Zoom lens and image-capturing device comprising same

Abstract

This zoom lens comprises, in order from an object side to an image side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a negative refractive power, wherein an interval between adjacent lens groups changes when changing magnification. Each of the first to third lens groups includes one or more aspherical lenses made of a resin material. During a change in magnification from a wide-angle end to a telephoto end, the first lens group does not move relative to an image surface. When designating the distance on the optical axis from the object-side lens surface of a lens disposed most on the object side in the first lens group to the image surface as TL, the maximum image height as imgH, the focal distance of the first lens group as f1, and the focal distance of the third lens group as f3, a prescribed conditional expression is satisfied.

Description

Zoom Lens and Imaging Device Having the Same

[0001] The disclosure of this specification relates to a zoom lens, and is particularly suitable for imaging devices such as cameras for smartphones, still cameras, video cameras, digital still cameras, in-vehicle cameras, surveillance cameras, etc.

[0002] Conventionally, as a zoom lens used in imaging devices such as cameras for smartphones and cameras for photography, a high-quality zoom lens that is small in size and has various aberrations well corrected has been demanded. Patent Document 1 discloses a zoom lens having a first lens group with a negative refractive power, a second lens group with a positive refractive power, and a third lens group with a negative refractive power in order from the object side to the image side.

[0003] U.S. Patent No. 2022 / 0171171

[0004] In a small-sized zoom lens, it is required to have a high magnification in zooming from the wide-angle end to the telephoto end, that is, a high magnification that covers a wide range of focal lengths. In order to realize a small-sized and high-magnification zoom lens, it is necessary to appropriately set various conditions such as the refractive power and arrangement of each lens group constituting the zoom lens.

[0005] The zoom lens according to one aspect of the present disclosure includes a first lens group with a negative refractive power, a second lens group with a positive refractive power, and a third lens group with a negative refractive power, which are arranged in order from the object side to the image side, and is a zoom lens in which the distance between adjacent lens groups changes during zooming. The first to third lens groups each have an aspherical lens made of one or more resin materials. When zooming from the wide-angle end to the telephoto end, the first lens group is immovable with respect to the image plane. Let the distance on the optical axis from the object-side lens surface of the lens arranged closest to the object side in the first lens group to the image plane be TL, the maximum image height be imgH, the focal length of the first lens group be f1, and the focal length of the third lens group be f3, then 0.11 < imgH / TL < 0.20 1.20 < f1 / f3 < 5.00

[0006] It is characterized by satisfying the following conditional expressions.

[0007] Furthermore, another aspect of this disclosure, a zoom lens, comprises a prism having a reflective surface arranged sequentially 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, wherein the distance between adjacent lens groups changes when the zoom is changed, the first lens group remains stationary with respect to the image plane when the zoom is changed from the wide-angle end to the telephoto end, and when TL is the distance on the optical axis from the object-side lens surface of the lens positioned closest to the object in the first lens group to the image plane, and the maximum image height is imgH, then 0.11 < imgH / TL < 0.20

[0008] It is characterized by satisfying the following conditional expression.

[0009] This makes it possible to provide a compact zoom lens that has a high magnification when changing from the wide-angle end to the telephoto end.

[0010] Schematic diagram of the optical system in each embodiment Lens cross-sectional view of the wide-angle and telephoto ends of Embodiment 1 Aberration diagram of the wide-angle end of Embodiment 1 Aberration diagram of the telephoto end of Embodiment 1 Lens cross-sectional view of the wide-angle and telephoto ends of Embodiment 2 Aberration diagram of the wide-angle end of Embodiment 2 Aberration diagram of the telephoto end of Embodiment 2 Lens cross-sectional view of the wide-angle and telephoto ends of Embodiment 3 Aberration diagram of the wide-angle end of Embodiment 3 Aberration diagram of the telephoto end of Embodiment 3 Lens cross-sectional view of the wide-angle and telephoto ends of Embodiment 4 Aberration diagram of the wide-angle end of Embodiment 4 Aberration diagram of the telephoto end of Embodiment 4 Lens cross-sectional view of the wide-angle and telephoto ends of Embodiment 5 Aberration diagram of the wide-angle end of Embodiment 5 Aberration diagram of the telephoto end of Embodiment 5 Schematic diagram of the main parts of the imaging device

[0011] 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 variable magnification is located at both ends of the range in which it can move along the optical axis due to the mechanism.

[0012] Figure 1 shows a schematic diagram of the optical system used in the zoom lens of each embodiment, with the optical system used in Embodiment 1 shown as a representative example. In Figure 1, SP is the aperture diaphragm that determines the light beam at the open F-number (Fno). IP is the image plane, and when used as the imaging optical system of a video camera or digital still camera, the imaging surface of a solid-state image sensor or photoelectric conversion element such as a CCD sensor or CMOS sensor is placed there. When used as the imaging optical system of a silver halide film camera, the photosensitive surface corresponding to the film surface is placed there. P is a prism with a reflective surface, and its role is to bend the light beam.

[0013] Figures 2, 4, 6, 8, and 10 are cross-sectional views of the zoom lens L0 at its wide-angle and telephoto ends, respectively, according to Embodiments 1 to 5. 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 positioned at the location 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 positioned on the image plane IP. In addition, in each cross-sectional view, SP represents the aperture diaphragm that determines the light beam at the open F number.

[0014] 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 when the magnification is changed. A lens group may consist of one lens or multiple lenses. In addition, each lens group may include an aspherical lens, Fresnel lens, metalens, and diffractive optical element. 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.

[0015] Figures 3A, 3B, 5A, 5B, 7A, 7B, 9A, 9B, 11A, and 11B are longitudinal aberration diagrams of the zoom lens L0 according to Embodiments 1 to 5, 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 3A, 5A, 7A, 9A, and 11A show the longitudinal aberration diagram at the wide-angle end, while Figures 3B, 5B, 7B, 9B, and 11B show the longitudinal aberration diagram at the telephoto end.

[0016] 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 for the d-line (wavelength 587.56 nm), and the dashed line g represents the amount of spherical aberration for the g-line (wavelength 435.835 nm). In the astigmatism diagram, the solid line ΔS represents the amount of astigmatism for the d-line in the sagittal image plane, and the dashed line ΔM represents the amount of astigmatism for the d-line in the meridional image plane. In the distortion diagram, the solid line represents the amount of distortion for the d-line. In the chromatic aberration diagram, the dashed line g represents the amount of chromatic aberration for the g-line.

[0017] Next, we will describe the characteristic configuration of the zoom lens L0 in each embodiment.

[0018] The zoom lens L0 in each embodiment has, in order from the object side, 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. With this configuration, a wide angle of view can be secured in the wide-angle range, while high magnification can be secured when changing from the wide-angle end to the telephoto end.

[0019] The zoom lens L0 in each embodiment includes at least one aspherical lens made of resin material in each lens group. By employing aspherical lenses, the number of lenses in the zoom lens L0 can be reduced, thereby enabling miniaturization of the zoom lens L0.

[0020] In the zoom lens L0 of each embodiment, the spacing between the lens groups changes when zooming from the wide-angle end to the telephoto end, while the first lens group L1 remains stationary with respect to the image plane. By keeping the first lens group L1 stationary during zooming, the eccentricity of the first lens group L1 that occurs during zooming due to manufacturing errors, etc., is suppressed, and the fluctuations of various aberrations due to eccentricity are reduced.

[0021] Furthermore, the zoom lens L0 of each embodiment is characterized in that, when the optical total length of the zoom lens L0 is TL and the maximum image height is imgH, it satisfies the following condition (1): 0.11 < imgH / TL < 0.20 (1)

[0022] Conditional equation (1) defines the ratio of the maximum image height imgH to the total optical length of the zoom lens L0. By satisfying conditional equation (1), it is possible to achieve both high magnification and miniaturization of the zoom lens L0. The maximum image height refers to the distance from the position on the image plane where the amount of peripheral light relative to the vicinity of the optical axis is 10% to the optical axis. 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.

[0023] If the upper limit of condition (1) is exceeded, the overall optical length becomes shorter, limiting the amount of movement of each lens during magnification, which makes it difficult to increase the magnification of the zoom lens L0 and is therefore undesirable. If the lower limit of condition (1) is exceeded, the overall optical length becomes longer, which makes the zoom lens L0 larger in the optical axis direction and is therefore undesirable.

[0024] Furthermore, it is more preferable to set the numerical range of condition (1) to the range of condition (1a) below: 0.12 < imgH / TL < 0.18 (1a)

[0025] Furthermore, it is even more preferable to set the numerical range of condition (1) to the range of condition (1b) below: 0.13 < imgH / TL < 0.16 (1b)

[0026] With the above configuration, it is possible to realize a zoom lens L0 that is compact and has high optical performance while maintaining high magnification during zoom changes.

