Zoom lens and image capturing device

Abstract

To provide a high-performance zoom lens which offers a large aperture ratio, and yet is compact as a whole and well corrected for aberrations.SOLUTION: A zoom lens provided herein consists of, in order from the object side to the image side, a lens group P1 having positive refractive power, an intermediate group having negative refractive power as a whole, a lens group P2 having positive refractive power, a lens group P3 having positive refractive power, a lens group N having negative refractive power, and a rear group, and has specific optical characteristics represented by specific expressions.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a zoom lens and an imaging device. [Background technology]

[0002] Imaging devices using solid-state imaging elements, such as digital still cameras and digital video cameras, are becoming increasingly popular. There are a variety of imaging devices, including digital still cameras, digital video cameras, broadcast cameras, surveillance cameras, and vehicle-mounted cameras. For all of these imaging devices, there is a strong market demand for zoom lenses that offer a large aperture ratio, a compact overall system, and high optical performance.

[0003] Under these circumstances, a large aperture ratio zoom lens is known, which has a lens group with positive, negative, positive, positive, negative refractive powers arranged in order from the object side, and has a zoom ratio of 2.37 and an F-number of 2.26 to 2.91 (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-197774 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technology described in Patent Document 1 has difficulty in miniaturizing the zoom lens because the combined positive refractive power of the first to fourth lens groups is weak. Furthermore, the negative refractive power of the second lens group is too strong compared to the positive refractive power of the first lens group, making it difficult to reduce the lens diameter of the first lens group. Thus, in order to solve these problems, the prior art leaves room for further consideration in terms of the power arrangement, imaging magnification, lens configuration, etc. of each lens group.

[0006] An object of one aspect of the present invention is to realize a high-performance zoom lens that has a large aperture ratio, is compact overall, and has excellent correction of various aberrations. [Means for solving the problem]

[0007] In order to solve the above-described problems, a zoom lens according to one aspect of the present invention includes, arranged in order from the object side to the image side, a lens group P1 having positive refractive power, a middle group including one or more lens groups and having negative refractive power as a whole, a lens group P2 having positive refractive power, a lens group P3 having positive refractive power, a lens group N having negative refractive power, and a rear group including one or more lens groups, wherein a lens component A having negative refractive power is located closest to the image side of lens group P2, and lens component A has a shape such that its object-side surface is concave toward the object side, and satisfies the following formula: -5.0 <fp12w / fw<-0.3···(1) however, fp12w: the composite focal length from the lens group P1 to the lens group P2 at the wide-angle end when the zoom lens is focused at infinity fw: focal length at the wide-angle end of the zoom lens when focused at infinity

[0008] In order to solve the above problem, an imaging device according to one aspect of the present invention includes the above zoom lens and a solid-state imaging element on the image plane side of the zoom lens that converts an optical image formed by the zoom lens into an electrical signal. [Effects of the Invention]

[0009] According to one aspect of the present invention, it is possible to realize a high-performance zoom lens that has a large aperture ratio, is compact overall, and has excellent correction of various aberrations. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a diagram illustrating an optical configuration of the zoom lens of Example 1 at the wide-angle end when focused on infinity. [Figure 2]3A to 3C are diagrams illustrating spherical aberration, astigmatism, and distortion at the wide-angle end of the zoom lens of Example 1 when focused on infinity. [Figure 3] 3A to 3C are diagrams illustrating spherical aberration, astigmatism, and distortion at an intermediate focal point of the zoom lens of Example 1 when focused at infinity. [Figure 4] 3A to 3C are diagrams illustrating spherical aberration, astigmatism, and distortion of the zoom lens of Example 1 at the telephoto end when focused on infinity. [Figure 5] FIG. 10 is a diagram schematically illustrating the optical configuration of the zoom lens of Example 2 at the wide-angle end when focused on infinity. [Figure 6] 10A to 10C are diagrams illustrating spherical aberration, astigmatism, and distortion at the wide-angle end of the zoom lens of Example 2 when focused on infinity. [Figure 7] 10A to 10C are diagrams illustrating spherical aberration, astigmatism, and distortion at an intermediate focal point of the zoom lens of Example 2 when focused at infinity. [Figure 8] 10A to 10C are diagrams illustrating spherical aberration, astigmatism, and distortion at the telephoto end of the zoom lens of Example 2 when focused on infinity. [Figure 9] FIG. 10 is a diagram illustrating an optical configuration of a zoom lens according to a third embodiment at the wide-angle end when focused on infinity. [Figure 10] 10A to 10C are diagrams illustrating spherical aberration, astigmatism, and distortion at the wide-angle end of the zoom lens of Example 3 when focused on infinity. [Figure 11] 10A to 10C are diagrams illustrating spherical aberration, astigmatism, and distortion at an intermediate focal point of the zoom lens of Example 3 when focused at infinity. [Figure 12] 10A to 10C are diagrams illustrating spherical aberration, astigmatism, and distortion at the telephoto end of the zoom lens of Example 3 when focused on infinity. [Figure 13] FIG. 10 is a diagram illustrating an optical configuration of a zoom lens according to a fourth embodiment at the wide-angle end when focused on infinity. [Figure 14] 10A to 10C are diagrams illustrating spherical aberration, astigmatism, and distortion at the wide-angle end of the zoom lens of Example 4 when focused on infinity. [Figure 15]10A to 10C are diagrams illustrating spherical aberration, astigmatism, and distortion at an intermediate focal point of the zoom lens of Example 4 when focused at infinity. [Figure 16] 10A to 10C are diagrams illustrating spherical aberration, astigmatism, and distortion at the telephoto end of the zoom lens of Example 4 when focused on infinity. [Figure 17] FIG. 10 is a diagram schematically illustrating the optical configuration of the zoom lens of Example 5 at the wide-angle end when focused on infinity. [Figure 18] 10A to 10C are diagrams illustrating spherical aberration, astigmatism, and distortion at the wide-angle end of the zoom lens of Example 5 when focused on infinity. [Figure 19] 10A to 10C are diagrams illustrating spherical aberration, astigmatism, and distortion at an intermediate focal point of the zoom lens of Example 5 when focused at infinity. [Figure 20] 10A to 10C are diagrams illustrating spherical aberration, astigmatism, and distortion of the zoom lens of Example 5 at the telephoto end when focused on infinity. [Figure 21] FIG. 13 is a diagram schematically illustrating the optical configuration of a zoom lens according to a sixth embodiment at the wide-angle end when focused on infinity. [Figure 22] 13A to 13C are diagrams illustrating spherical aberration, astigmatism, and distortion at the wide-angle end of the zoom lens of Example 6 when focused on infinity. [Figure 23] 13A to 13C are diagrams illustrating spherical aberration, astigmatism, and distortion at an intermediate focal point of the zoom lens of Example 6 when focused at infinity. [Figure 24] 13A to 13C are diagrams illustrating spherical aberration, astigmatism, and distortion of the zoom lens of Example 6 at the telephoto end when focused on infinity. [Figure 25] 1 is a diagram schematically illustrating an example of the configuration of an imaging device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] One known optical configuration for zoom lenses is the positive lead type, which has a lens group with positive refractive power closest to the object. In positive lead zoom lenses, a lens group with strong negative refractive power is typically placed as the second lens group, located second from the object. This configuration, which assigns a large magnification load to the second lens group, makes it easier to achieve high magnification. Because positive lead zoom lenses have a strong tendency toward telephotography, the overall length of the optical system can be shortened relative to the focal length.

[0012] Furthermore, in order to increase the diameter of a zoom lens, it is preferable to arrange a lens group having a strong positive refractive power on the image plane side.

[0013] However, if a lens group with a strong positive refractive power is located on the image plane side, it becomes difficult to obtain a zoom lens with a strong telephoto tendency, and it may be difficult to shorten the overall optical length. Furthermore, if the refractive power of the second lens group, which has a large burden on magnification, is too strong, it may be difficult to effectively correct various aberrations generated in the second lens group, making it difficult to obtain high optical performance. The present invention provides a technology that solves these problems.

[0014] Hereinafter, embodiments of a zoom lens and an imaging device according to the present invention will be described. More specifically, the present embodiments relate to a zoom lens and an imaging device suitable for an imaging device using a solid-state imaging element (CCD, CMOS, etc.) such as a digital still camera or a digital video camera. However, the zoom lens and imaging device described below are one aspect of the zoom lens and imaging device according to the present invention, and the zoom lens and imaging device according to the present invention are not limited to the following aspects.

[0015] In this specification, the term "zoom lens" is a general term for anything that has the optical characteristics specified in the present invention, and refers to either or both of the optical system itself that exhibits the optical characteristics and an article that includes the optical system. The front of a zoom lens refers to the object side of the zoom lens, and the rear of a zoom lens refers to the image plane side of the zoom lens.

[0016] 1. Zoom Lens Hereinafter, one embodiment of the present invention will be described in detail.

[0017] 1-1.Optical configuration The zoom lens according to this embodiment is composed of, arranged in order from the object side to the image plane side, a lens group P1 having positive refractive power, a middle group including one or more lens groups and having negative refractive power as a whole, a lens group P2 having positive refractive power, a lens group P3 having positive refractive power, a lens group N having negative refractive power, and a rear group including one or more lens groups. This zoom lens has a positive lead configuration, which is preferable from the viewpoint of achieving a high zoom ratio and compact size of the zoom lens.

[0018] In this specification, the term "lens group" refers to a collection of one or more lenses that work together during a magnification change. The lenses in a lens group move while maintaining their relative positional relationships during a magnification change. The magnification change is performed by changing the spacing between the lens groups, and the spacing between lenses belonging to the same lens group does not change during a magnification change.

[0019] The lens group P1 has a positive refractive power as a whole. The specific lens configuration of the lens group P1 is not particularly limited. For example, from the viewpoint of making the lens group P1 a lens group with a strong refractive power, the lens group P1 may be configured to include two lenses with positive refractive power. When the lens group P1 has a strong positive refractive power, a high zoom ratio can be achieved while enhancing the telephoto tendency at the telephoto end, which is preferable from the viewpoint of achieving a compact zoom lens. Alternatively, the lens group P1 may be configured to include at least one lens with negative refractive power. This configuration is preferable from the viewpoint of realizing a zoom lens with excellent optical performance, since it facilitates correction of spherical aberration, chromatic aberration, and the like.

[0020] The intermediate group has negative refractive power as a whole. The intermediate group may be composed of one lens group, or may be a collection of two or more lens groups. All of the lens groups constituting the intermediate group may have negative refractive power. If the intermediate group is composed of two or more lens groups each having negative refractive power, this facilitates correction of curvature of field and coma aberration that occurs during magnification change, which is preferable from the perspective of realizing a zoom lens with excellent optical performance.

[0021] The lens group P2 has a positive refractive power as a whole. It is preferable that the lens group P2 includes at least two lenses with positive refractive power and at least two lenses with negative refractive power. Diverging light is incident on the lens group P2. Having two or more lenses with positive refractive power in the lens group P2 is preferable for forming a highly converging surface for the diverging light. Having two or more lenses with negative refractive power in the lens group P2 is also preferable from the viewpoint of correcting various aberrations caused by the converging action of the lenses with positive refractive power. The number of lenses with positive refractive power and lenses with negative refractive power can be determined appropriately from the above viewpoint, and may be the same or different. The positions of these lenses in the lens group P2 can also be determined appropriately from the above viewpoint. The above configuration of the lens group P2 is preferable from the viewpoint of realizing a zoom lens that has a large aperture ratio and effectively corrects spherical aberration and axial chromatic aberration.

[0022] The lens group P2 has a lens component A with negative refractive power closest to the image plane. The lens component A has a shape with its object-side surface facing concave toward the object. Here, the lens group P3, which will be described later, has positive refractive power, so the combined refractive power of the lens groups P2 and P3 is a strong positive refractive power. For this reason, a large aperture ratio makes it easier for spherical aberration in the under-focus direction to occur. Because the object-side surface of the lens component A has a shape with its object-side surface facing concave toward the object, the axial light beam incident on the lens component A is a convergent light beam. Therefore, spherical aberration in the over-focus direction can be generated on the object-side surface of the lens component A. Thus, arranging the lens component A in the lens group P2 is preferable from the viewpoint of effectively correcting spherical aberration in the under-focus direction.

