Zoom lens and imaging device having same

Abstract

This zoom lens comprises a plurality of lens groups disposed in order from the object side to the image side, and the distances between adjacent lens groups change during zooming. A first lens group disposed closest to the object side among the plurality of lens groups is immobile with respect to an image surface during zooming. The plurality of lens groups each have one or more aspheric lenses comprising a resin material. The first lens group disposed closest to the object side among the plurality of lens groups has a positive lens Gp, and satisfies a predetermined conditional expression where υdp, θgFp, and ∆θgFp are the Abbe number, partial dispersion ratio, and anomalous partial dispersion of the material of the positive lens Gp, respectively.

Description

Zoom lens and imaging device having the same

[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.

[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.

[0003] US2022-0035132 publication

[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.

[0005] A zoom lens as one aspect of this disclosure comprises 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 magnification is changed, 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 arranged closest to 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, the following conditions are satisfied: 0.00 < νdp < 20.0 0.060 < ΔθgFp < 0.080 ΔθgFp = θgFp - (0.0018 × νdp - 0.6483).

[0006] Furthermore, another aspect of the present disclosure 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 stationary 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, the following conditions are satisfied: 0.060 < ΔθgFp < 0.080 ΔθgFp = θgFp - (0.0018 × νdp - 0.6483).

[0007] This allows us to provide a compact zoom lens with high optical performance.

[0008] Lens cross-sectional view at the wide-angle end of Example 1 Lens cross-sectional view at the telephoto end of Example 1 Aberration diagram at the wide-angle end of Example 1 Aberration diagram at the telephoto end of Example 1 Lens cross-sectional view at the wide-angle end of Example 2 Lens cross-sectional view at the telephoto end of Example 2 Aberration diagram at the wide-angle end of Example 2 Aberration diagram at the telephoto end of Example 2 Lens cross-sectional view at the wide-angle end of Example 3 Lens cross-sectional view at the telephoto end of Example 3 Aberration diagram at the wide-angle end of Example 3 Aberration diagram at the telephoto end of Example 3 Lens cross-sectional view at the wide-angle end of Example 4 Lens cross-sectional view at the telephoto end of Example 4 Aberration diagram at the wide-angle end of Example 4 Aberration diagram at the telephoto end of Example 4 Enlarged view of the main part of the imaging device

[0009] The embodiments disclosed herein will be described in detail below with reference to the drawings. Note that the drawings may be drawn to a different scale than the actual scale for convenience. In addition, the same reference numeral is used for the same components in each drawing, and redundant explanations are omitted. 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 in which it can move along the optical axis in the mechanism.

[0010] Figures 1A, 1B, 3A, 3B, 5A, 5B, 7A, and 7B are cross-sectional views of the zoom lens L0 according to Embodiments 1 to 4 at the wide-angle and telephoto ends, 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 the imaging surface of a solid-state image sensor such as a CCD sensor or CMOS sensor, or a photoelectric conversion element, is arranged at the position of the image plane IP. The zoom lens L0 of each embodiment may also be used as the photographic optical system of a silver halide film camera, in which 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 lens group (where i is a natural number) from the object side among the lens group included in the zoom lens L0. Also, Gk represents the k-th lens (where k is a natural number) from the object side among the lenses included in the zoom lens.

[0012] In each cross-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, and in-vehicle cameras. In the zoom lens L0, the distance between adjacent lens groups changes when the magnification is changed. That is, in this specification, a lens group refers to a group of lenses that move together when the magnification is changed, or a group of lenses that remain stationary relative to the image plane when the magnification is changed. Note that a lens group may consist of one lens or multiple lenses. In addition, each lens group may include aspherical lenses, Fresnel lenses, metalenses, and diffractive optical elements. In addition, each lens group may include an aperture diaphragm SP. If an optical element having a reflective surface is arranged on the object side of the first lens group L1, the optical element having the reflective surface shall not be included in the lens group. An example of an optical element having a reflective surface is a prism P.

