Zoom lens and imaging device having the same

Abstract

To provide a compact zoom lens with high optical performance. [Solution] A zoom lens comprising a plurality of lens groups arranged sequentially from the object side to the image side, wherein the distance between adjacent lens groups changes when the zoom is changed, the first lens group located furthest towards the object among the plurality of lens groups is immovable with respect to the image plane when the zoom is changed, each of the plurality of lens groups has one or more aspherical lenses made of resin material, the first lens group located furthest towards the object among the plurality of lens groups has a positive lens Gp, and when the Abbe number of the material of the positive lens Gp is ​​νdp, the partial dispersion ratio is θgFp, and the anomalous partial dispersion is ΔθgFp, a predetermined conditional equation is satisfied.

Description

[Technical Field]

[0001] This specification discloses zoom lenses, and is particularly suitable for imaging devices such as smartphone cameras, still cameras, video cameras, digital still cameras, in-vehicle cameras, and surveillance cameras. [Background technology]

[0002] Conventionally, there has been a demand for high-quality zoom lenses that are compact yet have good correction of various aberrations, used in imaging devices such as smartphone cameras and still cameras. Patent Document 1 discloses a zoom lens having, in order from the object side to the image side, a first lens group with negative refractive power, a second lens group with positive refractive power, and a third lens group with negative refractive power. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] US2022-0035132 publication [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] In telephoto lenses, chromatic aberrations such as axial chromatic aberration tend to occur at the telephoto end, so correcting these well can improve the optical performance of zoom lenses. [Means for solving the problem]

[0005] A zoom lens as one aspect of the present invention comprises a plurality of lens groups arranged sequentially from the object side to the image side, wherein the distance between adjacent lens groups changes during magnification, and each of the plurality of lens groups has one or more aspherical lenses made of resin material, and the first lens group, which is positioned closest to the object, has a positive lens Gp, and when the Abbe number of the material of the positive lens Gp is ​​νdp, the partial dispersion ratio is θgFp, and the anomalous partial dispersion is ΔθgFp, 0.00 < νdp < 20.0 0.060 < ΔθgFp < 0.080 ΔθgFp=θgFp-(0.0018×νdp-0.6483) It is characterized by satisfying the following conditional expression.

[0006] Furthermore, another aspect of the present invention is a zoom lens comprising a plurality of lens groups arranged sequentially from the object side to the image side, wherein the distance between adjacent lens groups changes during magnification, and the first lens group, which is positioned closest to the object among the plurality of lens groups, remains immovable with respect to the image plane during magnification, and the first lens group has a positive lens Gp, and when the Abbe number of the material of the positive lens Gp is ​​νdp, the partial dispersion ratio is θgFp, and the anomalous partial dispersion is ΔθgFp, 0.060 < ΔθgFp < 0.080 ΔθgFp=θgFp-(0.0018×νdp-0.6483) It is characterized by satisfying the following conditional expression. [Effects of the Invention]

[0007] This allows us to provide a compact zoom lens with high optical performance. [Brief explanation of the drawing]

[0008] [Figure 1] Lens cross-sectional view at the wide-angle and telephoto ends of Example 1 [Figure 2] Aberration diagrams at the wide-angle end and telephoto end of Example 1 (A) [Figure 3] Lens cross-sectional view at the wide-angle and telephoto ends of Example 2 [Figure 4] Aberration diagrams at the wide-angle end and telephoto end of Example 2 (A) [Figure 5] Lens cross-sectional view at the wide-angle and telephoto ends of Example 3 [Figure 6] Aberration diagrams at the wide-angle end and telephoto end of Example 3 (A) [Figure 7] Lens cross-sectional view at the wide-angle and telephoto ends of Example 4 [Figure 8] Aberration diagrams at the (A) wide-angle end and (B) telephoto end of Example 4 [Figure 9] Enlarged view of the main part of the imaging device

Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the drawings. Note that each drawing may be drawn at a scale different from the actual for convenience. Also, in each drawing, the same members are denoted by the same reference numerals, and redundant descriptions are omitted. Further, in the following embodiments, the wide-angle end and the telephoto end refer to the zoom positions when the lens group for zooming is located at both ends of the range where it can move on the optical axis due to the mechanism.

[0010] FIG. 1, FIG. 3, FIG. 5, and FIG. 7 are lens cross-sectional views at the wide-angle end and the telephoto end of the zoom lens L0 according to Embodiments 1 to 4, respectively. In each cross-sectional view, IP represents the image plane. The zoom lens L0 according to each embodiment is used in an imaging device, and an imaging surface of a solid-state imaging device or a photoelectric conversion element such as a CCD sensor or a CMOS sensor is arranged at the position of the image plane IP. Note that the zoom lens L0 of each embodiment may be used as an imaging optical system for a silver halide film camera. In that case, a photosensitive surface corresponding to the film surface is arranged on the image plane IP.

[0011] In the zoom lens L0 of each embodiment, Li represents the i-th (i is a natural number) lens group counted from the object side among the lens groups included in the zoom lens L0. Also, Gk represents the k-th (k is a natural number) lens counted from the object side among the lenses included in the zoom lens.

[0012] In each sectional view, the left side is the object side and the right side is the image side. The zoom lens L0 of each embodiment is suitable for imaging devices such as digital video cameras, digital still cameras, broadcast cameras, silver halide film cameras, surveillance cameras, in-vehicle cameras, etc. In the zoom lens L0, the distance between adjacent lens groups changes during zooming. That is, in this specification, the lens group refers to a collection of lenses that move integrally during zooming or a collection of lenses that are stationary with respect to the image plane during zooming. Note that the lens group may be composed of one lens or a plurality of lenses. In addition, each lens group may include an aspherical lens, a Fresnel lens, a metalens, a diffractive optical element, etc. Further, each lens group may include an aperture stop SP. When an optical member having a reflective surface is disposed on the object side of the first lens group L1, the optical member having the reflective surface shall not be included in the lens group. Examples of the optical member having a reflective surface include, for example, a prism P.

[0013] Figures 2, 4, 6, and 8 are longitudinal aberration diagrams of the zoom lens L0 according to Embodiments 1 to 4, respectively. In each aberration diagram, the spherical aberration diagram, the astigmatism diagram, the distortion diagram, and the chromatic aberration diagram are shown in order from the left side. Also, in each longitudinal aberration diagram, (A) shows the longitudinal aberration diagram at the wide-angle end, and (B) shows the longitudinal aberration diagram at the telephoto end.

[0014] In each longitudinal aberration diagram, Fno is the F-number, ω is the semi-field angle (°), and it is the field angle based on the ray tracing value. In the spherical aberration diagram, the solid line d indicates the spherical aberration amount for the d-line (wavelength 587.56 nm), and the two-dot chain line g indicates the spherical aberration amount for the g-line (wavelength 435.835 nm). Also, the two-dot chain line indicates the sine condition non-compliance amount of the zoom lens L0 in each embodiment. In the astigmatism diagram, the solid line ΔS indicates the astigmatism amount for the d-line on the sagittal image plane, and the broken line ΔM indicates the astigmatism amount for the d-line on the meridional image plane. In the distortion diagram, the solid line indicates the distortion amount for the d-line. In the longitudinal chromatic aberration diagram, the two-dot chain line g indicates the chromatic aberration amount for the g-line.

[0015] Next, we will describe the characteristic configuration of the zoom lens L0 in each embodiment.

[0016] The zoom lens L0 in each embodiment comprises multiple lens groups arranged sequentially from the object side to the image side, and the spacing between adjacent lens groups changes when the magnification is changed.

[0017] In the zoom lens L0 of each embodiment, the first lens group, which is positioned closest to the object among the multiple lens groups, remains stationary with respect to the image plane during magnification. By keeping the first lens group L1 stationary during magnification, the eccentricity of the first lens group L1 during zooming caused by manufacturing errors, etc., is suppressed, and variations in aberrations due to eccentricity are reduced.

[0018] In the zoom lens L0 of each embodiment, each lens group includes at least one aspherical lens made of resin material. By employing aspherical lenses, the number of lenses in the zoom lens L0 can be reduced, thereby enabling miniaturization of the zoom lens L0.

