Zoom lens and imaging device equipped with same

Abstract

[Problem] To provide a zoom lens that exhibits high imaging performance and is suitable for video capturing. [Solution] A zoom lens has, in order from the object side, a first lens group L1 having positive refractive power, a first intermediate lens group LM1 having negative refractive power as a whole, a second intermediate lens group LM2 having positive refractive power, a third intermediate lens group LM3 having positive refractive power, and a lens group LR having negative refractive power as a whole. The distances between the lens groups change during zooming, and the first lens group L1 and the second intermediate lens group LM2 are fixed with respect to the image plane. When the movement amount of a lens group that has the largest movement amount in the first intermediate lens group LM1 is denoted by mM1, the movement amount of the third intermediate lens group LM3 is denoted by mM3, the focal length of the first lens group L1 is denoted by f1, and the focal length of the first intermediate lens group LM1 at the wide angle end is denoted by fM1w, conditional expressions -2.2 < mM1 / mM3 < -1.0 and -5.0 < f1 / fM1w < -1.4 are satisfied.

Description

Zoom lens and imaging device having the same

[0001] This disclosure relates to a zoom lens and an imaging device having the same, and is suitably used in electronic cameras such as video cameras and digital still cameras, as well as film cameras and broadcast cameras.

[0002] Imaging devices such as digital cameras and video cameras require zoom lenses that are compact, cover a wide range from wide-angle to telephoto with a single lens, and have high image-forming performance throughout the entire zoom range.

[0003] Furthermore, with the increasing demand for video recording, there is a need for power zoom lenses with a fixed overall length.

[0004] Conventionally, zoom lens systems equipped with a group of lenses having positive refractive power on the object side have been advantageous for high magnification, and various proposals have been made for them.

[0005] For example, Patent Document 1 describes how to increase magnification by increasing the amount of movement of the second lens group.

[0006] Japanese Patent Publication No. 2022-80409

[0007] By the way, in addition to high magnification, there is a demand for rapid zooming in power zoom lenses.

[0008] Therefore, the purpose of this disclosure is to provide an electric zoom lens and an imaging device having the same, which have high imaging performance and are suitable for video recording.

[0009] A zoom lens as one aspect of this disclosure has, in order from the object side, a first lens group L1 having positive refractive power, a first intermediate lens group LM1 having negative refractive power as a whole, a second intermediate lens group LM2 having positive refractive power, a third intermediate lens group LM3 having positive refractive power, and a lens group LR having negative refractive power as a whole, and the distance between each lens group changes during zooming, and the first lens group and the second intermediate lens group LM2 are fixed with respect to the image plane, and when the amount of movement of the lens group with the largest amount of movement in the first intermediate lens group LM1 is mM1, the amount of movement of the third intermediate lens group LM3 is mM3, the focal length of the first lens group is f1, and the focal length of the first intermediate lens group LM1 at the wide-angle end is fM1w, the following conditions are satisfied: -2.2 < mM1 / mM3 < -1.0 -5.0 < f1 / fM1w < -1.4

[0010] Furthermore, another aspect of this disclosure is a zoom lens having a first lens group L1 having positive refractive power and positioned closest to the object, and a plurality of lens groups, wherein the first lens group L1 remains stationary during zooming.

[0011] According to this disclosure, it is possible to provide an electric zoom lens with high imaging performance and suitable for video recording, as well as an imaging device having the same.

[0012]

[0013] The following describes embodiments of the zoom lens and imaging device having the same according to this disclosure.

[0014] Figure 1 is a cross-sectional view of the zoom lens of Embodiment 1 of this disclosure when it is in focus on an object at infinity at its wide-angle end (short focal length end).

[0015] Figure 2 shows the longitudinal aberration when the zoom lens of Example 1 is focused on an object at infinity at its wide-angle end.

[0016] Figure 3 shows the longitudinal aberration when the zoom lens of Example 1 is focused on an object at infinity at its telephoto end (long focal length end).

[0017] Figure 4 is a cross-sectional view of the zoom lens of Embodiment 2 of this disclosure when it is in focus on an object at infinity at its wide-angle end.

[0018] Figure 5 shows the longitudinal aberration when the zoom lens of Example 2 is focused on an object at infinity at its wide-angle end.

[0019] Figure 6 shows the longitudinal aberration when the zoom lens of Example 2 is focused on an object at infinity at its telephoto end.

[0020] Figure 7 is a cross-sectional view of the zoom lens of Embodiment 3 of this disclosure when it is in focus on an object at infinity at its wide-angle end.

[0021] Figure 8 shows the longitudinal aberration when the zoom lens of Example 3 is focused on an object at infinity at its wide-angle end.

[0022] Figure 9 shows the longitudinal aberration when the zoom lens of Example 3 is focused on an object at infinity at its telephoto end.

[0023] Figure 10 is a cross-sectional view of the zoom lens of Embodiment 4 of this disclosure when it is in focus on an object at infinity at its wide-angle end.

[0024] Figure 11 shows the longitudinal aberration when the zoom lens of Example 4 is focused on an object at infinity at its wide-angle end.

[0025] Figure 12 shows the longitudinal aberration when the zoom lens of Example 4 is focused on an object at infinity at its telephoto end.

[0026] Figure 13 is a cross-sectional view of the zoom lens of Embodiment 5 of this disclosure when it is in focus on an object at infinity at its wide-angle end.

[0027] Figure 14 shows the longitudinal aberration when the zoom lens of Example 5 is focused on an object at infinity at its wide-angle end.

[0028] Figure 15 shows the longitudinal aberration when the zoom lens of Example 5 is focused on an object at infinity at its telephoto end.

[0029] Figure 16 is a cross-sectional view of the zoom lens of Embodiment 6 of this disclosure when it is in focus on an object at infinity at its wide-angle end.

[0030] Figure 17 shows the longitudinal aberration when the zoom lens of Example 6 is focused on an object at infinity at its wide-angle end.

[0031] Figure 18 shows the longitudinal aberration when the zoom lens of Example 6 is focused on an object at infinity at its telephoto end.

[0032] Figure 16 is a cross-sectional view of the zoom lens of Embodiment 6 of this disclosure when it is in focus on an object at infinity at its wide-angle end.

[0033] Figure 17 shows the longitudinal aberration when the zoom lens of Example 6 is focused on an object at infinity at its wide-angle end.

[0034] Figure 18 shows the longitudinal aberration when the zoom lens of Example 6 is focused on an object at infinity at its telephoto end.

[0035] Figure 16 is a cross-sectional view of the zoom lens of Embodiment 6 of this disclosure when it is in focus on an object at infinity at its wide-angle end.

[0036] Figure 17 shows the longitudinal aberration when the zoom lens of Example 6 is focused on an object at infinity at its wide-angle end.

[0037] Figure 18 shows the longitudinal aberration when the zoom lens of Example 6 is focused on an object at infinity at its telephoto end.

[0038] Figure 19 is a cross-sectional view of the zoom lens of Embodiment 7 of this disclosure when it is in focus on an object at infinity at its wide-angle end.

[0039] Figure 20 is a longitudinal aberration diagram when focusing on an infinite object at the wide-angle end of the zoom lens of Example 7.

[0040] Figure 21 is a longitudinal aberration diagram when focusing on an infinite object at the telephoto end of the zoom lens of Example 7.

[0041] Figure 22 is a lens cross-sectional view when focusing on an infinite object at the wide-angle end of the zoom lens of Example 8 of the present disclosure.

[0042] Figure 23 is a longitudinal aberration diagram when focusing on an infinite object at the wide-angle end of the zoom lens of Example 8.

[0043] Figure 24 is a longitudinal aberration diagram when focusing on an infinite object at the telephoto end of the zoom lens of Example 8.

[0044] Figure 25 is a lens cross-sectional view when focusing on an infinite object at the wide-angle end of the zoom lens of Example 9 of the present disclosure.

[0045] Figure 26 is a longitudinal aberration diagram when focusing on an infinite object at the wide-angle end of the zoom lens of Example 9.

[0046] Figure 27 is a longitudinal aberration diagram when focusing on an infinite object at the telephoto end of the zoom lens of Example 9.

[0047] Figure 28 is a schematic diagram of an imaging device.

[0048] The zoom lens of each example is a photographing lens system used in an imaging device such as a video camera, a digital camera, and a silver halide film camera.

[0049] In the lens cross-sectional view, the left side is the object side (front), and the right side is the image side (rear). In the lens cross-sectional view, i indicates the order of the lens groups from the object side, and Li is the i-th lens group.

[0050] SP is an aperture stop, which is arranged in the second intermediate lens group LM2. By arranging the stop in the fixed group LM2, the weight of the movable group can be reduced.

[0051] The IP (Image Interface) is the image plane. When used in the imaging optical system of a video camera or digital still camera, it is the image plane of a solid-state image sensor (photoelectric conversion element) such as a CCD sensor or CMOS sensor. In the case of a silver halide film camera, it is the photosensitive surface corresponding to the film plane.

[0052] In the aberration diagram, d and g represent the d-line and g-line, respectively. ΔM and ΔS represent the meridional and sagittal image planes, respectively, while chromatic aberration is represented by the g-line.

[0053] ω represents the half-angle, and Fno represents the F-number.

[0054] In the following embodiments, the wide-angle end and telephoto end refer to the zoom positions when each lens group is located at the ends of the range in which it can move along the optical axis due to the mechanism.

[0055] The arrows indicate the movement trajectory of each lens group during zooming from the wide-angle end to the telephoto end.

[0056] In Examples 1, 7, 11, 3, 4, and 9 shown in Figures 25, focusing is performed by moving the fifth lens group L5 along the optical axis. In Examples 6, 7, and 8 shown in Figures 16, 19, and 22, focusing is performed by moving the sixth lens group L6 along the optical axis. In Example 2 shown in Figure 4, focusing is performed by moving the fourth lens group L4 and the fifth lens group L5 along the optical axis. In Example 5 shown in Figure 13, focusing is performed by moving the fifth lens group L5 and the sixth lens group L6 along the optical axis.

[0057] Furthermore, focusing can be done by moving the entire zoom lens or any single lens group.

[0058] In Examples 1 to 8, the IS lens group moves to have a component approximately perpendicular to the optical axis, thereby displacing the image approximately perpendicular to the optical axis and correcting image blur when the entire zoom lens vibrates. In other words, it performs vibration isolation. By placing the IS lens group in the fixed group LM2, it becomes possible to reduce the weight of the movable group.

[0059] Next, the characteristics of each embodiment will be described. In positive lead type zoom lenses, an important challenge is to achieve good optical performance across a wide range of object distances while simultaneously achieving a high magnification ratio and miniaturizing the entire lens system.

[0060] To solve this problem, it is important to appropriately set the refractive power and lens configuration of each lens group, as well as the movement conditions associated with zooming of each lens group.

[0061] If these configurations are not set properly, it becomes extremely difficult to obtain a zoom lens that maintains a high magnification ratio while also possessing high optical performance across the entire zoom range.

[0062] In one embodiment of this disclosure, to solve the above, the lens has, in order from the object side, a first lens group L1 having positive refractive power, a first intermediate lens group LM1 having negative refractive power as a whole, and a second intermediate lens group LM2 having positive refractive power. On the image side of the second intermediate lens group LM2, there is a third intermediate lens group LM3 having positive refractive power and a lens group LR having negative refractive power as a whole. In a zoom lens in which the spacing between each lens group changes during zooming, and the first lens group and the second intermediate lens group LM2 are fixed with respect to the image plane, the following conditions are set.

[0063] When mM1 is the amount of movement of the lens group with the largest amount of movement among the first intermediate lens group LM1, and mM3 is the amount of movement of the third intermediate lens group LM3, the following condition is satisfied: -2.2 < mM1 / mM3 < -1.0 ... (1).

[0064] Conditional equation (1) specifies the amount of movement of the movable groups LM1 and LM3.

[0065] In power zoom lenses, it is crucial to appropriately set the amount of movement of the movable group in order to zoom quickly and with low power consumption. If the amount of movement of LM1 exceeds the lower limit of condition (1), quick zooming becomes difficult. In addition, the load on the actuator that moves LM1 becomes large, resulting in excessive power consumption. Furthermore, the center of gravity of the lens shifts significantly due to zooming.

