Zoom lens

Abstract

To provide a zoo lens which has a large aperture ratio and a minimized total length, offers less shift in the center of gravity while zooming and focusing and quiet autofocusing, and is suitable for video shooting.SOLUTION: A zoom lens of the present invention consists of a first lens group G1 having negative refractive power, an intermediate lens group GM having positive refractive power as a whole, a rear lens group GR, and a final lens group GN arranged in order from the object side, the intermediate lens group GM consisting of three or more lens groups including a focusing lens group configured to move along an optical axis while focusing from infinity to a short distance, and the rear lens group consisting of one or more lens groups. When zooming from the wide-angle end to the telephoto end, distances between the lens groups change as the intermediate lens group GM moves toward the object side, increasing the distance between the intermediate lens group GM and the rear lens group GR. The first lens group G1 and the final lens gup GN are stationary while zooming and focusing.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a zoom lens for use in digital cameras, video cameras, and the like. [Background technology]

[0002] In recent years, video shooting using interchangeable lens cameras has become common. To ensure smooth video shooting, it is desirable for the center of gravity in the lens to move as little as possible during zooming and focusing. Furthermore, quiet autofocus is also important, as loud motor noise during autofocusing can be picked up by the camera's audio recording.

[0003] As interchangeable lenses for SLR cameras, large-aperture zoom lenses with bright maximum apertures are popular because they combine the convenience of a zoom lens with the characteristics of a bright maximum aperture. In addition, large-format cameras, which have larger sensor sizes and superior image quality, have become popular in recent years, and there is a demand for large-aperture zoom lenses that are compatible with large-format cameras.

[0004] Examples of zoom lenses with a large aperture ratio include zoom lenses disclosed in the following patent documents. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2016 / 121939 [Patent Document 2] Japanese Patent Application Publication No. 2019-015956 Summary of the Invention [Problem to be solved by the invention]

[0006] Patent Document 1 discloses a negative-lead, large-aperture zoom lens with a maximum aperture of approximately F2.8. However, the focus lens group is heavy and contains many lenses, making it difficult to achieve fast and quiet autofocus. Furthermore, the overall length of the optical system is long, and further increases in the aperture ratio would result in a huge zoom lens, which is not practical.

[0007] Patent Document 2 discloses a positive-lead type large aperture ratio zoom lens with a bright maximum aperture of approximately F2. However, zooming causes the first lens group, which is large and heavy, to extend, which causes a large shift in the center of gravity, which is undesirable as it affects operability when shooting video.

[0008] The present invention has been made in view of these circumstances, and its object is to provide a zoom lens that has a large aperture ratio but a reduced overall length, has little center of gravity movement during zooming and focusing, is capable of quiet autofocusing, and is suitable for video shooting. [Means for solving the problem]

[0009] The zoom lens according to the present invention is characterized in that it is composed of, in order from the object side, a first lens group G1 with negative refractive power, an intermediate lens group GM with positive refractive power overall, a rear lens group GR, and a final lens group GN, wherein the intermediate lens group GM is composed of three or more lens groups and includes a focus lens group that moves along the optical axis during focusing from infinity to a close distance, the rear lens group GR is composed of one or more lens groups, the spacing between each group changes during magnification change from the wide-angle end to the telephoto end, the intermediate lens group GM moves toward the object side, and the spacing between the intermediate lens group GM and the rear lens group GR increases, and the first lens group G1 and the final lens group GN remain fixed during both magnification change and focusing. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a zoom lens that has a large aperture ratio but a reduced overall length, has little center of gravity movement during zooming and focusing, is capable of quiet autofocusing, and is suitable for video shooting. [Brief explanation of the drawings]

[0011] [Figure 1] Lens configuration diagram of Example 1 at the wide-angle end and when focused at infinity [Figure 2] Longitudinal aberration diagram of Example 1 at the wide-angle end when focused on infinity [Figure 3] Longitudinal aberration diagram of Example 1 at the wide-angle end and a shooting distance of 1275 mm [Figure 4] Transverse aberration diagram of Example 1 at the wide-angle end when focused on infinity [Figure 5] Lateral aberration diagram of Example 1 at the wide-angle end and a shooting distance of 1275 mm [Figure 6] Longitudinal aberration diagram of Example 1 at an intermediate focal length when focused at infinity [Figure 7] Longitudinal aberration diagram of Example 1 at an intermediate focal length and a shooting distance of 1523 mm [Figure 8] Transverse aberration diagram of Example 1 at an intermediate focal length and when focused at infinity [Figure 9] Lateral aberration diagram of Example 1 at an intermediate focal length and a shooting distance of 1523 mm [Figure 10] Longitudinal aberration diagram of Example 1 at the telephoto end when focused on infinity [Figure 11] Longitudinal aberration diagram of Example 1 at the telephoto end and a shooting distance of 1869 mm [Figure 12] Transverse aberration diagram of Example 1 at the telephoto end when focused on infinity [Figure 13] Lateral aberration diagram of Example 1 at the telephoto end and a shooting distance of 1869 mm [Figure 14] Lens configuration diagram of Example 2 at the wide-angle end and when focused at infinity [Figure 15] Longitudinal aberration diagram of Example 2 at the wide-angle end when focused on infinity [Figure 16] Longitudinal aberration diagram of Example 2 at the wide-angle end and a shooting distance of 1111 mm [Figure 17] Transverse aberration diagram of Example 2 at the wide-angle end when focused on infinity [Figure 18] Lateral aberration diagram of Example 2 at the wide-angle end and a shooting distance of 1111 mm [Figure 19] Longitudinal aberration diagram of Example 2 at an intermediate focal length when focused at infinity [Figure 20]Longitudinal aberration diagram of Example 2 at an intermediate focal length and a shooting distance of 1315 mm [Figure 21] Transverse aberration diagram of Example 2 at an intermediate focal length when focused at infinity [Figure 22] Lateral aberration diagram of Example 2 at an intermediate focal length and a shooting distance of 1315 mm [Figure 23] Longitudinal aberration diagram of Example 2 at the telephoto end when focused on infinity [Figure 24] Longitudinal aberration diagram of Example 2 at the telephoto end and a shooting distance of 1676 mm [Figure 25] Transverse aberration diagram of Example 2 at the telephoto end when focused on infinity [Figure 26] Lateral aberration diagram of Example 2 at the telephoto end and a shooting distance of 1676 mm [Figure 27] Lens configuration diagram of Example 3 at the wide-angle end and when focused at infinity [Figure 28] Longitudinal aberration diagram of Example 3 at the wide-angle end when focused on infinity [Figure 29] Longitudinal aberration diagram of Example 3 at the wide-angle end and a shooting distance of 1362 mm [Figure 30] Transverse aberration diagram of Example 3 at the wide-angle end when focused on infinity [Figure 31] Lateral aberration diagram of Example 3 at the wide-angle end and a shooting distance of 1362 mm [Figure 32] Longitudinal aberration diagram of Example 3 at an intermediate focal length when focused at infinity [Figure 33] Longitudinal aberration diagram of Example 3 at an intermediate focal length and a shooting distance of 1555 mm [Figure 34] Transverse aberration diagram of Example 3 at an intermediate focal length when focused at infinity [Figure 35] Lateral aberration diagram of Example 3 at an intermediate focal length and a shooting distance of 1555 mm [Figure 36] Longitudinal aberration diagram of Example 3 at the telephoto end when focused on infinity [Figure 37] Longitudinal aberration diagram of Example 3 at the telephoto end and a shooting distance of 2068 mm [Figure 38] Transverse aberration diagram of Example 3 at the telephoto end when focused on infinity [Figure 39] Lateral aberration diagram of Example 3 at the telephoto end and a shooting distance of 2068 mm [Figure 40]Lens configuration diagram of Example 4 at the wide-angle end and when focused at infinity [Figure 41] Longitudinal aberration diagram of Example 4 at the wide-angle end when focused on infinity [Figure 42] Longitudinal aberration diagram of Example 4 at the wide-angle end and a shooting distance of 1274 mm [Figure 43] Transverse aberration diagram of Example 4 at the wide-angle end when focused on infinity [Figure 44] Lateral aberration diagram of Example 4 at the wide-angle end and a shooting distance of 1274 mm [Figure 45] Longitudinal aberration diagram of Example 4 at an intermediate focal length when focused at infinity [Figure 46] Longitudinal aberration diagram of Example 4 at an intermediate focal length and a shooting distance of 1519 mm [Figure 47] Transverse aberration diagram of Example 4 at an intermediate focal length when focused at infinity [Figure 48] Lateral aberration diagram of Example 4 at an intermediate focal length and a shooting distance of 1519 mm [Figure 49] Longitudinal aberration diagram of Example 4 at the telephoto end when focused on infinity [Figure 50] Longitudinal aberration diagram of Example 4 at the telephoto end and a shooting distance of 1868 mm [Figure 51] Transverse aberration diagram of Example 4 at the telephoto end when focused on infinity [Figure 52] Lateral aberration diagram of Example 4 at the telephoto end and a shooting distance of 1868 mm [Figure 53] Lens configuration diagram of Example 5 at the wide-angle end and when focused at infinity [Figure 54] Longitudinal aberration diagram of Example 5 at the wide-angle end when focused on infinity [Figure 55] Longitudinal aberration diagram of Example 5 at the wide-angle end and a shooting distance of 1273 mm [Figure 56] Transverse aberration diagram of Example 5 at the wide-angle end when focused on infinity [Figure 57] Lateral aberration diagram of Example 5 at the wide-angle end and a shooting distance of 1273 mm [Figure 58] Longitudinal aberration diagram of Example 5 at an intermediate focal length when focused at infinity [Figure 59] Longitudinal aberration diagram of Example 5 at an intermediate focal length and a shooting distance of 1509 mm [Figure 60] Transverse aberration diagram of Example 5 at an intermediate focal length and focused at infinity [Figure 61] Lateral aberration diagram of Example 5 at an intermediate focal length and a shooting distance of 1509 mm [Figure 62] Longitudinal aberration diagram of Example 5 at the telephoto end when focused on infinity [Figure 63] Longitudinal aberration diagram of Example 5 at the telephoto end and a shooting distance of 1867 mm [Figure 64] Transverse aberration diagram of Example 5 at the telephoto end when focused on infinity [Figure 65] Lateral aberration diagram of Example 5 at the telephoto end and a shooting distance of 1867 mm [Figure 66] Lens configuration diagram of Example 6 at the wide-angle end and when focused at infinity [Figure 67] Longitudinal aberration diagram of Example 6 at the wide-angle end when focused on infinity [Figure 68] Longitudinal aberration diagram of Example 6 at the wide-angle end and a shooting distance of 1115 mm [Figure 69] Transverse aberration diagram of Example 6 at the wide-angle end when focused on infinity [Figure 70] Lateral aberration diagram of Example 6 at the wide-angle end and a shooting distance of 1115 mm [Figure 71] Longitudinal aberration diagram of Example 6 at an intermediate focal length when focused at infinity [Figure 72] Longitudinal aberration diagram of Example 6 at an intermediate focal length and a shooting distance of 1320 mm [Figure 73] Transverse aberration diagram of Example 6 at an intermediate focal length and focused at infinity [Figure 74] Transverse aberration diagram of Example 6 at an intermediate focal length and a shooting distance of 1320 mm [Figure 75] Longitudinal aberration diagram of Example 6 at the telephoto end when focused on infinity [Figure 76] Longitudinal aberration diagram of Example 6 at the telephoto end and a shooting distance of 1768 mm [Figure 77] Transverse aberration diagram of Example 6 at the telephoto end when focused on infinity [Figure 78] Lateral aberration diagram of Example 6 at the telephoto end and a shooting distance of 1768 mm [Figure 79] Lens configuration diagram of Example 7 at the wide-angle end and when focused at infinity [Figure 80] Longitudinal aberration diagram of Example 7 at the wide-angle end when focused on infinity [Figure 81]Longitudinal aberration diagram of Example 7 at the wide-angle end and a shooting distance of 1265 mm [Figure 82] Transverse aberration diagram of Example 7 at the wide-angle end when focused on infinity [Figure 83] Transverse aberration diagram of Example 7 at the wide-angle end and a shooting distance of 1265 mm [Figure 84] Longitudinal aberration diagram of Example 7 at an intermediate focal length when focused at infinity [Figure 85] Longitudinal aberration diagram of Example 7 at an intermediate focal length and a shooting distance of 1510 mm [Figure 86] Transverse aberration diagram of Example 7 at an intermediate focal length and focused at infinity [Figure 87] Transverse aberration diagram of Example 7 at an intermediate focal length and a shooting distance of 1510 mm [Figure 88] Longitudinal aberration diagram of Example 7 at the telephoto end when focused on infinity [Figure 89] Longitudinal aberration diagram of Example 7 at the telephoto end and a shooting distance of 1858 mm [Figure 90] Transverse aberration diagram of Example 7 at the telephoto end when focused on infinity [Figure 91] Transverse aberration diagram of Example 7 at the telephoto end and a shooting distance of 1858 mm [Figure 92] Lens configuration diagram of Example 8 at the wide-angle end and when focused at infinity [Figure 93] Longitudinal aberration diagram of Example 8 at the wide-angle end when focused on infinity [Figure 94] Longitudinal aberration diagram of Example 8 at the wide-angle end and a shooting distance of 1274 mm [Figure 95] Transverse aberration diagram of Example 8 at the wide-angle end when focused on infinity [Figure 96] Lateral aberration diagram of Example 8 at the wide-angle end and a shooting distance of 1274 mm [Figure 97] Longitudinal aberration diagram of Example 8 at an intermediate focal length when focused at infinity [Figure 98] Longitudinal aberration diagram of Example 8 at an intermediate focal length and a shooting distance of 1515 mm [Figure 99] Transverse aberration diagram of Example 8 at an intermediate focal length and focused at infinity [Figure 100] Transverse aberration diagram of Example 8 at an intermediate focal length and a shooting distance of 1515 mm [Figure 101]Longitudinal aberration diagram of Example 8 at the telephoto end when focused on infinity [Figure 102] Longitudinal aberration diagram of Example 8 at the telephoto end and a shooting distance of 1868 mm [Figure 103] Transverse aberration diagram of Example 8 at the telephoto end when focused on infinity [Figure 104] Lateral aberration diagram of Example 8 at the telephoto end and a shooting distance of 1868 mm DETAILED DESCRIPTION OF THE INVENTION