[0023] In this specification, the term "lens component" refers to a single lens or a cemented lens in which multiple single lenses are integrated without any air gap. In other words, even if a lens component has multiple optical surfaces, only the most object-side and most image-side surfaces are in contact with air, and the other surfaces are not in contact with air. Furthermore, the single lens may be either a spherical lens or an aspherical lens. Furthermore, in this specification, the term "aspherical lens" also includes a composite resin aspherical lens having a composite resin film molded into an aspherical shape attached to its surface.

[0024] It is preferable that lens group P2 has a cemented lens whose cemented surface faces convexly toward the object side. This configuration is preferable from the viewpoint of correcting the spherical aberration in the under-focus direction described above. From the same viewpoint, it is more preferable that the cemented surface is a diverging surface. The aforementioned lens component A may be a cemented lens, but it is different from the cemented lens referred to here. However, the cemented lens provides the same effect as lens component A.

[0025] The lens group P3 has a positive refractive power as a whole. The lens group P3 is located relatively far back in the zoom lens and is the lens group with the strongest positive refractive power in the optical system of the zoom lens. Having a lens group with positive refractive power is preferable from the viewpoint of achieving a large aperture. It is preferable that the lens group P3 be configured to include at least one lens with negative refractive power and at least two lenses with positive refractive power. This configuration is preferable from the viewpoint of effectively correcting spherical aberration, coma, and chromatic aberration.

[0026] The lens group N has a negative refractive power as a whole. The specific lens configuration of the lens group N is not particularly limited. For example, the lens group N may be composed of only one lens having a negative refractive power, or may be composed of a lens having a positive refractive power and a lens having a negative refractive power. By adopting a configuration including a lens having a positive refractive power and a lens having a negative refractive power, it becomes easy to obtain a high-performance zoom lens in which various aberrations such as spherical aberration and chromatic aberration are well corrected over the entire object distance.

[0027] The rear group is a group including one or more lens groups arranged closer to the image plane than the lens group N. The specific configuration of the rear group is not particularly limited. The rear group may be composed of one lens group from the viewpoint of shortening the length of the zoom lens optical system. On the other hand, the rear group may be a collection of two or more lens groups from the viewpoint of effectively correcting curvature of field throughout the entire zoom range.

[0028] The rear group is arranged to improve the optical characteristics of the zoom lens, and the arrangement of the lenses in the rear group may be determined appropriately from the viewpoint of improving the desired characteristics. For example, it is preferable that the rear group includes one convex lens and one concave lens from the viewpoint of effectively correcting curvature of field. Furthermore, from the above viewpoint, it is more preferable that the rear group includes one convex lens and two concave lenses.

[0029] The overall refractive power of the rear group is not particularly limited. The rear group may have positive refractive power as a whole. A configuration in which the rear group has positive refractive power is preferable from the viewpoint of reducing the F-number of the zoom lens. On the other hand, the rear group may have negative refractive power as a whole. A configuration in which the rear group has negative refractive power is preferable from the viewpoint of shortening the overall optical length at the telephoto end, because it makes it easier to obtain a zoom lens with a stronger telephoto tendency at the telephoto end.

[0030] It is preferable that the aperture stop be located adjacent to the object side of lens group P2 or be located inside lens group P2. A configuration in which the aperture stop is located adjacent to the object side of lens group P2 allows the entrance pupil to be positioned closer to the object than when the aperture stop is located inside lens group P2. This makes it easier to reduce the diameter of the peripheral light beam passing through lens group P1 at the telephoto end, which is preferable from the viewpoint of making it easier to reduce the diameter of the front lens.

[0031] 1-2.Operation 1-2-1.Magnification When the zoom lens changes magnification from the wide-angle end to the telephoto end, the zoom lens changes magnification by changing the air gap between adjacent lens groups on the optical axis.

[0032] When changing magnification from the wide-angle end to the telephoto end, it is preferable that the lens group P1 moves toward the object side. Such movement of the lens group P1 is preferable from the viewpoint of realizing a compact zoom lens with a short overall optical length at the wide-angle end.

[0033] The movement of each lens group constituting the intermediate group is not particularly limited. For example, when changing magnification from the wide-angle end to the telephoto end, each lens group constituting the intermediate group may move toward the image plane. By moving the intermediate group in this manner, it becomes easier to reduce the movement distance of lens group P1, which is preferable for achieving a zoom lens with a short overall optical length at the telephoto end.

[0034] When changing magnification from the wide-angle end to the telephoto end, it is preferable that the lens group P2, the lens group P3, and the lens group N move toward the object side. By moving the lens group P2, the lens group P3, and the lens group N in this manner, it becomes easy to increase the composite magnification ratio from the lens group P2 to the lens group N, and magnification can be suitably changed by each lens group, which is preferable from the viewpoint of achieving both high magnification and high performance.

[0035] When changing magnification from the wide-angle end to the telephoto end, the rear lens group may be fixed or may move toward the object. A configuration in which the rear lens group is fixed during magnification change is preferable from the viewpoints of simplifying the cam structure and preventing dust from entering the lens barrel. A configuration in which the rear lens group moves toward the object during magnification change from the wide-angle end to the telephoto end is preferable from the viewpoint of effectively correcting field curvature throughout the entire zoom range.

[0036] 1-2-2.Focus In this zoom lens, it is preferable to move lens group N along the optical axis during focusing. Here, lens group N is located on the image plane side of lens group P3. Because a light beam converged by lens group P3 enters lens group N, it is easy to make lens group N have a small lens diameter and a lightweight configuration. Therefore, using lens group N as the focusing group enables high-speed autofocus (AF) and facilitates reducing the load on the focus drive system. Furthermore, lens group N is located at the rear of the zoom lens. Therefore, using lens group N as the focusing group is also preferable from the viewpoint of suppressing fluctuations in the angle of view associated with movement of the focusing group. This configuration makes it easy to realize a zoom lens suitable for video capture using a tracking AF function, not only when a contrast AF system is used, but also when an image plane phase-difference AF system is used. Because the lateral magnification of lens group N is greater than 1, lens group F moves toward the image plane side when focusing from infinity to a close-distance object.

[0037] In this zoom lens, in addition to lens group N, a lens group other than lens group N or a part of the lens group may be moved during focusing. This configuration is a so-called floating focus system, and by employing this configuration, aberration correction for close-distance objects becomes easier, which is preferable from the viewpoint of obtaining a high-performance zoom lens. On the other hand, in this zoom lens, it is preferable that only lens group N moves during focusing. This configuration is preferable from the viewpoint of simplifying the focus drive mechanism and realizing a smaller and lighter zoom lens.

[0038] 1-3.Formula It is preferable that the zoom lens adopts the above-described configuration and satisfies at least one of the following expressions.

[0039] 1-3-1.Formula (1) -5.0 <fp12w / fw<-0.3···(1) however, fp12w: The composite focal length from lens group P1 to lens group P2 at the wide-angle end of the zoom lens when focused at infinity fw: focal length at the wide-angle end of a zoom lens when focused at infinity

[0040] Equation (1) is an equation for appropriately defining the ratio between the combined focal length of the lens group P1 and lens group P2 at the wide-angle end of the zoom lens and the focal length of the zoom lens at the wide-angle end. Satisfying equation (1) is preferable from the perspective of realizing a zoom lens with a fast F-number, because it makes it easy to arrange a lens group with strong positive refractive power at the rear of the optical system of the zoom lens, even though it is a positive-lead zoom lens.

[0041] If fp12w / fw is -5.0 or less, the negative composite focal length from lens group P1 to lens group P2 at the wide-angle end becomes too weak, which can make it difficult to relatively position a strong positive refractive power at the rear of the optical system of the zoom lens.On the other hand, if fp12w / fw is -0.3 or more, the negative composite focal length from lens group P1 to lens group P2 at the wide-angle end can become too strong.

[0042] From the viewpoint of favorably correcting various aberrations and obtaining high optical performance, fp12w / fw is preferably smaller than -0.5, more preferably smaller than -0.7, even more preferably smaller than -0.9, even more preferably smaller than -1.1, even more preferably smaller than -1.3, and even more preferably smaller than -1.5. Furthermore, from the viewpoint of obtaining a zoom lens with a bright F-number, with the front and rear refractive powers of the zoom lens set within a suitable range, fp12w / fw is preferably larger than -4.5, more preferably larger than -4.0, even more preferably larger than -3.7, preferably larger than -3.3, more preferably larger than -3.1, even more preferably larger than -2.9, even more preferably larger than -2.7, even more preferably larger than -2.5, even more preferably larger than -2.3, and even more preferably larger than -2.1.

[0043] Satisfying formula (1) is preferable from the viewpoint of realizing a wide-angle zoom lens. Note that, in this embodiment, a wide-angle zoom lens can be expressed as, for example, ωw being greater than 30° (ωw>30°), where ωw is the half angle of view of the most off-axis chief ray of the zoom lens at the wide-angle end.

[0044] 1-3-2.Formula (2) 0.5 <bfw / Yw<1.5···(2) however, bfw: Back focus at the wide-angle end of a zoom lens when focused at infinity Yw: Maximum image height at the wide-angle end of the zoom lens when focused at infinity

[0045] Equation (2) is an equation for appropriately defining the ratio between the back focus of a zoom lens at the wide-angle end and the maximum image height at the wide-angle end. Satisfying equation (2) is preferable because it shortens the back focus of the zoom lens at the wide-angle end, making it easier to reduce the overall length of the optical system.

[0046] If bfw / Yw is 0.5 or less, the back focus of the zoom lens at the wide-angle end may be too short, resulting in an excessively large exit angle from the zoom lens. Here, the imaging surface of the image sensor is provided with a condenser lens, such as an on-chip microlens, for each pixel to efficiently receive incident light, and the light receiving angle of the on-chip microlens is limited within a predetermined range. Therefore, if the exit angle from the zoom lens becomes large and the inclination angle of the incident angle on the imaging surface with respect to the optical axis becomes too large, vignetting (shading) due to mismatch with the on-chip microlens may become significant. On the other hand, if bfw / Yw is 1.5 or more, the back focus of the zoom lens at the wide-angle end may be too long.

[0047] From the viewpoint of shortening the back focal length and reducing the overall length of the optical system of the zoom lens, bfw / Yw is preferably smaller than 1.35, more preferably smaller than 1.3, even more preferably smaller than 1.25, preferably smaller than 1.2, even more preferably smaller than 1.15, and even more preferably smaller than 1.1. Furthermore, from the viewpoint of keeping the exit angle of the zoom lens within a suitable range and suppressing peripheral light falloff due to mismatch with the on-chip microlens, bfw / Yw is preferably larger than 0.55, more preferably larger than 0.60, even more preferably larger than 0.65, even more preferably larger than 0.70, even more preferably larger than 0.75, and even more preferably larger than 0.80.

[0048] 1-3-3.Formula (3) -5.0<(Rf+Rb) / (Rf-Rb)<-0.1...(3) however, Rf: Radius of curvature of the object-side lens surface of lens component A Rb: Radius of curvature of the image-side lens surface of lens component A

[0049] Equation (3) relates to the shape (shape factor) of lens component A. Satisfying equation (3) is preferable because it makes it easier to effectively correct spherical aberration over the entire zoom range.

[0050] If (Rf+Rb) / (Rf-Rb) is -5.0 or less, the diverging effect of lens component A may become too small. On the other hand, if (Rf+Rb) / (Rf-Rb) is -0.1 or more, the diverging effect of lens component A may become too large.

[0051] From the viewpoint of keeping the divergence effect of lens component A within a suitable range and correcting spherical aberration well throughout the zoom range, (Rf+Rb) / (Rf-Rb) is preferably smaller than -0.15, more preferably smaller than -0.2, even more preferably smaller than -0.25, still more preferably smaller than -0.3, even more preferably smaller than -0.35, and still more preferably smaller than -0.4. Also, from the viewpoint of keeping the divergence effect of lens component A within a suitable range and correcting spherical aberration well throughout the entire zoom range, (Rf+Rb) / (Rf-Rb) is preferably larger than -4.5, more preferably larger than -4.0, even more preferably larger than -3.5, even more preferably larger than -3.0, even more preferably larger than -2.5, and still more preferably larger than -2.0.

[0052] 1-3-4.Formula (4) -1.3 <fA / fp2<-0.001···(4) however, fA: focal length of lens component A fp2: focal length of lens group P2

[0053] Equation (4) is an equation for appropriately setting the ratio between the focal length of lens component A and the focal length of lens group P2. Satisfying equation (4) is preferable from the perspective of achieving a good balance between the wide angle of the zoom lens and optical performance.

