Zoom lens and imaging device having the same

Abstract

To provide a zoom lens that offers a high magnification ratio, excellent correction of various aberrations, a compact size, and fast zoom operation. [Solution] The zoom lens consists of a front group, an intermediate group, and a trailing group, each having one or more lens groups, arranged sequentially from the object side to the image side, and the distance between adjacent lens groups changes during zooming. The front group consists of a first front lens group with positive refractive power that is fixed during zooming, and the intermediate group consists of first and second intermediate lens groups with negative and negative refractive power, arranged sequentially from the object side to the image side, and a third intermediate lens group that moves from the object side to the image side when zooming from the wide-angle end to the telephoto end. The focal length of the first front lens group, the distance along the optical axis from the lens surface closest to the object to the lens surface closest to the image of the first intermediate lens group, and the distance along the optical axis from the lens surface closest to the object to the lens surface closest to the image of the second intermediate lens group are set appropriately.

Description

Technical Field

[0001] The present invention relates to a zoom lens and an imaging apparatus including the same. Background Art

[0002] In recent years, there has been a demand for compact zoom lenses that have a high zoom ratio, allow favorable correction of various aberrations, and enable high-speed zoom operation. Summary of Invention Problem to be Solved by Invention

[0003] There is a desire for a compact zoom lens that has a high zoom ratio, allows favorable correction of various aberrations, and enables high-speed zoom operation. Means for Solving Problem

[0004] A zoom lens according to one aspect of the present invention includes a front group, an intermediate group, and a rear group, each including one or more lens units, arranged in order from the object side to the image side, wherein the distance between adjacent lens units changes during zooming. The front group includes a first front lens unit having positive refractive power, the first front lens unit is fixed with respect to an image plane during zooming, the intermediate group includes a first intermediate lens unit having negative refractive power, a second intermediate lens unit having negative refractive power, and a third intermediate lens unit, arranged in order from the object side to the image side, and the third intermediate lens unit moves from the object side to the image side during zooming from the wide-angle end to the telephoto end. When the focal length of the first front lens unit is denoted as fLF1, the distance on the optical axis from the most object-side lens surface of the first intermediate lens unit to the most image-side lens surface of the first intermediate lens unit is denoted as TLM1, and the distance on the optical axis from the most object-side lens surface of the second intermediate lens unit to the most image-side lens surface of the second intermediate lens unit is denoted as TLM2, 0.001<TLM1 / fLF1<0.025 0.001<TLM2 / fLF1<0.022 the zoom lens satisfies the following conditional expression.

[0005] Furthermore, as another aspect of the present invention, the zoom lens comprises a front group, an intermediate group, and a successor group, each having one or more lens groups, arranged sequentially from the object side to the image side, wherein the spacing between adjacent lens groups changes during zooming, the front group consists of a first front lens group with positive refractive power, the first front lens group is fixed to the image plane during zooming, and the intermediate group consists of a first intermediate lens group, a second intermediate lens group, and a third intermediate lens group, arranged sequentially from the object side to the image side. [Brief explanation of the drawing]

[0006] [Figure 1] This is a cross-sectional view of the zoom lens in Example 1 when it is in focus on an object at infinity at the wide-angle end. [Figure 2] These are aberration diagrams of the zoom lens in Example 1, (A) when focused on an object at infinity at the wide-angle end and (B) when focused on an object at infinity at the telephoto end. [Figure 3] This is a cross-sectional view of the zoom lens in Example 2 when it is in focus on an object at infinity at the wide-angle end. [Figure 4] These are aberration diagrams of the zoom lens in Example 2, (A) when focused on an object at infinity at the wide-angle end and (B) when focused on an object at infinity at the telephoto end. [Figure 5] This is a cross-sectional view of the zoom lens in Example 3 when it is in focus on an object at infinity at the wide-angle end. [Figure 6] These are aberration diagrams of the zoom lens in Example 3, (A) when focused on an object at infinity at the wide-angle end and (B) when focused on an object at infinity at the telephoto end. [Figure 7] This is a cross-sectional view of the zoom lens in Example 4 when it is in focus on an object at infinity at the wide-angle end. [Figure 8] These are aberration diagrams of the zoom lens in Example 4, (A) when focused on an object at infinity at the wide-angle end and (B) when focused on an object at infinity at the telephoto end. [Figure 9] This is a cross-sectional view of the zoom lens in Example 5 when it is in focus on an object at infinity at the wide-angle end. [Figure 10]These are aberration diagrams of the zoom lens in Example 5, (A) when focused on an object at infinity at the wide-angle end and (B) when focused on an object at infinity at the telephoto end. [Figure 11] This is a cross-sectional view of the zoom lens in Example 6 when it is in focus on an object at infinity at the wide-angle end. [Figure 12] These are aberration diagrams of the zoom lens in Example 6, (A) when focused on an object at infinity at the wide-angle end and (B) when focused on an object at infinity at the telephoto end. [Figure 13] This is a schematic diagram of the imaging device. [Modes for carrying out the invention]

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

[0008] Figures 1, 3, 5, 7, 9, and 11 are cross-sectional views of the zoom lenses in Examples 1 to 6 when focused on an object at infinity at the wide-angle end. The zoom lenses L0 in each example are used in imaging devices such as digital video cameras, digital still cameras, broadcast cameras, silver halide film cameras, surveillance cameras, and in-vehicle cameras.

[0009] In each cross-sectional view, the left side is the object side and the right side is the image side. Note that the zoom lens L0 in each embodiment may also be used as a projection lens for a projector or the like. In this case, the left side is the screen side and the right side is the projected image side.

[0010] The zoom lens L0 in each embodiment is composed of multiple lens groups. In this specification, a lens group is a collection of lenses that move or remain stationary as a whole during zooming (magnification). That is, in the zoom lens L0 of each embodiment, the distance between adjacent lens groups changes during zooming. A lens group may consist of one lens or multiple lenses. Furthermore, a lens group may include an aperture diaphragm.

[0011] The zoom lens L0 of each embodiment consists of a front group LF, an intermediate group LM, and a rear group LR, which are arranged in order from the object side to the image side, each having at least one lens group.

[0012] In each cross-sectional view, LFi represents the i-th (i is a natural number) lens group counted from the object side among the lens groups included in the front group LF. LMi represents the i-th (i is a natural number) lens group counted from the object side among the lens groups included in the intermediate group LM. LRi represents the i-th (i is a natural number) lens group counted from the object side among the lens groups included in the rear group LR.

[0013] SP is an aperture stop, which determines (limits) the light flux of the open F-number (Fno). I is an image plane. When the zoom lens L0 of each embodiment is used as an imaging optical system of a digital still camera or a digital video camera, the imaging surface of an imaging element (photoelectric conversion element) such as a CCD sensor or a CMOS sensor is disposed thereon. When the zoom lens of each embodiment is used as an imaging optical system of a silver halide film camera, a photosensitive surface corresponding to the film surface is disposed on the image plane I.

[0014] Further, solid arrows indicate movement trajectories of the respective lens groups during zooming from the wide-angle end to the telephoto end. Furthermore, during focusing from an infinite-distance object to a closest-distance object, the lens group (focus group) moves as indicated by the arrow marked with FOCUS.

[0015] FIGS. 2, 4, 6, 8, 10, and 12 are aberration diagrams of the zoom lenses L0 of Embodiments 1 to 6, respectively, when focused on an infinite-distance object. In each aberration diagram, (A) is an aberration diagram at the wide-angle end, and (B) is an aberration diagram at the telephoto end.

[0016] In the spherical aberration diagram, Fno represents the F-number, and indicates the amount of spherical aberration for the d-line (wavelength 587.56 nm) and the g-line (wavelength 435.8 nm). In the astigmatism diagram, S indicates the amount of astigmatism on the sagittal image plane for the d-line, and M indicates the amount of astigmatism on the meridional image plane for the d-line. In the distortion diagram, the amount of distortion for the d-line is indicated. In the chromatic aberration diagram, the amount of chromatic aberration for the g-line is indicated. ω is the half imaging angle of view [°] obtained by paraxial calculation.

[0017] Hereinafter, characteristic configurations of the zoom lens L0 in each example will be described.

[0018] The front group LF consists of a first front lens group LF1 having positive refractive power. The first front lens group LF1 is fixed relative to the image surface during zooming. By fixing the first front lens group LF1, which tends to have a relatively large lens diameter and a large mass, during zooming, it is easy to achieve high-speed zoom operation.

[0019] The intermediate group LM consists of a first intermediate lens group LM1, a second intermediate lens group LM2, and a third intermediate lens group LM3, which are arranged in order from the object side to the image side.

[0020] Hereinafter, configurations that are preferably satisfied in the zoom lens L0 of each example will be described.

