Zoom lens and imaging device

Abstract

It provides a high-performance optical zoom lens. [Solution] The zoom lens is composed of a first lens group with positive refractive power, an intermediate group having two or more lens groups that move for zooming, and a rear lens group, and has an aperture diaphragm that does not move during zooming. When the focal length of the first lens group is f1, the focal length of the zoom lens at the wide-angle end is fw, the focal length of the zoom lens at the telephoto end is ft, the total optical length of the zoom lens when it is in focus on an object at infinity at the wide-angle end is TL, and the combined lateral magnification at the wide-angle end of all lens groups on the image side of the lens group with negative refractive power in the intermediate group is βr, the following conditions are satisfied: 0.0300≦fw / TL≦0.0390, 0.0500≦f1 / TL≦0.1900, 4.000≦ft / fw≦7.000, and -2.400≦βr≦-1.270.

Description

[Technical Field]

[0001] The present invention relates to a zoom lens suitable for imaging. [Background Art]

[0002] Zoom lenses are desired to have high optical performance while being compact and having a wide angle of view. Patent Document 1 discloses a zoom lens configured, in order from the object side to the image side, of a first lens group having positive refractive power that does not move for zooming, a plurality of lens groups that move for zooming, and a rear lens group that does not move for zooming. [Prior Art Literature] [Patent Literature]

[0003] [Patent Document 1] Japanese Patent Laid-Open No. 2021-032924 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] There is a demand for zoom lenses having higher optical performance than conventional ones. [Means for Solving the Problem]

[0005] One aspect of the present invention is a zoom lens in which a plurality of lens groups arranged sequentially from the object side to the image side consist of a first lens group with positive refractive power that does not move for zooming, an intermediate group including two or more lens groups that move for zooming, and a rear lens group, and the distance between adjacent lens groups changes when zooming. It has an aperture diaphragm that does not move when zooming. When the focal length of the first lens group is f1, the focal length of the zoom lens at the wide-angle end is fw, the focal length of the zoom lens at the telephoto end is ft, the distance TL is the distance on the optical axis from the lens surface closest to the object of the zoom lens to the final lens surface closest to the image of the zoom lens when it is in focus on an object at the wide-angle end and the final lens surface closest to the image of the zoom lens is added to the air equivalent distance on the optical axis from the final lens surface to the image surface, and the combined horizontal magnification at the wide-angle end of all lens groups on the image side of the lens group closer to the image of the intermediate group with negative refractive power is βr. 0.0300 ≤ fw / TL ≤ 0.0390 0.0500 ≤ f1 / TL ≤ 0.1900 4.000 ≤ ft / fw ≤ 7.000 -2.400 ≤ βr ≤ -1.270 It is characterized by satisfying the following conditions.

[0006] Another aspect of the present invention is a zoom lens in which a plurality of lens groups arranged sequentially from the object side to the image side consist of a first lens group with positive refractive power that does not move for zooming, an intermediate group having two or more lens groups that move for zooming, and a rear lens group, and the distance between adjacent lens groups changes when zooming. It has an aperture diaphragm that moves when zooming. When the focal length of the first lens group is f1, the focal length of the zoom lens at the wide-angle end is fw, the focal length of the zoom lens at the telephoto end is ft, and TL is the distance on the optical axis from the lens surface closest to the object to the final lens surface closest to the image when the zoom lens is in focus at the wide-angle end and an object at infinity is focused, plus the air-equivalent distance on the optical axis from the final lens surface to the image surface, 0.0250 ≤ fw / TL ≤ 0.0350 0.0500 ≤ f1 / TL ≤ 0.1900 4.000 ≤ ft / fw ≤ 7.000 It is characterized by satisfying the following conditions. Furthermore, an imaging device equipped with the above-mentioned zoom lenses also constitutes another aspect of the present invention. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a zoom lens having high optical performance. [Brief explanation of the drawing]

[0008] [Figure 1] Cross-sectional view of the zoom lens of Example 1 at its wide-angle end. [Figure 2] Aberration diagrams of the zoom lens of Example 1 at the wide-angle and telephoto ends. [Figure 3] Cross-sectional view of the zoom lens of Example 2 at its wide-angle end. [Figure 4] Aberration diagrams of the zoom lens of Example 2 at the wide-angle and telephoto ends. [Figure 5] Cross-sectional view of the zoom lens of Example 3 at its wide-angle end. [Figure 6] Aberration diagrams of the zoom lens of Example 3 at the wide-angle and telephoto ends. [Figure 7] Cross-sectional view of the zoom lens of Example 4 at its wide-angle end. [Figure 8] Aberration diagrams of the zoom lens of Example 4 at the wide-angle and telephoto ends. [Figure 9] Cross-sectional view of the zoom lens of Example 5 at its wide-angle end. [Figure 10] Aberration diagrams of the zoom lens of Example 5 at the wide-angle and telephoto ends. [Figure 11] Cross-sectional view of the zoom lens of Example 6 at its wide-angle end. [Figure 12] Aberration diagrams of the zoom lens of Example 6 at the wide-angle and telephoto ends. [Figure 13] Cross-sectional view of the zoom lens of Example 7 at its wide-angle end. [Figure 14] Aberration diagrams of the zoom lens of Example 7 at the wide-angle and telephoto ends. [Figure 15] Cross-sectional view of the zoom lens of Example 8 at its wide-angle end. [Figure 16]Aberration diagrams of the zoom lens of Example 8 at the wide-angle end and the telephoto end. [Figure 17] Cross-sectional view of the zoom lens of Example 9 at the wide-angle end. [Figure 18] Aberration diagrams of the zoom lens of Example 9 at the wide-angle end and the telephoto end. [Figure 19] Figure showing an imaging apparatus including the zoom lenses of Examples 1 to 9. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0010] FIG. 1, FIG. 3, FIG. 5, FIG. 7, FIG. 9, FIG. 11, FIG. 13, FIG. 15, and FIG. 17 each show a cross-section at the wide-angle end of the zoom lens of Examples 1 to 9 in a state focused on an infinite-distance object (hereinafter referred to as an infinite-focused state). The zoom lens of each example is used in various imaging apparatuses such as cinema cameras, broadcast cameras, video cameras, surveillance cameras, digital still cameras, and silver halide film cameras.

[0011] In a zoom lens, a lens unit is a group of one or more lenses that move integrally or do not move integrally during zooming and focusing between the wide-angle end and the telephoto end, and the distance between adjacent lens units changes during zooming. A lens unit may include an aperture stop. Further, the wide-angle end and the telephoto end respectively indicate zoom states of the maximum angle of view (shortest focal length) and the minimum angle of view (maximum focal length) when a lens unit that moves during zooming is located at both ends of a mechanically or controllably movable range on the optical axis.

[0012] In each diagram, the left side is the object side (front), and the right side is the image side (rear). OA indicates the optical axis of the zoom lens. Li is the i-th lens group counting from the object side, and L1m is the m-th sub-lens group counting from the object side in the first lens group L1. SP is the aperture diaphragm, and I is the image plane. The image plane I is where the imaging surface (light-receiving surface) of the image sensor in the imaging device or the film surface (photosensitive surface) of the silver halide film is located. Note that an optical block without refractive power, such as an optical filter, may be placed between the lens with the greatest refractive power on the image side of the zoom lens and the image plane I.

[0013] In each figure, below the lens group that moves during zooming, an arrow indicates the trajectory of that lens group when zooming from the wide-angle end to the telephoto end. Furthermore, below the lens group that moves during focusing (sub-lens group), an arrow labeled "FOCUS" indicates the direction of movement of that lens group when focusing from infinity to close.

[0014] Each embodiment of the zoom lens comprises a plurality of lens groups arranged sequentially from the object side to the image side, including a first lens group L1 with positive refractive power that does not move for zooming, an intermediate group including two or more intermediate lens groups LM (M=2~5) that move for zooming, and a rear lens group LR (R=4~6). It also has an aperture diaphragm SP that either does not move or moves during zooming.

[0015] In each embodiment, the first lens group L1 includes a first sub-lens group L11 that does not move for focusing, a second sub-lens group L12 that moves for focusing, and a third sub-lens group L13 that does not move for focusing. The second sub-lens group L12 moves toward the image when focusing from an object at infinity to a nearby object.

[0016] The zoom lenses of Examples 1, 2, and 3 have two or more intermediate lens groups LM, which are arranged in order from the object side to the image side as a variator group: a second lens group L2 with negative refractive power, a third lens group L3 with negative refractive power, and a fourth lens group L4 with positive refractive power. The second lens group L2 moves monotonically toward the image side when zooming from the wide-angle end to the telephoto end. The third lens group L3 and the fourth lens group L4 move toward the image side on different trajectories from each other when zooming from the wide-angle end to the telephoto end.

[0017] The rear lens group LR is composed of a fifth lens group L5 with positive refractive power. An optical unit such as an extender lens for focal length conversion may be inserted within the fifth lens group L5. The aperture diaphragm SP is positioned between the fourth lens group L4 and the fifth lens group L5 and does not move during zooming. By positioning the aperture diaphragm SP within or adjacent to the rear lens group LR and not moving during zooming, space can be created for each intermediate lens group LM to move, making it possible to realize a zoom lens with a high magnification ratio. This is also true in embodiments 4 and 5 described later.

[0018] The zoom lens of Example 4 has two or more intermediate lens groups LM, which are arranged sequentially from the object side to the image side. These include a second lens group L2 with negative refractive power as a variator group, and a third lens group L3 with negative refractive power. The second lens group L2 moves monotonically toward the image side when zooming from the wide-angle end to the telephoto end. The third lens group L3 also moves toward the image side when zooming from the wide-angle end to the telephoto end.

[0019] The rear lens group LR is composed of the fourth lens group L4, which has a positive refractive power. An optical unit such as an extender lens may be inserted within the fourth lens group L4. The aperture diaphragm SP is positioned between the third lens group L3 and the fourth lens group L4 and does not move during zooming.

[0020] The zoom lens of Example 5 has two or more intermediate lens groups LM, arranged in order from the object side to the image side: a second lens group L2 with negative refractive power as a variator group, a third lens group L3 also with negative refractive power as a variator group, a fourth lens group L4 with negative refractive power, and a fifth lens group L5 with positive refractive power. The second lens group L2 and the third lens group L3 move monotonically toward the image side along slightly different trajectories when zooming from the wide-angle end to the telephoto end. The fourth lens group L4 and the fifth lens group L5 move toward the image side along different trajectories when zooming from the wide-angle end to the telephoto end.

[0021] The rear lens group LR is composed of the sixth lens group L6, which has a positive refractive power. An optical unit such as an extender lens may be inserted within the sixth lens group L6. The aperture diaphragm SP is positioned between the fifth lens group L5 and the sixth lens group L6 and does not move during zooming.