[0012] As can be seen from the lens construction diagrams shown in Figures 1, 14, 27, 40, 53, 66, 79, and 92, the zoom lens of the present invention is composed of, in order from the object side, a first lens group G1 with negative refractive power, a middle lens group GM with positive refractive power overall, a rear lens group GR, and a final lens group GN, where the middle lens group GM is composed of three or more lens groups and includes a focus lens group that moves along the optical axis during focusing from infinity to a close distance, the rear lens group GR is composed of one or more lens groups, the spacing between each group changes during magnification change from the wide-angle end to the telephoto end, the middle lens group GM moves toward the object side, and the spacing between the middle lens group GM and the rear lens group GR increases, and the first lens group G1 and the final lens group GN remain fixed during both magnification change and focusing.

[0013] Negative-lead zoom lenses are known in which a lens group with negative refractive power is positioned closest to the object. In this invention, a middle lens group GM with positive refractive power is positioned on the image side of the first lens group G1 with negative refractive power, and the middle lens group GM moves toward the object when zooming from the wide-angle end to the telephoto end, thereby performing the main zooming function. A rear lens group GR is positioned on the image side of the middle lens group GM so that the distance between it and the middle lens group GM increases when zooming from the wide-angle end to the telephoto end. The rear lens group GR assists in correcting aberrations during zooming, which is advantageous for improving performance.

[0014] If the aperture ratio were to be increased even further with the above configuration, the overall lens diameter would increase. As the first lens group G1 becomes larger, its weight increases, and if it moves during magnification or focusing, the center of gravity shifts significantly, resulting in poor operability. Therefore, it is desirable to keep the first lens group G1 fixed during both magnification and focusing. This contributes to improved operability. Another advantage is that the leading edge of the optical system will no longer extend, improving robustness.

[0015] It is also desirable that the final lens group GN, which is closest to the image side, be fixed during both magnification and focusing. As lens diameters increase to accommodate larger aperture ratios and large-format cameras, it becomes difficult to secure space around the mount for placing a circuit board. By fixing the final lens group GN, the configuration around the mount is simplified, making it easier to place a circuit board.

[0016] Furthermore, the middle lens group GM is the group that primarily performs the zooming function, and requires a relatively large number of lenses for aberration correction. However, by dividing this group into multiple groups, it is possible to create a lightweight lens group with fewer lenses. In particular, configuring the middle lens group GM from three or more lens groups is advantageous for aberration correction during zooming, and makes it easier to achieve a large aperture ratio. Furthermore, if some of the lightweight lens groups that can be created by dividing the middle lens group GM into multiple groups are used as focus lens groups, it is also advantageous for achieving fast and quiet autofocus.

[0017] Furthermore, it is desirable for the zoom lens of the present invention to satisfy the following conditional expression (1): (1) -1.50 <f1 / ft<-0.70 however, f1: focal length of the first lens group G1 ft: focal length of the entire system at the telephoto end, focused at infinity Let's say.

[0018] Conditional expression (1) defines a preferable condition regarding the refractive power of the first lens group G1. By satisfying conditional expression (1), it is possible to achieve a large aperture ratio for the optical system while suppressing the overall optical length and various aberrations.

[0019] If the upper limit of conditional expression (1) is exceeded and the negative refractive power of the first lens group G1 becomes stronger, the divergence effect of the first lens group G1 on the axial light beam becomes stronger, which increases the diameter of the middle lens group GM, particularly at the telephoto end, resulting in an increase in the outer diameter of the product. Furthermore, the diameter of the focus lens group also increases, making the lens heavier and undesirably hindering the realization of high-speed autofocus. On the other hand, if the lower limit of conditional expression (1) is exceeded and the negative refractive power of the first lens group G1 becomes weaker, it becomes difficult to ensure sufficient back focus.

[0020] Furthermore, it is preferable to set the lower limit of the above-mentioned conditional expression (1) to -1.30 and the upper limit to -0.75, since this will ensure the above-mentioned effect.

[0021] Furthermore, in a zoom lens according to the present invention, it is desirable that the first lens group G1 include two or more negative lenses. If the first lens group G1 includes only one negative lens, the off-axis light beam must be strongly bent by that single negative lens, which increases the aberrations generated by each surface and makes it difficult to correct curvature of field and distortion. Having two or more negative lenses in the first lens group G1 is advantageous for correcting various aberrations.

[0022] Furthermore, it is desirable for the zoom lens of the present invention to satisfy the following conditional expression (2). (2) νdG1_2>57.0 however, νdG1_2: the second largest Abbe number among the negative lenses arranged in the first lens group G1 When the first lens group G1 has two or more negative lenses with the largest Abbe number, the largest Abbe number is defined as νdG1_2.

[0023] Conditional expression (2) defines a preferable condition for the Abbe number of the negative lens arranged in the first lens group G1, and is effective in suppressing lateral chromatic aberration. If the lens with the second largest Abbe number among the negative lenses arranged in the first lens group G1 satisfies conditional expression (2), then the first lens group G1 will have two or more negative lenses that satisfy conditional expression (2).

[0024] If the lower limit of conditional expression (2) is exceeded and the Abbe number of the negative lens in first lens group G1 becomes small, it becomes difficult to correct lateral chromatic aberration. If there is one or fewer negative lenses that satisfy conditional expression (2), the ability to correct lateral chromatic aberration becomes insufficient, so it is desirable to have two or more.

[0025] Furthermore, it is preferable to set the lower limit of the above-mentioned conditional expression (2) to 60.0, since this makes it possible to more reliably achieve the above-mentioned effect.

[0026] Furthermore, in the zoom lens of the present invention, it is desirable that the final lens LN, which is closest to the image side of the final lens group GN, has negative refractive power. Because this is a negative-lead zoom lens in which the first lens group G1 has negative refractive power, giving the final lens LN negative refractive power strengthens the symmetry of the refractive power, which is advantageous for correcting distortion.

[0027] Furthermore, it is desirable for the zoom lens of the present invention to satisfy the following conditional expression (3). (3) 0.0<(RLN1+RLN2) / (RLN1-RLN2)<1.0 however, RLN1: Radius of curvature of the object side of the final lens LN RLN2: Radius of curvature of the image side of the final lens LN Let's say.

[0028] Conditional expression (3) defines a preferable condition regarding the shape of the final lens LN. Satisfying conditional expression (3) is advantageous for correcting curvature of field and distortion.

[0029] If the upper limit of conditional expression (3) is exceeded and the final lens element LN assumes a meniscus shape, the ability to correct curvature of field becomes insufficient. On the other hand, if the lower limit of conditional expression (3) is exceeded and the curvature of the object-side surface of the final lens element LN becomes stronger than the curvature of the image-side surface, the ability to correct distortion becomes insufficient.

[0030] Furthermore, it is preferable to set the lower limit of the above-mentioned conditional expression (3) to 0.1 and the upper limit to 0.9, since this will ensure the above-mentioned effect.

