.

[0050] The first lens group L1 consists of a first sub-lens group L11 with negative refractive power, a second sub-lens group L12 with positive refractive power, and a third sub-lens group L13 with positive refractive power, arranged in order from the object side to the image side. The second sub-lens group L12 is a focusing group that moves towards the image side when focusing from infinity to close.

[0051] The second lens group L2 is a variator group (V lens group) that moves toward the image side when zooming from the wide-angle end to the telephoto end. The third lens group (N lens group) L3 and the fourth lens group (P lens group) L4 also move toward the image side when zooming from the wide-angle end to the telephoto end. The aperture diaphragm SP moves together with the fourth lens group L4 when zooming. An optical unit such as an extender lens for focal length conversion may be inserted into the fifth lens group L5.

[0052] Figure 6(A) shows the longitudinal aberrations (spherical aberration, astigmatism, distortion, and chromatic aberration) of the zoom lens of numerical example 3 at infinity focus and the wide-angle end. Figure 6(B) shows the longitudinal aberrations of the zoom lens of numerical example 3 at infinity focus and the telephoto end. [Examples]

[0053] The zoom lens of Embodiment 4 (Numerical Example 4) shown in Figure 7 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, a fourth lens group L4 with negative refractive power, a fifth lens group L5 with positive refractive power including the aperture diaphragm SP, and a sixth lens group L6 with positive refractive power, arranged in order from the object side to the image side. The first lens group L1 does not move for zooming. The second lens group L2, third lens group L3, fourth lens group L4, and fifth lens group L5 constitute three or more movable lens groups that move for zooming. The sixth lens group L6 is the final lens group for image formation and does not move for zooming.

[0054] The first lens group L1 consists of a first sub-lens group L11 with negative refractive power, a second sub-lens group L12 with positive refractive power, and a third sub-lens group L13 with positive refractive power, arranged in order from the object side to the image side. The second sub-lens group L12 is a focusing group that moves towards the image side when focusing from infinity to close.

[0055] The second lens group L2 and the third lens group L3 are variator groups (V lens groups) that move toward the image side when zooming from the wide-angle end to the telephoto end. The fourth lens group (N lens group) L4 and the fifth lens group (P lens group) L5 also move toward the image side when zooming from the wide-angle end to the telephoto end. The aperture diaphragm SP moves together with the fifth lens group L5 when zooming. An optical unit such as an extender lens for focal length conversion may be inserted into the sixth lens group L6.

[0056] Figure 8(A) shows the longitudinal aberrations (spherical aberration, astigmatism, distortion, and chromatic aberration) of the zoom lens of numerical example 4 at infinity focus and the wide-angle end. Figure 8(B) shows the longitudinal aberrations of the zoom lens of numerical example 4 at infinity focus and the telephoto end. [Examples]

[0057] The zoom lens of Embodiment 5 (Numerical Example 5) shown in Figure 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, a fourth lens group L4 with negative refractive power, a fifth lens group L5 with positive refractive power, an aperture diaphragm SP, and a sixth lens group L6 with positive refractive power, arranged in order from the object side to the image side. The first lens group L1 does not move for zooming. The second lens group L2, third lens group L3, fourth lens group L4, and fifth lens group L5 constitute three or more movable lens groups that move for zooming. The sixth lens group L6 is the final lens group for image formation and does not move for zooming.

[0058] The first lens group L1 consists of a first sub-lens group L11 with negative refractive power, a second sub-lens group L12 with positive refractive power, and a third sub-lens group L13 with positive refractive power, arranged in order from the object side to the image side. The second sub-lens group L12 is a focusing group that moves towards the image side when focusing from infinity to close.

[0059] The second lens group L2 and the third lens group L3 are variator groups (V lens groups) that move toward the image side when zooming from the wide-angle end to the telephoto end. The fourth lens group (N lens group) L4 and the fifth lens group (P lens group) L5 also move toward the image side when zooming from the wide-angle end to the telephoto end. An optical unit such as an extender lens for focal length conversion may be inserted into the sixth lens group L6.

[0060] Figure 10(A) shows the longitudinal aberrations (spherical aberration, astigmatism, distortion, and chromatic aberration) of the zoom lens of numerical example 5 at infinity focus and the wide-angle end. Figure 10(B) shows the longitudinal aberrations of the zoom lens of numerical example 5 at infinity focus and the telephoto end. [Examples]

[0061] The zoom lens of Embodiment 6 (Numerical Example 6) shown in Figure 11 is composed of a first lens group L1 with positive refractive power, a second lens group L2 with positive 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 diaphragm SP, and a sixth lens group L6 with positive refractive power, arranged in order from the object side to the image side. The first lens group L1 does not move for zooming. The second lens group L2, third lens group L3, fourth lens group L4, and fifth lens group L5 constitute three or more movable lens groups that move for zooming. The sixth lens group L6 is the final lens group for image formation and does not move for zooming.

[0062] The first lens group L1 consists of a first sub-lens group L11 with negative refractive power, a second sub-lens group L12 with positive refractive power, and a third sub-lens group L13 with positive refractive power, arranged in order from the object side to the image side. The second sub-lens group L12 is a focusing group that moves towards the image side when focusing from infinity to close.

[0063] The second lens group L2 and the third lens group L3 are variator groups (V lens groups) that move toward the image side when zooming from the wide-angle end to the telephoto end. The fourth lens group (N lens group) L4 and the fifth lens group (P lens group) L5 also move toward the image side when zooming from the wide-angle end to the telephoto end. An optical unit such as an extender lens for focal length conversion may be inserted into the sixth lens group L6.

[0064] Figure 12(A) shows the longitudinal aberrations (spherical aberration, astigmatism, distortion, and chromatic aberration) of the zoom lens of numerical example 6 at infinity focus and the wide-angle end. Figure 12(B) shows the longitudinal aberrations of the zoom lens of numerical example 6 at infinity focus and the telephoto end.

