Zoom lens and imaging device

Abstract

It provides a wide-angle, high-zoom-ratio, and compact, lightweight zoom lens. [Solution] The zoom lens is composed of a positive first lens group that is stationary for zooming, an intermediate group including three or more lens groups that move for zooming, and a positive rear lens group that is stationary for zooming. The intermediate group includes at least a first intermediate negative lens group that moves monotonically toward the image side when zooming from the wide-angle end to the telephoto end, a second intermediate negative lens group that moves when zooming, and an intermediate positive lens group that moves when zooming. The focal length f1 of the first lens group, the focal length fv of the first intermediate negative lens group, and the focal length ft of the zoom lens at the telephoto end satisfy 4.00 ≤ ft / f1 ≤ 8.00 and -9.00 ≤ f1 / fv ≤ -5.50.

Description

Technical Field

[0001] The present invention relates to a zoom lens used in an imaging device.

Background Art

[0002] A zoom lens is required to have a wide angle of view, a high zoom ratio, and be small and lightweight. The zoom lens disclosed in Patent Document 1 includes a first lens group having a positive refractive power that does not move for zooming, a second lens group having a negative refractive power that moves for zooming, and a third lens group having a negative refractive power that moves for zooming, which are arranged in order from the object side to the image side, and a rear lens group having a positive refractive power that does not move for zooming.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] There is a need for a zoom lens that has a wider angle of view, a higher zoom ratio, is smaller and lighter, and has higher optical performance than the zoom lens disclosed in Patent Document 1.

Means for Solving the Problems

[0005] A zoom lens as one aspect of the present invention comprises a first lens group having a fixed positive refractive power for zooming, arranged sequentially from the object side to the image side; an intermediate group including three or more lens groups that move for zooming; and a rear lens group having a fixed positive refractive power for zooming, wherein the spacing between adjacent lens groups changes during zooming. The intermediate group comprises a single lens group or two or more partial lens groups arranged sequentially from the object side to the image side, and a first intermediate negative lens group having a negative refractive power as a whole that moves monotonically towards the image side during zooming from the wide-angle end to the telephoto end, The lens includes at least a first intermediate negative lens group that moves monotonically toward the image side when zooming from the wide-angle end to the telephoto end and is composed of a single lens group or two or more partial lens groups and has a negative refractive power as a whole, a second intermediate negative lens group that moves during zooming and has a negative refractive power, and an intermediate positive lens group that moves during zooming and has a positive refractive power. When the focal length of the first lens group is f1, the focal length of the first intermediate negative lens group is fv, and the focal length of the zoom lens at the telephoto end is ft, 4.00 ≤ ft / f1 ≤ 8.00 -9.00 ≤ f1 / fv ≤ -5.50 The present invention is characterized by satisfying both or one of the above conditions. Furthermore, an imaging device that performs imaging through 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, lightweight, has a wide angle of view and a high zoom ratio, and possesses high optical performance. [Brief explanation of the drawing]

[0007] [Figure 1] Cross-sectional view of the zoom lens of Example 1. [Figure 2] Aberration diagram of the zoom lens in Example 1. [Figure 3] Cross-sectional view of the zoom lens in Example 2. [Figure 4] Aberration diagram of the zoom lens in Example 2. [Figure 5] Cross-sectional view of the zoom lens of Example 3. [Figure 6] Aberration diagram of the zoom lens in Example 3. [Figure 7] Cross-sectional view of the zoom lens of Example 4. [Figure 8] Aberration diagram of the zoom lens in Example 4. [Figure 9] Cross-sectional view of the zoom lens of Example 5. [Figure 10] Aberration diagram of the zoom lens in Example 5. [Figure 11] Cross-sectional view of the zoom lens of Example 6. [Figure 12] Aberration diagram of the zoom lens in Example 6. [Figure 13] A diagram showing the configuration of the imaging device. [Modes for carrying out the invention]

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0009] Before describing specific examples 1 to 6, we will explain the points common to each example using Figure 1, which shows the zoom lens of Example 1. The zoom lenses of each example are used in various imaging devices such as broadcast cameras, cinema cameras, video cameras, surveillance cameras, digital still cameras, and silver halide film cameras.

[0010] Figure 1 shows the configuration of the zoom lens of Example 1 at its wide-angle end and in focus on an object at infinity (hereinafter referred to as the infinity focus state).

[0011] In a zoom lens, a lens group is a collection of one or more lenses that move together or do not move during zooming (variation in magnification) between the wide-angle end and the telephoto end. That is, the distance between adjacent lens groups changes during zooming. The lens group may include an aperture stop. Also, the wide-angle end and the telephoto end respectively indicate the zoom states of the maximum angle of view (shortest focal length) and the minimum angle of view (longest focal length) when the lens group that moves during zooming is located at both ends of the range where it can move mechanically or controllably on the optical axis.

[0012] The zoom lens of each embodiment is composed of a first lens group L1, an intermediate group LM including three or more lens groups, and a rear lens group (relay lens group) LR as the final lens group on the most image side, which are arranged in order from the object side to the image side. The rear lens group LR includes an aperture stop SP.

[0013] The first lens group L1 does not move (is stationary) for zooming and has a positive refractive power.

[0014] The intermediate group LM has at least a first intermediate negative lens group LV having a negative refractive power, a second intermediate negative lens group LN having a negative refractive power, and an intermediate positive lens group LP having a positive refractive power, which are arranged in order from the object side to the image side. The intermediate positive lens group LP and the second intermediate negative lens group LN are arranged continuously in this order from the most object side in the intermediate group LM. In the figure, the movement trajectories of each lens group included in the intermediate group LM during zooming from the wide-angle end to the telephoto end are indicated by arrows.

[0015] The first intermediate negative lens group LV moves monotonically (i.e., without reciprocating) toward the image side during zooming from the wide-angle end to the telephoto end. Note that the first intermediate negative lens group LV may be configured as a single lens group, or may be composed of two or more partial lens groups that move independently of each other during zooming as shown in Embodiment 5 and have a negative refractive power as a whole.

[0016] The second intermediate negative lens group LN moves non-monotonic (back and forth) during zooming, tracing a convex trajectory toward the object. The intermediate positive lens group LP moves convexly toward the object during zooming from the wide-angle end to the telephoto end, and then moves non-monotonically, tracing a convex trajectory toward the image.

[0017] Note that the intermediate group LM may include other lens groups that move during zooming, other than the first intermediate negative lens group LV, the second intermediate negative lens group LN, and the intermediate positive lens group LP. In this case, "arranged in order from the object side to the image side" refers to the arrangement excluding those other lens groups.

[0018] The rear lens group LR is immobile for zooming and has positive refractive power. The aperture diaphragm SP is immobile during zooming. I is the image plane. The image plane I contains the imaging surface (light-receiving surface) of an image sensor or the film surface (photosensitive surface) of a silver halide film. A glass block such as a prism or optical filter may be placed between the rear lens group LR and the image plane I.

[0019] Furthermore, a portion of the first lens group L1 (the two lenses on the image side) moves for focusing. In the diagram, the direction of movement of the portion of the first lens group L1 when focusing from infinity to near distance is indicated by arrows labeled FOUCS. However, the entire first lens group L1 may also move during focusing.

[0020] In the zoom lens of each embodiment (each numerical example described later), the focal length of the first lens group L1 is f1, the focal length of the first intermediate negative lens group LV is fv, and the focal length of the zoom lens at the telephoto end is ft. In this case, the zoom lens is 4.00 ≤ ft / f1 ≤ 8.00 (1) -9.00 ≤ f1 / fv ≤ -5.50 (2) The conditions are met.

