Imaging optical system, imaging device and camera system equipped therewith

Abstract

The objective is to provide a zoom lens that provides good optical performance throughout the entire zoom range, an imaging device that uses the zoom lens, and an interchangeable lens device. [Solution] The imaging optical system consists of, in order from the object side to the image side, a first lens group with positive power, a second lens group with negative power, a third lens group with positive power, a fourth lens group with positive power, a fifth lens group with negative power, a sixth lens group with positive power, and a seventh lens group with negative power. When zooming from the wide-angle end to the telephoto end, the spacing between adjacent lens groups changes. The second and sixth lens groups are fixed with respect to the image plane.

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a zoom lens including, in order from the object side to the image side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, an intermediate group including a plurality of lens groups, and a final lens group having a negative refractive power. The zoom lens has an aperture stop, the interval between adjacent lens groups changes during zooming, the intermediate group has a negative lens group having a negative refractive power, and both the negative lens group and the final lens group move toward the object side during zooming from the wide-angle end to the telephoto end.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

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

Means for Solving the Problems

[0005] The imaging optical system in this disclosure consists of, 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 positive power, a fifth lens group having negative power, a sixth lens group having positive power, and a seventh lens group having negative power. The spacing between adjacent lens groups changes when zooming from the wide-angle end to the telephoto end. The second and sixth lens groups are fixed with respect to the image plane.

[0006] Furthermore, the imaging device in this disclosure is an imaging device that converts an optical image of an object into an electrical image signal, and performs at least one of displaying and storing the converted image signal. The imaging device comprises the aforementioned imaging optical system that forms the optical image of the object, and an image sensor that converts the optical image formed by the imaging optical system into the electrical image signal.

[0007] Furthermore, the camera system in this disclosure comprises an interchangeable lens device including the aforementioned imaging optical system, and a camera body detachably connected to the interchangeable lens device via a camera mount, and including an image sensor that receives the optical image formed by the imaging optical system and converts it into an electrical image signal. The interchangeable lens device forms an optical image of an object on the image sensor. [Effects of the Invention]

[0008] According to this disclosure, it is possible to provide an imaging optical system in which aberrations are well corrected throughout the entire zoom range, as well as an imaging device and an interchangeable lens device equipped therewith. [Brief explanation of the drawing]

[0009] [Figure 1A] Lens arrangement diagram showing the infinity focus state of the imaging optical system according to Embodiment 1 (Numerical Example 1) [Figure 1B] Longitudinal aberration diagram of the imaging optical system in the infinity focus state according to numerical example 1. [Figure 1C]Transverse aberration diagrams at the telephoto end of the imaging optical system according to numerical example 1, showing the basic state without image blur correction and the state with image blur correction. [Figure 2A] Lens arrangement diagram showing the infinity focus state of the imaging optical system according to Embodiment 2 (Numerical Example 2) [Figure 2B] Longitudinal aberration diagram of the imaging optical system in the infinite focus state according to numerical example 2 [Figure 2C] Transverse aberration diagrams at the telephoto end of the imaging optical system according to numerical example 2, showing the basic state without image blur correction and the state with image blur correction. [Figure 3A] Lens arrangement diagram showing the infinity focus state of the imaging optical system according to Embodiment 3 (Numerical Example 3) [Figure 3B] Longitudinal aberration diagram of the imaging optical system in the infinite focus state according to numerical example 3 [Figure 3C] Transverse aberration diagrams at the telephoto end of the imaging optical system according to numerical example 3, in the basic state without image blur correction and with image blur correction applied. [Figure 4A] Lens arrangement diagram showing the infinity focus state of the imaging optical system according to Embodiment 4 (Numerical Example 4) [Figure 4B] Longitudinal aberration diagram of the imaging optical system in the infinity focus state according to numerical example 4 [Figure 4C] Transverse aberration diagrams at the telephoto end of the imaging optical system according to numerical example 4, showing the basic state without image blur correction and the state with image blur correction. [Figure 5A] Lens arrangement diagram showing the infinity focus state of the imaging optical system according to Embodiment 5 (Numerical Example 5) [Figure 5B] Longitudinal aberration diagram of the imaging optical system in the infinite focus state according to numerical example 5 [Figure 5C] Transverse aberration diagrams at the telephoto end of the imaging optical system according to numerical example 5, showing the basic state without image blur correction and the state with image blur correction. [Figure 6A] Lens arrangement diagram showing the infinity focus state of the imaging optical system according to Embodiment 6 (Numerical Example 6) [Figure 6B] Longitudinal aberration diagram of the imaging optical system in the infinite focus state according to numerical example 6 [Figure 6C]Lateral aberration diagrams in the telephoto end of the imaging optical system according to Numerical Example 6, in the basic state without image blur correction and in the image blur correction state [Figure 7A] Lens layout diagram showing the infinity focus state of the imaging optical system according to Embodiment 7 (Numerical Example 7) [Figure 7B] Longitudinal aberration diagram of the imaging optical system in the infinity focus state according to Numerical Example 7 [Figure 7C] Lateral aberration diagrams in the telephoto end of the imaging optical system according to Numerical Example 7, in the basic state without image blur correction and in the image blur correction state [Figure 8] Schematic configuration diagram of the imaging device according to Embodiment 1 [Figure 9] Schematic configuration diagram of the camera system according to Embodiment 1

Embodiments for Carrying Out the Invention

[0010] Hereinafter, the embodiments will be described in detail with reference to the drawings as appropriate. However, a more detailed description than necessary may be omitted. For example, a detailed description of well-known matters and a redundant description of substantially the same configuration may be omitted. This is to avoid making the following description unnecessarily redundant and to facilitate the understanding of those skilled in the art.

[0011] Note that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and it is not intended to limit the subject matter described in the claims thereby.

[0012] (Embodiments 1 to 7) Hereinafter, the imaging optical systems according to Embodiments 1 to 7 will be individually described with reference to the drawings.

[0013] FIG. 1A, FIG. 2A, FIG. 3A, FIG. 4A, FIG. 5A, FIG. 6A, and FIG. 7A are lens layout diagrams of the imaging optical systems according to Embodiments 1 to 7, respectively, and each represents an imaging optical system in the infinity focus state.

[0014] Figures 1A, 2A, 3A, 4A, 5A, 6A, and 7A (a) show the lens configuration at the wide-angle end (shortest focal length: focal length fW). Figure (d) shows the lens configuration at the intermediate position (intermediate focal length: focal length fM = √(fW * fT)). Figure (e) shows the lens configuration at the telephoto end (longest focal length: focal length fT). Note that the aspect ratio is the same in (a), (d), and (e) of each figure.

[0015] In each figure (a), the asterisk * placed on the surface of a specific lens element indicates that the surface is aspherical.

[0016] Furthermore, the broken line arrows shown in (c) of each figure connect the positions of the lens group at the wide-angle end (WIDE), the intermediate position (MID), and the telephoto end (TELE), respectively, from top to bottom. Note that the arrows simply connect the wide-angle end and the intermediate position, and the intermediate position and the telephoto end with lines, and do not represent the actual movement of each lens group.

[0017] Furthermore, in (b) of each figure, the symbols G1 to G7 are indicated for each lens group, corresponding to the positions of each lens group shown in (a).

[0018] Furthermore, the symbols (+) and (-) attached to the signs of each lens group (G1 to G7) shown in (b) of each figure correspond to the power of each lens group. In other words, the symbol (+) indicates positive power, and the symbol (-) indicates negative power.

[0019] Furthermore, the arrows attached to the lens groups shown in (b) of each figure represent focusing from the infinity focus state to the near-focus state. Note that in Figures 1A, 2A, 3A, 4A, 5A, 6A, and 7A, the reference numerals of each lens group are written below the position of each lens group in Figure (a). For convenience, arrows representing focusing are attached below these reference numerals of each lens group. However, the direction in which each lens group moves during focusing in each zooming state will be explained in detail later for each embodiment.

[0020] In figures (a), (d), and (e), the straight line on the far right indicates the position of the image plane S (the object-facing side of the image sensor). Therefore, the left side of the diagram corresponds to the object side. Furthermore, a parallel plate P, such as a low-pass filter or cover glass, is placed between the last lens group facing the image plane S and the image plane S.

[0021] (Embodiment 1) Figure 1A shows the imaging optical system according to Embodiment 1.

[0022] The imaging optical system consists of, in order from the object side to the image side, a first lens group G1 with positive power, a second lens group G2 with negative power, a third lens group G3 with positive power, a fourth lens group G4 with positive power, a fifth lens group G5 with negative power, a sixth lens group G6 with positive power, and a seventh lens group G7 with negative power.

[0023] The imaging optical system forms an image at the position of the image plane S.

[0024] Let's explain each lens group.

[0025] The first lens group G1 consists of, in order from the object side to the image side, a first lens element L1 having negative power, a second lens element L2 having positive power, and a third lens element L3 having positive power.

[0026] The second lens group G2 consists of a second sub-lens group G2a with negative power and a second sub-lens group G2b with negative power, arranged in order from the object side to the image side.

[0027] The third lens group G3 consists of, in order from the object side to the image side, a ninth lens element L9 with positive power, a tenth lens element L10 with positive power, and an eleventh lens element L11 with negative power. The tenth lens element L10 and the eleventh lens element L11 are bonded lenses joined together with an adhesive or the like.

[0028] The fourth lens group G4 consists of, in order from the object side to the image side, an aperture diaphragm A, a 12th lens element L12 having negative power, and a 13th lens element L13 having positive power. The 12th lens element L12 and the 13th lens element L13 are bonded lenses joined together with an adhesive or the like.

[0029] The fifth lens group G5 consists of a 14th lens element L14 with positive power and a 15th lens element L15 with negative power, arranged in order from the object side to the image side. The 14th lens element L14 and the 15th lens element L15 are bonded together with an adhesive or the like.

[0030] The sixth lens group G6 consists of a 16th lens element L16 with positive power and a 17th lens element L17 with negative power, arranged in order from the object side to the image side. The 16th lens element L16 and the 17th lens element L17 are bonded together with an adhesive or the like.

[0031] The seventh lens group G7 consists of, in order from the object side to the image side, a 18th lens element L18 having negative power and a 19th lens element L19 having positive power. The 18th lens element L18 and the 19th lens element L19 are bonded lenses joined together with an adhesive or the like.

[0032] Each sub-lens group will be explained.

[0033] The second sub-lens group G2a consists of a fourth lens element L4 having positive power and a fifth lens element L5 having negative power, arranged in order from the object side to the image side. The fourth lens element L4 and the fifth lens element L5 are bonded together with an adhesive or the like.

[0034] The second sub-lens group G2b consists of, in order from the object side to the image side, a sixth lens element L6 with negative power, a seventh lens element L7 with negative power, and an eighth lens element L8 with positive power. The seventh lens element L7 and the eighth lens element L8 are bonded lenses joined together with an adhesive or the like.

[0035] Each lens element will be explained.

[0036] The lens elements in the first lens group G1 are described below. The first lens element L1 is a meniscus lens with a convex surface facing the object. The second lens element L2 is a meniscus lens with a convex surface facing the object. The third lens element L3 is a plano-convex lens with a convex surface facing the object.

[0037] The lens elements in the second lens group G2 are described below. The fourth lens element L4 is a biconvex lens. The fifth lens element L5 is a biconcave lens. The sixth lens element L6 is a biconcave lens. The seventh lens element L7 is a biconcave lens. The eighth lens element L8 is a meniscus lens with a convex surface on the object side.

[0038] The lens elements in the third lens group G3 are described below. The ninth lens element L9 is a biconvex lens. The tenth lens element L10 is a biconvex lens. The eleventh lens element L11 is a biconcave lens.

[0039] The lens elements in the fourth lens group G4 are described below. The twelfth lens element L12 is a biconcave lens. The thirteenth lens element L13 is a biconvex lens.

[0040] The lens elements in the fifth lens group G5 are described below. The 14th lens element L14 is a biconvex lens. The 15th lens element L15 is a biconcave lens.

[0041] The lens elements in the sixth lens group G6 are described below. The sixteenth lens element L16 is a biconvex lens. The seventeenth lens element L17 is a meniscus lens with a convex surface on the image side.

[0042] The lens elements in the seventh lens group G7 are described below. The eighteenth lens element L18 is a biconcave lens. The ninth lens element L19 is a meniscus lens with a convex surface on the object side.

[0043] 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 third lens group G3, the fourth lens group G4, the fifth lens group G5, and the seventh lens group G7 move toward the object side with respect 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 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 and then increases, the distance between the fourth lens group G4 and the fifth lens group G5 increases and then decreases, the distance between the fifth lens group G5 and the sixth lens group G6 increases, the distance between the sixth lens group G6 and the seventh lens group G7 decreases, and the distance between the seventh lens group G7 and the image plane S increases.

[0044] In the imaging optical system according to Embodiment 1, when focusing from a state of point focus on an object at infinity to a state of focus on a nearby object, the fifth lens group G5 moves toward the image side along the optical axis.

[0045] Furthermore, the second sub-lens group G2b (vibration-damping group) within the second lens group G2 moves perpendicular to the optical axis to optically correct image blur. This image blur correction lens element allows the imaging optical system to correct image point movement caused by vibrations of the entire system. In other words, the imaging optical system can optically correct image blur caused by camera shake, vibrations, etc.

[0046] (Embodiment 2) Figure 2A shows the imaging optical system according to Embodiment 2.