[0019] In the zoom lens L0 of each embodiment, the first lens group, which is positioned closest to the object among the multiple lens groups, has a positive lens Gp. Furthermore, when the Abbe number of the material of the positive lens Gp is ​​νdp, the partial dispersion ratio is θgFp, and the anomalous partial dispersion is ΔθgFp, the following condition (1) is satisfied. 0.060 < ΔθgFp < 0.080 (1)

[0020] However, in conditional equation (1), the values ​​are expressed as follows. Here, Ng, NF, NC, and Nd are the refractive indices for the Fraunhofer lines g, F, C, and d, respectively. ΔθgFp = θgFp - (B1 × νdp + B0) B1 = 0.0018 B0 = -0.6483 θgFp = (Ng - NF) / (NF - NC) νdp = (Nd-1) / (NF-NC)

[0021] Condition (1) defines the anomalous dispersion ΔθgFp of the positive lens Gp included in the first lens group. By placing a lens Gp that satisfies condition (1) in the first lens group L1, which has a large lens diameter and a high paraxial ray height, the effect of the anomalous dispersion of lens Gp can be enhanced.

[0022] If the value exceeds the upper limit of condition equation (1), the correction of axial chromatic aberration will be insufficient, which is undesirable. If the value falls below the lower limit of condition equation (1), the correction of axial chromatic aberration will be excessive, which is also undesirable.

[0023] Furthermore, it is more preferable to set the upper limit of condition (1) to one of the following: 0.079, 0.078, 0.077, 0.076, 0.075, 0.074, 0.073, 0.072, 0.071, 0.070, 0.069, or 0.068.

[0024] Furthermore, it is more preferable to set the lower limit of condition (1) to one of 0.066, 0.065, 0.064, 0.063, 0.062, or 0.061.

[0025] Next, we will describe the conditions that are preferable to satisfy in the zoom lens L0 of each embodiment.

[0026] The zoom lens L0 of each embodiment preferably satisfies one or more of the following conditional equations (2) to (18). In each conditional equation, the numerical values ​​are expressed as follows.

[0027] Let νdp be the Abbe number and ndp be the refractive index of the material of the positive lens Gp.

[0028] Let ndpa be the refractive index of the material of lens Gpa, which is positioned adjacent to the positive lens Gp, with respect to the d line, and let νdpa be the Abbe number.

[0029] Let skw be the back focus of the zoom lens L0 at the wide-angle end.

[0030] Let TL be the total optical length of the zoom lens L0, and imgH be the maximum image height.

[0031] Let wt be the half-angle of view of the zoom lens L0 at the telephoto end.

[0032] Among the multiple lens groups that make up the zoom lens L0, the optical axis displacement of the lens group with the largest displacement during magnification is denoted as mmx. However, for each lens group, the direction of movement toward the object on the optical axis is considered positive.

[0033] In the first lens group L1, ea1 is defined as half the effective diameter of the object-side lens surface of lens G1, which is positioned closest to the object, and eaR is defined as half the effective diameter of the image-side lens surface of lens GR, which is positioned closest to the image in the zoom lens L0.

[0034] Let f1 be the focal length of the first lens group L1, f2 be the focal length of the second lens group L2, f3 be the focal length of the third lens group L3, and fw be the total focal length of the zoom lens L0 at the wide-angle end. 0.00 < νdp < 20.00 (2) 1.50 <ndp<1.80 (3) 50.0 < νdpa < 100.0 (4) 1.40 <ndpa<1.60 (5) 7.00 < ωt < 20.00 (6) 0.08 <imgH / TL<0.20(7) 0.020 <skw / TL<0.300 (8) 0.15 <mmax / TL<0.30 (9) 0.75 <ea1 / imgH<1.00 (10) 0.60 <eaR / imgH<1.00 (11) 0.40 < |f2| / fw < 1.00 (12) 0.60 < |f3| / fw < 7.00 (13) |f2 / f3|<1.00 (14) 1.50 < |f1 / f2| < 3.70 (15) 0.10 < |f1 / f3| < 4.00 (16) 1.20 < |f1| / fw < 2.50 (17) 1.20 <ft / fw<2.50 (18)

[0035] Conditional equation (2) specifies an appropriate range for the Abbe number νdp of the material of the positive lens Gp. Exceeding the upper limit of conditional equation (2) is undesirable because it makes chromatic aberration correction difficult. Exceeding the lower limit of conditional equation (2) is also undesirable because it results in excessive chromatic aberration correction.

[0036] Furthermore, it is more preferable that the upper limit of condition (2) be one of the following: 18.95, 18.90, 18.85, 18.80, 18.75, 18.70, 18.65, 18.60, 18.55, 18.50, 18.45, 18.40, 18.35, or 18.30.

[0037] Furthermore, it is more preferable to set the lower limit of condition (2) to one of the following: 17.35, 17.40, 17.45, 17.50, 17.55, 17.60, 17.65, 17.70, 17.75, 17.80, 17.85, 17.90, 17.95, or 18.00.

[0038] Conditional equation (3) specifies the refractive index ndp for the d line of the material of the positive lens Gp included in the first lens group. If it exceeds the upper limit of conditional equation (3), it is undesirable because it reduces the manufacturability of the positive lens Gp. If it falls below the lower limit of conditional equation (3), the positive refractive power of the positive lens Gp becomes weak, which is undesirable because it makes it difficult to miniaturize the zoom lens L0.

[0039] Furthermore, it is more preferable that the upper limit of condition (3) be one of the following: 1.79, 1.78, 1.77, 1.76, 1.75, 1.74, 1.73, 1.72, 1.71, 1.70, or 1.69.

[0040] Furthermore, it is more preferable that the lower limit of condition (3) be one of 1.51, 1.52, 1.53, 1.54, 1.55, 1.56, 1.57, 1.58, 1.59, 1.60, 1.61, 1.62, 1.63, 1.64, 1.65, 1.66, or 1.67.

[0041] Conditional equation (4) specifies the Abbe number νdpa of lens Gpa positioned adjacent to the positive lens Gp. Chromatic aberration can be effectively corrected when the Abbe number of lens Gpa positioned adjacent to the positive lens Gp falls within an appropriate range. Exceeding the upper limit of conditional equation (4) is undesirable because it makes chromatic aberration correction difficult. Exceeding the lower limit of conditional equation (4) is also undesirable because it results in excessive chromatic aberration correction.

[0042] Conditional equation (5) specifies the refractive index ndpa of lens Gpa with respect to the d line. Chromatic aberration can be effectively corrected when the refractive index of lens Gpa is within an appropriate range. Exceeding the upper limit of conditional equation (5) is undesirable because the positive refractive power of lens Gpa becomes too large, making it difficult to correct spherical aberration and other distortions. Exceeding the lower limit of conditional equation (5) is undesirable because the positive refractive power of lens Gpa becomes too weak, increasing the amount of movement of the lens group including lens Gpa during zooming, and causing the zoom lens L0 to become larger in the optical axis direction.

[0043] Conditional equation (6) defines the half-angle of view ωt corresponding to the maximum image height of the zoom lens L0 at the telephoto end. The maximum image height refers to the distance from the position on the image plane where the peripheral light intensity relative to the vicinity of the optical axis is 10% to the optical axis. If the value exceeds the upper limit of conditional equation (6), the lens diameter of each lens group increases, and the zoom lens L0 becomes larger in the radial direction, which is undesirable. If the value falls below the lower limit of conditional equation (6), the overall optical length increases, and the zoom lens L0 becomes larger in the optical axis direction, which is also undesirable.

[0044] Conditional equation (7) specifies the ratio of the maximum image height imgH to the total optical length TL. The total optical length refers to the distance along the optical axis from the object-side lens surface of the lens positioned closest to the object in the first lens group L1 to the image plane IP.

[0045] If the upper limit of condition (7) is exceeded, the overall optical length becomes shorter, making it difficult to secure the necessary distance for the lens group to move along the optical axis during magnification, which is undesirable. If the lower limit of condition (7) is exceeded, the overall optical length becomes longer, causing the zoom lens L0 to become larger in the optical axis direction, which is also undesirable.

[0046] Conditional equation (8) defines the ratio of the back focus skw to the total optical length TL of the zoom lens L0 at the wide-angle end. If the ratio exceeds the upper limit of conditional equation (8), the back focus becomes long, making it difficult to secure the necessary distance along the optical axis for the lens group that moves during zoom variation, which is undesirable. If the ratio falls below the lower limit of conditional equation (8), the back focus becomes short, making it difficult to properly position components such as filters on the image plane side, which is also undesirable.

[0047] Conditional equation (9) defines the ratio of the optical axis displacement mmax to the optical total length TL of the lens group that has the largest optical axis displacement during magnification among the multiple lens groups that make up the zoom lens L0.