[0066] If the amount of movement of LM3 exceeds the upper limit of condition (1), the distance between the aperture and the lens group LM3 increases at the wide-angle end, causing the lens group LM3 to become larger and its mass to increase, making rapid zooming and low-power operation difficult.

[0067] When the focal length of the first lens group is f1 and the focal length of the first intermediate lens group LM1 at the wide-angle end is fM1w, the following condition is satisfied: -5.0 < f1 / fM1w < -1.4 ... (2).

[0068] Conditional equation (2) defines the ratio of the focal lengths of the first lens group L1 and the first intermediate lens group LM1.

[0069] If the refractive power of the first intermediate lens group LM1 becomes too strong, exceeding the lower limit of condition (2), the amount of movement due to zooming can be reduced, which is advantageous for miniaturizing the lens, but the fluctuation in field curvature due to zooming becomes too large.

[0070] If the refractive power of the first lens group L1 becomes too strong, exceeding the lower limit of condition (2), it becomes difficult to correct spherical aberration at the telephoto end. Therefore, it is possible to obtain a motorized zoom lens that has high imaging performance and is also suitable for video recording.

[0071] In another embodiment of the present disclosure, a zoom lens has a first lens group L1 having positive refractive power and positioned closest to the object, and a plurality of lens groups, wherein the first lens group L1 remains stationary during zooming.

[0072] This reduces the load on the actuator that moves LM1, thereby lowering power consumption. It also suppresses the shift in the lens's center of gravity due to zooming. Furthermore, by having multiple lens groups positioned closer to the image than the first lens group L1, it becomes easier to suppress variations in various aberrations that occur during zooming.

[0073] Based on the above, it is possible to obtain a power zoom lens that has high imaging performance and is also suitable for video recording.

[0074] In the optical system of each embodiment, it is preferable that one or more of the following configurations and conditional equations are satisfied. This will result in the effects corresponding to each configuration and conditional equation.

[0075] When zooming, it is desirable for the spacing between six or more lens groups to change.

[0076] In zooming, increasing the number of groups with varying intervals makes it possible to suppress various aberration variations caused by zooming.

[0077] The lens group positioned closest to the image plane should ideally be fixed relative to the image plane during zooming.

[0078] By fixing the lens group located closest to the image sensor, it becomes possible to suppress the intrusion of dust when changing lenses. Furthermore, it protects the movable lens group.

[0079] The third intermediate lens group LM3 should ideally consist of three or fewer lenses. By limiting the number of lenses in the movable lens group LM3 to three or fewer, the lens group can be made lighter, enabling rapid zooming.

[0080] The LR lens group should ideally include a focusing lens group.

[0081] By positioning the focusing lens group closer to the image plane, the weight of the focusing lens group can be reduced. Furthermore, focus breathing is easier to suppress, making it suitable for video recording. Ideally, the number of moving lens groups during zooming should be four or less.

[0082] By limiting the number of movable groups to four or fewer, it becomes possible to reduce power consumption in power zoom lenses.

[0083] When the focal length of the first lens group is f1 and the focal length of the entire lens system at the wide-angle end is fw, it is desirable to satisfy the following condition: 2.2 < f1 / fw < 3.8 ... (3).

[0084] Conditional equation (3) defines the focal length of the first lens group L1. If the refractive power of the first lens group L1 becomes too weak, exceeding the upper limit of conditional equation (3), it becomes difficult to shorten the overall length of the lens. If the refractive power of the first lens group L1 becomes too strong, exceeding the lower limit, it becomes difficult to correct spherical aberration at the telephoto end.

[0085] When the focal length of the first lens group is f1 and the focal length of the entire lens system at the telephoto end is ft, it is desirable to satisfy the following condition: 0.40 < f1 / ft < 1.0 ... (4).

[0086] Conditional equation (4) specifies the focal length of the first lens group L1. If the refractive power of the first lens group L1 becomes too weak, exceeding the upper limit of conditional equation (4), it becomes difficult to shorten the overall length of the lens. If the refractive power of the first lens group L1 becomes too strong, exceeding the lower limit, it becomes difficult to correct spherical aberration at the telephoto end.

[0087] When the focal length of the second lens group is f2 and the focal length of the entire lens system at the wide-angle end is fw, it is desirable to satisfy the following condition: -1.6 < f2 / fw < -0.40 ... (5).

[0088] Conditional equation (5) specifies the focal length of the second lens group L2. If the refractive power of the second lens group L2 becomes too strong, exceeding the upper limit of conditional equation (5), it becomes difficult to suppress the fluctuations in field curvature due to zooming.

[0089] If the refractive power of the second lens group L2 weakens too much beyond the lower limit, the amount of movement of the second lens group due to zooming becomes too large, making it difficult to achieve high magnification.

[0090] When the focal length of the second lens group is f2 and the focal length of the entire lens system at the telephoto end is ft, it is desirable to satisfy the following condition: -0.40 < f2 / ft < -0.10 ... (6).

[0091] Conditional equation (6) defines the focal length of the second lens group L2. If the refractive power of the second lens group L2 becomes too strong, exceeding the upper limit of conditional equation (6), it becomes difficult to suppress the fluctuation of field curvature due to zooming. If the refractive power of the second lens group L2 becomes too weak, exceeding the lower limit, the amount of movement of the second lens group due to zooming becomes too large, making it difficult to achieve high magnification.

[0092] When the focal length of the second intermediate lens group LM2 is fM2 and the focal length of the entire lens system at the wide-angle end is fw, it is desirable to satisfy the following condition: 1.7 < fM2 / fw < 17 ... (7).

[0093] Conditional equation (7) defines the focal length of the second intermediate lens group LM2. If the refractive power of the intermediate lens group LM2 becomes too weak, exceeding the upper limit of conditional equation (7), it becomes difficult to reduce the diameter of the subsequent lenses. Also, if the refractive power of the intermediate lens group LM3 becomes too strong, it becomes difficult to suppress the zoom variation of field curvature. If the refractive power of the second lens group L2 becomes too strong, exceeding the lower limit, it becomes difficult to correct spherical aberration at the telephoto end.

[0094] When the focal length of the second intermediate lens group LM2 is fM2 and the focal length of the entire lens system at the telephoto end is ft, it is desirable to satisfy the following condition: 0.30 < fM2 / ft < 3.3 ... (8).

[0095] Conditional equation (8) specifies the focal length of the second intermediate lens group LM2. If the refractive power of the intermediate lens group LM2 becomes too weak, exceeding the upper limit of conditional equation (8), it becomes difficult to reduce the diameter of the subsequent lens.

[0096] Furthermore, if the refractive power of the intermediate lens group LM3 becomes too strong, it becomes difficult to suppress the zoom variation in field curvature. If the refractive power of the second lens group L2 becomes too strong beyond the lower limit, it becomes difficult to correct spherical aberration at the telephoto end.

[0097] When the focal length of the third intermediate lens group LM3 is fM3 and the focal length of the entire lens system at the wide-angle end is fw, it is desirable to satisfy the following condition: 0.90 < fM3 / fw < 1.7 ... (9).

[0098] Conditional equation (9) defines the focal length of the third intermediate lens group LM3. If the refractive power of the intermediate lens group LM3 becomes too weak, exceeding the upper limit of conditional equation (9), the amount of movement of the intermediate lens group LM3 becomes too large during zooming, making it difficult to reduce the overall size of the lens. If the refractive power of the intermediate lens group LM3 becomes too strong, exceeding the lower limit, it becomes difficult to correct field curvature at the wide-angle end.

[0099] When the focal length of the third intermediate lens group LM3 is fM3 and the focal length of the entire lens system at the telephoto end is ft, it is desirable to satisfy the following condition: 0.20 < fM3 / ft < 0.45 ... (10).

[0100] Conditional equation (10) defines the focal length of the third intermediate lens group LM3. If the refractive power of the intermediate lens group LM3 becomes too weak, exceeding the upper limit of conditional equation (10), the amount of movement of the intermediate lens group LM3 becomes too large during zooming, making it difficult to reduce the overall size of the lens. If the refractive power of the intermediate lens group LM3 becomes too strong, exceeding the lower limit, it becomes difficult to correct field curvature at the wide-angle end.

[0101] When the focal length of lens group LR at the wide-angle end is fRw and the focal length of the entire lens system at the wide-angle end is fw, it is desirable to satisfy the following condition: -2.5 < fRw / fw < -1.0 ... (11).

[0102] Conditional equation (11) specifies the focal length of lens group LR. If the refractive power of lens group LR becomes too strong, exceeding the upper limit of conditional equation (11), it becomes difficult to correct pincushion distortion at the telephoto end. If the refractive power of lens group LR becomes too weak, exceeding the lower limit, it becomes difficult to shorten the overall length of the lens.

[0103] When the focal length of lens group LR at the wide-angle end is fRw and the focal length of the entire lens system at the telephoto end is ft, it is desirable to satisfy the following condition: -0.65 < fRw / ft < -0.20 ... (12).

[0104] Conditional equation (12) specifies the focal length of lens group LR. If the refractive power of lens group LR becomes too strong, exceeding the upper limit of conditional equation (12), it becomes difficult to correct pincushion distortion at the telephoto end. If the refractive power of lens group LR becomes too weak, exceeding the lower limit, it becomes difficult to shorten the overall length of the lens.

[0105] When the focal length of the second lens group L2 is f2, and the amount of movement of the lens group with the largest amount of movement among the first intermediate lens group LM1 is mM1, it is desirable to satisfy the following condition: -1.5 < f2 / mM1 < -0.40 ... (13).

[0106] Conditional equation (13) specifies the ratio of the focal length to the amount of displacement of the second lens group L2.

[0107] If the refractive power of the second lens group becomes too strong, exceeding the upper limit of condition (13), it becomes difficult to reduce the diameter of the front element. If the refractive power of the second lens group becomes too weak, exceeding the lower limit, it becomes difficult to increase the magnification.

[0108] When mM1 is the amount of movement of the lens group with the largest amount of movement among the first intermediate lens group LM1, and ft is the focal length of the entire lens system at the telephoto end, it is desirable to satisfy the following condition: 0.16 < mM1 / ft < 0.30 ... (14).

[0109] Conditional equation (14) specifies the amount of movement of the lens group with the largest amount of movement among the first intermediate lens group LM1.

[0110] If the amount of movement of the lens group LM1 exceeds the upper limit of condition (14), it becomes difficult to reduce the diameter of the front element. If the amount of movement of the lens group LM1 exceeds the lower limit, it becomes difficult to increase the magnification.

[0111] When the focal length of the third intermediate lens group LM3 is fM3 and the amount of movement of the third intermediate lens group LM3 is mM3, it is desirable to satisfy the following condition: -2.4 < fM3 / mM3 < -1.2 ... (15).

[0112] Conditional equation (15) specifies the ratio of the focal length to the amount of movement of the third intermediate lens group LM3.

[0113] If the refractive power of the third intermediate lens group LM3 becomes too strong, exceeding the upper limit of condition equation (15), it becomes difficult to correct the field curvature at the wide-angle end. If the refractive power of the third intermediate lens group LM3 becomes too weak, exceeding the lower limit, it becomes difficult to achieve high magnification.

[0114] When the amount of movement of the third intermediate lens group LM3 is mM3 and the focal length of the entire lens system at the telephoto end is ft, it is desirable to satisfy the following condition: -0.24 < mM3 / ft < -0.080 ... (16).

[0115] Conditional equation (16) specifies the amount of movement of the third intermediate lens group LM3.

[0116] If the amount of movement of the third intermediate lens group LM3 exceeds the upper limit of condition (16) and becomes too small, it becomes difficult to achieve high magnification. If the amount of movement of the third intermediate lens group LM3 exceeds the lower limit and becomes too large, at the wide-angle end, the position of the lens group LM3 becomes farther from the aperture, which increases the lens diameter and makes it difficult to reduce the weight of the lens group LM3.

