Zoom lens and imaging device

Abstract

To provide a compact, lightweight and wide-view-angle zoom lens having a high variable power ratio.SOLUTION: The zoom lens comprises a positive first lens group that does not move for zooming, three or more intermediate lens groups that move for zooming, and a positive rear lens group. The first lens group includes a negative first sub-lens group that does not move for focusing, a positive second sub-lens group that moves for focusing, and a positive third lens group. f1 representing the focal distance of the first lens group, bok1 representing the length on optical axis from the most image side lens face of the first lens group to the rear side main point of the first lens group when focused on an infinite distance object, and fw, ft representing the focal distance at the wide angle end and at the telephoto end of the zoom lens satisfy the conditions 2.430≤(f1+bok1) / f1≤4.500, 1.150≤ft / f1≤3.200, and 2.250≤f1 / fw≤6.700.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Zoom lenses used in imaging devices such as television cameras, movie cameras, digital still cameras, and video cameras are required to have high optical performance, such as being small and lightweight, having a wide angle of view, a high zoom ratio, high resolution from the center to the periphery of the optical axis, and little chromatic aberration.

[0003] Patent Document 1 discloses a zoom lens having, arranged in order from the object side to the image side, a first lens group with positive refractive power that does not move for zooming, three or more intermediate lens groups that move for zooming, and a rear lens group with positive refractive power that does not move for zooming. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-032924 Summary of the Invention [Problem to be solved by the invention]

[0005] In the zoom lens disclosed in Patent Document 1, if the angle of view is further increased or the zoom ratio is further increased, the diameter of the first lens group increases, and the zoom lens becomes larger.

[0006] The present invention provides a zoom lens that is small and lightweight, has high optical performance, and is capable of achieving a wide angle of view and a high zoom ratio, and an imaging apparatus equipped with the same. [Means for solving the problem]

[0007] A zoom lens according to one aspect of the present invention has lens groups arranged in order from the object side to the image side, including a first lens group with positive refractive power that does not move for zooming, three or more intermediate lens groups that move for zooming, and a rear lens group with positive refractive power, and the spacing between adjacent lens groups changes during zooming. The first lens group has a first sub-lens group with negative refractive power that does not move for focusing, a second sub-lens group with positive refractive power that moves for focusing, and a third sub-lens group with positive refractive power, which are arranged in order from the object side to the image side. Let f1 be the focal length of the first lens group, bok1 be the length on the optical axis from the lens surface of the first lens group closest to the image to the rear principal point of the first lens group when focused on an object at infinity, fw be the focal length at the wide-angle end of the zoom lens, and ft be the focal length at the telephoto end of the zoom lens. 2.430≦(f1+bok1) / f1≦4.500 1.150≦ft / f1≦3.200 2.250≦f1 / fw≦6.700 The present invention is characterized in that it satisfies the following conditions.

[0008] A zoom lens according to another aspect of the present invention has a first lens group having positive refractive power that does not move for zooming, three or more intermediate lens groups that move for zooming, an aperture stop, and a rear lens group having positive refractive power, which are arranged in order from the object side to the image side, and the distance between adjacent lens groups changes during zooming. The aperture stop is arranged in or adjacent to any of the intermediate lens groups among the three or more intermediate lens groups, and moves together with any of the intermediate lens groups during zooming. The first lens group has a first sub-lens group having negative refractive power that does not move for focusing, a second sub-lens group having positive refractive power that moves for focusing, and a third sub-lens group having positive refractive power, which are arranged in order from the object side to the image side. Let f1 be the focal length of the first lens group, bok1 be the length on the optical axis from the lens surface of the first lens group closest to the image side to the rear principal point of the first lens group when focused on an object at infinity, fw be the focal length at the wide-angle end of the zoom lens, and ft be the focal length at the telephoto end of the zoom lens. 2.000≦(f1+bok1) / f1≦4.500 1.950≦ft / f1≦3.200 The present invention is characterized in that the above conditions are satisfied. An image pickup apparatus including 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 and lightweight, has high optical performance, and is capable of achieving a wide angle of view and a high zoom ratio. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a cross-sectional view of the zoom lens of the first embodiment at the wide-angle end. [Diagram 2] 5A to 5C are aberration diagrams at the wide-angle end and the telephoto end in the zoom lens of the first embodiment. [Diagram 3] FIG. 11 is a cross-sectional view of a zoom lens at a wide-angle end according to a second embodiment. [Figure 4] 8A to 8C are aberration diagrams at the wide-angle end and the telephoto end in the zoom lens of Example 2. [Diagram 5] FIG. 11 is a cross-sectional view of a zoom lens at a wide-angle end according to a third embodiment. [Figure 6] 11A to 11C are aberration diagrams at the wide-angle end and the telephoto end in the zoom lens of Example 3. [Figure 7] FIG. 11 is a cross-sectional view of a zoom lens at a wide-angle end according to a fourth embodiment. [Figure 8] 11A to 11C are aberration diagrams at the wide-angle end and the telephoto end in the zoom lens of Example 4. [Figure 9] FIG. 13 is a cross-sectional view of a zoom lens at a wide-angle end according to a fifth embodiment. [Figure 10] 13A to 13C are aberration diagrams at the wide-angle end and the telephoto end in the zoom lens of Example 5. [Figure 11] FIG. 13 is a cross-sectional view of a zoom lens at a wide-angle end according to a sixth embodiment. [Figure 12] 13A to 13C are aberration diagrams at the wide-angle end and the telephoto end in the zoom lens of Example 6. [Figure 13] FIG. 1 is a diagram showing an image pickup apparatus equipped with a zoom lens according to any one of Examples 1 to 6. FIG. [Figure 14] FIG. 2 is a graph showing the relationship between the Abbe number ν and the partial dispersion ratio θ of an optical material. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, an overview of the zoom lenses of Examples 1 to 6 will be described. Figures 1, 3, 5, 7, 9, and 11 respectively show cross sections of the zoom lenses of Examples 1, 2, 3, 4, 5, and 6 in a state where the lenses are focused on an object at infinity (hereinafter, referred to as an infinity focused state) at the wide-angle end.

[0012] In a zoom lens, 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. That is, 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 zoom states with 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. A sub-lens group is a group of one or more lenses that move together during focus adjustment (focusing). That is, the spacing between adjacent sub-lens groups changes during focusing.

[0013] In each figure, the left side is the object side and the right side is the image side. Li (i = 1, 2, 3, ...) indicates the i-th lens group, which is the i-th lens group counted from the object side, and below the lens groups that move for zooming, the movement trajectory of each lens group when zooming from the wide-angle end to the telephoto end is shown.

[0014] L1 is a first lens group with positive refractive power that does not move for zooming. The first sub-lens group 1a in the first lens group L1 does not move for focusing, and the second sub-lens group 1b moves toward the image side when focusing from an infinity object to a close object. The third sub-lens group 1c in the first lens group L1 does not move for focusing.

[0015] L2 to Lm (m=4 in Examples 1, 3 to 6, m=5 in Example 2) are three or more intermediate lens groups that move for zooming, where L2 is a first intermediate lens group with negative refractive power, L3 is a second intermediate lens group with positive or negative refractive power, and L4 is a third intermediate lens group with positive refractive power. L5 in Example 2 is a fourth intermediate lens group with positive refractive power. The first intermediate lens group L2 moves monotonically on the optical axis toward the image side for zooming from the wide-angle end to the telephoto end. The second intermediate lens group L3 moves monotonically on the optical axis to draw a convex locus toward the object side (Examples 1, 3, and 6) or monotonically (Examples 2, 4, and 5) for zooming from the wide-angle end to the telephoto end. The third intermediate lens group L4 and the fourth intermediate lens group L5 in Example 2 move on the optical axis non-monotonically toward the image side and the object side (Examples 1, 2, 3, 4, and 6) or monotonically toward the image side (Example 5) for zooming from the wide-angle end to the telephoto end.

[0016] SP denotes an aperture stop. The aperture stop SP is provided in the third intermediate lens group L4 (Examples 1 and 3 to 6) or the fourth intermediate lens group L5 (Example 2), and moves together with these intermediate lens groups during zooming.

[0017] Ln (n=5 in Examples 1, 3 to 6, and n=6 in Example 2) is a rear lens group having positive refractive power. In each example, the rear lens group does not move for zooming, but the entirety or a part of the rear lens group (sub lens group) may move.

[0018] I is the image plane of the zoom lens. The image pickup surface (light receiving surface) of the image sensor and the film surface (photosensitive surface) of the silver halide film are disposed on the image plane I. GB is a glass block with no refractive power, such as a prism, disposed between the rear lens group Ln and the image plane I.

[0019] As described above, the zoom lens of each embodiment has, as lens groups arranged in order from the object side to the image side, a first lens group with positive refractive power that does not move for zooming, three or more intermediate lens groups that move for zooming, and a rear lens group with positive refractive power.

[0020] The first lens group includes a first sub-lens group having negative refractive power that does not move for focusing, a second sub-lens group having positive refractive power that moves for focusing, and a third sub-lens group having positive refractive power, which are arranged in this order from the object side to the image side. The third sub-lens group may not move for focusing as in each embodiment, or may move so as to change the distance between the third sub-lens group and the second sub-lens group. The first lens group may include a sub-lens group that may or may not move during focusing other than the first to third sub-lens groups.

[0021] In the zoom lens of each embodiment, the focal length of the first lens group is f1, and the length on the optical axis from the lens surface of the first lens group closest to the image side to the rear principal point of the first lens group when focused at infinity is bok1. The focal length of the zoom lens at the wide-angle end is fw, and the focal length of the zoom lens at the telephoto end is ft. In this case, the zoom lens of each embodiment has the following: 2.430≦(f1+bok1) / f1≦4.500 (1-1) 1.150≦ft / f1≦3.200 (2-1) 2.250≦f1 / fw≦6.700 (3) The following conditions are satisfied.

[0022] The zoom lens of each embodiment has a first lens group having positive refractive power that does not move for zooming, three or more intermediate lens groups that move for zooming, an aperture stop, and a rear lens group having positive refractive power, which are arranged in order from the object side to the image side. The aperture stop is arranged in one of the three or more intermediate lens groups and moves together with the intermediate lens group during zooming. The aperture stop may be arranged adjacent to one of the intermediate lens groups. The first lens group has a first sub lens group having negative refractive power that does not move for focusing, a second sub lens group having positive refractive power that moves for focusing, and a third sub lens group having positive refractive power, which are arranged in order from the object side to the image side. The third sub lens group may not move for focusing as in each embodiment, or may move to change the distance between the second sub lens group and the first lens group.

