CN213987011U

CN213987011U - Zoom optical system, zoom image capture module and electronic equipment

Info

Publication number: CN213987011U
Application number: CN202023327714.3U
Authority: CN
Inventors: 杨健; 李明
Original assignee: Jiangxi Jingchao Optical Co Ltd
Current assignee: Jiangxi Jingchao Optical Co Ltd
Priority date: 2020-12-31
Filing date: 2020-12-31
Publication date: 2021-08-17
Anticipated expiration: 2030-12-31

Abstract

The utility model relates to an optical system zooms, zooms and gets for instance module, electronic equipment and periscope formula optical system. The zoom optical system includes: a first lens group with positive refractive power, the first lens group comprising a first lens and a second lens; a second lens group with negative refractive power, the second lens group comprising a third lens and a fourth lens; a third lens group with positive refractive power, the third lens group comprising a fifth lens element, a sixth lens element and a seventh lens element; a fourth lens group with positive refractive power, the fourth lens group comprising an eighth lens; the distance between each lens group of the zooming optical system on the optical axis is adjustable, so that the focal length of the zooming optical system is changed; and the zoom optical system satisfies the following conditional expression: f7/f567 is less than or equal to-0.2; f7 is the effective focal length of the seventh lens, and f567 is the effective focal length of the third lens group. The zoom optical system has good imaging quality.

Description

Zoom optical system, zoom image capture module and electronic equipment

Technical Field

The utility model relates to a field of making a video recording especially relates to an optical system zooms, zooms and gets for instance module and electronic equipment.

Background

With the development of the field of image pickup, a periscopic image pickup apparatus has appeared, and a right-angle prism capable of changing the trend of an optical path is arranged on the object side of an optical system, so that the optical system can be transversely arranged in a shell of the periscopic image pickup apparatus during installation, and further the periscopic image pickup apparatus can have the characteristic of high zoom ratio while realizing a miniaturized design.

However, the imaging quality of the current periscopic imaging apparatus still needs to be improved.

SUMMERY OF THE UTILITY MODEL

Accordingly, there is a need for a zoom optical system, a zoom image capturing module and an electronic apparatus to improve the imaging quality of a periscopic imaging apparatus.

A zoom optical system includes, in order from an object side to an image side along an optical axis:

a first lens group with positive refractive power, the first lens group comprising a first lens with refractive power and a second lens with refractive power;

a second lens group with negative refractive power, the second lens group comprising a third lens with refractive power and a fourth lens with refractive power;

a third lens group with positive refractive power, the third lens group comprising a fifth lens with refractive power, a sixth lens with refractive power and a seventh lens with refractive power;

a fourth lens group with positive refractive power, the fourth lens group comprising an eighth lens with refractive power;

the distance between each lens group of the zooming optical system on the optical axis is adjustable, so that the focal length of the zooming optical system is changed;

and the zoom optical system satisfies the following conditional expression:

f7/f567≤-0.2；

where f7 is an effective focal length of the seventh lens, and f567 is an effective focal length of the third lens group, that is, a combined focal length of the fifth lens, the sixth lens, and the seventh lens.

In the zoom optical system, the seventh lens element provides negative refractive power for the third lens element, and when the conditional expression is satisfied, the negative refractive power borne by the seventh lens element in the third lens element can be reasonably configured, which is beneficial for the third lens element to balance spherical aberration generated by the first lens element and the second lens element; meanwhile, the seventh lens can provide reasonable negative refractive power for the zooming optical system so as to improve the imaging quality of the zooming optical system; in addition, the effective focal length of the third lens group can be controlled in a smaller range, so that the refractive power of the third lens group is increased, the third lens group can effectively converge the light at the rear end of the zoom optical system, and the total length of the zoom optical system can be shortened. When f7/f567 > -0.2, the refractive power distribution among the lenses of the third lens group is not uniform, which is not favorable for the third lens group to correct the aberrations generated by the first lens group and the second lens group.

In one embodiment, the zoom optical system satisfies the following conditional expression:

fc/fd≥1.4；

and fc is the effective focal length of the zoom optical system at the long-focus end, and fd is the effective focal length of the zoom optical system at the short-focus end. When the condition is satisfied, the ratio of the effective focal lengths of the zoom optical system at the long focal end and the short focal end can be reasonably configured, so that the zoom optical system obtains a higher zoom ratio, and a larger-range shooting magnification is realized. When fc/fd < 1.4, the zoom ratio of the zoom optical system is too small to satisfy the requirement of wide-range photographing.

3.5°/mm≤FOVc/ImgH≤6°/mm；

wherein, FOVc is the maximum angle of view of the zoom optical system at the telephoto end, and the unit is degree, and ImgH is the radius of the maximum effective imaging circle of the zoom optical system, and the unit is mm. When the condition formula is met, the ratio of the full-field angle of the zoom optical system at the telephoto end to the half-image height can be reasonably configured, so that the telephoto characteristic of the zoom optical system is favorably realized, and meanwhile, the zoom optical system has a large image surface and can be matched with photosensitive elements with higher pixels, so that high-definition shooting is realized.

15≤TTL/(ATg2+ATg3)≤150；

wherein TTL is a distance on an optical axis from an object-side surface of the first lens element to an image plane of the zoom optical system, i.e., an optical total length of the zoom optical system, ATg2 is a sum of air spaces on the optical axis between adjacent lens elements in the second lens element, i.e., a distance on the optical axis from an image-side surface of the third lens element to an object-side surface of the fourth lens element, and ATg3 is a sum of air spaces on the optical axis between adjacent lens elements in the third lens element, i.e., a sum of a distance on the optical axis from an image-side surface of the fifth lens element to an object-side surface of the sixth lens element and a distance on the optical axis from an image-side surface of the sixth lens element to an object-side surface of the seventh lens element. When the above conditional expressions are satisfied, the total optical length of the zoom optical system and the sum of the air intervals on the optical axis between the adjacent lenses in the second lens group and the third lens group can be reasonably configured, so that the total optical length of the zoom optical system can be shortened while a large zoom ratio of the zoom optical system is realized, the miniaturization design of the zoom optical system is realized, and the space is saved for electronic equipment carrying the zoom optical system. If the total length of the zoom optical system exceeds the upper limit of the above conditional expressions, the system tends to be too long, and this tends to increase the pressure on the spatial arrangement of the electronic device on which the zoom optical system is mounted, which is disadvantageous for the compact design of the electronic device, and also tends to decrease the stability of the zoom optical system itself.

1≤(R7+R8)/R14≤4；

wherein R7 is a radius of curvature of an object-side surface of the fourth lens element at an optical axis, R8 is a radius of curvature of an image-side surface of the fourth lens element at the optical axis, and R14 is a radius of curvature of an image-side surface of the seventh lens element at the optical axis. When the conditional expressions are satisfied, the curvature radius of the second lens group and the curvature radius of the image side surface of the seventh lens can be reasonably configured, which is beneficial to inhibiting the aberration generated by the second lens group, so that the aberration distribution of the second lens group and each lens group of the object side and the image side reaches a balanced state, and the imaging quality of the zoom optical system is further improved; in addition, the surface type of the fourth lens is restrained, so that the surface type of the fourth lens cannot be excessively bent, the forming processing difficulty of the fourth lens is reduced, and the surface type of the fourth lens cannot be too gentle, so that the fourth lens has proper deflection capability to light rays.

0.4≤f12/f567≤4；

wherein f12 is an effective focal length of the first lens group, i.e., a combined focal length of the first lens and the second lens, and f567 is an effective focal length of the third lens group, i.e., a combined focal length of the fifth lens, the sixth lens, and the seventh lens. When the above conditional expressions are satisfied, the ratio of the effective focal lengths of the first lens group and the third lens group can be reasonably configured, which is beneficial for the zoom optical system to obtain a larger zoom range, and in addition, the positive refractive power borne by the first lens group and the third lens group can also be reasonably configured, and the movement of the second lens group and the third lens group along the optical axis can realize different focal lengths of the zoom optical system in three states by matching with the negative refractive power contributed by the second lens group, thereby realizing the zoom characteristic of the zoom optical system.

