Zoom lens, camera device, and lens device

Abstract

The present invention provides a zoom lens, an imaging device and a lens device. The zoom lens includes, from the object side to the image side, a first lens unit with positive refractive power; a second lens unit with negative refractive power; a third lens unit with positive refractive power; a fourth lens unit with negative refractive power; a fifth lens unit with positive refractive power; a sixth lens unit with negative refractive power; a seventh lens unit with positive refractive power; and an eighth lens unit with negative refractive power, wherein the interval between each pair of adjacent lens units is changed to perform zooming, and wherein the eighth lens unit includes a positive lens and a negative lens.

Description

[0001] This application is a divisional application of the invention patent application with the application date of January 14, 2020, application number 202010037000.4, and invention name “Zoom lens, camera device and lens device”. Technical Field

[0002] Aspects of the embodiments relate to a zoom lens suitable for an imaging device using an imaging element, such as a digital video camera, a digital still camera, a broadcast camera, or a surveillance camera. Background Art

[0003] A so-called super-telephoto zoom lens having a high zoom ratio and a long focal length at the telephoto end is known. Such a zoom lens is required to have a high zoom ratio, high optical performance, easy and fast focusing, and a compact entire system as a zoom lens for the focal length at the telephoto end.

[0004] Japanese Patent Application Laid-Open No. 11-84241 discloses a zoom lens including first to sixth lens units having positive, negative, positive, negative, positive and negative refractive powers in order from the object side to the image side, wherein two lens units are configured to move for focusing.

[0005] In addition, in Japanese Patent Application Laid-Open No. 2014-228734, a zoom lens is disclosed, which includes first to sixth lens units having positive, negative, positive, negative, positive and negative refractive powers in order from the object side to the image side, wherein reducing the back focus allows the zoom lens to have a relatively reduced total length.

[0006] Linear actuators are known as actuators that can be used for fast focusing, but the focusing lens unit needs to be light in weight for driving. In addition, when floating focus is adopted to obtain good optical performance over the entire focusing range in a zoom lens with a high zoom ratio, the construction of an actuator with a high driving force and a complex metal cam is required. In addition, also in zooming and focusing, the freedom of movement may be limited by the trajectory of the cam.

[0007] In order to obtain high optical performance over the entire focusing range while reducing the size of the entire system in the zoom lens, it is necessary to appropriately set the elements forming the zoom lens. For example, it is necessary to appropriately set the zoom type (e.g., the number of lens units, and the refractive power and movement conditions for zooming of the lens units), the selection of the lens units configured to move for focusing, and the lens configuration of the lens units configured to move for focusing. Summary of the invention

[0008] According to at least one embodiment of the present disclosure, a zoom lens is provided, which includes, in sequence from the object side to the image side: a first lens unit with positive refractive power; a second lens unit with negative refractive power; a third lens unit with positive refractive power; a fourth lens unit with negative refractive power; a fifth lens unit with positive refractive power; a sixth lens unit with negative refractive power; a seventh lens unit with positive refractive power; and an eighth lens unit with negative refractive power, wherein the intervals between each pair of adjacent lens units are changed to perform zooming.

[0009] Further features of the present disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a lens cross-sectional diagram of a zoom lens according to Embodiment 1 of the present disclosure.

[0011] Figure 2A and Figure 2B 2 are aberration diagrams of the zoom lens according to Example 1 of the present disclosure.

[0012] Figure 3 is a lens cross-sectional diagram of a zoom lens according to Example 2 of the present disclosure.

[0013] Figure 4A and Figure 4B 2 are aberration diagrams of the zoom lens according to Example 2 of the present disclosure.

[0014] Figure 5 is a lens cross-sectional diagram of a zoom lens according to Example 3 of the present disclosure.

[0015] Fig. 6A and Figure 6B 2 are aberration diagrams of the zoom lens according to Example 3 of the present disclosure.

[0016] Figure 7 is a lens cross-sectional diagram of a zoom lens according to Example 4 of the present disclosure.

[0017] Fig. 8A and Figure 8B 2 are aberration diagrams of the zoom lens according to Example 4 of the present disclosure.

