Zoom lens and imaging device having the same

Abstract

To provide a compact and lightweight zoom lens that has high optical performance in the entire zoom range.SOLUTION: A zoom lens comprises, in arranged order from an object side to an image side; a first lens group L1 of positive refractive power; a second lens group L2 of negative refractive power; a third lens group L3 of positive refractive power; and a fourth lens group L4 of positive refractive power. During zooming from a wide angle end to a telephoto end, the first lens group moves, the interval between the first lens group and the second lens group expands, the interval between the second lens group and the third lens group contracts, and the interval between the third lens group and the fourth lens group contracts, and the fourth lens group is composed of a single positive lens. When it is assumed that TLt represents the total optical length of the zoom lens at the telephoto end and ft represents the focal distance of the zoom lens at the telephone end, then the conditional expression 0.10<TLt / ft<0.80 is satisfied.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a zoom lens, which is suitable for digital video cameras, digital still cameras, broadcast cameras, cameras for silver halide film, surveillance cameras, and the like. [Background technology]

[0002] In recent years, zoom lenses used in imaging devices are required to have high optical performance, and to be small and lightweight.

[0003] As a zoom lens that meets these requirements, Patent Document 1 discloses a zoom lens that has first to fourth lens groups with positive, negative, positive, and positive refractive powers arranged in this order from the object side to the image side, and in which the spacing between adjacent lens groups changes during zooming. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-43607 Summary of the Invention [Problem to be solved by the invention]

[0005] In a zoom lens such as that disclosed in Patent Document 1, in order to achieve high optical performance throughout the entire zoom range while reducing the size and weight of the entire system, it is important to appropriately set the various elements constituting the zoom lens, such as the number of lens groups, the movement conditions during zooming, and the lens configuration of each lens group.

[0006] An object of the present invention is to provide a small, lightweight zoom lens that has high optical performance over the entire zoom range, and an imaging device having the same. [Means for solving the problem]

[0007] The zoom lens according to one aspect of the present invention has a first lens group with a positive refractive power, a second lens group with a negative refractive power, a third lens group with a positive refractive power, and a fourth lens group with a positive refractive power, which are arranged in order from the object side to the image side. When zooming from the wide-angle end to the telephoto end, the first lens group moves, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the third lens group decreases, and the distance between the third lens group and the fourth lens group decreases. When zooming from the wide-angle end to the telephoto end, the spacing between adjacent lens groups changes. The zoom lens is characterized in that the fourth lens group consists of a single positive lens, and when the overall optical length of the zoom lens at the telephoto end is TLt, the focal length of the zoom lens at the telephoto end is ft, the focal length of the second lens group is fL2, and the focal length of the first lens group is fL1, it satisfies the conditional expressions 0.10 < TLt / ft < 0.80 and -0.80 < fL2 / fL1 < -0.20.

[0008] Other objects and features of the present invention will be described in the following embodiments.

Effects of the Invention

[0009] According to the present invention, a zoom lens having high optical performance over the entire zoom range and being small and lightweight can be obtained.

Brief Description of the Drawings

[0010] [Figure 1] It is a cross-sectional view at the wide-angle end of the zoom lens of Example 1. [Figure 2] It is a longitudinal chromatic aberration diagram of the zoom lens of Example 1 at (A) the wide-angle end and (B) the telephoto end. [Figure 3] It is a cross-sectional view at the wide-angle end of the zoom lens of Example 2. [Figure 4] It is a longitudinal chromatic aberration diagram of the zoom lens of Example 2 at (A) the wide-angle end and (B) the telephoto end. [Figure 5] It is a cross-sectional view at the wide-angle end of the zoom lens of Example 3. [Figure 6] It is a longitudinal chromatic aberration diagram of the zoom lens of Example 3 at (A) the wide-angle end and (B) the telephoto end. [Figure 7]FIG. 10 is a cross-sectional view of a zoom lens at the wide-angle end of Example 4. [Figure 8] 10A and 10B are longitudinal aberration diagrams of the zoom lens of Example 4 at the wide-angle end and the telephoto end, respectively. [Figure 9] FIG. 10 is a cross-sectional view of a zoom lens at a wide-angle end according to a fifth embodiment. [Figure 10] 10A and 10B are longitudinal aberration diagrams of the zoom lens of Example 5 at the wide-angle end and the telephoto end, respectively. [Figure 11] FIG. 10 is a cross-sectional view of a zoom lens at the wide-angle end of a sixth embodiment. [Figure 12] 10A and 10B are longitudinal aberration diagrams of the zoom lens of Example 6 at the wide-angle end and the telephoto end, respectively. [Figure 13] FIG. 1 is a schematic diagram of an imaging device. DETAILED DESCRIPTION OF THE INVENTION

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a zoom lens and an image pickup apparatus having the same according to the present invention will be described with reference to the accompanying drawings.

[0012] 1, 3, 5, 7, 9, and 11 are cross-sectional views of the zoom lenses of Examples 1 to 6, respectively, when focused at infinity (infinity focused state). 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, and surveillance cameras, as well as optical devices including interchangeable lenses.

[0013] In each lens cross-sectional view, the left side is the object side and the right side is the image side. The zoom lens of each embodiment is configured with multiple lens groups. In this specification, a lens group refers to a group of lenses that move or remain stationary as a unit during zooming. That is, in the zoom lens of each embodiment, the spacing between adjacent lens groups changes during zooming from the wide-angle end to the telephoto end. The wide-angle end and the telephoto end are zoom states when the lens group that moves during zooming is located at both ends of the range of movement in the optical axis direction due to the mechanism. Note that the lens group may be configured with one lens or multiple lenses. The lens group may also include an aperture stop.

[0014] In each lens cross-sectional view, Li represents the i-th lens group (i is a natural number) counting from the object side.

[0015] Additionally, SP denotes an aperture stop. IP denotes an image plane, on which the imaging surface of a solid-state imaging element (photoelectric conversion element) such as a CCD sensor or CMOS sensor is placed when the zoom lens of each embodiment is used as the imaging optical system of a digital still camera or digital video camera. When the zoom lens of each embodiment is used as the imaging optical system of a silver halide film camera, a photosensitive surface equivalent to the film surface is placed on the image plane IP.