[0031] Furthermore, in the zoom lens of the present invention, the intermediate lens group GM includes, in order from the object side, a second lens group G2 with positive refractive power and a third lens group G3 with negative refractive power, and it is desirable to move at least one of the second lens group G2 or the third lens group G3 along the optical axis when focusing from infinity to a close distance. Reducing the diameter is effective in making the focus lens group as light as possible. Furthermore, because the first lens group G1 has negative refractive power and diverges the axial light beam, as the distance from the first lens group G1 to the focus lens group increases, the axial light beam becomes thicker, resulting in a larger lens diameter. Therefore, in order to reduce weight, it is preferable to use the second lens group G2 or the third lens group G3, which are as close as possible to the first lens group G1, as the focus lens group.

[0032] Furthermore, in the zoom lens of the present invention, it is desirable to have a fourth lens group G4 with positive refractive power on the image side of the second lens group G2 with positive refractive power and the third lens group G3 with negative refractive power. By converging the light beam diverged by the third lens group G3 with negative refractive power with the fourth lens group G4 on the image side, it is possible to prevent the outer diameter of the optical system from becoming too large.

[0033] Furthermore, it is desirable for the zoom lens of the present invention to satisfy the following conditional expression (4). (4) -2.0 <f2 / f3<-1.0 however, f2: Focal length of the second lens group G2 f3: Focal length of the third lens group G3 Let's say.

[0034] Conditional expression (4) defines a preferable condition regarding the refractive power of the second lens group G2 and the third lens group G3. Satisfying conditional expression (4) is effective in ensuring the spacing between the lens groups and reducing the outer diameter of the product.

[0035] If the upper limit of conditional expression (4) is exceeded and the positive refractive power of the second lens group G2 becomes stronger or the negative refractive power of the third lens group G3 becomes weaker, the object-side principal point of the combined system of the second lens group G2 and the third lens group G3 moves toward the image side, making it difficult to maintain the distance between the first lens group G1 and the second lens group G2 at the telephoto end. On the other hand, if the lower limit of conditional expression (4) is exceeded and the negative refractive power of the third lens group G3 becomes stronger, the third lens group G3 becomes more sensitive to decentration, and changes in the amount of decentration of the third lens group G3 due to backlash during focusing or changes in the lens barrel attitude have a significant impact on optical performance. Furthermore, if the positive refractive power of the second lens group G2 becomes weaker, the combined system with the third lens group G3 becomes more negative, strengthening the effect of axial light beam deflection. This increases the lens diameter of the image-side lens group of the third lens group G3, resulting in an increased outer diameter of the product.

[0036] Furthermore, it is preferable to limit the lower limit of the above-mentioned conditional expression (4) to -1.9 and the upper limit to -1.1, since this will ensure the above-mentioned effect.

[0037] Additionally, in order to reduce the weight of the focus lens group, it is desirable that both the second lens group G2 and the third lens group G3 be composed of two or fewer lenses. By limiting the number of lenses to two or fewer, the length of the lens group in the optical axis direction is reduced, which is also advantageous for reducing the overall length of the product.

[0038] Furthermore, it is desirable for the zoom lens of the present invention to satisfy the following conditional expression (5). (5) 0.7<(βMt / βMw) / (ft / fw)<1.2 however, βMw: Imaging magnification of the middle lens group GM at the wide-angle end, when focused at infinity βMt: Imaging magnification of the middle lens group GM at the telephoto end, when focused at infinity fw: focal length of the entire system at the wide-angle end, focused at infinity ft: focal length of the entire system at the telephoto end, focused at infinity Let's say.

[0039] Conditional expression (5) defines a preferable condition regarding the proportion of the contribution of the intermediate lens group GM to zooming from the wide-angle end to the telephoto end. By satisfying conditional expression (5), it is possible to suppress aberration fluctuations during zooming while keeping the overall length of the optical system small.

[0040] If the upper limit of conditional formula (5) is exceeded and the magnification burden of the intermediate lens group GM increases, it is necessary to increase the refractive power of the intermediate lens group GM or increase the amount of movement. Increasing the refractive power of the intermediate lens group GM increases the amount of aberration, necessitating an increase in the number of lenses to improve performance. Moving the weight of the intermediate lens group GM, which has increased in number of lenses, significantly increases the center of gravity shift during magnification, which is undesirable. Furthermore, if the refractive power of the intermediate lens group GM becomes too strong, sensitivity to manufacturing errors also worsens. On the other hand, if the lower limit of conditional formula (5) is exceeded and the magnification burden of the intermediate lens group GM decreases, the proportion of magnification assistance provided by the rear lens group GR must be increased, which requires either increasing the refractive power of the rear lens group GR or increasing its amount of movement. In order to achieve high performance with the rear lens group GR having a strong refractive power, it is necessary to increase the number of lenses. Increasing the number of lenses in the rear lens group GR or increasing the amount of movement both affect the overall length of the optical system, making it difficult to reduce the overall length.

[0041] Furthermore, it is preferable to set the lower limit of the above-mentioned conditional expression (5) to 0.8 and the upper limit to 1.1, since this will ensure the above-mentioned effect.

[0042] Furthermore, in a zoom lens according to the present invention, it is desirable that the middle lens group GM has six or more lenses. The middle lens group GM is primarily responsible for the zooming effect, and therefore has strong refractive power. Arranging six or more lenses in this group is advantageous for suppressing aberration fluctuations while achieving a large aperture ratio. If the middle lens group GM has fewer than six lenses, it becomes difficult to correct spherical aberration.

[0043] In the zoom lens of the present invention, the boundary between the middle lens group GM and the rear lens group GR is the point where the lateral magnification of the rear lens group GR is greatest. This clarifies the division of roles, with the middle lens group GM, which has a relatively strong positive refractive power, moving toward the object side during zooming, thereby performing the primary zooming function, while the distance between the middle lens group GM and the rear lens group GR increases during zooming from the wide-angle end to the telephoto end, allowing the rear lens group GR to assist in correcting aberrations during zooming, making aberration correction easier.

[0044] Furthermore, in the zoom lens of the present invention, it is desirable to position the aperture diaphragm S in the rear lens group GR. In the configuration of the present invention, axial rays are deflected by the first lens group G1, which has a negative refractive power, resulting in a high height of axial marginal rays in the middle lens group GM. If an aperture diaphragm were placed here, the aperture diameter would be large, resulting in a large outer diameter and a heavy product. On the other hand, if an aperture diaphragm were placed in the final lens group GN, it would be positioned too close to the image plane, causing vignetting when the effective diameter of the first lens group is not increased. Therefore, by positioning an aperture diaphragm in the rear lens group GR, axial marginal rays are converged by the middle lens group GM, which has a positive refractive power, making it possible to prevent an increase in the effective diameter of the first lens group while preventing the aperture from becoming too large.

[0045] Next, we will explain the lens configurations of embodiments of the zoom lens of the present invention. In the following explanation, the lens configurations are described in order from the object side to the image side. In addition, in the lens configuration diagrams of each embodiment, I indicates the image sensor, and the dashed dotted line passing through the center indicates the optical axis.

[0046] [Example 1] FIG. 1 is a lens configuration diagram of a zoom lens according to a first embodiment of the present invention. The zoom lens according to the first embodiment is composed of a first lens group G1 with negative refractive power, a second lens group G2 with positive refractive power, a third lens group G3 with negative refractive power, a fourth lens group G4 with positive refractive power, a fifth lens group G5 with negative refractive power, a sixth lens group G6 with negative refractive power, and a seventh lens group G7 with positive refractive power. The spacing between each group changes during zooming from the wide-angle end to the telephoto end. All of the second lens group G2 through the fifth lens group G5 move toward the object, while the sixth lens group G6 moves toward the image plane. An aperture stop S is provided on the object side of the fifth lens group G5 and moves integrally with the fifth lens group G5 during zooming. During focusing from an object at infinity to a close-up object, the third lens group G3 moves toward the object along the optical axis. The first lens group G1 and the seventh lens group G7 are fixed during both magnification and focusing. In this embodiment, the middle lens group GM is composed of the second lens group G2, the third lens group G3, and the fourth lens group G4, the rear lens group GR is composed of the fifth lens group G5 and the sixth lens group G6, and the final lens group GN corresponds to the seventh lens group G7.

[0047] The first lens group G1 is composed of a negative meniscus lens with a convex surface facing the object side and both surfaces of which have a predetermined aspherical shape, a negative meniscus lens with a convex surface facing the object side, a biconcave lens, and a positive meniscus lens with a convex surface facing the object side.

[0048] The second lens group G2 is composed of a positive meniscus lens with its convex surface facing the object side.

[0049] The third lens group G3 is composed of a biconcave lens.

[0050] The fourth lens group G4 is composed of a positive meniscus lens with its convex surface facing the object side, a biconvex lens with predetermined aspherical shapes on both sides, a cemented lens consisting of a biconcave lens and a biconvex lens, and a biconvex lens.

[0051] The fifth lens group G5 is composed of an aperture stop S and a cemented lens made up of a biconvex lens and a biconcave lens.

[0052] The sixth lens group G6 is composed of a cemented lens made up of a positive meniscus lens with its concave surface facing the object side and a biconcave lens.

[0053] The seventh lens group G7 is composed of a biconvex lens, a biconvex lens, and a biconcave lens with a predetermined aspherical shape on both sides. The final lens LN corresponds to the biconcave lens arranged closest to the image side in the seventh lens group G7.

[0054] [Example 2] 14 is a lens configuration diagram of a zoom lens according to a second embodiment of the present invention. The zoom lens according to the second embodiment is composed of a first lens group G1 with negative refractive power, a second lens group G2 with positive refractive power, a third lens group G3 with negative refractive power, a fourth lens group G4 with positive refractive power, a fifth lens group G5 with negative refractive power, a sixth lens group G6 with negative refractive power, and a seventh lens group G7 with positive refractive power. The spacing between each group changes when zooming from the wide-angle end to the telephoto end. Each of the second lens group G2 through the fifth lens group G5 moves toward the object. The sixth lens group G6 moves toward the object from the wide-angle end to the intermediate focal length, and moves toward the image plane from the intermediate focal length to the telephoto end. An aperture stop S is provided on the object side of the fifth lens group G5 and moves integrally with the fifth lens group G5 when zooming. During focusing from an object at infinity to a close object, the third lens group G3 moves toward the object along the optical axis. The first lens group G1 and the seventh lens group G7 remain fixed during both magnification and focusing. In this embodiment, the middle lens group GM is composed of the second lens group G2, the third lens group G3, and the fourth lens group G4, the rear lens group GR is composed of the fifth lens group G5 and the sixth lens group G6, and the final lens group GN corresponds to the seventh lens group G7.