In one embodiment, when the zoom optical system is at a telephoto end, the image-side surface of the fourth lens is an aperture stop of the zoom optical system, when the zoom optical system is at a short-focus end, the object-side surface of the fifth lens is an aperture stop of the zoom optical system, and the zoom optical system satisfies the following conditional expressions:

1.01≤SD9/SD8≤1.5；

wherein SD9 is half of the maximum effective aperture of the object side surface of the fifth lens, and SD8 is half of the maximum effective aperture of the image side surface of the fourth lens. When the condition is met, the aperture diaphragm of the zooming optical system can block marginal field rays of the zooming optical system at the short-focus end, so that the generation of distortion and astigmatism is reduced, the aberration generated by the zooming optical system is reduced, and the optical performance of the zooming optical system is improved. If the upper limit of the above conditional expression is exceeded, the aberration sensitivity of the zoom optical system is likely to be increased, and the optical performance of the zoom optical system is likely to be decreased.

In one embodiment, the zoom optical system further includes a reflective element disposed on an object side of the first lens, and the reflective element is configured to change a direction of an optical path. The zoom optical system adopts the reflecting element, so that the zoom optical system can be applied to periscopic imaging equipment, and the miniaturization design of the periscopic imaging equipment is facilitated.

In some of the embodiments, when the optical system zooms from a short focal end to a long focal end, a distance between the first lens group and the second lens group increases, and a distance between the third lens group and the fourth lens group increases.

A zoom image capture module includes a photosensitive element and the zoom optical system of any of the above embodiments, wherein the photosensitive element is disposed on an image side of the zoom optical system. The zoom optical system is adopted in the zoom image capturing module, the third lens group can balance spherical aberration generated by the first lens group and the second lens group, and the seventh lens group can provide reasonable negative refractive power for the zoom optical system, so that the imaging quality of the zoom image capturing module is improved, and the miniaturization design of the zoom image capturing module is facilitated.

An electronic device comprises a shell and the zooming and image-capturing module, wherein the zooming and image-capturing module is arranged on the shell. Adopt above-mentioned getting for instance module of zooming in the electronic equipment, be favorable to promoting electronic equipment's imaging quality, be favorable to simultaneously electronic equipment's miniaturized design.

Drawings

FIG. 1 is a schematic structural diagram of a zoom optical system in a telephoto state according to a first embodiment of the present application;

FIG. 2 is a schematic structural diagram of a zoom optical system in a short-focus state according to a first embodiment of the present application;

FIG. 3 is a schematic structural diagram of a zoom optical system in a middle focus state according to a first embodiment of the present application;

FIG. 4 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the zoom optical system in a telephoto state according to the first embodiment of the present application;

FIG. 5 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the zoom optical system in a short-focus state according to the first embodiment of the present application;

FIG. 6 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the zoom optical system in a middle focus state according to the first embodiment of the present application;

FIG. 7 is a schematic structural diagram of a zoom optical system in a telephoto state according to a second embodiment of the present application;

FIG. 8 is a schematic structural diagram of a zoom optical system in a short-focus state according to a second embodiment of the present application;

FIG. 9 is a schematic structural diagram of a zoom optical system in a middle focus state according to a second embodiment of the present application;

FIG. 10 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the zoom optical system in a telephoto state according to the second embodiment of the present application;

FIG. 11 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the zoom optical system in a short-focus state according to the second embodiment of the present application;

FIG. 12 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the zoom optical system in a middle focus state according to the second embodiment of the present application;

FIG. 13 is a schematic structural diagram of a zoom optical system in a telephoto state according to a third embodiment of the present application;

FIG. 14 is a schematic structural diagram of a zoom optical system in a short-focus state according to a third embodiment of the present application;

FIG. 15 is a schematic structural diagram of a zoom optical system in a middle focus state according to a third embodiment of the present application;

FIG. 16 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the zoom optical system in a telephoto state according to the third embodiment of the present application;

FIG. 17 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the zoom optical system in a short-focus state according to the third embodiment of the present application;

FIG. 18 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the zoom optical system in an intermediate focus state according to the third embodiment of the present application;

FIG. 19 is a schematic structural diagram of a zoom optical system in a telephoto state according to a fourth embodiment of the present application;

FIG. 20 is a schematic structural diagram of a zoom optical system in a short-focus state according to a fourth embodiment of the present application;

FIG. 21 is a schematic structural diagram of a zoom optical system in a middle focus state according to a fourth embodiment of the present application;

FIG. 22 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the zoom optical system in a telephoto state according to the fourth embodiment of the present application;

FIG. 23 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of a zoom optical system in a short-focus state according to a fourth embodiment of the present application;

FIG. 24 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of a zoom optical system in an intermediate focus state according to a fourth embodiment of the present application;

FIG. 25 is a schematic structural diagram of a zoom optical system in a telephoto state according to a fifth embodiment of the present application;

FIG. 26 is a schematic structural diagram of a zoom optical system in a short-focus state according to a fifth embodiment of the present application;

FIG. 27 is a schematic structural diagram of a zoom optical system in a middle focus state according to a fifth embodiment of the present application;

FIG. 28 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the zoom optical system in a telephoto state according to the fifth embodiment of the present application;

FIG. 29 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of a zoom optical system in a short-focus state according to a fifth embodiment of the present application;

FIG. 30 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of a zoom optical system in a middle focus state according to a fifth embodiment of the present application;

FIG. 31 is a schematic structural diagram illustrating an embodiment of a zoom image capturing module according to the present application;

fig. 32 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Detailed Description

In order to make the above objects, features and advantages of the present invention more comprehensible, embodiments of the present invention are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, as those skilled in the art will be able to make similar modifications without departing from the spirit and scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present application, unless expressly stated or limited otherwise, the first feature may be directly on or directly under the second feature or indirectly via intermediate members. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

Referring to fig. 1, in some embodiments of the present application, a zoom optical system 100 includes, in order from an object side to an image side along an optical axis 110, a first lens group L12, a second lens group L34, a third lens group L567, and a fourth lens group. The first lens group L12 includes a first lens L1 and a second lens L2. The second lens group L34 includes a third lens L3 and a fourth lens L4. The third lens group L567 includes a fifth lens L5, a sixth lens L6, and a seventh lens L7. The fourth lens group includes an eighth lens L8. Specifically, the first lens L1 includes an object-side surface S1 and an image-side surface S2, the second lens L2 includes an object-side surface S3 and an image-side surface S4, the third lens L3 includes an object-side surface S5 and an image-side surface S6, the fourth lens L4 includes an object-side surface S7 and an image-side surface S8, the fifth lens L5 includes an object-side surface S9 and an image-side surface S10, the sixth lens L6 includes an object-side surface S11 and an image-side surface S12, the seventh lens L7 includes an object-side surface S13 and an image-side surface S14, and the eighth lens L8 includes an object-side surface S15 and an image-side surface S16.

The first lens group L12 has positive refractive power, the second lens group L34 has negative refractive power, the third lens group L567 has positive refractive power, and the fourth lens group has positive refractive power. The first lens element L1, the second lens element L2, the third lens element L3, the fourth lens element L4, the fifth lens element L5, the sixth lens element L6, the seventh lens element L7 and the eighth lens element L8 all have refractive power.