[0023] The zoom lens of each embodiment has the following features: 2.000≦(f1+bok1) / f1≦4.500 (1-2) 1.950≦ft / f1≦3.200 (2-2) The following conditions are satisfied.

[0024] Equations (1-1) and (1-2) show the conditions for obtaining a zoom lens that has a wide angle of view and is small and lightweight. (f1+bok1) / f1 is the retro ratio of the first lens group. Increasing the retro ratio is advantageous for a wide angle of view, but increases the diameter of the third sub-lens group and the number of lenses constituting the first lens group. If (f1+bok1) / f1 exceeds the upper limit of equation (1-1) or equation (1-2), the retro ratio of the first lens group becomes excessively large, and the diameter of the third sub-lens group increases, which is disadvantageous for obtaining a small and lightweight zoom lens, which is not preferable. Also, the number of lenses in the first lens group increases, which is disadvantageous for obtaining a small and lightweight zoom lens, which is not preferable. If (f1+bok1) / f1 falls below the lower limit of equations (1-1) and (1-2), the retro ratio of the first lens group becomes excessively small, which makes it difficult to obtain a zoom lens with a wide angle of view, which is not preferable. Furthermore, the diameter of the lens in the first lens group closest to the object increases, which is unfavorable for achieving a small and lightweight zoom lens.

[0025] Equations (2-1) and (2-2) show the conditions for obtaining a zoom lens with a high zoom ratio, small size, light weight, and high optical performance. Increasing ft / f1 is advantageous for obtaining a zoom lens with a high zoom ratio, but the aberration occurring in the first lens group is magnified at the telephoto end, making it difficult to keep the aberration within the allowable range. If ft / f1 exceeds the upper limit of equation (2-1) or equation (2-2), the focal length of the first lens group becomes too short, making it difficult to keep the aberration occurring in the first lens group within the allowable range at the telephoto end, which is not preferable. In addition, the number of lenses constituting the first lens group becomes too large, which is disadvantageous for obtaining a small and lightweight zoom lens, which is not preferable. If ft / f1 falls below the lower limit of equation (2-1) or equation (2-2), the focal length of the first lens group becomes too long, making it difficult to obtain a zoom lens with a high zoom ratio, which is not preferable. Moreover, the amount of movement of the intermediate lens group becomes excessively large, which is unfavorable for achieving a small and lightweight zoom lens.

[0026] Formula (3) shows the conditions for obtaining a zoom lens that has a wide angle of view, is small and lightweight, and has high optical performance. If f1 / fw exceeds the upper limit of formula (3), the diameter of the first lens group becomes large, which is undesirable because it becomes difficult to obtain a small zoom lens. If f1 / fw falls below the lower limit of formula (3), it becomes difficult to obtain a zoom lens with a wide angle of view, and it becomes difficult to keep aberrations (coma aberration, field curvature, etc.) at the wide-angle end within the allowable range, which is also undesirable.

[0027] By satisfying the above conditions of expressions (1-1), (2-1), and (3) or (1-2) and (2-2), it is possible to realize a zoom lens that is small and lightweight, has high optical performance, and is capable of achieving a wide angle of view and a high zoom ratio.

[0028] It is preferable that the zoom lens of each embodiment satisfies at least one of the conditions shown in the following expressions (4) to (15).

[0029] The first lens group has a negative lens G1 closest to the object side, and the focal length of the negative lens G1 is fG1. -2.10≦ft / fG1≦-0.50 (4) It is preferable to satisfy the following condition. Expression (4) shows the condition for obtaining a zoom lens having a high zoom ratio, small size, light weight, and high optical performance. When ft / fG1 exceeds the upper limit of expression (4), the focal length of the negative lens G1 becomes excessively long, and the entrance pupil of the zoom lens is located excessively toward the object side. As a result, the diameter of the first sub-lens group increases, making it difficult to obtain a small first lens group, which is not preferable. It is also difficult to obtain a zoom lens with a high zoom ratio, which is not preferable. When ft / fG1 falls below the lower limit of expression (4), the focal length of the negative lens G1 becomes excessively short, and the diameter of the axial light beam at the telephoto end increases. As a result, the diameter of the third sub-lens group increases, making it difficult to obtain a small first lens group, which is not preferable.

[0030] The first sub-lens group of the first lens group has a positive lens Gp, and the focal length of the positive lens Gp is ​​fGp. 0.40≦ft / fGp≦10.60 (5) It is preferable to satisfy the following condition. Expression (5) shows the condition for obtaining a first lens group in which chromatic aberration is well corrected. When ft / fGp exceeds the upper limit of expression (5), the focal length of the positive lens G1p becomes excessively short, making it difficult to correct spherical aberration at the telephoto end. As a result, it becomes difficult to obtain a first lens group in which aberration is well corrected, which is not preferable. It also becomes difficult to obtain a zoom lens with a high zoom ratio, which is not preferable. When ft / fGp exceeds the upper limit of expression (5), the focal length of the positive lens G1p becomes excessively long, making it difficult to satisfactorily correct chromatic aberration of the first sub-lens group. As a result, it becomes difficult to obtain a first lens group in which chromatic aberration is well corrected, which is not preferable.

[0031] The focal length of the first sub-lens group is f1a, the focal length of the second sub-lens group is f1b, and the focal length of the third sub-lens group is f1c. In this case, it is preferable that the zoom lenses of Examples 1 to 3 satisfy the conditions of the following expressions (6) to (8).

[0032] -1.50≦f1a / f1≦-0.60 (6) 2.00≦f1b / f1≦6.50 (7) 1.30≦f1c / f1≦4.50 (8) Each of the formulas (6) to (8) indicates a condition for obtaining a zoom lens with high optical performance. If the condition of formula (6) is not satisfied, the focal length f1 of the first lens group or the focal length f1a of the first sub lens group becomes excessively small, which is undesirable because it is difficult to keep the aberration occurring in the first lens group or the first sub lens group within the allowable range. If the condition of formula (7) is not satisfied, the focal length f1 of the first lens group or the focal length f1b of the second sub lens group becomes excessively small, which is undesirable because it is difficult to keep the aberration occurring in the first lens group or the second sub lens group within the allowable range. If the condition of formula (8) is not satisfied, the focal length f1 of the first lens group or the focal length f1c of the third sub lens group becomes excessively small, which is undesirable because it is difficult to keep the aberration occurring in the first lens group or the third sub lens group within the allowable range.

[0033] Also, the thickness on the optical axis from the lens surface of the first lens group closest to the object side to the lens surface closest to the image side is defined as LD1. 1.10≦LD1 / f1≦6.50 (9) It is preferable to satisfy the following condition. Expression (9) shows the condition for obtaining a zoom lens that is small, lightweight, and has high optical performance. If LD1 / f1 exceeds the upper limit of expression (9), the thickness of the first lens group becomes excessively large, making it difficult to obtain a small, lightweight zoom lens, which is not preferable. Also, the focal length of the first lens group becomes excessively short, making it difficult to keep the variation in aberration caused by focusing at the telephoto end within an allowable range, which is not preferable. If LD1 / f1 falls below the lower limit of expression (9), the thickness of the first lens group becomes excessively small, making it difficult to provide the number of lenses necessary to suppress the variation in aberration caused by focusing, which is not preferable. Also, the focal length of the first lens group becomes excessively long, making the amount of movement of the intermediate lens group for zooming excessive, making it difficult to obtain a small, lightweight zoom lens, which is not preferable.

[0034] When the zoom lens of each embodiment is used in an imaging device having an imaging surface with a diagonal size of 2Y, the half angle of view of the zoom lens at the wide-angle end is ω. 51.50°≦ωw≦65.00° (10) However, the half angle of view ωw is expressed as follows, using the focal length fw at the wide-angle end of the zoom lens: ωw=arctan(Y / fw) It is defined as follows. Equation (10) shows the condition for obtaining a zoom lens that has a wide angle of view and is small and lightweight. By satisfying the condition of equation (10), it is possible to obtain a wide angle in various format sizes. In particular, if ωw exceeds the upper limit of equation (10), it becomes difficult to obtain a small and lightweight zoom lens, which is not preferable.

[0035] The F-number of a zoom lens at the wide-angle end is Fnow. In this case, 1.30≦Fnow≦3.50 (11) It is preferable to satisfy the following condition. Expression (11) shows the condition for obtaining a small, lightweight, and bright zoom lens. If Fnow falls below the lower limit of expression (11), it is difficult to keep aberrations (spherical aberration, astigmatism, etc.) at the wide-angle end within the allowable range, which is not preferable. Also, in order to obtain high optical performance, each lens group becomes excessively large, which makes it difficult to obtain a small, lightweight zoom lens, which is not preferable. If Fnow exceeds the upper limit of expression (11), it is difficult to obtain a bright zoom lens, which is not preferable.

[0036] The length on the optical axis from the image side lens surface of the lens closest to the image side among the lenses (herein, an element having a finite focal length is called a lens) included in the zoom lens to the image plane is defined as BFw. In this case, 0.050≦fw / BFw≦0.430 (12) It is preferable to satisfy the following condition. Expression (12) shows the condition for obtaining a zoom lens that has a wide angle of view and is small and lightweight. If fw / BFw exceeds the upper limit of expression (12), the focal length at the wide-angle end becomes excessively long relative to the back focus of the zoom lens, making it difficult to obtain a zoom lens with a wide angle of view, which is not preferable. If fw / BFw falls below the lower limit of expression (12), the back focus becomes excessively long relative to the focal length at the wide-angle end, making it difficult to obtain a zoom lens that is small and lightweight, which is not preferable.

[0037] The length from the lens surface of the first lens group closest to the object to the aperture stop when the lens is focused at infinity and at the wide-angle end is LDs, and the total optical length of the zoom lens when the lens is focused at infinity and at the wide-angle end (the length on the optical axis from the lens surface of the first lens group closest to the object to the lens surface of the rear lens group closest to the image) is LT. In this case, 0.20≦LDs / LT≦0.60 (13) It is preferable to satisfy the following condition. Expression (13) shows the condition for obtaining a zoom lens that has a wide angle of view and is small and lightweight. If LDs / LT exceeds the upper limit of expression (13), the aperture diaphragm is disposed too far from the surface of the first lens group closest to the object. As a result, in order to realize a zoom lens with a wide angle of view, the diameter of the first lens group becomes too large, which is undesirable because it is difficult to obtain a zoom lens that has a wide angle of view and is small and lightweight. If LDs / LT falls below the lower limit of expression (13), the aperture diaphragm is disposed too far from the rear lens surface. As a result, the diameter of the rear lens group becomes too large, which is undesirable because it is difficult to obtain a zoom lens that is small and lightweight.