[0065] Numerical examples 1 to 6 are shown below. In each numerical example, the surface number i indicates the order of the surfaces from the object side, r is the radius of curvature of the i-th surface (mm), and d is the distance on the optical axis between the i-th surface and the (i+1)-th surface (mm). The (variable) of the distance d indicates the distance that changes during zooming, and the distance according to the focal length is shown in a separate table. nd is the absolute refractive index at 1 atmosphere at the d-line of the optical material between the i-th surface and the (i+1)-th surface. νd is the Abbe number of the optical material between the i-th surface and the (i+1)-th surface with respect to the d-line. The Abbe number νd with respect to the d-line is given by Nd, NF, and NC, respectively, when the refractive indices at the d-line, F-line, and C-line are Nd, NF, and NC. It is expressed as νd = (Nd-1) / (NF-NC).

[0066] θgF is the partial dispersion ratio of the optical material between the i-th plane and the (i+1)-th plane with respect to the g-line and the F-line. The partial dispersion ratio of the g-line and the F-line is given by, when the refractive index at the g-line is Ng, θgF = (Ng - NF) / (NF - NC) It is represented as follows.

[0067] Each numerical example also shows the half-angle of view (°) of the zoom lens, in addition to the specifications such as the focal length and F-number of the entire zoom lens system. BF is the back focus, which indicates the air-equivalent distance along the optical axis from the image-side lens surface (final surface) to the image plane. The total lens length is the distance along the optical axis from the object-side lens surface (frontmost) to the final surface of the zoom lens, plus the back focus. Furthermore, the lens group data shows the focal length of each lens group.

[0068] The asterisk (*) next to the surface number indicates that the surface has an aspherical shape. The aspherical shape is expressed by the following formula, where X is the displacement from the surface vertex in the optical axis direction, H is the height from the optical axis in the direction perpendicular to the optical axis, with the direction of light propagation being positive, R being the radius of paraxial curvature, k (K in the numerical example) being the cone constant, and A3 to A16 being the aspherical coefficients. The cone constant and aspherical coefficients "e±x" are multiplied by 10. ±x It means...

[0069]

