Zoom lens, and imaging device having zoom lens

Abstract

A zoom lens (1) has, in order from an object side to an image side, a first optical element group (G1), a second optical element group (G2), and a third optical element group (G3). The first optical element group (G1) has a lens group (10) and an optical element (15) that bends an optical axis (C). The second optical element group (G2) has a negative refractive power. The third optical element group (G3) has a positive refractive power. The lens group (10) has a positive refractive power and is disposed closer to the object side than the optical element (15). The second optical element group (G2) and the third optical element group (G3) are configured to be movable along the optical axis (C), respectively, so that the zoom lens (1) changes a magnification from a wide-angle end to a telephoto end.

Description

Technical Field

[0001] The present invention relates to a zoom lens having multiple optical element groups, and an imaging device having the zoom lens. Background Technology

[0002] Previously, zoom lenses with optical elements that bend the optical axis were known.

[0003] For example, the zoom lens described in Japanese Patent Application Publication No. 2007-34064 includes a first lens group, a second lens group, and a third lens group arranged sequentially from the object side to the image side. The first lens group includes a first lens with negative refractive power and a prism that bends the optical axis. The second lens group includes two lenses, and the third lens group includes three lenses. In the first lens group of this zoom lens, the first lens with negative refractive power is positioned on the object side of the prism.

[0004] Although this zoom lens can reduce the size of the incident light from the object (i.e., make it thinner), the F-value at the wide-angle end is around F28, so it cannot be said that the aperture has been fully enlarged.

[0005] Furthermore, in the zoom lens described in WO2021 / 085154A1, a prism is positioned on the object side of the lens group, meaning the prism is located closest to the object. While this zoom lens can reduce the size of the incident light direction, it cannot ensure a sufficient size for the maximum diameter of the first lens group calculated using the focal length (EFL) / F value, making it difficult to achieve a large aperture.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2007-34064

[0009] Patent Document 2: International Publication No. WO2021 / 085154A1 Summary of the Invention

[0010] The problem the invention aims to solve

[0011] Therefore, the objective of this invention is to provide a zoom lens that can be configured in a thin shooting device, has a large aperture and is capable of telephoto shooting, and a shooting device equipped with the zoom lens.

[0012] Solution for solving the problem

[0013] The zoom lens of the present invention comprises a first optical element group, a second optical element group, and a third optical element group arranged sequentially from the object side to the image side.

[0014] The first optical element group includes a lens group comprising at least one lens, and an optical element that bends the optical axis.

[0015] The second optical element group includes at least one lens and has negative refractive power.

[0016] The third optical element group includes at least one lens and has positive refractive power.

[0017] The lens group has positive refractive power and is positioned closer to the object than the optical element.

[0018] The second and third optical element groups are configured to move along the optical axis respectively, thereby allowing the zoom lens to change the magnification between the wide-angle end and the telephoto end.

[0019] In the zoom lens,

[0020] When the focal length of the first lens group is defined as f1, and the focal length of the entire optical system at infinity at the telephoto end is defined as ft, the following can be satisfied:

[0021] 0.5≤f1 / ft≤6.

[0022] In addition, in the zoom lens,

[0023] When the distance along the optical axis from the surface closest to the object side of the first optical element group to the surface closest to the object side of the second optical element group is defined as D12, and the distance along the optical axis from the surface closest to the object side of the first optical element group to the image plane is defined as TTL, the following can be satisfied:

[0024] 0.2≤D12 / TTL≤0.7.

[0025] In addition, in the zoom lens,

[0026] When the focal length of the third optical element group is defined as f3, the focal length of the entire optical system when focusing at infinity at the wide-angle end is defined as fw, and the focal length of the entire optical system when focusing at infinity at the telephoto end is defined as ft, the following can be satisfied:

[0027] 0.2≤f3 / √(fw×ft)≤1.1.

[0028] In addition, in the zoom lens,

[0029] When the focal length of the second optical element group is defined as f2, and the focal length of the entire optical system when focusing at infinity at the telephoto end is defined as ft, the following can be satisfied:

[0030] 0.2≤|f2 / ft|≤1.0.

[0031] In addition, in the zoom lens,

[0032] Alternatively, the maximum effective diameter h23 of the light transmission range in the second optical element group and the third optical element group can be less than 9 mm.

[0033] In addition, in the zoom lens,

[0034] The distance along the optical axis from the surface of the first optical element group closest to the object to the image plane can also be less than 40 mm.