It should be noted that, in some embodiments of the present application, the first lens group L12 and the fourth lens group are fixed relatively, and the second lens group L34 and the third lens group L567 are capable of moving along the optical axis 110, so as to implement the zooming function of the zooming optical system 100, such that the zooming optical system 100 has a long-focus state, a middle-focus state and a short-focus state, wherein the effective focal lengths of the zooming optical system 100 in the long-focus state, in the middle-focus state and in the short-focus state decrease sequentially. And when the zoom optical system 100 is at the telephoto end, the effective focal length of the zoom optical system 100 is the largest, and when the zoom optical system 100 is at the short-focus end, the effective focal length of the zoom optical system 100 is the smallest. It is understood that the third lens L3 and the fourth lens L4 move in synchronization along the optical axis 110 when the second lens group L34 moves along the optical axis 110, and the fifth lens L5, the sixth lens L6, and the seventh lens L7 move in synchronization along the optical axis 110 when the third lens group L567 moves along the optical axis 110. In addition, the second lens group L34 in some embodiments may move synchronously with the third lens group L567, or may move asynchronously.

For example, in some embodiments, the second lens group L34 is moved along the optical axis 110 in a direction away from the first lens group L12, and the third lens group L34 is moved along the optical axis 110 in a direction toward the fourth lens group, so that the effective focal length of the zoom optical system 100 is changed, achieving a zoom function of the zoom optical system 100. In some embodiments, when the second lens group L34 moves along the optical axis 110 in a direction away from the first lens group L12, i.e., the distance between the first lens group L12 and the second lens group L34 increases, and the third lens group L567 moves along the optical axis 110 in a direction away from the fourth lens group, i.e., the distance between the third lens group L567 and the fourth lens group also increases, the effective focal length of the zoom optical system 100 increases, in other words, the zoom optical system 100 transitions from a short-focus state to a medium-focus state, or from a medium-focus state to a long-focus state.

It should be noted that, in the present application, the long-focus state, the middle-focus state, and the short-focus state of the zoom optical system 100 are only examples of partial focal length states of the zoom optical system 100, and in other embodiments, as the relative positions of the second lens group L34 and the third lens group L567 and the first lens group L12 and the fourth lens group are changed, the effective focal length of the zoom optical system 100 may have other values, that is, the zoom optical system 100 may have other focal length states.

In some embodiments, the zoom optical system 100 may be applied to a zoom lens (not shown), and in this case, the zoom lens may further include a zoom ring and a fixed focus ring. The first lens group L12 and the fourth lens group are fixed in the zoom lens, a zoom ring and a fixed focus ring are arranged between the first lens group L12 and the fourth lens group, the zoom ring is fixedly connected with the second lens group L34, and the fixed focus ring is fixedly connected with the third lens group L567. The zoom ring can drive the second lens group L34 to move along the optical axis 110, and the fixed focus ring can drive the third lens group L567 to move along the optical axis 110, so as to implement the zoom function of the zoom lens. Of course, the zooming function of the zoom lens can be realized in other ways as long as the second lens group L34 and/or the third lens group L567 can be moved along the optical axis 110 to change the effective focal length of the zoom optical system 100, and will not be described herein again.

In addition, in some embodiments, the zoom optical system 100 further includes an infrared cut filter L9 disposed on the image side of the eighth lens L8, and the infrared cut filter L9 includes an object-side surface S17 and an image-side surface S18. Furthermore, the zoom optical system 100 further includes an image plane S19 located on the image side of the eighth lens L8, and incident light can be imaged on the image plane S19 after being adjusted by the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8. The infrared cut filter L9 is used to filter the interference light and prevent the interference light from reaching the image plane S19 of the zoom optical system 100 and affecting normal imaging.

In some embodiments, the object-side surface and the image-side surface of each lens of the zoom optical system 100 are aspheric, and the aspheric structure can improve the flexibility of each lens design, effectively correct the spherical aberration of the zoom optical system 100, and improve the imaging quality. In other embodiments, the object-side surface and the image-side surface of each lens of the optical system 100 may be spherical. It is noted that the above embodiments are merely examples of some embodiments of the present application, and in some embodiments, the surfaces of the lenses in the zoom optical system 100 may be aspheric surfaces or any combination of spherical surfaces.

In some embodiments, each lens in the zoom optical system 100 may be made of glass or plastic. The use of a plastic lens such as polycarbonate reduces the weight and production cost of the zoom optical system 100, while the use of a glass lens provides the zoom optical system 100 with excellent optical performance and high temperature resistance. The material of each lens of the zoom optical system 100 may be any combination of glass and plastic, and is not necessarily glass or plastic.

It is to be noted that the first lens L1 does not mean that there is only one lens, and in some embodiments, there may be two or more lenses in the first lens L1, and the two or more lenses can form a cemented lens, and a surface of the cemented lens closest to the object side can be regarded as the object side surface S1, and a surface of the cemented lens closest to the image side can be regarded as the image side surface S2. Alternatively, although no cemented lens is formed between the lenses of the first lens L1, the distance between the lenses is relatively fixed, and in this case, the object-side surface of the lens closest to the object side is the object-side surface S1, and the image-side surface of the lens closest to the image side is the image-side surface S2. In addition, the number of lenses in the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, or the eighth lens L8 in some embodiments may be greater than or equal to two, and a cemented lens may be formed between any two adjacent lenses, or a non-cemented lens may be used.

In some embodiments, the zoom optical system 100 may further include a right-angle prism 120, the material of the right-angle prism 120 may be glass or plastic, and the right-angle prism 120 is disposed on the object side of the first lens group L12 for changing the direction of the optical path. In some embodiments, the right-angle prism 120 can change the direction of the light path by 90 °, and at this time, the zoom optical system 100 forms a periscopic optical system, and the zoom optical system 100 can be applied to periscopic electronic devices with periscopic lens designs, such as smart phones and tablet computers. The right-angle prism 120 includes a first surface Sa, a second surface Sb and a third surface Sc, an included angle between the second surface Sb and the optical axis 110 is 90 °, and the second surface Sb can reflect light to change the direction of the optical path. The light enters the rectangular prism 120 from the first surface Sa, is reflected by the second surface Sb, and then exits from the third surface Sc, and further enters the first lens group L12. Of course, in other embodiments, the zoom optical system 100 may also use other reflective elements instead of the rectangular prism 120, as long as the reflective elements can change the direction of the optical path.

Further, in some embodiments, the zoom optical system 100 satisfies the conditional expression: f7/f567 is less than or equal to-0.2; where f7 is an effective focal length of the seventh lens L7, and f567 is an effective focal length of the third lens group L567. Specifically, f7/f567 may be: -0.81, -0.79, -0.78, -0.75, -0.73, -0.70, -0.64, -0.62, -0.60 or-0.59. The seventh lens element L7 provides negative refractive power for the third lens element L567, and when the above conditional expressions are satisfied, the negative refractive power of the seventh lens element L7 in the third lens element L567 can be reasonably configured, which is favorable for the third lens element L567 to balance the spherical aberration generated by the first lens element L12 and the second lens element L34; meanwhile, the seventh lens element L7 can provide a reasonable negative refractive power for the zoom optical system 100 to improve the imaging quality of the zoom optical system 100, and in addition, the effective focal length of the third lens element L567 can be controlled within a small range, so as to increase the refractive power of the third lens element L567, so that the third lens element L567 can effectively converge the light at the rear end of the zoom optical system 100, thereby facilitating shortening of the total system length of the zoom optical system 100. When f7/f567 > -0.2, the refractive power distribution among the lenses of the third lens group L567 is not uniform, which is not favorable for the third lens group L567 to correct the aberrations generated by the first lens group L12 and the second lens group L34.

In some embodiments, the zoom optical system 100 satisfies the conditional expression: fc/fd is more than or equal to 1.4; where fc is the effective focal length of the zoom optical system 100 at the telephoto end, and fd is the effective focal length of the zoom optical system 100 at the telephoto end. Specifically, fc/fd may be: 1.66, 1.68, 1.70, 1.71, 1.73, 1.76, 1.77, 1.78, 1.80 or 1.81. When the above conditional expressions are satisfied, the ratio of the effective focal lengths of the zoom optical system 100 at the telephoto end and the short-focus end can be reasonably configured, so that the zoom optical system 100 obtains a higher zoom ratio, thereby realizing a larger range of photographing magnification. When fc/fd < 1.4, the zoom ratio of the zoom optical system 100 is too small to satisfy the requirement of wide-range photographing.

