Zoom lens and image pickup apparatus

Abstract

To provide a compact zoom lens and an image pickup apparatus in which the variation in the position of the center of gravity is small. A zoom lens includes, in order from the object side, a first lens group (G1) having positive refractive power, a second lens group (G2) having negative refractive power, a third lens group (G3) having positive refractive power, a fourth lens group (G4) having negative refractive power, and a fifth lens group (G5), the interval between adjacent lens groups changes during zooming, the first lens group (G1) is fixed with respect to the image plane, the third lens group (G3) and the fifth lens group (G5) move in different directions from the second lens group (G2), and the zoom lens satisfies a prescribed mathematical expression.

Description

TECHNICAL FIELD

[0001] The present application relates to a zoom lens and an image pickup apparatus. BACKGROUND

[0002] With a demand for high image quality of digital cameras, the image pickup element is becoming larger, and the flange back is becoming shorter due to a mirrorless camera and the like, and there is an increasing need for miniaturization of optical systems. In addition, cameras mounted on mobile bodies such as drones are becoming increasingly popular, and in order to achieve stable photography while moving, a zoom lens that has little change in the position of the center of gravity during zooming is needed.

[0003] As a zoom lens that achieves miniaturization, a positive guide type zoom lens having a lens group with positive power at the most object side is known (for example, refer to Patent Documents 1 to 3).

[0004] PRIOR ART DOCUMENTS

[0005] PATENT DOCUMENTS

[0006] [Patent Document 1] International Publication No. 2016 / 157340

[0007] [Patent Document 2] Japanese Patent Application Publication No. 2012-113182

[0008] [Patent Document 3] Japanese Patent Application Publication No. 2014-215434 SUMMARY

[0009] PROBLEMS TO BE SOLVED BY THE INVENTION

[0010] In the zoom lens described in Patent Document 1, the first lens group moves during zooming, and thus the position of the center of gravity of the zoom lens greatly changes during zooming. In the case where this zoom lens is used as a zoom lens for a camera mounted on a mobile body such as a drone, it is difficult to suppress the change in the position of the center of gravity of the mobile body.

[0011] In the zoom lenses described in Patent Documents 2 and 3, the first lens group is fixed during zooming. However, the amount of movement of the third lens group with respect to the second lens group, or the amount of movement of the fifth lens group with respect to the second lens group during zooming is not appropriate, and thus the position of the center of gravity of the zoom lens greatly changes with the movement of these lens groups. In the case where these zoom lenses are used as zoom lenses for a camera mounted on a mobile body such as a drone, it is also difficult to suppress the change in the position of the center of gravity of the mobile body.

[0012] Therefore, the present application aims to provide a compact zoom lens and an image pickup apparatus in which the change in the position of the center of gravity during zooming is small.

[0013] MEANS FOR SOLVING THE PROBLEMS

[0014] To solve the above problems, the zoom lens according to the present application is characterized by comprising, in order from the object side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having negative refractive power, and a fifth lens group,

[0015] During zooming, the intervals of the adjacent lens groups change, the first lens group is fixed with respect to the image plane, the third lens group and the fifth lens group move in different directions from the second lens group,

[0016] The zoom lens satisfies the following equation:

[0017] 0.01 < |M3 / M2| < 1.34 ··· (1)

[0018] 0.61 < |M5 / M2| < 1.81 ··· (2)

[0019] wherein,

[0020] M2: movement amount of the second lens group from the wide-angle end to the telephoto end

[0021] M3: movement amount of the third lens group from the wide-angle end to the telephoto end

[0022] M5: movement amount of the fifth lens group from the wide-angle end to the telephoto end.

[0023] In addition, to solve the above problems, the imaging device according to the present application is characterized by comprising the above-described zoom lens and an imaging element that converts an optical image formed by the zoom lens into an electric signal.

[0024] Effects of the Invention

[0025] According to the present application, it is possible to provide a compact zoom lens and an imaging device in which the position of the center of gravity during zooming changes little. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a sectional view of the zoom lens of Example 1.

[0027] Figure 2 is an aberration diagram of the zoom lens of Example 1 at the wide-angle end.

[0028] Figure 3 is an aberration diagram of the zoom lens of Example 1 at the intermediate focal length position.

[0029] Figure 4 is an aberration diagram of the zoom lens of Example 1 at the telephoto end.

[0030] Figure 5 is a sectional view of the zoom lens of Example 2.

[0031] Figure 6 is an aberration map of the zoom lens of Example 2 at the wide-angle end.

[0032] Figure 7 is an aberration map of the zoom lens of Example 2 at the intermediate focal length position.

[0033] Figure 8 is an aberration map of the zoom lens of Example 2 at the telephoto end.

[0034] Figure 9 is a cross-sectional view of the zoom lens of Example 3.

[0035] Figure 10 is an aberration map of the zoom lens of Example 3 at the wide-angle end.

[0036] Figure 11 is an aberration map of the zoom lens of Example 3 at the intermediate focal length position.

[0037] Figure 12 is an aberration map of the zoom lens of Example 3 at the telephoto end.

[0038] Figure 13 is a cross-sectional view of the zoom lens of Example 4.

[0039] Figure 14 is an aberration map of the zoom lens of Example 4 at the wide-angle end.

[0040] Figure 15 is an aberration map of the zoom lens of Example 4 at the intermediate focal length position.

[0041] Figure 16 is an aberration map of the zoom lens of Example 4 at the telephoto end.

[0042] Figure 17 is a view schematically showing an example of the configuration of an image pickup apparatus according to an embodiment of the present application.

[0043] Explanation of Reference Numerals

[0044] S aperture stop

[0045] CG protective glass

[0046] IP image plane

[0047] G1 first lens group

[0048] G2 second lens group

[0049] G3 third lens group

[0050] G4 fourth lens group

[0051] G5... 5th lens group

[0052] G6... 6th lens group

[0053] 1... imaging device

[0054] 2... camera

[0055] 3... lens

[0056] 21... imaging element DETAILED DESCRIPTION

[0057] Hereinafter, an embodiment of a zoom lens and an imaging device according to the present application will be described. However, the zoom lens and the imaging device described hereinafter are one mode of the zoom lens and the imaging device according to the present application, and the zoom lens and the imaging device according to the present application are not limited to the mode described hereinafter.

