Zoom lens and imaging apparatus

Abstract

To provide a zoom lens that is compact and light weight, can perform appropriate vibration isolation, and has a high magnification variation ratio.SOLUTION: A zoom lens has, in order from an object side to an image side, a first lens group having positive refractive power not moving for magnification variation, an intermediate lens group comprising two or more negative lens groups moving for magnification variation, and a rear lens group having positive refractive power having an aperture stop and not moving for magnification variation. Every interval between the adjacent lens groups changes for magnification variation. The rear lens group has a vibration isolation group that can move an image in a direction perpendicular to an optical axis by moving in a direction including a component perpendicular to the optical axis. The lateral magnification at infinite focusing at a wide-angle end of an optical system included in the zoom lens located closer to the image side than the lens group having negative refractive power arranged on the most image side in the intermediate lens group, and the lateral magnification of the vibration isolation lens group, are appropriately set.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] When shooting nature programs using television cameras and the like (for example, shooting animals or birds outdoors from a long distance), there is a demand for zoom lenses with high zoom ratios, ultra-telephoto focal lengths (for example, a high magnification of 7x or more and a half-angle of view at the telephoto end of 2.0 degrees or less), and high optical performance. Furthermore, opportunities for video shooting are increasing, with single-lens reflex cameras and other cameras designed for still photography also now being used to shoot video. Generally, the size of the sensor (image sensor) in a single-lens reflex camera is larger than 1-inch, which is larger than the 1-inch or smaller sensors typically used in video cameras and broadcast television cameras. Therefore, there is a growing demand for high-magnification, ultra-telephoto zoom lenses that are compatible with large sensors exceeding 1-inch, yet offer excellent portability and functionality, and are suitable for video shooting.

[0003] Furthermore, suppressing image blur caused by vibrations or camera shake, which occurs particularly when using an imaging system with a long focal length, has become a major problem, and there is an increasing demand for an anti-shake function that prevents image blur.

[0004] Patent Document 1 discloses a four-group zoom lens having a telephoto end angle of view of about 3.0 degrees and a magnification ratio of about 10, which is compatible with sensors of 1 type or larger. Patent Document 2 discloses a zoom lens that has four lens groups, in order from the object side, a first group with positive refractive power, a second group with negative refractive power, a third group with negative refractive power, and a fourth group with positive refractive power, and that corrects blurring of a captured image caused by vibration by moving a part of the fourth group in a direction perpendicular to the optical axis. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-203296 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-281546 Summary of the Invention [Problem to be solved by the invention]

[0006] In the zoom lens of Patent Document 1, it is difficult to reduce the size of the entire lens when the telephoto lens and the zoom ratio are increased while maintaining the overall lens length. To accommodate even larger image sensors, the amount of correction required to correct blur in a captured image increases with the sensor size. In particular, in the zoom lens of Patent Document 2, the vibration reduction effect of the lens group that performs vibration reduction (the amount of movement of the optical axis relative to the amount of eccentricity) is relatively small, so there is a problem that the amount of eccentricity required for the vibration reduction lens group increases, resulting in an increase in the size of the drive mechanism.

[0007] SUMMARY OF THE INVENTION An object of the present invention is to provide a small, lightweight zoom lens with a high zoom ratio that is capable of providing appropriate vibration reduction. [Means for solving the problem]

[0008] In order to achieve the above object, a zoom lens of the present invention comprises, in order from the object side to the image side, a first lens group having positive refractive power that does not move for varying magnification, an intermediate lens group including two or more negative lens groups that move for varying magnification, and a rear lens group having positive refractive power that includes an aperture stop and does not move for varying magnification, wherein the distances between adjacent lens groups all change for varying magnification, and the rear lens group includes an image-stabilizing lens group that is capable of moving an image in a direction perpendicular to the optical axis by moving in a direction including a component perpendicular to the optical axis, and wherein the lateral magnification of an optical system included in the zoom lens, which is located closer to the image than the intermediate lens group having negative refractive power that is located closest to the image, at the wide-angle end is βMpR and the lateral magnification of the image-stabilizing lens group is βis, -3.00≦βMpR≦-1.80 -0.333≦1 / βis≦0.200 The present invention is characterized in that the following conditional expression is satisfied: [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a small, lightweight zoom lens with a high zoom ratio that is capable of providing appropriate vibration reduction. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a cross-sectional view of the zoom lens of Example 1 at the wide-angle end when focused on infinity. [Figure 2] 4A to 4C are longitudinal aberration diagrams at the wide-angle end and the telephoto end of the zoom lens of Example 1 when focused on infinity. [Figure 3] 4A to 4C are lateral aberration diagrams at the wide-angle end and the telephoto end of the zoom lens of Example 1 when focused on infinity. [Figure 4] 4A to 4C are lateral aberration diagrams at the wide-angle end and the telephoto end when focusing on infinity in the zoom lens of Example 1 with the image stabilization lens group decentered by 1 mm. [Figure 5] FIG. 10 is a cross-sectional view of the zoom lens of Example 2 at the wide-angle end when focused on infinity. [Figure 6] 10A and 10B are longitudinal aberration diagrams at the wide-angle end and the telephoto end of the zoom lens of Example 2 when focused on infinity. [Figure 7] 10A to 10C are lateral aberration diagrams at the wide-angle end and the telephoto end of the zoom lens of Example 2 when focused on infinity. [Figure 8] 10A and 10B are lateral aberration diagrams at the wide-angle end and the telephoto end when focusing on infinity in the zoom lens of Example 2 with the image stabilization lens group decentered by 1 mm. [Figure 9] FIG. 10 is a cross-sectional view of the zoom lens of Example 3 at the wide-angle end when focused on infinity. [Figure 10] 10A and 10B are longitudinal aberration diagrams at the wide-angle end and the telephoto end of the zoom lens of Example 3 when focused on infinity. [Figure 11] 10A to 10C are lateral aberration diagrams at the wide-angle end and the telephoto end of the zoom lens of Example 3 when focused on infinity. [Figure 12] 10A and 10B are lateral aberration diagrams at the wide-angle end and the telephoto end when focusing on infinity in the zoom lens of Example 3 with the image stabilization lens group decentered by 1 mm. [Figure 13]FIG. 10 is a cross-sectional view of the zoom lens of Example 4 at the wide-angle end when focused on infinity. [Figure 14] 10A and 10B are longitudinal aberration diagrams at the wide-angle end and the telephoto end of the zoom lens of Example 4 when focused on infinity. [Figure 15] 10A to 10C are lateral aberration diagrams at the wide-angle end and the telephoto end of the zoom lens of Example 4 when focused on infinity. [Figure 16] 10A and 10B are lateral aberration diagrams at the wide-angle end and the telephoto end when focusing on infinity in the zoom lens of Example 4 with the image stabilization lens group decentered by 1 mm. [Figure 17] FIG. 1 illustrates an example of the configuration of an imaging device. DETAILED DESCRIPTION OF THE INVENTION

[0011] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In principle (unless otherwise specified) throughout the drawings for explaining the embodiments, the same components will be designated by the same reference numerals, and repeated explanations will be omitted.

[0012] FIG. 1 is a cross-sectional view of a zoom lens according to an embodiment of the present invention at the wide-angle end. The zoom lens according to the embodiment includes, in order from the object side to the image side, a first lens group with positive refractive power that does not move for zooming, an intermediate lens group including two or more negative lens groups that moves for zooming, and a rear lens group with positive refractive power that has an aperture stop and does not move for zooming. The spacing between adjacent lens groups included in the zoom lens all changes for zooming. The rear lens group includes an image stabilization lens group that can move in a direction including a component perpendicular to the optical axis to move an image in a direction perpendicular to the optical axis.

[0013] The first lens group L1 does not move for zooming and has positive refractive power. The first lens group L1 is composed of, in order from the object side to the image side, a first sub-lens group L1a that does not move for focusing, and at least one second sub-lens group L1b that moves toward the object side for focusing from an object at infinity to a close object.

[0014] The intermediate lens group LM has two or more negative lens groups that move for zooming. Specifically, the intermediate lens group LM includes, in order from the object side to the image side, a first intermediate lens group LM1 with negative refractive power and a second intermediate lens group LM2 with negative refractive power. The first intermediate lens group LM1 has negative refractive power and moves monotonically on the optical axis toward the image side for zooming from the wide-angle end to the telephoto end. The second intermediate lens group LM2 has negative refractive power and moves on the optical axis along a locus convex toward the object side for zooming from the wide-angle end to the telephoto end.

[0015] The rear lens unit LR does not move for varying magnification, has positive refractive power, and includes an aperture stop SP that does not move for varying magnification. The vibration-proof lens group IS moves within a plane approximately perpendicular to the optical axis to correct blurring of the captured image when the entire zoom lens system vibrates. In Figure 1, I is the image plane of the zoom lens (the plane where the image is formed), and the image sensor of the imaging device is positioned at this image plane I to capture the image.