[0027] Next, we will describe the conditions that are preferable to satisfy in the zoom lens L0 of each embodiment.

[0028] The zoom lens L0 of each embodiment preferably satisfies one or more of the following conditional equations (2) to (23). In each conditional equation, the numerical values ​​are expressed as follows.

[0029] 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, fw be the total focal length of the zoom lens L0 at the wide-angle end, and ft be the total focal length of the zoom lens L0 at the telephoto end.

[0030] When changing magnification from the wide-angle end to the telephoto end, the amount of movement of the second lens group L2 along the optical axis is denoted as MD2, and the amount of movement of the third lens group L3 along the optical axis is denoted as MD3. However, the movement of each lens group is considered positive when it moves toward the object.

[0031] Let skw be the back focus at the wide-angle end, and skt be the back focus at the telephoto end.

[0032] Let Fnow be the F-number at the wide-angle end, and Fnot be the F-number at the telephoto end.

[0033] Let HOVw be the half-angle of view at the wide-angle end, and HOVt be the half-angle of view at the telephoto end.

[0034] In the first lens group L1, LD11 is defined as half the effective diameter of the object-side lens surface of the lens positioned closest to the object, and in the third lens group L3, LD3L is defined as half the effective diameter of the image-side lens surface of the lens positioned closest to the image.

[0035] Let SF11 be the shape factor of the lens closest to the object in the first lens group L1, and SF21 be the shape factor of the lens closest to the object in the second lens group L2. Similarly, let SF31 be the shape factor of the lens closest to the object in the third lens group L3, and SF3L be the shape factor of the lens closest to the image in the third lens group L3. Here, the shape factor SF is the shape factor of lens L, and is defined by the following equation, where fL is the focal length of lens L, R1 is the radius of curvature of the object-side lens surface, and R2 is the radius of curvature of the image-side lens surface. However, if the lens surface is aspherical, R represents the radius of the reference quadratic surface. sgn represents the sign function, taking +1 when fL is positive and -1 when fL is negative. SF = sgn(fL) × (R2 + R1) / (R2 - R1)

[0036] Let PL be the distance along the optical axis between the image-side lens surface of the prism P positioned on the object side of the first lens group L and the object-side lens surface of the lens positioned on the object side of the first lens group L1. 1.20<f1 / f3<5.00 (2) 1.70<ft / fw<2.50 (3) -2.10<f1 / fw<-1.20 (4) -1.10<f1 / ft<-0.50 (5) -6.00<f1 / f2<-1.00 (6) -1.30<f2 / f3<-0.30 (7) 0.60<ft / TL<1.30 (8) 0.10<MD2 / TL<0.35 (9) 0.10<MD3 / TL<0.40 (10) 2.00<Fnow<3.00 (11) 3.00<Fnot<5.70 (12) 20.00<TL×Fnot / imgH<35.00 (13) 0.12<skw / TL<0.23 (14) 0.12<skt / TL<0.46 (15) 0.30<HOVt / HOVw<0.65 (16) 0.55<LD11 / imgH<1.00 (17) 0.90<LD11 / LD3L<1.40 (18) -12.00<SF11<4.00 (19) -2.00<SF21<1.00 (20) -5.00<SF31<1.00 (21) -100.00<SF3L<50.00 (22) 0.04<PL / TL<0.07 (23)

[0037] Conditional equation (2) specifies the focal length of the first lens group L1 and the focal length of the third lens group L3. By satisfying conditional equation (2), it is possible to suppress changes in optical performance due to increased magnification and changes in magnification of the zoom lens L0.

[0038] If the refractive power exceeds the upper limit of condition (2), the refractive power of the third lens group L3 becomes too strong, making it difficult to correct the field curvature and chromatic aberration caused by the off-axis light beam of the third lens group L3, which is undesirable. If the refractive power falls below the lower limit of condition (2), the refractive power of the third lens group L3 becomes too weak, making it difficult to achieve high magnification, which is also undesirable.

[0039] The conditional expression (3) is an expression that defines the ratio of the overall focal length fw at the wide-angle end to the overall focal length ft at the telephoto end, and is a condition for ensuring the zoom ratio in zooming.

[0040] If it exceeds the upper limit of the conditional expression (3), it becomes difficult to suppress the change in optical performance due to zooming. In addition, the zoom lens L0 becomes large in the optical axis direction, which is not preferable. If it is below the lower limit of the conditional expression (3), it becomes difficult to ensure the zoom ratio, which is not preferable.

[0041] The conditional expression (4) is an expression that defines the ratio of the focal length of the first lens group L1 to the overall focal length at the wide-angle end, and aims to achieve both a wide angle of view at the wide-angle end and high optical performance.

[0042] If it exceeds the upper limit of the conditional expression (4), the focal length of the first lens group L1 with respect to the overall focal length at the wide-angle end becomes long, so it becomes difficult to ensure a wide angle of view at the wide-angle end, which is not preferable. If it is below the lower limit of the conditional expression (4), the refractive power of the first lens group L1 becomes strong, and field curvature and chromatic aberration of magnification are strongly generated, which is not preferable.

[0043] The conditional expression (5) is an expression that defines the ratio of the focal length of the first lens group L1 to the overall focal length at the telephoto end, and aims to achieve both a long focal length at the telephoto end and high optical performance.

[0044] If it exceeds the upper limit of the conditional expression (5), the focal length of the first lens group L1 with respect to the overall focal length at the telephoto end becomes long. As a result, it becomes easy to suppress the occurrence of aberrations generated in the first lens group L1, but it is necessary to increase the refractive power of the second lens group L2, which causes the occurrence of various aberrations such as spherical aberration, which is not preferable. If it is below the lower limit of the conditional expression (5), the refractive power of the first lens group L1 with respect to the overall focal length at the telephoto end becomes too strong, so it becomes difficult to ensure a long focal length at the telephoto end, which is not preferable.

[0045] The conditional expression (6) is an expression that defines the ratio of the focal length of the first lens group L1 to the focal length of the second lens group L2, and is a condition for achieving both miniaturization of the zoom lens L0 and suppression of changes in optical performance due to zooming.

[0046] If it exceeds the upper limit of conditional expression (6), the refractive power of the second lens group L2 becomes stronger than that of the first lens group L1, and spherical aberration occurs strongly, which is not preferable. If it is below the lower limit of conditional expression (6), the refractive power of the second lens group L2 becomes weaker than that of the first lens group L1, and the zoom lens L0 becomes larger in the optical axis direction, which is not preferable.

[0047] Conditional expression (7) is an expression that defines the ratio of the focal length of the second lens group L2 to the focal length of the third lens group L3, and is a condition for achieving both miniaturization of the entire system and suppression of optical performance changes due to zooming.

[0048] If it exceeds the upper limit of conditional expression (7), the refractive power of the third lens group L3 becomes stronger than that of the second lens group L2, and aberrations such as field curvature generated in the third lens group L3 occur strongly, which is not preferable. If it is below the lower limit of conditional expression (7), the refractive power of the third lens group L3 becomes weaker than that of the second lens group L2, and it becomes difficult to achieve both miniaturization of the entire system and high magnification, which is not preferable.

[0049] Conditional expression (8) is an expression that defines the ratio of the focal length of the entire system at the telephoto end to the overall optical length of the entire system, and is a condition for achieving both miniaturization of the entire system and high optical performance.

[0050] If it exceeds the upper limit of conditional expression (8), the focal length of the entire system at the telephoto end becomes long, and spherical aberration and axial chromatic aberration occur strongly, which is not preferable. If it is below the lower limit of conditional expression (8), the focal length at the telephoto end becomes short, and the zoom lens L0 becomes larger in the optical axis direction, which is not preferable.

[0051] Conditional expression (9) is an expression that defines the ratio of the amount of movement on the optical axis of the second lens group L2 to the overall optical length of the entire system when zooming from the wide-angle end to the telephoto end, and is a condition for achieving both high magnification and suppression of optical performance changes during zooming.

[0052] If the upper limit of condition (9) is exceeded, the distance the second lens group L2 moves during magnification becomes longer, resulting in a large change in optical performance during magnification, which is undesirable. If the lower limit of condition (9) is exceeded, the amount of movement of the second lens group L2 during magnification becomes smaller, making it difficult to secure a long focal length at the telephoto end, which is also undesirable.

[0053] Conditional equation (10) defines the ratio of the distance the third lens group L3 moves along the optical axis to the total optical length of the entire system when changing magnification from the wide-angle end to the telephoto end. This condition is necessary to achieve both high magnification and suppression of changes in optical performance during magnification.

[0054] If the upper limit of condition (10) is exceeded, the amount of movement of the third lens group L3 on the optical axis during magnification becomes large, which is undesirable because it leads to a large change in optical performance during magnification. If the lower limit of condition (10) is exceeded, the amount of movement of the third lens group L3 on the optical axis during magnification becomes small, which is undesirable because it makes it difficult to secure a long focal length at the telephoto end.

