Zoom lens and imaging apparatus

Abstract

To provide a zoom lens which is compactly configured, has a high variable power, and holds excellent optical performance and an imaging apparatus including the zoom lens.SOLUTION: The zoom lens comprises, in order from an object side to an image side, a front group, an intermediate group, and a rear group. The front group comprises two or less lens groups having positive refractive power. The lens group closest to the object side in the front group is fixed with respect to an image surface when varying power. The intermediate group comprises two or less lens groups having negative refractive power. The rear group comprises a plurality of lens groups. The lens group closest to the object side in the rear group has positive refractive power and the lens group closest to the image side in the rear group is fixed with respect to the image surface when varying power. When varying power, all intervals between adjacent lens groups change. The zoom lens satisfies a predetermined conditional expression.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The technology of the present disclosure relates to a zoom lens and an imaging device. [Background technology]

[0002] 2. Description of the Related Art Conventionally, as a zoom lens having a long focal length on the telephoto side, for example, the zoom lens described in Patent Document 1 below is known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-064153 A Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for zoom lenses that are compact, have a high zoom ratio, and maintain good optical performance, and the level of these demands is increasing year by year.

[0005] The present disclosure provides a zoom lens that is compact, has a high zoom ratio, and maintains good optical performance, and an imaging device that includes this zoom lens. [Means for solving the problem]

[0006] A zoom lens according to one embodiment of the present disclosure comprises, in order from the object side to the image side, a front group, an intermediate group, and a rear group, the front group consisting of two or less lens groups having positive refractive power, the lens group of the front group closest to the object side being fixed with respect to the image plane during zooming, the intermediate group consisting of two or less lens groups having negative refractive power, the rear group consisting of a plurality of lens groups, the lens group of the rear group closest to the object side having positive refractive power, the lens group of the rear group closest to the image side being fixed with respect to the image plane during zooming, and all of the intervals between adjacent lens groups change during zooming, 0.4<(ft / fw) / Movmax (1) The conditional expression (1) expressed by the following formula is satisfied. Here, ft is the focal length of the entire system when focused on an object at infinity at the telephoto end. fw is the focal length of the entire system when focused on an object at infinity at the wide-angle end. Of the lens groups that move during magnification change, the amount of displacement of the lens group that has the greatest amount of displacement during magnification change from the wide-angle end to the telephoto end is Movmax. The unit of Movmax is mm (millimeters).

[0007] When the sum of the distance on the optical axis from the lens surface of the front group closest to the object to the lens surface of the rear group closest to the image when focused on an object at infinity and the back focus in the air equivalent distance of the entire system is denoted as TL, and the maximum image height is denoted as Y, the zoom lens of the above embodiment satisfies the following conditions: TL / 2Y<80 (2) It is preferable to satisfy conditional expression (2) expressed as follows:

[0008] The zoom lens of the above aspect is 0.8<(ft / fw) / Movmax (1-1) It is preferable that conditional formula (1-1) represented by the following formula (1-1) is satisfied.

[0009] When the sum of the distance on the optical axis from the lens surface of the front group closest to the object to the lens surface of the rear group closest to the image when focused on an object at infinity and the back focus in terms of the air-equivalent distance of the entire system is denoted as TL, the zoom lens of the above embodiment has the following characteristics: 2 <ft / TL (3) It is preferable to satisfy conditional expression (3) expressed as follows:

[0010] When the back focus of the entire system in terms of the air equivalent distance is Bf, the zoom lens of the above embodiment has the following: 10 <ft / Bf (4) It is preferable to satisfy conditional expression (4) expressed as follows:

[0011] When the maximum image height is Y, the zoom lens of the above embodiment has the following characteristics: 30 <ft / 2Y (5) It is preferable to satisfy conditional expression (5) expressed as follows:

[0012] If the focal length of the lens unit closest to the object side in the front group is fF1, the zoom lens of the above aspect has the following: 0.5 <ft / fF1 (6) It is preferable to satisfy conditional expression (6) expressed as follows:

[0013] If the focal length of the lens unit closest to the object in the intermediate group is fM1, the zoom lens of the above aspect has the following characteristics: 5<|ft / fM1| (7) It is preferable to satisfy conditional expression (7) expressed as follows:

[0014] It is preferable that the front lens group closest to the object side includes at least four lenses, and that the third lens group from the object side of the rear group includes an aspheric lens.

[0015] If the focal length of the lens unit closest to the object in the rear group is fR1, the zoom lens of the above embodiment has the following characteristics: 0 <ft / fR1<100 (8) It is preferable to satisfy conditional expression (8) expressed as follows:

[0016] If the focal length of the lens unit closest to the image side in the rear group is fRe, the zoom lens of the above aspect has the following characteristics: -100 <ft / fRe<200 (9) It is preferable that the zoom lens of the above aspect satisfies the conditional expression (9) expressed as follows: 0 <ft / fRe<200 (9-1) The optical fiber may be configured to satisfy conditional formula (9-1) expressed by: -100 <ft / fRe<0 (9-6) The optical fiber 1 may be configured to satisfy conditional expression (9-6) expressed as follows:

[0017] In a configuration in which a zoom lens includes a focusing group that moves during focusing, if the lateral magnification of the focusing group when focused on an object at infinity at the telephoto end is βfoc, and the composite lateral magnification of all lenses on the image side of the focusing group when focused on an object at infinity at the telephoto end is βfocR, then the zoom lens of the above aspect has the following characteristics: |(1-βfoc 2 )×βfocR 2 |<50 (10) It is preferable to satisfy conditional expression (10) expressed as follows:

[0018] It is preferable that the lens group closest to the object side in the front group includes at least one cemented lens.

[0019] It is preferable that the lens group closest to the object side in the front group includes at least one positive lens element having an Abbe number of 70 or more based on the d-line.

[0020] It is preferable that the lens group closest to the object side in the front group includes at least one negative lens having an Abbe number of 60 or less based on the d-line.

[0021] It is preferable that the lens group closest to the object side of the intermediate group includes at least one positive lens having an Abbe number of 40 or less based on the d-line.

[0022] It is preferable that the lens group closest to the object side of the intermediate group includes at least one positive lens and at least two negative lenses.

[0023] Another aspect of the present disclosure is an imaging device including the zoom lens of the above aspect.

[0024] In addition, in this specification, "consisting of" and "consisting of" are intended to mean that, in addition to the listed components, the following may be included: a lens that has substantially no refractive power, optical elements other than lenses such as an aperture, a filter, and a cover glass, and mechanical parts such as a lens flange, a lens barrel, an image sensor, and an image stabilization mechanism.

[0025] In this specification, "group having positive refractive power" and "group has positive refractive power" mean that the group as a whole has positive refractive power. Similarly, "group having negative refractive power" and "group has negative refractive power" mean that the group as a whole has negative refractive power. "Lens having positive refractive power" and "positive lens" are synonymous. "Lens having negative refractive power" and "negative lens" are synonymous. "group" in this specification is not limited to a configuration consisting of multiple lenses, and may be a configuration consisting of only one lens.

[0026] A compound aspherical lens (a lens in which a lens (e.g. a spherical lens) and an aspherical film formed on the lens are integrally constructed and function as a single aspherical lens as a whole) is not considered a cemented lens, but is treated as a single lens. The sign of the refractive power and the surface shape of lenses including aspheric surfaces are those in the paraxial region, unless otherwise specified.

[0027] In this specification, "whole system" means a zoom lens. "Back focus in air equivalent distance" means the air equivalent distance on the optical axis from the lens surface closest to the image side of the whole system to the image plane. "Single lens" means one lens that is not cemented. "Focal length" used in the conditional expressions is the paraxial focal length. "Distance on the optical axis" used in the conditional expressions is a geometric distance unless otherwise specified. Values ​​used in the conditional expressions are values ​​based on the d-line when focused on an object at infinity, unless otherwise specified. Effect of the Invention

[0028] According to the present disclosure, it is possible to provide a zoom lens that is compact, has a high zoom ratio, and maintains good optical performance, and an imaging device that includes this zoom lens. [Brief description of the drawings]

[0029] [Figure 1] 1A and 1B correspond to the zoom lens of Example 1 and are diagrams showing a cross-sectional view of the configuration of a zoom lens according to an embodiment and a movement locus thereof. [Diagram 2]FIG. 2 is a cross-sectional view showing the configuration and light beams in each zoom state of the zoom lens in FIG. 1, and is a diagram for explaining symbols in conditional expressions. [Diagram 3] 3A to 3C are diagrams showing various aberrations of the zoom lens of Example 1. [Figure 4] 11A and 11B are diagrams illustrating a cross-sectional view of the configuration of a zoom lens according to a second embodiment and a movement locus thereof. [Diagram 5] 6A to 6C are diagrams showing various aberrations of the zoom lens of Example 2. [Figure 6] 11A and 11B are diagrams illustrating a cross-sectional view of the configuration of a zoom lens according to a third embodiment and a movement locus thereof. [Figure 7] 11A and 11B are diagrams illustrating the configuration and light beams in each magnification change state of a zoom lens according to a third embodiment. [Figure 8] 11A and 11B are diagrams illustrating a cross-sectional view of the configuration of a zoom lens according to a fourth embodiment and a movement locus thereof. [Figure 9] 11A to 11C are diagrams showing various aberrations of the zoom lens of Example 4. [Figure 10] 13A and 13B are diagrams illustrating a cross-sectional view of the configuration of a zoom lens according to a fifth embodiment and a movement locus thereof. [Figure 11] 13A to 13C are diagrams showing various aberrations of the zoom lens of Example 5. [Figure 12] 13A and 13B are diagrams illustrating a cross-sectional view of the configuration of a zoom lens according to a sixth embodiment and a movement locus thereof. [Figure 13] 13A to 13C are diagrams showing various aberrations of the zoom lens of Example 6. [Figure 14] 13A and 13B are diagrams illustrating a cross-sectional view and a movement locus of a zoom lens according to a seventh embodiment. [Figure 15] 13A to 13C are diagrams showing various aberrations of the zoom lens of Example 7. [Figure 16] 13A and 13B are diagrams illustrating a cross-sectional view of the configuration of a zoom lens according to an eighth embodiment and a movement locus thereof. [Figure 17] 13A to 13C are diagrams showing various aberrations of the zoom lens of Example 8. [Figure 18] 1 is a schematic configuration diagram of an imaging device according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0031] FIG. 1 shows a cross-sectional view of a zoom lens according to an embodiment of the present disclosure. In FIG. 1, arrows indicating the schematic movement trajectory of each group during magnification change from the wide-angle end to the telephoto end are also drawn under each group that moves during magnification change. FIG. 2 shows a diagram illustrating the cross-sectional view of the zoom lens in FIG. 1 together with light beams. In FIG. 2, the wide-angle end state is shown in the upper row labeled "Wide," and the telephoto end state is shown in the lower row labeled "Tele." In FIG. 2, the axial light beam and the maximum half angle of view light beam are shown as light beams in each state. The examples shown in FIG. 1 and FIG. 2 correspond to the zoom lens of Example 1 described later. In FIG. 1 and FIG. 2, a state in which an object at infinity is focused is shown, with the left side being the object side and the right side being the image side. The following description will be mainly made with reference to FIG. 1, and FIG. 2 will be referred to as necessary.

