Zoom lens and imaging device

Abstract

To provide a zoom lens that has good optical performance even during vibration isolation despite its small size.SOLUTION: A zoom lens L0 comprises a plurality of lens groups consisting of a first lens group L1 having a negative refractive power and a rear group LR including two or more lens groups, which are arranged in order from an object side to an image side, wherein an interval between the adjacent lens groups changes in zooming. The rear group includes an aperture diaphragm SP, and a vibration isolation group LIS having a negative refractive power and moving in a direction orthogonal to an optical axis. The zoom lens has a focus group closer to the object side than the vibration isolation group. When a distance on the optical axis from the aperture diaphragm to an image surface at a wide-angle end is defined as DSPw, and a distance on the optical axis from the aperture diaphragm to a surface on the most object side of the vibration isolation group at the wide-angle end is defined as DISw, a condition of 0.40≤DISw / DSPw≤0.80 is satisfied.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a zoom lens. [Background technology]

[0002] As an imaging optical system used in imaging devices such as digital still cameras, video cameras, broadcast cameras, and security cameras, there is a demand for an optical system that is small and lightweight and has high optical performance even if the amount of image blur correction is large. Patent Document 1 discloses a zoom lens having a subsequent lens group including a first lens group with negative refractive power, a second lens group with positive refractive power, and an anti-vibration lens group, which are arranged in order from the object side to the image side. The anti-vibration lens group performs OIS, which reduces (corrects) image blur caused by shaking of the imaging device due to hand shake or the like (hereinafter referred to as camera shake) by moving (shifting) in a direction perpendicular to the optical axis. In addition, the image sensor that captures the subject image formed by the imaging optical system can perform IIS, which corrects image blur by shifting in a direction perpendicular to the optical axis. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-36249 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a central projection type imaging optical system, the amount of movement of the image point on the image plane due to camera shake differs between the center and periphery of the image plane. In particular, the wider the angle of the imaging optical system, the greater the amount of movement of the image point in the periphery compared to the center. For this reason, in an ultra-wide-angle zoom lens with an angle of view exceeding 100°, a lot of image shake remains in the periphery.

[0005] Figure 2(A) shows the ratio of the amount of movement and direction of each image point when image blur in the -X direction occurs in the center due to camera shake (angular shake). Figure 2(B) shows the amount of residual image blur (amount of image point movement) and direction at each image point in the periphery when the image blur in the center shown in Figure 2(A) is corrected by IIS. As shown in Figure 2(A), the amount of image point movement is larger in the periphery than in the center. For this reason, as shown in Figure 2(B), a large amount of residual image blur remains in the periphery compared to the center where image blur is well corrected.

[0006] In the zoom lens of Patent Document 1, the curvature of field during image stabilization is corrected, but a large amount of residual image blur occurs in the peripheral areas due to the difference in the amount of image point movement between the center and the periphery. Also, in IIS, if the outer diameter of the image stabilization lens group is large, it becomes difficult to make the zoom lens compact.

[0007] The present invention provides a zoom lens that is small in size yet has good optical performance even when vibration is reduced, and an imaging apparatus using the same. [Means for solving the problem]

[0008] A zoom lens according to one aspect of the present invention includes a first lens group having a negative refractive power, the first lens group being arranged in order from an object side to an image side. 3 The zoom lens is a zoom lens having a first lens group and a second lens group, and the distance between adjacent lens groups changes during zooming. The second lens group includes an aperture stop and an anti-vibration group that has negative refractive power and moves during image blur correction so as to include a component in a direction perpendicular to the optical axis. A focus group is located closer to the object than the anti-vibration group. the vibration reduction group includes a negative lens, the negative lens having a meniscus shape with a convex surface facing the object side; The distance on the optical axis from the aperture stop at the wide-angle end to the image plane is DSPw, and the distance on the optical axis from the aperture stop at the wide-angle end to the surface of the vibration-reduction group closest to the object is DISw. , the radius of curvature of the object side surface of the negative lens is R1, and the radius of curvature of the image side surface of the negative lens is R2. When 0.4 5 ≦DISw / DSPw≦0.80 3.5≦(R1+R2) / (R1-R2)≦13.0 The present invention is characterized in that the above conditions are satisfied. Note that an image pickup device or an image pickup system having the above zoom lens also constitutes another aspect of the present invention. Effect of the Invention

[0009] According to the present invention, it is possible to provide a zoom lens that is small in size and has good optical performance even when vibration is reduced, and an imaging apparatus using the same. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional view of a zoom lens according to a first embodiment. [Diagram 2] (A) A diagram showing the amount and direction of movement of each image point when the image point at the center moves in the -X direction due to angular blur, and (B) A diagram showing the amount and direction of remaining image blur when the image blur at the center in Figure 2(A) is corrected by OIS. [Diagram 3] 5A to 5C are aberration diagrams of the zoom lens of the first embodiment. [Figure 4] 4A to 4C are diagrams showing the amount of remaining image blur in the zoom lens of the first embodiment. [Diagram 5] FIG. 11 is a cross-sectional view of a zoom lens according to a second embodiment. [Figure 6] 6A to 6C are aberration diagrams of the zoom lens of Example 2. [Figure 7] 8A to 8C are diagrams showing the amount of remaining image blur in the zoom lens of the second embodiment. [Figure 8] FIG. 11 is a cross-sectional view of a zoom lens according to a third embodiment. [Figure 9] 11A to 11C are aberration diagrams of the zoom lens of Example 3. [Figure 10] 13A to 13C are diagrams showing the amount of remaining image blur in the zoom lens of the third embodiment. [Figure 11] FIG. 11 is a cross-sectional view of a zoom lens according to a fourth embodiment. [Figure 12] 11A to 11C are aberration diagrams of the zoom lens of Example 4. [Figure 13] 13A to 13C are diagrams showing the amount of remaining image blur in the zoom lens of the fourth embodiment. [Figure 14] FIG. 13 is a cross-sectional view of a zoom lens according to a fifth embodiment. [Figure 15] 13A to 13C are aberration diagrams of the zoom lens of Example 5. [Figure 16] 13A to 13C are diagrams showing the amount of remaining image blur in the zoom lens of the fifth embodiment. [Figure 17]FIG. 13 is a cross-sectional view of a zoom lens according to a sixth embodiment. [Figure 18] 13A to 13C are aberration diagrams of the zoom lens of Example 6. [Figure 19] 13A to 13C are diagrams showing the amount of remaining image blur in the zoom lens of the sixth embodiment. [Figure 20] FIG. 13 is a cross-sectional view of a zoom lens according to a seventh embodiment. [Figure 21] 13A to 13C are aberration diagrams of the zoom lens of Example 7. [Figure 22] 13A to 13C are diagrams showing the amount of remaining image blur in the zoom lens of the seventh embodiment. [Figure 23] FIG. 1 is a schematic diagram of an imaging device including a zoom lens according to any one of the first to seventh embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0012] 1, 5, 8, 11, 14, 17 and 20 respectively show cross sections of the zoom lens L0 of Examples 1 to 7 at the wide-angle end and in a state focused at infinity. The zoom lens L0 of each Example is used in imaging devices and interchangeable lenses such as digital video cameras, digital still cameras, cameras for silver halide film, broadcast cameras and surveillance cameras.

[0013] In each cross-sectional view, the left side is the object side and the right side is the image side. The zoom lens L0 of each embodiment has multiple lens groups. A lens group is a group of one or more lenses that move together during zooming between the wide-angle end and the telephoto end. In other words, the spacing between adjacent lens groups changes during zooming. The lens group may include an aperture stop. The wide-angle end and the telephoto end respectively indicate the zoom states of the maximum angle of view (shortest focal length) and the minimum angle of view (maximum focal length) when the lens group that moves during zooming is located at both ends of the range that can be moved mechanically or controlled on the optical axis.

[0014] In each cross-sectional view, Li represents the i-th lens group (i is a natural number) counted from the object side among the lens groups included in the zoom lens L0. LR is a rear group including two or more lens groups arranged closer to the image side than the first lens group L1. LIS is an anti-vibration group having an anti-vibration function of correcting image blur by moving (shifting) in a direction perpendicular to the optical axis. Note that the anti-vibration group may move in a direction that includes a component of the direction perpendicular to the optical axis (for example, a rotation direction around the center on the optical axis).

[0015] In each embodiment, the image stabilization group is a group of one or more lenses in which the distance on the optical axis from the lens surface closest to the object to the lens surface closest to the image remains constant during zooming. The image stabilization group may be constituted by one lens group, or may be constituted as a part of one lens group.

[0016] In the figure, the lens group with the dashed arrow and "Focus" is a focus group that moves from the object side to the image side when focusing from infinity to a close distance. The focus group may be the entire lens group or a part of the lens group. LN is the lens group in the zoom lens L0 that is located closest to the image side.

[0017] In addition, SP is an aperture stop, and IP is an image plane, on which the imaging surface of a solid-state imaging element (photoelectric conversion element) such as a CCD sensor or a CMOS sensor, or the film surface (photosensitive surface) of a silver halide film is disposed.