[0047] The imaging optical system consists of, in order from the object side to the image side, a first lens group G1 with positive power, a second lens group G2 with negative power, a third lens group G3 with positive power, a fourth lens group G4 with positive power, a fifth lens group G5 with negative power, a sixth lens group G6 with positive power, and a seventh lens group G7 with negative power.

[0048] The imaging optical system forms an image at the position of the image plane S.

[0049] Let's explain each lens group.

[0050] The first lens group G1 consists of, in order from the object side to the image side, a first lens element L1 having negative power, a second lens element L2 having positive power, and a third lens element L3 having positive power.

[0051] The second lens group G2 consists of a second sub-lens group G2a with negative power and a second sub-lens group G2b with negative power, arranged in order from the object side to the image side.

[0052] The third lens group G3 consists of, in order from the object side to the image side, a ninth lens element L9 with positive power, a tenth lens element L10 with positive power, and an eleventh lens element L11 with negative power. The tenth lens element L10 and the eleventh lens element L11 are bonded lenses joined together with an adhesive or the like.

[0053] The fourth lens group G4 consists of, in order from the object side to the image side, an aperture diaphragm A, a 12th lens element L12 having negative power, and a 13th lens element L13 having positive power. The 12th lens element L12 and the 13th lens element L13 are bonded lenses joined together with an adhesive or the like.

[0054] The fifth lens group G5 consists of a 14th lens element L14 with positive power and a 15th lens element L15 with negative power, arranged in order from the object side to the image side. The 14th lens element L14 and the 15th lens element L15 are bonded together with an adhesive or the like.

[0055] The sixth lens group G6 consists of a 16th lens element L16 with positive power and a 17th lens element L17 with negative power, arranged in order from the object side to the image side. The 16th lens element L16 and the 17th lens element L17 are bonded together with an adhesive or the like.

[0056] The seventh lens group G7 consists of, in order from the object side to the image side, a 18th lens element L18 having negative power and a 19th lens element L19 having positive power. The 18th lens element L18 and the 19th lens element L19 are bonded lenses joined together with an adhesive or the like.

[0057] Each sub-lens group will be explained.

[0058] The second sub-lens group G2a consists of a fourth lens element L4 having positive power and a fifth lens element L5 having negative power, arranged in order from the object side to the image side. The fourth lens element L4 and the fifth lens element L5 are bonded together with an adhesive or the like.

[0059] The second sub-lens group G2b consists of, in order from the object side to the image side, a sixth lens element L6 with negative power, a seventh lens element L7 with negative power, and an eighth lens element L8 with positive power. The seventh lens element L7 and the eighth lens element L8 are bonded lenses joined together with an adhesive or the like.

[0060] Each lens element will be explained.

[0061] The lens elements in the first lens group G1 are described below. The first lens element L1 is a meniscus lens with a convex surface facing the object. The second lens element L2 is a plano-convex lens with a convex surface facing the object. The third lens element L3 is a plano-convex lens with a convex surface facing the object.

[0062] The lens elements in the second lens group G2 are described below. The fourth lens element L4 is a biconvex lens. The fifth lens element L5 is a biconcave lens. The sixth lens element L6 is a biconcave lens. The seventh lens element L7 is a biconcave lens. The eighth lens element L8 is a meniscus lens with a convex surface on the object side.

[0063] The lens elements in the third lens group G3 are described below. The ninth lens element L9 is a biconvex lens. The tenth lens element L10 is a biconvex lens. The eleventh lens element L11 is a biconcave lens.

[0064] The lens elements in the fourth lens group G4 are described below. The twelfth lens element L12 is a biconcave lens. The thirteenth lens element L13 is a biconvex lens.

[0065] The lens elements in the fifth lens group G5 are described below. The 14th lens element L14 is a plano-convex lens with a convex surface on the image side. The 15th lens element L15 is a biconcave lens.

[0066] The lens elements in the sixth lens group G6 are described below. The sixteenth lens element L16 is a biconvex lens. The seventeenth lens element L17 is a meniscus lens with a convex surface on the image side.

[0067] The lens elements in the seventh lens group G7 are described below. The eighteenth lens element L18 is a biconcave lens. The ninth lens element L19 is a meniscus lens with a convex surface on the object side.

[0068] In the imaging optical system according to Embodiment 2, when zooming from the wide-angle end to the telephoto end during imaging, the first lens group G1, the third lens group G3, the fourth lens group G4, the fifth lens group G5, and the seventh lens group G7 move toward the object side with respect 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 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 and then increases, the distance between the fourth lens group G4 and the fifth lens group G5 increases and then decreases, the distance between the fifth lens group G5 and the sixth lens group G6 increases, the distance between the sixth lens group G6 and the seventh lens group G7 decreases, and the distance between the seventh lens group G7 and the image plane S increases.

[0069] In the imaging optical system according to Embodiment 2, when focusing from a state of point focus on an object at infinity to a state of focus on a nearby object, the fifth lens group G5 moves toward the image side along the optical axis.

[0070] Furthermore, the second sub-lens group G2b (vibration-damping group) within the second lens group G2 moves perpendicular to the optical axis to optically correct image blur. This image blur correction lens element allows the imaging optical system to correct image point movement caused by vibrations of the entire system. In other words, the imaging optical system can optically correct image blur caused by camera shake, vibrations, etc.

[0071] (Embodiment 3) Figure 3A shows the imaging optical system according to Embodiment 3.

[0072] The imaging optical system consists of, in order from the object side to the image side, a first lens group G1 with positive power, a second lens group G2 with negative power, a third lens group G3 with positive power, a fourth lens group G4 with positive power, a fifth lens group G5 with negative power, a sixth lens group G6 with positive power, and a seventh lens group G7 with negative power.

[0073] The imaging optical system forms an image at the position of the image plane S.

[0074] Let's explain each lens group.

[0075] The first lens group G1 consists of, in order from the object side to the image side, a first lens element L1 having negative power, a second lens element L2 having positive power, and a third lens element L3 having positive power.

[0076] The second lens group G2 consists of a second sub-lens group G2a with positive power and a second sub-lens group G2b with negative power, arranged in order from the object side to the image side.

[0077] The third lens group G3 consists of, in order from the object side to the image side, a ninth lens element L9 with positive power, a tenth lens element L10 with positive power, and an eleventh lens element L11 with negative power. The tenth lens element L10 and the eleventh lens element L11 are bonded lenses joined together with an adhesive or the like.

[0078] The fourth lens group G4 consists of, in order from the object side to the image side, an aperture diaphragm A, a 12th lens element L12 having negative power, and a 13th lens element L13 having positive power. The 12th lens element L12 and the 13th lens element L13 are bonded lenses joined together with an adhesive or the like.

[0079] The fifth lens group G5 consists of a 14th lens element L14 with positive power and a 15th lens element L15 with negative power, arranged in order from the object side to the image side. The 14th lens element L14 and the 15th lens element L15 are bonded together with an adhesive or the like.

[0080] The sixth lens group G6 consists of a 16th lens element L16 with positive power and a 17th lens element L17 with negative power, arranged in order from the object side to the image side. The 16th lens element L16 and the 17th lens element L17 are bonded together with an adhesive or the like.

[0081] The seventh lens group G7 consists of, in order from the object side to the image side, a 18th lens element L18 having negative power and a 19th lens element L19 having positive power. The 18th lens element L18 and the 19th lens element L19 are bonded lenses joined together with an adhesive or the like.

[0082] Each sub-lens group will be explained.

[0083] The second sub-lens group G2a consists of a fourth lens element L4 having positive power and a fifth lens element L5 having negative power, arranged in order from the object side to the image side. The fourth lens element L4 and the fifth lens element L5 are bonded together with an adhesive or the like.

[0084] The second sub-lens group G2b consists of, in order from the object side to the image side, a sixth lens element L6 with negative power, a seventh lens element L7 with negative power, and an eighth lens element L8 with positive power. The seventh lens element L7 and the eighth lens element L8 are bonded lenses joined together with an adhesive or the like.

[0085] Each lens element will be explained.

[0086] The lens elements in the first lens group G1 are described below. The first lens element L1 is a meniscus lens with a convex surface facing the object. The second lens element L2 is a meniscus lens with a convex surface facing the object. The third lens element L3 is a biconvex lens.

[0087] The lens elements in the second lens group G2 are described below. The fourth lens element L4 is a biconvex lens. The fifth lens element L5 is a biconcave lens. The sixth lens element L6 is a biconcave lens. The seventh lens element L7 is a biconcave lens. The eighth lens element L8 is a meniscus lens with a convex surface on the object side.

[0088] The lens elements in the third lens group G3 are described below. The ninth lens element L9 is a biconvex lens. The tenth lens element L10 is a biconvex lens. The eleventh lens element L11 is a biconcave lens.

[0089] The lens elements in the fourth lens group G4 are described below. The twelfth lens element L12 is a biconcave lens. The thirteenth lens element L13 is a biconvex lens.

[0090] The lens elements in the fifth lens group G5 are described below. The 14th lens element L14 is a meniscus lens with a convex surface on the image side. The 15th lens element L15 is a biconcave lens.

[0091] The lens elements in the sixth lens group G6 are described below. The sixteenth lens element L16 is a biconvex lens. The seventeenth lens element L17 is a meniscus lens with a convex surface on the image side.

[0092] The lens elements in the seventh lens group G7 are described below. The eighteenth lens element L18 is a biconcave lens. The ninth lens element L19 is a meniscus lens with a convex surface on the object side.

[0093] In the imaging optical system according to Embodiment 3, when zooming from the wide-angle end to the telephoto end during imaging, the first lens group G1, the third lens group G3, the fourth lens group G4, the fifth lens group G5, and the seventh lens group G7 move toward the object side 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 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 and then increases, the distance between the fourth lens group G4 and the fifth lens group G5 increases and then decreases, the distance between the fifth lens group G5 and the sixth lens group G6 increases, the distance between the sixth lens group G6 and the seventh lens group G7 decreases, and the distance between the seventh lens group G7 and the image plane S increases.

[0094] In the imaging optical system according to Embodiment 3, when focusing from a state of point focus on an object at infinity to a state of focus on a nearby object, the fifth lens group G5 moves toward the image side along the optical axis.

[0095] Furthermore, the second sub-lens group G2b (vibration-damping group) within the second lens group G2 moves perpendicular to the optical axis to optically correct image blur. This image blur correction lens element allows the imaging optical system to correct image point movement caused by vibrations of the entire system. In other words, the imaging optical system can optically correct image blur caused by camera shake, vibrations, etc.

[0096] (Embodiment 4) Figure 4A shows the imaging optical system according to Embodiment 4.

[0097] The imaging optical system consists of, in order from the object side to the image side, a first lens group G1 with positive power, a second lens group G2 with negative power, a third lens group G3 with positive power, a fourth lens group G4 with positive power, a fifth lens group G5 with negative power, a sixth lens group G6 with positive power, and a seventh lens group G7 with negative power.

[0098] The imaging optical system forms an image at the position of the image plane S.

[0099] Let's explain each lens group.

[0100] The first lens group G1 consists of, in order from the object side to the image side, a first lens element L1 having negative power, a second lens element L2 having positive power, and a third lens element L3 having positive power.

[0101] The second lens group G2 consists of a second sub-lens group G2a with negative power and a second sub-lens group G2b with negative power, arranged in order from the object side to the image side.

[0102] The third lens group G3 consists of, in order from the object side to the image side, a ninth lens element L9 with positive power, a tenth lens element L10 with positive power, and an eleventh lens element L11 with negative power. The tenth lens element L10 and the eleventh lens element L11 are bonded lenses joined together with an adhesive or the like.

[0103] The fourth lens group G4 consists of, in order from the object side to the image side, an aperture diaphragm A, a 12th lens element L12 having negative power, and a 13th lens element L13 having positive power. The 12th lens element L12 and the 13th lens element L13 are bonded lenses joined together with an adhesive or the like.

[0104] The fifth lens group G5 consists of a 14th lens element L14 with positive power and a 15th lens element L15 with negative power, arranged in order from the object side to the image side. The 14th lens element L14 and the 15th lens element L15 are bonded together with an adhesive or the like.

[0105] The sixth lens group G6 consists of a 16th lens element L16 with positive power and a 17th lens element L17 with negative power, arranged in order from the object side to the image side. The 16th lens element L16 and the 17th lens element L17 are bonded together with an adhesive or the like.

[0106] The seventh lens group G7 consists of, in order from the object side to the image side, a 18th lens element L18 having negative power and a 19th lens element L19 having positive power. The 18th lens element L18 and the 19th lens element L19 are bonded lenses joined together with an adhesive or the like.

[0107] Each sub-lens group will be explained.

[0108] The second sub-lens group G2a consists of a fourth lens element L4 having positive power and a fifth lens element L5 having negative power, arranged in order from the object side to the image side. The fourth lens element L4 and the fifth lens element L5 are bonded together with an adhesive or the like.

[0109] The second sub-lens group G2b consists of, in order from the object side to the image side, a sixth lens element L6 with negative power, a seventh lens element L7 with negative power, and an eighth lens element L8 with positive power. The seventh lens element L7 and the eighth lens element L8 are bonded lenses joined together with an adhesive or the like.

[0110] Each lens element will be explained.

[0111] The lens elements in the first lens group G1 are described below. The first lens element L1 is a meniscus lens with a convex surface facing the object. The second lens element L2 is a meniscus lens with a convex surface facing the object. The third lens element L3 is a meniscus lens with a convex surface facing the object.