[0016] In the zoom lens of the present invention, when the lateral magnification at infinity focusing at the wide-angle end of all lens groups located closer to the image than the negative lens group located furthest to the image in the intermediate lens group LM is βMpR and the lateral magnification of the image stabilizing lens group is βis, -3.00≦βMpR≦-1.80 (1) -0.333≦1 / βis≦0.200 (2) The following condition is satisfied.

[0017] Here, the technical meaning of the above conditional expressions will be explained. Conditional formula (1) defines the lateral magnification of all lens groups, including the rear lens group, which is located closer to the image side than the negative lens group closest to the image side among the intermediate lens group LM. In the present invention, the intermediate lens group LM is composed of two or more negative lens groups. To achieve a high zoom ratio and a compact, lightweight zoom lens, it is preferable to vary the zoom ratio by moving multiple negative lens groups with strong refractive power. In this case, when attempting to achieve a high zoom ratio, the axial rays that form an image on the axis of the image sensor will be strongly divergent, as they emerge from the negative lens group closest to the image. In other words, by satisfying conditional expression (1), the overall length of the zoom lens can be reduced even in large-format cameras, and aberration fluctuations in the zoom lens can be effectively corrected, while achieving both a high zoom ratio and a compact, lightweight design.

[0018] If the upper limit of conditional expression (1) is exceeded, the lateral magnification of all lens groups located closer to the image than the negative lens group closest to the image in the intermediate lens group LM will be small, making it impossible to achieve a high zoom ratio. Furthermore, maintaining a high zoom ratio will increase the overall zoom length, making it difficult to achieve a compact lens. If the lower limit of conditional expression (1) is exceeded, the magnification of aberrations from the first lens group L1, which is primarily responsible for zooming, to the lens group closest to the image in the intermediate lens group LM will increase, making it difficult to correct aberrations.

[0019] Conditional formula (2) defines the lateral magnification of the image stabilization lens group IS. The lateral magnification of the image stabilization lens group IS is important for controlling the amount of decentering of the image stabilization lens group IS. In order to reduce the size of the image stabilization lens group IS and ensure an appropriate correction angle, the lateral magnification of the image stabilization lens group IS must be appropriate. If the range of conditional expression (2) is exceeded, the lateral magnification of the vibration-reduction lens group IS decreases and the amount of movement of the vibration-reduction lens group IS increases, which increases the diameter of the vibration-reduction unit and makes it difficult to reduce the size of the entire zoom lens.

[0020] By satisfying the above conditional expressions, the numerical examples of the present invention achieve a zoom lens for large-format cameras that has a high zoom ratio, is small and lightweight, and has an appropriate vibration-reduction lens group.

[0021] Furthermore, in the zoom lens according to the embodiment of the present invention, the image stabilization lens group IS is configured as part of the rear lens group. Because the rear lens group LR is fixed relative to the image plane I during magnification variation, the optical path of the chief ray in the rear lens group LR remains unchanged even during magnification variation. By including the image stabilization lens group IS in the rear lens group LR, good image blur compensation performance can be ensured throughout the entire zoom range.

[0022] Furthermore, in a zoom lens according to an embodiment of the present invention, the aperture diaphragm SP is configured as part of the rear lens group LR, which does not move for varying magnification. Because the aperture diaphragm SP does not move for varying magnification, brightness during magnification variation remains constant throughout most of the range of magnification variation. Furthermore, by locating the aperture diaphragm SP close to the object side of the image stabilization lens group IS, off-axial light rays can pass through approximately the center of the image stabilization lens group IS, and changes in the optical path of off-axial light rays when the image stabilization lens group IS is decentered can be minimized.

[0023] For this reason, it is preferable that the aperture stop SP is included in the rear lens group LR. It is even more preferable that the aperture stop SP is located inside the rear lens group LR, rather than at the front or rear end of the rear lens group LR.

[0024] In a zoom lens that satisfies conditional expression (1), light rays incident on a lens group that is located closer to the image than the negative lens group closest to the image among the intermediate lens group LM tend to diverge strongly, which means that the diameter of the aperture stop tends to be large in the rear lens group LR, closer to the object side. If the diameter of the aperture stop is large, it becomes difficult to secure space to store the aperture blades in the fully open aperture state (when the aperture is fully opened), and the diameter of the lens barrel increases, making it difficult to miniaturize the lens. For this reason, it is preferable that the aperture stop SP be located inside the rear lens group LR, rather than at the position closest to the object side of the rear lens group LR.

[0025] In the zoom lens according to the embodiment of the present invention, the rear lens group LR comprises, in order from the object side to the image side, a first rear sub-lens group LRa having positive refractive power, a second rear sub-lens group (anti-vibration lens group) IS having negative refractive power, and a third rear sub-lens group LRc having positive refractive power. By moving the anti-vibration lens group IS in a direction approximately perpendicular to the optical axis, it is possible to move the image in a direction perpendicular to the optical axis.

[0026] In a zoom lens that satisfies conditional expression (1), incident rays to a lens group located closer to the image than the negative lens group closest to the image among the intermediate lens group LM tend to diverge strongly, which means that the lens diameter of the rear lens group closest to the object tends to be large. Therefore, to achieve a compact zoom lens and reduce the size of the image-stabilizing lens group, it is necessary to use the first rear sub-lens group LRa, which has positive refractive power, to make the on-axis light incident on the second rear sub-lens group IS, which is the image-stabilizing lens group IS, a strongly convergent light. In an image-stabilizing lens group IS with negative refractive power, when the range of conditional expression (2) is exceeded, the on-axis light exiting from the image-stabilizing lens group IS becomes a strongly divergent light, which causes the refractive power of the image-stabilizing lens group to become too strong. This makes it difficult to ensure image blur correction performance.

[0027] In the present invention, the third rear sub-lens group LRc is provided with a gap that allows a built-in extender to be inserted into the rear lens group LR. To ensure an appropriate gap and good performance and extender magnification, it is necessary to ensure that the height of the axial ray of the third rear sub-lens group LRc is at least a certain level. Therefore, it is preferable that the axial ray incident on the third rear sub-lens group LRc, i.e., the axial ray emerging from the image stabilizing lens group IS, be a gently converging ray or a gently diverging ray. It is even more preferable that the axial ray incident on the image stabilizing lens group IS be a converging ray and the axial ray emerging from the image stabilizing lens group IS be a diverging ray. Therefore, it is more preferable that the numerical range of conditional expression (2) be a negative value range.

[0028] In addition, in the zoom lens according to the embodiment of the present invention, when the lateral magnification of the third rear sub-lens group LRc, which is a lens component arranged closer to the image side than the vibration reduction lens group IS in the rear lens group LR, is denoted as βRc, 1.70≦βis×βRc≦2.35 (3) It is preferable that the following conditions be further satisfied:

[0029] Conditional expression (3) defines the range of values ​​for the ratio of the lateral magnifications of the image stabilization lens group IS and the third rear sub-lens group LRc, which is disposed closer to the image than the image stabilization lens group IS. The lateral magnifications of the image stabilization lens group IS and the third rear sub-lens group LRc must be set appropriately to achieve both image stabilization performance and compactness and weight reduction. Satisfying conditional expression (3) makes it possible to appropriately set the incident ray of on-axis light onto the image stabilization lens group IS, thereby enabling both image stabilization performance and compactness and weight reduction of the image stabilization lens group IS.

[0030] If the lower limit of conditional expression (3) is exceeded, the axial light rays incident on image stabilization lens group IS will converge too gently, which will result in the image stabilization lens group IS becoming larger or the overall length of the product increasing, making it difficult to achieve compact and lightweight design.If the upper limit of conditional expression (3) is exceeded, the axial light rays incident on image stabilization lens group IS will converge too strongly, making it difficult to correct image stabilization performance.

[0031] Furthermore, in the zoom lens according to the embodiment of the present invention, when the lateral magnification of the optical system including the lens group from the lens group arranged closer to the image side than the negative lens group closest to the image side in the intermediate lens group LM to the first rear sub-lens group LRa arranged closer to the object side than the image-stabilizing lens group IS in the rear lens group LR is defined as βMpRa, -2.50≦βMpRa≦-0.700 (4) It is preferable that the following conditions be further satisfied:

[0032] Conditional formula (4) defines the range of the lateral magnification of all lens groups that are arranged closer to the image than the negative lens group closest to the image in the intermediate lens group LM and closer to the object than the image-stabilizing lens group IS in the rear lens group LR.