[0021] It is preferable that the third intermediate lens group LM3 moves from the object side to the image side during zooming from the wide-angle end to the telephoto end. This is preferable because it facilitates reducing the diameter and weight of the third intermediate lens group LM3 and achieving high-speed zoom operation.

[0022] It is preferable that the first rear lens group LR1, which is arranged closest to the object side among the lens groups included in the rear group LR, has positive refractive power. This is preferable because it facilitates shortening the overall length and reducing the size of the zoom lens.

[0023] The first subsequent lens group LR1 is preferably fixed to the image plane during zooming. This is preferable because it simplifies the mechanism and facilitates miniaturization.

[0024] The first subsequent lens group LR1 preferably has an aperture diaphragm SP. This is preferable because it facilitates aberration correction before and after the aperture diaphragm SP, making it easier to achieve high image quality.

[0025] It is preferable that the second subsequent lens group LR2, which is part of the subsequent lens group LR and is positioned adjacent to the image side of the first subsequent lens group LR1, moves during zooming. This is preferable because it facilitates aberration correction in the subsequent lens group LR and makes it easier to achieve high image quality.

[0026] The second subsequent lens group LR2 is preferably moved during focusing. Placing the lens group that moves during focusing on the image side, where the lens diameter is relatively smaller, is preferable because it simplifies the mechanism and facilitates miniaturization.

[0027] The second subsequent lens group LR2 preferably has negative refractive power. This is preferable because it facilitates shortening the overall length by using a telephoto configuration for the subsequent group LR.

[0028] It is preferable that the lens group positioned closest to the image plane be fixed to the image plane during zooming. Fixing the lenses near the image plane, which have relatively large lens diameters, to the image plane during zooming simplifies the mechanism and facilitates miniaturization, which is therefore preferable.

[0029] The front lens group LF and the intermediate lens group LM are preferably fixed to the image plane during focusing. Fixing the object-side lens, which has a relatively large lens diameter, to the image plane during focusing simplifies the mechanism and facilitates miniaturization, which is therefore preferable.

[0030] The first subsequent lens group LR1 preferably has the positive lens closest to the object. This is preferable because it results in a telephoto configuration, which facilitates shortening the overall length.

[0031] The following describes the conditions that the zoom lens L0 of each embodiment preferably satisfies. The zoom lens of each embodiment preferably satisfies one or more of the following conditional expressions (1) to (15).

[0032] 0.001 <TLM1 / fLF1<0.025 ···(1) 0.001 <TLM2 / fLF1<0.022 ···(2) 0.2 <fLF1 / ft<2.1 ···(3) -3.4 <fw / fLM1<-0.3 ···(4) -4.5 <fw / fLM2<-0.2 ···(5) -2.8 <fw / fLM3<2.3 ···(6) 0.7 <fw / fLR1<7.6 ···(7) 0.1 <MLM1 / fLF1<0.8 ···(8) 0.1 <MLM2 / fLF1<0.8 ···(9) 0.1 <MLM3 / fLF1<0.6 ···(10) -2.5 < βLRw < -0.2 ···(11) 0.3<βLRt / βLRw<2.7 (12) -8.8 < βLMt < -0.5 ···(13) 0.1 <BFw / fw<1.1 ···(14) 0.3 <Lt / ft<3.1 ···(15) Here, fLF1 is the focal length of the first front lens group LF1. TLM1 is the thickness of the first intermediate lens group LM1, i.e., the distance along the optical axis from the lens surface (vertex) closest to the object of the first intermediate lens group LM1 to the lens surface (vertex) closest to the image of the first intermediate lens group LM1. TLM2 is the thickness of the second intermediate lens group LM2, i.e., the distance along the optical axis from the lens surface (vertex) closest to the object of the second intermediate lens group LM2 to the lens surface (vertex) closest to the image of the second intermediate lens group LM2. ft is the focal length of the zoom lens L0 when focused on an object at infinity at the telephoto end. fw is the focal length of the zoom lens L0 when focused on an object at infinity at the wide-angle end. fLM1 is the focal length of the first intermediate lens group LM1. fLM2 is the focal length of the second intermediate lens group LM2. fLM3 is the focal length of the third intermediate lens group LM3. fLR1 is the focal length of the first subsequent lens group LR1. MLM1 is the amount of movement of the first intermediate lens group LM1 when zooming from the wide-angle end to the telephoto end (movement toward the object is considered positive). MLM2 is the amount of movement of the second intermediate lens group LM2 when zooming from the wide-angle end to the telephoto end (movement toward the object is considered positive). MLM3 is the amount of movement of the third intermediate lens group LM3 when zooming from the wide-angle end to the telephoto end (movement toward the object is considered positive). βLRw is the combined horizontal magnification of the subsequent group LR at the wide-angle end. βLRt is the combined horizontal magnification of the subsequent group LR at the telephoto end. βLMt is the combined horizontal magnification of the intermediate group LM at the telephoto end. BFw is the back focus when focusing on an object at infinity at the wide-angle end. Back focus is the distance along the optical axis from the image-side lens surface (vertex of the surface) of the lens positioned closest to the image in a power lens system to the image plane. If a flat plate or similar object is placed between the closest lens and the image plane, the distance should be calculated using air equivalent. Lt is the distance along the optical axis from the lens surface (vertex of the surface) closest to the object to the image plane when focusing on an object at infinity at the telephoto end.

[0033] Condition (1) specifies the thickness of the first intermediate lens group LM1. If the thickness of the first intermediate lens group LM1 exceeds the upper limit of condition (1), the mass of the first intermediate lens group LM1 increases, making it difficult to achieve high-speed zoom operation, which is undesirable. If the thickness of the first intermediate lens group LM1 falls below the lower limit of condition (1), it becomes difficult to correct various aberrations, especially astigmatism at the telephoto end, which is also undesirable.

[0034] Condition (2) specifies the thickness of the second intermediate lens group LM2. If the thickness of the second intermediate lens group LM2 exceeds the upper limit of condition (2), the mass of the second intermediate lens group LM2 increases, making it difficult to achieve high-speed zoom operation, which is undesirable. If the thickness of the second intermediate lens group LM2 falls below the lower limit of condition (2), it becomes difficult to correct various aberrations, especially astigmatism at the telephoto end, which is also undesirable.

[0035] Conditional equation (3) defines the relationship between the focal length of the first front lens group LF1 and the focal length of the zoom lens L0 when focused on an object at infinity at the telephoto end. Exceeding the upper limit of conditional equation (3) is undesirable because it makes it difficult to shorten the overall length and increases the size of the zoom lens L0. Exceeding the lower limit of conditional equation (3) is undesirable because it makes it difficult to correct various aberrations, especially chromatic aberration at the telephoto end.

[0036] Conditional equation (4) defines the relationship between the focal length of the first intermediate lens group LM1 and the focal length of the zoom lens L0 when focused on an object at infinity at the wide-angle end. Exceeding the upper limit of conditional equation (4) is undesirable because it becomes difficult to achieve a high magnification ratio. Exceeding the lower limit of conditional equation (4) is undesirable because it becomes difficult to correct various aberrations, especially spherical aberration at the telephoto end.

[0037] Conditional equation (5) defines the relationship between the focal length of the second intermediate lens group LM2 and the focal length of the zoom lens L0 when focused on an object at infinity at the wide-angle end. Exceeding the upper limit of conditional equation (5) is undesirable because it makes it difficult to achieve a high magnification ratio. Exceeding the lower limit of conditional equation (5) is undesirable because it makes it difficult to correct various aberrations, especially spherical aberration at the telephoto end.

[0038] Conditional equation (6) defines the relationship between the focal length of the third intermediate lens group LM3 and the focal length of the zoom lens L0 when focused on an object at infinity at the wide-angle end. Exceeding the upper limit of conditional equation (6) is undesirable because it becomes difficult to correct various aberrations, especially spherical aberration at the telephoto end. Exceeding the lower limit of conditional equation (6) is undesirable because it makes the zoom lens L0 larger.

[0039] Conditional equation (7) defines the relationship between the focal length of the first successor lens group LR1 and the focal length of the zoom lens L0 when focused on an object at infinity at the wide-angle end. Exceeding the upper limit of conditional equation (7) is undesirable because it becomes difficult to correct various aberrations, especially spherical aberration at the telephoto end. Exceeding the lower limit of conditional equation (7) is undesirable because it makes the zoom lens L0 larger.

[0040] Conditional equation (8) defines the relationship between the amount of movement of the first intermediate lens group LM1 during zooming from the wide-angle end to the telephoto end and the focal length of the first front lens group LF1. Exceeding the upper limit of conditional equation (8) is undesirable because it increases the size of the zoom lens L0. Exceeding the lower limit of conditional equation (8) is undesirable because it makes it difficult to achieve high magnification.