In some embodiments, the zoom optical system 100 satisfies the conditional expression: FOVc/imgH is more than or equal to 3.5 and less than or equal to 6; where FOVc is the maximum field angle of the zoom optical system 100 at the telephoto end, and is given in degrees, and ImgH is the radius of the maximum effective imaging circle of the zoom optical system 100, and is given in mm. Specifically, FOVc/ImgH may be: 4.52, 4.58, 4.60, 4.61, 4.67, 4.69, 4.70, 4.73, 4.77, or 4.91, in units of °/mm. When the above conditional expressions are satisfied, the ratio of the full field angle at the telephoto end of the zoom optical system 100 to the half-image height can be reasonably configured, which is beneficial to realizing the telephoto characteristic of the zoom optical system 100, and meanwhile, the zoom optical system 100 has a large image plane and can be matched with photosensitive elements with higher pixels, thereby realizing high-definition shooting.

It should be noted that, in the present application, the zoom optical system 100 may match a photosensitive element having a rectangular photosensitive surface, and the imaging surface of the zoom optical system 100 coincides with the photosensitive surface of the photosensitive element. At this time, the effective pixel area on the imaging plane of the zoom optical system 100 has a horizontal direction and a diagonal direction, and ImgH can be understood as a half length of the effective pixel area on the imaging plane of the zoom optical system 100 in the diagonal direction.

In some embodiments, the zoom optical system 100 satisfies the conditional expression: TTL/(ATg2+ ATg3) is more than or equal to 15 and less than or equal to 150; TTL is a distance from an object-side surface S1 of the first lens element L1 to an image plane of the zoom optical system 100 on the optical axis 110, ATg2 is a distance from an image-side surface S6 of the third lens element L3 to an object-side surface S9 of the fourth lens element L4 on the optical axis 110, and ATg3 is a sum of air gaps between adjacent lens elements in the third lens element L567 on the optical axis 110. Specifically, TTL/(ATg2+ ATg3) may be: 42.73, 46.52, 49.33, 55.04, 69.82, 70.85, 73.98, 79.55, 81.39, or 97.54. When the above conditional expressions are satisfied, the total optical length of the zoom optical system 100 and the sum of the air spaces on the optical axis 110 between the adjacent lenses in the second lens group L34 and the third lens group L567 can be arranged reasonably, which is advantageous for achieving a large zoom ratio of the zoom optical system 100, shortening the total system length of the zoom optical system 100, achieving a compact design of the zoom optical system 100, and saving space for an electronic device on which the zoom optical system 100 is mounted. If the upper limit of the above conditional expression is exceeded, the total system length of the zoom optical system 100 becomes too large, which tends to increase the pressure on the spatial arrangement of the electronic device on which the zoom optical system 100 is mounted, and is disadvantageous for the compact design of the electronic device, and also reduces the stability of the zoom optical system 100 itself.

In some embodiments, the zoom optical system 100 satisfies the conditional expression: 1 is more than or equal to (R7+ R8)/R14 is less than or equal to 4; wherein R7 is a radius of curvature of the object-side surface S7 of the fourth lens element L4 along the optical axis 110, R8 is a radius of curvature of the image-side surface S8 of the fourth lens element L4 along the optical axis 110, and R14 is a radius of curvature of the image-side surface S14 of the seventh lens element L7 along the optical axis 110. Specifically, (R7+ R8)/R14 may be: 1.67, 1.71, 1.73, 1.80, 1.88, 1.91, 1.94, 1.99, 2.13 or 2.25. When the above conditional expressions are satisfied, the curvature radius of the second lens element of the second lens group L34 and the curvature radius of the image-side surface S14 of the seventh lens element L7 can be reasonably arranged, which is favorable for suppressing the aberration generated by the second lens group L34, so that the aberration distribution of the second lens group L34 and each lens group on the object side and the image side reaches a balanced state, and further the imaging quality of the zoom optical system 100 is improved; in addition, the surface shape of the fourth lens L4 is restrained, the surface shape of the fourth lens L4 is not excessively bent, the forming processing difficulty of the fourth lens L4 is reduced, and the surface shape of the fourth lens is not excessively gentle, so that the fourth lens has proper deflection capability to light rays.

In some embodiments, the zoom optical system 100 satisfies the conditional expression: f12/f567 is more than or equal to 0.4 and less than or equal to 4; where f12 is the effective focal length of the first lens group L12, and f567 is the effective focal length of the third lens group L567. Specifically, f12/f567 may be: 1.68, 1.71, 1.74, 1.75, 1.80, 1.93, 1.95, 1.98, 2.02, or 2.47. When the above conditional expressions are satisfied, the ratio of the effective focal lengths of the first lens group L12 and the third lens group L567 can be reasonably configured, which is beneficial to obtaining a larger zoom range of the zoom optical system 100, and in addition, the positive refractive power borne by the first lens group L12 and the third lens group L567 can also be reasonably configured, and the negative refractive power contributed by the second lens group L34 is matched, so that the movement of the second lens group L34 and the third lens group L567 along the optical axis 110 can realize different focal lengths of the zoom optical system 100 in three states, thereby realizing the zoom characteristic of the zoom optical system 100.

In some embodiments, when the zoom optical system 100 is at the telephoto end, the image-side surface S8 of the fourth lens L4 is an aperture stop of the zoom optical system 100, when the zoom optical system 100 is at the short-focus end, the object-side surface S9 of the fifth lens L5 is an aperture stop of the zoom optical system 100, and the zoom optical system 100 satisfies the conditional expression: SD9/SD8 is more than or equal to 1.01 and less than or equal to 1.5; the SD9 is half of the maximum effective diameter of the object-side surface S9 of the fifth lens L5, and the SD8 is half of the maximum effective diameter of the image-side surface S8 of the fourth lens L4. Specifically, SD9/SD8 may be: 1.17, 1.18, 1.19, 1.20, 1.21 or 1.22. When the above conditional expressions are satisfied, the aperture stop of the zoom optical system 100 can block the marginal field ray when the zoom optical system 100 is at the short focal end, so as to reduce the distortion and astigmatism, further reduce the aberration generated by the zoom optical system 100, and improve the optical performance of the zoom optical system 100. If the upper limit of the above conditional expression is exceeded, the aberration sensitivity of the zoom optical system 100 tends to increase, and the optical performance of the zoom optical system 100 tends to decrease.

Based on the above description of the embodiments, more specific embodiments and drawings are set forth below for detailed description.

First embodiment

Referring to fig. 1, fig. 2, fig. 3, fig. 4, fig. 5, and fig. 6, fig. 1 is a schematic diagram of a zoom optical system 100 in a first embodiment in a telephoto state, fig. 2 is a schematic diagram of the zoom optical system 100 in the first embodiment in a short-focus state, and fig. 3 is a schematic diagram of the zoom optical system 100 in the first embodiment in a middle-focus state. The zoom optical system 100 includes, in order from an object side to an image side, a right-angled prism 120, a first lens element L1 with positive refractive power, a second lens element L2 with negative refractive power, a third lens element L3 with negative refractive power, a fourth lens element L4 with positive refractive power, a fifth lens element L5 with positive refractive power, a sixth lens element L6 with positive refractive power, a seventh lens element L7 with negative refractive power, and an eighth lens element L8 with positive refractive power. Fig. 4 is a graph of spherical aberration, astigmatism and distortion of the zoom optical system 100 in a telephoto state in the first embodiment, fig. 5 is a graph of spherical aberration, astigmatism and distortion of the zoom optical system 100 in a short focus state in the first embodiment, and fig. 6 is a graph of spherical aberration, astigmatism and distortion of the zoom optical system 100 in an intermediate focus state in the first embodiment, in which the reference wavelengths of the astigmatism diagram and the distortion diagram of the zoom optical system 100 in the three states are 587.56nm, and other embodiments are the same.