[0038] The average value of the refractive index at the d line (wavelength 587.6 nm) of at least one negative lens included in the first lens group is denoted by nd1n. In this case, 1.750≦nd1n≦2.000 (14) It is preferable to satisfy the following condition. Expression (14) shows the condition for obtaining a zoom lens that is small, lightweight, and has high optical performance. If nd1n is below the lower limit of expression (14), it is difficult to obtain a lightweight first lens group because optical materials (glass materials) with high refractive indexes tend to have high specific gravity, which is undesirable. If nd1n is below the lower limit of expression (14), the refractive index becomes excessively small, making it difficult to keep aberrations within the allowable range, which is undesirable.

[0039] The first sub-lens group has a positive lens L1ap, and the Abbe number of the positive lens L1ap based on the d-line is νd1ap. 17.0≦νd1ap≦35.0 (15) It is preferable to satisfy the following condition. Equation (15) shows the condition for suppressing the axial chromatic aberration at the telephoto end and the variation of the axial chromatic aberration due to focusing. FIG. 14 shows the relationship between the Abbe number ν and the partial dispersion ratio θ of the optical material. As can be seen from this figure, the optical material has a tendency to show anomalous dispersion such that the partial dispersion ratio deviates from the straight line shown by the broken line as the dispersion increases. If νd1ap exceeds the upper limit of Equation (15), it is difficult to keep the variation of the secondary spectrum of the axial chromatic aberration due to focusing within the allowable range, which is not preferable. If νd1ap falls below the lower limit of Equation (15), the anomalous dispersion becomes excessively high, and it is difficult to keep the secondary spectrum of the axial chromatic aberration at the telephoto end within the allowable range, which is not preferable. The positive lens L1ap may be a lens different from the positive lens Gp or may be the same lens. In each numerical example described later, the positive lens Gp and the positive lens L1ap are the same lens.

[0040] As described above, by having the first lens group comprise a negative first sub-lens group that does not move for focusing, a positive second sub-lens group that moves for focusing, and a positive third sub-lens group, it is possible to keep the fluctuation in aberration due to focusing within an acceptable range.

[0041] In the zoom lens of each embodiment, it is desirable that the aperture diaphragm is disposed within or adjacent to the intermediate lens group and does not move during zooming, thereby making it possible to secure a space for the intermediate lens group to move in order to obtain a zoom lens with a high zoom ratio.

[0042] In addition, it is preferable that the first sub-lens group has two or more negative lenses. If the first sub-lens group has only one negative lens, the refractive power of the negative lens needs to be strong in order to correct chromatic aberration in the first lens group, which makes it difficult to correct various aberrations other than chromatic aberration, such as spherical aberration, and this is not preferable. Furthermore, it is preferable that the two or more negative lenses are arranged consecutively in order from the object side to the image side in the first sub-lens group. Such an arrangement is advantageous for making the first sub-lens group small and lightweight.

[0043] It is more preferable that the numerical ranges of the formulas (1-1) to (15) are as follows:

[0044] 2.430≦(f1+bok1) / f1≦4.000 (1-1a) 1.150≦ft / f1≦3.000 (2-1a) 2.300≦f1 / fw≦6.500 (3a) 2.200≦(f1+bok1) / f1≦3.200 (1-2a) 2.000≦ft / f1≦2.950 (2-2a) -1.90≦ft / fG1≦-0.70 (4a) 0.60≦ft / fGp≦10.40 (5a) -1.30≦f1a / f1≦-0.70 (6a) 2.20≦f1b / f1≦6.45 (7a) 1.50≦f1c / f1≦4.00 (8a) 1.30≦LD1 / f1≦6.30 (9a) 51.70°≦ωw≦60.00° (10a) 1.50≦Fnow≦3.30 (11a) 0.055≦fw / BFw≦0.400 (12a) 0.30≦LDs / LT≦0.55 (13a) 1.770≦nd1n≦1.950 (14a) 17.0≦νd1ap≦29.0 (15a) It is more preferable that the numerical ranges of the formulas (1-1) to (15) are as follows:

[0045] 2.530≦(f1+bok1) / f1≦3.200 (1-1b) 1.150≦ft / f1≦2.950 (2-1b) 2.350≦f1 / fw≦6.500 (3b) 2.400≦(f1+bok1) / f1≦3.200 (1-2b) 2.040≦ft / f1≦2.500 (2-2b) -1.86≦ft / fG1≦-0.90 (4b) 0.80≦ft / fGp≦5.00 (5b) -1.10≦f1a / f1≦-0.95 (6b) 2.40≦f1b / f1≦6.45 (7b) 1.60≦f1c / f1≦3.80 (8b) 2.00≦LD1 / f1≦5.00 (9b) 52.00°≦ωw≦55.00° (10b) 1.70≦Fnow≦3.00 (11b) 0.065≦fw / BFw≦0.380 (12b) 0.40≦LDs / LT≦0.55 (13b) 1.770≦nd1n≦1.850 (14b) 17.0≦νd1ap≦26.0 (15b) Numerical Examples 1 to 6 corresponding to Examples 1 to 6 are shown below. In each numerical example, surface number i indicates the order of the surface when counted from the object side. r is the radius of curvature (mm) of the i-th surface from the object side, d is the lens thickness or air space (mm) between the i-th and (i+1)-th surfaces, and nd is the refractive index at the d-line of the optical material between the i-th and (i+1)-th surfaces. νd is the Abbe number based on the d-line of the optical material between the i-th and (i+1)-th surfaces. The Abbe number νd based on the d-line is expressed as follows, when the refractive indices at the d-line (wavelength 587.6 nm), F-line (wavelength 486.1 nm), and C-line (wavelength 656.3 nm) of the Fraunhofer lines are Nd, NF, and NC, respectively: νd=(Nd-1) / (NF-NC) It is expressed as:

[0046] θgF is the partial dispersion ratio, and when the refractive index at the g line (wavelength 435.8 nm) is Ng, θgF=(Ng-NF) / (NF-NC) The effective diameter is the diameter (mm) of the area of ​​the i-th lens surface through which light rays that contribute to image formation pass.

[0047] In each numerical example, the half angle of view (°) of the zoom lens is shown, and the maximum image height corresponding to the half angle of view is shown as "image height." The half angle of view ω is expressed as follows: fw is the focal length at the wide-angle end of a zoom lens used in an imaging device having an imaging surface of diagonal size 2Y. ω=arctan(Y / fw) The maximum image height corresponds to Y, which is half the diagonal size 2Y (for example, 29.60 mm).

[0048] In each numerical example, the focal length of each lens group at the d-line is shown as lens group data. Furthermore, in each numerical example, BF represents the back focus (mm). The back focus is the distance on the optical axis from the final surface of the zoom lens (the lens surface closest to the image) to the paraxial image plane, expressed as an air-equivalent length. The total lens length (total optical length) is the distance on the optical axis from the foreground surface of the zoom lens (the lens surface closest to the object) to the final surface plus the back focus.

[0049] An "*" next to a surface number means that the surface has an aspheric shape. An aspheric shape is expressed by the following formula, 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, the light traveling direction is positive, R is the paraxial radius of curvature, K is the conic constant, and A2 to A16 are aspheric coefficients. The conic constant and the aspheric coefficients "e±x" are ×10 ±x means.

[0050]

number

[0051] As described above, in the first to sixth embodiments, the rear lens group does not move for zooming, but the entire rear lens group or a part of it (sub lens group) may be moved. Even when the entire rear lens group or a part of it moves, by satisfying the conditions of the above-mentioned formulas (1-1) or (1-2) to (3), a zoom lens that is small and lightweight, has high optical performance, and can achieve a wide angle of view and a high variable magnification ratio can be realized. For example, in the first embodiment (Numerical Example 1), the portion of the 40th to 49th surfaces in the rear lens group L5 may be moved for zooming. Since a substantially afocal light beam is incident on this portion from the object side, even if this portion moves, the optical characteristics other than the back focus do not change substantially. Therefore, this portion can be used as a sub lens group that moves to compensate for the change in focus. The cause of the change in focus that is compensated for by the movement of the entire rear lens group or the sub lens group is at least one of the manufacturing error, temperature change, and attitude change of the zoom lens.

[0052] 2(A), 4(A), 6(A), 8(A), 10(A), and 12(A) respectively show longitudinal aberrations (spherical aberration, astigmatism, distortion, and chromatic aberration) at the wide-angle end of the zoom lenses of Numerical Examples 1 to 6. Fig. 2(B), 4(B), 6(B), 8(B), 10(B), and 12(B) respectively show longitudinal aberrations at the telephoto end of the zoom lenses of Numerical Examples 1 to 6.

[0053] In the spherical aberration diagram, Fno indicates the F-number, the solid line indicates the spherical aberration for the d-line (wavelength 587.6 nm), and the two-dot chain line indicates the spherical aberration for the g-line (wavelength 435.8 nm). In the astigmatism diagram, the solid line S indicates the astigmatism on the sagittal image plane, and the dashed line M indicates the astigmatism on the meridional image plane. The distortion diagram shows the distortion aberration at the d-line. The chromatic aberration diagram shows the lateral chromatic aberration at the g-line. ω is the half angle of view (°).