[0022] In the zoom lenses of Examples 1 to 5, in which the aperture diaphragm SP does not move during zooming, let f1 be the focal length of the first lens group L1, 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. Furthermore, let TL be the distance along the optical axis from the lens surface closest to the object to the final lens surface closest to the image, plus the air-equivalent distance along the optical axis from the final lens surface to the image plane I, when the zoom lens is in focus at the wide-angle end and infinity (total optical length). In addition, let βr be the combined lateral magnification at the wide-angle end of all lens groups on the image side of the intermediate lens group having negative refractive power (L4, L5 in Examples 1 to 3, L4 in Example 4, and L5, L6 in Example 5). At this time, it is preferable that at least one of the following conditions (1) to (4) is satisfied.

[0023] 0.0300 ≤ fw / TL ≤ 0.0390 (1) 0.0500 ≤ f1 / TL ≤ 0.1900 (2) 4.000 ≤ ft / fw ≤ 7.000 (3) -2.400 ≤ βr ≤ -1.270 (4) The zoom lens of Example 6 has two or more intermediate lens groups LM, which are arranged in order from the object side to the image side as a variator group: a second lens group L2 with negative refractive power, a third lens group L3 with negative refractive power, and a fourth lens group L4 with positive refractive power. The second lens group L2 moves toward the image side when zooming from the wide-angle end to the telephoto end. The third lens group L3 and the fourth lens group L4 move toward the image side on different trajectories from each other when zooming from the wide-angle end to the telephoto end.

[0024] The rear lens group LR is composed of the fifth lens group L5, which has a positive refractive power. The aperture diaphragm SP is positioned closest to the object in the fourth lens group L4 and moves with the fourth lens group L4 during zooming. By positioning the aperture diaphragm SP within or adjacent to the intermediate lens group LM and moving during zooming, the aperture diaphragm SP can be brought closer to the first lens group L1, thereby suppressing the diameter of the first lens group L1. As a result, it becomes possible to realize a wider-angle zoom lens. This is also true in embodiments 7 to 9 described later.

[0025] The zoom lens of Example 7 has two or more intermediate lens groups LM, arranged in order from the object side to the image side: a second lens group L2 with negative refractive power as a variator group, a third lens group L3 also with negative refractive power as a variator group, a fourth lens group L4 with negative refractive power, and a fifth lens group L5 with positive refractive power. The second lens group L2 and the third lens group L3 move monotonically toward the image side with slightly different trajectories when zooming from the wide-angle end to the telephoto end. The fourth lens group L4 and the fifth lens group L5 move toward the image side with different trajectories when zooming from the wide-angle end to the telephoto end.

[0026] The rear lens group LR is composed of the sixth lens group L6, which has a positive refractive power. The aperture diaphragm SP is located closest to the object on the fifth lens group L5 and moves together with the fifth lens group L5 during zooming.

[0027] The zoom lens of Example 8 has two or more intermediate lens groups LM, arranged in order from the object side to the image side: a second lens group L2 with positive refractive power, a third lens group L3 as a variator group with negative 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 moves toward the image side with a small amount of movement when zooming from the wide-angle end to the telephoto end. The second lens group L2, which moves a small amount when zooming from the wide-angle end to the telephoto end, may be considered as part of the first lens group L1. The third lens group L3 moves toward the image side monotonically when zooming from the wide-angle end to the telephoto end. The fourth lens group L4 and the fifth lens group L5 move toward the image side on different trajectories when zooming from the wide-angle end to the telephoto end.

[0028] The rear lens group LR is composed of the sixth lens group L6, which has a positive refractive power. The aperture diaphragm SP is located closest to the object on the fifth lens group L5 and moves together with the fifth lens group L5 during zooming.

[0029] The zoom lens of Example 9 has two or more intermediate lens groups LM, which are arranged in order from the object side to the image side as a variator group: a second lens group L2 with negative refractive power, a third lens group L3 with negative refractive power, and a fourth lens group L4 with positive refractive power. The second lens group L2 moves monotonically toward the image side when zooming from the wide-angle end to the telephoto end. The third lens group L3 and the fourth lens group L4 move toward the image side on different trajectories from each other when zooming from the wide-angle end to the telephoto end.

[0030] The rear lens group LR is composed of the fifth lens group L5, which has a positive refractive power. The aperture diaphragm SP is located closest to the object on the fourth lens group L4 and moves together with the fourth lens group L4 during zooming.

[0031] In the zoom lenses of Examples 6 to 9, in which the aperture diaphragm SP moves during zooming as described above, let f1 be the focal length of the first lens group L1, fw be the focal length of the entire zoom lens system at the wide-angle end, and ft be the focal length of the entire zoom lens system at the telephoto end. Furthermore, let TL be the distance (total optical length) obtained by adding the distance along the optical axis from the lens surface closest to the object to the final lens surface closest to the image to the final lens surface at the wide-angle end and in focus at infinity, to the air-equivalent distance along the optical axis from the final lens surface to the image plane I. At this time, it is preferable that at least one of the following conditions of equations (1'), (2'), and (3') is satisfied.

[0032] 0.0250 ≤ fw / TL ≤ 0.0350 (1′) 0.0500 ≤ f1 / TL ≤ 0.1900 (2′) 4.000 ≤ ft / fw ≤ 7.000 (3′) The conditions in equations (1) and (1') indicate the appropriate relationship between the focal length at the wide-angle end of a zoom lens and the total optical length in order to obtain a wide-angle, compact, and lightweight zoom lens. If fw / TL exceeds the upper limit of equations (1) and (1'), the total optical length becomes shorter, which is advantageous for making the zoom lens compact and lightweight, but the focal length at the wide-angle end becomes too long, making it difficult to achieve a wide angle of view, which is undesirable. If fw / TL falls below the lower limit of equations (1) and (1'), it is advantageous for making the zoom lens wide, but the total optical length becomes too long, making it difficult to make the lens compact and lightweight, which is undesirable.

[0033] Furthermore, it is more preferable to set the lower limit of equation (1) to 0.0305 or 0.0310. Also, it is more preferable to set the upper limit of equation (1) to 0.0385 or 0.0380.

[0034] It is more preferable to set the lower limit of equation (1') to 0.0255 or 0.0260. It is also more preferable to set the upper limit of equation (1') to 0.0348 or 0.0345.

[0035] The conditions in equations (2) and (2') indicate the appropriate relationship between the focal length of the first lens group L1 and the total optical length for obtaining a zoom lens with a wide angle of view, high magnification ratio, and compact, lightweight design with high optical performance. If f1 / TL exceeds the upper limit of equations (2) and (2'), the total optical length becomes shorter, which is advantageous for making the zoom lens compact and lightweight, but the focal length of the first lens group L1 becomes too long. In this case, the amount of movement of each intermediate lens group LM for high magnification ratio becomes too large, and the distance from the first lens group L1 to the aperture diaphragm SP tends to become longer. As a result, the diameter of the first lens group L1 increases, making the zoom lens larger, which is undesirable. If f1 / TL falls below the lower limit of equations (2) and (2'), the focal length of the first lens group L1 becomes too short, making it difficult to keep the aberrations occurring in the first lens group L1 at the telephoto end within an acceptable range. Also, the total optical length becomes too long, making it difficult to obtain a compact and lightweight zoom lens, which is undesirable.

[0036] Furthermore, it is more preferable to set the lower limit of equations (2) and (2') to 0.060 or 0.0700. Also, it is more preferable to set the upper limit of equations (2) and (2') to 0.1700, 0.150, 0.120, or 0.090.

[0037] The conditions in equations (3) and (3') indicate the appropriate relationship between the focal lengths at the telephoto and wide-angle ends of a zoom lens in order to obtain a zoom lens with a high magnification ratio and high optical performance. If ft / fw exceeds the upper limit of equations (3) and (3'), it is undesirable because the focal length at the telephoto end becomes too long, making it difficult to obtain a compact, lightweight zoom lens with high optical performance. If ft / fw falls below the lower limit of equations (3) and (3'), it is undesirable because it becomes difficult to obtain a zoom lens with a high magnification ratio.

[0038] Furthermore, it is more preferable to set the lower limit of equations (3) and (3') to 4.050 or 4.100. Also, it is more preferable to set the upper limit of equations (3) and (3') to 6.800, 6.500, 6.000, or 5.500.

[0039] The conditions in equation (4) indicate the appropriate range of combined lateral magnification at the wide-angle end for all lens groups (successor lens groups) closer to the image than the lens group closest to the image among the negative refractive power lens groups in the intermediate group. These are the conditions for obtaining a zoom lens with a wide angle of view, high magnification ratio, and small size, light weight, and high optical performance. If βr exceeds the upper limit of equation (4), the combined lateral magnification of the successor lens group becomes too large, increasing its diameter and making it difficult to miniaturize and lighten the zoom lens. Furthermore, aberrations occurring in the lens group closer to the object than the successor lens group increase, making it difficult to correct them effectively, which is undesirable. If βr falls below the lower limit of equation (4), the combined lateral magnification of the successor lens group becomes too small, increasing the diameter of the lens group closer to the object than the successor lens group, making it difficult to miniaturize and lighten the zoom lens, which is also undesirable.

[0040] -2.400 ≤ βr ≤ -1.270 Furthermore, it is more preferable to set the lower limit of equation (4) to -2.300 or -2.200. Also, it is more preferable to set the upper limit of equation (4) to -1.300, -1.350, or -1.400.

[0041] In the zoom lens of each embodiment, it is preferable that the first sub-lens group L11 of the first lens group L1 has a negative refractive power, and the second sub-lens group L12 and the third sub-lens group L13 have a positive refractive power. This configuration makes it possible to keep the variation in aberration associated with focusing within an acceptable range. Note that the configuration of the first lens group L1 is not limited to being composed of the three sub-lens groups described above, but may also have a configuration in which multiple sub-lens groups move for focusing, or may be composed of four or more sub-lens groups.

[0042] Furthermore, in the zoom lenses of each embodiment, it is preferable that the first sub-lens group L11 has two or more negative lenses. If the first sub-lens group L11 has only one negative lens, the refractive power of the negative lens in the first sub-lens group L11 becomes too strong in order to correct the chromatic aberration in the first lens group L1. As a result, it becomes difficult to correct aberrations other than chromatic aberration, such as spherical aberration, which is undesirable. Moreover, it is preferable that the two or more negative lenses of the first sub-lens group L11 are arranged in succession from the object side of the first sub-lens group L11. This configuration is advantageous for making the first sub-lens group L11 smaller and lighter.

[0043] Furthermore, in the zoom lenses of each embodiment, it is preferable that the intermediate group has three or more intermediate lens groups LM, which are two or more intermediate lens groups. By moving three or more intermediate lens groups to perform zooming, it becomes possible to effectively correct the various aberrations that occur with zooming.