[0016] In addition, in the zoom lens of each embodiment, when zooming from the wide-angle end to the telephoto end, each lens group is moved as shown by the solid arrow in each lens cross-sectional view, and when focusing from infinity to a close distance, each lens group is moved as shown by the dotted arrow.

[0017] 2, 4, 6, 8, 10, and 12 are longitudinal aberration diagrams of the zoom lenses of Examples 1 to 6. In each aberration diagram, (A) is a longitudinal aberration diagram in a state where the zoom lens is focused at infinity at the wide-angle end, and (B) is a longitudinal aberration diagram in a state where the zoom lens is focused at infinity at the telephoto end.

[0018] In the spherical aberration diagram, Fno is the F-number, and the amount of spherical aberration for the d-line (wavelength 587.6 nm) and g-line (wavelength 435.8 nm) is shown by the solid line and the two-dot chain line, respectively. In the astigmatism diagram, ΔS is the amount of astigmatism on the sagittal image plane (solid line), and ΔM is the amount of astigmatism on the meridional image plane (dashed line). The distortion diagram shows the amount of distortion for the d-line. The chromatic aberration diagram shows the amount of chromatic aberration for the g-line. ω is the imaging half angle of view (°).

[0019] Next, the characteristic configuration of the zoom lens of each embodiment will be described.

[0020] The zoom lens of each embodiment includes, arranged from the object side to the image side, a first lens unit L1 with positive refractive power, a second lens unit L2 with negative refractive power, a third lens unit L3 with positive refractive power, and a fourth lens unit L4 with positive refractive power. The first lens unit L1 moves during zooming from the wide-angle end to the telephoto end. During zooming from the wide-angle end to the telephoto end, the distance between the first lens unit L1 and the second lens unit L2 increases, the distance between the second lens unit L2 and the third lens unit L3 decreases, and the distance between the third lens unit L3 and the fourth lens unit L4 decreases. The zoom lens of each embodiment has a telephoto-type power arrangement at the telephoto end, which facilitates shortening the overall optical length. In this configuration, the movement distance of the fourth lens unit L4 during zooming from the wide-angle end to the telephoto end is large, so it is important to appropriately design the lens configuration of the fourth lens unit L4 to achieve rapid zooming. Therefore, in the zoom lens of each embodiment, the fourth lens unit L4 is composed of one positive lens, which reduces the weight of the lens unit that moves during zooming, enabling quick zooming.

[0021] Furthermore, the zoom lens of each embodiment satisfies the following conditional expression (1).

[0022] 0.10 <TLt / ft<0.80 (1) Here, TLt is the total optical length of the zoom lens at the telephoto end, and ft is the focal length of the zoom lens at the telephoto end.

[0023] Conditional formula (1) defines the conditions for the total optical length TLt at the telephoto end and the focal length ft of the zoom lens at the telephoto end. By appropriately setting the conditions for these parameters, it becomes easier to reduce the size of the zoom lens. If the lower limit of conditional formula (1) is exceeded, the total optical length at the telephoto end becomes too short relative to the focal length of the zoom lens at the telephoto end, the refractive power of each lens group becomes strong, and it becomes difficult to suppress fluctuations in various aberrations that occur during zooming. If the upper limit of conditional formula (1) is exceeded, the total optical length at the telephoto end becomes too long relative to the focal length of the zoom lens at the telephoto end, making it difficult to reduce the size.

[0024] With the above configuration, a small, lightweight zoom lens having high optical performance over the entire zoom range can be obtained.

[0025] Furthermore, it is preferable that the numerical range of conditional expression (1) be within the range of the following conditional expression (1a).

[0026] 0.45 <TLt / ft<0.79 (1a) It is more preferable that the numerical range of conditional expression (1) satisfies the range of the following conditional expression (1b).

[0027] 0.50 <TLt / ft<0.78 (1b) Next, the configurations that are preferably satisfied in the zoom lens of each embodiment will be described.

[0028] In the zoom lens of each embodiment, it is preferable that the first lens unit L1, which is closest to the object side, moves toward the object side during zooming from the wide-angle end to the telephoto end, thereby shortening the overall optical length of the zoom lens at the wide-angle end and enabling the zoom lens to be made more compact.

[0029] It is preferable that the second lens unit L2 does not move during zooming, which reduces the amount of relative decentering error between the first lens unit L1 and the second lens unit L2, thereby reducing performance degradation.

[0030] The second lens group L2 is preferably composed of two or fewer lenses, specifically, two lenses: one negative lens and one positive lens, arranged in that order from the object side to the image side. This facilitates reducing the weight of the second lens group L2. The third lens group L3 is preferably composed of two or fewer lenses, specifically, two lenses: one positive lens and one negative lens, arranged in that order from the object side to the image side. This facilitates reducing the weight of the third lens group L3. The fourth lens group L4 preferably has at least one aspherical surface. This facilitates suppressing fluctuations in various aberrations during zooming from the wide-angle end to the telephoto end.

[0031] The effective diameter of the light beam tends to be small in the lens group located closer to the image side than the aperture diaphragm SP. For this reason, it is preferable to use the lens group located closer to the image side than the aperture diaphragm SP as the focusing lens group. This simplifies the holding mechanism and drive mechanism and facilitates the miniaturization of the zoom lens. Furthermore, it is preferable that the focusing lens group be configured with two or fewer lenses. This facilitates the weight reduction of the focusing lens group. Furthermore, because the magnification change effect is relatively small on the image side of the aperture diaphragm SP, it is possible to reduce the change in image magnification when focusing from infinity to a close distance. This is optimal for video shooting, as it allows for a small change in the angle of view when the subject changes from infinity to a close distance.

[0032] It is preferable to arrange a lens group with negative refractive power closer to the image side than the fourth lens group L4, which results in a telephoto type power arrangement, making it easy to shorten the overall optical length.

[0033] It is preferable that the number of lenses arranged closer to the image side than the fourth lens unit L4 is 4 or less, which reduces the weight of the lens units that move during zooming, enabling quick zooming.

[0034] Driving all or part of any of the lens groups in a direction perpendicular to the optical axis direction can have the effect of reducing camera shake. In particular, using the second lens group L2, which is fixed during zooming, as an image stabilization lens group that moves in a direction that includes a component perpendicular to the optical axis during image shake correction can reduce the amount of movement of the image stabilization lens group, making it easier to achieve compactness, which is preferable.