[0041] Conditional equation (9) defines the relationship between the amount of movement of the second intermediate lens group LM2 during zooming from the wide-angle end to the telephoto end and the focal length of the first front lens group LF1. Exceeding the upper limit of conditional equation (9) is undesirable because it increases the size of the zoom lens L0. Exceeding the lower limit of conditional equation (9) is undesirable because it makes it difficult to achieve high magnification.

[0042] Conditional equation (10) defines the relationship between the amount of movement of the third intermediate lens group LM3 during zooming from the wide-angle end to the telephoto end and the focal length of the first front lens group LF1. Exceeding the upper limit of conditional equation (10) is undesirable because it increases the size of the zoom lens L0. Exceeding the lower limit of conditional equation (10) is undesirable because it makes it difficult to achieve high magnification.

[0043] Conditional equation (11) defines the combined lateral magnification at the wide-angle end of the subsequent LR group. Exceeding the upper limit of conditional equation (11) is undesirable because it makes it difficult to correct various aberrations, especially field curvature at the optical end. Exceeding the lower limit of conditional equation (11) is also undesirable because the focal length at the wide-angle end becomes too large.

[0044] Conditional equation (12) defines the relationship between the combined horizontal magnification at the wide-angle end of the subsequent LR group and the combined horizontal magnification at the telephoto end of the subsequent LR group. If the value exceeds the upper limit of conditional equation (12), it becomes difficult to correct various aberrations, especially field curvature at the telephoto end, which is undesirable. If the value falls below the lower limit of conditional equation (12), it becomes difficult to achieve high magnification, which is also undesirable.

[0045] Conditional equation (13) defines the combined lateral magnification at the telephoto end of the intermediate LM group. Exceeding the upper limit of conditional equation (13) is undesirable because it results in an excessively small focal length at the telephoto end. Exceeding the lower limit of conditional equation (13) is also undesirable because it makes it difficult to correct various aberrations, especially astigmatism at the telephoto end.

[0046] Conditional equation (14) defines the relationship between the back focus when focusing on an object at infinity at the wide-angle end and the focal length of the zoom lens L0 when focusing on an object at infinity at the wide-angle end. If the back focus becomes larger than the upper limit of conditional equation (14), the zoom lens L0 becomes larger, which is undesirable. If the back focus becomes smaller than the lower limit of conditional equation (14), the diameter of the rear lens element becomes larger, which is also undesirable.

[0047] Conditional equation (15) defines the relationship between the distance along the optical axis from the lens surface closest to the object to the image plane when focusing on an object at infinity at the telephoto end, and the focal length of the zoom lens when focusing on an object at infinity at the telephoto end. Exceeding the upper limit of conditional equation (15) is undesirable because it increases the size of the zoom lens L0. Exceeding the lower limit of conditional equation (15) is undesirable because it becomes difficult to correct various aberrations, especially field curvature at the telephoto end.

[0048] Furthermore, it is more preferable that the lower limit of condition (1) be set to 0.0015, 0.0020, 0.0025, 0.0030, 0.0035, 0.0040, 0.0042, 0.0044, 0.0046, or 0.0048. It is more preferable that the upper limit of condition (1) be set to 0.0240, 0.0230, 0.0225, 0.0220, 0.0215, 0.0210, 0.0205, 0.0200, 0.0195, or 0.0190.

[0049] Furthermore, it is more preferable that the lower limit of condition (2) be set to 0.0015, 0.0020, 0.0025, 0.0030, 0.0035, 0.0040, 0.0042, 0.0044, 0.0046, or 0.0048. It is more preferable that the upper limit of condition (2) be set to 0.0218, 0.0216, 0.0214, 0.0212, 0.0210, 0.0209, 0.0208, 0.0207, 0.0206, or 0.0205.

[0050] Furthermore, it is more preferable that the lower limit of conditional expression (3) be set to 0.22, 0.25, 0.28, 0.31, 0.34, 0.37, 0.39, 0.40, 0.41, or 0.42. It is more preferable that the upper limit of conditional expression (3) be set to 2.00, 1.80, 1.60, 1.40, 1.30, 1.20, 1.16, 1.13, 1.10, or 1.08.

[0051] Furthermore, it is more preferable that the lower limit of conditional expression (4) be set to -3.2, -3.0, -2.8, -2.6, -2.4, -2.2, -2.1, -2.0, -1.9, or -1.8. It is more preferable that the upper limit of conditional expression (4) be set to -0.35, -0.40, -0.45, -0.50, -0.55, -0.57, -0.59, -0.61, -0.63, or -0.65.

[0052] Furthermore, it is more preferable that the lower limit of conditional expression (5) be set to -4.1, -3.9, -3.7, -3.5, -3.3, -3.1, -2.9, -2.7, -2.5, or -2.3. It is more preferable that the upper limit of conditional expression (5) be set to -0.22, -0.24, -0.25, -0.26, -0.27, -0.28, -0.29, -0.30, -0.31, or -0.32.

[0053] Furthermore, it is more preferable that the lower limit of conditional expression (6) be set to -2.6, -2.4, -2.2, -2.0, -1.9, -1.8, -1.7, -1.6, -1.5, or -1.4. It is more preferable that the upper limit of conditional expression (6) be set to 2.2, 2.0, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, or 1.2.

[0054] Furthermore, it is more preferable that the lower limit of conditional expression (7) be set to 0.80, 1.00, 1.05, 1.10, 1.15, 1.20, 1.25, 1.30, 1.35, or 1.40. It is more preferable that the upper limit of conditional expression (7) be set to 7.4, 7.0, 6.6, 6.2, 5.8, 5.4, 5.0, 4.6, 4.2, or 3.8.

[0055] Furthermore, it is more preferable that the lower limit of conditional expression (8) be set to 0.110, 0.120, 0.125, 0.130, 0.135, 0.140, 0.145, 0.150, 0.155, or 0.158. It is more preferable that the upper limit of conditional expression (8) be set to 0.75, 0.70, 0.65, 0.60, 0.55, 0.50, 0.45, 0.40, 0.39, or 0.38.

[0056] Furthermore, it is more preferable that the lower limit of condition expression (9) be set to 0.110, 0.116, 0.118, 0.120, 0.122, 0.124, 0.126, 0.128, 0.130, or 0.132. It is more preferable that the upper limit of condition expression (9) be set to 0.75, 0.70, 0.65, 0.60, 0.55, 0.50, 0.45, 0.40, 0.39, or 0.38.

[0057] Furthermore, it is more preferable that the lower limit of condition expression (10) be set to 0.101, 0.103, 0.104, 0.105, 0.106, 0.107, 0.108, 0.109, 0.110, or 0.111. It is more preferable that the upper limit of condition expression (10) be set to 0.55, 0.50, 0.45, 0.40, 0.36, 0.35, 0.34, 0.33, 0.32, or 0.31.

[0058] Furthermore, it is more preferable that the lower limit of conditional expression (11) be set to -2.4, -2.2, -2.0, -1.9, -1.8, -1.7, -1.6, -1.5, -1.4, or -1.3. It is more preferable that the upper limit of conditional expression (11) be set to -0.21, -0.24, -0.27, -0.30, -0.33, -0.36, -0.39, -0.42, -0.45, or -0.48.

[0059] Furthermore, it is more preferable that the lower limit of condition expression (12) be set to 0.35, 0.40, 0.45, 0.50, 0.55, 0.56, 0.57, 0.58, 0.59, or 0.60. It is more preferable that the upper limit of condition expression (12) be set to 2.5, 2.3, 2.1, 2.0, 1.9, 1.8, 1.7, 1.6, 1.5, or 1.4.

[0060] Furthermore, it is more preferable that the lower limit of conditional expression (13) be set to -8.5, -8.0, -7.5, -7.0, -6.5, -6.0, -5.5, -5.0, -4.7, or -4.5. It is more preferable that the upper limit of conditional expression (13) be set to -0.55, -0.60, -0.65, -0.70, -0.75, -0.80, -0.85, -0.90, -0.95, or -1.00.

[0061] Furthermore, it is more preferable that the lower limit of conditional expression (14) be set to 0.110, 0.120, 0.130, 0.140, 0.150, 0.160, 0.170, 0.180, 0.185, or 0.190. It is more preferable that the upper limit of conditional expression (14) be set to 1.00, 0.90, 0.80, 0.70, 0.66, 0.64, 0.62, 0.60, 0.58, or 0.56.

[0062] Furthermore, it is more preferable that the lower limit of condition expression (15) be set to 0.35, 0.40, 0.44, 0.48, 0.50, 0.52, 0.54, 0.56, 0.57, or 0.58. It is more preferable that the upper limit of condition expression (15) be set to 3.0, 2.8, 2.6, 2.4, 2.2, 2.0, 1.9, 1.8, 1.7, or 1.6.

[0063] Next, we will describe the zoom lens L0 of each embodiment in detail.