[0117] When the focal length of the first intermediate lens group LM1 at the wide-angle end is fM1w and the focal length of the third intermediate lens group LM3 is fM3, it is desirable to satisfy the following condition: -1.7 < fM1w / fM3 < -0.40 ... (17).

[0118] Conditional equation (17) specifies the ratio of the refractive powers of lens groups LM1 and LM3.

[0119] If the refractive power of LM1 becomes too strong, exceeding the upper limit of condition equation (17), it becomes difficult to correct barrel distortion at the wide-angle end. If the refractive power of LM3 becomes too strong, exceeding the lower limit, it becomes difficult to correct field curvature at the wide-angle end.

[0120] When the focal length of the first intermediate lens group LM1 at the wide-angle end is fM1w and the focal length of the second intermediate lens group LM2 is fM2, it is desirable to satisfy the following condition: -0.50 < fM1w / fM2 < 0.00 ... (18).

[0121] Conditional equation (18) specifies the ratio of the refractive powers of lens groups LM1 and LM2.

[0122] If the refractive power of LM1 becomes too strong, exceeding the upper limit of condition equation (18), it becomes difficult to correct barrel distortion at the wide-angle end. If the refractive power of LM2 becomes too strong, exceeding the lower limit, it becomes difficult to correct spherical aberration at the telephoto end.

[0123] When the focal length of the first intermediate lens group LM1 at the wide-angle end is fM1w and the focal length of the lens group LR at the wide-angle end is fRw, it is desirable to satisfy the following condition: 0.20 < fM1w / fRw < 1.3 ... (19).

[0124] Conditional equation (19) specifies the ratio of the refractive powers of lens groups LM1 and LR.

[0125] If the refractive power of LR becomes too strong, exceeding the upper limit of condition equation (19), it becomes difficult to correct pincushion distortion at the telephoto end. If the refractive power of LM1 becomes too strong, exceeding the lower limit, it becomes difficult to correct field curvature at the wide-angle end.

[0126] When the focal length of the second intermediate lens group LM2 is fM2 and the focal length of the third intermediate lens group LM3 is fM3, it is desirable to satisfy the following condition: 1.3 < fM2 / fM3 < 14 ... (20).

[0127] Conditional equation (20) specifies the ratio of the refractive powers of lens groups LM2 and LM3.

[0128] If the refractive power of LM3 becomes too strong, exceeding the upper limit of condition equation (20), it becomes difficult to correct barrel distortion at the wide-angle end. If the refractive power of LM2 becomes too strong, exceeding the lower limit, it becomes difficult to correct spherical aberration at the telephoto end.

[0129] When the total optical length at the wide-angle end is Lw, the F-number at the wide-angle end is Fnow, and the back focus at the wide-angle end is skw, it is desirable to satisfy the following condition: 39 < Lw * Fnow / skw < 57 ... (21).

[0130] Conditional equation (21) appropriately sets the relationship between the F-number at the wide-angle end, the overall length, and the back focus. If the upper limit of conditional equation (21) is exceeded and the back focus at the wide-angle end becomes too short, it becomes difficult to use the lens in an interchangeable lens system. If the lower limit is exceeded and the F-number at the wide-angle end becomes too small, it becomes difficult to reduce the size of the front element.

[0131] Furthermore, in each embodiment, it is preferable to set the numerical ranges of the aforementioned conditional formulas (1) to (21) as follows.

[0132] -2.0<mM1 / mM3<-1.1...(1a) -4.7<f1 / fM1w<-1.5...(2a) 2.4<f1 / fw<3.5...(3a) 0.45<f1 / ft<0.90...(4a) -1.5<f2 / fw<-0.50...(5a) -0.35<f2 / ft<-0.12...(6a) 1.8<fM2 / fw<16...(7a) 0.35<fM2 / ft<3.2...(8a) 1.0<fM3 / fw<1.6...(9a) 0.22<fM3 / ft<0.40...(10a) -2.4<fRw / fw<-1.1...(11a) -0.60<fRw / ft<-0.22...(12a) -1.4<f2 / mM1<-0.50...(13a) 0.18<mM1 / ft<0.28...(14a) -2.3<fM3 / mM3<-1.3...(15a) -0.22<mM3 / ft<-0.10...(16a) -1.6<fM1w / fM3<-0.45...(17a) -0.45<fM1w / fM2<-0.05...(18a) 0.25<fM1w / fRw<1.2...(19a) 1.4<fM2 / fM3<13...(20a) 40 < Lw * Fnow / skw < 56 ... (21a) Furthermore, it is preferable to set the numerical range of the above-mentioned conditional equations (1) to (21) as follows.

[0133] -1.8<mM1 / mM3<-1.2...(1b) -4.5<f1 / fM1w<-1.6...(2b) 2.6<f1 / fw<3.2...(3b) 0.50<f1 / ft<0.80...(4b) -1.4<f2 / fw<-0.60...(5b) -0.30<f2 / ft<-0.14...(6b) 1.9<fM2 / fw<15...(7b) 0.40<fM2 / ft<3.15...(8b) 1.1<fM3 / fw<1.5...(9b) 0.24<fM3 / ft<0.35...(10b) -2.2<fRw / fw<-1.2...(11b) -0.55<fRw / ft<-0.24...(12b) -1.3<f2 / mM1<-0.60...(13b) 0.20<mM1 / ft<0.26...(14b) -2.2<fM3 / mM3<-1.4...(15b) -0.20<mM3 / ft<-0.12...(16b) -1.5<fM1w / fM3<-0.50...(17b) -0.40<fM1w / fM2<-0.10...(18b) 0.30<fM1w / fRw<1.1...(19b) 1.5<fM2 / fM3<12...(20b) 41 < Lw * Fnow / skw < 55 ... (21b) As described above, according to each embodiment, it is possible to provide an electric zoom lens and an imaging device having the same that have high imaging performance and are suitable for video recording.

[0134] Examples 1 to 9 and their corresponding numerical examples 1 to 9 are shown below. In each numerical example, i indicates the order of the faces from the object side, ri is the radius of curvature of the i-th (i-th face), di is the distance between the i-th face and the (i+1)th face, ndi and νdi are the refractive index and Abbe number, respectively, with respect to the d-line. f is the focal length, and Fno is the F-number.

[0135] The aspherical data shows the aspherical coefficient when the aspherical surface is represented by the following formula.

[0136] x = (h ２ / R) / [1+{1-(1+k)(h / R) ２} １／２ ] + A4 x h ４ + A6 × h ６ +A8×h８ +A10×h １０ +A12×h １２ However, x: displacement amount from the reference plane in the optical axis direction, h: height in the direction perpendicular to the optical axis, R: radius of the base quadratic surface, k: conic constant, An: aspherical coefficient of the nth order. Note that "e±XX" in each aspherical coefficient means "×10± ＸＸ ". [Example 1] In the lens cross-sectional view of Example 1 in FIG. 1, L1 is the first lens group with positive refractive power, L2 is the second lens group with negative refractive power (the first intermediate lens group LM1), and L3 is the third lens group with positive refractive power (the second intermediate lens group LM2). L4 is the fourth lens group with positive refractive power (the third intermediate lens group LM3), L5 is the fifth lens group with negative refractive power, and L6 is the sixth lens group with negative refractive power. The fifth lens group and the sixth lens group are the subsequent lens group LR.

[0137] The first lens group L1 is composed of, in order from the object side, a cemented positive lens formed by cementing a negative meniscus lens with a convex surface facing the object side and a positive meniscus lens with a convex surface facing the object side, and a positive meniscus lens with a convex surface facing the object side.

[0138] The second lens group L2 is composed of, in order from the object side, a negative lens with a negative meniscus shape with a convex surface facing the object side and an aspherical surface formed on the object side surface, a biconcave negative lens, a biconvex positive lens, and a negative meniscus lens with a concave surface facing the object side.

[0139] The third lens group L3 has, in order from the object side, a biconvex positive lens, a cemented negative lens formed by cementing a biconvex positive lens and a biconcave negative lens, and a cemented positive lens formed by cementing a negative meniscus lens with a convex surface facing the object side and a biconvex positive lens. A cemented negative lens formed by cementing a cemented positive lens, a biconcave negative lens, and a biconvex positive lens is arranged on the image side of the cemented positive lens.

[0140] The fourth lens group L4 is composed of a positive lens with a biconvex shape and aspherical surfaces formed on both surfaces, and a cemented positive lens formed by cementing a negative meniscus lens with a convex surface facing the object side and a biconvex positive lens.

[0141] The fifth lens group L5 is composed of a bonded negative lens formed by joining a biconvex positive lens and a biconcave negative lens. The sixth lens group L6 is composed of a bonded negative lens formed by joining a biconcave negative lens and a biconvex positive lens.

[0142] In Example 1, when zooming from the wide-angle end to the telephoto end, the first lens group L1 is fixed to the lens barrel as indicated by the arrow. The second lens group L2 moves toward the image while increasing its distance from the first lens group L1. The third lens group L3 is fixed to the lens barrel. The fourth lens group L4 moves toward the object while decreasing its distance from the third lens group L3. The fifth lens group L5 moves toward the object while decreasing its distance from the fourth lens group L4. The sixth lens group L6 is fixed to the lens barrel. The aperture SP is located in the third lens group L3.

[0143] The IS lens group is a bonded positive lens formed by joining a negative meniscus lens with a convex surface facing the object side and a biconvex positive lens. It moves so that it has a component in a direction approximately perpendicular to the optical axis, displacing the image in a direction approximately perpendicular to the optical axis, thereby correcting image blur when the entire zoom lens vibrates. In other words, it performs image stabilization. Focusing is performed by moving the fifth lens group L5 toward the image side.

[0144] (Numerical Example 1) Unit: mm Surface Data Surface Number rd nd νd Effective Diameter 1 84.196 1.50 2.00069 25.5 59.52 2 55.267 8.78 1.59522 67.7 55.76 3 750.026 0.15 54.03 4 54.546 5.98 1.59522 67.7 47.12 5 309.100 (Variable) 45.75 6* -988.539 0.05 1.53344 52.7 35.49 7 821.930 1.15 1.80400 46.5 35.41 8 21.912 7.11 27.79 9 -58.808 1.00 1.77250 49.6 27.23 10 66.073 0.16 26.10 11 44.782 4.87 1.84666 23.8 25.95 12 -63.564 1.28 25.30 13 -33.725 0.90 1.77250 49.6 25.15 14 -126.540 (variable) 24.61 15 44.905 3.30 1.51633 64.1 20.60 16 -78.016 0.15 20.71 17 134.328 2.39 1.80518 25.4 20.69 18 -66.117 1.00 2.00100 29.1 20.60 19 91.737 2.09 20.51 20 (aperture) ∞ 5.31 20.74 21 63.225 1.00 2.00069 25.5 21.68 22 25.274 5.85 1.83481 42.7 21.43 23 -106.757 3.51 21.36 24 -39.182 0.95 1.80400 46.5 20.79 25 68.840 3.19 2.00069 25.5 21.19 26 -725.066 (variable) 21.39 27* 40.560 9.11 1.58313 59.4 33.16 28* -49.434 2.29 33.60 29 112.821 1.00 2.05090 26.9 33.12 30 34.311 11.19 1.49700 81.5 32.38 31 -40.959 (variable) 32.86 32 69.567 6.48 1.92286 20.9 30.43 33 -40.129 0.90 2.00100 29.1 29.76 34 30.799 (variable) 27.69 35 -51.200 1.00 1.68893 31.1 31.98 36 44.189 5.97 2.00100 29.1 35.93 37 -366.942 (Variable) 36.41 Image plane ∞ Aspherical data 6th plane K = 0.00000e+00 A 4= 4.93619e-06 A 6=-1.10987e-08 A 8= 4.73029e-11 A10=-1.25475e-13 A12= 1.37335e-16 27th plane K = 0.00000e+00 A 4=-4.68809e-06 A 6= 1.86167e-10 A 8= 3.66056e-11 A10 = -1.19061e-13 A12 = 4.27671e-17 28th plane K = 0.00000e+00 A 4 = 8.19918e-06 A 6 = -6.21695e-09 A 8 = 3.70804e-11 A10 = -7.68887e-14 A12 = -4.36164e-17 Various data Zoom ratio 4.54 Wide angle Intermediate Telephoto Focal length 28.85 63.94 131.00 F-number 4.12 4.12 4.12 Half-angle of view 35.07 18.69 9.38 Image height 20.25 21.64 21.64 Lens length 183.50 183.50 183.50 BF 14.00 14.00 14.00 d 5 1.51 16.01 30.51 d14 30.50 16.00 1.50 d26 22.82 7.00 2.81 d31 4.74 2.06 4.40 d34 10.32 28.83 30.68 d37 14.00 14.00 14.00 Zoom lens group data group Starting plane Focal length 1 1 79.21 2 6 -20.30 3 15 73.63 4 27 35.66 5 32 -51.35 6 35 -282.79 [Example 2] In the cross-sectional view of the lens of Example 2 in Figure 4, L1 is the first lens group with positive refractive power, L2 is the second lens group with negative refractive power (first intermediate lens group LM1), and L3 is the third lens group with positive refractive power (second intermediate lens group LM2). L4 is the fourth lens group with positive refractive power (third intermediate lens group LM3), L5 is the fifth lens group with negative refractive power, and L6 is the sixth lens group with negative refractive power. The fifth and sixth lens groups are the successor lens group LR. The first lens group L1 consists, in order from the object side, a bonded positive lens formed by joining a negative meniscus lens with its convex surface facing the object side and a positive meniscus lens with its convex surface facing the object side, and a positive meniscus lens with its convex surface facing the object side.

