Zoom lens and imaging device having the same

Abstract

To provide a zoom lens with a wide angle of view, a high zoom ratio, a compact and lightweight design, and high optical performance across the entire zoom range. [Solution] The zoom lens has a first lens group that remains stationary during zooming, an intermediate group containing one or more lens groups, a second lens group with negative refractive power, and a final lens group containing three or more lens groups, arranged sequentially from the object side to the image side, and the spacing between adjacent lens groups changes during zooming.

Description

[Technical Field]

[0001] This disclosure relates to a zoom lens and an imaging device having the same. [Background technology]

[0002] In recent years, there has been a growing demand for zoom lenses that can deliver excellent performance across the entire zoom range, even when widening the angle or increasing the magnification. [Overview of the project] [Problems that the invention aims to solve]

[0003] There is a demand for a zoom lens that offers a wider angle of view, a higher zoom ratio, is more compact and lightweight than conventional lenses, and possesses high optical performance across the entire zoom range. [Means for solving the problem]

[0004] A zoom lens as one aspect of this disclosure has, arranged sequentially from the object side to the image side, a first lens group that is stationary during zooming, an intermediate group including one or more lens groups, a second lens group with negative refractive power, and a final lens group including three or more lens groups, wherein the spacing between adjacent lens groups changes during zooming, the first lens group and the intermediate group are composed of a total of five or more lenses, the lens closest to the image in the intermediate group is a positive lens, and when the focal length of the first lens group is f11, the focal length of the intermediate group is f12, and the zoom ratio of the zoom lens is Z, -0.5 <f12 / f11<0.5 Z≧4.0 It is characterized by satisfying the following conditional expression.

[0005] Furthermore, another aspect of this disclosure, the zoom lens, comprises a first lens group that remains stationary during zooming, an intermediate group including one or more lens groups, a second lens group with negative refractive power, and a final lens group including three or more lens groups, arranged sequentially from the object side to the image side, characterized in that the spacing between adjacent lens groups changes during zooming. [Brief explanation of the drawing]

[0006] [Figure 1] This is a cross-sectional view of the zoom lens in Example 1 when it is in focus on an object at infinity at the wide-angle end. [Figure 2] These are longitudinal aberration diagrams of the zoom lens of Example 1 at an object distance of infinity: (A) wide-angle end, (B) zoom position where the intermediate group is closest to the image, and (C) telephoto end. [Figure 3] This is a cross-sectional view of the zoom lens in Example 2 when it is in focus on an object at infinity at the wide-angle end. [Figure 4] The images show the longitudinal aberrations of the zoom lens of Example 2 at an object distance of infinity: (A) wide-angle end, (B) zoom position where the intermediate group is closest to the image, and (C) telephoto end. [Figure 5] This is a cross-sectional view of the zoom lens in Example 3 when it is in focus on an object at infinity at the wide-angle end. [Figure 6] This diagram shows the longitudinal aberration of the zoom lens of Example 3 at an object distance of infinity (A) wide-angle end, (B) zoom position where the intermediate group is closest to the image, and (C) telephoto end. [Figure 7] This is a cross-sectional view of the zoom lens in Example 4 when it is in focus on an object at infinity at the wide-angle end. [Figure 8] This diagram shows the longitudinal aberration of the zoom lens of Example 4 at an object distance of infinity (A) wide-angle end, (B) zoom position where the intermediate group is closest to the image, and (C) telephoto end. [Figure 9] This is a cross-sectional view of the zoom lens in Example 5 when it is in focus on an object at infinity at the wide-angle end. [Figure 10] This diagram shows the longitudinal aberration of the zoom lens of Example 5 at an object distance of infinity (A) wide-angle end, (B) zoom position where the intermediate group is closest to the image, and (C) telephoto end. [Figure 11] This is a schematic diagram of the main components of the imaging device. [Modes for carrying out the invention]

[0007] The embodiments of this disclosure will be described in detail below with reference to the drawings. In each drawing, the same reference numeral is used for identical components, and redundant descriptions are omitted.

[0008] Figures 1, 3, 5, 7, and 9 are cross-sectional views of the zoom lenses of Examples 1 to 5 when focused on an object at infinity at the wide-angle end. The zoom lenses of each example are used in imaging devices such as digital video cameras, digital still cameras, broadcast cameras, silver halide film cameras, surveillance cameras, and in-vehicle cameras.

[0009] In each cross-sectional view, the left side is the object side and the right side is the image side. Note that the zoom lens in each embodiment may also be used as a projection lens for a projector or the like. In this case, the left side is the screen side and the right side is the projected image side.

[0010] Each embodiment of the zoom lens is composed of multiple lens groups. In this specification, a lens group is a collection of lenses that move or remain stationary as a whole during zooming (magnification). That is, in each embodiment of the zoom lens, the distance between adjacent lens groups changes during zooming. A lens group may consist of a single lens or multiple lenses. Furthermore, a lens group may include an aperture diaphragm.

[0011] In each cross-sectional view, Li represents the i-th lens group (where i is a single-digit natural number) from the object side within the lens group included in the zoom lens.

[0012] SP is the aperture diaphragm. I is the image plane, and when the zoom lens of each embodiment is used as the shooting optical system of a digital still camera or digital video camera, the imaging surface of an image sensor (photoelectric conversion element) such as a CCD sensor or CMOS sensor is placed on it. When the zoom lens of each embodiment is used as the shooting optical system of a silver halide film camera, a photosensitive surface corresponding to the film plane is placed on the image plane I. P is a glass block such as a faceplate of a CCD sensor, a low-pass filter, or a color separation prism.

[0013] In addition, the solid arrows indicate the movement trajectories of the respective lens groups during zooming from the wide-angle end (short focal length end) to the telephoto end (long focal length end). Further, when focusing from infinity to the closest subject, the lens group (focus group) moves as indicated by the arrow marked FOCUS.

[0014] FIG. 2, FIG. 4, FIG. 6, FIG. 8, and FIG. 10 are aberration diagrams of the zoom lenses of Examples 1 to 5, respectively, at an infinite object distance. In each aberration diagram, (A) is the longitudinal aberration diagram at the wide-angle end, (B) is the aberration diagram at the zoom position where the intermediate group is located closest to the image side (the focal length of the zoom lens is fz), and (C) is the aberration diagram at the telephoto end.

[0015] In the spherical aberration diagram, Fno is the F-number and shows the amount of spherical aberration with respect to the e-line (wavelength 546.1 nm) and the g-line (wavelength 435.8 nm). In the astigmatism diagram, S shows the amount of astigmatism on the sagittal image plane of the e-line, and M shows the amount of astigmatism on the meridional image plane of the e-line. The distortion aberration diagram shows the amount of distortion aberration with respect to the e-line. The chromatic aberration diagram shows the amount of chromatic aberration with respect to the g-line. ω is the semi-aperture angle [°].

[0016] Hereinafter, the characteristic configurations of the zoom lenses of the respective examples will be described.