The object-side surface S1 of the first lens element L1 is convex at the paraxial region and convex at the peripheral region;

the image-side surface S2 of the first lens element L1 is convex at the paraxial region and concave at the peripheral region;

the object-side surface S3 of the second lens element L2 is concave at the paraxial region and concave at the peripheral region;

the image-side surface S4 of the second lens element L2 is concave at the paraxial region and convex at the peripheral region;

the object-side surface S5 of the third lens element L3 is concave at the paraxial region and concave at the peripheral region;

the image-side surface S6 of the third lens element L3 is concave at the paraxial region and convex at the peripheral region;

the object-side surface S7 of the fourth lens element L4 is convex at the paraxial region and concave at the peripheral region;

the image-side surface S8 of the fourth lens element L4 is concave at the paraxial region and convex at the peripheral region;

the object-side surface S9 of the fifth lens element L5 is convex at the paraxial region and convex at the peripheral region;

the image-side surface S10 of the fifth lens element L5 is convex at the paraxial region and convex at the peripheral region;

the object-side surface S11 of the sixth lens element L6 is convex at the paraxial region and convex at the peripheral region;

the image-side surface S12 of the sixth lens element L6 is convex at the paraxial region and convex at the peripheral region;

the object-side surface S13 of the seventh lens element L7 is concave at the paraxial region and concave at the peripheral region;

the image-side surface S14 of the seventh lens element L7 is concave at the paraxial region and concave at the peripheral region;

the object-side surface S15 of the eighth lens element L8 is concave at the paraxial region and convex at the peripheral region;

the image-side surface S16 of the eighth lens element L8 is convex at the paraxial region and convex at the peripheral region.

The object-side surface and the image-side surface of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8 are aspheric.

It should be noted that, in the present application, when a surface of the lens is described as being convex at the paraxial region (the central region of the side surface), it is understood that the region of the surface of the lens near the optical axis 110 is convex. When a surface of a lens is described as concave at the circumference, it is understood that the surface is concave near the region of maximum effective radius. For example, when the surface is convex at the paraxial region and also convex at the peripheral region, the shape of the surface from the center (optical axis 110) to the edge direction may be purely convex; or a convex shape at the center is firstly transited to a concave shape, and then becomes a convex shape near the maximum effective radius. Here, only examples are made to illustrate the relationship at the optical axis 110 and the circumference, and various shape structures (concave-convex relationship) of the surface are not fully embodied, but other cases can be derived from the above examples.

The first lens L1, the third lens L3, the fourth lens L4 and the eighth lens L8 are all made of plastic, and the second lens L2, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are all made of glass.

Further, the zoom optical system 100 satisfies the conditional expression: f7/f567 is-0.66; where f7 is an effective focal length of the seventh lens L7, and f567 is an effective focal length of the third lens group L567. The seventh lens element L7 provides negative refractive power for the third lens element L567, and when the above conditional expressions are satisfied, the negative refractive power of the seventh lens element L7 in the third lens element L567 can be reasonably configured, which is favorable for the third lens element L567 to balance the spherical aberration generated by the first lens element L12 and the second lens element L34; meanwhile, the seventh lens element L7 can provide a reasonable negative refractive power for the zoom optical system 100 to improve the imaging quality of the zoom optical system 100, and in addition, the effective focal length of the third lens element L567 can be controlled within a small range, so as to increase the refractive power of the third lens element L567, so that the third lens element L567 can effectively converge the light at the rear end of the zoom optical system 100, thereby facilitating shortening of the total system length of the zoom optical system 100.

The zoom optical system 100 satisfies the conditional expression: fc/fd is 1.66; where fc is the effective focal length of the zoom optical system 100 at the telephoto end, and fd is the effective focal length of the zoom optical system 100 at the telephoto end. When the above conditional expressions are satisfied, the ratio of the effective focal lengths of the zoom optical system 100 at the telephoto end and the short-focus end can be reasonably configured, so that the zoom optical system 100 obtains a higher zoom ratio, thereby realizing a larger range of photographing magnification.

The zoom optical system 100 satisfies the conditional expression: FOVc/imgH is 4.91; where FOVc is the maximum field angle of the zoom optical system 100 at the telephoto end, and is given in degrees, and ImgH is the radius of the maximum effective imaging circle of the zoom optical system 100, and is given in mm. When the above conditional expressions are satisfied, the ratio of the full field angle at the telephoto end of the zoom optical system 100 to the half-image height can be reasonably configured, which is beneficial to realizing the telephoto characteristic of the zoom optical system 100, and meanwhile, the zoom optical system 100 has a large image plane and can be matched with photosensitive elements with higher pixels, thereby realizing high-definition shooting.

The zoom optical system 100 satisfies the conditional expression: TTL/(ATg2+ ATg3) ═ 56.43; TTL is a distance from an object-side surface S1 of the first lens element L1 to an image plane of the zoom optical system 100 on the optical axis 110, ATg2 is a distance from an image-side surface S6 of the third lens element L3 to an object-side surface S9 of the fourth lens element L4 on the optical axis 110, and ATg3 is a sum of air gaps between adjacent lens elements in the third lens element L567 on the optical axis 110. When the above conditional expressions are satisfied, the total optical length of the zoom optical system 100 and the sum of the air spaces on the optical axis 110 between the adjacent lenses in the second lens group L34 and the third lens group L567 can be arranged reasonably, which is advantageous for achieving a large zoom ratio of the zoom optical system 100, shortening the total system length of the zoom optical system 100, achieving a compact design of the zoom optical system 100, and saving space for an electronic device on which the zoom optical system 100 is mounted.

The zoom optical system 100 satisfies the conditional expression: (R7+ R8)/R14 ═ 1.93; wherein R7 is a radius of curvature of the object-side surface S7 of the fourth lens element L4 along the optical axis 110, R8 is a radius of curvature of the image-side surface S8 of the fourth lens element L4 along the optical axis 110, and R14 is a radius of curvature of the image-side surface S14 of the seventh lens element L7 along the optical axis 110. When the above conditional expressions are satisfied, the curvature radius of the second lens element of the second lens group L34 and the curvature radius of the image-side surface S14 of the seventh lens element L7 can be reasonably arranged, which is favorable for suppressing the aberration generated by the second lens group L34, so that the aberration distribution of the second lens group L34 and each lens group on the object side and the image side reaches a balanced state, and further the imaging quality of the zoom optical system 100 is improved; in addition, the surface shape of the fourth lens L4 is restrained, the surface shape of the fourth lens L4 is not excessively bent, the forming processing difficulty of the fourth lens L4 is reduced, and the surface shape of the fourth lens is not excessively gentle, so that the fourth lens has proper deflection capability to light rays.

The zoom optical system 100 satisfies the conditional expression: f12/f567 is 2.47; where f12 is the effective focal length of the first lens group L12, and f567 is the effective focal length of the third lens group L567. When the above conditional expressions are satisfied, the ratio of the effective focal lengths of the first lens group L12 and the third lens group L567 can be reasonably configured, which is beneficial to obtaining a larger zoom range of the zoom optical system 100, and in addition, the positive refractive power borne by the first lens group L12 and the third lens group L567 can also be reasonably configured, and the negative refractive power contributed by the second lens group L34 is matched, so that the movement of the second lens group L34 and the third lens group L567 along the optical axis 110 can realize different focal lengths of the zoom optical system 100 in three states, thereby realizing the zoom characteristic of the zoom optical system 100.

When the zoom optical system 100 is at the telephoto end, the image-side surface S8 of the fourth lens L4 is an aperture stop of the zoom optical system 100, when the zoom optical system 100 is at the short-focus end, the object-side surface S9 of the fifth lens L5 is an aperture stop of the zoom optical system 100, and the zoom optical system 100 satisfies the conditional expressions: SD9/SD8 is 1.21; the SD9 is half of the maximum effective diameter of the object-side surface S9 of the fifth lens L5, and the SD8 is half of the maximum effective diameter of the image-side surface S8 of the fourth lens L4. When the above conditional expressions are satisfied, the aperture stop of the zoom optical system 100 can block the marginal field ray when the zoom optical system 100 is at the short focal end, so as to reduce the distortion and astigmatism, further reduce the aberration generated by the zoom optical system 100, and improve the optical performance of the zoom optical system 100. If the upper limit of the above conditional expression is exceeded, the aberration sensitivity of the zoom optical system 100 tends to increase, and the optical performance of the zoom optical system 100 tends to decrease.