[0035] Additionally, the zoom lens may have an aperture that allows adjustment of the amount of light passing through.

[0036] The aperture is positioned between the image-side surface of the optical elements in the first optical element group and the surface of the third optical element group closest to the object side.

[0037] In addition, in the zoom lens,

[0038] Alternatively, at least one surface of at least one lens in the third optical element group may be aspherical.

[0039] In addition, in the zoom lens,

[0040] Alternatively, at least one lens in the third optical element group may be made of plastic.

[0041] In addition, the imaging device of the present invention includes:

[0042] Any of the above zoom lenses; and

[0043] The imaging element is positioned at the image plane of the zoom lens and converts the formed optical image into an electrical signal. Attached Figure Description

[0044] Figure 1 This is a schematic diagram showing the configuration of the imaging device according to this embodiment.

[0045] Figure 2 This is a lens configuration diagram of the zoom lens of the shooting device.

[0046] Figure 3 This is a lens configuration diagram of the zoom lens in Embodiment 1, showing the lens configuration diagrams at the wide-angle end and the telephoto end.

[0047] Figure 4 It is the longitudinal aberration diagram of the zoom lens when focusing at infinity at the wide-angle end.

[0048] Figure 5 It is the longitudinal aberration diagram of the zoom lens when focusing at infinity at the telephoto end.

[0049] Figure 6 This is a lens configuration diagram of the zoom lens in Embodiment 2, showing the lens configuration diagrams at the wide-angle end and the telephoto end.

[0050] Figure 7 It is the longitudinal aberration diagram of the zoom lens when focusing at infinity at the wide-angle end.

[0051] Figure 8 It is the longitudinal aberration diagram of the zoom lens when focusing at infinity at the telephoto end. Detailed Implementation

[0052] Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings.

[0053] The shooting device in this embodiment is a device capable of shooting objects, such as a digital camera, smartphone, or tablet. The shooting device described below is, for example, a smartphone.

[0054] like Figure 1 As shown, the imaging device 100 includes: a zoom lens (optical system) 1, at least a portion of which is built into the imaging device body 101; and an image sensor (imaging element) 5, which is disposed at the imaging position (image plane position) of the zoom lens 1. Specifically, the imaging device 100 includes: an imaging device body 101, a zoom lens (optical system) 1, an image sensor 5, and a display unit 102, such as a liquid crystal display screen, that displays the imaging (image) data output from the image sensor 5. In addition, the imaging device 100 also includes: a control unit (processing unit) 103, which controls each component and performs processing on signals from the image sensor 5, etc.; and a power supply 104.

[0055] The image sensor 5, located at the imaging surface of the zoom lens 1, is an element that converts the optical image formed by the zoom lens 1 into electrical signals (image data). In this embodiment, the image sensor 5 is a CMOS image sensor. Furthermore, since the imaging surface of the zoom lens 1 and the light-receiving surface of the image sensor 5 are located at the same position, the image sensor (more specifically, the light-receiving surface of the image sensor) is sometimes referred to as the image surface 5 below.

[0056] Also Figure 2As shown, the zoom lens 1 includes at least a first optical element group G1, a second optical element group G2, and a third optical element group G3 arranged sequentially along the optical axis C from the object side to the image side. Each of these optical element groups G1, G2, and G3 includes at least one optical element such as a lens. In this embodiment, the zoom lens 1 includes the first optical element group G1, the second optical element group G2, the third optical element group G3, and a filter (an IR filter in this embodiment) 6 arranged sequentially along the optical axis C from the object side to the image side. Furthermore, the zoom lens 1 includes an aperture (aperture device) 7, which is disposed at a predetermined position on the optical axis C; and a protective glass 8, which is disposed on the object side of the first optical element group G1. In this embodiment, the aperture 7 is disposed on the object side of the third optical element group G3, and moves along the optical axis C together with the third optical element group G3 when changing the magnification or focusing.

[0057] The second optical element group G2 and the third optical element group G3 are configured to move along the optical axis C, thereby allowing the zoom lens 1 to change its magnification between the wide-angle end and the telephoto end (see reference). Figure 3 ).