[0145] The second lens group L2 consists of, in order from the object side, a negative meniscus lens with a convex surface facing the object side and an aspherical surface formed on the object-side surface, a biconcave negative lens, a biconvex positive lens, and a negative meniscus lens with a concave surface facing the object side.

[0146] The third lens group L3 consists of, in order from the object side, a biconvex positive lens, a negative meniscus lens with its convex surface facing the object, a bonded positive lens formed by joining a negative meniscus lens with its convex surface facing the object and a biconvex positive lens, and a bonded negative lens formed by joining a biconcave negative lens and a biconvex positive lens.

[0147] The fourth lens group L4 consists of a positive lens with a biconvex shape and aspherical surfaces formed on both sides, and a bonded positive lens formed by joining a negative meniscus lens with a convex surface facing the object side and the biconvex positive lens.

[0148] The fifth lens group L5 is composed of a bonded negative lens formed by joining a biconvex positive lens and a biconcave negative lens.

[0149] The sixth lens group L6 consists of a negative meniscus lens with its concave surface facing the object and a biconvex positive lens.

[0150] In Example 2, when zooming from the wide-angle end to the telephoto end, the first lens group L1 is fixed to the lens barrel as indicated by the arrow. The second lens group L2 moves toward the image while increasing its distance from the first lens group L1. The third lens group L3 is fixed to the lens barrel. The fourth lens group L4 moves toward the object while decreasing its distance from the third lens group L3. The fifth lens group L5 moves toward the object while increasing its distance from the fourth lens group L4. The sixth lens group L6 is fixed to the lens barrel. The aperture SP is located in the third lens group L3.

[0151] The IS lens group is a bonded positive lens formed by joining a negative meniscus lens with a convex surface facing the object side and a biconvex positive lens. It moves so that it has a component in a direction approximately perpendicular to the optical axis, displacing the image in a direction approximately perpendicular to the optical axis, thereby correcting image blur when the entire zoom lens vibrates. In other words, it performs vibration isolation. Focusing is achieved by moving the fourth lens group L4 and the fifth lens group L5 toward the image side along different trajectories.

[0152] (Numerical Example 2) Unit: mm Surface Data Surface Number rd nd νd Effective Diameter 1 98.194 1.50 2.00069 25.5 60.42 2 62.608 8.19 1.59522 67.7 56.91 3 1337.339 0.15 55.32 4 56.494 5.80 1.59522 67.7 48.42 5 258.147 (Variable) 47.12 6* -1314.634 0.05 1.53344 52.7 37.52 7 601.649 1.15 1.80400 46.5 37.45 8 23.888 7.73 29.84 9 -56.049 1.00 1.77250 49.6 29.29 10 54.479 0.62 28.13 11 49.725 5.13 1.84666 23.8 28.12 12 -67.006 1.33 27.66 13 -36.933 0.90 1.77250 49.6 27.55 14 -92.165 (variable) 27.27 15 48.614 2.81 1.72916 54.7 22.58 16 -278.363 0.15 22.61 17 89.175 1.00 2.00100 29.1 22.60 18 60.556 2.56 22.42 19 (aperture) ∞ 6.02 22.58 20 65.575 1.00 2.00069 25.5 23.35 21 26.443 4.92 1.83481 42.7 23.02 22 -121.269 7.17 22.93 23 -38.200 0.95 1.83481 42.7 21.33 24 60.696 2.16 2.00069 25.5 21.76 25 -1005.551 (variable) 21.86 26* 47.453 7.90 1.58313 59.4 32.93 27* -61.032 1.81 33.60 28 100.820 1.00 2.05090 26.9 34.01 29 39.206 11.46 1.49700 81.5 33.56 30 -38.547 (variable) 34.17 31 80.788 6.97 1.92286 20.9 31.62 32 -40.417 0.90 2.00100 29.1 30.86 33 33.413 (variable) 28.89 34 -35.738 1.00 1.84666 23.8 31.86 35 -93.115 0.20 34.00 36 96.572 4.77 2.00100 29.1 37.46 37 -366.942 (Variable) 38.00 Image plane ∞ Aspherical data 6th plane K = 0.00000e+00 A 4= 4.86039e-06 A 6=-6.48271e-09 A 8= 1.34950e-11 A10=-2.82401e-14 A12= 2.85745e-17 26th plane K = 0.00000e+00 A 4=-3.67049e-06 A 6=-2.03599e-09 A 8= 4.06979e-11 A10=-1.14505e-13 A12=-4.08223e-17 27th surface K = 0.00000e+00 A4= 6.78950e-06 A6=-5.09484e-09 A8= 3.56806e-11 A10=-6.57297e-14 A12=-1.24422e-16 Various data Zoom ratio 4.71 Wide angle Intermediate Telephoto Focal length 28.85 63.48 135.80 F-number 4.12 4.12 4.12 Half angle of view 35.63 18.82 9.05 Image height 20.67 21.64 21.64 Lens length 188.50 188.50 188.50 BF 15.13 15.13 15.13 d 5 1.58 17.76 33.95 d14 33.87 17.68 1.50 d25 25.25 7.74 1.00 d30 4.66 2.30 6.50 d33 9.71 29.58 32.12 d37 15.13 15.13 15.13 Zoom Lens Group Data Group Starting Surface Focal Length 1 1 87.34 2 6 -21.44 3 15 67.33 4 26 36.03 5 31 -52.58 6 34 -864.53 [Example 3] In the lens cross-section of Example 3 in Figure 7, L1 is the first lens group with positive refractive power, L2 is the second lens group with negative refractive power (first intermediate lens group LM1), and L3 is the third lens group with positive refractive power (second intermediate lens group LM2). L4 is the fourth lens group with positive refractive power (third intermediate lens group LM3), L5 is the fifth lens group with negative refractive power, and L6 is the sixth lens group with positive refractive power. The fifth and sixth lens groups are the successor lens groups LR.

[0153] The first lens group L1 consists of, in order from the object side, a bonded positive lens formed by joining a negative meniscus lens with its convex surface facing the object side and a positive meniscus lens with its convex surface facing the object side, and a positive meniscus lens with its convex surface facing the object side.

[0154] The second lens group L2 consists of, in order from the object side, a negative meniscus lens with a convex surface facing the object side and an aspherical surface formed on the object-side surface, a biconcave negative lens, a biconvex positive lens, and a negative meniscus lens with a concave surface facing the object side.

[0155] The third lens group L3 consists of, in order from the object side, a biconvex positive lens, a bonded negative lens formed by joining a biconvex lens and a biconcave lens, a bonded positive lens formed by joining a negative meniscus lens with its convex surface facing the object side and a biconvex positive lens, and a biconcave negative lens.

[0156] The fourth lens group L4 consists of a positive lens with a biconvex shape and aspherical surfaces formed on both sides, and a bonded positive lens formed by joining a negative meniscus lens with a convex surface facing the object side and the biconvex positive lens.

[0157] The fifth lens group L5 is composed of a bonded negative lens formed by joining a biconvex positive lens and a biconcave negative lens.

[0158] The sixth lens group L6 is composed of a bonded positive lens formed by joining a double concave negative lens and a double convex positive lens.

[0159] In Example 3, when zooming from the wide-angle end to the telephoto end, the first lens group L1 is fixed to the lens barrel as indicated by the arrow. The second lens group L2 moves toward the image while increasing its distance from the first lens group L1. The third lens group L3 is fixed to the lens barrel. The fourth lens group L4 moves toward the object while decreasing its distance from the third lens group L3. The fifth lens group L5 moves toward the object while increasing its distance from the fourth lens group L4. The sixth lens group L6 is fixed to the lens barrel. The aperture SP is located in the third lens group L3.

[0160] The IS lens group is a bonded positive lens formed by joining a negative meniscus lens with a convex surface facing the object side and a biconvex positive lens. It moves so that it has a component in a direction approximately perpendicular to the optical axis, displacing the image in a direction approximately perpendicular to the optical axis, thereby correcting image blur when the entire zoom lens vibrates. In other words, it performs image stabilization. Focusing is performed by moving the fifth lens group L5 toward the image side.

[0161] (Numerical Example 3) Unit: mm Surface Data Surface Number rd nd νd Effective Diameter 1 94.137 1.50 2.00069 25.5 60.19 2 59.619 8.56 1.59522 67.7 56.53 3 1499.871 0.15 54.88 4 54.869 6.02 1.59522 67.7 47.97 5 283.068 (Variable) 46.61 6* -5164.202 0.05 1.53344 52.7 36.46 7 522.822 1.15 1.80400 46.5 36.38 8 22.102 7.78 28.57 9 -50.986 1.00 1.77250 49.6 27.99 10 66.747 0.22 27.00 11 47.531 5.30 1.84666 23.8 26.93 12 -54.818 1.15 26.38 13 -33.750 0.90 1.77250 49.6 26.25 14 -111.140 (variable) 25.80 15 41.088 3.31 1.51633 64.1 21.33 16 -114.416 0.15 21.41 17 118.858 1.73 1.84666 23.8 21.41 18 -243.628 1.00 2.00100 29.1 21.32 19 113.369 2.00 21.19 20 (aperture) ∞ 8.05 21.26 21 53.976 1.00 2.00069 25.5 21.66 22 23.608 5.84 1.83481 42.7 21.21 23 -148.516 2.87 20.89 24 -38.687 0.95 1.62041 60.3 20.27 25 121.625 (variable) 20.31 26* 40.932 8.85 1.58313 59.4 32.54 27* -47.642 1.63 33.21 28 1038.337 1.00 2.05090 26.9 33.14 29 56.955 10.14 1.49700 81.5 33.06 30 -35.609 (variable) 33.73 31 84.549 7.44 1.92286 20.9 31.31 32 -33.137 0.90 2.00100 29.1 30.62 33 32.291 (variable) 28.62 34 -73.199 1.00 1.67270 32.1 33.86 35 44.796 6.38 2.00100 29.1 37.38 36 -366.942 (Variable) 37.81 Image plane ∞ Aspherical data 6th plane K = 0.00000e+00 A 4= 4.60966e-06 A 6=-1.07881e-08 A 8= 4.35578e-11 A10=-1.07997e-13 A12= 1.09275e-16 26th plane K = 0.00000e+00 A 4=-4.95344e-06 A 6=-7.10621e-10 A 8= 4.47414e-11 A10=-1.33591e-13 A12=-1.54267e-16 27th plane K = 0.00000e+00 A 4 = 9.88627e-06 A 6 = -8.87160e-09 A 8 = 6.36382e-11 A10 = -1.46197e-13 A12 = -1.75331e-16 Various Data Zoom Ratio 4.54 Wide-angle Intermediate Telephoto Focal Length 28.85 63.39 131.00 F-number 4.12 4.12 4.12 Half-angle 35.24 18.84 9.38 Image Height 20.38 21.64 21.64 Lens Length 183.50 183.50 183.50 BF 14.00 14.00 14.00 d 5 1.46 16.78 32.11 d14 32.15 16.82 1.50 d25 23.72 7.07 2.44 d30 4.12 2.48 5.78 d33 10.04 28.32 29.65 d36 14.00 14.00 14.00 Zoom lens group data group Starting plane Focal length 1 1 82.66 2 6 -20.90 3 15 66.05 4 26 35.25 5 31 -47.82 6 34 1066.28 [Example 4] In the lens cross-section of Example 4 in Figure 10, L1 is the first lens group with positive refractive power, L2 is the second lens group with negative refractive power (first intermediate lens group LM1), and L3 is the third lens group with positive refractive power (second intermediate lens group LM2). L4 is the fourth lens group with positive refractive power (third intermediate lens group LM3), L5 is the fifth lens group with negative refractive power, and L6 is the sixth lens group with positive refractive power. The fifth and sixth lens groups are the subsequent lens group LR.