[0055] Conditional equation (11) specifies the F-number at the wide-angle end.

[0056] If the upper limit of condition (11) is exceeded, the amount of light incident on the image plane IP decreases, making the subject more prone to blurring during shooting, which is undesirable. If the lower limit of condition (11) is exceeded, the diameter of the lens in the second lens group L2 increases, causing the zoom lens L0 to become larger in the radial direction, which is also undesirable. Furthermore, aberrations such as spherical aberration and axial chromatic aberration occur, which is also undesirable.

[0057] Conditional equation (12) specifies the F-number at the telephoto end.

[0058] If the light level exceeds the upper limit of condition (12), or falls below the lower limit of condition (12), the amount of light incident on the image plane IP decreases, making the subject more prone to blurring during shooting, which is undesirable. The diameter of the lens in the first lens group L1 increases, and the zoom lens L0 becomes larger in the radial direction, which is undesirable. Furthermore, aberrations such as spherical aberration and axial chromatic aberration occur, which is undesirable.

[0059] Conditional equation (13) defines the ratio of the product of the optical length of the zoom lens L0 and the F-number at the telephoto end to the maximum image height, and is a condition for achieving both miniaturization of the entire system and brightness at the telephoto end.

[0060] If the value exceeds the upper limit of condition equation (13), it is advantageous for correcting spherical aberration and axial chromatic aberration mainly caused by axial light beam at the telephoto end, but it is undesirable because it makes it difficult to miniaturize the entire system and ensure brightness at the telephoto end. If the value falls below the lower limit of condition equation (13), it is advantageous for miniaturizing the entire system and ensuring brightness at the telephoto end, but it is undesirable because it makes it difficult to correct spherical aberration and axial chromatic aberration mainly caused by axial light beam at the telephoto end.

[0061] Conditional equation (14) specifies the ratio of the back focus at the wide-angle end to the total optical length of the entire system, and is a condition for achieving both miniaturization of the entire system and securing the travel distance of the lens group that moves during magnification.

[0062] If the value exceeds the upper limit of condition (14), the back focus relative to the total optical length becomes long, 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 value falls below the lower limit of condition (14), the back focus becomes short, making it difficult to properly position components such as filters, which is also undesirable.

[0063] Conditional equation (15) defines the ratio of the back focus at the telephoto end to the total optical length of the entire system, and is a condition for achieving both miniaturization of the entire system and securing the travel distance of the lens group that moves during magnification.

[0064] If the value exceeds the upper limit of condition (15), the back focus becomes long relative to the total optical length, 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 value falls below the lower limit of condition (15), the back focus becomes short, making it difficult to properly position components such as filters on the image plane side, which is also undesirable.

[0065] Conditional equation (16) defines the ratio of the half-angle of view at the wide-angle end to the half-angle of view at the telephoto end.

[0066] If the upper limit of condition (16) is exceeded, the difference in angle of view between the wide-angle end and 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 lower limit of condition (16) is exceeded, the difference in angle of view between the wide-angle end and the telephoto end becomes too small, which is undesirable because it makes it difficult to increase the magnification of the zoom lens L0.

[0067] Conditional equation (17) defines the ratio of half the effective diameter of the object-side lens surface of the lens positioned closest to the object in the first lens group L1 to the maximum image height imgH.

[0068] If the upper limit of condition (17) is exceeded, the effective diameter of the object-side lens surface of the lens positioned closest to the object in the first lens group L1 becomes large relative to the maximum image height, which is undesirable because it causes the zoom lens L0 to become larger in the optical axis direction. If the lower limit of condition (17) is exceeded, the effective diameter of the object-side lens surface of the lens positioned closest to the object in the first lens group L1 becomes small, which is undesirable because it causes the F-number to become large at the telephoto end.

[0069] Conditional equation (18) specifies the ratio of half the effective diameter of the object-side lens surface of the lens positioned closest to the object in the first lens group L1 to half the effective diameter of the image-side lens surface of the lens positioned closest to the image in the third lens group L3.

[0070] If the upper limit of condition (18) is exceeded, the effective diameter of the object-side lens surface of the lens furthest to the object in the first lens group L1 becomes larger than the effective diameter of the image-side lens surface of the lens furthest to the image in the third lens group L3, which is undesirable because it causes the zoom lens L0 to become larger in the optical axis direction. If the lower limit of condition (18) is exceeded, the effective diameter of the object-side lens surface of the lens furthest to the object in the first lens group L1 becomes smaller than the effective diameter of the image-side lens surface of the lens furthest to the image in the third lens group L3, which is undesirable because it causes the F-number to become larger at the telephoto end.

[0071] Conditional equation (19) is an equation that specifies the shape factor of the lens positioned closest to the object in the first lens group L1.

[0072] If the upper limit of condition (19) is exceeded, the curvature of the object-side lens surface of the lens positioned closest to the object in the first lens group L1 becomes large, making it difficult to suppress field curvature caused by off-axis light beams at the wide-angle end, which is undesirable. If the lower limit of condition (19) is fallen below, the curvature of the object-side lens surface of the lens becomes small, making it difficult to correct spherical aberration caused by on-axis light beams, which is also undesirable.

[0073] Conditional equation (20) is an equation that specifies the shape factor of the lens positioned closest to the object in the second lens group L2.

[0074] If the upper limit of condition (20) is exceeded, the curvature of the object-side lens surface of the lens positioned closest to the object in the second lens group L2 becomes large, making it difficult to suppress field curvature caused by off-axis light beams at the wide-angle end, which is undesirable. If the lower limit of condition (20) is exceeded, the curvature of the object-side lens surface of the lens becomes small, making it difficult to correct spherical aberration caused by on-axis light beams, which is also undesirable.

[0075] Conditional equation (21) is an equation that specifies the shape factor of the lens in the third lens group L3 that is positioned closest to the object.

[0076] If the upper limit of condition (21) is exceeded, the curvature of the object-side surface of the lens positioned closest to the object in the third lens group L3 becomes large, making it difficult to suppress field curvature caused by off-axis light beams at the wide-angle end, which is undesirable. If the lower limit of condition (21) is fallen below, the curvature of the object-side lens surface of the lens becomes small, making it difficult to correct spherical aberration caused by on-axis light beams, which is also undesirable. Furthermore, a small curvature results in a meniscus-shaped lens, making lens processing and shaping difficult, which is also undesirable.

[0077] Conditional equation (22) is an equation that specifies the shape factor of the lens positioned closest to the image in the third lens group L3.

[0078] If the upper limit of condition (22) is exceeded, the curvature of the object-side lens surface of the lens positioned closest to the image in the third lens group L3 becomes large, making it difficult to suppress chromatic aberration caused by off-axis light beam, which is undesirable. If the lower limit of condition (22) is exceeded, the curvature of the object-side lens surface of the lens becomes small, making it difficult to correct axial chromatic aberration caused by on-axis light beam, which is also undesirable.

[0079] Conditional equation (23) defines the ratio of the optical axis distance PL between the image-side surface of the prism P positioned on the object side of the first lens group L1 and the object-side lens surface of the lens positioned on the object side of the first lens group L1, and the total optical length.

[0080] If the upper limit of condition (23) is exceeded, the reflective surface of the prism P for bending the off-axis light beam will be too far from the first lens group L1, which is undesirable because it will increase the size of the prism P. If the lower limit of condition (23) is exceeded, it will be difficult to position the lens holding member and other components between the prism P and the first lens group L1, which is also undesirable.