[0112] The lens elements in the second lens group G2 are described below. The fourth lens element L4 is a biconvex lens. The fifth lens element L5 is a biconcave lens. The sixth lens element L6 is a biconcave lens. The seventh lens element L7 is a meniscus lens with a convex surface on the object side. The eighth lens element L8 is a meniscus lens with a convex surface on the object side.

[0113] The lens elements in the third lens group G3 are described below. The ninth lens element L9 is a biconvex lens. The tenth lens element L10 is a biconvex lens. The eleventh lens element L11 is a biconcave lens.

[0114] The lens elements in the fourth lens group G4 are described below. The twelfth lens element L12 is a biconcave lens. The thirteenth lens element L13 is a biconvex lens.

[0115] The lens elements in the fifth lens group G5 are described below. The 14th lens element L14 is a meniscus lens with a convex surface on the image side. The 15th lens element L15 is a biconcave lens.

[0116] The lens elements in the sixth lens group G6 are described below. The sixteenth lens element L16 is a biconvex lens. The seventeenth lens element L17 is a meniscus lens with a convex surface on the image side.

[0117] The lens elements in the seventh lens group G7 are described below. The eighteenth lens element L18 is a biconcave lens. The ninth lens element L19 is a meniscus lens with a convex surface on the object side.

[0118] In the imaging optical system according to Embodiment 4, when zooming from the wide-angle end to the telephoto end during imaging, the first lens group G1, the third lens group G3, the fourth lens group G4, the fifth lens group G5, and the seventh lens group G7 move toward the object side 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 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 and then increases, the distance between the fourth lens group G4 and the fifth lens group G5 increases and then decreases, the distance between the fifth lens group G5 and the sixth lens group G6 increases, the distance between the sixth lens group G6 and the seventh lens group G7 decreases, and the distance between the seventh lens group G7 and the image plane S increases.

[0119] In the imaging optical system according to Embodiment 4, when focusing from a state of point focus on an object at infinity to a state of focus on a nearby object, the fifth lens group G5 moves toward the image side along the optical axis.

[0120] Furthermore, the second sub-lens group G2b (vibration-damping group) within the second lens group G2 moves perpendicular to the optical axis to optically correct image blur. This image blur correction lens element allows the imaging optical system to correct image point movement caused by vibrations of the entire system. In other words, the imaging optical system can optically correct image blur caused by camera shake, vibrations, etc.

[0121] (Embodiment 5) Figure 5A shows the imaging optical system according to Embodiment 5.

[0122] The imaging optical system consists of, in order from the object side to the image side, a first lens group G1 with positive power, a second lens group G2 with negative power, a third lens group G3 with positive power, a fourth lens group G4 with positive power, a fifth lens group G5 with negative power, a sixth lens group G6 with positive power, and a seventh lens group G7 with negative power.

[0123] The imaging optical system forms an image at the position of the image plane S.

[0124] Let's explain each lens group.

[0125] The first lens group G1 consists of, in order from the object side to the image side, a first lens element L1 having negative power, a second lens element L2 having positive power, and a third lens element L3 having positive power.

[0126] The second lens group G2 consists of a second sub-lens group G2a with negative power and a second sub-lens group G2b with negative power, arranged in order from the object side to the image side.

[0127] The third lens group G3 consists of, in order from the object side to the image side, a ninth lens element L9 with positive power, a tenth lens element L10 with positive power, and an eleventh lens element L11 with negative power. The tenth lens element L10 and the eleventh lens element L11 are bonded lenses joined together with an adhesive or the like.

[0128] The fourth lens group G4 consists of, in order from the object side to the image side, an aperture diaphragm A, a 12th lens element L12 having negative power, and a 13th lens element L13 having positive power. The 12th lens element L12 and the 13th lens element L13 are bonded lenses joined together with an adhesive or the like.

[0129] The fifth lens group G5 consists of a 14th lens element L14 with positive power and a 15th lens element L15 with negative power, arranged in order from the object side to the image side. The 14th lens element L14 and the 15th lens element L15 are bonded together with an adhesive or the like.

[0130] The sixth lens group G6 consists of a positive-powered 16th lens element L16, arranged sequentially from the object side to the image side.

[0131] The seventh lens group G7 consists of a 17th lens element L17 with negative power and a 18th lens element L18 with positive power, arranged in order from the object side to the image side. The 17th lens element L17 and the 18th lens element L18 are bonded lenses joined together with an adhesive or the like.

[0132] Each sub-lens group will be explained.

[0133] The second sub-lens group G2a consists of a fourth lens element L4 having positive power and a fifth lens element L5 having negative power, arranged in order from the object side to the image side. The fourth lens element L4 and the fifth lens element L5 are bonded together with an adhesive or the like.

[0134] The second sub-lens group G2b consists of, in order from the object side to the image side, a sixth lens element L6 with negative power, a seventh lens element L7 with negative power, and an eighth lens element L8 with positive power. The seventh lens element L7 and the eighth lens element L8 are bonded lenses joined together with an adhesive or the like.

[0135] Each lens element will be explained.

[0136] The lens elements in the first lens group G1 are described below. The first lens element L1 is a meniscus lens with a convex surface facing the object. The second lens element L2 is a meniscus lens with a convex surface facing the object. The third lens element L3 is a meniscus lens with a convex surface facing the object.

[0137] The lens elements in the second lens group G2 are described below. The fourth lens element L4 is a biconvex lens. The fifth lens element L5 is a biconcave lens. The sixth lens element L6 is a biconcave lens. The seventh lens element L7 is a biconcave lens. The eighth lens element L8 is a meniscus lens with a convex surface on the object side.

[0138] The lens elements in the third lens group G3 are described below. The ninth lens element L9 is a biconvex lens. The tenth lens element L10 is a biconvex lens. The eleventh lens element L11 is a biconcave lens.

[0139] The lens elements in the fourth lens group G4 are described below. The twelfth lens element L12 is a biconcave lens. The thirteenth lens element L13 is a biconvex lens.

[0140] The lens elements in the fifth lens group G5 are described below. The 14th lens element L14 is a biconvex lens. The 15th lens element L15 is a biconcave lens.

[0141] The lens elements in the sixth lens group G6 are described below. The sixteenth lens element L16 is a biconvex lens.

[0142] The lens elements in the seventh lens group G7 are described below. The seventeenth lens element L17 is a biconcave lens. The eighteenth lens element L18 is a meniscus lens with a convex surface on the object side.

[0143] In the imaging optical system according to Embodiment 5, when zooming from the wide-angle end to the telephoto end during imaging, the first lens group G1, the third lens group G3, the fourth lens group G4, the fifth lens group G5, and the seventh lens group G7 move toward the object side with respect 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 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 and then increases, the distance between the fourth lens group G4 and the fifth lens group G5 increases and then decreases, the distance between the fifth lens group G5 and the sixth lens group G6 increases, the distance between the sixth lens group G6 and the seventh lens group G7 decreases, and the distance between the seventh lens group G7 and the image plane S increases.

[0144] In the imaging optical system according to Embodiment 5, when focusing from a state of point focus on an object at infinity to a state of focus on a nearby object, the fifth lens group G5 moves toward the image side along the optical axis.

[0145] Furthermore, the second sub-lens group G2b (vibration-damping group) within the second lens group G2 moves perpendicular to the optical axis to optically correct image blur. This image blur correction lens element allows the imaging optical system to correct image point movement caused by vibrations of the entire system. In other words, the imaging optical system can optically correct image blur caused by camera shake, vibrations, etc.

[0146] (Embodiment 6) Figure 6A shows the imaging optical system according to Embodiment 6.

[0147] The imaging optical system consists of, in order from the object side to the image side, a first lens group G1 with positive power, a second lens group G2 with negative power, a third lens group G3 with positive power, a fourth lens group G4 with positive power, a fifth lens group G5 with negative power, a sixth lens group G6 with positive power, and a seventh lens group G7 with negative power.

[0148] The imaging optical system forms an image at the position of the image plane S.

[0149] Let's explain each lens group.

[0150] The first lens group G1 consists of, in order from the object side to the image side, a first lens element L1 having negative power, a second lens element L2 having positive power, and a third lens element L3 having positive power.

[0151] The second lens group G2 consists of a second sub-lens group G2a with positive power and a second sub-lens group G2b with negative power, arranged in order from the object side to the image side.

[0152] The third lens group G3 consists of, in order from the object side to the image side, a ninth lens element L9 with positive power, a tenth lens element L10 with positive power, and an eleventh lens element L11 with negative power. The tenth lens element L10 and the eleventh lens element L11 are bonded lenses joined together with an adhesive or the like.

[0153] The fourth lens group G4 consists of, in order from the object side to the image side, an aperture diaphragm A, a 12th lens element L12 having negative power, and a 13th lens element L13 having positive power. The 12th lens element L12 and the 13th lens element L13 are bonded lenses joined together with an adhesive or the like.

[0154] The fifth lens group G5 consists of a 14th lens element L14 with positive power and a 15th lens element L15 with negative power, arranged in order from the object side to the image side. The 14th lens element L14 and the 15th lens element L15 are bonded together with an adhesive or the like.

[0155] The sixth lens group G6 consists of a 16th lens element L16 with positive power and a 17th lens element L17 with negative power, arranged in order from the object side to the image side. The 16th lens element L16 and the 17th lens element L17 are bonded together with an adhesive or the like.

[0156] The seventh lens group G7 consists of, in order from the object side to the image side, a 18th lens element L18 having negative power and a 19th lens element L19 having positive power. The 18th lens element L18 and the 19th lens element L19 are bonded lenses joined together with an adhesive or the like.

[0157] Each sub-lens group will be explained.

[0158] The second sub-lens group G2a consists of a fourth lens element L4 having positive power and a fifth lens element L5 having negative power, arranged in order from the object side to the image side. The fourth lens element L4 and the fifth lens element L5 are bonded together with an adhesive or the like.

[0159] The second sub-lens group G2b consists of, in order from the object side to the image side, a sixth lens element L6 with negative power, a seventh lens element L7 with negative power, and an eighth lens element L8 with positive power. The seventh lens element L7 and the eighth lens element L8 are bonded lenses joined together with an adhesive or the like.

[0160] Each lens element will be explained.

[0161] The lens elements in the first lens group G1 are described below. The first lens element L1 is a meniscus lens with a convex surface facing the object. The second lens element L2 is a meniscus lens with a convex surface facing the object. The third lens element L3 is a biconvex lens.

[0162] The lens elements in the second lens group G2 are described below. The fourth lens element L4 is a biconvex lens. The fifth lens element L5 is a meniscus lens with a convex surface on the image side. The sixth lens element L6 is a biconcave lens. The seventh lens element L7 is a biconcave lens. The eighth lens element L8 is a meniscus lens with a convex surface on the object side.

[0163] The lens elements in the third lens group G3 are described below. The ninth lens element L9 is a biconvex lens. The tenth lens element L10 is a biconvex lens. The eleventh lens element L11 is a biconcave lens.

[0164] The lens elements in the fourth lens group G4 are described below. The twelfth lens element L12 is a biconcave lens. The thirteenth lens element L13 is a biconvex lens.

[0165] The lens elements in the fifth lens group G5 are described below. The 14th lens element L14 is a meniscus lens with a convex surface on the image side. The 15th lens element L15 is a biconcave lens.

[0166] The lens elements in the sixth lens group G6 are described below. The sixteenth lens element L16 is a biconvex lens. The seventeenth lens element L17 is a meniscus lens with a convex surface on the image side.

[0167] The lens elements in the seventh lens group G7 are described below. The eighteenth lens element L18 is a biconcave lens. The ninth lens element L19 is a meniscus lens with a convex surface on the object side.

[0168] In the imaging optical system according to Embodiment 6, when zooming from the wide-angle end to the telephoto end during imaging, the first lens group G1, the third lens group G3, the fourth lens group G4, the fifth lens group G5, and the seventh lens group G7 move toward the object 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 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 and then increases, the distance between the fourth lens group G4 and the fifth lens group G5 increases and then decreases, the distance between the fifth lens group G5 and the sixth lens group G6 increases, the distance between the sixth lens group G6 and the seventh lens group G7 decreases, and the distance between the seventh lens group G7 and the image plane S increases.

[0169] In the imaging optical system according to Embodiment 6, when focusing from a state of point focus on an object at infinity to a state of focus on a nearby object, the fifth lens group G5 moves toward the image side along the optical axis.

[0170] Furthermore, the second sub-lens group G2b (vibration-damping group) within the second lens group G2 moves perpendicular to the optical axis to optically correct image blur. This image blur correction lens element allows the imaging optical system to correct image point movement caused by vibrations of the entire system. In other words, the imaging optical system can optically correct image blur caused by camera shake, vibrations, etc.

[0171] (Embodiment 7) Figure 7A shows the imaging optical system according to Embodiment 7.

[0172] The imaging optical system consists of, in order from the object side to the image side, a first lens group G1 with positive power, a second lens group G2 with negative power, a third lens group G3 with positive power, a fourth lens group G4 with positive power, a fifth lens group G5 with negative power, a sixth lens group G6 with positive power, and a seventh lens group G7 with negative power.

[0173] The imaging optical system forms an image at the position of the image plane S.

[0174] Let's explain each lens group.