[0032] In Fig. 1, assuming that the zoom lens is applied to an imaging device, an example is shown in which a parallel plate-like optical member PP is disposed between the zoom lens and an image surface Sim. The optical member PP is a member assuming various filters and / or cover glass, etc. The various filters are low-pass filters, infrared cut filters, and / or filters that cut off specific wavelength ranges, etc. The optical member PP is a member that does not have refractive power. It is also possible to configure an imaging device without the optical member PP.

[0033] The zoom lens of the present disclosure comprises, in order from the object side to the image side along the optical axis Z, a front group GF, a middle group GM, and a rear group GR. The front group GF comprises two or less lens groups having positive refractive power. The middle group GM comprises two or less lens groups having negative refractive power. The rear group GR comprises a plurality of lens groups. When varying magnification, all of the intervals between adjacent lens groups change.

[0034] By configuring the front group GF with one or two lens groups having positive refractive power, it becomes easy to increase the focal length at the telephoto end. By configuring the middle group GM with one or two lens groups having negative refractive power, it becomes easy to shorten the focal length at the wide-angle end. The above configuration of the front group GF and the middle group GM makes it easy to realize a zoom lens with a high zoom ratio.

[0035] In this specification, a group whose distance in the optical axis direction between adjacent groups changes when the magnification is changed is defined as one lens group. When the magnification is changed, the distance between adjacent lenses in one lens group does not change. In other words, a "lens group" is a component of a zoom lens, and is a part including at least one lens separated by an air gap that changes when the magnification is changed. When the magnification is changed, each lens group is moved or fixed. In addition, the "lens group" may include a component other than a lens that does not have a refractive power, such as an aperture stop St.

[0036] In the zoom lens of the present disclosure, the lens group closest to the object in the front group GF is fixed relative to the image plane Sim during zooming. By making the lens group closest to the object immobile during zooming, the overall length of the lens system does not change during zooming, making it easy to configure an apparatus in which the zoom lens is housed in a housing. In addition, when installed outdoors, even if the zoom lens is housed in a waterproof case, it becomes easy to take pictures without vignetting from the telephoto end to the wide-angle end.

[0037] In addition, in the zoom lens of the present disclosure, the lens group closest to the image side of the rear group GR is fixed with respect to the image surface Sim during magnification change. By configuring in this way, the lens group can be manufactured without significantly changing the way the light rays pass through the rear group GR, making it easy to achieve stable performance from the wide-angle end to the telephoto end. Also, by configuring the lens group closest to the image side of the rear group GR to be immobile during magnification change, it becomes easy to prevent dust and the like from entering the inside of the zoom lens.

[0038] As an example, each group of the zoom lens shown in FIG. 1 is configured as follows. The front group GF is made up of one lens group having positive refractive power. The middle group GM is made up of one lens group having negative refractive power. The rear group GR is made up of three lens groups, in order from the object side to the image side, namely, a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having negative refractive power, and a third rear lens group GR3 having positive refractive power. During magnification change, the front group GF and the third rear lens group GR3 are fixed with respect to the image surface Sim, and the middle group GM, the first rear lens group GR1, and the second rear lens group GR2 move along the optical axis Z while changing the intervals between the adjacent lens groups. With the above configuration, it is possible to obtain a high-performance zoom lens that is compact and has various aberrations corrected throughout the zoom range while having a sufficiently long focal length at the telephoto end.

[0039] As an example, the elements constituting each lens group in FIG. 1 are as follows. The lens group constituting the front group GF is composed of five lenses, L11 to L15, in order from the object side to the image side. The lens group constituting the middle group GM is composed of three lenses, L21 to L23, in order from the object side to the image side. The first subsequent lens group GR1 is composed of two lenses, L31 to L32, in order from the object side to the image side. The second subsequent lens group GR2 is composed of three lenses, L41 to L43, in order from the object side to the image side. The third subsequent lens group GR3 is composed of an aperture stop St and 12 lenses, L51 to L62, in order from the object side to the image side. The aperture stop St shown in FIG. 1 does not indicate the size or shape, but indicates the position in the optical axis direction.

[0040] The zoom lens in FIG. 1 includes a focusing group that moves during focusing. Hereinafter, the group that moves along the optical axis Z during focusing will be referred to as the focusing group. Focusing is achieved by the movement of the focusing group. As an example, in the example in FIG. 1, the focusing group is made up of three lenses, lenses L57 to L59, of the third subsequent lens group GR3. In FIG. 1, a double-headed arrow pointing left and right is written in parentheses under the lens corresponding to the focusing group.

[0041] The zoom lens in FIG. 1 also includes an anti-vibration group that moves during image blur correction. Hereinafter, the group that moves in a direction intersecting the optical axis Z during image blur correction is referred to as the anti-vibration group. Image blur correction is performed by the movement of the anti-vibration group. As an example, in the example of FIG. 1, the anti-vibration group is made up of four lenses, lenses L52 to L55 of the third subsequent lens group GR3. In FIG. 1, a double-headed arrow pointing up and down is written in parentheses under the lens corresponding to the anti-vibration group.

[0042] It is preferable that the lens group closest to the object side in the front group GF has positive refractive power, which makes it easy to construct a compact telephoto optical system.

[0043] It is preferable that the lens group closest to the object side of the front group GF includes at least two lenses. By using two or more lenses in the lens group closest to the object side of the front group GF, it becomes easier to correct chromatic aberration, which is advantageous for achieving high resolution. It is more preferable that the lens group closest to the object side of the front group GF includes at least four lenses. By using four or more lenses in the lens group closest to the object side of the front group GF, it becomes easier to correct chromatic aberration, which is advantageous for achieving high resolution.

[0044] It is preferable that the lens group closest to the object side in the front group GF includes at least two positive lenses. In this case, it is easy to increase the positive refractive power of the lens group closest to the object side in the front group GF, which is advantageous for size reduction.

[0045] It is preferable that the lens group closest to the object side in the front group GF includes at least one positive lens whose Abbe number based on the d-line is equal to or greater than 70. In this case, chromatic aberration can be easily corrected, which is advantageous for achieving high resolution.

[0046] It is preferable that the lens group closest to the object side in the front group GF includes at least one negative lens, which is advantageous for achieving high resolution since it makes it easier to correct chromatic aberration.

[0047] It is preferable that the lens group closest to the object in the front group GF includes at least one negative lens having an Abbe number based on the d-line of 60 or less. In this case, chromatic aberration can be easily corrected, which is advantageous for achieving high resolution. It is more preferable that the lens group closest to the object in the front group GF includes at least one negative lens having an Abbe number based on the d-line of 40 or less. In this case, chromatic aberration can be easily corrected, which is advantageous for achieving high resolution.

[0048] It is preferable that the lens group closest to the object side in the front group GF includes at least two positive lenses and at least two negative lenses, which is advantageous for achieving high resolution since it makes it easier to correct chromatic aberration.

[0049] It is preferable that the lens group closest to the object side in the front group GF includes at least one cemented lens, which is advantageous for achieving high resolution since it makes it easier to correct chromatic aberration.

[0050] The lens group closest to the object in the front group GF may be configured to include two cemented lenses, which is advantageous for correcting axial chromatic aberration.

[0051] It is preferable that the lens group closest to the object side in the front group GF includes a single lens having positive refractive power closest to the object side, which is advantageous for achieving a long focal length and compact size.

[0052] It is preferable that the lens group closest to the object in the front group GF includes an aspherical lens, which is advantageous for correcting various aberrations and thus for achieving high resolution.

[0053] If the lens group closest to the object in the front group GF includes an aspherical lens, it is preferable that the Abbe number of that aspherical lens based on the d-line be equal to or greater than 40. In this case, chromatic aberration can be easily corrected, which is advantageous for achieving high resolution.

[0054] It is preferable that the second lens group from the object side of the front group GF move during zooming, which is advantageous for achieving a zoom lens with a high zoom ratio.

[0055] It is preferable that the second lens group from the object side of the front group GF has positive refractive power, which is advantageous for shortening the overall length of the lens system because it can converge the light beam.

[0056] The second lens group from the object side of the front group GF may be configured to consist of a single lens. This is advantageous for achieving weight reduction and rapid zooming. If the second lens group from the object side of the front group GF consists of a single lens, that lens may be configured to be a positive lens. This is advantageous for suppressing aberration fluctuations during zooming and for forming a compact zoom lens.