[0018] Fig. 9 : is a diagram for illustrating the configuration of a lens apparatus including a zoom lens according to Embodiment 1 of the present disclosure.

[0019] Fig.10 is a schematic diagram of a main part of an imaging device according to an example of the present disclosure. DETAILED DESCRIPTION

[0020] Exemplary embodiments of the present disclosure will now be described with reference to the accompanying drawings.

[0021] The zoom lens according to each embodiment of the present disclosure includes, from the object side to the image side, a first lens unit having positive refractive power, a second lens unit having negative refractive power, a third lens unit having positive refractive power, a fourth lens unit having negative refractive power, a fifth lens unit having positive refractive power, a sixth lens unit having negative refractive power, a seventh lens unit having positive refractive power, and an eighth lens unit having negative refractive power. In addition, the interval between each pair of adjacent lens units is changed to perform zooming.

[0022] Figure 1 , Figure 3 , Figure 5 and Figure 7 They are lens cross-sectional diagrams of zoom lenses at the wide-angle end (short focal length end) according to Embodiments 1 to 4 of the present disclosure, respectively. Figure 2A and Figure 2B , Figure 4A and Figure 4B , Fig. 6A and Figure 6B as well as Fig. 8A and Figure 8B They are respectively aberration diagrams of the zoom lens when the zoom lens according to Examples 1 to 4 is focused at infinity. In each group of aberration diagrams, aberrations at the wide-angle end and the telephoto end (long focal length end) of the zoom lens are shown in sequence from the top. Example 1 relates to a zoom lens having a zoom ratio of 4.80 and an aperture ratio (f-value) of approximately 4.60 to approximately 7.20. Example 2 relates to a zoom lens having a zoom ratio of 4.80 and an aperture ratio of approximately 4.10 to approximately 6.40. Example 3 relates to a zoom lens having a zoom ratio of 4.92 and an aperture ratio of approximately 4.60 to approximately 7.20.

[0023] Example 4 relates to a zoom lens having a zoom ratio of 3.92 and an aperture ratio of about 6.00 to about 8.50.

[0024] Fig. 9 1 and 2 are diagrams for explaining movement of each lens unit of the zoom lens according to Example 1. FIG.

[0025] Fig.10 is a schematic diagram of a main part of an image pickup device according to an embodiment of the present disclosure.

[0026] The zoom lens according to each embodiment is an imaging optical system to be used for an imaging device (e.g., a video camera, a digital still camera, a surveillance camera, and a television camera). The zoom lens according to each embodiment can also be used as a projection optical system for a projection device (projector). In the lens cross-sectional view, the left side is the object side (front) and the right side is the image side (rear). In addition, in the lens cross-sectional view, the zoom lens is represented by L0. When the order of the lens units from the object side is represented by "i", the i-th lens unit is represented by Bi.

[0027] The aperture stop ST0 is constructed to determine (limit) the light beam of the open f-number (Fno). When the zoom lens is used as an imaging optical system of a video camera or a digital still camera, the imaging surface of an imaging element (photoelectric conversion element) (such as a CCD sensor or a CMOS sensor) is placed at the image plane "img". The arrows indicate the movement trajectory of each lens unit for zooming from the wide-angle end to the telephoto end. The arrow related to "focus" indicates the movement direction of the lens unit for focusing from infinity to a close distance.

[0028] Solid arrows 4a and 6a indicate movement of the lens unit for zooming from the wide angle end to the telephoto end when the object distance is infinity, and dotted arrows 4b and 6b indicate movement of the lens unit for zooming from the wide angle end to the telephoto end when focusing on a close object distance.

[0029] The aberration diagrams include a spherical aberration diagram, an astigmatism diagram, a distortion diagram, and a chromatic aberration diagram, in order from the left side of the drawing. In the spherical aberration diagram, the solid line "d" indicates the aberration of the d-line (wavelength: 587.56nm), the dotted line "f" indicates the aberration of the f-line (wavelength: 486.13nm), the single-dot chain line C indicates the aberration of the C-line (wavelength: 656.27nm), and the double-dot chain line "g" indicates the aberration of the g-line (wavelength: 435.83nm). The scale on the horizontal axis indicates the defocus amount, and is -0.4mm to +0.4mm.