[0058] The first optical element group G1 includes a lens group 10 comprising at least one lens, and a reflective optical element (optical element) 15 that bends the optical axis C. The lens group 10 has positive refractive power (optical power) and is disposed closer to the object than the reflective optical element 15. In the first optical element group G1 of this embodiment, the lens group 10 includes a lens (first lens) 11, and the reflective optical element 15 is a prism having a reflecting surface 15a that bends the incident light ray (optical axis C) by reflecting it, and is made of glass. It should be noted that in Figure 2 In the image, a quadrilateral is used to represent a reflecting optical element (prism) 15. Figure 3 as well as Figure 6 The same applies to China.

[0059] Furthermore, the second optical element group G2 includes at least one lens and has negative refractive power. In this embodiment, the second optical element group G2 includes two lenses (second lens 21 and third lens 22). Additionally, the third optical element group G3 includes at least one lens and has positive refractive power. In this embodiment, the third optical element group G3 includes five lenses (fourth lens 31 to eighth lens 35).

[0060] Furthermore, the zoom lens 1 has a lens barrel 16 that holds each optical element group G1 to G3. The lens barrel 16 of this embodiment includes: a bending portion 16A that allows light (light from an object) to enter and bends the optical axis C of the incident light; and a main body portion 16B that is built into the main body 101 of the imaging device. The bending portion 16A is where the first optical element group G1 is disposed, and the main body portion 16B is where the second optical element group G2 and the third optical element group G3 are disposed.

[0061] It should be noted that in the zoom lens 1 of this embodiment, the lens group 10, the second optical element group G2, and the third optical element group G3 are convenient names, and also include cases where they are composed of only one optical element (lens, etc.). That is, the lens group 10, the second optical element group G2, and the third optical element group G3 each include at least one lens or the like (optical element).

[0062] Wherein, when the focal length of the first optical element group is defined as f1, and the focal length of the entire optical system when focusing at infinity at the telephoto end is defined as ft, the zoom lens 1 can satisfy the following condition (1).

[0063] 0.5≤f1 / ft≤6···(1)

[0064] It should be noted that the focal length of the entire optical system when focusing at infinity at the telephoto end refers to the focal length of the entire optical system when zoomed to the telephoto end and focused at infinity. Similarly, the focal length of the entire optical system when focusing at infinity at the wide-angle end refers to the focal length of the entire optical system when zoomed to the wide-angle end and focused at infinity.

[0065] When the value of f1 / ft is less than the lower limit (0.5), the positive refractive power of the first optical element group G1 is too strong, and therefore the spacing between the first lens 11 and the second optical element group G becomes smaller. As a result, it is impossible to ensure space for the reflective optical element 15 for bending the optical axis C. On the other hand, when the value of f1 / ft is greater than the upper limit (6), the positive refractive power of the first optical element group G1 is too weak. Therefore, the size (total length) of the optical system (zoom lens) 1 along the optical axis C at the telephoto end becomes larger, making it difficult to make the zoom lens 1 compact. That is, by satisfying the above-described condition (1) in the zoom lens 1, a balance can be achieved between ensuring the placement space of the reflective optical element 15 and making the size of the zoom lens 1 along the optical axis C compact.

[0066] It should be noted that, from the viewpoint of ensuring the configuration space of the reflective optical element 15 and the compact size of the zoom lens 1 along the optical axis C, it is more preferable that the zoom lens 1 satisfies the following condition (1a).

[0067] 1≤f1 / ft≤5···(1a)

[0068] Furthermore, in this zoom lens 1, when the distance on the optical axis C from the object-side surface (object-side surface of the first lens 11) 11a of the first optical element group G1 to the object-side surface (object-side surface of the second lens 21) 21a of the second optical element group G2 is defined as D12, and the distance on the optical axis C from the object-side surface 11a of the first optical element group G1 to the image plane 5 is defined as TTL, the zoom lens 1 can satisfy the following conditional expression (2).

[0069] 0.2≤D12 / TTL≤0.7···(2)

[0070] When the value of D12 / TTL is less than the lower limit (0.2), the distance between the first lens 11 and the second optical element group G2 along the optical axis C becomes too small, making it impossible to ensure space for the placement of the reflective optical element 15. On the other hand, when the value of D12 / TTL is greater than the upper limit (0.7), the distance between the first lens 11 and the second optical element group G2 along the optical axis C becomes too large, making it impossible to achieve compactness of the zoom lens 1 along the optical axis C. That is, by satisfying the above-described condition (2) in the zoom lens 1, a balance can be achieved between ensuring space for the placement of the reflective optical element 15 and compactness of the zoom lens 1 along the optical axis C.