In addition, the parameters of the zoom optical system 100 are given by table 1 and table 2. Among them, the image plane S19 in table 1 may be understood as an imaging plane of the optical system 100. The elements from the object plane (not shown) to the image plane S19 are sequentially arranged in the order of the elements from top to bottom in table 1. The Y radius in table 1 is the radius of curvature of the object-side or image-side surface at the optical axis 110 for the corresponding surface number. Surface number 1 and surface number 2 are the object-side surface S1 and the image-side surface S2 of the first lens L1, respectively, that is, in the same lens, the surface with the smaller surface number is the object-side surface, and the surface with the larger surface number is the image-side surface. The first value in the "thickness" parameter column of the first lens element L1 is the thickness of the lens element along the optical axis 110, and the second value is the distance from the image-side surface of the lens element to the object-side surface of the following lens element along the image-side direction along the optical axis 110.

Note that, in this embodiment and the following embodiments, the optical system 100 may not be provided with the infrared filter L9, but the distance from the image-side surface S16 of the eighth lens L8 to the image surface S19 is kept constant at this time.

In the first embodiment, the effective focal length f of the zoom optical system 100 at the short focal end is 13.8mm, the effective focal length f at the middle focal end is 18.0mm, and the effective focal length f at the long focal end is 23 mm; the zoom optical system 100 has a f-number FNO at the short focus end of 2.821, a f-number FNO at the middle focus end of 3.11, and a f-number FNO at the long focus end of 3.82; the maximum field angle FOV at the short focus end of the zoom optical system 100 is 32.8 °, the maximum field angle FOV at the intermediate focus end is 24.8 °, the maximum field angle FOV at the long focus end is 19.6 °, that is, the numerical values of the effective focal length, f-number, and field angle in table 1, where the first numerical value indicates the numerical value of the zoom optical system 100 at the short focus end, the second numerical value indicates the numerical value of the zoom optical system 100 at the intermediate focus end, and the third numerical value indicates the numerical value of the zoom optical system 100 at the long focus end, and the other embodiments are also the same. The total optical length TTL of the zoom optical system 100 is 25 mm.

And the reference wavelengths of the focal length, refractive index and abbe number of each lens are 587.56nm (d-line), and the same applies to other embodiments.

TABLE 1

TABLE 2

The relative position relationship of the lens groups of the zoom optical system 100 in the first embodiment in different focal length states is shown in the following table, where D1 is the distance between the first lens group L12 and the second lens group L34 on the optical axis 110, i.e., the distance between the image-side surface S4 of the second lens L2 and the object-side surface S5 of the third lens L3 on the optical axis 110, D2 is the air distance between the second lens group L34 and the third lens group L567 on the optical axis 110, D3 is the air distance between the third lens group L567 and the fourth lens group on the optical axis 110, and the numerical units of D1, D2, and D3 are all mm. As can be seen from the following table, when the second lens group L34 is moved along the optical axis 110 in a direction away from the first lens group L12, and the third lens group L567 is moved along the optical axis 110 in a direction away from the fourth lens group, the effective focal length of the zoom optical system 100 increases.

Variable distance	State of long focus	Short focal state	Middle coke state
				D1	2.6023	1.1037	2.1192
D2	1.0278	4.7870	2.7845
				D3	6.6585	4.4779	5.3091

Further, aspheric coefficients of the image-side surface or the object-side surface of each lens of the optical system 100 are given in table 3. In which the surface numbers 1-16 represent image side surfaces or object side surfaces S1-S16, respectively. And K-a20 from left to right respectively represent the type of aspheric coefficients, where K represents a conic coefficient, a4 represents a quartic aspheric coefficient, a6 represents a sextic aspheric coefficient, A8 represents an octal aspheric coefficient, and so on. In addition, the aspherical surface coefficient formula is as follows:

where Z is the distance from the corresponding point on the aspheric surface to the plane tangent to the surface vertex, r is the distance from the corresponding point on the aspheric surface to the optical axis 110, c is the curvature of the aspheric surface vertex, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th high order term in the aspheric surface profile formula.

TABLE 3

In addition, fig. 4, 5, and 6 include Longitudinal Spherical Aberration diagrams (Longitudinal Spherical aberrations) of the zoom optical system 100 in different focal length states, which indicate the convergent focus deviations of the light rays of different wavelengths after passing through the lens. The ordinate of the longitudinal spherical aberration diagram represents the Normalized Pupil coordinate (Normalized Pupil Coordinator) from the Pupil center to the Pupil edge, and the abscissa represents the distance (in mm) of the imaging plane from the intersection of the ray with the optical axis 110. It can be known from the longitudinal spherical aberration diagram that the convergent focus deviation degrees of the light rays with different wavelengths in the first embodiment tend to be consistent, and the diffuse speckle or the chromatic halo in the imaging picture is effectively suppressed. Fig. 4, 5 and 6 further include field curvature diagrams (ASTIGMATIC FIELD CURVES) of the zoom optical system 100 at different focal lengths, where the S-curve represents sagittal field curvature at 587.5618nm (d-line) and the T-curve represents meridional field curvature at 587.5618nm (d-line). As can be seen from the figure, the curvature of field of the optical system 100 is small, the curvature of field and astigmatism of each field are well corrected, and the center and the edge of the field have clear images. Fig. 4, 5 and 6 further include DISTORTION maps (distorsion) of the zoom optical system 100 in different focal length states, and it can be seen from the figures that the image DISTORTION caused by the main beam is small and the imaging quality of the system is excellent.

Second embodiment

Referring to fig. 7, 8, 9, 10, 11 and 12, fig. 7 is a schematic diagram of a zoom optical system 100 in a telephoto state in the second embodiment, fig. 8 is a schematic diagram of a zoom optical system 100 in a short-focus state in the second embodiment, and fig. 9 is a schematic diagram of a zoom optical system 100 in a middle-focus state in the second embodiment. The zoom optical system 100 includes, in order from an object side to an image side, a right-angled prism 120, a first lens element L1 with positive refractive power, a second lens element L2 with positive refractive power, a third lens element L3 with negative refractive power, a fourth lens element L4 with negative refractive power, a fifth lens element L5 with positive refractive power, a sixth lens element L6 with positive refractive power, a seventh lens element L7 with negative refractive power, and an eighth lens element L8 with positive refractive power. Fig. 10 is a graph sequentially showing the spherical aberration, astigmatism and distortion of the zoom optical system 100 in a telephoto state in the second embodiment from left to right, fig. 11 is a graph sequentially showing the spherical aberration, astigmatism and distortion of the zoom optical system 100 in a short focus state in the second embodiment from left to right, and fig. 12 is a graph sequentially showing the spherical aberration, astigmatism and distortion of the zoom optical system 100 in an intermediate focus state in the second embodiment from left to right.

the object-side surface S3 of the second lens element L2 is convex at the paraxial region and concave at the peripheral region;

the image-side surface S6 of the third lens element L3 is concave at the paraxial region and concave at the peripheral region;

the image-side surface S12 of the sixth lens element L6 is concave at the paraxial region and convex at the peripheral region;

the object-side surface S15 of the eighth lens element L8 is convex at the paraxial region and concave at the peripheral region;

The object-side surface and the image-side surface of the first lens L1 and the second lens L2 are spherical surfaces, and the object-side surface and the image-side surface of the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8 are aspherical surfaces.

In addition, the parameters of the optical system 100 are given in tables 4 and 5, and the definitions of the parameters can be obtained from the first embodiment, which is not described herein again.

