Optical zoom system, camera module and electronic equipment

Abstract

The present invention relates to an optical zoom system, a camera module and an electronic device. The optical zoom system comprises: a first lens group with negative refractive power, comprising a first lens and a second lens; a second lens group with positive refractive power, comprising a third lens, a fourth lens and a fifth lens; and a third lens group with negative refractive power, comprising a sixth lens and a seventh lens; in the zooming process from the short focal end to the long focal end, the distance between the first lens group and the second lens group decreases, and the distance between the third lens group and the imaging surface increases; the system satisfies the relationship: 0.2<(R5-R6) / R8<3; R5 is the curvature radius of the object side of the third lens at the optical axis, R6 is the curvature radius of the image side of the third lens at the optical axis, and R8 is the curvature radius of the image side of the fourth lens at the optical axis. An optical zoom system that satisfies the above relationship is conducive to achieving a balance between the aberration components between the lens groups, thereby facilitating improved imaging quality.

Description

Technical Field

[0001] The present invention relates to the field of photographic imaging technology, and in particular to an optical zoom system, a camera module and an electronic device. Background Art

[0002] With the development of camera technology, the camera module has gradually evolved from a fixed-focus system with limited camera conditions to a zoom system that can switch between different camera conditions. The zoom design enables the system to change parameters such as focal length, field of view, and aperture number accordingly, so that it can switch between the telephoto end and the short focal end, thereby ensuring a certain image quality while also adapting to different camera requirements such as object distance, depth of field, and shooting range.

[0003] However, generally, as some lenses in a zoom system move relative to each other, the aberrations produced by the lenses or lens groups will become difficult to control, which often results in the difficulty in improving the imaging quality of the zoom system. Summary of the invention

[0004] Based on this, it is necessary to provide an optical zoom system, a camera module and an electronic device to address the problem of how to control the aberration in the zoom system to improve the imaging quality.

[0005] An optical zoom system comprises, in sequence along an incident light path:

[0006] A first lens group with negative refractive power, comprising a first lens and a second lens;

[0007] a second lens group having positive refractive power, comprising a third lens, a fourth lens and a fifth lens; and

[0008] a third lens group having negative refractive power, comprising a sixth lens and a seventh lens;

[0009] During the zooming process of the optical zoom system from the short focal end to the long focal end, the distance between the first lens group and the second lens group decreases, and the distance between the third lens group and the imaging plane of the optical zoom system increases;

[0010] The optical zoom system satisfies the relationship:

[0011] 0.2<(R5-R6) / R8<3;

[0012] R5 is the curvature radius of the object side of the third lens at the optical axis, R6 is the curvature radius of the image side of the third lens at the optical axis, and R8 is the curvature radius of the image side of the fourth lens at the optical axis.

[0013] The above optical zoom system can make the aberrations between the lens groups be corrected well by distributing the refractive power of each lens group distributed along the incident light path and setting the number of lenses in each lens group. The third lens and the fourth lens are respectively the first lens and the second lens of the second lens group. When the above relationship is further satisfied, the curvature radius of the two side surfaces of the first lens in the second lens group at the optical axis and the curvature radius of the object side surface of the second lens at the optical axis can be controlled within a reasonable range, which is conducive to controlling the aberration generated by the second lens group and making it reach a balanced state with the aberration components contributed by the first lens group and the third lens group, that is, the aberration generated by any lens group will not be too large compared with other lens groups, which is conducive to the aberration correction between the three lens groups, and further improves the imaging quality of the optical zoom system. In addition, by satisfying the above relationship, it is also conducive to reasonably constraining the surface shape of the third lens and the fourth lens to prevent the surface shape from being too complicated, thereby reducing the difficulty of lens molding and processing.

[0014] In one embodiment, the optical zoom system satisfies the relationship:

[0015] fc / fd>1.6;

[0016] fc is the effective focal length of the optical zoom system at the telephoto end, and fd is the effective focal length of the optical zoom system at the short focal end. When the above relationship is satisfied, the ratio of the effective focal length at the telephoto end to the effective focal length at the short focal end of the optical zoom system can be reasonably configured, so that the optical zoom system can obtain a higher zoom ratio, thereby making the system's shooting magnification have a larger adjustable range. When fc / fd≤1.6, the adjustable range of the system's shooting magnification is too low, which is insufficient to meet users' higher requirements for shooting experience.

[0017] In one embodiment, the optical zoom system satisfies the relationship:

[0018] 20<TTL / (ATg2+ATg3)<45;

[0019] TTL is the distance from the object side of the first lens to the imaging surface of the optical zoom system on the optical axis, ATg2 is the sum of the spacings between adjacent lenses in the second lens group on the optical axis, and ATg3 is the sum of the spacings between adjacent lenses in the third lens group on the optical axis. When the above relationship is satisfied, by controlling the sum of the spacings between adjacent lenses in the second lens group and the sum of the spacings between adjacent lenses in the third lens group, the total length of the system can be effectively shortened on the basis of achieving a larger zoom ratio, thereby saving assembly space for electronic devices equipped with the optical zoom system.

[0020] In one embodiment, the optical zoom system satisfies the relationship:

[0021] TTL≤30mm;

[0022] TTL is the distance from the object side of the first lens to the imaging surface of the optical zoom system on the optical axis. When the above relationship and the relationship of 20<TTL / (ATg2+ATg3) are satisfied, the total length of the optical zoom system can be directly and effectively controlled, so that the system can be realized. When TTL>30mm, the total length of the optical zoom system is too large, which is easy to increase the pressure on the space configuration of the electronic device, squeeze other components in the device, and also reduce the stability of the optical zoom system.

[0023] In one embodiment, the optical zoom system satisfies the relationship:

[0024] 4° / mm<FOVc / ImgH<6° / mm;

[0025] FOVc is the maximum field of view of the optical zoom system at the telephoto end, and ImgH is half of the image height corresponding to the maximum field of view of the optical zoom system. When the above relationship is satisfied, the ratio of the maximum field of view of the system at the telephoto end to the half image height can be controlled within a reasonable range. On the one hand, the field of view at the telephoto end can be suppressed so that the optical zoom system has excellent telephoto characteristics; on the other hand, it is also beneficial for the optical zoom system to realize a large image plane design, so that the optical zoom system can match a higher pixel image sensor, thereby achieving high-definition shooting.

[0026] In one embodiment, the optical zoom system satisfies the relationship:

[0027] f3 / f345<1.5;

[0028] f3 is the effective focal length of the third lens, and f345 is the effective focal length of the second lens group. The third lens contributes a part of the overall positive refractive power of the second lens group. When the above relationship is satisfied, the positive focal power of the third lens can be within a reasonable range, which is beneficial for the second lens group to balance the spherical aberration generated by the first lens group, provide a reasonable and controllable positive refractive power for the optical zoom system, further improve the imaging quality, and also help to shorten the total length of the system. When f3 / f345≥1.5, the refractive power in the second lens group is unevenly distributed, which is not conducive to balancing the aberrations generated by the first lens group and the third lens group.

[0029] In one embodiment, the optical zoom system satisfies the relationship:

[0030] 0.4<f12 / f67<3;

[0031] f12 is the effective focal length of the first lens group, and f67 is the effective focal length of the third lens group. When the above relationship is satisfied, the ratio of the effective focal length of the first lens group to the effective focal length of the third lens group can be reasonably configured, which is conducive to obtaining a larger zoom range. In addition, by reasonably controlling the relationship between the negative refractive power borne by the first lens group and the third lens group, the positive refractive power contributed by the second lens group can be well matched to achieve the desired excellent zoom performance.

[0032] In one embodiment, the optical zoom system satisfies the relationship:

[0033] -3<f12 / (sd5*FNOc)<-0.5;

[0034] f12 is the effective focal length of the first lens group, sd5 is the maximum effective radius of the object side of the third lens, and FNOc is the aperture number of the optical zoom system at the telephoto end. When the above relationship is satisfied, it is equivalent to reasonably configuring the ratio of the effective focal length of the first lens group and the aperture number at the telephoto end, which is conducive to the optical zoom system to obtain a larger zoom range in the telephoto direction; at the same time, the first lens group can be allocated with a suitable refractive power, which is also conducive to correcting distortion and spherical aberration, thereby further improving the resolution of the optical zoom system. When the above relationship of the system is higher than the upper limit, the refractive power of the first lens group is too strong, which will force the light aperture of the third lens to increase, which is not conducive to reducing the radial size of the system.

[0035] In one embodiment, the optical zoom system satisfies the relationship:

[0036] [max(D2)-min(D2)] / TTL<0.1;

[0037] max(D2) is the maximum distance on the optical axis from the image side of the fifth lens to the object side of the sixth lens, min(D2) is the minimum distance on the optical axis from the image side of the fifth lens to the object side of the sixth lens, and TTL is the distance on the optical axis from the object side of the first lens to the imaging surface of the optical zoom system. When the above relationship is satisfied, the relative movement range between the second lens group and the third lens group can be reduced, so that the system can have good zoom performance and also help to make the zoom structure compact, thereby meeting actual use requirements. When the above relationship is higher than the upper limit, the linkage between the second lens group and the third lens group will deteriorate.

[0038] The optical zoom system includes a reflective element disposed on the light incident side of the first lens group, and the reflective element is used to reflect the incident light to the first lens group. By providing the reflective element to fold the optical path of the incident light, the optical zoom system can be used as a periscope camera system. When applied to electronic devices, the limitation on the thickness reduction of the device can be effectively avoided, which is conducive to the ultra-thin design of the device (such as a smart phone, a smart watch, etc.).

[0039] A camera module comprises an image sensor and any one of the above optical zoom systems, wherein the image sensor is arranged on the light-emitting side of the third lens group. By adopting the above optical zoom system, the camera module can effectively control the aberration caused by the lens groups to improve the image quality while having the zoom capability to cope with different shooting requirements.