[0162] The first lens group L1 consists of, in order from the object side, a bonded positive lens formed by joining a negative meniscus lens with its convex surface facing the object side and a positive meniscus lens with its convex surface facing the object side, and a positive meniscus lens with its convex surface facing the object side.

[0163] The second lens group L2 consists of, in order from the object side, a negative meniscus lens with a convex surface facing the object side and an aspherical surface formed on the object-side surface, a biconcave negative lens, a biconvex positive lens, and a negative meniscus lens with a concave surface facing the object side.

[0164] The third lens group L3 has, in order from the object side, a biconvex positive lens, a bonded negative lens formed by joining a biconvex lens and a biconcave lens, and a bonded positive lens formed by joining a negative meniscus lens with a convex surface facing the object side and a biconvex positive lens. On the image side of the bonded positive lens, a bonded negative lens formed by joining a biconcave negative lens and a positive meniscus lens with a convex surface facing the object side is arranged.

[0165] The fourth lens group L4 consists of a positive lens with a biconvex shape and aspherical surfaces formed on both sides, and a bonded positive lens formed by joining a negative meniscus lens with a convex surface facing the object side and the biconvex positive lens.

[0166] The fifth lens group L5 is composed of a bonded negative lens formed by joining a biconvex positive lens and a biconcave negative lens.

[0167] The sixth lens group L6 is composed of a bonded positive lens formed by joining a double concave negative lens and a double convex positive lens.

[0168] In Example 4, when zooming from the wide-angle end to the telephoto end, the first lens group L1 is fixed to the lens barrel as indicated by the arrow. The second lens group L2 moves toward the image side while increasing its distance from the first lens group L1. The third lens group L3 is fixed to the lens barrel.

[0169] The fourth lens group L4 moves toward the object while decreasing its distance from the third lens group L3. The fifth lens group L5 moves toward the object while increasing its distance from the fourth lens group L4. The sixth lens group L6 is fixed to the lens barrel. The aperture SP is located in the third lens group L3.

[0170] The IS lens group is a bonded negative lens formed by joining a double concave negative lens and a positive meniscus lens with its convex surface facing the object. It moves so that it has a component approximately perpendicular to the optical axis, displacing the image approximately perpendicular to the optical axis and correcting image blur when the entire zoom lens vibrates. In other words, it performs vibration isolation. Focusing is achieved by moving the fifth lens group L5 toward the image.

[0171] (Numerical Example 4) Unit: mm Surface Data Surface Number rd nd νd Effective Diameter 1 80.838 1.50 2.00069 25.5 61.09 2 54.297 9.54 1.59522 67.7 58.08 3 610.395 0.15 56.91 4 52.324 6.66 1.59522 67.7 50.59 5 220.850 (Variable) 48.97 6* -1104.096 0.05 1.53344 52.7 33.70 7 296.635 1.15 1.80400 46.5 33.62 8 18.354 8.08 25.55 9 -36.366 1.00 1.77250 49.6 24.83 10 69.872 0.39 24.19 11 49.309 4.40 1.84666 23.8 24.20 12 -55.609 1.79 23.83 13 -25.370 0.90 1.77250 49.6 23.70 14 -34.181 (variable) 23.78 15 54.873 2.39 1.51633 64.1 20.16 16 -199.078 0.15 20.29 17 76.057 3.23 1.74077 27.8 20.41 18 -45.580 1.00 2.00100 29.1 20.34 19 1268.405 2.00 20.37 20 (aperture) ∞ 11.39 20.47 21 41.297 1.00 2.00069 25.5 21.07 22 19.980 5.10 1.72916 54.7 20.48 23 -142.477 1.28 20.30 24 -351.985 0.95 1.83400 37.2 19.89 25 20.569 3.79 2.00069 25.5 19.47 26 41.623 (variable) 18.98 27* 31.790 7.66 1.58313 59.4 33.34 28* -169.426 0.15 33.60 29 171.411 1.00 2.05090 26.9 33.68 30 47.881 9.55 1.49700 81.5 33.45 31 -36.156 (variable) 33.87 32 78.378 8.11 1.92286 20.9 31.72 33 -30.760 0.90 2.00100 29.1 30.95 34 29.182 (variable) 28.59 35 -160.464 1.00 1.85025 30.1 33.28 36 27.905 11.24 2.00100 29.1 37.15 37 -366.942 (Variable) 38.00 Image plane ∞ Aspherical data 6th plane K = 0.00000e+00 A 4 = 1.15199e-05 A 6 = -3.00316e-08 A 8 = 1.17137e-10 A10 = -3.23728e-13 A12 = 3.95951e-16 27th plane K = 0.00000e+00 A 4 = -3.40518e-06 A 6 = -1.67219e-08 A 8 = 1.70298e-10 A10 = -7.03157e-13 A12 = 6.36132e-16 28th plane K = 0.00000e+00 A 4 = 1.18422e-05 A 6 = -3.04861e-08 A 8 = 2.53215e-10 A10 = -9.91356e-13 A12 = 9.83440e-16 Various data Zoom ratio 4.03 Wide angle Intermediate Telephoto Focal length 28.85 56.76 116.40 F-number 4.12 4.12 4.12 Half-angle of view 36.37 20.87 10.53 Image height 21.64 21.64 21.64 Lens length 183.50 183.50 183.50 BF 14.00 14.00 14.00 d 5 1.29 15.99 30.69 d14 30.90 16.20 1.50 d26 18.24 5.81 1.00 d31 2.44 3.20 6.50 d34 9.11 20.79 22.30 d37 14.00 14.00 14.00 Zoom Lens Group Data Group Starting Surface Focal Length 1 1 79.69 2 6 19.66 3 15 58.41 4 27 36.32 5 32 43.30 6 35 350.52 [Example 5] In the lens cross-sectional view of Example 5 in Figure 13, L1 is the first lens group with positive refractive power, L2 is the second lens group with negative refractive power (first intermediate lens group LM1), and L3 is the third lens group with positive refractive power (second intermediate lens group LM2). L4 is the fourth lens group with positive refractive power (third intermediate lens group LM3), L5 is the fifth lens group with negative refractive power, L6 is the sixth lens group with negative refractive power, and L7 is the sixth lens group with positive refractive power.

[0172] The fifth to seventh lens groups constitute the subsequent lens group LR.

[0173] The first lens group L1 consists of, in order from the object side, a bonded positive lens formed by joining a negative meniscus lens with its convex surface facing the object side and a positive meniscus lens with its convex surface facing the object side, and a positive meniscus lens with its convex surface facing the object side.

[0174] The second lens group L2 consists of, in order from the object side, a negative lens with a biconcave shape and an aspherical surface formed on the object-side surface, a biconcave negative lens, a biconvex positive lens, and a negative meniscus lens with a concave surface facing the object side.

[0175] The third lens group L3 consists of, in order from the object side, a biconvex positive lens, a negative meniscus lens with its convex surface facing the object, a bonded positive lens formed by joining a negative meniscus lens with its convex surface facing the object and a biconvex positive lens, and a bonded negative lens formed by joining a biconcave negative lens and a biconvex positive lens.

[0176] The fourth lens group L4 consists of a positive lens with a biconvex shape and aspherical surfaces formed on both sides, and a bonded positive lens formed by joining a negative meniscus lens with a convex surface facing the object side and the biconvex positive lens.

[0177] The fifth lens group L5 is composed of a bonded negative lens formed by joining a biconvex positive lens and a biconcave negative lens.

[0178] The sixth lens group L6 consists of a negative meniscus lens with its concave surface facing the object. The seventh lens group L7 consists of a biconvex lens.

[0179] In Example 5, when zooming from the wide-angle end to the telephoto end, the first lens group L1 is fixed to the lens barrel as indicated by the arrow. The second lens group L2 moves toward the image side while increasing its distance from the first lens group L1. The third lens group L3 is fixed to the lens barrel.

[0180] The fourth lens group L4 moves toward the object while decreasing its distance from the third lens group L3. The fifth lens group L5 moves toward the object while increasing its distance from the fourth lens group L4. The sixth lens group L6 moves toward the object while increasing its distance from the fifth lens group L5. The seventh lens group L7 is fixed to the lens barrel. The aperture SP is located in the third lens group L3.

[0181] The IS lens group is a bonded positive lens formed by joining a negative meniscus lens with a convex surface facing the object side and a biconvex positive lens. It moves so that it has a component in a direction approximately perpendicular to the optical axis, displacing the image in a direction approximately perpendicular to the optical axis, thereby correcting image blur when the entire zoom lens vibrates. In other words, it performs vibration isolation. Focusing is achieved by moving the fifth lens group L5 and the sixth lens group L6 toward the image side along different trajectories.

[0182] (Numerical Example 5) Unit: mm Surface Data Surface Number rd nd νd Effective Diameter 1 92.732 1.50 2.00069 25.5 60.04 2 59.148 8.59 1.59522 67.7 56.37 3 1473.295 0.15 54.70 4 55.968 5.71 1.59522 67.7 47.10 5 284.869 (Variable) 45.80 6* -328.146 0.05 1.53344 52.7 35.56 7 -12397.708 1.15 1.80400 46.5 35.49 8 22.684 7.18 28.15 9 ​​-55.432 1.00 1.77250 49.6 27.64 10 61.992 0.38 26.64 11 48.383 4.73 1.84666 23.8 26.58 12 -68.500 1.57 26.09 13 -32.577 0.90 1.77250 49.6 25.96 14 -64.136 (variable) 25.76 15 44.337 2.90 1.60562 43.7 21.36 16 -192.401 0.15 21.40 17 83.799 1.00 2.00100 29.1 21.40 18 54.208 2.57 21.22 19 (aperture) ∞ 2.52 21.42 20 64.533 1.00 2.00069 25.5 21.89 21 24.797 4.81 1.83481 42.7 21.62 22 -102.577 8.10 21.57 23 -34.264 0.95 1.83481 42.7 19.91 24 56.262 3.35 2.00069 25.5 20.42 25 -758.016 (variable) 20.68 26* 45.722 8.47 1.58313 59.4 32.14 27* -48.760 1.57 32.88 28 87.834 1.00 2.05090 26.9 33.08 29 35.139 11.07 1.49700 81.5 32.47 30 -39.206 (variable) 32.96 31 60.301 5.75 1.92286 20.9 30.54 32 -65.953 0.90 2.00100 29.1 29.74 33 30.049 (variable) 27.66 34 -35.607 1.00 1.72825 28.5 29.77 35 -238.938 (variable) 31.98 36 85.738 3.86 2.00100 29.1 37.76 37 -366.942 (variable) 38.00 Image plane ∞ Aspherical data 6th plane K = 0.00000e+00 A 4 = 6.49833e-06 A 6 = -1.03166e-08 A 8 = 3.07509e-11 A10 = -8.07863e-14 A12 = 9.55342e-17 26th plane K = 0.00000e+00 A 4 = -4.95315e-06 A 6 = -3.85148e-09 A 8 = 7.65220e-11 A10 = -2.47205e-13 A12 = 1.54283e-16 27th surface K = 0.00000e+00 A 4 = 6.96979e-06 A 6 = -7.05051e-09 A 8 = 5.48977e-11 A10 = -1.11307e-13 A12 = -6.66181e-17 Various data Zoom ratio 4.54 Wide angle Intermediate Telephoto Focal length 28.84 65.44 131.00 F-number 4.12 4.12 4.12 Half-angle of view 35.28 18.29 9.38 Image height 20.41 21.64 21.64 Lens length 183.50 183.50 183.50 BF 18.07 18.07 18.07 d 5 1.77 17.37 32.98 d14 32.72 17.11 1.50 d25 21.06 4.80 2.59 d30 3.80 1.55 6.48 d33 9.92 28.59 22.99 d35 2.32 2.14 5.04 d37 18.07 18.07 18.07 Zoom lens group data group Starting plane Focal length 1 1 83.39 2 6 -21.31 3 15 78.53 4 26 33.40 5 31 -57.46 6 34 -57.58 7 36 69.73 [Example 6] In the lens cross-sectional view of Example 6 in Figure 16, L1 is the first lens group with positive refractive power, L2 is the second lens group with negative refractive power (first intermediate lens group LM1), and L3 is the third lens group with positive refractive power (second intermediate lens group LM2). L4 is the fourth lens group (third intermediate lens group LM3) with positive refractive power, L5 is the fifth lens group with positive refractive power, L6 is the sixth lens group with negative refractive power, and L7 is the seventh lens group with negative refractive power. Lens groups 5 through 7 constitute the subsequent lens group LR.