TABLE 4

TABLE 5

The relative position relationship of the lens groups of the zoom optical system 100 in different focal length states in the second embodiment is shown in the following table, and the definitions of the parameters can be obtained from the first embodiment, which is not repeated herein.

Variable distance	State of long focus	Short focal state	Middle coke state
				D1	1.7870	1.1100	1.4683
D2	1.0719	4.7713	2.8296
				D3	7.4161	4.4737	5.8971

Further, the aspheric coefficients of the image-side surface or the object-side surface of each lens of the zoom optical system 100 are shown in table 6, and the definitions of the parameters can be derived from the first embodiment, which is not described herein again.

TABLE 6

And, according to the above provided parameter information, the following data can be derived:

f7/f567	-0.67	(R7+R8)/R14	1.79
				fc/fd	1.66	f12/f567	1.68
FOVc/ImgH	4.91	SD9/SD8	1.22
				TTL/(ATg2+ATg3)	43.33

in addition, as can be seen from the aberration diagrams in fig. 10, 11, and 12, the longitudinal spherical aberration, curvature of field, and distortion of the zoom optical system 100 in various focal length states are well controlled, so that the zoom optical system 100 of this embodiment has good imaging quality.

Third embodiment

Referring to fig. 13, 14, 15, 16, 17, and 18, fig. 13 is a schematic diagram of a zoom optical system 100 in a telephoto state in the third embodiment, fig. 14 is a schematic diagram of a zoom optical system 100 in a short-focus state in the third embodiment, and fig. 15 is a schematic diagram of a zoom optical system 100 in a middle-focus state in the third embodiment. The zoom optical system 100 includes, in order from an object side to an image side, a right-angled prism 120, a first lens element L1 with positive refractive power, a second lens element L2 with negative refractive power, a third lens element L3 with negative refractive power, a fourth lens element L4 with positive refractive power, a fifth lens element L5 with positive refractive power, a sixth lens element L6 with positive refractive power, a seventh lens element L7 with negative refractive power, and an eighth lens element L8 with positive refractive power. Fig. 16 is a graph sequentially showing the spherical aberration, astigmatism and distortion of the zoom optical system 100 in a telephoto state in the third embodiment from left to right, fig. 17 is a graph sequentially showing the spherical aberration, astigmatism and distortion of the zoom optical system 100 in a short focus state in the third embodiment from left to right, and fig. 18 is a graph sequentially showing the spherical aberration, astigmatism and distortion of the zoom optical system 100 in an intermediate focus state in the third embodiment from left to right.

the image-side surface S2 of the first lens element L1 is concave at the paraxial region and convex at the peripheral region;

the object-side surface S3 of the second lens element L2 is convex at the paraxial region and convex at the peripheral region;

the image-side surface S4 of the second lens element L2 is concave at the paraxial region and concave at the peripheral region;

the object-side surface S15 of the eighth lens element L8 is concave at the paraxial region and concave at the peripheral region;

In addition, the parameters of the optical system 100 are given in tables 7 and 8, and the definitions of the parameters can be obtained from the first embodiment, which is not described herein.

TABLE 7

TABLE 8

The relative position relationship of the lens groups of the zoom optical system 100 in different focal length states in the third embodiment is shown in the following table, and the definitions of the parameters can be obtained from the first embodiment, which is not repeated herein.

Variable distance	State of long focus	Short focal state	Middle coke state
				D1	2.4010	1.2284	1.8627
D2	1.0369	5.0599	2.9719
				D3	7.2363	4.4658	5.7596

Further, the aspheric coefficients of the image-side surface or the object-side surface of each lens of the zoom optical system 100 are given in table 9, and the definitions of the parameters can be derived from the first embodiment, which is not described herein again.

TABLE 9

f7/f567	-0.59	(R7+R8)/R14	2.25
				fc/fd	1.67	f12/f567	2.30
FOVc/ImgH	4.90	SD9/SD8	1.20
				TTL/(ATg2+ATg3)	42.73

in addition, as is clear from the aberration diagrams in fig. 16, 17, and 18, the longitudinal spherical aberration, curvature of field, and distortion of the zoom optical system 100 in various focal length states are well controlled, and the zoom optical system 100 of this embodiment has good imaging quality.

Fourth embodiment

Referring to fig. 19, fig. 20, fig. 21, fig. 22, fig. 23, and fig. 24, fig. 19 is a schematic diagram of a zoom optical system 100 in a telephoto state in the fourth embodiment, fig. 20 is a schematic diagram of a zoom optical system 100 in a short-focus state in the fourth embodiment, and fig. 21 is a schematic diagram of a zoom optical system 100 in a middle-focus state in the fourth embodiment. The zoom optical system 100 includes, in order from an object side to an image side, a right-angled prism 120, a first lens element L1 with positive refractive power, a second lens element L2 with negative refractive power, a third lens element L3 with negative refractive power, a fourth lens element L4 with positive refractive power, a fifth lens element L5 with positive refractive power, a sixth lens element L6 with positive refractive power, a seventh lens element L7 with negative refractive power, and an eighth lens element L8 with positive refractive power. Fig. 22 is a graph sequentially showing the spherical aberration, astigmatism and distortion of the zoom optical system 100 in a telephoto state in the fourth embodiment from left to right, fig. 23 is a graph sequentially showing the spherical aberration, astigmatism and distortion of the zoom optical system 100 in a short focus state in the fourth embodiment from left to right, and fig. 24 is a graph sequentially showing the spherical aberration, astigmatism and distortion of the zoom optical system 100 in an intermediate focus state in the fourth embodiment from left to right.

the image-side surface S2 of the first lens element L1 is convex at the paraxial region and convex at the peripheral region;

the image-side surface S4 of the second lens element L2 is convex at the paraxial region and concave at the peripheral region;

the object-side surface S9 of the fifth lens element L5 is convex at the paraxial region and concave at the peripheral region;

In addition, the parameters of the optical system 100 are given in tables 10 and 11, and the definitions of the parameters can be obtained from the first embodiment, which is not described herein again.

Watch 10

TABLE 11

The relative position relationship of the lens groups of the zoom optical system 100 in different focal length states in the fourth embodiment is shown in the following table, and the definitions of the parameters can be obtained from the first embodiment, which is not repeated herein.

Variable distance	State of long focus	Short focal state	Middle coke state
				D1	2.0017	0.8966	1.4590
D2	1.0572	5.2199	3.1805
				D3	7.4075	4.4299	5.7469

Further, the aspheric coefficients of the image-side surface or the object-side surface of each lens of the zoom optical system 100 are given in table 12, and the definitions of the parameters can be derived from the first embodiment, which is not described herein again.

TABLE 12

f7/f567	-0.70	(R7+R8)/R14	1.67
				fc/fd	1.74	f12/f567	1.92
FOVc/ImgH	4.70	SD9/SD8	1.19
				TTL/(ATg2+ATg3)	47.33

in addition, as is clear from the aberration diagrams in fig. 22, 23, and 24, the longitudinal spherical aberration, curvature of field, and distortion of the zoom optical system 100 in various focal length states are well controlled, and the zoom optical system 100 of this embodiment has good imaging quality.