[0018] Below the lens groups that move during zooming, solid arrows indicate the movement locus of the lens groups when zooming from the wide-angle end to the telephoto end, and below the lens groups that move during focusing, dashed arrows indicate the movement locus of the lens groups when focusing from infinity to a close distance.

[0019] The zoom lens L0 of each embodiment is made up of a plurality of lens groups arranged in order from the object side to the image side, the lens groups being made up of a first lens group L1 having negative refractive power and a rear group LR.

[0020] The first lens unit L1 has three or more negative lenses in order from the object side, and the focus unit is made up of one positive lens GP.

[0021] The zoom lens L0 of the first and second embodiments is composed of a first lens group L1, a second lens group L2 with positive refractive power, a third lens group L3 with positive refractive power, and a fourth lens group L4 with positive refractive power. The second lens group L2 includes an aperture stop SP. In the zoom lens L0 of the first and second embodiments, the second lens group L2, the third lens group L3, and the fourth lens group L4 are included in the rear group LR. During zooming from the wide-angle end to the telephoto end, the first lens group L1 moves along a convex locus toward the image side, and the second lens group L2 and the third lens group L3 move monotonically toward the object side. The fourth lens group L4 is immovable (fixed).

[0022] The zoom lens L0 of the third embodiment is composed of a first lens group L1, a second lens group L2 with positive refractive power, a third lens group L3 with positive refractive power, and a fourth lens group L4 with positive refractive power. The second lens group L2 includes an aperture stop SP. In the zoom lens L0 of the third embodiment, the second lens group L2, the third lens group L3, and the fourth lens group L4 are included in the rear group LR. During zooming from the wide-angle end to the telephoto end, the first lens group L1 moves along a convex locus toward the image side, and the second lens group L2 and the third lens group L3 move monotonically toward the object side. The fourth lens group L4 moves monotonically toward the image side.

[0023] The zoom lens L0 of the fourth embodiment is composed of a first lens group L1, a second lens group L2 with positive refractive power, a third lens group L3 with positive refractive power, a fourth lens group L4 with negative refractive power, and a fifth lens group L5 with positive refractive power. The second lens group L2 includes an aperture stop SP. In the zoom lens L0 of the fourth embodiment, the second lens group L2, the third lens group L3, the fourth lens group L4, and the fifth lens group L5 are included in the rear group LR. During zooming from the wide-angle end to the telephoto end, the first lens group L1 moves along a convex locus toward the image side, and the second lens group L2, the third lens group L3, and the fourth lens group L4 move monotonically toward the object side. The fifth lens group L5 moves monotonically toward the image side.

[0024] The zoom lens L0 of the fifth embodiment is composed of a first lens group L1, a second lens group L2 with positive refractive power, a third lens group L3 with negative refractive power, a fourth lens group L4 with positive refractive power, and a fifth lens group L5 with negative refractive power. The second lens group L2 includes an aperture stop SP. In the zoom lens L0 of the fifth embodiment, the second lens group L2, the third lens group L3, the fourth lens group L4, and the fifth lens group L5 correspond to the rear group LR. During zooming from the wide-angle end to the telephoto end, the first lens group L1 moves along a convex locus toward the image side, and the second lens group L2, the third lens group L3, the fourth lens group L4, and the fifth lens group L5 move monotonically toward the object side.

[0025] The zoom lens L0 of the sixth embodiment is composed of a first lens group L1, a second lens group L2 with positive refractive power, a third lens group L3 with negative refractive power, a fourth lens group L4 with positive refractive power, a fifth lens group L5 with negative refractive power, and a sixth lens group L6 with positive refractive power. The second lens group L2 includes an aperture stop SP. In the zoom lens L0 of the sixth embodiment, the second lens group L2, the third lens group L3, the fourth lens group L4, the fifth lens group L5, and the sixth lens group L6 are included in the rear group LR. During zooming from the wide-angle end to the telephoto end, the first lens group L1 moves along a convex locus toward the image side, and the second lens group L2, the third lens group L3, the fourth lens group L4, and the fifth lens group L5 move monotonically toward the object side. The sixth lens group L6 is stationary.

[0026] The zoom lens L0 of the seventh embodiment is composed of a first lens group L1, a second lens group L2 with negative refractive power, a third lens group L3 with positive refractive power, a fourth lens group L4 with positive refractive power, and a fifth lens group L5 with positive refractive power. In the zoom lens L0 of the seventh embodiment, the second lens group L2, the third lens group L3, the fourth lens group L4, and the fifth lens group L5 are included in the rear group LR. During zooming from the wide-angle end to the telephoto end, the first lens group L1 and the second lens group L2 move along a convex locus toward the image side, and the third lens group L3 and the fourth lens group L4 move monotonically toward the object side. The fifth lens group L5 does not move.

[0027] The zoom lens L0 of Examples 1 to 7 is designed to allow the occurrence of distortion, on the premise that distortion is corrected by image processing. Therefore, an imaging optical system using the zoom lens L0 has a designed amount of distortion that the zoom lens L0 has. Then, in an imaging device that performs imaging using the imaging optical system, an image processing unit performs image processing for correcting the designed amount of distortion for an acquired captured image. The zoom lens or imaging device as a lens device such as an interchangeable lens preferably has a storage unit that stores correction data used for correcting distortion.

[0028] In a zoom lens that allows the occurrence of distortion in this way, a lens for correcting distortion is not required, making it easy to make the zoom lens smaller and lighter. In particular, by making the effective imaging range (effective image circle diameter) of the image sensor on the wide-angle side smaller than the effective imaging range on the telephoto end to correct distortion, it is possible to make the first lens group L1 smaller.

[0029] In the zoom lens L0 of each embodiment, a parallel plate having substantially no refractive power, such as a low-pass filter or an infrared cut filter, may be disposed between the lens disposed closest to the image side and the image surface IP.

[0030] 3, 6, 9, 12, 15, 18, and 21 respectively show longitudinal aberrations (spherical aberration, astigmatism, distortion, and chromatic aberration) at (A) the wide-angle end and (B) the telephoto end in the infinity focused state of the zoom lens L0 of Numerical Examples 1 to 7 corresponding to Examples 1 to 7. In the spherical aberration diagrams, Fno is the F-number, and shows the amount of spherical aberration for the d-line (wavelength 587.6 nm) and the g-line (wavelength 435.8 nm). In the astigmatism diagrams, ΔS shows the amount of astigmatism in the sagittal image plane, and ΔM shows the amount of astigmatism in the meridional image plane. In the distortion aberration diagrams, the amount of distortion for the d-line is shown. In the chromatic aberration diagrams, the amount of chromatic aberration of magnification for the g-line is shown. ω is the half angle of view (°) by paraxial calculation.

[0031] 4, 7, 10, 13, 16, 19, and 22 respectively show the amount of remaining image blur when an angular shake of ±0.4 deg is applied to an imaging device having the zoom lens L0 of Examples 1 to 7 and an imaging element that receives an optical image formed by the zoom lens L0. Each figure shows the amount of remaining image blur at the wide-angle end of the zoom lens L0 and in the infinity focus state. (A) of each figure shows the amount of remaining image blur for each image height in the image point movement direction (image blur direction) and in the direction perpendicular thereto when the image blur at the center of the image surface IP is corrected by the OIS alone when the imaging device is tilted. Also, (B) shows the amount of remaining image blur for each image height in the image point movement direction and in the direction perpendicular thereto when the image blur at the center is corrected by using the OIS and IIS at a certain ratio when the imaging device is tilted.

[0032] Next, the characteristic configuration of the zoom lens L0 of each embodiment will be described. The zoom lens L0 of each embodiment is a so-called negative lead type zoom lens in which the refractive power of the first lens group L1 is negative. A negative lead type zoom lens is particularly effective for making the zoom lens have a wide angle. By arranging the focus group near the aperture stop SP, the height of the off-axis light rays incident on the focus group can be lowered, making it easy to make the focus group compact.

[0033] Since the amount of image point movement on the image plane caused by camera shake differs between the central and peripheral parts of the image plane, image blurring becomes large in the peripheral parts of a wide-angle zoom lens. Generally, a lens group with a high off-axis ray height has a large impact on the peripheral parts of the image plane when it shifts in a direction perpendicular to the optical axis. For this reason, if the height of the off-axis ray incident on the vibration-proof group is high, it becomes easier to suppress image blurring in the peripheral parts. On the other hand, if the height of the off-axis ray incident on the vibration-proof group is high, the lens diameter of the vibration-proof group becomes large. As a result, in order to achieve a compact vibration-proof group and good suppression of image blurring in the peripheral parts, it is important to place the vibration-proof group in an appropriate position.

[0034] Therefore, in the zoom lens L0 of each embodiment, the focus unit LF is disposed near the aperture stop SP, and the vibration isolation unit is appropriately disposed. Specifically, the zoom lens L0 of each embodiment satisfies the following conditional expression (1).