[0054] If fA / fp2 is -1.3 or less, the negative refractive power of lens component A becomes too small relative to the focal length of lens group P2, which may make it difficult to effectively correct spherical aberration occurring in lens group P2. On the other hand, if fA / fp2 is -0.001 or more, the negative refractive power of lens component A becomes too large relative to the focal length of lens group P2, which may cause the principal point of lens group P2 to be positioned closer to the object, thereby shortening the distance between the principal points of lens group P2 and a lens group with negative refractive power that is positioned closer to the object than lens group P2.

[0055] With the principal point distance within a preferred range, from the viewpoint of making it easier to widen the angle of the zoom lens and obtaining a desired angle of view at the wide-angle end, fA / fp2 is preferably smaller than −0.08, more preferably smaller than −0.12, even more preferably smaller than −0.15, and still more preferably smaller than −0.18. Furthermore, from the viewpoint of satisfactorily correcting spherical aberration occurring in lens group P2 and realizing a zoom lens with high optical performance using a small number of lenses, fA / fp2 is preferably larger than −1.1, more preferably larger than −1.0, even more preferably larger than −0.9, even more preferably larger than −0.8, and still more preferably larger than −0.75.

[0056] 1-3-5.Formula (5) 0.001 <fp3 / fp2<0.45···(5) however, fp3: focal length of lens group P3 fp2: focal length of lens group P2

[0057] Equation (5) is an equation for appropriately setting the ratio between the focal length of lens group P3 and the focal length of lens group P2. Satisfying equation (5) is preferable because it makes it easier to achieve both a large aperture and high performance in the zoom lens.

[0058] If fp3 / fp2 is 0.001 or less, the positive refractive power of the lens group P3 is too large relative to the focal length of the lens group P2, which can result in the height of the axial light beam passing through the lens group P3 being too high. On the other hand, if fp3 / fp2 is 0.45 or more, the positive refractive power of the lens group P3 is too small relative to the focal length of the lens group P2, which can result in the positive refractive power of the lens group P3 being too large, which can affect various aberrations such as spherical aberration and chromatic aberration that occur in the lens group P2. In this case, the number of lenses in the lens group P2 may need to be increased in order to obtain good imaging performance while maintaining the desired F-number of the lenses in the lens group P2.

[0059] From the viewpoints of effectively correcting aberrations occurring in lens group P2 and reducing the number of lenses to achieve a short overall length, fp3 / fp2 is preferably smaller than 0.40, more preferably smaller than 0.38, even more preferably smaller than 0.35, and even more preferably smaller than 0.32. Furthermore, from the viewpoints of effectively correcting spherical aberration at the telephoto end, with the refractive powers of lens group P3 and lens group P2 within a suitable range, fp3 / fp2 is preferably larger than 0.03, more preferably larger than 0.05, even more preferably larger than 0.08, even more preferably larger than 0.10, and even more preferably larger than 0.12.

[0060] 1-3-6.Formula (6) 0.4 <fp3 / fw<1.3···(6) however, fp3: focal length of lens group P3 fw: focal length at the wide-angle end of a zoom lens when focused at infinity

[0061] Equation (6) is an equation for appropriately setting the ratio between the focal length of lens group P3 and the focal length of the optical system of the zoom lens at the wide-angle end. Satisfying equation (6) is preferable because it makes it easier to achieve both a large aperture and a compact zoom lens. Furthermore, the effect of satisfying equation (6) is greatest when ωw>30° is satisfied.

[0062] If fp3 / fw is 0.4 or less, the positive refractive power of the lens group P3 becomes too large relative to the focal length of the optical system of the zoom lens at the wide-angle end, and the focal length of the lens group P3, which is located on the object side of the lens group N, may become too short. On the other hand, if fp3 / fw is 1.3 or more, the aperture becomes large at the wide-angle end, and it may become difficult to reduce the overall length.

[0063] From the viewpoint of increasing the aperture diameter at the wide-angle end and reducing the overall length, fp3 / fw is preferably smaller than 1.2, more preferably smaller than 1.15, even more preferably smaller than 1.1, still more preferably smaller than 1.05, and even more preferably smaller than 1.0. Furthermore, from the viewpoint of keeping the focal length of lens group P3 within a suitable range and effectively correcting astigmatism and coma at close distances, fp3 / fw is preferably greater than 0.5, more preferably greater than 0.6, even more preferably greater than 0.7, and even more preferably greater than 0.8.

[0064] 1-3-7.Formula (7) 15 <vd<40···(7) however, vd: Abbe number for the d-line of the lens having positive refractive power closest to the object in the lens group P2

[0065] Equation (7) is an equation for appropriately setting the Abbe number for the d-line of the lens with positive refractive power located closest to the object in lens group P2. Satisfying equation (7) is preferable because it facilitates good correction of axial chromatic aberration throughout the entire zoom range. Here, lenses with positive refractive power included in a lens group with positive refractive power correct chromatic aberration by using a material on the low-dispersion side. However, lens group P2 of this zoom lens has a large diverging effect due to the diverging surface, which tends to result in overcorrection of axial chromatic aberration on the short-wavelength side. Therefore, using a material on the high-dispersion side that satisfies equation (7) for the lens with positive refractive power located closest to the object in lens group P2 facilitates good correction of chromatic aberration.

[0066] If vd is 15 or less, axial chromatic aberration on the short wavelength side may tend to be undercorrected (insufficient correction). On the other hand, if vd is 40 or more, axial chromatic aberration on the short wavelength side may tend to be overcorrected, making correction difficult.

[0067] From the viewpoint of appropriately correcting axial chromatic aberration, vd is preferably smaller than 35, more preferably smaller than 32, even more preferably smaller than 30, and even more preferably smaller than 28. Furthermore, from the viewpoint of appropriately correcting axial chromatic aberration, vd is preferably larger than 18, and more preferably larger than 20.

[0068] 1-3-8.Formula (8) 2.5 <fp1 / fw<10.0···(8) however, fp1: focal length of lens group P1 fw: focal length at the wide-angle end of a zoom lens when focused at infinity

[0069] Equation (8) is an equation for appropriately setting the ratio between the focal length of lens group P1 and the focal length of the zoom lens optical system at the wide-angle end. Satisfying equation (8) makes it easy to achieve both a wider angle and a more compact size. Furthermore, the effect of satisfying equation (8) is greatest when ωw>30° is satisfied.

[0070] If fp1 / fw is 2.5 or less, the refractive power of the lens group P1 becomes too strong relative to the focal length of the optical system of the zoom lens at the wide-angle end, which may make it difficult to correct negative curvature of field.On the other hand, if fp1 / fw is 10.0 or more, the refractive power of the lens group P1 becomes too weak relative to the focal length of the optical system of the zoom lens at the wide-angle end, which may cause the movement distance of the lens group P1 to become too long.

[0071] From the viewpoints of shortening the travel distance of lens group P1, simplifying the cam structure, and realizing a compact lens barrel, fp1 / fw is preferably smaller than 8.0, more preferably smaller than 7.0, even more preferably smaller than 6.0, still more preferably smaller than 5.5, and even more preferably smaller than 5.0. Furthermore, from the viewpoints of appropriately correcting negative field distortion and realizing a wide angle of the zoom lens, fp1 / fw is preferably greater than 3.0, more preferably greater than 3.5, and even more preferably greater than 3.7.

[0072] 1-3-9.Formula (9) 0.7 <FNOp1_3<1.9···(9) however, FNOp1_3: The minimum open F-number in the zoom range from lens group P1 to lens group P3

[0073] Equation (9) is an equation for appropriately setting the minimum maximum F-number in the zoom range from lens group P1 to lens group P3. Satisfying equation (9) makes it easy to ensure the desired brightness of the zoom lens.

[0074] If FNOp1_3 is 0.7 or less, the maximum F-number from lens group P1 to lens group P3 becomes too small, which may make it difficult to effectively correct various aberrations. On the other hand, if FNOp1_3 is 1.9 or more, it may be difficult to ensure the desired brightness of the zoom lens. In this case, in order to achieve the desired brightness, it may be necessary to impart a strong positive refractive power to the rear lens group, which may weaken the telephoto tendency.

[0075] From the viewpoint of achieving a telephoto ratio in a suitable range and shortening the overall length, FNOp1_3 is preferably smaller than 1.7, more preferably smaller than 1.6, even more preferably smaller than 1.5, even more preferably smaller than 1.45, and even more preferably smaller than 1.4. Furthermore, from the viewpoint of effectively correcting various aberrations, FNOp1_3 is preferably larger than 0.8, more preferably larger than 0.9, and even more preferably larger than 1.0.

[0076] 1-3-10.Formula (10) 0.3<βp2w<5.0 (10) however, βp2w: Lateral magnification of lens group P2 at the wide-angle end when focusing at infinity

[0077] Equation (10) is an equation for appropriately setting the lateral magnification of lens unit P2 at the wide-angle end. By satisfying equation (10), it becomes easy to achieve both compactness and high performance of the zoom lens while ensuring a back focal length suitable for an interchangeable lens.

[0078] If βp2w is 0.3 or less, the light beam emerging from the lens group P2 becomes a strongly divergent light, which may result in a long back focus.On the other hand, if βp2w is 5.0 or more, the overall length of the optical system can be easily reduced, but the divergence effect of the lens group P2 may become too small.

[0079] From the viewpoint of effectively correcting spherical aberration occurring in lens group P2, βp2w is preferably smaller than 4.7, more preferably smaller than 4.5, even more preferably smaller than 4.2, still more preferably smaller than 4.0, and even more preferably smaller than 3.8. Also, from the viewpoint of shortening the back focal length and reducing the overall length of the optical system, βp2w is preferably larger than 0.5, more preferably larger than 0.6, and even more preferably larger than 0.7.

[0080] 1-3-11.Formula (11) 4.0 <Tw / Yw<8.5···(11) however, Tw: Total optical length of the zoom lens at the wide-angle end when focused at infinity Yw: Maximum image height at the wide-angle end of the zoom lens when focused at infinity

[0081] Equation (11) is an equation for appropriately setting the overall length of the optical system of a zoom lens at the wide-angle end with respect to the maximum image height at the wide-angle end. By satisfying equation (11), it becomes easy to achieve both a reduction in the overall length of the optical system at the wide-angle end and high performance.

[0082] If Tw / Yw is 4.0 or less, the overall optical length of the zoom lens at the wide-angle end may be too short relative to the maximum image height at the wide-angle end, whereas if Tw / Yw is 8.5 or more, the overall optical length of the zoom lens at the wide-angle end may be too long relative to the maximum image height at the wide-angle end.

[0083] In order to achieve compactness, Tw / Yw is preferably smaller than 8.2, more preferably smaller than 8.0, and even more preferably smaller than 7.8, with the total length of the optical system relative to the maximum image height being within a suitable range. In order to achieve high optical performance, Tw / Yw is preferably larger than 4.5, more preferably larger than 5.0, even more preferably larger than 5.5, and even more preferably larger than 5.8, with the total length of the optical system relative to the maximum image height being within a suitable range.

[0084] 2. Imaging device Next, an image pickup apparatus according to an embodiment of the present invention will be described, which includes the zoom lens according to the embodiment described above and an image pickup element provided on the image plane side of the zoom lens for converting an optical image formed by the zoom lens into an electrical signal.

[0085] Here, the imaging element is not limited, and solid-state imaging elements such as CCD (Charge Coupled Device) sensors and CMOS (Complementary Metal Oxide Semiconductor) sensors can be used as the imaging element. Silver halide film, infrared cut filters (IRCFs), and the like can also be used. The imaging device according to this embodiment is suitable for imaging devices using the above-described solid-state imaging elements, such as digital cameras and video cameras. The imaging device may also be a fixed-lens imaging device in which the lens is fixed to the housing, or an interchangeable-lens imaging device such as a single-lens reflex camera or a mirrorless single-lens camera. In particular, the zoom lens according to this embodiment can ensure a back focus suitable for an interchangeable lens system. Therefore, the zoom lens according to this embodiment is suitable for imaging devices such as single-lens reflex cameras equipped with an optical viewfinder, a phase difference sensor, and a reflex mirror for splitting light to these sensors.

[0086] Fig. 25 is a diagram schematically showing an example of the configuration of an imaging device according to this embodiment. As shown in Fig. 25, a mirrorless single-lens camera 1 has a main body 2 and a lens barrel 3 that is detachable from the main body 2. The lens barrel 3 has a zoom lens therein, and the lens barrel 3 and the zoom lens form a zoom lens. The mirrorless single-lens camera 1 is one form of an imaging device.