[0058] 1. Zoom lens

[0059] 1-1. Optical configuration

[0060] The zoom lens has a 1st lens group having positive refractive power, a 2nd lens group having negative refractive power, a 3rd lens group having positive refractive power, a 4th lens group having negative refractive power, and a 5th lens group. By adopting this refractive power configuration, an axial light beam similar in effective diameter is incident on the 3rd lens group, and thus it is possible to correct spherical aberration in the 3rd lens group. Furthermore, when the zoom lens is divided into an object side group and an image side group, the object side group is configured to have positive refractive power and the image side group is configured to have negative refractive power, and thus it is possible to configure a zoom lens of a telephoto type. By this configuration, it is possible to shorten the overall optical length of the zoom lens. At this time, the zoom lens is preferably configured such that the 1st lens group to the 3rd lens group constitute the object side group and the lens groups after the 4th lens group constitute the image side group.

[0061] (1) 1st lens group

[0062] The 1st lens group is the lens group disposed most on the object side in the zoom lens, and has positive refractive power. The 1st lens group is preferably configured by, in order from the object side, a lens having negative refractive power (hereinafter referred to as a negative lens) and a lens having positive refractive power (hereinafter referred to as a positive lens), and thus it is possible to well correct chromatic aberration. In addition, it is more preferable that these two lenses be cemented in order to shorten the overall optical length.

[0063] (2) 2nd lens group

[0064] The 2nd lens group is a lens group disposed on the image side of the 1st lens group, and has a negative refractive power. The 2nd lens group has, in order from the object side, a negative lens, a negative lens, a positive lens, and a negative lens, which are preferable because they easily correct various aberrations. In addition, the lens disposed on the most image side of the 2nd lens group is a negative meniscus lens having a concave surface on the object side, which is preferable in terms of correcting various aberrations within the 2nd lens group.

[0065] (3) 3rd lens group

[0066] The 3rd lens group is a lens group disposed on the image side of the 2nd lens group, and has a positive refractive power. In addition, the 3rd lens group has at least one aspherical surface, which is preferable because it easily achieves weight reduction of the lens. In addition, the 3rd lens group has four or fewer lenses, which is preferable in terms of suppressing the lens diameter of the 3rd lens group and correcting various aberrations.

[0067] (4) 4th lens group

[0068] The 4th lens group is a lens group disposed on the image side of the 3rd lens group, and has a negative refractive power. In addition, the negative meniscus lens having a concave surface on the image side is disposed on the most image side of the 4th lens group, which is preferable in terms of correcting the field curvature of the zoom lens.

[0069] (5) 5th lens group or later

[0070] The 5th lens group is a lens group disposed on the image side of the 4th lens group. In addition, the negative lens having a concave surface on the object side is disposed on the most object side of the 5th lens group, which is preferable because it easily corrects the field curvature of the zoom lens. In addition, the zoom lens can have one or more lens groups disposed on the image side of the 5th lens group. Furthermore, the lenses disposed between the 5th lens group and the image plane are preferably three or fewer in total in terms of simplifying the control of the variation in the center of gravity. In addition, the lens group including at least one positive lens and at least one negative lens is preferable because it easily corrects chromatic aberration.

[0071] (6) aperture stop

[0072] In the zoom lens, the position of the aperture stop is not particularly limited. Here, the aperture stop referred to herein means an aperture stop that defines the beam diameter of the zoom lens, i.e., an aperture stop that defines the F value of the zoom lens. The aperture stop is preferably disposed on the image side of the 2nd lens group. In addition, the aperture stop is preferably disposed on the object side of the 3rd lens group or within the 3rd lens group.

[0073] 1-2. Action

[0074] (1) zooming

[0075] The interval between the adjacent lens groups changes when zooming in the zoom lens. Furthermore, whether or not each lens group moves, the direction of movement, and the amount of movement are not particularly limited, and it is possible for all the lens groups to move along the optical axis when zooming, or for one or more of the lens groups among all the lens groups to be fixed relative to the image plane when zooming. It is preferable in this case to configure such that the interval between the first lens group and the second lens group changes in a manner such that it is larger at the telephoto end than at the wide-angle end when zooming. According to this configuration, it is easy to suppress variation in the position of the center of gravity, and in addition, it is possible to achieve a sufficient zoom ratio. It is preferable to move the second lens group in a manner such that the interval between the first lens group and the second lens group is largest at the telephoto end, in order to easily suppress variation in the position of the center of gravity. In addition, it is preferable for the first lens group to be fixed when zooming in terms of suppressing variation in the position of the center of gravity. It is preferable to move the third lens group and the fifth lens group in different directions from the second lens group, in order to easily suppress variation in the position of the center of gravity. In addition, it is preferable for the second lens group to move toward the image side when zooming in from the wide-angle end to the telephoto end. In addition, with respect to the lens groups after the third lens group, it is preferable for the third lens group and the fifth lens group to move toward the object side, but the direction of movement of the other lens groups is not particularly limited. For example, the fourth lens group can also move toward the image side. However, it is more preferable for all the lens groups after the third lens group to move toward the object side, from the viewpoint of suppressing variation in the position of the center of gravity.

[0076] (2) Focusing

[0077] In this zoom lens, the focusing group moves on the optical axis when focusing on a close-range object from infinity. The focusing group is not particularly limited, and the direction of movement of the focusing group when focusing is not particularly limited, but it is preferable to provide the fourth lens group as the focusing group. In this configuration, the fourth lens group can be configured from lenses having a small diameter, and thus miniaturization and weight reduction of the focusing group can be achieved. Therefore, miniaturization of an actuator or the like for moving the focusing group can be achieved, and compactness of the zoom lens can be achieved. In addition, the zoom lens can achieve miniaturization of the actuator or the like through weight reduction of the focusing group by configuring the fourth lens group from only one lens component. Furthermore, it is more preferable for the zoom lens to configure the fourth lens group from only one lens.

[0078] In addition, in the present specification, among lens components, there are lenses, and cemented lenses in which a plurality of the lenses are integrated without an air gap. Among the lenses, there are single lenses, and composite lenses in which a single lens and resin are integrated without an air gap. A single lens is configured from one kind of material. Specifically, one cemented lens in which two single lenses are cemented is counted as one lens component, and counted as two lenses. A lens (single lens and composite lens) is counted as one lens component, and counted as one lens. Here, a single lens indicates a spherical lens and an aspherical lens (including a composite aspherical lens).

[0079] 1-3. Mathematical expressions

[0080] The zoom lens preferably adopts the above-described configuration and satisfies at least one of the mathematical expressions described below.

[0081] 1-3-1. Expression (1)

[0082] 0.01 < |M3 / M2| < 1.34 • • • (1)

[0083] wherein

[0084] M2: movement amount of the second lens group from the wide-angle end to the telephoto end

[0085] M3: movement amount of the third lens group from the wide-angle end to the telephoto end

[0086] The above-described expression (1) is a mathematical expression that defines the absolute value of the ratio of the movement amount of the third lens group from the wide-angle end to the telephoto end to the movement amount of the second lens group from the wide-angle end to the telephoto end. By satisfying expression (1), it is easy to reduce the variation in the position of the center of gravity of the zoom lens. Here, the movement amount of a lens group refers to the difference between the position on the optical axis of the lens group at the wide-angle end and the position on the optical axis of the lens group at the telephoto end.