[0044] Furthermore, in the zoom lens of each embodiment, it is preferable that the intermediate lens group closest to the object among the two or more intermediate lens groups LM has a positive refractive power. In this case, it is preferable that the amount of movement of the intermediate lens group closest to the object when zooming from the wide-angle end to the telephoto end is 10% or less of the total optical length TL of the zoom lens. In this case, it is preferable that the focal length f1 of the first lens group L1 is considered to be the combined focal length of the combined lens group formed by the first lens group L1 and the intermediate lens group closest to the object at the wide-angle end and infinity focus state, and that the conditions of each equation using f1 are satisfied.

[0045] Furthermore, it is preferable that the zoom lens of each embodiment satisfies at least one of the following conditions (5) to (16).

[0046] -2.40 ≤ f1 / fv ≤ -0.30 (5) -1.50 ≤ f11 / f1 ≤ -0.60 (6) 2.00 ≤ f12 / f1 ≤ 6.50 (7) 1.30 ≤ f13 / f1 ≤ 4.50 (8) 1.10 ≤ LD1 / f1 ≤ 6.50 (9) 51.50°≦ωw≦65.00° (10) 2.00 ≤ Fnow ≤ 3.50 (11) 0.050 ≤ fw / BFw ≤ 0.430 (12) 0.20 ≤ LDs / TL ≤ 0.60 (13) 2.500≦(f1+bok1) / f1≦5.000 (14) 0.600 ≤ ft / f1 ≤ 5.000 (15) 1.700 ≤ f1 / fw ≤ 5.600 (16) In equations (5) to (16), when the lens is in focus at infinity, let fv be the focal length of the intermediate lens group (variator group) among two or more intermediate lens groups LM that has the largest absolute value obtained by dividing the lateral magnification at the telephoto end by the lateral magnification at the wide-angle end. Let f11 be the focal length of the first sub-lens group L11, f12 be the focal length of the second sub-lens group L12, and f13 be the focal length of the third sub-lens group L13. Let LD1 be the length along the optical axis from the lens surface closest to the object in the first lens group L1 to the lens surface closest to the image in the first lens group L1. Let Y be the image height of the zoom lens, and let ωw be the half-angle of view ωw at the wide-angle end, given by ωw = arctan(Y / fw). Let Fnow be the maximum aperture F number of the zoom lens at the wide-angle end. Let BFw be the distance along the optical axis from the lens surface closest to the image (the lens surface closest to the image with the greatest refractive power) to the image plane I in the zoom lens (back focus). Let LDs be the distance along the optical axis from the lens surface closest to the object in the first lens group L1 to the aperture diaphragm SP when the lens is in focus at infinity and at the wide-angle end. Let bok1 be the distance along the optical axis from the lens surface closest to the image in the first lens group L1 to the rear principal point of the first lens group L1 when the lens is in focus at infinity.

[0047] The conditions in equation (5) represent an appropriate relationship between the focal lengths of the first lens group L1 and the variator group, and are conditions for obtaining a zoom lens with a wide angle of view, high magnification ratio, and compact, lightweight design with high optical performance. If f1 / fv exceeds the upper limit of equation (5), the focal length of the first lens group L1 becomes longer, and the amount of movement of the variator group becomes excessive. As a result, it becomes difficult to obtain a zoom lens with a wide angle of view or a compact, lightweight design, which is undesirable. Alternatively, the focal length of the variator group becomes too short, which is undesirable because it increases aberration fluctuations during zooming or makes it difficult to reduce the size and weight in order to suppress aberration fluctuations. If f1 / fv falls below the lower limit of equation (5), the focal length of the first lens group L1 becomes shorter, which is undesirable because it makes it difficult to correct various aberrations. Alternatively, the focal length of the variator group becomes too long relative to the focal length of the first lens group L1, which is undesirable because it makes it difficult to achieve high magnification. Furthermore, if there is an intermediate lens group adjacent to the variator group that moves in the same direction as the variator group when zooming from the wide-angle end to the telephoto end, and whose ratio of movement to the variator group is 10% or less, that intermediate lens group may also be considered part of the variator group. In this case, the combined focal length at the wide-angle end of the variator group consisting of multiple intermediate lens groups may be defined as fv.

[0048] Furthermore, it is more preferable to set the lower limit of equation (5) to -2.30, -2.00, -1.50, or -1.00. Also, it is more preferable to set the upper limit of equation (5) to -0.40 or -0.50.

[0049] The conditions in equations (6) to (8) indicate the appropriate relationship between the focal lengths of the first lens group L1, the first sub-lens group L11, the second sub-lens group L12, and the third sub-lens group L13, and represent the conditions for obtaining a zoom lens with high optical performance. If f11 / f1 does not satisfy the condition in equation (6), the focal length f1 of the first lens group L1 or the focal length f11 of the first sub-lens group L11 becomes too small, making it difficult to keep the aberrations occurring in the first lens group L1 or the first sub-lens group L11 within an acceptable range, which is undesirable. If f12 / f1 does not satisfy the condition in equation (7), the focal length f1 of the first lens group L1 or the focal length f11 of the second sub-lens group L12 becomes too small, making it difficult to keep the aberrations occurring in the first lens group L1 or the first sub-lens group L12 within an acceptable range, which is undesirable. If f13 / f1 does not satisfy the conditions of equation (8), the focal length f1 of the first lens group L1 or the focal length f13 of the third sub-lens group L13 becomes too small, making it difficult to keep the aberrations occurring in the first lens group L1 or the third sub-lens group L13 within an acceptable range, which is undesirable.

[0050] Furthermore, it is more preferable to set the lower limit of equation (6) to -1.40, -1.30, or -1.20. Also, it is more preferable to set the upper limit of equation (6) to -0.65, -0.68, or -0.70.

[0051] Furthermore, it is more preferable to set the lower limit of equation (7) to 2.10 or 2.20. Also, it is more preferable to set the upper limit of equation (7) to 6.00, 5.50, or 5.00.

[0052] Furthermore, it is more preferable to set the lower limit of equation (8) to 1.50, 1.80, or 2.00. Also, it is more preferable to set the upper limit of equation (8) to 4.20, 4.00, or 3.80.

[0053] The conditions in equation (9) represent an appropriate relationship between the thickness of the first lens L1 and its focal length, and are conditions for obtaining a compact, lightweight zoom lens with high optical performance. If LD1 / f1 exceeds the upper limit of equation (9), the thickness of the first lens group L1 becomes too large, making it difficult to obtain a compact, lightweight zoom lens. Alternatively, the focal length of the first lens group L1 becomes too short, making it difficult to keep the aberration fluctuations associated with focusing within an acceptable range. This is undesirable. If LD1 / f1 falls below the lower limit of equation (9), the thickness of the first lens group L1 becomes too small, making it difficult to provide the necessary number of lenses in the first lens group L1 to suppress the aberration fluctuations associated with focusing. Alternatively, the focal length of the first lens group L1 becomes too long, increasing the amount of movement of the intermediate lens group LM during zooming, making it difficult to obtain a compact, lightweight zoom lens. This is undesirable.

[0054] Furthermore, it is more preferable to set the lower limit of equation (9) to 1.30, 1.50, 2.00, 2.50, or 3.00. Also, it is more preferable to set the upper limit of equation (9) to 6.00, 5.50, 5.00, or 4.50.

[0055] The conditions in equation (10) indicate an appropriate range of half-angle of view when a zoom lens is used in an imaging device with a diagonal image size of 2Y, and are the conditions for obtaining a wide-angle, compact, and lightweight zoom lens. When ωw satisfies the conditions in equation (10), it becomes possible to widen the angle of view in imaging devices using image sensors of various sizes. If ωw exceeds the upper limit of equation (10), it becomes difficult to obtain a compact and lightweight zoom lens, which is undesirable.

[0056] Furthermore, it is more preferable to set the lower limit of equation (10) to 52.00° or 52.50°. Also, it is more preferable to set the upper limit of equation (10) to 63.00° or 60.00°.

[0057] The conditions in equation (11) indicate an appropriate range for the maximum aperture F-number of a zoom lens at the wide-angle end, and are the conditions for obtaining a bright zoom lens. If Fnow falls below the lower limit of equation (11), it becomes difficult to keep spherical aberration, astigmatism, etc., within acceptable limits at the wide-angle end. Alternatively, it becomes necessary to enlarge each lens group to obtain high optical performance, making it difficult to obtain a small and lightweight zoom lens, which is undesirable. If Fnow exceeds the upper limit of equation (11), the zoom lens becomes too dark, which is also undesirable.

[0058] Furthermore, it is more preferable to set the lower limit of formula (11) to 2.30, 2.50, or 2.60. Also, it is more preferable to set the upper limit of formula (11) to 3.30, 3.10, or 3.00.

[0059] The conditions in equation (12) represent an appropriate relationship between the focal length of the entire zoom lens system at the wide-angle end and the back focus, and are conditions for obtaining a wide-angle zoom lens that is also compact and lightweight. If fw / BFw exceeds the upper limit of equation (12), the focal length at the wide-angle end becomes too long relative to the back focus, making it difficult to obtain a wide-angle zoom lens, which is undesirable. If fw / BFw falls below the lower limit of equation (12), the back focus becomes too long relative to the focal length at the wide-angle end, making it difficult to obtain a compact and lightweight zoom lens, which is also undesirable.

[0060] Furthermore, it is more preferable to set the lower limit of formula (12) to 0.070, 0.100, 0.150, or 0.200. Also, it is more preferable to set the upper limit of formula (12) to 0.400, 0.370, 0.330, or 0.300.

[0061] The conditions in equation (13) represent an appropriate relationship between the distance from the lens surface closest to the object in the first lens group L1 to the aperture diaphragm SP and the total optical length, in the state of infinity focus and at the wide-angle end. These are conditions for obtaining a wide-angle zoom lens that is also compact and lightweight. If LDs / TL exceeds the upper limit of equation (13), the aperture diaphragm SP will be positioned farther from the lens surface closest to the object in the first lens group L1. As a result, the diameter of the first lens group L1 becomes too large to achieve a wide-angle zoom lens, making it difficult to obtain a wide-angle zoom lens that is also compact and lightweight, which is undesirable. If LDs / TL falls below the lower limit of equation (13), the aperture diaphragm SP will be positioned farther from the lens surface closest to the image in the zoom lens. As a result, the diameter of the lens group closest to the image becomes too large, making it difficult to obtain a compact and lightweight zoom lens, which is also undesirable.

[0062] Furthermore, it is more preferable to set the lower limit of formula (13) to 0.30, 0.40, or 0.45. Also, it is more preferable to set the upper limit of formula (13) to 0.58 or 0.55.

[0063] The conditions in equation (14) indicate an appropriate range for the retrospective ratio (f1+bok1) of the first lens group L1, and are conditions for obtaining a wide-angle, compact, and lightweight zoom lens. Increasing the retrospective ratio of the first lens group L1 is advantageous for a wide angle of view, but it increases the diameter of the third sub-lens group L13 and the number of lenses in the first lens group L1. If (f1+bok1) exceeds the upper limit of equation (14), the diameter of the third sub-lens group L13 increases too much and the number of lenses in the first lens group L1 becomes too large, which is undesirable as it is disadvantageous for obtaining a compact and lightweight zoom lens. If (f1+bok1) falls below the lower limit of equation (14), it becomes difficult to obtain a wide-angle zoom lens, and the diameter of the lens closest to the object in the first lens group L1 increases, which is undesirable as it is disadvantageous for obtaining a compact and lightweight zoom lens.