[0021] The conditions in equation (1) represent the conditions for obtaining a zoom lens that is advantageous in terms of wide angle of view, high zoom ratio, compact size and light weight, and high optical performance. If ft / f1 exceeds the upper limit of equation (1), the magnification of the first lens group L1 at the telephoto end becomes too large. As a result, aberrations at the telephoto end increase and optical performance deteriorates, which is undesirable. If ft / f1 falls below the lower limit of equation (1), the focal length of the first lens group L1 becomes too long, and the lateral magnification of the first intermediate negative lens group LV at the wide-angle end becomes too small. As a result, the amount of movement of the first intermediate negative lens group LV becomes too large, and the entrance pupil of the zoom lens is positioned excessively towards the image side at the wide-angle end. Therefore, the diameter of the first lens group L1 increases, and the zoom lens becomes larger, which is undesirable.

[0022] Furthermore, it is more preferable to set the lower limit of formula (1) to 4.50, 4.70, or 4.95. It is also more preferable to set the upper limit of formula (1) to 7.50, 7.30, or 7.15.

[0023] The conditions in equation (2) represent the conditions for obtaining a zoom lens that is advantageous in terms of high zoom ratio, small size and light weight, and high optical performance. If f1 / fv exceeds the upper limit of equation (2), the refractive power of the first intermediate negative lens group LV becomes too strong. As a result, the variation in aberrations during zooming increases and the optical performance deteriorates, which is undesirable. If f1 / fv falls below the lower limit of equation (2), the refractive power of the first intermediate negative lens group LV becomes too weak. As a result, the amount of movement of the first intermediate negative lens group LV during zooming becomes too large, and the entrance pupil of the zoom lens is positioned excessively towards the image side at the wide-angle end. Therefore, the diameter of the first lens group L1 becomes larger, and the zoom lens becomes larger, which is undesirable. Furthermore, if the amount of movement of the first intermediate negative lens group LV becomes large, it is not possible to secure the amount of movement of the first lens group L1 necessary to obtain a high zoom ratio, which is undesirable.

[0024] It is more preferable to set the lower limit of equation (2) to -8.50, -8.00, or -7.80. It is also more preferable to set the upper limit of equation (2) to -6.00, -6.50, or -6.80.

[0025] Furthermore, it is preferable that the zoom lens of each embodiment satisfies at least one of the following conditions of equations (3) to (11).

[0026] In each embodiment, when the zoom lens is in the state of infinity focus, the distance on the optical axis from the image-side lens surface of the first lens group L1 to the image-side principal point of the first lens group L1 is denoted as ok1, 0.60 ≤ (f1 + ok1) / f1 ≤ 0.95 (3) It is preferable that the following conditions be satisfied.

[0027] The conditions in equation (3) also indicate the conditions for obtaining a zoom lens that is advantageous in terms of wide angle of view, high zoom ratio, compact size and light weight, and high optical performance. If (f1+ok1) / f1 exceeds the upper limit of equation (3), the principal point on the image side of the first lens group L1 is positioned excessively towards the image side. As a result, the lateral magnification of the first intermediate negative lens group LV at the wide-angle end becomes small, and the amount of movement of the first intermediate negative lens group LV becomes large. Therefore, the zoom lens becomes larger, which is undesirable. Also, the focal length of the first lens group L1 becomes too short, which increases aberrations at the telephoto end, which is undesirable. If (f1+ok1) / f1 falls below the lower limit of equation (3), the principal point on the image side of the first lens group L1 is positioned excessively towards the image side. As a result, the entrance pupil at the wide-angle end is positioned excessively towards the image side. Therefore, the diameter of the first lens group L1 becomes large, which is undesirable because the zoom lens becomes larger. Furthermore, the focal length of the first lens group L1 becomes excessively long, resulting in too little lateral magnification of the first intermediate negative lens group LV at the wide-angle end. Consequently, the amount of movement of the first intermediate negative lens group LV increases, leading to a larger zoom lens, which is undesirable.

[0028] Furthermore, it is more preferable to set the lower limit of equation (3) to 0.65, 0.70, or 0.73. It is also more preferable to set the upper limit of equation (3) to 0.93, 0.90, or 0.89.

[0029] In each embodiment, when the horizontal magnification of the first intermediate negative lens group LV at the wide-angle end is βvw, -0.35≦βvw≦-0.15 (4) It is preferable to satisfy the following conditions. The conditions in equation (4) also indicate conditions for obtaining a zoom lens that is advantageous in terms of wide angle of view, high zoom ratio, small size and light weight, and high optical performance. If βvw exceeds the upper limit of equation (4), the divergence of the light beam from the first intermediate negative lens group LV becomes too strong, which is undesirable because it increases the variation of various aberrations during zooming. If βvw falls below the lower limit of equation (4), the lateral magnification of the first intermediate negative lens group LV becomes too small, which increases the amount of movement of the first intermediate negative lens group LV, and is undesirable because it makes the zoom lens larger.

[0030] Furthermore, it is more preferable to set the lower limit of equation (4) to -0.33, -0.30, or -0.27. It is even more preferable to set the upper limit of equation (4) to -0.17, -0.19, or -0.20.

[0031] In each embodiment, when the lateral magnification of the first intermediate negative lens group LV at the telephoto end is βvw, -1000.00 ≤ βvt ≤ -2.00 (5) It is preferable to satisfy the following conditions. The conditions in equation (5) also indicate conditions for obtaining a zoom lens that is advantageous in terms of wide angle of view, high zoom ratio, small size and light weight, and high optical performance. If βvt exceeds the upper limit of equation (5), the magnification at the telephoto end becomes too small, and the zoom ratio becomes small, which is undesirable. Also, in order to increase the zoom ratio, the magnification at the telephoto end of the second intermediate negative lens group LN and the intermediate positive lens LP becomes too large, which is undesirable as it makes the zoom lens larger. If βvt falls below the lower limit of equation (5), the image point change of the first intermediate negative lens group LV at the telephoto end becomes too large, and the amount of movement of the second intermediate negative lens group LN and the intermediate positive lens group LP for image point correction becomes large, which is undesirable as it makes the zoom lens group larger.

[0032] Furthermore, it is more preferable to set the lower limit of equation (5) to -985.00, -100.00, or -20.00. It is even more preferable to set the upper limit of equation (5) to -3.00, -4.00, or -4.40.

[0033] In the zoom lens of each embodiment, mv is defined as the amount of change (movement) between the position of a single lens group in the first intermediate negative lens group LV at the wide-angle end and the position at the telephoto end, or the amount of change of the partial lens group with the largest change between the position at the wide-angle end and the position at the telephoto end among two or more partial lens groups. Note that the change in the position of a lens group is considered positive when that lens group is positioned closer to the image at the telephoto end compared to the wide-angle end. At this time, 6.00 ≤ ft / |mv| ≤ 15.00 (6) It is preferable to satisfy the following conditions. The conditions in equation (6) show an appropriate relationship between the amount of change in the position of the first intermediate negative lens group LV during zooming and the focal length of the zoom lens at the telephoto end. By satisfying the conditions in equation (6), the effect is obtained that the amount of movement of the first intermediate negative lens group LV does not become too large during zooming, or that the fluctuations of various aberrations do not become too large.

[0034] Furthermore, it is more preferable to set the lower limit of formula (6) to 6.50, 7.00, or 7.20. It is even more preferable to set the upper limit of formula (6) to 14.00, 13.00, or 12.60.

[0035] In each embodiment, when the focal length of the intermediate positive lens group LP is fp, 1.50 ≤ f1 / fp ≤ 5.00 (7) It is preferable to satisfy the following conditions. The conditions in equation (7) indicate an appropriate relationship between the focal lengths of the first lens group L1 and the intermediate positive lens group LP. By satisfying the conditions in equation (7), the effect is obtained that the amount of movement of the intermediate positive lens group LP during zooming does not become too large, or that the fluctuations of various aberrations do not become too large.