Fifth embodiment

Referring to fig. 25, fig. 26, fig. 27, fig. 28, fig. 29 and fig. 30, fig. 25 is a schematic diagram of a zoom optical system 100 in a telephoto state in the fifth embodiment, fig. 26 is a schematic diagram of a zoom optical system 100 in a short-focus state in the fifth embodiment, and fig. 27 is a schematic diagram of a zoom optical system 100 in a middle-focus state in the fifth embodiment. The zoom optical system 100 includes, in order from an object side to an image side, a right-angled prism 120, a first lens element L1 with positive refractive power, a second lens element L2 with negative refractive power, a third lens element L3 with negative refractive power, a fourth lens element L4 with positive refractive power, a fifth lens element L5 with positive refractive power, a sixth lens element L6 with positive refractive power, a seventh lens element L7 with negative refractive power, and an eighth lens element L8 with positive refractive power. Fig. 28 is a graph sequentially showing the spherical aberration, astigmatism and distortion of the zoom optical system 100 in a telephoto state in the fifth embodiment from left to right, fig. 29 is a graph sequentially showing the spherical aberration, astigmatism and distortion of the zoom optical system 100 in a short focus state in the fifth embodiment from left to right, and fig. 30 is a graph sequentially showing the spherical aberration, astigmatism and distortion of the zoom optical system 100 in an intermediate focus state in the fifth embodiment from left to right.

the image-side surface S4 of the second lens element L2 is convex at the paraxial region and convex at the peripheral region;

the object-side surface S7 of the fourth lens element L4 is convex at the paraxial region and convex at the peripheral region;

the image-side surface S16 of the eighth lens element L8 is convex at the paraxial region and concave at the peripheral region.

In addition, the parameters of the optical system 100 are given in tables 13 and 14, and the definitions of the parameters can be obtained from the first embodiment, which is not described herein.

Watch 13

TABLE 14

The relative position relationship of the lens groups of the zoom optical system 100 in different focal length states in the fifth embodiment is shown in the following table, and the definitions of the parameters can be obtained from the first embodiment, which is not repeated herein.

Variable distance	State of long focus	Short focal state	Middle coke state
				D1	2.7210	0.7663	2.0150
D2	1.0281	5.9586	3.7253
				D3	8.4935	5.5977	6.4224

Further, the aspheric coefficients of the image-side surface or the object-side surface of each lens of the zoom optical system 100 are given in table 15, and the definitions of the parameters can be derived from the first embodiment, which is not described herein again.

Watch 15

f7/f567	-0.81	(R7+R8)/R14	1.91
				fc/fd	1.81	f12/f567	2.24
FOVc/ImgH	4.52	SD9/SD8	1.17
				TTL/(ATg2+ATg3)	97.54

in addition, as is clear from the aberration diagrams in fig. 28, 29, and 30, the longitudinal spherical aberration, curvature of field, and distortion of the zoom optical system 100 in various focal length states are well controlled, and the zoom optical system 100 of this embodiment has good imaging quality.

Referring to fig. 31, in some embodiments, the zoom optical system 100 may be assembled with the photosensitive element 210 to form a zoom image capturing module 200. At this time, the light-sensing surface of the light-sensing element 210 may be regarded as the image surface S19 of the zoom optical system 100. The zoom image capturing module 200 may further include an ir-cut filter L9, wherein the ir-cut filter L9 is disposed between the image plane S19 and the image plane S16 of the eighth lens element L8. Specifically, the photosensitive element 210 may be a Charge Coupled Device (CCD) or a Complementary Metal-Oxide Semiconductor (CMOS) Device. By adopting the zoom optical system 100 in the zoom image capturing module 200, the third lens group L567 can balance the spherical aberration generated by the first lens group L12 and the second lens group L34, and the seventh lens group L7 can provide reasonable negative refractive power for the zoom optical system 100, so as to improve the imaging quality of the zoom image capturing module 200, and facilitate the miniaturization design of the zoom image capturing module 200.

Referring to fig. 31 and 32, in some embodiments, the zoom image capturing module 200 may be applied to an electronic device 300, the electronic device includes a housing 310, and the zoom image capturing module 200 is disposed in the housing 310. Specifically, the electronic apparatus 300 may be, but is not limited to, a wearable device such as a mobile phone, a video phone, a smart phone, an electronic book reader, a vehicle-mounted image capturing apparatus such as a car recorder, or a smart watch. When the electronic device 300 is a smartphone, the housing 310 may be a middle frame of the electronic device 300. The zoom image capturing module 200 is adopted in the electronic device 300, which is beneficial to improving the imaging quality of the electronic device 300 and is beneficial to the miniaturization design of the electronic device 300.

It should be noted that, in the embodiment shown in fig. 31 and fig. 32, the zoom optical system 100 may further include a right-angle prism 120, the right-angle prism 120 is disposed on the object side of the first lens group L12, and the right-angle lens 120 is capable of changing the routing of the optical path and thus changing the installation direction of the zoom optical system 100 in the electronic device 300. For example, in some embodiments, the rectangular lens 120 can change the direction of the optical path by 90 °, and the zoom image capturing module 200 composed of the zoom optical system 100 and the photosensitive element 210 can be installed in the electronic device 300 transversely, i.e. the optical axis 110 of the zoom optical system 100 can be perpendicular to the incident light direction of the electronic device 300. Therefore, the zoom optical system 100 constitutes a periscopic optical system, the electronic device 300 can be a periscopic imaging device, and the arrangement of the right-angle prism 120 is beneficial to reducing the thickness size of the electronic device 300 and realizing the miniaturization design of the electronic device 300.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. A zoom optical system, comprising, in order from an object side to an image side along an optical axis:

and the zoom optical system satisfies the following conditional expression:

f7/f567≤-0.2；

wherein f7 is an effective focal length of the seventh lens, and f567 is an effective focal length of the third lens group.

2. Zoom optical system according to claim 1, characterized in that the following conditional expression is satisfied:

fc/fd≥1.4；

and fc is the effective focal length of the zoom optical system at the long-focus end, and fd is the effective focal length of the zoom optical system at the short-focus end.

3. Zoom optical system according to claim 1, characterized in that the following conditional expression is satisfied:

3.5°/mm≤FOVc/ImgH≤6°/mm；

wherein, FOVc is the maximum field angle of the zoom optical system at the telephoto end, and ImgH is the radius of the maximum effective imaging circle of the zoom optical system.

4. Zoom optical system according to claim 1, characterized in that the following conditional expression is satisfied:

15≤TTL/(ATg2+ATg3)≤150；

wherein, TTL is an axial distance from an object-side surface of the first lens element to an image plane of the zoom optical system, ATg2 is an axial distance from an image-side surface of the third lens element to an object-side surface of the fourth lens element, and ATg3 is a total sum of axial air spaces between adjacent lens elements in the third lens element.

5. Zoom optical system according to claim 1, characterized in that the following conditional expression is satisfied:

1≤(R7+R8)/R14≤4；

wherein R7 is a radius of curvature of an object-side surface of the fourth lens element at an optical axis, R8 is a radius of curvature of an image-side surface of the fourth lens element at the optical axis, and R14 is a radius of curvature of an image-side surface of the seventh lens element at the optical axis.

6. Zoom optical system according to claim 1, characterized in that the following conditional expression is satisfied:

0.4≤f12/f567≤4；

where f12 is an effective focal length of the first lens group, and f567 is an effective focal length of the third lens group.

7. The zoom optical system according to claim 1, wherein an image-side surface of the fourth lens is an aperture stop of the zoom optical system when the zoom optical system is at a telephoto end, an object-side surface of the fifth lens is an aperture stop of the zoom optical system when the zoom optical system is at a short-focus end, and the zoom optical system satisfies the following conditional expressions:

1.01≤SD9/SD8≤1.5；

wherein SD9 is half of the maximum effective aperture of the object side surface of the fifth lens, and SD8 is half of the maximum effective aperture of the image side surface of the fourth lens.

8. A zoom optical system according to any one of claims 1 to 7, further comprising a reflective element disposed on an object side of the first lens, the reflective element being configured to change a direction of an optical path.

9. A zoom optical system according to any one of claims 1 to 7, wherein when the optical system zooms from a short focal end to a long focal end, a distance between the first lens group and the second lens group increases, and a distance between the third lens group and the fourth lens group increases.

10. A zoom image capturing module, comprising a photosensitive element and the zoom optical system according to any one of claims 1 to 9, wherein the photosensitive element is disposed on an image side of the zoom optical system.

11. An electronic device, comprising a housing and the zoom image capturing module of claim 10, wherein the zoom image capturing module is disposed on the housing.