Image pickup optical system, and image pickup apparatus and camera system including the same

Abstract

To provide a zoom lens capable of obtaining excellent optical performance over the entire zoom range, and to provide an imaging apparatus and an interchangeable lens apparatus using the zoom lens.SOLUTION: The imaging optical system includes, in order from an object side to an image side, a first lens group having positive optical power, a second lens group having negative optical power, an aperture stop, a third lens group having positive optical power, a fourth lens group having positive optical power, a fifth lens group having negative optical power, and a rear group including at least one lens group having optical power. During zooming from the wide angle end to the telephoto end, an interval between adjacent lens units changes. The fifth lens unit includes in order from the object side to the image side, a negative meniscus lens having a convex surface directed toward the object side, and a negative meniscus lens having a convex surface directed toward the image side. During focusing from a close-object in-focus condition to an infinity in-focus condition, the fifth lens unit moves from the object side to the image side.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] The present disclosure relates to an imaging optical system in which various aberrations are well corrected across the entire zoom range, and an imaging device and an interchangeable lens device that include the same. [Background technology]

[0002] Patent Document 1 discloses a zoom lens system including, in order from the object side to the image side, a first lens group having positive power, a second lens group having negative power, a third lens group having positive power, a fourth lens group having negative power, a fifth lens group having positive power, and a sixth lens group having negative power. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-118738 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to provide an imaging optical system in which various aberrations are well corrected across the entire zoom range, and an imaging device and camera system including the same. [Means for solving the problem]

[0005] The imaging optical system disclosed herein comprises, in order from the object side to the image side, a first lens group having positive power, a second lens group having negative power, an aperture stop, a third lens group having positive power, a fourth lens group having positive power, a fifth lens group having negative power, and a rear group including one or more lens groups having power. The spacing between adjacent lens groups changes during zooming from the wide-angle end to the telephoto end. The fifth lens group comprises, in order from the object side to the image side, a negative meniscus lens with a convex surface facing the object side and a negative meniscus lens with a convex surface facing the image side. During focusing from a close-up object focus state to an infinity focus state, the fifth lens group moves from the object side to the image side.

[0006] The camera system of the present disclosure also includes an interchangeable lens device including the aforementioned imaging optical system, and a camera body including an image sensor that is detachably connected to the interchangeable lens device via a camera mount and that receives an optical image formed by the imaging optical system and converts it into an electrical image signal.

[0007] The interchangeable lens device then forms the optical image of the object on the imaging element.

[0008] The imaging device according to the present disclosure converts an optical image of an object into an electrical image signal, and at least one of displays and stores the converted image signal. The imaging device includes the imaging optical system that forms the optical image of the object, and an imaging element that converts the optical image formed by the imaging optical system into an electrical image signal. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide an imaging optical system in which various aberrations are well corrected across the entire zoom range, and an imaging device and an interchangeable lens device that include the imaging optical system. [Brief explanation of the drawings]

[0010] [Figure 1A] FIG. 1 is a lens arrangement diagram showing an infinity focused state of an imaging optical system according to a first embodiment (numerical example 1); [Figure 1B] 1 is a longitudinal aberration diagram of the imaging optical system according to Numerical Example 1 in a state where the imaging optical system is focused at infinity. [Figure 2A] FIG. 10 is a lens arrangement diagram showing an infinity focused state of an imaging optical system according to a second embodiment (Numerical Example 2). [Figure 2B] 10A and 10B are longitudinal aberration diagrams of the imaging optical system according to Numerical Example 2 in a state of focusing at infinity. [Figure 3A] FIG. 10 is a lens arrangement diagram showing an infinity focused state of an imaging optical system according to a third embodiment (Numerical Example 3). [Figure 3B] FIG. 10 is a longitudinal aberration diagram of the imaging optical system according to Numerical Example 3 in a state of focusing at infinity. [Figure 4A] FIG. 10 is a lens arrangement diagram showing an infinity focused state of an imaging optical system according to a fourth embodiment (numerical example 4); [Figure 4B] FIG. 10 is a longitudinal aberration diagram of the imaging optical system according to Numerical Example 4 in a state where the imaging optical system is focused at infinity. [Figure 5A] FIG. 10 is a lens arrangement diagram showing an infinity focused state of an imaging optical system according to a fifth embodiment (numerical example 5). [Figure 5B] FIG. 10 is a longitudinal aberration diagram of the imaging optical system according to Numerical Example 5 in a state of focusing at infinity. [Figure 6] 1 is a schematic diagram of an imaging device according to a first embodiment; [Figure 7] 1 is a schematic diagram of a camera system according to a first embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, more detailed explanation than necessary may be omitted. For example, detailed explanation of well-known matters or redundant explanation of substantially the same configuration may be omitted. This is to avoid unnecessary redundancy in the following explanation and to facilitate understanding by those skilled in the art.

[0012] The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0013] (Embodiments 1 to 5) The imaging optical systems according to the first to fifth embodiments will be individually described below with reference to the drawings.

[0014] 1A, 2A, 3A, 4A, and 5A are lens layout diagrams of imaging optical systems according to first to fifth embodiments, respectively, and all show imaging optical systems in an infinity focused state.

[0015] (a) of Figures 1A, 2A, 3A, 4A, and 5A shows the lens arrangement at the wide-angle end (shortest focal length state: focal length fW). (d) of each figure shows the lens arrangement at the intermediate position (intermediate focal length state: focal length fM = √(fW * fT)). (e) of each figure shows the lens arrangement at the telephoto end (longest focal length state: focal length fT). Note that the aspect ratio is the same in (a), (d), and (e) of each figure.

[0016] An asterisk * attached to the surface of a particular lens element shown in (a) of each figure indicates that the surface is aspherical.

[0017] The broken arrows in (c) of each figure show, from top to bottom, the positions of the lens groups in each state: wide-angle end (WIDE), middle position (MID), and telephoto end (TELE). Note that the arrows simply connect the wide-angle end and middle position, and the middle position and telephoto end, and do not show the actual movement of each lens group.

[0018] In (b) of each figure, the lens groups are labeled G1 to G3 in accordance with the positions of the lens groups shown in (a).

[0019] The symbols (+) and (-) attached to the reference numerals of each lens group (G1 to G3) shown in (b) of each figure correspond to the power of each lens group. That is, the symbol (+) indicates positive power, and the symbol (-) indicates negative power.

[0020] The arrows attached to the lens groups shown in (b) of each figure represent focusing from an infinity-focused state to a close-focused state. In Figures 1A, 2A, 3A, 4A, and 5A, the reference numerals of each lens group are written below the positions of the lens groups in (a), and therefore, for convenience, arrows representing focusing are attached below the reference numerals of each lens group. However, the direction in which each lens group moves during focusing in each zoom state will be specifically explained later for each embodiment.

[0021] In each of the figures (a), (d), and (e), the line drawn on the far right indicates the position of the image plane S (the object-side surface of the image sensor). Therefore, the left side of the figure corresponds to the object side. Furthermore, a parallel plate such as a low-pass filter or cover glass CG is disposed between the image plane S and the final lens group facing the image plane S.

[0022] (Embodiment 1) FIG. 1A shows an imaging optical system according to the first embodiment.

[0023] The imaging optical system is composed of, in order from the object side to the image side, a first lens group G1 having positive power, a second lens group G2 having negative power, an aperture stop A, a third lens group G3 having positive power, a fourth lens group G4 having positive power, a fifth lens group G5 having negative power, and a sixth lens group G6 having positive power. The sixth lens group G6 is an example of the rear group GR.

[0024] The imaging optical system forms an image at the position of an image plane S.

[0025] The first lens group G1 is composed of, in order from the object side to the image side, a first lens element L1 having negative power and a second lens element L2 having positive power. The first lens element L1 and the second lens element L2 are a cemented lens bonded together with an adhesive or the like.

[0026] The second lens group G2 is composed of, in order from the object side to the image side, a third lens element L3 having negative power, a fourth lens element L4 having negative power, a fifth lens element L5 having positive power, and a sixth lens element L6 having negative power. The fourth lens element L4 and the fifth lens element L5 are a cemented lens bonded together with an adhesive or the like.

[0027] The third lens group G3 is composed of a seventh lens element L7 having positive power, an eighth lens element L8 having positive power, a ninth lens element L9 having negative power, and a tenth lens element L10 having positive power. The ninth lens element L9 and the tenth lens element L10 are a cemented lens bonded together with an adhesive or the like.

[0028] The fourth lens group G4 is composed of an eleventh lens element L11 having positive power and a twelfth lens element L12 having negative power.

[0029] The fifth lens group G5 is composed of a thirteenth lens element L13 having negative power and a fourteenth lens element L14 having negative power.

[0030] The sixth lens group G6 is composed of a fifteenth lens element L15 having negative power and a sixteenth lens element L16 having positive power.

[0031] Each lens element will now be described.

[0032] The lens elements in the first lens group G1 will be described. The first lens element L1 is a meniscus lens having a convex surface facing the object side. The second lens element L2 is a meniscus lens having a convex surface facing the object side.

[0033] The lens elements in the second lens group G2 will be described. The third lens element L3 is a meniscus lens having a convex surface facing the object side. The fourth lens element L4 is a biconcave lens. The object side surface of the fourth lens element L4 has an aspheric shape. The fifth lens element L5 is a meniscus lens having a convex surface facing the object side. The sixth lens element L6 is a meniscus lens having a convex surface facing the image side.

[0034] The lens elements in the third lens group G3 will be described. The seventh lens element L7 is a meniscus lens having a convex surface facing the object side. The eighth lens element L8 is a biconvex lens. The ninth lens element L9 is a biconcave lens. The tenth lens element L10 is a meniscus lens having a convex surface facing the object side.