[0036] Furthermore, it is more preferable to set the lower limit of equation (7) to 2.00, 2.30, or 2.50. It is even more preferable to set the upper limit of equation (7) to 4.50, 4.00, or 3.50. In each embodiment, when the focal length of the second intermediate negative lens group LN is fn, -4.00 ≤ f1 / fn ≤ -1.00 (8) It is preferable to satisfy the following conditions. The conditions in equation (8) indicate an appropriate relationship between the focal lengths of the first lens group L1 and the second intermediate negative lens group LN. By satisfying the conditions in equation (8), the effect is obtained that the amount of movement of the second intermediate negative lens group LN during zooming does not become too large, or that the fluctuations of various aberrations do not become too large.

[0037] Furthermore, it is more preferable to set the lower limit of equation (8) to -3.50, -3.20, or -3.00. It is even more preferable to set the upper limit of equation (8) to -1.10, -1.15, or -1.20.

[0038] In the zoom lens of each embodiment, the average value of the partial dispersion ratios with respect to the g-line and F-line of all positive lenses included in the first lens group L1 is θgF1P, and the average value of the partial dispersion ratios with respect to the g-line and F-line of all negative lenses included in the first lens group L1 is θgF1N. At this time, 0.000≦θgF1N-θgF1P≦0.030 (9) It is preferable to satisfy the following conditions.

[0039] The partial dispersion ratio θgF for the g-line and F-line is defined by θgF = (Ng-NF) / (NF-NC), where the refractive indices for the F-line (wavelength 486.1 nm), C-line (wavelength 656.3 nm), and g-line (wavelength 435.8 nm) are NF, Nd, and Ng, respectively.

[0040] The conditions in equation (9) indicate the appropriate achromatic conditions for the first lens group L1. Satisfying the conditions in equation (9) results in the effect of preventing axial chromatic aberration from becoming too large at the telephoto end, or preventing the first lens group L1 from becoming too large.

[0041] Furthermore, it is more preferable to set the lower limit of equation (9) to 0.004, 0.008, or 0.010. It is even more preferable to set the upper limit of equation (9) to 0.020, 0.018, or 0.015.

[0042] In the zoom lens of each embodiment, the average value of the partial dispersion ratios with respect to the g-line and F-line of all positive lenses included in the first intermediate negative lens group LV is θgFvP, and the average value of the partial dispersion ratios with respect to the g-line and F-line of all negative lenses included in the first intermediate negative lens group LV is θgFvN. At this time, -0.060≦θgFvN-θgFvP≦-0.020 (10) It is preferable to satisfy the following conditions. The conditions in equation (10) indicate appropriate achromatic conditions for the first intermediate negative lens group LV. By satisfying the conditions in equation (10), the effect is obtained that axial chromatic aberration at the telephoto end does not become too large, or that the fluctuation of lateral chromatic aberration during zooming does not become too large.

[0043] Furthermore, it is more preferable to set the lower limit of equation (10) to -0.055, -0.050, or -0.048. It is also more preferable to set the upper limit of equation (10) to -0.025, -0.030, or -0.035.

[0044] In each embodiment, when νd1P is the average value of the Abbe numbers on the d line of all positive lenses included in the first lens group L1, 80.00 ≤ νd1P ≤ 96.00 (11) It is preferable that the following conditions be satisfied.

[0045] The Abbe number νd, with respect to the d-line, is defined as νd = (Nd-1) / (NF-NC), where the refractive indices of the F-line (wavelength 486.1 nm), d-line (wavelength 587.6 nm), and C-line (wavelength 656.3 nm) are NF, Nd, and NC, respectively.

[0046] The conditions in equation (11) indicate the appropriate achromatic conditions for the first lens group L1. Satisfying the conditions in equation (11) results in the effect that axial chromatic aberration at the telephoto end does not become excessively large, or that all aberrations at the telephoto end do not become excessively large.

[0047] Furthermore, it is more preferable to set the lower limit of formula (11) to 83.00, 86.00, or 88.00. It is also more preferable to set the upper limit of formula (11) to 94.00, 93.00, or 92.00.

[0048] In the zoom lenses of each embodiment, it is preferable that the intermediate positive lens group LP moves in a convex trajectory toward the object side and then moves in a convex trajectory toward the image side when zooming from the wide-angle end to the telephoto end. By moving the intermediate positive lens group LP in a convex trajectory from the wide-angle end, the entrance pupil on the wide-angle side is positioned toward the object side, which is advantageous in terms of widening the angle and miniaturization. Furthermore, by having the intermediate positive lens group LP subsequently move in a convex trajectory toward the image side, it is possible to increase the zoom ratio obtained by the movement of the first intermediate negative lens group LV while preventing interference between the first intermediate negative lens group LN and the second intermediate negative lens group LP.

[0049] The zoom lenses of Examples 1 to 6 will be described in detail below. Furthermore, numerical examples 1 to 6 corresponding to each of Examples 1 to 6 will be shown after Example 6.

[0050] In each numerical example, the surface number i indicates the order of the optical surfaces counted from the object side. In the surface data, r is the radius of curvature of the i-th surface (mm), d is the lens thickness or air gap between the i-th and (i+1)th surfaces (mm), and nd is the absolute refractive index at 1 atmosphere at the d-line of the optical material between the i-th and (i+1)th surfaces. νd is the Abbe number with respect to the d-line of the optical material between the i-th and (i+1)th surfaces, and is defined as described above. θgF is the partial dispersion ratio with respect to the g-line and F-line of the optical material between the i-th and (i+1)th surfaces, and is defined as described above.

[0051] The half-angle of view ω(°) is calculated by setting the diagonal size of the image sensor of the imaging device using the zoom lens to 2Y, and the focal length of the zoom lens at the wide-angle end to fw. ω = arctan(Y / fw) The value is expressed by the following formula. Image height (mm) indicates the maximum image height corresponding to half Y (e.g., 5.50 mm) of the diagonal size 2Y (e.g., 11.00 mm). BF is back focus (mm), which is the distance along the optical axis from the image-side lens surface (final surface) of the zoom lens to the paraxial image plane, expressed in terms of air equivalent length. Lens length (mm) is the length obtained by adding the back focus to the distance along the optical axis from the object-side lens surface (frontmost surface) to the final surface of the zoom lens.

[0052] 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 direction of the optical axis, H is the height from the optical axis in the direction perpendicular to the optical axis, the direction of light propagation is positive, R is the radius of paraxial curvature, K is the cone constant, and A3 to A16 are the aspherical coefficients. The cone constant and aspherical coefficients "e±Z" are "×10 ±Z It means "...".

[0053]

number

[0054] The values ​​of equations (1) to (11) in numerical examples 1 to 6 are summarized in Table 1. The values ​​of the variables included in equations (1) to (11) in numerical examples 1 to 6 are summarized in Table 2. The zoom lenses in numerical examples 1 to 6 satisfy all the conditions of equations (1) to (11). [Examples]

[0055] In the zoom lens of Embodiment 1 (Numerical Example 1) shown in Figure 1, the first lens group L1 has surfaces 1 through 12 and is composed of two negative lenses and four positive lenses. The intermediate group LM has surfaces 13 through 27. The first intermediate negative lens group LV, having surfaces 13 through 19, is composed of one negative lens whose object-side surface is aspherical, two negative lenses, and one positive lens.

[0056] The second intermediate negative lens group LN, having surfaces 20 to 22, is composed of one negative lens and one positive lens. The intermediate positive lens group LP, having surfaces 23 to 27, is composed of one positive lens with an aspherical surface on the object side, one negative lens, and one positive lens. The rear lens group LR has surfaces 28 to 47 and is composed of five negative lenses and seven positive lenses. The aperture diaphragm SP is surface 33.