[0057] The lens surface closest to the image side of the lens unit closest to the object side in the front group GF may be a concave surface, and the lens surface closest to the object side of the lens unit closest to the object side in the middle group GM may be a convex surface, which makes it easier to effectively correct astigmatism and distortion on the telephoto side.

[0058] It is preferable that the lens unit closest to the object side of the middle group GM has negative refractive power and moves during zooming, which makes it easy to realize a zoom lens with a high zoom ratio.

[0059] It is preferable that the lens group closest to the object side of the middle group GM includes at least three lenses. In this case, it is advantageous for achieving high resolution because it is easy to correct chromatic aberration. In addition, it is easy to effectively correct various aberrations because the refractive power can be shared among the lenses.

[0060] The lens group closest to the object side of the middle group GM preferably includes at least one positive lens and at least two negative lenses. By including a combination of positive and negative lenses, it becomes easier to effectively correct various monochromatic and chromatic aberrations.

[0061] It is preferable that the lens unit closest to the object side of the middle group GM includes a plurality of negative lenses. In this case, the refractive power of each negative lens can be weakened compared to when the lens unit closest to the object side of the middle group GM does not include a plurality of negative lenses, making it easier to reduce error sensitivity to decentering and therefore easier to improve manufacturability.

[0062] It is preferable that the lens group closest to the object side of the middle group GM includes a plurality of negative lenses, at least one of which is cemented with a positive lens to form a cemented lens. By including a combination of positive and negative lenses, it becomes easy to effectively correct various monochromatic aberrations and chromatic aberrations.

[0063] It is preferable that the lens group closest to the object side of the intermediate group GM includes at least one positive lens having an Abbe number based on the d-line of 40 or less. In this case, chromatic aberration can be easily corrected, which is advantageous for achieving high resolution. More preferably, the lens group closest to the object side of the intermediate group GM includes at least one positive lens having an Abbe number based on the d-line of 25 or less. In this case, chromatic aberration can be easily corrected, which is advantageous for achieving high resolution.

[0064] It is preferable that the lens unit closest to the object side of the intermediate group GM includes at least one cemented lens, which is advantageous for achieving high resolution since it makes it easier to correct various monochromatic and chromatic aberrations.

[0065] It is preferable that the lens unit closest to the object side of the middle group GM includes an aspheric lens, which is advantageous for correcting various aberrations and thus for achieving high resolution.

[0066] If the lens unit closest to the object side of the intermediate group GM includes an aspherical lens, it is preferable that the Abbe number of that aspherical lens based on the d-line is equal to or less than 40. In this case, chromatic aberration can be easily corrected, which is advantageous for achieving high resolution.

[0067] The lens closest to the object side of the lens unit closest to the object side of the intermediate group GM may be a positive lens, which is advantageous in preventing the diameter of the intermediate group GM from becoming large.

[0068] It is preferable that the Abbe number based on the d-line of the lens in the lens unit closest to the object side in the intermediate group GM be equal to or less than 25. This is advantageous for correction of chromatic aberration.

[0069] The lens closest to the image side of the lens unit closest to the object side in the middle group GM may be an aspheric lens, which is advantageous for correcting various aberrations and thus for achieving high resolution.

[0070] It is preferable that the aspherical lens in the lens unit closest to the object side of the middle group GM is a negative lens, which makes it easier to correct spherical aberration and curvature of field.

[0071] It is preferable that the object-side surface of the lens closest to the image side of the lens unit closest to the object side in the intermediate group GM is a concave surface, which makes it easier to correct spherical aberration and curvature of field.

[0072] The second lens group from the object side of the rear group GR may be configured so that all or part of it is an image stabilization group. Since the second lens group from the object side of the middle group GM among the lens groups included in a zoom lens is relatively small, by providing this group with an image stabilization function, it becomes easy to make the image stabilization mechanism compact.

[0073] The lens unit closest to the object side in the rear group GR is designed to have positive refractive power, which makes it easy to reduce the lens diameter of the rear group GR.

[0074] The lens group closest to the object in the rear group GR may be configured to move when the magnification is changed. In this case, the fluctuation of spherical aberration during the magnification change can be suppressed, which is advantageous for improving performance. If the lens group closest to the object in the rear group GR has a positive refractive power and is configured to move during the magnification change, it becomes easier to make the lens system compact, and it is also advantageous for correcting image position shift during the magnification change.

[0075] The lens group closest to the object in the rear group GR may be configured to be fixed relative to the image plane Sim during zooming. In this case, the number of groups that move during zooming can be reduced compared to a configuration in which that lens group moves, making it easier to improve robustness.

[0076] It is preferable that the lens unit closest to the object side of the rear group GR includes a plurality of positive lenses. In this case, the refractive power of each positive lens can be weakened compared to when the lens unit closest to the object side of the rear group GR does not include a plurality of positive lenses, making it easier to reduce error sensitivity to decentering and therefore easier to improve manufacturability.

[0077] The lens group closest to the object side in the rear group GR preferably includes at least three positive lenses and at least one negative lens. By including a combination of positive and negative lenses, it becomes easier to effectively correct various monochromatic and chromatic aberrations.

[0078] It is preferable that the lens unit closest to the object side in the rear group GR includes at least one cemented lens, which is advantageous for correcting chromatic aberration.

[0079] It is preferable that the lens group closest to the object side in the rear group GR includes at least one negative lens having an Abbe number based on the d-line of not more than 35. This is advantageous for correcting chromatic aberration.

[0080] It is preferable that the lens unit closest to the object side of the rear group GR includes an aspheric lens, which is advantageous for correcting various aberrations and thus for achieving high resolution.

[0081] It is preferable that the aspherical lens in the lens unit closest to the object side in the rear group GR is a positive lens, which makes it easier to effectively correct spherical aberration.

[0082] The lens closest to the image side of the lens unit closest to the object side in the rear group GR may be a positive lens, which is advantageous for size reduction since it makes it easier to prevent the diameter of the lens unit closer to the image side than this positive lens from becoming large.

[0083] The lens closest to the image side of the lens unit closest to the object side in the rear group GR may be configured to have an Abbe number based on the d-line of 80 or more. This is advantageous for correcting chromatic aberration.

[0084] The image-side surface of the lens closest to the image side of the lens unit closest to the object side in the rear group GR may be configured to be convex, which is advantageous for size reduction since it makes it easier to prevent the diameter of the lens unit closest to the image side from becoming large.

[0085] The second lens group from the object side of the rear group GR may be configured to have negative refractive power and move when the magnification is changed. By making the second lens group from the object side of the rear group GR a group having negative refractive power, the light beam emitted from this group can be made into divergent light, which makes it easier to correct spherical aberration in the group on the image side of this group. In addition, by configuring the second lens group from the object side of the rear group GR to move when the magnification is changed, it is advantageous for correcting image position shift when the magnification is changed.

[0086] It is preferable that the second lens group from the object side in the rear group GR moves from the object side to the image side when changing magnification from the wide-angle end to the telephoto end. In this case, the direction of movement of the second lens group from the object side in the rear group GR when changing magnification can be the same as that of the middle group GM, making it easier to ensure the necessary amount of movement, and as a result, making it easier to shorten the overall length of the lens system.

[0087] It is preferable that the second lens group from the object side of the rear group GR includes an aspheric lens, which is advantageous for correcting various aberrations and thus for achieving high resolution.

[0088] It is preferable that the aspherical lens in the second lens group from the object side of the rear group GR be a negative lens. Since negative lenses have the effect of diverging light flux, if the focusing group is formed including this negative lens or a lens on the image side of this negative lens, it becomes easy to ensure the amount of movement required for focusing.

[0089] It is preferable that the third lens group from the object side of the rear group GR includes an aspheric lens, which is advantageous for correcting various aberrations and thus for achieving high resolution.

[0090] The lens unit closest to the image side in the rear group GR may be configured to have positive refractive power, which is advantageous for size reduction since the lens unit closest to the image side in the rear group GR can have a light-collecting effect.

[0091] The lens group closest to the image side of the rear group GR may be configured to have negative refractive power, which is advantageous in terms of ensuring the back focus and in terms of suppressing aberration fluctuations during zooming, since the refractive power of the lens group that moves during zooming can be weakened.

[0092] A part of the lens group closest to the image side of the rear group GR may be configured as the focusing group, which makes it possible to reduce the weight of the focusing group, facilitating high-speed focusing.

[0093] The focusing group may be configured to be included in a lens group that is fixed relative to the image plane Sim during zooming in the rear group GR. In this case, the structure is simpler than when the focusing group is included in a lens group that moves during zooming, which is advantageous for improving the accuracy of position control.

[0094] Alternatively, the focusing group may be configured to be included in a lens group that moves during zooming in the rear group GR. In this case, the number of groups that move can be reduced compared to when the focusing group is included in a lens group that is fixed relative to the image plane Sim during zooming, and the mechanical structure can be simplified, which is advantageous for making the device more compact.

[0095] The lens group in the rear group GR that is fixed relative to the image plane Sim during magnification may be configured to have negative refractive power, which is advantageous in terms of ensuring the back focus.

[0096] The lens group fixed relative to the image surface Sim during magnification in the rear group GR may be configured to include, in order from the object side to the image side, a first subgroup fixed relative to the image surface Sim during focusing, a second subgroup moving along the optical axis Z during focusing, and a third subgroup fixed relative to the image surface Sim during focusing. The second subgroup is a focusing group. In the above configuration, if the first subgroup has negative refractive power, the second subgroup has positive refractive power, and the third subgroup has negative refractive power, it is advantageous to suppress aberration fluctuations during focusing while ensuring the back focus. Alternatively, if the first subgroup has positive refractive power, the second subgroup has negative refractive power, and the third subgroup has positive refractive power, it is advantageous to suppress aberration fluctuations during focusing while configuring the lens compactly.