[0035] The lens elements in the fourth lens group G4 will be described. The eleventh lens element L11 is a biconvex lens. The twelfth lens element L12 is a meniscus lens with a convex surface facing the object side. Both surfaces of the twelfth lens element L12 are aspherical.

[0036] The lens elements in the fifth lens group G5 will be described. The thirteenth lens element L13 is a meniscus lens having a convex surface facing the object side. Both surfaces of the thirteenth lens element L13 are aspherical. The fourteenth lens element L14 is a meniscus lens having a convex surface facing the image side.

[0037] The lens elements in the sixth lens group G6 will be described. The fifteenth lens element L15 is a meniscus lens having a convex surface facing the image side. The sixteenth lens element L16 is a biconvex lens.

[0038] In the imaging optical system according to Embodiment 1, when zooming from the wide-angle end to the telephoto end during imaging, the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, the fifth lens group G5, and the sixth lens group G6 move relative to the image plane S. Then, when zooming from the wide-angle end to the telephoto end during imaging, each lens group moves along the optical axis so that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, the distance between the fourth lens group G4 and the fifth lens group G5 decreases, the distance between the fifth lens group G5 and the sixth lens group G6 increases, and the distance between the sixth lens group G6 and the image plane S increases.

[0039] In the imaging optical system according to the first embodiment, the fifth lens group G5 moves toward the image side along the optical axis during focusing from an infinite object point focused state to a close object focused state.

[0040] (Embodiment 2) FIG. 2A shows an imaging optical system according to the second embodiment.

[0041] The imaging optical system is composed of, in order from the object side to the image side, a first lens group G1 having positive power, a second lens group G2 having negative power, an aperture stop A, a third lens group G3 having positive power, a fourth lens group G4 having positive power, a fifth lens group G5 having negative power, and a sixth lens group G6 having positive power. The sixth lens group G6 is an example of the rear group GR.

[0042] The imaging optical system forms an image at the position of an image plane S.

[0043] The first lens group G1 is composed of, in order from the object side to the image side, a first lens element L1 having negative power and a second lens element L2 having positive power. The first lens element L1 and the second lens element L2 are a cemented lens bonded together with an adhesive or the like.

[0044] The second lens group G2 is composed of, in order from the object side to the image side, a third lens element L3 having negative power, a fourth lens element L4 having negative power, a fifth lens element L5 having positive power, and a sixth lens element L6 having negative power. The fourth lens element L4 and the fifth lens element L5 are a cemented lens bonded together with an adhesive or the like.

[0045] The third lens group G3 is composed of a seventh lens element L7 having positive power, an eighth lens element L8 having positive power, a ninth lens element L9 having negative power, and a tenth lens element L10 having positive power. The ninth lens element L9 and the tenth lens element L10 are a cemented lens bonded together with an adhesive or the like.

[0046] The fourth lens group G4 is composed of an eleventh lens element L11 having positive power and a twelfth lens element L12 having negative power.

[0047] The fifth lens group G5 is composed of a thirteenth lens element L13 having negative power and a fourteenth lens element L14 having negative power.

[0048] The sixth lens group G6 is composed of a fifteenth lens element L15 having negative power and a sixteenth lens element L16 having positive power. The fifteenth lens element L15 and the sixteenth lens element L16 are cemented together with an adhesive or the like.

[0049] Each lens element will now be described.

[0050] The lens elements in the first lens group G1 will be described. The first lens element L1 is a meniscus lens having a convex surface facing the object side. The second lens element L2 is a meniscus lens having a convex surface facing the object side.

[0051] The lens elements in the second lens group G2 will be described. The third lens element L3 is a meniscus lens having a convex surface facing the object side. The fourth lens element L4 is a biconcave lens. The object side surface of the fourth lens element L4 has an aspheric shape. The fifth lens element L5 is a meniscus lens having a convex surface facing the object side. The sixth lens element L6 is a meniscus lens having a convex surface facing the image side.

[0052] The lens elements in the third lens group G3 will be described. The seventh lens element L7 is a meniscus lens having a convex surface facing the object side. The eighth lens element L8 is a biconvex lens. The ninth lens element L9 is a biconcave lens. The tenth lens element L10 is a meniscus lens having a convex surface facing the object side.

[0053] The lens elements in the fourth lens group G4 will be described. The eleventh lens element L11 is a biconvex lens. The twelfth lens element L12 is a meniscus lens with a convex surface facing the object side. Both surfaces of the twelfth lens element L12 are aspherical.

[0054] The lens elements in the fifth lens group G5 will be described. The thirteenth lens element L13 is a meniscus lens having a convex surface facing the object side. Both surfaces of the thirteenth lens element L13 are aspherical. The fourteenth lens element L14 is a meniscus lens having a convex surface facing the image side.

[0055] The lens elements in the sixth lens group G6 will be described. The fifteenth lens element L15 is a biconcave lens. The sixteenth lens element L16 is a biconvex lens.

[0056] In the imaging optical system according to Embodiment 1, during zooming from the wide-angle end to the telephoto end during imaging, the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, the fifth lens group G5, and the sixth lens group G6 move relative to the image plane S. Then, during zooming from the wide-angle end to the telephoto end during imaging, each lens group moves along the optical axis such that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, the distance between the fourth lens group G4 and the fifth lens group G5 decreases from the wide-angle end to the intermediate position and increases from the intermediate position to the telephoto end, the distance between the fifth lens group G5 and the sixth lens group G6 increases, and the distance between the sixth lens group G6 and the image plane S increases.

[0057] In the imaging optical system according to the second embodiment, the fifth lens group G5 moves toward the image side along the optical axis during focusing from an infinite object point focused state to a close object focused state.

[0058] (Embodiment 3) FIG. 3A shows an imaging optical system according to the third embodiment.

[0059] The imaging optical system is composed of, in order from the object side to the image side, a first lens group G1 having positive power, a second lens group G2 having negative power, an aperture stop A, a third lens group G3 having positive power, a fourth lens group G4 having positive power, a fifth lens group G5 having negative power, and a sixth lens group G6 having positive power. The sixth lens group G6 is an example of the rear group GR.

[0060] The imaging optical system forms an image at the position of an image plane S.

[0061] The first lens group G1 is composed of, in order from the object side to the image side, a first lens element L1 having negative power and a second lens element L2 having positive power. The first lens element L1 and the second lens element L2 are a cemented lens bonded together with an adhesive or the like.

[0062] The second lens group G2 is composed of, in order from the object side to the image side, a third lens element L3 having negative power, a fourth lens element L4 having negative power, a fifth lens element L5 having positive power, and a sixth lens element L6 having negative power. The fourth lens element L4 and the fifth lens element L5 are a cemented lens bonded together with an adhesive or the like.

[0063] The third lens group G3 is composed of a seventh lens element L7 having positive power, an eighth lens element L8 having positive power, a ninth lens element L9 having negative power, and a tenth lens element L10 having positive power. The ninth lens element L9 and the tenth lens element L10 are a cemented lens bonded together with an adhesive or the like.

[0064] The fourth lens group G4 is composed of an eleventh lens element L11 having positive power and a twelfth lens element L12 having negative power.

[0065] The fifth lens group G5 is composed of a thirteenth lens element L13 having negative power and a fourteenth lens element L14 having negative power.

[0066] The sixth lens group G6 is composed of a fifteenth lens element L15 having negative power and a sixteenth lens element L16 having positive power.

[0067] Each lens element will now be described.

[0068] The lens elements in the first lens group G1 will be described. The first lens element L1 is a meniscus lens having a convex surface facing the object side. The second lens element L2 is a meniscus lens having a convex surface facing the object side.

[0069] The lens elements in the second lens group G2 will be described. The third lens element L3 is a meniscus lens having a convex surface facing the object side. The fourth lens element L4 is a biconcave lens. The object side surface of the fourth lens element L4 has an aspheric shape. The fifth lens element L5 is a meniscus lens having a convex surface facing the object side. The sixth lens element L6 is a meniscus lens having a convex surface facing the image side.

[0070] The lens elements in the third lens group G3 will be described. The seventh lens element L7 is a meniscus lens having a convex surface facing the object side. The eighth lens element L8 is a biconvex lens. The ninth lens element L9 is a biconcave lens. The tenth lens element L10 is a meniscus lens having a convex surface facing the object side.

[0071] The lens elements in the fourth lens group G4 will be described. The eleventh lens element L11 is a meniscus lens having a convex surface facing the object side. Both surfaces of the eleventh lens element L11 are aspherical. The twelfth lens element L12 is a biconvex lens.

[0072] The lens elements in the fifth lens group G5 will be described. The thirteenth lens element L13 is a meniscus lens having a convex surface facing the object side. Both surfaces of the thirteenth lens element L13 are aspherical. The fourteenth lens element L14 is a meniscus lens having a convex surface facing the image side.

[0073] The lens elements in the sixth lens group G6 will be described. The fifteenth lens element L15 is a biconcave lens. The sixteenth lens element L16 is a biconvex lens.

[0074] In the imaging optical system according to Embodiment 1, when zooming from the wide-angle end to the telephoto end during imaging, the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, the fifth lens group G5, and the sixth lens group G6 move relative to the image plane S. Then, when zooming from the wide-angle end to the telephoto end during imaging, each lens group moves along the optical axis so that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, the distance between the fourth lens group G4 and the fifth lens group G5 decreases, the distance between the fifth lens group G5 and the sixth lens group G6 increases, and the distance between the sixth lens group G6 and the image plane S increases.

[0075] In the imaging optical system according to the third embodiment, the fifth lens group G5 moves toward the image side along the optical axis during focusing from an infinite object point focused state to a close object focused state.

[0076] (Fourth embodiment) FIG. 4A shows an imaging optical system according to the fourth embodiment.