[0035] Next, conditions that the zoom lens of each embodiment should preferably satisfy will be described. The zoom lens of each embodiment should preferably satisfy one or more of the following conditional expressions (2) to (12).

[0036] 1.40 <ndL4<1.70 (2) -0.35 <fL2 / ft<-0.10 (3) 0.10 <fL3 / ft<0.90 (4) 0.30 <ML4 / ML1<3.70 (5) -0.80 <fL2 / fL1<-0.20 (6) 0.05 <fL4 / ft<0.50 (7) 0.10 <fL4 / fL1<0.70 (8) 0.05 <fL4 / fL3<1.00 (9) 1.00 <SL4ave<3.90 (10) 55<νdL1Pave<99 (11) 55<νdL3Pave<99 (12) Here, ndL4 is the refractive index of the fourth lens group L4. fL2 is the focal length of the second lens group L2. fL3 is the focal length of the third lens group L3. ML4 is the movement amount of the fourth lens group L4 during zooming from the wide-angle end to the telephoto end. The sign of the movement amount ML4 is negative when the fourth lens group L4 is located closer to the object at the telephoto end than at the wide-angle end, and positive when it is located closer to the image. ML1 is the movement amount of the first lens group L1 during zooming from the wide-angle end to the telephoto end. The sign of the movement amount ML1 is negative when the first lens group L1 is located closer to the object at the telephoto end than at the wide-angle end, and positive when it is located closer to the image. fL1 is the focal length of the first lens group L1. fL4 is the focal length of the fourth lens group L4. SL4ave is the average specific gravity of the lenses in the fourth lens group L4. νdL1Pave is the average value of the Abbe number for the d-line of the positive lenses included in the first lens unit L1, and νdL3Pave is the average value of the Abbe number for the d-line of the positive lenses included in the third lens unit L3.

[0037] Conditional expression (2) defines the condition for the refractive index ndL4 of the fourth lens unit L4. Generally, as the refractive index of a lens material increases, the specific gravity of the lens material increases. If the lower limit of conditional expression (2) is exceeded, the curvature of the lens surface increases in order to obtain the necessary refractive power, making it difficult to suppress fluctuations in various aberrations such as spherical aberration and curvature of field that occur during zooming, which is undesirable. If the upper limit of conditional expression (2) is exceeded, the specific gravity of the lens increases, making it difficult to reduce the lens weight, which is also undesirable.

[0038] Conditional expression (3) defines the conditions for the focal length ft of the zoom lens at the telephoto end and the focal length fL2 of the second lens unit L2. If the lower limit of conditional expression (3) is exceeded, the focal length fL2 becomes short, making it difficult to suppress fluctuations in various aberrations such as spherical aberration and curvature of field that occur during zooming, which is undesirable. If the upper limit of conditional expression (3) is exceeded, the focal length ft of the zoom lens at the telephoto end becomes short, making it difficult to achieve a high zoom ratio, which is also undesirable.

[0039] Conditional expression (4) defines the conditions for the focal length ft of the zoom lens at the telephoto end and the focal length fL3 of the third lens unit L3. If the lower limit of conditional expression (4) is not met, the focal length fL3 becomes short, making it difficult to suppress fluctuations in various aberrations such as spherical aberration and curvature of field that occur during zooming, which is undesirable. If the upper limit of conditional expression (4) is exceeded, the focal length ft of the zoom lens at the telephoto end becomes short, making it difficult to achieve a high zoom ratio, which is also undesirable.

[0040] Conditional expression (5) defines the conditions for the amount of movement ML1 of the first lens unit L1 and the amount of movement ML4 of the fourth lens unit L4 during zooming from the wide-angle end to the telephoto end. If the lower limit of conditional expression (5) is not met, the amount of movement ML4 of the fourth lens unit L4 becomes small, making it difficult to achieve a high zoom ratio, which is undesirable. If the upper limit of conditional expression (5) is exceeded, the amount of movement ML4 of the fourth lens unit L4 becomes large, making it difficult to achieve a compact size, which is also undesirable.

[0041] Conditional expression (6) defines the conditions for the focal length fL1 of the first lens group L1 and the focal length fL2 of the second lens group L2. If the lower limit of conditional expression (6) is not met, the focal length fL1 of the first lens group L1 becomes long, which increases the amount of movement of the first lens group L1 during zooming from the wide-angle end to the telephoto end, making it difficult to reduce the size of the zoom lens, which is undesirable. If the upper limit of conditional expression (6) is met, the focal length fL1 of the first lens group L1 becomes short, which makes it difficult to correct spherical aberration generated in the first lens group L1, which is undesirable.

[0042] Conditional expression (7) defines the conditions for the focal length ft of the zoom lens at the telephoto end and the focal length fL4 of the fourth lens unit L4. If the lower limit of conditional expression (7) is exceeded, the focal length fL4 becomes short, making it difficult to suppress fluctuations in various aberrations such as spherical aberration and curvature of field that occur during zooming, which is undesirable. If the upper limit of conditional expression (7) is exceeded, the focal length ft of the zoom lens at the telephoto end becomes short, making it difficult to achieve a high zoom ratio, which is also undesirable.

[0043] Conditional expression (8) defines the conditions for the focal length fL1 of the first lens group L1 and the focal length fL4 of the fourth lens group L4. If the lower limit of conditional expression (8) is not met, the focal length fL4 becomes short, making it difficult to suppress fluctuations in various aberrations such as spherical aberration and curvature of field that occur during zooming, which is undesirable. If the upper limit of conditional expression (8) is exceeded, the focal length fL4 of the fourth lens group L4 becomes long, weakening the refractive power of the fourth lens group L4 and increasing the amount of movement of the fourth lens group L4 that occurs during zooming, which is also undesirable.