[0040] An electronic device comprises a fixing part and the camera module, wherein the camera module is arranged on the fixing part. By adopting the camera module, the electronic device will have excellent zoom performance, and thus can still have excellent imaging quality under zoom adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a schematic structural diagram of the optical zoom system in the first embodiment of the present application when it is at the short focal end;

[0042] Figure 2 This is a schematic diagram of the structure of the optical zoom system in the first embodiment of the present application when it is at the mid-focus end;

[0043] Figure 3 This is a schematic structural diagram of the optical zoom system in the first embodiment of the present application when it is at the telephoto end;

[0044] Figure 4 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram when the optical zoom system is at the short focal end in the first embodiment of the present application;

[0045] Figure 5 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram when the optical zoom system is at the mid-focus end in the first embodiment of the present application;

[0046] Figure 6 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram when the optical zoom system is at the telephoto end in the first embodiment of the present application;

[0047] Figure 7 This is a schematic structural diagram of the optical zoom system in the second embodiment of the present application when it is at the short focal end;

[0048] Figure 8 This is a schematic diagram of the structure of the optical zoom system in the second embodiment of the present application when it is at the middle focal end;

[0049] Fig. 9 This is a schematic diagram of the structure of the optical zoom system in the second embodiment of the present application when it is at the telephoto end;

[0050] Fig.10 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram when the optical zoom system is at the short focal end in the second embodiment of the present application;

[0051] Fig.11 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram when the optical zoom system is at the mid-focus end in the second embodiment of the present application;

[0052] Fig.12 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram when the optical zoom system is at the telephoto end in the second embodiment of the present application;

[0053] Fig.13 This is a schematic structural diagram of the optical zoom system in the third embodiment of the present application when it is at the short focal end;

[0054] Fig.14 This is a schematic diagram of the structure of the optical zoom system in the third embodiment of the present application when it is at the mid-focus end;

[0055] Fig.15 This is a schematic structural diagram of the optical zoom system in the third embodiment of the present application when it is at the telephoto end;

[0056] Fig.16 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram when the optical zoom system is at the short focal end in the third embodiment of the present application;

[0057] Fig.17 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram when the optical zoom system is at the mid-focus end in the third embodiment of the present application;

[0058] Fig.18 A longitudinal spherical aberration diagram, an astigmatism diagram, and a distortion diagram when the optical zoom system is at the telephoto end in the third embodiment of the present application;

[0059] Fig.19 This is a schematic structural diagram of the optical zoom system in the fourth embodiment of the present application when it is at the short focal end;

[0060] Fig. 20 This is a schematic structural diagram of the optical zoom system in the fourth embodiment of the present application when it is at the mid-focus end;

[0061] Fig.21 This is a schematic structural diagram of the optical zoom system in the fourth embodiment of the present application when it is at the telephoto end;

[0062] Fig. 22 A longitudinal spherical aberration diagram, an astigmatism diagram, and a distortion diagram when the optical zoom system is at the short focal end in the fourth embodiment of the present application;

[0063] Fig.23 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram when the optical zoom system is at the middle focal end in the fourth embodiment of the present application;

[0064] Fig.24 A longitudinal spherical aberration diagram, an astigmatism diagram, and a distortion diagram when the optical zoom system is at the telephoto end in the fourth embodiment of the present application;

[0065] Fig.25 This is a schematic structural diagram of the optical zoom system in the fifth embodiment of the present application when it is at the short focal end;

[0066] Fig.26 This is a structural schematic diagram of the optical zoom system in the fifth embodiment of the present application when it is at the mid-focus end;

[0067] Fig. 27 This is a schematic structural diagram of the optical zoom system in the fifth embodiment of the present application when it is at the telephoto end;

[0068] Fig.28 A longitudinal spherical aberration diagram, an astigmatism diagram, and a distortion diagram when the optical zoom system is at the short focal end in the fifth embodiment of the present application;

[0069] Fig.29 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram when the optical zoom system is at the middle focal end in the fifth embodiment of the present application;

[0070] Fig.30 A longitudinal spherical aberration diagram, an astigmatism diagram, and a distortion diagram when the optical zoom system is at the telephoto end in the fifth embodiment of the present application;

[0071] Fig.31 This is a schematic diagram of the structure of the optical zoom system in the sixth embodiment of the present application when it is at the short focal end;

[0072] Fig.32 This is a schematic structural diagram of the optical zoom system in the sixth embodiment of the present application when it is at the mid-focus end;

[0073] Fig.33 This is a schematic structural diagram of the optical zoom system in the sixth embodiment of the present application when it is at the telephoto end;

[0074] Fig.34 A longitudinal spherical aberration diagram, an astigmatism diagram, and a distortion diagram when the optical zoom system is at the short focal end in the sixth embodiment of the present application;

[0075] Fig.35 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram when the optical zoom system is at the middle focal end in the sixth embodiment of the present application;

[0076] Fig.36A longitudinal spherical aberration diagram, an astigmatism diagram, and a distortion diagram when the optical zoom system is at the telephoto end in the sixth embodiment of the present application;

[0077] Fig.37 A schematic diagram of the structure of a camera module provided in one embodiment of the present application;

[0078] Fig.38 A schematic diagram of the structure of an electronic device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0079] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0080] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0081] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0082] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0083] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0084] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0085] refer to Figure 1 , the embodiment of the present application provides an optical zoom system 10, which includes: a first lens group G1 with negative refractive power, the first lens group G1 includes a first lens L1 and a second lens L2; ​​a second lens group G2 with positive refractive power, the second lens group G2 includes a third lens L3, a fourth lens L4 and a fifth lens L5; and a third lens group G3 with negative refractive power, the third lens group G3 includes a sixth lens L6 and a seventh lens L7. The lenses in the optical zoom system 10 are coaxially arranged, that is, the centers of the optical axes of the lenses are all located on the same straight line, which can also be called the optical axis 101 of the optical zoom system 10.

[0086] The optical zoom system 10 can change the effective focal length of the system by changing the distance between the first lens group G1, the second lens group G2 and the third lens group G3, thereby achieving optical zoom. In the embodiment of the present application, the optical zoom system 10 can switch between different effective focal lengths through zooming operations, for example, it can switch between the short focal end, the middle focal end and the long focal end. When the optical zoom system 10 is at the short focal end, the optical zoom system 10 will have the shortest effective focal length during the zooming process; when the optical zoom system 10 is at the long focal end, the optical zoom system 10 will have the longest effective focal length during the zooming process. The effective focal length of the optical zoom system 10 when it is at the middle focal end will be between the longest effective focal length and the shortest effective focal length, but it does not mean that it can only be the middle value between the two. It should also be noted that the optical zoom system 10 in some embodiments is not limited to switching between the short focal end, the medium focal end, and the long focal end. The optical zoom system 10 can also be switched to any state between the short focal end and the long focal end to have any effective focal length between the longest effective focal length and the shortest effective focal length, thereby achieving different shooting effects.

[0087] Specifically, in the embodiment of the present application, during the zooming process of the optical zoom system 10 from the short focal end to the long focal end, the distance between the first lens group G1 and the second lens group G2 decreases, and the distance between the third lens group G3 and the imaging surface S15 of the optical zoom system 10 increases. The above optical zoom system 10 can make the aberration between the lens groups be better corrected by the distribution of the refractive power of each lens group distributed along the incident light path and the setting of the number of lenses in each lens group. In some embodiments, the total optical length of the optical zoom system 10 is fixed, and the first lens group G1 remains fixed relative to the imaging surface S15 of the optical zoom system 10, and the second lens group G2 and the third lens group G3 move along the optical axis relative to the first lens group G1 to achieve optical zoom. In other embodiments, the total optical length of the optical zoom system 10 may also change with zoom adjustment. In this case, the first lens group G1, the second lens group G2, and the third lens group G3 can all move along the optical axis relative to the imaging surface S15. When the optical zoom system 10 is assembled with an image sensor, it can also be understood that the three lens groups will all move along the optical axis relative to the image sensor during zoom adjustment. It should be noted that when the lens groups move, the lenses therein also keep moving synchronously.

[0088] For each lens, 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, and the seventh lens L7 includes an object side surface S13 and an image side surface S14. The optical zoom system 10 also has a virtual imaging surface S15, and the imaging surface S15 is located on the light exit side of the third lens group G3. Generally, the imaging surface S15 of the optical zoom system 10 coincides with the photosensitive surface of the image sensor. For ease of understanding, when the optical zoom system 10 and the image sensor are assembled into a camera module, the photosensitive surface of the image sensor can be regarded as the imaging surface S15, and the effective photosensitive area on the photosensitive surface is the effective imaging area of ​​the imaging surface S15.

[0089] In the embodiment of the present application, the optical zoom system 10 satisfies the relationship:

[0090] 0.2<(R5-R6) / R8<3; R5 is the curvature radius of the object-side surface S5 of the third lens L3 at the optical axis, R6 is the curvature radius of the image-side surface S6 of the third lens L3 at the optical axis, and R8 is the curvature radius of the image-side surface S7 of the fourth lens L4 at the optical axis. In some embodiments, the relationship (R5-R6) / R8 can be specifically 0.75, 0.8, 0.9, 1, 1.1, 1.3, 1.4, 1.5, 1.6, 1.65 or 1.7. Since the third lens L3 and the fourth lens L4 are respectively the first lens and the second lens of the second lens group G2, when the optical zoom system 10 satisfies the above lens group design and further satisfies the relationship, the curvature radius of the two side surfaces of the first lens in the second lens group G2 at the optical axis and the curvature radius of the object side surface of the second lens at the optical axis can be controlled within a reasonable range, which is conducive to controlling the aberration generated by the second lens group G2, so that it reaches a balanced state with the aberration components contributed by the first lens group G1 and the third lens group G3, that is, the aberration generated by any lens group will not be too large compared with the other lens groups, which is conducive to the aberration correction between the three lens groups, and further improves the imaging quality of the optical zoom system 10. In addition, by satisfying the above relationship, it is also conducive to reasonably constraining the surface shape of the third lens L3 and the fourth lens L4, preventing the surface shape from being too complicated, thereby reducing the difficulty of lens molding processing.