[0071] It should be noted that, from the viewpoint of ensuring the configuration space of the reflective optical element 15 and compacting the size of the zoom lens 1 along the optical axis C, it is more preferable that the zoom lens 1 satisfies the following condition (2a).

[0072] 0.25≤D12 / TTL≤0.65···(2a)

[0073] Furthermore, in this zoom lens 1, when the focal length of the third optical element group G3 is defined as f3, the focal length of the entire zoom lens (optical system) when focusing at infinity at the wide-angle end is defined as fw, and the focal length of the entire zoom lens (optical system) when focusing at infinity at the telephoto end is defined as ft, the zoom lens 1 can satisfy the following condition (3).

[0074] 0.2≤f3 / √(fw×ft)≤1.1···(3)

[0075] The aforementioned conditional expression (3) defines the ratio of the focal length f3 of the third optical element group G3 to the effective focal length of the zoom lens 1. Furthermore, among the optical element groups G1 to G3 constituting the zoom lens 1, the third optical element group G3 is the main group. Therefore, by placing the third optical element group G3 within an appropriate range of refractive power—that is, by satisfying the aforementioned conditional expression (3) in the zoom lens 1—the magnification of the second optical element group G2 and the third optical element group G3 becomes appropriate, and the performance from the wide-angle end to the telephoto end becomes optimal.

[0076] Specifically, when the value of f3 / √(fw×ft) is less than the lower limit (0.2), the refractive power of the third optical element group G3 increases, and the refractive power of the second optical element group G2 also increases. Therefore, the variations in image plane curvature, spherical aberration, etc., increase, and the performance variation from the wide-angle end to the telephoto end increases, making it difficult to ensure good performance across the entire range from the wide-angle end to the telephoto end. On the other hand, when the value of f3 / √(fw×ft) is greater than the upper limit (1.1), the refractive power of the third optical element group G3 decreases. As a result, the size of the zoom lens 1 along the optical axis C increases, and the correction of spherical aberration weakens. Therefore, it is difficult to construct a bright F-value zoom lens (optical system) 1.

[0077] It should be noted that, in zoom lens 1, it is more preferable to satisfy the following condition (3a).

[0078] 0.25≤f3 / √(fw×ft)≤1.0···(3a)

[0079] Furthermore, in this zoom lens 1, when the focal length of the second optical element group G2 is defined as f2, and the focal length of the entire zoom lens (optical system) when focusing at infinity at the telephoto end is defined as ft, the zoom lens 1 can satisfy the following conditional expression (4).

[0080] 0.2≤|f2 / ft|≤1.0···(4)

[0081] Condition (4) specifies the ratio of the focal length f2 of the second optical element group G2 to the focal length ft of the entire zoom lens (optical system) when focusing at infinity at the telephoto end. In the zoom lens 1 of this embodiment, when changing the magnification from the wide-angle end to the telephoto end, the first optical element group G1 is fixed, and the second optical element group G2 and the third optical element group G3, as zoom groups, move along the optical axis C in a manner that the intervals between them decrease along different trajectories. Furthermore, based on the relationship between the amount of movement of the zoom groups (magnification groups) G2 and G3 when changing the magnification and the refractive power (1 / focal length) of the zoom groups G2 and G3, if the zoom groups G2 and G3 exceed a certain range of refractive power, it is impossible to obtain a compact and high-performance zoom lens 1.

[0082] Specifically, when the value of |f2 / ft| is greater than the upper limit (1.0), the refractive power of the second optical element group G2 becomes too weak, and the amount of movement when changing the magnification increases. Therefore, in order to ensure the zoom ratio in the zoom lens 1, the overall length (the dimension along the optical axis C) becomes larger, which makes it difficult to make the zoom lens 1 compact. On the other hand, when the value of |f2 / ft| is less than the lower limit (0.2), the refractive power of the second optical element group G2 becomes too strong, and the changes such as image plane curvature when changing the magnification increase. Therefore, the overall performance is unbalanced.

[0083] It should be noted that, from the perspective of compactness and high performance, it is more preferable that the zoom lens 1 satisfies the following condition (4a).

[0084] 0.3≤|f² / ft|≤0.9···(4a)

[0085] Furthermore, in this zoom lens 1, the maximum effective diameter h23 of the light transmission range in the second optical element group G2 and the third optical element group G3 can be less than 9 mm.