[0048] If the upper limit of condition (9) is exceeded, the distance the lens group moves during magnification becomes too long, resulting in a large change in optical performance during magnification, which is undesirable. If the lower limit of condition (9) is exceeded, the distance the lens group moves during magnification becomes too short, making it difficult to secure a long focal length at the telephoto end, which is also undesirable.

[0049] Conditional equation (10) defines the ratio of the maximum image height imgH to half the effective diameter of the object-side lens surface of lens G1, which is positioned closest to the object in the first lens group L1, ea1.

[0050] If the upper limit of condition (10) is exceeded, the effective diameter of lens G1 becomes large, which is undesirable because it causes the zoom lens L0 to become larger in the radial direction. If the lower limit of condition (10) is exceeded, the effective diameter of lens G1 becomes too small. Lens G1 is the lens that is positioned closest to the object among the lenses that make up the zoom lens L0, and if the effective diameter of lens G1 becomes too small, the angle of incidence to the image plane IP becomes large, which is undesirable because it causes color unevenness.

[0051] Conditional equation (11) defines the ratio of eaR, which is half the effective diameter of the image-side lens surface of the lens GR positioned closest to the image in the zoom lens L0, to the maximum image height imgH.

[0052] If the upper limit of condition (11) is exceeded, the effective diameter of lens GR becomes larger, and the zoom lens L0 becomes larger in the radial direction, which is undesirable. If the lower limit of condition (11) is exceeded, the angle of incidence to the image plane IP becomes larger, which is undesirable as it causes color unevenness.

[0053] Conditional equation (12) defines the ratio of the focal length f2 of the second lens group L2 to the total focal length of the zoom lens L0 at its wide-angle end. If the ratio exceeds the upper limit of conditional equation (12), the refractive power of the second lens group L2 becomes too weak, making it difficult to correct aberrations such as image field distortion, which is undesirable. If the ratio falls below the lower limit of conditional equation (12), the refractive power of the second lens group L2 becomes too strong, making it difficult to correct aberrations such as spherical aberration, which is also undesirable.

[0054] Conditional equation (13) defines the ratio of the focal length f3 of the third lens group L3 to the total focal length of the zoom lens L0 at its wide-angle end. If the value exceeds the upper limit of conditional equation (13), the refractive power of the third lens group L3 becomes too weak, which is undesirable because it increases the amount of movement of the third lens group L3 in the optical axis direction during zooming, causing the zoom lens L0 to become larger in the optical axis direction. If the value falls below the lower limit of conditional equation (13), the refractive power of the third lens group L3 becomes too strong, which is undesirable because it makes it difficult to correct various aberrations such as spherical aberration.

[0055] Conditional equation (14) specifies the ratio of the focal length f2 of the second lens group L2 to the focal length f3 of the third lens group. If the ratio exceeds the upper limit of conditional equation (14), the refractive power of the second lens group L2 becomes too weak, which is undesirable because it increases the amount of movement of the second lens group L2 in the optical axis direction during zooming, causing the zoom lens L0 to become larger in the optical axis direction. If the ratio falls below the lower limit of conditional equation (14), the refractive power of the second lens group L2 becomes too strong, which is undesirable because it makes it difficult to correct various aberrations such as spherical aberration.

[0056] Conditional equation (15) specifies the ratio of the focal length f1 of the first lens group L1 to the focal length f2 of the second lens group L2. If the ratio exceeds the upper limit of conditional equation (15), the refractive power of the second lens group L2 becomes too strong, making it difficult to correct various aberrations such as spherical aberration, which is undesirable. If the ratio falls below the lower limit of conditional equation (15), the refractive power of the second lens group L2 becomes too weak, resulting in a large amount of movement of the second lens group L2 in the optical axis direction during zooming, and causing the zoom lens L0 to become larger in the optical axis direction, which is also undesirable.

[0057] Conditional equation (16) specifies the ratio of the focal length f1 of the first lens group L1 to the focal length f3 of the third lens group L3. If the ratio exceeds the upper limit of conditional equation (16), the refractive power of the first lens group L1 becomes too weak, which is undesirable because it increases the amount of movement of the first lens group L1 in the optical axis direction during zooming, causing the zoom lens L0 to become larger in the optical axis direction. If the ratio falls below the lower limit of conditional equation (16), the refractive power of the first lens group L1 becomes too strong, which is undesirable because it makes it difficult to correct various aberrations such as spherical aberration.

[0058] Conditional equation (17) defines the ratio of the focal length f1 of the first lens group L1 to the total focal length of the zoom lens L0 at its wide-angle end. If the value exceeds the upper limit of conditional equation (17), the refractive power of the first lens group L1 becomes too weak, which is undesirable because it increases the amount of movement of the first lens group L1 in the optical axis direction during zooming, causing the zoom lens L0 to become larger in the optical axis direction. If the value falls below the lower limit of conditional equation (17), the refractive power of the first lens group L1 becomes too strong, which is undesirable because it makes it difficult to correct various aberrations such as spherical aberration.

[0059] Conditional equation (18) defines the ratio of the total focal length of the zoom lens L0 at the wide-angle end to the total focal length of the zoom lens L0 at the telephoto end. If the ratio exceeds the upper limit of conditional equation (18), the total focal length of the zoom lens L0 at the telephoto end becomes too large, which is undesirable because it causes the zoom lens L0 to become larger in the optical axis direction. If the ratio falls below the lower limit of conditional equation (18), the magnification ratio of the zoom lens L0 becomes too small, which is also undesirable.

[0060] Furthermore, it is more preferable to use the following conditional expressions (2a) to (18a) for the numerical ranges of conditional expressions (2) to (18). 17.00 < νdp < 19.50 (2a) 1.55 <ndp<1.75 (3a) 51.0 < νdpa < 90.0 (4a) 1.45 <ndpa<1.58 (5a) 7.50 < ωt < 19.00 (6a) 0.09 <imgH / TL<0.19 (7a) 0.025 <skw / TL<0.250 (8a) 0.16 <mmax / TL<0.28 (9a) 0.76 <ea1 / imgH<0.98 (10a) 0.61 <eaR / imgH<0.95 (11a) 0.45 < |f2| / fw < 0.95 (12a) 0.70 < |f3| / fw < 6.50 (13a) |f2 / f3|<0.98 (14a) 1.60 < |f1 / f2| < 3.60 (15a) 0.15 < |f1 / f3| < 3.50 (16a) 1.30 < |f1| / fw < 2.40 (17a) 1.30 <ft / fw<2.30 (18a)

[0061] Furthermore, it is even more preferable to use the following conditional expressions (2) to (18) for the numerical ranges of conditional expressions (2b) to (18b). 17.00 < νdp < 19.00 (2b) 1.60 <ndp<1.70 (3b) 52.0 < νdpa < 80.0 (4b) 1.50 <ndpa<1.56 (5b) 8.00 < ωt < 18.00 (6b) 0.08 <imgH / TL<0.18 (7b) 0.030 <skw / TL<0.200 (8b) 0.17 <mmax / TL<0.26 (9b) 0.77 <ea1 / imgH<0.96 (10b) 0.62 <eaR / imgH<0.90 (11b) 0.50 < |f2| / fw < 0.90 (12b) 0.80 < |f3| / fw < 6.00 (13b) |f2 / f3|<0.95 (14b) 1.50 < |f1 / f2| < 3.70 (15b) 0.20 < |f1 / f3| < 3.00 (16b) 1.40 < |f1| / fw < 2.30 (17b) 1.40 <ft / fw<2.10 (18b)

[0062] Next, we will describe the preferred configurations that the zoom lens L0 of each embodiment should satisfy.

[0063] In the zoom lens L0 of each embodiment, it is preferable that the first lens group L1 includes an aspherical lens having an inflection point. An inflection point on the lens surface is a point where the sign of the refractive power of the lens changes from near the optical axis to the periphery of the lens surface. By including an aspherical lens with an inflection point, image field distortion and astigmatism can be corrected effectively.

[0064] As an example of an aspherical lens with an inflection point, the object-side lens surface of the aspherical lens is convex towards the object near the optical axis and concave towards the object at the periphery. Similarly, the image-side lens surface of the aspherical lens is concave towards the image near the optical axis and convex towards the image at the periphery. This allows for correction of Petzval sum near the optical axis while correcting astigmatism at the periphery. Furthermore, the object-side lens surface of the aspherical lens may be concave towards the object near the optical axis and convex towards the object at the periphery. Similarly, the image-side lens surface of the aspherical lens may be concave towards the image near the optical axis and convex towards the image at the periphery.