[0055] The first lens group G1 is composed of a negative meniscus lens with a convex surface facing the object side and both surfaces of which have a predetermined aspherical shape, a negative meniscus lens with a convex surface facing the object side and both surfaces of which have a predetermined aspherical shape, a biconcave lens, and a positive meniscus lens with a convex surface facing the object side.

[0056] The second lens group G2 is composed of a positive meniscus lens with its convex surface facing the object side.

[0057] The third lens group G3 is composed of a biconcave lens.

[0058] The fourth lens group G4 is composed of a biconvex lens having a predetermined aspherical shape on both sides, a cemented lens consisting of a negative meniscus lens with its convex surface facing the object side and a biconvex lens, and a biconvex lens.

[0059] The fifth lens group G5 is composed of an aperture stop S and a cemented lens made up of a biconvex lens and a biconcave lens.

[0060] The sixth lens group G6 is composed of a cemented lens made up of a positive meniscus lens with its concave surface facing the object side and a biconcave lens.

[0061] The seventh lens group G7 is composed of a biconvex lens, a biconvex lens, and a biconcave lens with a predetermined aspherical shape on both sides. The final lens LN corresponds to the biconcave lens arranged closest to the image side in the seventh lens group G7.

[0062] [Example 3] 27 is a lens configuration diagram of a zoom lens according to a third embodiment of the present invention. The zoom lens according to the third embodiment is composed of a first lens group G1 with negative refractive power, a second lens group G2 with positive refractive power, a third lens group G3 with negative refractive power, a fourth lens group G4 with positive refractive power, a fifth lens group G5 with negative refractive power, a sixth lens group G6 with negative refractive power, and a seventh lens group G7 with positive refractive power. The spacing between each group changes when zooming from the wide-angle end to the telephoto end. Each of the second lens group G2 through the fifth lens group G5 moves toward the object side. The sixth lens group G6 moves toward the object side from the wide-angle end to the intermediate focal length, and moves toward the image plane side from the intermediate focal length to the telephoto end. An aperture stop S is provided within the fifth lens group G5 and moves integrally with it when zooming. During focusing from an object at infinity to a close object, the third lens group G3 moves toward the object along the optical axis. The first lens group G1 and the seventh lens group G7 remain fixed during both magnification and focusing. In this embodiment, the middle lens group GM is composed of the second lens group G2, the third lens group G3, and the fourth lens group G4, the rear lens group GR is composed of the fifth lens group G5 and the sixth lens group G6, and the final lens group GN corresponds to the seventh lens group G7.

[0063] The first lens group G1 is composed of a negative meniscus lens having a convex surface facing the object side and both surfaces of which have a predetermined aspherical shape, a biconcave lens, and a positive meniscus lens having a convex surface facing the object side.

[0064] The second lens group G2 is composed of a biconvex lens.

[0065] The third lens group G3 is composed of a biconcave lens.

[0066] The fourth lens group G4 is composed of a biconvex lens, a biconvex lens with a predetermined aspherical shape on both sides, a cemented lens consisting of a biconcave lens and a biconvex lens, and a biconvex lens.

[0067] The fifth lens group G5 is composed of a biconvex lens, an aperture stop S, and a cemented lens consisting of a biconvex lens and a biconcave lens.

[0068] The sixth lens group G6 is composed of a cemented lens made up of a positive meniscus lens with its concave surface facing the object side and a biconcave lens.

[0069] The seventh lens group G7 is composed of a biconvex lens, a biconvex lens, and a biconcave lens with a predetermined aspherical shape on both sides. The final lens LN corresponds to the biconcave lens arranged closest to the image side in the seventh lens group G7.

[0070] [Example 4] FIG. 40 is a lens configuration diagram of a zoom lens according to a fourth embodiment of the present invention. The zoom lens according to the fourth embodiment is composed of a first lens group G1 with negative refractive power, a second lens group G2 with positive refractive power, a third lens group G3 with negative refractive power, a fourth lens group G4 with positive refractive power, a fifth lens group G5 with negative refractive power, and a sixth lens group G6 with positive refractive power. The spacing between each group changes during zooming from the wide-angle end to the telephoto end, and each of the second lens group G2 through the fifth lens group G5 moves toward the object. An aperture stop S is provided on the object side of the fifth lens group G5 and moves integrally with the fifth lens group G5 during zooming. During focusing from an object at infinity to a close-up object, the second lens group G2 moves toward the image plane along the optical axis. The first lens group G1 and the sixth lens group G6 remain fixed during both zooming and focusing. In this embodiment, the middle lens group GM is composed of the second lens group G2, the third lens group G3, and the fourth lens group G4, the rear lens group GR is composed of the fifth lens group G5, and the final lens group GN corresponds to the sixth lens group G6.

[0071] The first lens group G1 is composed of a negative meniscus lens with a convex surface facing the object side and both surfaces of which have a predetermined aspherical shape, a negative meniscus lens with a convex surface facing the object side, a biconcave lens, and a positive meniscus lens with a convex surface facing the object side.

[0072] The second lens group G2 is composed of a biconvex lens.

[0073] The third lens group G3 is composed of a biconcave lens.

[0074] The fourth lens group G4 is composed of a positive meniscus lens with its convex surface facing the object side, a biconvex lens with predetermined aspherical shapes on both sides, a cemented lens consisting of a biconcave lens and a biconvex lens, and a biconvex lens.

[0075] The fifth lens group G5 is composed of an aperture stop S and a cemented lens made up of a biconvex lens and a biconcave lens.

[0076] The sixth lens group G6 is composed of a cemented lens consisting of a positive meniscus lens with its concave surface facing the object side and a biconcave lens, a biconvex lens, a biconcave lens, and a biconcave lens with predetermined aspherical surfaces on both sides. The final lens LN corresponds to the biconcave lens located closest to the image in the sixth lens group G6.

[0077] [Example 5] Figure 53 is a lens configuration diagram of a zoom lens according to a fifth embodiment of the present invention. The zoom lens according to the fifth embodiment is composed of a first lens group G1 with negative refractive power, a second lens group G2 with positive refractive power, a third lens group G3 with negative refractive power, a fourth lens group G4 with positive refractive power, a fifth lens group G5 with negative refractive power, a sixth lens group G6 with negative refractive power, and a seventh lens group G7 with positive refractive power. The spacing between each group changes during zooming from the wide-angle end to the telephoto end. All of the second lens group G2 through the fifth lens group G5 move toward the object, while the sixth lens group G6 moves toward the image plane. An aperture stop S is provided on the object side of the fifth lens group G5 and moves integrally with the fifth lens group G5 during zooming. During focusing from an object at infinity to a close-up object, the third lens group G3 moves toward the object along the optical axis. The first lens group G1 and the seventh lens group G7 are fixed during both magnification and focusing. In this embodiment, the middle lens group GM is composed of the second lens group G2, the third lens group G3, and the fourth lens group G4, the rear lens group GR is composed of the fifth lens group G5 and the sixth lens group G6, and the final lens group GN corresponds to the seventh lens group G7.

[0078] The first lens group G1 is composed of a negative meniscus lens with a convex surface facing the object side and both surfaces of which have a predetermined aspherical shape, a negative meniscus lens with a convex surface facing the object side, a biconcave lens, and a positive meniscus lens with a convex surface facing the object side.

[0079] The second lens group G2 is composed of a positive meniscus lens with its convex surface facing the object side.

[0080] The third lens group G3 is composed of a cemented lens consisting of a biconcave lens and a positive meniscus lens with its convex surface facing the object side.

[0081] The fourth lens group G4 is composed of a positive meniscus lens with its convex surface facing the object side, a biconvex lens with predetermined aspherical shapes on both sides, a cemented lens consisting of a biconcave lens and a biconvex lens, and a biconvex lens.

[0082] The fifth lens group G5 is composed of an aperture stop S and a cemented lens made up of a biconvex lens and a biconcave lens.

[0083] The sixth lens group G6 is composed of a cemented lens made up of a positive meniscus lens with its concave surface facing the object side and a biconcave lens.

[0084] The seventh lens group G7 is composed of a biconvex lens, a biconvex lens, and a biconcave lens with a predetermined aspherical shape on both sides. The final lens LN corresponds to the biconcave lens arranged closest to the image side in the seventh lens group G7.

[0085] [Example 6] Figure 66 is a lens configuration diagram of a zoom lens according to a sixth embodiment of the present invention. The zoom lens according to the sixth embodiment is composed of a first lens group G1 with negative refractive power, a second lens group G2 with positive refractive power, a third lens group G3 with negative refractive power, a fourth lens group G4 with positive refractive power, a fifth lens group G5 with positive refractive power, a sixth lens group G6 with negative refractive power, a seventh lens group G7 with negative refractive power, and an eighth lens group G8 with positive refractive power. The spacing between each group changes when varying magnification from the wide-angle end to the telephoto end. Each of the second lens group G2 through the sixth lens group G6 moves toward the object side. The seventh lens group G7 moves toward the object side from the wide-angle end to the intermediate focal length and moves toward the image plane side from the intermediate focal length to the telephoto end. An aperture stop S is provided on the object side of the sixth lens group G6 and moves integrally with the sixth lens group G6 when varying magnification. During focusing from an object at infinity to a close distance, the third lens group G3 moves toward the object along the optical axis. The first lens group G1 and the eighth lens group G8 remain fixed during both magnification and focusing. In this embodiment, the middle lens group GM is composed of the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5, the rear lens group GR is composed of the sixth lens group G6 and the seventh lens group G7, and the final lens group GN corresponds to the eighth lens group G8.

[0086] The first lens group G1 is composed of a negative meniscus lens whose convex surface faces the object side and whose both surfaces have predetermined aspherical shapes, a negative meniscus lens whose convex surface faces the object side and whose both surfaces have predetermined aspherical shapes, and a cemented lens made up of a biconcave lens and a positive meniscus lens whose convex surface faces the object side.

[0087] The second lens group G2 is composed of a positive meniscus lens with its convex surface facing the object side.

[0088] The third lens group G3 is composed of a biconcave lens.

[0089] The fourth lens group G4 is composed of a biconvex lens having a predetermined aspherical shape on both sides, and a biconcave lens.

[0090] The fifth lens group G5 is composed of a cemented lens made up of a negative meniscus lens with its convex surface facing the object side and a biconvex lens, and a biconvex lens.

[0091] The sixth lens group G6 is composed of an aperture stop S and a cemented lens made up of a biconvex lens and a biconcave lens.

[0092] The seventh lens group G7 is composed of a cemented lens made up of a biconvex lens and a biconcave lens.