[0030] In the astigmatism diagram, the solid line S indicates the field curvature of the sagittal image plane relative to the d-line, and the dotted line M indicates the field curvature of the meridional image plane relative to the d-line. The horizontal axis is the same as in the spherical aberration diagram. In the distortion diagram, the scale on the horizontal axis is -5% to +5%. The chromatic aberration diagram indicates the deviation of the magnification chromatic aberration from the d-line, and the scale on the horizontal axis is -0.03mm to +0.03mm.

[0031] The zoom lens L0 according to each embodiment includes the above-mentioned eight lens units. In this specification, a "lens unit" may include a plurality of lenses or one lens.

[0032] The eight lens units forming the zoom lens include, in order from the object side to the image side, a first lens unit B1 having positive refractive power, a second lens unit B2 having negative refractive power, a third lens unit B3 having positive refractive power, a fourth lens unit B4 having negative refractive power, a fifth lens unit B5 having positive refractive power, a sixth lens unit B6 having negative refractive power, a seventh lens unit B7 having positive refractive power, and an eighth lens unit B8 having negative refractive power. As a result, a zoom lens having a high zoom ratio and having a long focal length at the telephoto end can be obtained.

[0033] With the telephoto optical arrangement of the first lens unit B1 having positive refractive power and the second lens unit B2 having negative refractive power, the principal point can be set long relative to the overall length of the zoom lens to reduce the overall length of the zoom lens compared with the focal length.

[0034] Furthermore, with the above-described refractive power arrangement, it is possible to easily ensure a lens on the image side of the second lens unit and to reduce the diameter of the lens unit including a relatively small number of lenses. As a result, it is possible to easily reduce the weight of at least a portion of the lens unit, and thus it is easier to arrange a focus lens unit configured to move for focusing on the image side of the second lens unit. Furthermore, the drive mechanism can be used as both a drive mechanism for zooming and a drive mechanism for focusing, and therefore, in a lens apparatus including the zoom lens according to each embodiment, it is easier to simplify the drive mechanism.

[0035] In addition, the first lens unit B1 is configured to move toward the object side to zoom from the wide-angle end to the telephoto end, and the fourth lens unit B4 and the sixth lens unit B6 are configured to move to zoom. Compared with the wide-angle end, at the telephoto end, the interval between the first lens unit B1 and the second lens unit B2 increases, the interval between the second lens unit B2 and the third lens unit B3 decreases, and the interval between the seventh lens unit B7 and the eighth lens unit B8 decreases.

[0036] During zooming from the wide-angle end to the telephoto end, the interval between the first lens unit B1 and the second lens unit B2 increases, while the interval between the second lens unit B2 and the third lens unit B3 decreases. As a result, the effect of changing the magnification is obtained. In addition, in order to zoom from the wide-angle end to the telephoto end, the first lens unit B1 and the third lens unit B3 to the seventh lens unit B7 are configured to move toward the object side. As a result, the effect of a compensator is obtained, and the total length of the zoom lens becomes the shortest at the wide-angle end.

[0037] In addition, the interval between the seventh lens unit B7 having positive refractive power and the eighth lens unit B8 having negative refractive power can be reduced to zoom from the wide-angle end to the telephoto end, thereby obtaining a further effect of changing the magnification. In addition, the eighth lens unit B8 can be moved for zooming, thereby reducing the change of magnification chromatic aberration and other aberrations caused by zooming.

[0038] The third lens unit B3 to the seventh lens unit B7 are configured to move toward the object side to perform zooming.

[0039] In addition, the third lens unit B3 and the fifth lens unit B5 move along the same locus to perform zooming. As a result, in the lens apparatus including the zoom lens according to each embodiment of the present disclosure, complication of a driving mechanism for zooming can be prevented.

[0040] At least a portion of the second lens unit B2 is used as an image stabilization lens unit, which is configured to move in a direction having a component in a direction perpendicular to the optical axis of the zoom lens to correct image blur. In addition, the second lens unit B2 does not move for zooming. As a result, the zoom lens becomes advantageous in terms of the stability of the position of the image stabilization lens unit and the ease of arranging a drive mechanism configured to drive the second lens unit B2. Figure 1 and Figure 3 In Embodiments 1 and 2 respectively shown in FIG. 1 and 2 , the entire second lens unit B2 functions as an image stabilization lens unit, and Figure 5 and Figure 7 In Embodiments 3 and 4 shown in FIG. 1 , the lens sub-unit 2 b forming a part of the second lens unit B2 serves as an image stabilizing lens unit.