[0065] In the zoom lens L0 of each embodiment, vibration isolation can be achieved by moving any entire lens group or a part thereof as a vibration isolation group so as to include a component perpendicular to the optical axis, or by rotating it in a plane including the optical axis. In this case, it is preferable to move any entire lens group or a part thereof, which is positioned closer to the image than the first lens group L1, so as to include a component perpendicular to the optical axis, in order to perform vibration isolation.

[0066] In the zoom lens L0 of each embodiment, focusing can also be achieved by moving any entire lens group or a part thereof as a focusing group to include a component in the optical axis direction.

[0067] In each embodiment, it is preferable that the zoom lens L0 does not include a diffractive optical element. While providing a diffractive optical element in the optical system is advantageous from the viewpoint of correcting chromatic aberration, it is undesirable because diffraction flare occurs in the diffractive optical element.

[0068] In each embodiment of the zoom lens L0, it is preferable that the total number of lens elements is 7 or less. By reducing the number of lens elements, the weight of the lenses in the zoom lens L0 can be reduced, making the zoom lens L0 lighter.

[0069] In the zoom lens L0 of each embodiment, it is preferable that the first lens group L1 remains stationary during magnification. This suppresses the eccentricity of the first lens group L1 caused by manufacturing errors, and reduces variations in aberrations due to eccentricity.

[0070] Next, we will describe the detailed configurations of Examples 1 to 4. Note that for the zoom lens L0 in each example, we will omit the explanation of configurations similar to the zoom lens L0 in Example 1, and will mainly describe the differences from Example 1.

[0071] [Example 1] The zoom lens L0 of Example 1 consists of a prism P, a first lens group L1 with negative refractive power, a second lens group L2 with positive refractive power, and a third lens group L3 with negative refractive power, arranged in order from the object side to the image side.

[0072] In the zoom lens L0 of Example 1, the first lens group L1 consists of G1 to G3 lenses, the second lens group L2 consists of G4 and G5 lenses, and the third lens group L3 consists of G6 and G7 lenses. Furthermore, the G2 lens corresponds to the positive lens Gp which has anomalous dispersion.

[0073] In the zoom lens L0 of Example 1, the G1, G2, G3, G4, G6, and G7 lenses are aspherical lenses made of resin material. Each of the lens surfaces of the G1, G3, and G7 lenses has an inflection point.

[0074] In the zoom lens L0 of Example 1, when zooming from the wide-angle end to the telephoto end, the first lens group L1 remains stationary in the optical axis direction, while the second and third lens groups move toward the object. By keeping the first lens group L1 stationary relative to the image plane during zooming, the eccentricity of the first lens group L1 that occurs during zooming due to manufacturing errors, etc., is suppressed, and variations in aberrations due to eccentricity are reduced.

[0075] [Example 2] The zoom lens L0 of Example 2 consists of a prism P, a first lens group L1 with positive refractive power, a second lens group L2 with positive refractive power, and a third lens group L3 with negative refractive power, arranged in order from the object side to the image side. The lens surfaces of the G3, G6, and G7 lenses each have an inflection point.

[0076] [Example 3] The zoom lens L0 of Example 3 consists of a prism P, a first lens group L1 with negative refractive power, a second lens group L2 with positive refractive power, and a third lens group L3 with positive refractive power, arranged in order from the object side to the image side. The lens surfaces of the G1 lens and the G7 lens each have an inflection point.

[0077] [Example 4] The zoom lens L0 of Example 4 consists of a prism P, a first lens group L1 with positive refractive power, a second lens group L2 with negative refractive power, a third lens group L3 with positive refractive power, and a fourth lens group L4 with positive refractive power, arranged in order from the object side to the image side. In addition, the G2 lens corresponds to a positive lens Gp with anomalous dispersion.

[0078] In the zoom lens L0 of Example 4, the G1, G2, G3, G4, G6, and G7 lenses are aspherical lenses made of resin material. The lens surfaces of the G1 and G7 lenses each have an inflection point.

[0079] The numerical values ​​corresponding to the zoom lens L0 of Examples 1 to 4 are shown below.

[0080] In the surface data for each numerical example, r(mm) represents the radius of curvature of each optical surface, and d(mm) represents the distance on the optical axis between the k-th surface and the (k+1)-th surface. Here, k is the surface number counted from the object side. Also, nd represents the refractive index of the material of each optical component with respect to the d line, νd represents the Abbe number of the material of each optical component, and θgF represents the partial dispersion ratio. The Abbe number νd and partial dispersion ratio θgF of a certain material can be expressed as follows, when the refractive indices of the Fraunhofer lines d line (587.6 nm), F line (486.1 nm), C line (656.3 nm), and g line (wavelength 435.8 nm) are Nd, NF, NC, and Ng, respectively. νd = (Nd-1) / (NF-NC) θgF = (Ng - NF) / (NF - NC)

[0081] In each numerical example, the half-angle of view (°) of the zoom lens L0 is shown, and the maximum image height corresponding to that half-angle of view is shown as "image height". Furthermore, in each numerical example, the focal length at the d line of each lens group is shown as lens group data. Note that d, focal length (mm), F number, and half-angle of view (°) are the values ​​when the zoom lens L0 of each example is focused at infinity. BF (back focus) represents the distance along the optical axis from the final lens surface (the surface closest to the image) to the paraxial image plane, converted to air equivalent. The total lens length is the sum of the distance along the optical axis from the object-side lens surface of the lens positioned closest to the object among the lenses included in the zoom lens L0 to the image-side lens surface of the lens positioned closest to the image, and the back focus.

[0082] In each numerical example, surface numbers 1 to 3 correspond to the respective surfaces of prism P. Surface number 1 corresponds to the object-side prism surface in the optical axis, surface number 2 corresponds to the reflective surface of prism P, and surface number 3 corresponds to the image-side prism surface.

[0083] Also, in each lens, when the lens surface is an aspherical surface, an asterisk (*) is attached to the right side of the surface number. The aspherical shape is represented by the following formula when X is the displacement amount from the surface vertex in the optical axis direction, h is the height from the optical axis in the direction perpendicular to the optical axis, R is the paraxial curvature radius, k is the conic constant, and A4, A6, A8, A10, A12, A14, A16 are the aspherical coefficients of each order. X=(h 2 / R) / [1+{1-(1+k)(h / R) 2} 1 / 2 +A4×h 4 +A6× h6 +A8×h 8 +A10×h 10 +A12×h 12 +A14×h 14 +A16×h 16

[0084] For "e±XX" in each aspherical coefficient, it means "×10±XX".