number

[0070] [Numerical Example 1] Unit: mm Surface data Face number rd nd νd θgF 1* 42606.960 2.15 1.89190 37.1 0.5780 2 27.149 13.48 3* 58.306 1.50 1.76385 48.5 0.5589 4 36.394 14.57 5 -48.784 1.40 1.90525 35.0 0.5848 6 -139.348 0.20 7 179.434 6.60 1.89286 20.4 0.6393 8 -95.675 3.64 9 1043.755 7.00 1.59522 67.7 0.5442 10* -68.849 4.43 11 1328.657 1.70 2.00069 25.5 0.6136 12 58.203 12.40 1.49700 81.5 0.5375 13 -103.477 0.21 14 -1068.202 14.28 1.43875 94.7 0.5340 15 -39.902 2.00 1.91650 31.6 0.5911 16 -47.581 0.20 17 23517.470 8.27 1.69930 51.1 0.5552 18 -75.192 (variable) 19* -125.330 1.20 1.69930 51.1 0.5552 20 35.256 3.86 21 -220.824 0.82 1.88300 40.8 0.5667 22 25.736 5.81 1.78880 28.4 0.6009 23 -147.111 (variable) 24 -40.955 0.85 1.53775 74.7 0.5392 25 45.600 2.10 1.85478 24.8 0.6122 26 74.105 (Variable) 27* 42.580 5.03 1.73800 32.3 0.5900 28 285.359 (variable) 29 (aperture) ∞ 1.00 30 56.171 1.30 2.05090 26.9 0.6054 31 38.832 6.45 1.53172 48.8 0.5631 32 -318.824 0.42 33 71.419 12.00 1.48749 70.2 0.5300 34 -36.119 1.30 2.00100 29.1 0.5997 35 -113.167 41.07 36 59.085 7.09 1.43875 94.7 0.5340 37 -57.872 6.06 38 -83.704 1.20 2.00100 29.1 0.5997 39 37.639 7.27 1.89286 20.4 0.6393 40 -75.902 0.30 41 48.469 9.55 1.43875 94.7 0.5340 42 -28.911 1.71 2.00100 29.1 0.5997 43 74.397 0.20 44 38.078 7.37 1.48749 70.2 0.5300 45 -77.399 42.48 Image plane ∞ Aspherical data Page 1 K = 0.00000e+00 A 4= 1.84806e-05 A 6= 1.22511e-07 A 8= 1.72935e-09 A10= 5.44089e-12 A12= 3.71223e-15 A14= 1.19089e-19 A16=-3.17244e-23 A 3=-5.50989e-05 A 5=-1.04907e-06 A 7=-1.74321e-08 A 9=-1.16501e-10 A11=-1.75300e-13 A13=-4.44063e-17 A15= 3.53356e-21 Page 3 K = 0.00000e+00 A 4=-1.16790e-05 A 6=-2.08251e-07 A 8=-1.47790e-09 A10=-1.44163e-13 A12= 4.86545e-15 A14= 1.20477e-18 A 3= 4.09795e-05 A 5= 1.39718e-06 A 7= 2.21440e-08 A 9= 5.34933e-11 A11=-9.07942e-14 A13=-1.19736e-16 Page 10 K = 0.00000e+00 A 4= 1.89977e-06 A 6=-8.05631e-10 A 8=-5.52707e-13 A 3= 3.80032e-06 A 5= 1.35474e-08 A 7= 1.53113e-11 Page 19 K = 0.00000e+00 A 4= 4.23146e-06 A 6=-1.89360e-07 A 8=-2.71304e-09 A10=-1.38629e-11 A12=-1.37448e-14 A 3= 1.88284e-06 A 5= 4.88427e-07 A 7= 2.93381e-08 A 9= 2.00605e-10 A11 = 6.65827e-13 Page 27 K = 0.00000e+00 A 4=-2.00990e-06 A 6= 1.28494e-08 A 8= 1.11305e-11 A 3=-1.12208e-06 A 5=-9.53336e-08 A 7=-6.19970e-10 Various data Zoom ratio 4.79 Wide-angle, Medium, Telephoto Focal length 11.48 29.42 55.01 F-numbers: 2.72, 2.73, 3.66 Half-angle (°): 52.20 26.71 15.06 Image height 14.80 14.80 14.80 Lens length 321.01 321.01 321.01 BF 42.48 42.48 42.48 d18 1.09 36.15 51.18 d23 32.77 4.24 5.29 d26 10.43 9.60 1.11 d28 16.22 10.52 2.95 Lens group data Group starting plane focal length 1 1 28.85 2 19 -36.48 3 24 -56.10 4 27 67.22 5 29 71.59 [Numerical Example 2] Unit: mm Surface data Face number rd nd νd θgF 1* 99476.214 2.10 1.83481 42.7 0.5648 2 26.526 14.50 3* 60.656 1.50 1.80400 46.5 0.5577 4 36.393 15.23 5 -52.015 1.40 1.91650 31.6 0.5911 6 -221.790 0.15 7 148.608 8.53 1.80810 22.8 0.6307 8 -87.769 1.20 9 -1825.418 7.71 1.59522 67.7 0.5442 10* -66.130 3.82 11 330.801 12.62 1.49700 81.5 0.5375 12 -41.914 1.70 1.95375 32.3 0.5905 13 -69.223 0.20 14 250.952 1.70 2.00100 29.1 0.5997 15 52.142 14.71 1.53775 74.7 0.5392 16 -71.364 0.20 17 903.164 6.96 1.65412 39.7 0.5737 18 -72.430 (variable) 19 84.669 0.93 1.85150 40.8 0.5695 20 32.767 3.97 21 -229.954 0.85 1.76385 48.5 0.5589 22 21.414 6.33 1.85478 24.8 0.6122 23 -75.689 0.15 24 -70.958 0.75 2.00100 29.1 0.5997 25 69.265 (Variable) 26 107.428 0.70 1.83481 42.7 0.5648 27 21.997 4.53 1.78880 28.4 0.6009 28 -1529.445 1.99 29 -32.371 0.70 1.90525 35.0 0.5848 30 -367.030 (variable) 31 (aperture) ∞ 5.25 32* 156.160 3.17 1.51633 64.1 0.5353 33 -243.291 0.15 34 49.145 1.10 1.89190 37.1 0.5780 35 35.423 6.28 1.68893 31.1 0.6004 36 -1097.453 (variable) 37 99.723 1.00 1.96300 24.1 0.6212 38 31.772 8.14 1.60311 60.6 0.5415 39 -89.135 41.03 40 71.446 7.08 1.53775 74.7 0.5392 41 -57.888 4.57 42 -92.881 2.50 2.00100 29.1 0.5997 43 48.437 8.07 1.94594 18.0 0.6546 44 -85.330 0.20 45 52.351 8.39 1.49700 81.5 0.5375 46 -35.707 1.00 2.05090 26.9 0.6054 47 45.574 0.19 48 32.012 11.52 1.53172 48.8 0.5631 49 -29.284 1.00 2.00100 29.1 0.5997 50 -60.145 38.36 Image plane ∞ Aspherical data Front page K = 0.00000e+00 A 4=-2.99616e-06 A 6=-4.30031e-07 A 8=-1.39827e-09 A10=-2.33775e-13 A12= 2.12083e-16 