[0064] Furthermore, it is more preferable to set the lower limit of formula (14) to 2.600, 2.800, 3.000, or 3.200. Also, it is more preferable to set the upper limit of formula (14) to 4.800, 4.500, 4.300, or 4.100.

[0065] The conditions in equation (15) indicate an appropriate relationship between the focal length of the first lens group L1 and the total focal length of the zoom lens system at the telephoto end, in order to obtain a zoom lens with a high magnification ratio, compact size, light weight, and high optical performance. Increasing ft / f1 is advantageous in obtaining a zoom lens with a high magnification ratio, but the aberrations generated by the first lens group L1 are amplified at the telephoto end, making it difficult to keep these aberrations within an acceptable range. If ft / f1 exceeds the upper limit of equation (15), the focal length of the first lens group L1 becomes too short, making it difficult to keep the aberrations generated by the first lens group L1 within an acceptable range at the telephoto end. Alternatively, the number of lenses in the first lens group L1 becomes too large, which is undesirable as it is disadvantageous in obtaining a compact and light zoom lens. If ft / f1 falls below the lower limit of equation (15), the focal length of the first lens group L1 becomes too long, making it difficult to obtain a zoom lens with a high magnification ratio. Alternatively, the amount of movement of each intermediate lens group (LM) during zooming becomes too large, which is undesirable as it hinders the creation of a compact and lightweight zoom lens.

[0066] Furthermore, it is more preferable to set the lower limit of formula (15) to 0.800, 1.000, 1.200, or 1.400. Also, it is more preferable to set the upper limit of formula (15) to 4.000, 3.500, 3.000, or 2.500.

[0067] The conditions in equation (16) indicate an appropriate relationship between the focal length of the first lens group L1 and the total focal length of the zoom lens system at the wide-angle end, in order to obtain a zoom lens that is wide-angle, compact, lightweight, and has high optical performance. If f1 / fw exceeds the upper limit of equation (16), the diameter of the first lens group L1 becomes large, making it difficult to obtain a compact zoom lens, which is undesirable. If f1 / fw falls below the lower limit of equation (16), it becomes difficult to obtain a wide-angle zoom lens, or it becomes difficult to keep coma aberration, field curvature, etc. at the wide-angle end within acceptable limits, which is also undesirable.

[0068] Furthermore, it is more preferable to set the lower limit of formula (16) to 1.750 or 1.800. Also, it is more preferable to set the upper limit of formula (16) to 5.000, 4.000, 3.600, or 3.000.

[0069] In the zoom lenses of each embodiment, the rear lens group does not move during zooming, however, all or part of the sub-lens groups of the rear lens group may move during zooming. For example, in Embodiment 1, the fifth lens group L5, which is the rear lens group, may move during zooming. Since the light beam that is generally afocal is incident on the object-side surface of the fifth lens group L5 from the object side, even if the fifth lens group L5 moves, the optical characteristics other than the back focus remain largely unchanged. Therefore, the fifth lens group L5 can be moved to compensate for focus changes caused by manufacturing errors, temperature changes, or changes in the orientation of the zoom lens.

[0070] The following numerical examples 1 to 9, corresponding to each of Examples 1 to 9, are shown. In each numerical example, i indicates the order of the optical surfaces when counted from the object side. r is the radius of curvature (mm) of the i-th optical surface, and d is the distance (lens thickness or air thickness mm) between the i-th optical surface and the (i+1)-th optical surface. Also, (variable) in d indicates that the air thickness changes during zooming, and the correspondence between air thickness and focal length is shown in a separate table. nd is the refractive index of the optical material at the d-line between the i-th optical surface and the (i+1)-th optical surface. νd is the Abbe number of the optical material with respect to the d-line. The Abbe number νd with respect to the d-line is defined by the following equation, where the refractive indices at the Fraunhofer lines F-line (wavelength 486.1 nm), d-line (wavelength 587.6 nm), and C-line (wavelength 656.3 nm) are nF, nd, and nC, respectively.

[0071] νd=(nd-1) / (nF-nC) Various data show the focal length (mm) of the zoom lens for the d-line (wavelength 587.6 nm), along with the half-angle of view ω (°), and the maximum image height corresponding to the half-angle of view is shown as "image height". The half-angle of view ω is calculated by setting the diagonal image size of the imaging device using the zoom lens to 2Y and the focal length of the zoom lens at the wide-angle end to fw. ω = arctan(Y / fw) It is expressed as follows. The maximum image height corresponds to Y, which is half of the diagonal image size 2Y (for example, when 2Y = 29.60 mm, Y = 14.80 mm). BF is the back focus (mm), which is the distance along the optical axis from the final lens surface on the image side of the zoom lens to the paraxial image plane, expressed as an air-equivalent length. The total lens length is the length obtained by adding the back focus to the distance along the optical axis from the front lens surface on the object side of the zoom lens to the final lens surface, and corresponds to the total optical length TL.

[0072] The asterisk (*) next to the surface number indicates that the optical surface is aspherical. The aspherical shape is expressed by the following formula, where X is the displacement from the surface vertex in the direction of the optical axis, H is the height from the optical axis in the direction perpendicular to the optical axis, the direction of light propagation is positive, R is the radius of paraxial curvature, K is the cone constant, and A3 to A16 are the aspherical coefficients. The cone constant and aspherical coefficients e±M are ×10 ±M It means...

[0073]

number

[0074] Furthermore, the lens group data shows the starting plane and focal length of each lens group.