[0064] The zoom lens L0 of Example 1 consists of a front group LF, an intermediate group LM, and a trailing group LR, each having one or more lens groups, arranged in order from the object side to the image side. The front group LF consists of a first front lens group LF1 with positive refractive power. The first front lens group LF1 is fixed to the image plane during zooming. The intermediate group LM consists of a first intermediate lens group LM1 with negative refractive power, a second intermediate lens group LM2 with negative refractive power, and a third intermediate lens group LM3 with positive refractive power, arranged in order from the object side to the image side. The first intermediate lens group LM1, the second intermediate lens group LM2, and the third intermediate lens group LM3 move from the object side to the image side during zooming from the wide-angle end to the telephoto end. The trailing group LR consists of a first trailing lens group LR1 to a fifth trailing lens group LR5 with positive, negative, positive, negative, and negative refractive powers, arranged in order from the object side to the image side. The first trailing lens group LR1 is fixed to the image plane during zooming. The first trailing lens group LR1 has an aperture diaphragm. The second trailing lens group LR2 moves during zooming. The second trailing lens group LR2 moves towards the image when focusing from infinity to near distance. The third trailing lens group LR3 is fixed to the image plane during zooming. The fourth trailing lens group LR4 moves during zooming. The fourth trailing lens group LR4 moves towards the image when focusing from infinity to near distance. The fifth trailing lens group LR5 is fixed to the image plane during zooming.

[0065] The zoom lens L0 of Examples 2 to 5 consists of a front group LF, an intermediate group LM, and a trailing group LR, each having one or more lens groups, arranged sequentially from the object side to the image side. The front group LF consists of a first front lens group LF1 with positive refractive power. The first front lens group LF1 is fixed to the image plane during zooming. The intermediate group LM consists of a first intermediate lens group LM1 with negative refractive power, a second intermediate lens group LM2 with negative refractive power, and a third intermediate lens group LM3 with positive refractive power, arranged sequentially from the object side. The first intermediate lens group LM1, the second intermediate lens group LM2, and the third intermediate lens group LM3 move from the object side to the image side during zooming from the wide-angle end to the telephoto end. The trailing group LR consists of a first trailing lens group LR1 to a third trailing lens group LR3 with positive, negative, and positive refractive powers, arranged sequentially from the object side to the image side. The first trailing lens group LR1 is fixed to the image plane during zooming. The first trailing lens group LR1 has an aperture diaphragm. The second trailing lens group LR2 moves during zooming. The second trailing lens group LR2 moves towards the image plane when focusing from infinity to near distance. The third trailing lens group LR3 is fixed to the image plane during zooming.

[0066] The zoom lens L0 of Example 6 consists of a front group LF, an intermediate group LM, and a trailing group LR, each having one or more lens groups, arranged sequentially from the object side to the image side. The front group LF consists of a first front lens group LF1 with positive refractive power. The first front lens group LF1 is fixed to the image plane during zooming. The intermediate group LM consists of a first intermediate lens group LM1 with negative refractive power, a second intermediate lens group LM2 with negative refractive power, and a third intermediate lens group LM3 with negative refractive power, arranged sequentially from the object side. The first intermediate lens group LM1, the second intermediate lens group LM2, and the third intermediate lens group LM3 move from the object side to the image side during zooming from the wide-angle end to the telephoto end. The trailing group LR consists of a first trailing lens group LR1 to a third trailing lens group LR3 with positive, negative, and positive refractive powers, arranged sequentially from the object side to the image side. The first trailing lens group LR1 is fixed to the image plane during zooming. The first trailing lens group LR1 has an aperture diaphragm. The second trailing lens group LR2 moves during zooming. The second trailing lens group LR2 moves towards the image plane when focusing from infinity to near distance. The third trailing lens group LR3 is fixed to the image plane during zooming.

[0067] In the zoom lenses L0 of Examples 1 to 6, all surfaces having refractive power are composed of refractive surfaces. Compared to cases where diffractive optical elements or reflective surfaces are used, optical performance equivalent to or better than that of cases where diffractive optical elements or reflective surfaces are used can be easily obtained with lower manufacturing difficulty.

[0068] In the zoom lenses L0 of Examples 1 to 6, no optical elements such as prisms that bend the optical path are arranged. Having prisms or the like that bends the optical path increases the thickness of the lens, making miniaturization difficult, which is undesirable.

[0069] The numerical values ​​corresponding to Examples 1 to 6 are shown below.

[0070] In the surface data for each numerical example, r represents the radius of curvature of each optical surface, and d (mm) represents the on-axial spacing (distance along the optical axis) between the m-th surface and the (m+1)-th surface. Here, m is the surface number counted from the light incidence side. Furthermore, nd represents the refractive index of each optical component with respect to the d-line, and νd represents the Abbe number of each optical component with respect to the d-line. Note that the Abbe number νd of a certain material is given by Nd, NF, and NC, respectively, when the refractive indices at the Fraunhofer lines d-line (587.6 nm), F-line (486.1 nm), and C-line (656.3 nm) are Nd, NF, and NC, respectively. νd = (Nd-1) / (NF-NC) It is represented as follows.

[0071] In each numerical example, d, focal length (mm), F-number, and half-angle of view (°) are all values ​​when the zoom lens L0 of each example is focused on an object at infinity. "Back focus (BF)" is the distance along the optical axis from the final surface (the lens surface closest to the image) of the zoom lens L0 to the paraxial image plane, expressed in terms of air equivalent length. "Total lens length" is the length obtained by adding the back focus to the distance along the optical axis from the frontmost surface (the lens surface closest to the object) to the final surface of the zoom lens L0.

[0072] Furthermore, if the optical surface is aspherical, the sign * is added to the right of the surface number. The aspherical shape is defined as follows, where X is the displacement from the surface vertex in the optical axis direction, H is the height from the optical axis perpendicular to the optical axis, R is the paraaxial radius of curvature, K is the cone constant, and A4, A5, A6, A7, A8, A9, A10, A11, A12 are the aspherical coefficients of their respective orders.

[0073]

number

[0074] This is expressed as follows. Note that "e±XX" in each aspherical coefficient is "×10± XX It means "...".