A14=-1.50655e-19 A16=-1.63467e-23 A 3= 1.54769e-05 A 5= 3.14838e-06 A 7= 3.17770e-08 A 9= 3.38993e-11 A11=-9.41310e-15 A13= 2.01907e-18 A15= 2.56691e-21 Page 3 K = 0.00000e+00 A 4= 7.64711e-06 A 6= 8.91121e-07 A 8= 9.97080e-09 A10=-6.05496e-12 A12=-6.58184e-14 A14= 8.33873e-17 A16= 2.60566e-20 A 3=-1.33614e-05 A 5=-4.27804e-06 A 7=-1.18897e-07 A 9=-4.13489e-10 A11= 1.59614e-12 A13=-9.76086e-18 A15=-2.57790e-18 Page 10 K = 1.82623e-01 A 4= 1.00880e-06 A 6=-2.39484e-08 A 8=-5.09044e-11 A10= 3.02634e-13 A12= 7.13817e-17 A14= 8.73615e-20 A16= 2.64940e-23 A 3= 7.14913e-07 A 5= 1.43878e-07 A 7= 1.91949e-09 A 9=-3.22022e-12 A11=-8.95740e-15 A13=-4.96495e-21 A15=-2.93804e-21 Page 32 K = 1.89717e+00 A 4=-4.16229e-06 A 6=-1.65595e-08 A 8=-1.32731e-11 A 3= 1.62956e-06 A 5= 1.81038e-07 A 7= 7.51656e-10 Various data Zoom ratio 4.81 Wide-angle, Medium, Telephoto Focal length 11.44 28.45 55.01 F-number 2.72 2.72 3.56 Half-angle (°): 52.30 27.49 15.06 Image height 14.80 14.80 14.80 Lens length 312.24 312.24 312.24 BF 38.36 38.36 38.36 d18 0.99 30.23 42.76 d25 22.60 3.77 2.24 d30 12.78 11.02 1.84 d36 11.76 3.11 1.30 Lens group data Group starting plane focal length 1 1 27.09 2 19 -29.26 3 26 -53.96 4 31 54.38 5 37 80.80 [Numerical Example 3] Unit: mm Surface data Face number rd nd νd θgF 1* 179.573 2.40 1.76385 48.5 0.5589 2 25.440 18.65 3 318.391 1.60 2.00100 29.1 0.5997 4 33.939 17.70 5 -28.402 1.50 1.88300 40.8 0.5667 6 -35.572 2.02 7 330.868 6.00 1.89286 20.4 0.6393 8 -115.543 4.49 9 88.344 11.14 1.61800 63.3 0.5441 10* -72.817 7.57 11 -260.027 6.89 1.49700 81.5 0.5375 12 -53.581 0.20 13 -52.211 1.80 1.76385 48.5 0.5589 14 -57.628 0.20 15 -72.831 1.65 1.95375 32.3 0.5905 16 58.180 11.99 1.43875 94.9 0.5340 17 -50.512 0.20 18 215.291 6.35 1.76385 48.5 0.5589 19 -81.563 (variable) 20* -497.881 1.20 1.90525 35.0 0.5848 21 43.394 3.08 22 346.670 0.80 1.59522 67.7 0.5442 23 62.311 3.89 1.85478 24.8 0.6122 24 -104.816 1.89 25 -36.380 0.80 1.76385 48.5 0.5589 26 -65.756 (variable) 27 -107.553 0.80 1.60300 65.4 0.5401 28 38.040 3.39 1.85478 24.8 0.6122 29 61.093 (Variable) 30 (aperture) ∞ 1.00 31* 25.325 5.76 1.58144 40.8 0.5774 32 206.363 0.20 33 60.369 3.79 1.78472 25.7 0.6161 34 -379.736 0.90 2.00069 25.5 0.6136 35 37.943 (variable) 36 65.725 5.11 1.56732 42.8 0.5731 37 -117.940 0.20 38 35.649 1.00 2.05090 26.9 0.6054 39 25.226 2.18 1.53775 74.7 0.5392 40 30.680 40.06 41 40.073 8.67 1.55200 70.7 0.5421 42 -92.024 0.40 43 56.543 6.46 1.80810 22.8 0.6307 44 -70.758 1.10 1.88300 40.8 0.5667 45 24.114 1.30 46 25.036 13.97 1.43875 94.7 0.5340 47 -21.157 1.50 2.05090 26.9 0.6054 48 -370.722 0.39 49 122.453 9.20 1.48749 70.2 0.5300 50 -28.190 (variable) Image plane ∞ Aspherical data Front page K = 0.00000e+00 A 4= 7.43558e-06 A 6=-7.80017e-09 A 8= 9.10700e-12 A10=-6.70803e-15 A12= 2.80350e-18 A14=-4.53420e-22 A16=-7.00875e-27 Side 10 K = 0.00000e+00 A 4= 1.72368e-06 A 6=-4.58123e-10 A 8= 1.22222e-13 Page 20 K = 0.00000e+00 A 4= 3.76155e-06 A 6=-5.12921e-09 A 8= 5.36326e-11 A10=-2.48915e-13 A12= 4.27201e-16 Page 31 K = 0.00000e+00 A 4=-7.79399e-06 A 6=-3.25647e-09 A 8=-1.21086e-11 Various data Zoom ratio 3.83 Wide-angle, Medium, Telephoto Focal length 10.38 22.89 39.78 F-number 2.90 2.90 3.85 Half-angle (°): 54.95, 32.88, 20.41 Image height 14.80 14.80 14.80 Lens length 323.96 323.96 323.96 BF 37.01 37.01 37.01 d19 0.87 36.91 52.35 d26 21.74 0.71 9.01 d29 24.72 16.64 1.20 d35 18.22 11.30 3.00 d50 37.01 37.01 37.01 Lens group data Group starting plane focal length 1 1 28.24 2 20 -56.53 3 27 -77.08 4 30 101.27 5 36 67.21 [Numerical Example 4] Unit: mm Surface data Face number rd nd νd θgF 1* 10000.000 2.20 1.83481 42.7 0.5648 2 27.261 10.90 3* 43.746 1.55 1.85150 40.8 0.5695 4 29.780 16.94 5 -54.008 1.45 1.95375 32.3 0.5905 6 2340.232 0.20 7 126.680 7.91 1.80810 22.8 0.6307 8 -96.980 1.49 9 337.211 8.36 1.59522 67.7 0.5442 10* -58.106 2.89 11 311.073 13.21 1.43875 94.7 0.5340 12 -37.563 1.60 1.95375 32.3 0.5905 13 -52.130 0.20 14 195.594 1.60 2.00100 29.1 0.5997 15 53.751 14.24 1.43875 94.7 0.5340 16 -56.590 0.20 17 -307.119 4.72 1.76634 35.8 0.5792 18 -68.430 (variable) 19 67.923 0.95 1.80400 46.5 0.5577 20 32.553 2.99 21 -4920.510 0.85 1.76385 48.5 0.5589 22 22.528 5.55 1.78880 28.4 0.6009 23 -75.906 (variable) 24 -70.205 0.75 1.88300 40.8 0.5667 25 50.820 (Variable) 26 -32.470 0.70 1.80400 46.5 