[0175] The first lens group G1 consists of, in order from the object side to the image side, a first lens element L1 having negative power, a second lens element L2 having positive power, and a third lens element L3 having positive power.

[0176] The second lens group G2 consists of a second sub-lens group G2a with negative power and a second sub-lens group G2b with negative power, arranged in order from the object side to the image side.

[0177] The third lens group G3 consists of, in order from the object side to the image side, a ninth lens element L9 with positive power, a tenth lens element L10 with positive power, and an eleventh lens element L11 with negative power. The tenth lens element L10 and the eleventh lens element L11 are bonded lenses joined together with an adhesive or the like.

[0178] The fourth lens group G4 consists of, in order from the object side to the image side, an aperture diaphragm A, a 12th lens element L12 having negative power, and a 13th lens element L13 having positive power. The 12th lens element L12 and the 13th lens element L13 are bonded lenses joined together with an adhesive or the like.

[0179] The fifth lens group G5 consists of a 14th lens element L14 with positive power and a 15th lens element L15 with negative power, arranged in order from the object side to the image side. The 14th lens element L14 and the 15th lens element L15 are bonded together with an adhesive or the like.

[0180] The sixth lens group G6 consists of a 16th lens element L16 with positive power and a 17th lens element L17 with negative power, arranged in order from the object side to the image side. The 16th lens element L16 and the 17th lens element L17 are bonded together with an adhesive or the like.

[0181] The seventh lens group G7 consists of, in order from the object side to the image side, a 18th lens element L18 having negative power and a 19th lens element L19 having positive power. The 18th lens element L18 and the 19th lens element L19 are bonded lenses joined together with an adhesive or the like.

[0182] Each sub-lens group will be explained.

[0183] The second sub-lens group G2a consists of a fourth lens element L4 having positive power and a fifth lens element L5 having negative power, arranged in order from the object side to the image side. The fourth lens element L4 and the fifth lens element L5 are bonded together with an adhesive or the like.

[0184] The second sub-lens group G2b consists of, in order from the object side to the image side, a sixth lens element L6 with negative power, a seventh lens element L7 with negative power, and an eighth lens element L8 with positive power. The seventh lens element L7 and the eighth lens element L8 are bonded lenses joined together with an adhesive or the like.

[0185] Each lens element will be explained.

[0186] The lens elements in the first lens group G1 are described below. The first lens element L1 is a meniscus lens with a convex surface facing the object. The second lens element L2 is a meniscus lens with a convex surface facing the object. The third lens element L3 is a biconvex lens.

[0187] The lens elements in the second lens group G2 are described below. The fourth lens element L4 is a biconvex lens. The fifth lens element L5 is a biconcave lens. The sixth lens element L6 is a biconcave lens. The seventh lens element L7 is a meniscus lens with a convex surface on the object side. The eighth lens element L8 is a meniscus lens with a convex surface on the object side.

[0188] The lens elements in the third lens group G3 are described below. The ninth lens element L9 is a biconvex lens. The tenth lens element L10 is a biconvex lens. The eleventh lens element L11 is a biconcave lens.

[0189] The lens elements in the fourth lens group G4 are described below. The twelfth lens element L12 is a biconcave lens. The thirteenth lens element L13 is a biconvex lens.

[0190] The lens elements in the fifth lens group G5 are described below. The 14th lens element L14 is a biconvex lens. The 15th lens element L15 is a biconcave lens.

[0191] The lens elements in the sixth lens group G6 are described below. The sixteenth lens element L16 is a biconvex lens. The seventeenth lens element L17 is a meniscus lens with a convex surface on the image side.

[0192] The lens elements in the seventh lens group G7 are described below. The eighteenth lens element L18 is a biconcave lens. The ninth lens element L19 is a meniscus lens with a convex surface on the object side.

[0193] In the imaging optical system according to Embodiment 7, when zooming from the wide-angle end to the telephoto end during imaging, the first lens group G1, the third lens group G3, the fourth lens group G4, the fifth lens group G5, and the seventh lens group G7 move toward the object side with respect 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 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 and then increases, the distance between the fourth lens group G4 and the fifth lens group G5 increases and then decreases, the distance between the fifth lens group G5 and the sixth lens group G6 increases, the distance between the sixth lens group G6 and the seventh lens group G7 decreases, and the distance between the seventh lens group G7 and the image plane S increases.

[0194] In the imaging optical system according to Embodiment 7, when focusing from a state of point focus on an object at infinity to a state of focus on a nearby object, the fifth lens group G5 moves toward the image side along the optical axis.

[0195] Furthermore, the second sub-lens group G2b (vibration-damping group) within the second lens group G2 moves perpendicular to the optical axis to optically correct image blur. This image blur correction lens element allows the imaging optical system to correct image point movement caused by vibrations of the entire system. In other words, the imaging optical system can optically correct image blur caused by camera shake, vibrations, etc.

[0196] (Other embodiments) As described above, Embodiments 1 to 7 have been explained as examples of the technology disclosed in this application. However, the technology in this disclosure is not limited thereto and can be applied to embodiments that are modified, replaced, added, or omitted as appropriate.

[0197] In the imaging optical systems described in Embodiments 1 to 7 above, the entire zoom range from the wide-angle end to the telephoto end was used as an example, but it is not always necessary to use the entire zoom range. For example, depending on the desired zoom range, a range in which optical performance is ensured may be selected and used as the imaging optical system. In other words, it may be used as an imaging optical system with a lower magnification than the imaging optical system described in Numerical Examples 1 to 7 corresponding to Embodiments 1 to 7 below. Also, depending on the desired zoom position, a focal length in which optical performance is ensured may be selected and used as a fixed-focal-length lens system.

[0198] Furthermore, the number of lens groups and the number of lens elements within each lens group are practical numbers, and it is acceptable to add lenses that do not actually possess any power.

[0199] Furthermore, while image blur correction is performed by moving the image blur correction lens element perpendicular to the optical axis, it is possible to correct image blur by moving it in a way that has a vertical component. For example, if the complexity of the lens barrel structure is acceptable, image blur correction may be performed by rotating the image blur correction lens element so that its center of rotation is on the optical axis.

[0200] (Conditions and effects, etc.) The following describes the conditions that the imaging optical systems according to Embodiments 1 to 7 can satisfy. While multiple possible conditions are defined for the imaging optical systems according to Embodiments 1 to 7, the configuration that satisfies all of these conditions is the most effective. However, it is also possible to obtain an imaging optical system that achieves the corresponding effect by satisfying individual conditions.

[0201] The imaging optical system according to Embodiments 1 to 7 consists 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, 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 positive power, and a seventh lens group G7 having negative power. When zooming from the wide-angle end to the telephoto end, the spacing between adjacent lens groups changes. The second lens group G2 and the sixth lens group G6 are fixed with respect to the image plane S. This configuration is the basic configuration.

[0202] The basic configuration of the imaging optical system is well-suited for miniaturizing zoom lenses. This allows for the cancellation of various aberrations that occur in each lens group during zooming. As a result, it is possible to provide an imaging optical system in which aberrations are well corrected across the entire zoom range.

[0203] Furthermore, for example, in an imaging optical system, the second lens group G2 consists of a second sub-lens group G2a and a second sub-lens group G2b. It is desirable to perform vibration isolation by moving the second sub-lens group G2b in a direction perpendicular to the optical axis, thereby satisfying the following condition (1).

[0204] 0.8 <f2b / f2 < 1.3 ···(1) Here, f2: Focal length of the second lens group G2, f2b: Focal length of the second sub-lens group G2b, That is the case.

[0205] Condition (1) is a condition for defining the ratio of the focal length of the second lens group G2 to the focal length of the second sub-lens group G2b in the imaging optical system.

[0206] By satisfying condition (1), aberration fluctuations during vibration isolation can be suppressed, and the imaging optical system can be miniaturized.

[0207] If the value falls below the lower limit of condition (1), the negative refractive power of the second sub-lens group G2b becomes too strong, causing various aberrations occurring within the second sub-lens group G2b, particularly spherical aberration and coma aberration, to increase. As a result, it becomes difficult to suppress variations in aberrations due to eccentricity during vibration isolation, especially coma aberration and astigmatism.

[0208] Conversely, if the upper limit of condition (1) is exceeded, the negative refractive power of the second sub-lens group G2b becomes too weak. As a result, the amount of movement perpendicular to the optical axis during vibration isolation increases, the outer diameter of the imaging optical system increases, and miniaturization and weight reduction become difficult.

[0209] Preferably, the above effects can be further enhanced by satisfying either or both of the following conditions (1a) and (1b).

[0210] 0.9 <f2b / f2 ···(1a) f2b / f2 < 1.2 ···(1b) More preferably, the aforementioned effects can be further enhanced by satisfying either or both of the following conditions (1c) and (1d).

[0211] 0.95 <f2b / f2 ···(1c) f2b / f2 < 1.15 ···(1d) Furthermore, for example, in an imaging optical system, the fifth lens group G5 consists of a positive lens element and a negative lens element, arranged in order from the object side to the image side. When focusing from an object at infinity to an object at a close distance, the fifth lens group G5 moves toward the image side. And it is desirable that the following condition (2) is satisfied.

[0212] -11 < (1 - βTF × βTF) × (βTR × βTR) < -7 ... (2) Here, βTF: Horizontal magnification of the 5th lens group G5 when focused at infinity at the telephoto end, βTR: The combined horizontal magnification of the lens group positioned closer to the image than the 5th lens group G5 when in focus at the telephoto end. That is the case.

[0213] Condition (2) is a condition for defining a preferred range of focus position sensitivity of the focusing lens in the imaging optical system. By satisfying condition (2), the focus position sensitivity of the focus lens can be appropriately set.

[0214] If the value falls below the lower limit of condition (2), the positional sensitivity of the focus lens group increases, making it difficult to control the focus lens group, which is undesirable.

[0215] Conversely, exceeding the upper limit of condition (2) is undesirable because it increases the amount of movement of the focus lens group, resulting in a larger overall imaging optical system.

[0216] Preferably, the above effects can be further enhanced by satisfying either or both of the following conditions (2a) and (2b).

[0217] -10.2<(1-βTF×βTF)×(βTR×βTR) ···(2a) (1-βTF×βTF)×(βTR×βTR)<-7.8 (2b) More preferably, the aforementioned effects can be further enhanced by satisfying either or both of the following conditions (2c) and (2d).

[0218] -9.5<(1-βTF×βTF)×(βTR×βTR) ···(2c) (1-βTF×βTF)×(βTR×βTR)<-8.5 (2d) Furthermore, for example, the imaging optical system should preferably satisfy the following condition (3).

[0219] 0.16 <BFw / fw < 0.3 ···(3) Here, BFw: The distance along the optical axis from the closest lens element to the image plane at the wide-angle end. fw: Total focal length of the system when in focus at infinity at the wide-angle end. That is the case.

[0220] Condition (3) is a condition for defining the ratio of the back focus at the wide-angle end (the distance along the optical axis from the image-side lens element to the image plane S) to the total focal length of the system when in focus at infinity at the wide-angle end of the imaging optical system.

[0221] By satisfying condition (3), aberrations can be well corrected across the entire zoom range, and the imaging optical system can be miniaturized.

[0222] If the value falls below the lower limit of condition (3), the back focus at the wide-angle end becomes shorter, increasing the outer diameter of the final lens, which is undesirable.

[0223] Conversely, exceeding the upper limit of condition (3) is undesirable because it increases the back focus at the wide-angle end, making the entire imaging optical system larger and making it difficult to correct various aberrations, especially chromatic aberration.

[0224] Preferably, the above effects can be further enhanced by satisfying either or both of the following conditions (3a) and (3b).

[0225] 0.18 <BFw / fw ···(3a) BFw / fw < 0.28 ···(3b) More preferably, the aforementioned effects can be further enhanced by satisfying either or both of the following conditions (3c) and (3d).

[0226] 0.20 <BFw / fw ···(3c) BFw / fw < 0.26 ···(3d) Furthermore, for example, the imaging optical system should preferably satisfy the following condition (4).

[0227] 0.1 < f1 / ft < 0.6 ···(4) Here, f1: Focal length of the first lens group G1, ft: Total focal length of the system when in focus at infinity at the telephoto end. That is the case.

[0228] Condition (4) is a condition for defining the ratio of the focal length of the first lens group G1 to the total focal length of the entire system when in focus at infinity at the telephoto end of the imaging optical system.

[0229] By satisfying condition (4), aberrations can be well corrected across the entire zoom range, and the imaging optical system can be miniaturized.

[0230] If the value falls below the lower limit of condition (4), the focal length of the first lens group G1 becomes shorter than the total focal length of the entire system when focused at infinity at the telephoto end, and the image magnification of the combined system from the second lens group onward becomes too high at the telephoto end. This makes it difficult to correct various aberrations, especially axial chromatic aberration at the telephoto end, which is undesirable.

[0231] Conversely, if the upper limit of condition (4) is exceeded, the focal length of the first lens group G1 becomes longer than the total focal length of the entire system when focusing at infinity at the telephoto end, and the amount of movement of the first lens group G1 increases when zooming from the wide-angle end to the telephoto end. This makes it difficult to miniaturize the entire imaging optical system.

[0232] Preferably, the above effects can be further enhanced by satisfying either or both of the following conditions (4a) and (4b).

[0233] 0.2 < f1 / ft ···(4a) f1 / ft < 0.5 ···(4b) More preferably, the aforementioned effects can be further enhanced by satisfying either or both of the following conditions (4c) and (4d).