[0086] Based on this configuration, a compact size can be achieved for use in portable shooting devices such as smartphones. It should be noted that in the zoom lens 1 of this embodiment, the maximum effective diameter h23 of the light transmission range in the second optical element group G2 and the third optical element group G3 is the outer diameter of the fourth lens 31.

[0087] Furthermore, in this zoom lens 1, the distance on the optical axis C from the surface 11a closest to the object side of the first optical element group G1 to the image plane 5 can be 40mm or less.

[0088] This configuration also enables the realization of a compact size for use in portable shooting devices 100, such as smartphones.

[0089] Furthermore, in this zoom lens 1, at least one surface of at least one lens (fourth lens 31 to eighth lens 35) in the third optical element group G3 can be aspherical.

[0090] Thus, by making at least one surface of at least one lens 31-35 of the third optical element group G3 aspherical, it becomes advantageous to improve the performance of the zoom lens 1. In particular, by making at least one surface of the lens with positive refractive power aspherical, the effect of correcting spherical aberration can be significantly obtained.

[0091] In addition, in this zoom lens 1, at least one lens (fourth lens 31 to eighth lens 35) in the third optical element group G3 can be made of plastic.

[0092] This configuration allows for a reduction in cost and weight of the zoom lens 1.

[0093] Based on the zoom lens 1 described above, it can be configured in a thin shooting device 100, enabling large-aperture and telephoto shooting. Details are as follows.

[0094] In the zoom lens 1 of this embodiment, a first optical element group G1 with positive refractive power, a second optical element group G2 with negative refractive power, and a third optical element group G3 with positive refractive power are arranged sequentially from the object side. Furthermore, by reducing the contribution of the first optical element group G1 to the refractive power of the entire zoom lens 1 system and setting it to a weak telephoto photography configuration with positive refractive power, a large-aperture telephoto zoom lens 1 can be obtained.

[0095] Furthermore, in the zoom lens 1 of this embodiment, by moving the second optical element group G2 with negative refractive power and the third optical element group G3 with positive refractive power as a zoom group in a direction that approaches each other on the optical axis C, the image plane position remains unchanged.

[0096] It should be noted that in the zoom lens 1 of this embodiment, when the magnification is changed from the wide-angle end to the telephoto end, the second optical element group G2 moves unidirectionally from the object side to the image side. However, the second optical element group G2 may also be configured to move from the middle to the object side when changing the magnification from the wide-angle end to the telephoto end. Even with this configuration, the third optical element group G3 moves from the image side to the object side along with the movement of the second optical element group G2 when the magnification is changed.

[0097] Furthermore, in the zoom lens 1 of this embodiment, the first optical element group G1 is fixed relative to the optical axis C. Therefore, the second optical element group G2 is used for focusing and vibration stabilization in the zoom lens 1. In addition, the third optical element group G3 is also used for focusing and vibration stabilization in the zoom lens 1.

[0098] Furthermore, in the zoom lens 1 of this embodiment, the first optical element group G1 with positive refractive power includes: a first lens 11 with positive refractive power, and a reflective optical element 15 such as a prism having a reflective surface 15a. Thus, the zoom lens 1 is configured such that the light rays (optical axis C) in the first optical element group G1 are bent (bent 90° in this embodiment's example). Therefore, by aligning the entire length direction of the zoom lens (optical system) 1 (the dimension along the optical axis C of the portion closer to the image plane than the reflective optical element 15) with the length direction of the shooting device (smartphone) 100 (…),… Figure 1 The zoom lens 1 is configured in a manner consistent with the vertical direction, which can suppress the effective diameter direction of the zoom lens 1. Figure 1 The dimensions of the camera (smartphone) 100 (in the left-right direction), i.e., the thickness of the camera 100.

[0099] Furthermore, by using a lens with positive refractive power as the first lens 11, and configuring the light rays passing through the first lens 11 to converge while traveling within the second optical element group G2, the effective diameter of each optical element group G2 and G3, which is closer to the image side than the reflecting optical element 15, can be suppressed more effectively. That is, the thickness of the shooting device (smartphone) 100 can be suppressed more effectively.

[0100] It should be noted that the zoom lens 1 and the shooting device 100 equipped with the zoom lens 1 of the present invention are not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, the configuration of other embodiments can be added to the configuration of one embodiment, and a part of the configuration of one embodiment can be replaced with the configuration of other embodiments. Moreover, a part of the configuration of one embodiment can be deleted.