[0085] [Numerical Example 1] Unit: mm Surface Data Surface Number r d nd νd Effective Diameter 1 ∞ 2.40 1.71700 29.5 8.84 2 ∞ 2.40 1.71700 29.5 7.95 3 ∞ 1.00 7.07 4* 12.532 1.50 1.54400 56.0 6.00 5* -8.913 0.10 5.25 6* 18.049 1.17 1.68040 18.1 5.09 7* 29.535 0.12 4.49 8* 11.380 0.40 1.54400 56.0 4.40 9* 2.081 (Variable) 4.20 10* 4.476 2.02 1.54400 56.0 4.21 11* -3.473 0.10 3.82 12* -3.292 2.00 1.66100 20.4 3.81 13* -5.442 (variable) 3.69 14* -17.607 1.00 1.54400 56.0 3.49 15* 11.799 4.37 3.20 16* 11.737 1.00 1.53500 55.7 5.03 17* 8.639 (variable) 5.66 Image plane ∞ Aspherical data Side 4 K = 0.00000e+00 A 4= 2.70694e-03 A 6= 6.68449e-05 A 8=-5.35323e-06 A10= 5.42463e-07 5th page K = 0.00000e+00 A 4= 1.34103e-02 A 6=-1.43755e-03 A 8= 1.64671e-04 A10=-1.06006e-05 A12= 1.74090e-07 A14=-3.55253e-09 Page 6 K = 0.00000e+00 A 4=-5.24655e-03 A 6= 5.80725e-04 A 8=-1.42311e-04 A10= 3.03920e-05 A12=-3.60757e-06 A14= 1.57726e-07 Side 7 K = 0.00000e+00 A 4=-1.11035e-02 A 6= 4.05950e-03 A 8=-1.46726e-03 A10= 3.17207e-04 A12=-3.58981e-05 A14= 1.61229e-06 Side 8 K = 1.89574e+01 A 4=-1.22279e-02 A 6= 3.55223e-03 A 8=-1.85160e-03 A10= 4.54917e-04 A12=-5.40245e-05 A14= 2.27451e-06 Page 9 K =-3.95797e-01 A 4=-3.05619e-02 A 6= 2.31615e-03 A 8=-9.12601e-04 A10= 2.10205e-04 A12=-2.56904e-05 A14= 6.83543e-07 Page 10 K =-3.59255e-01 A 4= 1.44138e-03 A 6= 3.61225e-04 A 8=-9.78925e-05 A10= 7.28813e-05 A12=-1.61049e-05 A14= 1.83553e-06 Page 11 K = 4.66552e-01 A 4= 9.39397e-03 A 6= 9.41415e-04 A 8=-3.73794e-04 A10= 3.11720e-04 A12=-9.97229e-05 A14= 1.21784e-05 Page 12 K = 9.93097e-01 A 4= 8.84036e-03 A 6= 9.97302e-04 A 8=-1.32851e-05 A10= 6.85775e-05 A12=-2.85490e-05 A14= 4.32400e-06 Page 13 K =-2.86101e+01 A 4=-1.84352e-02 A 6= 8.08662e-03 A 8=-2.76445e-03 A10= 5.55867e-04 A12=-1.24483e-05 A14=-1.76275e-05 A16= 2.39248e-06 Page 14 K =-5.37439e+02 A 4=-1.23329e-02 A 6= 6.75968e-03 A 8=-2.86155e-03 A10= 6.77737e-04 A12=-4.20889e-06 A14=-3.41075e-05 A16= 5.14680e-06 Page 15 K = 0.00000e+00 A 4=-5.74117e-03 A 6= 1.02371e-03 A 8=-5.34455e-04 A10= 5.04984e-04 A12=-2.47346e-04 A14= 5.90030e-05 A16=-5.40935e-06 Page 16 K =-2.09123e+01 A 4=-1.25180e-02 A 6= 2.72123e-03 A 8=-1.80422e-03 A10= 7.60218e-04 A12=-1.78340e-04 A14= 2.17682e-05 A16=-1.06113e-06 Page 17 K =-6.19310e+01 A 4=-3.27250e-03 A 6=-1.07305e-03 A 8=-1.40250e-04 A10= 1.91245e-04 A12=-5.13709e-05 A14= 6.00912e-06 A16=-2.59937e-07 Various data Zoom ratio 1.98 Wide-angle end Telephoto end Focal length 10.10 20.00 F-number 3.00 4.00 Half-angle 17.58 9.09 Image height 3.20 3.20 Lens length: 26.99 x 27.00 mm BF 1.07 7.01 d 9 5.01 0.20 d13 1.33 0.20 d17 1.07 7.01 Zoom lens group data Group starting plane focal length L1 1 -19.85 L2 10 5.70 L3 14 -9.92 Single lens data Lens starting plane, focal length θgF G1 4 9.82 G2 6 65.51 0.6827 G3 8 -4.75 G4 10 3.95 G5 12 -20.00 G6 14 -12.83 G7 16 -68.93

[0086] [Numerical Example 2] Unit: mm Surface data Face number rd nd νd Effective diameter 1 ∞ 2.40 1.71700 29.5 8.41 2 ∞ 2.40 1.71700 29.5 7.27 3 ∞ 1.00 6.13 4* -16.988 1.00 1.54400 56.0 5.20 5* -6.474 0.10 4.70 6* 17.725 1.00 1.68040 18.1 4.30 7* 39.123 0.10 3.75 8* 6.211 0.40 1.54400 56.0 3.48 9* 3.211 (variable) 3.11 10* 6.700 1.70 1.54400 56.0 2.41 11* -2.499 0.10 2.28 12* -2.761 2.00 1.66100 20.4 2.15 13* -4.836 (variable) 1.97 14* -74.691 1.00 1.54400 56.0 3.39 15* -10.999 0.53 3.56 16* 19.758 0.40 1.53500 55.7 3.56 17* 2.147 (variable) 5.09 Image plane ∞ Aspherical data Side 4 K = 0.00000e+00 A 4= 6.63635e-03 A 6=-1.99222e-04 A 8= 3.23275e-05 A10=-3.03033e-06 5th page K = 0.00000e+00 A 4= 9.45181e-03 A 6=-6.81361e-04 A 8= 9.30947e-05 A10= 6.21559e-06 A12=-4.18120e-06 A14= 3.18295e-07 Page 6 K = 0.00000e+00 A 4=-7.32948e-03 A 6=-4.43590e-04 A 8= 7.32573e-05 A10= 2.82778e-05 A12=-6.95028e-06 A14= 5.06881e-07 Side 7 K = 0.00000e+00 A 4=-1.40419e-02 A 6= 2.03098e-03 A 8=-6.55149e-04 A10= 2.70182e-04 A12=-5.62453e-05 A14= 4.34999e-06 Side 8 K = 7.14760e+00 A 4=-4.32183e-02 A 6= 8.62435e-03 A 8=-2.71381e-03 A10= 6.56000e-04 A12=-1.16809e-04 A14= 7.46141e-06 9th page K = 7.11123e-01 A 4=-4.87087e-02 A 6= 8.81093e-03 A 8=-2.79245e-03 A10= 5.15933e-04 A12=-5.82030e-05 A14= 2.21426e-06 Page 10 K =-2.44795e+01 A 4= 6.51283e-03 A 6=-5.94835e-03 A 8= 4.70020e-03 A10=-4.74420e-03 A12= 2.40847e-03 A14=-5.62744e-04 Page 11 K = 1.08996e+00 A 4= 1.24807e-02 A 6=-3.52700e-04 A 8= 4.13984e-03 A10=-3.83714e-03 A12= 1.65972e-03 A14=-3.11920e-04 Page 12 K =-3.69391e+00 A 4=-2.36958e-02 A 6= 2.82976e-03 A 8=-1.74219e-03 A10= 2.74051e-03 A12=-2.60581e-03 A14= 6.51033e-04 Page 13 K =-6.99637e+01 A 4=-7.25343e-02 A 6= 7.85417e-02 A 8=-7.92670e-02 A10= 6.57334e-02 A12=-4.43006e-02 A14= 2.16105e-02 A16=-5.20276e-03 Page 14 K =-4.72164e+04 A 4= 1.37224e-02 A 6= 5.69656e-03 A 8=-5.79033e-03 A10= 3.02824e-03 A12=-5.93510e-04 A14=-2.76547e-05 A16= 1.63544e-05 Page 15 K = 0.00000e+00 A 4= 2.65893e-02 A 6=-1.68957e-03 A 8=-2.81449e-03 A10= 2.56303e-03 A12=-9.17418e-04 A14= 2.17686e-04 A16=-2.29080e-05 Page 16 K =-1.61999e+03 A 4=-9.71558e-02 A 6= 3.87285e-02 A 8=-1.71832e-02 A10= 5.41453e-03 A12=-8.68684e-04 A14=-1.84291e-06 A16= 2.02030e-05 Page 17 K =-9.54230e+00 A 4=-3.10755e-02 A 6= 9.19910e-03 A 8=-1.44049e-03 A10= 1.86391e-04 A12=-5.35676e-05 A14= 1.04048e-05 A16=-7.04537e-07 Various data Zoom ratio 1.50 Wide-angle end Telephoto end Focal length 6.96 10.43 F-number 3.00 4.00 Half-angle 24.71 17.05 Image height 3.20 3.20 Lens length 19.43 19.44 BF 1.00 4.41 d 9 2.33 0.68 d13 1.96 0.22 d17 1.00 4.41 Zoom lens group data Group starting plane focal length L1 1 198.42 L2 10 5.63 L3 14 -5.84 Single lens data Lens starting plane, focal length θgF G1 4 18.61 G2 6 46.75 0.6827 G3 8 -12.82 G4 10 3.58 G5 12 -15.80 G6 14 23.58 G7 16 -4.54