[0017] The zoom lens of each example has a lens group (first lens group) L11 that is stationary during zooming, an intermediate group including one or more lens groups, a second group (second lens group) L2 having a negative refractive power, and a final lens group including three or more lens groups, which are arranged in order from the object side to the image side.

[0018] Hereinafter, in the zoom lenses of the respective examples, configurations that are preferably satisfied will be described.

[0019] It is preferable that the lens group L11 and the intermediate group are composed of a total of five or more lenses. This is preferable because it enables both high magnification and correction of various aberrations at the telephoto end.

[0020] The lens closest to the image in the intermediate group is preferably a positive lens. This is preferable because it allows for effective correction of distortion and is advantageous for wide-angle lenses.

[0021] The intermediate group preferably includes a lens group that moves toward the object along the optical axis when focusing from infinity to near. This is preferable because it allows for both miniaturization and suppression of aberrations (especially negative field curvature).

[0022] The aperture diaphragm SP is preferably located within the lens group closest to the image, or on the object side of that lens group. This is preferable because it suppresses and maintains a constant F-number due to zooming up to the F-drop point.

[0023] It is preferable that the lens group closest to the object in the intermediate group (the first intermediate lens group) L12 moves toward the image side when zooming from the wide-angle end to the telephoto end. This is preferable because it can suppress positive distortion and various other aberrations such as field curvature. In particular, wide-angle, high-magnification zoom lenses generally tend to exhibit significant positive distortion between the wide-angle end and the middle of the zoom range. Therefore, it is preferable that the lens group L12 moves toward the image side in a convex trajectory when zooming. That is, it is preferable that the lens group L12 extends the furthest between the wide-angle end and the middle of the zoom range so that distortion can be effectively corrected.

[0024] The intermediate group preferably has a positive refractive power as a whole. This is preferable because it can suppress positive distortion and other aberrations such as field curvature.

[0025] The lens group L11 is preferably composed of two or more lenses. This is preferable because it allows for good correction of aberrations occurring in the lens group L11.

[0026] It is preferable that the lens group closest to the image sensor in the final lens group remain stationary during zooming. This is preferable because it allows the overall length of the lens to remain constant during zooming, thereby maintaining weight balance.

[0027] The following describes the conditions that the zoom lenses of each embodiment preferably satisfy. The zoom lenses of each embodiment preferably satisfy one or more of the following conditional formulas (1) to (7).

[0028] -0.5 <f12 / f11<0.5 ···(1) Z≧4.0 ···(2) fw×Z 0.08 <fz<fw×Z 0.50 ...(3) 1.1 <M2 / M12<50.5 ···(4) 0.1<(L1z-L1w) / fw<4.0 (5) |L1t-L1w| / L1w<0.5 ···(6) 0.2 < |f1w / f2| < 14.0 ···(7) Here, f11 is the focal length of lens group L11. f12 is the focal length of the intermediate group. Z is the zoom ratio of the zoom lens. fw is the focal length of the zoom lens at the wide-angle end. fz is the focal length of the zoom lens at the zoom position where the intermediate group is located closest to the image. M12 is the maximum amount of movement of lens group L12, which is located closest to the object in the intermediate group and moves during zooming. M2 is the maximum amount of movement of the second group L2 during zooming. L1z is the distance between lens group L11 and the intermediate group at the zoom position where the intermediate group is located closest to the image (the distance along the optical axis from the lens surface closest to the image of lens group L11 to the lens surface closest to the object of the intermediate group). L1w is the distance between lens group L11 and the intermediate group at the wide-angle end (the distance along the optical axis from the lens surface closest to the image of lens group L11 to the lens surface closest to the object of the intermediate group). L1t is the distance between lens group L11 and the intermediate group at the telephoto end (the distance along the optical axis from the image-side lens surface of lens group L11 to the object-side lens surface of the intermediate group). f1w is the combined focal length of lens group L11 and the intermediate group at the wide-angle end. f2 is the focal length of the second group L2.

[0029] Conditional equation (1) specifies the ratio of the focal lengths of lens group L11 to that of the intermediate group. If the ratio exceeds the upper limit or falls below the lower limit of conditional equation (1), the refractive power of lens group L11 is too strong, resulting in excessive aberrations in lens group L11, making it difficult to correct these aberrations in the intermediate group and beyond.

[0030] Conditional equation (2) defines the zoom ratio of the zoom lens, that is, the ratio of the focal length of the zoom lens at the wide-angle end to the telephoto end. If the zoom ratio is small, the aberration fluctuations during zooming are small, and therefore the effects of this disclosure cannot be fully realized.

[0031] Condition (3) defines the focal length at the zoom position where the intermediate group is located closest to the image. Satisfying condition (3) allows for effective correction of the zoom position from the wide-angle end, where positive distortion is large, to the middle of the zoom range, which is advantageous for good aberration correction.

[0032] Conditional equation (4) specifies the ratio of the maximum movement of lens group L12 to that of lens group L2. For higher magnification, it is desirable that the maximum movement of lens group L2 be greater than a certain amount relative to lens group L12. If this value exceeds the upper limit of conditional equation (4), the movement of lens group L12 becomes too small, reducing the aberration correction effect and making good aberration correction difficult. If this value falls below the lower limit of conditional equation (4), the movement of lens group L2 becomes too small, making it difficult to achieve both high magnification and compact, lightweight design.

[0033] Condition (5) specifies the maximum distance between lens group L11 and the intermediate group (lens group L12, which is positioned closest to the object in the intermediate group and moves during zooming). If the distance exceeds the upper limit of condition (5), the amount of movement of lens group L12 is too large, resulting in excessive correction of distortion and image plane aberration, making it difficult to correct various aberrations in a balanced manner. If the distance falls below the lower limit of condition (5), the amount of movement of lens group L12 is too small, resulting in little correction effect and making it difficult to correct various aberrations well.

[0034] Conditional equation (6) specifies the distance between lens group L11 and the intermediate group at the wide-angle and telephoto ends. It is desirable that the distance between lens group L11 and the intermediate group be approximately the same at both the wide-angle and telephoto ends. If the upper limit of conditional equation (6) is exceeded, the distance between lens group L11 and the intermediate group will differ significantly between the wide-angle and telephoto ends. If the distance at the wide-angle end is too large compared to the distance at the telephoto end, the front element diameter will increase, making miniaturization difficult. Also, if the distance at the telephoto end is too large compared to the distance at the wide-angle end, the magnification ratio of the combined intermediate group and the second group L2 will decrease, shortening the focal length at the telephoto end. As a result, in order to maintain the same focal length at the telephoto end, the amount of movement of the second group L2 needs to be increased, which increases the overall zoom length and makes miniaturization difficult.