[0081] Furthermore, it is more preferable to use the following conditional expressions (2a) to (23a) for the numerical ranges of conditional expressions (2) to (23). 1.30<f1 / f3<4.80 (2a) 1.80<ft / fw<2.40 (3a) -2.00<f1 / fw<-1.30 (4a) -1.05<f1 / ft<-0.55 (5a) -5.00<f1 / f2<-1.50 (6a) -1.20<f2 / f3<-0.40 (7a) 0.70<ft / TL<1.20 (8a) 0.15<MD2 / TL<0.30 (9a) 0.15<MD3 / TL<0.35 (10a) 2.20<Fnow<2.80 (11a) 3.50<Fnot<5.00 (12a) 23.00<TL×Fnot / imgH<33.50 (13a) 0.13<skw / TL<0.22 (14a) 0.13<skt / TL<0.45 (15a) 0.35<HOVt / HOVw<0.60 (16a) 0.60<LD11 / imgH<0.95 (17a) 0.95<LD11 / LD3L<1.30 (18a) -11.00<SF11<3.00 (19a) -1.00<SF21<0.50 (20a) -3.00<SF31<0.50 (21a) -90.00<SF3L<20.00 (22a) 0.045<PL / TL<0.065 (23a)

[0082] Furthermore, it is even more preferable to use the following conditional expressions (2) to (23) for the numerical ranges of conditional expressions (2b) to (23b). 1.40<f1 / f3<4.50 (2b) 1.90<ft / fw<2.30 (3b) -1.90<f1 / fw<-1.40 (4b) -1.00<f1 / ft<-0.60 (5b) -4.50<f1 / f2<-2.00 (6b) -1.10<f2 / f3<-0.50 (7b) 0.80<ft / TL<1.10 (8b) 0.20<MD2 / TL<0.25 (9b) 0.20<MD3 / TL<0.30 (10b) 2.40<Fnow<2.60 (11b) 3.80<Fnot<4.50 (12b) 25.00<TL×Fnot / imgH<32.00 (13b) 0.14<skw / TL<0.21 (14b) 0.14<skt / TL<0.44 (15b) 0.40<HOVt / HOVw<0.55 (16b) 0.65<LD11 / imgH<0.90 (17b) 1.00<LD11 / LD3L<1.25 (18b) -10.00<SF11<2.5 (19b) -0.10<SF21<0.25 (20b) -2.00<SF31<0.20 (21b) -80.00<SF3L<10.00 (22b) 0.050<PL / TL<0.060 (23b)

[0083] Next, we will describe the preferred configurations that the zoom lens L0 of each embodiment should satisfy.

[0084] In the zoom lens L0 of each embodiment, it is preferable to place the prism on the object side of the first lens group L1. By having the light beam bent by the prism incident on the first lens group L1, the zoom lens L0 can be made smaller. If it is not necessary to bend the light rays, the prism does not need to be placed.

[0085] In the zoom lens L0 of each embodiment, it is preferable that the first lens group L1 has two positive lenses in order from the object side to the image side. This makes it possible to shorten the focal length at the wide-angle end. Furthermore, it is more preferable to have a positive lens, a positive lens, and a negative lens in order from the object side to the image side, as this allows for the correction of aberrations such as spherical aberration and axial chromatic aberration at the telephoto end.

[0086] Furthermore, it is preferable that the lenses constituting the first lens group L1 are aspherical lenses. This makes it easier to effectively correct field curvature at the wide-angle end while correcting spherical aberration at the telephoto end, thereby facilitating miniaturization.

[0087] In the zoom lens L0 of each embodiment, the second lens group L2 preferably consists of two lenses, one with positive refractive power and the other with negative refractive power, in order from the object side to the image side. This converges the light beam diverged by the first lens group L1, making it possible to achieve both a long focal length at the telephoto end and miniaturization of the third lens group L3.

[0088] In the zoom lens L0 of each embodiment, lens groups such as the fourth lens group L4 and the fifth lens group L5 may be arranged on the image side of the third lens group L3. By arranging a large number of lens groups, it becomes possible to more effectively correct the optical performance associated with high magnification.

[0089] In the zoom lens L0 of each embodiment, it is preferable to position the aperture diaphragm SP between the first lens group L1 and the second lens group L2. This allows the exit pupil to be positioned on the object side, enabling miniaturization of the first lens group L1. Furthermore, since more lenses can be positioned on the image side of the aperture diaphragm SP, it becomes easier to suppress field curvature and chromatic aberration variations caused by magnification changes, which are mainly caused by off-axis rays.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] Next, we will describe the detailed configurations of Examples 1 to 5. 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.

[0096] [Example 1] Figure 2 is a cross-sectional view of the zoom lens L0 of Example 1 at the wide-angle end and the telephoto end. Figures 3A and 3B are aberration diagrams of the zoom lens L0 of Example 1 at the wide-angle end (Figure 3A) and the telephoto end (Figure 3B), respectively. Example 1 is a zoom lens L0 with a magnification ratio of approximately 2.0 and an aperture ratio of approximately 1.6.

[0097] 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.

[0098] 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 G1, G3, G4, G6, and G7 lenses are aspherical lenses made of resin material. The lens surfaces of the G3 and G7 lenses each have inflection points.

[0099] In the zoom lens L0 of Example 1, under the reference state where the object distance is infinity, when zooming from the wide-angle end to the telephoto end, the first lens group L1 remains stationary relative to the image plane, while the second lens group L2 and the third lens group L3 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.

[0100] In the zoom lens L0 of Example 1, the G1 lens has a positive refractive power, the G2 lens has a positive refractive power, and the G3 lens has a negative refractive power.

[0101] In the zoom lens L0 of Example 1, the second lens group L2 consists of positive and negative lenses arranged in order from the object side to the image side. This allows the light beam diverged by the first lens group L1 to be focused by the second lens group L2, ensuring a long focal length at the telephoto end while miniaturizing the third lens group L3.

[0102] In the zoom lens L0 of Example 1, the aperture diaphragm SP is positioned between the first lens group L1 and the second lens group L2. This allows the exit pupil to be positioned on the object side, enabling miniaturization of the first lens group L1. Furthermore, since more lenses can be positioned on the image side of the aperture diaphragm SP, it is possible to suppress field curvature and variations in magnification chromatic aberration mainly caused by off-axis rays.

[0103] [Example 2] Figure 4 is a cross-sectional view of the zoom lens L0 of Example 2 at its wide-angle and telephoto ends. Figures 5A and 5B are aberration diagrams of the zoom lens L0 of Example 2 at its wide-angle (Figure 5A) and telephoto (Figure 5B) ends, respectively. Example 2 is a zoom lens L0 with a zoom ratio of approximately 2.0 and an aperture ratio of approximately 1.6.

[0104] In the zoom lens L0 of Example 2, the first lens group L1 consists of G1 and G2 lenses, the second lens group L2 consists of G3 and G4 lenses, and the third lens group L3 consists of G5 and G6 lenses. Furthermore, the G2, G3, G5, and G6 lenses are aspherical lenses made of resin material. Each lens surface of the G1, G2, and G5 lenses has an inflection point.

[0105] [Examples 3 and 4] Figure 6 is a cross-sectional view of the zoom lens L0 of Example 3 at its wide-angle and telephoto ends. Figures 7A and 7B are aberration diagrams of the zoom lens L0 of Example 3 at its wide-angle (Figure 7A) and telephoto (Figure 7B) ends, respectively. Example 3 is a zoom lens L0 with a zoom ratio of approximately 2.2 and an aperture ratio of approximately 1.6.

[0106] Figure 8 is a cross-sectional view of the zoom lens L0 of Example 4 at its wide-angle and telephoto ends. Figures 9A and 9B are aberration diagrams of the zoom lens L0 of Example 4 at its wide-angle (Figure 9A) and telephoto (Figure 9B) ends, respectively. Example 4 is a zoom lens L0 with a zoom ratio of approximately 2.1 and an aperture ratio of approximately 1.7.

[0107] The zoom lens L0 of Examples 3 and 4 consists of a prism P, a first lens group L1 with negative refractive power, a second lens group L2 with positive refractive power, a third lens group L3 with negative refractive power, and a fourth lens group L4 with positive refractive power, arranged in order from the object side to the image side.

[0108] In the zoom lenses L0 of Examples 3 and 4, the first lens group L1 consists of G1 to G3 lenses, the second lens group L2 consists of G4 and G5 lenses, the third lens group L3 consists of G6 and G7 lenses, and the fourth lens L4 consists of G8 lens. Furthermore, the G1, G3, G4, G6, and G7 lenses are aspherical lenses made of resin material. Each lens surface of the G1, G3, G6, and G7 lenses has an inflection point.

[0109] In the zoom lens L0 of Examples 3 and 4, under the reference state where the object distance is infinity, when changing magnification from the wide-angle end to the telephoto end, the first lens group L1 and the fourth lens group L4 remain stationary relative to the image plane, while the second lens group L2 and the third lens group L3 move toward the object.

[0110] [Example 5] Figure 10 is a cross-sectional view of the zoom lens L0 of Example 5 at its wide-angle and telephoto ends. Figures 11A and 11B are aberration diagrams of the zoom lens L0 of Example 5 at its wide-angle (Figure 11A) and telephoto (Figure 11B) ends, respectively. Example 5 is a zoom lens L0 with a zoom ratio of approximately 2.0 and an aperture ratio of approximately 1.6.

[0111] The zoom lens L0 of Example 5 consists of a prism P, a first lens group L1 with negative refractive power, a second lens group L2 with positive refractive power, a third lens group L3 with negative refractive power, a fourth lens group L4 with positive refractive power, and a fifth lens group L5 with negative refractive power, arranged in order from the object side to the image side.

[0112] In the zoom lens L0 of Example 5, the first lens group L1 consists of G1 to G3 lenses, the second lens group L2 consists of G4 and G5 lenses, the third lens group L3 consists of G6 and G7 lenses, the fourth lens L4 consists of G8 lens, and the fifth lens group L5 consists of G9 lens. Furthermore, the G1, G3, G4, G6, G7, and G9 lenses are aspherical lenses made of resin material.