[0035] 0.40≦DISw / DSPw≦0.80 (1) Conditional formula (1) specifies the ratio of the distance DSPw on the optical axis from the aperture stop SP to the image plane at the wide-angle end to the distance DISw on the optical axis from the aperture stop SP to the surface of the vibration-reduction group LIS closest to the object. By arranging the vibration-reduction group LIS at an appropriate position, it becomes easy to arrange the drive unit for driving the vibration-reduction group LIS and the focus group while making the diameter of the vibration-reduction group LIS small. If the distance from the aperture stop SP to the vibration-reduction group LIS becomes too short so that DISw / DSPw falls below the lower limit of conditional formula (1), the height of the off-axis light rays incident on the vibration-reduction group becomes low, making it difficult to suppress image blurring in the peripheral areas. Furthermore, the distance between the focus group LF and the vibration-reduction group LIS, which are arranged near the aperture stop SP, becomes too short, making it difficult to arrange the drive unit for driving the focus group LF and the drive unit for driving the vibration-reduction group LIS and the focus group. On the other hand, if the distance from the aperture stop SP to the vibration isolation group LIS becomes too long so that DISw / DSPw exceeds the upper limit of conditional formula (1), the height of the off-axis light rays entering the vibration isolation group LIS becomes high, which makes it difficult to reduce the diameter of the vibration isolation group LIS and thus the size of the zoom lens L0.

[0036] With the above configuration, a zoom lens that is small in size and has good optical characteristics can be obtained.

[0037] Moreover, it is preferable that the zoom lens L0 of each embodiment satisfies at least one of the following conditional expressions (2) to (13).

[0038] 25≦νdGP≦45 (2) 0.48≦DLFw / TLw≦0.65 (3) 0.04≦Skw / TLw≦0.25 (4) -0.45≦fL1 / fLF≦-0.15 (5) 0.00<|fL1 / fLN|≦0.40 (6) 0.50≦|fLN / fLIS|≦1.60 (7) 1.60≦ndGP≦1.91 (8) 35≦νdGIS≦60 (9) 22≦νdG1P≦50 (10) 3.5≦(R1+R2) / (R1-R2)≦13.0 (11) -1.60≦Ymax_w / fL1≦-0.40 (12) -20.0≦Dist_w≦-8.0 (13) By configuring the focus group LF with one positive lens GP, it is possible to reduce the weight of the focus group LF. In order to suppress fluctuations in chromatic aberration during focusing, it is important to appropriately select the glass material of the positive lens GP.

[0039] Conditional formula (2) defines the Abbe number νdGP for the d-line of the positive lens GP. If νdGP is below the lower limit of conditional formula (2), it becomes difficult to suppress the chromatic aberration fluctuation during focusing. On the other hand, if νdGP is above the upper limit of conditional formula (2), it becomes difficult to suppress the chromatic aberration fluctuation during focusing.

[0040] In a zoom lens, if the height of off-axial light rays entering a lens group is high, the lens diameter becomes large. Therefore, in order to realize a compact and lightweight focus group, it is important to position the focus group at a position where the height of off-axial light rays is low. By positioning the focus group near the aperture stop SP, the height of off-axial light rays entering the focus group can be lowered.

[0041] Conditional formula (3) specifies the ratio of the total optical length TLw at the wide-angle end to the distance DLFw on the optical axis from the surface of the zoom lens L0 closest to the object to the surface of the focus group LF closest to the object. The total optical length is the distance on the optical axis from the lens surface of the zoom lens L0 closest to the object to the image plane IP. If the focus group is located on the object side so that DLFw / TLw is below the lower limit of conditional formula (3), the height of the off-axis light rays entering the focus group becomes high, making it difficult to reduce the size of the focus group. On the other hand, if the focus group is located on the image side so that DLFw / TLw exceeds the upper limit of conditional formula (3), the height of the off-axis light rays entering the focus group becomes high, making it difficult to reduce the size of the focus group.

[0042] Conditional formula (4) defines the ratio of the back focus Skw at the wide-angle end to the total optical length TLw at the wide-angle end. If the back focus SKw is too short so that Skw / TLw falls below the lower limit of conditional formula (4), it becomes difficult to place an optical element such as a low-pass filter near an image sensor that receives an optical image formed by the zoom lens L0. If the back focus SKw is too long so that Skw / TLw exceeds the upper limit of conditional formula (4), the total optical length of the zoom lens L0 at the wide-angle end becomes long, making it difficult to reduce the size.

[0043] Conditional formula (5) defines the ratio of the focal length fL1 of the first lens group L1 to the focal length fLF of the focus group. If the refractive power of the first lens group L1 is too weak, such that fL1 / fLF is below the lower limit of conditional formula (5), it becomes difficult to achieve a wide angle of view exceeding 100° at the wide-angle end. In addition, the diameter of the first lens group L1 becomes large, and the zoom lens becomes large in the radial direction. On the other hand, if the refractive power of the first lens group L1 is too strong, such that fL1 / fLF exceeds the upper limit of conditional formula (5), the asymmetry of the refractive power arrangement of the zoom lens L0 becomes strong, and it becomes difficult to correct distortion at the wide-angle end.

[0044] Conditional expression (6) defines the ratio between the focal length fL1 of the first lens group L1 and the focal length fLN of the lens group LN arranged closest to the image side in the zoom lens L0. When |fL1 / fLN| satisfies conditional expression (6), it is possible to achieve both a compact zoom lens L0 and high optical performance (high image quality). If the positive refractive power of the lens group LN becomes too strong so that |fL1 / fLN| falls below the lower limit of conditional expression (6), the retrofocus refractive power arrangement becomes strong, and the asymmetry of the refractive power arrangement of the zoom lens L0 becomes stronger. As a result, it becomes difficult to correct distortion at the wide-angle end or to shorten the overall length at the wide-angle end. If the negative refractive power of the lens group LN becomes too strong so that |fL1 / fLN| exceeds the upper limit of conditional expression (6), it becomes difficult to achieve a retrofocus refractive power arrangement, and it becomes difficult to widen the angle of view while ensuring the back focus at the wide-angle end.

[0045] Conditional expression (7) specifies the ratio between the focal length fLN of the lens group LN arranged closest to the image and the focal length fLIS of the image-stabilizing group LIS. If the refractive power of the image-stabilizing group LIS becomes too weak so that |fLN / fLIS| falls below the lower limit of conditional expression (7), the amount of movement of the image-stabilizing group LIS during image stabilization becomes large, making it difficult to reduce the size of the zoom lens in the radial direction. If the refractive power of the image-stabilizing group LIS becomes too strong so that |fLN / fLIS| exceeds the upper limit of conditional expression (7), it becomes difficult to suppress fluctuations in coma aberration and field curvature during image stabilization.

[0046] Conditional formula (8) specifies the refractive index ndGP of the positive lens GP constituting the focus group LF with respect to the d-line. If ndGP is below the lower limit of conditional formula (8), the curvature of the positive lens GP becomes large in order to impart the necessary refractive power to the positive lens GP, making it difficult to suppress the fluctuation of various aberrations such as astigmatism during focusing. On the other hand, if ndGP is above the upper limit of conditional formula (8), the curvature of the positive lens GP becomes small, making it difficult to suppress the fluctuation of various aberrations such as spherical aberration during focusing.

[0047] Conditional formula (9) specifies the Abbe number νdGIS for the d-line of the negative lens GIS that constitutes the image stabilization group. If νdGIS is below the lower limit of conditional formula (9), it becomes difficult to correct lateral chromatic aberration during image stabilization. On the other hand, if νdGIS is above the upper limit of conditional formula (9), the refractive index of the negative lens GIS becomes low, the amount of movement of the image stabilization group LIS during image stabilization becomes large, and it becomes difficult to reduce the size of the zoom lens L0 in the radial direction.

[0048] Conditional expression (10) defines the Abbe number νdG1P for the d-line of the positive lens G1P having the strongest refractive power among the at least one positive lens included in the first lens group L1. The refractive power is expressed as the reciprocal of the focal length. If νdG1P is below the lower limit of conditional expression (10), it becomes difficult to correct lateral chromatic aberration during zooming. If νdG1P is above the upper limit of conditional expression (10), it becomes difficult to correct axial chromatic aberration during zooming.

[0049] Conditional expression (11) specifies the shape of the negative lens GIS constituting the image stabilization group. The negative lens GIS has a meniscus shape with a convex surface facing the object side, and suppresses the fluctuation of coma aberration during image stabilization. R1 is the radius of curvature of the lens surface on the object side of the negative lens GIS, R2 is the radius of curvature of the lens surface on the image side of the negative lens GIS, and (R1+R2) / (R1-R2) is the shape factor. If (R1+R2) / (R1-R2) is below the lower limit of conditional expression (11), it becomes difficult to suppress the fluctuation of coma aberration during image stabilization. Also, if (R1+R2) / (R1-R2) is above the upper limit of conditional expression (11), it becomes difficult to suppress the fluctuation of coma aberration during image stabilization.

[0050] Conditional formula (12) defines the ratio between the effective (imageable) maximum image height Ymax_w at the wide-angle end and the focal length fL1 of the first lens group L1. The maximum image height Ymax_w is the distance from the optical axis to the image point farthest from the optical axis among imageable (image-receivable by the image sensor) image points, and is the maximum image height taking into consideration the change in magnification due to the amount of distortion. By adjusting the lenses and lens movement mechanism to this maximum image height, it is possible to reduce the size and weight of a lens device having the zoom lens L0.