0.5577 27 29.951 2.65 1.78880 28.4 0.6009 28 433.737 (variable) 29 (aperture) ∞ 2.04 30 -8622.845 1.00 1.83481 42.7 0.5648 31 54.401 3.85 1.67300 38.3 0.5757 32 -599.694 0.20 33* 36.239 7.96 1.57501 41.5 0.5767 34 -138.526 (variable) 35 263.730 2.31 1.48749 70.2 0.5300 36 -187.158 0.20 37 72.439 1.20 2.00069 25.5 0.6136 38 32.243 8.37 1.51823 58.9 0.5457 39 -113.669 41.34 40 74.294 7.17 1.49700 81.5 0.5375 41 -55.213 0.72 42 -216.396 1.20 2.00100 29.1 0.5997 43 25.638 9.15 1.89286 20.4 0.6393 44 -2098.664 0.20 45 29.296 8.30 1.67300 38.3 0.5757 46 -108.576 1.58 2.00100 29.1 0.5997 47 24.135 0.20 48 21.983 14.17 1.43875 94.7 0.5340 49 -24.253 1.00 2.00100 29.1 0.5997 50 -52.485 39.12 Image plane ∞ Aspherical data Front page K = 0.00000e+00 A 4=-4.39106e-05 A 6=-1.26499e-06 A 8=-3.62054e-09 A10=-6.42274e-13 A12= 3.92028e-16 A14= 6.61559e-20 A16= 7.34553e-24 A 3= 1.49036e-04 A 5= 1.08520e-05 A 7= 8.69501e-08 A 9= 8.38675e-11 A11=-1.50177e-14 A13=-3.97045e-18 A15=-1.20551e-21 3rd page K = 0.00000e+00 A 4= 2.70307e-05 A 6= 9.13168e-07 A 8= 9.74093e-09 A10= 2.53181e-11 A12=-1.22397e-14 A14= 7.66186e-17 A16= 2.34551e-20 A 3=-9.70765e-05 A 5=-6.69142e-06 A 7=-1.01727e-07 A 9=-6.68975e-10 A11=-1.89298e-13 A13=-6.65266e-16 A15=-2.28044e-18 Side 10 K = 0.00000e+00 A 4= 3.66220e-06 A 6= 4.66240e-09 A 8= 4.98196e-13 A 3=-5.18478e-06 A 5=-9.23355e-08 A 7=-9.72622e-11 Page 33 K = 0.00000e+00 A 4=-7.27259e-06 A 6= 2.24551e-09 A 8=-2.15475e-12 Various data Zoom ratio 4.81 Wide-angle, Medium, Telephoto Focal length 11.44 28.81 55.02 F-number 2.72 2.72 3.64 Half-angle (°): 52.30 27.19 15.06 Image height 14.80 14.80 14.80 Lens length 307.39 307.39 307.39 BF 39.12 39.12 39.12 d18 0.98 27.50 38.86 d23 1.00 2.87 4.26 d25 23.60 4.18 4.43 d28 11.96 10.23 2.97 d34 14.47 7.22 1.48 Lens group data Group starting plane focal length 1 1 26.71 2 19 -1804.98 3 24 -33.29 4 26 -36.79 5 29 55.77 6 35 70.65 [Numerical Example 5] Unit: mm Surface data Face number rd nd νd θgF 1* ∞ 2.10 1.83481 42.7 0.5648 2 25.809 14.59 3* 84.172 1.50 1.80400 46.5 0.5577 4 40.603 13.67 5 -44.135 1.40 1.89190 37.1 0.5780 6 -112.235 0.11 7 188.051 7.90 1.80810 22.8 0.6307 8 -76.990 1.45 9 -237.991 7.64 1.49700 81.5 0.5375 10* -49.723 4.09 11 -946.175 10.96 1.48749 70.2 0.5300 12 -40.594 1.75 2.00100 29.1 0.5997 13 -65.641 0.21 14 282.349 1.70 2.00100 29.1 0.5997 15 65.774 15.54 1.43875 94.7 0.5340 16 -56.568 0.19 17 1916.533 7.65 1.76385 48.5 0.5589 18 -74.742 (variable) 19* 205.779 1.20 1.83481 42.7 0.5648 20 27.352 4.21 21 -167.761 0.82 1.83481 42.7 0.5648 22 22.203 6.79 1.78880 28.4 0.6009 23 -63.011 (variable) 24 -32.050 0.82 1.88300 40.8 0.5667 25 -84.151 (variable) 26 -39.149 0.85 1.59522 67.7 0.5442 27 62.164 2.31 1.85478 24.8 0.6122 28 157.587 (variable) 29* 52.222 4.12 1.85150 40.8 0.5695 30 -199.701 (variable) 31 (aperture) ∞ 1.80 32 39.995 6.88 1.51742 52.4 0.5564 33 -146.845 0.23 34 279.585 1.00 2.00100 29.1 0.5997 35 33.798 6.40 1.51633 64.1 0.5353 36 -160.634 0.43 37 -368.954 5.64 1.67270 32.1 0.5988 38 -30.284 1.00 2.00100 29.1 0.5997 39 -80.389 41.40 40 93.888 5.18 1.43875 94.7 0.5340 41 -60.517 0.70 42 57.562 7.87 1.80809 22.7 0.6306 43 -35.852 1.10 1.89190 37.1 0.5780 44 34.242 0.82 45 31.872 13.49 1.43875 94.7 0.5340 46 -23.478 1.10 2.00100 29.1 0.5997 47 171.178 0.13 48 52.667 8.91 1.48749 70.2 0.5300 49 -35.296 Image plane ∞ Aspherical data Front page K = 0.00000e+00 A 4= 2.01487e-05 A 6= 2.48992e-08 A 8= 2.17115e-11 A10=-1.96498e-13 A12=-1.74230e-16 A14=-3.30200e-19 A16=-4.27190e-23 A 3=-4.92267e-05 A 5=-8.40544e-07 A 7=-9.83600e-10 A 9= 2.28192e-12 A11= 6.34512e-15 A13= 8.73990e-18 A15= 6.07222e-21 Page 3 K = 0.00000e+00 A 4=-1.79865e-05 A 6= 1.08737e-07 A 8= 2.67194e-09 A10=-2.65927e-10 A12=-1.84184e-12 A14=-1.97641e-15 A16=-1.90543e-19 A 3= 4.04572e-05 A 5= 1.49144e-06 A 7=-5.30553e-08 A 9= 1.16096e-09 A11= 2.84179e-11 A13= 7.62209e-14 A15= 2.93416e-17 Page 10 K = 0.00000e+00 A 4=-2.18415e-06 A 6=-2.03336e-07 A 8=-1.52986e-09 A10= 5.10495e-12 A12= 2.25271e-14 A14= 9.63941e-19 A16=-1.87371e-21 A 3= 9.29120e-06 A 5= 1.14812e-06 A 7= 2.31796e-08 A 9= 2.52009e-11 A11=-5.09518e-13 A13=-4.71919e-16 A15= 1.41597e-19 Page 19 K = 0.00000e+00 A 4= 5.62296e-06 A 6= 9.66460e-07 A 8= 6.14358e-08 A10=-8.91142e-10 A12=-2.54378e-11 A14=-7.20136e-14 A16=-1.75328e-17 A 3=-3.52425e-07 A 5=-1.20759e-06 A 7=-3.48990e-07 A 