[0087] The zoom lens includes first to sixth lens groups G1 to G6. The zoom lens is configured to satisfy, for example, the above-mentioned formula (1). A diaphragm S is disposed on the object side of lens L9 included in second lens group G3.

[0088] The first lens group G1 has a positive refractive power as a whole and is made up of lenses L1 to L3. The second lens G2 has a negative refractive power as a whole and is made up of lenses L4 to L8. The third lens G3 has a positive refractive power as a whole and is made up of lenses L9 to L12. The fourth lens G4 has a positive refractive power as a whole and is made up of lenses L13 to L15. The fifth lens group G5 has a negative refractive power as a whole and is made up of lens L16. The sixth lens group G6 has a negative refractive power as a whole and is made up of lenses L17 to L19.

[0089] The main body 2 has a CCD sensor IP as an imaging element and a cover glass CG. The CCD sensor I is disposed in the main body 2 at a position where the central axis is the optical axis OA of the zoom lens in the lens barrel 3 attached to the main body 2. The main body 2 may have a plane-parallel plate with no substantial refractive power, such as an infrared cut filter (IRCF), instead of the cover glass CG.

[0090] The mirrorless single-lens camera 1 includes a zoom lens, so it is possible to achieve both high optical performance and a compact product.

[0091] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0092] (summary) A zoom lens according to a first aspect of the present invention includes, arranged in order from the object side to the image plane side, a lens group P1 having positive refractive power, a middle group including one or more lens groups and having negative refractive power as a whole, a lens group P2 having positive refractive power, a lens group P3 having positive refractive power, a lens group N having negative refractive power, and a rear group including one or more lens groups; The lens group P2 has a lens component A having negative refractive power closest to the image side, and the lens component A has a shape in which the object side surface is concave toward the object side, and satisfies the following formula: -5.0 <fp12w / fw<-0.3···(1) however, fp12w: the composite focal length from the lens group P1 to the lens group P2 at the wide-angle end when the zoom lens is focused at infinity fw: focal length at the wide-angle end of the zoom lens when focused at infinity

[0093] The zoom lens according to the second aspect of the present invention, in the first aspect, satisfies the following formula: 0.5 <bfw / Yw<1.5···(2) however, bfw: Back focus at the wide-angle end of the zoom lens when focused at infinity Yw: Maximum image height at the wide-angle end of the zoom lens when focused at infinity

[0094] The zoom lens according to the third aspect of the present invention, in the first or second aspect, satisfies the following formula: -5.0<(Rf+Rb) / (Rf-Rb)<-0.1...(3) however, Rf: radius of curvature of the object-side lens surface in the lens component A Rb: radius of curvature of the image-side lens surface in the lens component A

[0095] The zoom lens according to the fourth aspect of the present invention, in any one of the first to third aspects, satisfies the following formula: -1.3 <fA / fp2<-0.001···(4) however, fA: focal length of the lens component A fp2: focal length of the lens group P2

[0096] The zoom lens according to aspect 5 of the present invention, in any one of aspects 1 to 4, satisfies the following formula: 0.001 <fp3 / fp2<0.45···(5) however, fp3: focal length of the lens group P3

[0097] The zoom lens according to the sixth aspect of the present invention, in any one of the first to fifth aspects, satisfies the following formula: 0.4 <fp3 / fw<1.3···(6)

[0098] The zoom lens according to the seventh aspect of the present invention, in any one of the first to sixth aspects, satisfies the following formula: 15 <vd<40···(7) however, vd: Abbe number for the d-line of the lens having positive refractive power closest to the object in the lens group P2

[0099] The zoom lens according to aspect 8 of the present invention, in any one of aspects 1 to 7, satisfies the following formula: 2.5 <fp1 / fw<10.0···(8) however, fp1: focal length of the lens group P1

[0100] The zoom lens according to aspect 9 of the present invention, in any one of aspects 1 to 8, satisfies the following formula: 0.7 <FNOp1_3<1.9···(9) however, FNOp1_3: The minimum open F-number in the zoom range from the lens group P1 to the lens group P3

[0101] The zoom lens according to aspect 10 of the present invention, in any of aspects 1 to 9, satisfies the following formula: 0.3<βp2w<5.0 (10) however, βp2w: lateral magnification of the lens group P2 at the wide-angle end when focused on infinity

[0102] The zoom lens according to aspect 11 of the present invention, in any one of aspects 1 to 10, satisfies the following formula: 4.0 <Tw / Yw<8.5···(11) however, Tw: total optical length of the zoom lens at the wide-angle end when focused at infinity

[0103] A zoom lens according to Aspect 12 of the present invention is the same as that of any one of Aspects 1 to 11, in which the lens group P2 has a cemented lens whose cemented surface faces the object side in a convex manner.

[0104] A zoom lens according to Aspect 13 of the present invention is the same as that of any one of Aspects 1 to 12, in which the lens group P2 has at least two lenses having positive refractive power and at least two lenses having negative refractive power.

[0105] A zoom lens according to Aspect 14 of the present invention is the same as any one of Aspects 1 to 13, in that the lens group N moves on the optical axis during focusing.

[0106] An imaging device according to a fifteenth aspect of the present invention includes the zoom lens according to any one of the first to fourteenth aspects, and an imaging element on the image plane side of the zoom lens that converts an optical image formed by the zoom lens into an electrical signal. [Example]

[0107] An embodiment of the present invention will be described below. In the following tables, unless otherwise specified, all units of length are "mm", all units of angle of view are "°", and "E+a" is "×10 a " indicates.

[0108] [Example 1] (1) Optical system configuration 1 is a diagram schematically showing the optical configuration of a zoom lens of Example 1 when focusing at infinity at the wide-angle end. The zoom lens of Example 1 is composed of, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, a fourth lens group G4 having positive refractive power, a fifth lens group G5 having negative refractive power, and a sixth lens group G6 having negative refractive power.

[0109] The first lens group G1 is composed of, in order from the object side, a cemented lens of a meniscus lens L1 having negative refractive power with its convex surface facing the object side and a biconvex lens L2, and a meniscus lens L3 having positive refractive power with its convex surface facing the object side.

[0110] The second lens group G2 is composed of, in order from the object side, a meniscus lens L4 having negative refractive power and a convex surface facing the object side, a biconcave lens L5, a cemented lens consisting of a biconcave lens L6 and a biconvex lens L7, and a meniscus lens L8 having negative refractive power and a concave surface facing the object side. The biconcave lens L5 is a glass-molded aspherical lens with aspherical surfaces on both sides. The meniscus lens L8 having negative refractive power is a glass-molded aspherical lens with aspherical surfaces on both sides.

[0111] The third lens group G3 is composed of, in order from the object side, a meniscus lens L9 having a convex surface facing the object side and positive refractive power, a cemented lens of a meniscus lens L10 having a convex surface facing the object side and negative refractive power and a biconvex lens L11, and a biconcave lens L12.

[0112] The fourth lens group G4 is composed of, in order from the object side, a cemented lens consisting of a meniscus lens L13 with negative refractive power and a biconvex lens L14, whose convex surface faces the object side, and a biconvex lens L15. The biconvex lens L15 is a glass-molded aspherical lens with aspherical surfaces on both sides.

[0113] The fifth lens group G5 is composed of a meniscus lens L16 having a negative refractive power and a convex surface facing the object side.

[0114] The sixth lens group G6 is composed of a biconvex lens L17, a biconcave lens L18, and a meniscus lens L19 with negative refractive power and a concave surface facing the object side. The biconcave lens L18 is a glass-molded aspherical lens with aspherical surfaces on both sides.

[0115] The aperture stop S is disposed adjacent to the object side of the third lens group G3.

[0116] "CG" is a cover glass, and "IP" is an image plane. These points are the same as those in the diagrams showing the optical configurations of other examples, so explanations will be omitted below.

[0117] The first lens group G1 corresponds to the lens group P1 mentioned above. The second lens group G2 corresponds to the intermediate group mentioned above. The third lens group G3 corresponds to the lens group P2 mentioned above. The fourth lens group G4 corresponds to the lens group P3 mentioned above. The fifth lens group G5 corresponds to the lens group N mentioned above. The sixth lens group G6 corresponds to the rear group mentioned above. The biconcave lens L12 corresponds to the lens component A mentioned above.

[0118] 1, the intermediate group is denoted as M and the rear group as R, and this also applies to schematic diagrams showing the optical configurations of other embodiments. Hereinafter, the configuration corresponding to the intermediate group described above will sometimes be referred to as the intermediate group M, and the configuration corresponding to the rear group described above will sometimes be referred to as the rear group R.

[0119] In the first embodiment, the zoom lens changes magnification by changing the air gap between adjacent lens groups on the optical axis. This is the same in the other embodiments, so a description thereof will be omitted below.

[0120] 1 indicate the direction and manner of movement of each lens group in the zoom lens of Example 1 when changing magnification from the wide-angle end to the telephoto end. When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object side, the second lens group G2 moves toward the image plane side, the third lens group G3 moves toward the object side, the fourth lens group G4 moves toward the object side, the fifth lens group G5 moves toward the object side, and the sixth lens group G6 moves toward the object side.

[0121] Focusing from an object at infinity to an object at a close distance is performed by moving the fifth lens group G5 toward the image plane side.

[0122] (2) Numerical examples Next, a description will be given of a numerical example in which specific numerical values ​​of the zoom lens are applied. Table 1 shows data on each surface included in the zoom lens of Example 1.

[0123] In Table 1, the surface numbers indicate the order of the lens surfaces counted from the object side, "r" indicates the radius of curvature, "d" indicates the surface spacing, nd indicates the refractive index at the d-line (λ=587.56 nm), and νd indicates the Abbe number based on the d-line (λ=587.56 nm). Additionally, "S" next to the surface numbers in the table indicates an aperture stop, and "ASPH" indicates an aspherical lens. "∞" means infinity. In the "d" column, notations such as "D(0)" indicate that the spacing on the optical axis of the lens surfaces is a variable spacing that changes when zooming or focusing.

[0124] In Table 1, surface numbers 1 to 5 are surface numbers of lenses in the first lens group G1. Surface numbers 6 to 14 are surface numbers of the second lens group G2. Surface number 15 represents the aperture. Surface numbers 16 to 22 are surface numbers of the third lens group G3. Surface numbers 23 to 27 are surface numbers of the fourth lens group G4. Surface numbers 28 and 29 are surface numbers of lenses in the fifth lens group G5. Surface numbers 30 to 35 are surface numbers of the sixth lens group G6. Surface numbers 36 and 37 represent the cover glass (CG).

[0125] [Table 1] Surface number rd nd νd Object plane ∞ d(0) 1 5402.8349 1.7000 1.84666 23.78 2 247.5120 6.9802 1.49700 81.61 3 -234.2591 0.2000 4 60.6817 7.3816 1.72916 54.67 5 155.7737 d(5) 6 78.0464 1.5000 1.72916 54.67 7 20.5900 9.1211 8ASPH -91.9998 1.5000 1.51633 64.06 9ASPH 511.0181 3.9786 10 -42.7291 1.2000 1.49700 81.61 11 59.7131 7.4736 1.60342 38.01 12 -32.7331 2.2573 13ASPH -20.2370 1.5000 1.59201 67.02 14ASPH -31.5949 d(14) 15S ∞ 1.0000 16 37.8208 5.8112 1.92286 20.88 17 179.4192 0.5000 18 51.0737 1.2000 1.90366 31.31 19 20.8927 10.3180 1.59282 68.62 20 -559.8174 2.8570 21 -45.6201 1.0000 1.92286 20.88 22 144.7843 d(22) 23 33.6250 1.0000 1.87070 40.73 24 20.1801 13.5982 1.59282 68.62 25 -73.2918 0.1500 26ASPH 37.2974 7.2684 1.59201 67.02 27ASPH -64.8061 d(27) 28 66.0293 0.9000 1.83481 42.72 29 26.0936 d(29) 30 68.7274 6.2835 1.80518 25.46 31 -47.4786 0.1500 32ASPH -69.2213 1.5000 1.77377 47.17 33ASPH 116.9797 7.9477 34 -20.3610 1.2000 1.83481 42.72 35 -34.5463 d(35) 36 ∞ 2.5000 1.51680 64.20 37∞1.0000 Image plane ∞

[0126] Table 2 shows the specifications of the zoom lens of the first embodiment.