[0101] In the zoom lens 1 of the above embodiment, the aperture 7 is disposed on the object side of the third optical element group G3, but is not limited to this configuration. The aperture 7 can be disposed between the image-side surface 15b of the reflecting optical element 15 of the first optical element group G1 and the surface 31a of the third optical element group G3 closest to the object side. According to this configuration, by limiting the width of the light incident on the third optical element group G3, the amount of light when changing the magnification can be ensured, and the variation in the performance of the zoom lens 1 can be suppressed.

[0102] Furthermore, the reflective optical element 15 of the zoom lens 1 in the above embodiment is composed of a prism, which bends the optical axis (optical path) C using the reflective surface 15a inside the prism, but is not limited to this configuration. The reflective optical element 15 may also be a mirror or the like.

[0103] Next, embodiments 1 and 2 of the imaging apparatus of the present invention will be described. In the following embodiments, the same reference numerals are used for the configurations corresponding to the zoom lens 1 of the above embodiments. Furthermore, in the tables of the following embodiments, r is the radius of curvature, d is the lens thickness or lens spacing, Nd is the refractive index of the d-line, and Vd represents the Abbe number based on the d-line. Additionally, the surface profile of the aspherical shape is given, for example, by the mathematical formula 1 shown below.

[0104] Mathematical Formula 1

[0105]

[0106] (Where, c is the curvature (1 / r), h is the height (distance) from the optical axis, k is the conic coefficient, and A4, A6, A8, A10... are the aspheric coefficients of each order.)

[0107] In addition, the longitudinal aberration diagrams, from left to right, represent spherical aberration (SA (mm)), astigmatism (AST (mm)), and distortion aberration (DIS (%)). In the spherical aberration diagram, the vertical axis represents the F-value (denoted as FNO in the diagram), the solid line represents the characteristics of the d-line, the dashed line represents the characteristics of the F-line, and the long dashed line represents the characteristics of the C-line. Similarly, in the astigmatism diagram, the vertical axis represents the field of view, the solid line represents the characteristics of the sagittal plane, and the long dashed line represents the characteristics of the meridional plane. In the distortion aberration diagram, the vertical axis represents the field of view.

[0108] In addition, Table 1 shows various data in each embodiment of Examples 1 and 2 below.

[0109] Table 1

[0110]

[0111] Example 1

[0112] Figure 3 This is a lens configuration diagram showing the positions of lenses 11, 15, 21, 22, and 31-35 at the wide-angle and telephoto ends of the zoom lens 1 constituting Embodiment 1. Specifically, the zoom lens 1 of Embodiment 1, from the object side to the image side, sequentially includes a first optical element group G1 with positive refractive power, a second optical element group G2 with negative refractive power, and a third optical element group G3 with positive refractive power. In this zoom lens 1, incident light passes through the first optical element group G1, causing the optical axis C to be bent by 90 degrees, and then passes through the second and third optical element groups G2 and G3, thereby forming an image on the imaging surface of an image sensor 5 such as a CMOS sensor. In addition, a UVIR cutoff filter 6 that modulates the wavelength of the incident light is disposed between the third optical element group G3 and the image sensor (imaging surface) 5.

[0113] In this zoom lens 1, the first optical element group G1, starting from the object side, includes: a first lens 11 (lens group 10) with positive refractive power, and a prism (reflective optical element) 15 that bends the light path. The second optical element group G2, starting from the object side, includes: a second lens 21 with positive refractive power, and a third lens 22 with negative refractive power. In the third lens 22 of the second optical element group G2, both the object-side and image-side surfaces are concave. The third optical element group G3, starting from the object side, includes: an aperture 7, a fourth lens 31 with positive refractive power, a fifth lens 32 with positive refractive power, a sixth lens 33 with negative refractive power, a seventh lens 34 with positive refractive power, and an eighth lens 35 with negative refractive power. In the fourth lens 31 of the third optical element group G3, the object-side surface is convex.