9=-3.12076e-09 A11= 2.23374e-10 A13= 1.72991e-12 A15= 1.70114e-15 Page 29 K = 0.00000e+00 A 4=-8.28442e-06 A 6=-4.71556e-07 A 8=-5.90301e-09 A10= 3.62432e-12 A12= 6.58822e-14 A14= 8.73138e-17 A16=-5.58289e-21 A 3= 3.07013e-06 A 5= 1.82756e-06 A 7= 7.02954e-08 A 9= 2.30046e-10 A11=-9.68540e-13 A13=-3.02124e-15 A15=-9.83633e-19 Various data Zoom ratio 5.45 Wide-angle, Medium, Telephoto Focal length 10.99 29.91 59.97 F-number 3.00 3.00 4.00 Half-angle (°): 53.39 26.33 13.86 Image height 14.80 14.80 14.80 Lens length 320.99 320.99 320.99 BF 43.15 43.15 43.15 d18 1.26 36.15 51.10 d23 5.70 1.47 3.38 d25 28.22 4.92 3.83 d28 3.82 6.42 0.35 d30 21.20 11.23 1.52 d49 43.15 43.15 43.15 Lens group data Group starting plane focal length 1 1 27.60 2 19 -53.93 3 24 -59.06 4 26 -60.47 5 29 48.98 6 31 74.85 [Numerical Example 6] Unit: mm Surface data Face number rd nd νd θgF 1* 32025.967 2.10 1.88300 40.8 0.5667 2 25.188 15.84 3* 67.098 1.50 1.81600 46.6 0.5568 4 33.609 14.35 5 -45.494 1.40 1.89190 37.1 0.5780 6 -175.968 0.11 7 147.991 9.13 1.80810 22.8 0.6307 8 -70.127 3.60 9 -401.419 9.01 1.49700 81.5 0.5375 10* -47.804 3.37 11 -206.425 9.48 1.49700 81.5 0.5375 12 -39.441 1.75 2.00100 29.1 0.5997 13 -77.540 0.21 14 314.673 1.70 2.00100 29.1 0.5997 15 63.316 12.42 1.49700 81.5 0.5375 16 -91.416 0.19 17 -43432.849 8.51 1.76385 48.5 0.5589 18 -63.887 (variable) 19 -448.811 4.00 1.54814 45.8 0.5686 20 -129.702 (variable) 21* 205.338 1.20 1.76385 48.5 0.5589 22 32.138 3.76 23 -437.917 0.82 1.88300 40.8 0.5667 24 21.787 7.62 1.78880 28.4 0.6009 25 -111.023 1.86 26 -33.406 0.82 1.80400 46.5 0.5577 27 -62.031 (variable) 28 -40.123 0.85 1.59522 67.7 0.5442 29 69.035 2.23 1.85478 24.8 0.6122 30 133.400 (Variable) 31* 50.308 4.36 1.90525 35.0 0.5848 32 -885.960 (variable) 33 (aperture) ∞ 1.83 34 49.240 7.04 1.51633 64.1 0.5353 35 -93.077 0.23 36 301.450 1.00 2.00100 29.1 0.5997 37 36.338 3.91 1.48749 70.2 0.5300 38 132.742 0.90 39 133.267 7.48 1.67270 32.1 0.5988 40 -28.996 1.00 2.00100 29.1 0.5997 41 -75.883 41.40 42 90.521 5.95 1.43875 94.7 0.5340 43 -54.467 0.69 44 53.233 6.97 1.80810 22.8 0.6307 45 -53.329 1.08 1.95375 32.3 0.5905 46 31.751 0.80 47 30.505 13.23 1.43875 94.7 0.5340 48 -23.011 1.08 1.90525 35.0 0.5848 49 259.671 0.13 50 66.488 9.43 1.48749 70.2 0.5300 51 -34.191 Image plane ∞ Aspherical data Front page K = 0.00000e+00 A 4= 2.00541e-05 A 6=-3.42922e-08 A 8=-1.96464e-10 A10=-3.17767e-13 A12=-2.34366e-16 A14=-3.94796e-19 A16=-4.94163e-23 A 3=-2.86173e-05 A 5=-4.52340e-07 A 7= 3.59128e-09 A 9= 8.81916e-12 A11= 8.18517e-15 A13= 1.11800e-17 A15= 7.05971e-21 3rd page K = 0.00000e+00 A 4=-1.88331e-05 A 6= 1.14270e-08 A 8= 1.30341e-09 A10=-2.67870e-10 A12=-1.84916e-12 A14=-1.97828e-15 A16=-1.87581e-19 A 3= 2.27092e-05 A 5= 1.82398e-06 A 7=-3.77855e-08 A 9= 1.22914e-09 A11= 2.85083e-11 A13= 7.65065e-14 A15= 2.91896e-17 Page 10 K = 0.00000e+00 A 4=-1.04727e-06 A 6=-1.13930e-07 A 8=-8.44236e-10 A10= 4.39087e-12 A12= 2.18351e-14 A14= 2.78997e-18 A16=-2.06909e-21 A 3= 4.82558e-06 A 5= 6.83653e-07 A 7= 1.27477e-08 A 9= 8.01220e-12 A11=-4.50335e-13 A13=-5.25228e-16 A15= 1.31968e-19 Page 21 K = 0.00000e+00 A 4= 5.17293e-06 A 6= 1.28509e-06 A 8= 6.92690e-08 A10=-9.64150e-10 A12=-2.51078e-11 A14=-6.52470e-14 A16=-1.41428e-17 A 3=-7.31277e-07 A 5=-1.93707e-06 A 7=-4.20485e-07 A 9=-3.21626e-09 A11= 2.29445e-10 A13= 1.63961e-12 A15= 1.46228e-15 Page 31 K = 0.00000e+00 A 4=-7.18317e-06 A 6=-3.62693e-07 A 8=-3.91598e-09 A10= 2.80039e-11 A12= 9.56574e-14 A14= 3.62934e-17 A16= 2.35414e-20 A 3= 3.94266e-06 A 5= 1.44915e-06 A 7= 5.37076e-08 A 9=-1.42934e-11 A11=-2.39595e-12 A13=-1.99041e-15 A15=-1.27281e-18 Various data Zoom ratio 3.89 Wide angle, medium, telephoto Focal length 10.29, 24.16, 40.00 F-number 2.73, 2.73, 3.66 Half angle of view (°) 55.18, 31.50, 20.31 Image height 14.80, 14.80, 14.80 Overall lens length 320.98, 320.98, 320.98 BF 43.08, 43.08, 43.08 d18 0.20, 1.94, 2.99 d20 0.99, 30.14, 42.33 d27 27.69, 3.60, 3.67 d30 4.96, 5.55, 0.36 d32 17.72, 10.32, 2.21 d51 43.08, 43.08, 43.08 Lens group data Group, starting surface, focal length 1, 1, 32.57 2, 19, 331.33 3, 21, -31.53 4, 28, -56.85 [[ID=4,5]]5, 31, 52.70 6, 33, 73.57 The values of formulas (1) to (9) in Numerical Examples 1 to 6 are summarized in Table 1. The zoom lenses of each numerical example satisfy all the conditions of formulas (1) to (9).