[0077] The imaging optical system is composed of, in order from the object side to the image side, a first lens group G1 having positive power, a second lens group G2 having negative power, an aperture stop A, a third lens group G3 having positive power, a fourth lens group G4 having positive power, a fifth lens group G5 having negative power, and a sixth lens group G6 having positive power. The sixth lens group G6 is an example of the rear group GR.

[0078] The imaging optical system forms an image at the position of an image plane S.

[0079] The first lens group G1 is composed of, in order from the object side to the image side, a first lens element L1 having negative power and a second lens element L2 having positive power. The first lens element L1 and the second lens element L2 are a cemented lens bonded together with an adhesive or the like.

[0080] The second lens group G2 is composed of, in order from the object side to the image side, a third lens element L3 having negative power, a fourth lens element L4 having negative power, a fifth lens element L5 having positive power, and a sixth lens element L6 having negative power. The fourth lens element L4 and the fifth lens element L5 are a cemented lens bonded together with an adhesive or the like.

[0081] The third lens group G3 is composed of a seventh lens element L7 having positive power, an eighth lens element L8 having positive power, a ninth lens element L9 having negative power, and a tenth lens element L10 having positive power. The ninth lens element L9 and the tenth lens element L10 are a cemented lens bonded together with an adhesive or the like.

[0082] The fourth lens group G4 is composed of an eleventh lens element L11 having negative power and a twelfth lens element L12 having positive power.

[0083] The fifth lens group G5 is composed of a thirteenth lens element L13 having negative power and a fourteenth lens element L14 having negative power.

[0084] The sixth lens group G6 is composed of a fifteenth lens element L15 having negative power and a sixteenth lens element L16 having positive power. The fifteenth lens element L15 and the sixteenth lens element L16 are cemented together with an adhesive or the like.

[0085] Each lens element will now be described.

[0086] The lens elements in the first lens group G1 will be described. The first lens element L1 is a meniscus lens having a convex surface facing the object side. The second lens element L2 is a meniscus lens having a convex surface facing the object side.

[0087] The lens elements in the second lens group G2 will be described. The third lens element L3 is a meniscus lens having a convex surface facing the object side. The fourth lens element L4 is a biconcave lens. The object side surface of the fourth lens element L4 has an aspheric shape. The fifth lens element L5 is a meniscus lens having a convex surface facing the object side. The sixth lens element L6 is a meniscus lens having a convex surface facing the image side.

[0088] The lens elements in the third lens group G3 will be described. The seventh lens element L7 is a meniscus lens having a convex surface facing the object side. The eighth lens element L8 is a biconvex lens. The ninth lens element L9 is a biconcave lens. The tenth lens element L10 is a meniscus lens having a convex surface facing the object side.

[0089] The lens elements in the fourth lens group G4 will be described. The eleventh lens element L11 is a meniscus lens having a convex surface facing the object side. The twelfth lens element L12 is a biconvex lens.

[0090] The lens elements in the fifth lens group G5 will be described. The thirteenth lens element L13 is a meniscus lens having a convex surface facing the object side. Both surfaces of the thirteenth lens element L13 are aspherical. The fourteenth lens element L14 is a meniscus lens having a convex surface facing the image side.

[0091] The lens elements in the sixth lens group G6 will be described. The fifteenth lens element L15 is a biconcave lens. The sixteenth lens element L16 is a biconvex lens.

[0092] In the imaging optical system according to Embodiment 1, when zooming from the wide-angle end to the telephoto end during imaging, the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, the fifth lens group G5, and the sixth lens group G6 move relative to the image plane S. Then, when zooming from the wide-angle end to the telephoto end during imaging, each lens group moves along the optical axis so that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, the distance between the fourth lens group G4 and the fifth lens group G5 increases, the distance between the fifth lens group G5 and the sixth lens group G6 increases, and the distance between the sixth lens group G6 and the image plane S increases.

[0093] In the imaging optical system according to the fourth embodiment, the fifth lens group G5 moves toward the image side along the optical axis during focusing from an infinite object point focused state to a close object focused state.

[0094] (Embodiment 5) FIG. 5A shows an imaging optical system according to the fifth embodiment.

[0095] The imaging optical system is composed of, in order from the object side to the image side, a first lens group G1 having positive power, a second lens group G2 having negative power, an aperture stop A, a third lens group G3 having positive power, a fourth lens group G4 having positive power, a fifth lens group G5 having negative power, a sixth lens group G6 having negative power, and a seventh lens group G7 having positive power. The sixth lens group G6 and the seventh lens group G7 having positive power are examples of the rear group GR.

[0096] The imaging optical system forms an image at the position of an image plane S.

[0097] The first lens group G1 is composed of, in order from the object side to the image side, a first lens element L1 having negative power and a second lens element L2 having positive power. The first lens element L1 and the second lens element L2 are a cemented lens bonded together with an adhesive or the like.

[0098] The second lens group G2 is composed of, in order from the object side to the image side, a third lens element L3 having negative power, a fourth lens element L4 having negative power, a fifth lens element L5 having positive power, and a sixth lens element L6 having negative power. The fourth lens element L4 and the fifth lens element L5 are a cemented lens bonded together with an adhesive or the like.

[0099] The third lens group G3 is composed of a seventh lens element L7 having positive power, an eighth lens element L8 having positive power, a ninth lens element L9 having negative power, and a tenth lens element L10 having positive power. The ninth lens element L9 and the tenth lens element L10 are a cemented lens bonded together with an adhesive or the like.

[0100] The fourth lens group G4 is composed of an eleventh lens element L11 having positive power and a twelfth lens element L12 having negative power.

[0101] The fifth lens group G5 is composed of a thirteenth lens element L13 having negative power and a fourteenth lens element L14 having negative power.

[0102] The sixth lens group G6 is composed of a fifteenth lens element L15 having negative power.

[0103] The seventh lens group G7 is composed of a sixteenth lens element L16 having positive power.

[0104] Each lens element will now be described.

[0105] The lens elements in the first lens group G1 will be described. The first lens element L1 is a meniscus lens having a convex surface facing the object side. The second lens element L2 is a meniscus lens having a convex surface facing the object side.

[0106] The lens elements in the second lens group G2 will be described. The third lens element L3 is a meniscus lens having a convex surface facing the object side. The fourth lens element L4 is a biconcave lens. The object side surface of the fourth lens element L4 has an aspheric shape. The fifth lens element L5 is a meniscus lens having a convex surface facing the object side. The sixth lens element L6 is a meniscus lens having a convex surface facing the image side.

[0107] The lens elements in the third lens group G3 will be described. The seventh lens element L7 is a meniscus lens having a convex surface facing the object side. The eighth lens element L8 is a biconvex lens. The ninth lens element L9 is a biconcave lens. The tenth lens element L10 is a meniscus lens having a convex surface facing the object side.

[0108] The lens elements in the fourth lens group G4 will be described. The eleventh lens element L11 is a biconvex lens. The twelfth lens element L12 is a meniscus lens with a convex surface facing the object side. Both surfaces of the twelfth lens element L12 are aspherical.

[0109] The lens elements in the fifth lens group G5 will be described. The thirteenth lens element L13 is a meniscus lens having a convex surface facing the object side. Both surfaces of the thirteenth lens element L13 are aspherical. The fourteenth lens element L14 is a meniscus lens having a convex surface facing the image side.

[0110] The lens elements in the sixth lens group G6 will now be described. The fifteenth lens element L15 is a meniscus lens having a convex surface on the image side.

[0111] The lens elements in the seventh lens group G7 will be described. The sixteenth lens element L16 is a biconvex lens.

[0112] In the imaging optical system of embodiment 1, when zooming from the wide-angle end to the telephoto end during imaging, the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, the fifth lens group G5, the sixth lens group G6, and the seventh lens group G7 move relative to the image plane S. When zooming from the wide-angle end to the telephoto end during image capture, each lens group moves along the optical axis so that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, the distance between the fourth lens group G4 and the fifth lens group G5 increases from the wide-angle end to the intermediate position and decreases from the intermediate position to the telephoto end, the distance between the fifth lens group G5 and the sixth lens group G6 decreases from the wide-angle end to the intermediate position and increases from the intermediate position to the telephoto end, the distance between the sixth lens group G6 and the seventh lens group G7 increases, and the distance between the seventh lens group G7 and the image plane S increases.

[0113] In the imaging optical system according to the fifth embodiment, the fifth lens group G5 moves toward the image side along the optical axis during focusing from an infinite object point focused state to a close object focused state.

[0114] (Other embodiments) As described above, the first to fifth embodiments have been described as examples of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to these, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made as appropriate.

[0115] In the imaging optical systems according to the first to fifth embodiments, the aperture diaphragm A moves integrally with the third lens group G3 during zooming. Alternatively, the aperture diaphragm A may be located on the image side of the second lens group G2 and move integrally with the second lens group G2 during zooming. Furthermore, if the lens barrel can be made more complex in order to move the aperture diaphragm A along a path separate from the other lens groups during zooming, the aperture diaphragm A may move along a path separate from the second lens group G2 and the third lens group G3, and the aperture diaphragm A may be located between the second lens group G2 and the third lens group G3. However, by configuring the aperture diaphragm A to move integrally with the second lens group G2 or the third lens group G3, the lens barrel can be made less complex to move the aperture diaphragm A.

[0116] Although the imaging optical systems according to the first to fifth embodiments have been described above as examples in which the entire zoom range from the wide-angle end to the telephoto end is used, it is not necessary to use the entire zoom range. For example, a range in which optical performance is ensured may be selected according to a desired zoom range and used as an imaging optical system. In other words, it may be used as an imaging optical system with a lower magnification than the imaging optical systems described below in Numerical Examples 1 to 5 corresponding to the first to fifth embodiments. Furthermore, a focal length in which optical performance is ensured according to a desired zoom position may be selected and used as a single focal length lens system.

[0117] Furthermore, the number of lens groups and the number of lens elements in each lens group are substantial, and lenses with substantially no power may be added.