[0075] [Numerical Example 1] Unit: mm Surface data Face number rd nd νd Effective diameter 1 262.061 2.00 1.74951 35.3 71.95 2 112.605 9.48 1.49700 81.5 70.42 3 -460.620 0.20 69.99 4 80.743 8.75 1.49700 81.5 67.61 5 473.802 (Variable) 66.42 6 79.217 1.40 1.80400 46.5 43.59 7 40.318 (variable) 40.28 8 -95.544 1.40 1.59282 68.6 40.22 9 143.830 (Variable) 40.93 10 59.016 6.29 1.80518 25.4 42.35 11 3274.925 2.93 42.04 12 -83.952 1.60 1.49700 81.5 41.99 13 142.209 (variable) 42.15 14* 80.299 5.50 1.58313 59.4 42.54 15* -441.519 0.15 42.49 16 62.104 7.47 1.43387 95.1 41.88 17 -116.621 3.26 41.27 18 (aperture) ∞ 4.09 38.04 19 -100.306 1.40 1.77047 29.7 36.51 20 55.864 5.93 35.48 21 74.214 1.20 1.85478 24.8 36.84 22 42.266 7.47 1.76385 48.5 36.55 23* -194.403 0.48 36.41 24 70.089 5.10 1.61800 63.4 35.67 25 -184.791 (variable) 35.03 26 745.543 2.75 1.92286 20.9 32.98 27 -150.403 1.00 1.61340 44.3 32.33 28 33.408 (variable) 30.35 29 50.960 10.21 1.51633 64.1 40.08 30 -57.713 (variable) 40.13 31 -129.079 1.30 1.90110 27.1 39.03 32 101.826 (variable) 38.83 33 165.501 5.86 1.84666 23.8 41.04 34 -87.663 12.99 41.11 35* -28.324 2.10 1.58313 59.4 37.66 36* -275.175 (variable) 39.59 Image plane ∞ Aspherical data Page 14 K = 0.00000e+00 A 4=-1.35279e-06 A 6=-1.41239e-10 A 8=-1.79295e-12 Page 15 K = 0.00000e+00 A 4=-1.79535e-07 A 6=-2.14412e-10 A 8=-1.70807e-12 Page 23 K = 0.00000e+00 A 4= 7.64577e-07 A 6= 1.37775e-10 A 8=-1.38956e-13 Page 35 K = 0.00000e+00 A 4= 1.21476e-05 A 6=-1.50760e-08 A 8= 1.75889e-11 A10= 9.64191e-16 Page 36 K = 0.00000e+00 A 4= 4.88184e-06 A 6=-1.70817e-08 A 8= 9.50057e-12 Various data Zoom ratio 1.90 Wide-angle, Medium, Telephoto Focal length 72.10 99.23 136.89 F number 2.05 2.05 2.05 Half-angle (°): 16.70, 12.30, 8.98 Image height 21.64 21.64 21.64 Lens length 211.33 211.33 211.33 BF 14.02 14.02 14.02 d 5 9.24 27.85 44.43 d 7 11.82 10.23 9.50 d 9 7.33 3.11 0.98 d13 27.65 14.85 1.12 d25 2.04 1.98 0.98 d28 17.35 17.41 18.41 d30 4.18 3.92 0.85 d32 5.40 5.67 8.73 d36 14.02 14.02 14.02 Entrance pupil position 93.38 133.52 173.45 Exit pupil position -47.28 -47.45 -49.67 Front principal point position 80.67 72.56 16.10 Back principal point position -58.08 -85.21 -122.87 Zoom lens group data Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 146.81 20.43 5.72 -7.81 2 6 -103.79 1.40 1.61 0.82 3 8 -96.63 1.40 0.35 -0.53 4 10 206.56 10.82 -13.45 -19.69 5 14 49.56 42.05 20.90 -18.79 6 26 -66.67 3.75 2.31 0.25 7 29 54.15 10.21 3.26 -3.69 8 31 -63.00 1.30 0.38 -0.30 9 33 -25075.54 20.95 6441.30 5110.94 Single lens data Lens starting plane, focal length 1 1 -264.95 2 2 183.07 3 4 194.40 4 6 -103.79 5 8 -96.63 6 10 74.58 7 12 -105.97 8 14 116.97 9 16 94.60 10 19 -46.39 11 21 -116.89 12 22 46.08 13 24 82.86 14 26 135.82 15 27 -44.47 16 29 54.15 17 31 -63.00 18 33 68.41 19 35 -54.32 [Numerical Example 2] Unit: mm Surface data Face number rd nd νd Effective diameter 1 361.011 6.57 1.48749 70.2 96.73 2 -1485.054 0.20 96.32 3 160.947 9.95 1.43387 95.1 94.12 4 31391.523 33.74 93.01 5 120.834 10.19 1.43875 94.7 75.81 6 -788.983 2.40 1.61340 44.3 74.21 7 128.256 (variable) 70.69 8 143.575 1.80 1.49700 81.5 39.88 9 48.690 (Variable) 38.48 10 -137.556 1.60 1.72916 54.1 38.29 11 226.174 (Variable) 38.60 12 78.992 3.44 1.85478 24.8 39.32 13 399.071 2.60 39.18 14 -100.748 1.60 1.49700 81.5 39.16 15 215.566 (variable) 39.48 16 99.030 4.66 1.49700 81.5 40.45 17 -217.632 0.15 40.46 18 54.964 4.94 1.49700 81.5 40.03 19 369.405 3.20 39.51 20 (aperture) ∞ 0.10 38.39 21 35.805 3.76 1.49700 81.5 36.29 22 60.656 2.00 1.72047 34.7 35.34 23 38.091 4.93 33.27 24 25878.787 1.60 1.83481 42.7 32.79 25 47.455 2.87 31.79 26 95.521 1.80 1.92119 24.0 32.04 27 57.392 4.34 1.49700 81.5 31.83 28 -211.192 0.15 31.92 29 86.334 3.11 1.85150 40.8 31.97 30 -578.932 0.49 31.75 31 48.486 3.18 1.51742 52.4 30.63 32 148.932 (variable) 29.97 33 -327.562 3.11 1.92286 20.9 27.61 34 -84.741 0.14 27.01 35 -97.830 1.30 1.90043 37.4 26.74 36 53.965 (Variable) 25.65 37 83.713 1.99 1.92286 20.9 44.99 38 55.434 9.43 1.66565 35.6 44.60 39 -93.812 17.20 44.61 40 -64.497 2.00 1.49700 81.5 39.16 41 197.784 (Variable) 39.19 Image plane ∞ Various data Zoom ratio 1.90 Wide-angle, Medium, Telephoto Focal length 205.00 282.33 389.99 F-number 4.10 4.10 4.10 Half-angle (°): 6.02, 4.38, 3.18 Image height 21.64 21.64 21.64 Lens length 367.04 367.04 367.04 BF 40.00 40.00 40.00 d 7 48.74 72.22 94.04 d 9 9.75 7.30 8.47 d11 13.15 7.13 0.99 d15 32.86 17.85 1.00 d32 4.98 5.40 3.54 d36 67.03 66.60 68.47 d41 40.00 40.00 40.00 Entrance pupil position 343.05 437.50 530.25 Exit pupil position -128.35 -127.79 -130.22 Front principal point position 298.40 244.74 26.72 Back principal point position -165.01 -242.34 -349.99 Zoom lens group data Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 283.25 63.06 -23.47 -69.53 2 8 -149.18 1.80 1.83 0.62 3 10 -117.09 1.60 0.35 -0.57 4 12 554.67 7.64 -21.54 -26.09 5 16 54.03 41.27 14.64 -22.56 6 33 -55.97 4.55 2.20 -0.23 7 37 172.20 30.61 -34.06 -49.05 Single lens data Lens starting plane, focal length 1 1 596.43 2 3 372.83 3 5 239.65 4 6 -179.68 5 8 -149.18 6 10 -117.09 7 12 114.65 8 14 -137.92 9 16 137.61 10 18 129.25 11 21 167.43 12 22 -147.59 13 24 -56.95 14 26 -159.70 15 27 91.29 16 29 88.42 17 31 137.46 18 33 123.11 19 35 -38.47 20 37 -184.03 21 38 53.70 22 40 -97.61 [Numerical Example 3] Unit: mm Surface data Face number rd nd νd Effective diameter 1 158.503 11.23 1.49700 81.5 95.12 2 -656.114 28.23 94.66 3 121.416 10.82 1.43387 95.1 80.38 4 -496.455 0.55 79.23 5 -404.867 2.40 1.61340 44.3 79.07 6 203.113 (Variable) 75.98 7 178.872 1.80 1.49700 81.5 42.18 8 44.729 (variable) 40.35 9 -82.215 1.60 1.59282 68.6 40.23 10 433.502 (variable) 41.02 11 77.860 2.63 1.92286 20.9 42.19 12 143.615 (Variable) 42.06 13 100.199 5.29 1.43875 94.7 43.47 14 -196.438 0.20 43.39 15 99.801 3.95 1.49700 81.5 42.78 16 -1602.137 6.72 42.40 17 (aperture) ∞ 0.10 39.66 18 78.912 4.33 1.95375 32.3 38.66 19 89.393 3.55 36.92 20 -116.222 2.00 1.83481 42.7 36.85 21 67.734 3.05 36.24 22 186.228 1.80 1.92286 20.9 36.65 23 75.596 5.91 1.49700 81.5 36.81 24 -90.585 0.15 37.16 25 93.922 3.70 1.90366 31.3 37.59 26 -427.193 3.95 37.39 27 -60.792 1.80 1.92286 20.9 36.87 28 -76.936 6.49 37.19 29 -963.152 3.91 1.51633 64.1 35.38 30 -63.777 (variable) 35.18 31 -492.111 3.00 1.92286 20.9 30.20 32 -63.830 1.30 1.80000 29.8 29.84 33 61.152 (Variable) 28.45 34 91.134 2.00 1.90366 31.3 43.77 35 53.201 8.77 1.66565 35.6 43.32 36 -109.742 15.96 43.31 37 -81.075 2.00 1.49700 81.5 38.88 38 138.155 (variable) 38.77 Image plane ∞ Various data Zoom ratio 1.90 Wide-angle, Medium, Telephoto Focal length 205.00 281.99 389.98 F-number 4.10 4.06 4.10 Half-angle (°): 6.02, 4.39, 3.18 Image height 21.64 21.64 21.64 Lens length 367.20 367.20 367.20 BF 41.25 41.25 41.25 d 6 37.46 64.41 88.05 d 8 19.13 10.81 12.18 d10 13.11 8.82 1.07 d12 32.76 18.42 1.16 d30 10.13 7.07 0.99 d33 64.17 67.23 73.30 d38 41.25 41.25 41.25 Entrance pupil position 274.06 369.25 471.29 Exit pupil position -119.92 -122.98 -129.00 Front principal point position 218.32 167.07 -32.00 Back principal point position -163.74 -240.74 -348.73 Zoom lens group data Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 247.51 53.24 -6.81 -49.36 2 7 -120.54 1.80 1.61 0.40 3 9 -116.44 1.60 0.16 -0.84 4 11 180.80 2.63 -1.59 -2.93 5 13 72.38 56.89 29.36 -26.76 6 31 -76.54 4.30 2.05 -0.22 7 34 266.03 28.73 -48.74 -60.83 Single lens data Lens starting plane, focal length 1 1 258.05 2 3 226.05 3 5 -220.17 4 7 -120.54 5 9 -116.44 6 11 180.80 7 13 152.06 8 15 189.18 9 18 587.36 10 20 -51.01 11 22 -138.97 12 23 83.90 13 25 85.49 14 27 -331.70 15 29 132.08 16 31 79.21 17 32 -38.86 18 34 -145.07 19 35 55.01 20 37 -102.49 [Numerical Example 4] Unit: mm Surface data Face number rd nd νd Effective diameter 1 224.467 6.23 1.48749 70.2 74.94 2 -1478.792 0.20 74.39 3 106.561 9.39 1.43875 94.7 72.04 4 56342.074 0.50 70.63 5 92.631 9.59 1.43875 94.7 66.22 6 -2496.668 2.40 1.61340 44.3 63.95 7 101.371 (variable) 59.74 8 167.578 0.90 1.83481 42.7 34.58 9 41.686 (Variable) 32.40 10 -58.759 0.90 1.49700 81.5 30.38 11 165.505 (Variable) 31.17 12 67.095 4.07 1.80518 25.5 32.16 13 -276.671 1.64 32.17 14 -68.524 0.90 1.49700 81.5 32.15 15 117.733 (variable) 32.56 16 (aperture) ∞ 1.00 33.16 17 158.836 3.36 1.49700 81.5 33.73 18 -145.337 0.15 33.91 19 67.714 3.34 1.49700 81.5 34.15 20 470.676 2.50 33.97 21 42.015 3.27 1.49700 81.5 33.13 22 85.105 8.21 32.59 23 305.660 1.60 1.80610 33.3 29.98 24 42.602 8.95 29.04 25 99.947 1.80 1.80810 22.8 30.03 26 50.437 4.56 1.49700 81.5 29.84 27 -158.338 0.15 29.92 28 65.861 3.31 1.59270 35.3 29.88 29 -601.824 0.63 29.62 30 59.167 3.46 1.49700 81.5 28.87 31 473.594 (Variable) 28.60 32 -172.382 3.28 1.92286 20.9 26.77 33 -61.471 0.20 26.72 34 -64.352 1.30 1.87070 40.7 26.59 35 51.203 (Variable) 26.40 36 146.103 7.32 1.57099 50.8 42.46 37 -59.877 20.65 42.71 38 -55.103 2.00 1.75500 52.3 37.95 39 -133.162 (variable) 38.69 Image plane ∞ Various data Zoom ratio 4.03 Wide-angle, Medium, Telephoto Focal length 72.15 144.77 290.97 F-numbers: 3.97, 4.07, 4.10 Half-angle (°): 16.69, 8.50, 4.25 Image height 21.64 21.64 21.64 Lens length 289.03 289.03 289.03 BF 39.99 39.99 39.99 d 7 7.05 43.72 71.72 d 9 10.19 7.27 10.21 d11 13.55 6.99 1.10 d15 55.36 28.16 3.13 d31 3.18 8.85 10.87 d35 41.95 36.27 34.25 d39 39.99 39.99 39.99 Entrance pupil position 93.14 198.70 315.76 Exit pupil position -130.27 -116.95 -112.54 Front principal point position 134.72 209.92 51.65 Back principal point position -32.16 -104.78 -250.98 Zoom lens group data Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 172.09 28.31 -7.30 -25.08 2 8 -66.69 0.90 0.66 0.16 3 10 -87.13 0.90 0.16 -0.44 4 12 251.99 6.62 -10.25 -14.17 5 16 48.69 46.29 25.89 -23.88 6 32 -47.61 4.78 2.11 -0.47 7 36 132.22 29.97 -18.93 -39.19 Single lens data Lens starting plane, focal length 1 1 400.25 2 3 243.32 3 5 203.80 4 6 -158.76 5 8 -66.69 6 10 -87.13 7 12 67.42 8 14 -87.01 9 17 153.27 10 19 158.70 11 21 162.86 12 23 -61.58 13 25 -128.08 14 26 77.53 15 28 100.34 16 30 135.67 17 32 102.08 18 34 -32.58 19 36 75.35 20 38 -125.89 [Numerical Example 5] Unit: mm Surface data Face number rd nd νd Effective diameter 1 302.311 7.55 1.48749 70.2 90.77 2 -710.185 0.20 90.50 3 124.076 10.99 1.43875 94.7 88.43 4 3241.233 24.75 87.25 5 106.160 9.87 1.49700 81.5 70.87 6 -1100.392 2.40 1.78590 44.2 68.94 7 109.956 (variable) 65.17 8 138.206 1.80 1.77250 49.6 36.68 9 62.038 (variable) 35.64 10 -127.548 1.60 1.72916 54.7 35.25 11 106.526 (Variable) 35.46 12 77.322 4.95 1.75520 27.5 36.30 13 -158.781 1.01 36.26 14 -89.784 1.60 1.65160 58.5 36.22 15 168.194 (variable) 36.38 16 83.693 4.67 1.49700 81.5 36.80 17 -175.796 0.15 36.78 18 80.974 3.29 1.49700 81.5 36.41 19 838.241 0.15 36.09 20 54.407 5.40 1.49700 81.5 35.17 21 -250.393 2.00 1.83400 37.2 34.35 22 111.236 23.11 33.10 23 (aperture) ∞ 4.03 25.46 24 28862.747 1.60 1.85150 40.8 24.06 25 39.576 3.33 23.43 26 65.096 1.80 1.92286 20.9 23.91 27 38.527 3.32 1.49700 81.5 23.69 28 -5353.836 0.15 23.80 29 65.866 2.65 1.80000 29.8 23.93 30 -463.819 0.99 23.78 31 31.610 4.21 1.51742 52.4 23.02 32 -514.608 (variable) 22.23 33 166.520 1.20 2.00069 25.5 18.86 34 28.095 2.63 17.93 35 -45.099 1.20 1.75500 52.3 17.90 36 40.087 3.54 1.80518 25.4 18.26 37 -65.948 (variable) 18.44 38 42.326 2.00 1.94594 18.0 22.16 39 30.021 6.20 1.66565 35.6 21.89 40 -32.066 0.55 21.90 41 -30.868 1.50 1.53775 74.7 21.63 42 41.432 (variable) 21.41 Image plane ∞ Various data Zoom ratio 3.28 Wide-angle, Medium, Telephoto Focal length 180.01 325.22 589.97 F-number 6.50 6.50 6.50 Half-angle (°): 6.85, 3.81, 2.10 Image height 21.64 21.64 21.64 Lens length 351.92 351.92 351.92 BF 99.92 99.92 99.92 d 7 4.44 46.31 80.65 d 9 5.84 5.84 7.14 d11 13.31 6.08 1.80 d15 66.99 32.35 1.00 d32 2.09 4.85 3.27 d37 12.95 10.19 11.76 d42 99.92 99.92 99.92 Entrance pupil position 201.46 405.20 744.92 Exit pupil position -39.71 -37.37 -38.71 Front principal point position 149.40 -39.99 -1175.92 Back principal point position -80.09 -225.31 -490.05 Zoom lens group data Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 248.74 55.76 -31.78 -66.67 2 8 -147.23 1.80 1.86 0.84 3 10 -79.38 1.60 0.50 -0.42 4 12 266.20 7.56 -8.75 -13.11 5 16 54.09 60.85 48.34 -39.11 6 33 -31.78 8.56 -0.11 -6.25 7 38 198.65 10.25 -16.61 -21.11 Single lens data Lens starting plane, focal length 1 1 436.04 2 3 293.74 3 5 195.34 4 6 -127.09 5 8 -147.23 6 10 -79.38 7 12 69.48 8 14 -89.62 9 16 114.77 10 18 180.09 11 20 90.46 12 21 -92.12 13 24 -46.54 14 26 -105.72 15 27 76.98 16 29 72.26 17 31 57.71 18 33 -33.92 19 35 -27.94 20 36 31.43 21 38 -118.53 22 39 24.26 23 41 -32.66 [Numerical Example 6] Unit: mm Surface data Face number rd nd νd Effective diameter 1 291.195 5.68 1.48749 70.2 86.35 2 ∞ 0.20 85.71 3 138.423 9.37 1.43387 95.1 83.16 4 ∞ 46.70 81.94 5 85.483 9.89 1.43875 94.7 59.73 6 -555.465 2.40 1.61340 44.3 57.82 7 83.239 (variable) 54.42 8 138.233 3.00 1.80518 25.5 39.67 9 189.316 0.20 38.92 10 121.944 2.00 1.48749 70.2 38.66 11 43.718 (Variable) 37.07 12 -129.186 2.00 1.65160 58.5 36.70 13 227.142 0.20 36.99 14 70.540 3.50 1.90110 27.1 37.44 15 132.369 (variable) 37.11 16 -82.573 1.60 1.49700 81.5 36.98 17 296.509 (Variable) 37.58 18 120.012 3.87 1.49700 81.5 38.13 19 -221.000 0.15 38.24 20 65.531 3.80 1.49700 81.5 38.33 21 322.439 8.24 38.05 22 (aperture) ∞ 0.22 36.37 23 37.108 3.67 1.49700 81.5 35.34 24 47.195 2.00 1.72047 34.7 34.16 25 45.919 3.69 33.16 26 243.949 1.60 1.83481 42.7 32.75 27 45.084 3.06 31.74 28 98.030 1.80 1.92119 24.0 31.97 29 57.965 4.19 1.49700 81.5 31.76 30 -238.013 0.15 31.84 31 87.164 3.06 1.85150 40.8 31.89 32 -628.278 0.50 31.67 33 54.225 2.99 1.60311 60.6 30.68 34 138.135 (variable) 29.99 35 -637.126 3.23 1.92286 20.9 27.96 36 -90.315 0.23 27.34 37 -99.554 1.30 1.91082 35.2 27.03 38 57.256 (Variable) 25.97 39 99.439 2.00 1.92286 20.9 42.70 40 70.070 7.37 1.66565 35.6 42.52 41 -103.243 17.95 42.57 42 -73.912 2.00 1.49700 81.5 38.41 43 235.759 (variable) 38.54 Image plane ∞ Various data Zoom ratio 1.89 Wide-angle, Medium, Telephoto Focal length 180.01 247.34 340.94 F-number 4.10 4.10 4.10 Half-angle (°): 6.85, 5.00, 3.63 Image height 21.64 21.64 21.64 Lens length 350.00 350.00 350.00 BF 40.69 40.69 40.69 d 7 6.30 33.12 54.08 d11 19.91 13.60 10.76 d15 15.00 8.74 10.29 d17 35.00 20.74 1.08 d34 3.70 4.24 4.89 d38 65.60 65.06 64.41 d43 40.69 40.69 40.69 Entrance pupil position 300.58 390.67 475.99 Exit pupil position -122.35 -121.77 -121.08 Front principal point position 281.84 261.45 98.36 Rear principal point position -139.32 -206.65 -300.26 Zoom lens group data Group Starting surface Focal length Lens configuration length Front principal point position Rear principal point position 1 1 289.99 74.25 -51.16 -96.57 2 8 -185.70 5.20 6.57 3.25 3 12 -538.93 5.70 3.99 0.76 4 16 -129.77 1.60 0.23 -0.83 5 18 51.40 42.99 17.61 -22.34 6 35 -61.44 4.76 2.54 -0.04 7 39 190.70 29.31 -33.10 -48.96 Single lens data Lens Starting surface Focal length 1 1 597.34 2 3 319.04 3 5 169.65 4 6 -117.85 5 8 620.01 6 10 -140.98 7 12 -126.10 8 14 163.22 9 16 -129.77 10 18 157.08 11 20 164.68 12 23 311.69 13 24 -6856.10 14 26 -66.49 15 28 -157.35 16 29 94.23 17 31 90.07 18 33 146.05 19 35 113.71 20 37 -39.75 21 39 -265.76 22 40 63.79 23 42 -112.98 The various values ​​in each numerical example are summarized in Table 1 below.