[0051] If the maximum image height becomes too small, such as when Ymax_w / fL1 falls below the lower limit of conditional expression (12), the angle of view becomes narrower than the required angle of view. On the other hand, if the maximum image height becomes too large, such as when Ymax_w / fL1 exceeds the upper limit of conditional expression (12), a wider range of light rays than the required angle of view will be imaged on the imaging surface. This causes the lenses and lens movement mechanism to become excessively large, making it difficult to reduce the size and weight.

[0052] Conditional expression (13) specifies the amount of distortion Dist_w at the maximum image height Ymax_w in the infinity focused state at the wide-angle end. If Dist_w falls below the lower limit of conditional expression (13), it becomes difficult to suppress deterioration of image quality at the periphery of the image when correcting distortion by image processing. On the other hand, if Dist_w exceeds the upper limit of conditional expression (13), the amount of distortion in the equidistant projection method becomes too large, resulting in significant deterioration of peripheral image quality during image stabilization. Also, in the OIS, the amount of image blur correction at the periphery becomes insufficient.

[0053] When the ideal image height in the central projection method is y and the real image height is yp, the distortion amount Dist_w [%] at an arbitrary image height at the wide-angle end can be expressed as follows.

[0054] Dist_w[%]=((yp-y) / y1)×100 The ideal image height y in the central projection method is defined as follows using the focal length f of the zoom lens L0 and the half angle of view θi of the actual light ray at an arbitrary image height.

[0055] y=ftanθi The ideal image height y can be expressed as follows using the focal length f of the zoom lens L0 and the half angle of view θ of the actual light ray at the maximum image height:

[0056] y1=ftanθ It is more preferable that the numerical ranges of the conditional expressions (1) to (13) be as follows:

[0057] 0.42≦DISw / DSPw≦0.70 (1a) 27≦νdGP≦43 (2a) 0.49≦DLFw / TLw≦0.60 (3a) 0.05≦Skw / TLw≦0.20 (4a) -0.40≦fL1 / fLF≦-0.17 (5a) 0.00<|fL1 / fLN|≦0.35 (6a) 0.60≦|fLN / fLIS|≦1.50 (7a) 1.63≦ndGP≦1.89 (8a) 37≦νdGIS≦55 (9a) 25≦νdG1P≦45 (10a) 4.0≦(R1+R2) / (R1-R2)≦11.0 (11a) -1.40≦Ymax_w / fL1≦-0.60 (12a) -16.0≦Dist_w≦-9.0 (13a) Moreover, it is more preferable that the numerical range of conditional formula (13) is as follows:

[0058] 0.45≦DISw / DSPw≦0.60 (1b) 28≦νdGP≦40 (2b) 0.50≦DLFw / TLw≦0.55 (3b) 0.06≦Skw / TLw≦0.15 (4b) -0.38≦fL1 / fLF≦-0.20 (5b) 0.00<|fL1 / fLN|≦0.33 (6b) 0.70≦|fLN / fLIS|≦1.40 (7b) 1.65≦ndGP≦1.87 (8b) 39≦νdGIS≦50 (9b) 28≦νdG1P≦42 (10b) 4.5≦(R1+R2) / (R1-R2)≦9.0 (11b) -1.20≦Ymax_w / fL1≦-0.70 (12b) -14.0≦Dist_w≦-10.0 (13b) Next, a configuration that is preferably satisfied in the zoom lens of each embodiment will be described.

[0059] The first lens group L1 has three or more negative lenses in order from the object side. This makes it possible to ensure a sufficiently wide angle (for example, a field angle of 100° or more at the wide angle end). It is also preferable that the first lens group L1 has four or more negative lenses and at least one positive lens. This makes it possible to ensure a sufficient zoom ratio (for example, about 2x) while ensuring a sufficiently wide angle.

[0060] It is also preferable that the aperture stop SP be disposed closer to the object side than the focus unit and move monotonically toward the object side during zooming from the wide-angle end to the telephoto end, which makes it easier to make the aperture stop SP more compact.

[0061] It is also preferable that the rear group LR has three or more lens groups in which the spacing between adjacent lens groups changes during zooming, which makes it possible to achieve a sufficient zoom ratio (for example, about 2x).

[0062] Furthermore, it is preferable that the lens group LN arranged closest to the image side in the zoom lens L0 is composed of three lenses or less, which allows the zoom lens L0 to be made compact.

[0063] Furthermore, at the wide-angle end, it is preferable that the distance between the first lens group L1 and the second lens group L2 is the largest among the distances between all the lens groups included in the zoom lens L0, which results in a strong retrofocus configuration at the wide-angle end, making it possible to achieve a sufficient zoom ratio (for example, about 2x) while widening the angle.

[0064] In addition, when performing OIS by shifting the image stabilization group LIS, it is preferable to also shift the image sensor to perform IIS. By combining OIS and IIS, it becomes easier to suppress image blurring in the peripheral areas.

[0065] Next, Numerical Examples 1 to 7 are shown. In the surface data of each Numerical Example, the surface number m indicates the order of the surface when counted from the object side. r indicates the radius of curvature of the mth surface, and d (mm) indicates the axial distance (distance on the optical axis) between the mth surface and the (m+1)th surface. In addition, nd indicates the refractive index for the d-line of the optical material between the mth surface and the (m+1)th surface, and νd indicates the Abbe number of the optical material. The Abbe number νd is given by Nd, NF, and NC, respectively, when the refractive indices at the d-line (587.6 nm), F-line (486.1 nm), and C-line (656.3 nm) of the Fraunhofer lines are Nd, NF, and NC, respectively. νd=(Nd-1) / (NF-NC) It is expressed as:

[0066] In each numerical example, d, focal length (mm), F-number, and half angle of view (°) are all values ​​when the zoom lens L0 is focused at infinity. The back focus is the distance on the optical axis from the final lens surface, which is the lens surface closest to the image side of the zoom lens, to the paraxial image surface, expressed as an air-equivalent length. The total lens length is the length obtained by adding the back focus to the distance on the optical axis from the front lens surface, which is the lens surface closest to the object side of the zoom lens L0, to the final lens surface.