[0118] (Conditions and effects, etc.) Below, we will explain conditions that can be satisfied by the imaging optical systems according to, for example, Embodiments 1 to 5. Note that, although multiple possible conditions are defined for the imaging optical systems according to Embodiments 1 to 5, the most effective imaging optical system configuration is one that satisfies all of these multiple conditions. However, it is also possible to obtain imaging optical systems that achieve the respective corresponding effects by satisfying individual conditions.

[0119] Hereinafter, unless otherwise specified, the deviation ΔθgF of the partial dispersion ratio is expressed as follows, where the partial dispersion ratio for the g-line is θgF and the Abbe number for the d-line is νd: ΔθgF=θgF-(0.648285-0.00180123×νd) (A) The value is determined by

[0120] The imaging optical systems according to the first to fifth embodiments each include, in order from the object side to the image side, a first lens group G1 having positive power, a second lens group G2 having negative power, an aperture stop A, a third lens group G3 having positive power, a fourth lens group G4 having positive power, a fifth lens group G5 having negative power, and a rear group GR including one or more lens groups having power. The fifth lens group G5 includes, in order from the object side to the image side, a negative meniscus lens with a convex surface facing the object side and a negative meniscus lens with a convex surface facing the image side. When zooming from the wide-angle end to the telephoto end, the spacing between adjacent lens groups changes, and when focusing from a close-up object-focused state to an infinity-focused state, the fifth lens group G5 moves from the object side to the image side.

[0121] This makes it possible to cancel out various aberrations that occur in each lens group during zooming while still achieving compactness, thereby providing an imaging optical system in which various aberrations are well corrected throughout the entire zoom range.

[0122] Furthermore, by configuring the fifth lens group G5, which moves during focusing, with two negative lenses facing each other, it is possible to reduce the weight of the focus group while suppressing fluctuations in various aberrations, particularly astigmatism, distortion, and other aberrations, during focusing.

[0123] Furthermore, in an imaging optical system, for example, it is desirable that the second lens group G2 has a cemented lens and satisfies the following condition (1):

[0124] -0.002 < ΔθgF_2p < 0.015 (1) where: ΔθgF_2p: deviation ΔθgF of the partial dispersion ratio for the g-line of the positive lens element among the lens elements constituting the cemented lens, is.

[0125] Condition (1) is a condition for defining a desirable range of the deviation ΔθgF of the partial dispersion ratio for the g-line of the positive lens element that constitutes the cemented lens in the second lens group G2 in the imaging optical system.

[0126] If the lower limit of the condition (1) is not met, it becomes difficult to correct various aberrations, particularly axial chromatic aberration at the wide-angle end, which is undesirable.

[0127] Conversely, if the upper limit of the condition (1) is exceeded, it becomes difficult to correct various aberrations, particularly chromatic aberration of magnification at the wide-angle end, which is not preferable.

[0128] Preferably, the above-mentioned effects can be further enhanced by satisfying either one or both of the following conditions (1a) and (1b):

[0129] 0.000 < ΔθgF_2p (1a) ΔθgF_2p < 0.010 (1b) More preferably, the above-mentioned effect can be further enhanced by satisfying either one or both of the following conditions (1c) and (1d):

[0130] 0.002 < ΔθgF_2p (1a) ΔθgF_2p < 0.008 (1b) Furthermore, in the imaging optical system, for example, it is desirable that the second lens group G2 has a cemented lens and satisfies the following condition (2):

[0131] 50 < νd_2n < 90 (2) where: νd_2n: Abbe number of the negative lens in the cemented lens at the d line, is.

[0132] Condition (2) is a condition for defining a desirable range of the Abbe number, relative to the d-line, of the negative lens among the lenses constituting the cemented lens in the second lens group G2 in the imaging optical system.

[0133] If the lower limit of the condition (2) is not met, it becomes difficult to correct various aberrations, particularly chromatic aberration of magnification at the wide-angle end, which is not preferable.

[0134] Conversely, if the upper limit of the condition (2) is exceeded, the sensitivity to decentering increases, making manufacturing difficult, which is not preferable.

[0135] Preferably, the above-mentioned effect can be further enhanced by satisfying either one or both of the following conditions (2a) and (2b).

[0136] 55 < νd_2n (2a) νd_2n < 85 (2b) More preferably, the above-mentioned effect can be further enhanced by satisfying either one or both of the following conditions (2c) and (2d):

[0137] 60 < νd_2n (2c) νd_2n < 80 (2d) Furthermore, in the imaging optical system, for example, it is desirable that the third lens group G3 has a cemented lens and satisfies the following condition (3):

[0138] -0.010 < ΔθgF_3n < 0.005 (3) where: ΔθgF_3n: deviation ΔθgF of the partial dispersion ratio for the g-line of the negative lens element among the lens elements constituting the cemented lens, is.

[0139] Condition (3) is a condition for defining a desirable range of the deviation ΔθgF of the partial dispersion ratio for the g-line of the negative lens element constituting the cemented lens in the third lens group G3 in the imaging optical system.

[0140] If the lower limit of condition (3) is exceeded or the upper limit of condition (3) is exceeded, it becomes difficult to correct secondary spectral chromatic aberration, which is undesirable because it makes it difficult to correct various aberrations, particularly axial chromatic aberration.

[0141] Preferably, the above-mentioned effects can be further enhanced by satisfying either one or both of the following conditions (3a) and (3b):

[0142] -0.008 < ΔθgF_3n (3a) ΔθgF_3n < 0.003 (3b) More preferably, the above-mentioned effect can be further enhanced by satisfying either one or both of the following conditions (3c) and (3d):

[0143] -0.005 < ΔθgF_3n (3c) ΔθgF_3n < 0.001 (3d) Furthermore, in an imaging optical system, for example, it is desirable that at least three positive lens elements located on the image side of aperture stop A satisfy the following condition (4):

[0144] 50 < νdp < 100 (4) where: νdp: Abbe number of at least three positive lens elements located on the image side of aperture stop A, is.

[0145] Condition (4) is a condition for setting forth a desirable range of the Abbe number of at least three positive lens elements located on the image side of aperture stop A.

[0146] If the lower limit of the condition (4) is not met, it becomes difficult to correct various aberrations, particularly axial chromatic aberration, which is undesirable.

[0147] Conversely, if the upper limit of the condition (4) is exceeded, it becomes difficult to correct various aberrations, particularly chromatic aberration of magnification at the telephoto end, which is undesirable.

[0148] Preferably, the above-mentioned effect can be further enhanced by satisfying either one or both of the following conditions (4a) and (4b):

[0149] 55 < νdp (4a) νdp < 95 (4b) More preferably, the above-mentioned effect can be further enhanced by satisfying either one or both of the following conditions (4c) and (4d):

[0150] 60 < νdp (4c) νdp < 90 (4d) Furthermore, in an imaging optical system, for example, it is desirable that the lens element closest to the image side be a positive lens element and satisfy the following condition (5):

[0151] 0.012 < ΔθgF_Lp < 0.040 (5) where: ΔθgF_Lp: deviation ΔθgF of the partial dispersion ratio for the g-line of the positive lens element closest to the image side, is.

[0152] Condition (5) is a condition for defining a desirable range of the deviation ΔθgF of the partial dispersion ratio for the g-line of the positive lens element that is the lens element closest to the image side in the imaging optical system.

[0153] If the lower limit of the condition (5) is not met, it becomes difficult to correct various aberrations, particularly chromatic aberration of magnification at the wide-angle end, which is not preferable.

[0154] Conversely, exceeding the upper limit of condition (5) is undesirable because it results in correction of various aberrations, particularly chromatic aberration of magnification at the telephoto end.

[0155] Preferably, the above-mentioned effects can be further enhanced by satisfying either one or both of the following conditions (5a) and (5b):

[0156] 0.013 < ΔθgF_Lp (5a) ΔθgF_Lp < 0.038 (5b) More preferably, the above-mentioned effect can be further enhanced by satisfying either one or both of the following conditions (5c) and (5d):

[0157] 0.015 < ΔθgF_Lp (5c) ΔθgF_Lp < 0.035 (5d) Furthermore, for example, it is desirable that the imaging optical system satisfy the following condition (6):

[0158] 0.5 < BFw / Yw < 1.0 (6) where: BFw: The distance from the lens element closest to the image plane at the wide-angle end, Yw: Maximum image height at the wide-angle end, is.

[0159] Condition (6) sets forth the ratio of the distance from the lens element closest to the image side at the wide-angle end to the image plane in the imaging optical system to the maximum image height at the wide-angle end.

[0160] If the lower limit of condition (6) is not reached, the lens element closest to the image side and the imaging surface will tend to interfere with each other, which is undesirable.

[0161] Conversely, if the upper limit of the condition (6) is exceeded, the entire imaging optical system becomes large, which is not preferable.

[0162] Preferably, the above-mentioned effect can be further enhanced by satisfying either one or both of the following conditions (6a) and (6b):

[0163] 0.6 < BFw / Yw (6a) BFw / Yw < 0.8 (6b) More preferably, the above-mentioned effect can be further enhanced by satisfying either one or both of the following conditions (6c) and (6d):

[0164] 0.7 < BFw / Yw (6c) BFw / Yw < 0.75 (6d) Furthermore, for example, it is desirable that the imaging optical system satisfy the following condition (7):

[0165] 0.0 < f3 / fGRw < 1.0 (7) where: f3: focal length of the third lens group G3, fGRw: focal length of rear group GR at the wide-angle end, is.

[0166] Condition (7) sets forth the ratio of the focal length of the third lens group G3 to the focal length of the rear group GR at the wide-angle limit in the imaging optical system.

[0167] If the lower limit of condition (7) is not met, it becomes difficult to correct various aberrations, particularly coma, and this is not desirable.