[0127] [Table 2] Wide-angle end Mid-range Telephoto end f 28.8361 40.0054 67.9005 F No. 2.0600 2.0613 2.0609 ω 37.7855 27.9037 16.8751 Y 21.6330 21.6330 21.6330

[0128] Table 3 shows the distances of the variable intervals of the zoom lens of Example 1.

[0129] [Table 3] Wide-angle end Mid-range Telephoto end d(0) ∞ ∞ ∞ d(5) 1.0000 11.5468 30.9112 d(14) 29.6624 17.9669 1.3559 d(22) 0.9055 0.8000 1.8018 d(27) 2.1949 2.7053 3.9280 d(29) 7.9609 7.8481 11.6693 d(35) 13.3000 17.0654 17.7959 Wide-angle end Mid-range Telephoto end d(0) 134.0000 211.0912 271.5617 d(5) 1.0000 11.5468 30.9112 d(14) 29.6624 17.9669 1.3559 d(22) 0.9055 0.8000 1.8018 d(27) 4.6405 5.3385 8.8504 d(29) 5.5154 5.2149 6.7468 d(35) 13.3000 17.0654 17.7959

[0130] Table 4 shows the focal length of each lens group of the zoom lens of Example 1.

[0131] [Table 4] Group number Focal length G1 117.4710 G2 -29.6588 G3 190.1650 G4 24.9945 G5 -52.2155 G6 -346.7190

[0132] Table 5 shows the aspherical coefficients of the aspherical surfaces in the zoom lens of Example 1. The aspherical coefficients in this table are values ​​when each aspherical shape is defined by the following formula (1).

[0133]

number

[0134] In equation (1), "x" is the amount of displacement from the reference plane in the optical axis direction, "r" is the paraxial radius of curvature, "H" is the height from the optical axis in the direction perpendicular to the optical axis, "k" is the conic coefficient, and "An" is the n-th order aspheric coefficient.

[0135] [Table 5] Surface number k A4 A6 8 0.0000 1.12279E-05 -1.19074E-08 9 0.0000 1.18400E-05 2.47416E-09 13 0.0000 3.46151E-05 -7.86166E-08 14 0.0000 2.41764E-05 -9.75381E-08 26 0.0000 -1.02603E-05 -5.81510E-09 27 6.5998 4.18321E-06 -5.64567E-09 32 0.0000 -9.47323E-06 9.12347E-08 33 0.0000 -1.44113E-05 6.46613E-08 Face number A8 A10 A12 8 4.9265E-13 4.55475E-14 0.00000E+00 9 -8.77722E-12 1.48655E-13 0.00000E+00 13 2.26606E-10 -2.04828E-13 0.00000E+00 14 2.11579E-10 -3.04187E-13 0.00000E+00 26 -3.74566E-11 6.3631E-14 -1.08552E-16 27 -4.61082E-11 1.49319E-13 -2.99476E-16 32 -1.5746E-10 -1.26436E-13 1.13841E-15 33 6.63953E-12 -9.17756E-13 2.418E-15

[0136] Fig. 2 shows longitudinal aberration diagrams of the zoom lens of Example 1 at the wide-angle end when focused at infinity. Fig. 3 shows longitudinal aberration diagrams of the zoom lens of Example 1 at the intermediate focus when focused at infinity. Fig. 4 shows longitudinal aberration diagrams of the zoom lens of Example 1 at the telephoto end when focused at infinity. In each diagram, spherical aberration (mm), astigmatism (mm), and distortion (%) are shown from the left as you face the diagram.

[0137] In the graph showing spherical aberration, the vertical axis represents the ratio to the maximum aperture F-number, and the horizontal axis represents defocus. In the spherical aberration graph, the solid line represents spherical aberration for the d-line (wavelength 587.56 nm), the dashed line represents spherical aberration for the C-line (wavelength 656.28 nm), and the dotted line represents spherical aberration for the g-line (wavelength 435.84 nm).

[0138] In the diagrams showing astigmatism, the solid line indicates the sagittal image plane (ds) of the d-line, and the broken line indicates the meridional image plane (dm) of the d-line.

[0139] In the diagram showing distortion, the vertical axis represents image height (mm) and the horizontal axis represents %.

[0140] [Example 2] (1) Optical system configuration 5 is a diagram schematically illustrating the optical configuration of the zoom lens of Example 2 when focusing on infinity at the wide-angle end. The zoom lens of Example 2 is composed of, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, a fourth lens group G4 having positive refractive power, a fifth lens group G5 having negative refractive power, and a sixth lens group G6 having negative refractive power.

[0141] The first lens group G1 is composed of, in order from the object side, a cemented lens of a meniscus lens L1 having negative refractive power with its convex surface facing the object side and a biconvex lens L2, and a meniscus lens L3 having positive refractive power with its convex surface facing the object side.

[0142] The second lens group G2 is composed of, in order from the object side, a meniscus lens L4 having negative refractive power with its convex surface facing the object side, a biconcave lens L5, a biconvex lens L6, and a meniscus lens L7 having negative refractive power with its concave surface facing the object side. The meniscus lens L4 having negative refractive power is a glass-molded aspherical lens with aspherical surfaces on both sides.

[0143] The third lens group G3 is composed of, in order from the object side, a biconvex lens L8, a cemented lens of a biconvex lens L9 and a biconcave lens L10, a cemented lens of a meniscus lens L11 with a convex surface facing the object side and having negative refractive power and a meniscus lens L12 with a convex surface facing the object side and having positive refractive power, and a meniscus lens L13 with a concave surface facing the object side and having negative refractive power.

[0144] The fourth lens group G4 is composed of, in order from the object side, a cemented lens made up of a meniscus lens L14 with negative refractive power and a convex surface facing the object side, a biconvex lens L15, and a biconvex lens L16. The biconvex lens L16 is a glass-molded aspherical lens with aspherical surfaces on both sides.

[0145] The fifth lens group G5 is composed of a meniscus lens L17 having a negative refractive power and a convex surface facing the object side.

[0146] The sixth lens group G6 is composed of a biconvex lens L18, a biconcave lens L19, and a meniscus lens L20 with negative refractive power and a concave surface facing the object side. The meniscus lens L20 with negative refractive power is a glass-molded aspherical lens with aspherical surfaces on both sides.

[0147] The aperture stop S is disposed adjacent to the object side of the third lens group G3.

[0148] The first lens group G1 corresponds to the lens group P1 described above. The second lens group G2 corresponds to the middle group M described above. The third lens group G3 corresponds to the lens group P2 described above. The fourth lens group G4 corresponds to the lens group P3 described above. The fifth lens group G5 corresponds to the lens group N described above. The sixth lens group G6 corresponds to the rear group R described above. The meniscus lens L13 having negative refractive power corresponds to the lens component A described above.

[0149] 5 indicate the direction and manner of movement of each lens group in the zoom lens of Example 2 when changing magnification from the wide-angle end to the telephoto end. When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object side, the second lens group G2 moves toward the image plane side, the third lens group G3 moves toward the object side, the fourth lens group G4 moves toward the object side, the fifth lens group G5 moves toward the object side, and the sixth lens group G6 moves toward the object side.

[0150] Focusing from an object at infinity to an object at a close distance is performed by moving the fifth lens group G5 toward the image plane side.

[0151] (2) Numerical examples Table 6 shows data on each surface included in the zoom lens of Example 2.

[0152] [Table 6] Surface number rd nd νd Object plane ∞ d(0) 1 147.9240 1.5000 2.00100 29.13 2 89.2297 8.1669 1.49700 81.61 3 -1013.4225 0.1500 4 62.5899 7.3342 1.59282 68.62 5 217.6192 d(5) 6ASPH 1146.3450 1.5000 1.85108 40.12 7ASPH 21.2737 8.9791 8 -32.8324 1.0000 1.59282 68.62 9 54.7576 0.1500 10 45.7575 5.7592 1.77047 29.74 11 -40.6524 1.6538 12 -24.8195 1.0000 1.49700 81.61 13 -72.3565 d(13) 14S∞1.0000 15 35.6743 5.4465 1.84666 23.78 16 -261.9933 0.3434 17 83.4176 4.6628 1.49700 81.61 18 -60.8050 1.0000 2.00069 25.46 19 223.6863 0.2000 20 33.0763 1.0000 2.00100 29.13 21 19.5530 6.0475 1.49700 81.61 22 137.4886 3.1524 23 -35.6888 1.0000 1.90366 31.31 24 -204.7501 d(24) 25 26.7857 1.1000 1.83400 37.34 26 17.1629 10.6700 1.59282 68.62 27 -49.5364 0.1500 28ASPH 35.1548 3.9177 1.59201 67.02 29ASPH -400.2043 d(29) 30 75.8566 0.8000 1.83481 42.72 31 24.8752 d(31) 32 92.9598 6.5913 1.84666 23.78 33 -32.3756 0.1500 34 -47.3662 1.0000 1.84666 23.78 35 457.6853 5.3920 36ASPH -25.6131 1.5000 1.69350 53.18 37ASPH -84.9510 d(37) 38 ∞ 2.5000 1.51680 64.20 39∞1.0000 Image plane ∞

[0153] Table 7 shows the specifications of the zoom lens of the second embodiment.

[0154] [Table 7] Wide-angle end Mid-range Telephoto end f 25.7043 39.9974 96.9898 F No. 2.9082 2.9084 2.9109 ω 41.9883 28.0844 11.9873 Y 21.6330 21.6330 21.6330

[0155] Table 8 shows the distances of each variable interval of the zoom lens of Example 2.

[0156] [Table 8] Wide-angle end Mid-range Telephoto end d(0) ∞ ∞ ∞ d(5) 1.0000 11.8903 44.9323 d(13) 24.2967 15.3815 1.1000 d(24) 4.3009 2.1402 0.8000 d(29) 2.2964 2.4602 5.8854 d(31) 10.7891 10.7561 10.7223 d(37) 13.5000 22.4107 27.7965 Wide-angle end Mid-range Telephoto end d(0) 28.0000 139.1441 362.9468 d(5) 1.0000 11.8903 44.9323 d(13) 24.2967 15.3815 1.1000 d(24) 4.3009 2.1402 0.8000 d(29) 7.1003 5.1342 11.0187 d(31) 5.9852 8.0821 5.5890 d(37) 13.5000 22.4107 27.7965

[0157] Table 9 shows the focal length of each lens group of the zoom lens of Example 2.

[0158] [Table 9] Group number Focal length G1 118.4930 G2 -21.6505 G3 90.9915 G4 23.0848 G5 -44.6553 G6 -1057.4300

[0159] Table 10 shows the aspherical coefficients of the aspherical surface in the zoom lens of Example 2.

[0160] [Table 10] Surface number k A4 A6 6 0.0000 8.15512E-06 -2.58308E-08 7 0.0000 3.01464E-06 -3.12833E-08 28 3.1421 -2.62006E-05 -6.73925E-08 29 0.0000 2.45836E-07 -4.74396E-08 36 -2.6052 -4.31172E-05 1.49865E-07 37 0.0000 -2.01518E-05 1.26793E-07 Face number A8 A10 A12 6 9.56254E-11 -1.87198E-13 1.86771E-16 7 1.79591E-10 -8.23604E-13 2.01475E-15 28 -1.51087E-10 -5.58708E-13 0.00000E+00 29 -9.84238E-11 -3.35970E-13 0.00000E+00 36 -4.98188E-10 4.35226E-13 0.00000E+00 37 -4.42043E-10 5.17893E-13 0.00000E+00

[0161] Fig. 6 shows longitudinal aberration diagrams of the zoom lens of Example 2 at the wide-angle end when focusing at infinity. Fig. 7 shows longitudinal aberration diagrams of the zoom lens of Example 2 at the intermediate focus when focusing at infinity. Fig. 8 shows longitudinal aberration diagrams of the zoom lens of Example 2 at the telephoto end when focusing at infinity.

[0162] [Example 3] (1) Optical system configuration 9 is a diagram schematically illustrating the optical configuration of the zoom lens of Example 3 when focusing at infinity at the wide-angle end. The zoom lens of Example 3 is composed of, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, a fourth lens group G4 having positive refractive power, a fifth lens group G5 having negative refractive power, and a sixth lens group G6 having negative refractive power.

[0163] The first lens group G1 is composed of, in order from the object side, a cemented lens of a meniscus lens L1 having negative refractive power with its convex surface facing the object side and a biconvex lens L2, and a meniscus lens L3 having positive refractive power with its convex surface facing the object side.