[0057] Figure 2 shows the longitudinal aberrations (spherical aberration, astigmatism, distortion, and chromatic aberration) of the zoom lens of Numerical Example 1 at infinity focus in (a) wide-angle end, (b) intermediate zoom position, and (c) telephoto end. The spherical aberration diagram shows the spherical aberration at the d line (wavelength 587.6 nm), g line (wavelength 435.8 nm), C line (wavelength 656.3 nm), and F line (wavelength 486.1 nm), respectively, indicated by solid, dashed, single-dot, and dashed lines. The astigmatism diagram shows the astigmatism at the meridional image plane M and sagittal image plane S, respectively, indicated by dashed and solid lines. The distortion diagram shows the distortion at the d line. The chromatic aberration diagram shows the lateral chromatic aberration at the d line, g line, C line, and F line, respectively, indicated by solid, dashed, single-dot, and dashed lines. Fno represents the F number, and ω represents the half-angle (°).

[0058] The full scale of the horizontal axis in the spherical aberration diagram is ±0.400 mm, and the full scale of the horizontal axis in the astigmatism diagram is also ±0.400 mm. The full scale of the horizontal axis in the distortion diagram is ±5.000%. The full scale of the horizontal axis in the chromatic aberration diagram is ±0.100 mm. The above explanations for the aberration diagrams are the same for the other numerical examples described later. [Examples]

[0059] Figure 3 shows the configuration of the zoom lens in Example 2 (Numerical Example 2) at the wide-angle end and in the infinity focus state. In this embodiment, the first lens group L1 has surfaces 1 to 12 and is composed of two negative lenses and four positive lenses. The intermediate group LM has surfaces 13 to 28. The first intermediate negative lens group LV, having surfaces 12 to 19, is composed of one negative lens whose object-side surface is aspherical, two negative lenses, and one positive lens.

[0060] The second intermediate negative lens group LN, having surfaces 20 to 23, is composed of one negative lens and one positive lens. The intermediate positive lens group LP, having surfaces 24 to 28, is composed of one positive lens with an aspherical surface on the object side, one negative lens, and one positive lens. The rear lens group LR has surfaces 29 to 46 and is composed of five negative lenses and six positive lenses. The aperture diaphragm SP is surface 33.

[0061] Figure 4 shows the longitudinal aberrations of the zoom lens of numerical example 2 at (a) the wide-angle end, (b) the intermediate zoom position, and (c) the telephoto end when the lens is in focus at infinity. [Examples]

[0062] Figure 5 shows the configuration of the zoom lens in Example 3 (Numerical Example 3) at the wide-angle end and infinity focus state. In this embodiment, the first lens group L1 has surfaces 1 to 12 and is composed of two negative lenses and four positive lenses. The intermediate group LM has surfaces 13 to 24. The first intermediate negative lens group LV, having surfaces 13 to 19, is composed of one negative lens whose object-side surface is aspherical, two negative lenses, and one positive lens.

[0063] The second intermediate negative lens group LN, having surfaces 20 to 22, is composed of one negative lens and one positive lens. The intermediate positive lens group LP, having surfaces 23 to 24, is composed of one positive lens with aspherical surfaces on both the object-side and image-side. The rear lens group LR has surfaces 25 to 44 and is composed of five negative lenses and seven positive lenses. The aperture diaphragm SP is surface 30.

[0064] Figure 6 shows the longitudinal aberrations of the zoom lens of numerical example 3 at (a) the wide-angle end, (b) the intermediate zoom position, and (c) the telephoto end when the lens is in focus at infinity. [Examples]

[0065] Figure 7 shows the configuration of the zoom lens in Example 4 (Numerical Example 4) at the wide-angle end and infinity focus state. In this embodiment, the first lens group L1 has surfaces 1 to 12 and is composed of two negative lenses and four positive lenses. The intermediate group LM has surfaces 13 to 29. The first intermediate negative lens group LV, having surfaces 13 to 19, is composed of one negative lens whose object-side surface is aspherical, two negative lenses, and one positive lens.

[0066] The second intermediate negative lens group LN, having surfaces 20 to 24, is composed of two negative lenses and one positive lens. The intermediate positive lens group LP, having surfaces 25 to 29, is composed of one positive lens with an aspherical surface facing the object, one negative lens, and one positive lens. The rear lens group LR has surfaces 30 to 49 and is composed of five negative lenses and seven positive lenses. The aperture diaphragm SP is surface 35.

[0067] Figure 8 shows the longitudinal aberrations of the zoom lens of numerical example 4 at (a) the wide-angle end, (b) the intermediate zoom position, and (c) the telephoto end when the lens is in focus at infinity. [Examples]

[0068] Figure 9 shows the configuration of the zoom lens in Example 5 (Numerical Example 5) at its wide-angle end and infinity focus state. In this example, the first lens group L1 has surfaces 1 through 12 and is composed of two negative lenses and four positive lenses. The intermediate group LM has surfaces 13 through 29.

[0069] The first intermediate negative lens group LV is composed of a first partial lens group LV1 and a second partial lens group LV2, starting from the object side. The first and second partial lens groups LV1 and LV2 move monotonically toward the image side, with the distance between them changing minutely (smaller than the change in distance between other lens groups) during zooming from the wide-angle end to the telephoto end. The first partial lens group LV1, having surfaces 13 and 17, is composed of one negative lens, one negative lens, and one positive lens, both of which have aspherical surfaces on the object side. The second partial lens group LV2, having surfaces 18 and 19, is composed of one negative lens, both of which have aspherical surfaces on the image side. Note that the first intermediate negative lens group LV may be composed of three or more partial lens groups.

[0070] Alternatively, the first partial lens group LV1 and the second partial lens group LV2 may be treated as independent, single lens groups. For example, they may be treated as a negative lens group corresponding to the first partial lens group LV1 and a negative lens group corresponding to the second partial lens group LV2.

[0071] The second intermediate negative lens group LN has surfaces 20 to 24 and is composed of two negative lenses and one positive lens. The intermediate positive lens group LP has surfaces 25 to 29 and is composed of one positive lens with an aspherical surface on the object side, one negative lens, and one positive lens. The rear lens group LR has surfaces 30 to 49 and is composed of five negative lenses and seven positive lenses. The aperture diaphragm SP is surface 35.

[0072] Figure 10 shows the longitudinal aberrations of the zoom lens of numerical example 5 at (a) the wide-angle end, (b) the intermediate zoom position, and (c) the telephoto end when the lens is in focus at infinity. [Examples]

[0073] Figure 11 shows the configuration of the zoom lens in Example 6 (Numerical Example 6) at its wide-angle end and infinity focus state. In this embodiment, the first lens group L1 has surfaces 1 to 12 and is composed of two negative lenses and four positive lenses. The intermediate group LM has surfaces 13 to 27. The first intermediate negative lens group LV, having surfaces 13 to 19, is composed of one negative lens with an aspherical surface on the object side, two negative lenses, and one positive lens. The second intermediate negative lens group LN, having surfaces 20 to 22, is composed of one negative lens and one positive lens. The positive lens group LP, having surfaces 23 to 27, is composed of one positive lens with an aspherical surface on the object side, one negative lens, and one positive lens. The rear lens group LR has surfaces 28 to 49 and is composed of five negative lenses and eight positive lenses. The aperture diaphragm SP is surface 33.

[0074] Figure 12 shows the longitudinal aberrations of the zoom lens of numerical example 6 at (a) the wide-angle end, (b) the intermediate zoom position, and (c) the telephoto end when the lens is in focus at infinity.