[0097] When the lens group in the rear group GR that is fixed relative to the image plane Sim during magnification variation includes a focusing group having negative refractive power, it is preferable that the average value of the refractive index for the d-line of all the lenses included in this focusing group is 1.8 or more, which is advantageous for suppressing aberration fluctuations during focusing.

[0098] The focusing group may be the lens group closest to the object in the rear group GR, the lens group second from the object side in the rear group GR, or the lens group closest to the image in the rear group GR, or it may be only a part of any of these lens groups. In this case, it is possible to reduce the size and weight compared to when the focusing group is located in the front group GF, which is advantageous for high-speed focusing.

[0099] A part of the lens group closest to the image side in the rear group GR may be configured as an anti-vibration group. Since the lens group closest to the image side in the rear group GR among the lens groups included in the zoom lens is small, by providing this group with an anti-vibration function, it becomes easy to miniaturize the anti-vibration mechanism.

[0100] It is preferable that the aperture stop St is disposed within the rear group GR. In this case, the aperture stop St is disposed at a position relatively closer to the image side within the zoom lens, making it easy to separate the on-axis light beam from the peripheral off-axis light beam on the object side of the aperture stop St. This makes it easy to suppress astigmatism at the wide-angle end.

[0101] It is preferable that two positive lenses are successively arranged on the image side of the aperture stop St. In this case, it becomes easier to correct spherical aberration well. It is more preferable that three positive lenses are successively arranged on the image side of the aperture stop St. In this case, it becomes easier to correct spherical aberration well.

[0102] Next, preferred and possible configurations for the conditional expressions of the zoom lens of the present disclosure will be described. In the following description of the conditional expressions, in order to avoid redundant explanations, the same symbols are used for elements with the same definitions, and some of the duplicated explanations of the symbols are omitted. In addition, in the following, in order to avoid redundant explanations, the "zoom lens of the present disclosure" will also be simply referred to as the "zoom lens."

[0103] It is preferable that the zoom lens satisfies the following conditional formula (1). Here, the focal length of the entire system when focused on an object at infinity at the telephoto end is ft. The focal length of the entire system when focused on an object at infinity at the wide-angle end is fw. Among the lens groups that move during magnification, the displacement amount of the lens group that has the largest displacement amount during magnification change from the wide-angle end to the telephoto end is Movmax. In other words, if the lens group that moves during magnification and has the largest displacement amount during magnification change from the wide-angle end to the telephoto end is called the maximum displacement lens group, Movmax is the distance on the optical axis between the position of the maximum displacement lens group at the wide-angle end and the position of the maximum displacement lens group at the telephoto end. In the example of FIG. 1, the maximum displacement lens group is the second subsequent lens group GR2. As an example, FIG. 2 shows the above displacement amount Movmax. The unit of Movmax is mm (millimeter). By making sure that the corresponding value of conditional expression (1) is not equal to or smaller than the lower limit, it becomes easy to realize a compact structure while still achieving a high zoom ratio. 0.4<(ft / fw) / Movmax (1)

[0104] To obtain better characteristics, it is more preferable that the zoom lens satisfies the following conditional formula (1-1). It is also preferable that the zoom lens satisfies the following conditional formula (1-2). By ensuring that the corresponding value of conditional formula (1-2) is not equal to or greater than the upper limit, Movmax does not become too small, making it easier to perform precise zoom control. To obtain better characteristics, it is more preferable that the zoom lens satisfies the following conditional formula (1-3), it is even more preferable that the zoom lens satisfies the following conditional formula (1-4), and it is even more preferable that the zoom lens satisfies the following conditional formula (1-5). 0.8<(ft / fw) / Movmax (1-1) 0.55<(ft / fw) / Movmax<10 (1-2) 0.7<(ft / fw) / Movmax<5 (1-3) 0.8<(ft / fw) / Movmax<4 (1-4) 1<(ft / fw) / Movmax<3 (1-5)

[0105] It is preferable that the zoom lens satisfies the following conditional expression (2). Here, TL is the sum of the distance on the optical axis from the lens surface of the front group GF closest to the object to the lens surface of the rear group GR closest to the image when focused on an object at infinity, and the back focus in terms of the air-equivalent distance of the entire system. Y is the maximum image height. As an example, the maximum image height Y is shown in Figure 2. Note that TL is the total length of the lens system. By ensuring that the corresponding value of conditional expression (2) is not greater than the upper limit, compactness is facilitated, and high resolution is also facilitated because the maximum image height Y does not become too small. TL / 2Y<80 (2)

[0106] To obtain better characteristics, it is more preferable that the zoom lens satisfies the following conditional formula (2-1). By ensuring that the corresponding value of conditional formula (2-1) is not below the lower limit, TL does not become too small, making it easy to increase the zoom ratio. To obtain better characteristics, it is more preferable that the zoom lens satisfies the following conditional formula (2-2), more preferably the following conditional formula (2-3), and even more preferably the following conditional formula (2-4). 30 <TL / 2Y<78 (2-1) 40 <TL / 2Y<75 (2-2) 45 <TL / 2Y<70 (2-3) 55 <TL / 2Y<68 (2-4)

[0107] It is preferable that the zoom lens satisfies the following conditional expression (3): By making sure that the corresponding value of conditional expression (3) is not equal to or smaller than the lower limit, it is possible to prevent TL from becoming too long, which makes it easier to achieve a compact size. 2 <ft / TL (3)

[0108] To obtain better characteristics, it is more preferable that the zoom lens satisfies the following conditional formula (3-1). By ensuring that the corresponding value of conditional formula (3-1) is not equal to or greater than the upper limit, TL does not become too small, making it easy to suppress high sensitivity to manufacturing errors. To obtain better characteristics, it is more preferable that the zoom lens satisfies the following conditional formula (3-2), more preferably satisfies the following conditional formula (3-3), and even more preferably satisfies the following conditional formula (3-4). 2.2 <ft / TL<5 (3-1) 2.4 <ft / TL<4.5 (3-2) 2.5 <ft / TL<4 (3-3) 2.8 <ft / TL<3.5 (3-4)

[0109] It is preferable that the zoom lens satisfies the following conditional expression (4). Here, the back focus in the air-equivalent distance of the entire system is Bf. By ensuring that the corresponding value of conditional expression (4) is not below the lower limit, it is advantageous for miniaturization and telephotography. 10 <ft / Bf (4)

[0110] To obtain better characteristics, it is more preferable that the zoom lens satisfies the following conditional formula (4-1). By making sure that the corresponding value of conditional formula (4-1) is not equal to or greater than the upper limit, the back focus does not become too small, making it easier to arrange an image sensor for capturing an image formed by the zoom lens. To obtain better characteristics, it is more preferable that the zoom lens satisfies the following conditional formula (4-2), and even more preferable that the zoom lens satisfies the following conditional formula (4-3). 30 <ft / Bf<300 (4-1) 40 <ft / Bf<200 (4-2) 50 <ft / Bf<150 (4-3)

[0111] It is preferable that the zoom lens satisfies the following conditional expression (5): By ensuring that the corresponding value of conditional expression (5) is not equal to or smaller than the lower limit, the maximum image height Y does not become too large, which is advantageous for miniaturization and telephotography. 30 <ft / 2Y (5)

[0112] To obtain better characteristics, it is more preferable that the zoom lens satisfies the following conditional formula (5-1). By ensuring that the corresponding value of conditional formula (5-1) is not equal to or greater than the upper limit, it becomes easier to increase the size of the image sensor that captures the image formed by the zoom lens, which is advantageous for achieving higher resolution. To obtain better characteristics, it is more preferable that the zoom lens satisfies the following conditional formula (5-2), and even more preferable that the zoom lens satisfies the following conditional formula (5-3). 50 <ft / 2Y<300 (5-1) 70 <ft / 2Y<200 (5-2) 80 <ft / 2Y<150 (5-3)

[0113] It is preferable for the zoom lens to satisfy the following conditional expression (6). Here, the focal length of the lens group closest to the object in the front group GF is set to fF1. By ensuring that the corresponding value of conditional expression (6) is not below the lower limit, it becomes easy to strengthen the refractive power of the lens group closest to the object in the front group GF, which is advantageous for size reduction and telephotography. 0.5 <ft / fF1 (6)

[0114] To obtain better characteristics, it is more preferable that the zoom lens satisfies the following conditional expression (6-1). By making sure that the corresponding value of conditional expression (6-1) is not equal to or greater than the upper limit, the refractive power of the lens group closest to the object in the front group GF does not become too strong, making it easy to suppress high sensitivity to manufacturing errors. To obtain better characteristics, it is more preferable that the zoom lens satisfies the following conditional expression (6-2), and even more preferable that the zoom lens satisfies the following conditional expression (6-3). 1 <ft / fF1<16 (6-1) 2 <ft / fF1<13 (6-2) 3.5 <ft / fF1<10 (6-3)

[0115] It is preferable for the zoom lens to satisfy the following conditional expression (7). Here, the focal length of the lens group closest to the object in the middle group GM is set to fM1. By ensuring that the corresponding value of conditional expression (7) is not below the lower limit, it becomes easy to strengthen the refractive power of the lens group closest to the object in the middle group GM, which is advantageous for size reduction and telephotography. 5<|ft / fM1| (7)

[0116] In order to obtain better characteristics, it is more preferable that the zoom lens satisfies the following conditional expression (7-1). By making sure that the corresponding value of conditional expression (7-1) is not equal to or greater than the upper limit, the refractive power of the lens group closest to the object side of the middle group GM does not become too strong, making it easy to suppress high sensitivity to manufacturing errors. In order to obtain better characteristics, it is more preferable that the zoom lens satisfies the following conditional expression (7-2), more preferably satisfies the following conditional expression (7-3), and even more preferably satisfies the following conditional expression (7-4). 10<|ft / fM1|<90 (7-1) 20<|ft / fM1|<75 (7-2) 30<|ft / fM1|<60 (7-3) 33<|ft / fM1|<55 (7-4)