[0113] In the zoom lens L0 of Example 5, under the reference state where the object distance is infinity, when changing magnification from the wide-angle end to the telephoto end, the first lens group L1 and the fifth lens group L5 remain stationary relative to the image plane, while the second lens group L2, the third lens L3, and the fourth lens group L4 each move toward the object so that the spacing between adjacent lens groups changes.

[0114] The following shows the numerical values ​​corresponding to the zoom lens L0 of Examples 1 to 5.

[0115] 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, and νd represents the Abbe number of the material of each optical component. Here, the Abbe number νd is given by νd = (nd-1) / (nF-nC), where the refractive indices of the Fraunhofer lines c-line (656.3 nm), d-line (587.56 nm), and F-line (486.1 nm) are nC, nd, and nF, respectively.

[0116] It is represented as follows.

[0117] In each numerical example, the half-angle of view (°) of the optical system 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 of each lens group at the d line is shown as lens group data. Note that d, focal length (mm), F number, and half-angle of view (°) are the values ​​when the optical system 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 length of the lens is the sum of the distance along the optical axis from the object-side lens surface of the lens placed closest to the object among the lenses included in the optical system L0 to the image-side lens surface of the lens placed closest to the image, and the back focus.

[0118] Furthermore, for each lens, if the lens surface is aspherical, the symbol * is added to the right of the surface number. The aspherical shape is expressed by the following formula, where X is the displacement from the surface vertex in the optical axis direction, h is the height from the optical axis perpendicular to the optical axis, R is the radius of paraxial curvature, k is the cone constant, and A4, A6, A8, A10, A12, A14, and A16 are the aspherical coefficients of each order: X = (h² / R) / [1 + {1 - (1 + k)(h / R)²}¹ / ²] + A4 × h⁴ + A6 × h⁶ + A8 × h⁸ + A10 × h⁰ + A12 × h⁰ + A14 × h⁴ + A16 × h⁰

[0119] For each aspherical coefficient, "e±XX" means "×10±XX".

[0120] [Numerical Example 1] Unit: mm Surface Data Surface Number rd nd νd Effective Diameter 1 ∞ 2.40 1.71700 29.5 7.43 2 ∞ 2.40 1.71700 29.5 6.57 3 ∞ (Variable) 5.71 4* 13.422 1.05 1.54400 56.0 5.06 5* -7.499 0.10 5.00 6* -16.595 1.26 1.67100 19.4 4.88 7* -8.762 0.10 4.68 8* 11.940 0.40 1.54400 56.0 4.60 9* 1.952 (Variable) 4.50 10 (aperture) ∞ -0.31 4.85 11* 4.134 2.50 1.54400 56.0 4.97 12* -3.187 0.08 4.81 13* -3.405 2.00 1.67100 19.4 4.76 14* -5.632 (variable) 4.80 15* -8.614 2.21 1.54400 56.0 4.49 16* 8.763 1.24 4.37 17* 8.685 0.50 1.53110 55.9 4.53 18* 6.680 (Variable) 4.88 Image plane ∞ Aspherical data 4th plane K = -5.00000e+01 A 4 = 6.45679e-03 A 6 = -1.16102e-03 A 8 = 2.18287e-04 A10 = -4.02094e-05 A12 = 5.46786e-06 A14 = -3.58895e-07 5th plane K = -5.08534e+01 A 4 = 1.08521e-02 A 6 = -4.87577e-03 A 8 = 6.58589e-04 A10 = 5.93687e-05 A12 = -2.33811e-05 A14= 1.51970e-06 6th side K =-9.48145e+00 A 4= 1.05753e-02 A 6=-4.62981e-03 A 8= 4.96157e-04 A10= 1.38482e-04 A12=-3.85259e-05 A14= 2.53746e-06 7th side K =-4.72191e+01 A 4= 7.38711e-03 A 6=-6.57375e-03 A 8= 1.76459e-03 A10=-1.86570e-04 A12=-1.48471e-07 A14= 8.08853e-07 Side 8 K =-5.00000e+01 A 4=-2.49546e-02 A 6=-6.44448e-04 A 8= 1.46722e-03 A10=-3.12811e-04 A12= 2.59455e-05 A14=-7.10552e-07 9th side K =-3.23281e+00 A 4=-2.93176e-02 A 6= 9.49505e-03 A 8=-1.95840e-03 A10= 2.52087e-04 A12=-1.76853e-05 A14= 5.07998e-07 11th side K = 8.63012e-01 A 4=-1.98280e-03 A 6=-3.18847e-04 A 8= 1.00730e-04 A10=-3.24980e-05 A12= 4.37044e-06 A14=-2.46703e-07 Page 12 K = -2.16519e+00 A4 = 8.78145e-03 A6 = -2.76510e-03 A8 = 7.67430e-04 A10 = -1.32057e-04 A12 = 1.33261e-05 A14 = -5.82661e-07 Page 13 K = -6.65165e+00 A4 = -6.61555e-03 A6 = 1.01882e-03 A8 = -6.86452e-05 A10 = 4.46382e-06 A12 = -6.62627e-07 A14 = 1.31549e-07 A16 = -1.20755e-08 Page 14 K = -1.42286e+01 A4 = -3.01368e-03 A6 = 8.95654e-04 A8 = -1.93368e-04 A10 = 3.76241e-05 A12 = -4.90321e-06 A14 = 3.33301e-07 A16 = -4.88393e-09 Page 15 K = -1.85471e+00 A4 = 6.37349e-03 A6 = -1.45487e-03 A8 = 3.51614e-04 A10 = -9.02821e-05 A12 = 1.52255e-05 A14 = -1.65158e-06 A16 = 1.05077e-07 Face 16 K = -5.00000e+01 A4 = -1.07975e-03 A6 = 2.02774e-04 A8 = 1.82165e-04 A10 = -1.28967e-04 A12 = 3.84059e-05 A14 = -6.90048e-06 A16 = 6.81804e-07 Face 17 K = -8.18574e+00 A4 = -5.38803e-02 A6 = 3.50951e-03 A8 = 1.69084e-03 A10 = -5.61345e-04 A12 = -2.54279e-05 A14 = 2.86424e-05 A16 = -2.60802e-06 Page 18 K = 4.80230e+00 A4 = -5.12492e-02 A6 = 5.91592e-03 A8 = 5.61131e-04 A10 = -5.01211e-04 A12 = 9.07719e-05 A14=-5.46291e-06 A16= 2.50860e-08 Various Data Zoom Ratio 1.97 Wide-angle end Telephoto end Focal Length 10.26 20.24 F-number 2.43 4.00 Half-angle 17.33 8.99 Image Height 3.20 3.20 Lens Length 26.99 26.99 BF 3.37 8.51 d 3 1.25 1.25 d 9 5.43 0.81 d14 1.02 0.50 d18 3.37 8.51 Zoom Lens Group Data Group Starting Plane Focal Length L1 4 -18.74 L2 10 5.27 L3 15 -6.44 .