[0033] To achieve both a small lens diameter for the image stabilization lens group IS and image stabilization performance, the lateral magnification of the relevant lens group must be within an appropriate range. If the upper limit of conditional formula (4) is exceeded, the light rays incident on the image stabilization lens group IS will converge too strongly, making it difficult to ensure image stabilization performance. If the lower limit of conditional formula (4) is exceeded, the light rays incident on the image stabilization lens group IS will converge too weakly, and the lens diameter of the image stabilization lens group IS will increase, which in turn increases the diameter of the image stabilization unit and makes it difficult to miniaturize the product.

[0034] Furthermore, the zoom lens according to the embodiment of the present invention has -4.00≦(1-βis)×βRc≦-1.90 (5) It is preferable that the following conditions be further satisfied:

[0035] Conditional formula (5) defines the vibration-reduction coefficient of the vibration-reduction lens group IS in order to determine the optimal amount of decentering for the vibration-reduction lens group IS. To ensure a compact size and an appropriate correction angle for the vibration-reduction lens group IS, it is necessary to provide appropriate lateral magnifications for the vibration-reduction lens group IS and the third rear sub-lens group LRc. Satisfying conditional formula (5) makes it possible to appropriately set the amount of decentering for the vibration-reduction lens group IS, thereby achieving both vibration-reduction performance and a compact and lightweight vibration-reduction lens group IS. If the lower limit of conditional formula (5) is exceeded, aberration fluctuations during vibration reduction become large, making it difficult to correct vibration-reduction performance. If the upper limit of conditional formula (5) is exceeded, the amount of decentering for the vibration-reduction lens group IS becomes large, which increases the diameter of the vibration-reduction unit and makes it difficult to miniaturize the product.

[0036] Furthermore, in the zoom lens according to the embodiment of the present invention, when the focal length of the first lens group L1 is f1, the focal length of the second lens group L2, which is the lens group arranged closest to the object among the intermediate lens groups LM, is f2, and the focal length of the zoom lens at the telephoto end is ft, 3.50≦ft / f1≦8.00 (6) -8.00≦f1 / f2≦-4.00 (7) It is preferable to satisfy the following condition:

[0037] Conditional expression (6) defines the ratio of the focal length of the zoom lens at the telephoto end to the focal length of the first lens unit L1. By satisfying conditional expression (6), it is possible to achieve both compactness and lightness, high magnification, and high performance. To achieve both compactness and lightness and high magnification, it is desirable to reduce the focal length f1 of the first lens unit L1. Reducing the focal length f1 brings the image point position of the first lens unit L1, i.e., the object point position of the second lens unit L2, closer to the second lens unit L2, thereby reducing the stroke required for zooming. On the other hand, if the imaging magnification of the lens unit closer to the image side than the first lens unit L1 is high, the magnification of spherical aberration, axial chromatic aberration, and other aberrations generated in the first lens unit L1, particularly at the telephoto end, increases, making it difficult to achieve high performance. Therefore, an appropriate setting is required.

[0038] If the upper limit of conditional expression (6) is exceeded, the focal length f1 of the first lens group L1 relative to the focal length ft at the telephoto end of the zoom lens becomes too small, making it difficult to achieve high performance.If the lower limit of conditional expression (6) is exceeded, the focal length f1 of the first lens group L1 relative to the focal length ft at the telephoto end of the zoom lens becomes too large, making it difficult to achieve small size, light weight, and high magnification.

[0039] Conditional expression (7) defines the ratio between the focal length f1 of the first lens unit L1 and the focal length f2 of the second lens unit L2. By satisfying conditional expression (7), it is possible to achieve both compactness and light weight, high magnification, and high performance.

[0040] If the upper limit of conditional expression (7) is exceeded, the focal length f1 of the first lens unit L1 becomes too small, making it difficult to correct spherical aberration, axial chromatic aberration, and the like, particularly at the telephoto end, and the focal length f2 of the second lens unit L2 becomes too large, increasing the amount of movement of the variable magnification lens unit for varying magnification, making it difficult to achieve both a high variable magnification ratio and a compact, lightweight design.

[0041] If the lower limit of conditional expression (7) is exceeded, the focal length f1 of the first lens unit L1 becomes too long, which increases the effective diameter and overall lens length of the first lens unit L1, making it difficult to achieve compact and lightweight designs. Also, the focal length f2 of the second lens unit L2 becomes too short, making it difficult to correct fluctuations in spherical aberration, coma, and chromatic aberration that occur during zooming.

[0042] In the zoom lens according to the embodiment of the present invention, when the composite focal length of the second lens group L2 and the third lens group L3 arranged in order from the lens group closest to the object in the intermediate lens group LM at the wide-angle end when focusing at infinity is f23, -8.00≦f1 / f23≦-4.00 (8) It is preferable to satisfy the following condition:

[0043] Conditional expression (8) defines the ratio of the focal length f1 of the first lens unit L1 to the combined focal length f23 of the second and third lens units L2 and L3. By satisfying conditional expression (8), it is possible to achieve both a compact, lightweight lens, high magnification, and high performance. When the second and third lens units L2 and L3 both move toward the image side during zooming from the wide-angle end to the telephoto end, the second and third lens units L2 and L3 can be regarded as a single lens unit responsible for zooming.

[0044] If the upper limit of conditional expression (8) is exceeded, the focal length f1 of the first lens unit L1 becomes too small, making it difficult to correct spherical aberration, axial chromatic aberration, and the like, particularly at the telephoto end. Furthermore, the combined focal length f23 of the second and third lens units L2 and L3 becomes too large, increasing the amount of movement of the variable magnification lens units required for magnification. This makes it difficult to achieve both a high zoom ratio and compact, lightweight design. If the lower limit of conditional expression (8) is exceeded, the focal length f1 of the first lens unit L1 becomes too large, which increases the effective diameter and overall lens length of the first lens unit L1, making it difficult to achieve compact and lightweight designs. Also, the combined focal length f23 of the second and third lens units L2 and L3 becomes too small, making it difficult to correct fluctuations in spherical aberration, coma, and chromatic aberration that occur during zooming.

[0045] In addition, in the zoom lens according to the embodiment of the present invention, it is preferable that the image stabilization lens group IS is composed of, in order from the object side, a negative lens, a positive lens, and a negative lens. With such a configuration, even when image stabilization is high, it is possible to suppress the occurrence of chromatic aberration and other aberrations and perform good correction. For example, a single-lens configuration makes it difficult to correct chromatic aberration, while a configuration with one negative lens and one positive lens can suppress chromatic aberration to some extent, but the correction of other aberrations is insufficient. With a configuration of four or more lenses, the lenses become heavy, which requires a large driving mechanism, making it difficult to make the product smaller and lighter.

[0046] Furthermore, when lenses are cemented together, the degree of freedom is significantly reduced due to the small number of lenses used in the configuration, making it difficult to achieve good aberration correction during image stabilization. Furthermore, because the lens groups are decentered to achieve image stabilization, the distance on the optical axis before and after the image stabilization lens group must be such that the lenses and units do not interfere with each other, and it is preferable to ensure a distance of at least 1 mm.

[0047] In addition, in the zoom lens according to the embodiment of the present invention, the first lens group L1 includes, in order from the object side to the image side, a first sub-lens group L1a with negative refractive power that does not move for focusing, and a second sub-lens group L1b with positive refractive power that moves for focusing. This configuration allows the amount of movement during focusing to be constant regardless of the magnification. The first lens group L1 is not limited to a configuration consisting of these two sub-lens groups. For example, the first lens group L1 may be configured such that multiple sub-lens groups move for focusing, or may include another sub-lens group.

[0048] Furthermore, the focal length of the first lens group L1 is f1, the focal length of the first sub-lens group L1a is f1a, and the focal length of the second sub-lens group L1b is f1b, -50.00≦f1a / f1≦ -5.00 (9) 0.20≦f1b / f1≦ 2.00 (10) It is preferable to further satisfy the following conditional expressions: Conditional expressions (9) and (10) define the ratio of the focal lengths f1a, f1b of the first sub-lens group L1a and the second sub-lens group L1b in the first lens group L1 of the zoom lens to the focal length f1 of the first lens group. By satisfying conditional expressions (9) and (10), it is possible to achieve both a compact, lightweight design, high magnification, and high performance.

[0049] Here, the first lens group L1 may be composed of, in order from the object side to the image side, a first sub-lens group L1a with negative refractive power that does not move for focusing, and multiple second sub-lens groups with positive refractive power that move for focusing. In this case, for conditional expression (10), the focal length f1b of the second sub-lens group L1b can be treated as a composite focal length of the multiple second sub-lens groups. In other words, for conditional expression (10), the second sub-lens group L1b, which is made up of one or more lens groups, can be treated as a composite focal length f1b when focusing at infinity.