[0035] Conditional equation (7) specifies the ratio of the combined focal length of the composite lens group, which consists of lens group L11 and the intermediate group, at the wide-angle end to the focal length of the second group L2. If the upper limit of conditional equation (7) is exceeded, the refractive power of the second group L2 becomes too strong relative to the refractive power of the composite lens group consisting of lens group L11 and the intermediate group, increasing the various aberrations generated in the second group L2 and making good aberration correction difficult. If the lower limit of conditional equation (7) is exceeded, the refractive power of the second group L2 becomes too weak relative to the refractive power of the composite lens group consisting of lens group L11 and the intermediate group, increasing the amount of movement of the second group L2, lengthening the zoom length, and making miniaturization difficult.

[0036] Furthermore, it is more preferable that the lower limit of conditional expression (1) be set to -0.45, -0.40, -0.35, -0.30, -0.25, -0.20, -0.15, -0.10, -0.05, or -0.01. It is more preferable that the upper limit of conditional expression (1) be set to 0.48, 0.46, 0.44, 0.42, 0.40, 0.38, 0.36, 0.34, 0.32, or 0.30.

[0037] Furthermore, it is more preferable that the lower limit of condition (2) be set to 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, or 9.0.

[0038] Furthermore, it is preferable to set the numerical range of conditional expression (3) to the numerical range of conditional expression (3a) below.

[0039] fw×Z 0.10 <fz<fw×Z 0.47 ...(3a) Furthermore, it is more preferable to set the numerical range of condition (3) to the numerical range of condition (3b) below.

[0040] fw×Z 0.13 <fz<fw×Z 0.44 ...(3b) Furthermore, it is more preferable that the lower limit of conditional expression (4) be set to 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, or 6.0. It is more preferable that the upper limit of conditional expression (4) be set to 50.0, 48.0, 47.0, 46.0, 45.0, 44.0, 43.0, 42.0, 41.0, or 40.0.

[0041] Furthermore, it is more preferable that the lower limit of conditional expression (5) be set to 0.12, 0.14, 0.16, 0.18, 0.20, 0.21, 0.22, 0.23, 0.24, or 0.25. It is more preferable that the upper limit of conditional expression (5) be set to 3.80, 3.65, 3.50, 3.30, 3.10, 2.90, 2.80, 2.70, 2.60, or 2.5.

[0042] Furthermore, it is more preferable that the upper limit of conditional expression (6) be set to 0.48, 0.46, 0.44, 0.42, 0.40, 0.39, 0.38, 0.37, 0.36, or 0.35.

[0043] Furthermore, it is more preferable that the lower limit of conditional expression (7) be set to 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.30. It is more preferable that the upper limit of conditional expression (7) be set to 13.8, 13.6, 13.4, 13.2, 13.0, 12.8, 12.6, 12.4, 12.2, or 12.0.

[0044] Next, we will describe the zoom lenses of each embodiment in detail.

[0045] The zoom lenses of Examples 1 and 2 have a first group L1, a second group L2, a third group (third lens group) L3, a fourth group (fourth lens group) L4, and a fifth group (fifth lens group) L5, arranged in order from the object side to the image side. The first group L1 includes a lens group L11 that is stationary during zooming, and an intermediate group consisting of one or more lens groups, arranged in order from the object side to the image side. The intermediate group consists of a lens group L12 with positive refractive power that moves during zooming. Lens group L11 is composed of three lenses. The intermediate group (lens group L12) is composed of three lenses. In other words, lens group L11 and the intermediate group consist of a total of six lenses. The lens closest to the image side of lens group L12 is a positive lens. Lens group L12 moves in a convex trajectory toward the image side during zooming from the wide-angle end to the telephoto end. Furthermore, lens group L12 moves towards the object when focusing from infinity to near distance. Second group L2 has negative refractive power and moves towards the image when zooming from the wide-angle end to the telephoto end. Third group L3 has positive refractive power and moves during zooming. Fourth group L4 has positive refractive power and moves during zooming. Fourth group L4 moves nonlinearly along the optical axis in conjunction with the movement of second group L2 and third group L3, correcting image plane fluctuations associated with zooming. Fifth group L5 has positive refractive power and remains stationary during zooming. Fifth group L5 also includes an aperture diaphragm SP. In Examples 1 and 2, the final lens group is composed of third group L3, fourth group L4, and fifth group L5.

[0046] The zoom lens of Example 3 has lens groups L1, L2, L3, L4, and L5 arranged in order from the object side to the image side. Lens group L1 includes a lens group L11 that is fixed during zooming and an intermediate group consisting of one or more lens groups, arranged in order from the object side to the image side. The intermediate group consists of a lens group L12 with positive refractive power and a lens group (second intermediate lens group) L13 with positive refractive power, arranged in order from the object side to the image side. Lens groups L12 and L13 move during zooming. Lens group L11 is composed of 5 lenses. The intermediate group (lens groups L12 and L13) is composed of 3 lenses. That is, lens group L11 and the intermediate group consist of a total of 8 lenses. The lens closest to the image in lens group L12 is a positive lens. Lens group L12 moves in a convex trajectory toward the image when zooming from the wide-angle end to the telephoto end. Lens groups L12 and L13 move toward the object by different amounts when focusing from infinity to close distance. The amount of movement of lens groups L12 and L13 during focusing may be different. Second group L2 has negative refractive power and moves toward the image when zooming from the wide-angle end to the telephoto end. Third group L3 has positive refractive power and moves during zooming. Fourth group L4 has positive refractive power and moves during zooming. Fourth group L4 moves in conjunction with the movement of second group L2 and third group L3, correcting image plane fluctuations associated with zooming. Fifth group L5 has positive refractive power and remains stationary during zooming. Fifth group L5 is equipped with an aperture diaphragm SP. In Example 3, the final lens group is composed of the third group L3, the fourth group L4, and the fifth group L5.

[0047] The zoom lens of Example 4 has lens groups L1, L2, L3, L4, and L5 arranged in order from the object side to the image side. Lens group L1 includes a lens group L11 that is stationary during zooming and an intermediate group consisting of one or more lens groups, arranged in order from the object side to the image side. The intermediate group consists of a lens group L12 with positive refractive power that moves during zooming. Lens group L11 is composed of four lenses. The intermediate group (lens group L12) is composed of two lenses. In other words, lens group L11 and the intermediate group consist of a total of six lenses. The lens closest to the image in lens group L12 is a positive lens. Lens group L12 moves in a convex trajectory toward the image side when zooming from the wide-angle end to the telephoto end. Also, lens group L12 moves toward the object side when focusing from infinity to near distance. The second group L2 has negative refractive power and moves toward the image side when zooming from the wide-angle end to the telephoto end. The third group L3 has negative refractive power and moves when zooming. The fourth group L4 has positive refractive power and moves when zooming. The fourth group L4 moves in conjunction with the movement of the second group L2 and the third group L3, correcting the image plane fluctuation associated with zooming. The fifth group L5 has positive refractive power and remains stationary when zooming. The fifth group L5 also includes an aperture diaphragm SP. In Embodiment 4, the final lens group is composed of the third group L3, the fourth group L4, and the fifth group L5.