[0164] The second lens group G2 is composed of, in order from the object side, a meniscus lens L4 with negative refractive power and a convex surface facing the object side, a biconcave lens L5, a biconvex lens L6, and a biconcave lens L7. The meniscus lens L4 with negative refractive power is a composite resin aspherical lens with a composite resin film molded into an aspherical shape attached to the object side surface.

[0165] The third lens group G3 is composed of, in order from the object side, a biconvex lens L8, a cemented lens consisting of a meniscus lens L9 with negative refractive power and a biconvex lens L10 with its convex surface facing the object side, and a biconcave lens L11. The biconcave lens L11 is a composite resin aspherical lens with an aspherical composite resin film attached to its object-side surface.

[0166] The fourth lens group G4 is composed of, in order from the object side, a biconvex lens L12, a cemented lens made up of a meniscus lens L13 with negative refractive power and a biconvex lens L14, with its convex surface facing the object side, and a biconvex lens L14. The biconvex lens L12 is a glass-molded aspherical lens with aspherical surfaces on both sides.

[0167] The fifth lens group G5 is composed of a meniscus lens L15 having a negative refractive power and a convex surface facing the object side.

[0168] The sixth lens group G6 is composed of a biconvex lens L16, a biconcave lens L17, and a meniscus lens L18 with negative refractive power and a concave surface facing the object side. The biconcave lens L17 is a glass-molded aspherical lens with aspherical surfaces on both sides.

[0169] The aperture stop S is disposed adjacent to the object side of the third lens group G3.

[0170] The first lens group G1 corresponds to the lens group P1 mentioned above. The second lens group G2 corresponds to the middle group M mentioned above. The third lens group G3 corresponds to the lens group P2 mentioned above. The fourth lens group G4 corresponds to the lens group P3 mentioned above. The fifth lens group G5 corresponds to the lens group N mentioned above. The sixth lens group G6 corresponds to the rear group R mentioned above. The biconcave lens L11 corresponds to the lens component A mentioned above.

[0171] 9 indicate the direction and manner of movement of each lens group in the zoom lens of Example 3 when changing magnification from the wide-angle end to the telephoto end. When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object side, the second lens group G2 moves toward the image plane side, the third lens group G3 moves toward the object side, the fourth lens group G4 moves toward the object side, the fifth lens group G5 moves toward the object side, and the sixth lens group G6 moves toward the object side.

[0172] Focusing from an object at infinity to an object at a close distance is performed by moving the fifth lens group G5 toward the image plane side.

[0173] (2) Numerical examples Table 11 shows data on each surface included in the zoom lens of Example 3.

[0174] [Table 11] Surface number rd nd νd Object plane ∞ d(0) 1 138.2908 1.2000 1.80610 33.27 2 71.8697 6.1991 1.43700 95.10 3 -988.4424 0.1500 4 67.3585 5.2760 1.59282 68.62 5 393.4351 d(5) 6ASPH 573.0039 0.1500 1.53610 41.21 7 321.4213 1.1000 1.87070 40.73 8 21.9192 6.6163 9 -49.5626 0.9000 1.61800 63.39 10 45.1799 0.2000 11 37.8072 5.3924 1.76182 26.61 12 -56.7238 1.0469 13 -35.3413 0.9000 1.49700 81.61 14 1826.5869 d(14) 15S ∞ 0.9000 16 28.6445 3.6114 1.72825 28.32 17 -348.1430 0.4976 18 64.4085 1.0000 1.87070 40.73 19 14.2600 6.4318 1.71300 53.94 20 -51.1336 1.1604 21ASPH -24.1532 0.2500 1.53610 41.21 22 -24.9658 0.9000 1.90366 31.31 23 153.0864 d(23) 24ASPH 23.2470 4.8366 1.69350 53.18 25ASPH -47.0915 0.1500 26 72.4595 0.8000 1.91082 35.25 27 16.3102 6.7146 1.49700 81.61 28 -31.0772 d(28) 29 270.9536 0.8000 1.74330 49.22 30 24.9181 d(30) 31 66.2570 6.2513 1.74077 27.76 32 -30.1383 0.1500 33ASPH -80.1228 1.2000 1.77377 47.17 34ASPH 143.2701 5.7280 35 -20.4217 1.0000 1.83481 42.72 36 -65.8384 d(36) 37 ∞ 2.5000 1.51680 64.20 38∞1.0000 Image plane ∞

[0175] Table 12 shows the specifications of the zoom lens of the third embodiment.

[0176] [Table 12] Wide-angle end Mid-range Telephoto end f 25.7546 69.9544 193.9096 F No. 2.9057 4.8999 5.8078 ω 42.1987 16.4979 6.0975 Y 21.6330 21.6330 21.6330

[0177] Table 13 shows the distances of each variable interval of the zoom lens of Example 3.

[0178] [Table 13] Wide-angle end Mid-range Telephoto end d(0) ∞ ∞ ∞ d(5) 1.0000 25.8321 60.1497 d(14) 27.6992 12.5791 2.2253 d(23) 7.3672 3.3794 0.9000 d(28) 2.5516 3.1846 3.5983 d(30) 10.8695 10.2367 9.8243 d(36) 13.5000 34.6456 46.2901 Wide-angle end Mid-range Telephoto end d(0) 52.0000 335.1301 601.9999 d(5) 1.0000 25.8321 60.1497 d(14) 27.6992 12.5791 2.2253 d(23) 7.3672 3.3794 0.9000 d(28) 5.2579 5.0519 9.2535 d(30) 8.1632 8.3694 4.1690 d(36) 13.5000 34.6456 46.2901

[0179] Table 14 shows the focal length of each lens group of the zoom lens of Example 3.

[0180] [Table 14] Group number Focal length G1 118.4280 G2 -21.5568 G3 110.9760 G4 22.6744 G5 -36.9701 G6 -393.4930

[0181] Table 15 shows the aspherical coefficients of the aspherical surface in the zoom lens of Example 3.

[0182] [Table 15] Surface number k A4 A6 6 0.0000 3.47547E-06 -6.46906E-09 21 -0.6908 1.58671E-05 -3.34765E-08 24 -0.1672 -1.06914E-05 6.20122E-08 25 1.6757 3.10823E-05 -1.62150E-08 33 0.0000 3.59573E-05 -3.20004E-07 34 0.0000 3.71296E-05 -3.11950E-07 Face number A8 A10 A12 6 1.20971E-11 -8.06212E-15 0.00000E+00 21 6.78963E-10 -4.79627E-12 1.18873E-14 24 -1.07651E-10 -1.38851E-12 8.03578E-15 25 4.82024E-10 -6.07374E-12 2.25207E-14 33 1.35042E-09 -1.88981E-12 0.00000E+00 34 1.20140E-09 -1.27418E-12 0.00000E+00

[0183] Fig. 10 shows longitudinal aberration diagrams of the zoom lens of Example 3 at the wide-angle end when focusing at infinity. Fig. 11 shows longitudinal aberration diagrams of the zoom lens of Example 3 at the intermediate focus when focusing at infinity. Fig. 12 shows longitudinal aberration diagrams of the zoom lens of Example 3 at the telephoto end when focusing at infinity.

[0184] [Example 4] (1) Optical system configuration 13 is a diagram schematically illustrating the optical configuration of the zoom lens of Example 4 when focusing at infinity at the wide-angle end. The zoom lens of Example 4 is composed of, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, a fourth lens group G4 having positive refractive power, a fifth lens group G5 having negative refractive power, and a sixth lens group G6 having positive refractive power.

[0185] The aperture stop S is disposed adjacent to the object side of the third lens group G3.

[0186] The first lens group G1 corresponds to the lens group P1 described above. The second lens group G2 corresponds to the middle group M described above. The third lens group G3 corresponds to the lens group P2 described above. The fourth lens group G4 corresponds to the lens group P3 described above. The fifth lens group G5 corresponds to the lens group N described above. The sixth lens group G6 corresponds to the rear group R described above. The meniscus lens L12 having negative refractive power corresponds to the lens component A described above.

[0187] The first lens group G1 is composed of, in order from the object side, a cemented lens of a meniscus lens L1 having negative refractive power with its convex surface facing the object side and a biconvex lens L2, and a meniscus lens L3 having positive refractive power with its convex surface facing the object side.

[0188] The second lens group G2 is composed of, in order from the object side, a meniscus lens L4 with negative refractive power and a convex surface facing the object side, a biconcave lens L5, a biconvex lens L6, and a meniscus lens L7 with negative refractive power and a concave surface facing the object side. The meniscus lens L4 with negative refractive power is a composite resin aspherical lens with a composite resin film molded into an aspherical shape attached to its object-side surface.

[0189] The third lens group G3 is composed of, in order from the object side, a meniscus lens L8 having a convex surface facing the object side and positive refractive power, a meniscus lens L9 having a convex surface facing the object side and positive refractive power, a cemented lens made up of a meniscus lens L10 having a convex surface facing the object side and a meniscus lens L11 having a convex surface facing the object side and positive refractive power, and a meniscus lens L12 having a concave surface facing the object side and negative refractive power.

[0190] The fourth lens group G4 is composed of, in order from the object side, a cemented lens formed by a meniscus lens L13 having negative refractive power with its convex surface facing the object side and a biconvex lens L14, and a biconvex lens L15. The biconvex lens L15 is a glass-molded aspherical lens with aspherical surfaces on both sides.

[0191] The fifth lens group G5 is composed of a meniscus lens L16 having a negative refractive power and a convex surface facing the object side.

[0192] The sixth lens group G6 is composed of a biconvex lens L17, a biconcave lens L18, and a meniscus lens L19 with negative refractive power and a concave surface facing the object side. The negative meniscus lens L19 is a glass-molded aspherical lens with aspherical surfaces on both sides.

[0193] The aperture stop S is disposed adjacent to the object side of the third lens group G3.

[0194] The first lens group G1 corresponds to the lens group P1 described above. The second lens group G2 corresponds to the middle group M described above. The third lens group G3 corresponds to the lens group P2 described above. The fourth lens group G4 corresponds to the lens group P3 described above. The fifth lens group G5 corresponds to the lens group N described above. The sixth lens group G6 corresponds to the rear group R described above. The meniscus lens L12 having negative refractive power corresponds to the lens component A described above.

[0195] 13 indicate the direction and manner of movement of each lens group in the zoom lens of Example 4 when changing magnification from the wide-angle end to the telephoto end. When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object side, the second lens group G2 moves toward the image plane side, the third lens group G3 moves toward the object side, the fourth lens group G4 moves toward the object side, the fifth lens group G5 moves toward the object side, and the sixth lens group G6 moves toward the object side.

[0196] Focusing from an object at infinity to an object at a close distance is performed by moving the fifth lens group G5 toward the image plane side.

[0197] (2) Numerical examples Table 16 shows data on each surface included in the zoom lens of Example 4.

[0198] [Table 16] Surface number rd nd νd Object plane ∞ d(0) 1 296.6831 1.2000 1.92286 20.88 2 134.1778 5.3920 1.49700 81.61 3 -471.7083 0.1500 4 58.6469 5.3973 1.71300 53.94 5 151.2506 d(5) 6ASPH 150.4957 0.1500 1.53610 41.21 7 113.4623 1.0000 1.83481 42.72 8 18.7143 8.0145 9ASPH -30.9776 1.2000 1.59201 67.02 10ASPH 64.5070 0.9138 11 81.5363 4.5034 1.85883 30.00 12 -39.0770 2.6889 13 -21.4086 0.8000 1.49700 81.61 14 -43.2664 d(14) 15S ∞ 1.0000 16 33.6847 3.7131 1.84666 23.78 17 112.2668 0.8479 18 36.2397 3.7139 1.49700 81.61 19 172.4471 0.2486 20 32.3567 0.9000 2.00100 29.13 21 17.6460 5.3332 1.49700 81.61 22 84.1237 3.1191 23 -31.1917 0.9000 1.90110 27.06 24 -131.8726 d(24) 25 24.7660 1.0000 1.87070 40.73 26 15.1370 9.5165 1.59282 68.62 27 -42.2846 0.1500 28ASPH 37.8209 3.5040 1.59201 67.02 29ASPH -236.9395 d(29) 30 129.9592 0.8000 1.80420 46.50 31 24.1132 9.2212 32 80.7795 7.0611 1.85883 30.00 33 -30.1291 0.1500 34 -41.6003 0.9000 1.80000 29.84 35 190.9861 4.9812 36ASPH -33.2555 1.3000 1.69350 53.18 37ASPH -100.3331 d(37) 38 ∞ 2.5000 1.51680 64.20 39∞1.0000 Image plane ∞

[0199] Table 17 shows the specifications of the zoom lens of the fourth embodiment.