[0013] Figures 2A, 2B, 4A, 4B, 6A, 6B, 8A, and 8B are longitudinal aberration diagrams of the zoom lens L0 according to Examples 1 to 4, respectively. In each aberration diagram, the spherical aberration diagram, astigmatism diagram, distortion diagram, and chromatic aberration diagram are shown from left to right. Furthermore, in each longitudinal aberration diagram, Figures 2A, 4A, 6A, and 8A show the longitudinal aberration diagram at the wide-angle end, while Figures 2B, 4B, 6B, and 8B show the longitudinal aberration diagram at the telephoto end.

[0014] In each longitudinal aberration diagram, Fno is the F-number, ω is the half-angle of view (°), and is the angle of view determined by ray tracing. In the spherical aberration diagram, the solid line d represents the amount of spherical aberration with respect to the d-line (wavelength 587.56 nm), and the dashed line g represents the amount of spherical aberration with respect to the g-line (wavelength 435.835 nm). The dashed line also indicates the amount of sinusoidal condition unsatisfaction of the zoom lens L0 in each embodiment. In the astigmatism diagram, the solid line ΔS represents the amount of astigmatism with respect to the d-line in the sagittal image plane, and the dashed line ΔM represents the amount of astigmatism with respect to the d-line in the meridional image plane. In the distortion diagram, the solid line represents the amount of distortion with respect to the d-line. In the chromatic aberration diagram, the dashed line g represents the amount of chromatic aberration with respect to 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] Conditional equation (1) defines the anomalous dispersion ΔθgFp of the positive lens Gp included in the first lens group. By arranging lens Gp that satisfies conditional equation (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 that the upper limit of conditional expression (1) be 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 movement of the lens group with the largest movement on the optical axis during magnification is defined as mmax. 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 conditional expression (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 expression (3) defines the refractive index ndp of the material of the positive lens Gp included in the first lens group with respect to the d-line. If it exceeds the upper limit of conditional expression (3), the manufacturability of the positive lens Gp deteriorates, which is not preferable. If it is below the lower limit of conditional expression (3), the positive refractive power of the positive lens Gp becomes weak, and it becomes difficult to miniaturize the zoom lens L0, which is not preferable.

[0039] Further, regarding the upper limit of conditional expression (3), it is more preferable to set it to any one of 1.79, 1.78, 1.77, 1.76, 1.75, 1.74, 1.73, 1.72, 1.71, 1.70, 1.69.

[0040] Further, regarding the lower limit of conditional expression (3), it is more preferable to set it to any 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, 1.67.

[0041] Conditional expression (4) defines the Abbe number νdpa of the lens Gpa arranged adjacent to the positive lens Gp. By making the Abbe number of the lens Gpa arranged adjacent to the aforementioned positive lens Gp fall within an appropriate range, chromatic aberration can be corrected well. If it exceeds the upper limit of conditional expression (4), it becomes difficult to correct chromatic aberration, which is not preferable. If it is below the lower limit of conditional expression (4), the correction of chromatic aberration becomes excessive, which is not preferable.

[0042] Conditional expression (5) defines the refractive index ndpa of the lens Gpa with respect to the d-line. By making the refractive index of the lens Gpa fall within an appropriate range, chromatic aberration can be corrected well. If it exceeds the upper limit of conditional expression (5), the positive refractive power of the lens Gpa becomes too large, making it difficult to correct spherical aberration and the like, which is not preferable. If it is below the lower limit of conditional expression (5), the positive refractive power of the lens Gpa becomes too weak, resulting in a large movement amount when the lens group including the lens Gpa is zoomed, and the zoom lens L0 becomes large in the optical axis direction, which is not preferable.