[0048] The zoom lens of Example 5 has lens groups L1, L2, L3, L4, L5, L6 (sixth lens group), and L7 (seventh lens group), arranged in order from the object side to the image side. Lens group L1 includes a lens group L11 that is stationary during zooming and an intermediate group consisting of one or more lens groups, arranged in order from the object side to the image side. The intermediate group consists of a lens group L12 with positive refractive power that moves during zooming. Lens group L11 is composed of four lenses. The intermediate group (lens group L12) is composed of two lenses. That is, lens group L11 and the intermediate group consist of a total of six lenses. The lens closest to the image in lens group L12 is a positive lens. Lens group L12 moves in a convex trajectory toward the image side during zooming from the wide-angle end to the telephoto end. Furthermore, lens group L12 moves towards the object when focusing from infinity to near distance. The second group L2 has negative refractive power and moves towards the image when zooming from the wide-angle end to the telephoto end. The third group L3 has negative refractive power and moves when zooming. The fourth group L4 has negative refractive power and moves when zooming. The fifth group L5 has positive refractive power and moves when zooming. The fifth group L5 moves in conjunction with the movement of the second group L2, the third group L3, and the fourth group L4, correcting image plane fluctuations associated with zooming. The sixth group L6 has negative refractive power and remains stationary when zooming. The seventh group L7 has positive refractive power and moves when zooming. In Example 5, the final lens group is composed of the third group L3, the fourth group L4, the fifth group L5, the sixth group L6, and the seventh group L7.

[0049] The numerical values ​​corresponding to Examples 1 to 5 are shown below.

[0050] In the surface data for each numerical example, r represents the radius of curvature of each optical surface, and d (mm) represents the on-axial spacing (distance along the optical axis) between the m-th surface and the (m+1)-th surface. Here, m is the surface number counted from the light incidence side. Furthermore, nd represents the refractive index of each optical element with respect to the d-line, and νd represents the Abbe number of each optical element with respect to the d-line. Note that the Abbe number νd of a certain material is given by Nd, NF, and NC, respectively, when the refractive indices at the Fraunhofer lines d-line (587.6 nm), F-line (486.1 nm), and C-line (656.3 nm) are Nd, NF, and NC. νd = (Nd-1) / (NF-NC) It is represented as follows.

[0051] In each numerical example, d, focal length (mm), F-number, and half-angle of view [°] are all values ​​when the zoom lens of each example is focused on an object at infinity. The half-angle of view is a value obtained by ray tracing. "Lens length" is expressed as the distance along the optical axis from the lens surface closest to the object among the optically powerful lens surfaces to the paraxial image plane, expressed as the air-equivalent length (length excluding optical block G). "BF" is the back focus, expressed as the distance along the optical axis from the lens surface closest to the image among the optically powerful lens surfaces to the paraxial image plane, expressed as the air-equivalent length.

[0052] Furthermore, if the optical surface is aspherical, the sign * is added to the right of the surface number. The aspherical shape is defined as follows, where X is the displacement from the surface vertex in the optical axis direction, H is the height from the optical axis perpendicular to the optical axis, R is the paraaxial radius of curvature, k is the cone constant, and A3, A4, A5, A6, A7, A8, A9, A10, A11, A12 are the aspherical coefficients of their respective orders.

[0053]

number

[0054] This is expressed as follows. Note that "e±XX" in each aspherical coefficient is "×10± XX It means "...".

[0055] Furthermore, in the "Zoom Lens Group Data," groups 1, M1, and M2 correspond to lens groups L11, L12, and L13, respectively.