[0093] The eighth lens group G8 is composed of a biconvex lens, a biconvex lens, and a biconcave lens with a predetermined aspherical shape on both sides. The final lens LN corresponds to the biconcave lens arranged closest to the image in the eighth lens group G8.

[0094] [Example 7] Figure 79 is a lens configuration diagram of a zoom lens according to Example 7 of the present invention. The zoom lens according to Example 7 is composed of a first lens group G1 with negative refractive power, a second lens group G2 with positive refractive power, a third lens group G3 with negative refractive power, a fourth lens group G4 with positive refractive power, a fifth lens group G5 with negative refractive power, a sixth lens group G6 with negative refractive power, and a seventh lens group G7 with positive refractive power. The spacing between each group changes when varying magnification from the wide-angle end to the telephoto end. Each of the second lens group G2 to the fifth lens group G5 moves toward the object side. The sixth lens group G6 moves toward the object side from the wide-angle end to the intermediate focal length and moves toward the image plane side from the intermediate focal length to the telephoto end. An aperture stop S is provided on the object side of the fifth lens group G5 and moves integrally with the fifth lens group G5 when varying magnification. During focusing from an object at infinity to a close object, the third lens group G3 moves toward the object along the optical axis. The first lens group G1 and the seventh lens group G7 remain fixed during both magnification and focusing. In this embodiment, the middle lens group GM is composed of the second lens group G2, the third lens group G3, and the fourth lens group G4, the rear lens group GR is composed of the fifth lens group G5 and the sixth lens group G6, and the final lens group GN corresponds to the seventh lens group G7.

[0095] The first lens group G1 is composed of a negative meniscus lens with a convex surface facing the object side and both surfaces of which have a predetermined aspherical shape, a negative meniscus lens with a convex surface facing the object side, a biconcave lens, and a positive meniscus lens with a convex surface facing the object side.

[0096] The second lens group G2 is composed of a biconvex lens and a biconcave lens.

[0097] The third lens group G3 is composed of a biconcave lens.

[0098] The fourth lens group G4 is composed of a biconvex lens having a predetermined aspherical shape on both sides, a cemented lens consisting of a negative meniscus lens with its convex surface facing the object side and a biconvex lens, and a biconvex lens.

[0099] The fifth lens group G5 is composed of an aperture stop S and a cemented lens made up of a biconvex lens and a biconcave lens.

[0100] The sixth lens group G6 is composed of a cemented lens made up of a positive meniscus lens with its concave surface facing the object side and a biconcave lens.

[0101] The seventh lens group G7 is composed of a biconvex lens, a biconvex lens, and a biconcave lens with a predetermined aspherical shape on both sides. The final lens LN corresponds to the biconcave lens arranged closest to the image side in the seventh lens group G7.

[0102] [Example 8] Figure 92 is a lens configuration diagram of a zoom lens according to Example 8 of the present invention. The zoom lens according to Example 8 is composed of a first lens group G1 with negative refractive power, a second lens group G2 with positive refractive power, a third lens group G3 with negative refractive power, a fourth lens group G4 with positive refractive power, a fifth lens group G5 with negative refractive power, a sixth lens group G6 with negative refractive power, and a seventh lens group G7 with positive refractive power. When varying magnification from the wide-angle end to the telephoto end, the spacing between each group changes. Each of the second lens group G2 through the fifth lens group G5 moves toward the object, while the sixth lens group G6 moves toward the image plane. An aperture stop S is provided on the object side of the fifth lens group G5 and moves integrally with the fifth lens group G5 during magnification. When focusing from an object at infinity to a close-up object, the second lens group G2 moves toward the image plane along the optical axis, and the third lens group G3 moves toward the object along the optical axis. The first lens group G1 and the seventh lens group G7 are fixed during both magnification and focusing. In this embodiment, the middle lens group GM is composed of the second lens group G2, the third lens group G3, and the fourth lens group G4, the rear lens group GR is composed of the fifth lens group G5 and the sixth lens group G6, and the final lens group GN corresponds to the seventh lens group G7.

[0103] The first lens group G1 is composed of a negative meniscus lens with a convex surface facing the object side and both surfaces of which have a predetermined aspherical shape, a negative meniscus lens with a convex surface facing the object side, a biconcave lens, and a positive meniscus lens with a convex surface facing the object side.

[0104] The second lens group G2 is composed of a positive meniscus lens with its convex surface facing the object side.

[0105] The third lens group G3 is composed of a biconcave lens.

[0106] The fourth lens group G4 is composed of a positive meniscus lens with its convex surface facing the object side, a biconvex lens with predetermined aspherical shapes on both sides, a cemented lens consisting of a biconcave lens and a biconvex lens, and a biconvex lens.

[0107] The fifth lens group G5 is composed of an aperture stop S and a cemented lens made up of a biconvex lens and a biconcave lens.

[0108] The sixth lens group G6 is composed of a cemented lens made up of a positive meniscus lens with its concave surface facing the object side and a biconcave lens.

[0109] The seventh lens group G7 is composed of a biconvex lens, a biconvex lens, and a biconcave lens with a predetermined aspherical shape on both sides. The final lens LN corresponds to the biconcave lens arranged closest to the image side in the seventh lens group G7.

[0110] Specific numerical data for each of the above-described embodiments of the zoom lens of the present invention will be shown below.

[0111] In [Surface Data], the surface number is the number of the lens surface or aperture stop S counted from the object side, r is the radius of curvature of each surface, d is the spacing between surfaces, nd is the refractive index for the d-line (wavelength 587.56 nm), and vd is the Abbe number for the d-line.

[0112] An asterisk (*) next to a surface number indicates that the lens surface is aspherical, and BF represents the back focal length.

[0113] The (stop) attached to the surface number indicates that the aperture stop S is located at that position. The radius of curvature for the plane or aperture stop S is marked as ∞ (infinity).

[0114] [Aspherical Data] shows the values of each coefficient that determines the aspherical shape of lens surfaces marked with an * in [Surface Data]. The aspherical shape is defined as follows: y is the displacement from the optical axis in a direction perpendicular to the optical axis, z is the displacement (sag) from the intersection of the aspherical surface and the optical axis in the direction of the optical axis, r is the radius of curvature of the reference sphere, K is the Conic coefficient, and A4, A6, . . ., and A20 are the aspherical coefficients of the 4th, 6th, . . ., and 20th orders, respectively. The coordinates of the aspherical shape are expressed by the following equations: TIFF2025116419000002.tif19168

[0115] [Various Data] shows values such as zoom ratio and focal length for each focal length state.

[0116] [Variable Distance Data] shows the variable distance and BF values for each focal length state.

[0117] [Lens Group Data] shows the surface number of each lens group closest to the object and the composite focal length of the entire group.

[0118] In addition, for all of the values of the following specifications, the focal length f, radius of curvature r, lens surface spacing d, and other length units are given in millimeters (mm) unless otherwise specified; however, this is not a limitation, as optical systems can achieve equivalent optical performance with proportional magnification and proportional reduction.

[0119] In the aberration diagrams corresponding to the respective examples, d, g, and C represent the d-line, g-line, and C-line, respectively, and ΔS and ΔM represent the sagittal image surface and meridional image surface, respectively.

[0120] Numerical Example 1 Unit: mm [Face Data] Surface number rd nd vd Object surface ∞ (d0) 1* 62.8412 2.5000 1.69350 53.18 2* 33.7141 6.8143 3 69.5030 1.6000 1.55200 70.70 4 32.0589 11.4771 5 -100.6393 1.2000 1.59349 67.00 6 131.3025 0.2000 7 55.0603 3.3027 1.94594 17.98 8 105.6073 (d8) 9 57.1246 4.1036 1.72916 54.67 10 370.9703 (d10) 11 -46.6108 1.0000 1.70300 52.38 12 316.5784 (d12) 13 82.6292 5.5014 2.00100 29.13 14 1000.0000 0.1500 15* 113.6023 6.2500 1.85135 40.10 16* -85.0000 0.1500 17 -161.1335 1.0000 1.75520 27.53 18 43.4754 10.4757 1.55032 75.50 19 -138.4530 0.1500 20 145.7610 9.1551 1.48071 85.29 21 -50.0098 (d21) 22 (Aperture) ∞ 1.0000 23 48.4843 5.9411 1.55032 75.50 24 -63.0665 1.0000 1.84666 23.78 25 41.9346 (d25) 26 -54.6452 3.8799 1.59282 68.62 27 -21.9774 1.0000 1.61340 44.27 28 392.2475 (d28) 29 91.5064 3.0439 1.98612 16.48 30 -237.3723 0.1500 31 160.0150 3.9676 1.87070 40.73 32 -71.3877 7.8385 33* -266.3635 3.9000 1.80610 40.73 34* 101.2174 (BF) Image plane ∞ [Aspherical data] 1st floor 2nd floor 15th floor 16th floor 33rd floor K -0.42595 0.01244 0.00000 0.00000 0.00000 A4 3.19947E-06 2.50431E-06 -2.95295E-06 1.50717E-06 5.31830E-06 A6 4.62317E-09 4.40329E-09 -1.06620E-09 -1.33491E-09 -2.40499E-08 A8 -6.84866E-11 -6.90636E-11 6.01008E-12 6.00753E-12 3.63138E-13 A10 2.57540E-13 1.99490E-13 -6.93914E-15 -7.78748E-15 8.24299E-14 A12 -5.43557E-16 -2.59035E-16 -1.84198E-17 -7.70817E-18 -1.23832E-16 A14 7.14031E-19 1.13939E-19 4.86069E-20 2.17147E-20 0.00000E+00 A16 -5.84993E-22 1.47896E-23 -3.15520E-23 -1.06508E-23 0.00000E+00 A18 2.74723E-25 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 A20 -5.60150E-29 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 34 pages K 0.00000 A4 1.39286E-05 A6 -1.66494E-08 A8 -5.42999E-11 A10 4.53620E-13 A12 -1.57009E-15 A14 2.86549E-18 A16 -1.95585E-21 A18 0.00000E+00 A20 0.00000E+00 [Various data] Zoom ratio 1.51 Wide-angle Mid-range Telephoto Focal length 28.84 35.06 43.66 F-number 1.86 1.86 1.86 Full angle of view 2ω 75.19 62.38 50.51 Image height Y 21.63 21.63 21.63 Lens total length 168.66 168.66 168.66 [Variable Interval Data] Focusing at infinity Wide-angle Mid-range Telephoto d0 ∞ ∞ ∞ d8 19.1743 11.2712 3.5000 d10 12.0903 14.6497 14.1166 d12 6.1487 4.1025 2.8831 d21 2.3000 6.6293 11.3402 d25 4.4326 7.8911 14.0817 d28 3.2698 2.8719 1.4941 BF 24.4912 24.4912 24.4912 At 40x magnification Wide-angle Mid-range Telephoto d0 1105.8626 1354.7984 1700.3387 d8 19.1743 11.2712 3.5000 d10 11.3155 13.9869 13.5524 d12 6.9235 4.7652 3.4473 d21 2.3000 6.6293 11.3402 d25 4.4326 7.8911 14.0817 d28 3.2698 2.8719 1.4941 BF 24.4912 24.4912 24.4912 [Lens group data] Group Starting plane Focal length G1 1 -46.04 G2 9 92.09 G3 11 -57.73 G4 13 32.98 G5 22 -80.77 G6 26 -74.48 G7 29 40.70