[0087] In contrast, if the value of expression (1) is lower than the lower limit value, the movement amount of the second lens group becomes larger relative to the movement amount of the third lens group, and the variation in the position of the center of gravity at the time of zooming becomes large. Therefore, it is not preferable from the viewpoint of reducing the variation in the position of the center of gravity of the zoom lens. On the other hand, if the value of expression (1) is equal to or higher than the upper limit value, the movement amount of the third lens group becomes larger relative to the movement amount of the second lens group, and the variation in the position of the center of gravity at the time of zooming becomes large. Therefore, it is not preferable from the viewpoint of reducing the variation in the position of the center of gravity of the zoom lens.

[0088] In terms of obtaining the above-described effects, the lower limit value of expression (1) is preferably 0.20, and more preferably 0.40. In addition, the upper limit value of expression (1) is preferably 1.32, and more preferably 1.30. Furthermore, in the case where these preferable lower limit value or upper limit value is adopted, the inequality sign (<) in expression (1) can be replaced with an inequality sign with equality (≤). The same is true for other mathematical expressions as a principle.

[0089] 1-3-2. Expression (2)

[0090] 0.61 < |M5 / M2| < 1.81 • • • (2)

[0091] wherein

[0092] M2: movement amount of the second lens group from the wide-angle end to the telephoto end

[0093] M5: moving amount of the 5th lens group from the wide angle end to the telephoto end

[0094] The above formula (2) is a mathematical formula that defines the absolute value of the ratio of the moving amount of the 5th lens group from the wide angle end to the telephoto end to the moving amount of the 2nd lens group from the wide angle end to the telephoto end. By satisfying formula (2), the variation in the center of gravity position of the zoom lens is easily reduced.

[0095] In this regard, if the value of formula (2) is lower than the lower limit value, the moving amount of the 2nd lens group relative to the 5th lens group becomes large, and thus the variation in the center of gravity position at the time of zooming becomes large. Therefore, it is not preferable from the viewpoint of reducing the variation in the center of gravity position of the zoom lens. On the other hand, if the value of formula (2) is equal to or higher than the upper limit value, the moving amount of the 5th lens group relative to the 2nd lens group becomes large, and thus the variation in the center of gravity position at the time of zooming becomes large. Therefore, it is not preferable from the viewpoint of reducing the variation in the center of gravity position of the zoom lens.

[0096] In terms of obtaining the above effects, the lower limit value of formula (2) is preferably 0.65, and more preferably 0.70. In addition, the upper limit value of formula (2) is preferably 1.70, and more preferably 1.60.

[0097] 1-3-3. Formula (3)

[0098] 0.90 < β3t / β3w / (β2t / β2w) < 1.75 ··· (3)

[0099] wherein,

[0100] β2w: lateral magnification of the 2nd lens group at the time of focusing on an infinite distance at the wide angle end

[0101] β2t: lateral magnification of the 2nd lens group at the time of focusing on an infinite distance at the telephoto end

[0102] β3w: lateral magnification of the 3rd lens group at the time of focusing on an infinite distance at the wide angle end

[0103] β3t: lateral magnification of the 3rd lens group at the time of focusing on an infinite distance at the telephoto end

[0104] The above formula (3) is a mathematical formula that defines the ratio of the ratio of the lateral magnifications of the 2nd lens group and the 3rd lens group at the time of zooming from the wide angle end to the telephoto end of the zoom lens. By satisfying formula (3), the respective lateral magnifications of the 2nd lens group and the 3rd lens group are appropriately made, the moving amounts are defined while the zoom ratio of the zoom lens is ensured, and in addition, the variation in the center of gravity position of the zoom lens is reduced.

[0105] On the other hand, if the value of the formula (3) is equal to or more than the upper limit value, the lateral magnification ratio of the third lens group is too large with respect to the lateral magnification ratio of the second lens group, and thus the movement amount of the third lens group becomes large, and the variation of the center of gravity position at the time of zooming becomes large. Therefore, it is not preferable from the viewpoint of reducing the variation of the center of gravity position of the zoom lens. In addition, the lower limit value of the formula (3) is preferably 1.00, and more preferably 1.10, and the upper limit value of the formula (3) is preferably 1.65, and more preferably 1.60, in terms of obtaining the above-described effects.

[0106] In terms of obtaining the above-described effects, the lower limit value of the formula (3) is preferably 1.00, and more preferably 1.10. In addition, the upper limit value of the formula (3) is preferably 1.65, and more preferably 1.60.

[0107] 1-3-4. Formula (4)

[0108] 0.75 < β4t / β4w / (β2t / β2w) < 1.30 ··· (4)

[0109] wherein,

[0110] β2w: lateral magnification of the second lens group at the time of focusing on an infinite object at the wide-angle end

[0111] β2t: lateral magnification of the second lens group at the time of focusing on an infinite object at the telephoto end

[0112] β4w: lateral magnification of the fourth lens group at the time of focusing on an infinite object at the wide-angle end

[0113] β4t: lateral magnification of the fourth lens group at the time of focusing on an infinite object at the telephoto end

[0114] The above-described formula (4) is a mathematical formula that defines the ratio of the lateral magnification ratios of the second lens group and the fourth lens group at the time of zooming from the wide-angle end to the telephoto end of the zoom lens. By satisfying the formula (4), the respective lateral magnifications of the second lens group and the fourth lens group can be appropriately made, the movement amount is defined while the zoom ratio of the zoom lens is ensured, and the variation of the center of gravity position of the zoom lens can be reduced.

[0115] On the other hand, if the value of the formula (4) is equal to or greater than the upper limit value, the lateral magnification ratio of the 4th lens group is too large with respect to the lateral magnification ratio of the 2nd lens group, and thus the movement amount of the 4th lens group becomes large, and the variation of the center of gravity position at the time of zooming becomes large. Therefore, it is not preferable from the viewpoint of reducing the variation of the center of gravity position of the zoom lens. In order to obtain the above-mentioned effects, the lower limit value of the formula (4) is preferably 0.76, more preferably 0.77. In addition, the upper limit value of the formula (4) is preferably 1.20, more preferably 1.00.

[0116] In order to obtain the above-mentioned effects, the lower limit value of the formula (4) is preferably 0.76, more preferably 0.77. In addition, the upper limit value of the formula (4) is preferably 1.20, more preferably 1.00.