[0075] In the zoom lenses of Examples 1 to 6, the rear lens group LR was not moved for zooming, but a partial lens group, which is a part of the rear lens group, may be made to move, and the above-described effects can be obtained in that case as well. For example, in Example 1, the partial lens group from the 37th to the 47th surface of the rear lens group LR may be made to move. Since an afocal light beam is incident on the 37th surface from the object side, even if this partial lens group moves, the optical characteristics other than back focus will remain largely unchanged. Furthermore, by moving this partial lens group, it is possible to correct the focus change due to changes in the state of the zoom lens, such as zooming, focusing, aperture diaphragm operation, temperature, atmospheric pressure, attitude, and insertion / removal of the zoom-adjusting optical system (extender). [Numerical Example 1] Unit: mm Surface data Face number rd nd νd θgF 1 161.551 16.13 1.49700 81.5 0.5375 2 -948.095 0.20 3 171.346 4.00 1.77250 49.6 0.5520 4 100.435 3.60 5 104.049 16.19 1.43387 95.1 0.5373 6 1685.391 8.56 7 -251.961 3.20 1.72916 54.7 0.5444 8 388.842 15.63 9 321.287 12.18 1.43387 95.1 0.5373 10 -232.884 0.15 11 145.177 9.40 1.43387 95.1 0.5373 12 968.682 (variable) 13* -295.187 1.20 1.59522 67.7 0.5442 14 33.348 6.82 15 -65.974 1.00 1.59522 67.7 0.5442 16 27.520 8.50 1.72047 34.7 0.5834 17 -47.897 2.47 18 -30.076 1.20 1.77250 49.6 0.5520 19 984.542 (variable) 20 -69.448 1.00 1.77250 49.6 0.5520 21 129.752 3.26 1.92119 24.0 0.6203 22 -2436.113 (variable) 23* 294.629 7.12 1.43875 94.7 0.5340 24 -63.833 0.20 25 50.902 1.20 2.05090 26.9 0.6054 26 40.772 7.63 1.59522 67.7 0.5442 27 138.945 (variable) 28 105.524 5.94 1.51860 69.9 0.5318 29 -126.376 0.20 30 59.773 5.68 1.43875 94.7 0.5340 31 -1164.171 1.20 2.00100 29.1 0.5997 32 147.018 4.04 33 (aperture) ∞ 31.31 34 -515.221 4.22 1.80810 22.8 0.6307 35 -22.458 0.80 1.95375 32.3 0.5905 36 99.786 37.60 37 47.943 6.76 1.51860 69.9 0.5318 38 -35.664 0.17 39 -108.641 4.05 1.60342 38.0 0.5835 40 -29.497 1.00 1.88300 40.8 0.5667 41 27.303 1.80 42 29.813 11.40 1.76182 26.5 0.6136 43 -19.084 1.00 2.00100 29.1 0.5997 44 83.726 0.64 45 52.520 9.09 1.64769 33.8 0.5938 46 -26.930 1.10 1.98612 16.5 0.6657 47 -38.388 49.90 Image plane ∞ Aspherical data Page 13 K =-1.18082e+00 A 4= 4.07830e-06 A 6= 7.17765e-10 A 8=-5.40864e-12 A10= 5.06878e-14 A12=-1.25398e-16 A14= 1.04671e-19 A16= 6.53328e-23 Page 23 K = 0.00000e+00 A 4=-1.12738e-06 A 6= 2.39065e-11 A 8=-1.48685e-13 Various data Zoom ratio 30.00 Wide-angle, Medium, Telephoto Focal length 40.00 220.00 1200.00 F-number 4.60 4.60 10.00 Half-angle (°): 20.30 3.85 0.71 Image height 14.80 14.80 14.80 Lens length 455.16 455.16 455.16 BF 49.90 49.90 49.90 d12 1.68 89.54 121.68 d19 116.23 8.11 7.06 d22 13.29 37.96 1.96 d27 15.22 10.81 15.72 Lens group data Group starting plane focal length 1 1 195.06 2 13 -25.06 3 20 -104.35 4 23 71.04 5 28 253.10 [Numerical Example 2] Unit: mm Surface data Face number rd nd νd θgF 1 138.810 17.65 1.48749 70.2 0.5300 2 -1097.218 0.20 3 144.845 4.00 1.77250 49.6 0.5520 4 80.525 3.30 5 81.788 23.99 1.43387 95.1 0.5373 6 -415.122 5.30 7 -202.823 3.20 1.72916 54.7 0.5444 8 257.764 11.77 9 193.666 14.93 1.43387 95.1 0.5373 10 -187.833 0.15 11 105.178 8.08 1.43875 94.9 0.5340 12 214.366 (variable) 13* -175.753 1.20 1.69930 51.1 0.5552 14 34.554 7.09 15 -285.388 1.00 1.53775 74.7 0.5392 16 23.984 7.45 1.73800 32.3 0.5900 17 -104.372 4.30 18 -33.528 1.20 1.72916 54.7 0.5444 19 113.996 (variable) 20 60.546 3.22 1.84666 23.8 0.6205 21 90.761 3.98 22 -90.201 1.20 1.72916 54.7 0.5444 23 143.298 (variable) 24* 115.215 8.11 1.43875 94.7 0.5340 25 -50.693 0.20 26 43.991 1.20 2.00069 25.5 0.6136 27 33.683 8.22 1.59522 67.7 0.5442 28 214.033 (variable) 29 40.173 6.46 1.43875 94.7 0.5340 30 -509.769 0.20 31 59.218 1.20 2.00100 29.1 0.5997 32 40.334 5.94 33 (aperture) ∞ 19.98 34 56.580 4.67 1.80810 22.8 0.6307 35 -28.993 0.80 1.95375 32.3 0.5905 36 35.473 37.60 37 129.653 4.75 1.57501 41.5 0.5767 38 -37.617 0.25 39 -84.905 4.14 1.56732 42.8 0.5731 40 -26.352 1.00 1.88300 40.8 0.5667 41 53.228 1.08 42 43.345 8.99 1.63980 34.5 0.5922 43 -23.250 1.00 2.00100 29.1 0.5997 44 -353.793 0.19 45 89.816 5.61 1.59551 39.2 0.5803 46 -47.048 43.98 Image plane ∞ Aspherical data Page 13 K =-1.71296e+00 A 4= 3.65648e-06 A 6=-7.05147e-10 A 8=-3.84223e-13 A10= 3.30964e-14 A12=-1.90987e-16 A14= 5.13656e-19 A16=-5.30788e-22 Page 24 K = 0.00000e+00 A 4=-2.67796e-06 A 6= 5.34861e-10 A 8=-1.47716e-13 Various data Zoom ratio 20.00 Wide-angle, Medium, Telephoto Focal length 50.00 220.00 1000.00 F-number 4.60 4.60 8.55 Half-angle (°): 16.49 3.85 0.85 Image height 14.80 14.80 14.80 Lens length 400.53 400.53 400.53 BF 43.98 43.98 43.98 d12 7.67 65.79 87.67 d19 95.70 13.96 2.07 d23 6.40 26.00 1.97 d28 1.98 6.00 20.03 Lens group data Group starting plane focal length 1 1 166.07 2 13 -22.61 3 20 -129.50 4 24 48.42 5 29 6430.16 [Numerical Example 3] Unit: mm Surface data Face number rd nd νd θgF 1 160.363 16.21 1.49700 81.5 0.5375 2 -789.513 0.20 3 165.662 4.00 1.77250 49.6 0.5520 4 99.928 3.57 5 103.373 15.00 1.43387 95.1 0.5373 6 762.000 11.55 7 -242.547 3.20 1.72916 54.7 0.5444 8 366.855 16.41 9 361.413 11.80 1.43387 95.1 0.5373 10 -220.022 0.15 11 146.506 9.67 1.43875 94.9 0.5340 12 1341.013 (variable) 13* -145.353 1.20 1.53775 74.7 0.5392 14 31.534 6.22 15 -70.009 1.00 1.52841 76.5 0.5396 16 30.782 7.03 1.76634 35.8 0.5792 17 -62.868 1.87 18 -39.946 1.20 1.77250 49.6 0.5520 19 117.269 (variable) 20 -68.392 1.00 1.72916 54.7 0.5444 21 142.635 3.11 1.92119 24.0 0.6203 22 2987.046 (Variable) 23* 51.791 10.29 1.43875 94.7 0.5340 24* -92.944 (variable) 25 101.269 8.58 1.48749 70.2 0.5300 26 -69.900 0.20 27 115.977 7.92 1.43875 94.7 0.5340 28 -57.389 1.20 2.00100 29.1 0.5997 29 -221.465 7.59 30 (aperture) ∞ 30.96 31 129.704 4.34 1.80810 22.8 0.6307 32 -28.640 0.80 1.95375 32.3 0.5905 33 48.513 37.60 34 52.241 7.75 1.51633 64.1 0.5353 35 -37.812 0.16 36 -111.053 4.75 1.60342 38.0 0.5835 37 -27.496 1.00 1.88300 40.8 0.5667 38 32.716 1.56 39 33.408 10.71 1.85478 24.8 0.6122 40 -21.733 1.00 2.00100 29.1 0.5997 41 48.205 1.21 42 43.954 10.39 1.60342 38.0 0.5835 43 -24.443 1.10 1.95906 17.5 0.6598 44 -35.431 47.09 Image plane ∞ Aspherical data Page 13 K = 1.98235e+00 A 4= 3.46474e-06 A 6=-1.08846e-09 A 8= 1.60965e-12 A10=-2.29039e-15 A12= 2.12071e-17 A14=-5.50356e-20 A16= 4.35851e-23 Page 23 K = 0.00000e+00 A 4=-1.79332e-06 A 6= 5.48389e-10 A 8=-2.57959e-13 Page 24 K = 0.00000e+00 A 4= 1.09898e-06 A 6= 4.54644e-10 A 8= 6.59687e-14 Various data Zoom ratio 25.00 Wide-angle, Medium, Telephoto Focal length 45.00 220.00 1125.00 F-number 4.60 4.60 9.62 Half-angle (°): 18.21 3.85 0.75 Image height 14.80 14.80 14.80 Lens