[0044] Conditional expression (9) defines the conditions for the focal length fL3 of the third lens group L3 and the focal length fL4 of the fourth lens group L4. If the lower limit of conditional expression (9) is not met, the focal length fL4 becomes short, making it difficult to suppress fluctuations in various aberrations such as spherical aberration and curvature of field that occur during zooming, which is undesirable. If the upper limit of conditional expression (9) is exceeded, the focal length fL4 of the fourth lens group L4 becomes long, weakening the refractive power of the fourth lens group L4 and increasing the amount of movement of the fourth lens group L4 that occurs during zooming, which is also undesirable.

[0045] Conditional expression (10) defines the condition for the average value SL4ave of the specific gravity of the lenses in the fourth lens unit L4. Generally, as the specific gravity of a lens material increases, the refractive index of the lens material increases. If the lower limit of conditional expression (10) is exceeded, the curvature of the lens surface becomes strong in order to obtain the necessary refractive power, making it difficult to suppress fluctuations in various aberrations such as spherical aberration and curvature of field that occur during zooming, which is undesirable. If the upper limit of conditional expression (10) is exceeded, the specific gravity of the lens increases, making it difficult to reduce the lens weight, which is also undesirable.

[0046] Conditional expression (11) is a condition regarding the average value νdL1Pave of the Abbe number for the d-line of the positive lenses included in the first lens unit L1. If the lower limit of conditional expression (11) is not met, it becomes difficult to correct axial chromatic aberration and lateral chromatic aberration at the telephoto end, which is undesirable. If the upper limit of conditional expression (11) is exceeded, it becomes difficult to correct lateral chromatic aberration at the wide-angle end, which is undesirable.

[0047] Conditional expression (12) defines a condition regarding the average Abbe number νdL3Pave of the d-line of the positive lenses included in the third lens unit L3. Below the lower limit of conditional expression (12), it becomes difficult to correct longitudinal chromatic aberration at the telephoto end, which is undesirable. Above the upper limit of conditional expression (12), it becomes difficult to correct longitudinal chromatic aberration at the wide-angle end, which is undesirable.

[0048] It is more preferable that the numerical ranges of the conditional expressions (2) to (12) be within the ranges of the following conditional expressions (2a) to (12a).

[0049] 1.43 <ndL4<1.67 (2a) -0.33 <fL2 / ft<-0.12 (3a) 0.20 <fL3 / ft<0.85 (4a) 0.40 <ML4 / ML1<3.60 (5a) -0.75 <fL2 / fL1<-0.23 (6a) 0.07 <fL4 / ft<0.40 (7a) 0.10 <fL4 / fL1<0.65 (8a) 0.15 <fL4 / fL3<0.80 (9a) 2.30 <SL4ave<3.80 (10a) 58<νdL1Pave<90 (11a) 58<νdL3Pave<97 (12a) It is more preferable that the numerical ranges of the conditional expressions (2) to (12) be within the ranges of the following conditional expressions (2b) to (12b).

[0050] 1.45 <ndL4<1.65 (2b) -0.30 <fL2 / ft<-0.14 (3b) 0.25 <fL3 / ft<0.80 (4b) 0.50 <ML4 / ML1<3.50 (5b) -0.70 <fL2 / fL1<-0.25 (6b) 0.15 <fL4 / ft<0.30 (7b) 0.20 <fL4 / fL1<0.60 (8b) 0.25 <fL4 / fL3<0.70 (9b) 2.50 <SL4ave<3.70 (10b) 60<νdL1Pave<85 (11b) 60<νdL3Pave<95 (12b) Next, the zoom lens of each embodiment will be described in detail.

[0051] The zoom lenses of Examples 1 and 2 are composed of the above-mentioned first to fourth lens units L1 to L4 and a fifth lens unit L5 with negative refractive power, arranged in this order from the object side to the image side. An aperture stop SP is arranged between the second lens unit L2 and the third lens unit L3. The fifth lens unit L5 is a focusing lens unit.

[0052] The zoom lens of Example 3 is composed of the above-mentioned first to fourth lens groups L1 to L4, a fifth lens group with positive refractive power, and a sixth lens group with negative refractive power, arranged in this order from the object side to the image side. An aperture stop SP is arranged between the second lens group L2 and the third lens group L3. The sixth lens group L6 is a focusing lens group.

[0053] The zoom lenses of Examples 4 and 5 are composed of the above-mentioned first to fourth lens groups L1 to L4, a fifth lens group L5 with negative refractive power, and a sixth lens group L6 with positive refractive power, arranged in this order from the object side to the image side. An aperture stop SP is arranged between the second lens group L2 and the third lens group L3. The fifth lens group L5 is a focusing lens group.

[0054] The zoom lens of Example 6 is composed of the above-mentioned first to fourth lens groups L1 to L4, a fifth lens group L5 with negative refractive power, a sixth lens group L6 with positive refractive power, and a seventh lens group L7 with negative refractive power, arranged in this order from the object side to the image side. An aperture stop SP is arranged between the second lens group L2 and the third lens group L3. The fifth lens group L5 is a focusing lens group.

[0055] Numerical Examples 1 to 6 corresponding to Examples 1 to 6, respectively, are shown below.

[0056] In the surface data of each numerical example, r represents the radius of curvature of each optical surface, and d (mm) represents the axial spacing (distance on the optical axis) between the mth surface and the (m+1)th surface. Here, m is the surface number counted from the light incident side. Also, nd represents the refractive index of each optical element with respect to the d-line, and vd represents the Abbe number of the optical element. Note that the Abbe number vd of a certain material is given by the following when the refractive indices at the d-line (587.6 nm), F-line (486.1 nm), and C-line (656.3 nm) of the Fraunhofer lines are Nd, NF, and NC, respectively: νd=(Nd-1) / (NF-NC) It is expressed as:

[0057] 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. "Back focus" is the distance on the optical axis from the final lens surface (the lens surface closest to the image) to the paraxial image plane, expressed as an air-equivalent length. "Total lens length" is the distance on the optical axis from the frontmost lens surface (the lens surface closest to the object) to the final lens surface plus the back focus. "Lens group" is not limited to cases where it is composed of multiple lenses, but also includes cases where it is composed of a single lens.