[0054] Moreover, the values ​​of the formulas (1-1) and (1-2) to (15) in each numerical example are summarized in Table 1. [Numerical example 1] Unit: mm Surface Data Surface number rd nd νd θgf Effective diameter 1* -945.881 2.50 1.83481 42.7 0.5648 80.48 2 29.270 18.31 54.30 3* 280.173 2.00 1.83481 42.7 0.5648 53.75 4 155.870 5.45 52.52 5 -375.961 1.80 1.83481 42.7 0.5648 51.60 6 225.928 0.15 50.99 7 84.818 3.18 1.92286 18.9 0.6495 50.77 8 163.735 1.67 50.35 9 105.795 7.28 1.60300 65.4 0.5401 50.50 10* -150.548 4.41 50.53 11 -4717.965 4.81 1.43387 95.1 0.5373 51.08 12 -94.980 0.30 51.23 13 -88.919 1.70 1.80000 29.8 0.6017 51.23 14 -232.086 0.18 52.15 15 175.795 1.70 1.91650 31.6 0.5911 53.05 16 49.947 16.88 1.43875 94.7 0.5340 52.95 17 -59.093 0.40 54.17 18 96.943 9.06 1.43387 95.1 0.5373 57.99 19 -139.950 0.40 58.13 20 226.739 8.09 1.76385 48.5 0.5589 57.84 21 -96.159 (variable) 57.58 22 116.531 0.70 2.00100 29.1 0.5997 16.83 23 15.705 2.44 15.03 24 -221.676 0.70 1.43875 94.7 0.5340 14.83 25 29.388 2.33 14.89 26 -297.693 5.26 1.85478 24.8 0.6122 15.36 27 -11.681 0.70 1.88300 40.8 0.5667 15.85 28 79.733 0.21 16.87 29 28.756 2.74 1.64769 33.8 0.5938 17.66 30 3447.924 (variable) 17.82 31 -33.370 0.80 1.72916 54.7 0.5444 18.16 32 67.737 2.57 1.84666 23.8 0.6205 19.12 33 -860.675 (variable) 19.68 34(Aperture) ∞ 1.20 26.42 35* 93.760 4.97 1.59522 67.7 0.5442 27.65 36 -80.813 0.20 28.34 37 405.249 5.77 1.53172 48.8 0.5631 28.65 38 -31.138 1.00 1.88300 40.8 0.5667 28.83 39 -50.564 (variable) 29.46 40 67.650 4.97 1.63980 34.5 0.5922 27.49 41 -56.802 2.51 27.38 42 -125.211 0.90 1.88300 40.8 0.5667 25.84 43 27.932 4.22 1.48749 70.2 0.5300 25.25 44 363.120 0.20 25.41 45 59.287 8.08 1.43875 94.7 0.5340 25.68 46 -20.425 0.90 2.00100 29.1 0.5997 25.68 47 -45.910 0.13 27.14 48 72.344 5.70 1.48749 70.2 0.5300 28.02 49 -35.435 3.31 28.06 50 ∞ 33.00 1.60859 46.4 0.5664 40.00 51 ∞ 13.20 1.51680 64.2 0.5347 40.00 52∞8.30 40.00 Image plane ∞ Aspheric Data Front page K = 0.00000e+00 A 4= 2.84749e-06 A 6=-4.72980e-08 A 8=-3.14612e-11 A10= 9.09207e-14 A12= 1.11026e-16 A14= 1.64083e-20 A16= 3.93184e-25 A 3= 4.11397e-05 A 5= 3.88082e-07 A 7= 2.10099e-09 A 9=-1.07103e-12 A11=-3.93486e-15 A13=-1.84824e-18 A15=-8.23382e-23 3rd page K = 0.00000e+00 A 4=-5.14521e-07 A 6=-6.20253e-08 A 8=-7.56683e-10 A10=-3.25392e-13 A12= 1.57466e-15 A14=-6.47873e-19 A16=-2.07821e-22 A 3=-2.71914e-05 A 5= 2.02826e-07 A 7= 9.51601e-09 A 9= 3.14741e-11 A11=-3.27113e-14 A13=-1.73567e-17 A15= 2.23429e-20 Side 10 K = 0.00000e+00 A 4= 2.75132e-06 A 6= 2.08109e-08 A 8= 2.91496e-10 A10= 2.00838e-13 A12=-7.68144e-16 A14= 1.11564e-18 A16= 2.19134e-22 A 3=-1.01147e-05 A 5=-7.53981e-08 A 7=-3.16716e-09 A 9=-1.46328e-11 A11= 1.68471e-14 A13=-5.56537e-18 A15=-2.76125e-20 Page 35 K = 7.99321e+00 A 4=-3.72150e-06 A 6= 1.86956e-09 A 8=-4.16672e-12 Various data Zoom ratio 15.31 Wide Angle Mid-Telephoto Focal length 4.26 15.50 65.29 F-number 1.87 1.86 3.06 Half angle of view (°) 52.21 19.54 4.81 Image height 5.50 5.50 5.50 Lens total length 313.33 313.33 313.33 BF 8.30 8.30 8.30 d21 0.47 34.24 47.41 d30 27.65 4.81 3.25 d33 16.80 19.50 2.10 d39 61.12 47.49 53.27 Entrance pupil position 27.35 50.24 98.54 Exit pupil position 93.65 151.47 119.26 Front principal point position 31.83 67.42 202.26 Back principal point position 4.04 -7.20 -56.99 Lens Group Data Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 26.94 90.27 40.28 37.44 2 22 -15.68 15.08 0.04 -11.20 3 31 -52.40 3.37 -0.14 -1.99 4 34 48.60 13.14 5.10 -3.93 5 40 51.91 77.12 14.09 -40.11 Single lens data Lens starting surface focal length 1(G1) 1 -33.78 2 3 -421.61 3 5 -167.88 4(Gp) 7 184.76 5 9 103.78 6 11 222.78 7 13 -179.72 8 15 -76.05 9 16 64.59 10 18 133.22 11 20 88.93 12 22 -18.05 13 24 -58.94 14 26 13.97 15 27 -11.43 16 29 44.45 17 31 -30.43 18 32 73.53 19 35 73.45 20 37 54.37 21 38 -93.52 22 40 48.69 23 42 -25.64 24 43 61.61 25 45 35.64 26 46 -37.12 27 48 49.49 [Numerical example 2] Unit: mm Surface Data Surface number rd nd νd θgf Effective diameter 1* 12211.103 2.50 1.83481 42.7 0.5648 80.82 2 30.014 20.06 55.36 3* -809.246 2.00 1.83481 42.7 0.5648 54.89 4 289.295 6.77 54.04 5 -103.864 1.80 1.83481 42.7 0.5648 53.57 6 -366.769 0.15 54.08 7 93.191 3.39 1.95906 17.5 0.6598 54.55 8 191.645 1.67 54.24 9 119.971 7.96 1.60300 65.4 0.5401 53.64 10* -143.650 4.41 52.75 11 -3915.938 4.55 1.43387 95.1 0.5373 51.26 12 -100.849 0.30 51.06 13 -94.025 1.70 1.80000 29.8 0.6017 51.03 14 -563.927 0.18 51.07 15 138.558 1.70 1.91650 31.6 0.5911 52.27 16 50.209 15.72 1.43875 94.7 0.5340 52.58 17 -68.242 0.40 54.01 18 105.486 9.06 1.43387 95.1 0.5373 57.90 19 -125.338 0.40 58.03 20 111.550 7.77 1.76385 48.5 0.5589 57.41 21 -185.845 (variable) 56.90 22 120.162 0.70 2.00100 29.1 0.5997 23.10 23 19.419 3.86 20.55 24 -103.913 0.70 1.43875 94.7 0.5340 20.36 25 38.940 2.33 19.75 26 219.020 6.04 1.85478 24.8 0.6122 19.59 27 -14.964 0.70 1.88300 40.8 0.5667 19.34 28 123.675 (variable) 18.96 29 28.588 2.11 1.64769 33.8 0.5938 18.95 30 50.473 (variable) 18.79 31 -32.068 0.80 1.72916 54.7 0.5444 19.10 32 36.940 2.57 1.84666 23.8 0.6205 20.43 33 242.027 (variable) 20.83 34(Aperture) ∞ 1.20 27.23 35* 62.453 7.05 1.59522 67.7 0.5442 28.92 36 -41.280 0.20 29.68 37 23.453 7.21 1.53172 48.8 0.5631 29.40 38 2133.833 1.00 1.88300 40.8 0.5667 28.27 39 28.913 (variable) 26.44 40 73.142 4.66 1.63980 34.5 0.5922 28.49 41 -61.591 4.70 28.30 42 2025.038 0.90 1.88300 40.8 0.5667 25.80 43 30.653 4.05 1.48749 70.2 0.5300 25.21 44 891.785 0.20 25.25 45 45.385 8.05 1.43875 94.7 0.5340 25.36 46 -22.226 0.90 2.00100 29.1 0.5997 25.03 47 -80.463 0.13 26.05 48 71.951 5.72 1.48749 70.2 0.5300 26.60 49 -35.437 3.31 26.65 50 ∞ 33.00 1.60859 46.4 0.5664 40.00 51 ∞ 13.20 1.51680 64.2 0.5347 40.00 52∞6.60 40.00 Image plane ∞ Aspheric Data Front page K = 0.00000e+00 A 4= 5.02691e-07 A 6=-2.29078e-07 A 8=-9.93791e-10 A10=-3.56214e-13 A12=-2.64958e-17 A14=-2.68484e-19 A16=-1.77502e-23 A 3= 2.93295e-05 A 5= 1.35804e-06 A 7= 1.96430e-08 A 9= 2.88206e-11 A11=-2.10419e-15 A13= 8.63402e-18 A15= 3.51972e-21 3rd page K = 0.00000e+00 A 4= 2.36250e-06 A 6= 6.71936e-08 A 8= 1.49253e-09 A10= 1.43219e-11 A12= 8.70708e-15 A14=-1.67551e-17 A16=-2.24090e-21 A 3=-2.44336e-05 A 5=-5.96676e-07 A 7=-8.04704e-09 A 9=-1.92209e-10 A11=-5.85477e-13 A13= 2.91912e-16 A15= 3.17497e-19 Side 10 K = 0.00000e+00 A 4= 3.65510e-06 A 6= 1.13965e-07 A 8= 1.02220e-09 A10= 2.65923e-13 A12=-9.29090e-16 A14= 5.32742e-18 A16= 8.66633e-22 A 3=-1.07786e-05 A 5=-6.47589e-07 A 7=-1.34289e-08 A 9=-4.23846e-11 A11= 4.98125e-14 A13=-9.28559e-17 A15=-1.11408e-19 Page 35 K = 7.10084e+00 A 4=-1.09453e-05 A 6= 1.58919e-09 A 8=-1.94765e-11 Various data Zoom ratio 15.31 Wide Angle Mid-Telephoto Focal length 4.26 15.50 65.29 F-number 1.87 1.87 3.06 Half angle of view (°) 52.21 19.54 4.81 Image height 5.50 5.50 5.50 Lens total length 313.33 313.33 313.33 BF 6.60 6.60 6.60 d21 0.47 34.56 50.47 d28 -0.19 0.23 0.43 d30 39.54 7.88 4.97 d33 13.78 16.68 2.09 d39 45.34 39.59 40.98 Entrance pupil position 28.51 48.56 98.71 Exit pupil position 125.35 182.15 164.14 Front principal point position 32.93 65.43 191.07 Back principal point position 2.34 -8.90 -58.69 Lens Group Data Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 28.55 92.49 42.24 42.05 2 22 -14.29 14.33 2.31 -7.64 