[0183] The first lens group L1 consists of, in order from the object side, a bonded positive lens formed by joining a negative meniscus lens with its convex surface facing the object side and a positive meniscus lens with its convex surface facing the object side, and a positive meniscus lens with its convex surface facing the object side.

[0184] The second lens group L2 consists of, in order from the object side, a negative lens with a biconcave shape and an aspherical surface formed on the object-side surface, a biconcave negative lens, a biconvex positive lens, and a negative meniscus lens with a concave surface facing the object side.

[0185] The third lens group L3 comprises, in order from the object side, a biconvex positive lens, a bonded negative lens formed by joining a biconvex positive lens and a biconcave negative lens, and a bonded positive lens formed by joining a negative meniscus lens with a convex surface facing the object side and a biconvex positive lens. A bonded negative lens formed by joining a biconcave negative lens and a biconvex positive lens is positioned on the image side of the bonded positive lens.

[0186] The fourth lens group L4 consists of positive lenses with a biconvex shape and aspherical surfaces formed on both sides. The fifth lens group L5 consists of a bonded positive lens formed by joining a negative meniscus lens with its convex surface facing the object side and a biconvex positive lens.

[0187] The sixth lens group L6 is composed of a bonded negative lens formed by joining a biconvex positive lens and a biconcave negative lens. The seventh lens group L7 is composed of a bonded negative lens formed by joining a biconcave negative lens and a biconvex positive lens.

[0188] In Example 6, when zooming from the wide-angle end to the telephoto end, the first lens group L1 is fixed to the lens barrel as indicated by the arrow. The second lens group L2 moves toward the image side while increasing its distance from the first lens group L1. The third lens group L3 is fixed to the lens barrel.

[0189] The fourth lens group L4 moves toward the object while decreasing its distance from the third lens group L3. The fifth lens group L5 moves toward the object while increasing its distance from the fourth lens group L4. The sixth lens group L6 moves toward the object while increasing its distance from the fifth lens group L5. The seventh lens group L7 is fixed to the lens barrel. The aperture SP is located in the third lens group L3.

[0190] The IS lens group is a bonded positive lens formed by joining a negative meniscus lens with a convex surface facing the object side and a biconvex positive lens. It moves so that it has a component in a direction approximately perpendicular to the optical axis, displacing the image in a direction approximately perpendicular to the optical axis, thereby correcting image blur when the entire zoom lens vibrates. In other words, it performs image stabilization. Focusing is performed by moving the sixth lens group L6 toward the image side.

[0191] (Numerical Example 6) Unit: mm Surface Data Surface Number rd nd νd Effective Diameter 1 90.277 1.50 2.00069 25.5 59.97 2 58.489 8.46 1.59522 67.7 56.52 3 766.678 0.15 55.26 4 56.295 6.14 1.59522 67.7 48.64 5 325.584 (Variable) 47.49 6* -626.769 0.05 1.53344 52.7 36.58 7 1503.091 1.15 1.80400 46.5 36.50 8 22.843 7.23 28.83 9 -63.917 1.00 1.77250 49.6 28.32 10 65.179 0.15 27.20 11 45.400 4.92 1.84666 23.8 27.07 12 -73.310 1.52 26.46 13 -34.632 0.90 1.77250 49.6 26.31 14 -96.715 (variable) 25.89 15 43.255 3.15 1.51633 64.1 20.57 16 -99.481 0.15 20.66 17 91.138 2.32 1.80518 25.4 20.63 18 -92.951 1.00 2.00100 29.1 20.50 19 66.757 2.30 20.32 20 (aperture) ∞ 4.15 20.55 21 61.827 1.00 2.00069 25.5 21.33 22 24.686 4.63 1.83481 42.7 21.09 23 -105.918 5.60 21.05 24 -37.445 0.95 1.80400 46.5 20.04 25 58.557 3.27 2.00069 25.5 20.46 26 -1047.377 (variable) 20.65 27* 39.446 9.10 1.58313 59.4 33.03 28* -50.755 (variable) 33.48 29 86.659 1.00 2.05090 26.9 33.10 30 31.799 10.15 1.49700 81.5 32.23 31 -42.075 (variable) 32.51 32 66.687 6.02 1.92286 20.9 30.03 33 -44.980 0.90 2.00100 29.1 29.38 34 29.817 (variable) 27.31 35 -49.179 1.00 1.68893 31.1 31.45 36 42.931 5.99 2.00100 29.1 35.48 37 -366.942 (Variable) 35.97 Image plane ∞ Aspherical data 6th plane K = 0.00000e+00 A 4= 4.64558e-06 A 6=-8.75218e-09 A 8= 3.25797e-11 A10=-7.97868e-14 A12= 8.18321e-17 27th plane K = 0.00000e+00 A 4=-4.98542e-06 A 6= 1.22225e-09 A 8= 3.58713e-11 A10 = -1.25533e-13 A12 = 5.34137e-17 28th surface K = 0.00000e+00 A 4 = 8.09090e-06 A 6 = -6.14400e-09 A 8 = 4.31741e-11 A10 = -1.03719e-13 A12 = -1.28248e-17 Various data Zoom ratio 4.54 Wide angle Intermediate Telephoto Focal length 28.84 64.58 131.00 F-number 4.12 4.12 4.12 Half-angle of view 34.94 18.52 9.38 Image height 20.15 21.64 21.64 Lens length 183.50 183.50 183.50 BF 14.73 14.73 14.73 d 5 1.59 17.06 32.53 d14 32.44 16.97 1.50 d26 22.08 6.57 3.35 d28 1.83 2.06 2.39 d31 4.74 2.04 4.21 d34 10.24 28.22 28.95 d37 14.73 14.73 14.73 Zoom lens group data group Starting plane Focal length 1 1 83.15 2 6 -21.55 3 15 78.30 4 27 39.53 5 29 143.50 6 32 -50.62 7 35 -258.12 [Example 7] In the lens cross-sectional view of Example 7 in Figure 19, L1 is the first lens group with positive refractive power, L2 is the second lens group with negative refractive power, and L3 is the third lens group with positive refractive power (the second and third lens groups are the first intermediate lens group LM1). L4 is the fourth lens group with positive refractive power (second intermediate lens group LM2), L5 is the fifth lens group with positive refractive power (third intermediate lens group LM3), L6 is the sixth lens group with negative refractive power, and L7 is the seventh lens group with negative refractive power. The sixth and seventh lens groups constitute the subsequent lens group LR.

[0192] The first lens group L1 consists of, in order from the object side, a bonded positive lens formed by joining a negative meniscus lens with its convex surface facing the object side and a positive meniscus lens with its convex surface facing the object side, and a positive meniscus lens with its convex surface facing the object side.

[0193] The second lens group L2 consists of, in order from the object side, a negative lens with a biconcave shape and an aspherical surface formed on the object-side surface, a biconcave negative lens, a biconvex positive lens, and a negative meniscus lens with a concave surface facing the object side.

[0194] The third lens group L3 consists of, in order from the object side, a biconvex positive lens, a bonded negative lens formed by joining a biconvex positive lens and a biconcave negative lens. The fourth lens group L4 consists of a bonded positive lens formed by joining a negative meniscus lens with its convex surface facing the object side and a biconvex positive lens, and a bonded negative lens formed by joining a biconcave negative lens and a biconvex positive lens.

[0195] The fifth lens group L5 consists of a positive lens with a biconvex shape and aspherical surfaces formed on both sides, and a bonded positive lens formed by joining a negative meniscus lens with a convex surface facing the object side and the biconvex positive lens.

[0196] The sixth lens group L6 is composed of a bonded negative lens formed by joining a biconvex positive lens and a biconcave negative lens.

[0197] The seventh lens group L7 is composed of a bonded negative lens formed by joining a double concave negative lens and a double convex positive lens. In Embodiment 7, when zooming from the wide-angle end to the telephoto end, the first lens group L1 is fixed to the lens barrel as indicated by the arrow. The second lens group L2 moves toward the image while increasing its distance from the first lens group L1. The third lens group L3 moves toward the image while decreasing its distance from the second lens group L2. The fourth lens group L4 is fixed to the lens barrel.

[0198] The fifth lens group L5 moves toward the object while reducing its distance from the fourth lens group L4. The sixth lens group L6 also moves toward the object while reducing its distance from the fifth lens group L5. The seventh lens group L7 is fixed to the lens barrel. The aperture SP is located in the fourth lens group L4.

[0199] The IS lens group is a bonded positive lens formed by joining a negative meniscus lens with a convex surface facing the object side and a biconvex positive lens. It moves so that it has a component in a direction approximately perpendicular to the optical axis, displacing the image in a direction approximately perpendicular to the optical axis, thereby correcting image blur when the entire zoom lens vibrates. In other words, it performs image stabilization. Focusing is performed by moving the sixth lens group L6 toward the image side.