[0121] Numerical Example 2 Unit: mm [Face Data] Surface number rd nd vd Object surface ∞ (d0) 1* 175.6195 3.2188 1.69350 53.18 2* 38.6465 4.6809 3* 61.8505 2.5198 1.59201 67.02 4* 37.2488 12.7752 5 -96.6987 1.6000 1.49700 81.61 6 61.7440 0.1500 7 47.7086 4.0295 1.92286 20.88 8 95.9441 (d8) 9 50.0000 3.8501 1.83481 42.72 10 155.0631 (d10) 11 -40.3089 0.9000 1.61340 44.27 12 157.5857 (d12) 13* 53.8625 11.8461 1.85135 40.10 14* -67.4806 0.1500 15 550.8385 0.9000 1.80000 29.84 16 34.5485 11.2421 1.59282 68.62 17 -207.2689 0.1500 18 80.3648 8.3437 1.48071 85.29 19 -52.3655 (d19) 20 (Aperture) ∞ 0.9000 21 50.1862 5.3447 1.48071 85.29 22 -59.0132 0.9000 1.72825 28.32 23 34.9946 (d23) 24 -240.5948 3.3078 1.49700 81.61 25 -37.6917 0.9000 1.65412 39.68 26 121.1138 (d26) 27 63.0453 5.2892 1.94594 17.98 28 -179.1150 0.1500 29 237.1249 5.6413 1.77250 49.63 30 -47.9368 1.0765 31* -115.9631 1.9088 1.80610 40.73 32* 64.7407 (BF) Image plane ∞ [Aspherical data] 1st page 2nd page 3rd page 4th page 13th page K 8.28836 0.00000 0.35877 0.00000 0.00000 A4 4.81552E-06 2.86558E-06 7.61058E-06 1.15632E-05 -4.15242E-06 A6 -6.06818E-09 -6.03010E-09 -1.62747E-08 -1.24378E-08 1.18236E-09 A8 7.32458E-12 8.92771E-12 3.59158E-11 3.07916E-11 2.03139E-12 A10 -5.21062E-15 1.07998E-14 -3.15307E-14 -4.17458E-14 0.00000E+00 A12 1.63460E-18 -1.49185E-17 0.00000E+00 0.00000E+00 0.00000E+00 14th page 31st page 32nd page K 0.00000 0.00000 0.00000 A4 2.38768E-06 -1.45417E-07 9.85508E-06 A6 -7.38320E-10 -3.12416E-08 -2.50647E-08 A8 3.35215E-12 3.25289E-11 2.81686E-11 A10 0.00000E+00 0.00000E+00 0.00000E+00 A12 0.00000E+00 0.00000E+00 0.00000E+00 [Various data] Zoom ratio 1.57 Wide-angle Mid-range Telephoto Focal length 24.72 29.82 38.82 F-number 1.86 1.86 1.86 Full angle of view 2ω 85.45 71.84 55.91 Image height Y 21.63 21.63 21.63 Lens total length 164.03 164.03 164.03 [Variable Interval Data] Focusing at infinity Wide-angle Mid-range Telephoto d0 ∞ ∞ ∞ d8 18.7777 11.8537 3.5000 d10 12.8935 15.8557 16.0246 d12 6.9584 4.5468 2.4885 d19 0.9000 4.2517 8.5205 d23 5.3985 7.6001 14.5477 d26 2.1153 2.9352 1.9620 BF 25.2096 25.2096 25.2096 At 40x magnification Wide-angle Mid-range Telephoto d0 947.0854 1151.0626 1511.9902 d8 18.7777 11.8537 3.5000 d10 12.2762 15.3274 15.5936 d12 7.5756 5.0751 2.9195 d19 0.9000 4.2517 8.5205 d23 5.3985 7.6001 14.5477 d26 2.1153 2.9352 1.9620 BF 25.2096 25.2096 25.2096 [Lens group data] Group Starting plane Focal length G1 1 -39.41 G2 9 86.95 G3 11 -52.24 G4 13 28.98 G5 20 -68.96 G6 24 -85.49 G7 27 46.55

[0122] Numerical Example 3 Unit: mm [Face Data] Surface number rd nd vd Object surface ∞ (d0) 1* 72.7404 2.5000 1.59201 67.02 2* 26.8534 16.9134 3 -53.0602 1.4000 1.61997 63.88 4 115.1537 0.1500 5 75.9031 3.5248 1.94594 17.98 6 262.1067 (d6) 7 57.3272 5.7198 1.70300 52.38 8 -1468.0937 (d8) 9 -45.4258 1.0000 1.65844 50.86 10 185.1358 (d10) 11 77.1076 5.6006 1.91082 35.25 12 -1971.5067 0.4916 13* 123.6521 6.2500 1.85135 40.10 14* -95.1170 0.1500 15 -316.1223 1.0000 1.74077 27.76 16 43.3771 10.4687 1.55032 75.50 17 -286.7891 0.1500 18 128.2806 9.6229 1.49700 81.61 19 -64.1796 (d19) 20 551.1609 2.6678 1.55397 71.76 21 -135.5689 1.0000 22 (Aperture) ∞ 1.0000 23 76.9783 6.0111 1.55032 75.50 24 -50.3799 1.0000 1.92119 23.96 25 62.7566 (d25) 26 -129.5027 3.2188 1.55032 75.50 27 -37.9790 1.0000 1.61340 44.27 28 78.9789 (d28) 29 74.7276 4.4496 1.98612 16.48 30 -229.3531 0.1500 31 104.2405 5.0988 1.76385 48.49 32 -86.1034 5.2227 33* -134.6538 3.8503 1.80610 40.73 34* 71.0603 (BF) Image plane ∞ [Aspherical data] Page 1 Page 2 Page 13 Page 14 Page 33 K -1.32185 -0.01863 0.00000 0.00000 0.00000 A4 2.52291E-06 -1.92779E-07 -3.00986E-06 8.88334E-07 3.87114E-06 A6 -2.23915E-09 2.66457E-09 -5.89472E-11 -7.99717E-10 -1.90089E-08 A8 -9.22253E-12 -5.02266E-11 -2.88854E-12 -1.83314E-12 1.89250E-11 A10 3.11359E-14 1.09736E-13 7.72533E-15 6.33449E-15 -1.29806E-14 A12 -3.50316E-17 -9.70686E-17 -4.56627E-18 -3.85109E-18 0.00000E+00 A14 1.40886E-20 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 34 sides K 0.00000 A4 1.13079E-05 A6 -1.47420E-08 A8 1.60794E-11 A10 -1.66539E-14 A12 0.00000E+00 A14 0.00000E+00 [Various data] Zoom ratio 1.57 Wide-angle Mid-range Telephoto Focal length 30.88 35.69 48.48 F-number 1.86 1.86 1.86 Full angle of view 2ω 73.11 62.81 46.05 Image height Y 21.63 21.63 21.63 Lens length 174.77 174.77 174.78 [Variable Interval Data] Focusing at infinity Wide-angle Mid-range Telephoto d0 ∞ ∞ ∞ d6 23.2844 16.3368 3.5000 d8 13.4095 15.2114 14.3989 d10 4.2954 3.6722 3.2920 d19 1.5500 4.6952 11.9169 d25 3.7924 6.1380 13.5272 d28 7.7825 8.0605 7.4792 BF 21.0500 21.0500 21.0500 At 40x magnification Wide-angle Mid-range Telephoto d0 1186.9374 1379.8682 1893.6821 d6 23.2844 16.3368 3.5000 d8 12.6898 14.5788 13.9055 d10 5.0151 4.3048 3.7855 d19 1.5500 4.6952 11.9169 d25 3.7924 6.1380 13.5272 d28 7.7825 8.0605 7.4792 BF 21.0500 21.0500 21.0500 [Lens group data] Group Starting plane Focal length G1 1 -42.33 G2 7 78.60 G3 9 -55.30 G4 11 33.77 G5 20 -116.94 G6 26 -72.52 G7 29 48.82

[0123] Numerical Example 4 Unit: mm [Face Data] Surface number rd nd vd Object surface ∞ (d0) 1* 158.4085 3.1378 1.69350 53.18 2* 58.6578 2.5000 3 56.0610 2.0000 1.61997 63.88 4 29.2384 13.6544 5 -107.5990 1.6000 1.61997 63.88 6 106.6667 0.1500 7 51.9869 3.8874 1.94594 17.98 8 97.6675 (d8) 9 159.6771 4.1822 1.81600 46.62 10 -131.6527 (d10) 11 -49.1740 1.0000 1.76385 48.49 12 329.1747 (d12) 13 62.6924 4.5207 1.88100 40.14 14 319.9991 1.4935 15* 124.6808 11.0241 1.85108 40.12 16* -66.8239 0.1500 17 -105.9516 1.0000 1.72825 28.32 18 45.0463 10.5246 1.55032 75.50 19 -98.8414 0.1500 20 431.0136 11.7395 1.55397 71.76 21 -47.9183 (d21) 22 (Aperture) ∞ 1.0000 23 55.8267 6.7168 1.55032 75.50 24 -40.5425 1.0000 1.85883 30.00 25 60.0420 (d25) 26 -94.7190 3.2945 1.57144 71.61 27 -28.1463 1.0000 1.60342 38.01 28 54.0238 4.0472 29 71.7642 3.3101 1.94594 17.98 30 -284.2638 0.1500 31 103.9551 6.4920 1.83400 37.34 32 -44.8608 1.7741 33* -111.7094 4.6794 1.80610 40.73 34* 58.7605 (BF) Image plane ∞ [Aspherical data] 1st floor 2nd floor 15th floor 16th floor 33rd floor K 0.00000 0.00000 0.00000 0.00000 0.00000 A4 4.69562E-06 4.69560E-06 -3.18717E-06 1.84191E-06 -1.71829E-06 A6 -3.68771E-09 -2.59530E-09 -4.61571E-11 9.78127E-11 -2.51984E-08 A8 3.75879E-12 3.62499E-12 1.92620E-12 2.27963E-12 1.85179E-11 A10 -2.46887E-15 -2.20139E-15 0.00000E+00 0.00000E+00 0.00000E+00 A12 6.54735E-19 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 34 sides K 0.00000 A4 8.66839E-06 A6 -2.52264E-08 A8 2.10638E-11 A10 0.00000E+00 A12 0.00000E+00 [Various data] Zoom ratio 1.51 Wide-angle Mid-range Telephoto Focal length 28.85 34.93 43.65 F-number 1.86 1.86 1.86 Full angle of view 2ω 75.96 62.93 50.54 Image height Y 21.63 21.63 21.63 Lens total length 169.80 169.80 169.80 [Variable Interval Data] Focusing at infinity Wide-angle Mid-range Telephoto d0 ∞ ∞ ∞ d8 9.6328 5.5335 3.5003 d10 12.1320 14.3924 12.4689 d12 12.0652 7.4078 2.5000 d21 1.4000 4.7773 8.9948 d25 3.6846 6.8036 11.4505 BF 24.7114 24.7114 24.7114 At 40x magnification Wide-angle Mid-range Telephoto d0 1104.4175 1349.1052 1698.4065 d8 11.5983 7.1915 4.8447 d10 10.1665 12.7343 11.1246 d12 12.0652 7.4078 2.5000 d21 1.4000 4.7773 8.9948 d25 3.6846 6.8036 11.4505 BF 24.7114 24.7114 24.7114 [Lens group data] Group Starting plane Focal length G1 1 -46.78 G2 9 89.00 G3 11 -55.95 G4 13 33.15 G5 22 -90.09 G6 26 131.38