[0234] 0.3 < f1 / ft ···(4c) f1 / ft < 0.4 ···(4d) Furthermore, in an imaging optical system, for example, it is desirable that the image surface of the positive lens element LG4Fp1, which is the closest to the object in the fourth lens group G4, has a convex shape toward the object.

[0235] This allows for good correction of the flatness of the image plane S across the entire zoom range.

[0236] Furthermore, for example, the imaging optical system should preferably satisfy the following condition (5).

[0237] 0.5 < f3 / f4 < 1.1 ···(5) Here, f3: Focal length of the third lens group G3, f4: Focal length of the fourth lens group G4, That is the case.

[0238] Condition (5) is a condition for defining the ratio of the focal length of the third lens group G3 to the focal length of the fourth lens group G4 in the imaging optical system.

[0239] If the value falls below the lower limit of condition (5), the focal length of the third lens group G3 becomes too small. This makes it difficult to correct various aberrations, especially spherical aberration and axial chromatic aberration at the telephoto end, which is undesirable.

[0240] Conversely, if the upper limit of condition (5) is exceeded, the focal length of the third lens group G3 becomes too large, increasing the amount of movement of the third lens group G3 when zooming from the wide-angle end to the telephoto end. This makes it difficult to miniaturize the entire imaging optical system, which is undesirable.

[0241] Preferably, the above effects can be further enhanced by satisfying either or both of the following conditions (5a) and (5b).

[0242] 0.6 < f3 / f4 ···(5a) f3 / f4 < 1.0 ···(5b) More preferably, the aforementioned effects can be further enhanced by satisfying either or both of the following conditions (5c) and (5d).

[0243] 0.7 < f3 / f4 ···(5c) f3 / f4 < 0.9 ···(5d) Furthermore, for example, the imaging optical system should preferably satisfy the following condition (6).

[0244] 0.08 < f6 / ft < 0.20 ···(6) Here, f6: Focal length of lens group G6, ft: Total focal length of the system when in focus at infinity at the telephoto end. That is the case.

[0245] Condition (6) is a condition for defining the ratio of the focal length of the sixth lens group G6 to the total focal length of the entire system when in focus at infinity at the telephoto end of the imaging optical system.

[0246] If the value falls below the lower limit of condition (6), the focal length of the sixth lens group G6 becomes too small. This makes it difficult to correct various aberrations, especially chromatic aberration, which is undesirable.

[0247] Conversely, if the upper limit of condition (6) is exceeded, the focal length of the sixth lens group G6 becomes too large. The amount of movement of the seventh lens group increases when zooming from the wide-angle end to the telephoto end. This makes it difficult to miniaturize the entire imaging optical system, which is undesirable.

[0248] Preferably, the above effects can be further enhanced by satisfying either or both of the following conditions (6a) and (6b).

[0249] 0.10 < f6 / ft ···(6a) f6 / ft < 0.18 ···(6b) More preferably, the aforementioned effects can be further enhanced by satisfying either or both of the following conditions (6c) and (6d).

[0250] 0.12 < f6 / ft ···(6c) f6 / ft < 0.16 ···(6d) Furthermore, in an imaging optical system, for example, the seventh lens group G7 preferably consists of a negative lens element and a positive lens element in order from the object side to the image side, and satisfies the following condition (7).

[0251] -0.18 < f7 / ft< -0.06 (7) Here, f7: Focal length of lens group G7, That is the case.

[0252] Condition (7) is a condition for defining the ratio of the focal length of the seventh lens group G7 to the total focal length of the entire system when in focus at infinity at the telephoto end of the imaging optical system.

[0253] If the value falls below the lower limit of condition (7), the focal length of lens group G7 becomes too small. This results in large fluctuations in spherical aberration and coma aberration associated with zooming, which is undesirable.

[0254] Conversely, if it exceeds the upper limit of condition (7), the focal length of the seventh lens group G7 becomes too large, and the movement amount of the seventh lens group G7 during zooming from the wide-angle end to the telephoto end increases. Therefore, it becomes difficult to miniaturize the entire imaging optical system.

[0255] Preferably, by satisfying either one or both of the following conditions (7a) and (7b), the above effects can be further achieved.

[0256] -0.16 < f7 / ft ···(7a) f7 / ft < -0.08 ···(7b) More preferably, by satisfying either one or both of the following conditions (7c) and (7d), the above-mentioned effects can be further achieved.

[0257] -0.14 < f7 / ft ···(7c) f7 / ft < -0.10 ···(7d) Also, for example, in the imaging optical system, the first lens group G1 is preferably composed of a negative lens element, a positive lens element, and a positive lens element in order from the object side to the image side. Thereby, various aberrations, particularly spherical aberration and axial chromatic aberration, can be corrected well.

[0258] Also, for example, in the imaging optical system, it is desirable to satisfy the following condition (8).

[0259] 1.85 < nd_3Gn < 2.15 ···(8) Here, nd_3Gn: The refractive index of the negative lens element in the third lens group G3 with respect to the d-line, is.

[0260] Condition (i) is a condition for defining the refractive index of the negative lens element in the third lens group G3 with respect to the d-line in the imaging optical system.

[0261] If the refractive index falls below the lower limit of condition (8), the refractive index of the negative lens element in the third lens group G3 becomes low, making it difficult to correct various aberrations, especially field curvature, which is undesirable.

[0262] Conversely, if the upper limit of condition (8) is exceeded, the refractive index of the negative lens element in the third lens group G3 increases, resulting in a decrease in light transmittance, which is undesirable.

[0263] Preferably, the above effects can be further enhanced by satisfying either or both of the following conditions (8a) and (8b).

[0264] 1.90 < nd_3Gn ···(8a) nd_3Gn< 2.10 ···(8b) More preferably, the aforementioned effects can be further enhanced by satisfying either or both of the following conditions (8c) and (8d).

[0265] 1.95 < nd_3Gn ···(8c) nd_3Gn< 2.05 ···(8d) Furthermore, for example, in an imaging optical system, it is desirable that the following condition (9) be satisfied.

[0266] 1.85 < nd_4Gn < 2.15 (9) Here, nd_4Gn: Refractive index of the negative lens element in the fourth lens group G4 with respect to the d line. That is the case.

[0267] Condition (9) is a condition for defining the refractive index of the negative lens element in the fourth lens group G4 of the imaging optical system with respect to the d line.

[0268] If the refractive index falls below the lower limit of condition (9), the refractive index of the negative lens element in the fourth lens group G4 becomes low, making it difficult to correct various aberrations, especially field curvature, which is undesirable.

[0269] Conversely, if it exceeds the upper limit of condition (9), the refractive index of the negative lens element in the fourth lens group G4 becomes high and the light transmittance becomes low, which is not preferable.

[0270] Preferably, by satisfying either one or both of the following conditions (9a) and (9b), the above effects can be further achieved.

[0271] 1.90 < nd_4Gn ···(9a) nd_4Gn < 2.10 ···(9b) More preferably, by satisfying either one or both of the following conditions (9c) and (9d), the above-mentioned effects can be further achieved.

[0272] 1.95 < nd_4Gn ···(9c) nd_4Gn < 2.05 ···(9d) Also, for example, in an imaging optical system, the second a sub-lens group G2a preferably consists of a positive lens element and a negative lens element in order from the object side and satisfies the following condition (10).

[0273] 20 < vd_2ap < 30 ···(10) Here, vd_2ap: Abbe number of the positive lens element in the second a sub-lens group G2a with respect to the d-line, is.

[0274] Condition (10) is a condition for defining the Abbe number of the positive lens element in the second a sub-lens group G2a in the imaging optical system with respect to the d-line.

[0275] If it is below the lower limit of condition (10), it is not preferable because it becomes difficult to correct various aberrations, particularly the longitudinal chromatic aberration at the wide-angle end.

[0276] Conversely, if it exceeds the upper limit of condition (10), it is not preferable because it becomes difficult to correct various aberrations, particularly the longitudinal chromatic aberration at the telephoto end.

[0277] Preferably, the above effects can be further enhanced by satisfying either or both of the following conditions (10a) and (10b).

[0278] 22 < vd_2ap ···(10a) vd_2ap < 28 ···(10b) More preferably, the above-mentioned effects can be further enhanced by satisfying either or both of the following conditions (10c) and (10d).

[0279] 24 < vd_2ap ···(10c) vd_2ap < 26 ···(10d) (Schematic configuration of the imaging device to which Embodiment 1 is applied) Figure 8 shows a schematic configuration of an imaging device to which the imaging optical system according to Embodiment 1 is applied. It is also possible to apply the imaging optical systems according to Embodiments 2 to 7 to the imaging device.

[0280] The imaging device 100 consists of a housing 104, an image sensor 102, and an imaging optical system 101 according to Embodiment 1. A specific example of the imaging device 100 is a digital camera.

[0281] The lens barrel 302 holds each lens group of the imaging optical system 101 and the aperture diaphragm A.

[0282] The image sensor 102 is positioned at the image plane S in the imaging optical system according to this embodiment 1.

[0283] The imaging optical system 101 is configured such that, when zooming from the wide-angle end to the telephoto end, the spacing between adjacent lens groups G1, G3, G4, G5, G6, and G7 changes, and the lens frames included in the lens barrel 302 are attached to or engaged with it.

[0284] Furthermore, actuators and lens frames controlled by a controller inside the lens barrel 302 are configured so that the fifth lens group G5 moves during focusing.

[0285] This makes it possible to realize an imaging device that can effectively correct various aberrations.

[0286] Although the image imaging optical system according to Embodiment 1 described above was shown as being applied to a digital camera, it can also be applied to surveillance cameras, smartphones, and the like.

[0287] (Schematic configuration of the camera system to which Embodiment 1 is applied) Figure 9 shows a schematic configuration of a camera system to which the imaging optical system according to Embodiment 1 is applied. It is also possible to apply the imaging optical systems according to Embodiments 2 to 7 to the camera system.

[0288] The camera system 200 comprises a camera body 201 and an interchangeable lens device 300 that is detachably connected to the camera body 201.

[0289] 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) for storing the image signal, a camera mount section 204, and a viewfinder 205.

[0290] The imaging optical system of the interchangeable lens device 300 is the imaging optical system according to Embodiment 1.

[0291] The lens barrel 302 includes each lens group of the imaging optical system 301 and a lens mount portion 304 that holds the aperture diaphragm A and is connected to the camera mount portion 204 of the camera body 201.

[0292] The camera mount section 204 and the lens mount section 304 not only provide a physical connection, but also function as an interface that electrically connects the controller (not shown) in the camera body 201 and the controller (not shown) in the interchangeable lens device 300, enabling the exchange of signals between them.

[0293] The imaging optical system 301 is incorporated into the lens barrel 302, and is configured such that the lens frame included in the lens barrel 302 can be attached to or engaged with the lens frame so that the spacing between adjacent lens groups of the first lens group G1, third lens group G3, fourth lens group G4, fifth lens group G5, sixth lens group G6, and seventh lens group G7 can be changed when zooming from the wide-angle end to the telephoto end.

[0294] The imaging optical system 301, which consists of each lens group held by the lens barrel 302 and the camera body 201, is configured with actuators and lens frames controlled by a controller in the interchangeable lens device 300 so that the fifth lens group G5 moves during focusing.

[0295] (Examples of numerical values) The following describes numerical examples of the imaging optical systems according to Embodiments 1 to 7. In each numerical example, the unit of length in the table is "mm" and the unit of field of view is "°". In each numerical example, r is the radius of curvature, d is the interplanar 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, the surface marked with an asterisk (*) is an aspherical surface, and the aspherical shape is defined by the following formula.

[0296]

number

[0297] Here, Z: The distance from a point on the aspherical surface at height h from the optical axis to the tangent plane of the aspherical surface's vertex. h: height from the optical axis, r: radius of curvature of the vertex, κ: cone constant, An: nth-order aspherical coefficient That is the case.

[0298] Figures 1B, 2B, 3B, 4B, 5B, 6B, and 7B are longitudinal aberration diagrams of the imaging optical systems according to Embodiments 1 to 7 in the state of infinity focus.

[0299] In each longitudinal aberration diagram, (a) shows the aberration at the wide-angle end, (b) shows the aberration at the mid-angle position, and (c) shows the aberration at the telephoto end. Each longitudinal aberration diagram shows, from left to right, spherical aberration (SA (mm)), astigmatism (AST (mm)), and distortion (DIS (%)). In the spherical aberration diagram, the vertical axis represents the F-number (indicated as F in the diagram), the solid line represents the d-line, the short dashed line represents the F-line, and the long dashed line represents the C-line. In the astigmatism diagram, the vertical axis represents the image height (indicated as H in the diagram), the solid line represents the sagittal plane (indicated as s in the diagram), and the dashed line represents the meridional plane (indicated as m in the diagram). In the distortion diagram, the vertical axis represents the image height (indicated as H in the diagram).

[0300] Figures 1C, 2C, 3C, 4C, 5C, 6C, and 7C are lateral aberration diagrams at the telephoto end of the imaging optical systems according to Embodiments 1 to 7, respectively.