[0076] [Table 1]

[0077] [Imaging device] Next, an embodiment of a digital still camera (imaging device) using the zoom lens L0 of the present invention as an imaging optical system will be described with reference to Figure 13. In Figure 13, 10 is the camera body, and 11 is the imaging optical system composed of any of the zoom lenses L0 described in Embodiments 1 to 6. The imaging optical system 11 and the camera body 10 may be configured as a single unit or as detachable. 12 is a solid-state image sensor (photoelectric conversion element) such as a CCD sensor or CMOS sensor, which is built into the camera body 10 and receives the optical image formed by the imaging optical system 11 and converts it into photoelectric energy. The camera body 10 may be a so-called single-lens reflex camera with a quick-turn mirror, or a so-called mirrorless camera without a quick-turn mirror.

[0078] By applying the zoom lens L0 of the present invention to an imaging device such as a digital still camera, an imaging device with a compact lens can be obtained.

[0079] This embodiment includes the following configuration. (Composition 1) A zoom lens consisting of a front group, an intermediate group, and a trailing group, each having one or more lens groups, arranged sequentially from the object side to the image side, wherein the spacing between adjacent lens groups changes during zooming. The aforementioned front group consists of a first front lens group with positive refractive power, The first front lens group is fixed to the image plane during zooming. The intermediate group consists of a first intermediate lens group having negative refractive power, a second intermediate lens group having negative refractive power, and a third intermediate lens group, which are arranged in order from the object side to the image side, the third intermediate lens group moves from the object side to the image side during zooming from a wide-angle end to a telephoto end, when the focal length of the first front lens group is fLF1, the distance on the optical axis from the lens surface closest to the object side of the first intermediate lens group to the lens surface closest to the image side of the first intermediate lens group is TLM1, and the distance on the optical axis from the lens surface closest to the object side of the second intermediate lens group to the lens surface closest to the image side of the second intermediate lens group is TLM2, 0.001<TLM1 / fLF1<0.025 0.001<TLM2 / fLF1<0.022 A zoom lens satisfying the following conditional expression. (Configuration 1) The zoom lens according to Configuration 1, characterized in that a first succeeding lens group arranged closest to the object side among lens groups included in the succeeding group has positive refractive power. (Configuration 2) The zoom lens according to Configuration 1 or 2, characterized in that a first succeeding lens group arranged closest to the object side among lens groups included in the succeeding group is fixed with respect to an image plane during zooming. (Configuration 3) The zoom lens according to any one of Configurations 1 to 3, characterized in that a first succeeding lens group arranged closest to the object side among lens groups included in the succeeding group has an aperture stop. (Configuration 4) The zoom lens according to any one of Configurations 1 to 4, characterized in that a second succeeding lens group arranged adjacently to the image side of a first succeeding lens group arranged closest to the object side among lens groups included in the succeeding group moves during zooming. (Configuration 5) A zoom lens according to any one of configurations 1 to 5, characterized in that the second successor lens group, which is positioned adjacent to the image side of the first successor lens group, which is positioned closest to the object among the lens groups included in the aforementioned successor group, moves during focusing. (Composition 7) A zoom lens according to any one of configurations 1 to 6, characterized in that the second subsequent lens group, which is positioned adjacent to the image side of the first subsequent lens group, which is positioned furthest towards the object among the lens groups included in the aforementioned subsequent group, has a negative refractive power. (Composition 8) A zoom lens according to any one of configurations 1 to 7, characterized in that the lens group positioned closest to the image plane is fixed to the image plane during zooming. (Composition 9) A zoom lens according to any one of configurations 1 to 8, characterized in that the front group and the intermediate group are fixed to the image plane during focusing. (Composition 10) The zoom lens according to any one of configurations 1 to 9, characterized in that the first subsequent lens group, which is positioned closest to the object among the lens groups included in the aforementioned subsequent group, has a positive lens closest to the object. (Composition 11) When the focal length of a zoom lens at the telephoto end is ft when it is in focus on an object at infinity, 0.2 <fLF1 / ft<2.1 A zoom lens according to any one of configurations 1 to 10, characterized by satisfying the following conditional expression. (Composition 12) When the focal length of the zoom lens when focused on an object at infinity at the wide-angle end is fw, and the focal length of the first intermediate lens group is fLM1, -3.4 <fw / fLM1<-0.3 A zoom lens according to any one of configurations 1 to 11, characterized by satisfying the following conditional expression. (Composition 13) When the focal length of the zoom lens when focused on an object at infinity at the wide-angle end is fw, and the focal length of the second intermediate lens group is fLM2, -4.5 <fw / fLM2<-0.2 A zoom lens according to any one of configurations 1 to 12, characterized by satisfying the following conditional expression. (Composition 14) When the focal length of the zoom lens when focused on an object at infinity at the wide-angle end is fw, and the focal length of the third intermediate lens group is fLM3, -2.8 <fw / fLM3<2.3 A zoom lens according to any one of configurations 1 to 13, characterized by satisfying the following conditional expression. (Composition 15) When the focal length of the zoom lens when focused on an object at infinity at the wide-angle end is fw, and the focal length of the first successor lens group that is positioned closest to the object among the lens groups included in the successor group is fLR1, 0.7 <fw / fLR1<7.6 A zoom lens according to any one of configurations 1 to 14, characterized by satisfying the following conditional expression. (Composition 16) When the amount of movement of the first intermediate lens group during zooming from the wide-angle end to the telephoto end (with the amount of movement toward the object being considered positive) is denoted as MLM1, 0.1 <MLM1 / fLF1<0.8 A zoom lens according to any one of configurations 1 to 15, characterized by satisfying the following conditional expression. (Composition 17) When the amount of movement of the second intermediate lens group during zooming from the wide-angle end to the telephoto end (with the amount of movement toward the object being considered positive) is denoted as MLM2, 0.1 <MLM2 / fLF1<0.8 A zoom lens according to any one of configurations 1 to 16, characterized by satisfying the following conditional expression. (Composition 18) When the amount of movement of the third intermediate lens group during zooming from the wide-angle end to the telephoto end (with the amount of movement toward the object being considered positive) is denoted as MLM3, 0.1 <MLM3 / fLF1<0.6 A zoom lens according to any one of configurations 1 to 17, characterized by satisfying the following conditional expression. (Composition 19) When the combined horizontal magnification at the wide-angle end of the aforementioned subsequent group is denoted as βLRw, -2.5 < βLRw < -0.2 A zoom lens according to any one of configurations 1 to 18, characterized by satisfying the following conditional expression. (Composition 20) When the combined horizontal magnification at the wide-angle end of the aforementioned successor group is βLRw, and the combined horizontal magnification at the telephoto end of the aforementioned successor group is βLRt, 0.3 < βLRt / βLRw < 2.7 A zoom lens according to any one of configurations 1 to 19, characterized by satisfying the following conditional expression. (Composition 21) When the combined horizontal magnification at the telephoto end of the aforementioned intermediate group is βLMt, -8.8 < βLMt < -0.5 A zoom lens according to any one of configurations 1 to 20, characterized by satisfying the following conditional expression. (Composition 22) When the back focus at the wide-angle end is BFw when focusing on an object at infinity, and the focal length of the zoom lens at the wide-angle end is fw when focusing on an object at infinity, 0.1 <BFw / fw<1.1 A zoom lens according to any one of configurations 1 to 21, characterized by satisfying the following conditional expression. (Composition 23) When the focal length of the zoom lens at the telephoto end is ft when it is in focus on an object at infinity, and the distance along the optical axis from the lens surface closest to the object to the image plane at the telephoto end is Lt, 0.3 <Lt / ft<3.1 A zoom lens according to any one of configurations 1 to 22, characterized by satisfying the following conditional expression. (Composition 24) A zoom lens consisting of a front group, an intermediate group, and a trailing group, each having one or more lens groups, arranged sequentially from the object side to the image side, wherein the spacing between adjacent lens groups changes during zooming. The aforementioned front group consists of a first front lens group with positive refractive power, The first front lens group is fixed to the image plane during zooming. The zoom lens is characterized in that the intermediate group consists of a first intermediate lens group, a second intermediate lens group, and a third intermediate lens group, arranged in order from the object side to the image side. (Composition 25) An imaging device characterized by comprising a zoom lens described in any one of configurations 1 to 24, and an image sensor that receives the image formed by the zoom lens.