[0041] The two lens units arranged on the image side of the second lens unit are moved for focusing. In addition, the two lens units configured to move for focusing are the fourth lens unit B4 and the sixth lens unit B6, and one of the two lens units is used as a main focusing lens unit and the other is used as a floating lens unit.

[0042] The sixth lens unit B6 is a main focusing lens unit. The sixth lens unit B6 is configured to move during the change of magnification from the wide-angle end to the telephoto end to reduce the interval with the fifth lens unit B5 and assist in changing the magnification, and has a function of moving toward the image side as shown by arrow 6c to focus from an object at infinity to an object at a close distance.

[0043] The fourth lens unit B4 is a floating lens unit. The fourth lens unit B4 can control the field curvature at the wide-angle end, and the spherical aberration and focus movement at the telephoto end. As a result, the fourth lens unit B4 reduces the aberration variation over the entire zoom range and the entire focus range to obtain high optical performance. Arrow 4c indicates the movement direction from infinity to close focus.

[0044] Each of the fourth lens unit B4 and the sixth lens unit B6 includes two or less lenses. As a result, the weight of the lens unit configured to move for focusing can be reduced for fast focusing. In addition, as in the case of the fourth lens unit B4 and the sixth lens unit B6, the lens unit to be moved has a negative refractive power, thereby having a relatively small lens diameter and reduced weight.

[0045] The third to seventh lens units B3 to B7 are lens units having positive, negative, positive, negative, and positive refractive powers in which different refractive powers are alternately arranged and magnifications are changed with the assistance of a subsystem, thereby obtaining a high zoom ratio.

[0046] Furthermore, a telephoto zoom lens having high optical performance throughout the entire zoom range and throughout the entire focus range is obtained, which facilitates fast focusing.

[0047] also, Fig. 9 1 is a diagram showing the configuration of a lens apparatus including a zoom lens according to Example 1. Fig. 9 As shown, at least the third lens unit B3, the fourth lens unit B4, and the fifth lens unit B5 are held by an integral barrel, and are integrally moved by a zoom cam 20 (first moving mechanism).

[0048] The third lens unit B3, the fourth lens unit B4, and the fifth lens unit B5 tend to produce significant changes in optical performance through tilted decentering and parallel decentering. Therefore, when the third lens unit B3, the fourth lens unit B4, and the fifth lens unit B5 are constructed as an integrated structure, displacement can be reduced and good optical performance can be easily maintained. In addition, with the integrated structure, the mechanical structure can be simplified even with a large number of lens units.

[0049] In addition, the fourth lens unit B4 is moved by the actuator A21 (second moving mechanism), and the sixth lens unit B6 is moved by the actuator B22 (third moving mechanism). By the actuator A21 and the actuator B22, the fourth lens unit B4 and the sixth lens unit B6 can move along a trajectory different from that of the other lens units moved by the zoom cam 20.

[0050] As a result, the number of mechanical zoom cams can be reduced to simplify the structure of the lens device. In addition, the lens unit configured to move for zooming is configured to move for focusing, so the drive mechanism can be doubled and the structure of the lens device can be simplified. In the configuration in which the actuator A 21 and the actuator B 22 are arranged in the lens barrel portion inside the zoom cam 20, the actuator unit can be easily and satisfactorily held.

[0051] exist Figure 1 The embodiment 1 and Figure 3 In the embodiment 2 shown in FIG. 1 , the third lens unit B3 to the seventh lens unit B7 form an integrated tube structure, and Figure 5 Example 3 and Figure 7 In the illustrated embodiment 4, the third lens unit B3 to the sixth lens unit B6 form an integrated structure.

[0052] When the seventh lens unit B7 moves along different trajectories, the degree of freedom is increased during zooming, and it is easier to correct aberrations and focus position more finely when finely adjusting the position from the wide-angle end to the intermediate zoom position and from the intermediate zoom position to the telephoto end.