[0168] Conversely, if the upper limit of the condition (7) is exceeded, it becomes difficult to correct various aberrations, particularly curvature of field, and this is not desirable.

[0169] Preferably, the above-mentioned effect can be further enhanced by satisfying either one or both of the following conditions (7a) and (7b):

[0170] 0.2 < f3 / fGRw (7a) f3 / fGRw < 0.8 (7b) More preferably, the above-mentioned effect can be further enhanced by satisfying either one or both of the following conditions (7c) and (7d):

[0171] 0.4 < f3 / fGRw (7c) f3 / fGRw < 0.65 (7d) Furthermore, for example, it is desirable that the imaging optical system satisfy the following condition (8):

[0172] 0.5 < |f5 / f4| < 2.0 (8) where: f4: focal length of the fourth lens group G4, f5: focal length of the fifth lens group G5, is.

[0173] The condition (8) sets forth the ratio of the focal length of the fourth lens group G4 to the focal length of the fifth lens group G5 in the imaging optical system.

[0174] If the lower limit of the condition (8) is not met, the focus group becomes large, which is undesirable.

[0175] Conversely, if the upper limit of the condition (8) is exceeded, it becomes difficult to correct aberration fluctuations during focusing, which is undesirable.

[0176] Preferably, the above-mentioned effect can be further enhanced by satisfying either one or both of the following conditions (8a) and (8b):

[0177] 1.0 < |f5 / f4| (8a) |f5 / f4| < 1.5 (8b) More preferably, the above-mentioned effect can be further enhanced by satisfying either one or both of the following conditions (8c) and (8d):

[0178] 1.1 < |f5 / f4| (8c) |f5 / f4| < 1.3 (8d) Furthermore, for example, it is desirable that the imaging optical system satisfy the following condition (9):

[0179] 0.2 < tGR / tG5 < 1.0 (9) where: tG5: the length of the fifth lens group G5 on the optical axis, tGR: the length on the optical axis from the object side surface of the lens element closest to the object in the rear group GR to the image side surface of the lens element closest to the image in the rear group GR at the wide-angle end, is.

[0180] Condition (9) is a condition for specifying the ratio, in an imaging optical system, between the axial length of the fifth lens group G5 and the axial length from the object-side surface of the lens element in the rear group GR closest to the object to the image-side surface of the lens element in the rear group GR closest to the image, at the wide-angle end.

[0181] If the lower limit of condition (9) is not met, it becomes difficult to correct various aberrations, particularly curvature of field and distortion, and this is not desirable.

[0182] Conversely, if the upper limit of the condition (9) is exceeded, it becomes difficult to correct aberration fluctuations during focusing, which is undesirable.

[0183] Preferably, the above-mentioned effect can be further enhanced by satisfying either one or both of the following conditions (9a) and (9b):

[0184] 0.3 < tGR / tG5 (9a) tGR / tG5 < 0.9 (9b) More preferably, the above-mentioned effect can be further enhanced by satisfying either one or both of the following conditions (9c) and (9d):

[0185] 0.4 < tGR / tG5 (9c) tGR / tG5 < 0.8 (9d) (Schematic configuration of an imaging device to which the first embodiment is applied) 6 shows a schematic configuration of an imaging device to which the imaging optical system according to Embodiment 1 is applied. Note that the imaging optical systems according to Embodiments 2 to 5 can also be applied to imaging devices.

[0186] The imaging device 100 is made up of a housing 104, an imaging element 102, and an imaging optical system 101 according to Embodiment 1. A specific example of the imaging device 100 is a digital camera.

[0187] The lens barrel 302 holds the lens groups of the imaging optical system 101 and the aperture stop A.

[0188] The image pickup element 102 is disposed at the position of the image plane S in the image pickup optical system according to the first embodiment.

[0189] The imaging optical system 101 is configured so that the lens frames included in the lens barrel 302 are attached or engaged with each other so that the lens frames holding the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, the fifth lens group G5, and the sixth lens group G6 can be moved during zooming.

[0190] The imaging optical system 301, which has each lens group held by the lens barrel 302, is configured with an actuator and a lens frame controlled by a controller within the imaging device 100 so that the fifth lens group G5 moves during focusing.

[0191] This makes it possible to realize an imaging device that can effectively correct various aberrations.

[0192] Although the imaging optical system according to the first embodiment described above is applied to a digital camera, it can also be applied to a digital video camera, a surveillance camera, a smartphone, and the like.

[0193] (Schematic configuration of a camera system to which the first embodiment is applied) 7 shows a schematic configuration of a camera system to which the imaging optical system according to Embodiment 1 is applied. Note that the imaging optical systems according to Embodiments 2 to 5 can also be applied to a camera system.

[0194] The camera system 200 includes a camera body 201 and an interchangeable lens device 300 that is detachably connected to the camera body 201 .

[0195] The camera body 201 includes an image sensor 202 that receives an optical image formed by the imaging optical system of the interchangeable lens device 300 and converts it into an electrical image signal, a monitor 203 that displays the image signal converted by the image sensor 202, a memory (not shown) that stores the image signal, a camera mount unit 204, and a viewfinder 205.

[0196] The imaging optical system of the interchangeable lens device 300 is the imaging optical system according to the first embodiment.

[0197] The lens barrel 302 holds each lens group of the imaging optical system 301 and an aperture stop A, and includes a lens mount section 304 that is connected to the camera mount section 204 of the camera body 201 .

[0198] The camera mount unit 204 and the lens mount unit 304 not only provide a physical connection, but also function as an interface that electrically connects a controller (not shown) in the camera body 201 and a controller (not shown) in the interchangeable lens device 300, enabling the exchange of signals between them.

[0199] The imaging optical system 301 is configured so that the lens frames included in the lens barrel 302 can be attached or engaged with each other so that the lens barrel 302 can move each of the lens frames holding the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, the fifth lens group G5, and the sixth lens group G6 during zooming.

[0200] The imaging optical system 301 is composed of each lens group held by a lens barrel 302 and a camera body 201. The imaging optical system 301 is equipped with an actuator and a lens frame controlled by a controller within the interchangeable lens device 300 so that the fifth lens group G5 moves during focusing.

[0201] This makes it possible to realize an imaging device that can effectively correct various aberrations.

[0202] Although the imaging optical system according to the first embodiment described above is applied to a digital camera, it can also be applied to a digital video camera, a surveillance camera, a smartphone, and the like.

[0203] (Numerical example) Numerical examples that specifically implement the imaging optical systems according to Embodiments 1 to 5 will be described below. In each numerical example, all lengths in the tables are in "mm" and all angles of view are in "°". In each numerical example, r is the radius of curvature, d is the surface spacing, nd is the refractive index for the d-line, and νd (also written as vd) is the Abbe number for the d-line. In each numerical example, surfaces marked with an * are aspherical, and the aspherical shape is defined by the following equation:

[0204]

number

[0205] 1B, 2B, 3B, 4B, and 5B are longitudinal aberration diagrams of the imaging optical systems according to the first to fifth embodiments in the infinity focused state.

[0206] In each longitudinal aberration diagram, (a) shows the aberrations at the wide-angle end, (b) shows the aberrations at the intermediate position, and (c) shows the aberrations at the telephoto end. Each longitudinal aberration diagram, from left to right, shows spherical aberration (SA (mm)), astigmatism (AST (mm)), and distortion (DIS (%)). In each spherical aberration diagram, the vertical axis represents the F-number (denoted by F in the diagram), with the solid line representing the d-line, the short-dashed line representing the F-line, and the long-dashed line representing the C-line characteristics. In each astigmatism diagram, the vertical axis represents the image height (denoted by H in the diagram), with the solid line representing the sagittal plane (denoted by s) and the dashed line representing the meridional plane (denoted by m). In each distortion diagram, the vertical axis represents the image height (denoted by H in the diagram).

[0207] (Numerical Example 1) The imaging optical system of Numerical Example 1 corresponds to Embodiment 1 shown in Fig. 1A. Surface data of the imaging optical system of Numerical Example 1 is shown in Table 1A, aspherical surface data is shown in Table 1B, and various data in an infinity focused state are shown in Tables 1C to 1F.