[0200] (Numerical Example 7) Unit: mm Surface Data Surface Number rd nd νd Effective Diameter 1 96.866 1.50 2.00069 25.5 60.36 2 62.022 8.35 1.59522 67.7 57.19 3 1333.617 0.15 55.96 4 58.352 6.03 1.59522 67.7 49.19 5 330.979 (Variable) 48.06 6* -895.545 0.05 1.53344 52.7 36.81 7 2099.367 1.15 1.80400 46.5 36.74 8 23.865 6.88 29.34 9 -77.459 1.00 1.77250 49.6 28.88 10 61.743 0.15 27.66 11 44.210 5.09 1.84666 23.8 27.50 12 -74.619 1.22 26.82 13 -39.416 0.90 1.77250 49.6 26.69 14 -397.651 (variable) 25.96 15 44.739 3.12 1.51633 64.1 20.37 16 -92.346 0.15 20.49 17 139.127 2.13 1.80518 25.4 20.50 18 -83.378 1.00 2.00100 29.1 20.44 19 91.555 (Variable) 20.37 20 (Aperture) ∞ 3.49 20.62 21 64.488 1.00 2.00069 25.5 21.36 22 25.250 4.61 1.83481 42.7 21.15 23 -99.809 5.51 21.13 24 -35.988 0.95 1.80400 46.5 20.22 25 66.647 3.27 2.00069 25.5 20.71 26 -378.165 (variable) 20.95 27* 41.983 9.01 1.58313 59.4 33.04 28* -48.548 1.69 33.60 29 92.282 1.00 2.05090 26.9 33.39 30 33.370 11.33 1.49700 81.5 32.62 31 -40.081 (variable) 33.07 32 67.430 6.04 1.92286 20.9 30.32 33 -45.560 0.90 2.00100 29.1 29.66 34 30.526 (variable) 27.56 35 -45.583 1.00 1.68893 31.1 31.30 36 44.513 5.79 2.00100 29.1 35.39 37 -366.942 (Variable) 35.90 Image plane ∞ Aspherical data 6th plane K = 0.00000e+00 A 4= 3.32523e-06 A 6=-7.34101e-09 A 8= 3.11622e-11 A10=-8.02878e-14 A12= 8.18080e-17 27th plane K = 0.00000e+00 A 4=-4.85244e-06 A 6= 4.21067e-10 A 8= 4.15042e-11 A10 = -1.42932e-13 A12 = 7.30031e-17 28th plane K = 0.00000e+00 A 4 = 8.01999e-06 A 6 = -5.96094e-09 A 8 = 4.25670e-11 A10 = -1.01013e-13 A12 = -1.45457e-17 Various data Zoom ratio 4.54 Wide angle Intermediate Telephoto Focal length 28.85 63.94 131.00 F-number 4.12 4.12 4.12 Half-angle of view 34.92 18.69 9.38 Image height 20.14 21.64 21.64 Lens length 183.50 183.50 183.50 BF 14.00 14.00 14.00 d 5 1.61 17.53 33.44 d14 28.38 15.03 1.50 d19 7.03 4.46 2.08 d26 22.60 7.18 3.01 d31 5.09 1.84 4.10 d34 10.34 29.01 30.92 d37 14.00 14.00 14.00 Zoom lens group data group Starting plane Focal length 1 1 85.73 2 6 -21.26 3 15 98.35 4 20 406.55 5 27 34.01 6 32 -52.19 7 35 -191.41 [Example 8] In the lens cross-sectional view of Example 8 in Figure 22, L1 is the first lens group with positive refractive power, L2 is the second lens group with negative refractive power, and L3 is the third lens group with negative refractive power (the second and third lens groups are the first intermediate lens group LM1). L4 is the fourth lens group with positive refractive power (second intermediate lens group LM2), L5 is the fifth lens group with positive refractive power (third intermediate lens group LM3), L6 is the sixth lens group with negative refractive power, and L7 is the seventh lens group with negative refractive power. The sixth and seventh lens groups constitute the subsequent lens group LR.

[0201] The first lens group L1 consists of, in order from the object side, a bonded positive lens formed by joining a negative meniscus lens with its convex surface facing the object side and a positive meniscus lens with its convex surface facing the object side, and a positive meniscus lens with its convex surface facing the object side.

[0202] The second lens group L2 consists of, in order from the object side, a negative lens with a biconcave shape and an aspherical surface formed on the object-side surface, a biconcave negative lens, and a biconvex positive lens. The third lens group L3 consists of a negative meniscus lens with its concave surface facing the object side.

[0203] The third lens group L3 comprises, in order from the object side, a biconvex positive lens, a bonded negative lens formed by joining a biconvex positive lens and a biconcave negative lens, and a bonded positive lens formed by joining a negative meniscus lens with a convex surface facing the object side and a biconvex positive lens. A bonded negative lens formed by joining a biconcave negative lens and a biconvex positive lens is positioned on the image side of the bonded positive lens.

[0204] The fifth lens group L5 consists of a positive lens with a biconvex shape and aspherical surfaces formed on both sides, and a bonded positive lens formed by joining a negative meniscus lens with a convex surface facing the object side and the biconvex positive lens.

[0205] The sixth lens group L6 is composed of a bonded negative lens formed by joining a biconvex positive lens and a biconcave negative lens.

[0206] The seventh lens group L7 is composed of a bonded negative lens formed by joining a biconcave negative lens and a biconvex positive lens.

[0207] In Example 8, when zooming from the wide-angle end to the telephoto end, the first lens group L1 is fixed to the lens barrel as indicated by the arrow. The second lens group L2 moves toward the image while increasing its distance from the first lens group L1. The third lens group L3 moves toward the image while decreasing its distance from the second lens group L2. The fourth lens group L4 is fixed to the lens barrel.

[0208] The fifth lens group L5 moves toward the object while reducing its distance from the fourth lens group L4. The sixth lens group L6 also moves toward the object while reducing its distance from the fifth lens group L5. The seventh lens group L7 is fixed to the lens barrel. The aperture SP is located in the fourth lens group L4.

[0209] The IS lens group is a bonded positive lens formed by joining a negative meniscus lens with a convex surface facing the object side and a biconvex positive lens. It moves so that it has a component in a direction approximately perpendicular to the optical axis, displacing the image in a direction approximately perpendicular to the optical axis, thereby correcting image blur when the entire zoom lens vibrates. In other words, it performs image stabilization. Focusing is performed by moving the sixth lens group L6 toward the image side.

[0210] (Numerical Example 8) Unit: mm Surface Data Surface Number rd nd νd Effective Diameter 1 ∞ 1.50 68.70 2 94.128 1.50 2.00069 25.5 59.29 3 60.646 8.26 1.59522 67.7 55.68 4 925.015 0.15 53.72 5 57.685 6.02 1.59522 67.7 46.78 6 323.395 (Variable) 45.15 7* -400.574 1.20 1.80400 46.5 37.32 8 23.535 7.18 29.56 9 -73.375 1.00 1.77250 49.6 29.12 10 61.797 0.18 28.04 11 45.150 5.05 1.84666 23.8 27.95 12 -79.690 (variable) 27.36 13 -34.182 0.90 1.77250 49.6 24.45 14 -82.282 (variable) 24.07 15 45.472 3.37 1.51633 64.1 20.91 16 -75.526 0.15 21.00 17 97.529 2.64 1.80518 25.4 20.94 18 -65.680 1.00 2.00100 29.1 20.79 19 67.946 2.30 20.58 20 (aperture) ∞ 2.44 20.81 21 62.518 1.00 2.00069 25.5 21.32 22 24.678 4.64 1.83481 42.7 21.08 23 -103.287 3.15 21.04 24 -40.750 0.95 1.80400 46.5 20.53 25 57.763 3.29 2.00069 25.5 20.90 26 -3034.108 (variable) 21.06 27* 43.289 8.74 1.58313 59.4 33.10 28* -50.831 2.37 33.60 29 99.728 1.00 2.05090 26.9 33.32 30 34.454 11.13 1.49700 81.5 32.59 31 -39.364 (variable) 33.02 32 71.543 6.22 1.92286 20.9 30.13 33 -41.256 0.90 2.00100 29.1 29.46 34 30.673 (variable) 27.38 35 -45.792 1.00 1.68893 31.1 31.25 36 44.173 5.82 2.00100 29.1 35.37 37 -366.942 (Variable) 35.88 Image plane ∞ Aspherical data 7th plane K = 0.00000e+00 A 4= 3.51980e-06 A 6=-6.66394e-09 A 8= 2.49372e-11 A10=-5.97048e-14 A12= 5.76943e-17 27th plane K = 0.00000e+00 A 4=-4.26212e-06 A 6=-1.22453e-09 A 8= 4.40696e-11 A10 = -1.55352e-13 A12 = 9.58998e-17 28th plane K = 0.00000e+00 A 4 = 8.14403e-06 A 6 = -7.83620e-09 A 8 = 5.04990e-11 A10 = -1.36535e-13 A12 = 3.88366e-17 Various data Zoom ratio 4.54 Wide angle Intermediate Telephoto Focal length 28.84 64.76 131.00 F-number 4.12 4.12 4.12 Half-angle of view 34.84 18.47 9.38 Image height 21.64 21.64 21.64 Lens length 185.00 185.00 185.00 BF 14.00 14.00 14.00 d 6 1.83 17.80 33.77 d12 3.67 2.67 2.67 d14 32.43 17.47 1.50 d26 22.73 6.94 3.94 d31 5.09 1.71 4.15 d34 10.19 29.37 29.92 d37 14.00 14.00 14.00 Zoom lens group data group Starting plane Focal length 1 1 85.49 2 7 -38.17 3 13 -76.31 4 15 79.28 5 27 35.13 6 32 -49.93 7 35 -196.00 [Example 9] In the cross-sectional view of the lens of Example 9 in Figure 25, L1 is the first lens group with positive refractive power, L2 is the second lens group with negative refractive power (first intermediate lens group LM1), and L3 is the third lens group with positive refractive power (second intermediate lens group LM2). L4 is the fourth lens group with positive refractive power (third intermediate lens group LM3), L5 is the fifth lens group with negative refractive power, and L6 is the sixth lens group with negative refractive power. The fifth and sixth lens groups constitute the subsequent lens group LR.

[0211] The first lens group L1 consists of, in order from the object side, a bonded positive lens formed by joining a negative meniscus lens with its convex surface facing the object side and a positive meniscus lens with its convex surface facing the object side, and a positive meniscus lens with its convex surface facing the object side.

[0212] The second lens group L2 consists of, in order from the object side, a negative lens with a biconcave shape and an aspherical surface formed on the object-side surface, a biconcave negative lens, a biconvex positive lens, and a negative meniscus lens with a concave surface facing the object side.

[0213] The third lens group L3 consists of, in order from the object side, a positive meniscus lens with its convex surface facing the object, a bonded positive lens formed by joining a negative meniscus lens with its convex surface facing the object and a positive meniscus lens with its convex surface facing the object.

[0214] The fourth lens group L4 consists of a positive lens with a biconvex shape and aspherical surfaces formed on both sides, and a bonded positive lens formed by joining a biconcave negative lens and a biconvex positive lens.

[0215] The fifth lens group L5 is composed of a bonded negative lens formed by joining a biconvex positive lens and a biconcave negative lens.

[0216] The sixth lens group L6 is composed of a bonded negative lens formed by joining a biconcave negative lens and a biconvex positive lens.

[0217] In Example 9, when zooming from the wide-angle end to the telephoto end, the first lens group L1 is fixed to the lens barrel as indicated by the arrow. The second lens group L2 moves toward the image while increasing its distance from the first lens group L1. The third lens group L3 is fixed to the lens barrel. The fourth lens group L4 moves toward the object while decreasing its distance from the third lens group L3. The fifth lens group L5 moves toward the object while increasing its distance from the fourth lens group L4. The sixth lens group L6 is fixed to the lens barrel. The aperture SP is located in the third lens group L3.

[0218] Focusing is achieved by moving the fifth lens group, L5, towards the image.

[0219] (Numerical Example 9) Unit: mm Surface Data Surface Number rd nd νd Effective Diameter 1 102.809 1.50 1.85478 24.8 58.97 2 62.532 7.74 1.59522 67.7 55.38 3 1115.014 0.15 53.80 4 58.873 5.32 1.59522 67.7 47.21 5 266.316 (Variable) 45.95 6* -460.445 0.05 1.53344 52.7 33.85 7 -4719.483 1.15 1.83481 42.7 33.79 8 20.865 7.08 26.90 9 -54.444 1.00 1.75500 52.3 26.51 10 61.608 0.15 25.85 11 42.370 4.81 1.84666 23.8 25.87 12 -71.337 1.10 25.43 13 -38.456 0.90 1.77250 49.6 25.34 14 -96.617 (Variable) 25.05 15 (Aperture) ∞ 4.89 21.87 16* 26.563 4.04 1.64769 33.8 25.48 17 88.904 1.41 25.20 18 44.233 1.00 2.00100 29.1 25.02 19 19.391 5.84 1.51742 52.4 23.92 20 209.539 (variable) 24.01 21* 37.981 5.65 1.58313 59.4 24.99 22* -78.546 2.21 25.39 23 -193.967 1.00 1.85478 24.8 25.70 24 52.950 8.86 1.53996 59.5 26.10 25 -26.005 (variable) 27.02 26 106.231 4.91 1.92286 20.9 25.26 27 -33.078 0.90 1.91650 31.6 24.85 28 27.313 (variable) 23.39 29 -107.013 1.00 1.80518 25.4 34.81 30 109.568 3.13 2.00100 29.1 36.19 31 -366.942 (variable) 36.51 Image plane ∞ Aspherical data 6th plane K = 0.00000e+00 A 4= 5.32801e-06 A 6=-1.21119e-08 A 8= 3.64359e-11 A10=-7.12135e-14 A12= 5.54925e-17 Surface 16 K = 0.00000e+00 A 4=-2.72885e-06 A 6=-3.19037e-09 A 8= 6.62045e-11 A10=-4.00482e-13 A12= 7.65965e-16 21st side K = 0.00000e+00 A 4= 2.43569e-07 A 6=-9.92478e-09 A 8= 6.48752e-11 A10=-7.24622e-13 A12=-1.91392e-15 22nd side K = 0.00000e+00 A 4= 2.20287e-05 A 6=-1.28583e-08 A 8= 1.71061e-10 A10=-1.51641e-12 A12= 1.83054e-17 Various Data Zoom Ratio 4.54 Wide-angle Intermediate Telephoto Focal Length 28.87 60.88 131.00 F-number 4.12 4.12 4.12 Half-angle 35.29 19.56 9.38 Image Height 20.43 21.64 21.64 Lens Length 177.50 177.50 177.50 BF 14.00 14.00 14.00 d 5 2.54 18.69 34.85 d14 33.81 17.65 1.49 d20 24.74 8.14 2.00 d25 2.72 2.31 5.83 d28 23.92 40.94 43.55 d31 14.00 14.00 14.00 Zoom lens group data group Starting plane Focal length 1 1 87.49 2 6 -20.32 3 15 72.29 4 21 33.36 5 26 -42.02 6 29 -337.19. [Modification] In contrast to Example 1, the second lens group L2 may be composed of one negative lens or two negative lenses. This configuration makes it easier to reduce the weight of the second lens group L2.