[0117] It is preferable that the zoom lens satisfies the following conditional expression (8). Here, the focal length of the lens group closest to the object in the rear group GR is fR1. In the zoom lens of the present disclosure, the lens group closest to the object in the rear group GR has positive refractive power, so the lower limit of conditional expression (8) is "0<". By ensuring that the corresponding value of conditional expression (8) is not equal to or greater than the upper limit, the refractive power of the lens group closest to the object in the rear group GR does not become too strong, making it easy to suppress high sensitivity to manufacturing errors. This makes it easier to maintain good manufacturability, which is advantageous for realizing the zoom lens of the present disclosure. 0 <ft / fR1<100 (8)

[0118] In order to obtain better characteristics, it is more preferable that the zoom lens satisfies the following conditional formula (8-1). By ensuring that the corresponding value of conditional formula (8-1) is not below the lower limit, it becomes easy to strengthen the refractive power of the lens group in the rear group GR that is closest to the object, which is advantageous for size reduction. In order to obtain better characteristics, it is more preferable that the zoom lens satisfies the following conditional formula (8-2), more preferably the following conditional formula (8-3), and even more preferably the following conditional formula (8-4). 1 <ft / fR1<70 (8-1) 3 <ft / fR1<50 (8-2) 5 <ft / fR1<45 (8-3) 7 <ft / fR1<40 (8-4)

[0119] It is preferable that the zoom lens satisfies the following conditional expression (9). Here, the focal length of the lens group closest to the image side in the rear group GR is fRe. By making the corresponding value of conditional expression (9) not equal to or less than the lower limit, the negative refractive power of the lens group closest to the image side in the rear group GR does not become too strong, making it easy to suppress high sensitivity to manufacturing errors. By making the corresponding value of conditional expression (9) not equal to or more than the upper limit, the positive refractive power of the lens group closest to the image side in the rear group GR does not become too strong, making it easy to suppress high sensitivity to manufacturing errors. By satisfying conditional expression (9), it becomes easy to maintain good manufacturability, which is advantageous for realizing the zoom lens of the present disclosure. -100 <ft / fRe<200 (9)

[0120] According to the above conditional formula (9), when the lens unit closest to the image side of the rear group GR has positive refractive power, it is preferable that the zoom lens satisfies the following conditional formula (9-1). In order to obtain better characteristics, it is more preferable that the zoom lens satisfies the following conditional formula (9-2). By ensuring that the corresponding value of conditional formula (9-2) is not equal to or smaller than the lower limit, it becomes easy to strengthen the refractive power of the lens unit closest to the image side of the rear group GR, which is advantageous for miniaturization. In order to obtain better characteristics, it is more preferable that the zoom lens satisfies the following conditional formula (9-3), more preferably satisfies the following conditional formula (9-4), and even more preferably satisfies the following conditional formula (9-5). 0 <ft / fRe<200 (9-1) 10 <ft / fRe<100 (9-2) 20 <ft / fRe<80 (9-3) twenty five <ft / fRe<60 (9-4) 30 <ft / fRe<50 (9-5)

[0121] According to the above conditional formula (9), when the lens unit closest to the image side of the rear group GR has negative refractive power, it is preferable that the zoom lens satisfies the following conditional formula (9-6). In order to obtain better characteristics, it is more preferable that the zoom lens satisfies the following conditional formula (9-7). By ensuring that the corresponding value of conditional formula (9-7) is not equal to or greater than the upper limit, it becomes easy to strengthen the refractive power of the lens unit closest to the image side of the rear group GR, which is advantageous for ensuring the back focus. In order to obtain better characteristics, it is more preferable that the zoom lens satisfies the following conditional formula (9-8), more preferably the following conditional formula (9-9), and even more preferably the following conditional formula (9-10). -100 <ft / fRe<0 (9-6) -50 <ft / fRe<-0.5 (9-7) -30 <ft / fRe<-1 (9-8) -20 <ft / fRe<-1.5 (9-9) -10 <ft / fRe<-2 (9-10)

[0122] In a zoom lens configuration including a focusing group, it is preferable that the zoom lens satisfy the following conditional expression (10). Here, the lateral magnification of the focusing group when focused on an object at infinity at the telephoto end is βfoc. The combined lateral magnification of all lenses on the image side of the focusing group when focused on an object at infinity at the telephoto end is βfocR. If there is no lens on the image side of the focusing group, βfocR=1. By ensuring that the corresponding value of conditional expression (10) is not greater than the upper limit, the amount of movement of the image per unit movement of the focusing group can be reduced, making precise focusing easier. |(1-βfoc 2 )×βfocR 2 |<50 (10)

[0123] In order to obtain better characteristics, it is more preferable for the zoom lens to satisfy the following conditional formula (10-1), even more preferable for it to satisfy the following conditional formula (10-2), even more preferable for it to satisfy the following conditional formula (10-3), and even more preferable for it to satisfy the following conditional formula (10-4). 0<|(1-βfoc 2 )×βfocR 2 |<20 (10-1) 0<|(1-βfoc 2 )×βfocR 2 |<10 (10-2) 0<|(1-βfoc 2 )×βfocR 2 |<8 (10-3) 0<|(1-βfoc 2 )×βfocR 2 |<6 (10-4)

[0124] It is preferable that the zoom lens satisfies the following conditional expression (11). Here, the lens group closest to the object in the intermediate group GM is referred to as the first intermediate lens group. The lateral magnification of the first intermediate lens group when focused on an object at infinity at the telephoto end is βM1. The combined lateral magnification of all lenses on the image side of the first intermediate lens group when focused on an object at infinity at the telephoto end is βM1R. Making sure that the corresponding value of conditional expression (11) is not equal to or less than the lower limit is advantageous for size reduction. Making sure that the corresponding value of conditional expression (11) is not equal to or more than the upper limit is advantageous for preventing the movement amount of the image per unit movement amount of the first intermediate lens group from becoming too large, making it easy to prevent the difficulty of manufacturing from becoming too high. 10<|(1-βM1 2 )×βM1R 2 |<100 (11) When the middle group GM is made up of only one lens group, the middle group GM becomes the first intermediate lens group.

[0125] In order to obtain better characteristics, it is more preferable that the zoom lens satisfy the following conditional formula (11-1), it is even more preferable that the zoom lens satisfy the following conditional formula (11-2), and it is even more preferable that the zoom lens satisfy the following conditional formula (11-3). 20<|(1-βM1 2 )×βM1R 2 |<90 (11-1) 30<|(1-βM1 2 )×βM1R 2 |<80 (11-2) 40<|(1-βM1 2 )×βM1R 2 |<70 (11-3)

[0126] The example shown in Fig. 1 is merely an example, and various modifications are possible within the scope of the gist of the technology of the present disclosure. For example, the number of lens groups included in each of the front group GF, the middle group GM, and the rear group GR may be different from that in the example of Fig. 1. Also, the number of lenses included in each lens group, the number of lenses included in the focusing group, and the number of lenses included in the vibration reduction group may be different from that in the example of Fig. 1. The lenses corresponding to the focusing group, the lenses corresponding to the vibration reduction group, the position of the aperture stop St, and the lens groups that move during magnification may be configured differently from that in the example of Fig. 1.

[0127] At least one of an infrared cut filter, a visible light cut filter, a filter that transmits only light of a specific wavelength, an ND (Neutral Density) filter, a polarizing filter, and the like may be disposed at any position of the zoom lens.

[0128] The above-mentioned preferred and possible configurations can be arbitrarily combined within a range not causing any contradiction, and it is preferable that they are appropriately and selectively adopted according to the required specifications.

[0129] As an example, a preferred embodiment of the zoom lens of the present disclosure comprises, in order from the object side to the image side, a front group GF, a middle group GM, and a rear group GR, wherein the front group GF consists of two or less lens groups having positive refractive power, the lens group of the front group GF closest to the object is fixed with respect to the image surface Sim during zooming, the middle group GM consists of two or less lens groups having negative refractive power, the rear group GR consists of a plurality of lens groups, the lens group of the rear group GR closest to the object has positive refractive power, the lens group of the rear group GR closest to the image is fixed with respect to the image surface Sim during zooming, and all of the spacings between adjacent lens groups change during zooming, satisfying the above conditional formula (1).

[0130] Next, an embodiment of the zoom lens of the present disclosure will be described with reference to the drawings. Note that the reference symbols given to each lens and each group in the cross-sectional views of each embodiment are used independently for each embodiment to avoid the explanation and the drawings becoming complicated due to the increase in the number of digits of the reference symbols. Therefore, even if common reference symbols are given in the drawings of different embodiments, they do not necessarily have the same configuration.

[0131] [Example 1] The configuration and movement locus of the zoom lens of Example 1 are shown in FIG. 1, and the method of illustration and the configuration are as described above, so some overlapping explanations will be omitted here. The zoom lens of Example 1 is composed of, in order from the object side to the image side, a front group GF, a middle group GM, and a rear group GR. The front group GF is composed of one lens group having positive refractive power. The middle group GM is composed of one lens group having negative refractive power. The rear group GR is composed of three lens groups, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having negative refractive power, and a third rear lens group GR3 having positive refractive power. When changing the magnification from the wide-angle end to the telephoto end, the front group GF and the third subsequent lens group GR3 are fixed with respect to the image plane Sim, and the middle group GM, the first subsequent lens group GR1, and the second subsequent lens group GR2 move along the optical axis Z while changing the spacing between the adjacent lens groups.

[0132] For the zoom lens of Example 1, Table 1 shows basic lens data, Table 2 shows specifications, Table 3 shows variable surface spacing, and Table 4 shows aspheric coefficients.