3 29 98.08 2.11 -1.61 -2.85 4 31 -43.19 3.37 0.22 -1.63 5 34 43.17 16.66 -3.30 -12.19 6 40 47.47 78.82 11.25 -45.62 Single lens data Lens starting surface focal length 1(G1) 1 -36.04 2 3 -255.07 3 5 -174.11 4(Gp) 7 186.01 5 9 109.66 6 11 238.50 7 13 -141.28 8 15 -86.71 9 16 68.71 10 18 133.61 11 20 92.30 12 22 -23.22 13 24 -64.46 14 26 16.58 15 27 -15.08 16 29 98.08 17 31 -23.43 18 32 51.19 19 35 42.84 20 37 44.54 21 38 -33.20 22 40 52.98 23 42 -35.26 24 43 65.02 25 45 35.29 26 46 -30.92 27 48 49.57 [Numerical example 3] Unit: mm Surface Data Surface number rd nd νd θgf Effective diameter 1* -253.468 2.40 1.76385 48.5 0.5589 74.29 2 27.608 14.31 50.21 3 105.984 1.60 2.00100 29.1 0.5997 49.47 4 40.143 18.02 46.06 5 -31.685 1.50 1.76385 48.5 0.5589 46.21 6 -50.980 0.20 50.65 7 3003.474 7.72 1.89286 20.4 0.6393 56.17 8 -72.723 1.50 56.85 9 82.988 9.11 1.61800 63.3 0.5441 56.82 10* -147.576 5.06 56.57 11 133.599 13.21 1.52841 76.5 0.5396 56.36 12 -55.404 1.80 1.95375 32.3 0.5905 55.95 13 -71.004 0.20 56.43 14 238.752 1.65 2.05090 26.9 0.6054 51.72 15 41.558 14.30 1.49700 81.5 0.5375 48.40 16 -84.763 0.20 48.22 17 2180.027 4.69 1.76385 48.5 0.5589 46.68 18 -107.580 (variable) 46.44 19* 99.650 1.20 1.89190 37.1 0.5780 26.29 20 24.509 5.04 23.47 21 -66.164 0.80 1.59522 67.7 0.5442 22.71 22 51.110 3.42 1.85478 24.8 0.6122 21.87 23 -79.694 1.60 21.70 24 -28.497 0.80 1.76385 48.5 0.5589 21.67 25 -50.982 (variable) 22.14 26 -40.299 0.80 1.59522 67.7 0.5442 22.42 27 43.233 2.06 1.85478 24.8 0.6122 23.66 28 77.509 (variable) 23.89 29(Aperture) ∞ 1.00 27.50 30* 31.967 7.75 1.60342 38.0 0.5835 30.37 31 -52.247 0.20 30.40 32 1068.339 6.21 1.76182 26.5 0.6136 29.46 33 -27.253 0.90 2.05090 26.9 0.6054 29.04 34 374.491 (variable) 29.04 35 95.983 3.24 1.56732 42.8 0.5731 29.61 36 -180.749 0.20 29.52 37 110.142 1.00 2.05090 26.9 0.6054 29.18 38 31.469 5.68 1.53775 74.7 0.5392 28.39 39 -128.437 40.06 28.43 40 59.850 10.55 1.48749 70.2 0.5300 37.65 41 -71.930 0.40 37.51 42 58.181 8.55 1.85896 22.7 0.6284 35.71 43 -50.800 1.10 1.88300 40.8 0.5667 34.43 44 33.103 1.60 30.86 45 45.400 10.93 1.43875 94.9 0.5340 30.88 46 -24.480 1.50 2.05090 26.9 0.6054 30.35 47 1603.558 0.20 32.66 48 77.994 8.15 1.53775 74.7 0.5392 34.19 49 -36.510 36.98 34.73 Image plane ∞ Aspheric Data Front page K = 0.00000e+00 A 4= 9.63421e-06 A 6=-1.25665e-08 A 8= 1.63812e-11 A10=-1.59429e-14 A12= 1.01106e-17 A14=-3.64168e-21 A16= 5.61323e-25 Side 10 K = 0.00000e+00 A 4= 2.59557e-06 A 6=-4.92566e-10 A 8= 7.10252e-14 Page 19 K = 0.00000e+00 A 4= 5.04595e-06 A 6=-1.12643e-08 A 8= 1.49775e-10 A10=-9.03675e-13 A12= 2.07771e-15 Page 30 K = 0.00000e+00 A 4=-6.97394e-06 A 6= 2.67278e-09 A 8=-2.91492e-12 Various data Zoom ratio 4.87 Wide Angle Mid-Telephoto Focal length 11.30 21.67 55.00 F-number 2.73 2.72 3.65 Half angle of view (°) 52.65 34.34 15.06 Image height 14.80 14.80 14.80 Lens total length 310.95 310.95 310.95 BF 36.98 36.98 36.98 d18 1.00 22.30 41.97 d25 21.21 3.96 6.77 d28 12.85 12.68 0.99 d34 16.51 12.63 1.84 Entrance pupil position 24.75 30.08 43.75 Exit pupil position -1294.01 -610.82 -239.02 Front principal point position 35.95 51.02 87.79 Back principal point position 25.68 15.31 -18.02 Lens Group Data Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 26.85 97.46 39.05 50.85 2 19 -30.40 12.86 1.88 -7.96 3 26 -50.15 2.86 0.74 -0.86 4 29 51.67 16.06 -1.78 -10.98 5 35 68.54 93.16 39.19 -50.26 Single lens data Lens starting surface focal length 1(G1) 1 -32.47 2 3 -65.35 3 5 -113.42 4(Gp) 7 79.62 5 9 87.27 6 11 75.95 7 12 -280.17 8 14 -48.09 9 15 58.30 10 17 134.34 11 19 -36.72 12 21 -48.32 13 22 36.87 14 24 -85.91 15 26 -34.92 16 27 111.29 17 30 34.05 18 32 34.97 19 33 -24.15 20 35 110.98 21 37 -42.20 22 38 47.59 23 40 68.82 24 42 32.76 25 43 -22.56 26 45 38.07 27 46 -22.93 28 48 47.43 [Numerical example 4] Unit: mm Surface Data Surface number rd nd νd θgf Effective diameter 1* -444.176 2.40 1.80100 35.0 0.5864 87.01 2 43.777 11.69 69.79 3* 36.086 1.80 1.90366 31.3 0.5946 61.22 4 30.593 13.59 50.59 5 404.168 1.65 1.90366 31.3 0.5946 49.92 6 55.901 9.87 47.41 7 -70.923 1.66 1.48749 70.2 0.5300 47.44 8 72.406 9.73 1.80518 25.5 0.6156 54.45 9 -327.068 2.67 55.58 10 164.678 7.64 1.73800 32.3 0.5900 58.85 11 -225.402 1.24 59.21 12 182.121 6.41 1.43875 94.9 0.5340 59.29 13* -275.332 1.19 59.02 14 164.419 1.74 1.84666 23.8 0.6205 58.28 15 55.949 16.44 1.43875 94.9 0.5340 56.58 16 -72.396 0.60 56.59 17 323.358 9.97 1.52841 76.5 0.5396 55.42 18 -69.307 (variable) 54.99 19 88.263 1.00 1.59282 68.6 0.5458 29.67 20 31.954 4.22 28.42 21 -1142.816 1.00 1.72916 54.7 0.5444 28.35 22 43.019 2.67 28.23 23 39.842 5.61 1.72825 28.5 0.6077 29.75 24 -90.784 1.00 1.71300 53.9 0.5459 29.62 25 579.762 2.20 29.42 26 -57.618 1.00 1.91082 35.2 0.5824 29.41 27 129.891 (variable) 30.14 28 146.603 2.71 1.49700 81.5 0.5375 31.09 29 -143.508 (variable) 31.42 30(Aperture) ∞ 5.31 31.82 31* 56.511 6.08 1.72047 34.7 0.5834 34.78 32 -62.820 0.20 34.73 33 -149.624 4.78 1.51633 64.1 0.5353 33.85 34 -32.589 1.20 1.80400 46.5 0.5577 33.58 35 276.298 (variable) 33.50 36 -124.952 2.11 1.59282 68.6 0.5458 33.87 37 -65.314 0.20 34.29 38 43.650 1.27 1.59270 35.3 0.5933 36.66 39 32.430 8.28 1.49700 81.5 0.5375 36.31 40 -96.477 11.34 36.26 41 68.905 6.07 1.53775 74.7 0.5392 32.17 42 -42.512 1.17 1.95375 32.3 0.5898 31.80 43 34.421 1.23 31.11 44 38.129 10.03 1.49700 81.5 0.5375 32.20 45 -29.669 1.00 1.71700 47.9 0.5605 32.58 46 -95.177 0.20 34.15 47 70.065 1.10 1.91082 35.2 0.5824 35.62 48 28.894 6.88 1.68893 31.1 0.6004 35.30 49 850.653 0.69 35.43 50 ∞ 2.62 1.51680 64.2 0.5342 35.56 51∞40.64 35.99 Image plane ∞ Aspheric Data Front page K = 0.00000e+00 A 4= 1.21350e-05 A 6=-1.99552e-08 A 8= 3.37079e-11 A10=-4.48716e-14 A12= 4.39832e-17 A14=-2.99515e-20 A16= 1.33049e-23 A18=-3.44636e-27 A20= 3.94087e-31 3rd page K = 0.00000e+00 A 4=-1.09431e-05 A 6= 4.70382e-09 A 8=-1.54386e-12 A10=-1.93669e-14 A12= 6.27322e-17 A14=-1.14572e-19 A16= 1.27270e-22 A18=-7.87089e-26 A20= 2.02484e-29 Page 13 K = 0.00000e+00 A 4= 9.20115e-07 A 6=-1.11586e-09 A 8= 8.17021e-12 A10=-3.66809e-14 A12= 1.04629e-16 A14=-1.89350e-19 A16= 2.08229e-22 A18=-1.26362e-25 A20= 3.23875e-29 Page 31 K = 0.00000e+00 A 4=-1.28333e-06 A 6=-1.91066e-09 A 8= 2.52806e-11 A10=-1.34916e-13 A12=-1.41160e-16 A14= 5.94365e-18 A16=-3.14443e-20 A18=7.12585e-23 A20=-6.11458e-26 Various data Zoom ratio 2.73 Wide Angle Mid-Telephoto Focal length 16.50 22.43 45.00 F-number 2.75 2.74 2.77 Half angle of view (°) 52.67 43.97 25.68 Image height 21.64 21.64 21.64 Lens length 287.74 287.74 287.74 BF 40.64 40.64 40.64 d18 0.20 19.79 49.19 d27 2.00 1.84 1.61 d29 23.02 18.78 0.20 d35 28.44 13.25 2.67 Entrance pupil position 30.32 34.08 41.80 Exit pupil position -95.28 -63.98 -50.09 Front principal point position 44.81 51.70 64.49 Back principal point position 24.14 18.21 -4.36 Lens Group Data Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 38.96 100.29 53.47 80.33 2 19 -26.22 18.69 7.74 -5.48 3 28 146.37 2.71 0.92 -0.90 4 30 99.52 17.56 -0.07 -12.19 5 36 75.13 54.18 -10.73 -45.80 Single lens data Lens starting surface focal length 1(G1) 1 -49.64 2 3 -263.37 3 5 -71.95 4 7 -73.22 5(Gp)8 74.43 6 10 130.02 7 12 250.91 8 14 -100.91 9 15 74.85 10 17 108.97 11 19 -85.05 12 21 -56.84 13 23 38.72 14 24 -110.02 15 26 -43.71 16 28 146.37 17 31 42.19 18 33 79.58 19 34 -36.19 20 36 227.84 21 38 -222.21 22 39 49.90 23 41 49.84 24 42 -19.80 25 44 35.31 26 45 -60.50 27 47 -54.68 28 48 43.27 [Numerical example 5] Unit: mm Surface Data Surface number rd nd νd θgf Effective diameter 1* 126.921 2.40 1.76385 48.5 0.5589 70.48 2 24.756 18.01 47.75 3 205.334 1.60 2.00100 29.1 0.5997 46.22 4 31.331 16.61 40.59 5 -28.826 1.50 1.88300 40.8 0.5667 40.69 6 -38.396 3.89 43.56 7 362.828 5.91 1.89286 20.4 0.6393 50.00 8 -99.897 4.53 50.39 9 79.733 9.49 1.61800 63.3 0.5441 50.07 10* -98.509 4.47 49.78 11 462.544 8.59 1.49700 81.5 0.5375 46.73 12 -52.417 0.20 45.93 13 -51.044 1.80 1.76385 48.5 0.5589 45.86 14 -59.895 0.20 45.65 15 -92.715 1.65 1.95375 32.3 0.5905 43.69 16 50.357 11.35 1.43875 94.9 0.5340 42.17 17 -52.496 0.20 42.39 18 329.681 6.39 1.76385 48.5 0.5589 42.77 19 -86.347 (variable) 42.81 20* 463.639 1.20 1.90525 35.0 0.5848 27.55 21 40.082 3.64 25.69 22 -250.829 0.80 1.59522 67.7 0.5442 24.98 23 72.439 4.04 1.85478 24.8 0.6122 24.31 24 -64.263 1.25 23.70 25 -33.758 0.80 1.76385 48.5 0.5589 23.43 26 -151.628 (variable) 23.78 27 -62.341 0.80 1.60300 65.4 0.5401 24.05 28 36.556 2.38 1.85478 24.8 0.6122 25.09 29 65.408 (variable) 25.24 30(Aperture) ∞ 3.19 26.88 31* 25.857 8.14 1.58144 40.8 0.5774 31.37 32 -79.991 0.20 31.17 33 72.746 6.52 1.78472 25.7 0.6161 29.85 34 -36.630 0.90 2.00069 25.5 0.6136 29.04 35 39.449 (variable) 27.39 36 793.020 3.49 1.56732 42.8 0.5731 28.43 37 -55.886 0.20 28.63 38 44.558 1.00 2.05090 26.9 0.6054 28.21 39 28.061 3.94 1.53775 74.7 0.5392 27.34 40 84.241 40.06 27.11 41 48.281 8.81 1.55200 70.7 0.5421 37.73 42 -60.818 0.40 37.50 43 51.915 6.05 1.80810 22.8 0.6307 33.90 44 -84.930 1.10 1.88300 40.8 0.5667 32.89 45 32.067 2.44 29.24 46 68.206 10.30 1.43875 94.7 0.5340 29.14 47 -20.155 1.50 2.05090 26.9 0.6054 28.29 48 -886.515 3.11 31.02 49 76.996 9.29 1.48749 70.2 0.5300 35.18 50 -32.448 37.00 35.79 Image plane ∞ Aspheric Data Front page K = 0.00000e+00 A 4= 7.30634e-06 A 6=-7.54574e-09 A 8= 8.65243e-12 A10=-4.83724e-15 A12= 2.60356e-19 A14= 1.10034e-21 A16=-3.45510e-25 Side 10 K = 0.00000e+00 A 4= 1.72912e-06 A 6=-5.37259e-10 A 8= 1.75411e-13 Page 20 K = 0.00000e+00 A 4= 3.88741e-06 A 6=-5.31069e-09 A 8= 7.99823e-11 A10=-4.60328e-13 A12= 9.77729e-16 Page 31 K = 0.00000e+00 A 4=-1.08698e-05 A 6=-8.27919e-10 A 8=-1.03830e-11 Various data Zoom ratio 3.85 Wide Angle Mid-Telephoto Focal length 10.40 18.86 40.02 F-number 2.89 2.89 3.61 Half angle of view (°) 54.91 38.12 20.30 Image height 14.80 14.80 14.80 Lens total length 320.72 320.72 320.72 BF 37.00 37.00 37.00 d19 1.00 27.80 52.53 d26 35.34 11.78 2.23 d29 6.01 7.29 0.99 d35 17.03 12.52 3.63 Entrance pupil position 25.23 28.56 33.80 Exit pupil position 2418.18 -1423.06 -346.31 Front principal point position 35.67 47.18 69.65 Back principal point position 26.60 18.13 -3.02 Lens Group Data Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 29.16 98.79 44.15 79.54 2 20 -41.45 11.73 2.27 -6.07 3 27 -62.78 3.18 1.24 -0.52 4 30 63.68 18.96 -8.67 -17.65 5 36 63.55 91.69 38.16 -65.64 Single lens data Lens starting surface focal length 1(G1) 1 -40.68 2 3 -37.11 3 5 -141.36 4(Gp) 7 88.26 5 9 72.78 6 11 95.26 7 13 -495.88 8 15 -34.02 9 16 60.62 10 18 90.18 11 20 -48.53 12 22 -94.34 13 23 40.39 14 25 -57.02 15 27 -38.10 16 28 93.41 17 31 34.59 18 33 31.88 19 34 -18.87 20 36 92.16 21 38 -74.44 22 39 76.38 23 41 50.20 24 43 40.68 25 44 -26.25 26 46 36.77 27 47 -19.64 28 49 48.17 [Numerical example 6] Unit: mm Surface Data Surface number rd nd νd θgf Effective diameter 1* -651.846 2.50 1.83481 42.7 0.5648 80.83 2 29.886 17.96 54.93 3* 205.029 2.00 1.83481 42.7 0.5648 54.39 4 133.762 8.37 53.04 5 -93.844 1.80 1.83481 42.7 0.5648 52.38 6 -529.040 0.15 52.82 7 94.300 3.70 1.92286 18.9 0.6495 53.20 8 254.951 1.67 52.90 9 137.316 7.43 1.60300 65.4 0.5401 52.15 10* -129.387 4.41 51.25 11 -3986.720 6.22 1.43387 95.1 0.5373 51.04 12 -72.185 0.30 51.43 13 -68.763 1.70 1.80000 29.8 0.6017 51.43 14 -129.110 0.18 52.89 15 177.001 1.70 1.91650 31.6 0.5911 54.56 16 53.973 15.73 1.43875 94.7 0.5340 54.69 17 -72.950 0.40 55.94 18 145.677 9.06 1.43387 95.1 0.5373 58.68 19 -98.739 0.40 58.81 20 198.764 6.83 1.76385 48.5 0.5589 57.74 21 -143.417 (variable) 57.35 22 109.025 0.70 2.00100 29.1 0.5997 20.35 23 17.638 3.22 18.16 24 -147.134 0.70 1.43875 94.7 0.5340 17.98 25 52.607 2.33 17.53 26 -222.929 5.23 1.85478 24.8 0.6122 17.21 27 -13.213 0.70 1.88300 40.8 0.5667 17.04 28 124.147 0.21 17.90 29 32.929 2.64 1.64769 33.8 0.5938 18.56 30 640.048 (variable) 18.66 31 -29.435 0.80 1.72916 54.7 0.5444 18.90 32 42.341 2.57 1.84666 23.8 0.6205 20.20 33 558.323 (variable) 20.64 34(Aperture) ∞ 1.20 27.23 35* 66.693 6.40 1.59522 67.7 0.5442 28.92 36 -55.306 0.20 29.53 37 129.439 6.58 1.53172 48.8 0.5631 29.55 38 -31.398 1.00 1.88300 40.8 0.5667 29.40 39 -87.887 (variable) 29.86 40 65.836 5.42 1.63980 34.5 0.5922 27.58 41 -55.379 3.39 27.13 42 -71.478 0.90 1.88300 40.8 0.5667 24.95 43 30.858 5.07 1.48749 70.2 0.5300 24.66 44 -107.443 0.20 24.93 45 51.336 7.84 1.43875 94.7 0.5340 25.21 46 -21.995 0.90 2.00100 29.1 0.5997 25.04 47 -59.375 0.13 26.13 48 92.546 5.49 1.48749 70.2 0.5300 26.63 49 -34.223 3.27 26.70 50 ∞ 33.00 1.60859 46.4 0.5664 40.00 51 ∞ 13.20 1.51680 64.2 0.5347 40.00 52∞6.60 40.00 Image plane ∞ Aspheric Data Front page K = 0.00000e+00 A 4= 6.48442e-06 A 6= 2.19226e-09 A 8= 6.50797e-12 A10= 8.92330e-14 A12= 1.11240e-16 A14= 1.77070e-20 A16= 3.15292e-25 A 3= 8.54799e-06 A 5=-1.41802e-07 A 7=-4.53639e-11 A 9=-1.10620e-12 A11=-4.05612e-15 A13=-1.83948e-18 A15=-9.72378e-23 3rd page K = 0.00000e+00 A 4=-3.35608e-06 A 6=-7.00472e-08 A 8=-7.37142e-10 A10=-3.24129e-13 A12= 1.58966e-15 A14=-6.55545e-19 A16=-2.03600e-22 A 3=-8.90697e-07 A 5= 3.79740e-07 A 7= 9.30814e-09 A 9= 3.11630e-11 A11=-3.28771e-14 A13=-1.76087e-17 A15= 2.23720e-20 Side 10 K = 0.00000e+00 A 4= 1.29716e-06 A 6= 1.84566e-08 A 8= 2.81340e-10 A10= 2.05135e-13 A12=-7.68327e-16 A14= 1.04059e-18 A16= 2.18082e-22 A 3= 3.31773e-07 A 5=-5.38599e-08 A 7=-2.96537e-09 A 9=-1.45178e-11 A11= 1.68411e-14 A13=-4.57121e-18 A15=-2.62172e-20 Page 35 K = 6.60773e+00 A 4=-4.74213e-06 A 6=-9.99912e-11 A 8=-7.56379e-12 Various data Zoom ratio 15.32 Wide Angle Mid-Telephoto Focal length 4.26 15.50 65.32 F-number 1.87 1.86 3.05 Half angle of view (°) 52.22 19.53 4.81 Image height 5.50 5.50 5.50 Lens total length 313.33 313.33 313.33 BF 6.60 6.60 6.60 d21 0.47 36.42 53.16 d30 39.91 5.86 3.67 d33 14.99 17.75 2.07 d39 45.53 40.87 42.01 Entrance pupil position 27.99 48.37 98.34 Exit pupil position 165.32 219.89 203.28 Front principal point position 32.37 65.00 185.35 Back principal point position 2.33 -8.91 -58.73 Lens Group Data Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 29.67 92.51 42.41 43.37 2 22 -19.60 15.73 -0.17 -12.19 3 31 -42.47 3.37 0.06 -1.79 4 34 45.06 15.39 3.75 -6.62 5 40 52.58 78.82 14.21 -41.97 Single lens data Lens starting surface focal length 1(G1) 1 -34.17 2 3 -466.93 3 5 -136.91 4(Gp) 7 160.39 5 9 111.65 6 11 169.36 7 13 -186.23 8 15 -85.29 9 16 73.48 10 18 137.18 11 20 110.01 12 22 -21.10 13 24 -88.23 14 26 16.25 15 27 -13.49 16 29 53.51 17 31 -23.70 18 32 53.99 19 35 51.81 20 37 48.21 21 38 -55.78 22 40 47.85 23 42 -24.31 24 43 49.77 25 45 36.28 26 46 -35.33 27 48 51.99