[0050] It is more preferable that conditional expressions (1) through (10), which have been described as being to be satisfied by at least one of the zoom lenses according to the embodiments of the present invention described above, be replaced by the following conditional expressions (1a) through (10a), respectively: -2.60≦βMpR≦-2.00 (1a) -0.250≦1 / βis≦-0.010 (2a) 1.90≦βis×βRc≦2.34 (3a) -1.50≦βMpRa≦-0.80 (4a) -3.50≦(1-βis)×βRc≦-2.00 (5a) 3.70≦ft / f1≦6.50 (6a) -7.90≦f1 / f2≦-5.70 (7a) -7.90≦f1 / f23≦-5.70 (8a) -40.00≦f1a / f1≦-10.00 (9a) 0.50≦f1b / f1≦1.00 (10a)

[0051] FIG. 17 is a diagram showing an example of the configuration of an imaging device equipped with the zoom lens of the present invention. In FIG. 17, 101 denotes a zoom lens according to any one of Examples 1 to 4. 124 denotes a camera (image capture device) body. The zoom lens 101 is detachable from the camera body 124. 125 denotes an image capture device configured by attaching the zoom lens 101 to the camera body 124. The zoom lens 101 includes a first lens group F, an intermediate lens group LZ having two or more negative lenses, and a rear lens group R for imaging. A vibration-proof lens group is included in the rear lens group R. The first lens group F includes a second sub-lens group L1b that moves on the optical axis for focusing, and a first sub-lens group L1a that does not move for focusing.

[0052] The intermediate lens group LZ, which has two or more negative lens groups, moves on the optical axis for varying magnification. SP is an aperture stop included in the rear lens group R. 114 and 115 are drive mechanisms for driving the second sub-lens group L1b and the intermediate lens group LZ, which has two or more negative lens groups, in the optical axis direction, respectively. The drive mechanisms may be configured to include a helicoid, a cam, or the like. 116 to 118 are motors (drive units) for driving the drive mechanisms 114 and 115 and the aperture stop SP, respectively.

[0053] Reference numerals 119 to 121 denote detection units for detecting the on-axis position of the second sub-lens group L1b, the on-axis position of two or more intermediate lens groups LZ, and the aperture diameter of the aperture stop SP, respectively. The detection units may be configured to include an encoder, potentiometer, photosensor, etc. In the camera body 124, reference numeral 109 denotes a glass block including an optical filter, etc., and 110 denotes an image sensor (photoelectric conversion element) that captures the subject image formed by the zoom lens 101. The image sensor may be configured to include a CCD, CMOS sensor, etc.

[0054] Also, reference numerals 111 and 122 respectively denote a CPU serving as a processing unit (control unit) in the camera body 124 and a CPU serving as a processing unit (control unit) in the zoom lens 101. In this way, by attaching the zoom lens according to this embodiment to a camera body, it is possible to provide a useful imaging device including this zoom lens that has the advantageous effects described above and below. Examples 1 to 4 of the zoom lens according to this embodiment and corresponding Numerical Examples 1 to 4 will be described in detail below.

[0055] In Examples 1 to 4, the rear lens group LR does not move during zooming, but the rear lens group or a part of it (sub lens group) may be moved. Even in this case, the effects described above can be obtained, and such a modification would be easy for a person skilled in the art.

[0056] For example, in Example 1 (Numerical Example 1), the portion of the rear lens group L5 with surface numbers 49 to 52 may be configured to move. Because a light beam that is nearly afocal is incident on surface 49 from the object side, even if this portion moves, the optical characteristics other than the back focus remain largely unchanged. Therefore, this portion can be used as a sub-lens group that moves to compensate for changes in focus. Note that factors that cause changes in focus to be compensated for by movement of the rear lens group LR or a sub-lens group thereof may include, for example, at least one of manufacturing errors, temperature changes, and attitude changes of the zoom lens. [Example]

[0057] A zoom lens according to Example 1 of the present invention will be described below with reference to Figs. 1 to 4. Fig. 1 is a diagram showing a cross section of the zoom lens according to Example 1 at the wide-angle end. Fig. 2 is a longitudinal aberration diagram showing aberrations at (a) the wide-angle end and (b) the telephoto end when focusing on infinity. Fig. 3 is a lateral aberration diagram showing aberrations at (a) the wide-angle end and (b) the telephoto end when focusing on infinity. Fig. 4 is a lateral aberration diagram showing aberrations at (a) the wide-angle end and (b) the telephoto end when focusing on infinity when the image stabilization lens group is decentered by 1.1 mm.

[0058] The zoom lens according to Example 1 includes, in order from the object side to the image side, a first lens unit L1 having positive refractive power, an intermediate lens unit LM, and a fourth lens unit L4 as a rear lens unit LR having positive refractive power. In the zoom lens, the distances between adjacent lens units change during zooming. The first lens group L1 does not move for zooming. The intermediate lens group LM has two or more negative lens groups that move during zooming, specifically, a second lens group L2 with negative refractive power and a third lens group L3 with negative refractive power. In the zoom lens of Example 1, the first intermediate lens group LM1 corresponds to the second lens group L2, and the second intermediate lens group LM2 corresponds to the third lens group L3. The fourth lens group L4 does not move for zooming.

[0059] An aperture stop SP, which does not move for zooming, is located inside the fourth lens group L4. The fourth lens group L4 consists of, in order from the object side, a first rear sub-lens group LRa with positive refractive power, a second rear sub-lens group (anti-vibration lens group) IS with negative refractive power, and a third rear sub-lens group LRc with positive refractive power. By moving the second rear sub-lens group IS in a direction approximately perpendicular to the optical axis, it is possible to move the image in a direction perpendicular to the optical axis.

[0060] The first lens group L1 includes, in order from the object side to the image side, a first sub-lens group L1a with negative refractive power and a second sub-lens group L1b with positive refractive power. The first sub-lens group L1a does not move for focusing. The second sub-lens group L1b moves toward the object side for focusing from an object at infinity to a close object.

[0061] The second lens unit L2 moves monotonically toward the image side on the optical axis during zooming from the wide-angle end to the telephoto end, and the third lens unit L3 moves along the optical axis along a locus convex toward the object side during zooming from the wide-angle end to the telephoto end. The fourth lens group L4 does not move for zooming. I is the image plane (plane where an image is formed) of the zoom lens, and the image sensor of the imaging device is disposed at this position to capture an image.

[0062] The first lens group L1 consists of surfaces 1 to 12. The first sub-lens group L1a consists of surfaces 1 to 8 and is composed of two positive lenses and two negative lenses. The second sub-lens group L1b consists of surfaces 9 to 12 and is composed of two positive lenses.

[0063] The second lens group L2 and the third lens group L3, which serve as intermediate lens groups LM having two or more negative lens groups, are composed of surfaces 13 to 24. The second lens group L2 is composed of surfaces 13 to 21 and consists of three negative lenses and two positive lenses. The third lens group L3 is composed of surfaces 22 to 24 and consists of one negative lens and one positive lens.

[0064] The fourth lens group L4 consists of surfaces Nos. 25 to 52, the aperture stop SP consists of surface No. 29, and is composed of seven negative lens elements and eight positive lens elements. The image stabilization lens group IS consists of surfaces Nos. 37 to 42, and is composed, in order from the object side to the image side, of a negative lens element, a positive lens element, and a negative lens element.

[0065] The zoom lens according to this embodiment has the above configuration and satisfies conditional expressions (1) to (10), thereby making it possible to provide a zoom lens that has a high zoom ratio, is small and lightweight, and is capable of performing appropriate vibration reduction. [Example]

[0066] A zoom lens according to Example 2 of the present invention will be described with reference to Figures 5 to 8. Figure 5 is a diagram showing a cross section of the zoom lens according to Example 2 at the wide-angle end. Figure 6 is a longitudinal aberration diagram showing aberrations at (a) the wide-angle end and (b) the telephoto end when focusing on infinity. Figure 7 is a lateral aberration diagram showing aberrations at (a) the wide-angle end and (b) the telephoto end when focusing on infinity. Figure 8 is a lateral aberration diagram showing aberrations at (a) the wide-angle end and (b) the telephoto end when focusing on infinity when the image stabilization lens group is decentered by 1.1 mm.

[0067] The zoom lens according to Example 2 includes, in order from the object side to the image side, a first lens unit L1 having positive refractive power, an intermediate lens unit LM, and a fifth lens unit L5 as a rear lens unit LR having positive refractive power. In the zoom lens, the distances between adjacent lens units change during zooming.

[0068] The first lens group L1 does not move for zooming. The intermediate lens group LM has two or more negative lens groups that move during zooming, specifically, a second lens group L2 with negative refractive power, a third lens group L3 with negative refractive power, and a fourth lens group L4 with positive refractive power. In the zoom lens of Example 2, the first intermediate lens group LM1 corresponds to the second lens group L2, and the second intermediate lens group LM2 corresponds to the third lens group L3 and the fourth lens group L4. The fifth lens group L5 does not move for zooming.