[0133] The basic lens data table is written as follows. The Sn column shows the surface numbers, with the surface closest to the object being surface 1 and the numbers increasing by one as you move towards the image side. The R column shows the radius of curvature of each surface. The D column shows the surface spacing on the optical axis between each surface and its adjacent surface on the image side. The Nd column shows the refractive index for each lens with respect to the d line. The νd column shows the Abbe number of each lens based on the d line.

[0134] The terms "d-line," "C-line," and "F-line" used in this specification are emission lines, and the wavelength of the d-line is treated as 587.56 nm (nanometers), the wavelength of the C-line is 656.27 nm (nanometers), and the wavelength of the F-line is 486.13 nm (nanometers).

[0135] In the basic lens data table, the sign of the radius of curvature of a surface with a convex shape facing the object side is positive, and the sign of the radius of curvature of a surface with a convex shape facing the image side is negative. Table 1 also shows the aperture stop St and optical member PP. In the column for the surface number of the surface corresponding to the aperture stop St, the surface number and the word (St) are entered. The value in the bottom row of the D column in the table is the distance between the surface in the table closest to the image side and the image plane Sim. The symbol DD[ ] is used to indicate the variable surface distance when varying magnification, and the surface number on the object side of this distance is entered in [ ] in the D column.

[0136] Table 2 shows the zoom ratio Zr, focal length f, back focal length Bf in air equivalent distance, maximum open F-number FNo., maximum total angle of view 2ω, and maximum image height Y based on the d-line. The zoom ratio is synonymous with the zoom magnification. [°] in the 2ω column indicates that the unit is degrees. In Table 2, the columns labeled "Wide" and "Tele" show the values ​​for the wide-angle end state and the telephoto end state, respectively.

[0137] Table 3 shows the variable surface distances when changing the magnification. In Table 3, the columns labeled "Wide" and "Tele" show the values ​​for the wide-angle end state and the telephoto end state, respectively.

[0138] In the basic lens data, the surface numbers of aspheric surfaces are marked with an *, and the value of the paraxial radius of curvature is given in the column for the radius of curvature of the aspheric surface. In Table 4, the Sn row shows the surface numbers of the aspheric surfaces, and the KA and Am rows show the numerical values ​​of the aspheric coefficients for each aspheric surface. Note that m in Am is an integer of 3 or more, and differs depending on the surface. For example, for the 11th surface of Example 1, m = 3, 4, 5, ... 20. The numerical values ​​of the aspheric coefficients in Table 4, "E±n" (n: integer), are expressed as "×10 ±n " KA and Am are aspheric coefficients in the aspheric equation expressed below. Zd = C × h2 / {1+(1-KA×C 2 ×h 2 ) 1 / 2}+ΣAm×h m however, Zd: Aspheric depth (the length of the perpendicular line drawn from a point on the aspheric surface at height h to a plane perpendicular to the optical axis Z where the apex of the aspheric surface is in contact) h: Height (distance from optical axis Z to lens surface) C: Reciprocal of paraxial curvature radius KA, Am: Aspheric coefficients In the aspheric surface formula, Σ means the summation with respect to m.

[0139] In the data in each table, the angle unit is degrees and the length unit is millimeters, but since the optical system can be used with proportional enlargement or reduction, other appropriate units can be used. Also, in each table shown below, values ​​are rounded to a predetermined number of decimal places.

[0140] [Table 1]

[0141] [Table 2]

[0142] [Table 3]

[0143] [Table 4]

[0144] FIG. 3 shows each aberration diagram of the zoom lens of Example 1 in a state where the lens is focused on an object at infinity. In FIG. 3, from the left, spherical aberration, astigmatism, distortion, and lateral chromatic aberration are shown. In FIG. 3, the upper row labeled "Wide" shows the aberration in the wide-angle end state, and the lower row labeled "Tele" shows the aberration in the telephoto end state. In the spherical aberration diagram, the aberrations at the d-line, C-line, and F-line are shown by solid lines, long dashed lines, and short dashed lines, respectively. In the astigmatism diagram, the aberration at the d-line in the sagittal direction is shown by solid lines, and the aberration at the d-line in the tangential direction is shown by short dashed lines. In the distortion diagram, the aberration at the d-line is shown by solid lines. In the lateral chromatic aberration diagram, the aberration at the C-line and F-line are shown by long dashed lines and short dashed lines, respectively. In the spherical aberration diagram, the value of the open F-number is shown after FNo.=. In other aberration diagrams, the value of the maximum half angle of view is shown after ω=.

[0145] The symbols, meanings, description methods, and illustration methods of each piece of data related to the above-mentioned Example 1 are basically the same in the following Examples unless otherwise specified, so duplicated explanations will be omitted below.

[0146] [Example 2] The configuration and movement locus of the zoom lens of the second embodiment are shown in FIG. 4. The zoom lens of the second embodiment is composed of, in order from the object side to the image side, a front group GF, a middle group GM, and a rear group GR. The front group GF is composed of one lens group having positive refractive power. The middle group GM is composed of one lens group having negative refractive power. The rear group GR is composed of three lens groups, in order from the object side to the image side, a first subsequent lens group GR1 having positive refractive power, a second subsequent lens group GR2 having negative refractive power, and a third subsequent lens group GR3 having positive refractive power. When varying the magnification from the wide-angle end to the telephoto end, the front group GF and the third subsequent lens group GR3 are fixed with respect to the image surface Sim, and the middle group GM, the first subsequent lens group GR1, and the second subsequent lens group GR2 move along the optical axis Z while changing the intervals between the adjacent lens groups.

[0147] The front group GF is made up of five lenses, L11 to L15, in order from the object side to the image side. The middle group GM is made up of three lenses, L21 to L23, in order from the object side to the image side. The first subsequent lens group GR1 is made up of two lenses, L31 to L32, in order from the object side to the image side. The second subsequent lens group GR2 is made up of three lenses, L41 to L43, in order from the object side to the image side. The third subsequent lens group GR3 is made up of an aperture stop St and eleven lenses, L51 to L61, in order from the object side to the image side. The focusing group is made up of three lenses, L56 to L58. The vibration reduction group is made up of four lenses, L51 to L54.

[0148] Regarding the zoom lens of Example 2, basic lens data is shown in Table 5, specifications are shown in Table 6, variable surface spacing is shown in Table 7, aspheric coefficients are shown in Table 8, and each aberration diagram is shown in FIG.

[0149] [Table 5]

[0150] [Table 6]

[0151] [Table 7]

[0152] [Table 8]

[0153] [Example 3] The configuration and movement locus of the zoom lens of Example 3 are shown in FIG. 6. The zoom lens of Example 3 is composed of, in order from the object side to the image side, a front group GF, a middle group GM, and a rear group GR. The front group GF is composed of one lens group having positive refractive power. The middle group GM is composed of one lens group having negative refractive power. The rear group GR is composed of three lens groups, in order from the object side to the image side, a first subsequent lens group GR1 having positive refractive power, a second subsequent lens group GR2 having negative refractive power, and a third subsequent lens group GR3 having positive refractive power. When varying the magnification from the wide-angle end to the telephoto end, the front group GF, the first subsequent lens group GR1, and the third subsequent lens group GR3 are fixed with respect to the image surface Sim, and the middle group GM and the second subsequent lens group GR2 move along the optical axis Z while changing the interval between the adjacent lens groups.

[0154] The front group GF is made up of four lenses, L11 to L14, in order from the object side to the image side. The middle group GM is made up of five lenses, L21 to L25, in order from the object side to the image side. The first subsequent lens group GR1 is made up of four lenses, L31 to L34, and an aperture stop St, in order from the object side to the image side. The second subsequent lens group GR2 is made up of four lenses, L41 to L44, in order from the object side to the image side. The third subsequent lens group GR3 is made up of fifteen lenses, L51 to L65, in order from the object side to the image side. The focusing group is made up of the second subsequent lens group GR2.

[0155] For the zoom lens of Example 3, basic lens data is shown in Tables 9A and 9B, specifications are shown in Table 10, variable surface spacing is shown in Table 11, aspheric coefficients are shown in Table 12, and each aberration diagram is shown in Fig. 7. In Examples 3, 4, 7, and 8, the basic lens data is shown in two tables to avoid making one table too long.

[0156] [Table 9A]

[0157] [Table 9B]

[0158] [Table 10]

[0159] [Table 11]

[0160] [Table 12]

[0161] [Example 4] The configuration and movement locus of the zoom lens of Example 4 are shown in FIG. 8. The zoom lens of Example 4 is composed of, in order from the object side to the image side, a front group GF, a middle group GM, and a rear group GR. The front group GF is composed of one lens group having positive refractive power. The middle group GM is composed of one lens group having negative refractive power. The rear group GR is composed of three lens groups, in order from the object side to the image side, a first subsequent lens group GR1 having positive refractive power, a second subsequent lens group GR2 having negative refractive power, and a third subsequent lens group GR3 having positive refractive power. When varying the magnification from the wide-angle end to the telephoto end, the front group GF, the first subsequent lens group GR1, and the third subsequent lens group GR3 are fixed with respect to the image surface Sim, and the middle group GM and the second subsequent lens group GR2 move along the optical axis Z while changing the interval between the adjacent lens groups.

[0162] The front group GF is made up of four lenses, L11 to L14, in order from the object side to the image side. The middle group GM is made up of five lenses, L21 to L25, in order from the object side to the image side. The first subsequent lens group GR1 is made up of five lenses, L31 to L35, in order from the object side to the image side, and an aperture stop St. The second subsequent lens group GR2 is made up of four lenses, L41 to L44, in order from the object side to the image side. The third subsequent lens group GR3 is made up of fifteen lenses, L51 to L65, in order from the object side to the image side. The focusing group is made up of the second subsequent lens group GR2.

[0163] Regarding the zoom lens of Example 4, basic lens data is shown in Tables 13A and 13B, specifications are shown in Table 14, variable surface spacing is shown in Table 15, aspheric coefficients are shown in Table 16, and each aberration diagram is shown in FIG.