[0117] 1-3-5. Formula (5)

[0118] Nd2n < 1.80 ··· (5)

[0119] wherein,

[0120] Nd2n: refractive index at the d line of the most object side disposed negative lens among at least one negative lens included in the 2nd lens group

[0121] The above-mentioned formula (5) is a mathematical formula that defines the refractive index at the d line of the most object side disposed negative lens among at least one negative lens included in the 2nd lens group. The specific gravity of a lens has a tendency that the higher the refractive index of the glass material thereof, the larger the specific gravity of the lens. By satisfying the formula (5), the lightening of the 2nd lens group can be achieved, and the variation of the center of gravity position of the zoom lens can be reduced.

[0122] On the other hand, if the value of the formula (5) is equal to or greater than the upper limit value, it is difficult to achieve the lightening of the 2nd lens group, and the variation of the center of gravity position of the zoom lens becomes large. In order to obtain the above-mentioned effects, the upper limit value of the formula (5) is preferably 1.78, further preferably 1.76.

[0123] In order to well correct the field curvature, the lower limit value of the formula (5) is preferably 1.40, more preferably 1.50, further preferably 1.55.

[0124] 1-3-6. Formula (6)

[0125] 0.10 < |f2| / f1 < 0.40 ··· (6)

[0126] wherein,

[0127] f1: focal length of the 1st lens group

[0128] f2: focal length of the second lens group

[0129] The above formula (6) is a mathematical formula that defines the ratio of the focal length of the second lens group to the focal length of the first lens group. By satisfying formula (6), both the correction of each aberration and the shortening of the optical overall length can be taken into account, and the size of the zoom lens can be reduced.

[0130] In this regard, if the value of formula (6) is below the lower limit value, the power of the first lens group is weak relative to the power of the second lens group, the telephoto is weak, and it is difficult to achieve a shortening of the optical overall length. Therefore, it is not preferable from the viewpoint of reducing the size of the zoom lens. On the other hand, if the value of formula (6) is above the upper limit value, the power of the first lens group is too strong relative to the power of the second lens group, and it is difficult to correct the distortion aberration at the wide-angle end, the spherical aberration at the telephoto end, and the axial chromatic aberration, which is not preferable.

[0131] In terms of achieving the above effects, the lower limit value of formula (6) is preferably 0.15, and more preferably 0.20. In addition, the upper limit value of formula (6) is preferably 0.35, and further preferably 0.30.

[0132] 1-3-7. Formula (7)

[0133] 1.50 < β3t / β3w < 2.50 ··· (7)

[0134] wherein

[0135] β3w: lateral magnification of the third lens group at the time of focusing on an infinite distance at the wide-angle end

[0136] β3t: lateral magnification of the third lens group at the time of focusing on an infinite distance at the telephoto end

[0137] The above formula (7) is a mathematical formula that defines the lateral magnification ratio of the third lens group when the zoom lens is zoomed from the wide-angle end to the telephoto end. By satisfying formula (7), both sufficient zooming action and shortening of the optical overall length can be taken into account, and the size of the zoom lens can be reduced.

[0138] In this regard, if the value of formula (7) is below the lower limit value, the lateral magnification ratio of the third lens group becomes small, and it is therefore difficult to ensure a sufficient zoom ratio. On the other hand, if the value of formula (7) is above the upper limit value, the lateral magnification ratio of the third lens group becomes large, and the movement amount of the third lens group increases. Therefore, the optical overall length becomes long, which is not preferable from the viewpoint of reducing the size of the zoom lens.

[0139] In terms of achieving the above effects, the lower limit value of formula (7) is preferably 1.60, and more preferably 1.70. In addition, the upper limit value of formula (7) is preferably 2.40, and further preferably 2.30.

[0140] 1-3-8. Formula (8)

[0141] 0.30 < |f2 / fw| < 1.00 ··· (8)

[0142] wherein,

[0143] f2: focal length of the second lens group

[0144] fw: focal length of the zoom lens at infinity focus at the wide-angle end

[0145] The above formula (8) is a mathematical formula that defines the ratio of the focal length of the second lens group to the focal length of the zoom lens at infinity focus at the wide-angle end. By satisfying formula (8), it is possible to achieve both correction of various aberrations and miniaturization of the zoom lens.

[0146] In this regard, if the value of formula (8) is below the lower limit value, the power of the second lens group is too strong, and it is difficult to correct the field curvature and distortion aberration at the wide-angle end, and thus it is not preferable. On the other hand, if the value of formula (8) is above the upper limit value, the power of the second lens group is too weak, and in order to achieve a prescribed zoom ratio, it is necessary to increase the movement amount of the second lens group at zooming, and thus the optical total track length becomes long. Therefore, from the viewpoint of miniaturization of the zoom lens, it is not preferable.

[0147] In terms of achieving the above effects, the lower limit value of formula (8) is preferably 0.40, and more preferably 0.50. In addition, the upper limit value of formula (8) is preferably 0.90, and more preferably 0.80.

[0148] 1-3-9. Formula (9)

[0149] 0.50 < f1 / ft < 2.00 ··· (9)

[0150] wherein,

[0151] f1: focal length of the first lens group

[0152] ft: focal length of the zoom lens at infinity focus at the telephoto end

[0153] The above formula (9) is a mathematical formula that defines the ratio of the focal length of the first lens group to the focal length of the zoom lens at infinity focus at the telephoto end. By satisfying formula (9), it is possible to achieve both correction of various aberrations and miniaturization of the zoom lens.

[0154] In this regard, if the value of formula (9) is below the lower limit value, the power of the first lens group is too strong, and it is difficult to correct the spherical aberration and axial chromatic aberration at the telephoto end, and thus it is not preferable. On the other hand, if the value of formula (9) is above the upper limit value, the power of the first lens group is too weak, and it is difficult to shorten the optical total track length at the telephoto end, and thus it is not preferable.

[0155] In terms of achieving the above effects, the lower limit value of formula (9) is preferably 0.70, more preferably 0.90. In addition, the upper limit value of formula (9) is preferably 1.70, more preferably 1.40.

[0156] 1-3-10. Formula (10)

[0157] 0.50 < f4 / f2 < 3.50 ··· (10)

[0158] wherein,

[0159] f2: focal length of the second lens group

[0160] f4: focal length of the fourth lens group

[0161] The above formula (10) is a mathematical formula that defines the ratio of the focal length of the fourth lens group to the focal length of the second lens group. By satisfying formula (10), it is possible to achieve both correction of various aberrations and miniaturization of the zoom lens.