[0301] In each lateral aberration diagram, the top three diagrams correspond to the basic state without image blur correction at the telephoto end, and the bottom three diagrams correspond to the image blur correction state at the telephoto end, where the image blur correction lens group has been moved by a predetermined amount in a direction perpendicular to the optical axis. In each lateral aberration diagram of the basic state, the top diagram corresponds to the lateral aberration at the image point at 70% of the maximum image height, the middle diagram corresponds to the lateral aberration at the on-axis image point, and the bottom diagram corresponds to the lateral aberration at the image point at -70% of the maximum image height. In each lateral aberration diagram of the image blur correction state, the top diagram corresponds to the lateral aberration at the image point at 70% of the maximum image height, the middle diagram corresponds to the lateral aberration at the on-axis image point, and the bottom diagram corresponds to the lateral aberration at the image point at -70% of the maximum image height. In each lateral aberration diagram, the horizontal axis represents the distance from the principal ray on the pupil plane, with solid lines representing the d-line, short dashed lines representing the F-line, and long dashed lines representing the C-line.

[0302] Furthermore, for each embodiment of the imaging optical system, the amount of movement of the image blur correction lens group in the direction perpendicular to the optical axis at the telephoto end in the image blur correction state is as follows.

[0303] Numerical Example 1: 0.738 mm Numerical example 2: 0.806 mm Numerical example 3: 0.683 mm Numerical example 4: 0.921 mm Numerical example 5: 0.806 mm Numerical example 6: 0.806 mm Numerical example 7: 0.806 mm At the telephoto end with an infinity focus distance, the image eccentricity when the imaging optical system is tilted by 0.3 degrees is equal to the image eccentricity when the image blur correction lens group is translated by the above values ​​in a direction perpendicular to the optical axis.

[0304] As is clear from each lateral aberration diagram, the symmetry of lateral aberration at the on-axis image point is good. Furthermore, comparing the lateral aberration at the +70% image point and the -70% image point in the basic state, both show small curvature and nearly equal slopes of the aberration curves, indicating small eccentric coma and eccentric astigmatism. This means that sufficient imaging performance is obtained even in the image shake correction state. In addition, when the image shake correction angle of the imaging optical system is the same, the amount of parallel shift required for image shake correction decreases as the focal length of the entire imaging optical system decreases. Therefore, at any zoom position, it is possible to perform sufficient image shake correction for an image shake correction angle of about 0.3 degrees without degrading the imaging characteristics.

[0305] (Numerical Example 1) The imaging optical system of Numerical Example 1 corresponds to Embodiment 1 shown in Figure 1A. The surface data of the imaging optical system of Numerical Example 1 is shown in Table 1A, the aspherical data in Table 1B, and the various data in the infinity focus state are shown in Tables 1C to 1F.

[0306] (Table 1A: Surface data) Face number rd nd vd object surface ∞ 1 146.05180 2.20000 1.83481 42.7 2 85.08960 0.30000 3 88.63860 7.41070 1.43700 95.1 4 757.12520 0.30000 5 79.51600 8.76930 1.43700 95.1 6 ∞ Variable 7 129.63500 3.63600 1.85451 25.2 8 -115.64990 0.01000 1.56732 42.8 9 -115.64990 1.20000 1.83400 37.3 10 118.18150 4.10500 11 -510.39340 1.10000 1.72916 54.7 12 68.31050 2.65380 13 -118.91230 0.90000 1.49700 81.6 14 77.31990 0.01000 1.56732 42.8 15 77.31990 1.95520 1.80809 22.8 16 203.53620 Variable 17 143.79420 3.31330 1.80420 46.5 18 -76.44480 1.59080 19 48.42100 5.29970 1.43700 95.1 20 -48.42100 0.01000 1.56732 42.8 21 -48.42100 1.00000 2.05090 26.9 22 419.43030 Variable 23 (aperture) ∞ 4.33140 24 -713.21390 0.80000 2.00069 25.5 25 114.08840 0.01000 1.56732 42.8 26 114.08840 4.49120 1.73037 32.2 27 -54.81050 Variable 28 1245.70520 3.35910 1.73037 32.2 29 -26.61610 0.01000 1.56732 42.8 30 -26.61610 0.60000 1.70154 41.1 31 39.16700 Variable 32 70.08010 5.02930 1.56732 42.8 33 -40.82180 0.01000 1.56732 42.8 34 -40.82180 1.00000 1.80610 33.3 35 -62.10300 Variable 36 -81.79000 1.20000 1.74400 44.8 37 33.68260 0.01000 1.56732 42.8 38 33.68260 3.54170 1.77047 29.7 39 88.21410 Variable 40 ∞ 2.10000 1.51680 64.2 41 ∞ 1.00000 Image plane ∞ (Table 1B: Aspherical data) In this embodiment, there are no aspherical surfaces.

[0307] (Various data at infinity focus) (Table 1C: Various Data) Zoom ratio 4.64197 Wide-angle, Medium, Telephoto Focal length 103.7170 223.4935 481.4513 F-numbers: 5.24558, 6.52617, 7.34838 Field of view: 11.6554 5.4576 2.5299 Image height 21.6300 21.6300 21.6300 Lens length: 214.3996 262.6363 294.2207 d6 1.5000 49.7366 81.3209 d16 39.6200 24.7691 2.0000 d22 16.1820 10.3386 17.5127 d27 6.1968 10.7947 2.0290 d31 11.1553 27.2518 51.6125 d35 43.9285 21.8038 1.8000 d39 22.5605 44.6852 64.6891 Entrance pupil position 81.8616 215.0681 437.0218 Exit pupil position -61.5790 -91.2134 -124.3783 Front principal point position 11.0150 -108.5639 -946.2412 Back principal point position 110.7271 39.2235 -187.3029 (Table 1D: Single lens data) Lens starting plane, focal length 1 1 -248.2714 2 3 228.9569 3 5 181.9584 4 7 72.0209 5 9 -69.9219 6 11 -82.5591 7 13 -94.1311 8 15 153.2364 9 17 62.4819 10 19 56.3391 11 21 -41.2620 12 24 -98.2394 13 26 51.2669 14 28 35.7194 15 30 -22.5043 16 32 46.2283 17 34 -150.9471 18 36 -31.9253 19 38 68.7758 (Table 1E: Zoom lens group data) Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 174.13737 18.98000 5.25422 11.09334 2 7 -61.25908 15.57000 9.49860 13.15424 3 17 87.20008 11.21380 -4.89577 -0.44000 4 23 103.19866 9.63260 8.36583 10.70474 5 28 -61.68471 3.96910 2.41286 4.07824 6 32 66.56373 6.03930 2.01348 4.21837 7 36 -58.00576 4.75170 1.33112 3.41964 (Table 1F: Zoom lens group magnification) Group, Starting plane, Wide-angle, Intermediate, Telephoto 1 1 0.00000 0.00000 0.00000 2 7 -0.65174 -1.33881 -4.32251 3 17 -1.70566 -1.11278 -0.36582 4 23 0.34067 0.40143 0.55854 5 28 52.27458 5.11953 3.16394 6 32 0.02070 0.22833 0.45427 7 36 1.45377 1.83582 2.17805 (Numerical Example 2) The imaging optical system of Numerical Example 2 corresponds to Embodiment 2 shown in Figure 2A. The surface data of the imaging optical system of Numerical Example 2 is shown in Table 2A, the aspherical data in Table 2B, and the various data in the infinity focus state are shown in Tables 2C to 2F.

[0308] (Table 2A: Surface data) Face number rd nd vd object surface ∞ 1 199.53900 2.20000 1.83481 42.7 2 93.61560 0.30000 3 97.96830 7.56330 1.49700 81.6 4 ∞ 0.30000 5 82.28870 8.54720 1.43700 95.1 6 ∞ Variable 7 145.83190 3.82640 1.85451 25.2 8 -107.83310 0.01000 1.56732 42.8 9 -107.83310 1.20000 1.83400 37.3 10 117.95330 9.84060 11 -287.62100 1.10000 1.72916 54.7 12 90.82490 1.54040 13 -340.94700 0.90000 1.59410 60.5 14 53.04970 0.01000 1.56732 42.8 15 53.04970 2.06200 1.85451 25.2 16 106.35160 Variable 17 211.98460 3.13870 1.80420 46.5 18 -66.28980 0.20000 19 44.58360 5.37340 1.43700 95.1 20 -44.58360 0.01000 1.56732 42.8 21 -44.58360 1.00000 2.00100 29.1 22 365.69600 Variable 23 (aperture) ∞ 4.50000 24 -232.47420 0.80000 2.00069 25.5 25 169.54910 0.01000 1.56732 42.8 26 169.54910 2.87500 1.73037 32.2 27 -48.21570 Variable 28 ∞ 3.21290 1.73037 32.2 29 -26.42410 0.01000 1.56732 42.8 30 -26.42410 0.60000 1.70154 41.1 31 39.95230 Variable 32 73.56440 4.94280 1.56732 42.8 33 -37.62000 0.01000 1.56732 42.8 34 -37.62000 1.00000 1.80610 33.3 35 -57.38700 Variable 36 -75.65570 1.20000 1.74400 44.8 37 32.56640 0.01000 1.56732 42.8 38 32.56640 3.90700 1.77047 29.7 39 95.59890 Variable 40 ∞ 2.10000 1.51680 64.2 41 ∞ 1.00000 Image plane ∞ (Table 2B: Aspherical data) In this embodiment, there are no aspherical surfaces.

[0309] (Various data at infinity focus) (Table 2C: Various Data) Zoom ratio 4.65000 Wide-angle, Medium, Telephoto Focal length 103.5368 223.3469 481.4459 F-numbers: 5.14529, 6.42294, 7.34765 Field of view: 11.6354 5.4454 2.5292 Image height 21.6300 21.6300 21.6300 Lens length: 214.3998 mm, 262.0680 mm, 294.3997 mm d6 1.5000 49.1684 81.5000 d16 40.1711 25.5321 2.4695 d22 16.3792 10.9487 14.8526 d27 6.3143 11.4192 2.8405 d31 9.2070 24.1715 51.9089 d35 44.3285 21.5033 1.8000 d39 21.2000 44.0251 63.7285 Entrance pupil position 89.9508 228.1830 435.2043 Exit pupil position -59.4766 -88.7994 -124.2914 Front principal point position 13.4060 -109.5373 -949.3943 Back principal point position 110.9143 38.8306 -187.1229 (Table 2D: Single lens data) Lens starting plane, focal length 1 1 -213.2660 2 3 197.1204 3 5 188.3032 4 7 73.0565 5 9 -67.3829 6 11 -94.5511 7 13 -77.2053 8 15 121.7017 9 17 63.1108 10 19 51.9631 11 21 -39.6507 12 24 -97.8781 13 26 51.6868 14 28 36.1790 15 30 -22.5870 16 32 44.5923 17 34 -138.6184 18 36 -30.4561 19 38 62.4228 (Table 2E: Zoom lens group data) Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 177.09249 18.91050 5.91802 11.97663 2 7 -60.82376 20.48940 14.89947 18.71196 3 17 84.70732 9.72210 -3.93264 0.18636 4 23 106.13844 8.18500 7.75915 9.41307 5 28 -60.75012 3.82290 2.24171 3.84867 6 32 65.73755 5.95280 2.12098 4.29548 7 36 -57.83677 5.11700 1.31708 3.56940 (Table 2F: Zoom lens group magnification) Group, Starting plane, Wide-angle, Intermediate, Telephoto 1 1 0.00000 0.00000 0.00000 2 7 -0.65447 -1.34367 -4.70212 3 17 -1.57040 -1.04293 -0.32278 4 23 0.36575 0.42295 0.57051 5 28 79.99248 5.08963 3.19413 6 32 0.01355 0.22832 0.45328 7 36 1.43542 1.83107 2.16853 (Numerical Example 3) The imaging optical system of Numerical Example 3 corresponds to Embodiment 3 shown in Figure 3A. The surface data of the imaging optical system of Numerical Example 3 is shown in Table 3A, the aspherical data in Table 3B, and the various data in the infinity focus state are shown in Tables 3C to 3F.

[0310] (Table 3A: Surface Data) Face number rd nd vd object surface ∞ 1 179.18700 2.20000 1.83481 42.7 2 88.86910 0.30000 3 92.75360 7.49370 1.49700 81.6 4 1411.95210 0.30000 5 80.80650 8.68650 1.43700 95.1 6 -36217.93590 Variable 7 233.38680 3.09370 1.84666 23.8 8 -128.98370 0.01000 1.56732 42.8 9 -128.98370 1.20000 1.80610 33.3 10 259.58780 4.26740 11 -332.92580 1.10000 1.72916 54.7 12 66.93240 2.53810 13 -162.14800 0.90000 1.59410 60.5 14 55.96470 0.01000 1.56732 42.8 15 55.96470 2.50710 1.85451 25.2 16 169.85150 Variable 17 153.53120 3.50650 1.80420 46.5 18 -72.60560 1.58750 19 48.08620 5.41460 1.43700 95.1 20 -48.08620 0.01000 1.56732 42.8 21 -48.08620 1.00000 2.00100 29.1 22 339.35950 Variable 23 (aperture) ∞ 4.50000 24 -703.42570 0.80000 2.05090 26.9 25 101.50080 0.01000 1.56732 42.8 26 101.50080 2.87540 1.72047 34.7 27 -53.41750 Variable 28 -1349.00030 3.19560 1.73037 32.2 29 -25.76990 0.01000 1.56732 42.8 30 -25.76990 0.60000 1.70154 41.1 31 41.68530 Variable 32 80.09280 4.82790 1.56732 42.8 33 -37.49920 0.01000 1.56732 42.8 34 -37.49920 1.00000 1.80610 33.3 35 -57.14520 Variable 36 -72.74060 1.20000 1.74400 44.8 37 33.48490 0.01000 1.56732 42.8 38 33.48490 4.02070 1.77047 29.7 39 107.80300 Variable 40 ∞ 2.10000 1.51680 64.2 41 ∞ 1.00000 Image plane ∞ (Table 3B: Aspheric data) In this embodiment, there are no aspherical surfaces.