[0069] An aperture stop SP, which does not move for zooming, is located inside the fifth lens group L5. The fifth lens group L5 consists of, in order from the object side, a first rear sub-lens group LRa with positive refractive power, a second rear sub-lens group (image-stabilizing lens group) IS with negative refractive power, and a third rear sub-lens group LRc with positive refractive power. By moving the second rear sub-lens group IS in a direction approximately perpendicular to the optical axis, it is possible to move the image in a direction perpendicular to the optical axis.

[0070] The first lens group L1 includes, in order from the object side to the image side, a first sub-lens group L1a with negative refractive power and a second sub-lens group L1b with positive refractive power. The first sub-lens group L1a does not move for focusing. The second sub-lens group L1b moves toward the object side for focusing from an object at infinity to a close object.

[0071] The second lens unit L2 moves monotonically toward the image side on the optical axis when zooming from the wide-angle end to the telephoto end. The third lens unit L3 moves along the optical axis in a convex locus toward the object side when zooming from the wide-angle end to the telephoto end. The fourth lens unit L4 moves non-monotonically along the optical axis when zooming from the wide-angle end to the telephoto end, as shown in Figure 5, for example. The fifth lens group L5 does not move for zooming. I is the image plane (plane where an image is formed) of the zoom lens, and the image sensor of the imaging device is disposed at this position to capture an image.

[0072] The first lens group L1 consists of surfaces 1 to 12. The first sub-lens group L1a consists of surfaces 1 to 8 and is composed of two positive lenses and two negative lenses. The second sub-lens group L1b consists of surfaces 9 to 12 and is composed of two positive lenses.

[0073] The second lens group L2, the third lens group L3, and the fourth lens group L4, which serve as intermediate lens groups LM having two or more negative lens groups, are composed of surfaces 13 to 26. The second lens group L2 is composed of surfaces 13 to 21 and consists of three negative lenses and two positive lenses. The third lens group L3 is composed of surfaces 22 to 24 and consists of one negative lens and one positive lens. The fourth lens group L4 is composed of surfaces 25 to 26 and consists of one positive lens.

[0074] The fifth lens group L5 consists of surfaces Nos. 27 to 52, the aperture stop SP consists of surface No. 29, and is composed of seven negative lenses and seven positive lenses. The image stabilization lens group IS consists of surfaces Nos. 37 to 42, and is composed, in order from the object side to the image side, of a negative lens, a positive lens, and a negative lens.

[0075] The zoom lens according to this embodiment has the above configuration and satisfies conditional expressions (1) to (10), thereby making it possible to provide a zoom lens that has a high zoom ratio, is small and lightweight, and is capable of performing appropriate vibration reduction. [Example]

[0076] A zoom lens according to Example 3 of the present invention will be described below with reference to Figures 9 to 12. Figure 9 is a diagram showing a cross section of the zoom lens according to Example 3 at the wide-angle end. Figure 10 is a longitudinal aberration diagram showing aberrations at (a) the wide-angle end and (b) the telephoto end when focusing on infinity. Figure 11 is a lateral aberration diagram showing aberrations at (a) the wide-angle end and (b) the telephoto end when focusing on infinity. Figure 12 is a lateral aberration diagram showing aberrations at (a) the wide-angle end and (b) the telephoto end when focusing on infinity when the image stabilization lens group is decentered by 1.1 mm.

[0077] The zoom lens according to Example 3 includes, in order from the object side to the image side, a first lens unit L1 having positive refractive power, an intermediate lens unit LM, and a fifth lens unit L5 as a rear lens unit also having positive refractive power. In the zoom lens, the distances between adjacent lens units change during zooming.

[0078] The first lens group L1 does not move for zooming. The intermediate lens group LM has two or more negative lens groups that move during zooming, specifically, a second lens group L2 with negative refractive power, a third lens group L3 with positive refractive power, and a fourth lens group L4 with negative refractive power. In the zoom lens of Example 3, the first intermediate lens group LM1 corresponds to the second lens group L2 and the third lens group L3, and the second intermediate lens group LM2 corresponds to the fourth lens group L4. The fifth lens group L5 does not move for zooming.

[0079] An aperture stop SP, which does not move for zooming, is located inside the fifth lens group L5. The fifth lens group L5 consists of, in order from the object side, a first rear sub-lens group LRa with positive refractive power, a second rear sub-lens group (anti-vibration lens group) IS with negative refractive power, and a third rear sub-lens group LRc with positive refractive power. By moving the second rear sub-lens group IS in a direction approximately perpendicular to the optical axis, it is possible to move the image in a direction perpendicular to the optical axis.

[0080] The first lens group L1 includes, in order from the object side to the image side, a first sub-lens group L1a with negative refractive power and a second sub-lens group L1b with positive refractive power. The first sub-lens group L1a does not move for focusing. The second sub-lens group L1b moves toward the object side for focusing from an object at infinity to a close object. The second lens group L2 moves monotonically along the optical axis toward the image side when zooming from the wide-angle end to the telephoto end. The third lens group L3 moves monotonically along the optical axis toward the image side when zooming from the wide-angle end to the telephoto end. The fourth lens group L4 moves along the optical axis along a locus convex toward the object side when zooming from the wide-angle end to the telephoto end. The fifth lens group L5 does not move for zooming. I is the image plane (plane where an image is formed) of the zoom lens, and the image sensor of the imaging device is located at this position to capture an image.

[0081] The first lens group L1 consists of surfaces 1 to 12. The first sub-lens group L1a consists of surfaces 1 to 8 and is composed of two positive lenses and two negative lenses. The second sub-lens group L1b consists of surfaces 9 to 12 and is composed of two positive lenses.

[0082] The second lens group L2, the third lens group L3, and the fourth lens group L4, which serve as intermediate lens groups LM having two or more negative lens groups, are composed of surfaces 13 to 24. The second lens group L2 is composed of surfaces 13 to 19 and consists of three negative lenses and two positive lenses. The third lens group L3 is composed of surfaces 20 to 21 and consists of one positive lens. The fourth lens group L4 is composed of surfaces 22 to 24 and consists of one negative lens and one positive lens.

[0083] The fifth lens group L5 consists of surfaces Nos. 25 to 52, the aperture stop SP consists of surface No. 29, and is composed of seven negative lens elements and eight positive lens elements. The image stabilization lens group IS consists of surfaces Nos. 37 to 42, and is composed, in order from the object side to the image side, of a negative lens element, a positive lens element, and another negative lens element.

[0084] The zoom lens according to this embodiment has the above configuration and satisfies conditional expressions (1) to (6) and conditional expressions (8) to (10), thereby making it possible to provide a zoom lens that has a high zoom ratio, is small and lightweight, and is capable of performing appropriate image stabilization. [Example]

[0085] A zoom lens according to Example 4 of the present invention will be described below with reference to Figs. 13 to 16. Fig. 13 is a diagram showing a cross section of the zoom lens according to Example 4 at the wide-angle end. Fig. 14 is a longitudinal aberration diagram showing aberrations at (a) the wide-angle end and (b) the telephoto end when focusing on infinity, Fig. 15 is a lateral aberration diagram showing aberrations at (a) the wide-angle end and (b) the telephoto end when focusing on infinity, and Fig. 16 is a lateral aberration diagram showing aberrations at (a) the wide-angle end and (b) the telephoto end when focusing on infinity when the image stabilization lens group is decentered by 1.1 mm.

[0086] The zoom lens according to Example 4 includes, in order from the object side to the image side, a first lens unit L1 having positive refractive power, an intermediate lens unit LM, and a fifth lens unit L5 as a rear lens unit also having positive refractive power. In the zoom lens, the distances between adjacent lens units change during zooming.

[0087] The first lens group L1 does not move for zooming. The intermediate lens group LM has two or more negative lens groups that move during zooming, specifically, a second lens group L2 with negative refractive power, a third lens group L3 with negative refractive power, and a fourth lens group L4 with negative refractive power. In the zoom lens of Example 4, the first intermediate lens group LM1 corresponds to the second lens group L2 and the third lens group L3, and the second intermediate lens group LM2 corresponds to the fourth lens group L4. The fifth lens group L5 does not move for zooming.

[0088] An aperture stop SP, which does not move for zooming, is located inside the fifth lens group L5. The fifth lens group L5 consists of, in order from the object side, a first rear sub-lens group LRa having positive refractive power, a second rear sub-lens group (anti-vibration lens group) IS having negative refractive power, and a third rear sub-lens group LRc having positive refractive power. By moving the second rear sub-lens group IS in a direction approximately perpendicular to the optical axis, it is possible to move the image in a direction perpendicular to the optical axis.