[0164] [Table 13A]

[0165] [Table 13B]

[0166] [Table 14]

[0167] [Table 15]

[0168] [Table 16]

[0169] [Example 5] The configuration and movement locus of the zoom lens of the fifth embodiment are shown in FIG. 10. The zoom lens of the fifth embodiment is composed of, in order from the object side to the image side, a front group GF, a middle group GM, and a rear group GR. The front group GF is composed of one lens group having positive refractive power. The middle group GM is composed of one lens group having negative refractive power. The rear group GR is composed of two lens groups, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, and a second rear lens group GR2 having negative refractive power. When varying the magnification from the wide-angle end to the telephoto end, the front group GF and the second rear lens group GR2 are fixed with respect to the image surface Sim, and the middle group GM and the first rear lens group GR1 move along the optical axis Z while changing the interval between the adjacent lens groups.

[0170] The front group GF is composed of four lenses, L11 to L14, in order from the object side to the image side. The middle group GM is composed of three lenses, L21 to L23, in order from the object side to the image side. The first subsequent lens group GR1 is composed of four lenses, L31 to L34, in order from the object side to the image side. The second subsequent lens group GR2 is composed of an aperture stop St, lenses L41 to L47, a filter P1, and lenses L48 to L49, in order from the object side to the image side. The focusing group is composed of three lenses, L45 to L47.

[0171] Regarding the zoom lens of Example 5, basic lens data is shown in Table 17, specifications are shown in Table 18, variable surface spacing is shown in Table 19, aspheric coefficients are shown in Table 20, and each aberration diagram is shown in FIG.

[0172] [Table 17]

[0173] [Table 18]

[0174] [Table 19]

[0175] [Table 20]

[0176] [Example 6] The configuration and movement locus of the zoom lens of Example 6 are shown in FIG. 12. The zoom lens of Example 6 is composed of, in order from the object side to the image side, a front group GF, a middle group GM, and a rear group GR. The front group GF is composed of one lens group having positive refractive power. The middle group GM is composed of one lens group having negative refractive power. The rear group GR is composed of two lens groups, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, and a second rear lens group GR2 having negative refractive power. When varying the magnification from the wide-angle end to the telephoto end, the front group GF and the second rear lens group GR2 are fixed with respect to the image surface Sim, and the middle group GM and the first rear lens group GR1 move along the optical axis Z while changing the interval between the adjacent lens groups.

[0177] The front group GF is composed of four lenses, L11 to L14, in order from the object side to the image side. The middle group GM is composed of three lenses, L21 to L23, in order from the object side to the image side. The first subsequent lens group GR1 is composed of four lenses, L31 to L34, in order from the object side to the image side. The second subsequent lens group GR2 is composed of an aperture stop St, lenses L41 to L47, a filter P1, and lenses L48 to L49, in order from the object side to the image side. The focusing group is composed of three lenses, L45 to L47.

[0178] Regarding the zoom lens of Example 6, basic lens data is shown in Table 21, specifications are shown in Table 22, variable surface spacing is shown in Table 23, aspheric coefficients are shown in Table 24, and each aberration diagram is shown in FIG.

[0179] [Table 21]

[0180] [Table 22]

[0181] [Table 23]

[0182] [Table 24]

[0183] [Example 7] The configuration and movement locus of the zoom lens of Example 7 are shown in FIG. 14. The zoom lens of Example 7 is composed of, in order from the object side to the image side, a front group GF, a middle group GM, and a rear group GR. The front group GF is composed of two lens groups, in order from the object side to the image side, a first front lens group GF1 having positive refractive power, and a second front lens group GF2 having positive refractive power. The middle group GM is composed of one lens group having negative refractive power. The rear group GR is composed of two lens groups, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, and a second rear lens group GR2 having negative refractive power. When changing magnification from the wide-angle end to the telephoto end, the first front lens group GF1 and the second rear lens group GR2 are fixed with respect to the image plane Sim, and the second front lens group GF2, the middle group GM, and the first rear lens group GR1 move along the optical axis Z while changing the spacing between adjacent lens groups.

[0184] The first front lens group GF1 consists of three lenses, L11 to L13, in order from the object side to the image side. The second front lens group GF2 consists of one lens, L14. The middle group GM consists of four lenses, L21 to L24, in order from the object side to the image side. The first rear lens group GR1 consists of three lenses, L31 to L33, in order from the object side to the image side. The second rear lens group GR2 consists of an aperture stop St, lenses L41 to L52, a filter P1, and lenses L53 to L57, in order from the object side to the image side. The focusing group consists of four lenses, L47 to L50.

[0185] Regarding the zoom lens of Example 7, basic lens data is shown in Tables 25A and 25B, specifications are shown in Table 26, variable surface spacing is shown in Table 27, aspheric coefficients are shown in Table 28, and each aberration diagram is shown in FIG.

[0186] [Table 25A]

[0187] [Table 25B]

[0188] [Table 26]

[0189] [Table 27]

[0190] [Table 28]

[0191] [Example 8] The configuration and movement locus of the zoom lens of Example 8 are shown in FIG. 16. The zoom lens of Example 8 is composed of, in order from the object side to the image side, a front group GF, an intermediate group GM, and a rear group GR. The front group GF is composed of one lens group having positive refractive power. The intermediate group GM is composed of two lens groups, in order from the object side to the image side, a first intermediate lens group GM1 having negative refractive power and a second intermediate lens group GM2 having negative refractive power. The rear group GR is composed of two lens groups, in order from the object side to the image side, a first subsequent lens group GR1 having positive refractive power and a second subsequent lens group GR2 having negative refractive power. When changing the magnification from the wide-angle end to the telephoto end, the front group GF and the second subsequent lens group GR2 are fixed with respect to the image surface Sim, and the first intermediate lens group GM1, the second intermediate lens group GM2, and the first subsequent lens group GR1 move along the optical axis Z while changing the intervals between the adjacent lens groups.

[0192] The front group GF is made up of five lenses, L11 to L15, in order from the object side to the image side. The first intermediate lens group GM1 is made up of one lens, L21. The second intermediate lens group GM2 is made up of four lenses, L31 to L34, in order from the object side to the image side. The first subsequent lens group GR1 is made up of four lenses, L41 to L44, in order from the object side to the image side. The second subsequent lens group GR2 is made up of an aperture stop St, lenses L51 to L61, a filter P1, and lenses L62 to L63, in order from the object side to the image side. The focusing group is made up of three lenses, lenses L55 to L57.

[0193] Regarding the zoom lens of Example 8, basic lens data is shown in Tables 29A and 29B, specifications are shown in Table 30, variable surface spacing is shown in Table 31, aspheric coefficients are shown in Table 32, and each aberration diagram is shown in FIG.

[0194] [Table 29A]

[0195] [Table 29B]

[0196] [Table 30]

[0197] [Table 31]

[0198] [Table 32]

[0199] Tables 33 and 34 show values ​​corresponding to conditional formulas (1) to (11) for the zoom lenses of Examples 1 to 8. The corresponding values ​​for the Examples shown in Tables 33 and 34 may be used as upper or lower limits to set preferred ranges for the conditional formulas.

[0200] [Table 33]

[0201] [Table 34]

[0202] All of the zoom lenses in Examples 1 to 8 have a high zoom ratio, achieving a zoom ratio of 40 or more while being compact. In addition, all of the zoom lenses in Examples 1 to 8 maintain high optical performance with various aberrations being well corrected. The zoom ratio of the zoom lens of the present disclosure is preferably 50 or more, more preferably 55 or more, and even more preferably 57 or more.

[0203] Next, an imaging device according to an embodiment of the present disclosure will be described. Fig. 18 shows a schematic configuration diagram of an imaging device 100 according to an embodiment of the present disclosure. The imaging device 100 is configured to include a zoom lens 1 according to an embodiment of the present disclosure. Examples of the imaging device 100 include a surveillance camera, a broadcast camera, a cinema camera, and a video camera.

[0204] The imaging device 100 includes a zoom lens 1, a filter 2 arranged on the image side of the zoom lens 1, and an image sensor 3 arranged on the image side of the filter 2. Note that multiple lenses included in the zoom lens 1 are illustrated in schematic form in FIG.

[0205] The image sensor 3 converts the optical image formed by the zoom lens 1 into an electrical signal, and may be, for example, a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). The image sensor 3 is disposed so that its imaging plane coincides with the image plane of the zoom lens 1.

[0206] The imaging device 100 also includes a signal processing unit 5, a display unit 6, a magnification control unit 7, and a focus control unit 8. The signal processing unit 5 performs arithmetic processing on the output signal from the imaging element 3. The display unit 6 displays the image formed by the signal processing unit 5. The magnification control unit 7 controls the magnification of the zoom lens 1. The focus control unit 8 controls the focus of the zoom lens 1. Note that although only one imaging element 3 is shown in FIG. 18, a so-called three-plate type imaging device having three imaging elements may also be used.

[0207] Although the technology of the present disclosure has been described above with reference to the embodiments and examples, the technology of the present disclosure is not limited to the above embodiments and examples, and various modifications are possible. For example, the radius of curvature, surface spacing, refractive index, Abbe number, aspheric coefficient, etc. of each lens are not limited to the values ​​shown in the above examples, and may take other values.