[0091] In addition, in some embodiments, the optical zoom system 10 further satisfies at least one of the following relationships, and when the optical zoom system 10 with the above-mentioned seven-piece structure satisfies any of the following relationships, it can bring corresponding effects:

[0092] fc / fd>1.6; fc is the effective focal length of the optical zoom system 10 at the telephoto end, and fd is the effective focal length of the optical zoom system 10 at the short focal end. In some embodiments, this relationship condition can be specifically 1.65, 1.7, 1.75, 1.85, 1.9, 1.95 or 2. When the above relationship is met, the ratio of the effective focal length at the telephoto end and the effective focal length at the short focal end of the optical zoom system 10 can be reasonably configured, so that the optical zoom system 10 can obtain a higher zoom ratio, thereby making the system's shooting magnification have a larger adjustable range. When fc / fd≤1.6, the adjustable range of the system's shooting magnification is too low, which is insufficient to meet the user's higher requirements for shooting experience.

[0093] 20<TTL / (ATg2+ATg3)<45; TTL is the distance on the optical axis from the object side surface S1 of the first lens L1 to the imaging surface S15 of the optical zoom system 10, ATg2 is the sum of the spacings between adjacent lenses in the second lens group G2 on the optical axis, and ATg3 is the sum of the spacings between adjacent lenses in the third lens group G3 on the optical axis. In some embodiments, this relationship condition can be specifically 27, 28, 30, 32, 35, 38, 40, 42, 43 or 44. When the above relationship is satisfied, by controlling the sum of the spacings between adjacent lenses in the second lens group G2 and the sum of the spacings between adjacent lenses in the third lens group G3, the total length of the system can be effectively shortened on the basis of achieving a larger zoom ratio, thereby saving assembly space for electronic devices equipped with the optical zoom system 10.

[0094] TTL≤30mm; TTL is the distance from the object side S1 of the first lens L1 to the imaging surface S15 of the optical zoom system 10 on the optical axis. In some embodiments, this relationship condition can be specifically 25mm, 25.1mm, 25.3mm, 25.4mm or 25.5mm. When the above relationship and the relationship of 20<TTL / (ATg2+ATg3) are met, the total length of the optical zoom system 10 can be directly and effectively controlled, so that the system can be realized. When TTL>30mm, the total length of the optical zoom system 10 is too large, which is easy to increase the pressure on the spatial configuration of the electronic device, squeeze other components in the device, and also reduce the stability of the optical zoom system 10.

[0095] 4° / mm<FOVc / ImgH<6° / mm; FOVc is the maximum field angle of the optical zoom system 10 at the telephoto end, and ImgH is half of the image height corresponding to the maximum field angle of the optical zoom system 10. In some embodiments, this relationship condition can be 4.65, 4.67, 4.7, 4.8, 4.85, 4.9, 4.93 or 4.95, and the numerical unit is ° / mm. When the above relationship is met, the ratio of the maximum field angle of the system at the telephoto end to the half image height can be controlled within a reasonable range. On the one hand, the field angle at the telephoto end can be suppressed so that the optical zoom system 10 has excellent telephoto characteristics; on the other hand, it is also beneficial for the optical zoom system 10 to realize a large image plane design, so that the optical zoom system 10 can match a higher pixel image sensor, thereby realizing high-definition shooting. It should be noted that in the embodiment of the present application, the value of ImgH of the optical zoom system 10 remains unchanged when zooming, that is, the value of ImgH corresponding to the maximum field angle of the optical zoom system 10 in different zoom states remains unchanged.

[0096] It should be noted that ImgH can also be referred to as half of the diagonal length of the rectangular effective imaging area on the imaging surface S15. After assembling the image sensor, ImgH can also be understood as the distance from the center to the diagonal edge of the rectangular effective pixel area of ​​the image sensor, and the diagonal direction of the above-mentioned effective imaging area is the diagonal direction of the rectangular effective pixel area. Correspondingly, FOVc can also be understood as the maximum field of view angle in the diagonal direction when the optical zoom system 10 is at the telephoto end. Since the image sensor in the camera module remains unchanged after assembly, the value of ImgH of the optical zoom system 10 in different zoom states in some embodiments remains unchanged.

[0097] f3 / f345<1.5; f3 is the effective focal length of the third lens L3, and f345 is the effective focal length of the second lens group G2. In some embodiments, the relationship condition can be 0.82, 0.83, 0.85, 0.87, 0.88, 0.89 or 0.9. The third lens L3 contributes a part of the overall positive refractive power of the second lens group G2. When the above relationship is satisfied, the positive focal power of the third lens L3 can be within a reasonable range, which is beneficial for the second lens group G2 to balance the spherical aberration generated by the first lens group G1, provide a reasonable and controllable positive refractive power for the optical zoom system 10, and further improve the image quality. In addition, it is also beneficial to shorten the total length of the system. When f3 / f345≥1.5, the refractive power in the second lens group G2 is unevenly distributed, which is not conducive to balancing the aberrations generated by the first lens group G1 and the third lens group G3.

[0098] 0.4<f12 / f67<3; f12 is the effective focal length of the first lens group G1, and f67 is the effective focal length of the third lens group G3. In some embodiments, this relationship condition can be specifically 0.95, 0.97, 1, 1.05, 1.1, 1.15, 1.18 or 1.2. When the above relationship is satisfied, the ratio of the effective focal length of the first lens group G1 to the effective focal length of the third lens group G3 can be reasonably configured, which is conducive to obtaining a larger zoom range. In addition, by reasonably controlling the relationship between the negative refractive power borne by the first lens group G1 and the third lens group G3, the positive refractive power contributed by the second lens group G2 can be well matched to achieve the desired excellent zoom performance.

[0099] -3<f12 / (sd5*FNOc)<-0.5; f12 is the effective focal length of the first lens group G1, sd5 is the maximum effective radius of the object side surface S5 of the third lens L3, and FNOc is the aperture number of the optical zoom system 10 at the telephoto end. In some embodiments, this relationship condition can be specifically -1.6, -1.57, -1.55, -1.52, -1.5, -1.48 or -1.45. When the above relationship is satisfied, it is equivalent to reasonably configuring the ratio of the effective focal length of the first lens group G1 and the aperture number at the telephoto end, which is beneficial for the optical zoom system 10 to obtain a larger zoom range in the telephoto direction; at the same time, the first lens group G1 can be allocated with a suitable refractive power, which is also beneficial for correcting distortion and spherical aberration, thereby further improving the resolution of the optical zoom system 10. When the above relationship of the system is higher than the upper limit, the refractive power of the first lens group G1 is too strong, which will force the light aperture of the third lens L3 to increase, which is not conducive to reducing the radial size of the system.

[0100] [max(D2)-min(D2)] / TTL<0.1; max(D2) is the maximum distance between the image side surface S10 of the fifth lens L5 and the object side surface S11 of the sixth lens L6 on the optical axis, min(D2) is the minimum distance between the image side surface S10 of the fifth lens L5 and the object side surface S11 of the sixth lens L6 on the optical axis, the maximum distance is the maximum distance that can be adjusted between the image side surface S10 of the fifth lens L5 and the object side surface S11 of the sixth lens L6 on the optical axis 101 during zoom adjustment, the minimum distance is the minimum distance that can be adjusted between the image side surface S10 of the fifth lens L5 and the object side surface S11 of the sixth lens L6 on the optical axis 101 during zoom adjustment, and TTL is the distance between the object side surface S1 of the first lens L1 and the imaging surface S15 of the optical zoom system 10 on the optical axis. In some embodiments, the relationship condition can be specifically 0.02, 0.022, 0.025, 0.026, 0.028 or 0.03. When the above relationship is satisfied, the relative movement range between the second lens group G2 and the third lens group G3 can be reduced, so that the system can have good zoom performance and also help to make the zoom structure compact, thereby meeting actual use requirements. When the above relationship is higher than the upper limit, the linkage between the second lens group G2 and the third lens group G3 will deteriorate.

[0101] The optical zoom system 10 also includes an aperture stop (not shown), which is used to limit the amount of light entering the system, and can also achieve a certain degree of suppression of aberrations and stray light. The aperture stop can be a single light-blocking member assembled between the lenses, or can also be formed by a clamping member of a fixed lens. In some embodiments, the aperture stop during the zooming process can remain fixed relative to the imaging surface S15 of the system. In other embodiments, the aperture stop during the zooming process can move synchronously with one of the movable lens groups, for example, the aperture stop is part of the second lens group G2 or the third lens group G3, and the aperture stop during the zooming process moves synchronously with the second lens group G2 or the third lens group G3. In some embodiments, the aperture stop is disposed between the second lens L2 and the third lens L3, and is fixed relative to the second lens group G2.

[0102] In some embodiments, at least one side of the light-transmitting surface of at least one lens in the optical zoom system 10 is an aspherical surface. That is, the object side surface and / or the image side surface of at least one of the first lens L1 to the seventh lens L7 is an aspherical surface. The aspherical surface design can make the light-transmitting surface of the lens have a more flexible design, so that the lens can well solve the undesirable phenomena such as unclear imaging, distorted field of view, narrow field of view, etc. when it is smaller and thinner. In this way, the system can have good imaging quality without setting too many lenses, and it helps to shorten the length of the optical zoom system 10. Specifically, in some embodiments, the object side surface and the image side surface of each lens in the optical zoom system 10 are aspherical surfaces.

[0103] The calculation of the aspheric surface can refer to the aspheric surface formula:

[0104]

[0105] Among them, Z is the distance from the corresponding point on the aspheric surface to the tangent plane of the surface at the optical axis, r is the distance from the corresponding point on the aspheric surface to the optical axis, c is the curvature of the aspheric surface at the optical axis, k is the cone coefficient, and Ai is the coefficient of the high-order term corresponding to the i-th high-order term in the aspheric surface shape formula.