[0075] Table 1 summarizes the values ​​of equations (1) to (16) for each numerical example. The zoom lenses in numerical examples 1 to 5 satisfy all the conditions of equations (1) to (4) and equations (5) to (16), while the zoom lenses in numerical examples 6 to 9 satisfy all the conditions of equations (1') to (3') and equations (5) to (16). [Numerical Example 1] Unit: mm Surface data Face number rd nd νd 1* 26370.983 2.15 1.90525 35.0 2 25.769 11.04 3* 50.047 1.50 1.88300 40.8 4 26.803 15.85 5 -52.153 1.40 2.00100 29.1 6 -514.230 0.20 7 166.616 8.01 1.92286 18.9 8 -59.949 5.18 9 1579.614 7.00 1.59522 67.7 10* -65.339 3.71 11 -1254.167 1.70 2.00069 25.5 12 48.319 11.73 1.49700 81.5 13 -155.449 0.21 14 1789.973 13.88 1.43875 94.7 15 -34.780 2.00 1.91650 31.6 16 -44.567 0.20 17 -36400.381 8.05 1.69930 51.1 18 -56.180 (variable) 19* -1117.897 1.20 1.69930 51.1 20 32.125 4.20 21 -148.088 0.82 1.88300 40.8 22 23.509 6.20 1.78880 28.4 23 -151.683 (variable) 24 -35.559 0.85 1.53775 74.7 25 53.686 1.80 1.85478 24.8 26 79.225 (Variable) 27* 43.850 5.36 1.71736 29.5 28 -10837.450 (variable) 29 (aperture) ∞ 1.00 30 40.103 1.30 2.05090 26.9 31 27.538 9.23 1.53172 48.8 32 -260.043 0.45 33 74.392 12.00 1.48749 70.2 34 -42.184 1.30 2.00100 29.1 35 -203.464 41.07 36 38.740 8.89 1.43875 94.7 37 -52.924 1.91 38 -148.399 1.20 2.00100 29.1 39 22.919 9.01 1.89286 20.4 40 -164.418 0.30 41 48.813 9.92 1.43875 94.7 42 -23.944 1.71 2.00100 29.1 43 57.516 0.20 44 36.664 9.06 1.48749 70.2 45 -41.397 40.59 Image plane ∞ Aspherical data Front page K = 0.00000e+00 A 4= 1.13075e-05 A 6=-1.19162e-08 A 8= 9.01150e-12 A10=-1.96581e-15 A12=-3.56941e-18 A14= 3.66370e-21 A16=-1.21144e-24 3rd page K = 0.00000e+00 A 4=-2.63185e-06 A 6=-7.27956e-10 A 8=-3.61729e-12 A10= 1.06773e-13 A12=-2.90229e-16 A14= 2.67601e-19 Side 10 K = 0.00000e+00 A 4= 2.85123e-06 A 6=-1.01285e-09 A 8=-9.44276e-13 A 3= 1.00487e-06 A 5= 4.16484e-09 A 7= 3.72608e-11 Page 19 K = 0.00000e+00 A 4= 4.06457e-06 A 6=-2.38082e-08 A 8= 2.05429e-10 A10=-1.06222e-12 A12= 2.35470e-15 Page 27 K = 0.00000e+00 A 4=-2.88291e-06 A 6= 3.72138e-09 A 8=-4.97460e-12 Various data Zoom ratio 4.20 Wide-angle, Medium, Telephoto Focal length 10.00 20.50 42.01 F-numbers: 2.72, 2.73, 3.65 Half-angle (°): 55.95, 35.83, 19.41 Image height 14.80 14.80 14.80 Lens length 319.55 319.55 319.55 BF 40.59 40.59 40.59 d18 1.17 28.67 47.64 d23 29.16 6.95 5.25 d26 7.70 7.66 0.98 d28 18.18 12.91 2.34 Lens group data Group starting plane focal length 1 1 23.07 2 19 -37.03 3 24 -49.64 4 27 60.89 5 29 70.71 [Numerical Example 2] Unit: mm Surface data Face number rd nd νd 1* 183.509 2.15 1.90525 35.0 2 24.087 14.00 3* 50.180 1.50 1.88300 40.8 4 29.765 13.67 5 -49.244 1.40 2.00100 29.1 6 -319.022 0.20 7 158.322 7.97 1.92286 18.9 8 -67.874 6.37 9 -695.713 7.00 1.59522 67.7 10* -66.565 3.77 11 -736.697 1.70 2.00069 25.5 12 52.528 12.06 1.59410 60.5 13 -120.674 0.21 14 -300.326 10.09 1.43875 94.7 15 -36.334 2.00 1.91650 31.6 16 -45.922 0.20 17 ∞ 7.48 1.69930 51.1 18 -58.880 (variable) 19* -265.632 1.20 1.69930 51.1 20 38.843 3.95 21 -108.472 0.82 1.88300 40.8 22 28.909 5.46 1.78880 28.4 23 -114.173 (variable) 24 -37.078 0.85 1.53775 74.7 25 46.695 2.26 1.85478 24.8 26 82.227 (Variable) 27* 48.922 5.04 1.71736 29.5 28 928.043 (variable) 29 (aperture) ∞ 1.00 30 44.860 1.30 2.05090 26.9 31 28.952 10.66 1.53172 48.8 32 -246.831 0.20 33 78.153 12.00 1.48749 70.2 34 -40.778 1.30 2.00100 29.1 35 -133.975 41.07 36 46.735 8.71 1.43875 94.7 37 -54.504 5.40 38 -92.054 1.20 2.00100 29.1 39 30.885 8.50 1.89286 20.4 40 -89.801 0.30 41 45.633 9.73 1.43875 94.7 42 -28.044 1.71 2.00100 29.1 43 62.810 0.20 44 37.709 7.65 1.48749 70.2 45 -71.937 39.99 Image plane ∞ Aspherical data Front page K = 0.00000e+00 A 4= 8.79520e-06 A 6=-7.38303e-09 A 8= 4.23172e-12 A10= 2.34534e-15 A12=-6.46927e-18 A14= 4.97396e-21 A16=-1.47719e-24 3rd page K = 0.00000e+00 A 4=-4.06853e-06 A 6= 5.81069e-10 A 8=-2.47073e-12 A10= 6.81538e-14 A12=-2.02500e-16 A14= 2.08706e-19 Side 10 K = 0.00000e+00 A 4= 2.08931e-06 A 6=-2.70180e-10 A 8=-8.29142e-13 A 3= 9.79858e-07 A 5= 7.80187e-10 A 7= 1.72211e-11 Page 19 K = 0.00000e+00 A 4= 2.71692e-06 A 6=-2.04573e-08 A 8= 2.07708e-10 A10=-1.09233e-12 A12= 2.23810e-15 Page 27 K = 0.00000e+00 A 4=-1.45811e-06 A 6= 1.82030e-09 A 8=-1.79204e-12 Various data Zoom ratio 4.09 Wide-angle, Medium, Telephoto Focal length 11.00 22.25 45.00 F-numbers: 2.72, 2.73, 3.65 Half-angle (°): 53.38, 33.63, 18.21 Image height 14.80 14.80 14.80 Lens length: 318.02 318.02 318.02 BF 39.99 39.99 39.99 d18 1.20 29.30 48.67 d23 31.93 8.15 3.53 d26 9.97 9.39 1.00 d28 12.64 8.91 2.54 Lens group data Group starting plane focal length 1 1 25.88 2 19 -40.34 3 24 -54.84 4 27 71.82 5 29 68.82 [Numerical Example 3] Unit: mm Surface data Face number rd nd νd 1* 9276.246 2.15 1.90525 35.0 2 27.003 9.51 3* 35.717 1.50 1.88300 40.8 4 28.085 16.81 5 -49.867 1.40 2.00100 29.1 6 -1005.683 0.20 7 198.552 8.56 1.92286 18.9 8 -72.501 1.30 9 1229.524 7.00 1.59522 67.7 10* -60.440 3.54 11 3426.893 1.70 2.00069 25.5 12 57.143 11.86 1.49700 81.5 13 -124.693 0.21 14 -434.337 12.70 1.43875 94.7 15 -35.692 2.00 1.91650 31.6 16 -43.199 0.20 17 -90234.679 8.50 1.69930 51.1 18 -62.296 (variable) 19* -173.993 1.20 1.69930 51.1 20 31.710 4.41 21 -151.890 0.82 1.88300 40.8 22 27.816 5.56 1.78880 28.4 23 -113.698 (variable) 24 -32.540 0.85 1.53775 74.7 25 49.092 2.21 1.85478 24.8 26 86.868 (variable) 27* 49.486 5.21 1.71736 29.5 28 -1142.521 (variable) 29 (aperture) ∞ 1.00 30 46.387 1.30 2.05090 26.9 31 30.575 11.75 1.53172 48.8 32 -148.630 0.20 33 80.374 12.00 1.48749 70.2 34 -41.688 1.30 2.00100 29.1 35 -174.156 41.07 36 49.100 8.16 1.43875 94.7 37 -55.601 6.36 38 -137.778 1.20 2.00100 29.1 39 29.198 7.43 1.89286 20.4 40 -163.757 0.30 41 54.592 10.35 1.43875 94.7 42 -24.908 1.71 2.00100 29.1 43 94.313 0.20 44 40.231 7.80 1.48749 70.2 45 -55.638 39.34 Image plane ∞ Aspherical data Front page K = 0.00000e+00 A 4= 1.13386e-05 A 6=-1.34090e-08 A 8= 1.37928e-11 A10=-9.23646e-15 A12= 3.29596e-18 A14= 1.16533e-23 A16=-2.94801e-25 3rd page K = 0.00000e+00 A 4=-6.02843e-06 A 6= 4.81093e-09 A 8=-2.61308e-11 A10= 1.16845e-13 A12=-2.42398e-16 A14= 1.73499e-19 Side 10 K = 0.00000e+00 A 4= 3.36349e-06 A 6= 3.76853e-09 A 8= 2.37394e-13 A 3=-4.84936e-07 A 5=-5.90923e-08 A 7=-1.00200e-10 Page 19 K = 0.00000e+00 A 4= 4.90330e-06 A 6=-2.82873e-08 A 8= 2.65298e-10 A10=-1.29371e-12 A12= 2.43058e-15 Page 27 K = 0.00000e+00 A 4=-1.91764e-06 A 6= 1.86218e-09 A 8=-1.89581e-12 Various data Zoom ratio 5.00 Wide-angle, Medium, Telephoto Focal length 11.00 24.60 55.00 F-number 2.72 2.72 3.66 Half-angle (°): 53.38, 31.04, 15.06 Image height 14.80 14.80 14.80 Lens length 319.51 319.51 319.51 BF 39.34 39.34 39.34 d18 1.20 30.87 49.93 d23 31.69 7.11 5.53 d26 10.08 9.89 0.99 d28 15.70 10.80 2.21 Lens group data Group starting plane focal length 1 1 27.22 2 19 -35.94 3 24 -49.86 4 27 66.24 5 29 70.32 [Numerical Example 4] Unit: mm Surface data Face number rd nd νd 1* 34960.559 2.10 1.83481 42.7 2 25.044 10.28 3* 35.103 1.50 1.80400 46.5 4 23.989 13.00 5 -235.445 1.40 1.91650 31.6 6 59.555 1.71 7 60.907 4.76 1.80810 22.8 8 208.438 1.20 9 98.891 7.17 1.59522 67.7 10* -73.731 2.17 11 294.913 7.53 1.49700 81.5 12 -60.508 1.70 1.95375 32.3 13 -56.341 0.18 14 -173.321 1.70 2.00100 29.1 15 48.657 15.31 1.53775 74.7 16 -43.544 0.18 17 365.187 8.35 1.65412 39.7 18 -48.584 (variable) 19 99.966 0.93 1.85150 40.8 20 28.319 4.13 21 -2609.158 0.85 1.76385 48.5 22 18.928 6.65 1.85478 24.8 23 -87.356 0.65 24 -49.469 0.75 2.00100 29.1 25 -341.451 (variable) 26 -79.639 0.70 1.83481 42.7 27 53.321 2.65 1.78880 28.4 28 1746.164 1.53 29 -40.607 0.70 1.90525 35.0 30 -91.150 (variable) 31 (aperture) ∞ 3.14 32* 31.993 9.23 1.51633 64.1 33 -36.783 2.00 34 -30.802 1.10 1.89190 37.1 35 44.974 9.48 1.68893 31.1 36 -35.581 0.32 37 -117.334 1.15 1.96300 24.1 38 5229.124 7.05 1.60311 60.6 39 -51.585 41.05 40 80.519 7.39 1.53775 74.7 41 -52.164 3.24 42 -353.472 1.44 2.00100 29.1 43 31.400 5.74 1.94594 18.0 44 206.797 0.20 45 33.980 10.38 1.49700 81.5 46 -30.342 2.00 2.05090 26.9 47 43.525 0.20 48 29.986 13.22 1.53172 48.8 49 -24.020 1.00 2.00100 29.1 50 -40.523 37.99 Image plane ∞ Aspherical data Front page K = 0.00000e+00 A 4= 2.21477e-06 A 6=-4.47868e-07 A 8=-1.42130e-09 A10=-2.19658e-13 A12= 1.90576e-16 A14=-1.48299e-19 A16=-1.50672e-23 A 3=-4.81538e-06 A 5= 3.17522e-06 A 7= 3.27388e-08 A 9= 3.39242e-11 A11=-9.44625e-15 A13= 2.54975e-18 A15= 2.37910e-21 3rd page K = 0.00000e+00 A 4= 1.01288e-06 A 6= 8.30390e-07 A 8= 9.93911e-09 A10=-5.85579e-12 A12=-6.65131e-14 A14= 9.14279e-17 A16= 3.15131e-20 A 3= 1.30888e-05 A 5=-3.36283e-06 A 7=-1.17418e-07 A 9=-4.14549e-10 A11= 1.59809e-12 A13=-5.24135e-17 A15=-2.93989e-18 Side 10 K =-3.43995e+00 A 4= 4.17249e-06 A 6=-2.91552e-08 A 8=-1.01820e-10 A10= 7.78074e-14 A12=-5.50285e-16 A14=-3.48381e-19 A16= 1.69044e-23 A 3= 4.25353e-06 A 5= 2.43307e-07 A 7= 2.28900e-09 A 9= 8.85240e-13 A11= 2.84191e-15 A13= 2.29147e-17 A15= 2.13039e-22 Page 32 K = 1.12407e-03 A 4=-3.94468e-06 A 6= 1.24411e-07 A 8= 1.26096e-10 A 3=-8.30887e-06 A 5=-1.09517e-06 A 7=-6.28430e-09 Various data Zoom ratio 4.11 Wide-angle, Medium, Telephoto Focal length 11.20 22.70 45.99 F-numbers: 2.73, 2.72, 3.66 Half-angle (°): 52.88, 33.11, 17.84 Image height 14.80 14.80 14.80 Lens length 295.37 295.37 295.37 BF 37.99 37.99 37.99 d18 0.97 20.64 32.19 d25 17.36 2.98 5.09 d30 19.93 14.64 0.98 Lens group data Group starting plane focal length 1 1 20.95 2 19 -39.71 3 26 -40.78 4 31 46.52 [Numerical Example 5] Unit: mm Surface data Face number rd nd νd 1* ∞ 2.10 1.83481 42.7 2 26.064 14.43 3* 99.261 1.50 1.80400 46.5 4 33.614 15.30 5 -43.024 1.40 1.89190 37.1 6 -112.144 0.11 7 175.826 8.54 1.80810 22.8 8 -69.511 1.44 9 -274.515 7.63 1.49700 81.5 10* -48.322 3.55 11 -1075.998 10.51 1.48749 70.2 12 -38.574 1.75 2.00100 29.1 13 -67.496 0.21 14 282.316 1.70 2.00100 29.1 15 62.592 15.42 1.43875 94.7 16 -54.962 0.19 17 2653.660 7.92 1.76385 48.5 18 -71.062 (variable) 19* 191.478 1.20 1.83481 42.7 20 28.027 3.99 21 -283.148 0.82 1.83481 42.7 22 22.803 6.63 1.78880 28.4 23 -68.546 (variable) 24 -34.253 0.82 1.88300 40.8 25 -90.006 (variable) 26 -36.238 0.85 1.59522 67.7 27 54.863 2.45 1.85478 24.8 28 134.425 (variable) 29* 50.041 4.28 1.85150 40.8 30 -214.006 (variable) 31 (aperture) ∞ 1.78 32 36.649 7.76 1.51742 52.4 33 -126.244 0.23 34 395.014 1.00 2.00100 29.1 35 31.543 5.81 1.51633 64.1 36 -464.533 0.41 37 550.314 6.32 1.67270 32.1 38 -28.473 1.00 2.00100 29.1 39 -78.321 41.40 40 90.435 