[0162] In this regard, if the value of formula (10) is below the lower limit value, the power of the fourth lens group is too strong with respect to the second lens group, and it is difficult to correct spherical aberration, coma, and field curvature, which is not preferable. On the other hand, if the value of formula (10) is above the upper limit value, the power of the fourth lens group is too weak with respect to the second lens group, and the fourth lens group becomes large, and the diameter of the lens barrel becomes large, which is not preferable. Furthermore, when the fourth lens group is provided as a focus adjustment group, the movement amount of the fourth lens group at the time of focusing becomes large, and thus it is difficult to shorten the optical total track.

[0163] In terms of achieving the above effects, the lower limit value of formula (10) is preferably 1.00, more preferably 1.50. In addition, the upper limit value of formula (10) is preferably 3.00, more preferably 2.50.

[0164] 1-3-11. Formula (11)

[0165] 4.55 < |f5| / f3 < 7.10 ··· (11)

[0166] wherein,

[0167] f3: focal length of the third lens group

[0168] f5: focal length of the fifth lens group

[0169] The above formula (11) is a mathematical formula that defines the ratio of the focal length of the fifth lens group to the focal length of the third lens group. By satisfying formula (11), it is possible to achieve both correction of various aberrations and miniaturization of the zoom lens.

[0170] On the other hand, if the value of the formula (11) is equal to or more than the upper limit value, the power of the third lens group is too strong with respect to the fifth lens group, and it is difficult to correct the spherical aberration, and it is difficult to balance the correction of each aberration and the miniaturization of the zoom lens.

[0171] In terms of obtaining the above-described effects, the lower limit value of the formula (11) is preferably 4.70, and more preferably 4.85. In addition, the upper limit value of the formula (11) is preferably 7.00, and more preferably 6.90.

[0172] 2. Imaging device

[0173] Next, an imaging device according to the present application will be described. The imaging device according to the present application is characterized by including the above-described zoom lens according to the present application, and an imaging element that converts an optical image formed by the zoom lens into an electric signal. In addition, the imaging element is preferably disposed on an image side of the zoom lens.

[0174] Here, the imaging element and the like are not particularly limited, and a solid-state imaging element such as a CCD (Charge Coupled Device) sensor, a CMOS (Complementary Metal Oxide Semiconductor) sensor, or the like can be used. The imaging device according to the present application is suitable for an imaging device such as a digital camera, a video camera, or the like that uses these solid-state imaging elements. In addition, the imaging device can be applied to various imaging devices such as a single-lens reflex camera, a mirrorless single-lens camera, a digital still camera, a surveillance camera, a camera for a vehicle, a camera for a drone, or the like. In addition, these imaging devices can be either interchangeable-lens-type imaging devices or fixed-lens-type imaging devices in which a lens is fixed to a housing. The zoom lens according to the present application is particularly suitable as a zoom lens for an imaging device that mounts a large-sized imaging element such as a full-size imaging element. The zoom lens is small and light in its entirety, and has high optical performance, and thus a high-quality captured image can be obtained when used as a zoom lens for such an imaging device.

[0175] Figure 17 is a diagram schematically showing an example of the configuration of an imaging device 1. The camera 2 has a detachable zoom lens 3, an imaging element 21 (CCD sensor or CMOS sensor) disposed at an image plane IP of the zoom lens 3, and a protection glass CG disposed on an object side of the imaging element 21. The zoom lens 3 has an aperture stop 31.

[0176] Next, embodiments will be shown and the present application will be specifically described. However, the present application is not limited to the following embodiments.

[0177] [Example 1]

[0178] (1) Optical configuration

[0179] Figure 1 is a sectional view of the zoom lens of Example 1 of the present application at the time of focusing on an infinite object at the wide-angle end, intermediate focus, and telephoto end. The zoom lens is composed of, in order from the object side, a first lens group G1 having positive power, a second lens group G2 having negative power, a third lens group G3 having positive power, a fourth lens group G4 having negative power, and a fifth lens group G5 having positive power.

[0180] When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed with respect to the image plane without moving, the second lens group G2 moves toward the image side, the third lens group G3 moves toward the object side, the fourth lens group G4 first moves toward the object side and then moves toward the image side, and the fifth lens group G5 moves toward the object side. In addition, when zooming, the third lens group G3 and the fifth lens group G5 move in the same trajectory in different directions from the second lens group G2.

[0181] When focusing from an infinite object to a close object, the fourth lens group G4 moves along the optical axis.

[0182] The aperture stop S is disposed adjacent to the object side of the third lens group G3.

[0183] The configuration of each lens group will be described below.

[0184] The first lens group G1 is composed of a cemented lens in which a negative meniscus lens having a convex shape on the object side and a positive meniscus lens are cemented in order from the object side.

[0185] The second lens group G2 is composed of, in order from the object side, a negative meniscus lens having a complex aspherical surface on the object side, a double concave lens, a double convex lens, and a negative meniscus lens having a concave shape on the object side.

[0186] The third lens group G3 is composed of, in order from the object side, the aperture stop S, a double convex lens, a double convex lens, and a cemented lens in which a negative meniscus lens having a convex shape on the object side and a double convex lens are cemented.

[0187] The fourth lens group G4 is composed of a negative meniscus lens having a convex shape on the object side.

[0188] The fifth lens group G5 is composed of, in order from the object side, a double concave lens and a double convex lens.

[0189] Further, in Figure 1In the present embodiment, "IP" is an image plane, specifically, an image plane of a solid-state image pickup element such as a CCD sensor or a CMOS sensor, or a film plane of a silver halide film, and the like. Further, on the object side of the image plane IP, a parallel plate having no substantial optical power such as a protection glass CG is provided. Further, on the image plane IP, a half mirror HM is provided. Figure 1 In the present embodiment, the lenses constituting each lens group are not assigned a mark. These aspects are the same in each lens sectional view shown in other embodiments, and thus the description will be omitted hereafter.

[0190] (2) Numerical Embodiment

[0191] Next, a numerical embodiment in which specific numerical values are applied to the zoom lens will be described. Hereafter, "lens data", "various specification tables", "variable intervals", "aspherical coefficients", and "lens group data" are shown. Further, the values of each formula (Table 1) are collectively shown after Embodiment 4.

[0192] In the (lens data), "No." indicates the serial number of the lens surface counted from the object side, "R" indicates the radius of curvature of the lens surface, "D" indicates the thickness of the lens wall or the air interval on the optical axis, "Nd" indicates the refractive index at the d-line (wavelength λ = 587.6 nm), and "ABV" indicates the Abbe number at the d-line. Further, in the column of "No.", "ASPH" added after the serial number indicates that the lens surface is an aspherical surface, and "STOP" indicates that the surface is a stop. In the column of "D", the meaning indicated by "D(3)", "D(12)", and the like is that the interval on the optical axis of the lens surface is a variable interval that changes at the time of zooming. Further, the meaning of "0.0000" in the column of the radius of curvature is infinity, meaning that the lens surface is a plane.