[0311] (Various data at infinity focus) (Table 3C: Various Data) Zoom ratio 4.64218 Wide-angle, Medium, Telephoto Focal length 103.7181 223.4873 481.4781 F-numbers: 5.14537, 6.42171, 7.34885 Field of view: 11.6206 5.4405 2.5285 Image height 21.6300 21.6300 21.6300 Lens length: 214.3997 263.5550 294.3995 d6 1.5000 50.6554 81.4999 d16 40.4562 26.4454 2.0000 d22 19.0361 13.5876 18.7815 d27 6.3317 10.7911 2.4611 d31 9.5806 24.5805 52.1619 d35 44.7104 21.3695 1.8000 d39 20.5000 43.8408 63.4104 Entrance pupil position 83.5453 225.0988 436.3083 Exit pupil position -59.6171 -89.0419 -123.9735 Front principal point position 6.9687 -111.8609 -953.1361 Back principal point position 110.7304 40.1450 -187.1447 (Table 3D: Single lens data) Lens starting plane, focal length 1 1 -213.5686 2 3 199.3739 3 5 184.5133 4 7 98.5033 5 9 -106.7483 6 11 -76.3399 7 13 -69.9225 8 15 96.6969 9 17 61.7227 10 19 55.9768 11 21 -42.0217 12 24 -84.3626 13 26 48.9581 14 28 35.9338 15 30 -22.6171 16 32 45.6996 17 34 -138.4583 18 36 -30.6717 19 38 61.5918 (Table 3E: Zoom lens group data) Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 175.96655 18.98020 5.55320 11.62012 2 7 -61.47908 15.62630 9.16998 12.98462 3 17 81.86261 11.51860 -4.25484 0.26403 4 23 112.97252 8.18540 7.51151 9.15283 5 28 -61.48665 3.80560 2.15668 3.75894 6 32 68.27813 5.83790 2.17471 4.31273 7 36 -59.58614 5.23070 1.22759 3.52921 (Table 3F: Zoom lens group magnification) Group, Starting plane, Wide-angle, Intermediate, Telephoto 1 1 0.00000 0.00000 0.00000 2 7 -0.63737 -1.29971 -3.73562 3 17 -1.42013 -0.97047 -0.39044 4 23 0.41338 0.46697 0.59695 5 28 22.47428 4.64073 3.13657 6 32 0.04959 0.25733 0.47002 7 36 1.41343 1.80563 2.13164 (Numerical Example 4) The imaging optical system of Numerical Example 4 corresponds to Embodiment 4 shown in Figure 4A. The surface data of the imaging optical system of Numerical Example 4 is shown in Table 4A, the aspherical data in Table 4B, and the various data in the infinity focus state are shown in Tables 4C to 4F.

[0312] (Table 4A: Surface Data) Face number rd nd vd object surface ∞ 1 192.47500 2.20000 1.83481 42.7 2 95.43520 0.30000 3 99.92370 7.36540 1.49700 81.6 4 4159.45830 0.30000 5 82.84250 8.46480 1.43700 95.1 6 6324.92620 Variable 7 216.53410 3.71690 1.84666 23.8 8 -79.19890 0.01000 1.56732 42.8 9 -79.19890 1.20000 1.80610 33.3 10 117.99730 6.23740 11 -185.60650 1.10000 1.72916 54.7 12 99.92190 0.95480 13 613.57660 0.90000 1.59410 60.5 14 48.24590 0.01000 1.56732 42.8 15 48.24590 2.18910 1.85451 25.2 16 99.23610 Variable 17 152.66730 3.10750 1.80420 46.5 18 -76.19430 0.20000 19 46.55980 5.21320 1.43700 95.1 20 -46.55980 0.01000 1.56732 42.8 21 -46.55980 1.00000 2.00100 29.1 22 406.90510 Variable 23 (aperture) ∞ 4.50000 24 -288.52940 0.80000 2.05090 26.9 25 170.68240 0.01000 1.56732 42.8 26 170.68240 2.99740 1.72047 34.7 27 -50.72510 Variable 28 -3113.76140 3.26870 1.73037 32.2 29 -25.95240 0.01000 1.56732 42.8 30 -25.95240 0.60000 1.70154 41.1 31 41.28700 Variable 32 80.17210 4.84600 1.56732 42.8 33 -36.25730 0.01000 1.56732 42.8 34 -36.25730 1.00000 1.80610 33.3 35 -55.14330 Variable 36 -69.84620 1.20000 1.74400 44.8 37 32.89050 0.01000 1.56732 42.8 38 32.89050 4.07420 1.77047 29.7 39 107.85200 Variable 40 ∞ 2.10000 1.51680 64.2 41 ∞ 1.00000 Image plane ∞ (Table 4B: Aspheric data) In this embodiment, there are no aspherical surfaces.

[0313] (Various data at infinity focus) (Table 4C: Various Data) Zoom ratio 4.64257 Wide-angle, Medium, Telephoto Focal length 103.7062 223.5160 481.4634 F-numbers: 5.14433, 6.42195, 7.34792 Field of view: 11.6203 5.4386 2.5282 Image height 21.6300 21.6300 21.6300 Lens length: 213.4997 261.7567 293.4999 d6 5.9004 54.1573 85.9004 d16 41.1489 26.9212 2.3482 d22 14.9756 9.5295 14.2557 d27 5.9722 10.8964 2.0011 d31 8.6649 23.4146 52.1567 d35 45.4323 21.8582 1.8000 d39 20.5000 44.0741 64.1324 Entrance pupil position 89.3066 229.8824 428.9099 Exit pupil position -58.9416 -88.3734 -124.1755 Front principal point position 10.6846 -111.3384 -957.4666 Back principal point position 109.8388 38.3322 -188.0346 (Table 4D: Single lens data) Lens starting plane, focal length 1 1 -229.1131 2 3 205.8797 3 5 192.0072 4 7 68.8882 5 9 -58.6308 6 11 -88.9358 7 13 -88.1910 8 15 107.7511 9 17 63.5871 10 19 54.1946 11 21 -41.6914 12 24 -101.9572 13 26 54.5851 14 28 35.8158 15 30 -22.6317 16 32 44.6808 17 34 -134.5073 18 36 -29.9060 19 38 60.0001 (Table 4E: Zoom lens group data) Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 177.20131 18.63020 5.47539 11.44167 2 7 -62.41026 16.31820 10.01445 14.04913 3 17 83.73245 9.53070 -3.69020 0.31083 4 23 113.87810 8.30740 7.87595 9.58114 5 28 -62.04811 3.87870 2.24109 3.87279 6 32 66.99002 5.85600 2.22046 4.36374 7 36 -58.14241 5.28420 1.20920 3.53546 (Table 4F: Zoom lens group magnification) Group, Starting plane, Wide-angle, Intermediate, Telephoto 1 1 0.00000 0.00000 0.00000 2 7 -0.68068 -1.43701 -5.33983 3 17 -1.37521 -0.89208 -0.26763 4 23 0.40571 0.46352 0.60359 5 28 47.32800 4.84053 3.12208 6 32 0.02286 0.23955 0.46431 7 36 1.42445 1.83070 2.17289 (Numerical Example 5) The imaging optical system of Numerical Example 5 corresponds to Embodiment 5 shown in Figure 5A. The surface data of the imaging optical system of Numerical Example 5 is shown in Table 5A, the aspherical data in Table 5B, and the various data in the infinity focus state are shown in Tables 5C to 5F.

[0314] (Table 5A: Surface Data) Face number rd nd vd object surface ∞ 1 182.99640 2.20000 1.83481 42.7 2 91.75180 0.30000 3 95.83110 7.45750 1.49700 81.6 4 1645.47830 0.30000 5 81.54410 8.48520 1.43700 95.1 6 4335.10100 Variable 7 128.39020 4.01090 1.85451 25.2 8 -112.08400 0.01000 1.56732 42.8 9 -112.08400 1.20000 1.83400 37.3 10 107.26130 9.68560 11 -345.10310 1.10000 1.72916 54.7 12 83.51730 1.77440 13 -235.20450 0.90000 1.59410 60.5 14 62.79780 0.01000 1.56732 42.8 15 62.79780 1.96660 1.85451 25.2 16 138.43260 Variable 17 183.17620 3.19200 1.80420 46.5 18 -67.99260 0.20000 19 44.82500 5.36220 1.43700 95.1 20 -44.82500 0.01000 1.56732 42.8 21 -44.82500 1.00000 2.00100 29.1 22 282.34340 Variable 23 (aperture) ∞ 4.50000 24 -437.75800 0.80000 2.00069 25.5 25 113.72670 0.01000 1.56732 42.8 26 113.72670 4.56490 1.73037 32.2 27 -50.19590 Variable 28 1629.89800 3.10790 1.73037 32.2 29 -27.97090 0.01000 1.56732 42.8 30 -27.97090 0.60000 1.70154 41.1 31 40.08680 Variable 32 76.18540 3.62710 1.54814 45.8 33 -75.23800 Variable 34 -75.33160 1.20000 1.74400 44.8 35 34.40260 0.01000 1.56732 42.8 36 34.40260 3.76640 1.77047 29.7 37 104.06390 Variable 38 ∞ 2.10000 1.51680 64.2 39 ∞ 1.00000 Image plane ∞ (Table 5B: Aspherical data) In this embodiment, there are no aspherical surfaces.

[0315] (Various data at infinity focus) (Table 5C: Various Data) Zoom ratio 4.69657 Wide-angle, Medium, Telephoto Focal length 102.5141 222.1702 481.4640 F-numbers: 5.14538, 6.42102, 7.34793 Field of view: 11.7669 5.4851 2.5330 Image height 21.6300 21.6300 21.6300 Lens length: 214.4001 261.8792 294.3998 d6 1.5000 48.9792 81.5000 d16 42.1259 25.5636 2.1767 d22 15.4667 9.9974 15.3229 d27 6.2783 10.7685 2.0010 d31 8.7649 26.3062 53.1350 d33 44.6036 22.3608 1.8000 d37 21.2000 43.4428 64.0035 Entrance pupil position 91.0083 225.9910 437.4405 Exit pupil position -59.7072 -89.2885 -124.1769 Front principal point position 17.8280 -104.0867 -948.2289 Back principal point position 111.9937 39.7999 -187.0895 (Table 5D: Single lens data) Lens starting plane, focal length 1 1 -222.8715 2 3 204.4177 3 5 190.0613 4 7 70.5737 5 9 -65.5561 6 11 -92.1212 7 13 -83.3339 8 15 132.9151 9 17 62.0111 10 19 52.2372 11 21 -38.5858 12 24 -90.1461 13 26 48.2485 14 28 37.6805 15 30 -23.3992 16 32 69.6503 17 34 -31.5961 18 36 65.1694 (Table 5E: Zoom lens group data) Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 178.57933 18.74270 5.37589 11.37624 2 7 -61.67992 20.65750 15.07900 18.83567 3 17 87.74919 9.76420 -4.50010 -0.28821 4 23 99.22284 9.87490 8.80543 11.19058 5 28 -62.50563 3.71790 2.24283 3.80329 6 32 69.65025 3.62710 1.18885 2.45303 7 34 -59.88319 4.97640 1.21659 3.40431 (Table 5F: Zoom lens group magnification) Group, Starting plane, Wide-angle, Intermediate, Telephoto 1 1 0.00000 0.00000 0.00000 2 7 -0.66355 -1.35636 -4.76148 3 17 -1.61582 -1.09038 -0.32851 4 23 0.33699 0.39095 0.54633 5 28 15.92164 4.53925 3.06111 6 32 0.07018 0.26436 0.48287 7 34 1.42189 1.79305 2.13445 (Numerical Example 6) The imaging optical system of numerical example 6 corresponds to embodiment 6 shown in Figure 6A. The surface data of the imaging optical system of numerical example 6 is shown in Table 6A, the aspherical data in Table 6B, and the various data in the infinity focus state are shown in Tables 6C to 6F.