[0058] If the optical surface is aspherical, an asterisk (*) is added to the right of the surface number. The aspherical shape is expressed as follows: X is the displacement from the vertex of the surface in the optical axis direction, h is the height from the optical axis in the direction perpendicular to the optical axis, R is the paraxial radius of curvature, k is the conic constant, and A4, A6, A8, A10, and A12 are the aspherical coefficients of each order. x=(h 2 / R) / [1+{1-(1+k)(h / R) 2} 1 / 2 +A4×h 4 +A6×h 6 +A8×h 8 +A10×h 10 +A12×h 12 ] In addition, "e±XX" in each aspherical coefficient is "×10± XX" means.

[0059] [Numerical Example 1] Unit: mm Surface Data Surface number rd nd νd 1 87.531 1.90 1.88300 40.8 2 56.811 0.00 3 55.779 7.61 1.49700 81.5 4 -439.396 (variable) 5 -104.645 1.00 1.55032 75.5 6 30.959 0.05 7 28.872 1.68 2.00069 25.5 8 37.914 (variable) 9 (Aperture) ∞ 0.60 10 33.189 4.19 1.43875 94.7 11 -61.580 13.10 12 -25.906 0.90 1.76182 26.6 13 -54.746 (variable) 14* -190.901 2.20 1.58313 59.4 15* -33.214 (variable) 16 512.143 2.94 1.85478 24.8 17 -57.069 0.95 1.82648 43.0 18 51.620 (variable) Image plane ∞ Aspheric data Page 14 K = 0.00000e+000 A 4=-5.39999e-007 A 6= 6.34393e-008 A 8=-3.79967e-010 A10= 8.30529e-012 A12= 1.74306e-015 Page 15 K = 0.00000e+000 A 4= 4.16480e-006 A 6= 6.11437e-008 A 8=-2.84194e-010 A10= 5.96480e-012 A12= 1.62427e-014 Various data Zoom ratio 3.77 Wide-angle Mid-range Telephoto Focal length 103.01 201.88 387.98 F-number 6.30 8.24 8.24 Half angle of view (°) 11.86 6.12 3.19 Image height 21.64 21.64 21.64 Lens total length 183.99 229.42 280.00 BF 32.00 70.38 122.21 d 4 17.46 62.89 113.47 d 8 31.20 18.76 4.90 d13 24.73 15.61 1.28 d15 41.47 24.65 1.00 d18 32.00 70.38 122.21 Zoom lens group data Group starting plane focal length 1 1 216.34 2 5 -68.82 3 9 108.09 4 14 68.60 5 16 -72.53 [Numerical Example 2] Unit: mm Surface Data Surface number rd nd νd 1 62.907 5.61 1.48749 70.2 2∞0.15 3 210.346 1.90 1.72916 54.7 4 40.374 6.77 1.49700 81.5 5 492.013 (variable) 6 -131.985 1.00 1.59522 67.7 7 37.307 1.94 1.95375 32.3 8 60.853 (variable) 9 (Aperture) ∞ 0.60 10 33.647 7.31 1.49700 81.5 11 -60.065 6.15 12 -34.716 1.30 1.83400 37.2 13 -281.865 (variable) 14* -57.716 3.40 1.55332 71.7 15* -24.458 (variable) 16 -199.990 2.27 1.77047 29.7 17 -63.813 0.95 1.55032 75.5 18 46.014 (variable) Image plane ∞ Aspheric data Page 14 K = 0.00000e+000 A 4=-2.42159e-005 A 6=-5.60843e-008 A 8=-5.65820e-010 A10=3.91315e-012 A12=-3.83605e-014 Page 15 K = 0.00000e+000 A 4=-1.21658e-005 A 6=-4.48929e-008 A 8=-4.63309e-010 A10=2.98002e-012 A12=-2.72588e-014 Various data Zoom ratio 3.37 Wide-angle Mid-range Telephoto Focal length 103.01 208.71 347.20 F-number 5.13 7.06 8.24 Half angle of view (°) 11.86 5.92 3.57 Image height 21.64 21.64 21.64 Lens total length 198.72 238.36 267.94 BF 32.99 86.36 136.99 d 5 10.63 50.26 79.85 d 8 57.55 34.33 3.09 d13 14.40 6.64 3.27 d15 43.81 21.42 5.39 d18 32.99 86.36 136.99 Zoom lens group data Group starting plane focal length 1 1 214.41 2 6 -95.15 3 9 172.34 4 14 74.01 5 16 -80.60 [Numerical Example 3] Unit: mm Surface Data Surface number rd nd νd 1 70.628 4.50 1.48749 70.2 2 497.873 0.15 3 125.487 1.90 1.88300 40.8 4 45.656 6.06 1.59410 60.5 5 779.334 (variable) 6 -131.250 1.00 1.69680 55.5 7 23.941 2.87 2.00100 29.1 8 40.105 (variable) 9 (Aperture) ∞ 0.60 10 38.410 3.76 1.59410 60.5 11 -88.739 4.01 12 -38.203 1.00 1.91650 31.6 13 -130.976 (variable) 14* -53.565 2.56 1.55332 71.7 15* -25.964 (variable) 16 32.489 1.00 1.80400 46.5 17 21.387 3.54 1.49700 81.5 18 108.864 (variable) 19 -158.524 2.14 1.85451 25.2 20 -54.586 0.95 1.61800 63.4 21 42.000 (variable) Image plane ∞ Aspheric data Page 14 K = 0.00000e+000 A 4=-3.12831e-006 A 6=-3.81685e-008 A 8= 8.78299e-010 A10=-7.67854e-012 A12= 2.64316e-014 Page 15 K = 0.00000e+000 A 4= 2.66305e-006 A 6=-3.18962e-008 A 8= 7.75928e-010 A10=-6.58078e-012 A12= 2.23140e-014 Various data Zoom ratio 4.29 Wide-angle Mid-range Telephoto Focal length 70.00 146.89 300.00 F-number 4.40 6.09 7.20 Half angle of view (°) 17.17 8.38 4.12 Image height 21.64 21.64 21.64 Lens total length 165.01 196.65 231.87 BF 27.80 62.32 102.92 d 5 3.72 35.36 70.59 d 8 41.20 24.87 6.70 d13 20.09 11.82 2.62 d15 1.00 5.07 9.60 d18 35.17 21.18 3.43 