[0121] [Numerical Example 2] Unit: mm Surface Data Surface Number rd nd νd Effective Diameter 1 ∞ 2.40 1.53340 55.9 6.29 2 ∞ 2.40 1.53340 55.9 5.32 3 ∞ (Variable) 5.09 4* -36.104 0.63 1.67100 19.4 5.09 5* -14.075 0.10 4.97 6* 3.477 0.50 1.54400 56.0 4.95 7* 2.161 (Variable) 4.99 8 (Aperture) ∞ -0.23 5.33 9* 4.854 2.67 1.53110 55.9 5.46 10* -3.042 0.08 5.33 11* -3.018 2.00 1.67100 19.4 5.29 12* -4.849 (variable) 5.38 13* -18.993 1.81 1.53110 55.9 5.11 14* 14.875 1.52 4.95 15* -8.595 1.56 1.54400 56.0 4.38 16* 34.025 (variable) 5.06 Image plane ∞ Aspherical data 4th plane K =-4.99895e+01 A 4 = 1.19638e-02 A 6 = -3.71411e-03 A 8 = 1.05986e-03 A10 = -1.82235e-04 A12 = 1.73568e-05 A14 = -6.79253e-07 Page 5 K = -2.88784e+01 A 4 = 1.17930e-02 A 6 = -5.49272e-03 A 8 = 2.02058e-03 A10 = -3.97381e-04 A12 = 4.00922e-05 A14 = -1.59737e-06 Page 6 K = 4.85132e-01 A 4 = -4.84156e-02 A 6 = 3.84854e-03 A 8 = 1.10944e-03 A 10 = -4.31811e-04 A 12 = 5.41742e-05 A 14 = -2.54972e-06 Page 7 K = -2.89730e+00 A 4 = -3.28694e-02 A 6 = 7.59573e-03 A 8 = -9.03799e-04 A 10 = 2.35523e-05 A 12 = 5.21754e-06 A 14 = -3.74025e-07 Page 9 K = 9.19476e-01 A 4 = -1.05162e-03 A 6 = -3.47130e-04 A 8 = 8.97635e-05 A10 = -1.95003e-05 A12 = 1.81030e-06 A14 = -6.95774e-08 Page 10 K = -1.05177e+01 A 4 = -2.67912e-02 A 6 = 8.27490e-03 A 8 = -1.27026e-03 A10 = 9.19955e-05 A12 = -1.92072e-06 A14 = -4.49002e-08 Page 11 K = -9.85560e+00 A 4 = -2.74927e-02 A 6 = 8.25163e-03 A A10 = -1.16435e-03 A12 = 4.31003e-06 A14 = -6.25392e-07 A16 = 2.11104e-08 Page 12 K = -2.57934e+00 A4 = 2.24486e-03 A6 = -3.89127e-04 A8 = 2.17263e-04 A10=-4.40455e-05 A12= 4.95075e-06 A14=-3.12117e-07 A16= 9.38660e-09 13th side K =-4.99883e+01 A 4=-2.56468e-04 A 6=-5.29857e-04 A 8= 1.25362e-04 A10= 1.53768e-05 A12=-9.45397e-06 A14= 1.36178e-06 A16=-6.48844e-08 14th side K =-5.00000e+01 A 4=-1.06646e-02 A 6=-6.39275e-04 A 8= 3.21417e-04 A10=-6.54862e-05 A12= 8.52574e-06 A14=-4.54975e-07 A16=-2.02868e-11 15th side K = 3.24312e+00 A 4=-1.80892e-02 A 6=-3.99267e-03 A 8= 2.99970e-03 A10=-1.25057e-03 A12= 3.06264e-04 A14=-3.76162e-05 A16= 1.78677e-06 16th side K = 5.00000e+01 A 4=-8.58187e-03 A 6=-7.65024e-04 A 8= 9.48955e-04 A10=-3.16805e-04 A12= 5.71957e-05 A14=-5.26736e-06 A16= 1.92688e-07 Various Data Zoom Ratio 1.99 Wide-angle end Telephoto end Focal Length 10.25 20.37 F-number 2.43 4.00 Half-angle 17.34 8.93 Image Height 3.20 3.20 Lens Length 27.05 27.05 BF 3.49 9.14 d 3 1.25 1.25 d 7 5.79 0.72 d12 1.09 0.50 d16 3.49 9.14. Zoom lens group data: Starting plane, focal length L1 4 -19.60, L2 8 5.82, L3 13 -6.38.

[0122] [Numerical Example 3] Unit: mm Surface Data Surface Number: rd nd νd Effective Diameter: 1 ∞ 2.40 1.71700 29.5 7.42 2 ∞ 2.40 1.71700 29.5 6.34 3 ∞ (Variable) 5.27 4* -8.182 0.47 1.54400 56.0 4.44 5* -10.343 0.16 4.43 6* -81.705 0.87 1.67100 19.4 4.42 7* -13.920 0.13 4.42 8* 9.213 0.55 1.54400 56.0 4.41 9* 3.142 (Variable) 4.60 10 (aperture) ∞ -0.51 5.01 11* 3.614 2.64 1.54400 56.0 5.20 12* -3.049 0.08 5.04 13* -3.306 1.39 1.65100 21.5 4.96 14* -7.174 (variable) 4.45 15* -7.461 0.82 1.53110 55.9 4.50 16* -165.448 0.77 4.41 17* 4.329 0.57 1.54400 56.0 4.07 18* 2.866 (variable) 4.39 19* -6.587 0.92 1.68100 18.1 5.28 20* -5.783 (variable) 5.58 Image plane ∞ Aspherical data 4th plane K = -2.91778e+01 A 4 = 8.94780e-03 A 6 = -1.49623e-03 A 8 = 3.37729e-04 A10 = -4.24950e-05 A12 = 6.50851e-07 A14 = 1.77120e-07 5th plane K = -3.67398e+00 A 4 = 1.63182e-02 A 6=-3.62487e-03 A 8= 7.12025e-04 A10=-7.25494e-05 A12=-3.02057e-06 A14= 7.44186e-07 6th side K =-1.24055e+01 A 4= 5.98067e-03 A 6=-1.95205e-03 A 8= 2.83289e-04 A10=-2.35439e-05 A12=-3.57306e-07 A14= 1.99547e-07 7th side K =-1.19082e+01 A 4= 4.50144e-03 A 6=-1.79196e-03 A 8= 2.74779e-04 A10=-6.14895e-05 A12= 1.26859e-05 A14=-1.03754e-06 8th side K =-4.85569e+01 A 4=-3.68409e-02 A 6= 7.24505e-03 A 8=-1.10310e-03 A10= 8.33933e-05 A12= 2.19402e-06 A14=-6.60356e-07 9th side K =-7.90054e+00 A 4=-2.53300e-02 A 6= 6.69641e-03 A 8=-1.21377e-03 A10= 1.48881e-04 A12=-1.08664e-05 A14= 3.59802e-07 Side 11 K = 5.03507e-02 A 4=-6.32634e-04 A 6=-1.51802e-04 A 8= 4.04476e-05 A10=-1.10689e-05 A12= 1.32663e-06 A14=-1.00187e-07 Page 12 K =-1.63758e+00 A 4= 1.06150e-02 A 6=-1.23691e-05 A 8= 1.34442e-04 A10=-3.38532e-05 A12= 1.58283e-07 A14= 1.57392e-07 Page 13 K =-1.07718e+00 A 4= 3.22772e-03 A6= 2.59553e-03 A8= 3.10670e-05 A10=-1.42458e-04 A12= 3.06453e-05 A14=-3.16991e-06 A16= 1.37181e-07 Page 14 K =-1.35814e+01 A4=-2.20006e-03 A6= 3.65569e-03 A8=-4.69467e-04 A10= 6.91819e-05 A12=-9.18123e-06 A14= 2.52947e-06 A16=-3.17042e-07 Page 15 K =-3.73694e+01 A 4= 1.78201e-02 A 6=-1.13257e-03 A 8=-2.69236e-05 A10= 3.67488e-05 A12= 1.54726e-05 A14=-4.52877e-06 A16= 1.79803e-07 Face 16 K =-6.82689e+00 A 4= 4.42700e-03 A 6= 3.52616e-04 A 8=-6.30919e-04 A10=-2.30033e-04 A12= 2.10063e-04 A14=-4.81014e-05 A16= 3.52390e-06 Page 17 K = -2.04580e+01 A4 = -4.38567e-02 A6 = 5.56492e-04 A8 = 3.14719e-03 A10 = -2.28902e-03 A12 = 8.13838e-04 A14 = -1.47458e-04 A16 = 1.06745e-05 Side 18 K =-1.03932e+00 A 4=-6.58199e-02 A 6= 1.95415e-02 A 8=-6.46549e-03 A10= 1.86883e-03 A12=-3.68161e-04 A14= 4.23520e-05 A16=-2.12215e-06 Surface 19 K =-1.17128e+00 A 4= 4.01418e-03 A 6=-3.51171e-05 A 8=-2.17475e-05 A10= 6.83404e-07 A12=-2.54535e-08 20th side K = 5.13974e-01 A 4= 3.98428e-03 A 6= 6.60626e-05 A 8=-2.17634e-05 A10= 7.62470e-07 A12=-2.26608e-08 Various Data Zoom Ratio 2.20 Wide-angle end Telephoto end Focal Length 8.06 17.77 F-number 2.43 4.00 Half-angle 21.65 10.21 Image Height 3.20 3.20 Lens Length 26.99 26.99 BF 4.33 4.33 d 3 1.25 1.25 d 9 6.16 1.01 d14 0.50 0.59 d18 1.08 6.13 d20 4.33 4.33 Zoom lens group data group Starting plane Focal length L1 4 -12.00 L2 10 5.11 L3 15 -7.52 L4 19 47.48 .