[0087] [Numerical Example 3] Unit: mm Surface data Face number rd nd νd Effective diameter 1 ∞ 2.40 1.71700 29.5 9.61 2 ∞ 2.40 1.71700 29.5 8.53 3 ∞ 1.00 7.46 4* 16.610 1.32 1.54400 56.0 6.00 5* -7.512 0.20 5.14 6* 20.815 1.23 1.68040 18.1 5.14 7* 53.003 0.10 4.53 8* 15.221 0.40 1.54400 56.0 4.25 9* 1.903 (variable) 3.55 10* 3.936 1.85 1.54400 56.0 3.57 11* -5.142 0.20 3.32 12* -3.380 1.35 1.66100 20.4 3.28 13* -6.729 (variable) 3.27 14* -71.208 1.00 1.54400 56.0 2.53 15* -4478.515 1.43 2.92 16* 4.079 0.87 1.53500 55.7 4.03 17* 4.735 (variable) 4.21 Image plane ∞ Aspherical data Side 4 K = 0.00000e+00 A 4= 4.92511e-03 A 6= 1.16050e-04 A 8=-5.25175e-06 A10= 1.19348e-06 5th page K = 0.00000e+00 A 4= 1.76636e-02 A 6=-1.28599e-03 A 8= 1.65441e-04 A10=-8.46016e-06 A12= 7.90524e-07 A14=-4.74111e-08 Page 6 K = 0.00000e+00 A 4=-6.88065e-03 A 6= 8.61892e-04 A 8=-1.46100e-04 A10= 3.11606e-05 A12=-3.64391e-06 A14= 1.54237e-07 Side 7 K = 0.00000e+00 A 4=-1.27661e-02 A 6= 4.48204e-03 A 8=-1.48536e-03 A10= 3.26088e-04 A12=-3.74015e-05 A14= 1.67446e-06 Side 8 K = 3.65207e+01 A 4=-1.13695e-02 A 6= 3.91188e-03 A 8=-1.77874e-03 A10= 4.44843e-04 A12=-5.24332e-05 A14= 2.07152e-06 9th page K =-4.70816e-01 A 4=-3.89119e-02 A 6= 4.27070e-03 A 8=-1.30165e-03 A10= 2.75418e-04 A12=-3.43124e-05 A14= 1.05184e-06 Side 10 K =-1.03974e+00 A 4= 2.33834e-03 A 6= 3.02178e-04 A 8=-1.36480e-04 A10= 8.22601e-05 A12=-1.93019e-05 A14= 1.75289e-06 Page 11 K = 1.91805e+00 A 4= 9.81886e-03 A 6= 5.92268e-04 A 8=-2.38391e-04 A10= 2.38180e-04 A12=-8.81283e-05 A14= 1.09810e-05 Page 12 K = 5.95631e-01 A 4= 1.53725e-02 A 6= 2.92303e-04 A 8= 2.49689e-05 A10= 5.83474e-05 A12=-3.70446e-05 A14= 5.91338e-06 Page 13 K =-4.56299e+01 A 4=-1.18730e-02 A 6= 7.36989e-03 A 8=-2.67312e-03 A10= 5.86780e-04 A12=-2.40260e-05 A14=-1.83130e-05 A16= 2.85602e-06 Page 14 K =-9.66056e+03 A 4=-1.34139e-03 A 6= 2.30325e-03 A 8=-1.62118e-03 A10= 5.09101e-04 A12=-3.82421e-05 A14=-3.75986e-05 A16= 9.74817e-06 Page 15 K = 0.00000e+00 A 4=-1.67623e-03 A 6= 1.38555e-03 A 8=-7.75068e-04 A10= 3.67412e-04 A12=-2.25186e-04 A14= 8.12346e-05 A16=-1.18527e-05 Page 16 K =-1.34531e+00 A 4=-1.35830e-02 A 6= 3.80097e-03 A 8=-1.87313e-03 A10= 7.44081e-04 A12=-1.81707e-04 A14= 2.26347e-05 A16=-1.09307e-06 Page 17 K =-1.43332e+01 A 4= 4.52046e-05 A 6=-9.60769e-04 A 8=-1.37795e-04 A10= 1.87854e-04 A12=-5.50307e-05 A14= 6.24369e-06 A16=-2.14389e-07 Various data Zoom ratio 1.80 Wide-angle end Telephoto end Focal length 9.25 16.66 F-number 3.00 4.00 Half-angle 19.07 10.87 Image height 3.20 3.20 Lens length 26.90 26.91 BF 4.93 7.47 d 9 4.21 0.20 d13 2.02 3.50 d17 4.93 7.47 Zoom lens group data Group starting plane focal length L1 1 -13.19 L2 10 6.95 L3 14 52.66 Single lens data Lens starting plane, focal length θgF G1 4 9.69 G2 6 49.61 0.6827 G3 8 -4.04 G4 10 4.41 G5 12 -12.24 G6 14 -133.02 G7 16 37.63

[0088] [Numerical Example 4] Unit: mm Surface data Face number rd nd νd Effective diameter 1 ∞ 2.40 1.71700 29.5 9.14 2 ∞ 2.40 1.71700 29.5 8.19 3 ∞ 1.00 7.24 4* -216.214 1.00 1.54400 56.0 6.00 5* -14.372 0.28 5.24 6* 7.534 1.12 1.68040 18.1 5.16 7* 8.240 (variable) 4.60 8* 12.182 0.41 1.54400 56.0 4.08 9* 2.941 (variable) 4.00 10* 4.469 1.68 1.53500 55.7 4.07 11* -6.818 0.15 3.85 12* -4.419 1.94 1.66100 20.4 3.85 13* -9.367 (Variable) 3.80 14* 49.203 0.92 1.54400 56.0 3.14 15* -17.875 5.06 3.24 16* 6.266 0.92 1.53500 55.7 5.19 17* 3.917 (variable) 5.66 Image plane ∞ Aspherical data Side 4 K = 0.00000e+00 A 4= 1.20278e-02 A 6=-6.36216e-04 A 8= 4.91562e-05 A10=-9.69433e-07 5th page K = 0.00000e+00 A 4= 1.66177e-02 A 6=-8.29837e-04 A 8= 4.11334e-05 A10= 1.09558e-05 A12=-1.21343e-06 A14= 3.71098e-08 Page 6 K = 0.00000e+00 A 4=-7.06438e-03 A 6= 8.52892e-04 A 8=-2.33492e-04 A10= 5.16881e-05 A12=-5.36245e-06 A14= 1.96746e-07 Page 7 K = 0.00000e+00 A 4=-1.47899e-02 A 6= 4.12311e-03 A 8=-1.28771e-03 A10= 2.77575e-04 A12=-3.12749e-05 A14= 1.37174e-06 Page 8 K = 2.31067e+01 A 4=-2.33103e-02 A 6= 7.91978e-03 A 8=-2.46716e-03 A10= 5.20264e-04 A12=-5.99061e-05 A14= 2.55592e-06 Page 9 K = 9.38991e-02 A 4=-3.14648e-02 A 6= 7.34049e-03 A 8=-2.23024e-03 A10= 4.90817e-04 A12=-6.49976e-05 A14= 3.43554e-06 Page 10 K = 8.37232e-01 A 4=-7.48025e-04 A 6=-5.68116e-04 A 8= 3.76213e-04 A10=-9.91140e-05 A12= 1.08344e-05 A14=-6.49833e-08 Page 11 K = 8.18035e+00 A 4= 1.28628e-02 A 6=-1.02023e-03 A 8= 1.79070e-04 A10= 1.63132e-04 A12=-5.86086e-05 A14= 6.89466e-06 Page 12 K = 2.14697e+00 A 4= 1.56575e-02 A 6=-1.24782e-03 A 8= 1.10664e-04 A10= 1.16756e-04 A12=-3.30929e-05 A14= 2.56666e-06 Page 13 K =-7.72697e+01 A 4=-5.02763e-03 A 6= 4.28588e-03 A 8=-1.80165e-03 A10= 5.69473e-04 A12=-1.15095e-04 A14= 1.22954e-05 A16=-5.27441e-07 Page 14 K =-4.78612e+03 A 4= 1.56635e-02 A 6=-1.01185e-03 A 8=-2.62419e-04 A10= 8.86325e-04 A12=-5.13221e-04 A14= 1.32266e-04 A16=-1.30657e-05 Page 15 K = 0.00000e+00 A 4= 8.31849e-03 A 6= 2.37385e-03 A 8=-1.41714e-03 A10= 9.30305e-04 A12=-3.23566e-04 A14= 6.01486e-05 A16=-4.50511e-06 Page 16 K = 1.09848e+00 A 4=-2.18003e-02 A 6= 2.63147e-03 A 8=-1.41875e-03 A10= 7.04722e-04 A12=-1.70260e-04 A14= 1.98918e-05 A16=-9.05272e-07 Page 17 K =-9.18532e+00 A 4=-6.90928e-03 A 6=-6.51804e-04 A 8= 5.69353e-05 A10= 1.61993e-04 A12=-4.86958e-05 A14= 5.58213e-06 A16=-2.33696e-07 Various data Zoom ratio 2.00 Wide-angle end Telephoto end Focal length 9.00 18.00 F-number 3.00 4.00 Half-angle 19.57 10.08 Image height 3.20 3.20 Lens length 29.65 29.66 BF 1.62 4.65 d 7 0.70 0.20 d 9 5.30 0.20 d13 2.76 5.34 d17 1.62 4.65 Zoom lens group data Group starting plane focal length L1 1 20.02 L2 8 -7.24 L3 10 8.59 L4 14 100.00 Single lens data Lens starting plane, focal length θgF G1 4 28.25 G2 6 78.67 0.6827 G3 8 -7.24 G4 10 5.32 G5 12 -14.99 G6 14 24.22 G7 16 -22.62

[0089] The various values ​​in each numerical example are summarized in Tables 1 and 2 below.