[0208] (Table 1A: Surface data) Surface number rd nd vd ΘgF object surface ∞ 1 68.33540 1.00000 1.69895 30.1 0.6028 2 52.19320 8.11430 1.71300 53.9 0.5442 3 203.07390 Variable 4 61.77170 1.00000 1.83481 42.7 0.5647 5 21.63920 11.13950 6* -111.03420 1.51230 1.55332 71.7 0.5398 7 26.51620 5.30190 1.90110 27.1 0.6072 8 105.54770 5.54610 9 -34.42640 1.04500 1.68960 31.1 0.6031 10 -47.98700 Variable 11 (Aperture) ∞ 1.95000 12 32.87000 4.20340 1.83400 37.3 0.5790 13 158.57010 0.30000 14 36.72240 5.44000 1.49700 81.6 0.5389 15 -48.25920 1.47520 16 -38.31620 1.00000 1.74951 35.3 0.5818 17 22.57500 4.41560 1.49700 81.6 0.5389 18 90.94350 Variable 19 26.91730 7.13640 1.55032 75.5 0.5401 20 -40.97870 0.30000 21* 101.83500 1.18300 1.69350 53.2 0.5482 22* 55.69330 Variable 23* 69.00380 1.44010 1.81055 41.1 0.5690 24* 33.23450 12.00310 25 -16.12390 1.00000 1.48749 70.4 0.5306 26 -23.46450 Variable 27 -117.06070 2.89820 1.49700 81.6 0.5389 28 -329.67380 0.30000 29 158.46070 5.48700 1.92119 24.0 0.6202 30 -162.97620 Variable 31 ∞ 1.80000 1.51680 64.2 0.5343 32∞1.00000 Image plane ∞ (Table 1B: Aspheric Data) Page 6 K= 0.00000E+00, A4= 1.65418E-06, A6= 2.35613E-09, A8=-6.17277E-12 A10= 1.77861E-14, A12= 0.00000E+00 Page 21 K= 0.00000E+00, A4=-7.15927E-06, A6=-9.60538E-08, A8= 2.44811E-10 A10=-8.38030E-14, A12= 0.00000E+00 Page 22 K= 0.00000E+00, A4= 1.63430E-05, A6=-6.55930E-08, A8= 2.59214E-10 A10= 2.75345E-13, A12= 0.00000E+00 Page 23 K= 0.00000E+00, A4=-3.27630E-06, A6= 1.66759E-07, A8=-1.98459E-10 A10=-3.44918E-13, A12= 2.38114E-15 Page 24 K= 0.00000E+00, A4=-9.87207E-06, A6= 1.59487E-07, A8=-1.15095E-11 A10=-1.39913E-12, A12= 5.93558E-15 (Various data when focused at infinity) (Table 1C: Various data) Zoom ratio 2.69085 Wide-angle Mid-range Telephoto Focal length 36.0455 59.1290 96.9931 F-number 4.11984 4.11992 4.11983 Angle of view 38.1948 24.9661 15.7173 Image height 27.5000 27.5000 27.5000 Lens total length 150.4098 164.4459 189.9700 d3 1.2133 15.2146 31.0268 d10 28.0712 14.5482 5.6396 d18 5.9766 3.4487 2.2896 d22 3.3108 2.2530 1.8554 d26 6.5833 13.0003 27.7508 d30 17.2633 27.9899 33.4165 Entrance pupil position 37.6444 58.4850 90.0938 Exit pupil position -87.1151 -108.4367 -162.6349 Front principal point position 58.7871 85.3818 129.2237 Back principal point position 114.4324 105.3505 92.9264 (Table 1D: Single lens data) Lens starting surface focal length 1 1 -324.3870 2 2 96.3675 3 4 -40.3553 4 6 -38.5330 5 7 38.0883 6 9 -182.3974 7 12 48.9739 8 14 42.8708 9 16 -18.8207 10 17 59.1528 11 19 30.6649 12 21 -179.1199 13 23 -80.5512 14 25 -110.6675 15 27 -366.8778 16 29 87.9368 (Table 1E: Zoom lens group data) Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 139.26679 9.11430 -2.58158 1.35187 2 4 -29.96265 25.54480 4.49970 10.15475 3 12 67.93943 16.83420 -12.56341 -2.64530 4 19 35.85333 8.61940 0.94607 3.92484 5 23 -44.36713 14.44320 5.45330 6.84847 6 27 113.72847 8.68520 5.05321 8.69302 (Table 1F: Zoom lens group magnification) Group Starting plane Wide angle Intermediate Telephoto 1 1 0.00000 0.00000 0.00000 2 4 -0.31267 -0.36617 -0.45388 3 12 -29.67497 7.05458 4.26990 4 19 0.01714 -0.08934 -0.16995 5 23 1.96427 2.50498 3.07595 6 27 0.82845 0.73443 0.68746 (Numerical Example 2) The imaging optical system of Numerical Example 2 corresponds to Embodiment 1 shown in Fig. 2A. Surface data of the imaging optical system of Numerical Example 2 is shown in Table 2A, aspherical surface data is shown in Table 2B, and various data in an infinity focused state are shown in Tables 2C to 2F.

[0209] (Table 2A: Surface data) Surface number rd nd vd ΘgF object surface ∞ 1 65.23670 1.00000 1.69895 30.1 0.6028 2 56.60000 6.75650 1.67790 55.3 0.5434 3 196.17120 Variable 4 64.69750 1.00000 1.80420 46.5 0.5573 5 21.63270 10.83010 6* -150.64320 1.30000 1.55032 75.5 0.5401 7 24.61880 5.46990 1.90366 31.3 0.5948 8 80.50070 6.68610 9 -32.53260 1.05400 1.65412 39.7 0.5737 10 -42.38930 Variable 11 (Aperture) ∞ 1.51420 12 31.78970 4.38350 1.80610 33.3 0.5884 13 154.23990 0.61720 14 38.28680 4.98850 1.48071 85.3 0.5362 15 -50.40560 1.53860 16 -39.84250 1.00000 1.73800 32.3 0.5900 17 22.93020 6.55820 1.49700 81.6 0.5389 18 83.75100 Variable 19 25.80210 6.91760 1.55397 71.8 0.5392 20 -44.39380 0.30000 21* 329.91120 1.00000 1.69350 53.2 0.5482 22* 88.12460 Variable 23* 97.37870 1.51650 1.78590 43.9 0.5612 24* 41.06630 11.90690 25 -17.46520 1.00000 1.51823 59.0 0.5442 26 -26.51840 Variable 27 -759.04430 4.24880 1.53775 74.7 0.5392 28 107.17240 6.41800 1.92119 24.0 0.6202 29 -162.14370 Variable 30 ∞ 1.80000 1.51680 64.2 0.5343 31∞1.00000 Image plane ∞ (Table 2B: Aspheric Data) Page 6 K= 0.00000E+00, A4= 1.21134E-06, A6= 3.01137E-09, A8=-7.21597E-12 A10= 2.18986E-14, A12= 0.00000E+00 Page 21 K= 0.00000E+00, A4= 1.04425E-05, A6=-6.72768E-08, A8=-1.97410E-10 A10= 8.63866E-13, A12= 0.00000E+00 Page 22 K= 0.00000E+00, A4= 3.44909E-05, A6=-2.88964E-08, A8=-2.15446E-10 A10= 1.21806E-12, A12= 0.00000E+00 Page 23 K= 0.00000E+00, A4= 2.46392E-05, A6=-2.37704E-08, A8= 7.03553E-10 A10=-3.36243E-12, A12= 7.01117E-15 Page 24 K= 0.00000E+00, A4= 2.14544E-05, A6=-3.94060E-08, A8= 9.85168E-10 A10=-4.82209E-12, A12= 1.09432E-14 (Various data when focused at infinity) (Table 2C: Various data) Zoom ratio 2.69110 Wide-angle Mid-range Telephoto Focal length 36.0408 59.1258 96.9894 F-number 4.11907 4.11948 4.12000 Angle of view 38.4782 24.9898 15.6901 Image height 27.5000 27.5000 27.5000 Lens total length 153.5989 166.5498 189.9600 d3 1.0000 15.5580 29.0750 d10 29.9083 15.0525 4.9096 d18 5.0005 2.8734 1.7798 d22 2.3475 1.6063 1.7583 d26 7.3107 13.4966 30.6737 d29 17.2269 27.1581 30.9585 Entrance pupil position 37.2815 58.3731 82.2774 Exit pupil position -88.2249 -108.7980 -171.4573 Front principal point position 58.6098 85.3750 124.3781 Back principal point position 117.6211 107.4502 92.8947 (Table 2D: Single lens data) Lens starting surface focal length 1 1 -642.2605 2 2 115.1008 3 4 -40.8349 4 6 -38.3503 5 7 37.5030 6 9 -223.3333 7 12 48.8934 8 14 46.1065 9 16 -19.5884 10 17 61.3361 11 19 30.5290 12 21 -173.6808 13 23 -91.4444 14 25 -102.5858 15 27 -174.3407 16 28 70.8538 (Table 2E: Zoom lens group data) Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 141.75183 7.75650 -2.29227 0.95793 2 4 -31.43545 26.34010 4.42993 10.03925 3 12 70.71889 19.08600 -14.35543 -3.27707 4 19 36.02684 8.21760 0.86097 3.68349 5 23 -45.98707 14.42340 5.95077 7.40975 6 27 117.45130 10.66680 5.21184 9.76815 (Table 2F: Zoom lens group magnification) Group Starting plane Wide angle Intermediate Telephoto 1 1 0.00000 0.00000 0.00000 2 4 -0.32048 -0.37634 -0.44900 3 12 -26.73900 6.76400 3.86145 4 19 0.01831 -0.09025 -0.18681 5 23 1.96089 2.44610 2.97206 6 27 0.82652 0.74228 0.71079 (Numerical Example 3) The imaging optical system of Numerical Example 3 corresponds to Embodiment 1 shown in Fig. 3A. Surface data of the imaging optical system of Numerical Example 3 is shown in Table 3A, aspherical surface data is shown in Table 3B, and various data in an infinity focused state are shown in Tables 3C to 3F.