4.78 1.43875 94.7 41 -64.730 0.69 42 57.600 8.05 1.80809 22.7 43 -32.651 1.09 1.89190 37.1 44 32.931 0.70 45 30.638 12.19 1.43875 94.7 46 -21.686 1.08 2.00100 29.1 47 324.070 0.13 48 64.563 9.83 1.48749 70.2 49 -29.650 42.78 Image plane ∞ Aspherical data Front page K = 0.00000e+00 A 4= 2.12211e-05 A 6= 2.92747e-08 A 8= 3.16369e-11 A10=-1.92722e-13 A12=-1.71481e-16 A14=-3.33400e-19 A16=-4.37434e-23 A 3=-5.79764e-05 A 5=-8.99814e-07 A 7=-1.23840e-09 A 9= 2.02850e-12 A11= 6.28310e-15 A13= 8.71668e-18 A15= 6.17837e-21 Sheet 3 K = 0.00000e+00 A 4=-1.79110e-05 A 6= 1.11375e-07 A 8= 2.62789e-09 A10=-2.66313e-10 A12=-1.84190e-12 A14=-1.97779e-15 A16=-1.91116e-19 A 3= 4.38754e-05 A 5= 1.49389e-06 A 7=-5.31826e-08 A 9= 1.16762e-09 A11= 2.84275e-11 A13= 7.62336e-14 A15= 2.93897e-17 Sheet 10 K = 0.00000e+00 A 4=-1.92976e-06 A 6=-2.03689e-07 A 8=-1.53666e-09 A10= 5.07998e-12 A12= 2.24283e-14 A14= 1.18243e-18 A16=-1.80400e-21 A 3= 8.88433e-06 A 5= 1.13723e-06 A 7= 2.32798e-08 A 9= 2.54606e-11 A11=-5.07035e-13 A13=-4.72942e-16 A15= 1.34791e-19 Sheet 19 K = 0.00000e+00 A 4= 5.11909e-06 A 6= 9.82184e-07 A 8= 6.17276e-08 A10=-8.92220e-10 A12=-2.54383e-11 A14=-7.19649e-14 A16=-1.75358e-17 A 3= 1.93551e-06 A 5=-1.25952e-06 A 7=-3.51791e-07 A 9=-3.13215e-09 A11= 2.23517e-10 A13= 1.72911e-12 A15= 1.70029e-15 Page 29 K = 0.00000e+00 A 4=-8.69389e-06 A 6=-4.59870e-07 A 8=-5.52191e-09 A10= 3.37450e-12 A12= 6.59970e-14 A14= 1.13614e-16 A16=-1.95539e-21 A 3= 2.83601e-06 A 5= 1.82880e-06 A 7= 6.72368e-08 A 9= 2.08662e-10 A11=-8.86327e-13 A13=-3.47365e-15 A15=-1.55784e-18 Various data Zoom ratio 4.76 Wide-angle, Medium, Telephoto Focal length 10.50 22.91 49.99 F-numbers: 2.99, 3.00, 3.98 Half-angle (°): 54.65, 32.86, 16.49 Image height 14.80 14.80 14.80 Lens length 319.84 319.84 319.84 BF 42.78 42.78 42.78 d18 1.26 30.26 49.27 d23 5.39 1.52 3.13 d25 27.06 7.74 3.76 d28 4.03 5.77 0.34 d30 20.34 12.79 1.59 Lens group data Group starting plane focal length 1 1 25.29 2 19 -59.81 3 24 -63.06 4 26 -55.05 5 29 47.99 6 31 76.15 [Numerical Example 6] Unit: mm Surface data Face number rd nd νd 1* 158.339 2.40 1.76385 48.5 2 26.149 16.26 3 98.808 1.60 2.00100 29.1 4 29.788 17.43 5 -31.955 1.50 1.88300 40.8 6 -47.052 1.88 7 290.590 5.87 1.89286 20.4 8 -108.119 1.50 9 82.067 10.75 1.61800 63.3 10* -68.506 6.10 11 -4155.712 5.81 1.49700 81.5 12 -66.925 0.20 13 -64.491 1.80 1.76385 48.5 14 -59.861 0.20 15 -65.245 1.65 1.95375 32.3 16 51.828 11.82 1.43875 94.9 17 -44.109 0.20 18 138.884 6.10 1.76385 48.5 19 -84.859 (variable) 20* 2592.723 1.20 1.90525 35.0 21 33.764 3.72 22 -101.320 0.80 1.59522 67.7 23 68.653 3.53 1.85478 24.8 24 -52.494 0.97 25 -31.663 0.80 1.76385 48.5 26 -106.993 (variable) 27 -54.981 0.80 1.60300 65.4 28 41.685 2.10 1.85478 24.8 29 79.385 (Variable) 30 (aperture) ∞ 1.00 31* 27.319 6.83 1.58144 40.8 32 -96.058 0.20 33 51.988 5.61 1.78472 25.7 34 -53.308 0.90 2.00069 25.5 35 36.481 (variable) 36 205.721 2.98 1.56732 42.8 37 -90.051 0.20 38 52.560 1.00 2.05090 26.9 39 30.878 3.82 1.53775 74.7 40 139.636 40.06 41 65.300 7.10 1.55200 70.7 42 -63.226 0.40 43 53.865 6.23 1.80810 22.8 44 -87.935 1.10 1.88300 40.8 45 27.056 1.30 46 25.986 13.14 1.43875 94.7 47 -25.415 1.50 2.05090 26.9 48 450.763 2.45 49 64.014 8.57 1.48749 70.2 50 -40.768 38.21 Image plane ∞ Aspherical data Front page K = 0.00000e+00 A 4= 6.66512e-06 A 6=-6.63901e-09 A 8= 7.94299e-12 A10=-6.37720e-15 A12= 3.24442e-18 A14=-8.73462e-22 A16= 9.75612e-26 Side 10 K = 0.00000e+00 A 4= 2.21622e-06 A 6=-8.91734e-10 A 8= 1.91386e-13 Page 20 K = 0.00000e+00 A 4= 4.49580e-06 A 6=-1.08843e-08 A 8= 1.64151e-10 A10=-1.12739e-12 A12= 2.82068e-15 Page 31 K = 0.00000e+00 A 4=-9.58966e-06 A 6=-2.12938e-10 A 8=-7.66613e-12 Various data Zoom ratio 4.29 Wide-angle, Medium, Telephoto Focal length 10.50 21.74 45.00 F-number 2.90 2.90 3.86 Half-angle (°): 54.65, 34.25, 18.21 Image height 14.80 14.80 14.80 Lens length 305.00 305.00 305.00 BF 38.21 38.21 38.21 d19 1.00 27.32 45.12 d26 25.73 5.10 5.30 d29 10.13 10.47 1.00 d35 18.58 12.55 4.01 Lens group data Group starting plane focal length 1 1 26.17 2 20 -33.84 3 27 -63.37 4 30 60.82 5 36 63.21 [Numerical Example 7] Unit: mm Surface data Surface No. r d nd νd 1* 350.864 2.40 1.76385 48.5 2 25.537 17.03 3 134.403 1.60 2.00100 29.1 4 30.378 17.97 5 -28.502 1.50 1.88300 40.8 6 -38.150 0.20 7 346.737 5.98 1.89286 20.4 8 -99.139 6.87 9 56.481 10.65 1.61800 63.3 10* -143.091 3.20 11 -574.247 6.84 1.49700 81.5 12 -67.366 0.20 13 -90.441 1.80 1.76385 48.5 14 -78.944 0.20 15 -117.593 1.65 1.95375 32.3 16 42.108 12.56 1.43875 94.9 17 -64.471 0.20 18 193.247 6.41 1.76385 48.5 19 -80.389 (variable) 20* 281.571 1.20 1.90525 35.0 21 37.339 3.96 22 -218.752 0.80 1.59522 67.7 23 50.820 3.89 1.85478 24.8 24 -106.921 (variable) 25 -32.651 0.80 1.76385 48.5 26 -73.269 (variable) 27 -60.566 0.80 1.60300 65.4 28 36.843 2.21 1.85478 24.8 29 64.596 (Variable) 30 (aperture) ∞ 1.00 31* 26.184 7.54 1.58144 40.8 32 -76.659 0.20 33 72.527 6.65 1.78472 25.7 34 -30.818 0.90 2.00069 25.5 35 42.789 (Variable) 36 114.623 5.01 1.56732 42.8 37 -59.726 0.20 38 35.394 1.00 2.05090 26.9 39 23.101 3.11 1.53775 74.7 40 37.927 40.06 41 44.767 10.08 1.55200 70.7 42 -68.744 0.40 43 70.859 6.39 1.80810 22.8 44 -57.109 1.10 1.88300 40.8 45 30.515 1.30 46 36.659 12.38 1.43875 94.7 47 -21.039 1.50 2.05090 26.9 48 -184.013 0.93 49 177.920 8.91 1.48749 70.2 50 -28.747 37.00 Image plane ∞ Aspherical data Sheet 1 K = 0.00000e+00 A 4= 9.27537e-06 A 6=-1.12171e-08 A 8= 1.42929e-11 A10=-1.25541e-14 A12= 6.97431e-18 A14=-2.11861e-21 A16= 2.69883e-25 Sheet 10 K = 0.00000e+00 A 4= 2.51032e-06 A 6=-6.65025e-10 A 8= 3.23129e-13 Sheet 20 K = 0.00000e+00 A 4= 3.82368e-06 A 6=-7.36056e-09 A 8= 9.10597e-11 A10=-4.40990e-13 A12= 7.80182e-16 Sheet 31 K = 0.00000e+00 A 4=-1.02901e-05 A 6= 6.69079e-11 A 8=-7.47431e-12 Various Data Zoom ratio 4.20 Wide-angle Intermediate Telephoto Focal length 10.00 20.49 42.00 F-number 2.90 2.90 3.83 Half angle of view (°) 55.95 35.84 19.41 Image height 14.80 14.80 14.80 Total lens length 319.50 319.50 319.50 BF 37.00 37.00 37.00 d19 1.00 31.12 51.87 d24 3.00 3.57 3.96 d26 32.37 7.43 3.93 d29 9.44 9.52 1.00 d35 17.13 11.30 2.18 Lens unit data Group starting plane focal length 1 1 27.54 2 20 -107.60 3 25 -77.77 4 27 -60.84 5 30 61.28 6 36 64.59 [Numerical Example 8] Unit: mm Surface data Face number rd nd νd 1* 165.643 2.40 1.76385 48.5 2 26.247 16.07 3 91.382 1.60 2.00100 29.1 4 30.125 17.05 5 -33.996 1.50 1.88300 40.8 6 -55.220 1.44 7 298.799 6.48 1.89286 20.4 8 -101.097 3.56 9 78.821 10.83 1.61800 63.3 10* -69.014 6.77 11 -231.617 5.39 1.49700 81.5 12 -62.833 0.20 13 -64.046 1.80 1.76385 48.5 14 -59.505 0.20 15 -65.336 1.65 1.95375 32.3 16 51.877 11.39 1.43875 94.9 17 -48.570 (variable) 18 135.062 6.74 1.76385 48.5 19 -74.542 (variable) 20* 240.387 1.20 1.90525 35.0 21 31.834 3.95 22 -110.534 0.80 1.59522 67.7 23 57.055 3.49 1.85478 24.8 24 -72.545 1.20 25 -33.861 0.80 1.76385 48.5 26 -92.926 (variable) 27 -54.081 0.80 1.60300 65.4 28 47.402 2.04 1.85478 24.8 29 92.243 (Variable) 30 (aperture) ∞ 1.00 31* 32.147 6.56 1.58144 40.8 32 -83.684 0.20 33 60.222 6.98 1.78472 25.7 34 -47.389 0.90 2.00069 25.5 35 46.808 (variable) 36 158.561 2.93 1.56732 42.8 37 -121.891 0.20 38 53.973 1.00 2.05090 26.9 39 29.777 4.26 1.53775 74.7 40 189.562 40.06 41 77.349 6.94 1.55200 70.7 42 -57.716 0.40 43 51.292 6.53 1.80810 22.8 44 -79.357 1.10 1.88300 40.8 45 26.363 1.30 46 25.239 12.90 1.43875 94.7 47 -25.868 1.50 2.05090 26.9 48 285.606 3.86 49 63.506 8.48 1.48749 70.2 50 -41.835 37.00 Image plane ∞ Aspherical data Front page K = 0.00000e+00 A 4= 6.51517e-06 A 6=-6.50746e-09 A 8= 7.68974e-12 A10=-6.01137e-15 A12= 2.85409e-18 A14=-6.64601e-22 A16= 5.25588e-26 Side 10 K = 0.00000e+00 A 4= 2.33473e-06 A 6=-8.80364e-10 A 8= 1.83146e-13 Page 20 K = 0.00000e+00 A 4= 3.68428e-06 A 6=-9.78901e-09 A 8= 1.36129e-10 A10=-8.57822e-13 A12= 2.01401e-15 Page 31 K = 0.00000e+00 A 4=-6.79151e-06 A 6= 9.62450e-10 A 8=-3.51924e-12 Various data Zoom ratio 4.29 Wide-angle, Medium, Telephoto Focal length 10.50 21.74 45.00 F-number 2.90 2.90 3.88 Half-angle (°): 54.65, 34.25, 18.20 Image height 14.80 14.80 14.80 Lens length 315.00 315.00 315.00 BF 37.00 37.00 37.00 d17 0.20 0.80 1.20 d19 1.00 28.74 47.54 d26 27.74 5.48 5.11 d29 10.94 11.25 1.00 d35 21.68 15.28 6.70 Lens group data Group starting plane focal length 1 1 -56.39 2 18 63.77 3 20 -35.13 4 27 -65.85 5 30 60.03 6 36 67.49 [Numerical Example 9] Unit: mm Surface data Face number rd nd νd 1* -136.222 2.40 1.76385 48.5 2 26.189 13.28 3 54.337 1.60 2.00100 29.1 4 28.256 18.44 5 -33.251 1.50 1.88300 40.8 6 -66.547 0.20 7 1222.224 6.25 1.89286 20.4 8 -78.167 7.12 9 69.770 10.70 1.61800 63.3 10* -103.132 3.88 11 232.726 9.27 1.49700 81.5 12 -63.103 0.20 13 -81.310 1.80 1.76385 48.5 14 -73.135 0.20 15 -102.222 1.65 1.95375 32.3 16 45.873 10.59 1.43875 94.9 17 -106.650 0.20 18 139.851 7.73 1.76385 48.5 19 -70.546 (variable) 20* 225.861 1.20 1.90525 35.0 21 27.807 3.70 22 203.080 0.80 1.59522 67.7 23 94.954 3.45 1.85478 24.8 24 -61.715 1.50 25 -30.177 0.80 1.76385 48.5 26 -81.962 (variable) 27 -27.949 0.80 1.60300 65.4 28 29.305 2.42 1.85478 24.8 29 54.725 (Variable) 30 (aperture) ∞ 0.99 31* 36.277 6.52 1.58144 40.8 32 -53.839 0.20 33 35.053 10.41 1.78472 25.7 34 -22.983 0.90 2.00069 25.5 35 44.535 (Variable) 36 80.796 3.55 1.56732 42.8 37 -76.345 0.20 38 102.310 1.00 2.05090 26.9 39 26.728 5.01 1.53775 74.7 40 -132.946 40.05 41 70.290 9.84 1.55200 70.7 42 -53.403 0.40 43 82.202 7.09 1.80810 22.8 44 -43.181 1.10 1.88300 40.8 45 32.882 1.29 46 36.837 12.93 1.43875 94.7 47 -21.611 1.50 2.05090 26.9 48 -97.493 0.20 49 2759.380 8.59 1.48749 70.2 50 -28.183 36.97 Image plane ∞ Aspherical data Front page K = 0.00000e+00 A 4= 1.48127e-05 A 6=-2.03754e-08 A 8= 2.39046e-11 A10=-1.95154e-14 A12= 1.01413e-17 A14=-2.97641e-21 A16= 3.74129e-25 Side 10 K = 0.00000e+00 A 4= 3.18927e-06 A 6=-4.99601e-10 A 8= 1.20063e-13 Page 20 K = 0.00000e+00 A 4= 9.11689e-06 A 6=-2.67545e-08 A 8= 2.34853e-10 A10=-9.60572e-13 A12= 1.62212e-15 Page 31 K = 0.00000e+00 A 4=-4.86756e-06 A 6= 1.16575e-08 A 8= 1.59033e-12 Various data Zoom ratio 4.65 Wide-angle, Medium, Telephoto Focal length 8.60 18.55 40.00 F-number 2.90 2.90 3.62 Half-angle (°): 59.84, 38.59, 20.31 Image height 14.80 14.80 14.80 Lens length 319.52 319.52 319.52 BF 36.97 36.97 36.97 d19 0.99 31.47 52.22 d26 31.78 8.79 4.04 d29 6.42 6.01 0.99 d35 19.90 12.83 1.85 Lens group data Group starting plane focal length 1 1 24.86 2 20 -40.56 3 27 -34.55 4 30 37.83 5 36 64.01