[0193] In the (various specification tables), "f" indicates the focal length of the zoom lens, "Fno" indicates the F-number, "ω" indicates the half field angle, "Y" indicates the image height, and "TL" indicates the total track length. The values at the wide-angle end, the intermediate focal length, and the telephoto end are shown, respectively.

[0194] In the (variable intervals), the values at the time of focusing on infinity at the wide-angle end, the intermediate focal length, and the telephoto end are shown, respectively.

[0195] The (aspherical coefficients) indicate the aspherical coefficients when the aspherical shape is defined as follows. Here, x is set as the amount of displacement from the reference surface in the direction of the optical axis, r is set as the paraxial radius of curvature, H is set as the height with respect to the optical axis in the direction perpendicular to the optical axis, k is set as the conic coefficient, and An is set as the aspherical coefficient of the n-th order. Further, in the table of "aspherical coefficients", "E±XX" represents an exponential mark, and the meaning is "× 10 ±XX ".

[0196] [Formula 1]

[0197]

[0198] The matters in each table described above are the same in each table shown in other embodiments, and thus the explanation is omitted below.

[0199] In addition, in Figure 2 , Figure 3 and Figure 4 , the longitudinal aberration diagrams at the time of focusing on an infinite object distance at the wide-angle end, the intermediate focal length, and the telephoto end of the zoom lens are shown. The longitudinal aberration diagrams shown in each figure are, in order from the left side of the drawing, the spherical aberration (mm), the coma (mm), and the distortion aberration (%). In the spherical aberration diagram, the solid line indicates the spherical aberration at the d line (wavelength 587.6 nm), the broken line indicates the spherical aberration at the F line (wavelength 486.1 nm), and the dotted line indicates the spherical aberration at the C line (wavelength 656.3 nm). In the coma diagram, the vertical axis is the image height (Y), the horizontal axis is the defocus, the solid line indicates the sagittal image surface (S) of the d line, and the broken line indicates the tangential image surface (T) of the d line. In the distortion aberration diagram, the vertical axis is the image height (Y), and the horizontal axis is the distortion aberration. These matters are the same in each aberration diagram shown in other embodiments, and thus the explanation is omitted below.

[0200] (Lens data)

[0201]

[0202]

[0203] (Variety of specification table)

[0204] Wide angle end Intermediate Telephoto end f 28.8419 44.3139 72.7392 Fno 4.1128 4.1402 4.1053 ω 37.8908 26.1810 15.9258 Y 20.2060 21.4087 21.6330 TL 130.000 130.000 130.000

[0205] (Variation of interval)

[0206] Wide angle end Intermediate Telephoto end D(3) 0.9000 7.8954 15.2490 D(12) 27.4467 14.6673 2.2598 D(20) 1.8078 4.2359 9.9958 D(22) 16.5562 14.1281 8.3682 D(26) 24.5619 30.3458 35.3998

[0207] (Aspherical surface coefficient)

[0208]

[0209]

[0210] (Lens group data)

[0211] Group Focal length G1 84.44 G2 -20.02 G3 23.78 G4 -43.35 G5 150.55

[0212] [Embodiment 2]

[0213] (1) Optical configuration

[0214] Figure 5is a sectional view of the zoom lens of Embodiment 2 of the present application at the time of focusing on an infinite object at the wide-angle end, the intermediate focus, and the telephoto end. The zoom lens is composed of, in order from the object side, a first lens group G1 having positive power, a second lens group G2 having negative power, a third lens group G3 having positive power, a fourth lens group G4 having negative power, and a fifth lens group G5 having positive power.

[0215] When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed with respect to the image plane without moving, the second lens group G2 moves toward the image side, the third lens group G3 moves toward the object side, the fourth lens group G4 moves first toward the object side and then toward the image side, and the fifth lens group G5 moves toward the object side.

[0216] When focusing from an infinite object to a close object, the fourth lens group G4 moves along the optical axis.

[0217] The aperture stop S is disposed adjacent to the object side of the third lens group G3.

[0218] The following describes the configuration of each lens group.

[0219] The first lens group G1 is composed of a cemented lens in which a negative meniscus lens having a convex shape on the object side and a positive meniscus lens are cemented in order from the object side.

[0220] The second lens group G2 is composed of, in order from the object side, a negative meniscus lens having a complex aspherical surface on the object side, a double concave lens, a double convex lens, and a negative meniscus lens having a concave shape on the object side.

[0221] The third lens group G3 is composed of, in order from the object side, the aperture stop S, a double convex lens, a double convex lens, and a cemented lens in which a negative meniscus lens having a convex shape on the object side and a double convex lens are cemented.

[0222] The fourth lens group G4 is composed of a negative meniscus lens having a convex shape on the object side.

[0223] The fifth lens group G5 is composed of, in order from the object side, a double concave lens and a double convex lens.

[0224] (2) Numerical Example

[0225] Next, as a numerical example of the zoom lens to which specific numerical values are applied, "lens data", "various specification tables", "variable intervals", "aspherical surface coefficients", and "lens group data" are shown. In addition, in Figure 6 , Figure 7 and Figure 8 , longitudinal aberration diagrams of the zoom lens at the time of focusing on an infinite object at the wide-angle end, the intermediate focus, and the telephoto end are shown.

[0226] (Lens Data)

[0227] Surface number R D Nd ABV 1 43.6206 1.5000 1.84666 23.78 2 29.1642 9.7000 1.72916 54.67 3 211.9514 D(3) 4 ASPH 338.8778 0.2000 1.53610 41.21 5 140.3579 1.1000 1.72916 54.67 6 16.8372 8.2077 7 -56.6957 1.0000 1.79952 42.22 8 47.3109 0.1000 9 34.9299 6.2583 1.85025 30.06 10 -45.5169 1.3323 11 -25.7327 1.1000 1.53996 59.46 12 -260.9036 D(12) 13 STOP 0.0000 1.0000 14 ASPH 23.5767 4.1015 1.59201 67.02 15 ASPH -148.5272 3.1447 16 59.2940 1.8766 1.48749 70.44 17 208.4901 0.1993 18 40.9023 1.0000 1.80610 40.73 19 14.1474 8.3877 1.49700 81.61 20 -31.5958 D(20) 21 ASPH 120.4655 1.1000 1.59201 67.02 22 ASPH 21.3635 D(22) 23 -41.6645 1.2000 1.66680 33.05 24 265.6613 1.8599 25 71.8601 5.6514 1.65160 58.55 26 -46.2660 D(26) 27 0.0000 2.5000 1.51680 64.20 28 0.0000 1.0000 29 0.0000

[0228] (various specification tables)