[0124] Numerical Example 5 Unit: mm [Face Data] Surface number rd nd vd Object surface ∞ (d0) 1* 95.4476 2.8000 1.69350 53.18 2* 42.7004 2.5001 3 48.2745 1.9000 1.55200 70.70 4 30.3400 13.7098 5 -98.3978 1.5000 1.59349 67.00 6 69.2811 0.1500 7 54.0201 3.6539 1.94594 17.98 8 106.6149 (d8) 9 57.4746 4.7246 1.72916 54.67 10 3049.2390 (d10) 11 -50.8811 1.0000 1.70154 41.15 12 55.5124 3.4052 1.77047 29.74 13 156.5356 (d13) 14 66.2068 4.2342 1.91082 35.25 15 290.3463 0.4366 16* 114.9141 5.4541 1.85108 40.12 17* -88.3955 0.1500 18 -157.4833 1.0000 1.72825 28.32 19 48.8079 8.6020 1.55032 75.50 20 -172.0320 0.1500 21 117.3905 10.3208 1.45860 90.19 22 -48.6001 (d22) 23 (Aperture) ∞ 1.0000 24 51.4101 6.4819 1.55032 75.50 25 -49.5975 1.0000 1.85478 24.80 26 43.0890 (d26) 27 -67.8016 2.8774 1.59282 68.62 28 -33.0837 1.0000 1.61340 44.27 29 117.5712 (d29) 30 89.0690 3.4343 1.98612 16.48 31 -203.5393 0.1500 32 89.9935 5.0130 1.81600 46.62 33 -71.4049 8.2339 34* -242.8360 2.0664 1.80610 40.73 35* 78.8468 (BF) Image plane ∞ [Aspherical data] 1st floor 2nd floor 16th floor 17th floor 34th floor K 0.00000 0.00000 0.00000 0.00000 0.00000 A4 3.67142E-06 3.30429E-06 -3.02126E-06 1.57456E-06 8.98285E-06 A6 -4.73370E-09 -4.04569E-09 -1.45149E-09 -1.42264E-09 -4.93588E-08 A8 3.79551E-12 7.54794E-13 2.47699E-12 2.81789E-12 5.10479E-11 A10 -2.26030E-15 -7.99250E-16 0.00000E+00 0.00000E+00 0.00000E+00 A12 6.36996E-19 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 35 sides K 0.00000 A4 1.83832E-05 A6 -4.59065E-08 A8 5.08853E-11 A10 0.00000E+00 A12 0.00000E+00 [Various data] Zoom ratio 1.51 Wide-angle Mid-range Telephoto Focal length 28.85 34.74 43.65 F-number 1.86 1.86 1.86 Full angle of view 2ω 76.05 63.32 50.53 Image height Y 21.63 21.63 21.63 Lens total length 168.50 168.50 168.50 [Variable Interval Data] Focusing at infinity Wide-angle Mid-range Telephoto d0 ∞ ∞ ∞ d8 19.6531 11.3661 3.5000 d10 12.7208 15.2882 14.7120 d13 6.0493 4.6251 3.2564 d22 1.4000 5.5541 11.0359 d26 4.9170 8.1820 13.7036 d29 3.0939 2.8185 1.6261 BF 23.7172 23.7172 23.7172 At 40x magnification Wide-angle Mid-range Telephoto d0 1104.4566 1340.5701 1698.5073 d8 19.6531 11.3661 3.5000 d10 11.8864 14.5802 14.1258 d13 6.8836 5.3331 3.8426 d22 1.4000 5.5541 11.0359 d26 4.9170 8.1820 13.7036 d29 3.0939 2.8185 1.6261 BF 23.7172 23.7172 23.7172 [Lens group data] Group Starting plane Focal length G1 1 -43.55 G2 9 80.28 G3 11 -56.76 G4 14 32.75 G5 23 -71.14 G6 27 -68.00 G7 30 36.94

[0125] Numerical Example 6 Unit: mm [Face Data] Surface number rd nd vd Object surface ∞ (d0) 1* 214.4813 2.9004 1.69350 53.18 2* 46.1965 1.8288 3* 60.4817 2.2000 1.59201 67.02 4* 41.0054 13.8206 5 -162.5716 1.6000 1.49700 81.61 6 36.3963 4.5897 1.92286 20.88 7 57.5758 (d7) 8 50.0849 3.9180 1.83481 42.72 9 135.3956 (d9) 10 -37.8690 0.9000 1.61340 44.27 11 315.0424 (d11) 12* 56.1261 10.2707 1.85135 40.10 13* -57.5994 0.1500 14 -215.6171 0.9000 1.64769 33.84 15 144.3980 (d15) 16 141.4326 0.9000 1.80000 29.84 17 40.3988 10.2430 1.55032 75.50 18 -127.9767 0.1500 19 80.2060 9.2661 1.48071 85.29 20 -52.6130 (d20) 21 (Aperture) ∞ 0.9000 22 51.9735 5.7169 1.48071 85.29 23 -53.1568 0.9000 1.74077 27.76 24 36.0203 (d24) 25 1347.1378 2.9303 1.49700 81.61 26 -51.8880 0.9000 1.65412 39.68 27 74.0671 (d27) 28 61.7138 6.6387 1.94594 17.98 29 -193.2019 0.1500 30 150.5369 5.4082 1.77250 49.63 31 -54.2750 0.8499 32* -300.0000 2.5062 1.80610 40.73 33* 54.1984 (BF) Image plane ∞ [Aspherical data] 1st page 2nd page 3rd page 4th page 12th page K -22.00362 0.00000 1.49222 0.00000 0.00000 A4 2.04562E-06 2.94297E-06 5.88995E-06 4.51938E-06 -4.17716E-06 A6 -8.27556E-10 -6.26872E-09 -6.26269E-09 4.63180E-09 5.67456E-10 A8 3.63705E-13 1.23231E-11 9.54129E-12 -9.65526E-12 2.04941E-12 A10 -1.27327E-16 -7.28332E-15 -7.06530E-15 1.83871E-15 0.00000E+00 A12 3.42673E-20 6.96303E-19 0.00000E+00 0.00000E+00 0.00000E+00 13th page 32nd page 33rd page K 0.00000 0.00000 0.00000 A4 2.62844E-06 -2.42175E-06 6.21081E-06 A6 -1.50606E-09 -1.72567E-08 -1.24109E-08 A8 3.33229E-12 1.13344E-11 7.85935E-12 A10 0.00000E+00 0.00000E+00 0.00000E+00 A12 0.00000E+00 0.00000E+00 0.00000E+00 [Various data] Zoom ratio 1.66 Wide-angle Mid-range Telephoto Focal length 24.72 29.84 41.00 F-number 1.86 1.86 1.86 Full angle of view 2ω 86.64 72.59 53.35 Image height Y 21.63 21.63 21.63 Lens total length 168.00 168.00 168.00 [Variable Interval Data] Focusing at infinity Wide-angle Mid-range Telephoto d0 ∞ ∞ ∞ d7 20.4639 12.8159 3.5295 d9 13.3078 15.9680 14.2121 d11 7.0445 4.8985 2.5994 d15 2.2176 2.7321 3.0553 d20 0.9000 4.8441 11.4048 d24 4.8511 6.8808 13.8837 d27 3.0342 3.6797 3.1343 BF 25.6419 25.6419 25.6419 At 40x magnification Wide-angle Mid-range Telephoto d0 946.6421 1151.8197 1599.7326 d7 20.4639 12.8159 3.5295 d9 12.6962 15.4401 13.7865 d11 7.6562 5.4264 3.0250 d15 2.2176 2.7321 3.0553 d20 0.9000 4.8441 11.4048 d24 4.8511 6.8808 13.8837 d27 3.0342 3.6797 3.1343 BF 25.6419 25.6419 25.6419 [Lens group data] Group Starting plane Focal length G1 1 -38.53 G2 8 93.27 G3 10 -55.06 G4 12 45.57 G5 16 54.45 G6 21 -65.57 G7 25 -87.00 G8 28 43.10