[0123] [Numerical Example 4] Unit: mm Surface Data Surface Number rd nd νd Effective Diameter 1 ∞ 2.40 1.71700 29.5 7.40 2 ∞ 2.40 1.71700 29.5 6.63 3 ∞ (Variable) 5.85 4* 7.240 1.14 1.54400 56.0 5.45 5* -25.012 0.11 5.27 6* -109.362 0.82 1.67100 19.4 5.14 7* -23.744 0.33 4.90 8* 10.113 0.40 1.54400 56.0 4.81 9* 2.090 (Variable) 4.64 10 (aperture) ∞ -0.46 5.11 11* 3.812 2.60 1.49700 81.5 5.23 12* -3.871 0.08 5.04 13* -6.768 2.00 1.67100 19.4 4.87 14* -7.556 (variable) 4.68 15* -5.414 0.80 1.53110 55.9 4.29 16* 15.473 1.29 4.10 17* 25.226 0.50 1.54400 56.0 4.20 18* 6.044 (variable) 4.49 19* -12.496 1.22 1.56700 38.0 5.50 20* -7.136 (variable) 5.91 Image plane ∞ Aspherical data 4th plane K = -1.33774e+01 A 4 = 6.53398e-03 A 6 = -1.22627e-03 A 8 = 2.54391e-04 A10 = -3.69418e-05 A12 = 3.19170e-06 A14 = -1.07792e-07 5th plane K = -5.34359e+02 A 4 = 1.20361e-02 A 6=-5.55145e-03 A 8= 1.09991e-03 A10=-1.04501e-04 A12= 3.89772e-06 A14=-5.98149e-09 6th side K = 4.99960e+01 A 4= 1.28672e-02 A 6=-4.06632e-03 A 8= 2.50721e-04 A10= 1.08468e-04 A12=-2.13526e-05 A14= 1.11293e-06 7th side K = 7.71717e+00 A 4= 1.49464e-02 A 6=-5.15666e-03 A 8= 3.71943e-04 A10= 1.47525e-04 A12=-3.22377e-05 A14= 1.83041e-06 8th side K =-5.00000e+01 A 4=-2.63609e-02 A 6= 1.00502e-03 A 8= 6.97554e-04 A10=-1.23881e-04 A12= 5.77558e-06 A14= 4.40681e-08 9th side K =-2.80067e+00 A 4=-3.28764e-02 A 6= 9.79311e-03 A 8=-1.58270e-03 A10= 1.45980e-04 A12=-6.61810e-06 A14= 8.17964e-08 11th side K = 3.97222e-01 A 4=-2.13330e-03 A 6=-4.80760e-05 A 8= 5.27041e-06 A10=-5.61443e-06 A12= 8.87337e-07 A14=-7.37008e-08 Page 12 K =-1.58152e+00 A 4= 1.22773e-02 A 6=-3.45919e-03 A 8= 7.98886e-04 A10=-1.05882e-04 A12= 6.83670e-06 A14=-1.60520e-07 Page 13 K =-4.51421e+00 A 4= 6.52327e-03 A 6=-2.99333e-03 A 8= 5.40251e-04 A10=-1.35430e-05 A12=-1.13411e-05 A14= 1.72482e-06 A16=-7.73859e-08 Page 14 K =-3.85569e+00 A 4= 1.03711e-02 A 6=-3.80301e-03 A 8= 8.06985e-04 A10=-8.62803e-05 A12=-2.07853e-06 A14= 1.35510e-06 A16=-8.81206e-08 Page 15 K =-1.90890e+01 A 4= 1.48613e-02 A 6=-2.41812e-03 A 8= 9.72581e-04 A10=-3.87948e-04 A12= 8.54333e-05 A14=-1.23428e-05 A16= 7.36637e-07 Face 16 K =-2.34847e+01 A 4=-2.38623e-03 A 6= 7.60779e-03 A 8=-1.28126e-03 A10=-2.42572e-04 A12= 2.33222e-04 A14=-6.11953e-05 A16= 5.19704e-06 Page 17 K = 8.71923e+00 A4 = -8.21595e-02 A6 = 2.78008e-02 A8 = -5.27161e-03 A10 = 2.99002e-04 A12 = 1.34236e-04 A14 = -3.10348e-05 A16 = 1.90586e-06 18th side K =-2.67798e+01 A 4=-5.47926e-02 A 6= 2.42748e-02 A 8=-7.74179e-03 A10= 1.88215e-03 A12=-3.18062e-04 A14= 3.31317e-05 A16=-1.58421e-06 Surface 19 K = 1.67875e+01 A 4=-1.25306e-03 A 6=-2.76878e-04 A 8= 1.18557e-04 A10=-6.86074e-06 A12=-7.65998e-07 A14= 1.01358e-07 20th surface K = 3.81201e+00 A 4=-1.34682e-03 A 6= 8.77461e-05 A 8= 7.34437e-06 A10= 7.10758e-06 A12=-1.21921e-06 A14= 7.03805e-08 Various data Zoom ratio 2.09 Wide-angle end Telephoto end Focal length 11.50 24.00 F-number 2.55 4.40 Half-angle of view 15.55 7.60 Image height 3.20 3.20 Lens length 28.05 28.05 BF 3.50 3.50 d 3 1.25 1.25 d 9 6.27 0.96 d14 0.61 0.50 d18 0.80 6.21 d20 3.50 3.50 Zoom lens group data group Starting plane Focal length L1 4 -20.00 L2 10 4.87 L3 15 -4.52 L4 19 27.12 .

[0124] [Numerical Example 5] Unit: mm Surface Data Surface Number rd nd νd Effective Diameter 1 ∞ 2.40 1.71700 29.5 7.40 2 ∞ 2.40 1.71700 29.5 6.54 3 ∞ (Variable) 5.67 4* 58.969 1.16 1.54400 56.0 5.20 5* -6.190 0.16 4.95 6* -9126.338 0.84 1.68100 18.1 4.87 7* -26.415 0.11 4.80 8* 10.788 0.49 1.54400 56.0 4.77 9* 2.000 (Variable) 4.76 10 (aperture) ∞ -0.37 5.40 11* 4.106 3.46 1.54400 56.0 5.59 12* -3.079 0.08 5.16 13* -2.880 1.55 1.65100 21.5 5.11 14* -5.297 (variable) 4.79 15* -10.498 1.79 1.54400 56.0 5.04 16* 9.738 0.56 4.68 17* 3.666 0.50 1.53110 55.9 4.70 18* 3.770 (variable) 4.94 19* 20.641 1.10 1.67100 19.4 5.16 20* 34.074 (variable) 5.10 21* -9.884 0.96 1.54400 56.0 5.27 22* -12.047 (variable) 5.61 Image plane ∞ Aspherical data 4th plane K = 1.60780e+02 A 4= 7.15059e-03 A 6=-7.32627e-04 A 8= 1.06621e-04 A10=-2.91538e-06 A12=-7.18025e-07 A14= 7.26937e-08 5th side K =-2.53909e+01 A 4= 1.43403e-02 A 6=-4.28845e-03 A 8= 8.76556e-04 A10=-9.99220e-05 A12= 5.84879e-06 A14=-1.24361e-07 6th side K =-5.00000e+01 A 4= 4.98077e-03 A 6=-2.41076e-03 A 8= 7.12172e-05 A10= 7.70043e-05 A12=-1.32593e-05 A14= 6.67605e-07 Page 7 K =-6.34515e+00 A 4= 4.21810e-03 A 6=-2.49743e-03 A 8=-2.96743e-05 A10= 1.38845e-04 A12=-2.39780e-05 A14= 1.27474e-06 8th side K 9th side K =-3.59670e+00 A 4=-2.22828e-02 A 6= 6.45526e-03 A 8=-1.21411e-03 A10= 1.41562e-04 A12=-9.26228e-06 A14= 2.63159e-07 Page 11 K =-4.54498e-01 A 4=-5.66826e-05 A 6=-3.35579e-05 A 8= 2.47052e-05 A10=-5.14797e-06 A12= 4.90263e-07 A14=-1.93944e-08 Page 12 K =-2.15732e+00 A 4= 9.71327e-03 A 6 = -1.85190e-03 A 8 = 6.87839e-04 A10 = -1.23851e-04 A12 = 9.83569e-06 A14 = -2.94912e-07 Page 13 K = -3.85644e+00 A 4 = 1.92840e-03 A 6 = 7.97940e-05 A 8 = 3.81896e-04 A10 = -8.79922e-05 A12 = 7.30552e-06 A14 = -2.17505e-07 A16 = 2.02197e-10 Page 14 K = -1.22409e+01 A 4 = 1.69136e-03 A 6 = 1.74422e-03 A 8 = -4.36989e-04 A10 = 1.36753e-04 A12 = -1.93036e-05 A14 = 1.34743e-06 A16 = -4.61776e-08 Page 15 K = 1.29447e+01 A 4 = 5.78937e-03 A 6 = 2.55002e-03 A 8 = -1.06338e-03 A10 = 3.67042e-04 A12 = -6.23094e-05 A14 = 5.15146e-06 A16 = -1.67749e-07 Page 16 K = -2.30774e+01 A 4 = -3.22174e-02 A 6 = 1.52108e-02 A 8 = -5.48208e-03 A10 = 1.47836e-03 A12 = -2.62504e-04 A14 = 2.89748e-05 A16 = -1.46572e-06 Page 17 K = -1.00921e+01 A 4 = -4.93490e-02 A 6= 5.51742e-03 A 8= 1.47806e-03 A10=-1.15470e-03 A12= 3.09248e-04 A14=-3.65384e-05 A16= 1.58589e-06 18th side K = 8.61463e-04 A 4=-5.15586e-02 A 6= 7.98846e-03 A 8=-4.71954e-04 A10=-2.78959e-04 A12= 9.48032e-05 A14=-1.17956e-05 A16= 5.28423e-07 Page 19 K =-5.00000e+01 A 4= 1.27014e-03 A 6= 4.20218e-04 A 8=-2.64899e-05 A10= 7.22494e-07 A12=-2.31248e-07 A14= 1.00673e-08 20th side K =-5.00000e+01 A 4= 5.49598e-05 A 6= 4.50586e-04 A 8=-6.61358e-06 A10= 2.15575e-07 A12=-5.77095e-07 A14= 2.32139e-08 21st side K = 9.85050e+00A 4=-1.75353e-03 A 6= 4.55529e-04 A 8= 1.45292e-05 A10=-6.57578e-06 A12= 3.30016e-07 A14= 2.25865e-08 Face 22 K =-7.38914e+00 A 4=-2.84411e-03 A 6= 3.43728e-04 A 8=-1.10704e-05 A10=-2.52120e-06 A12= 1.67633e-07 A14= 1.53265e-09 Various data Zoom ratio 2.04 Wide-angle end Telephoto end Focal length 10.21 20.80 F-number 2.43 4.00 Half-angle of view 17.40 8.75 Image height 3.20 3.20 Lens length 30.05 30.05 BF 3.50 3.50 d 3 1.25 1.25 d 9 6.09 0.87 d14 0.53 0.50 d18 0.50 3.74 d20 1.00 3.00 d22 3.50 3.50 Zoom lens group data group Starting plane Focal length L1 4 -14.68 L2 10 5.73 L3 15 -9.60 L4 19 75.55 L5 21 -120.00 .