[0067] If an optical surface has an aspheric shape, a * symbol is added to the right of the surface number. The aspheric shape is expressed as follows, where X is the displacement from the apex of the surface in the optical axis direction, h is the height from the optical axis in a direction perpendicular to the optical axis, R is the paraxial radius of curvature, K is the conic constant, and A4, A6, A8, A10, and A12 are the aspheric coefficients of each order: X = (h 2 / R) / [1+[1-(1+K)(h / R) 2 ] 1 / 2 ]+A4×h 4 +A6×h 6 +A8×h 8 +A10×h 10 +A12×h 12 +A14×h 14 The "e±XX" in the conic constant and aspheric coefficient is expressed as "×10± XX " means. [Numerical example 1] Unit: mm Surface Data Surface number rd nd νd 1* 37.000 3.00 1.58313 59.4 2* 17.814 12.20 3 52.582 1.23 1.91082 35.2 4 17.849 5.54 5 30.037 1.15 1.59282 68.6 6 18.728 9.86 7 -28.561 1.10 1.43875 94.7 8 33.065 4.99 1.88300 40.8 9 -88.917 (variable) 10 (Aperture) ∞ (Variable) 11 76.538 1.86 1.72047 34.7 12 -170.686 (variable) 13 21.263 0.69 1.80810 22.8 14 10.223 4.67 1.67300 38.3 15 101.506 0.80 16 -48.763 0.55 1.88300 40.8 17 13.497 2.73 1.92286 20.9 18 39.963 0.35 19 19.540 5.55 1.49700 81.5 20* -31.043 0.15 21 18.566 0.64 2.05090 26.9 22 11.089 7.99 1.49700 81.5 23 -43.632 0.35 24 22.204 0.90 1.88300 40.8 25 16.576 5.56 26* -26.667 1.90 1.85400 40.4 27* -55.445 (variable) 28 -497.495 7.36 1.49700 81.5 29 -33.423 (variable) Image plane ∞ Aspheric Data Front page K = 0.00000e+00 A 4= 2.59429e-06 A 6=-2.61399e-08 A 8= 5.21697e-11 A10=-5.59197e-14 A12= 3.27515e-17 A14=-8.57311e-21 2nd side K =-8.76022e-01 A 4= 9.21103e-06 A 6=-3.58438e-08 A 8=-4.52147e-11 A10= 2.92832e-13 A12=-4.25258e-16 A14= 2.03592e-19 Page 20 K = 0.00000e+00 A 4= 2.45229e-05 A 6=-3.72036e-08 A 8=-1.08800e-09 A10= 1.03970e-11 A12=-1.91023e-14 Page 26 K = 0.00000e+00 A 4= 1.66615e-04 A 6=-1.90317e-06 A 8= 1.23230e-08 A10=-9.41453e-11 A12= 4.39584e-13 Page 27 K = 0.00000e+00 A 4= 1.69532e-04 A 6=-1.38711e-06 A 8= 4.53596e-09 A10=-6.87436e-12 A12= 2.41668e-14 Various data Zoom ratio 1.88 Wide Angle Mid-Telephoto Focal length 10.33 15.00 19.39 F-number 4.08 4.08 4.12 Half angle of view (°) 61.36 55.26 48.13 Image height 18.92 21.64 21.64 Lens length 128.82 122.35 123.27 BF 12.13 12.13 12.13 d 9 24.06 9.31 2.42 d10 3.18 3.92 3.78 d12 4.97 4.23 4.37 d27 3.36 11.64 19.44 d29 12.13 12.13 12.13 Lens Group Data Group starting plane focal length 1 1 -19.37 2 11 73.58 3 13 49.46 4 28 71.72 [Numerical example 2] Unit: mm Surface Data Surface number rd nd νd 1* 36.964 2.00 1.76450 49.1 2* 17.381 12.97 3 38.540 1.00 1.83400 37.2 4 17.838 8.18 5 35.542 1.00 1.49700 81.5 6 17.493 9.44 7 -32.408 0.80 1.43875 94.7 8 29.388 4.33 1.88300 40.8 9 -153.902 (variable) 10 (Aperture) ∞ (Variable) 11 60.063 1.50 1.77047 29.7 12 4073.289 (variable) 13 24.469 0.50 1.80810 22.8 14 10.086 6.29 1.80610 33.3 15 65.185 0.67 16 -92.079 0.50 2.00100 29.1 17 10.799 3.89 1.86966 20.0 18 60.938 0.10 19 18.584 4.65 1.43875 94.7 20* -29.965 0.10 21 16.998 0.50 2.05090 26.9 22 11.071 6.27 1.43875 94.7 23 -72.227 4.03 24 21.999 0.90 1.88300 40.8 25 16.878 5.45 26* -21.844 1.20 1.85400 40.4 27* -29.304 (variable) 28 -242.542 7.32 1.49700 81.5 29 -31.336 (variable) Image plane ∞ Aspheric Data Front page K = 0.00000e+00 A 4=-5.05120e-07 A 6=-2.59180e-08 A 8= 5.64585e-11 A10=-6.28825e-14 A12= 3.59492e-17 A14=-8.73398e-21 2nd side K =-8.50179e-01 A 4= 6.50619e-06 A 6=-3.67327e-08 A 8=-4.18782e-11 A10= 3.45919e-13 A12=-5.82222e-16 A14= 3.42039e-19 Page 20 K = 0.00000e+00 A 4= 1.88217e-05 A 6=-1.07644e-07 A 8=-8.81979e-10 A10= 3.51547e-12 A12= 2.13797e-14 Page 26 K = 0.00000e+00 A 4= 1.99287e-04 A 6=-1.86752e-06 A 8= 9.76715e-09 A10=-7.11283e-11 A12= 4.03250e-13 Page 27 K = 0.00000e+00 A 4= 2.02967e-04 A 6=-1.31168e-06 A 8= 1.15301e-09 A10=2.03422e-11 A12=-3.00629e-14 Various data Zoom ratio 1.94 Wide Angle Mid-Telephoto Focal length 9.20 16.04 17.90 F-number 4.08 4.08 4.12 Half angle of view (°) 64.04 53.45 50.40 Image height 18.90 21.64 21.64 Lens length 125.26 118.57 119.35 BF 10.50 10.50 10.50 d 9 24.00 4.83 2.21 d10 2.10 3.01 3.07 d12 4.14 3.23 3.17 d27 0.93 13.41 16.81 d29 10.50 10.50 10.50 Lens Group Data Group starting plane focal length 1 1 -17.03 2 11 79.11 3 13 42.64 4 28 71.58 [Numerical example 3] Unit: mm Surface Data Surface number rd nd νd 1* 34.540 2.00 1.76450 49.1 2* 17.538 12.00 3 27.845 1.00 2.05090 26.9 4 17.335 12.15 5 -102.534 1.00 1.49700 81.5 6 24.557 4.63 7 -163.874 1.40 1.83400 37.2 8 -79.091 0.80 1.43875 94.7 9 23.675 5.93 1.88300 40.8 10 685.207 (variable) 11 (Aperture) ∞ (Variable) 12 73.782 1.50 1.85025 30.1 13 -353.985 (variable) 14 22.242 0.50 1.96300 24.1 15 10.175 6.30 1.88300 40.8 16 40.767 0.92 17 -465.076 0.50 1.91082 35.2 18 10.734 4.46 1.86966 20.0 19 30.913 0.10 20 17.320 4.70 1.43875 94.7 21* -61.628 0.10 22 17.378 0.50 2.05090 26.9 23 11.257 7.57 1.43875 94.7 24 -32.482 1.49 25 27.690 0.90 1.88300 40.8 26 20.124 5.98 27* -29.240 1.20 1.85400 40.4 28* -43.741 (variable) 29 -130.532 6.39 1.49700 81.5 30 -34.115 (variable) Image plane ∞ Aspheric Data Front page K = 0.00000e+00 A 4=-5.58771e-07 A 6=-1.77995e-08 A 8= 4.41109e-11 A10=-6.23317e-14 A12= 4.47696e-17 A14=-1.40227e-20 2nd side K =-8.15972e-01 A 4= 8.81718e-06 A 6=-1.49702e-08 A 8=-1.54936e-11 A10= 2.29531e-13 A12=-5.29361e-16 A14= 3.75849e-19 Page 21 K = 0.00000e+00 A 4= 1.85120e-05 A 6=-1.09055e-07 A 8= 4.00606e-10 A10=-1.62869e-11 A12= 9.72903e-14 Page 27 K = 0.00000e+00 A 4= 3.73139e-05 A 6=-5.43373e-07 A 8= 2.13025e-09 A10=-2.57230e-11 A12= 1.92965e-13 Page 28 K = 0.00000e+00 A 4= 5.07750e-05 A 6=-4.00620e-07 A 8= 1.66532e-10 A10= 4.59683e-12 A12= 8.96637e-15 Various data Zoom ratio 2.12 Wide Angle Mid-Telephoto Focal length 11.30 16.61 23.90 F-number 4.08 4.08 4.12 Half angle of view (°) 59.29 52.49 42.15 Image height 19.02 21.64 21.64 Lens length 129.79 125.70 129.33 BF 14.54 12.80 10.54 d10 24.00 10.61 2.20 d11 2.10 2.30 2.09 d13 3.77 3.57 3.78 d28 1.36 12.39 26.70 d30 14.54 12.80 10.54 Lens Group Data Group starting plane focal length 1 1 -19.47 2 12 71.93 3 14 53.25 4 29 90.93 [Numerical example 4] Unit: mm Surface Data Surface number rd nd νd 1* 35.655 2.00 1.55332 71.7 2* 18.553 10.14 3 43.354 1.00 1.96300 24.1 4 18.994 9.15 5 54.034 1.00 1.59270 35.3 6 26.677 8.97 7 -33.675 0.80 1.49700 81.5 8 35.482 6.14 1.85883 30.0 9 -84.554 (variable) 10 (Aperture) ∞ (Variable) 11 123.998 1.70 1.85025 30.1 12 -234.488 (variable) 13* 26.749 1.00 1.80810 22.8 14 13.432 7.73 1.80610 40.7 15 83.403 0.67 16 495.726 0.50 2.00100 29.1 17 13.374 4.37 1.94594 18.0 18 28.803 0.10 19 18.829 6.49 1.43875 94.7 20* -34.371 0.10 21 16.112 0.50 2.05090 26.9 22 11.216 8.27 1.43875 94.7 23 373.115 (variable) 24 31.589 0.90 1.88300 40.8 25 20.666 4.64 26* -27.639 1.20 1.80400 46.5 27* -31.668 (variable) 28 -110.630 1.00 1.80610 33.3 29 -432.539 6.50 1.59282 68.6 30 -34.154 (variable) Image plane ∞ Aspheric Data Front page K = 0.00000e+00 A 4= 8.84489e-07 A 6=-1.74958e-08 A 8= 4.77183e-11 A10=-6.77556e-14 A12= 5.30183e-17 A14=-1.85401e-20 2nd side K =-9.16996e-01 A 4= 9.24051e-06 A 6=-2.08874e-08 A 8= 6.43752e-11 A10=-1.33742e-13 A12= 3.26127e-16 A14=-3.48263e-19 Page 13 K = 0.00000e+00 A 4=-3.08173e-06 A 6=-9.07213e-09 A 8= 3.76703e-11 A10=-9.38527e-14 Page 20 K = 0.00000e+00 A 4= 1.39904e-05 A 6= 6.25811e-09 A 8=-8.77158e-10 A10= 1.49936e-11 A12=-6.74357e-14 Page 26 K = 0.00000e+00 A 4= 1.02392e-04 A 6=-1.86870e-07 A 8=-5.03914e-09 A10=3.67314e-11 A12=-3.01596e-14 Page 27 K = 0.00000e+00 A 4= 1.16632e-04 A 6=-1.10396e-08 A 8=-7.02472e-09 A10= 5.73923e-11 A12=-1.51353e-13 Various data Zoom ratio 1.95 Wide Angle Mid-Telephoto Focal length 11.30 14.97 22.00 F-number 2.89 2.89 2.89 Half angle of view (°) 59.44 55.32 44.52 Image height 19.14 21.64 21.64 Lens length 137.35 129.65 125.58 BF 13.50 12.41 10.50 d 9 29.39 16.54 3.44 d10 2.10 2.10 2.53 d12 4.88 4.88 4.45 d23 1.00 2.19 4.27 d27 1.61 6.66 15.52 d30 13.50 12.41 10.50 Lens Group Data Group starting plane focal length 1 1 -20.99 2 11 95.60 3 13 33.35 4 24 -57.66 5 28 89.95 [Numerical example 5] Unit: mm Surface Data Surface number rd nd νd 1* 36.363 1.60 1.76450 49.1 2* 15.487 6.54 3 27.280 1.00 2.05090 26.9 4 18.536 6.70 5 32.793 1.00 1.49700 81.5 6 17.362 10.47 7 -34.260 0.80 1.43875 94.7 8 34.586 3.94 1.90525 35.0 9 -201.854 (variable) 10 (Aperture) ∞ (Variable) 11 51.209 1.50 1.67300 38.3 12 -111.251 (variable) 13 -61.646 0.80 2.00100 29.1 14 -204.214 (variable) 15 19.146 0.50 2.05090 26.9 16 10.112 4.75 1.80610 40.7 17 152.402 0.35 18 -367.791 0.50 1.91082 35.2 19 11.324 2.84 1.89286 20.4 20 31.987 0.10 21 17.704 4.27 1.43875 94.7 22* -54.171 0.10 23 18.960 0.50 2.05090 26.9 24 11.500 8.01 1.43875 94.7 25 -21.312 0.49 26 21.333 1.00 1.83481 42.7 27 16.304 (variable) 28* -24.186 1.20 1.85400 40.4 29* -41.948 (variable) Image plane ∞ Aspheric Data Front page K = 0.00000e+00 A 4=-7.44158e-06 A 6= 2.17599e-08 A 8=-4.81867e-11 A10= 6.22617e-14 A12=-4.40517e-17 A14= 1.19690e-20 2nd side K =-8.72295e-01 A 4= 5.42531e-07 A 6= 9.78315e-09 A 8= 1.72802e-10 A10=-9.18661e-13 A12= 2.12915e-15 A14=-1.99953e-18 Page 22 K = 0.00000e+00 A 4= 3.62847e-05 A 6=-2.63477e-07 A 8= 1.92638e-09 A10=-6.70834e-11 A12= 4.52971e-13 Page 28 K = 0.00000e+00 A 4= 1.17855e-04 A 6=-1.63605e-06 A 8= 9.00680e-09 A10=-6.51152e-11 A12= 3.38027e-13 Page 29 K = 0.00000e+00 A 4= 1.30738e-04 A 6=-1.32589e-06 A 8= 4.36587e-09 A10=-2.34452e-12 A12= 1.29797e-14 Various data Zoom ratio 1.90 Wide Angle Mid-Telephoto Focal length 10.30 16.00 19.60 F-number 4.08 4.08 4.12 Half angle of view (°) 61.86 53.52 47.83 Image height 19.26 21.64 21.64 Lens length 114.35 105.41 104.44 BF 14.75 21.84 26.22 d 9 24.50 7.84 2.10 d10 2.10 2.82 3.40 d12 3.35 3.32 3.17 d14 2.03 1.34 0.91 d27 8.66 9.29 9.68 d29 14.75 21.84 26.22 Lens Group Data Group starting plane focal length 1 1 -18.06 2 11 52.30 3 13 -88.46 4 15 27.53 5 28 -69.03 [Numerical example 6] Unit: mm Surface Data Surface number rd nd νd 1* 36.245 2.00 1.76450 49.1 2* 18.260 13.76 3 36.879 1.00 1.95375 32.3 4 18.000 10.79 5 53.599 1.00 1.49700 81.5 6 21.569 8.03 7 -31.559 0.80 1.43875 94.7 8 31.309 4.96 1.88300 40.8 9 -94.449 (variable) 10 (Aperture) ∞ (Variable) 11 53.950 1.50 1.66565 35.6 12 -175.277 (variable) 13 268.814 0.80 1.61772 49.8 14 56.472 (variable) 15 22.881 0.50 1.96300 24.1 16 10.376 5.45 1.90043 37.4 17 94.514 0.58 18 -137.963 0.50 1.95375 32.3 19 10.860 3.42 1.86966 20.0 20 34.673 0.10 21 17.287 5.79 1.43875 94.7 22* -61.411 0.10 23 16.219 0.50 2.05090 26.9 24 11.080 8.94 1.43875 94.7 25 -31.009 0.50 26 20.448 1.00 1.83481 42.7 27 15.800 (variable) 28* -15.305 1.20 1.85400 40.4 29* -22.734 (variable) 30 -116.151 6.84 1.49700 81.5 31 -29.679 (variable) Image plane ∞ Aspheric Data Front page K = 0.00000e+00 A 4= 3.92202e-08 A 6=-2.69648e-08 A 8= 6.09684e-11 A10=-7.05373e-14 A12= 4.15238e-17 A14=-1.05285e-20 2nd side K =-8.62038e-01 A 4= 8.10669e-06 A 6=-3.15674e-08 A 8=-3.37489e-11 A10= 3.31967e-13 A12=-5.81678e-16 A14= 3.32304e-19 Page 22 K = 0.00000e+00 A 4= 2.23580e-05 A 6=-1.43420e-07 A 8= 1.13126e-09 A10=-2.96786e-11 A12= 1.87767e-13 Page 28 K = 0.00000e+00 A 4= 1.89068e-04 A 6=-1.82499e-06 A 8= 8.70129e-09 A10=-5.29084e-11 A12= 3.77732e-13 Page 29 K = 0.00000e+00 A 4= 1.81235e-04 A 6=-1.41031e-06 A 8= 3.38789e-09 A10= 1.58728e-11 A12=-5.28155e-14 Various data Zoom ratio 1.92 Wide Angle Mid-Telephoto Focal length 10.30 15.22 19.80 F-number 2.89 3.50 4.12 Half angle of view (°) 61.76 54.87 47.54 Image height 19.18 21.64 21.64 Lens length 132.94 126.11 127.01 BF 11.35 11.35 11.35 d 9 24.44 9.22 2.28 d10 2.17 2.34 2.10 d12 3.85 4.20 4.93 d14 2.01 1.49 1.00 d27 7.87 7.76 7.66 d29 1.19 9.69 17.64 d31 11.35 11.35 11.35 Lens Group Data Group starting plane focal length 1 1 -19.36 2 11 62.14 3 13 -115.90 4 15 30.94 5 28 -59.25 6 30 78.16 [Numerical example 7] Unit: mm Surface Data Surface number rd nd νd 1* 40.468 3.00 1.58313 59.4 2* 18.279 10.33 3 41.125 1.23 1.91082 35.2 4 18.235 7.50 5 34.985 1.15 1.59282 68.6 6 18.756 9.56 7 -34.618 1.10 1.43875 94.7 8 29.346 5.41 1.88300 40.8 9 -90.407 (variable) 10 -56.739 1.00 1.76385 48.5 11 -112.660 (variable) 12 (Aperture) ∞ (Variable) 13 63.090 1.59 1.72047 34.7 14 -227.320 (variable) 15 21.699 0.69 1.80810 22.8 16 10.106 5.14 1.67300 38.3 17 121.574 0.70 18 -51.133 0.55 1.88300 40.8 19 13.133 2.71 1.92286 20.9 20 38.530 0.35 21 19.973 5.25 1.49700 81.5 22* -31.304 0.15 23 18.415 0.64 2.05090 26.9 24 11.103 8.58 1.49700 81.5 25 -41.834 0.35 26 22.000 0.90 1.88300 40.8 27 16.493 5.28 28* -23.968 1.90 1.85400 40.4 29* -43.861 (variable) 30 -345.096 6.53 1.49700 81.5 31 -35.363 (variable) Image plane ∞ Aspheric Data Front page K = 0.00000e+00 A 4= 9.61528e-06 A 6=-3.60704e-08 A 8= 5.97941e-11 A10=-5.54186e-14 A12= 2.90939e-17 A14=-6.66932e-21 2nd side K =-1.23054e+00 A 4= 2.50795e-05 A 6=-3.04254e-08 A 8=-9.21626e-11 A10= 3.40025e-13 A12=-3.47266e-16 A14= 9.28758e-20 Page 22 K = 0.00000e+00 A 4= 2.19912e-05 A 6=-6.02422e-08 A 8=-9.31268e-10 A10=8.72477e-12 A12=-1.88516e-14 Page 28 K = 0.00000e+00 A 4= 1.68018e-04 A 6=-1.88198e-06 A 8= 1.28345e-08 A10=-9.75590e-11 A12= 4.53596e-13 Page 29 K = 0.00000e+00 A 4= 1.65677e-04 A 6=-1.34196e-06 A 8= 4.55621e-09 A10=-6.90232e-12 A12= 1.71906e-14 Various data Zoom ratio 1.88 Wide Angle Mid-Telephoto Focal length 10.33 15.00 19.39 F-number 4.08 4.08 4.12 Half angle of view (°) 61.35 55.27 48.13 Image height 18.90 21.64 21.64 Lens length 128.34 123.04 124.10 BF 12.36 12.36 12.36 d 9 3.98 2.86 1.10 d11 18.86 6.19 1.20 d12 3.18 4.32 4.18 d14 4.50 3.36 3.50 d29 3.86 12.35 20.15 d31 12.36 12.36 12.36 Lens Group Data Group starting plane focal length 1 1 -24.89 2 10 -150.81 3 13 68.70 4 15 47.71 5 30 78.73 The values ​​of the above conditional expressions (1) to (13) in each numerical example are shown in Table 1.