[0053] Furthermore, in the zoom lens according to each embodiment, one or more of the following inequalities are satisfied.

[0054] 0.5 <m5 / m7<1.5…(1)

[0055] 1.2 <m8 / bfw<7.0…(2)

[0056] 5<|Es1|<12…(3)

[0057] 0.1<|Es2 / Es1|<0.8…(4)

[0058] In the expression, m5 represents the movement amount of the fifth lens unit B5, and m7 represents the movement amount of the seventh lens unit B7 for zooming from the wide-angle end to the telephoto end. The "movement amount of the lens unit" used here refers to the difference between the positions on the optical axis of the lens unit at the wide-angle end and the telephoto end, and the movement amount is negative when the lens unit is located on the object side of the telephoto end compared to the wide-angle end, and the movement amount is positive when the lens unit is located on the image side of the telephoto end compared to the wide-angle end. In addition, in the expression, "bfw" represents the back focus at the wide-angle end, and m8 represents the movement amount of the eighth lens unit B8 for zooming from the wide-angle end to the telephoto end.

[0059] The fourth lens unit B4 and the sixth lens unit B6 are configured to move for focusing. Of the fourth lens unit B4 and the sixth lens unit B6, one having a higher focus sensitivity serves as a focus lens unit, and the other having a lower focus sensitivity serves as a floating lens unit. When the zoom lens is focused at infinity, Es1 represents the focus sensitivity of the focus lens unit at the telephoto end, and Es2 represents the focus sensitivity of the floating lens unit at the telephoto end.

[0060] Next, the technical meaning of the above inequality is described.

[0061] When the ratio m5 / m7 is lower than the lower limit of inequality (1), the interval between the fifth lens unit B5 and the seventh lens unit B7 becomes too narrow at the telephoto end, and the movement amount of the sixth lens unit B6 as the main focusing lens unit is limited to unfavorably increase the close distance that the zoom lens can focus, or unfavorably increase the focusing sensitivity. When the ratio m5 / m7 exceeds the upper limit of inequality (1), the movement amount of the seventh lens unit B7 is reduced, and thus the movement amount of the eighth lens unit B8 is significantly reduced. Then, the effect of correcting aberrations is unfavorably reduced during zooming, and during zooming from the telephoto end to the wide-angle end, the sixth lens unit B6 and the seventh lens unit B7 tend to unfavorably interfere with each other.

[0062] When the ratio m8 / bfw is lower than the lower limit of inequality (2), the amount of movement of the eighth lens unit B8 relative to the imaging plane becomes too small, and it is disadvantageously difficult to satisfactorily correct aberrations. When the ratio m8 / bfw exceeds the upper limit of inequality (2), the amount of movement of the eighth lens unit B8 becomes too large, and the total length of the zoom lens becomes disadvantageously long.

[0063] In the zoom lens according to each embodiment, when the focus lens unit is also moved to perform zooming, and the movement is made to follow the trajectory of the lens unit by the operation of the actuator (the operation is not physically performed by a metal cam or the like), a follow-up delay and a stop position shift may occur depending on the performance of the actuator. Therefore, when the focus sensitivity of the focus lens unit at the telephoto end and at an infinite object distance is represented by Es1, inequality (3) is satisfied.

[0064] When the value |Es1| is lower than the lower limit of inequality (3), the compensator function during the change of magnification is reduced, resulting in difficulty in obtaining a high zoom magnification, and difficulty in obtaining a high magnification at a close object distance. When the value |Es1| exceeds the upper limit, the focus deviation caused by the position deviation of the actuator tends to exceed the allowable circle of confusion, and accurate focusing becomes difficult.

[0065] At the same time, when the focus sensitivity is increased, the advantages of achieving a high zoom ratio and a high magnification at a close object distance are obtained. Therefore, in order to perform accurate focusing while maintaining a high focus sensitivity within the range of inequality (3), a floating lens unit is used as an auxiliary lens unit. In the present application, the focus sensitivities of the focus lens unit and the floating lens unit are appropriately set to sense a focus offset caused by a positional offset of the focus lens unit, and as a result, a configuration for correcting a focus offset by the floating lens unit is easily implemented.