[0106] In some embodiments, at least one side surface of at least one lens in the optical zoom system 10 may also be a spherical surface. The manufacturing process of spherical lenses is simple and the manufacturing cost is low. The surface shape of the light-transmitting surface of each lens in the optical zoom system 10 can be a combination of a spherical surface and an aspherical surface, thereby effectively eliminating the aberration of the system, so that the optical zoom system 10 has good imaging quality, and at the same time improves the flexibility of lens design and assembly, so that the system achieves a better balance between high image quality and low cost. The specific surface shape of each lens in the optical zoom system 10 can be determined according to actual design requirements, and the matching method of the lens surface shape is not repeated here.

[0107] In some embodiments, at least one of the first lens L1 to the seventh lens L7 is made of plastic. Plastic lenses can reduce the weight of the optical zoom system 10 and reduce the manufacturing cost, and because the weight of the plastic lens is reduced, the power burden of the zoom drive structure (such as a voice coil motor) can also be reduced accordingly. In some embodiments, at least one of the first lens L1 to the seventh lens L7 is made of glass, and the glass lens can withstand higher temperatures and has excellent and stable optical properties. The materials of different lenses in the optical zoom system 10 can be made of glass and plastic, so that some lenses in the system are glass lenses and some lenses are plastic lenses, thereby balancing the manufacturing cost and optical performance of the optical zoom system 10. The material of each lens in the optical zoom system 10 can be determined according to actual design requirements, and the matching method of the lens materials in the system is not repeated here.

[0108] In some embodiments, the optical zoom system 10 further includes a reflective element 110 located on the light incident side of the first lens group G1, and the optical axis 101 of the optical zoom system 10 will be bent due to the reflection of the reflective element 110. The reflective element 110 is used to reflect the incident light to the first lens group G1. By providing the reflective element 110 to fold the optical path of the incident light, the optical zoom system 10 can be used as a periscope camera system. When applied to electronic devices, the limitation on the thickness reduction of the device can be effectively avoided, which is conducive to the ultra-thin design of the device (such as a smart phone, a smart watch, etc.). In some embodiments, the reflective element 110 is a right-angle prism, specifically an isosceles right-angle prism. The reflective element 110 includes an incident surface 1101, a reflective surface 1102, and an exit surface 1103. The incident surface 1101 and the exit surface 1103 form an angle of 90°, and the reflective surface 1102 and the incident surface 1101, the exit surface 1103, and the optical axes of each lens group all form an angle of 45°. The incident light enters the right-angle prism through the incident surface 1101, and then is reflected toward the exit surface 1103 at the reflective surface 1102, and is finally emitted from the exit surface 1103 to the first lens group G1.

[0109] In some embodiments, the optical zoom system 10 includes an infrared cutoff filter 120, which is disposed on the light-exiting side of the third lens group G3, that is, on the light-exiting side of the seventh lens L7. The infrared cutoff filter 120 is used to filter out infrared light to prevent infrared light from reaching the imaging surface S13 of the system, thereby preventing infrared light from interfering with normal imaging. The infrared cutoff filter 120 can be assembled together with each lens as a part of the optical zoom system 10. In other embodiments, the infrared cutoff filter 120 does not belong to the components of the optical zoom system 10. In this case, the infrared cutoff filter 120 can be installed between the optical zoom system 10 and the image sensor when the optical zoom system 10 and the image sensor are assembled into a camera module. In other embodiments, the function of filtering out infrared light can also be achieved by providing a filter coating on at least one lens from the first lens L1 to the seventh lens L7.

[0110] To achieve the zoom function, in some embodiments, the optical zoom system 10 includes a driving member, which is connected to at least the second lens group G2 and the third lens group G3, and is used to drive the lens groups to move along the optical axis direction of the system so that the distance between the lens groups changes, that is, relative displacement occurs, thereby adjusting the focal length of the system. There can be multiple driving members, each of which corresponds to a position-adjustable lens group. The driving member can be a conventional voice coil motor structure or a gear drive structure, and the specific configuration can be determined according to actual needs, which will not be described in detail here.

[0111] Next, the optical zoom system 10 of the present application is described with more specific and detailed embodiments:

[0112] First embodiment

[0113] refer to Figure 1 , Figure 2 and Figure 3 , Figure 1 embodies a schematic diagram of the structure of the optical zoom system 10 at the short focal end, Figure 2 embodies a schematic diagram of the structure of the optical zoom system 10 at the mid-focus end, Figure 3 embodies the schematic diagram of the structure of the optical zoom system 10 at the telephoto end. It should be noted that Figures 1 to 3 The relative movement relationship between the lens groups during the zooming process of the system is given, but it does not mean that each system can only be adjusted between these three states, and the same is true for the following embodiments.

[0114] In the first embodiment, the optical zoom system 10 includes, in sequence along the incident light path: a reflective element 110 (a right angle prism in the table below), a first lens group G1 with negative refractive power, wherein the first lens group G1 includes a first lens L1 with positive refractive power and a second lens L2 with negative refractive power; a second lens group G2 with positive refractive power, wherein the second lens group G2 includes a third lens L3 with positive refractive power, a fourth lens L4 with negative refractive power, and a fifth lens L5 with positive refractive power; and a third lens group G3 with negative refractive power, wherein the third lens group G3 includes a sixth lens L6 with positive refractive power and a seventh lens L7 with negative refractive power.

[0115] In this embodiment, the total optical length TTL of the optical zoom system 10 remains unchanged during the zooming process, that is, the first lens group G1 remains fixed relative to the imaging surface S15 during the zooming process, that is, the distance from the object side surface S1 of the first lens L1 to the imaging surface S15 of the system remains unchanged. During the zooming process of the optical zoom system 10 from the short focal end to the long focal end, the distance between the first lens group G1 and the second lens group G2 decreases, and the distance between the third lens group G3 and the imaging surface S15 of the optical zoom system 10 increases. The above optical zoom system 10 can make the aberrations between the lens groups be better corrected by the distribution of the refractive power of each lens group distributed along the incident light path and the setting of the number of lenses in each lens group.

[0116] The object-side surface S1 of the first lens L1 is convex at the paraxial position, and the image-side surface S2 is concave at the paraxial position; the object-side surface S1 is convex at the circumference, and the image-side surface S2 is concave at the circumference.

[0117] The object-side surface S3 of the second lens L2 is concave at the paraxial position, and the image-side surface S4 is concave at the paraxial position; the object-side surface S3 is concave at the circumference, and the image-side surface S4 is convex at the circumference.

[0118] The object-side surface S5 of the third lens L3 is convex at the paraxial position, and the image-side surface S6 is convex at the paraxial position; the object-side surface S5 is concave at the circumference, and the image-side surface S6 is convex at the circumference.

[0119] The object-side surface S7 of the fourth lens L4 is concave at the paraxial position, and the image-side surface S8 is concave at the paraxial position; the object-side surface S7 is convex at the circumference, and the image-side surface S8 is concave at the circumference.

[0120] The object-side surface S9 of the fifth lens L5 is convex at the paraxial position, and the image-side surface S10 is convex at the paraxial position; the object-side surface S9 is convex at the circumference, and the image-side surface S10 is concave at the circumference.

[0121] The object-side surface S11 of the sixth lens L6 is concave at the paraxial position, and the image-side surface S12 is convex at the paraxial position; the object-side surface S11 is convex at the circumference, and the image-side surface S12 is convex at the circumference.

[0122] The object-side surface S13 of the seventh lens L7 is concave at the paraxial position, and the image-side surface S14 is concave at the paraxial position; the object-side surface S13 is concave at the circumference, and the image-side surface S14 is convex at the circumference.

[0123] The optical zoom system 10 in this embodiment also satisfies the relationship: (R5-R6) / R8=1.47; R5 is the radius of curvature of the object side surface S5 of the third lens L3 at the optical axis, R6 is the radius of curvature of the image side surface S6 of the third lens L3 at the optical axis, and R8 is the radius of curvature of the image side surface S7 of the fourth lens L4 at the optical axis. Since the third lens L3 and the fourth lens L4 are respectively the first lens and the second lens of the second lens group G2, when the optical zoom system 10 satisfies the above lens group design and further satisfies the relationship, the radius of curvature of the two side surfaces of the first lens in the second lens group G2 at the optical axis and the radius of curvature of the object side surface of the second lens at the optical axis can be controlled within a reasonable range, which is conducive to controlling the aberration generated by the second lens group G2, so that it reaches a balanced state with the aberration components contributed by the first lens group G1 and the third lens group G3, that is, the aberration generated by any lens group will not be too large compared with the other lens groups, which is conducive to the aberration correction between the three lens groups, and further improves the imaging quality of the optical zoom system 10. In addition, by satisfying the above relationship, it is also helpful to reasonably constrain the surface shapes of the third lens L3 and the fourth lens L4, prevent the surface shapes from being too complicated, and thus reduce the difficulty of lens molding processing.

[0124] The parameters of the reflective element 110 and each lens in the optical zoom system 10 are given in the following Tables 1 and 2. Table 2 gives the aspheric coefficients of the corresponding surfaces of each lens in Table 1, where K is the cone coefficient and Ai is the coefficient of the high-order term corresponding to the i-th high-order term in the aspheric surface formula. The components from the object surface to the image surface (imaging surface S15, which can also be understood as the photosensitive surface of the image sensor during later assembly) are arranged in the order of the components from top to bottom in Table 1. The surfaces corresponding to the surface numbers 4 and 5 represent 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 a smaller surface number is the object side surface, and the surface with a larger surface number is the image side surface. The Y radius in Table 1 is the radius of curvature of the object side surface or the image side surface of the corresponding surface number at the optical axis. The absolute value of the first value of the lens in the "thickness" parameter column is the thickness of the lens on the optical axis, and the absolute value of the second value is the distance from the image side surface of the lens to the object side surface of the next optical element on the optical axis. In particular, surface number 1 corresponds to the incident surface 1101 of the reflective element 110, surface number 2 corresponds to the reflective surface 1102 of the reflective element 110, and surface number 3 corresponds to the exit surface 1103 of the reflective element 110. The filter in the table represents the infrared cutoff filter 120. In this embodiment, the object side surface and the image side surface of each lens are both aspherical surfaces, and the material of each lens is plastic, and the material of the reflective element 110 is glass.