[0316] (Table 6A: Surface Data) Face number rd nd vd object surface ∞ 1 181.80860 2.64000 1.83481 42.7 2 102.89260 0.30000 3 107.62260 7.35900 1.43700 95.1 4 2006.17260 0.36000 5 94.98790 8.36700 1.43700 95.1 6 -19500.99580 Variable 7 948.08950 3.04770 1.85451 25.2 8 -103.63710 0.01000 1.56732 42.8 9 -103.63710 1.20000 1.83400 37.3 10 -10569.98480 4.22240 11 -414.95470 1.32000 1.72916 54.7 12 78.61220 2.46170 13 -174.69870 1.08000 1.59410 60.5 14 67.45880 0.01000 1.56732 42.8 15 67.45880 2.39040 1.85451 25.2 16 212.39620 Variable 17 294.54840 3.24060 1.80420 46.5 18 -76.38330 1.42120 19 54.40660 5.42940 1.43700 95.1 20 -54.40660 0.01000 1.56732 42.8 21 -54.40660 1.20000 2.00100 29.1 22 511.49230 Variable 23 (aperture) ∞ 4.00000 24 -284.10890 0.80000 2.00069 25.5 25 134.29080 0.01200 1.56732 42.8 26 134.29080 2.83840 1.73037 32.2 27 -57.95140 Variable 28 -3152.61830 3.08100 1.73037 32.2 29 -30.24960 0.01000 1.56732 42.8 30 -30.24960 0.72000 1.70154 41.1 31 50.43480 Variable 32 98.95330 3.87340 1.56732 42.8 33 -44.54020 0.01000 1.56732 42.8 34 -44.54020 1.11570 1.80610 33.3 35 -67.01280 Variable 36 -77.16830 1.20000 1.74400 44.8 37 36.22610 0.01000 1.56732 42.8 38 36.22610 3.79430 1.77047 29.7 39 126.36980 Variable 40 ∞ 2.10000 1.51680 64.2 41 ∞ 1.20000 Image plane ∞ (Table 6B: Aspherical data) In this embodiment, there are no aspherical surfaces.

[0317] (Various data at infinity focus) (Table 6C: Various Data) Zoom ratio 4.64174 Wide-angle, Medium, Telephoto Focal length 124.4642 268.1635 577.7308 F-numbers: 5.76911, 7.23666, 8.27965 Field of view: 9.7254 4.5463 2.1144 Image height 21.6300 21.6300 21.6300 Lens length: 239.9997 297.1724 334.9996 d6 1.8343 59.0071 96.8343 d16 44.7757 28.9973 2.1642 d22 25.3069 18.8175 22.9367 d27 9.0666 14.4122 3.4162 d31 9.1484 26.0705 59.7804 d35 55.7568 26.9847 1.8000 d39 23.2768 52.0489 77.2336 Entrance pupil position 92.9377 254.0451 503.7952 Exit pupil position -66.5163 -100.5096 -141.3741 Front principal point position -15.3342 -192.7714-1280.7271 Back principal point position 115.5810 29.0779 -242.8110 (Table 6D: Single lens data) Lens starting plane, focal length 1 1 -288.3424 2 3 259.9296 3 5 216.3376 4 7 109.4781 5 9 -125.5020 6 11 -90.5383 7 13 -81.7803 8 15 114.8160 9 17 75.7169 10 19 63.2091 11 21 -49.0745 12 24 -91.0381 13 26 55.7741 14 28 41.8006 15 30 -26.8541 16 32 54.6747 17 34 -168.4997 18 36 -32.9869 19 38 64.7278 (Table 6E: Zoom lens group data) Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 202.57815 19.02600 5.57913 11.48438 2 7 -74.32439 15.74220 8.90299 12.89366 3 17 99.87577 11.30120 -4.04839 0.27767 4 23 138.92564 7.65040 7.47738 9.11527 5 28 -75.82053 3.81100 2.20352 3.80538 6 32 81.27966 4.99910 1.95487 3.82198 7 36 -65.96566 5.00430 1.10524 3.30164 (Table 6F: Zoom lens group magnification) Group, Starting plane, Wide-angle, Intermediate, Telephoto 1 1 0.00000 0.00000 0.00000 2 7 -0.67583 -1.40760 -4.96328 3 17 -1.46327 -0.93459 -0.29008 4 23 0.40724 0.47121 0.61380 5 28 23.14197 4.33034 2.88041 6 32 0.04647 0.26583 0.50138 7 36 1.41854 1.85507 2.23460 (Numerical Example 7) The imaging optical system of numerical example 7 corresponds to embodiment 7 shown in Figure 7A. The surface data of the imaging optical system of numerical example 7 is shown in Table 7A, the aspherical data in Table 7B, and the various data in the infinity focus state are shown in Tables 7C to 7F.

[0318] (Table 7A: Surface Data) Face number rd nd vd object surface ∞ 1 147.66260 2.20000 1.83481 42.7 2 85.12700 0.30000 3 89.53180 6.66280 1.43700 95.1 4 1624.78950 0.30000 5 76.39980 7.63190 1.43700 95.1 6 -27405.22370 Variable 7 149.23190 3.37520 1.85451 25.2 8 -83.74560 0.01000 1.56732 42.8 9 -83.74560 1.20000 1.83400 37.3 10 113.24000 2.18510 11 -204.88120 1.10000 1.72916 54.7 12 98.80680 0.88180 13 1485.68180 0.90000 1.59410 60.5 14 41.51830 0.01000 1.56732 42.8 15 41.51830 2.00470 1.85451 25.2 16 76.30770 Variable 17 228.15550 2.68260 1.80420 46.5 18 -64.61140 0.37310 19 42.36620 4.64700 1.43700 95.1 20 -42.36620 0.01000 1.56732 42.8 21 -42.36620 1.00000 2.00100 29.1 22 319.25620 Variable 23 (aperture) ∞ 4.00000 24 -172.58810 0.80000 2.00069 25.5 25 173.39690 0.01000 1.56732 42.8 26 173.39690 2.52070 1.73037 32.2 27 -44.29950 Variable 28 3626.97520 2.83960 1.73037 32.2 29 -26.51420 0.01000 1.56732 42.8 30 -26.51420 0.60000 1.70154 41.1 31 40.39450 Variable 32 69.29630 4.60240 1.56732 42.8 33 -37.00710 0.01000 1.56732 42.8 34 -37.00710 1.12340 1.80610 33.3 35 -55.69350 Variable 36 -69.22250 1.20000 1.74400 44.8 37 30.08860 0.01000 1.56732 42.8 38 30.08860 3.92440 1.77047 29.7 39 84.90730 Variable 40 ∞ 2.10000 1.51680 64.2 41 ∞ 1.00000 Image plane ∞ (Table 7B: Aspherical data) In this embodiment, there are no aspherical surfaces.

[0319] (Various data at infinity focus) (Table 7C: Various data) Zoom ratio 4.96198 Wide-angle, Medium, Telephoto Focal length 97.0253 216.2159 481.4376 F-numbers: 5.76950, 7.23895, 8.27890 Field of view: 12.4121 5.6241 2.5257 Image height 21.6300 21.6300 21.6300 Lens length: 199.9998 247.1544 278.9998 d6 1.5000 48.6546 80.5000 d16 40.7007 25.7481 2.6930 d22 15.7666 9.5630 14.2579 d27 5.6945 11.5683 2.0018 d31 7.6258 22.9083 50.8350 d35 45.9875 23.2036 1.8000 d39 20.5000 43.2838 64.6874 Entrance pupil position 73.2750 200.7248 401.2941 Exit pupil position -56.0800 -84.9614 -120.1490 Front principal point position 2.6001 -132.5795-1047.6503 Back principal point position 103.0298 31.0501 -202.5162 (Table 7D: Single lens data) Lens starting plane, focal length 1 1 -244.6990 2 3 216.5399 3 5 174.3562 4 7 63.1981 5 9 -57.5651 6 11 -91.2800 7 13 -71.9101 8 15 103.8163 9 17 62.8684 10 19 49.2960 11 21 -37.3137 12 24 -86.3359 13 26 48.5482 14 28 36.0507 15 30 -22.7332 16 32 43.1996 17 34 -140.6006 18 36 -28.0445 19 38 58.6596 (Table 7E: Zoom lens group data) Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 161.73574 17.09470 5.02403 10.29913 2 7 -59.66757 11.66680 7.05124 10.78863 3 17 88.85529 8.71270 -4.06444 -0.41949 4 23 107.04016 7.33070 7.22327 8.73229 5 28 -62.24925 3.44960 2.05242 3.50098 6 32 62.50711 5.73580 2.04899 4.15634 7 36 -52.07924 5.13440 1.34125 3.60540 (Table 7F: Zoom lens group magnification) Group, Starting plane, Wide-angle, Intermediate, Telephoto 1 1 0.00000 0.00000 0.00000 2 7 -0.68804 -1.50802 -7.72759 3 17 -1.79941 -1.06600 -0.20597 4 23 0.33072 0.40439 0.58306 5 28 -20.43948 5.81008 3.07061 6 32 -0.04877 0.18547 0.45109 7 36 1.46984 1.90840 2.31574 (Corresponding value for the condition) The corresponding values ​​for conditions (1) to (10) are shown in Table 1 below.

[0320] [Table 1] [Industrial applicability]

[0321] The imaging optical system described herein is applicable to digital still cameras, interchangeable lens digital cameras, digital video cameras, cameras in mobile phone devices such as smartphones, cameras in PDAs (Personal Digital Assistance), surveillance cameras in surveillance systems, webcams, in-vehicle cameras, etc., 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]

[0322] G1 First Lens Group G2 2nd lens group G3 3rd 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 6th lens element L7 7th lens element L8 8th lens element L9 9th lens element L10 10th lens element L11 11th lens element L12 12th lens element L13 13th lens element L14 14th lens element L15 15th lens element L16 16th lens element L17 17th lens element L18 18th lens element L19 19th lens element A aperture diaphragm P parallel plate S image plane 100 Imaging device 101 Imaging optical system 102 Image sensor 104 cabinets 200 Camera System 201 Camera body 202 Image sensor 203 Monitor 204 Camera mount section 205 Finder 300 interchangeable lens device 301 Imaging Optical System 302 Telescope Tube 304 Lens mount section

Claims

1. From the object side to the image side, in order The first lens group has positive power, The second lens group possesses negative power, The third lens group possesses positive power, The fourth lens group possesses positive power, The fifth lens group possesses negative power, The sixth lens group possesses positive power, The seventh lens group possesses negative power, It consists of, When zooming from the wide-angle end to the telephoto end, the spacing between adjacent lens groups changes. The second lens group and the sixth lens group are fixed to the image plane. Imaging optical system.

2. The second lens group consists of a second a sub-lens group and a second b sub-lens group. Vibration isolation is performed by moving the second sub-lens group perpendicular to the optical axis. The following conditions (1) must be met: 0.8 <f2b / f2 < 1.3...(1) Here, f2: Focal length of the second lens group, f2b: Focal length of the second b sub-lens group, That is, The imaging optical system according to claim 1.

3. The fifth lens group consists of a positive lens element and a negative lens element, arranged in order from the object side to the image side. When focusing from an object at infinity to an object at a close distance, the fifth lens group moves toward the image side. The following conditions (2) must be met: -11 < (1 - βTF × βTF) × (βTR × βTR) < -7 ... (2) Here, βTF: Lateral magnification of the fifth lens group when in focus at the telephoto end, βTR: The combined lateral magnification of the lens group positioned closer to the image than the fifth lens group when in focus at the telephoto end. That is, The imaging optical system according to claim 1.

4. The following conditions (3) must be met: 0.16 <BFw / fw < 0.3...(3) Here, BFw: The distance along the optical axis from the closest lens element to the image plane at the wide-angle end. fw: Total focal length of the system when focused at infinity at the wide-angle end. That is, The imaging optical system according to claim 1.

5. The following conditions (4) must be met: 0.1 < f1 / ft < 0.6 (4) Here, f1: Focal length of the first lens group, ft: Total focal length of the system when in focus at infinity at the telephoto end. That is, The imaging optical system according to claim 1.

6. The following conditions (5) must be met: 0.5 < f3 / f4 < 1.1 (5) Here, f3: Focal length of the third lens group, f4: Focal length of the fourth lens group, That is, The imaging optical system according to claim 1.

7. The following conditions (6) must be met: 0.08 < f6 / ft < 0.20 (6) Here, f6: Focal length of the sixth lens group, ft: Total focal length of the system when in focus at infinity at the telephoto end. That is, The imaging optical system according to claim 1.

8. The seventh lens group consists of a negative lens element and a positive lens element, in order from the object side to the image side. The following conditions (7) must be met: -0.18 < f7 / ft < -0.06 (7) Here, f7: Focal length of the seventh lens group, That is, The imaging optical system according to claim 1.

9. The first lens group is arranged in order from the object side to the image side, It consists of a negative lens element, a positive lens element, and another positive lens element. The imaging optical system according to claim 1.

10. The following conditions (8) must be met: 1.85 < nd_3Gn < 2.15 (8) Here, nd_3Gn: Refractive index of the negative lens element in the third lens group with respect to the d line, That is, The imaging optical system according to claim 1.

11. The following conditions (9) must be met: 1.85 < nd_4Gn < 2.15 (9) Here, nd_4Gn: Refractive index of the negative lens element in the fourth lens group with respect to the d line, That is, The imaging optical system according to claim 1.

12. The second sub-lens group is arranged in order from the object side: It consists of a positive lens element and a negative lens element. The following conditions (10) must be met: 20 < vd_2ap < 30 (10) Here, vd_2ap: Abbe number of the positive lens element in the second sub-lens group with respect to the d line, That is, The imaging optical system according to claim 1.

13. An imaging device that converts an optical image of the object into an electrical image signal, and performs at least one of displaying and storing the converted image signal, The imaging optical system according to claim 1, which forms the optical image of the object, An image sensor that converts the optical image formed by the imaging optical system into an electrical image signal, Equipped with, Imaging device.

14. An interchangeable lens device including the imaging optical system described in claim 1, The camera body includes an image sensor that is detachably connected to the interchangeable lens device via a camera mount and receives an optical image formed by the imaging optical system and converts it into an electrical image signal. A camera system comprising, The interchangeable lens device forms the optical image of the object on the image sensor. Camera system.

Images