length 455.25 455.25 455.25 BF 47.09 47.09 47.09 d12 2.55 87.18 122.51 d19 113.58 10.47 8.82 d22 10.88 33.98 1.95 d24 17.67 13.04 11.38 Lens group data Group starting plane focal length 1 1 200.16 2 13 -26.47 3 20 -103.93 4 23 77.48 5 25 201.58 [Numerical Example 4] Unit: mm Surface data Face number rd nd νd θgF 1 165.030 15.30 1.48749 70.2 0.5300 2 -1313.308 0.20 3 218.690 4.00 1.77250 49.6 0.5520 4 107.799 3.66 5 112.723 18.98 1.43387 95.1 0.5373 6 -503.677 5.43 7 -228.473 3.20 1.72916 54.7 0.5444 8 486.081 16.29 9 269.883 13.71 1.43387 95.1 0.5373 10 -225.795 0.15 11 128.440 8.20 1.43387 95.1 0.5373 12 303.829 (variable) 13* 300.010 1.20 1.69680 55.5 0.5434 14 37.805 7.60 15 -75.928 1.00 1.53775 74.7 0.5392 16 32.390 8.36 1.78880 28.4 0.6009 17 -75.065 3.70 18 -38.040 1.20 1.89190 37.1 0.5780 19 205.380 (Variable) 20 -208.092 1.00 1.81600 46.6 0.5568 21 65.632 4.20 1.78880 28.4 0.6009 22 -392.329 2.59 23 -65.175 1.20 1.76385 48.5 0.5589 24 -242.068 (variable) 25* 309.873 7.72 1.43875 94.7 0.5340 26 -58.171 0.20 27 51.920 1.20 2.00069 25.5 0.6136 28 42.906 6.74 1.59522 67.7 0.5442 29 100.977 (variable) 30 79.282 7.09 1.43875 94.7 0.5340 31 -120.764 0.20 32 53.635 6.03 1.43875 94.7 0.5340 33 -3034.900 1.20 2.00100 29.1 0.5997 34 149.884 4.02 35 (aperture) ∞ 26.05 36 123.165 4.87 1.80810 22.8 0.6307 37 -26.296 0.80 1.95375 32.3 0.5905 38 45.378 37.60 39 50.473 7.57 1.48749 70.2 0.5300 40 -33.478 0.19 41 -60.696 3.55 1.62588 35.7 0.5893 42 -29.626 1.00 1.71700 47.9 0.5605 43 26.472 1.61 44 27.624 10.60 1.69895 30.1 0.6030 45 -19.972 1.00 2.00100 29.1 0.5997 46 58.122 1.06 47 47.761 8.00 1.64769 33.8 0.5938 48 -32.145 1.10 1.95906 17.5 0.6598 49 -40.304 51.10 Image plane ∞ Aspherical data Page 13 K =-1.99830e+00 A 4= 1.72502e-06 A 6= 9.97353e-10 A 8=-3.37565e-12 A10= 2.99247e-14 A12=-9.88585e-17 A14= 1.67968e-19 A16=-1.09038e-22 Page 25 K = 0.00000e+00 A 4=-1.22645e-06 A 6= 7.17200e-11 A 8=-1.39369e-13 Various data Zoom ratio 30.00 Wide-angle, Medium, Telephoto Focal length 40.00 220.00 1200.00 F-number 4.60 4.60 10.26 Half-angle (°): 20.30 3.85 0.71 Image height 14.80 14.80 14.80 Lens length 460.35 460.35 460.35 BF 51.10 51.10 51.10 d12 1.00 92.09 126.00 d19 111.05 6.75 3.10 d24 18.38 37.72 1.94 d29 18.26 12.13 17.64 Lens group data Group starting plane focal length 1 1 199.61 2 13 -27.46 3 20 -90.98 4 25 73.97 5 30 242.73 [Numerical Example 5] Unit: mm Surface data Face number rd nd νd θgF 1 180.137 15.28 1.49700 81.5 0.5375 2 -789.237 0.20 3 198.814 4.00 1.77250 49.6 0.5520 4 112.942 3.46 5 116.871 14.26 1.43387 95.1 0.5373 6 1241.126 8.75 7 -251.002 3.20 1.72916 54.7 0.5444 8 506.225 18.11 9 385.502 11.64 1.43387 95.1 0.5373 10 -241.896 0.15 11 150.904 9.72 1.43875 94.9 0.5340 12 1094.599 (variable) 13* -484.077 1.20 1.43875 94.7 0.5340 14 34.038 7.44 15 -170.791 1.00 1.72916 54.7 0.5444 16 24.472 10.03 1.76634 35.8 0.5792 17 -94.125 (variable) 18 -32.819 1.20 1.72916 54.7 0.5444 19* 2578.580 (variable) 20 -113.177 1.00 1.77250 49.6 0.5520 21 55.549 4.74 1.78880 28.4 0.6009 22 -176.378 2.12 23 -64.063 1.20 1.88300 40.8 0.5667 24 -379.478 (variable) 25* 494.977 8.41 1.43875 94.7 0.5340 26 -57.733 0.20 27 59.015 1.20 2.00069 25.5 0.6136 28 48.014 7.41 1.59522 67.7 0.5442 29 126.247 (variable) 30 84.799 8.13 1.49700 81.5 0.5375 31 -127.181 0.20 32 54.553 7.37 1.43875 94.7 0.5340 33 -504.241 1.20 2.00100 29.1 0.5997 34 189.224 3.96 35 (aperture) ∞ 29.33 36 242.230 4.79 1.80810 22.8 0.6307 37 -24.515 0.80 1.95375 32.3 0.5905 38 48.987 37.60 39 58.665 7.22 1.48749 70.2 0.5300 40 -28.824 0.14 41 -83.714 4.52 1.62588 35.7 0.5893 42 -22.600 1.00 1.88300 40.8 0.5667 43 28.400 1.59 44 29.985 10.75 1.78472 25.7 0.6161 45 -16.678 1.00 2.00100 29.1 0.5997 46 62.135 0.73 47 44.975 10.62 1.63980 34.5 0.5922 48 -22.382 1.10 1.95906 17.5 0.6598 49 -31.899 47.86 Image plane ∞ Aspherical data Page 13 K = 2.03811e+00 A 4= 4.46960e-06 A 6=-3.73984e-09 A 8= 3.24444e-11 A10=-1.53241e-13 A12= 4.01107e-16 A14=-5.27746e-19 A16= 2.79747e-22 Page 19 K = 0.00000e+00 A 4= 1.70977e-07 A 6=-9.87190e-09 A 8= 2.03848e-10 A10=-2.27112e-12 A12= 1.35250e-14 A14=-4.07636e-17 A16= 4.89496e-20 Page 25 K = 0.00000e+00 A 4=-1.01951e-06 A 6= 6.03432e-11 A 8=-1.16440e-13 Various data Zoom ratio 37.50 Wide-angle, Medium, Telephoto Focal length 40.00 245.00 1500.00 F-number 4.67 4.67 12.95 Half-angle (°): 20.30 3.46 0.57 Image height 14.80 14.80 14.80 Lens length 480.70 480.70 480.70 BF 47.86 47.86 47.86 d12 1.25 101.72 137.29 d17 5.36 4.09 3.90 d19 109.64 6.63 2.96 d24 25.06 39.17 1.86 d29 23.55 13.24 18.84 Lens group data Group starting plane focal length 1 1 210.69 2 13 -143.37 3 18 -44.44 4 20 -73.06 5 25 78.18 6 30 241.93 [Numerical Example 6] Unit: mm Surface data Face number rd nd νd θgF 1 223.553 10.47 1.49700 81.5 0.5375 2 4872.086 0.20 3 222.915 4.00 1.77250 49.6 0.5520 4 122.849 3.56 5 128.542 16.84 1.43387 95.1 0.5373 6 -675.158 4.69 7 -305.451 3.20 1.72916 54.7 0.5444 8 707.100 18.23 9 219.674 13.02 1.43387 95.1 0.5373 10 -361.396 0.15 11 203.109 7.80 1.43387 95.1 0.5373 12 1310.329 (variable) 13* -166.991 1.20 1.59522 67.7 0.5442 14 39.134 7.57 15 -74.564 1.00 1.61800 63.3 0.5441 16 39.845 8.95 1.72047 34.7 0.5834 17 -49.455 2.28 18 -35.140 1.20 1.69680 55.5 0.5434 19 10411.645 (variable) 20 -72.656 1.00 1.74100 52.6 0.5467 21 116.868 2.91 1.92119 24.0 0.6203 22 1161.315 (variable) 23* 207.814 6.86 1.43875 94.7 0.5340 24 -62.876 0.20 25 43.874 1.20 2.05090 26.9 0.6054 26 34.099 6.29 1.59522 67.7 0.5442 27 69.479 (Variable) 28 57.769 4.44 1.51860 69.9 0.5318 29 235.920 0.20 30 77.694 1.20 2.00100 29.1 0.5997 31 72.492 5.35 1.43875 94.7 0.5340 32 -215.992 2.78 33 (aperture) ∞ 13.92 34 35.798 3.37 1.54814 45.8 0.5686 35 112.952 1.65 36 -4564.752 3.70 1.80810 22.8 0.6307 37 -35.558 0.80 1.95375 32.3 0.5905 38 31.225 37.60 39 126.474 5.21 1.51860 69.9 0.5318 40 -36.239 4.82 41 783.670 4.68 1.63980 34.5 0.5922 42 -27.602 1.00 1.88300 40.8 0.5667 43 33.127 1.54 44 33.990 8.63 1.76182 26.5 0.6136 45 -22.163 1.00 2.00100 29.1 0.5997 46 56.905 1.15 47 47.481 6.99 1.54814 45.8 0.5686 48 -33.602 1.10 1.98612 16.5 0.6657 49 -37.135 50.41 Image plane ∞ Aspherical data Page 13 K = 1.85228e+00 A 4= 2.97887e-06 A 6=-3.95919e-10 A 8= 3.16332e-12 A10=-1.72732e-14 A12= 5.61306e-17 A14=-8.21795e-20 A16= 4.86328e-23 Page 23 K = 0.00000e+00 A 4=-9.86545e-07 A 6= 4.93421e-11 A 8=-8.03224e-15 Various data Zoom ratio 30.00 Wide-angle, Medium, Telephoto Focal length 35.00 190.00 1050.00 F-number 4.60 4.60 8.98 Half-angle (°): 22.92 4.45 0.81 Image height 14.80 14.80 14.80 Lens length 455.65 455.65 455.65 BF 50.41 50.41 50.41 d12 2.26 106.45 147.54 d19 128.50 5.85 3.79 d22 17.98 42.50 1.93 d27 22.55 16.48 18.03 Lens group data Group starting plane focal length 1 1 213.01 2 13 -30.76 3 20 -105.75 4 23 82.62 5 28 196.68