d21 27.80 62.32 102.92 Zoom lens group data Group starting plane focal length 1 1 166.60 2 6 -57.69 3 9 142.16 4 14 88.15 5 16 161.27 6 19 -63.11 [Numerical Example 4] Unit: mm Surface Data Surface number rd nd νd 1 115.611 4.22 1.48749 70.2 2 -1038.183 0.15 3 120.522 1.90 1.61340 44.3 4 49.517 6.84 1.49700 81.5 5 276.538 (variable) 6 -337.127 1.00 1.69680 55.5 7 25.459 2.87 2.00100 29.1 8 42.323 (variable) 9 (Aperture) ∞ 0.60 10 32.626 3.66 1.49700 81.5 11 -88.505 4.22 12 -39.908 1.30 1.95375 32.3 13 -137.260 (variable) 14* -1279.904 2.94 1.49710 81.6 15* -29.523 (variable) 16 -81.052 2.02 1.91082 35.3 17 -34.073 0.95 1.65160 58.5 18 41.604 (variable) 19 53.259 3.19 1.91082 35.3 20 73.114 (variable) Image plane ∞ Aspheric data Page 14 K = 0.00000e+000 A 4=-7.57502e-006 A 6=-1.75887e-008 A 8= 1.59201e-010 A10=-2.48608e-012 A12= 1.65600e-014 Page 15 K = 0.00000e+000 A 4= 1.62454e-006 A 6=-1.77799e-008 A 8= 1.48215e-010 A10=-2.01153e-012 A12= 1.32915e-014 Various data Zoom ratio 3.50 Wide-angle Mid-range Telephoto Focal length 100.00 185.57 350.00 F-number 5.80 8.00 8.00 Half angle of view (°) 12.21 6.65 3.54 Image height 21.64 21.64 21.64 Lens total length 189.94 228.10 270.57 BF 46.21 41.93 37.16 d 5 7.91 46.06 88.53 d 8 46.34 31.03 13.98 d13 20.04 11.40 1.77 d15 30.00 21.26 3.93 d18 3.58 40.56 89.33 d20 46.21 41.93 37.16 Zoom lens group data Group starting plane focal length 1 1 174.87 2 6 -74.36 3 9 172.46 4 14 60.75 5 16 -51.50 June 19, 200.00 [Numerical Example 5] Unit: mm Surface Data Surface number rd nd νd 1 79.761 5.32 1.59349 67.0 2 232.622 0.15 3 115.078 1.90 1.80400 46.5 4 56.015 7.98 1.43875 94.7 5 1105.719 (variable) 6 -1601.984 1.00 1.80400 46.5 7 37.802 3.30 1.77047 29.7 8 127.270 (variable) 9 (Aperture) ∞ 0.60 10 40.008 3.50 1.49700 81.5 11 310.943 2.45 12 -514.239 1.30 2.05090 26.9 13 175.138 (variable) 14* 186.844 2.57 1.58313 59.4 15* -92.387 (variable) 16 272.120 2.40 1.63980 34.5 17 -57.921 0.95 1.61800 63.4 18 48.017 (variable) 19 -115.592 1.00 1.49700 81.5 20 711.620 (variable) Image plane ∞ Aspheric data Page 14 K = 0.00000e+000 A 4=-7.31606e-006 A 6=-1.29819e-008 A 8=-9.66867e-011 A10= 1.81145e-013 A12=-1.53314e-015 Page 15 K = 0.00000e+000 A 4=-5.36687e-006 A 6=-1.20074e-008 A 8=-1.00369e-010 A10=2.11582e-013 A12=-1.41922e-015 Various data Zoom ratio 2.40 Wide-angle Mid-range Telephoto Focal length 250.00 439.53 600.00 F-number 6.24 9.67 11.33 Half angle of view (°) 4.95 2.82 2.07 Image height 21.64 21.64 21.64 Lens total length 305.44 320.00 336.20 BF 29.45 93.01 163.77 d 5 49.00 63.56 79.76 d 8 93.78 50.69 2.72 d13 31.18 24.12 16.27 d15 32.57 12.66 1.00 d18 35.04 41.54 38.26 d20 29.45 93.01 163.77 Zoom lens group data Group starting plane focal length 1 1 195.38 2 6 -134.04 3 9 302.31 4 14 106.38 5 16 -99.21 6 19 -200.00 [Numerical Example 6] Unit: mm Surface Data Surface number rd nd νd 1 150.513 3.83 1.48749 70.2 2 -727.209 0.15 3 135.452 1.90 1.61340 44.3 4 53.804 5.72 1.49700 81.5 5 457.290 (variable) 6 -212.782 1.00 1.69680 55.5 7 29.502 2.72 2.00100 29.1 8 54.046 (variable) 9 (Aperture) ∞ 0.60 10 38.360 3.65 1.49700 81.5 11 -78.576 5.83 12 -39.181 1.00 2.00100 29.1 13 -100.785 (variable) 14* -1267.433 3.12 1.49710 81.6 15* -32.773 (variable) 16 -185.607 1.87 1.95375 32.3 17 -51.634 0.95 1.69680 55.5 18 46.639 (variable) 19 57.189 4.06 1.51742 52.4 20 -118.132 (variable) 21 -81.943 1.20 1.49700 81.5 22 64.321 (variable) Image plane ∞ Aspheric data Page 14 K = 0.00000e+000 A 4=-2.97172e-006 A 6=-1.48820e-008 A 8= 7.90438e-010 A10=-7.62434e-012 A12= 3.72875e-014 Page 15 K = 0.00000e+000 A 4= 3.36430e-006 A 6=-1.79473e-008 A 8= 8.09788e-010 A10=-7.69535e-012 A12= 3.69102e-014 Various data Zoom ratio 3.50 Wide-angle Mid-range Telephoto Focal length 100.00 186.24 350.00 F-number 5.80 7.25 8.00 Half angle of view (°) 12.21 6.63 3.54 Image height 21.64 21.64 21.64 Lens total length 183.64 224.40 269.79 BF 29.97 46.31 64.50 d 5 3.51 44.27 89.65 d 8 44.94 28.11 9.37 d13 20.89 11.77 1.62 d15 24.85 16.28 1.05 d18 6.03 31.07 64.63 d20 15.85 9.00 1.37 d22 29.97 46.31 64.50 Zoom lens group data Group starting plane focal length 1 1 191.25 2 6 -88.32 3 9 175.16 4 14 67.62 5 16 -66.00 6 19 75.07 7 21 -72.31 The various values in each numerical example are summarized in Table 1 below.