[0125] Table 1

[0126]

[0127]

[0128] In Table 1, the X semi-aperture parameter (mm) corresponding to each surface number is half of the side length of the effective light-transmitting area of ​​the corresponding surface in the X direction, and the Y semi-aperture parameter (mm) corresponding to each surface number is half of the side length of the light-transmitting area of ​​the corresponding surface in the Y direction. The X direction and the Y direction in the system are perpendicular to each other. The units of the Y radius, thickness and focal length in the table are all in millimeters (mm). The reference wavelength of the refractive index, Abbe number and focal length is 587.6nm. The reference wavelength of the parameter values ​​involving focal length and refractive index in the relationship characteristics of this application is 587.56nm. In addition, D1 in Table 1 represents the distance on the optical axis from the image side surface S4 of the second lens L2 to the object side surface S5 of the third lens L3, that is, it represents the distance on the optical axis between the first lens group G1 and the second lens group G2. D2 represents the distance on the optical axis from the image side surface S10 of the fifth lens L5 to the object side surface S11 of the sixth lens L6, that is, it represents the distance on the optical axis between the second lens group G2 and the third lens group G3. D3 represents the distance on the optical axis from the image side surface S14 of the seventh lens L7 to the imaging surface S15 of the system, that is, it represents the distance on the optical axis between the third lens group G3 and the imaging surface S15. The values ​​of D1, D2 and D3 in different zoom states can be referred to the following table, the value unit is millimeter (mm):

[0129] Variable distance D1 D2 D3 Short focal length 4.1162 5.0104 1.8259 Telephoto end 0.2802 4.8704 5.8024 Mid-focus 2.0526 4.4904 4.4090

[0130] In addition, in Table 1, the effective focal length f, aperture number FNO and maximum field of view FOV of the optical zoom system 10 are given three parameter values, which represent the parameter values ​​of the system at the short focal end, the medium focal end and the long focal end from left to right. For example, according to these parameter values ​​in Table 1, it can be concluded that at the short focal end, the effective focal length fd of the optical zoom system 10 is 13.9 mm, the aperture number FNOd is 2.61, and the maximum field of view FOVd is 32.4°. At the medium focal end, the effective focal length fz of the optical zoom system 10 is 18.4 mm, the aperture number FNOd is 3.14, and the maximum field of view FOVd is 24.7°. At the long focal end, the effective focal length fc of the optical zoom system 10 is 23 mm, the aperture number FNOc is 3.63, and the maximum field of view FOVc is 19.8°. In addition, the total optical length of the optical zoom system 10 in this embodiment remains unchanged during the zooming process, that is, the first lens group G1 is stationary relative to the imaging surface S15, and TTL=25 mm.

[0131] Table 2

[0132]

[0133]

[0134] In addition, the optical zoom system 10 in the first embodiment also satisfies the following relationships:

[0135] fc / fd=1.65; fc is the effective focal length of the optical zoom system 10 at the telephoto end, and fd is the effective focal length of the optical zoom system 10 at the short focal end. When the above relationship is satisfied, the ratio of the effective focal length at the telephoto end to the effective focal length at the short focal end of the optical zoom system 10 can be reasonably configured, so that the optical zoom system 10 can obtain a higher zoom ratio, thereby making the shooting magnification of the system have a larger adjustable range.

[0136] TTL / (ATg2+ATg3)=30.44; TTL is the distance on the optical axis from the object side surface S1 of the first lens L1 to the imaging surface S15 of the optical zoom system 10, ATg2 is the sum of the spacings between adjacent lenses in the second lens group G2 on the optical axis, and ATg3 is the sum of the spacings between adjacent lenses in the third lens group G3 on the optical axis. When the above relationship is satisfied, by controlling the sum of the spacings between adjacent lenses in the second lens group G2 and the sum of the spacings between adjacent lenses in the third lens group G3, the total length of the system can be effectively shortened on the basis of achieving a larger zoom ratio, thereby saving assembly space for electronic devices equipped with the optical zoom system 10.

[0137] TTL=25mm; TTL is the distance on the optical axis from the object side surface S1 of the first lens L1 to the imaging surface S15 of the optical zoom system 10. When the above relationship and the above relationship of TTL / (ATg2+ATg3) are satisfied, the total length of the optical zoom system 10 can be directly and effectively controlled, so that the system can be realized.

[0138] FOVc / ImgH=4.95° / mm; FOVc is the maximum field angle of the optical zoom system 10 at the telephoto end, and ImgH is half of the image height corresponding to the maximum field angle of the optical zoom system 10. When the above relationship is satisfied, the ratio of the maximum field angle of the system at the telephoto end to the half image height can be controlled within a reasonable range. On the one hand, the field angle at the telephoto end can be suppressed so that the optical zoom system 10 has excellent telephoto characteristics; on the other hand, it is also beneficial for the optical zoom system 10 to realize a large image plane design, so that the optical zoom system 10 can match a higher pixel image sensor, thereby realizing high-definition shooting.

[0139] f3 / f345=0.83; f3 is the effective focal length of the third lens L3, and f345 is the effective focal length of the second lens group G2. The third lens L3 contributes a part of the overall positive refractive power of the second lens group G2. When the above relationship is satisfied, the positive refractive power of the third lens L3 can be within a reasonable range, which is beneficial for the second lens group G2 to balance the spherical aberration generated by the first lens group G1, and provide a reasonable and controllable positive refractive power for the optical zoom system 10, so as to further improve the image quality, and also help to shorten the total length of the system.

[0140] f12 / f67=1.15; f12 is the effective focal length of the first lens group G1, and f67 is the effective focal length of the third lens group G3. When the above relationship is satisfied, the ratio of the effective focal length of the first lens group G1 to the effective focal length of the third lens group G3 can be reasonably configured, which is conducive to obtaining a larger zoom range. In addition, by reasonably controlling the relationship between the negative refractive power borne by the first lens group G1 and the third lens group G3, the positive refractive power contributed by the second lens group G2 can be well matched to achieve the desired excellent zoom performance.

[0141] f12 / (sd5*FNOc)=-1.57; f12 is the effective focal length of the first lens group G1, sd5 is the maximum effective radius of the object side surface S5 of the third lens L3, and FNOc is the aperture number of the optical zoom system 10 at the telephoto end. When the above relationship is satisfied, it is equivalent to reasonably configuring the ratio of the effective focal length of the first lens group G1 and the aperture number at the telephoto end, which is beneficial for the optical zoom system 10 to obtain a larger zoom range in the telephoto direction; at the same time, the first lens group G1 can be allocated with appropriate refractive power, which is also beneficial for correcting distortion and spherical aberration, thereby further improving the resolution of the optical zoom system 10.

[0142] [max(D2)-min(D2)] / TTL=0.02; max(D2) is the maximum distance on the optical axis from the image side surface S10 of the fifth lens L5 to the object side surface S11 of the sixth lens L6, min(D2) is the minimum distance on the optical axis from the image side surface S10 of the fifth lens L5 to the object side surface S11 of the sixth lens L6, and TTL is the distance on the optical axis from the object side surface S1 of the first lens L1 to the imaging surface S15 of the optical zoom system 10. When the above relationship is satisfied, the relative movement range between the second lens group G2 and the third lens group G3 can be reduced, so that the system can have good zoom performance and also help to make the zoom structure compact, thereby meeting actual use requirements.

[0143] in addition, Figure 4 It shows the longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram when the optical zoom system in this embodiment is at the short focal end. Figure 5 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical zoom system 10 in this embodiment when it is at the mid-focus end are shown. Figure 6 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram when the optical zoom system 10 in this embodiment is at the telephoto end are reflected. Figures 4 to 6 The reference wavelength for the astigmatism and distortion diagrams in the image is 587.6nm. Figures 4 to 6Each of the longitudinal spherical aberration diagrams includes a longitudinal spherical aberration diagram of the optical zoom system 10, which indicates the deviation of the convergence focus of light of different wavelengths after passing through the lens. The ordinate of the longitudinal spherical aberration diagram indicates the normalized pupil coordinate from the center of the pupil to the edge of the pupil, and the abscissa indicates the distance from the imaging plane to the intersection of the light and the optical axis (in mm). It can be seen from each longitudinal spherical aberration diagram that in the three zoom states of the short focal end, the medium focal end and the long focal end, the degree of deviation of the convergence focus of light of each wavelength in the first embodiment tends to be consistent, and the diffuse spots or color halo in the imaging picture are effectively suppressed. Figures 4 to 6 The optical zoom system 10 also includes field curvature diagrams (Astigmatic Field Curves), where the S curve represents the sagittal field curvature at 587.56nm, and the T curve represents the meridian field curvature at 587.56nm. As can be seen from the figure, in the three zoom states of short focal end, medium focal end and long focal end, the field curvature of the system is small, the field curvature and astigmatism of each field of view are well corrected, and the center and edge of the field of view have clear imaging. Figures 4 to 6 The figures also include distortion diagrams of the optical zoom system 10 . It can be seen from the figures that in the three zoom states of the short focal end, the medium focal end and the long focal end, the image deformation caused by the main light beam is small, and the zoom performance of the system is excellent.

[0144] Second embodiment

[0145] refer to Figures 7 to 9 , Figure 7 embodies a schematic diagram of the structure of the optical zoom system 10 at the short focal end, Figure 8 embodies a schematic diagram of the structure of the optical zoom system 10 at the mid-focus end, Fig. 9 The schematic diagram shows the structure of the optical zoom system 10 at the telephoto end.

[0146] In the second embodiment, the optical zoom system 10 includes, in sequence along the incident light path: a reflective element 110, a first lens group G1 with negative refractive power, wherein the first lens group G1 includes a first lens L1 with positive refractive power and a second lens L2 with negative refractive power; a second lens group G2 with positive refractive power, wherein the second lens group G2 includes a third lens L3 with positive refractive power, a fourth lens L4 with negative refractive power, and a fifth lens L5 with positive refractive power; and a third lens group G3 with negative refractive power, wherein the third lens group G3 includes a sixth lens L6 with negative refractive power and a seventh lens L7 with negative refractive power.