[0210] (Table 3A: Surface data) Surface number rd nd vd ΘgF object surface ∞ 1 70.22080 1.20000 1.71736 29.5 0.6040 2 56.37810 7.74670 1.61997 63.9 0.5426 3 310.12240 Variable 4 59.18530 1.20000 1.77250 49.6 0.5504 5 21.45970 10.65510 6* -84.18400 1.20900 1.59522 67.7 0.5442 7 25.38940 5.83960 1.90110 27.1 0.6072 8 109.57310 7.47580 9 -27.55880 1.10220 1.85883 30.0 0.5979 10 -34.14760 Variable 11 (Aperture) ∞ 1.95000 12 29.61560 4.74000 1.83400 37.3 0.5790 13 173.50610 1.49150 14 32.83960 5.77650 1.48071 85.3 0.5362 15 -49.54460 0.94920 16 -41.96250 1.10000 1.80610 33.3 0.5884 17 19.53310 5.04800 1.49700 81.6 0.5389 18 151.81360 Variable 19* 32.37300 1.80000 1.58913 61.3 0.5374 20* 26.46100 1.54860 21 43.27560 5.93590 1.59410 60.5 0.5552 22 -31.52090 Variable 23* 44.06500 2.40000 1.51742 52.1 0.5590 24* 22.85170 11.41190 25 -17.77980 1.10000 1.65412 39.7 0.5737 26 -25.86070 Variable 27 -399.82650 1.40000 1.49700 81.6 0.5389 28 156.11760 0.60480 29 129.42900 6.41460 1.92286 20.9 0.6390 30 -164.81960 Variable 31 ∞ 1.80000 1.51680 64.2 0.5343 32∞1.00000 Image plane ∞ (Table 3B: Aspheric data) Page 6 K= 0.00000E+00, A4= 1.72279E-06, A6= 2.79186E-09, A8=-8.36623E-12 A10= 2.98422E-14, A12= 0.00000E+00 Page 19 K= 0.00000E+00, A4=-6.59969E-05, A6=-1.88243E-07, A8= 1.59662E-09 A10=-1.35900E-12, A12=-6.56008E-15 Page 20 K= 0.00000E+00, A4=-4.81652E-05, A6=-1.94906E-07, A8= 2.06212E-09 A10=-4.62436E-12, A12= 0.00000E+00 Page 23 K= 0.00000E+00, A4=-1.08239E-05, A6= 1.81885E-07, A8=-3.21931E-10 A10= 7.64378E-13, A12=-1.67905E-15 Page 24 K= 0.00000E+00, A4=-2.42718E-05, A6= 1.87934E-07, A8=-2.63574E-10 A10=6.52787E-13, A12=-4.20668E-17 (Various data when focused at infinity) (Table 3C: Various data) Zoom ratio 2.69076 Wide-angle Mid-range Telephoto Focal length 36.0490 59.1337 96.9991 F-number 4.12016 4.11997 4.12001 Angle of view 38.4736 24.7131 15.5336 Image height 27.5000 27.5000 27.5000 Lens total length 152.3625 168.3296 189.9700 d3 1.0000 18.5819 30.8626 d10 24.8492 11.5617 1.8361 d18 4.5641 2.4660 1.5000 d22 1.5024 2.3419 4.1206 d26 10.5041 16.6542 33.6712 d30 17.0426 23.8239 25.0795 Entrance pupil position 36.6347 63.0895 83.6421 Exit pupil position -97.2859 -116.0608 -182.9796 Front principal point position 59.3308 92.0978 129.2046 Back principal point position 116.3492 109.2092 92.9118 (Table 3D: Single Lens Data) Lens starting surface focal length 1 1 -413.6524 2 2 109.8587 3 4 -44.1942 4 6 -32.6374 5 7 35.5063 6 9 -180.2352 7 12 42.1871 8 14 42.0405 9 16 -16.4039 10 17 44.5414 11 19 -277.2412 12 21 31.6329 13 23 -95.4216 14 25 -91.9357 15 27 -225.7228 16 29 79.3886 (Table 3E: Zoom Lens Group Data) Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 151.58354 8.94670 -1.84557 1.70280 2 4 -28.64718 27.48170 5.64351 11.69491 3 12 57.07889 19.10530 -11.35209 -0.51001 4 19 35.99221 9.28450 4.77732 7.41479 5 23 -44.88423 14.91190 7.36853 8.85572 6 27 120.52257 8.41940 4.23977 7.78585 (Table 3F: Zoom lens group magnification) Group Starting plane Wide angle Intermediate Telephoto 1 1 0.00000 0.00000 0.00000 2 4 -0.26270 -0.31320 -0.36177 3 12 -6.81310 16.48200 4.83833 4 19 0.07980 -0.04106 -0.17063 5 23 1.99444 2.36305 2.78619 6 27 0.83489 0.77881 0.76900 (Numerical Example 4) The imaging optical system of Numerical Example 4 corresponds to Embodiment 1 shown in Fig. 4A. Surface data of the imaging optical system of Numerical Example 4 is shown in Table 4A, aspherical surface data is shown in Table 4B, and various data in an infinity focused state are shown in Tables 4C to 4F.

[0211] (Table 4A: Surface data) Surface number rd nd vd ΘgF object surface ∞ 1 69.66960 1.20000 1.84666 23.8 0.6192 2 60.89710 7.24470 1.60300 65.4 0.5401 3 319.22350 Variable 4 50.43900 1.20000 1.75700 47.8 0.5565 5 20.95100 10.87310 6* -74.24630 1.20000 1.59282 68.6 0.5440 7 24.52520 5.84880 1.85451 25.2 0.6103 8 108.67750 7.51440 9 -27.11370 1.13820 1.85896 22.7 0.6284 10 -33.86710 Variable 11 (Aperture) ∞ 1.95000 12 29.92820 4.54310 1.79360 37.1 0.5828 13 168.56510 0.98680 14 32.14470 5.81000 1.49700 81.6 0.5389 15 -46.85350 0.70000 16 -41.89790 1.10000 1.76634 35.8 0.5792 17 18.06420 5.19220 1.55032 75.5 0.5401 18 95.28780 Variable 19* 35.26310 1.80000 1.58313 59.5 0.5405 20* 28.37100 1.89560 21 44.23910 5.93020 1.59282 68.6 0.5440 22 -31.90170 Variable 23* 41.86300 2.40000 1.54814 45.8 0.5700 24* 22.40810 11.52360 25 -17.53480 1.10000 1.71700 47.9 0.5557 26 -24.71080 Variable 27 -430.53610 1.43700 1.49700 81.6 0.5389 28 117.41060 6.84760 1.96300 24.1 0.6390 29 -157.31790 Variable 30 ∞ 1.80000 1.51680 64.2 0.5343 31∞1.00000 Image plane ∞ (Table 4B: Aspheric data) Page 6 K= 0.00000E+00, A4= 2.21934E-06, A6= 1.91303E-09, A8=-5.63345E-12 A10= 2.59893E-14, A12= 0.00000E+00 Page 19 K= 0.00000E+00, A4=-6.01713E-05, A6=-1.67972E-07, A8= 1.53081E-09 A10=-1.80043E-12, A12=-5.73727E-15 Page 20 K= 0.00000E+00, A4=-3.98147E-05, A6=-1.69363E-07, A8= 1.88884E-09 A10=-4.49408E-12, A12= 0.00000E+00 Page 23 K= 0.00000E+00, A4=-1.45191E-05, A6= 1.91284E-07, A8=-2.81320E-10 A10=2.70352E-13, A12=-6.19268E-16 Page 24 K= 0.00000E+00, A4=-2.85137E-05, A6= 1.98251E-07, A8=-2.51667E-10 A10= 3.75128E-13, A12= 4.19724E-16 (Various data when focused at infinity) (Table 4C: Various data) Zoom ratio 2.69101 Wide-angle Mid-range Telephoto Focal length 36.0444 59.1298 96.9960 F-number 4.11976 4.11966 4.11998 Angle of view 38.4772 24.7026 15.5338 Image height 27.5000 27.5000 27.5000 Lens total length 150.0833 167.0568 189.9600 d3 1.0000 19.7316 32.2577 d10 22.5697 9.5843 0.4677 d18 4.6266 2.5154 1.6339 d22 1.5056 2.7028 4.7131 d26 11.2321 15.8518 33.1182 d29 16.9135 24.4352 25.5335 Entrance pupil position 36.0714 63.9619 84.7674 Exit pupil position -99.5590 -115.6880 -190.1240 Front principal point position 59.0696 92.8722 132.2677 Back principal point position 114.0640 107.9364 92.9209 (Table 4D: Single Lens Data) Lens starting surface focal length 1 1 -609.4449 2 2 123.4943 3 4 -48.1852 4 6 -30.9578 5 7 35.9155 6 9 -171.6657 7 12 45.1977 8 14 39.3202 9 16 -16.3406 10 17 39.5590 11 19 -275.4262 12 21 32.1997 13 23 -91.9837 14 25 -89.9733 15 27 -185.4584 16 28 70.6803 (Table 4E: Zoom Lens Group Data) Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 156.77062 8.44470 -1.94189 1.40892 2 4 -28.00033 27.77450 6.47064 12.52690 3 12 54.00256 18.33210 -8.67840 1.14756 4 19 36.62137 9.62580 5.23646 7.87903 5 23 -43.57185 15.02360 7.35461 8.88469 6 27 112.52416 8.28460 3.48352 7.30276 (Table 4F: Zoom lens group magnification) Group Starting plane Wide angle Intermediate Telephoto 1 1 0.00000 0.00000 0.00000 2 4 -0.24505 -0.29310 -0.33733 3 12 -5.40125 32.89088 5.67253 4 19 0.10365 -0.02139 -0.15151 5 23 2.04051 2.42450 2.86346 6 27 0.82130 0.75460 0.74530 (Numerical Example 5) The imaging optical system of Numerical Example 5 corresponds to Embodiment 1 shown in Fig. 5A. Surface data of the imaging optical system of Numerical Example 5 is shown in Table 5A, aspherical surface data is shown in Table 5B, and various data in an infinity focused state are shown in Tables 5C to 5F.