[0076] [Table 1]

[0077] Figures 2(A), 4(A), 6(A), 8(A), 10(A), 12(A), 14(A), 16(A), and 18(A) respectively show the longitudinal aberrations (spherical aberration, astigmatism, distortion, and chromatic aberration) of the zoom lenses for numerical examples 1 to 9 at infinity focus and at the wide-angle end. Figures 2(B), 4(B), 6(B), 8(B), 10(B), 12(B), 14(B), 16(B), and 18(B) respectively show the longitudinal aberrations of the zoom lenses for numerical examples 1 to 9 at infinity focus and at the telephoto end.

[0078] In the spherical aberration diagram, Fno indicates the F number, the solid line shows the spherical aberration for the d line (wavelength 587.6 nm), and the dashed line shows the spherical aberration for the g line (wavelength 435.8 nm). The dashed line shows the spherical aberration for the C line (wavelength 656.3 nm), and the long dashed line shows the spherical aberration for the F line (wavelength 486.1 nm). In the astigmatism diagram, the solid line S shows astigmatism at the sagittal image plane, and the dashed line M shows astigmatism at the meridional image plane. The distortion diagram shows distortion at the d line. The chromatic aberration diagram shows lateral chromatic aberration at the g line, C line, and F line.

[0079] The astigmatism and chromatic aberration diagrams show the amount of aberration when the central ray of the light beam at the aperture position is considered the principal ray. ω is the paraxial half-angle of view (°). Spherical aberration is plotted on a scale of 0.2 mm, astigmatism on 0.2 mm, distortion on 5%, and chromatic aberration on 0.05 mm.

[0080] [Imaging device] Figure 19 shows an imaging device (video camera) 125 equipped with a zoom lens 101 according to Examples 1 to 9. 124 is the camera body. The zoom lens 101 is detachable from the camera body 124. The zoom lens 101 has a first lens group F, an intermediate group LZ including two or more intermediate lens groups, and rear lens groups (R1, R2) for imaging. The first lens group F has a first sub-lens group and a third sub-lens group that do not move for focusing, and a second sub-lens group that moves for focusing. SP is the aperture diaphragm.

[0081] 114 and 115 are drive mechanisms that drive the second sub-lens group and the intermediate group LZ in the optical axis direction, respectively. The drive mechanism consists of a helicoid, a cam, and the like.

[0082] Components 116 to 118 are drive units, respectively, which include the drive mechanisms 114 and 115 and the motor that drives the aperture diaphragm SP. Components 119 to 121 are detection units, respectively, which detect the position of the second sub-lens group on the optical axis, the position of the intermediate group LZ on the optical axis, and the aperture diameter of the aperture diaphragm SP. The detection units are configured using encoders, potentiometers, photosensors, etc.

[0083] In the camera body 124, 109 is a glass block including an optical filter, and 110 is an image sensor that captures the subject image (of the subject through the zoom lens) formed by the zoom lens 101. The image sensor is composed of photoelectric conversion elements such as a CCD or CMOS sensor.

[0084] 111 and 122 are the camera CPU, which acts as the control unit for the camera body 124, and the lens CPU, which acts as the control unit for the zoom lens 101, respectively.

[0085] By using the zoom lenses described in each embodiment, it is possible to realize a compact and lightweight imaging device capable of producing high-quality images with a wide field of view and high magnification ratio.

[0086] The above embodiments include the following configuration.