[0055] [Table 1]

[0056] [Imaging device] 13 shows the configuration of an imaging device 125 that uses the zoom lens according to any one of the first to sixth embodiments as an imaging optical system. Reference numeral 101 denotes the zoom lens according to any one of the first to sixth embodiments. Reference numeral 124 denotes a camera body. The zoom lens 101 is detachable from the camera body 124. However, the zoom lens may be provided integrally with the camera body.

[0057] The zoom lens 101 has a first lens group F, three or more intermediate lens groups LZ that move for zooming, and an imaging rear lens group R. The first lens group F includes a second sub-lens group that moves for focusing, and a first sub-lens group and a third sub-lens group that do not move for focusing. The zoom lens 101 also has an aperture stop SP.

[0058] Reference numerals 114 and 115 denote driving mechanisms for driving the second sub-lens group and the three or more intermediate lens groups LZ, respectively. The driving mechanisms include a helicoid, a cam, and the like.

[0059] Reference numerals 116 to 118 denote motors that drive drive mechanisms 114 and 115 and aperture diaphragm SP, respectively. Reference numerals 119 to 121 denote detection units for detecting the positions on the optical axis of the second sub-lens group and intermediate lens group LZ and the aperture diameter of the aperture diaphragm SP, respectively. The detection units are constituted by an encoder, a potentiometer, a photosensor, etc.

[0060] In the camera body 124, reference numeral 109 denotes a glass block including an optical filter and the like, and reference numeral 110 denotes an imaging element (photoelectric conversion element) such as a CCD sensor or a CMOS sensor that captures an image of a subject through the zoom lens 101. Reference numerals 111 and 122 denote a CPU as a processing unit in the camera body 124 and a CPU as a processing unit in the zoom lens 101, respectively.

[0061] According to an imaging device using the zoom lens of each embodiment, imaging can be performed with a small size and light weight, a wide angle of view, and a high zoom ratio, and images of good quality can be obtained.

[0062] The above embodiment includes the following configurations.

[0063] (Configuration 1) A zoom lens having lens groups arranged in order from the object side to the image side, the lens groups being a first lens group having positive refractive power that does not move for zooming, three or more intermediate lens groups that move for zooming, and a rear lens group having positive refractive power, in which the spacing between adjacent lens groups changes during zooming, the first lens group includes a first sub-lens group having negative refractive power that does not move for focusing, a second sub-lens group having positive refractive power that moves for focusing, and a third sub-lens group having positive refractive power, which are arranged in this order from the object side to the image side; Let f1 be the focal length of the first lens group, bok1 be the length on the optical axis from the lens surface of the first lens group closest to the image side to the rear principal point of the first lens group when focused on an object at infinity, fw be the focal length of the zoom lens at the wide-angle end, and ft be the focal length of the zoom lens at the telephoto end. 2.430≦(f1+bok1) / f1≦4.500 1.150≦ft / f1≦3.200 2.250≦f1 / fw≦6.700 A zoom lens characterized by satisfying the following conditions. (Configuration 2) A negative lens is disposed closest to the object side in the first lens group. When the focal length of the negative lens is fG1, -2.10≦ft / fG1≦-0.50 2. The zoom lens according to claim 1, wherein the following condition is satisfied: (Configuration 3) The first sub-lens group has a positive lens, When the focal length of the positive lens is fGp, 0.40≦ft / fGp≦10.60 3. The zoom lens according to configuration 1 or 2, which satisfies the following conditions: (Configuration 4) When the focal length of the first sub-lens group is f1a, -1.50≦f1a / f1≦-0.60 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 second sub-lens group is f1b, 2.00≦f1b / f1≦6.50 5. The zoom lens according to any one of configurations 1 to 4, which satisfies the following condition: (Configuration 6) When the focal length of the third sub-lens group is f1c, 1.30≦f1c / f1≦4.50 6. The zoom lens according to any one of configurations 1 to 5, which satisfies the following condition: (Configuration 7) Let LD1 be the thickness on the optical axis from the lens surface of the first lens group closest to the object side to the lens surface closest to the image side, 1.10≦LD1 / f1≦6.50 7. The zoom lens according to any one of configurations 1 to 6, which satisfies the following condition: (Configuration 8) When the zoom lens is used in an imaging device having an imaging surface with a diagonal size of 2Y, the focal length of the zoom lens at the wide-angle end is fw, and the half angle of view of the zoom lens at the wide-angle end is ωw. 51.50°≦ωw≦65.00° ωw=arctan(Y / fw) 8. The zoom lens according to any one of configurations 1 to 7, which satisfies the following condition: (Configuration 9) When the F-number at the wide-angle end of the zoom lens is Fnow, 1.30≦Fnow≦3.50 9. The zoom lens according to any one of configurations 1 to 8, which satisfies the following condition: (Configuration 10) Let BFw be the length on the optical axis from the image-side lens surface of the lens closest to the image side among the lenses included in the zoom lens to the image plane. 0.050≦fw / BFw≦0.430 10. The zoom lens according to any one of configurations 1 to 9, which satisfies the following condition: (Configuration 11) the zoom lens has an aperture stop; When the length on the optical axis from the lens surface of the first lens group closest to the object to the aperture stop at the wide-angle end in a state where an object at infinity is focused on is defined as LDs, and when the length on the optical axis from the lens surface of the first lens group closest to the object to the lens surface of the rear lens group closest to the image at the wide-angle end in a state where an object at infinity is focused on is defined as LT, 0.20≦LDs / LT≦0.60 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 average value of the refractive index at the d-line of at least one negative lens included in the first lens group is denoted by nd1n, 1.750≦nd1n≦2.000 12. The zoom lens according to any one of configurations 1 to 11, characterized in that the following condition is satisfied: (Configuration 13) The first sub-lens group has a positive lens. When the Abbe number of the positive lens based on the d-line is νd1ap, 17.0≦νd1ap≦35.0 13. The zoom lens according to any one of configurations 1 to 12, characterized in that the following condition is satisfied: (Configuration 14) A zoom lens having a first lens group having positive refractive power that does not move for zooming, three or more intermediate lens groups that move for zooming, an aperture stop, and a rear lens group having positive refractive power, which are arranged in this order from an object side to an image side, and in which a distance between adjacent lens groups changes during zooming, the aperture diaphragm is disposed within or adjacent to any one of the three or more intermediate lens groups, and moves together with any one of the intermediate lens groups during zooming; the first lens group includes a first sub-lens group having negative refractive power that does not move for focusing, a second sub-lens group having positive refractive power that moves for focusing, and a third sub-lens group having positive refractive power, which are arranged in this order from the object side to the image side; Let f1 be the focal length of the first lens group, bok1 be the length on the optical axis from the lens surface of the first lens group closest to the image side to the rear principal point of the first lens group when focused on an object at infinity, fw be the focal length of the zoom lens at the wide-angle end, and ft be the focal length of the zoom lens at the telephoto end. 2.000≦(f1+bok1) / f1≦4.500 1.950≦ft / f1≦3.200 A zoom lens characterized by satisfying the following conditions. (Configuration 15) A negative lens is disposed closest to the object side in the first lens group. When the focal length of the negative lens is fG1, -2.10≦ft / fG1≦-0.50 15. The zoom lens according to claim 14, wherein the following condition is satisfied: (Configuration 16) The first sub-lens group has a positive lens, When the focal length of the positive lens Gp is ​​fGp, 0.40≦ft / fGp≦10.60 16. The zoom lens according to claim 14 or 15, wherein the following condition is satisfied: (Configuration 17) When the focal length of the first sub-lens group is f1a, -1.50≦f1a / f1≦-0.60 17. The zoom lens according to any one of configurations 14 to 16, wherein the following condition is satisfied: (Configuration 18) When the focal length of the second sub-lens group is f1b, 2.00≦f1b / f1≦6.50 18. The zoom lens according to any one of configurations 14 to 17, wherein the following condition is satisfied: (Configuration 19) When the focal length of the third sub-lens group is f1c, 1.30≦f1c / f1≦4.50 19. The zoom lens according to any one of configurations 14 to 18, wherein the following condition is satisfied: (Configuration 20) Let LD1 be the thickness on the optical axis from the lens surface of the first lens group closest to the object side to the lens surface closest to the image side, 1.10≦LD1 / f1≦6.50 20. A zoom lens according to any one of configurations 14 to 19, characterized in that the following condition is satisfied: (Configuration 21) When the zoom lens is used in an imaging device having an imaging surface with a diagonal size of 2Y, the focal length of the zoom lens at the wide-angle end is fw, and the half angle of view of the zoom lens at the wide-angle end is ωw. 51.50°≦ωw≦65.00° ωw=arctan(Y / fw) 21. The zoom lens according to any one of configurations 14 to 20, characterized in that the following condition is satisfied: (Configuration 22) When the F-number at the wide-angle end of the zoom lens is Fnow, 1.30≦Fnow≦3.50 22. The zoom lens according to any one of configurations 14 to 21, characterized in that the following condition is satisfied: (Configuration 23) Let BFw be the length on the optical axis from the image-side lens surface of the lens closest to the image side among the lenses having a finite focal length included in the zoom lens to the image plane. 0.050≦fw / BFw≦0.430 23. The zoom lens according to any one of configurations 14 to 22, characterized in that the following condition is satisfied: (Configuration 24) When the length on the optical axis from the lens surface of the first lens group closest to the object to the aperture stop at the wide-angle end in a state where an object at infinity is focused on is defined as LDs, and when the length on the optical axis from the lens surface of the first lens group closest to the object to the lens surface of the rear lens group closest to the image at the wide-angle end in a state where an object at infinity is focused on is defined as LT, 0.20≦LDs / LT≦0.60 24. The zoom lens according to any one of configurations 14 to 23, wherein the following condition is satisfied: (Configuration 25) When the average value of the refractive index at the d-line of at least one negative lens included in the first lens group is denoted by nd1n, 1.750≦nd1n≦2.000 25. The zoom lens according to any one of configurations 14 to 24, wherein the following condition is satisfied: (Configuration 26) The first sub-lens group has a positive lens. When the Abbe number of the positive lens based on the d-line is νd1ap, 17.0≦νd1ap≦35.0 26. The zoom lens according to any one of configurations 14 to 25, wherein the following condition is satisfied: (Configuration 27) The zoom lens according to any one of configurations 1 to 26, and an image sensor for capturing an image of a subject through the zoom lens.