[0066] When the ratio |Es2 / Es1| is lower than the lower limit of inequality (4), and when the focus deviation caused by the position error of the focus lens unit is assisted by the floating lens unit, the movement amount of the floating lens unit becomes too large, and the field curvature and spherical aberration are unfavorably increased. When the ratio |Es2 / Es1| exceeds the upper limit of inequality (4), the focus sensitivities of the focus lens unit and the floating lens unit become too close, and the assisting effect of the floating lens unit is reduced.

[0067] In one embodiment, the numerical ranges of inequalities (1) to (4) are set as follows.

[0068] 0.6 <m5 / m7<1.3…(1a)

[0069] 1.8 <m8 / bfw<6.0…(2a)

[0070] 6.0<|Es1|<11.0…(3a)

[0071] 0.15<|Es2 / Es1|<0.75…(4a)

[0072] It is further preferred that the numerical ranges of inequalities (1) to (4) be set as follows.

[0073] 0.7 <m5 / m7<1.2…(1b)

[0074] 2.0 <m8 / bfw<5.0…(2b)

[0075] 7.0<|Es1|<10.0…(3b)

[0076] 0.2<|Es2 / Es1|<0.5…(4b)

[0077] Exemplary embodiments of the present disclosure are described above, but the present disclosure is not limited to those embodiments, and various modifications and changes can be made within the scope of the gist thereof.

[0078] For example, as the lens unit configured to move for focusing, at least two lens units among the third lens unit B3 to the seventh lens unit B7 arranged along the optical axis direction are moved.

[0079] As described above, according to the embodiments, as a zoom lens having a high zoom ratio and a long focal length at the telephoto end, a telephoto zoom lens having high optical performance throughout the entire zoom range and the entire focus range which is easy to focus quickly can be obtained.

[0080] Now, numerical examples 1 to 4 corresponding to examples 1 to 4 are provided. In numerical examples 1 to 4, B represents the lens unit number. S represents the surface number and indicates the order of the optical surface from the object side. R represents the radius of curvature of the optical surface (mm), "d" represents the interval between adjacent optical surfaces (mm), "nd" represents the refractive index of the material of the optical member with respect to the d-line, and "νd" represents the Abbe number of the material of the optical member with respect to the d-line.

[0081] When the refractive index of a material with respect to the g-line (wavelength: 435.8 nm), the F-line (486.1 nm), the d-line (587.6 nm) and the C-line (656.3 nm) are represented by Ng, NF, Nd and NC, respectively, the Abbe number "νd" of the material is represented by: νd = (Nd-1) / (NF-NC). The back focal length is represented by BF. The "back focal length" is the air equivalent length of the distance from the rearmost side of the zoom lens (the surface closest to the image side) to the image plane "img" on the optical axis. The "total length of the zoom lens" is the value obtained by adding the back focal length to the distance on the optical axis from the frontmost side of the zoom lens (the surface closest to the object side) to the rearmost side. "EA" means effective diameter, and "obj" means object.

[0082] In addition, Table 1 shows the values ​​corresponding to the inequalities in Numerical Examples 1 to 4.

[0083] (Numerical Example 1)

[0084]

[0085]

[0086]

[0087]

[0088] Lens unit data

[0089]

[0090]

[0091] (Numerical Example 2)

[0092]

[0093]

[0094]

[0095]

[0096] Lens unit data

[0097]

[0098] (Numerical Example 3)

[0099]

[0100]

[0101]

[0102]

[0103] Lens unit data

[0104]

[0105] (Numerical Example 4)

[0106]

[0107]

[0108]

[0109]

[0110] Lens unit data

[0111]

[0112]

[0113] Table 1

[0114] Conditional Expressions Example 1 Example 2 Example 3 Example 4 1 m5 / m7 1.000 1.000 1.126 0.757 2 m8 / bfw 2.170 2.507 3.910 2.715 3 |Es1| 7.856 8.029 8.539 8.966 4 |Es2 / Es1| 0.314 0.322 0.214 0.422

[0115] Next, refer to Fig.10 An example of a digital still camera using the zoom lens according to any one of the embodiments of the present disclosure as an imaging optical system is described. Fig.10 In the embodiment, the digital still camera includes a camera body 10 and an imaging optical system 11 including any of the zoom lenses described in Embodiments 1 to 4. An imaging element (photoelectric conversion element) 12 (such as a CCD sensor or a CMOS sensor) is included in the camera body 10 to receive an object image formed by the imaging optical system 11.