[0043] Conditional expression (6) defines the half angle ωt corresponding to the maximum image height of the zoom lens L0 at the far end. Note that the maximum image height refers to the distance from the position where the peripheral light amount with respect to the vicinity of the optical axis on the image plane becomes 10% to the optical axis. If it exceeds the upper limit of conditional expression (6), the lens diameters of each lens group increase, and the zoom lens L0 becomes larger in the radial direction, which is not preferable. If it is below the lower limit of conditional expression (6), the overall optical length becomes longer, and the zoom lens L0 becomes larger in the optical axis direction, which is not preferable.

[0044] Conditional expression (7) defines the ratio of the maximum image height imgH to the overall optical length TL. Note that the overall optical length refers to the distance on the optical axis from the object-side lens surface of the lens disposed most on the object side in the first lens group L1 to the image plane IP.

[0045] If it exceeds the upper limit of conditional expression (7), the overall optical length becomes shorter, and it becomes difficult to secure the moving distance on the optical axis of the lens group that moves during zooming, which is not preferable. If it is below the lower limit of conditional expression (7), the overall optical length becomes longer, and the zoom lens L0 becomes larger in the optical axis direction, which is not preferable.

[0046] Conditional expression (8) defines the ratio of the back focus skw of the zoom lens L0 at the wide-angle end to the overall optical length TL. If it exceeds the upper limit of conditional expression (8), the back focus becomes longer, and it becomes difficult to secure the moving distance on the optical axis of the lens group that moves during zooming, which is not preferable. If it is below the lower limit of conditional expression (8), the back focus becomes shorter, and it becomes difficult to appropriately arrange members such as filters on the image plane side, which is not preferable.

[0047] Conditional expression (9) defines the ratio of the moving amount mmax on the optical axis of the lens group with the largest moving amount on the optical axis during zooming among the plurality of lens groups constituting the zoom lens L0 to the overall optical length TL.

[0048] If it exceeds the upper limit of conditional expression (9), the distance that the lens group moves during zooming becomes too long, and the change in optical performance during zooming becomes large, which is not preferable. If it is below the lower limit of conditional expression (9), the distance that the lens group moves during zooming becomes short, and it becomes difficult to secure a long focal length at the telephoto end, which is not preferable.

[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 the lens G1 positioned closest to the object in the first lens group L1, e.g.

[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, and color unevenness occurs, which is also undesirable.

[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 image field distortion and other aberrations, 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 various 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, which is undesirable as it causes the zoom lens L0 to become larger in the optical axis direction.

[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 direction 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 chromatic aberration correction, 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 seven 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 that may occur due to manufacturing errors, and reduces variations in aberrations caused by 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 a positive lens Gp having anomalous dispersion properties.

[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 lens, G6 lens, and G7 lens 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 having 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 following shows the numerical values ​​corresponding to the zoom lens L0 of Examples 1 to 4.

[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 are expressed as follows, when the refractive indices at 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 the zoom lens L0 is shown, and the maximum image height corresponding to the half-angle is shown as the "image height". Further, in each numerical example, as lens group data, the focal length of each lens group on the d-line is shown. Note that d, focal length (mm), F-number, and half-angle (°) are the values when the zoom lens L0 of each example is focused at infinity. BF (back focus) represents the value obtained by air-converting the distance on the optical axis from the final lens surface (the surface closest to the image side) to the paraxial image plane. The overall length of the lens is the sum of the distance on the optical axis from the object-side lens surface of the lens arranged on the most object side among the lenses included in the zoom lens L0 to the image-side lens surface of the lens arranged on the most image side, and the back focus.

[0082] In each numerical example, surface numbers 1 to 3 correspond to the respective surfaces of the prism P. Surface number 1 corresponds to the object-side prism surface on the optical axis, surface number 2 corresponds to the reflecting surface of the 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 symbol 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 vertex of the surface in the optical axis direction, h is the height from the optical axis in the direction perpendicular to the optical axis, R is the paraxial 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 "e±XX" in each aspherical coefficient means "×10±XX".