[0076] [Table 1]

[0077] [Table 2]

[0078] [Imaging device] Figure 13 shows an example configuration of the imaging device 125. In Figure 13, 101 is a zoom lens from one of Examples 1 to 6. 124 is the camera body. The zoom lens 101 is detachable from the camera body 124. In this figure, the first lens group L1 is shown as lens group F, the intermediate group M as lens group LZ, and the rear lens group LR as lens group R. SP is the aperture diaphragm. 114 and 115 are drive mechanisms that drive the lens group that moves for focusing and the lens group LZ that moves for zooming, respectively, and include helicoids, cams, etc.

[0079] 116-118 are motors (actuators) that drive the drive mechanisms 114 and 115 and the aperture diaphragm SP. 119-121 are detectors for detecting the position of the lens group for focusing and the lens group LZ, and the aperture diameter of the aperture diaphragm SP, and are composed of encoders, potentiometers, photosensors, etc.

[0080] In the camera body 124, 109 is a glass block such as a prism or optical filter. 110 is an image sensor, such as a CCD sensor or CMOS sensor, which is a photoelectric conversion element that converts the subject image formed by the zoom lens 101 into photoelectric data (imaging the subject through the zoom lens 101). 111 and 122 are processing units that perform various processes and controls in the camera body 124 and the zoom lens 101, respectively, and include a processor such as a CPU.

[0081] By using the zoom lenses described in Examples 1 to 6 above, a compact and lightweight imaging device 125 that can obtain good captured images can be provided.

[0082] The embodiment described above includes the following configuration.