[0200] [Table 17] Wide-angle end Mid-range Telephoto end f 25.7546 35.0033 67.8990 F No. 2.9145 2.9088 2.9111 ω 41.6631 31.7316 16.8781 Y 21.6330 21.6330 21.6330

[0201] Table 18 shows the distances of each variable interval of the zoom lens of Example 4.

[0202] [Table 18] Wide-angle end Mid-range Telephoto end d(0) ∞ ∞ ∞ d(5) 1.0000 6.9228 31.1977 d(14) 18.3845 11.3837 1.1000 d(24) 4.0497 2.5058 0.8000 d(29) 2.2963 2.3578 3.7918 d(30) 9.2212 9.1596 7.7257 d(37) 13.5001 20.0168 28.6047 Wide-angle end Mid-range Telephoto end d(0) 47.4999 143.6051 222.7317 d(5) 1.0000 6.9228 31.1977 d(14) 18.3845 11.3837 1.1000 d(24) 4.0497 2.5058 0.8000 d(29) 5.9266 4.5611 7.7281 d(30) 5.5909 6.9563 3.7894 d(37) 13.5001 20.0168 28.6047

[0203] Table 19 shows the focal length of each lens group of the zoom lens of Example 4.

[0204] [Table 19] Group number Focal length G1 116.0210 G2 -22.2393 G3 77.8801 G4 22.1736 G5 -36.9394 G6 275.7600

[0205] Table 20 shows the aspherical coefficients of the aspherical surface in the zoom lens of Example 4.

[0206] [Table 20] Surface number k A4 A6 6 0.0000 2.50501E-06 5.94770E-09 9 0.0000 -7.41327E-07 1.16639E-08 10 0.0000 -1.39080E-05 2.05285E-08 28 5.3869 -3.54718E-05 -1.17535E-07 29 0.0000 -3.60481E-06 -9.22916E-08 36 -2.6692 -4.51555E-05 1.34822E-07 37 0.0000 -2.78980E-05 1.36510E-07 Face number A8 A10 A12 6 -3.74581E-11 1.29604E-13 0.00000E+00 9 2.11265E-10 -2.75877E-12 7.76677E-15 10 4.20522E-12 -1.53609E-12 5.27214E-15 28 -1.45989E-10 -1.16193E-12 0.00000E+00 29 -3.70956E-11 -9.84939E-13 0.00000E+00 36 -4.33964E-10 2.47746E-13 0.00000E+00 37 -4.64722E-10 5.30207E-13 0.00000E+00

[0207] Fig. 14 shows longitudinal aberration diagrams of the zoom lens of Example 4 at the wide-angle end when focusing at infinity. Fig. 15 shows longitudinal aberration diagrams of the zoom lens of Example 4 at the intermediate focus when focusing at infinity. Fig. 16 shows longitudinal aberration diagrams of the zoom lens of Example 4 at the telephoto end when focusing at infinity.

[0208] [Example 5] (1) Optical system configuration 17 is a diagram schematically illustrating the optical configuration of the zoom lens of Example 5 when focusing on infinity at the wide-angle end. The zoom lens of Example 5 is composed of, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, a fourth lens group G4 having positive refractive power, a fifth lens group G5 having negative refractive power, a sixth lens group G6 having negative refractive power, and a seventh lens group G7 having positive refractive power.

[0209] The first lens group G1 is composed of, in order from the object side, a cemented lens of a meniscus lens L1 having a convex surface facing the object side and negative refractive power and a meniscus lens L2 having a convex surface facing the object side and positive refractive power, and a meniscus lens L3 having a convex surface facing the object side and positive refractive power.

[0210] The second lens group G2 is composed of, in order from the object side, a meniscus lens L4 having negative refractive power and a convex surface facing the object side, a cemented lens of a biconcave lens L5 and a biconvex lens L6, and a meniscus lens L7 having negative refractive power and a concave surface facing the object side. The meniscus lens L4 having negative refractive power is a glass-molded aspherical lens with aspherical surfaces on both sides.

[0211] The third lens group G3 is composed of, in order from the object side, a biconvex lens L8, a cemented lens made up of a meniscus lens L9 with a convex surface facing the object side and having negative refractive power and a meniscus lens L10 with a convex surface facing the object side and having positive refractive power, and a meniscus lens L11 with a concave surface facing the object side and having negative refractive power. The meniscus lens L11 with negative refractive power is a composite resin aspherical lens with a composite resin film molded into an aspherical shape attached to its object-side surface.

[0212] The fourth lens group G4 is composed of, in order from the object side, a biconvex lens L12, a cemented lens made up of a meniscus lens L13 with negative refractive power and a biconvex lens L14, with its convex surface facing the object side, and a biconvex lens L14. The biconvex lens L12 is a glass-molded aspherical lens with aspherical surfaces on both sides.

[0213] The fifth lens group G5 is composed of a meniscus lens L15 having a negative refractive power and a convex surface facing the object side.

[0214] The sixth lens group G6 is composed of a biconvex lens L16, a biconcave lens L17, and a meniscus lens L18 with negative refractive power and a concave surface facing the object side. The meniscus lens L18 with negative refractive power is a glass-molded aspherical lens with aspherical surfaces on both sides.

[0215] The seventh lens group G7 is composed of a meniscus lens L19 having a positive refractive power and a concave surface facing the object side.

[0216] The aperture stop S is disposed adjacent to the object side of the third lens group G3.

[0217] The first lens group G1 corresponds to the aforementioned lens group P1. The second lens group G2 corresponds to the aforementioned middle group M. The third lens group G3 corresponds to the aforementioned lens group P2. The fourth lens group G4 corresponds to the aforementioned lens group P3. The fifth lens group G5 corresponds to the aforementioned lens group N. The sixth lens group G6 and the seventh lens group G7 correspond to the aforementioned rear group R. The meniscus lens L11 having negative refractive power corresponds to the aforementioned lens component A.

[0218] The arrows in Figure 17 indicate the direction and manner of movement of each lens group in the zoom lens of Example 5 when changing magnification from the wide-angle end to the telephoto end. When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object side, the second lens group G2 moves toward the object side and then moves toward the image plane side, the third lens group G3 moves toward the object side, the fourth lens group G4 moves toward the object side, the fifth lens group G5 moves toward the object side, and the sixth lens group G6 moves toward the object side. The seventh lens group G7 is fixed.

[0219] (2) Numerical examples Table 21 shows data for each surface included in the zoom lens of Example 5.

[0220] [Table 21] Face number rd nd νd Object plane∞ d(0) 1 110.7216 1.2000 1.85451 25.15 2 72.5779 6.6342 1.49700 81.61 3 5904.4734 0.2000 4 70.3930 5.3298 1.59282 68.62 5 299.6427 d(5) 6ASPH 367.3039 1.1000 1.85108 40.12 7ASPH 25.7259 5.9188 8 -45.4958 0.8000 1.87070 40.73 9 29.4021 6.5753 1.84666 23.78 10 -36.1481 1.2911 11 -24.3260 0.9000 1.80420 46.50 12 -51.0707 d(12) 13S ∞ 1.2000 14 34.5559 3.6217 1.73037 32.23 15 -133.5237 0.2000 16 45.0896 0.9000 1.84666 23.78 17 22.8972 3.3750 1.49700 81.61 18 112.3422 3.4962 19ASPH -22.2277 0.1791 1.53610 41.21 20 -23.5450 0.8000 1.83400 37.34 21 -226.1977 d(21) 22ASPH 28.7372 5.5000 1.69350 53.18 23ASPH -42.1245 0.2000 24 44.2837 0.8000 1.91082 35.25 25 18.9412 7.3628 1.49700 81.61 26 -27.3898 d(26) 27 93.7741 0.9000 1.59349 67.00 28 21.6209 d(28) 29 59.0955 5.7479 1.67270 32.17 30 -27.9562 0.2000 31 -54.7327 0.9000 1.72916 54.67 32 55.6187 6.0527 33ASPH -17.7852 1.0000 1.85108 40.12 34ASPH -46.7904 d(34) 35 -54.1638 3.3102 1.72916 54.67 36 -37.3895 13.5000 37 ∞ 2.5000 1.51680 64.20 38∞1.0000 Image plane ∞

[0221] Table 22 shows the specifications of the zoom lens of Example 5.

[0222] [Table 22] Wide-angle end Mid-range Telephoto end f 28.8064 74.9872 193.9857 F No. 2.9014 4.4993 5.7496 ω 37.1023 15.3532 6.1514 Y 21.6330 21.6330 21.6330

[0223] Table 23 shows the distances of each variable interval of the zoom lens of Example 5.

[0224] [Table 23] Wide-angle end Mid-range Telephoto end d(0) ∞ ∞ ∞ d(5) 1.5773 27.7653 55.0572 d(12) 24.4779 11.7651 1.4488 d(21) 4.2685 2.5440 1.1000 d(26) 1.2967 2.1596 1.9736 d(28) 11.8850 11.0222 11.2082 d(34) 0.8000 18.2640 28.5176 Wide-angle end Mid-range Telephoto end d(0) 53.0000 333.7851 608.0000 d(5) 1.5773 27.7653 55.0572 d(12) 24.4779 11.7651 1.4488 d(21) 4.2685 2.5440 1.1000 d(26) 4.4116 4.3239 7.6790 d(28) 8.7701 8.8579 5.5028 d(34) 0.8000 18.2640 28.5176

[0225] Table 24 shows the focal length of each lens group of the zoom lens of Example 5.

[0226] [Table 24] Group number Focal length G1 109.4860 G2 -21.8790 G3 1306.1700 G4 19.4722 G5 -47.5671 G6 -60.5808 G7 152.8530

[0227] Table 25 shows the aspherical coefficients of the aspherical surface in the zoom lens of Example 5.

[0228] [Table 25] Surface number k A4 A6 6 0.0000 9.00415E-06 1.85580E-08 7 0.0000 5.04380E-06 3.14390E-09 19 0.6312 2.52959E-05 -3.11325E-09 22 0.8967 -1.75956E-05 5.94776E-08 23 0.0000 3.07843E-05 -5.62021E-09 33 0.0000 5.23372E-06 -5.24911E-08 34 0.0000 9.36697E-06 -6.75384E-08 Face number A8 A10 A12 6 -1.23003E-10 3.25071E-13 0.00000E+00 7 4.60209E-10 -4.09687E-12 1.29672E-14 19 2.16182E-10 2.79801E-12 -1.75798E-14 22 3.07654E-10 -4.13089E-12 1.57682E-14 23 8.06530E-10 -6.27345E-12 2.02272E-14 33 -3.31991E-10 3.41038E-12 0.00000E+00 34 2.11397E-10 3.02298E-13 0.00000E+00

[0229] Fig. 18 shows longitudinal aberration diagrams of the zoom lens of Example 5 at the wide-angle end when focusing at infinity. Fig. 19 shows longitudinal aberration diagrams of the zoom lens of Example 5 at the intermediate focus when focusing at infinity. Fig. 20 shows longitudinal aberration diagrams of the zoom lens of Example 5 at the telephoto end when focusing at infinity.

[0230] [Example 6] (1) Optical system configuration 21 is a diagram schematically illustrating the optical configuration of the zoom lens of Example 6 when focusing on infinity at the wide-angle end. The zoom lens of Example 6 is composed of, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having negative refractive power, a fourth lens group G4 having positive refractive power, a fifth lens group G5 having positive refractive power, a sixth lens group G6 having negative refractive power, and a seventh lens group G7 having positive refractive power.

[0231] The first lens group G1 corresponds to the aforementioned lens group P1. The second lens group G2 and the third lens group G3 correspond to the aforementioned middle group M. The fourth lens group G4 corresponds to the aforementioned lens group P2. The fifth lens group G5 corresponds to the aforementioned lens group P3. The sixth lens group G6 corresponds to the aforementioned lens group N. The seventh lens group G7 corresponds to the aforementioned rear group R. The meniscus lens L11 having negative refractive power corresponds to the aforementioned lens component A.

[0232] The first lens group G1 is composed of, in order from the object side, a cemented lens of a meniscus lens L1 having negative refractive power with its convex surface facing the object side and a biconvex lens L2, and a meniscus lens L3 having positive refractive power with its convex surface facing the object side.