[0229] Wide angle end Intermediate Telephoto end f 28.8361 44.3099 72.7320 Fno 4.0833 4.2061 4.1269 ω 37.8973 26.2598 15.9475 Y 20.2060 21.4087 21.6330 TL 130.000 130.000 130.000

[0230] (variable intervals)

[0231] Wide angle end Intermediate Telephoto end D(3) 0.9000 6.3702 13.8327 D(12) 27.4863 14.4033 1.6217 D(20) 2.2215 4.1491 9.5833 D(22) 12.9683 13.4442 7.4664 D(26) 22.9045 28.1138 33.9765

[0232] (aspherical coefficients)

[0233] Surface number K A4 A6 A8 A10 4 1.00000E+00 5.98733E-06 -2.42232E-09 -5.90416E-12 2.53587E-14 14 3.09547E-01 -7.15932E-06 -5.93023E-08 9.23203E-10 -5.81614E-12 15 0.00000E+00 1.38775E-05 -5.39596E-08 9.99946E-10 -6.34338E-12 21 -2.02913E+01 -2.53852E-05 6.78813E-08 2.47336E-10 7.35212E-13 22 1.14267E-02 -1.65687E-05 4.22860E-08 1.03838E-10 2.85655E-13

[0234] (lens group data)

[0235] Group Focal length G1 80.93 G2 -20.22 G3 23.83 G4 -44.05 G5 163.66

[0236] [Embodiment 3]

[0237] (1) Optical configuration

[0238] Figure 9 is a sectional view of the zoom lens of Embodiment 3 at the time of focusing on an infinite object at the wide-angle end, the intermediate focal length, and the telephoto end. The zoom lens is composed of, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, a fourth lens group G4 having negative refractive power, a fifth lens group G5 having negative refractive power, and a sixth lens group G6 having positive refractive power.

[0239] When zooming from the wide-angle end to the telephoto end, the first lens group G1 does not move, is fixed with respect to the image plane, the second lens group G2 moves toward the image side, the third lens group G3 moves toward the object side, the fourth lens group G4 moves toward the object side, the fifth lens group G5 moves toward the object side, and the sixth lens group G6 moves toward the object side.

[0240] When focusing from an infinite object to a close object, the fourth lens group G4 moves along the optical axis.

[0241] The aperture stop S is disposed adjacent to the object side of the third lens group G3.

[0242] The configuration of each lens group will be described below.

[0243] The first lens group G1 is composed of a cemented lens in which a negative meniscus lens having a convex shape on the object side and a positive meniscus lens are cemented in order from the object side.

[0244] The second lens group G2 is composed of, in order from the object side, a negative meniscus lens which is a composite aspherical surface having an aspherical surface on the object side, a double concave lens, a double convex lens, and a negative meniscus lens having a concave shape on the object side.

[0245] The 3rd lens group G3 is composed of, in order from the object side, an aperture stop S, a biconvex lens, a positive meniscus lens having a convex shape on the object side, and a joint lens which joins a negative meniscus lens having a convex shape on the object side and a biconvex lens.

[0246] The 4th lens group G4 is composed of a biconcave lens.

[0247] The 5th lens group G5 is composed of a negative meniscus lens having a concave shape on the object side.

[0248] The 6th lens group G6 is composed of a biconvex lens.

[0249] (2) Numerical Example

[0250] Next, as a numerical example in which specific numerical values are applied to the zoom lens, "lens data", "various specification tables", "variable intervals", "aspheric coefficients", and "lens group data" are shown. In addition, in Figs. 1 to 3, longitudinal aberration diagrams of the zoom lens at the time of focusing on infinity at the wide-angle end, at the intermediate focal length, and at the telephoto end are shown. Figure 10 , Figure 11 and Figure 12

[0251] (1ens Data)

[0252]

[0253]

[0254] (Various Specification Tables)

[0255] Wide angle end Intermediate Telephoto end f 28.8400 44.3100 77.2417 Fno 4.4078 4.3636 4.5054 ω 37.8977 26.4518 15.2674 Y 20.2060 21.4087 21.6330 TL 140.170 140.170 140.170

[0256] (Variable Intervals)

[0257] Wide angle end Intermediate Telephoto end D(3) 0.9000 8.4515 14.0365 D(12) 30.6905 16.6590 1.1333 D(20) 2.3398 3.6644 9.4586 D(22) 13.3101 14.3464 3.4960 D(24) 10.8331 5.7620 6.2517 D(26) 17.5000 26.6901 41.1974

[0258] (Aspheric Coefficients)

[0259] Surface number K A4 A6 A8 A10 4 10.00000E-01 5.13382E-06 -7.00902E-10 -8.03582E-12 2.14741E-14 14 4.65713E-01 -4.77138E-06 -5.97403E-08 7.25836E-10 -3.26740E-12 15 0.00000E+00 8.81851E-06 -5.28576E-08 8.45021E-10 -3.73875E-12 21 -1.11036E+05 -2.23784E-05 6.39109E-08 -1.06215E-09 1.11899E-11 22 5.18849E-01 -9.84438E-06 2.71436E-08 -8.81225E-10 7.85457E-12

[0260] (Lens Group Data)

[0261] Group Focal length G1 84.19 G2 -20.07 G3 24.12 G4 -41.82 G5 -120.58 G6 63.64

[0262] [Example 4]

[0263] (1) Optical Configuration

[0264] Figure 13 ​is a sectional view of the zoom lens of Embodiment 4 of the present application at the time of focusing on an infinite object at the wide-angle end and the telephoto end. The zoom lens is composed of, in order from the object side, a first lens group G1 having positive power, a second lens group G2 having negative power, a third lens group G3 having positive power, a fourth lens group G4 having negative power, and a fifth lens group G5 having positive power.

[0265] When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed with respect to the image plane without moving, the second lens group G2 moves toward the image side, the third lens group G3 moves toward the object side, the fourth lens group G4 moves first toward the object side and then toward the image side, and the fifth lens group G5 moves toward the object side.

[0266] When focusing from an infinite object to a close object, the fourth lens group G4 moves along the optical axis.

[0267] The aperture stop S is disposed adjacent to the object side of the third lens group G3.

[0268] The following describes the configuration of each lens group.

[0269] The first lens group G1 is composed of a cemented lens in which a negative meniscus lens having a convex shape on the object side and a positive meniscus lens are cemented in order from the object side.

[0270] The second lens group G2 is composed of, in order from the object side, a negative meniscus lens having a complex aspherical surface on the object side, a double concave lens, a double convex lens, and a negative meniscus lens having a concave shape on the object side.

[0271] The third lens group G3 is composed of, in order from the object side, the aperture stop S, a double convex lens, a positive meniscus lens, and a cemented lens in which a negative meniscus lens having a convex shape on the object side and a double convex lens are cemented.