[0056] [Numerical Example 1] Unit: mm Surface data Face number rd nd νd 1 -4415.863 4.00 1.85150 40.8 2 216.944 1.51 3 217.109 23.89 1.43387 95.1 4 -799.803 0.21 5 333.827 12.21 1.43387 95.1 6 -2542.190 (variable) 7 269.078 11.15 1.43387 95.1 8 -5031.647 0.21 9 204.595 11.83 1.43387 95.1 10 1781.304 1.60 11 153.491 9.55 1.59522 67.7 12 334.887 (variable) 13* -455.048 1.84 2.00330 28.3 14 29.454 15.68 15 -32.142 1.21 1.71999 50.2 16 116.008 8.78 1.92286 18.9 17 -48.317 5.41 18 -37.856 1.67 1.88300 40.8 19 -60.186 (variable) 20 98.119 7.71 1.76385 48.5 21* 1517.336 8.01 22 988.260 8.56 1.43875 94.7 23 -89.280 0.41 24 495.806 2.17 1.85478 24.8 25 116.397 (variable) 26 114.332 7.56 1.49700 81.5 27 -225.587 2.34 1.84666 23.8 28 2305.585 0.17 29* 186.826 6.95 1.59522 67.7 30 -140.233 (variable) 31 (aperture) ∞ 3.00 32 -184.527 1.40 1.88300 40.8 33 36.123 1.35 34 34.659 4.35 1.89286 20.4 35 143.936 6.28 36 -38.937 1.50 1.80400 46.5 37 -49.407 7.40 38 -711.226 1.50 1.89190 37.1 39 35.307 4.68 1.78880 28.4 40 163.410 8.15 41 -95.624 1.50 1.88300 40.8 42 170.125 7.76 1.51742 52.4 43 -34.067 10.48 44 64.253 4.56 1.53172 48.8 45 -237.619 1.40 46 -89.925 1.50 1.89190 37.1 47 39.553 8.15 1.49700 81.5 48 -63.040 0.20 49 65.896 8.10 1.51633 64.1 50 -44.456 1.50 1.88300 40.8 51 -178.266 0.20 52 113.261 6.39 1.54814 45.8 53 -53.637 10.00 54 ∞ 33.00 1.60859 46.4 55 ∞ 13.20 1.51633 64.2 56 ∞ 13.27 Image plane ∞ Aspherical data Page 13 K =-1.99999e+00 A 4= 3.80072e-06 A 6=-2.20511e-09 A 8= 8.83118e-13 A10=-4.40840e-15 A12= 1.49106e-17 A14=-1.96476e-20 A16= 9.37076e-24 Page 21 K =-1.02705e+04 A 4= 8.74044e-07 A 6=-5.10504e-10 A 8= 6.71945e-13 A10=-4.80538e-16 A12= 1.44450e-19 Page 29 K =-1.10170e+02 A 4= 1.67228e-06 A 6=-2.73625e-09 A 8= 3.34704e-12 A10=-2.61307e-15 A12= 9.14984e-19 Various data Zoom ratio 68.00 Wide-angle fz telephoto Focal length 6.75 16.33 459.00 F-number 1.76 1.76 3.64 Half-angle [°] 39.17 18.61 0.69 Image height 5.50 5.50 5.50 Lens length 533.81 533.81 533.81 BF 52.44 52.44 52.44 d 6 9.67 23.67 12.66 d12 3.34 38.48 129.67 d19 216.09 125.12 4.00 d25 3.32 29.80 15.67 d30 2.97 18.32 73.39 Zoom lens group data Group starting plane focal length 1 1 -43430.21 M1 7 177.08 2 13 -20.43 3 20 138.13 4 26 104.03 5 31 41.16 [Numerical Example 2] Unit: mm Surface data Face number rd nd νd 1 -2221.349 6.00 1.83481 42.7 2 342.333 1.50 3 340.133 24.31 1.43387 95.1 4 -911.250 0.20 5 565.719 14.49 1.43387 95.1 6 -1543.644 (variable) 7 376.540 17.36 1.43387 95.1 8 -3838.033 0.25 9 295.848 17.80 1.43387 95.1 10 3814.344 1.60 11 192.957 15.11 1.43387 95.1 12 420.467 (variable) 13* -238.965 2.20 2.00330 28.3 14 36.896 10.74 15 -52.546 1.45 1.80610 40.9 16 47.404 11.69 1.89286 20.4 17 -48.436 3.85 18 -38.895 2.00 1.83481 42.7 19 -128.592 (variable) 20 120.021 10.14 1.78800 47.4 21* -749.646 2.46 22 119.605 16.42 1.43875 94.7 23 -148.456 0.50 24 181.335 2.50 1.85478 24.8 25 74.456 (Variable) 26 88.360 13.64 1.49700 81.5 27 -302.319 2.60 1.84666 23.8 28 10294.031 0.20 29* 293.116 6.81 1.53775 74.7 30 -219.650 (variable) 31 (aperture) ∞ 2.74 32 -607.740 1.40 1.88300 40.8 33 41.820 0.70 34 33.865 4.29 1.80810 22.8 35 91.433 4.58 36 -66.359 1.50 1.88300 40.8 37 -286.035 8.19 38 -149.141 1.50 1.89190 37.1 39 45.053 6.01 1.84666 23.8 40 -128.089 3.18 41 -43.757 1.50 1.88300 40.8 42 116.859 8.22 1.51742 52.4 43 -29.469 10.21 44 79.819 4.96 1.53172 48.8 45 -88.967 1.40 46 -82.335 1.50 1.89190 37.1 47 34.621 7.78 1.48749 70.2 48 -73.557 0.20 49 130.522 7.48 1.51633 64.1 50 -32.217 1.50 1.88300 40.8 51 -85.050 0.20 52 90.792 7.25 1.54814 45.8 53 -46.746 10.00 54 ∞ 33.00 1.60859 46.4 55 ∞ 13.20 1.51633 64.2 56 ∞ 13.00 Image plane ∞ Aspherical data Page 13 K =-1.93181e+00 A 4= 2.22919e-06 A 6= 2.38151e-08 A 8= 7.72743e-10 A10= 2.13595e-12 A12=-3.64187e-15 A14=-4.78958e-18 A16=-3.47247e-22 A 3= 2.52939e-07 A 5=-4.19447e-08 A 7=-5.95656e-09 A 9=-5.68561e-11 A11=-4.13651e-15 A13= 1.87641e-16 A15= 6.43023e-20 Page 21 K = 1.95058e+00 A 4= 3.74052e-07 A 6= 1.99549e-10 A 8= 2.51258e-13 A10=-2.73849e-17 A12=-1.59352e-19 A14=-1.48582e-23 A16=-5.53240e-27 A 3=-1.37836e-07 A 5=-2.64991e-09 A 7=-9.23121e-12 A 9=-3.74119e-15 A11= 5.03388e-18 A13= 1.89531e-21 A15= 4.46991e-25 Page 29 K =-2.00000e+00 A 4= 1.60386e-07 A 6= 1.28452e-08 A 8= 5.45892e-11 A10=-6.18393e-15 A12= 3.22244e-18 A14= 3.40708e-20 A16= 1.98023e-24 A 3=-1.02506e-06 A 5=-8.91670e-08 A 7=-1.10781e-09 A 9=-1.25958e-12 A11= 8.63627e-16 A13=-1.17716e-18 A15=-4.20681e-22 Various data Zoom ratio 144.44 Wide-angle fz telephoto Focal length 8.10 28.97 1169.95 F-number 1.76 1.77 6.08 Half-angle [°] 34.18 10.75 0.27 Image height 5.50 5.50 5.50 Lens length 663.41 663.41 663.41 BF 52.17 52.17 52.17 d 6 24.80 29.80 24.80 d12 4.04 96.01 197.98 d19 297.46 164.48 2.00 d25 9.84 33.00 8.70 d30 2.98 15.84 105.65 Zoom lens group data Group starting plane focal length 1 1 33246.95 M1 7 262.10 2 13 -22.51 3 20 121.34 4 26 118.74 5 31 46.47 [Numerical Example 3] Unit: mm Surface data Face number rd nd νd 1 4771.429 4.00 1.80400 46.5 2 922.789 0.70 3 689.008 10.00 1.43387 95.1 4 -5276.409 1.50 5 -5637.082 4.00 1.83481 42.7 6 213.905 1.47 7 213.520 23.46 1.43387 95.1 8 -834.787 0.21 9 351.588 11.67 1.43387 95.1 10 -2378.908 (variable) 11 274.898 10.36 1.43387 95.1 12 18647.577 0.21 13 197.643 12.46 1.43387 95.1 14 2346.661 (variable) 15 152.277 9.37 1.61800 63.3 16 331.275 (variable) 17* -335.080 1.84 2.00330 28.3 18 30.261 15.63 19 -31.989 1.21 1.71999 50.2 20 137.870 8.77 1.92286 