[0083] (Composition 1) A zoom lens comprising a first lens group arranged sequentially from the object side to the image side, having a fixed positive refractive power for zooming; an intermediate group including three or more lens groups that move for zooming; and a rear lens group having a fixed positive refractive power for zooming, wherein the spacing between adjacent lens groups changes during zooming. The aforementioned intermediate group is arranged in order from the object side to the image side. A first intermediate negative lens group, consisting of a single lens group or two or more partial lens groups, which moves monotonically toward the image side during zooming from the wide-angle end to the telephoto end and has a negative refractive power as a whole, A second group of intermediate negative lenses having a negative refractive force that moves during zooming, It includes at least an intermediate positive lens group having a positive refractive force that moves during zooming, When the focal length of the first lens group is f1, the focal length of the first intermediate negative lens group is fv, and the focal length of the zoom lens at the telephoto end is ft, 4.00 ≤ ft / f1 ≤ 8.00 -9.00 ≤ f1 / fv ≤ -5.50 A zoom lens characterized by satisfying the following conditions. (Configuration 2) The zoom lens according to configuration 1, characterized in that the intermediate positive lens group and the second intermediate negative lens group are arranged in this order continuously from the object side in the intermediate group. (Composition 3) When ok1 is the distance along the optical axis from the image-side lens surface of the first lens group to the image-side principal point of the first lens group, 0.60 ≤ (f1 + ok1) / f1 ≤ 0.95 A zoom lens according to configuration 1 or 2, characterized by satisfying the following conditions. (Composition 4) When the lateral magnification of the first intermediate negative lens group at the wide-angle end is βvw, -0.35≦βvw≦-0.15 A zoom lens according to any one of configurations 1 to 3, characterized by satisfying the following conditions. (Composition 5) When the lateral magnification at the telephoto end of the first intermediate negative lens group is βvt, -1000.00≦βvt≦-2.00 The zoom lens according to any one of Configurations 1 to 4, characterized in that it satisfies the condition. (Configuration 6) When the amount of change in the position of the single lens group or the amount of change in the position of the portion lens group having the largest amount of change in the position between the wide-angle end and the telephoto end in the first intermediate negative lens group is mv, The first intermediate negative lens group is composed of two or more partial lens groups, When the amount of change in the position of the portion lens group having the largest amount of change in the position between the wide-angle end and the telephoto end among the two or more partial lens groups is mv, 6.00≦ft / |mv|≦15.00 The zoom lens according to any one of Configurations 1 to 5, characterized in that it satisfies the condition. (Configuration 7) When the focal length of the intermediate positive lens group is fp, 1.50≦f1 / fp≦5.00 The zoom lens according to any one of Configurations 1 to 6, characterized in that it satisfies the condition. (Configuration 8) When the focal length of the second intermediate negative lens group is fn, -4.00≦f1 / fn≦-1.00 The zoom lens according to any one of Configurations 1 to 7, characterized in that it satisfies the condition. (Configuration 9) When the average value of the partial dispersion ratios of all the positive lenses included in the first lens group with respect to the g-line and the F-line is θgF1P, and the average value of the partial dispersion ratios of all the negative lenses included in the first lens group with respect to the g-line and the F-line is θgF1N, 0.000≦θgF1N-θgF1P≦0.030 The zoom lens according to any one of Configurations 1 to 8, characterized in that it satisfies the condition. (Configuration 10) When the average value of the partial dispersion ratios of all the positive lenses included in the first intermediate negative lens group with respect to the g-line and the F-line is θgFvP, and the average value of the partial dispersion ratios of all the negative lenses included in the second intermediate negative lens group with respect to the g-line and the F-line is θgFvN, -0.060 ≤ θgFvN - θgFvP ≤ -0.020 The zoom lens according to any one of Configurations 1 to 9, characterized by satisfying the condition. (Configuration 11) When the average value of the Abbe numbers of all the positive lenses included in the first lens group with respect to the d-line is νd1P, 80.00 ≤ νd1P ≤ 96.00 The zoom lens according to any one of Configurations 1 to 310, characterized by satisfying the condition. ​​​​​​​​​​​​​​​​​​4.00 ≤ ft / f1 ≤ 8.00 A zoom lens characterized by satisfying the following conditions. (Composition 14) A zoom lens described in any one of configurations 1 to 13, An imaging device characterized by having an image sensor that captures an image of a subject through the aforementioned zoom lens.

[0084] 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]

[0085] L1 First lens group M intermediate group LR rear lens group LV First Intermediate Negative Lens Group v1 11th lens group v2 12th lens group LN Second Intermediate Negative Lens Group LP Intermediate Positive Lens Group SP aperture diaphragm I image plane

Claims

1. A zoom lens comprising a first lens group arranged sequentially from the object side to the image side and having a fixed positive refractive power for zooming, an intermediate group including three or more lens groups that move for zooming, and a rear lens group having a fixed positive refractive power for zooming, wherein the spacing between adjacent lens groups changes during zooming, The aforementioned intermediate group is arranged in order from the object side to the image side. A first intermediate negative lens group, composed of a single lens group or two or more partial lens groups, which has a negative refractive power as a whole and moves monotonically toward the image side when zooming from the wide-angle end to the telephoto end, A second group of intermediate negative lenses having a negative refractive force that moves during zooming, It includes at least an intermediate positive lens group having a positive refractive force that moves during zooming, When the focal length of the first lens group is f1, the focal length of the first intermediate negative lens group is fv, and the focal length of the zoom lens at the telephoto end is ft, 4.00 ≤ ft / f1 ≤ 8.00 -9.00 ≤ f1 / fv ≤ -5.50 A zoom lens characterized by satisfying the following conditions.

2. The zoom lens according to claim 1, characterized in that the intermediate positive lens group and the second intermediate negative lens group are arranged in this order continuously from the object side in the intermediate group.

3. When the lens group is in focus on an object at infinity, let OK1 be the distance along the optical axis from the image-side lens surface of the first lens group to the image-side principal point of the first lens group. 0.60≦(f1+ok1) / f1≦0.95 The zoom lens according to claim 1, characterized by satisfying the following conditions.

4. When the lateral magnification of the first intermediate negative lens group at the wide-angle end is βvw, -0.35 ≤ βvw ≤ -0.15 The zoom lens according to claim 1, characterized by satisfying the following conditions.

5. When the lateral magnification of the first intermediate negative lens group at the telephoto end is βvt, -1000.00 ≤ βvt ≤ -2.00 The zoom lens according to claim 1, characterized by satisfying the following conditions.

6. When mv is the amount of change between the position at the wide-angle end and the telephoto end of the single lens group in the first intermediate negative lens group, or the amount of change of the partial lens group among the two or more partial lens groups that has the largest change between the position at the wide-angle end and the telephoto end, 6.00≦ft / |mv|≦15.00 The zoom lens according to claim 1, characterized by satisfying the following conditions.

7. When the focal length of the aforementioned intermediate positive lens group is fp, 1.50 ≤ f1 / fp ≤ 5.00 The zoom lens according to claim 1, characterized by satisfying the following conditions.

8. When the focal length of the second intermediate negative lens group is fn, -4.00 ≤ f1 / fn ≤ -1.00 The zoom lens according to claim 1, characterized by satisfying the following conditions.

9. When the average value of the partial dispersion ratios of all positive lenses included in the first lens group with respect to the g-line and F-line is θgF1P, and the average value of the partial dispersion ratios of all negative lenses included in the first lens group with respect to the g-line and F-line is θgF1N, 0.000 ≤ θgF1N - θgF1P ≤ 0.030 The zoom lens according to claim 1, characterized by satisfying the following conditions.

10. When the average value of the partial dispersion ratios with respect to the g-line and F-line of all positive lenses included in the first intermediate negative lens group is θgFvP, and the average value of the partial dispersion ratios with respect to the g-line and F-line of all negative lenses included in the second intermediate negative lens group is θgFvN, -0.060 ≤ θgFvN - θgFvP ≤ -0.020 The zoom lens according to claim 1, characterized by satisfying the following conditions.

11. The average value of the Abbe numbers with respect to the d line of all positive lenses included in the first lens group is When νd1P is used, 80.00 ≤ νd1P ≤ 96.00 The zoom lens according to claim 1, characterized by satisfying the following conditions.

12. The zoom lens according to claim 1, characterized in that the intermediate positive lens group moves in a convex trajectory toward the object side and then moves in a convex trajectory toward the image side when zooming from the wide-angle end to the telephoto end.

13. A zoom lens comprising a first lens group arranged sequentially from the object side to the image side and having a fixed positive refractive power for zooming, an intermediate group including three or more lens groups that move for zooming, and a rear lens group having a fixed positive refractive power for zooming, wherein the spacing between adjacent lens groups changes during zooming, The aforementioned intermediate group is arranged in order from the object side to the image side. A first intermediate negative lens group, composed of a single lens group or two or more partial lens groups, which has a negative refractive power as a whole and moves monotonically toward the image side when zooming from the wide-angle end to the telephoto end, A second group of intermediate negative lenses having a negative refractive force that moves during zooming, It includes at least an intermediate positive lens group having a positive refractive force that moves during zooming, When the focal length of the first intermediate negative lens group is fv and the focal length of the zoom lens at the telephoto end is ft, 4.00 ≤ ft / f1 ≤ 8.00 A zoom lens characterized by satisfying the following conditions.

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

Images