[0147] In this embodiment, the total optical length TTL of the optical zoom system 10 remains unchanged during the zooming process, that is, the first lens group G1 remains fixed relative to the imaging surface S15 during the zooming process, that is, the distance from the object side surface S1 of the first lens L1 to the imaging surface S15 of the system remains unchanged. During the zooming process of the optical zoom system 10 from the short focal end to the long focal end, the distance between the first lens group G1 and the second lens group G2 decreases, and the distance between the third lens group G3 and the imaging surface S15 of the optical zoom system 10 increases. The above optical zoom system 10 can make the aberrations between the lens groups be better corrected by the distribution of the refractive power of each lens group distributed along the incident light path and the setting of the number of lenses in each lens group.

[0148] The object-side surface S1 of the first lens L1 is convex at the paraxial position, and the image-side surface S2 is concave at the paraxial position; the object-side surface S1 is convex at the circumference, and the image-side surface S2 is concave at the circumference.

[0149] The object-side surface S3 of the second lens L2 is convex at the paraxial position, and the image-side surface S4 is concave at the paraxial position; the object-side surface S3 is concave at the circumference, and the image-side surface S4 is convex at the circumference.

[0150] The object-side surface S5 of the third lens L3 is convex at the paraxial position, and the image-side surface S6 is convex at the paraxial position; the object-side surface S5 is concave at the circumference, and the image-side surface S6 is convex at the circumference.

[0151] The object-side surface S7 of the fourth lens L4 is convex at the paraxial position, and the image-side surface S8 is concave at the paraxial position; the object-side surface S7 is convex at the circumference, and the image-side surface S8 is concave at the circumference.

[0152] The object-side surface S9 of the fifth lens L5 is concave at the paraxial position, and the image-side surface S10 is convex at the paraxial position; the object-side surface S9 is convex at the circumference, and the image-side surface S10 is concave at the circumference.

[0153] The object-side surface S11 of the sixth lens L6 is concave at the paraxial position, and the image-side surface S12 is convex at the paraxial position; the object-side surface S11 is convex at the circumference, and the image-side surface S12 is concave at the circumference.

[0154] The object-side surface S13 of the seventh lens L7 is concave at the paraxial position, and the image-side surface S14 is concave at the paraxial position; the object-side surface S13 is concave at the circumference, and the image-side surface S14 is convex at the circumference.

[0155] In addition, the lens parameters of the optical zoom system 10 in the second embodiment are given in Table 3 and Table 4, wherein the definitions of the structures and parameters can be obtained from the first embodiment and are not described in detail here.

[0156] Table 3

[0157]

[0158]

[0159] In addition, in the above table, three parameter values ​​are given for the effective focal length f, aperture number FNO and maximum field of view FOV of the optical zoom system 10, which, from left to right, represent the parameter values ​​of the system at the short focal end, medium focal end and long focal end respectively.

[0160] The values ​​of D1, D2 and D3 in different zoom states can be found in the following table. The value unit is millimeter (mm):

[0161] Variable distance D1 D2 D3 Short focal length 4.3127 5.4933 1.7677 Telephoto end 0.2860 5.2358 6.0524 Mid-focus 2.1267 4.9433 4.5031

[0162] Table 4

[0163] K A4 A6 A8 A10 A12 A14 A16 A18 A20 1.804E-01 -1.120E-03 6.000E-05 -1.000E-05 0.000E+00 0 0 0 0 0 -1.122E+01 -1.800E-03 2.800E-04 -6.000E-05 0.000E+00 0 0 0 0 0 -2.064E+01 9.860E-03 -1.220E-03 1.000E-04 -1.000E-05 0 0 0 0 0 -1.129E+01 4.490E-03 -7.900E-04 8.000E-05 0.000E+00 0 0 0 0 0 -4.467E+00 -2.010E-03 7.000E-05 -1.000E-05 0.000E+00 0 0 0 0 0 -7.895E+00 -4.200E-04 -2.000E-04 2.000E-05 0.000E+00 0 0 0 0 0 -5.126E+01 1.930E-03 -2.900E-04 3.000E-05 0.000E+00 0 0 0 0 0 -3.879E+00 1.200E-03 -1.700E-04 0.000E+00 0.000E+00 0 0 0 0 0 8.387E+00 -2.890E-03 -3.000E-05 0.000E+00 0.000E+00 0 0 0 0 0 -2.195E+01 1.960E-03 -4.600E-04 4.000E-05 0.000E+00 0 0 0 0 0 2.835E+00 -4.720E-03 -8.000E-05 -4.000E-05 1.000E-05 0 0 0 0 0 -9.787E-01 1.068E-02 -2.820E-03 2.800E-04 -1.000E-05 0 0 0 0 0 -3.759E+01 2.484E-02 -4.110E-03 3.700E-04 -1.000E-05 0 0 0 0 0 -4.308E+01 6.630E-03 -6.400E-04 5.000E-05 0.000E+00 0 0 0 0 0

[0164] The camera module 10 in this embodiment satisfies the following relationship:

[0165] (R5-R6) / R8 1.70 f12 / (sd5*FNOc) -1.59 fc / fd 1.65 [max(D2)-min(D2)] / TTL 0.02 FOVc / ImgH 4.96 f3 / f345 0.85 TTL / (ATg2+ATg3) 31.42 f12 / f67 1.13

[0166] Fig.10 It shows the longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram when the optical zoom system in this embodiment is at the short focal end. Fig.11 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical zoom system 10 in this embodiment when it is at the mid-focus end are shown. Fig.12 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram when the optical zoom system 10 in this embodiment is at the telephoto end are reflected. Figures 10 to 12 The reference wavelength of the astigmatism and distortion diagrams in is 555nm. Figures 10 to 12 It can be seen that in the three zoom states of the short focal end, the medium focal end and the long focal end, the longitudinal spherical aberration, the field curvature and the distortion of the optical zoom system 10 are all well controlled, so the optical zoom system 10 has good zoom performance.

[0167] Third embodiment

[0168] refer to Figures 13 to 15 , Fig.13 embodies a schematic diagram of the structure of the optical zoom system 10 at the short focal end, Fig.14 embodies a schematic diagram of the structure of the optical zoom system 10 at the mid-focus end, Fig.15 The schematic diagram shows the structure of the optical zoom system 10 at the telephoto end.

[0169] In this embodiment, the optical zoom system 10 includes, in sequence along the incident light path: a reflective element 110, a first lens group G1 with negative refractive power, wherein the first lens group G1 includes a first lens L1 with positive refractive power and a second lens L2 with negative refractive power; a second lens group G2 with positive refractive power, wherein the second lens group G2 includes a third lens L3 with positive refractive power, a fourth lens L4 with negative refractive power and a fifth lens L5 with positive refractive power; and a third lens group G3 with negative refractive power, wherein the third lens group G3 includes a sixth lens L6 with negative refractive power and a seventh lens L7 with positive refractive power.

[0170] In this embodiment, the total optical length TTL of the optical zoom system 10 remains unchanged during the zooming process, that is, the first lens group G1 remains fixed relative to the imaging surface S15 during the zooming process, that is, the distance from the object side surface S1 of the first lens L1 to the imaging surface S15 of the system remains unchanged. During the zooming process of the optical zoom system 10 from the short focal end to the long focal end, the distance between the first lens group G1 and the second lens group G2 decreases, and the distance between the third lens group G3 and the imaging surface S15 of the optical zoom system 10 increases. The above optical zoom system 10 can make the aberrations between the lens groups be better corrected by the distribution of the refractive power of each lens group distributed along the incident light path and the setting of the number of lenses in each lens group.

[0171] The object-side surface S1 of the first lens L1 is convex at the paraxial position, and the image-side surface S2 is convex at the paraxial position; the object-side surface S1 is convex at the circumference, and the image-side surface S2 is concave at the circumference.

[0172] The object-side surface S3 of the second lens L2 is convex at the paraxial position, and the image-side surface S4 is concave at the paraxial position; the object-side surface S3 is concave at the circumference, and the image-side surface S4 is convex at the circumference.

[0173] The object-side surface S5 of the third lens L3 is convex at the paraxial position, and the image-side surface S6 is convex at the paraxial position; the object-side surface S5 is concave at the circumference, and the image-side surface S6 is convex at the circumference.

[0174] The object-side surface S7 of the fourth lens L4 is concave at the paraxial position, and the image-side surface S8 is concave at the paraxial position; the object-side surface S7 is convex at the circumference, and the image-side surface S8 is concave at the circumference.

[0175] The object-side surface S9 of the fifth lens L5 is concave at the paraxial position, and the image-side surface S10 is convex at the paraxial position; the object-side surface S9 is convex at the circumference, and the image-side surface S10 is concave at the circumference.

[0176] The object-side surface S11 of the sixth lens L6 is concave at the paraxial position, and the image-side surface S12 is convex at the paraxial position; the object-side surface S11 is concave at the circumference, and the image-side surface S12 is convex at the circumference.

[0177] The object-side surface S13 of the seventh lens L7 is convex at the paraxial position, and the image-side surface S14 is convex at the paraxial position; the object-side surface S13 is concave at the circumference, and the image-side surface S14 is concave at the circumference.

[0178] In addition, the lens parameters of the optical zoom system 10 in the third embodiment are given in Table 5 and Table 6, wherein the definitions of the structures and parameters can be obtained from the first embodiment and are not described in detail here.

[0179] Table 5

[0180]

[0181]

[0182] In addition, in the above table, three parameter values ​​are given for the effective focal length f, aperture number FNO and maximum field of view FOV of the optical zoom system 10, which, from left to right, represent the parameter values ​​of the system at the short focal end, medium focal end and long focal end respectively.