18.9 21 -46.510 5.26 22 -37.511 1.67 1.88300 40.8 23 -60.834 (variable) 24 96.845 7.93 1.76385 48.5 25* 2003.641 8.00 26 1266.159 8.33 1.43875 94.7 27 -93.806 0.41 28 382.987 2.17 1.85478 24.8 29 104.575 (Variable) 30 112.876 7.32 1.49700 81.5 31 -291.208 2.34 1.84666 23.8 32 1002.458 0.17 33* 172.703 7.18 1.59522 67.7 34 -143.446 (variable) 35 (aperture) ∞ 3.00 36 -187.095 1.40 1.88300 40.8 37 38.099 1.32 38 36.175 5.47 1.89286 20.4 39 147.424 6.02 40 -42.633 1.50 1.80400 46.5 41 -56.720 7.30 42 -680.542 1.50 1.89190 37.1 43 34.213 4.56 1.78880 28.4 44 177.781 9.04 45 -103.323 1.50 1.88300 40.8 46 290.428 6.69 1.51742 52.4 47 -36.785 10.78 48 69.944 4.57 1.53172 48.8 49 -183.073 1.40 50 -91.276 1.50 1.89190 37.1 51 39.436 8.28 1.49700 81.5 52 -60.358 0.20 53 64.800 8.26 1.51633 64.1 54 -43.066 1.50 1.88300 40.8 55 -189.110 0.20 56 121.607 6.41 1.54814 45.8 57 -51.827 10.00 58 ∞ 33.00 1.60859 46.4 59 ∞ 13.20 1.51633 64.2 60 ∞ 13.27 Image plane ∞ Aspherical data Page 17 K =-2.00000e+00 A 4= 3.86699e-06 A 6=-2.18466e-09 A 8= 5.86719e-13 A10=-3.50266e-15 A12= 1.39895e-17 A14=-1.94494e-20 A16= 9.51845e-24 Page 25 K =-1.80745e+04 A 4= 7.68196e-07 A 6=-3.57069e-10 A 8= 4.36154e-13 A10=-2.81265e-16 A12= 7.50695e-20 Page 33 K =-8.98152e+01 A 4= 1.76801e-06 A 6=-2.69561e-09 A 8= 3.15027e-12 A10=-2.37636e-15 A12= 8.08405e-19 Various data Zoom ratio 67.50 Wide-angle fz telephoto Focal length 6.80 17.06 459.00 F-number 1.76 1.76 3.64 Half-angle [°] 38.97 17.87 0.69 Image height 5.50 5.50 5.50 Lens length 551.04 551.04 551.04 BF 52.44 52.44 52.44 d10 10.33 24.13 12.57 d14 0.50 2.90 4.99 d16 3.86 39.03 125.56 d23 217.74 123.45 4.00 d29 3.67 29.41 16.74 d34 2.49 19.67 74.73 Zoom lens group data Group starting plane focal length 1 1 960128.67 M1 11 281.14 M2 15 445.39 2 17 -20.53 3 24 144.75 4 30 103.06 5 35 41.62 [Numerical Example 4] Unit: mm Surface data Face number rd nd νd 1 -170.465 2.30 1.72047 34.7 2 153.068 5.28 3 1004.162 2.20 1.84666 23.8 4 356.614 8.44 1.43875 94.9 5 -161.248 0.40 6 159.556 11.44 1.43387 95.1 7 -126.321 (variable) 8 128.272 7.44 1.59240 68.3 9 -594.874 0.15 10 64.043 6.08 1.72916 54.7 11 130.908 (variable) 12 63.188 1.00 1.88300 40.8 13 14.978 6.20 14 -47.067 6.81 1.80810 22.8 15 -12.485 0.75 1.88300 40.8 16 82.252 0.18 17 29.773 2.34 1.66680 33.0 18 76.161 (variable) 19 -38.027 0.75 1.75700 47.8 20 54.286 2.50 1.84649 23.9 21 -3220.929 (variable) 22 67.270 5.22 1.64000 60.1 23* -47.250 (variable) 24 (aperture) ∞ 6.04 25 38.377 7.66 1.49700 81.5 26 -46.954 1.00 1.88300 40.8 27 119.689 33.00 28 -559.213 4.16 1.51633 64.1 29 -40.371 3.48 30 77.570 0.80 1.80100 35.0 31 44.142 6.29 1.50127 56.5 32 868.309 2.22 33 132.618 6.27 1.48749 70.2 34 -26.074 0.85 1.88300 40.8 35 -1116.372 0.13 36 34.010 4.89 1.51633 64.1 37 -121.238 1.00 38 ∞ 33.00 1.60859 46.4 39 ∞ 13.20 1.51633 64.1 40 ∞ 6.50 Image plane ∞ Aspherical data Page 23 K =-7.68287e-01 A 4= 2.36357e-06 A 6= 5.80132e-10 A 8= 1.25835e-11 A10=-7.28207e-14 A12= 1.30593e-16 Various data Zoom ratio 21.67 Wide-angle fz telephoto Focal length 7.80 18.46 169.00 F-number 1.80 1.80 2.70 Half-angle [°] 35.19 16.59 1.86 Image height 5.50 5.50 5.50 Lens length 262.30 262.30 262.30 BF 36.67 36.67 36.67 d 7 7.03 12.02 7.01 d11 0.49 23.92 56.01 d18 59.00 16.65 13.60 d21 6.77 15.45 0.81 d23 6.07 11.30 1.91 Zoom lens group data Group starting plane focal length 1 1 1451.85 M1 8 85.83 2 12 -13.99 3 19 -55.60 4 22 43.98 5 24 50.09 [Numerical Example 5] Unit: mm Surface data Face number rd nd νd 1 171.298 15.59 1.48749 70.2 2 -1602.009 0.20 3 272.177 4.00 1.77250 49.6 4 109.084 3.35 5 111.574 18.63 1.43387 95.1 6 -563.181 4.57 7 -255.278 3.20 1.72916 54.7 8 -19143.915 (variable) 9 375.930 10.57 1.43387 95.1 10 -291.540 0.15 11 161.475 4.71 1.49700 81.5 12 255.297 (variable) 13* 205.850 1.20 1.76385 48.5 14 37.452 9.43 15 -71.317 1.00 1.43875 94.7 16 49.147 6.13 1.85478 24.8 17 -316.918 (variable) 18 -58.603 1.20 1.76385 48.5 19 176.107 (variable) 20 -212.784 1.00 1.77250 49.6 21 117.037 2.63 1.89286 20.4 22 2393.445 2.09 23 -90.478 1.20 1.88300 40.8 24 -404.132 (variable) 25* 185.854 4.51 1.77250 49.6 26 -107.506 2.27 27 63.711 7.56 1.59522 67.7 28 -84.888 0.20 29 134.901 4.59 1.43875 94.7 30 -135.450 1.20 1.95375 32.3 31 75.723 (Variable) 32 (aperture) ∞ 1.50 33 35.632 5.11 1.49700 81.5 34 136.622 34.72 35 -54.552 1.20 2.00069 25.5 36 22.428 4.67 1.80810 22.8 37 -95.807 (variable) 38 67.659 3.92 1.51742 52.4 39 -606.143 1.00 40 111.252 5.99 1.85478 24.8 41 -40.733 1.00 1.88300 40.8 42 44.148 2.00 43 40.554 7.24 1.58144 40.8 44 -53.115 1.00 1.95906 17.5 45 -162.122 (variable) Image plane ∞ Aspherical data Page 13 K =-2.74888e+02 A 4= 4.85578e-06 A 6=-1.19946e-08 A 8= 3.81463e-11 A10=-9.11845e-14 A12= 1.32936e-16 A14=-9.56136e-20 A16= 2.19823e-23 Page 25 K =-3.45593e+01 A 4=-7.12754e-07 A 6=-3.56316e-10 A 8=-6.82442e-14 Various data Zoom ratio 30.00 Wide-angle fz telephoto Focal length 35.00 56.85 1050.00 F-number 4.70 4.66 9.14 Half-angle [°] 22.92 14.59 0.81 Image height 14.80 14.80 14.80 Lens length 467.29 467.29 467.29 BF 52.06 57.00 28.48 d 8 20.16 29.19 20.16 d12 1.00 27.86 150.57 d17 3.87 5.87 10.15 d19 157.21 90.01 4.17 d24 2.40 9.83 2.39 d31 12.10 33.95 9.29 d37 38.00 33.06 61.58 d45 52.06 57.00 28.48 Zoom lens group data Group starting plane focal length 1 1 1000.00 M1 9 263.47 2 13 -95.78 3 18 -57.16 4 20 -94.07 5 25 59.66 6 32 -3309.08 7 38 108.23 The various values ​​in each numerical example are summarized in Table 1 below.