[0089] The first lens group L1 includes, from the object side to the image side, a first sub-lens group L1a with negative refractive power and a second sub-lens group L1b with positive refractive power. The first sub-lens group L1a does not move for focusing. The second sub-lens group L1a moves toward the object side for focusing from an object at infinity to a close object. The second lens group L2 moves monotonically along the optical axis toward the image side when zooming from the wide-angle end to the telephoto end. The third lens group L3 moves monotonically along the optical axis toward the image side when zooming from the wide-angle end to the telephoto end. The fourth lens group L4 moves along the optical axis along a locus convex toward the object side when zooming from the wide-angle end to the telephoto end. The fifth lens group L5 does not move for zooming. IP is the image plane (the surface where an image is formed) of the zoom lens, and the image sensor of the imaging device is located at this position to capture an image.

[0090] The first lens group L1 consists of surfaces 1 to 12. The first sub-lens group L1a consists of surfaces 1 to 8 and is composed of two positive lenses and two negative lenses. The second sub-lens group L1b consists of surfaces 9 to 12 and is composed of two positive lenses.

[0091] The second lens group L2, the third lens group L3, and the fourth lens group L4, which serve as intermediate lens groups LM having two or more negative lens groups, are each composed of surfaces 13 to 24. The second lens group L2 is composed of surfaces 13 to 14 and is composed of one negative lens. The third lens group L3 is composed of surfaces 15 to 21 and is composed of two negative lenses and two positive lenses. The fourth lens group L4 is composed of surfaces 22 to 24 and is composed of one negative lens and one positive lens.

[0092] The fifth lens group L5 consists of surfaces Nos. 25 to 52, the aperture stop SP consists of surface No. 29, and is composed of seven negative lens elements and eight positive lens elements. The image stabilization lens group IS consists of surfaces Nos. 37 to 42, and is composed, in order from the object side to the image side, of a negative lens element, a positive lens element, and another negative lens element.

[0093] The zoom lens according to this embodiment has the above configuration and satisfies conditional expressions (1) to (6) and conditional expressions (8) to (10), thereby making it possible to provide a zoom lens that has a high zoom ratio, is small and lightweight, and is capable of performing appropriate image stabilization.

[0094] Numerical Examples 1 to 4 corresponding to the above-mentioned Examples 1 to 4 are shown below. In each numerical example, r is the radius of curvature (mm) of the surface with the surface number (i), and d is the distance (lens thickness or air thickness; mm) between the i-th surface and the (i+1)-th surface. The notation "(variable)" in the d column indicates that the air thickness changes during zooming, and the correspondence between the air thickness and the focal length is shown in a separate table. nd is the refractive index for the d-line of the material of the i-th optical element.

[0095] νd is the Abbe number of the material of the i-th optical member based on the d-line. The Abbe number νd is defined by the following formula: νd=(nd-1) / (nF-nC) (A) Here, nF, nd, and nC are refractive indices for the F line (wavelength 486.1 nm), d line (wavelength 587.6 nm), and C line (wavelength 656.3 nm) of the Fraunhofer lines. θgF is the partial dispersion ratio and is defined by the following equation: θgF=(ng-nF) / (nF-nC) (B) Here, ng is the refractive index at the g-line (wavelength 435.8 nm).

[0096] In each numerical example, the half angle of view (°) of the zoom lens is shown, and the maximum image height corresponding to this half angle of view is shown as "image height." The "half angle of view" ω is expressed by the formula ω = arctan(Y / fw), where 2Y is the diagonal image size of the camera in which the zoom lens is used, and fw is the focal length of the zoom lens at the wide-angle end. The "maximum image height" corresponds to half Y (e.g., 14.80 mm) of the diagonal image size 2Y (e.g., 29.60 mm). The focal length of each lens group is also shown as lens group data.

[0097] The back focus (mm) is shown as "BF." Back focus is the distance on the optical axis from the image side of the lens with refractive power closest to the image (the final surface of the zoom lens) to the paraxial image plane, expressed as an air-equivalent length. The "total lens length" is also shown. The total lens length is the distance on the optical axis from the front surface of the zoom lens (the object side surface of the lens closest to the object) to the final surface of the zoom lens, plus the back focus. An "*" next to a surface number indicates that the surface with that surface number is aspherical.

[0098] The height of a point on the aspherical surface on an axis perpendicular to the optical axis is H, and the direction of light travel on the optical axis is positive. Also, R is the paraxial radius of curvature of the aspherical surface, K is the conic constant, and A2, A4, A6, A8, A 10 , A 12 , A 14 , A 16 is the aspherical coefficient. Then, the deviation amount X from the reference spherical surface at the point at the height H on the axis parallel to the optical axis is expressed by the following equation:

number

[0099] In the conic constants and aspherical coefficients of each numerical example, e±X is × 10 ±X The focal length in each numerical example is the focal length for the e-line (wavelength 546.07 nm).

[0100] [Numerical Example 1] Unit: mm Surface Data Surface number rd nd vd θgf 1 180.535 17.03 1.48749 70.2 0.5300 2 -1280.724 1.00 3 166.543 3.40 1.72916 54.7 0.5444 4 114.018 5.74 5 121.536 22.48 1.43387 95.1 0.5373 6 -527.620 1.50 7 -412.349 3.20 1.72916 54.7 0.5444 8 160.819 17.07 9 148.643 17.14 1.43387 95.1 0.5373 10 -689.698 0.37 11 140.793 7.14 1.43387 95.1 0.5373 12 267.379 (variable) 13* 1762.187 1.20 1.76385 48.5 0.5589 14 30.824 5.62 15 71.023 1.00 1.59522 67.7 0.5442 16 26.978 7.18 1.72047 34.7 0.5834 17 618.683 3.56 18 -35.603 1.00 1.59522 67.7 0.5442 19 60.649 0.20 20 58.410 3.18 1.56732 42.8 0.5731 21 -406.335 (variable) 22 -79.858 1.00 1.61800 63.3 0.5441 23 192.413 2.70 1.80518 25.4 0.6161 24 7656.520 (variable) 25 103.174 6.83 1.59522 67.7 0.5442 26* -78.803 11.16 27 44.385 10.49 1.53775 74.7 0.5392 28 -275.209 3.00 29 (Aperture) ∞ 3.00 30 127.840 8.09 1.43875 94.9 0.5340 31 -65.608 1.20 2.00100 29.1 0.5997 32 53.279 1.20 33 41.213 7.88 1.59551 39.2 0.5803 34 -122.187 9.20 35 738.836 1.20 1.74400 44.8 0.5655 36 100.516 3.92 37 -138.127 1.20 1.95375 32.3 0.5905 38 47.360 1.50 39 29.984 3.72 1.80810 22.8 0.6307 40 85.934 1.00 41 69.006 1.20 1.83481 42.7 0.5648 42 30.811 4.02 43 44.437 4.52 1.48749 70.2 0.5300 44 -22.177 0.50 45 -21.448 1.00 1.88300 40.8 0.5667 46 7333.187 4.68 1.71736 29.5 0.6047 47 -43.454 37.60 48 86.574 3.27 1.68893 31.1 0.6004 49 -109.800 1.00 1.62041 60.3 0.5427 50 -310.185 9.02 51 -48.153 2.00 1.95375 32.3 0.5905 52 -65.672 49.27 Image plane ∞ Aspheric data Page 13 K = 3.27657e+03 A 4= 3.26733e-06 A 6=-1.68078e-09 A 8= 1.83394e-11 A10=-1.45265e-13 A12= 6.12446e-16 A14=-1.34269e-18 A16= 1.25050e-21 Page 26 K =-5.68941e-01 A 4= 6.99855e-07 A 6= 2.69485e-11 A 8= 1.89035e-13 A10=-7.76775e-16 A12= 8.61000e-19 A14= 7.47575e-22 A16=-1.35080e-24 Various data Zoom ratio 19.01 Wide-angle Mid-range Telephoto Focal length 49.98 230.35 949.95 F-number 4.50 4.50 7.00 Angle of view 16.50 3.68 0.89 Image height 14.80 14.80 14.80 Lens total length 477.00 477.00 477.00 BF 49.27 49.27 49.27 d12 5.94 106.49 145.59 d21 154.55 26.05 15.03 d24 1.12 29.08 1.00 Zoom lens group data Group starting plane focal length 1 1 239.70 2 13 -33.84 3 22 -145.60 4 25 66.07