[0212] (Table 5A: Surface data) Surface number rd nd vd ΘgF object surface ∞ 1 66.12760 1.00000 1.67270 32.2 0.5963 2 54.54890 7.31560 1.65160 58.5 0.5390 3 201.93410 Variable 4 64.90660 1.00000 1.77250 49.6 0.5504 5 22.25610 11.51590 6* -111.49280 1.30220 1.59410 60.5 0.5552 7 26.04880 5.91880 1.90110 27.1 0.6072 8 106.84540 8.25670 9 -29.00300 1.31260 1.78472 25.7 0.6161 10 -37.06510 Variable 11 (Aperture) ∞ 1.00000 12 36.43040 4.12880 1.85026 32.3 0.5980 13 235.20720 0.30000 14 41.02180 5.39620 1.49700 81.6 0.5389 15 -46.90520 1.45070 16 -38.19560 1.00000 1.73800 32.3 0.5900 17 25.07090 4.43870 1.49700 81.6 0.5389 18 142.65900 Variable 19 26.88840 8.50000 1.57144 71.6 0.5419 20 -47.10080 0.30000 21* 231.37020 1.06680 1.74320 49.3 0.5529 22* 78.29200 Variable 23* 84.76800 1.65640 1.77200 50.0 0.5550 24* 39.37440 12.24910 25 -17.39970 1.00000 1.56883 56.0 0.5485 26 -25.83360 Variable 27 -74.94550 2.06710 1.53775 74.7 0.5392 28 -154.23320 Variable 29 244.37400 5.36960 1.92286 20.9 0.6390 30 -134.67810 Variable 31 ∞ 1.80000 1.51680 64.2 0.5343 32∞1.00000 Image plane ∞ (Table 5B: Aspheric Data) Page 6 K= 0.00000E+00, A4= 1.64784E-06, A6= 2.87775E-09, A8=-4.97948E-12 A10= 1.92071E-14, A12= 0.00000E+00 Page 21 K= 0.00000E+00, A4= 1.68154E-05, A6=-1.10404E-07, A8=-1.91961E-11 A10= 5.40909E-13, A12= 0.00000E+00 Page 22 K= 0.00000E+00, A4= 3.82582E-05, A6=-7.47593E-08, A8=-8.76528E-11 A10= 1.02249E-12, A12= 0.00000E+00 Page 23 K= 0.00000E+00, A4= 1.76371E-05, A6= 4.69672E-08, A8= 8.22120E-11 A10=-2.29508E-13, A12= 1.72982E-15 Page 24 K= 0.00000E+00, A4= 1.39831E-05, A6= 2.79755E-08, A8= 4.17758E-10 A10=-2.10853E-12, A12= 7.43407E-15 (Various data when focused at infinity) (Table 5C: Various data) Zoom ratio 2.69064 Wide-angle Mid-range Telephoto Focal length 36.0503 59.1316 96.9982 F-number 4.12006 4.11999 4.11990 Angle of view 38.4723 24.9654 15.6905 Image height 27.5000 27.5000 27.5000 Lens total length 151.7299 163.9823 189.9700 d3 1.0000 14.2146 30.4175 d10 25.8837 11.4937 2.5865 d18 7.7347 5.0640 3.7024 d22 1.6329 1.8841 1.7927 d26 8.0268 5.3203 12.9104 d28 0.3000 8.5802 14.5835 d30 16.8063 27.0798 33.6313 Entrance pupil position 37.7146 55.7567 85.6054 Exit pupil position -84.1725 -107.7779 -160.4767 Front principal point position 58.3353 82.4467 123.9552 Back principal point position 115.7364 104.8523 92.9193 (Table 5D: Single Lens Data) Lens starting surface focal length 1 1 -479.7778 2 2 112.4963 3 4 -44.2972 4 6 -35.4169 5 7 36.9447 6 9 -183.0214 7 12 50.2194 8 14 44.9469 9 16 -20.3727 10 17 60.4426 11 19 31.2599 12 21 -159.6979 13 23 -96.7821 14 25 -97.9040 15 27 -273.5992 16 29 94.7284 (Table 5E: Zoom Lens Group Data) Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 148.78669 8.31560 -2.44850 0.95989 2 4 -30.01799 29.30620 5.54470 11.90396 3 12 64.53751 16.71440 -10.11001 -1.44490 4 19 37.46183 9.86680 0.92045 4.40300 5 23 -46.28058 14.90550 6.52506 8.05898 6 27 -273.59919 2.06710 -1.28231 -0.57182 7 29 94.72836 5.36960 1.81265 4.37062 (Table 5F: Zoom lens group magnification) Group Starting plane Wide angle Intermediate Telephoto 1 1 0.00000 0.00000 0.00000 2 4 -0.28624 -0.32752 -0.39785 3 12 -8.90307 10.93442 5.08243 4 19 0.05774 -0.05957 -0.14997 5 23 1.88104 2.26201 2.72527 6 27 1.11032 1.21020 1.28918 7 29 0.78835 0.68048 0.61189 (Condition's corresponding value) Table 1 below shows the corresponding values ​​for conditions (1) to (14).

[0213] [Table 1] [Industrial Applicability]

[0214] The imaging optical system according to the present disclosure is applicable to digital still cameras, digital cameras with interchangeable lenses, digital video cameras, cameras in mobile phone devices such as smartphones, cameras in PDAs (Personal Digital Assistances), surveillance cameras in surveillance systems, web cameras, in-vehicle cameras, and the like, and is particularly suitable for imaging optical systems that require high image quality, such as digital still camera systems and digital video camera systems. [Explanation of symbols]

[0215] G1 First lens group G2 Second lens group G3 Third lens group G4 4th lens group G5 5th lens group G6 6th lens group G7 7th lens group L1 First lens element L2 Second lens element L3 Third lens element L4 Fourth lens element L5 Fifth lens element L6 Sixth lens element L7 Seventh lens element L8 Eighth lens element L9 9th lens element L10: Tenth lens element L11 Eleventh lens element L12 12th lens element L13 13th lens element L14 14th lens element L15 15th lens element L16 16th lens element A aperture stop CG cover glass S image plane 100 Imaging device 101 Imaging optical system 102 Image sensor 104 Case 200 Camera System 201 Camera body 202 Image sensor 203 Monitor 204 Camera mount 205 Finder 300 Interchangeable lens device 301 Imaging Optical System 302 Telescope tube 304 Lens mount

Claims

1. From the object side to the image side, a first lens group having positive power; a second lens group having negative power; An aperture stop, a third lens group having positive power; a fourth lens group having positive power; a fifth lens group having negative power; a rear group including one or more lens groups having power; It consists of When zooming from the wide-angle end to the telephoto end, the spacing between adjacent lens groups changes, The fifth lens group, in order from the object side to the image side, is a negative meniscus lens with its convex surface facing the object side; a negative meniscus lens with a convex surface facing the image side; It consists of During focusing from a close object focused state to an infinity focused state, the fifth lens group moves from the object side to the image side. Imaging optical system.

2. the second lens group has a cemented lens, The following condition (1) is satisfied: -0.002 < ΔθgF_2p < 0.015 ... (1) where: ΔθgF_2p: deviation ΔθgF of the partial dispersion ratio for the g-line of the positive lens element among the lens elements constituting the cemented lens, The deviation ΔθgF is expressed as follows, where θgF is the partial dispersion ratio for the g-line and νd is the Abbe number for the d-line: ΔθgF=θgF-(0.648285-0.00180123×νd)...(A) is a value determined by The imaging optical system according to claim 1 .

3. the second lens group has a cemented lens, The following condition (2) is satisfied: 50 < νd_2n < 90 (2) where: νd_2n: Abbe number of the negative lens among the lenses constituting the cemented lens with respect to the d line, That is, The imaging optical system according to claim 1 .

4. the third lens group has a cemented lens; The following condition (3) is satisfied: -0.010 < ΔθgF_3n < 0.005 (3) where: ΔθgF_3n: deviation ΔθgF of the partial dispersion ratio for the g-line of the negative lens element among the lens elements constituting the cemented lens, The deviation ΔθgF is expressed as follows, where θgF is the partial dispersion ratio for the g-line and νd is the Abbe number for the d-line: ΔθgF=θgF-(0.648285-0.00180123×νd)...(A) is a value determined by The imaging optical system according to claim 1 .

5. At least three positive lens elements located on the image side of the aperture stop satisfy the following condition (4): 50 < νdp < 100 (4) where: νdp: Abbe number of at least three positive lens elements located on the image side of the aperture stop, That is, The imaging optical system according to claim 1 .

6. The lens element closest to the image side is a positive lens element, The following condition (5) is satisfied: 0.012 < ΔθgF_Lp < 0.040 (5) where: ΔθgF_Lp: deviation ΔθgF of the partial dispersion ratio for the g-line of the positive lens element closest to the image side, The deviation ΔθgF is expressed as follows, where θgF is the partial dispersion ratio for the g-line and νd is the Abbe number for the d-line: ΔθgF=θgF-(0.648285-0.00180123×νd)...(A) is a value determined by The imaging optical system according to claim 1 .

7. The following condition (6) is satisfied: 0.5 < BFw / Yw < 1.0...(6) where: BFw: distance from the lens element closest to the image side to the image plane at the wide-angle end, Yw: maximum image height at the wide-angle end, That is, The imaging optical system according to claim 1 .

8. The following condition (7) is satisfied: 0.0 < f3 / fGRw < 1.0 (7) where: f3: the focal length of the third lens group, fGRw: focal length of the rear group at the wide-angle end, That is, The imaging optical system according to claim 1 .

9. The following condition (8) is satisfied: 0.5 < | f5 / f4 | < 2.0 ... (8) where: f4: the focal length of the fourth lens group, f5: focal length of the fifth lens group, That is, The imaging optical system according to claim 1 .

10. The following condition (9) is satisfied: 0.2 < tGR / tG5 < 1.0 (9) where: tG5: the length of the fifth lens group on the optical axis, tGR: the length on the optical axis from the object-side surface of the lens element closest to the object in the rear group to the image-side surface of the lens element closest to the image in the rear group at the wide-angle end, That is, The imaging optical system according to claim 1 .

11. an interchangeable lens device including the imaging optical system according to claim 1; a camera body that is detachably connected to the interchangeable lens device via a camera mount and includes an image sensor that receives an optical image formed by the imaging optical system and converts the optical image into an electrical image signal; A camera system comprising: The interchangeable lens device forms an optical image of an object on the imaging element. Camera system.

12. 1. An imaging device that converts an optical image of an object into an electrical image signal and at least one of displays and stores the converted image signal, an imaging optical system according to claim 1 that forms the optical image of the object; an imaging element that converts the optical image formed by the imaging optical system into the electrical image signal; Equipped with Imaging device.

Images