[0060] [Table 1]

[0061] [Imaging device] Next, an embodiment of a digital still camera (image pickup device, optical equipment) 10 using the zoom lens of the present invention as an image pickup optical system will be described with reference to FIG.

[0062] In Fig. 13, 13 is a camera body, and 11 is a photographing optical system. 12 is a solid-state image sensor (photoelectric conversion element) such as a CCD sensor or a CMOS sensor that is built into the camera body 13 and receives the optical image formed by the photographing optical system 11 and performs photoelectric conversion.

[0063] The camera body 13 may be a so-called single-lens reflex camera having a quick-return mirror, or may be a so-called mirrorless camera having no quick-return mirror.

[0064] By using any one of the zoom lenses according to Examples 1 to 6 in an imaging device 10 such as a digital still camera, an imaging device with a compact lens can be obtained. Furthermore, by incorporating any one of the zoom lenses according to Examples 1 to 6 in an interchangeable lens (optical equipment), a compact interchangeable lens can be obtained.

[0065] The embodiments described above are merely representative examples, and various modifications and alterations are possible to each embodiment when implementing the present invention.

[0066] The optical systems of the above-described embodiments are not limited to imaging devices such as digital still cameras, but can also be applied to various optical instruments such as telescopes.

[0067] Although the preferred embodiments and examples of the present invention have been described above, the present invention is not limited to these embodiments and examples, and various combinations, modifications, and changes are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0068] L1 First lens group L2 Second lens group L3: Third lens group L4 4th lens group

Claims

1. a zoom lens having, arranged in order from the object side to the image side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a fourth lens group having positive refractive power, wherein, during zooming from a wide-angle end to a telephoto end, the first lens group moves, a distance between the first lens group and the second lens group increases, a distance between the second lens group and the third lens group decreases, and a distance between the third lens group and the fourth lens group decreases, and a distance between each of the adjacent lens groups changes during zooming from the wide-angle end to the telephoto end; the fourth lens group is made up of one positive lens element, When the total optical length of the zoom lens at the telephoto end is TLt, the focal length of the zoom lens at the telephoto end is ft, the focal length of the second lens group is fL2, and the focal length of the first lens group is fL1, 0.10<TLt / ft<0.80 -0.80<fL2 / fL1<-0.20 A zoom lens characterized by satisfying the following conditional expressions:

2. 2. The zoom lens according to claim 1, wherein the second lens group remains stationary during zooming from the wide-angle end to the telephoto end.

3. a zoom lens having, arranged in order from the object side to the image side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a fourth lens group having positive refractive power, wherein, during zooming from a wide-angle end to a telephoto end, the first lens group moves and the second lens group remains stationary, a distance between the first lens group and the second lens group increases, a distance between the second lens group and the third lens group decreases, and a distance between the third lens group and the fourth lens group decreases, and a distance between each of the adjacent lens groups changes during zooming from the wide-angle end to the telephoto end; the fourth lens group is made up of one positive lens element, When the total optical length of the zoom lens at the telephoto end is TLt and the focal length of the zoom lens at the telephoto end is ft, 0.10<TLt / ft<0.80 A zoom lens characterized by satisfying the following conditional expressions:

4. When the refractive index of the fourth lens group is ndL4, 1.40<ndL4<1.70 4. The zoom lens according to claim 1, wherein the following condition is satisfied:

5. When the focal length of the second lens group is fL2, -0.35<fL2 / ft<-0.10 5. The zoom lens according to claim 1, wherein the following condition is satisfied:

6. a zoom lens having, arranged in order from the object side to the image side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a fourth lens group having positive refractive power, wherein, during zooming from a wide-angle end to a telephoto end, the first lens group moves, a distance between the first lens group and the second lens group increases, a distance between the second lens group and the third lens group decreases, and a distance between the third lens group and the fourth lens group decreases, and a distance between each of the adjacent lens groups changes during zooming from the wide-angle end to the telephoto end; the fourth lens group is made up of one positive lens element, When the total optical length of the zoom lens at the telephoto end is TLt, the focal length of the zoom lens at the telephoto end is ft, and the focal length of the second lens group is fL2, 0.10<TLt / ft<0.80 -0.35<fL2 / ft<-0.10 A zoom lens characterized by satisfying the following conditional expressions:

7. When the focal length of the third lens group is fL3, 0.10<fL3 / ft<0.90 7. The zoom lens according to claim 1, wherein the following condition is satisfied:

8. When zooming from the wide-angle end to the telephoto end, the movement amount of the fourth lens group is ML4, and the movement amount of the first lens group is ML1, 0.30<ML4 / ML1<3.70 8. The zoom lens according to claim 1, wherein the following condition is satisfied:

9. When the focal length of the fourth lens group is fL4, 0.05<fL4 / ft<0.50 9. The zoom lens according to claim 1, wherein the following condition is satisfied:

10. When the focal length of the fourth lens group is fL4 and the focal length of the first lens group is fL1, 0.10<fL4 / fL1<0.70 10. The zoom lens according to claim 1, wherein the following condition is satisfied:

11. a zoom lens having, arranged in order from the object side to the image side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a fourth lens group having positive refractive power, wherein, during zooming from a wide-angle end to a telephoto end, the first lens group moves, a distance between the first lens group and the second lens group increases, a distance between the second lens group and the third lens group decreases, and a distance between the third lens group and the fourth lens group decreases, and a distance between each of the adjacent lens groups changes during zooming from the wide-angle end to the telephoto end; the fourth lens group is made up of one positive lens element, When the total optical length of the zoom lens at the telephoto end is TLt, the focal length of the zoom lens at the telephoto end is ft, the focal length of the fourth lens group is fL4, and the focal length of the first lens group is fL1, 0.10<TLt / ft<0.80 0.10<fL4 / fL1<0.70 A zoom lens characterized by satisfying the following conditional expressions:

12. When the focal length of the fourth lens group is fL4 and the focal length of the third lens group is fL3, 0.05<fL4 / fL3<1.00 12. The zoom lens according to claim 1, wherein the following condition is satisfied:

13. a zoom lens having, arranged in order from the object side to the image side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a fourth lens group having positive refractive power, wherein, during zooming from a wide-angle end to a telephoto end, the first lens group moves, a distance between the first lens group and the second lens group increases, a distance between the second lens group and the third lens group decreases, and a distance between the third lens group and the fourth lens group decreases, and a distance between each of the adjacent lens groups changes during zooming from the wide-angle end to the telephoto end; the fourth lens group is made up of one positive lens element, When the total optical length of the zoom lens at the telephoto end is TLt, the focal length of the zoom lens at the telephoto end is ft, the focal length of the fourth lens group is fL4, and the focal length of the third lens group is fL3, 0.10<TLt / ft<0.80 0.05<fL4 / fL3<1.00 A zoom lens characterized by satisfying the following conditional expressions:

14. When the average value of the specific gravity of the lenses in the fourth lens group is SL4ave, 1.00<SL4ave<3.90 14. The zoom lens according to claim 1, wherein the following condition is satisfied:

15. When the average value of the Abbe numbers of the positive lenses included in the first lens group with respect to the d-line is νdL1Pave, 55<νdL1Pave<99 15. The zoom lens according to claim 1, wherein the following condition is satisfied:

16. When the average value of the Abbe numbers of the positive lenses included in the third lens group with respect to the d-line is νdL3Pave, 55<νdL3Pave<99 16. The zoom lens according to claim 1, wherein the following condition is satisfied:

17. 17. The zoom lens according to claim 1, wherein the second lens group consists of one negative lens and one positive lens, arranged in order from the object side to the image side.

18. a zoom lens having, arranged in order from the object side to the image side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a fourth lens group having positive refractive power, wherein, during zooming from a wide-angle end to a telephoto end, the first lens group moves, a distance between the first lens group and the second lens group increases, a distance between the second lens group and the third lens group decreases, and a distance between the third lens group and the fourth lens group decreases, and a distance between each of the adjacent lens groups changes during zooming from the wide-angle end to the telephoto end; the second lens group is composed of one negative lens and one positive lens, arranged in this order from the object side to the image side, the fourth lens group is made up of one positive lens element, When the total optical length of the zoom lens at the telephoto end is TLt and the focal length of the zoom lens at the telephoto end is ft, 0.10<TLt / ft<0.80 A zoom lens characterized by satisfying the following conditional expressions:

19. 19. The zoom lens according to claim 1, wherein the third lens group consists of one positive lens and one negative lens arranged in this order from the object side to the image side.

20. 20. The zoom lens according to claim 1, wherein focusing from infinity to a close distance is performed by a lens group arranged closer to the image side than the aperture stop.

21. 21. The zoom lens according to claim 1, wherein the fourth lens group has an aspherical surface.

22. 22. The zoom lens according to claim 1, wherein the number of lenses arranged closer to the image side than the fourth lens group is four or less.

23. 23. The zoom lens according to claim 1, further comprising a lens group having negative refractive power, which is arranged closer to the image side than the fourth lens group.

24. a zoom lens having, arranged in order from the object side to the image side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having positive refractive power, and a lens group having negative refractive power arranged closer to the image side than the fourth lens group, wherein, during zooming from the wide-angle end to the telephoto end, the first lens group moves, a distance between the first lens group and the second lens group increases, a distance between the second lens group and the third lens group decreases, and a distance between the third lens group and the fourth lens group decreases, and the distance between the third lens group and the fourth lens group changes during zooming from the wide-angle end to the telephoto end; the fourth lens group is made up of one positive lens element, When the total optical length of the zoom lens at the telephoto end is TLt and the focal length of the zoom lens at the telephoto end is ft, 0.10<TLt / ft<0.80 A zoom lens characterized by satisfying the following conditional expressions:

25. 25. The zoom lens according to claim 1, wherein the second lens group moves in a direction including a component perpendicular to the optical axis during image blur correction.

26. 26. The zoom lens according to claim 1, wherein the zoom lens comprises, in order from the object side to the image side, the first lens group, the second lens group, the third lens group, the fourth lens group, and a fifth lens group.

27. 26. The zoom lens according to claim 1, wherein the zoom lens comprises, in order from the object side to the image side, the first lens group, the second lens group, the third lens group, the fourth lens group, a fifth lens group, and a sixth lens group.

28. A zoom lens comprising, arranged in order from the object side to the image side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having positive refractive power, a fifth lens group, and a sixth lens group, wherein, during zooming from the wide-angle end to the telephoto end, the first lens group moves, a distance between the first lens group and the second lens group increases, a distance between the second lens group and the third lens group decreases, and a distance between the third lens group and the fourth lens group decreases, and the distance between the third lens group and the fourth lens group decreases, and the distance between adjacent lens groups changes during zooming from the wide-angle end to the telephoto end, the fourth lens group is made up of one positive lens element, When the total optical length of the zoom lens at the telephoto end is TLt and the focal length of the zoom lens at the telephoto end is ft, 0.10<TLt / ft<0.80 A zoom lens characterized by satisfying the following conditional expressions:

29. 26. The zoom lens according to claim 1, wherein the zoom lens comprises, in order from the object side to the image side, the first lens group, the second lens group, the third lens group, the fourth lens group, a fifth lens group, a sixth lens group, and a seventh lens group.

30. a zoom lens comprising, arranged in order from the object side to the image side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having positive refractive power, a fifth lens group, a sixth lens group, and a seventh lens group, wherein, during zooming from the wide-angle end to the telephoto end, the first lens group moves, a distance between the first lens group and the second lens group increases, a distance between the second lens group and the third lens group decreases, and a distance between the third lens group and the fourth lens group decreases, and the distance between the third lens group and the fourth lens group decreases, and the distances between adjacent lens groups change during zooming from the wide-angle end to the telephoto end; the fourth lens group is made up of one positive lens element, When the total optical length of the zoom lens at the telephoto end is TLt and the focal length of the zoom lens at the telephoto end is ft, 0.10<TLt / ft<0.80 A zoom lens characterized by satisfying the following conditional expressions:

31. 31. An imaging device comprising: the zoom lens according to claim 1; and an imaging element that receives an image formed by the zoom lens.

Images