[0208] Regarding the above-mentioned embodiments and examples, the following supplementary notes are further disclosed. [Appendix 1] The lens consists of, in order from the object side to the image side, a front group, an intermediate group, and a rear group. the front group is made up of two or less lens groups each having a positive refractive power, the lens group closest to the object side of the front group is fixed with respect to the image plane during zooming; the intermediate group is composed of two or less lens groups each having a negative refractive power, the rear group is made up of a plurality of lens groups, the lens unit closest to the object side in the rear group has positive refractive power, the lens unit closest to the image side of the rear group is fixed with respect to the image plane during zooming; When changing magnification, the spacing between all adjacent lens groups changes, The focal length of the entire system when focused on an object at infinity at the telephoto end is ft. The focal length of the entire system when focused on an object at infinity at the wide-angle end is fw. Among the lens groups that move during magnification change, the displacement amount of the lens group that has the largest displacement amount during magnification change from the wide-angle end to the telephoto end is defined as Movmax, If Movmax is in mm, 0.4<(ft / fw) / Movmax (1) A zoom lens that satisfies conditional expression (1) expressed by: [Appendix 2] TL is the sum of the distance on the optical axis from the lens surface of the front group closest to the object to the lens surface of the rear group closest to the image when the lens is focused on an object at infinity, and the back focus in air equivalent distance of the entire system; If the maximum image height is Y, TL / 2Y<80 (2) 2. The zoom lens according to claim 1, which satisfies conditional expression (2) expressed by: [Appendix 3] When the lens is focused on an object at infinity, the sum of the distance on the optical axis from the lens surface of the front group closest to the object to the lens surface of the rear group closest to the image and the back focus in air equivalent distance of the entire system is defined as TL. 2 <ft / TL (3) The zoom lens according to claim 1 or 2, which satisfies conditional expression (3) represented by: [Appendix 4] If the back focus in air equivalent distance of the entire system is Bf, 10 <ft / Bf (4) The zoom lens according to any one of claims 1 to 3, which satisfies conditional expression (4) represented by: [Appendix 5] If the maximum image height is Y, 30 <ft / 2Y (5) The zoom lens according to any one of claims 1 to 4, which satisfies conditional expression (5) represented by: [Appendix 6] If the focal length of the lens unit closest to the object in the front group is fF1, 0.5 <ft / fF1 (6) The zoom lens according to any one of claims 1 to 5, which satisfies conditional expression (6) represented by: [Appendix 7] If the focal length of the lens unit closest to the object in the intermediate group is fM1, 5<|ft / fM1| (7) The zoom lens according to any one of claims 1 to 6, which satisfies conditional expression (7) represented by: [Appendix 8] the lens group closest to the object side of the front group includes at least four lenses, 8. The zoom lens according to claim 1, wherein the third lens group from the object side of the rear group includes an aspheric lens. [Appendix 9] If the focal length of the lens unit closest to the object in the rear group is fR1, 0 <ft / fR1<100 (8) The zoom lens according to any one of claims 1 to 8, which satisfies conditional expression (8) represented by: [Appendix 10] If the focal length of the lens unit closest to the image side in the rear group is fRe, -100 <ft / fRe<200 (9) The zoom lens according to any one of claims 1 to 9, which satisfies conditional expression (9) represented by: [Appendix 11] 0 <ft / fRe<200 (9-1) The zoom lens according to claim 10, which satisfies conditional expression (9-1) represented by: [Appendix 12] -100 <ft / fRe<0 (9-6) The zoom lens according to claim 10, which satisfies conditional expression (9-6) represented by: [Appendix 13] the zoom lens includes a focusing group that moves during focusing; The lateral magnification of the focusing group when focused on an object at infinity at the telephoto end is βfoc, When the composite lateral magnification of all the lenses on the image side of the focusing group in a state where an object at infinity is focused at the telephoto end is βfocR, |(1-βfoc 2 )×βfocR 2 |<50 (10) The zoom lens according to any one of claims 1 to 12, which satisfies conditional expression (10) represented by: [Appendix 14] The zoom lens according to any one of claims 1 to 13, wherein the lens group closest to the object side in the front group includes at least one cemented lens. [Appendix 15] 15. The zoom lens according to claim 1, wherein the lens group closest to the object side in the front group includes at least one positive lens having an Abbe number of 70 or more based on the d-line. [Appendix 16] 16. The zoom lens according to claim 1, wherein the lens group closest to the object side in the front group includes at least one negative lens having an Abbe number of 60 or less based on the d-line. [Appendix 17] 17. The zoom lens according to claim 1, wherein the lens group closest to the object side in the intermediate group includes at least one positive lens having an Abbe number of 40 or less based on the d-line. [Appendix 18] The zoom lens according to any one of claims 1 to 17, wherein the lens group closest to the object side of the intermediate group includes at least one positive lens and at least two negative lenses. [Appendix 19] 0.8<(ft / fw) / Movmax (1-1) The zoom lens according to any one of claims 1 to 18, which satisfies conditional expression (1-1) represented by: [Appendix 20] An imaging device comprising the zoom lens according to any one of claims 1 to 19. [Explanation of symbols]

[0209] 1 Zoom lens 2. Filters 3. Image sensor 5. Signal Processing Section 6 Display section 7 Magnification control section 8 Focus control section 100 Imaging device GF front group GF1 First front lens group GF2 Second front lens group GM intermediate group GM1 First intermediate lens group GM2 Second intermediate lens group GR rear group GR1 First succeeding lens group GR2 2nd lens group GR3 3rd lens group L11~L65 Lens Movmax Displacement P1 Filter PP Optical Components Sim image plane St Aperture Y Maximum image height Z optical axis

Claims

1. The lens consists of, in order from the object side to the image side, a front group, an intermediate group, and a rear group. the front group is composed of two or less lens groups each having a positive refractive power, the lens group closest to the object side of the front group is fixed with respect to the image plane during zooming; the intermediate group is composed of two or less lens groups each having a negative refractive power, the rear group is made up of a plurality of lens groups, the lens unit closest to the object side in the rear group has positive refractive power, the lens unit closest to the image side of the rear group is fixed with respect to the image plane during zooming; When changing magnification, the spacing between all adjacent lens groups changes, The focal length of the entire system when focused on an object at infinity at the telephoto end is ft. The focal length of the entire system when focused on an object at infinity at the wide-angle end is fw. Among the lens groups that move during magnification change, the displacement amount of the lens group that has the largest displacement amount during magnification change from the wide-angle end to the telephoto end is defined as Movmax, If the unit of Movmax is mm, 0.4<(ft / fw) / Movmax (1) A zoom lens that satisfies the conditional expression (1) expressed by:

2. TL is the sum of the distance on the optical axis from the lens surface of the front group closest to the object side to the lens surface of the rear group closest to the image side when focused on an object at infinity, and the back focus in terms of the air equivalent distance of the entire system; If the maximum image height is Y, TL / 2Y<80 (2) 2. The zoom lens according to claim 1, which satisfies conditional expression (2) expressed as follows:

3. 0.8<(ft / fw) / Movmax (1-1) 2. The zoom lens according to claim 1, which satisfies the conditional expression (1-1) expressed by:

4. When the sum of the distance on the optical axis from the lens surface of the front group closest to the object side to the lens surface of the rear group closest to the image side in a state in which the lens is focused on an object at infinity and the back focus in terms of the air equivalent distance of the entire system is defined as TL, 2<ft / TL (3) 2. The zoom lens according to claim 1, which satisfies conditional expression (3) expressed as follows:

5. If the back focus of the entire system in air equivalent distance is Bf, 10<ft / Bf (4) 2. The zoom lens according to claim 1, which satisfies conditional expression (4) expressed as follows:

6. If the maximum image height is Y, 30<ft / 2Y (5) 2. The zoom lens according to claim 1, which satisfies conditional expression (5) expressed by:

7. If the focal length of the lens unit closest to the object side in the front group is fF1, 0.5<ft / fF1 (6) 2. The zoom lens according to claim 1, which satisfies conditional expression (6) expressed as follows:

8. If the focal length of the lens unit closest to the object side in the intermediate group is fM1, 5<|ft / fM1| (7) 2. The zoom lens according to claim 1, which satisfies conditional expression (7) expressed as follows:

9. the lens group closest to the object side of the front group includes at least four lenses, 2. The zoom lens according to claim 1, wherein the third lens unit from the object side of the rear group includes an aspheric lens.

10. If the focal length of the lens unit closest to the object in the rear group is fR1, 0<ft / fR1<100 (8) 2. The zoom lens according to claim 1, which satisfies conditional expression (8) expressed as follows:

11. If the focal length of the lens unit closest to the image side in the rear group is fRe, -100<ft / fRe<200 (9) 2. The zoom lens according to claim 1, which satisfies conditional expression (9) expressed as follows:

12. 0<ft / fRe<200 (9-1) 12. The zoom lens according to claim 11, which satisfies conditional expression (9-1) expressed by:

13. -100<ft / fRe<0 (9-6) 12. The zoom lens according to claim 11, which satisfies conditional expression (9-6) expressed by:

14. the zoom lens includes a focusing group that moves during focusing; The lateral magnification of the focusing group when focused on an object at infinity at the telephoto end is β, When the composite lateral magnification of all the lenses on the image side of the focusing group in a state where an object at infinity is focused at the telephoto end is βfocR, |(1-βfoc ２ )×βfocR ２ |<50 (10) 2. The zoom lens according to claim 1, which satisfies conditional expression (10) expressed as follows:

15. 2. The zoom lens according to claim 1, wherein the lens group closest to the object side in the front group includes at least one cemented lens.

16. 2. The zoom lens according to claim 1, wherein the lens group closest to the object side in the front group includes at least one positive lens having an Abbe number of 70 or more based on the d-line.

17. 2. The zoom lens according to claim 1, wherein the lens group closest to the object side in the front group includes at least one negative lens having an Abbe number of 60 or less based on the d-line.

18. 2. The zoom lens according to claim 1, wherein the lens group closest to the object side of the intermediate group includes at least one positive lens having an Abbe number of 40 or less based on the d-line.

19. 2. The zoom lens according to claim 1, wherein the lens group closest to the object side of the intermediate group includes at least one positive lens and at least two negative lenses.

20. An imaging device comprising the zoom lens according to any one of claims 1 to 19.

Images