[0126] Numerical Example 7 Unit: mm [Face Data] Surface number rd nd vd Object surface ∞ (d0) 1* 151.2935 3.1469 1.59201 67.02 2* 45.2619 4.2544 3 55.0000 2.6207 1.51680 64.20 4 34.0938 12.5765 5 -98.0840 1.8000 1.55032 75.50 6 60.7277 0.1500 7 47.5967 4.0234 1.92286 20.88 8 90.1388 (d8) 9 54.5729 5.6886 1.83481 42.72 10 -218.8108 1.3561 11 -109.4054 0.9000 1.68893 31.16 12 463.2564 (d12) 13 -40.5579 1.0000 1.61340 44.27 14 171.7313 (d14) 15* 53.7420 8.0508 1.85135 40.10 16* -81.7253 0.1500 17 385.7122 1.0000 1.77047 29.74 18 38.4652 9.4584 1.59282 68.62 19 -130.4543 0.1500 20 130.7756 7.0947 1.45860 90.19 21 -55.2486 (d21) 22 (Aperture) ∞ 1.0000 23 55.5821 5.5016 1.49700 81.61 24 -56.9481 1.0000 1.78472 25.72 25 42.3391 (d25) 26 -139.5559 2.6016 1.49700 81.61 27 -59.9232 1.0000 1.67300 38.26 28 77.1324 (d28) 29 71.1197 4.0378 1.94594 17.98 30 -257.8344 0.1868 31 88.3966 5.5155 1.80610 40.73 32 -53.9988 2.6345 33* -198.4404 1.6147 1.80610 40.73 34* 59.4646 (BF) Image plane ∞ [Aspherical data] 1st floor 2nd floor 15th floor 16th floor 33rd floor K 0.00000 0.00000 0.00000 0.00000 0.00000 A4 7.81541E-06 8.14455E-06 -3.69821E-06 2.29659E-06 -3.47887E-06 A6 -9.93809E-09 -7.63347E-09 4.45971E-10 -1.03287E-09 -2.64534E-08 A8 7.52865E-12 1.42939E-12 1.16423E-12 1.96655E-12 2.95296E-11 A10 -3.60632E-15 -1.55413E-16 0.00000E+00 0.00000E+00 0.00000E+00 A12 8.33833E-19 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 34 sides K 0.00000 A4 5.66543E-06 A6 -2.37242E-08 A8 2.51244E-11 A10 0.00000E+00 A12 0.00000E+00 [Various data] Zoom ratio 1.51 Wide-angle Mid-range Telephoto Focal length 28.85 34.97 43.65 F-number 1.86 1.86 1.86 Full angle of view 2ω 76.25 63.04 50.53 Image height Y 21.63 21.63 21.63 Lens total length 162.33 162.33 162.33 [Variable Interval Data] Focusing at infinity Wide-angle Mid-range Telephoto d0 ∞ ∞ ∞ d8 18.6422 10.6242 3.5907 d12 12.8154 16.2059 16.2423 d14 6.4537 4.3583 2.6081 d21 1.0000 4.8080 8.8997 d25 5.1875 7.5926 13.0126 d28 2.8817 3.3916 2.6272 BF 26.8359 26.8359 26.8359 At 40x magnification Wide-angle Mid-range Telephoto d0 1102.9005 1347.8982 1695.9129 d8 18.6422 10.6242 3.5907 d12 12.0729 15.5787 15.7213 d14 7.1963 4.9854 3.1291 d21 1.0000 4.8080 8.8997 d25 5.1875 7.5926 13.0126 d28 2.8817 3.3916 2.6272 BF 26.8359 26.8359 26.8359 [Lens group data] Group Starting plane Focal length G1 1 -45.75 G2 9 85.28 G3 13 -53.39 G4 15 28.90 G5 22 -72.32 G6 26 -65.23 G7 29 39.13

[0127] Numerical Example 8 Unit: mm [Face Data] Surface number rd nd vd Object surface ∞ (d0) 1* 82.5266 3.0487 1.69350 53.18 2* 36.2990 3.7884 3 46.7945 2.0001 1.55200 70.70 4 30.5078 13.2730 5 -80.2645 1.6514 1.59349 67.00 6 112.2046 0.1500 7 57.7050 4.4915 1.94594 17.98 8 123.9598 (d8) 9 60.9931 4.3075 1.75500 52.32 10 717.4604 (d10) 11 -47.8401 1.0000 1.71700 47.98 12 312.3310 (d12) 13 81.4410 3.9454 1.95375 32.32 14 925.4696 0.3086 15* 118.8010 6.2885 1.85135 40.10 16* -88.7875 0.1500 17 -200.2821 1.0000 1.72825 28.32 18 48.1183 8.4664 1.55032 75.50 19 -189.7894 0.1500 20 138.4636 10.0407 1.45860 90.19 21 -46.7727 (d21) 22 (Aperture) ∞ 1.0000 23 44.8318 6.3865 1.55032 75.50 24 -60.8773 1.0000 1.84666 23.78 25 37.4078 (d25) 26 -68.1433 2.9314 1.58913 61.25 27 -32.9603 1.0000 1.61340 44.27 28 163.3201 (d28) 29 89.7384 3.1704 1.98612 16.48 30 -370.7990 0.1500 31 90.6033 5.0445 1.88100 40.14 32 -74.4172 6.9034 33* -261.5985 3.0493 1.80610 40.73 34* 80.4965 (BF) Image plane ∞ [Aspherical data] 1st floor 2nd floor 15th floor 16th floor 33rd floor K 0.00000 0.00000 0.00000 0.00000 0.00000 A4 4.45612E-06 4.19561E-06 -3.01951E-06 1.60051E-06 9.31498E-06 A6 -7.35312E-09 -7.83666E-09 5.57287E-10 3.70925E-10 -4.11172E-08 A8 6.53333E-12 3.54901E-12 -8.89539E-13 -2.92734E-13 4.80031E-11 A10 -3.48030E-15 -2.27814E-15 3.41066E-15 3.16457E-15 -3.23261E-14 A12 8.19092E-19 0.00000E+00 -3.99452E-18 -3.96270E-18 0.00000E+00 34 sides K 0.00000 A4 1.85247E-05 A6 -3.87392E-08 A8 5.45102E-11 A10 -5.04663E-14 A12 0.00000E+00 [Various data] Zoom ratio 1.51 Wide-angle Mid-range Telephoto Focal length 28.85 34.86 43.65 F-number 1.86 1.86 1.86 Full angle of view 2ω 75.49 62.78 50.53 Image height Y 21.63 21.63 21.63 Lens length 167.96 167.96 167.96 [Variable Interval Data] Focusing at infinity Wide-angle Mid-range Telephoto d0 ∞ ∞ ∞ d8 19.1974 11.3471 3.5000 d10 12.9069 15.5491 14.9091 d12 6.3179 4.5085 3.3586 d21 1.5500 5.4832 9.8349 d25 5.1477 8.8955 16.2294 d28 4.2072 3.5436 1.4950 BF 23.9358 23.9358 23.9358 At 40x magnification Wide-angle Mid-range Telephoto d0 1105.8040 1346.7088 1699.9441 d8 19.2374 11.4271 3.6720 d10 12.0656 14.8055 14.2268 d12 7.1191 5.1721 3.8689 d21 1.5500 5.4832 9.8349 d25 5.1477 8.8955 16.2294 d28 4.2072 3.5436 1.4950 BF 23.9358 23.9358 23.9358 [Lens group data] Group Starting plane Focal length G1 1 -45.91 G2 9 88.04 G3 11 -57.79 G4 13 32.56 G5 22 -72.77 G6 26 -75.58 G7 29 39.07

[0128] Also shown is a list of values corresponding to the conditional expressions in each of these embodiments.

[0129] [Table 1]

[0130] The above description of the embodiment has been given of one example of the zoom lens of the present invention, and the present invention is not limited to this embodiment as long as it does not deviate from the gist of the present invention. Various design changes, modifications, combinations, and sub-combinations are possible, and all of these are within the scope of the equivalents of the present invention. [Explanation of symbols]

[0131] G1 First lens group G2 Second lens group G3 Third lens group G4 4th lens group G5 5th lens group G6 6th lens group G7 7th lens group G8 8th lens group GM intermediate lens group GR rear lens group GN final lens group LN final lens S aperture stop I Image sensor

Claims

1. The lens is composed of, in order from the object side, a first lens group G1 having a negative refractive power, a middle lens group GM having a positive refractive power as a whole, a rear lens group GR, and a final lens group GN. the intermediate lens group GM is composed of three or more lens groups, and includes a focus lens group that moves along the optical axis during focusing from infinity to a close distance, the rear lens group GR is composed of one or more lens groups, When zooming from the wide-angle end to the telephoto end, the spacing between the lens groups changes, the middle lens group GM moves toward the object side, and the spacing between the middle lens group GM and the rear lens group GR widens. A zoom lens, wherein the first lens group G1 and the final lens group GN are fixed during both magnification and focusing.

2. 2. The zoom lens according to claim 1, wherein the following conditional expression (1) is satisfied: (1) -1.50<f1 / ft<-0.70 however, f1: focal length of the first lens group G1 ft: focal length of the entire system at the telephoto end, focused at infinity Let's say.

3. 2. The zoom lens according to claim 1, wherein the first lens group G1 has two or more negative lenses.

4. 4. The zoom lens according to claim 3, wherein the following conditional expression (2) is satisfied: (2) νdG1_2>57.0 however, νdG1_2: the second largest Abbe number among the negative lenses arranged in the first lens group G1 When the first lens group G1 has two or more negative lenses with the largest Abbe number, the largest Abbe number is defined as νdG1_2.

5. 2. The zoom lens according to claim 1, wherein a final lens LN in the final lens group GN, which is closest to the image side, has negative refractive power and satisfies the following conditional expression (3): (3) 0.0<(RLN1+RLN2) / (RLN1-RLN2)<1.0 however, RLN1: radius of curvature of the object side surface of the final lens LN RLN2: Radius of curvature of the image side of the final lens LN Let's say.

6. 2. The zoom lens according to claim 1, wherein the intermediate lens group GM comprises, in order from the object side, a second lens group G2 with positive refractive power and a third lens group G3 with negative refractive power, and at least one of the second lens group G2 and the third lens group G3 moves along the optical axis during focusing from infinity to a close distance.

7. 7. The zoom lens according to claim 6, wherein the intermediate lens group GM includes a fourth lens group G4 having a positive refractive power.

8. 7. The zoom lens according to claim 6, wherein the following conditional expression (4) is satisfied: (4) -2.0<f2 / f3<-1.0 however, f2: focal length of the second lens group G2 f3: focal length of the third lens group G3 Let's say.

9. 9. The zoom lens according to claim 6, wherein the second lens group G2 and the third lens group G3 each include two or less lenses.

10. 9. The zoom lens according to claim 1, wherein the following conditional expression (5) is satisfied: (5) 0.7<(βMt / βMw) / (ft / fw)<1.2 however, βMw: Imaging magnification of the intermediate lens group GM at the wide-angle end and in the infinity focused state βMt: Imaging magnification of the intermediate lens group GM at the telephoto end, in a state focused on infinity fw: focal length of the entire system at the wide-angle end, focused at infinity ft: focal length of the entire system at the telephoto end, focused at infinity Let's say.

11. 9. The zoom lens according to claim 1, wherein the intermediate lens group GM has six or more lenses.

12. 9. The zoom lens according to claim 1, wherein the boundary between the intermediate lens group GM and the front rear lens group GR is a location where the lateral magnification of the front rear lens group GR is maximum.

13. 9. The zoom lens according to claim 1, wherein the rear lens group GR includes an aperture stop S.

Images