[0068] [Table 1]

[0069] [Imaging device] 23 shows an outline of an imaging device (digital still camera) 10 that uses the zoom lens of each embodiment as an imaging optical system. The imaging device 10 includes a camera body 13, an imaging optical system 11, and an imaging element 12 that photoelectrically converts (captures) an optical image formed by the imaging optical system 11.

[0070] The imaging device 10 has an imaging optical system 11 that is small and has good optical characteristics, and therefore can obtain a high-quality captured image. In this case, an image processing unit (not shown) in the imaging device 10 electrically corrects various aberrations in the captured image, such as distortion aberration and chromatic aberration, to thereby improve the quality of the output image.

[0071] The zoom lens L0 of each of the above-mentioned embodiments can be used not only in the digital still camera shown in FIG. 23, but also in various optical instruments such as silver halide film cameras, video cameras, and telescopes. [Imaging system] An imaging system (surveillance camera system) may be configured including the zoom lens L0 of each embodiment and a control unit that controls the zoom lens L0. In this case, the control unit can control the zoom lens L0 so that each lens group moves as described above during zooming, focusing, and image blur correction. In this case, the control unit does not need to be configured integrally with the zoom lens L0, and the control unit may be configured separately from the zoom lens L0. For example, a configuration may be adopted in which a control unit (control device) disposed far away from a drive unit that drives each lens group of the zoom lens L0 includes a transmission unit that sends a control signal (command) for controlling the zoom lens L0. With such a control unit, the zoom lens L0 can be remotely controlled.

[0072] Also, the control unit may be provided with an operation unit such as a controller or buttons for remotely controlling the zoom lens L0, so that the zoom lens L0 is controlled in response to a user's input to the operation unit. For example, a zoom-in button and a zoom-out button may be provided as the operation unit. In this case, the control unit may be configured to send a signal to a drive unit for the zoom lens L0 so that the magnification of the zoom lens L0 increases when the user presses the zoom-in button, and decreases when the user presses the zoom-out button.

[0073] The imaging system may also have a display unit such as a liquid crystal panel that displays information (movement state) related to the zoom of the zoom lens L0. The information related to the zoom of the zoom lens L0 is, for example, the zoom magnification (zoom state) and the movement amount (movement state) of each lens group. In this case, the user can remotely operate the zoom lens L0 via the operation unit while viewing the information related to the zoom of the zoom lens L0 displayed on the display unit. In this case, the display unit and the operation unit may be integrated by adopting, for example, a touch panel.

[0074] The above embodiment includes the following configurations.

[0075] (Configuration 1) A zoom lens including a plurality of lens groups arranged in order from the object side to the image side, the plurality of lens groups being a first lens group having a negative refractive power and a rear group including two or more lens groups, the plurality of lens groups being arranged in order from the object side to the image side ... image side to the image side, The rear group is an aperture stop and a vibration isolation group having negative refractive power and moving in a direction perpendicular to the optical axis; a focus group on the object side of the image stabilization group, Let DSPw be the distance on the optical axis from the aperture stop to the image plane at the wide-angle end, and DISw be the distance on the optical axis from the aperture stop to the surface of the image stabilization group closest to the object at the wide-angle end. 0.40≦DISw / DSPw≦0.80 A zoom lens characterized by satisfying the following conditions. (Configuration 2) the focus group includes a positive lens; When the Abbe number of the positive lens for the d line is νdGP, 25≦νdGP≦45 2. The zoom lens according to claim 1, wherein the following condition is satisfied: (Configuration 3) The zoom lens according to configuration 1 or 2, wherein the total optical length of the zoom lens at the wide-angle end is TLw, and the distance on the optical axis from the surface of the zoom lens closest to the object to the surface of the focus group closest to the object is DLFw, satisfies the following conditional expression:

[0076] 0.48≦DLFw / TLw≦0.65 2. The zoom lens according to claim 1, wherein the following condition is satisfied: (Configuration 4) When the back focus of the zoom lens at the wide-angle end is Skw and the total optical length of the zoom lens at the wide-angle end is TLw, 0.04≦Skw / TLw≦0.25 4. The zoom lens according to any one of configurations 1 to 3, which satisfies the following condition: (Configuration 5) When the focal length of the first lens group is fL1 and the focal length of the second lens group is fLF, -0.45≦fL1 / fLF≦-0.15 5. The zoom lens according to any one of configurations 1 to 4, which satisfies the following condition: (Configuration 6) Let fL1 be the focal length of the first lens group, and fLN be the focal length of the lens group located closest to the image side in the zoom lens, 0.00<|fL1 / fLN|≦0.40 6. The zoom lens according to any one of configurations 1 to 5, which satisfies the following condition: (Configuration 7) Let fLN be the focal length of the lens group located closest to the image side in the zoom lens, and fLIS be the focal length of the image stabilization group. 0.50≦|fLN / fLIS|≦1.60 7. The zoom lens according to any one of configurations 1 to 6, which satisfies the following condition: (Configuration 8) the focus group includes a positive lens; When the refractive index of the positive lens for the d line is ndGP, 1.60≦ndGP≦1.91 8. The zoom lens according to any one of configurations 1 to 7, which satisfies the following condition: (Configuration 9) the vibration reduction group includes a negative lens, When the Abbe number of the negative lens for the d line is νdGIS, 35≦νdGIS≦60 9. The zoom lens according to any one of configurations 1 to 8, which satisfies the following condition: (Configuration 10) the first lens group includes at least one positive lens; When the Abbe number for the d-line of the positive lens having the strongest refractive power among the at least one positive lens is νdG1P, 22≦νdG1P≦50 10. The zoom lens according to any one of configurations 1 to 9, which satisfies the following condition: (Configuration 11) The image stabilization group includes a negative lens having a meniscus shape with a convex surface facing the object side. When the radius of curvature of the object side surface of the negative lens is R1 and the radius of curvature of the image side surface of the negative lens is R2, 3.5≦(R1+R2) / (R1-R2)≦13.0 11. The zoom lens according to any one of configurations 1 to 10, characterized in that the following condition is satisfied: (Configuration 12) When the maximum image height at the wide-angle end and in the infinity focused state is Ymax_w and the focal length of the first lens group is fL1, -1.60≦Ymax_w / fL1≦-0.40 12. The zoom lens according to any one of configurations 1 to 11, characterized in that the following condition is satisfied: (Configuration 13) When the amount of distortion at the wide-angle end and the maximum image height in the infinity focused state is Dist_w, -20≦Dist_w≦-8.0 13. The zoom lens according to any one of configurations 1 to 12, characterized in that the following condition is satisfied: (Configuration 14) 14. The zoom lens according to any one of configurations 1 to 13, further comprising a storage unit that stores correction data used to correct distortion of the zoom lens. (Configuration 15) 15. The zoom lens according to any one of configurations 1 to 14, wherein the first lens group has four or more negative lenses and at least one positive lens. (Configuration 16) 16. The zoom lens according to any one of configurations 1 to 15, wherein the first lens group moves during zooming. (Configuration 17) 17. The zoom lens according to any one of configurations 1 to 16, wherein the lens group arranged closest to the image side in the zoom lens has three or less lenses. (Configuration 18) 18. The zoom lens of any one of configurations 1 to 17, wherein at the wide-angle end, the distance between the first lens group and the second lens group is the largest among the distances between all lens groups included in the zoom lens. (Configuration 19) 19. The zoom lens according to any one of configurations 1 to 18, wherein the rear group has three or more lens groups whose spacing changes during zooming. (Configuration 20) 20. The zoom lens according to any one of configurations 1 to 19, wherein the lens group arranged closest to the image side in the zoom lens does not move during zooming. (Configuration 21) 21. The zoom lens according to any one of configurations 1 to 20, wherein the aperture stop is disposed closer to the object side than the focus group. (Configuration 22) The zoom lens according to any one of configurations 1 to 21, characterized in that the two or more lens groups included in the rear group consist of a second lens group with positive refractive power, a third lens group with positive refractive power, and a fourth lens group with positive refractive power, arranged in that order from the object side to the image side. (Configuration 23) The zoom lens according to any one of configurations 1 to 22, characterized in that the two or more lens groups included in the rear group consist of, arranged in order from the object side to the image side, a second lens group with positive refractive power, a third lens group with positive refractive power, a fourth lens group with negative refractive power, and a fifth lens group with positive refractive power. (Configuration 24) The zoom lens according to any one of configurations 1 to 23, characterized in that the two or more lens groups included in the rear group consist of, arranged in order from the object side to the image side, a second lens group with positive refractive power, a third lens group with negative refractive power, a fourth lens group with positive refractive power, and a fifth lens group with negative refractive power. (Configuration 25) The zoom lens according to any one of configurations 1 to 24, characterized in that the two or more lens groups included in the rear group consist of, arranged in order from the object side to the image side, a second lens group with positive refractive power, a third lens group with negative refractive power, a fourth lens group with positive refractive power, a fifth lens group with negative refractive power, and a sixth lens group with positive refractive power. (Configuration 26) The zoom lens according to any one of configurations 1 to 25, characterized in that the two or more lens groups included in the rear group consist of, arranged in order from the object side to the image side, a second lens group with negative refractive power, a third lens group with positive refractive power, a fourth lens group with negative refractive power, a fifth lens group with negative refractive power, and a sixth lens group with positive refractive power. (Configuration 27) The zoom lens according to any one of configurations 1 to 26, and an image sensor that receives an optical image formed by the zoom lens. (Configuration 28) 28. The imaging apparatus according to configuration 27, wherein an effective image circle diameter on the imaging element at the wide-angle end is smaller than an effective image circle diameter at the telephoto end. (Configuration 29) 29. The imaging apparatus according to configuration 27 or 28, wherein the imaging element moves together with the vibration isolation group in a direction perpendicular to the optical axis. (Configuration 30) The zoom lens according to any one of configurations 1 to 26, and a control unit that controls the zoom lens during zooming. (Configuration 31) 31. The imaging system according to configuration 30, wherein the control unit is configured separately from the zoom lens and has a transmission unit that transmits a control signal for controlling the zoom lens. (Configuration 32) 32. The imaging system according to configuration 30 or 31, wherein the control unit is configured as a separate entity from the zoom lens and has an operation unit for operating the zoom lens. (Configuration 33) 33. The imaging system according to any one of configurations 30 to 32, further comprising a display unit that displays information regarding the zoom of the zoom lens.