[0183] The values ​​of D1, D2 and D3 in different zoom states can be found in the following table. The value unit is millimeter (mm):

[0184] Variable distance D1 D2 D3 Short focal length 4.6644 5.4002 1.6067 Telephoto end 0.2800 5.1782 6.2137 Mid-focus 2.2233 4.8751 4.5725

[0185] Table 6

[0186] Surface number K A4 A6 A8 A10 A12 A14 A16 A18 A20 4 2.388E+00 -1.320E-03 8.000E-05 -1.000E-05 0.000E+00 0 0 0 0 0 5 -2.021E+01 -2.050E-03 2.300E-04 -4.000E-05 0.000E+00 0 0 0 0 0 6 9.358E+00 9.200E-03 -1.310E-03 1.300E-04 -1.000E-05 0 0 0 0 0 7 -1.143E+01 4.640E-03 -8.900E-04 1.000E-04 -1.000E-05 0 0 0 0 0 8 -4.571E+00 -2.230E-03 1.300E-04 -1.000E-05 0.000E+00 0 0 0 0 0 9 -6.401E+00 1.200E-04 -1.800E-04 2.000E-05 0.000E+00 0 0 0 0 0 10 -5.051E+01 5.900E-04 -2.200E-04 2.000E-05 0.000E+00 0 0 0 0 0 11 -1.448E+00 -1.400E-04 -1.100E-04 0.000E+00 0.000E+00 0 0 0 0 0 12 -7.002E+00 -1.650E-03 -1.400E-04 0.000E+00 0.000E+00 0 0 0 0 0 13 -4.327E+01 1.780E-03 -4.700E-04 5.000E-05 0.000E+00 0 0 0 0 0 14 3.113E+00 -8.900E-04 -8.600E-04 1.000E-05 1.000E-05 0 0 0 0 0 15 2.658E+01 1.897E-02 -3.780E-03 2.800E-04 -1.000E-05 0 0 0 0 0 16 1.242E+01 3.264E-02 -4.580E-03 2.900E-04 0.000E+00 0 0 0 0 0 17 -5.427E+01 8.350E-03 -9.800E-04 1.100E-04 -1.000E-05 0 0 0 0 0

[0187] The camera module 10 in this embodiment satisfies the following relationship:

[0188] (R5-R6) / R8 0.85 f12 / (sd5*FNOc) -1.52 fc / fd 1.65 [max(D2)-min(D2)] / TTL 0.02 FOVc / ImgH 4.96 f3 / f345 0.83 TTL / (ATg2+ATg3) 35.49 f12 / f67 0.93

[0189] Fig.16 It shows the longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram when the optical zoom system in this embodiment is at the short focal end. Fig.17 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical zoom system 10 in this embodiment when it is at the mid-focus end are shown. Fig.18 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram when the optical zoom system 10 in this embodiment is at the telephoto end are reflected. Figures 16 to 18 The reference wavelength of the astigmatism and distortion diagrams in is 555nm. Figures 16 to 18 It can be seen that in the three zoom states of the short focal end, the medium focal end and the long focal end, the longitudinal spherical aberration, the field curvature and the distortion of the optical zoom system 10 are all well controlled, so the optical zoom system 10 has good zoom performance.

[0190] Fourth embodiment

[0191] refer to Figures 19 to 21 , Fig.19 embodies a schematic diagram of the structure of the optical zoom system 10 at the short focal end, Fig. 20 embodies a schematic diagram of the structure of the optical zoom system 10 at the mid-focus end, Fig.21 The schematic diagram shows the structure of the optical zoom system 10 at the telephoto end.

[0192] In this embodiment, the optical zoom system 10 includes, in sequence along the incident light path: a reflective element 110, a first lens group G1 with negative refractive power, wherein the first lens group G1 includes a first lens L1 with negative refractive power and a second lens L2 with negative refractive power; a second lens group G2 with positive refractive power, wherein the second lens group G2 includes a third lens L3 with positive refractive power, a fourth lens L4 with negative refractive power and a fifth lens L5 with positive refractive power; and a third lens group G3 with negative refractive power, wherein the third lens group G3 includes a sixth lens L6 with negative refractive power and a seventh lens L7 with negative refractive power.

[0193] In this embodiment, the total optical length TTL of the optical zoom system 10 remains unchanged during the zooming process, that is, the first lens group G1 remains fixed relative to the imaging surface S15 during the zooming process, that is, the distance from the object side surface S1 of the first lens L1 to the imaging surface S15 of the system remains unchanged. During the zooming process of the optical zoom system 10 from the short focal end to the long focal end, the distance between the first lens group G1 and the second lens group G2 decreases, and the distance between the third lens group G3 and the imaging surface S15 of the optical zoom system 10 increases. The above optical zoom system 10 can make the aberrations between the lens groups be better corrected by the distribution of the refractive power of each lens group distributed along the incident light path and the setting of the number of lenses in each lens group.

[0194] The object-side surface S1 of the first lens L1 is concave at the paraxial position, and the image-side surface S2 is convex at the paraxial position; the object-side surface S1 is convex at the circumference, and the image-side surface S2 is concave at the circumference.

[0195] The object-side surface S3 of the second lens L2 is convex at the paraxial position, and the image-side surface S4 is concave at the paraxial position; the object-side surface S3 is convex at the circumference, and the image-side surface S4 is convex at the circumference.

[0196] The object-side surface S5 of the third lens L3 is convex at the paraxial position, and the image-side surface S6 is convex at the paraxial position; the object-side surface S5 is concave at the circumference, and the image-side surface S6 is convex at the circumference.

[0197] The object-side surface S7 of the fourth lens L4 is concave at the paraxial position, and the image-side surface S8 is concave at the paraxial position; the object-side surface S7 is convex at the circumference, and the image-side surface S8 is concave at the circumference.

[0198] The object-side surface S9 of the fifth lens L5 is concave at the paraxial position, and the image-side surface S10 is convex at the paraxial position; the object-side surface S9 is convex at the circumference, and the image-side surface S10 is concave at the circumference.

[0199] The object-side surface S11 of the sixth lens L6 is concave at the paraxial position, and the image-side surface S12 is convex at the paraxial position; the object-side surface S11 is concave at the circumference, and the image-side surface S12 is concave at the circumference.

[0200] The object-side surface S13 of the seventh lens L7 is concave at the paraxial position, and the image-side surface S14 is concave at the paraxial position; the object-side surface S13 is concave at the circumference, and the image-side surface S14 is convex at the circumference.

[0201] In addition, the lens parameters of the optical zoom system 10 in the fourth embodiment are given in Table 7 and Table 8, wherein the definitions of the structures and parameters can be obtained from the first embodiment and are not elaborated here.

[0202] Table 7

[0203]

[0204]

[0205] In addition, in the above table, three parameter values ​​are given for the effective focal length f, aperture number FNO and maximum field of view FOV of the optical zoom system 10, which, from left to right, represent the parameter values ​​of the system at the short focal end, medium focal end and long focal end respectively.

[0206] The values ​​of D1, D2 and D3 in different zoom states can be found in the following table. The value unit is millimeter (mm):

[0207] Variable distance D1 D2 D3 Short focal length 4.0684 4.9214 1.8451 Telephoto end 0.2800 4.6030 5.9522 Mid-focus 2.0493 4.4139 4.3711

[0208] Table 8

[0209] Surface number K A4 A6 A8 A10 A12 A14 A16 A18 A20 4 6.434E-02 -3.050E-03 2.700E-04 -4.000E-05 0.000E+00 0 0 0 0 0 5 9.795E+00 1.750E-03 -7.100E-04 8.000E-05 0.000E+00 0 0 0 0 0 6 -5.186E+00 1.065E-02 -1.610E-03 1.900E-04 -1.000E-05 0 0 0 0 0 7 -1.086E+01 1.950E-03 -2.100E-04 2.000E-05 0.000E+00 0 0 0 0 0 8 -4.556E+00 -2.320E-03 1.300E-04 -1.000E-05 0.000E+00 0 0 0 0 0 9 -5.797E+00 -8.800E-04 1.000E-05 1.000E-05 0.000E+00 0 0 0 0 0 10 -3.410E+01 8.000E-05 -1.200E-04 1.000E-05 0.000E+00 0 0 0 0 0 11 -8.319E-01 4.500E-04 -1.700E-04 0.000E+00 0.000E+00 0 0 0 0 0 12 -2.168E+00 -2.410E-03 -4.000E-05 0.000E+00 0.000E+00 0 0 0 0 0 13 -5.792E+01 2.300E-04 -3.600E-04 4.000E-05 0.000E+00 0 0 0 0 0 14 3.057E+00 -5.580E-03 -1.300E-04 3.000E-05 0.000E+00 0 0 0 0 0 15 -1.241E+01 1.960E-03 -1.460E-03 1.400E-04 0.000E+00 0 0 0 0 0 16 -2.587E+01 1.757E-02 -3.080E-03 2.900E-04 -1.000E-05 0 0 0 0 0 17 -5.427E+01 9.270E-03 -1.270E-03 1.300E-04 -1.000E-05 0 0 0 0 0

[0210] The camera module 10 in this embodiment satisfies the following relationship:

[0211] (R5-R6) / R8 0.80 f12 / (sd5*FNOc) -1.58 fc / fd 1.65 [max(D2)-min(D2)] / TTL 0.02 FOVc / ImgH 4.91 f3 / f345 0.85 TTL / (ATg2+ATg3) 26.11 f12 / f67 1.51

[0212] Fig. 22 It shows the longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram when the optical zoom system in this embodiment is at the short focal end. Fig.23 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical zoom system 10 in this embodiment when it is at the mid-focus end are shown. Fig.24 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram when the optical zoom system 10 in this embodiment is at the telephoto end are reflected. Figure 22 to Figure 24The reference wavelength of the astigmatism and distortion diagrams in is 555nm. Figure 22 to Figure 24 It can be seen that in the three zoom states of the short focal end, the medium focal end and the long focal end, the longitudinal spherical aberration, the field curvature and the distortion of the optical zoom system 10 are all well controlled, so the optical zoom system 10 has good zoom performance.

[0213] Fifth embodiment

[0214] refer to Figure 25 to Figure 27 , Fig.25 embodies a schematic diagram of the structure of the optical zoom system 10 at the short focal end, Fig.26 embodies a schematic diagram of the structure of the optical zoom system 10 at the mid-focus end, Fig. 27 The schematic diagram shows the structure of the optical zoom system 10 at the telephoto end.