[0057] [Table 1]

[0058] [Imaging device] Figure 11 illustrates the outline of the imaging device (television camera system) using the zoom lens of each embodiment as the imaging optical system. Figure 11 is a schematic diagram of the main parts of the imaging device 125. The zoom lens 101 is one of the zoom lenses from Embodiments 1 to 5 and is detachably attached to the camera body 124.

[0059] The zoom lens 101 comprises a first group L1, a variable magnification group LZ, a focal length conversion optical system FDC, and a fifth group L5. The first group L1 includes a lens group for focusing. The variable magnification group LZ includes a group that moves along the optical axis during zooming and a group that moves along the optical axis to correct image plane fluctuations associated with zooming. The fifth lens group U5 is stationary during zooming and includes the focal length conversion optical system FDC. The fifth group L5 also includes an aperture diaphragm SP.

[0060] The drive mechanism 114 is a drive mechanism such as a helicoid, cam, or actuator that moves a part of the first lens group L1 along the optical axis. The drive mechanism 115 is a drive mechanism such as a helicoid, cam, or actuator that moves the zoom lens group LZ along the optical axis. The motors (driving means) 116, 117, and 118 electrically drive the drive mechanisms 114, 115, and the aperture diaphragm SP. The detectors 119, 120, and 121 are detectors such as encoders, potentiometers, or photosensors that detect the position of the focusing lens group and the zoom lens group LZ on the optical axis, and the aperture diameter of the aperture diaphragm SP. Inside the camera body 123 are a glass block 109 corresponding to an optical filter and a color separation prism, and an image sensor (photoelectric conversion element) 110 such as a CCD sensor or CMOS sensor that receives the subject image formed by the zoom lens 101.

[0061] Furthermore, CPUs 111 and 122 control various components of the camera body 123 and the zoom lens 101, respectively.

[0062] Thus, by applying the zoom lens of this disclosure to an imaging device, an imaging device with high optical performance can be obtained. This embodiment includes the following configuration. (Composition 1) A zoom lens having a first lens group that is stationary during zooming, an intermediate group including one or more lens groups, a second lens group having a negative refractive power, and a final lens group including three or more lens groups, which are arranged in order from the object side to the image side, and in which the distance between adjacent lens groups changes during zooming, The first lens group and the intermediate group are composed of a total of five or more lenses, The lens closest to the image side in the intermediate group is a positive lens, [[ID=!]] When the focal length of the first lens group is f11, the focal length of the intermediate group is f12, and the zoom ratio of the zoom lens is Z, -0.5 < f12 / f11 < 0.5 Z ≧ 4.0 The zoom lens is characterized by satisfying the conditional expression. (Configuration 2) When the focal length of the zoom lens at the wide-angle end is fw and the focal length of the zoom lens at the zoom position where the intermediate group is located closest to the image side is fz, fw × Z 0.08 < fz < fw × Z 0.50 The zoom lens according to Configuration 1, characterized by satisfying the conditional expression. (Configuration 3) The intermediate group includes a lens group that moves toward the object side during focusing from infinity to the nearest point. The zoom lens according to Configuration 1 or 2. (Configuration 4) The intermediate group includes a first intermediate lens group that is arranged closest to the object side and moves during zooming, The second lens group moves during zooming, When the maximum movement amount of the first intermediate lens group during zooming is M12 and the maximum movement amount of the second lens group during zooming is M2, 1.1 < M2 / M12 < 50.5 The zoom lens according to any one of Configurations 1 to 3, characterized by satisfying the conditional expression. (Configuration 5) When the focal length of the zoom lens at the wide-angle end is fw, and the zoom position where the intermediate group is located closest to the image, and the distance along the optical axis from the lens surface closest to the image of the first lens group to the lens surface closest to the object of the intermediate group at the wide-angle end are L1z and L1w, respectively, 0.1 < (L1z - L1w) / fw < 4.0 A zoom lens according to any one of configurations 1 to 4, characterized by satisfying the following conditional expression. (Composition 6) When L1w and L1t are the distances along the optical axis from the image-side lens surface of the first lens group to the object-side lens surface of the intermediate group at the wide-angle and telephoto ends, respectively, |L1t-L1w| / L1w<0.5 A zoom lens according to any one of configurations 1 to 5, characterized by satisfying the following conditional expression. (Composition 7) When the combined focal length of the first lens group and the intermediate group at the wide-angle end is f1w, and the focal length of the second lens group is f2, 0.2 < |f1w / f2| < 14.0 A zoom lens according to any one of configurations 1 to 6, characterized by satisfying the following conditional expression. (Composition 8) A zoom lens according to any one of configurations 1 to 7, further comprising an aperture diaphragm located within the lens group closest to the image, or located closest to the object within the lens group. (Composition 9) A zoom lens according to any one of configurations 1 to 8, characterized in that the first intermediate lens group closest to the object in the aforementioned intermediate group moves during zooming. (Composition 10) The zoom lens according to configuration 9, characterized in that the first intermediate lens group moves toward the image side when zooming from the wide-angle end to the telephoto end. (Composition 11) The zoom lens according to any one of configurations 1 to 10, characterized in that the intermediate group as a whole has a positive refractive power. (Composition 12) The zoom lens according to any one of configurations 1 to 11, characterized in that the first lens group is composed of two or more lenses. (Composition 13) A zoom lens according to any one of configurations 1 to 12, characterized in that the image-side lens group of the final lens group remains stationary during zooming. (Composition 14) The zoom lens according to any one of configurations 1 to 13, characterized in that the second lens group moves during zooming. (Composition 15) The zoom lens according to configuration 14, characterized in that the second lens group moves toward the image side when zooming from the wide-angle end to the telephoto end. (Composition 16) A zoom lens according to any one of configurations 1 to 15, characterized in that the first lens group is composed of three lenses and the intermediate group is composed of three lenses. (Composition 17) A zoom lens according to any one of configurations 1 to 15, characterized in that the first lens group consists of five lenses and the intermediate group consists of three lenses. (Composition 18) A zoom lens according to any one of configurations 1 to 15, characterized in that the first lens group is composed of four lenses and the intermediate group is composed of two lenses. (Composition 19) The zoom lens according to any one of configurations 1 to 15, characterized in that the intermediate group consists of a first intermediate lens group having positive refractive power. (Composition 20) The zoom lens according to any one of configurations 1 to 15, characterized in that the intermediate group consists of a first intermediate lens group with positive refractive power and a second intermediate lens group with positive refractive power, arranged in order from the object side to the image side. (Composition 21) The zoom lens according to any one of configurations 1 to 20, characterized in that the final lens group consists of a third lens group with positive refractive power, a fourth lens group with positive refractive power, and a fifth lens group with positive refractive power, arranged in order from the object side to the image side. (Configuration 22) Examples 3, 4 The zoom lens according to any one of configurations 1 to 20, characterized in that the final lens group consists of a third lens group with negative refractive power, a fourth lens group with positive refractive power, and a fifth lens group with positive refractive power, arranged in order from the object side to the image side. (Configuration 23) Example 5 The zoom lens according to any one of configurations 1 to 20, characterized in that the final lens group consists of a third lens group with negative refractive power, a fourth lens group with negative refractive power, a fifth lens group with positive refractive power, a sixth lens group with negative refractive power, and a seventh lens group with positive refractive power, arranged in order from the object side to the image side. (Composition 24) A zoom lens characterized by having a first lens group that remains stationary during zooming, an intermediate group containing one or more lens groups, a second lens group with negative refractive power, and a final lens group containing three or more lens groups, arranged sequentially from the object side to the image side, wherein the spacing between adjacent lens groups changes during zooming. (Composition 25) An imaging device characterized by comprising a zoom lens described in any one of configurations 1 to 24, and an image sensor that receives the image formed by the zoom lens.