[0272] The fourth lens group G4 is composed of a negative meniscus lens having a convex shape on the object side.

[0273] The fifth lens group G5 is composed of, in order from the object side, a double concave lens and a double convex lens.

[0274] (2) Numerical Example

[0275] Next, as a numerical example of the zoom lens to which specific numerical values are applied, "lens data", "various specification tables", "variable intervals", "aspherical surface coefficients", and "lens group data" are shown. In addition, in Figure 14 , Figure 15 and Figure 16 , longitudinal aberration diagrams of the zoom lens at the time of focusing on an infinite object at the wide-angle end, the intermediate focal length, and the telephoto end are shown.

[0276] (Lens Data)

[0277]

[0278]

[0279] (various specification tables)

[0280] Wide angle end Intermediate Telephoto end f 28.8359 44.3130 72.7244 Fno 4.0939 4.0016 3.9376 ω 37.9013 26.3367 15.9533 Y 20.2060 21.4087 21.6330 TL 130.000 130.000 130.000

[0281] (variable intervals)

[0282] Wide angle end Intermediate Telephoto end D(3) 0.9000 10.1487 18.3918 D(12) 28.0453 14.6530 1.8027 D(20) 1.9434 3.9552 8.1997 D(22) 16.9047 11.0041 3.8517 D(26) 21.4551 29.4876 37.0026

[0283] (aspherical coefficients)

[0284] Surface number K A4 A6 A8 A10 4 1.00000E+00 7.65705E-06 -5.39614E-10 -1.56730E-11 4.65804E-14 14 3.39394E-01 -6.86626E-06 -5.42233E-08 9.15665E-10 -7.68331E-12 15 0.00000E+00 1.70457E-05 -4.71781E-08 9.32692E-10 -8.15032E-12 21 2.77018E+00 -2.40136E-05 6.17240E-08 6.37727E-11 3.27147E-12 22 -1.12409E-01 -1.84230E-05 1.33924E-08 -9.77149E-11 1.99878E-12

[0285] (lens group data)

[0286] Group Focal length G1 91.18 G2 -21.14 G3 23.26 G4 -39.73 G5 130.36

[0287] [table 1]

[0288] Formula Example 1 Example 2 Example 3 Example 4 Formula (1) |M3 / M2| 0.76 1.00 1.25 0.50 Formula (2) |M5 / M2| 0.76 0.86 1.46 0.89 Formula (3) β3t / β3w / (β2t / β2w) 1.34 1.35 1.54 1.25 Formula (4) β4t / β4w / (β2t / β2w) 0.79 0.81 0.97 0.79 Formula (5) Nd2n 1.73 1.73 1.73 1.73 Formula (6) |f2| / f1 0.24 0.25 0.24 0.23 Formula (7) β3t / β3w 1.84 1.83 2.06 1.80 Formula (8) |f2| / fw 0.69 0.70 0.70 0.73 Formula (9) f1 / ft 1.16 1.11 1.09 1.25 Formula (10) f4 / f2 2.17 2.18 2.08 1.88 Formula (11) |f5| / f3 6.33 6.87 5.00 5.61

[0289] industrial applicability

[0290] The zoom lens according to the present application is suitably applicable, for example, as an imaging optical system of an imaging device such as a thin film camera, a digital still camera, a digital video camera, or the like.

Claims

1. A zoom lens, The zoom lens, starting from the object side, comprises, in sequence: a first lens group with positive optical power, a second lens group with negative optical power, a third lens group with positive optical power, a fourth lens group with negative optical power, and a fifth lens group. During zooming, the spacing between adjacent lens groups changes. The first lens group is fixed relative to the image plane, while the third and fifth lens groups move in directions different from those of the second lens group. The zoom lens satisfies the following formula: 0.01 <|M3 / M2| < 1.34 ·····(1) 0.61 <|M5 / M2| < 1.81 ·····(2) 0.75 < β4t / β4w / (β2t / β2w) < 1.30 ·····(4) 0.40 < | f2 | / fw < 1.00 ·····(8) in, M2: The amount of movement of the second lens group from the wide-angle end to the telephoto end. M3: The amount of movement of the third lens group from the wide-angle end to the telephoto end. M5: The amount of movement of the fifth lens group from the wide-angle end to the telephoto end. β2w: Horizontal magnification of the second lens group when focusing at infinity at the wide-angle end. β2t: Horizontal magnification of the second lens group when focusing at infinity at the telephoto end. β4w: Horizontal magnification of the fourth lens group when focusing at infinity at the wide-angle end. β4t: Horizontal magnification of the fourth lens group when focusing at infinity at the telephoto end. f2: Focal length of the second lens group fw: The focal length of the zoom lens when focusing at infinity at the wide-angle end.

2. The zoom lens as described in claim 1, Satisfy the following formula: 0.90 < β3t / β3w / (β2t / β2w) < 1.75 ·····(3) in, β3w: Horizontal magnification of the third lens group when focusing at infinity at the wide-angle end. β3t: The horizontal magnification of the third lens group when focusing at infinity at the telephoto end.

3. The zoom lens as described in claim 1 or claim 2, Satisfy the following formula: Nd2n < 1.80 ·····(5) in, Nd2n: The refractive index at the d-line of the negative lens closest to the object side among the at least one negative lens included in the second lens group.

4. The zoom lens as described in claim 1, Satisfy the following formula: 0.10 < | f2 | / f1 < 0.40 ·····(6) in, f1: The focal length of the first lens group.

5. The zoom lens as described in claim 1, Satisfy the following formula: 1.50 < β3t / β3w < 2.50 ·····(7) in, β3w: Horizontal magnification of the third lens group when focusing at infinity at the wide-angle end. β3t: The horizontal magnification of the third lens group when focusing at infinity at the telephoto end.

6. The zoom lens as described in claim 1, Satisfy the following formula: 0.50 < f1 / ft < 2.00 ·····(9) in, f1: Focal length of the first lens group ft: The focal length of the zoom lens when focusing at infinity at the telephoto end.

7. The zoom lens as described in claim 1, Satisfy the following formula: 0.50 < f4 / f2 < 3.50 ·····(10) in, f4: The focal length of the fourth lens group.

8. The zoom lens as described in claim 1, The third lens group has at least one aspherical positive lens.

9. The zoom lens as described in claim 1, During focusing, the fourth lens group moves along the optical axis.

10. The zoom lens as described in claim 1, The fourth lens group consists of only one lens component.

11. A camera device, characterized in that, have: The zoom lens as claimed in any one of claims 1 to 10; and The camera element converts the optical image formed by the zoom lens into an electrical signal on the image side of the zoom lens.

Images