[0101] [Numerical Example 2] Unit: mm Surface Data Surface number rd nd vd θgf 1 182.820 17.03 1.48749 70.2 0.5300 2 -1166.669 1.00 3 168.045 3.40 1.72916 54.7 0.5444 4 114.297 5.74 5 121.854 22.48 1.43387 95.1 0.5373 6 -561.730 1.50 7 -408.565 3.20 1.72916 54.7 0.5444 8 162.164 17.07 9 146.519 17.14 1.43387 95.1 0.5373 10 -659.407 0.37 11 142.039 7.14 1.43387 95.1 0.5373 12 279.552 (variable) 13* 1487.835 1.20 1.76385 48.5 0.5589 14 29.313 5.00 15 82.374 1.00 1.59522 67.7 0.5442 16 28.804 5.70 1.72047 34.7 0.5834 17 12725.073 3.56 18 -32.368 1.00 1.59522 67.7 0.5442 19 65.244 0.20 20 59.138 3.65 1.56732 42.8 0.5731 21 -157.533 (variable) 22 -81.618 1.00 1.61800 63.3 0.5441 23 171.783 2.85 1.80518 25.4 0.6161 24 3250.204 (variable) 25 98.193 7.37 1.59522 67.7 0.5442 26* -78.968 (variable) 27 43.296 11.14 1.53775 74.7 0.5392 28 -281.045 3.00 29 (Aperture) ∞ 3.00 30 129.847 8.21 1.43875 94.9 0.5340 31 -65.158 1.20 2.00100 29.1 0.5997 32 53.165 1.20 33 42.894 7.68 1.59551 39.2 0.5803 34 -129.408 9.18 35 1524.651 1.20 1.74400 44.8 0.5655 36 85.318 3.82 37 -130.035 1.20 1.95375 32.3 0.5905 38 46.494 1.50 39 31.743 5.04 1.80810 22.8 0.6307 40 78.536 1.00 41 63.803 1.20 1.83481 42.7 0.5648 42 33.791 3.65 43 43.213 4.42 1.48749 70.2 0.5300 44 -22.171 0.50 45 -21.564 1.00 1.88300 40.8 0.5667 46 -768.948 5.05 1.71736 29.5 0.6047 47 -48.478 37.60 48 91.758 6.32 1.68893 31.1 0.6004 49 -80.423 1.37 1.62041 60.3 0.5427 50 -150.701 8.91 51 -44.276 2.00 1.95375 32.3 0.5905 52 -61.477 49.27 Image plane ∞ Aspheric data Page 13 K = 5.09480e+03 A 4= 3.85781e-06 A 6=-2.35443e-09 A 8= 1.84932e-11 A10=-1.41646e-13 A12= 5.27121e-16 A14=-9.72016e-19 A16= 7.78966e-22 Page 26 K =-6.67378e-01 A 4= 7.24042e-07 A 6=-2.91074e-12 A 8= 3.33901e-13 A10=-9.88999e-16 A12= 8.52885e-19 A14= 8.61450e-22 A16=-1.26402e-24 Various data Zoom ratio 19.00 Wide-angle Mid-range Telephoto Focal length 50.01 217.96 949.98 F-number 4.50 4.50 7.00 Angle of view 16.49 3.88 0.89 Image height 14.80 14.80 14.80 Lens total length 477.00 477.00 477.00 BF 49.27 49.27 49.27 d12 5.75 103.00 145.48 d21 155.33 26.39 17.10 d24 1.90 30.71 1.30 d26 5.73 8.61 4.82 Zoom lens group data Group starting plane focal length 1 1 237.08 2 13 -33.86 3 22 -148.62 4 25 74.69 5 27 399.10

[0102] [Numerical Example 3] Unit: mm Surface Data Surface number rd nd vd θgf 1 180.922 17.03 1.48749 70.2 0.5300 2 -1259.905 1.00 3 166.732 3.40 1.72916 54.7 0.5444 4 113.990 5.74 5 121.758 22.48 1.43387 95.1 0.5373 6 -534.658 1.50 7 -411.981 3.20 1.72916 54.7 0.5444 8 161.135 17.07 9 148.009 17.14 1.43387 95.1 0.5373 10 -683.082 0.37 11 140.827 7.14 1.43387 95.1 0.5373 12 268.897 (variable) 13* 1399.970 1.20 1.76385 48.5 0.5589 14 30.684 5.00 15 73.140 1.00 1.59522 67.7 0.5442 16 27.535 6.81 1.72047 34.7 0.5834 17 1181.623 3.56 18 -34.607 1.00 1.59522 67.7 0.5442 19 59.270 (variable) 20 59.384 3.22 1.56732 42.8 0.5731 21 -345.984 (variable) 22 -80.102 1.00 1.61800 63.3 0.5441 23 187.450 2.72 1.80518 25.4 0.6161 24 5412.417 (variable) 25 101.877 6.93 1.59522 67.7 0.5442 26* -78.504 8.50 27 44.210 10.68 1.53775 74.7 0.5392 28 -272.323 3.00 29 (Aperture) ∞ 3.00 30 129.202 8.11 1.43875 94.9 0.5340 31 -66.176 1.20 2.00100 29.1 0.5997 32 53.217 1.20 33 41.557 7.83 1.59551 39.2 0.5803 34 -125.270 9.32 35 1071.034 1.20 1.74400 44.8 0.5655 36 95.063 4.06 37 -136.659 1.20 1.95375 32.3 0.5905 38 47.237 1.50 39 30.621 4.28 1.80810 22.8 0.6307 40 82.911 1.00 41 66.868 1.20 1.83481 42.7 0.5648 42 31.701 3.93 43 44.615 4.42 1.48749 70.2 0.5300 44 -22.188 0.50 45 -21.459 1.00 1.88300 40.8 0.5667 46 735.037 5.32 1.71736 29.5 0.6047 47 -44.178 37.60 48 84.603 3.19 1.68893 31.1 0.6004 49 -141.641 1.00 1.62041 60.3 0.5427 50 -263.513 10.06 51 -47.975 2.00 1.95375 32.3 0.5905 52 -64.578 49.27 Image plane ∞ Aspheric data Page 13 K = 4.52544e+03 A 4= 3.39870e-06 A 6=-1.99419e-09 A 8= 1.83278e-11 A10=-1.44600e-13 A12= 5.96546e-16 A14=-1.30101e-18 A16= 1.21300e-21 Page 26 K =-6.21007e-01 A 4= 7.12996e-07 A 6= 2.08910e-11 A 8= 2.26748e-13 A10=-7.91782e-16 A12= 7.87282e-19 A14= 7.39718e-22 A16=-1.23162e-24 Various data Zoom ratio 19.00 Wide-angle Mid-range Telephoto Focal length 49.99 217.92 949.97 F-number 4.50 4.50 7.00 Angle of view 16.49 3.89 0.89 Image height 14.80 14.80 14.80 Lens total length 477.00 477.00 477.00 BF 49.27 49.27 49.27 d12 6.00 104.61 145.82 d19 1.40 0.91 1.09 d21 154.28 28.67 14.99 d24 1.22 28.72 1.00 Zoom lens group data Group starting plane focal length 1 1 239.19 2 13 -22.77 3 20 89.60 4 22 -145.71 5 25 68.80

[0103] [Numerical Example 4] Unit: mm Surface Data Surface number rd nd vd θgf 1 180.939 17.03 1.48749 70.2 0.5300 2 -1259.098 1.00 3 166.827 3.40 1.72916 54.7 0.5444 4 114.018 5.74 5 121.689 22.48 1.43387 95.1 0.5373 6 -535.044 1.50 7 -411.816 3.20 1.72916 54.7 0.5444 8 161.081 17.07 9 147.994 17.14 1.43387 95.1 0.5373 10 -678.950 0.37 11 140.905 7.14 1.43387 95.1 0.5373 12 269.081 (variable) 13* 1428.563 1.20 1.76385 48.5 0.5589 14 30.733 (variable) 15 73.739 1.00 1.59522 67.7 0.5442 16 27.300 6.22 1.72047 34.7 0.5834 17 1019.797 3.56 18 -34.535 1.00 1.59522 67.7 0.5442 19 60.398 0.20 20 58.204 3.24 1.56732 42.8 0.5731 21 -339.003 (variable) 22 -80.542 1.00 1.61800 63.3 0.5441 23 186.741 2.73 1.80518 25.4 0.6161 24 5615.301 (variable) 25 101.984 6.92 1.59522 67.7 0.5442 26* -78.445 8.31 27 44.266 10.67 1.53775 74.7 0.5392 28 -271.397 3.00 29 (Aperture) ∞ 3.00 30 129.031 8.11 1.43875 94.9 0.5340 31 -66.076 1.20 2.00100 29.1 0.5997 32 53.169 1.20 33 41.571 7.83 1.59551 39.2 0.5803 34 -125.177 9.32 35 1030.583 1.20 1.74400 44.8 0.5655 36 95.612 4.15 37 -136.154 1.20 1.95375 32.3 0.5905 38 47.103 1.50 39 30.648 4.48 1.80810 22.8 0.6307 40 82.792 1.00 41 66.773 1.20 1.83481 42.7 0.5648 42 31.641 3.94 43 44.726 4.40 1.48749 70.2 0.5300 44 -22.144 0.50 45 -21.437 1.00 1.88300 40.8 0.5667 46 755.869 5.32 1.71736 29.5 0.6047 47 -44.368 37.60 48 84.756 3.40 1.68893 31.1 0.6004 49 -150.471 1.69 1.62041 60.3 0.5427 50 -263.919 9.82 51 -48.394 2.00 1.95375 32.3 0.5905 52 -64.097 49.27 Image plane ∞ Aspheric data Page 13 K = 4.38377e+03 A 4= 3.36919e-06 A 6=-1.94264e-09 A 8= 1.89415e-11 A10=-1.46516e-13 A12= 5.86428e-16 A14=-1.22181e-18 A16= 1.10723e-21 Page 26 K =-6.13567e-01 A 4= 7.11740e-07 A 6= 2.45116e-11 A 8= 2.21402e-13 A10=-8.02167e-16 A12= 8.15269e-19 A14= 7.51599e-22 A16=-1.26883e-24 Various data Zoom ratio 19.00 Wide-angle Mid-range Telephoto Focal length 50.00 217.94 949.99 F-number 4.50 4.50 7.00 Angle of view 16.49 3.88 0.89 Image height 14.80 14.80 14.80 Lens total length 477.00 477.00 477.00 BF 49.27 49.27 49.27 d12 6.11 104.24 145.62 d14 6.33 5.72 5.46 d21 153.82 28.69 15.30 d24 1.30 28.91 1.18 Zoom lens group data Group starting plane focal length 1 1 239.09 2 13 -41.13 3 15 -455.70 4 22 -146.81 5 25 70.24