[0063] While preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to these embodiments, and various modifications and changes are possible within the scope of its essence. [Explanation of symbols]

[0064] L11 lens group (first lens group) L12 lens group (intermediate group) L2 Second lens group (second lens group) L3 Third group (final lens group) L4 4th group (final lens group) L5 5th group (final lens group)

Claims

1. A zoom lens having, arranged sequentially from the object side to the image side, a first lens group that remains stationary during zooming, an intermediate group including one or more lens groups, a second lens group with negative refractive power, and a final lens group including three or more lens groups, wherein the spacing between adjacent lens groups changes during zooming. The first lens group and the intermediate group are composed of a total of five or more lenses. The lens closest to the image in the aforementioned intermediate group is a positive lens. When the focal length of the first lens group is f11, the focal length of the intermediate group is f12, and the zoom ratio of the zoom lens is Z, -0.5<f12 / f11<0.5 Z ≥ 4.0 A zoom lens characterized by satisfying the following conditional equation.

2. When the focal length of the zoom lens at the wide-angle end is fw, and the focal length of the zoom lens at the zoom position where the intermediate group is located closest to the image, fw×Z ０．０８ <fz<fw×Z ０．５０ The zoom lens according to claim 1, characterized in that it satisfies the following condition.

3. The zoom lens according to claim 1 or 2, characterized in that the intermediate group includes a group of lenses that move toward the object when focusing from infinity to near.

4. The aforementioned intermediate group includes a first intermediate lens group that is positioned closest to the object and moves during zooming. The aforementioned second lens group moves during zooming. When the maximum amount of movement of the first intermediate lens group during zooming is M12, and the maximum amount of movement of the second lens group during zooming is M2, 1.1<M2 / M12<50.5 A zoom lens according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

5. When the focal length of the zoom lens at the wide-angle end is fw, and the zoom position where the intermediate group is located closest to the image, and the distance along the optical axis from the lens surface closest to the image of the first lens group to the lens surface closest to the object of the intermediate group at the wide-angle end are L1z and L1w, respectively, 0.1<(L1z-L1w) / fw<4.0 A zoom lens according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

6. When L1w and L1t are the distances along the optical axis from the image-side lens surface of the first lens group to the object-side lens surface of the intermediate group at the wide-angle and telephoto ends, respectively, |L1t−L1w| / L1w<0.5 A zoom lens according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

7. When the combined focal length of the first lens group and the intermediate group at the wide-angle end is f1w, and the focal length of the second lens group is f2, 0.2<|f1w / f2|<14.0 A zoom lens according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

8. The zoom lens according to claim 1 or 2, further comprising an aperture diaphragm located in the lens group closest to the image, or the lens group closest to the object.

9. The zoom lens according to claim 1 or 2, characterized in that the first intermediate lens group closest to the object in the intermediate group moves during zooming.

10. The zoom lens according to claim 9, characterized in that the first intermediate lens group moves toward the image side when zooming from the wide-angle end to the telephoto end.

11. The zoom lens according to claim 1 or 2, characterized in that the intermediate group as a whole has a positive refractive power.

12. The zoom lens according to claim 1 or 2, characterized in that the first lens group is composed of two or more lenses.

13. The zoom lens according to claim 1 or 2, characterized in that the image-side lens group of the final lens group remains stationary during zooming.

14. The zoom lens according to claim 1 or 2, characterized in that the second lens group moves when zooming.

15. The zoom lens according to claim 14, characterized in that the second lens group moves toward the image side when zooming from the wide-angle end to the telephoto end.

16. The zoom lens according to claim 1 or 2, characterized in that the first lens group is composed of three lenses and the intermediate group is composed of three lenses.

17. The zoom lens according to claim 1 or 2, characterized in that the first lens group is composed of five lenses and the intermediate group is composed of three lenses.

18. The zoom lens according to claim 1 or 2, characterized in that the first lens group is composed of four lenses and the intermediate group is composed of two lenses.

19. The zoom lens according to claim 1 or 2, characterized in that the intermediate group consists of a first intermediate lens group having a positive refractive power.

20. The zoom lens according to claim 1 or 2, characterized in that the intermediate group consists of a first intermediate lens group with positive refractive power and a second intermediate lens group with positive refractive power, arranged in order from the object side to the image side.

21. The zoom lens according to claim 1 or 2, characterized in that the final lens group consists of a third lens group with positive refractive power, a fourth lens group with positive refractive power, and a fifth lens group with positive refractive power, arranged in order from the object side to the image side.

22. The zoom lens according to claim 1 or 2, characterized in that the final lens group consists of a third lens group with negative refractive power, a fourth lens group with positive refractive power, and a fifth lens group with positive refractive power, arranged in order from the object side to the image side.

23. The zoom lens according to claim 1 or 2, characterized in that the final lens group consists of a third lens group with negative refractive power, a fourth lens group with negative refractive power, a fifth lens group with positive refractive power, a sixth lens group with negative refractive power, and a seventh lens group with positive refractive power, arranged in order from the object side to the image side.

24. A zoom lens characterized by having a first lens group that remains stationary during zooming, an intermediate group containing one or more lens groups, a second lens group with negative refractive power, and a final lens group containing three or more lens groups, arranged sequentially from the object side to the image side, wherein the spacing between adjacent lens groups changes during zooming.

25. An imaging device characterized by comprising a zoom lens according to claim 1 or 2, and an image sensor that receives light from an image formed by the zoom lens.

Images