[0071] [[ID=,54]]

Table 1

[0072] [Imaging device] Figure 13 shows an imaging device equipped with the zoom lenses of Examples 1 to 6 as the imaging optical system. In Figure 13, 101 is one of the zoom lenses of Examples 1 to 6. 124 is the camera body. 125 is the imaging device configured by attaching the zoom lens 101 to the camera body 124. The zoom lens 101 is detachable from the camera body 124. However, the zoom lens 101 may be integrally provided with the camera body 124.

[0073] The zoom lens 101 has, in order from the object side to the image side, a first lens group F, a zoom section LZ, and an imaging lens group R. The first lens group F includes a focus group that moves during focusing. The zoom section LZ includes at least three or more movable lens groups. On the image side of the zoom section LZ are the aperture diaphragm SP, lens group R1, and lens group R2. The imaging device 125 also has an optical unit IE that can be inserted into and removed from the optical path between lens group R1 and lens group R2. By inserting the lens unit IE between lens group R1 and lens group R2, the range of the focal length of the entire zoom lens 101 system can be changed.

[0074] 114 and 115 are drive mechanisms that move the first lens group F and the lens group included in the zoom section LZ along the optical axis, respectively. 116 to 118 are motors that drive the drive mechanisms 114 and 115 and the aperture diaphragm SP, respectively. 119 to 121 are detection units that detect the position of the first lens group F and the lens group included in the zoom section LZ on the optical axis, and detect the aperture diameter of the aperture diaphragm SP, respectively.

[0075] In the camera body 124, 109 is a glass block such as an optical filter, and 110 is an image sensor that captures the subject image (i.e., the subject through the zoom lens 101) formed by the zoom lens 101. The image sensor 110 is composed of photoelectric conversion elements such as a CCD sensor or a CMOS sensor. 111 and 122 are the camera CPU, which is the processing unit in the camera body 124, and the lens CPU, which is the processing unit in the zoom lens 101, respectively.

[0076] The above embodiments include the following configuration.

[0077] (Composition 1) A zoom lens comprising multiple lens groups, The aforementioned group of lenses consists of a first lens group with positive refractive power that does not move for zooming, arranged sequentially from the object side to the image side, three or more moving lens groups that move for zooming, and a final lens group with positive refractive power that does not move for zooming, and the spacing between adjacent lens groups changes during zooming. The three or more moving lens groups include a group of P lenses with positive refractive power, a group of N lenses with negative refractive power, and one or more V lens groups, arranged in order from the image side to the object side. Let f1 be the focal length of the first lens group, and fVi be the focal length of the i-th moving lens group from the object side among the one or more V lens groups. Let Σ(f1 / fVi) be the sum of f1 / fVi. Let Z be the ratio of the focal length at the telephoto end of the zoom lens when focused on an object at infinity to the focal length at the wide-angle end of the zoom lens when focused on an object at infinity, and let ZV be the ratio of the combined horizontal magnification at the telephoto end of the one or more V lens groups when focused on an object at infinity to the combined horizontal magnification at the wide-angle end. -1.0 ≤ Σ(f1 / fVi) ≤ -0.4 0 <Z / ZV≦1.0 3.0 ≤ Z ≤ 10.0 A zoom lens characterized by satisfying the following conditions. (Configuration 2) When bok1 is the distance along the optical axis from the image-side surface of the first lens group to the rear principal point of the first lens group, 2.5 ≤ (f1 + bok1) / f1 ≤ 5.0 A zoom lens according to configuration 1, characterized by satisfying the following conditions. (Composition 3) When the focal length of the P lens group is fP, -3.0 ≤ Σ(fP / fVi) ≤ -0.5 A zoom lens according to configuration 1 or 2, characterized by satisfying the following conditions. (Composition 4) The aforementioned group of one or more V-lenses includes one or more groups of lenses with negative refractive power. When Lm is the amount of movement from the object side to the image side when zooming from the wide-angle end to the telephoto end of the lens group with the largest negative refractive power among the one or more lens groups with negative refractive power, and L is the length along the optical axis from the object-side surface of the first lens group to the image-side surface of the final lens group, 0 <Lm / L≦0.3 A zoom lens according to any one of configurations 1 to 3, characterized by satisfying the following conditions. (Composition 5) The aforementioned one or more V lens groups include one or more lens groups with negative refractive power, When LV is the length along the optical axis from the object-side surface to the image-side surface of the lens group with the largest negative refractive power among the one or more lens groups with negative refractive power, and fm is the focal length of the lens group with the largest negative refractive power, -0.7≦LV / fm<0 A zoom lens according to any one of configurations 1 to 4, characterized by satisfying the following conditions. (Composition 6) When the lateral magnification of the final lens group is βr, |βr|≦1.0 A zoom lens according to any one of configurations 1 to 5, characterized by satisfying the following conditions. (Composition 7) When the focal length of the zoom lens at its wide-angle end is denoted as fw, 1.0 ≤ f1 / fw ≤ 5.0 A zoom lens according to any one of configurations 1 to 6, characterized by satisfying the following conditions. (Composition 8) The zoom lens according to any one of configurations 1 to 7, characterized in that the first lens group comprises a first sub-lens group with negative refractive power that does not move for focusing and is positioned on the object side of the focus group that moves for focusing, a second sub-lens group with positive refractive power as the focus group, and a third sub-lens group with positive refractive power that does not move for focusing and is positioned on the image side of the focus group. (Configuration 9) The plurality of lens groups is composed of, in order from the object side to the image side, the first lens group, a second lens group having a negative refractive power, a third lens group having a negative refractive power, a fourth lens group having a positive refractive power, and a fifth lens group which is the final lens group, and is characterized in that it is the zoom lens according to any one of Configurations 1 to 8. (Configuration 10) The plurality of lens groups is composed of, in order from the object side to the image side, the first lens group, a second lens group having a negative refractive power, a third lens group having a negative refractive power, a fourth lens group having a negative refractive power, a fifth lens group having a positive refractive power, and a sixth lens group which is the final lens group, and is characterized in that it is the zoom lens according to any one of Configurations 1 to 8. (Configuration 11) The plurality of lens groups is composed of, in order from the object side to the image side, the first lens group, a second lens group having a positive refractive power, a third lens group having a negative refractive power, a fourth lens group having a negative refractive power, a fifth lens group having a positive refractive power, and a sixth lens group which is the final lens group, and is characterized in that it is the zoom lens according to any one of Configurations 1 to 8. (Configuration 12) A zoom lens including a plurality of lens groups, The plurality of lens groups is composed of, in order from the object side to the image side, a first lens group having a positive refractive power that does not move for zooming, three or more moving lens groups that move for zooming, and a final lens group having a positive refractive power that does not move for zooming, and the distance between adjacent lens groups changes during zooming. The three or more moving lens groups include, in order from the image side to the object side, a P lens group having a positive refractive power, an N lens group having a negative refractive power, and one or more V lens groups. When the focal length of the first lens group is f1 and the focal length of the i-th lens group from the object side among the one or more V lens groups is fVi, and the sum of f1 / fVi is represented by Σ(f1 / fVi), -1.0≦Σ(f1 / fVi)≦-0.4 A zoom lens characterized by satisfying the condition. (Composition 13) A zoom lens described in any one of configurations 1 to 12, An imaging device characterized by having an image sensor that captures an image of a subject through the zoom lens.