[0114] Furthermore, in this zoom lens 1, the second optical element group G2 and the third optical element group G3 respectively perform zoom functions by moving along the optical axis C. Additionally, in the zoom lens 1, at each zoom position, the second optical element group G2 moves along the optical axis C to adjust the focus from infinity to near. Furthermore, in the zoom lens 1, based on the vibration applied to the zoom lens 1, the third optical element group G3 shifts in a plane orthogonal to the optical axis C, thereby performing vibration correction. Alternatively, in the zoom lens 1, based on the aforementioned vibration, the image sensor (shooting surface) 5 may also shift in a plane orthogonal to the optical axis C, thereby performing vibration correction.

[0115] in addition, Figure 4 It is a longitudinal aberration map when focusing at infinity at the wide-angle end. Figure 5 This is the longitudinal aberration diagram when focusing at infinity at the telephoto end. Additionally, Table 2 below shows the surface data for each lens, Table 3 shows the aspherical data for each lens, Table 4 shows various data for focusing at infinity, Table 5 shows the position data of the focusing group when focusing at an object distance of 500mm, and Table 6 shows the group data for the zoom lens.

[0116] Table 2

[0117] Surface data

[0118]

[0119] ASP is an aspherical surface

[0120] Table 3

[0121]

[0122] Table 4

[0123] Various data when focusing at infinity

[0124]

[0125] Table 5

[0126] Position data of the focusing group when focusing at an object distance of 500m

[0127]

[0128] Table 6

[0129] Zoom lens group data

[0130]

[0131] Example 2

[0132] Figure 6This is a lens configuration diagram showing the positions of lenses 11, 15, 21, 22, and 31-37 of the zoom lens 1A constituting the wide-angle and telephoto ends of this embodiment 1. Specifically, the zoom lens 1A of this embodiment 2 includes, from the object side to the image side, a first optical element group G1 with positive refractive power, a second optical element group G2 with negative refractive power, and a third optical element group G3 with positive refractive power. In this zoom lens 1A, incident light passes through the first optical element group G1, causing the optical axis C to be bent by 90 degrees, and then passes through the second and third optical element groups G2 and G3, thereby forming an image on the imaging surface of an image sensor 5 such as a CMOS sensor. In addition, a UVIR cutoff filter 6 that modulates the wavelength of the incident light is disposed between the third optical element group G3 and the image sensor (imaging surface) 5.

[0133] In this zoom lens 1A, the first optical element group G1, starting from the object side, includes: a first lens 11 (lens group 10) with positive refractive power, and a prism (reflective optical element) 15 that bends the light path. The second optical element group G2, starting from the object side, includes: a second lens 21 with positive refractive power, a third lens 22 with negative refractive power, and an aperture 7. In the third lens 22 of the second optical element group G2, both the object-side and image-side surfaces are concave. The third optical element group G3, starting from the object side, includes: a fourth lens 31 with positive refractive power, a fifth lens 32 with positive refractive power, a sixth lens 33 with negative refractive power, a seventh lens 34 with negative refractive power, an eighth lens 35 with positive refractive power, a ninth lens 36 with negative refractive power, and a tenth lens 38 with positive refractive power. In the fourth lens 31 of the third optical element group G3, the object-side surface is convex.

[0134] Furthermore, in this zoom lens 1A, the second optical element group G2 and the third optical element group G3 respectively perform zoom functions by moving along the optical axis C. Additionally, in the zoom lens 1A, at each zoom position, the second optical element group G2 moves along the optical axis C to adjust the focus from infinity to near. Furthermore, in the zoom lens 1A, based on the vibration applied to the zoom lens 1, the third optical element group G3 shifts in a plane orthogonal to the optical axis C, thereby performing vibration correction. Alternatively, in the zoom lens 1, based on the aforementioned vibration, the image sensor (shooting surface) 5 may also shift in a plane orthogonal to the optical axis C, thereby performing vibration correction.

[0135] in addition, Figure 7 It is a longitudinal aberration map when focusing at infinity at the wide-angle end. Figure 8This is the longitudinal aberration diagram when focusing at infinity at the telephoto end. Additionally, Table 7 below shows the surface data for each lens, Table 8 shows the aspherical data for each lens, Table 9 shows various data for focusing at infinity, Table 10 shows the position data of the focusing group when focusing at an object distance of 500mm, and Table 11 shows the group data for the zoom lens.