[0125] The values ​​corresponding to conditional expressions (1) to (22) in each numerical example are shown in Tables 1 and 2 below.

[0126]

[0127]

[0128] [Imaging Device] Next, we will describe an example of a smartphone using the zoom lens L0 of each embodiment as the imaging optical system.

[0129] In Figure 12, 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 5. The smartphone body 10 may have multiple zoom lenses L0, or it may have other zoom lenses.

[0130] 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.

[0131] By applying the zoom lens L0 of this embodiment to an imaging device such as a smartphone, it is possible to obtain an imaging device that is compact yet capable of high-magnification zoom.

[0132] While preferred embodiments and examples of the disclosure 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.

[0133] This application claims priority based on Japanese Patent Application No. 2024-205411, filed on November 26, 2024, and all of its contents are incorporated herein by reference.

Claims

1. A zoom lens comprising 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 distance between adjacent lens groups changes during magnification, the first to third lens groups each have one or more aspherical lenses made of resin material, the first lens group remains stationary with respect to the image plane during magnification from the wide-angle end to the telephoto end, and when TL is the distance on the optical axis from the object-side lens surface of the lens positioned closest to the object in the first lens group to the image plane, imgH is the maximum image height, f1 is the focal length of the first lens group, and f3 is the focal length of the third lens group, the zoom lens satisfies the following conditions: 0.11 < imgH / TL < 0.20 and 1.20 < f1 / f3 < 5.

00.

2. A zoom lens comprising a prism having a reflective surface arranged 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, wherein the distance between adjacent lens groups changes when the zoom is changed, the first lens group remains stationary with respect to the image plane when the zoom is changed from the wide-angle end to the telephoto end, and when TL is the distance on the optical axis from the object-side lens surface of the lens positioned closest to the object in the first lens group to the image plane, and imgH is the maximum image height, the zoom lens satisfies the condition 0.11 < imgH / TL < 0.

20.

3. The zoom lens according to claim 1 or 2, characterized in that when the F-number at the telephoto end is Fnot, the condition 3.00 < Fnot < 5.70 is satisfied.

4. The zoom lens according to any one of claims 1 to 3, characterized in that when the F-number at the wide-angle end is Fnow, the condition 2.00 < Fnow < 3.00 is satisfied.

5. A zoom lens according to any one of claims 1 to 4, characterized in that it has a prism having a reflective surface that is positioned closest to the object in the first lens group, and when PL is the distance on the optical axis between the image-side surface of the prism and the object-side lens surface of the lens positioned closest to the object in the first lens group, the condition 0.04 < PL / TL < 0.07 is satisfied.

6. The zoom lens according to any one of claims 1 to 5, characterized in that, 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, the condition 1.70 < ft / fw < 2.50 is satisfied.

7. The zoom lens according to any one of claims 1 to 6, characterized in that, when the total focal length of the zoom lens at the wide-angle end is fw, the condition -2.10 < f1 / fw < -1.20 is satisfied.

8. The zoom lens according to any one of claims 1 to 7, characterized in that when the total focal length of the zoom lens at its telephoto end is ft, the condition -1.10 < f1 / ft < -0.50 is satisfied.

9. The zoom lens according to any one of claims 1 to 8, characterized in that when the focal length of the second lens group is f2, the condition -6.00 < f1 / f2 < -1.00 is satisfied.

10. The zoom lens according to any one of claims 1 to 9, characterized in that when the focal length of the second lens group is f2, the condition -1.30 < f2 / f3 < -0.30 is satisfied.

11. The zoom lens according to any one of claims 1 to 10, characterized in that when the total focal length of the zoom lens at its telephoto end is ft, the condition 0.60 < ft / TL < 1.30 is satisfied.

12. The zoom lens according to any one of claims 1 to 11, characterized in that when the amount of movement of the second lens group during the change in magnification from the wide-angle end to the telephoto end is MD2, the condition 0.10 < MD2 / TL < 0.35 is satisfied.

13. The zoom lens according to any one of claims 1 to 12, characterized in that when the amount of movement of the third lens group during magnification from the wide-angle end to the telephoto end is MD3, the condition 0.10 < MD3 / TL < 0.40 is satisfied.

14. A zoom lens according to any one of claims 1 to 13, characterized in that, when the back focus at the wide-angle end is skw, the condition 0.12 < skw / TL < 0.23 is satisfied.

15. A zoom lens according to any one of claims 1 to 14, characterized in that, when the back focus at the telephoto end is skt, the condition 0.12 < skt / TL < 0.46 is satisfied.

16. A zoom lens according to any one of claims 1 to 15, characterized in that, when the half-angle of view at the wide-angle end is HOVw and the half-angle of view at the telephoto end is HOVt, the following condition is satisfied: 0.30 < HOVt / HOVw < 0.

65.

17. The zoom lens according to any one of claims 1 to 16, characterized in that when LD11 is half the effective diameter of the object-side lens surface of the lens positioned closest to the object in the first lens group, the condition 0.55 < LD11 / imgH < 1.00 is satisfied.

18. The zoom lens according to any one of claims 1 to 17, characterized in that when LD11 is half the effective diameter of the object-side lens surface of the lens positioned furthest towards the object in the first lens group, and LD3L is half the effective diameter of the image-side lens surface of the lens positioned furthest towards the image in the third lens group, the condition 0.90 < LD11 / LD3L < 1.40 is satisfied.

19. The zoom lens according to any one of claims 1 to 18, characterized in that, when the shape factor of the lens positioned closest to the object in the first lens group is SF11, the condition -12.00 < SF11 < 4.00 is satisfied.

20. The zoom lens according to any one of claims 1 to 19, characterized in that, when the shape factor of the lens positioned closest to the object in the second lens group is SF21, the condition -2.00 < SF21 < 1.00 is satisfied.

21. The zoom lens according to any one of claims 1 to 20, characterized in that, when the shape factor of the lens positioned closest to the object in the third lens group is SF31, the condition -5.00 < SF31 < 1.00 is satisfied.

22. The zoom lens according to any one of claims 1 to 21, characterized in that, when the shape factor of the lens positioned closest to the image in the third lens group is SF3L, the condition -100.00 < SF3L < 50.00 is satisfied.

23. The zoom lens according to any one of claims 1 to 22, characterized in that the first lens group includes an aspherical lens having an inflection point.

24. A zoom lens according to any one of claims 1 to 23, comprising a prism having a reflective surface arranged in order from the object side to the image side, the first to third lens groups, and a fourth lens group with positive refractive power, characterized in that the distance between each lens group changes when the magnification is changed from the wide-angle end to the telephoto end.

25. A zoom lens according to any one of claims 1 to 23, comprising a prism having a reflective surface arranged in order from the object side to the image side, the first to third lens groups, a fourth lens group with positive refractive power, and a fifth lens group with negative refractive power, characterized in that the distance between each lens group changes when the zoom is changed from the wide-angle end to the telephoto end.

26. An imaging device characterized by comprising a zoom lens according to any one of claims 1 to 25 and an image sensor that receives an image formed by the zoom lens.

Images