[0090] [Table 1]

[0091] [Table 2]

[0092] [Imaging device] Next, we will describe an example of a smartphone using the zoom lens L0 of each embodiment as the imaging optical system.

[0093] In Figure 9, 10 is the smartphone body, and 12 is the imaging optical system composed of any of the zoom lenses L0 described in Examples 1 to 4. The smartphone body 10 may have multiple zoom lenses L0, or it may have other zoom lenses.

[0094] The smartphone body 10 may also be a digital still camera or an in-car camera. In this case, the camera body contains a solid-state image sensor such as a CCD sensor or CMOS sensor that receives the optical image formed by the zoom lens 12 and converts it into photoelectric energy.

[0095] Although 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 its gist.

[0096] In the zoom lens L0 of each embodiment, the multiple lens groups may consist of a negative first lens group and a positive second lens group, positioned from the object side to the image side. By using a two-group configuration, the zoom lens L0 can be made smaller and lighter.

[0097] In the zoom lens L0 of each embodiment, the prism P is located on the object side of the first lens group L1, but is not limited to this, and may be located between multiple lens groups.

[0098] In the zoom lens L0 of each embodiment, it is preferable, but not limited to, that each lens group has one or more aspherical lenses made of resin material.

[0099] Furthermore, the disclosure of this embodiment includes the following configuration.

[0100] (Composition 1) A zoom lens comprising multiple lens groups arranged sequentially from the object side to the image side, wherein the distance between adjacent lenses changes when the magnification is changed, Each of the aforementioned lens groups has one or more aspherical lenses made of resin material. Of the aforementioned multiple lens groups, the first lens group positioned closest to the object has a positive lens Gp. When the Abbe number of the material of the positive lens Gp is ​​νdp, the partial dispersion ratio is θgFp, and the anomalous partial dispersion is ΔθgFp, 0.00 < νdp < 20.0 0.060 < ΔθgFp < 0.080 ΔθgFp = θgFp - (×νdp - 0.6483) A zoom lens characterized by satisfying the following conditional equation.

[0101] (Configuration 2) A zoom lens comprising multiple lens groups arranged sequentially from the object side to the image side, wherein the distance between adjacent lenses changes when the magnification is changed, Of the aforementioned multiple lens groups, the first lens group, which is positioned closest to the object, remains stationary with respect to the image plane during magnification. The first lens group has a positive lens Gp, When the Abbe number of the material of the positive lens Gp is ​​νdp, the partial dispersion ratio is θgFp, and the anomalous partial dispersion is ΔθgFp, 0.060 < ΔθgFp < 0.080 ΔθgFp = θgFp - (×νdp - 0.6483) A zoom lens characterized by satisfying the following conditional equation.

[0102] (Composition 3) When the refractive index of the material of the positive lens Gp with respect to the d line is ndp, 1.50 <ndp<1.80 A zoom lens according to configuration 1 or 2, characterized by satisfying the following conditional expression.

[0103] (Composition 4) When the Abbe number of the material of lens Gpa, which is positioned adjacent to the positive lens Gp, is νdpa, 50.0 < νdpa < 100.0 A zoom lens according to any one of configurations 1 to 3, characterized in that it satisfies the following conditional expression.

[0104] (Composition 5) When the refractive power of the lens material Gpa with respect to the d line is ndpa, 1.40 <ndpa<1.60 A zoom lens according to any one of configurations 1 to 4, characterized in that it satisfies the following conditional expression.

[0105] (Composition 6) When the half-angle of view at the telephoto end of the aforementioned zoom lens is ωt[°], 7.00 < ωt < 20.00 A zoom lens according to any one of configurations 1 to 5, characterized in that it satisfies the following conditional expression.

[0106] (Composition 7) When the maximum image height of the zoom lens is imgH and the total optical length is TL, 0.08 <imgH / TL<0.20 A zoom lens according to any one of configurations 1 to 6, characterized by satisfying the following conditional expression.

[0107] (Composition 8) When the back focus at the wide-angle end of the aforementioned zoom lens is skw and the total optical length is TL, 0.020 <skw / TL<0.300 A zoom lens according to any one of configurations 1 to 7, characterized by satisfying the following conditional expression.

[0108] (Composition 9) A zoom lens according to any one of configurations 1 to 8, characterized in that the total number of lenses constituting the plurality of lens groups is 7.

[0109] (Composition 10) A zoom lens according to any one of configurations 1 to 9, characterized by comprising a prism having a reflective surface, which is positioned on the object side of the first lens group.

[0110] (Composition 11) When mmax is the amount of movement of the lens group with the largest amount of movement along the optical axis during magnification among the aforementioned multiple lens groups, 0.15 <mmax / TL<0.30 A zoom lens according to any one of configurations 1 to 10, characterized by satisfying the following conditional expression.

[0111] (Composition 12) When ea1 is half the effective diameter of the object-side lens surface of lens G1, which is positioned closest to the object in the first lens group, and imgH is the maximum image height, 0.75 <ea1 / imgH<1.00 A zoom lens according to any one of configurations 1 to 11, characterized by satisfying the following conditional expression.

[0112] (Composition 13) In the aforementioned zoom lens, when eaR is half the effective diameter of the image-side lens surface of lens GR, which is positioned closest to the image, and imgH is the maximum image height, 0.60 <eaR / imgH<1.00 A zoom lens according to any one of configurations 1 to 12, characterized by satisfying the following conditional expression.

[0113] (Composition 14) A zoom lens comprising a second lens group and a third lens group arranged adjacent to the image side of the first lens group, wherein the distance between the second lens group and the third lens group changes during zooming from the wide-angle end to the telephoto end, the zoom lens being any one of configurations 1 to 13.

[0114] (Configuration 15) When the focal length of the second lens group is f2 and the focal length of the entire zoom lens at the wide-angle end is fw, 0.40 < |f2| / fw < 1.00 The zoom lens according to any one of configurations 1 to 14, characterized by satisfying the conditional expression.

[0115] (Configuration 16) When the focal length of the third lens group is f3 and the focal length of the entire zoom lens at the wide-angle end is fw, 0.60 < |f3| / fw < 7.00 The zoom lens according to any one of configurations 1 to 15, characterized by satisfying the conditional expression.

[0116] (Configuration 17) When the focal length of the second lens group is f2 and the focal length of the third lens group is f3, |f2 / f3| < 1.00 The zoom lens according to any one of configurations 1 to 16, characterized by satisfying the conditional expression.

[0117] (Configuration 18) When the focal length of the first lens group is f1 and the focal length of the second lens group is f2, 1.50 < |f1 / f2| < 3.70 The zoom lens according to any one of configurations 1 to 17, characterized by satisfying the conditional expression.

[0118] (Configuration 19) When the focal length of the first lens group is f1 and the focal length of the third lens group is f3, 0.10 < |f1 / f3| < 4.00 A zoom lens according to any one of configurations 1 to 18, characterized by satisfying the following conditional expression.

[0119] (Composition 20) When the focal length of the first lens group is f1 and the focal length of the entire zoom lens system at the wide-angle end is fw, 1.20 < |f1| / fw < 2.50 A zoom lens according to any one of configurations 1 to 19, characterized by satisfying the following conditional expression.

[0120] (Composition 21) When the total focal length of the zoom lens at the wide-angle end is fw, and the total focal length of the zoom lens at the telephoto end is ft, 1.20 <fw / ft<2.50 A zoom lens according to any one of configurations 1 to 20, characterized by satisfying the following conditional expression.

[0121] (Composition 22) The zoom lens according to any one of configurations 1 to 21, characterized in that the first lens group includes an aspherical lens having an inflection point.