[0084] [Numerical Example 1] Unit: mm Surface Data Surface Number: rd 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 4th plane K = 0.00000e+00 A 4 = 2.70694e-03 A 6 = 6.68449e-05 A 8 = -5.35323e-06 A10 = 5.42463e-07 5th plane 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 6th plane 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 7th side 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 8th side 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 9th side 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 10th side K =-3.59255e-01 A 4= 1.44138e-03 A 6= 3.61225e-04A 8=-9.78925e-05 A10= 7.28813e-05 A12=-1.61049e-05 A14= 1.83553e-06 11th side 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 12th side 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 13th side 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 14th side 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 15th side 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 16th side 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 17th side 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 27.00 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 .

[0085] [Numerical Example 2] Unit: mm Surface Data Surface 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 4th plane K = 0.00000e+00 A 4 = 6.63635e-03 A 6 = -1.99222e-04 A 8 = 3.23275e-05 A10 = -3.03033e-06 5th plane 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 6th plane 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 7th side 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 8th side 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 side 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 10th side 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 Side 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 12th side 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 13th side 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 14th side 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 15th side 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 16th side 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 17th side K =-9.54230e+00 A 4=-3.10755e-02A 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 of view 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 .

[0086] [Numerical Example 3] Unit: mm Surface Data Surface 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 4th plane K = 0.00000e+00 A 4 = 4.92511e-03 A 6 = 1.16050e-04 A 8 = -5.25175e-06 A10 = 1.19348e-06 5th plane 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 6th plane 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 7th side 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 8th side 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 side 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 10th side 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 11th side 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 12th side 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 13th side 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 14th side 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 15th side K = 0.00000e+00 A 4=-1.67623e-03 A 6= 1.38555e-03A 8=-7.75068e-04 A10= 3.67412e-04 A12=-2.25186e-04 A14= 8.12346e-05 A16=-1.18527e-05 16th side 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 17th side K =-1.43332e+01 A 4= 4.52046e-05A 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 .

[0087] [Numerical Example 4] Unit: mm Surface Data Surface 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 4th plane K = 0.00000e+00 A 4 = 1.20278e-02 A 6 = -6.36216e-04 A 8 = 4.91562e-05 A10 = -9.69433e-07 5th plane 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 6th plane 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 7th side 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 8th side 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 9th side 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 10th side 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 Side 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 12th side 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 13th side 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 14th side 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 15th side 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 16th side 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 17th side K =-9.18532e+00 A 4=-6.90928e-03A 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 of view 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 .

[0088] The various values ​​in each numerical example are summarized in Tables 1 and 2 below.

[0089]

[0090]

[0091] [Imaging Device] Next, we will describe an example of a smartphone using the zoom lens L0 of each embodiment as the imaging optical system.

[0092] 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.

[0093] 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.

[0094] While preferred embodiments and examples of the disclosure herein have been described above, this disclosure is not limited to these embodiments and examples, and various combinations, modifications, and changes are possible within the scope of its essence.

[0095] 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.

[0096] 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.

[0097] In the zoom lens L0 of each embodiment, it is preferable that each lens group has one or more aspherical lenses made of resin material, but it is not limited to this, and each lens group may have one or more lenses made of resin material.

[0098] This application claims priority based on Japanese Patent Application No. 2024-205412, filed on November 26, 2024, and all of its contents are incorporated herein by reference.

Claims

1. A zoom lens comprising a plurality of lens groups arranged sequentially from the object side to the image side, wherein the spacing between adjacent lens groups changes when the magnification is changed, each of the plurality of lens groups has one or more aspherical lenses made of resin material, the first lens group positioned closest to 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, the following conditions are satisfied: 0.00 < νdp < 20.0 0.060 < ΔθgFp < 0.080 ΔθgFp = θgFp - (0.0018 × νdp - 0.6483).