[0087] (Composition 1) Multiple lens groups are arranged sequentially from the object side to the image side, consisting of a first lens group with positive refractive power that does not move for zooming, an intermediate group having two or more lens groups that move for zooming, and a rear lens group, and the spacing between adjacent lens groups changes during zooming. It has an aperture diaphragm that does not move during zooming, When the focal length of the first lens group is f1, the focal length of the zoom lens at the wide-angle end is fw, the focal length of the zoom lens at the telephoto end is ft, the distance TL is the distance along the optical axis from the lens surface closest to the object to the final lens surface closest to the image, plus the air-equivalent distance along the optical axis from the final lens surface to the image surface, when the zoom lens is in focus on an object at the wide-angle end and the zoom lens is in focus on an object at infinity, and the combined lateral magnification at the wide-angle end of all lens groups closer to the image than the lens group closest to the image among the lens groups having negative refractive power in the intermediate group is βr, 0.0300 ≤ fw / TL ≤ 0.0390 0.0500 ≤ f1 / TL ≤ 0.1900 4.000 ≤ ft / fw ≤ 7.000 -2.400 ≤ βr ≤ -1.270 A zoom lens characterized by satisfying the following conditions. (Configuration 2) Multiple lens groups are arranged sequentially from the object side to the image side, consisting of a first lens group with positive refractive power that does not move for zooming, an intermediate group having two or more lens groups that move for zooming, and a rear lens group, and the spacing between adjacent lens groups changes during zooming. It has an aperture diaphragm that moves when zooming, When the focal length of the first lens group is f1, the focal length of the zoom lens at the wide-angle end is fw, the focal length of the zoom lens at the telephoto end is ft, and TL is the distance along the optical axis from the lens surface closest to the object to the final lens surface closest to the image, plus the air-equivalent distance along the optical axis from the final lens surface to the image plane, when the zoom lens is in focus on an object at the wide-angle end and infinity, 0.0250 ≤ fw / TL ≤ 0.0350 0.0500 ≤ f1 / TL ≤ 0.1900 4.000 ≤ ft / fw ≤ 7.000 A zoom lens characterized by satisfying the following conditions. (Composition 3) The zoom lens according to configuration 1 or 2, characterized in that the first lens group comprises 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. (Composition 4) When the object is in focus at infinity, if fv is the focal length of the lens group among the two or more lens groups included in the intermediate group whose absolute value is the ratio of the lateral magnification at the telephoto end to the lateral magnification at the wide-angle end, -2.40 ≤ f1 / fv ≤ -0.30 A zoom lens according to any one of configurations 1 to 3, characterized by satisfying the following conditions. (Composition 5) When the focal length of the first sub-lens group is f11, the focal length of the second sub-lens group is f12, and the focal length of the third sub-lens group is f13, -1.50 ≤ f11 / f1 ≤ -0.60 2.00 ≤ f12 / f1 ≤ 6.50 1.30 ≤ f13 / f1 ≤ 4.50 A zoom lens according to configuration 3 or 4, characterized by satisfying the following conditions. (Composition 6) When LD1 is 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 first lens group, 1.10 ≤ LD1 / f1 ≤ 6.50 A zoom lens according to any one of configurations 1 to 5, characterized by satisfying the following conditions. (Composition 7) Let Y be the image height of the aforementioned zoom lens, and let ωw be the half-angle of view at the wide-angle end. ωw = arctan(Y / fw) In that case, 51.50°≦ωw≦65.00° A zoom lens according to any one of configurations 1 to 6, characterized by satisfying the following conditions. (Composition 8) When the maximum aperture F-number of the zoom lens at the wide-angle end is denoted as Fnow, 2.00 ≤ Fnow ≤ 3.50 A zoom lens according to any one of configurations 1 to 7, characterized by satisfying the following conditions. (Composition 9) When BFw is the distance along the optical axis from the image-side lens surface to the image plane of the lens with the greatest refractive power on the image side in the aforementioned zoom lens, 0.050 ≤ fw / BFw ≤ 0.430 A zoom lens according to any one of configurations 1 to 8, characterized by satisfying the following conditions. (Composition 10) When the lens group is in focus on an object at infinity and at the wide-angle end, the distance along the optical axis from the lens surface closest to the object to the aperture diaphragm is denoted as LDs. 0.20 ≤ LDs / TL ≤ 0.60 A zoom lens according to any one of configurations 1 to 9, characterized by satisfying the following conditions. (Composition 11) When the lens group is in focus on an object at infinity, let bok1 be the distance 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. 2.500 ≤ (f1 + bok1) / f1 ≤ 5.000 A zoom lens according to any one of configurations 1 to 10, characterized by satisfying the following conditions. (Composition 12) 0.600 ≤ ft / f1 ≤ 5.000 A zoom lens according to any one of configurations 1 to 11, characterized by satisfying the following conditions. (Composition 13) 1.700 ≤ f1 / fw ≤ 5.600 A zoom lens according to any one of configurations 1 to 12, characterized by satisfying the following conditions. (Composition 14) The zoom lens according to configuration 3, characterized in that the first sub-lens group has two or more negative lenses. (Composition 15) A zoom lens according to any one of configurations 1 to 14, characterized in that it has three or more lens groups as two or more lens groups included in the intermediate group. (Composition 16) A zoom lens characterized by having multiple lens groups arranged sequentially from the object side to the image side, each consisting of a first lens group with positive refractive power that does not move for zooming, an intermediate group having two or more lens groups that move for zooming, and a rear lens group, wherein the spacing between adjacent lens groups changes during zooming, and the lens has an aperture diaphragm. (Composition 17) A zoom lens as described in any one of configurations 1 to 16, An imaging device characterized by having an image sensor that captures an image of a subject through the zoom lens.

[0088] The embodiments described above are merely representative examples, and various modifications and changes can be made to each embodiment when implementing the present invention. [Explanation of Symbols]

[0089] L1 First lens group L2 Second lens group L3 Third lens group L4 4th lens group L5 5th lens group L6 6th lens group SP aperture diaphragm I image plane

Claims

1. Multiple lens groups are arranged sequentially from the object side to the image side, consisting of a first lens group with positive refractive power that does not move for zooming, an intermediate group having two or more lens groups that move for zooming, and a rear lens group, and the spacing between adjacent lens groups changes during zooming. It has an aperture diaphragm that does not move during zooming, When the focal length of the first lens group is f1, the focal length of the zoom lens at the wide-angle end is fw, the focal length of the zoom lens at the telephoto end is ft, TL is the distance along the optical axis from the lens surface closest to the object to the final lens surface closest to the image, plus the air-equivalent distance along the optical axis from the final lens surface to the image surface, when the zoom lens is in focus on an object at the wide-angle end and infinity, and βr is the combined lateral magnification at the wide-angle end of all lens groups closer to the image than the lens group closest to the image among the lens groups having negative refractive power in the intermediate group, 0.0300 ≤ fw / TL ≤ 0.0390 0.0500 ≤ f1 / TL ≤ 0.1900 4.000 ≤ ft / fw ≤ 7.000 -2.400 ≤ βr ≤ -1.270 A zoom lens characterized by satisfying the following conditions.

2. Multiple lens groups are arranged sequentially from the object side to the image side, consisting of a first lens group with positive refractive power that does not move for zooming, an intermediate group having two or more lens groups that move for zooming, and a rear lens group, and the spacing between adjacent lens groups changes during zooming. It has an aperture diaphragm that moves when zooming, When the focal length of the first lens group is f1, the focal length of the zoom lens at the wide-angle end is fw, the focal length of the zoom lens at the telephoto end is ft, and TL is the distance along the optical axis from the lens surface closest to the object to the final lens surface closest to the image, plus the air-equivalent distance along the optical axis from the final lens surface to the image plane, when the zoom lens is in focus on an object at the wide-angle end and infinity, 0.0250 ≤ fw / TL ≤ 0.0350 0.0500 ≤ f1 / TL ≤ 0.1900 4.000 ≤ ft / fw ≤ 7.000 A zoom lens characterized by satisfying the following conditions.

3. The zoom lens according to claim 1 or 2, characterized in that the first lens group comprises 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.

4. When the object is in focus at infinity, if fv is the focal length of the lens group among the two or more lens groups included in the intermediate group whose absolute value is the ratio of the lateral magnification at the telephoto end to the lateral magnification at the wide-angle end, -2.40 ≤ f1 / fv ≤ -0.30 A zoom lens according to claim 1 or 2, characterized by satisfying the following conditions.

5. When the focal length of the first sub-lens group is f11, the focal length of the second sub-lens group is f12, and the focal length of the third sub-lens group is f13, -1.50 ≤ f11 / f1 ≤ -0.60 2.00 ≤ f1² / f1 ≤ 6.50 1.30 ≤ f13 / f1 ≤ 4.50 The zoom lens according to claim 3, characterized in that it satisfies the following conditions.

6. When LD1 is 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 first lens group, 1.10 ≤ LD1 / f1 ≤ 6.50 A zoom lens according to claim 1 or 2, characterized by satisfying the following conditions.

7. Let Y be the image height of the aforementioned zoom lens, and ωw be the half-angle of view at the wide-angle end. ωw=arctan(Y / fw) In that case, 51.50° ≤ ωw ≤ 65.00° A zoom lens according to claim 1 or 2, characterized by satisfying the following conditions.

8. When the maximum aperture F-number of the zoom lens at the wide-angle end is denoted as Fnow, 2.00 ≤ Fnow ≤ 3.50 A zoom lens according to claim 1 or 2, characterized by satisfying the following conditions.

9. When BFw is the distance along the optical axis from the image-side lens surface to the image plane of the lens with the strongest refractive power on the image side in the zoom lens, 0.050 ≤ fw / BFw ≤ 0.430 A zoom lens according to claim 1 or 2, characterized by satisfying the following conditions.

10. When the lens group is in focus on an object at infinity and at the wide-angle end, the distance along the optical axis from the lens surface closest to the object to the aperture diaphragm is denoted as LDs. 0.20 ≤ LDs / TL ≤ 0.60 A zoom lens according to claim 1 or 2, characterized by satisfying the following conditions.

11. When bok1 is the distance 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 in a state where it is in focus on an object at infinity, 2.500≦(f1+bok1) / f1≦5.000 A zoom lens according to claim 1 or 2, characterized by satisfying the following conditions.

12. 0.600 ≤ ft / f1 ≤ 5.000 A zoom lens according to claim 1 or 2, characterized by satisfying the following conditions.

13. 1.700 ≤ f1 / fw ≤ 5.600 A zoom lens according to claim 1 or 2, characterized by satisfying the following conditions.

14. The zoom lens according to claim 3, characterized in that the first sub-lens group has two or more negative lenses.

15. The zoom lens according to claim 1 or 2, characterized in that it has three or more lens groups as two or more lens groups included in the intermediate group.

16. A zoom lens characterized by having multiple lens groups arranged sequentially from the object side to the image side, each consisting of a first lens group with positive refractive power that does not move for zooming, an intermediate group having two or more lens groups that move for zooming, and a rear lens group, wherein the spacing between adjacent lens groups changes during zooming, and the lens has an aperture diaphragm.

17. A zoom lens according to claim 1, 2, or 16, An imaging device characterized by having an image sensor that captures an image of a subject through the zoom lens.

Images