[0233] The second lens group G2 is composed of, in order from the object side, a meniscus lens L4 with negative refractive power and a convex surface facing the object side, a biconcave lens L5, and a biconvex lens L6. The meniscus lens L4 with negative refractive power is a composite resin aspherical lens with a composite resin film molded into an aspherical shape attached to the object side surface.

[0234] The third lens group G3 is composed of a meniscus lens L7 having a negative refractive power and a concave surface facing the object side.

[0235] The fourth lens group G4 is composed of, in order from the object side, a meniscus lens L8 having a convex surface facing the object side and positive refractive power, a cemented lens of a meniscus lens L9 having a convex surface facing the object side and a biconvex lens L10, and a meniscus lens L11 having a negative refractive power and a concave surface facing the object side.

[0236] The fifth lens group G5 is composed of, in order from the object side, a cemented lens made up of a meniscus lens L12 with negative refractive power and a biconvex lens L13, whose convex surface faces the object side, and a biconvex lens L14, which is a glass-molded aspherical lens with aspherical surfaces on both sides.

[0237] The sixth lens group G6 is composed of a meniscus lens L15 having a negative refractive power and a convex surface facing the object side.

[0238] The seventh lens group G7 is composed of a biconvex lens L16, a biconcave lens L17, and a meniscus lens L18 with negative refractive power and a concave surface facing the object side. The negative meniscus lens L18 is a glass-molded aspherical lens with aspherical surfaces on both sides.

[0239] The aperture stop S is disposed adjacent to the object side of the fourth lens group G4.

[0240] The first lens group G1 corresponds to the aforementioned lens group P1. The second lens group G2 and the third lens group G3 correspond to the aforementioned middle group M. The fourth lens group G4 corresponds to the aforementioned lens group P2. The fifth lens group G5 corresponds to the aforementioned lens group P3. The sixth lens group G6 corresponds to the aforementioned lens group N. The seventh lens group G7 corresponds to the aforementioned rear group R. The meniscus lens L11 having negative refractive power corresponds to the aforementioned lens component A.

[0241] 21 indicate the direction and manner of movement of each lens group in the zoom lens of Example 6 when zooming from the wide-angle end to the telephoto end. When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object side, the second lens group G2 moves toward the image plane side, the third lens group G3 moves toward the image plane side, the fourth lens group G4 moves toward the object side, the fifth lens group G5 moves toward the object side, the sixth lens group G6 moves toward the object side, and the seventh lens group G7 moves toward the object side.

[0242] (2) Numerical examples Table 26 shows data for each surface included in the zoom lens of Example 6.

[0243] [Table 26] Surface number rd nd νd Object plane ∞ d(0) 1 370.1554 1.2000 1.92286 20.88 2 150.3426 5.1496 1.49700 81.61 3 -476.6968 0.1500 4 63.0526 5.6352 1.71300 53.94 5 191.9941 d(5) 6ASPH 97.5623 0.1500 1.53610 41.21 7 90.6798 1.0000 1.83481 42.72 8 18.7797 8.8963 9ASPH -33.5783 1.2000 1.59201 67.02 10ASPH 53.5806 0.9349 11 63.8828 4.7956 1.85883 30.00 12 -46.1671 d(12) 13 -23.4540 0.8000 1.49700 81.61 14 -63.2605 d(14) 15S∞1.0000 16 34.2676 4.1404 1.84666 23.78 17 269.5000 3.0015 18 33.4285 0.9000 2.00100 29.13 19 19.4500 6.5640 1.49700 81.61 20 -152.5289 2.0904 21 -36.3956 0.9000 2.00069 25.46 22 -252.3384 d(22) 23 24.7246 1.0000 1.90043 37.37 24 15.6693 10.5231 1.59282 68.62 25 -46.9021 0.1500 26ASPH 38.5015 3.7059 1.59201 67.02 27ASPH -155.3688 d(27) 28 208.9647 0.8000 1.83481 42.72 29 26.1008 d(29) 30 87.5342 6.6262 1.90110 27.06 31 -31.8039 0.1500 32 -56.6524 0.9000 1.85451 25.15 33 190.9861 5.6309 34ASPH -25.1037 1.3000 1.69350 53.18 35ASPH -77.1513 d(35) 36 ∞ 2.5000 1.51680 64.20 37∞1.0000 Image plane ∞

[0244] Table 27 shows the specifications of the zoom lens of Example 6.

[0245] [Table 27] Wide-angle end Mid-range Telephoto end f 24.7171 35.0035 67.9017 F No. 2.9084 2.9087 2.9112 ω 43.1699 31.8220 16.8756 Y 21.6330 21.6330 21.6330

[0246] Table 28 shows the distances of each variable interval of the zoom lens of Example 6.

[0247] [Table 28] Wide-angle end Mid-range Telephoto end d(0) ∞ ∞ ∞ d(5) 1.0000 6.7190 31.6762 d(12) 3.7810 3.6747 2.2945 d(14) 18.0647 10.3046 1.1734 d(22) 4.1524 2.3014 0.8000 d(27) 2.2946 2.4729 3.8855 d(29) 9.4133 9.2348 7.8225 d(35) 13.5000 21.1010 29.5541 Wide-angle end Mid-range Telephoto end d(0) 45.0000 141.3976 219.9999 d(5) 1.0000 6.7190 31.6762 d(12) 3.7810 3.6747 2.2945 d(14) 18.0647 10.3046 1.1734 d(22) 4.1524 2.3014 0.8000 d(27) 5.4558 4.4611 7.3945 d(29) 6.2522 7.2466 4.3135 d(35) 13.5000 21.1010 29.5541

[0248] Table 29 shows the focal length of each lens group in the zoom lens of Example 6.

[0249] [Table 29] Group number Focal length G1 118.4220 G2 -39.5535 G3 -75.5002 G4 82.4445 G5 22.5617 G6 -35.7995 G7 305.1600

[0250] Table 30 shows the aspherical coefficients of the aspherical surface in the zoom lens of Example 6.

[0251] [Table 30] Surface number k A4 A6 6 0.0000 -4.85277E-07 7.14721E-09 9 0.0000 8.13071E-06 -1.13425E-07 10 0.0000 -4.17869E-06 -1.10048E-07 26 4.6042 -2.82667E-05 -8.55996E-08 27 0.0000 -9.01447E-07 -6.76185E-08 34 0.8868 -2.43431E-05 1.44228E-07 35 0.0000 -2.32474E-05 1.29644E-07 Face number A8 A10 A12 6 -2.58125E-11 5.78287E-14 0.00000E+00 9 9.65317E-10 -4.37798E-12 7.39167E-15 10 9.69284E-10 -4.66443E-12 8.56193E-15 26 -6.43844E-11 -1.04820E-12 0.00000E+00 27 -1.57302E-12 -1.06441E-12 0.00000E+00 34 -3.61210E-10 1.57287E-13 0.00000E+00 35 -4.26328E-10 4.26440E-13 0.00000E+00

[0252] Fig. 22 shows longitudinal aberration diagrams of the zoom lens of Example 6 at the wide-angle end when focusing at infinity. Fig. 23 shows longitudinal aberration diagrams of the zoom lens of Example 6 at the intermediate focus when focusing at infinity. Fig. 24 shows longitudinal aberration diagrams of the zoom lens of Example 6 at the telephoto end when focusing at infinity.

[0253] The values ​​calculated by the above formulas in Examples 1 to 6 are shown in Table 31.

[0254] [Table 31] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Equation (1) -1.749 -1.760 -1.705 -2.224 -0.859 -2.214 Equation (2) 0.737 0.746 0.746 0.746 0.746 0.746 Equation (3) -0.521 -1.422 -0.727 -1.620 -1.218 -1.337 Equation (4) -0.197 -0.527 -0.210 -0.585 -0.023 -0.517 Equation (5) 0.131 0.254 0.204 0.285 0.015 0.274 Equation (6) 0.867 0.898 0.880 0.861 0.676 0.913 Equation (7) 20.880 23.780 28.320 23.780 32.230 23.780 Equation (8) 4.074 4.610 4.598 4.505 3.801 4.791 Equation (9) 1.165 1.383 1.487 1.369 1.365 1.316 Equation (10) 1.144 1.532 1.536 1.923 0.806 1.938 Equation (11) 7.634 6.987 6.340 6.086 6.294 6.201

[0255] Table 32 shows the values ​​used in the above formulas in Examples 1 to 6.

[0256] [Table 32] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 fp12w -50.437 -45.243 -43.915 -57.274 -24.745 -54.721 bfw 15.948 16.148 16.148 16.148 16.148 16.148 Rf -45.620 -35.689 -24.153 -31.192 -22.228 -36.396 Rb 144.784 -204.750 153.086 -131.873 -226.198 -252.338 fA -37.495 -47.966 -23.256 -45.532 -30.257 -42.589 fp1 117.471 118.493 118.428 116.021 109.486 118.422 fp2 190.165 90.992 110.976 77.880 1306.170 82.445 fp3 24.995 23.085 22.674 22.174 19.472 22.562 Tw 165.148 151.148 137.148 131.648 136.148 134.148 [Explanation of symbols]

[0257] 1. Mirrorless single-lens camera (imaging device) 2 Main unit 3 Telescope tube

Claims

1. The lens comprises, arranged in order from the object side to the image plane side, a lens group P1 having positive refractive power, a middle group including one or more lens groups and having negative refractive power as a whole, a lens group P2 having positive refractive power, a lens group P3 having positive refractive power, a lens group N having negative refractive power, and a rear group including one or more lens groups, a lens component A having negative refractive power located closest to the image side of the lens group P2, the lens component A having a shape in which the object side surface is concave toward the object side, and the following formula is satisfied: -5.0<fp12w / fw<-0.3...(1) however, fp12w: composite focal length from the lens group P1 to the lens group P2 at the wide-angle end when the zoom lens is focused at infinity fw: focal length at the wide-angle end of the zoom lens when focused at infinity

2. 2. The zoom lens of claim 1, wherein the following formula is satisfied: 0.5<bfw / Yw<1.5...(2) however, bfw: back focus at the wide-angle end of the zoom lens when focused at infinity Yw: maximum image height at the wide-angle end of the zoom lens when focused at infinity

3. 2. The zoom lens of claim 1, wherein the following formula is satisfied: -5.0<(Rf+Rb) / (Rf-Rb)<-0.1...(3) however, Rf: radius of curvature of the object-side lens surface of the lens component A Rb: radius of curvature of the image-side lens surface in the lens component A

4. 2. The zoom lens of claim 1, wherein the following formula is satisfied: -1.3<fA / fp2<-0.001...(4) however, fA: focal length of the lens component A fp2: focal length of the lens group P2

5. 2. The zoom lens of claim 1, wherein the following formula is satisfied: 0.001<fp3 / fp2<0.45...(5) however, fp3: focal length of the lens group P3

6. 2. The zoom lens of claim 1, wherein the following formula is satisfied: however, 0.4<fp3 / fw<1.3...(6)

7. 2. The zoom lens of claim 1, wherein the following formula is satisfied: 15<vd<40...(7) however, vd: Abbe number for the d-line of the lens having positive refractive power that is closest to the object in the lens group P2

8. 2. The zoom lens of claim 1, wherein the following formula is satisfied: 2.5<fp1 / fw<10.0...(8) however, fp1: focal length of the lens group P1

9. 2. The zoom lens of claim 1, wherein the following formula is satisfied: 0.7<FNOp1_3<1.9...(9) however, FNOp1_3: The minimum open F-number in the zoom range from the lens group P1 to the lens group P3

10. 2. The zoom lens of claim 1, wherein the following formula is satisfied: 0.3<βp2w<5.0...(10) however, βp2w: lateral magnification of the lens group P2 at the wide-angle end when focused on infinity

11. 2. The zoom lens of claim 1, wherein the following formula is satisfied: 4.0<Tw / Yw<8.5...(11) however, Tw: total optical length of the zoom lens at the wide-angle end when focused at infinity

12. 2. The zoom lens according to claim 1, wherein the lens group P2 has a cemented lens whose cemented surface faces the object side.

13. 2. The zoom lens according to claim 1, wherein the lens group P2 comprises at least two lenses having positive refractive power and at least two lenses having negative refractive power.

14. 2. The zoom lens according to claim 1, wherein said lens group N moves on the optical axis during focusing.

15. 15. An imaging apparatus comprising: the zoom lens according to claim 1; and an image sensor on an image plane side of the zoom lens that converts an optical image formed by the zoom lens into an electrical signal.

Images