2. 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, wherein the first lens group, which is positioned closest to the object among the plurality of lens groups, remains stationary with respect to the image plane during magnification, 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, the following conditions are satisfied: 0.060 < ΔθgFp < 0.080 ΔθgFp = θgFp - (0.0018 × νdp - 0.6483).

3. The zoom lens according to claim 1 or 2, characterized in that, when the refractive index of the material of the positive lens Gp with respect to the d line is ndp, the condition 1.50 < ndp < 1.80 is satisfied.

4. The zoom lens according to any one of claims 1 to 3, characterized in that, when the Abbe number of the material of the lens Gpa arranged adjacent to the positive lens Gp is ​​νdpa, the condition 50.0 < νdpa < 100.0 is satisfied.

5. The zoom lens according to claim 4, characterized in that when the refractive power of the lens material Gpa with respect to the d line is ndpa, the condition 1.40 < ndpa < 1.60 is satisfied.

6. The zoom lens according to any one of claims 1 to 5, characterized in that when the half angle of view at the telephoto end of the zoom lens is ωt [°], the condition 7.00 < ωt < 20.00 is satisfied.

7. The zoom lens according to any one of claims 1 to 6, characterized in that when the maximum image height of the zoom lens is imgH and the total optical length is TL, the condition 0.08 < imgH / TL < 0.20 is satisfied.

8. The zoom lens according to any one of claims 1 to 7, characterized in that when the back focus at the wide-angle end of the zoom lens is skw and the total optical length is TL, the condition 0.020 < skw / TL < 0.300 is satisfied.

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

10. The zoom lens according to any one of claims 1 to 9, characterized in that it comprises a prism having a reflective surface, which is positioned on the object side of the first lens group.

11. The zoom lens according to any one of claims 1 to 10, characterized in that, when mmax is the amount of movement of the lens group with the largest amount of movement on the optical axis during magnification among the plurality of lens groups, the condition 0.15 < mmax / TL < 0.30 is satisfied.

12. The zoom lens according to any one of claims 1 to 11, characterized in that when ea1 is half the effective diameter of the object-side lens surface of the lens G1 positioned closest to the object in the first lens group, and imgH is the maximum image height, the condition 0.75 < ea1 / imgH < 1.00 is satisfied.

13. The zoom lens according to any one of claims 1 to 12, characterized in that 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, the condition 0.60 < eaR / imgH < 1.00 is satisfied.

14. A zoom lens according to any one of claims 1 to 13, 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 magnification changes from the wide-angle end to the telephoto end.

15. The zoom lens according to claim 14, characterized in that, 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, the condition 0.40 < |f2| / fw < 1.00 is satisfied.

16. The zoom lens according to claim 14, characterized in that, 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, the condition 0.60 < |f3| / fw < 7.00 is satisfied.

17. The zoom lens according to claim 14, characterized in that when the focal length of the second lens group is f2 and the focal length of the third lens group is f3, the condition |f2 / f3| < 1.00 is satisfied.

18. The zoom lens according to any one of claims 1 to 17, characterized in that the first lens group includes an aspherical lens having an inflection point.

19. The zoom lens according to any one of claims 1 to 18, wherein the plurality of lens groups consist 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, wherein the first lens group remains stationary with respect to the image plane, and the second and third lens groups move toward the object side during magnification.

20. The zoom lens according to any one of claims 1 to 18, wherein the plurality of lens groups consist 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, wherein the first lens group remains stationary with respect to the image plane, and the second and third lens groups move toward the object side during magnification.

21. The zoom lens according to any one of claims 1 to 18, wherein the plurality of lens groups consist 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, wherein the first lens group remains stationary with respect to the image plane, and the second and third lens groups move toward the object side during magnification.

22. The zoom lens according to any one of claims 1 to 18, wherein the plurality of lens groups consist 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, wherein the first lens group remains stationary with respect to the image plane, and the second to fourth lens groups move toward the object side during magnification.

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