[0136] Table 7

[0137] Surface data

[0138]

[0139] ASP is an aspherical surface

[0140] Table 8

[0141] Aspherical data

[0142]

[0143] Table 9

[0144] Various data when focusing at infinity

[0145]

[0146] Table 10

[0147] Position data of the focusing group when focusing at an object distance of 500m

[0148]

[0149] Table 11

[0150] Zoom lens group data

[0151]

[0152] To illustrate the invention, the invention has been appropriately and sufficiently described above with reference to the accompanying drawings and embodiments. However, those skilled in the art should recognize that modifications and / or improvements to the above embodiments are readily achievable. Therefore, any modifications or improvements implemented by those skilled in the art that do not depart from the scope of the claims set forth in the claims can be interpreted as being included within the scope of the claims.

[0153] Explanation of reference numerals in the attached figures:

[0154] 1. 1A: Zoom lens

[0155] 5: Image sensor

[0156] 8: Protective Glass

[0157] 10: Lens Group

[0158] 11: First Lens

[0159] 11a: The object-side surface of the first lens (the surface of the first optical element group closest to the object side).

[0160] 15: Reflective optical elements (prisms)

[0161] 15a: Reflective surface

[0162] 15b: Image-side surface of a reflecting optical element

[0163] 16: Lens tube

[0164] 16A: Bend

[0165] 16B: Main body

[0166] 21: Second Lens

[0167] 21a: The object-side surface of the second lens (the surface of the second optical element group closest to the object side).

[0168] 22: Third Lens

[0169] 31-38: Lenses 4-11

[0170] 31a: The surface of the third optical element group closest to the object.

[0171] 100: Filming equipment

[0172] 101: Main body of the filming device

[0173] 102: Display Section

[0174] 103: Control Unit (Computing Device)

[0175] 104: Power Supply

[0176] C: Optical axis

[0177] G1: First Optical Component Group

[0178] G2: Second optical element group

[0179] G3: Third Optical Component Group

Claims

1. A zoom lens, wherein, The zoom lens consists of a first optical element group, a second optical element group, and a third optical element group arranged sequentially from the object side to the image side. The first optical element group includes a lens group consisting of at least one lens, and an optical element that bends the optical axis. The second optical element group consists of at least one lens and has negative refractive power. The third optical element group consists of at least one lens and has positive refractive power. The lens group has positive refractive power and is positioned closer to the object than the optical element. The second and third optical element groups are configured to move along the optical axis, thereby allowing the zoom lens to change its magnification between the wide-angle and telephoto ends. Wherein, when the focal length of the first optical element group is defined as f1, and the focal length of the entire optical system at infinity at the telephoto end is defined as ft, the following conditions are met: 0.5≤f1 / ft≤6.

2. The zoom lens according to claim 1, wherein, When the distance along the optical axis from the surface closest to the object side of the first optical element group to the surface closest to the object side of the second optical element group is defined as D12, and the distance along the optical axis from the surface closest to the object side of the first optical element group to the image plane is defined as TTL, the following conditions are met: 0.2≤D12 / TTL≤0.

7.

3. The zoom lens according to claim 1 or 2, wherein, When the focal length of the third optical element group is defined as f3, the focal length of the entire optical system when focusing at infinity at the wide-angle end is defined as fw, and the focal length of the entire optical system when focusing at infinity at the telephoto end is defined as ft, the following conditions are met: 0.2≤f3 / √(fw×ft)≤1.

1.

4. The zoom lens according to claim 1 or 2, wherein, When the focal length of the second optical element group is defined as f2, and the focal length of the entire optical system at infinity at the telephoto end is defined as ft, the following conditions are met: 0.2≤|f2 / ft|≤1.

0.

5. The zoom lens according to claim 1 or 2, wherein, The maximum effective diameter h23 of the light transmission range in the second optical element group and the third optical element group is less than 9 mm.

6. The zoom lens according to claim 1 or 2, wherein, The distance along the optical axis from the surface of the first optical element group closest to the object to the image plane is less than 40 mm.

7. The zoom lens according to claim 1 or 2, wherein, The zoom lens has an aperture that adjusts the amount of light passing through. The aperture is positioned between the image-side surface of the optical elements in the first optical element group and the surface of the third optical element group closest to the object side.

8. The zoom lens according to claim 1 or 2, wherein, At least one surface of at least one lens in the third optical element group is aspherical.

9. The zoom lens according to claim 1 or 2, wherein, At least one lens in the third optical element group is made of plastic.

10. A shooting device, wherein, The imaging device includes: The zoom lens according to any one of claims 1 to 9; and The imaging element is positioned at the image plane of the zoom lens and converts the formed optical image into an electrical signal.

Images