[0116] While the present disclosure has been described with reference to exemplary embodiments, it is to be understood that the present disclosure is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A zoom lens, comprising, from the object side to the image side, a first lens unit having positive refractive power; a second lens unit having negative refractive power; a third lens unit having positive refractive power; a fourth lens unit having negative refractive power; a fifth lens unit having positive refractive power; a sixth lens unit having negative refractive power; a seventh lens unit having positive refractive power; as well as The eighth lens unit has negative refractive power, wherein the intervals between each pair of adjacent lens units are changed to perform zooming, and Wherein, the eighth lens unit includes a positive lens and a negative lens, Among them, the following inequality is satisfied: 0.5 <m5 / m7<1.5, Here, m5 represents a movement amount of the fifth lens unit for zooming from the wide angle end to the telephoto end, and m7 represents a movement amount of the seventh lens unit for zooming from the wide angle end to the telephoto end.

2. The zoom lens according to claim 1, wherein: The first lens unit is moved toward the object side to zoom from a wide-angle end to a telephoto end.

3. The zoom lens according to claim 1, wherein: The fourth lens unit and the sixth lens unit are moved to perform zooming.

4. The zoom lens according to claim 1, wherein: An interval between the first lens unit and the second lens unit is wider at a telephoto end than at a wide-angle end.

5. The zoom lens according to claim 1, wherein: An interval between the second lens unit and the third lens unit is reduced to zoom from a wide angle end to a telephoto end.

6. The zoom lens according to claim 1, wherein: An interval between the seventh lens unit and the eighth lens unit is reduced to zoom from a wide angle end to a telephoto end.

7. The zoom lens according to claim 1, wherein: Two lens units arranged on the image side of the second lens unit are moved to perform focusing.

8. The zoom lens according to claim 7, wherein: The fourth lens unit and the sixth lens unit are moved to perform focusing.

9. The zoom lens according to claim 8, wherein: The fourth lens unit is moved toward the object side to focus from an infinitely distant object to a close object, and the sixth lens unit is moved toward the image side to focus from an infinitely distant object to a close object.

10. The zoom lens according to claim 8, wherein: Each of the fourth lens unit and the sixth lens unit consists of two lenses or less.

11. The zoom lens according to claim 1, wherein: The third lens unit and the fifth lens unit are moved along the same locus to perform zooming.

12. The zoom lens according to claim 1, wherein: The following inequality is satisfied: 1.2 <m8 / bfw<7.0, Here, bfw represents a back focus at the wide angle end, and m8 represents a movement amount of the eighth lens unit for zooming from the wide angle end to the telephoto end.

13. The zoom lens according to claim 1, in, The fourth lens unit and the sixth lens unit are moved for focusing, one of the fourth lens unit and the sixth lens unit having a higher focus sensitivity is defined as a focusing lens unit, and the other of the fourth lens unit and the sixth lens unit having a lower focus sensitivity is defined as a floating lens unit, and Among them, the following inequality is satisfied: 5<|Es1|<12, Wherein, Es1 represents the focusing sensitivity of the focusing lens unit at the telephoto end when the zoom lens is focused at infinity.

14. The zoom lens according to claim 1, in, The fourth lens unit and the sixth lens unit are moved for focusing, one of the fourth lens unit and the sixth lens unit having a higher focus sensitivity is defined as a focusing lens unit, and the other of the fourth lens unit and the sixth lens unit having a lower focus sensitivity is defined as a floating lens unit, and Among them, the following inequality is satisfied: 0.1<|Es2 / Es1|<0.8, Here, Es1 represents the focusing sensitivity of the focusing lens unit at the telephoto end when the zoom lens is focused at infinity, and Es2 represents the focusing sensitivity of the floating lens unit at the telephoto end when the zoom lens is focused at infinity.