[0220] In the optical system of each embodiment, it is preferable to deposit a fluorine coating on the object-side lens surface of the lens positioned closest to the object and on the image-side lens surface of the lens positioned closest to the image. Since the object-side lens surface of the lens positioned closest to the object and the image-side lens surface of the lens positioned closest to the image are more likely to be exposed to the outside world, depositing a fluorine coating enhances water and oil repellency, suppresses flare, and allows for high optical performance.

[0221] In particular, since the lens surface on the object side of the lens positioned closest to the object has a large diameter, it is preferable to deposit a fluorine coating on it.

[0222] In the cemented lens arranged in the optical system of each embodiment, it is preferable that the positive and negative lenses constituting at least one cemented lens are bonded together with an adhesive having a thickness of 0.005 mm or more and 0.05 mm or less along the optical axis. If it is less than 0.005 mm, it is prone to peeling, and if it is greater than 0.03 mm, the distance along the optical axis from the lens surface closest to the object to the lens surface closest to the image becomes longer, thus increasing the overall length of the lens. More preferably, it is desirable to satisfy the condition of 0.008 mm or more and 0.02 mm or less.

[0223] At least one lens arranged in the optical system of each embodiment is provided with an anti-reflective coating to prevent reflection, and the anti-reflective coating is composed of multiple films. Here, it is preferable that the anti-reflective coating PC has a refractive index of 1.32 or less when Nd is the refractive index of the film closest to the air interface with respect to the d line.

[0224] By setting Nd to 1.32 or less, the refractive index difference with air can be reduced, which in turn reduces light reflection and thus reduces ghosting.

[0225] Specific examples of the configuration of the anti-reflective coating PC include, but are not limited to, the multilayer film using the wet method described in Japanese Patent Publication No. 2012-230211 and Japanese Patent Publication No. 2014-95877. More preferably, ghosting can be further reduced by setting Nd to 1.30 or less.

[0226] In this case, it is preferable to apply an anti-reflective coating PC to the image-side lens surface of the negative lens with its concave surface facing the image side, among the negative lenses arranged in the optical system. Light reflected by a negative lens with its concave surface facing the image side tends to be reflected at a large angle with respect to the normal direction of the lens surface of the negative lens with its concave surface facing the image side, so the reflectivity tends to be high. Also, light reflected by a negative lens with its concave surface facing the image side tends to be focused at the image plane, so ghosting is likely to be noticeable. Therefore, by applying an anti-reflective coating PC to the image-side lens surface of a negative lens with its concave surface facing the image side, ghosting can be reduced.

[0227] The various values ​​in each numerical example are summarized in Table 1 below.

[0228]

[0229] Next, an embodiment using the zoom lens of this disclosure as an imaging optical system will be described with reference to Figure 28.

[0230] In Figure 28, 10 is a diagram showing an example of an imaging device, 11 is an imaging optical system composed of the zoom lens of this disclosure, and 12 is a solid-state image sensor (photoelectric conversion element) such as a CCD sensor or CMOS sensor that receives the subject image formed by the imaging optical system 11. Also, 13 is a recording means for recording the subject image received by the image sensor 12, and 14 is a viewfinder for observing the subject image displayed on an unshown display element.

[0231] The above-mentioned display element is composed of a liquid crystal panel or the like, and displays an image of the subject formed on the image sensor 12.

[0232] By applying the zoom lens of this disclosure to optical equipment such as digital cameras, optical equipment with high optical performance can be realized.

[0233] Furthermore, this disclosure can also be applied to SLR (Single Lens Reflex) cameras without a quick-return mirror.

[0234] Furthermore, the zoom lens described herein can also be applied to video cameras.

[0235] While preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to these embodiments, and various modifications and changes are possible within the scope of its essence.

Claims

The zoom lens comprises, in order from the object side, a first lens group L1 having positive refractive power, a first intermediate lens group LM1 having negative refractive power as a whole, a second intermediate lens group LM2 having positive refractive power, a third intermediate lens group LM3 having positive refractive power, and a lens group LR having negative refractive power as a whole. The spacing between each lens group changes during zooming, and the first lens group L1 and the second intermediate lens group LM2 are fixed relative to the image plane. When mM1 is the amount of movement of the lens group with the largest movement among the first intermediate lens group LM1, mM3 is the amount of movement of the third intermediate lens group LM3, f1 is the focal length of the first lens group L1, and fM1w is the focal length of the first intermediate lens group LM1 at the wide-angle end, -2.2<mM1 / mM3<-1.0 -5.0<f1 / fM1w<-1.4 A zoom lens characterized by satisfying the following conditional equation. The zoom lens according to claim 1, characterized in that the spacing between six or more lens groups changes during zooming. 　 The zoom lens according to claim 1 or 2, characterized in that the lens group positioned closest to the image plane is fixed to the image plane during zooming. 　 The zoom lens according to any one of claims 1 to 3, characterized in that the third intermediate lens group LM3 is composed of three or fewer lenses. 　 The zoom lens according to any one of claims 1 to 4, characterized in that the lens group LR has a focusing lens group. 　 A zoom lens according to any one of claims 1 to 5, characterized in that the number of moving lens groups is four or less during zooming. 　 When the focal length of the first lens group L1 is f1 and the focal length of the entire lens system at the wide-angle end is fw, 2.2<f1 / fw<3.8 A zoom lens according to any one of claims 1 to 6, characterized in that it satisfies the following conditional expression. 　 When the focal length of the first lens group L1 is f1 and the focal length of the entire lens system at the telephoto end is ft, 0.40<f1 / ft<1.0 A zoom lens according to any one of claims 1 to 7, characterized in that it satisfies the following conditional expression. 　 The first intermediate lens group LM1 has a second lens group L2 that is positioned closest to the object, When the focal length of the second lens group L2 is f2 and the focal length of the entire lens system at the wide-angle end is fw, -1.6<f2 / fw<-0.40 A zoom lens according to any one of claims 1 to 8, characterized in that it satisfies the following conditional expression. 　 The first intermediate lens group LM1 has a second lens group L2 that is positioned closest to the object, When the focal length of the second lens group L2 is f2 and the focal length of the entire lens system at the telephoto end is ft, -0.40<f2 / ft<-0.10 A zoom lens according to any one of claims 1 to 9, characterized in that it satisfies the following conditional expression. 　 When the focal length of the second intermediate lens group LM2 is fM2 and the focal length of the entire lens system at the wide-angle end is fw, 1.7<fM2 / fw<17 A zoom lens according to any one of claims 1 to 10, characterized in that it satisfies the following conditional expression. 　 When the focal length of the second intermediate lens group LM2 is fM2 and the focal length of the entire lens system at the telephoto end is ft, 0.30<fM2 / ft<3.3 A zoom lens according to any one of claims 1 to 11, characterized in that it satisfies the following conditional expression. 　 When the focal length of the third intermediate lens group LM3 is fM3 and the focal length of the entire lens system at the wide-angle end is fw, 0.90<fM3 / fw<1.7 A zoom lens according to any one of claims 1 to 12, characterized in that it satisfies the following conditional expression. 　 When the focal length of the third intermediate lens group LM3 is fM3 and the focal length of the entire lens system at the telephoto end is ft, 0.20<fM3 / ft<0.45 A zoom lens according to any one of claims 1 to 13, characterized in that it satisfies the following conditional expression. 　 When the focal length of the lens group LR at the wide-angle end is fRw, and the focal length of the entire lens system at the wide-angle end is fw, -2.5<fRw / fw<-1.0 A zoom lens according to any one of claims 1 to 14, characterized in that it satisfies the following conditional expression. 　 When the focal length of the lens group LR at the wide-angle end is fRw, and the focal length of the entire lens system at the telephoto end is ft, -0.65<fRw / ft<-0.20 A zoom lens according to any one of claims 1 to 15, characterized in that it satisfies the following conditional expression. 　 The first intermediate lens group LM1 has a second lens group L2 that is positioned closest to the object, When the focal length of the second lens group L2 is f2, and the amount of movement of the lens group with the largest amount of movement among the first intermediate lens group LM1 is mM1, -1.5<f2 / mM1<-0.40 A zoom lens according to any one of claims 1 to 16, characterized in that it satisfies the following conditional expression. 　 When the amount of movement of the lens group with the largest amount of movement among the first intermediate lens group LM1 is mM1, and the focal length of the entire lens system at the telephoto end is ft, 0.16<mM1 / ft<0.30 A zoom lens according to any one of claims 1 to 17, characterized in that it satisfies the following conditional expression. 　 When the focal length of the third intermediate lens group LM3 is fM3 and the amount of movement of the third intermediate lens group LM3 is mM3, -2.4<fM3 / mM3<-1.2 A zoom lens according to any one of claims 1 to 18, characterized in that it satisfies the following conditional expression. 　 When the amount of movement of the third intermediate lens group LM3 is mM3 and the focal length of the entire lens system at the telephoto end is ft, -0.24<mM3 / ft<-0.080 A zoom lens according to any one of claims 1 to 19, characterized in that it satisfies the following conditional expression. 　 When the focal length of the first intermediate lens group LM1 at the wide-angle end is fM1w and the focal length of the third intermediate lens group LM3 is fM3, -1.7<fM1w / fM3<-0.40 A zoom lens according to any one of claims 1 to 20, characterized in that it satisfies the following conditional expression. 　 When the focal length of the first intermediate lens group LM1 at the wide-angle end is fM1w and the focal length of the second intermediate lens group LM2 is fM2, -0.50<fM1w / fM2<0.00 A zoom lens according to any one of claims 1 to 21, characterized in that it satisfies the following conditional expression. 　 When the focal length of the first intermediate lens group LM1 at the wide-angle end is fM1w, and the focal length of the lens group LR at the wide-angle end is fRw, 0.20<fM1w / fRw<1.3 A zoom lens according to any one of claims 1 to 22, characterized in that it satisfies the following conditional expression. 　 When the focal length of the second intermediate lens group LM2 is fM2 and the focal length of the third intermediate lens group LM3 is fM3, 1.3<fM2 / fM3<14 A zoom lens according to any one of claims 1 to 23, characterized in that it satisfies the following conditional expression. 　 When the total optical length at the wide-angle end is Lw, the F-number at the wide-angle end is Fnow, and the back focus at the wide-angle end is skw, 39<Lw*Fnow / skw<57 A zoom lens according to any one of claims 1 to 24, characterized in that it satisfies the following conditional expression. 　 A zoom lens having a first lens group L1 having positive refractive power and positioned closest to the object, and a plurality of lens groups, characterized in that the first lens group L1 remains stationary during zooming. 　 An imaging device characterized by having a zoom lens according to any one of claims 1 to 26 and an image sensor that receives an image formed by the zoom lens.

Images