[0064] 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]

[0065] L1 First lens group L2 Second lens group L3: Third lens group L4 4th lens group L5 Fifth lens group L6 6th lens group SP Aperture I image plane

Claims

1. A zoom lens having a group of lenses arranged sequentially from the object side to the image side, comprising a first lens group with positive refractive power that does not move for zooming, three or more intermediate lens groups that move for zooming, and a rear lens group with positive refractive power, wherein the spacing between adjacent lens groups changes during zooming. The first lens group comprises a first sub-lens group with negative refractive power that does not move for focusing, arranged in order from the object side to the image side, a second sub-lens group with positive refractive power that moves for focusing, and a third sub-lens group with positive refractive power. When the focal length of the first lens group is f1, the length along the optical axis from the image-side lens surface of the first lens group to the rear principal point of the first lens group when in focus on an object at infinity is bok1, the focal length at the wide-angle end of the zoom lens is fw, and the focal length at the telephoto end of the zoom lens is ft, 2.430≦(f1+bok1) / f1≦4.500 1.150 ≤ ft / f1 ≤ 3.200 2.250 ≤ f1 / fw ≤ 6.700 The following conditions are met: When the zoom lens is used in an imaging device having an imaging plane with a diagonal size of 2Y, and the half-angle of view at the wide-angle end of the zoom lens is ωw, 51.50° ≤ ωw ≤ 65.00° ωw=arctan(Y / fw) A zoom lens characterized by satisfying the following conditions.

2. A negative lens is positioned closest to the object in the first lens group, and when the focal length of this negative lens is fG1, -2.10 ≤ ft / fG1 ≤ -0.50 The zoom lens according to claim 1, characterized by satisfying the following conditions.

3. The first sub-lens group has a positive lens, When the focal length of the positive lens is fGp, 0.40 ≤ ft / fGp ≤ 10.60 The zoom lens according to claim 1, characterized by satisfying the following conditions.

4. When the focal length of the first sub-lens group is f1a, -1.50 ≤ f1a / f1 ≤ -0.60 The zoom lens according to claim 1, characterized by satisfying the following conditions.

5. When the focal length of the second sub-lens group is f1b, 2.00 ≤ f1b / f1 ≤ 6.50 The zoom lens according to claim 1, characterized by satisfying the following conditions.

6. When the focal length of the third sub-lens group is f1c, 1.30 ≤ f1c / f1 ≤ 4.50 The zoom lens according to claim 1, characterized by satisfying the following conditions.

7. When LD1 is the thickness along the optical axis from the lens surface closest to the object to the lens surface closest to the image of the first lens group, 1.10 ≤ LD1 / f1 ≤ 6.50 The zoom lens according to claim 1, characterized by satisfying the following conditions.

8. When the F-number of the zoom lens at its wide-angle end is denoted as Fnow, 1.30 ≤ Fnow ≤ 3.50 The zoom lens according to claim 1, characterized by satisfying the following conditions.

9. When BFw is the length along the optical axis from the image-side lens surface to the image plane of the lens closest to the image among the lenses included in the zoom lens, 0.050 ≤ fw / BFw ≤ 0.430 The zoom lens according to claim 1, characterized by satisfying the following conditions.

10. The zoom lens has an aperture diaphragm, When the lens group is in focus on an object at infinity and at the wide-angle end, the length along the optical axis from the lens surface closest to the object in the first lens group to the aperture diaphragm is LDs, and when the lens group is in focus on an object at infinity and at the wide-angle end, the length along the optical axis from the lens surface closest to the object in the first lens group to the lens surface closest to the image in the rear lens group is LT. 0.20 ≤ LDs / LT ≤ 0.60 The zoom lens according to claim 1, characterized by satisfying the following conditions.

11. When the average value of the refractive index at the d line of at least one negative lens included in the first lens group is nd1n, 1.750 ≤ nd1n ≤ 2.000 The zoom lens according to claim 1, characterized by satisfying the following conditions.

12. The first sub-lens group has a positive lens, and when the Abbe number with respect to the d line of the positive lens is νd1ap, 17.0 ≤ νd1ap ≤ 35.0 The zoom lens according to claim 1, characterized by satisfying the following conditions.

13. A zoom lens having a first lens group with positive refractive power that does not move for zooming and is arranged sequentially from the object side to the image side, three or more intermediate lens groups that move for zooming, an aperture diaphragm, and a rear lens group with positive refractive power, wherein the spacing between adjacent lens groups changes during zooming, The aperture diaphragm is positioned within or adjacent to one of the three or more intermediate lens groups, and moves together with one of the lens groups of the intermediate lens group during zooming. The first lens group comprises a first sub-lens group with negative refractive power that does not move for focusing, arranged in order from the object side to the image side, a second sub-lens group with positive refractive power that moves for focusing, and a third sub-lens group with positive refractive power. When the focal length of the first lens group is f1, the length along the optical axis from the image-side lens surface of the first lens group to the rear principal point of the first lens group when in focus on an object at infinity is bok1, and the focal length at the telephoto end of the zoom lens is ft, 2.000≦(f1+bok1) / f1≦4.500 1.950 ≤ ft / f1 ≤ 3.200 A zoom lens characterized by satisfying the following conditions.

14. A negative lens is positioned closest to the object in the first lens group, and when the focal length of this negative lens is fG1, -2.10 ≤ ft / fG1 ≤ -0.50 The zoom lens according to claim 13, characterized in that it satisfies the following conditions.

15. The first sub-lens group has a positive lens, When the focal length of the positive lens is fGp, 0.40 ≤ ft / fGp ≤ 10.60 The zoom lens according to claim 13, characterized in that it satisfies the following conditions.

16. When the focal length of the first sub-lens group is f1a, -1.50 ≤ f1a / f1 ≤ -0.60 The zoom lens according to claim 13, characterized in that it satisfies the following conditions.

17. When the focal length of the second sub-lens group is f1b, 2.00 ≤ f1b / f1 ≤ 6.50 The zoom lens according to claim 13, characterized in that it satisfies the following conditions.

18. When the focal length of the third sub-lens group is f1c, 1.30 ≤ f1c / f1 ≤ 4.50 The zoom lens according to claim 13, characterized in that it satisfies the following conditions.

19. When LD1 is the thickness along the optical axis from the lens surface closest to the object to the lens surface closest to the image of the first lens group, 1.10 ≤ LD1 / f1 ≤ 6.50 The zoom lens according to claim 13, characterized in that it satisfies the following conditions.

20. When the zoom lens is used in an imaging device having an imaging plane with a diagonal size of 2Y, and the focal length at the wide-angle end of the zoom lens is fw, and the half-angle of view at the wide-angle end of the zoom lens is ωw, 51.50° ≤ ωw ≤ 65.00° ωw=arctan(Y / fw) The zoom lens according to claim 13, characterized in that it satisfies the following conditions.

21. When the F-number of the zoom lens at its wide-angle end is denoted as Fnow, 1.30 ≤ Fnow ≤ 3.50 The zoom lens according to claim 13, characterized in that it satisfies the following conditions.

22. When the focal length of the zoom lens at the wide-angle end is fw, and the length along the optical axis from the image-side lens surface to the image plane of the lens closest to the image among the lenses included in the zoom lens is BFw, 0.050 ≤ fw / BFw ≤ 0.430 The zoom lens according to claim 13, characterized in that it satisfies the following conditions.

23. When the lens group is in focus on an object at infinity and at the wide-angle end, the length along the optical axis from the lens surface closest to the object in the first lens group to the aperture diaphragm is LDs, and when the lens group is in focus on an object at infinity and at the wide-angle end, the length along the optical axis from the lens surface closest to the object in the first lens group to the lens surface closest to the image in the rear lens group is LT. 0.20 ≤ LDs / LT ≤ 0.60 The zoom lens according to claim 13, characterized in that it satisfies the following conditions.

24. When the average value of the refractive index at the d line of at least one negative lens included in the first lens group is nd1n, 1.750 ≤ nd1n ≤ 2.000 The zoom lens according to claim 13, characterized in that it satisfies the following conditions.

25. The first sub-lens group has a positive lens, and when the Abbe number with respect to the d line of the positive lens is νd1ap, 17.0 ≤ νd1ap ≤ 35.0 The zoom lens according to claim 13, characterized in that it satisfies the following conditions.

26. A zoom lens according to any one of claims 1 to 25, An imaging device characterized by having an image sensor that captures an image of a subject through the aforementioned zoom lens.

Images