[0104] Table 1 shows the values ​​for each conditional expression in Numerical Examples 1 to 4. [Table 1] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention.

[0105] The disclosure of this embodiment includes the following configuration. (Configuration 1) A zoom lens comprising, in order from the object side to the image side, a first lens group having positive refractive power that does not move for varying magnification, an intermediate lens group including two or more negative lens groups that moves for varying magnification, and a rear lens group having positive refractive power that includes an aperture stop and does not move for varying magnification, The spacing between adjacent lens groups changes due to magnification. the rear lens group includes an image stabilization lens group that is capable of moving an image in a direction perpendicular to the optical axis by moving in a direction including a component perpendicular to the optical axis, When the lateral magnification of an optical system included in the zoom lens, which is located closer to the image side than the lens group having negative refractive power and arranged closest to the image side among the intermediate lens groups, at infinity focusing at the wide-angle end is βMpR, and the lateral magnification of the image stabilization lens group is βis, -3.00≦βMpR≦-1.80 -0.333≦1 / βis≦0.200 A zoom lens characterized by satisfying the following conditional expressions: (Configuration 2) When the lateral magnification of the lens component of the rear lens group, which is arranged closer to the image side than the vibration reduction lens group, is βRc, 1.70≦βis×βRc≦2.35 2. The zoom lens according to claim 1, wherein the following condition is satisfied: (Configuration 3) When the lateral magnification of an optical system that is located closer to the image side than the negative lens group that is located closest to the image side among the intermediate lens groups and closer to the object side than the vibration reduction lens group is defined as βMpRa, -2.50≦βMpRa≦-0.700 3. The zoom lens according to configuration 1 or 2, wherein the following condition is satisfied: (Configuration 4) When the lateral magnification of the lens component of the rear lens group, which is arranged closer to the image side than the vibration reduction lens group, is βRc, -4.00≦(1-βis)×βRc≦-1.90 4. The zoom lens according to any one of configurations 1 to 3, wherein the following condition is satisfied: (Configuration 5) the intermediate lens group includes a second lens group arranged closest to the object, When the focal length of the first lens group is f1, the focal length of the second lens group is f2, and the focal length of the zoom lens at the telephoto end is ft, 3.50≦ft / f1≦ 8.00 -8.00≦f1 / f2≦-4.00 5. The zoom lens according to any one of configurations 1 to 4, wherein the following condition is satisfied: (Configuration 6) the intermediate lens group includes a second lens group and a third lens group arranged in this order from the object side to the image side, When the composite focal length of the second lens group and the third lens group at the wide-angle end when focusing at infinity is f23, -8.00≦f1 / f23≦-4.00 5. The zoom lens according to any one of configurations 1 to 4, wherein the following condition is satisfied: (Configuration 7) the first lens group includes a first sub-lens group that does not move for focusing, and one or more second sub-lens groups that move for focusing, which are arranged in order from the object side to the image side, When the focal length of the first sub-lens group is f1a and the composite focal length of the one or more second sub-lens groups is f1b, -50.00≦f1a / f1≦-5.00 0.20≦f1b / f1≦2.00 7. The zoom lens according to any one of configurations 1 to 6, wherein the following condition is satisfied: (Configuration 8) A zoom lens according to any one of configurations 1 to 7, characterized in that the rear lens group consists of, in order from the object side to the image side, a first rear sub-lens group having positive refractive power, the vibration-proof lens group having negative refractive power, and a third rear sub-lens group having positive refractive power. (Configuration 9) 9. The zoom lens according to any one of configurations 1 to 8, wherein the vibration reduction lens group comprises, in order from the object side to the image side, a negative lens, a positive lens, and a negative lens. (Configuration 10) A zoom lens according to any one of configurations 1 to 9, and an image sensor for capturing an image formed by the zoom lens. [Explanation of symbols]

[0106] L1 First lens group L2: Second lens group (intermediate lens group) L3: Third lens group (intermediate lens group) L4: Fourth lens group (middle lens group (Examples 2, 3, and 4) / rear lens group (Example 1)) L5: Fifth lens group (rear lens group (Examples 2, 3, and 4)) LM intermediate lens group LR rear lens group IS vibration-proof lens group SP aperture stop

Claims

1. A zoom lens comprising, in order from the object side to the image side, a first lens group having positive refractive power and not moving for varying magnification, an intermediate lens group including two or more negative lens groups that move for varying magnification, and a rear lens group having positive refractive power and including an aperture stop that does not move for varying magnification, The spacing between adjacent lens groups changes due to magnification. the rear lens group includes an image stabilization lens group that is capable of moving an image in a direction perpendicular to the optical axis by moving in a direction including a component perpendicular to the optical axis, When the lateral magnification of an optical system included in the zoom lens, which is located closer to the image side than the lens group having negative refractive power and arranged closest to the image side among the intermediate lens groups, at infinity focusing at the wide-angle end is βMpR, and the lateral magnification of the image stabilization lens group is βis, -3.00≦βMpR≦-1.80 −0.333≦1 / βis≦0.200 A zoom lens characterized by satisfying the following conditional expressions:

2. When the lateral magnification of the lens component of the rear lens group, which is arranged closer to the image side than the vibration reduction lens group, is βRc, 1.70≦βis×βRc≦2.35 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

3. When the lateral magnification of an optical system that is located closer to the image side than the negative lens group that is located closest to the image side among the intermediate lens groups and closer to the object side than the vibration reduction lens group is defined as βMpRa, -2.50≦βMpRa≦-0.700 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

4. When the lateral magnification of the lens component of the rear lens group, which is arranged closer to the image side than the vibration reduction lens group, is βRc, -4.00≦(1-βis)×βRc≦-1.90 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

5. the intermediate lens group includes a second lens group arranged closest to the object, When the focal length of the first lens group is f1, the focal length of the second lens group is f2, and the focal length of the zoom lens at the telephoto end is ft, 3.50≦ft / f1≦8.00 -8.00≦f1 / f2≦-4.00 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

6. the intermediate lens group includes a second lens group and a third lens group arranged in this order from the object side to the image side, When the composite focal length of the second lens group and the third lens group at the wide-angle end when focusing at infinity is f23, -8.00≦f1 / f23≦-4.00 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

7. the first lens group includes a first sub-lens group that does not move for focusing, and one or more second sub-lens groups that move for focusing, which are arranged in order from the object side to the image side, When the focal length of the first sub-lens group is f1a and the composite focal length of the one or more second sub-lens groups is f1b, -50.00≦f1a / f1≦-5.00 0.20≦f1b / f1≦2.00 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

8. 2. The zoom lens according to claim 1, wherein the rear lens group comprises, in order from the object side to the image side, a first rear sub-lens group having positive refractive power, the vibration-proof lens group having negative refractive power, and a third rear sub-lens group having positive refractive power.

9. 2. The zoom lens according to claim 1, wherein the vibration reduction lens group comprises, in order from the object side to the image side, a negative lens, a positive lens, and a negative lens.

10. A zoom lens according to any one of claims 1 to 9; and an image sensor for capturing an image formed by the zoom lens.

Images