[0080] Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of its gist. [Explanation of Symbols]

[0081] LF anterior group LF1 First front lens group LM intermediate group LM1 First Intermediate Lens Group LM2 Second Intermediate Lens Group LM3 Third Intermediate Lens Group LR successor group

Claims

1. A zoom lens consisting of a front group, an intermediate group, and a trailing group, each having one or more lens groups, arranged sequentially from the object side to the image side, wherein the spacing between adjacent lens groups changes during zooming. The aforementioned front group consists of a first front lens group with positive refractive power, The first front lens group is fixed to the image plane during zooming. The aforementioned intermediate lens group consists of a first intermediate lens group with negative refractive power, a second intermediate lens group with negative refractive power, and a third intermediate lens group, arranged in order from the object side to the image side. The third intermediate lens group moves from the object side to the image side when zooming from the wide-angle end to the telephoto end. When the focal length of the first front lens group is fLF1, the distance along the optical axis from the lens surface closest to the object of the first intermediate lens group to the lens surface closest to the image of the first intermediate lens group is TLM1, and the distance along the optical axis from the lens surface closest to the object of the second intermediate lens group to the lens surface closest to the image of the second intermediate lens group is TLM2, 0.001<TLM1 / fLF1<0.025 0.001<TLM2 / fLF1<0.022 A zoom lens characterized by satisfying the following conditional equation.

2. The zoom lens according to claim 1, characterized in that the first subsequent lens group, which is positioned closest to the object among the lens groups included in the aforementioned subsequent group, has a positive refractive power.

3. The zoom lens according to claim 1 or 2, characterized in that the first subsequent lens group, which is positioned closest to the object among the lens groups included in the aforementioned subsequent group, is fixed to the image plane during zooming.

4. The zoom lens according to claim 1 or 2, characterized in that the first subsequent lens group, which is positioned closest to the object among the lens groups included in the aforementioned subsequent group, has an aperture diaphragm.

5. The zoom lens according to claim 1 or 2, wherein the second subsequent lens group, which is positioned adjacent to the image side of the first subsequent lens group, which is positioned closest to the object among the lens groups included in the aforementioned subsequent group, moves during zooming.

6. The zoom lens according to claim 1 or 2, wherein the second successor lens group, which is positioned adjacent to the image side of the first successor lens group, which is positioned closest to the object among the lens groups included in the successor group, moves during focusing.

7. The zoom lens according to claim 1 or 2, characterized in that the second subsequent lens group, which is positioned adjacent to the image side of the first subsequent lens group, which is positioned furthest towards the object among the lens groups included in the aforementioned subsequent group, has a negative refractive power.

8. The zoom lens according to claim 1 or 2, characterized in that the lens group positioned closest to the image plane is fixed to the image plane during zooming.

9. The zoom lens according to claim 1 or 2, characterized in that the front group and the intermediate group are fixed to the image plane during focusing.

10. The zoom lens according to claim 1 or 2, characterized in that the first subsequent lens group, which is positioned closest to the object among the lens groups included in the aforementioned subsequent group, has a positive lens closest to the object.

11. When the focal length of a zoom lens at the telephoto end is ft when it is in focus on an object at infinity, 0.2<fLF1 / ft<2.1 A zoom lens according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

12. When the focal length of the zoom lens when focused on an object at infinity at the wide-angle end is fw, and the focal length of the first intermediate lens group is fLM1, -3.4<fw / fLM1<-0.3 A zoom lens according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

13. When the focal length of the zoom lens when focused on an object at infinity at the wide-angle end is fw, and the focal length of the second intermediate lens group is fLM2, -4.5<fw / fLM2<-0.2 A zoom lens according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

14. When the focal length of the zoom lens when focused on an object at infinity at the wide-angle end is fw, and the focal length of the third intermediate lens group is fLM3, -2.8<fw / fLM3<2.3 A zoom lens according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

15. When the focal length of the zoom lens when focused on an object at infinity at the wide-angle end is fw, and the focal length of the first successor lens group that is positioned closest to the object among the lens groups included in the successor group is fLR1, 0.7<fw / fLR1<7.6 A zoom lens according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

16. When the amount of movement of the first intermediate lens group during zooming from the wide-angle end to the telephoto end (with the amount of movement toward the object being considered positive) is MLM1, 0.1<MLM1 / fLF1<0.8 A zoom lens according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

17. When the amount of movement of the second intermediate lens group during zooming from the wide-angle end to the telephoto end (with the amount of movement toward the object being considered positive) is denoted as MLM2, 0.1<MLM2 / fLF1<0.8 A zoom lens according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

18. When the amount of movement of the third intermediate lens group during zooming from the wide-angle end to the telephoto end (with the amount of movement toward the object being considered positive) is denoted as MLM3, 0.1<MLM3 / fLF1<0.6 A zoom lens according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

19. When the combined horizontal magnification at the wide-angle end of the aforementioned subsequent group is denoted as βLRw, -2.5<βLRw<-0.2 A zoom lens according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

20. When the combined horizontal magnification at the wide-angle end of the aforementioned successor group is βLRw, and the combined horizontal magnification at the telephoto end of the aforementioned successor group is βLRt, 0.3<βLRt / βLRw<2.7 A zoom lens according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

21. When the combined horizontal magnification at the telephoto end of the aforementioned intermediate group is denoted as βLMt, -8.8<βLMt<-0.5 A zoom lens according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

22. When the back focus at the wide-angle end is BFw when the object at infinity is in focus, and the focal length of the zoom lens at the wide-angle end is fw when the object at infinity is in focus, 0.1<BFw / fw<1.1 A zoom lens according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

23. When the focal length of the zoom lens at the telephoto end is ft when it is in focus on an object at infinity, and the distance along the optical axis from the lens surface closest to the object to the image plane at the telephoto end is Lt, 0.3<Lt / ft<3.1 A zoom lens according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

24. A zoom lens consisting of a front group, an intermediate group, and a trailing group, each having one or more lens groups, arranged sequentially from the object side to the image side, wherein the spacing between adjacent lens groups changes during zooming. The aforementioned front group consists of a first front lens group with positive refractive power, The first front lens group is fixed to the image plane during zooming. The zoom lens is characterized in that the intermediate group consists of a first intermediate lens group, a second intermediate lens group, and a third intermediate lens group, arranged in order from the object side to the image side.

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

Images