[0077] The embodiments described above are merely representative examples, and various modifications and alterations are possible for each embodiment when implementing the present invention. [Explanation of symbols]

[0078] L0 Zoom Lens L1 First lens group L2 Second lens group L3: Third lens group L4 4th lens group L5 Fifth lens group L6 6th lens group LR rear group LIS vibration isolation group LN: The lens group located closest to the image

Claims

1. A zoom lens comprising a first lens group having negative refractive power and a rear group including three or more lens groups, which are arranged in this order from an object side to an image side, and in which the spacing between adjacent lens groups changes during zooming, The rear group is an aperture stop; and a vibration-proof group having negative refractive power that moves during image blur correction so as to include a component in a direction perpendicular to the optical axis; a focus group on the object side of the image stabilization group, the image stabilization group includes a negative lens, the negative lens having a meniscus shape with a convex surface facing an object side, Let DSPw be the distance on the optical axis from the aperture stop to the image plane at the wide-angle end, DISw be the distance on the optical axis from the aperture stop to the surface of the image-side vibration control group closest to the object, R1 be the radius of curvature of the object-side surface of the negative lens, and R2 be the radius of curvature of the image-side surface of the negative lens. 0.45≦DISw / DSPw≦0.80 3.5≦(R1+R2) / (R1-R2)≦13.0 A zoom lens characterized by satisfying the following conditions.

2. the focus group includes a positive lens; When the Abbe number of the positive lens with respect to the d line is νdGP, 25≦νdGP≦45 2. The zoom lens according to claim 1, which satisfies the following condition:

3. 2. The zoom lens according to claim 1, wherein the total optical length of the zoom lens at a wide-angle end is TLw, and the distance on the optical axis from the surface of the zoom lens closest to the object side to the surface of the focus group closest to the object side is DLFw, and the following conditional expression is satisfied: 0.48≦DLFw / TLw≦0.65 2. The zoom lens according to claim 1, which satisfies the following condition:

4. When the back focus of the zoom lens at the wide-angle end is Skw and the total optical length of the zoom lens at the wide-angle end is TLw, 0.04≦Skw / TLw≦0.25 2. The zoom lens according to claim 1, which satisfies the following condition:

5. A second lens group is disposed closest to the object side among the lens groups included in the rear group, When the focal length of the first lens group is fL1 and the focal length of the second lens group is fLF, −0.45≦fL1 / fLF≦−0.15 2. The zoom lens according to claim 1, which satisfies the following condition:

6. When the focal length of the first lens group is fL1 and the focal length of the lens group disposed closest to the image side in the zoom lens is fLN, 0.00<|fL1 / fLN|≦0.40 2. The zoom lens according to claim 1, which satisfies the following condition:

7. Let fLN be the focal length of the lens group disposed closest to the image side in the zoom lens, and fLIS be the focal length of the image stabilization group. 0.50≦|fLN / fLIS|≦1.60 2. The zoom lens according to claim 1, which satisfies the following condition:

8. the focus group includes a positive lens; When the refractive index of the positive lens with respect to the d line is ndGP, 1.60≦ndGP≦1.91 2. The zoom lens according to claim 1, which satisfies the following condition:

9. the vibration reduction group includes a negative lens, When the Abbe number of the negative lens with respect to the d-line is νdGIS, 35≦νdGIS≦60 2. The zoom lens according to claim 1, which satisfies the following condition:

10. the first lens group includes at least one positive lens; When the Abbe number for the d-line of the positive lens having the strongest refractive power among the at least one positive lens is νdG1P, 22≦νdG1P≦50 2. The zoom lens according to claim 1, which satisfies the following condition:

11. When the maximum image height at the wide-angle end and in the infinity focused state is Ymax_w and the focal length of the first lens group is fL1, -1.60≦Ymax_w / fL1≦-0.40 2. The zoom lens according to claim 1, which satisfies the following condition:

12. When the amount of distortion at the wide-angle end and at the maximum image height in the infinity focused state is Dist_w, −20≦Dist_w≦−8.0 2. The zoom lens according to claim 1, which satisfies the following condition:

13. 2. The zoom lens according to claim 1, further comprising a storage unit for storing correction data used for correcting distortion of the zoom lens.

14. 2. The zoom lens according to claim 1, wherein the first lens group comprises four or more negative lenses and at least one positive lens.

15. 2. The zoom lens according to claim 1, wherein the first lens group moves during zooming.

16. 2. The zoom lens according to claim 1, wherein the lens group disposed closest to the image side in the zoom lens has three or less lenses.

17. A second lens group is disposed closest to the object side among the lens groups included in the rear group, 2. The zoom lens according to claim 1, wherein at a wide-angle end, the distance between the first lens group and the second lens group is the largest among the distances between all lens groups included in the zoom lens.

18. 2. The zoom lens according to claim 1, wherein the rear group has three or more lens groups whose spacing changes during zooming.

19. 2. The zoom lens according to claim 1, wherein the lens unit disposed closest to the image side in the zoom lens does not move during zooming.

20. 2. The zoom lens according to claim 1, wherein the aperture stop is disposed closer to the object side than the focus unit.

21. 2. The zoom lens according to claim 1, wherein the two or more lens groups included in the rear group consist of, arranged in order from the object side to the image side, a second lens group having positive refractive power, a third lens group having positive refractive power, and a fourth lens group having positive refractive power.

22. 2. The zoom lens according to claim 1, wherein the two or more lens groups included in the rear group consist of, arranged in order from the object side to the image side, a second lens group having positive refractive power, a third lens group having positive refractive power, a fourth lens group having negative refractive power, and a fifth lens group having positive refractive power.

23. 2. The zoom lens according to claim 1, wherein the two or more lens groups included in the rear group consist of, arranged in order from the object side to the image side, a second lens group having positive refractive power, a third lens group having negative refractive power, a fourth lens group having positive refractive power, and a fifth lens group having negative refractive power.

24. 2. The zoom lens according to claim 1, wherein the two or more lens groups included in the rear group consist of, arranged in order from the object side to the image side, a second lens group having positive refractive power, a third lens group having negative refractive power, a fourth lens group having positive refractive power, a fifth lens group having negative refractive power, and a sixth lens group having positive refractive power.

25. 2. The zoom lens according to claim 1, wherein the two or more lens groups included in the rear group consist of, arranged in order from the object side to the image side, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having positive refractive power, and a fifth lens group having positive refractive power.

26. A zoom lens according to any one of claims 1 to 25; and an image sensor that receives an optical image formed by the zoom lens.

27. 27. The image pickup apparatus according to claim 26, wherein an effective image circle diameter on said image pickup element at a wide-angle end is smaller than an effective image circle diameter at a telephoto end.

28. 27. The image pickup apparatus according to claim 26, wherein the image pickup element moves together with the vibration isolation group in a direction perpendicular to the optical axis.

29. A zoom lens according to any one of claims 1 to 25; and a control unit that controls the zoom lens during zooming.

30. 30. The imaging system according to claim 29, wherein the control unit is configured as a separate unit from the zoom lens and includes a transmission unit that transmits a control signal for controlling the zoom lens.

31. 30. The imaging system according to claim 29, wherein the control unit is configured as a separate unit from the zoom lens, and has an operation unit for operating the zoom lens.

32. 30. The imaging system according to claim 29, further comprising a display unit that displays information related to the zoom of the zoom lens.

Images