[0122] (Composition 23) The aforementioned group of lenses consists of a first lens group with negative refractive power, a second lens group with positive refractive power, and a third lens group with negative refractive power, arranged in order from the object side to the image side. A zoom lens according to any one of configurations 1 to 22, characterized in that the first lens group remains stationary with respect to the image plane during magnification, and the second and third lens groups move toward the object.

[0123] (Composition 24) The aforementioned group of lenses consists of a first lens group with positive refractive power, a second lens group with positive refractive power, and a third lens group with negative refractive power, arranged in order from the object side to the image side. In the case of zooming, the first lens group is stationary with respect to the image plane, and the second lens group and the third lens group move toward the object side. The zoom lens according to any one of Configurations 1 to 23, characterized in that.

[0124] (Configuration 25) The plurality of lens groups are composed of the first lens group having a negative refractive power, the second lens group having a positive refractive power, and the third lens group having a positive refractive power, which are arranged in order from the object side to the image side. In the case of zooming, the first lens group is stationary with respect to the image plane, and the second lens group and the third lens group move toward the object side. The zoom lens according to any one of Configurations 1 to 24, characterized in that.

[0125] (Configuration 26) The plurality of lens groups are composed of the first lens group having a positive refractive power, the second lens group having a negative refractive power, the third lens group having a positive refractive power, and the fourth lens group having a positive refractive power, which are arranged in order from the object side to the image side. In the case of zooming, the first lens group is stationary with respect to the image plane, and the second to fourth lens groups move toward the object side. The zoom lens according to any one of Configurations 1 to 25, characterized in that.

[0126] (Configuration 27) A zoom lens including a plurality of lens groups arranged in order from the object side to the image side, wherein the distance between adjacent lenses changes during zooming. Each of the plurality of lens groups has a lens made of one or more resin materials. The first lens group arranged closest to the object side among the plurality of lens groups has a positive lens Gp. When the Abbe number of the material of the positive lens Gp is νdp, the partial dispersion ratio is θgFp, and the anomalous partial dispersibility is ΔθgFp. 0.00 < νdp < 20.0 0.060 < ΔθgFp < 0.080 ΔθgFp = θgFp - (×νdp - 0.6483) A zoom lens characterized by satisfying the conditional expression.

[0127] (Composition 28) An imaging device characterized by comprising a zoom lens according to any one of configurations 1 to 27 and an image sensor that receives an image formed by the zoom lens. [Explanation of symbols]

[0128] P Prism L0 Zoom Lens L1 First lens group L2 Second lens group L3 Third lens group Gp positive lens IP image plane

Claims

1. A zoom lens comprising multiple lens groups arranged sequentially from the object side to the image side, wherein the distance between adjacent lens groups changes when the zoom is changed, Each of the aforementioned lens groups has one or more aspherical lenses made of resin material. Of the aforementioned plurality of lens groups, the first lens group positioned closest to the object has a positive lens Gp. When the Abbe number of the material of the positive lens Gp is ​​νdp, the partial dispersion ratio is θgFp, and the anomalous partial dispersion is ΔθgFp, 0.00<νdp<20.0 0.060<ΔθgFp<0.080 ΔθgFp=θgFp-(0.0018×νdp-0.6483) A zoom lens characterized by satisfying the following conditional equation.

2. When the refractive index of the material of the positive lens Gp with respect to the d line is ndp, 1.50<ndp<1.80 The zoom lens according to claim 1, characterized in that it satisfies the following condition.

3. When the Abbe number of the material of lens Gpa, which is positioned adjacent to the positive lens Gp, is νdpa, 50.0<νdpa<100.0 The zoom lens according to claim 1, characterized in that it satisfies the following condition.

4. When the refractive power of the lens material Gpa with respect to the d line is ndpa, 1.40<ndpa<1.60 The zoom lens according to claim 3, characterized in that it satisfies the following condition.

5. When the half-angle of view at the telephoto end of the zoom lens is ωt [°], 7.00<ωt<20.00 The zoom lens according to claim 1, characterized in that it satisfies the following condition.

6. When the maximum image height of the zoom lens is imgH and the total optical length is TL, 0.08<imgH / TL<0.20 The zoom lens according to claim 1, characterized in that it satisfies the following condition.

7. When the back focus at the wide-angle end of the zoom lens is skw and the total optical length is TL, 0.020<skw / TL<0.300 The zoom lens according to claim 1, characterized in that it satisfies the following condition.

8. The zoom lens according to claim 1, characterized in that the total number of lenses constituting the plurality of lens groups is seven.

9. The zoom lens according to claim 1, further comprising a prism having a reflective surface, which is positioned on the object side of the first lens group.

10. When the amount of movement of the lens group with the largest amount of movement along the optical axis during magnification is denoted as mmax, 0.15<mmax / TL<0.30 The zoom lens according to claim 1, characterized in that it satisfies the following condition.

11. When the first lens group has a lens G1 positioned closest to the object, and the effective diameter of the object-side lens surface is half of the effective diameter of the object-side lens surface is ea1, and the maximum image height is imgH, 0.75<ea1 / imgH<1.00 The zoom lens according to claim 1, characterized in that it satisfies the following condition.

12. In the aforementioned zoom lens, when eaR is half the effective diameter of the image-side lens surface of the lens GR positioned closest to the image, and imgH is the maximum image height, 0.60<eaR / imgH<1.00 The zoom lens according to claim 1, characterized in that it satisfies the following condition.

13. The zoom lens according to claim 1, further comprising a second lens group and a third lens group arranged adjacent to the image side of the first lens group, wherein the distance between the second lens group and the third lens group changes when the zoom is changed from the wide-angle end to the telephoto end.

14. When the focal length of the second lens group is f2 and the focal length of the entire zoom lens system at the wide-angle end is fw, 0.40<|f2| / fw<1.00 The zoom lens according to claim 13, characterized in that it satisfies the following condition.

15. When the focal length of the third lens group is f3 and the focal length of the entire zoom lens system at the wide-angle end is fw, 0.60<|f3| / fw<7.00 The zoom lens according to claim 13, characterized in that it satisfies the following condition.

16. When the focal length of the second lens group is f2 and the focal length of the third lens group is f3, |f2 / f3|<1.00 The zoom lens according to claim 13, characterized in that it satisfies the following condition.

17. The zoom lens according to claim 1, characterized in that the first lens group includes an aspherical lens having an inflection point.

18. The aforementioned group of lenses consists of a first lens group with negative refractive power, a second lens group with positive refractive power, and a third lens group with negative refractive power, arranged in order from the object side to the image side. The zoom lens according to claim 1, characterized in that the first lens group remains stationary with respect to the image plane during magnification, while the second and third lens groups move toward the object.

19. The aforementioned group of lenses consists of a first lens group with positive refractive power, a second lens group with positive refractive power, and a third lens group with negative refractive power, arranged in order from the object side to the image side. The zoom lens according to claim 1, characterized in that the first lens group remains stationary with respect to the image plane during magnification, while the second and third lens groups move toward the object.

20. The aforementioned group of lenses consists of a first lens group with negative refractive power, a second lens group with positive refractive power, and a third lens group with positive refractive power, arranged in order from the object side to the image side. The zoom lens according to claim 1, characterized in that the first lens group remains stationary with respect to the image plane during magnification, while the second and third lens groups move toward the object.

21. The aforementioned group of lenses consists of a first lens group with positive refractive power, a second lens group with negative refractive power, a third lens group with positive refractive power, and a fourth lens group with positive refractive power, arranged in order from the object side to the image side. The zoom lens according to claim 1, characterized in that the first lens group remains stationary with respect to the image plane during magnification, while the second to fourth lens groups move toward the object.

22. A zoom lens comprising multiple lens groups arranged sequentially from the object side to the image side, wherein the distance between adjacent lens groups changes when the zoom is changed, Of the aforementioned multiple lens groups, the first lens group positioned closest to the object remains stationary with respect to the image plane during magnification. The first lens group has a positive lens Gp, When the Abbe number of the material of the positive lens Gp is ​​νdp, the partial dispersion ratio is θgFp, and the anomalous partial dispersion is ΔθgFp, 0.060<ΔθgFp<0.080 ΔθgFp=θgFp-(0.0018×νdp-0.6483) A zoom lens characterized by satisfying the following conditional equation.

23. An imaging device comprising a zoom lens according to any one of claims 1 to 22, and an image sensor that receives an image formed by the zoom lens.

Images