15. The zoom lens according to claim 1, wherein: The fourth lens unit is moved toward the object side to focus from an infinitely distant object to a close object, and the sixth lens unit is moved toward the image side to focus from an infinitely distant object to a close object.

16. The zoom lens according to claim 1, wherein: The third lens unit to the eighth lens unit are moved toward the object side to zoom from a wide angle end to a telephoto end.

17. A zoom lens, comprising, from the object side to the image side, a first lens unit having positive refractive power; a second lens unit having negative refractive power; a third lens unit having positive refractive power; a fourth lens unit having negative refractive power; a fifth lens unit having positive refractive power; a sixth lens unit having negative refractive power; a seventh lens unit having positive refractive power; as well as The eighth lens unit has negative refractive power, wherein the intervals between each pair of adjacent lens units are changed to perform zooming, and Wherein, the eighth lens unit includes a positive lens and a negative lens, Among them, the following inequality is satisfied: 1.2 <m8 / bfw<7.0, Here, bfw represents a back focus at the wide angle end, and m8 represents a movement amount of the eighth lens unit for zooming from the wide angle end to the telephoto end.

18. A zoom lens, comprising, from the object side to the image side, a first lens unit having positive refractive power; a second lens unit having negative refractive power; a third lens unit having positive refractive power; a fourth lens unit having negative refractive power; a fifth lens unit having positive refractive power; a sixth lens unit having negative refractive power; a seventh lens unit having positive refractive power; as well as The eighth lens unit has negative refractive power, wherein the intervals between each pair of adjacent lens units are changed to perform zooming, and Wherein, the eighth lens unit includes a positive lens and a negative lens, wherein the fourth lens unit and the sixth lens unit are moved for focusing, one of the fourth lens unit and the sixth lens unit having a higher focus sensitivity is defined as a focusing lens unit, and the other of the fourth lens unit and the sixth lens unit having a lower focus sensitivity is defined as a floating lens unit, and Among them, the following inequality is satisfied: 5<|Es1|<12, Wherein, Es1 represents the focusing sensitivity of the focusing lens unit at the telephoto end when the zoom lens is focused at infinity.

19. A zoom lens, comprising, from the object side to the image side, a first lens unit having positive refractive power; a second lens unit having negative refractive power; a third lens unit having positive refractive power; a fourth lens unit having negative refractive power; a fifth lens unit having positive refractive power; a sixth lens unit having negative refractive power; a seventh lens unit having positive refractive power; as well as The eighth lens unit has negative refractive power, wherein the intervals between each pair of adjacent lens units are changed to perform zooming, and Wherein, the eighth lens unit includes a positive lens and a negative lens, wherein the fourth lens unit and the sixth lens unit are moved for focusing, one of the fourth lens unit and the sixth lens unit having a higher focus sensitivity is defined as a focusing lens unit, and the other of the fourth lens unit and the sixth lens unit having a lower focus sensitivity is defined as a floating lens unit, and Among them, the following inequality is satisfied: 0.1<|Es2 / Es1|<0.8, Here, Es1 represents the focusing sensitivity of the focusing lens unit at the telephoto end when the zoom lens is focused at infinity, and Es2 represents the focusing sensitivity of the floating lens unit at the telephoto end when the zoom lens is focused at infinity.

20. A camera device, comprising: The zoom lens according to any one of claims 1 to 19; as well as An image pickup element receives an image formed by the zoom lens.

21. A lens device comprising: The zoom lens according to any one of claims 1 to 19; a first moving mechanism that moves the third lens unit, the fourth lens unit, and the fifth lens unit along the same trajectory in the optical axis direction; as well as A second moving mechanism moves the fourth lens unit in the optical axis direction along a trajectory different from those of the third lens unit and the fifth lens unit.

22. The lens apparatus according to claim 21, comprising a third moving mechanism that moves the sixth lens unit in the direction of the optical axis, in, The first moving mechanism moves the sixth lens unit along the same locus as those of the third lens unit, the fourth lens unit, and the fifth lens unit, and The third moving mechanism moves the sixth lens unit along a trajectory different from those of the third lens unit, the fourth lens unit, and the fifth lens unit.

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