[0078] The embodiments described above are merely representative examples, and various modifications and changes can be made to each embodiment when implementing the present invention. [Explanation of Symbols]

[0079] L1 First lens group L12 Second sub-lens group (focusing group) L2 Second lens group L3 Third lens group L4 4th lens group L5 5th lens group SP aperture diaphragm I image plane

Claims

1. A zoom lens comprising multiple lens groups, The aforementioned group of lenses consists of a first lens group with positive refractive power that does not move for zooming, arranged sequentially from the object side to the image side, three or more moving lens groups that move for zooming, and a final lens group with positive refractive power that does not move for zooming, and the spacing between adjacent lens groups changes during zooming. The three or more moving lens groups include a group of P lenses with positive refractive power, a group of N lenses with negative refractive power, and one or more V lens groups, arranged in order from the image side to the object side. Let f1 be the focal length of the first lens group, fVi be the focal length of the i-th moving lens group from the object side among the one or more V lens groups, and let Σ(f1 / fVi) be the sum of f1 / fVi. Let Z be the ratio of the focal length at the telephoto end of the zoom lens when focused on an object at infinity to the focal length at the wide-angle end of the zoom lens when focused on an object at infinity, and let ZV be the ratio of the combined horizontal magnification at the telephoto end of the one or more V lens groups when focused on an object at infinity to the combined horizontal magnification at the wide-angle end. -1.0≦Σ(f1 / fVi)≦-0.4 0<Z / ZV≦1.0 3.0 ≤ Z ≤ 10.0 A zoom lens characterized by satisfying the following conditions.

2. When bok1 is the distance along the optical axis from the image-side surface of the first lens group to the rear principal point of the first lens group, 2.5≦(f1+bok1) / f1≦5.0 The zoom lens according to claim 1, characterized by satisfying the following conditions.

3. When the focal length of the P lens group is fP, -3.0≦Σ(fP / fVi)≦-0.5 The zoom lens according to claim 1, characterized by satisfying the following conditions.

4. The aforementioned group of one or more V-lenses includes one or more lens groups with negative refractive power. When Lm is the amount of movement from the object side to the image side when zooming from the wide-angle end to the telephoto end of the lens group with the largest negative refractive power among the one or more lens groups with negative refractive power, and L is the length along the optical axis from the object-side surface of the first lens group to the image-side surface of the final lens group, 0<Lm / L≦0.3 The zoom lens according to claim 1, characterized by satisfying the following conditions.

5. The aforementioned one or more V-lens groups include one or more lens groups with negative refractive power, When LV is the length along the optical axis from the object-side surface to the image-side surface of the lens group with the largest negative refractive power among the one or more lens groups with negative refractive power, and fm is the focal length of the lens group with the largest negative refractive power, -0.7≦LV / fm<0 The zoom lens according to claim 1, characterized by satisfying the following conditions.

6. When the lateral magnification of the final lens group is βr, |βr|≦1.0 The zoom lens according to claim 1, characterized by satisfying the following conditions.

7. When the focal length of the zoom lens at its wide-angle end is fw, 1.0 ≤ f1 / fw ≤ 5.0 The zoom lens according to claim 1, characterized by satisfying the following conditions.

8. The zoom lens according to claim 1, characterized in that the first lens group comprises a first sub-lens group with negative refractive power that does not move for focusing and is positioned on the object side of the focus group that moves for focusing, a second sub-lens group with positive refractive power that serves as the focus group, and a third sub-lens group with positive refractive power that does not move for focusing and is positioned on the image side of the focus group.

9. The zoom lens according to claim 1, characterized in that the plurality of lens groups are composed of a first lens group, a second lens group with negative refractive power, a third lens group with negative refractive power, a fourth lens group with positive refractive power, and a fifth lens group which is the final lens group, arranged in order from the object side to the image side.

10. The zoom lens according to claim 1, characterized in that the plurality of lens groups are composed of a first lens group, a second lens group with negative refractive power, a third lens group with negative refractive power, a fourth lens group with negative refractive power, a fifth lens group with positive refractive power, and a sixth lens group which is the final lens group, arranged in order from the object side to the image side.

11. The zoom lens according to claim 1, characterized in that the plurality of lens groups are composed of a first lens group, a second lens group with positive refractive power, a third lens group with negative refractive power, a fourth lens group with negative refractive power, a fifth lens group with positive refractive power, and a sixth lens group which is the final lens group, arranged in order from the object side to the image side.

12. A zoom lens comprising multiple lens groups, The aforementioned group of lenses consists of a first lens group with positive refractive power that does not move for zooming, arranged sequentially from the object side to the image side, three or more moving lens groups that move for zooming, and a final lens group with positive refractive power that does not move for zooming, and the spacing between adjacent lens groups changes during zooming. The three or more moving lens groups include a group of P lenses with positive refractive power, a group of N lenses with negative refractive power, and one or more V lens groups, arranged in order from the image side to the object side. When the focal length of the first lens group is f1, and the focal length of the i-th lens group from the object side among the one or more V lens groups is fVi, and the sum of f1 / fVi is expressed as Σ(f1 / fVi), -1.0≦Σ(f1 / fVi)≦-0.4 A zoom lens characterized by satisfying the following conditions.

13. A zoom lens according to any one of claims 1 to 12, An imaging device characterized by having an image sensor that captures an image of a subject through the zoom lens.

Images