[0215] In this embodiment, the optical zoom system 10 includes, in sequence along the incident light path: a reflective element 110, a first lens group G1 with negative refractive power, wherein the first lens group G1 includes a first lens L1 with positive refractive power and a second lens L2 with negative refractive power; a second lens group G2 with positive refractive power, wherein the second lens group G2 includes a third lens L3 with positive refractive power, a fourth lens L4 with negative refractive power and a fifth lens L5 with positive refractive power; and a third lens group G3 with negative refractive power, wherein the third lens group G3 includes a sixth lens L6 with positive refractive power and a seventh lens L7 with negative refractive power.

[0216] In this embodiment, the total optical length TTL of the optical zoom system 10 remains unchanged during the zooming process, that is, the first lens group G1 remains fixed relative to the imaging surface S15 during the zooming process, that is, the distance from the object side surface S1 of the first lens L1 to the imaging surface S15 of the system remains unchanged. During the zooming process of the optical zoom system 10 from the short focal end to the long focal end, the distance between the first lens group G1 and the second lens group G2 decreases, and the distance between the third lens group G3 and the imaging surface S15 of the optical zoom system 10 increases. The above optical zoom system 10 can make the aberrations between the lens groups be better corrected by the distribution of the refractive power of each lens group distributed along the incident light path and the setting of the number of lenses in each lens group.

[0217] The object-side surface S1 of the first lens L1 is convex at the paraxial position, and the image-side surface S2 is concave at the paraxial position; the object-side surface S1 is convex at the circumference, and the image-side surface S2 is concave at the circumference.

[0218] The object-side surface S3 of the second lens L2 is convex at the paraxial position, and the image-side surface S4 is concave at the paraxial position; the object-side surface S3 is concave at the circumference, and the image-side surface S4 is convex at the circumference.

[0219] The object-side surface S5 of the third lens L3 is convex at the paraxial position, and the image-side surface S6 is convex at the paraxial position; the object-side surface S5 is concave at the circumference, and the image-side surface S6 is convex at the circumference.

[0220] The object-side surface S7 of the fourth lens L4 is concave at the paraxial position, and the image-side surface S8 is concave at the paraxial position; the object-side surface S7 is convex at the circumference, and the image-side surface S8 is concave at the circumference.

[0221] The object-side surface S9 of the fifth lens L5 is convex at the paraxial position, and the image-side surface S10 is concave at the paraxial position; the object-side surface S9 is convex at the circumference, and the image-side surface S10 is concave at the circumference.

[0222] The object-side surface S11 of the sixth lens L6 is concave at the paraxial position, and the image-side surface S12 is convex at the paraxial position; the object-side surface S11 is convex at the circumference, and the image-side surface S12 is concave at the circumference.

[0223] The object-side surface S13 of the seventh lens L7 is convex at the paraxial position, and the image-side surface S14 is concave at the paraxial position; the object-side surface S13 is concave at the circumference, and the image-side surface S14 is convex at the circumference.

[0224] In addition, the lens parameters of the optical zoom system 10 in the fifth embodiment are given in Tables 9 and 10, wherein the definitions of the structures and parameters can be obtained from the first embodiment and are not elaborated here.

[0225] Table 9

[0226]

[0227]

[0228] In addition, in the above table, three parameter values ​​are given for the effective focal length f, aperture number FNO and maximum field of view FOV of the optical zoom system 10, which, from left to right, represent the parameter values ​​of the system at the short focal end, medium focal end and long focal end respectively.

[0229] The values ​​of D1, D2 and D3 in different zoom states can be found in the following table. The value unit is millimeter (mm):

[0230] Variable distance D1 D2 D3 Short focal length 4.1492 4.7857 1.8004 Telephoto end 0.2800 4.4357 6.0200 Mid-focus 2.0712 4.0857 4.5778

[0231] Table 10

[0232] Surface number K A4 A6 A8 A10 A12 A14 A16 A18 A20 4 1.487E-01 -1.480E-03 1.400E-04 -3.000E-05 0.000E+00 0 0 0 0 0 5 8.470E+00 -2.010E-03 3.500E-04 -8.000E-05 1.000E-05 0 0 0 0 0 6 -6.287E+00 9.640E-03 -1.290E-03 1.100E-04 -1.000E-05 0 0 0 0 0 7 -1.186E+01 4.570E-03 -8.700E-04 1.000E-04 -1.000E-05 0 0 0 0 0 8 -4.477E+00 -2.030E-03 5.000E-05 1.000E-05 0.000E+00 0 0 0 0 0 9 -4.188E+00 1.600E-04 2.000E-05 1.000E-05 0.000E+00 0 0 0 0 0 10 -5.107E+01 -3.500E-04 1.200E-04 -2.000E-05 0.000E+00 0 0 0 0 0 11 4.996E+00 -3.200E-04 -1.400E-04 0.000E+00 0.000E+00 0 0 0 0 0 12 -3.565E+01 -1.650E-03 -1.000E-05 0.000E+00 0.000E+00 0 0 0 0 0 13 -5.792E+01 4.300E-04 -2.100E-04 3.000E-05 0.000E+00 0 0 0 0 0 14 3.575E+00 -4.230E-03 9.000E-05 -5.000E-05 0.000E+00 0 0 0 0 0 15 -4.177E+00 2.140E-03 -4.800E-04 2.000E-05 0.000E+00 0 0 0 0 0 16 -7.870E+00 1.570E-02 -1.240E-03 3.000E-05 0.000E+00 0 0 0 0 0 17 -8.325E+00 1.036E-02 -1.030E-03 8.000E-05 0.000E+00 0 0 0 0 0

[0233] The camera module 10 in this embodiment satisfies the following relationship:

[0234] (R5-R6) / R8 0.72 f12 / (sd5*FNOc) -1.61 fc / fd 1.65 [max(D2)-min(D2)] / TTL 0.03 FOVc / ImgH 4.95 f3 / f345 0.90 TTL / (ATg2+ATg3) 44.97 f12 / f67 1.04

[0235] Fig.28It shows the longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram when the optical zoom system in this embodiment is at the short focal end. Fig.29 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical zoom system 10 in this embodiment when it is at the mid-focus end are shown. Fig.30 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram when the optical zoom system 10 in this embodiment is at the telephoto end are reflected. Figures 28 to 30 The reference wavelength of the astigmatism and distortion diagrams in is 555nm. Figures 28 to 30 It can be seen that in the three zoom states of the short focal end, the medium focal end and the long focal end, the longitudinal spherical aberration, the field curvature and the distortion of the optical zoom system 10 are all well controlled, so the optical zoom system 10 has good zoom performance.

[0236] Sixth embodiment

[0237] refer to Figure 31 to Figure 33 , Fig.31 embodies a schematic diagram of the structure of the optical zoom system 10 at the short focal end, Fig.32 embodies a schematic diagram of the structure of the optical zoom system 10 at the mid-focus end, Fig.33 The schematic diagram shows the structure of the optical zoom system 10 at the telephoto end.

[0238] In this embodiment, the optical zoom system 10 includes, in sequence along the incident light path: a reflective element 110, a first lens group G1 with negative refractive power, wherein the first lens group G1 includes a first lens L1 with positive refractive power and a second lens L2 with negative refractive power; a second lens group G2 with positive refractive power, wherein the second lens group G2 includes a third lens L3 with positive refractive power, a fourth lens L4 with negative refractive power and a fifth lens L5 with positive refractive power; and a third lens group G3 with negative refractive power, wherein the third lens group G3 includes a sixth lens L6 with positive refractive power and a seventh lens L7 with negative refractive power.

[0239] In this embodiment, the total optical length TTL of the optical zoom system 10 remains unchanged during the zooming process, that is, the first lens group G1 remains fixed relative to the imaging surface S15 during the zooming process, that is, the distance from the object side surface S1 of the first lens L1 to the imaging surface S15 of the system remains unchanged. During the zooming process of the optical zoom system 10 from the short focal end to the long focal end, the distance between the first lens group G1 and the second lens group G2 decreases, and the distance between the third lens group G3 and the imaging surface S15 of the optical zoom system 10 increases. The above optical zoom system 10 can make the aberrations between the lens groups be better corrected by the distribution of the refractive power of each lens group distributed along the incident light path and the setting of the number of lenses in each lens group.

[0240] The object-side surface S1 of the first lens L1 is convex at the paraxial position, and the image-side surface S2 is convex at the paraxial position; the object-side surface S1 is convex at the circumference, and the image-side surface S2 is concave at the circumference.

[0241] The object-side surface S3 of the second lens L2 is concave at the paraxial position, and the image-side surface S4 is concave at the paraxial position; the object-side surface S3 is concave at the circumference, and the image-side surface S4 is convex at the circumference.

[0242] The object-side surface S5 of the third lens L3 is convex at the paraxial position, and the image-side surface S6 is convex at the paraxial position; the object-side surface S5 is concave at the circumference, and the image-side surface S6 is convex at the circumference.

[0243] The object-side surface S7 of the fourth lens L4 is concave at the paraxial position, and the image-side surface S8 is concave at the paraxial position; the object-side surface S7 is convex at the circumference, and the image-side surface S8 is concave at the circumference.

[0244] The object-side surface S9 of the fifth lens L5 is convex at the paraxial position, and the image-side surface S10 is convex at the paraxial position; the object-side surface S9 is convex at the circumference, and the image-side surface S10 is concave at the circumference.

[0245] The object-side surface S11 of the sixth lens L6 is concave at the paraxial position, and the image-side surface S12 is convex at the paraxial position; the object-side surface S11 is convex at the circumference, and the image-side surface S12 is concave at the circumference.

[0246] The object-side surface S13 of the seventh lens L7 is concave at the paraxial position, and the image-side surface S14 is concave at the paraxial position; the object-side surface S13 is concave at the circumference, and the image-side surface S14 is convex at the circumference.

[0247] In addition, the lens parameters of the optical zoom system 10 in the sixth embodiment are given in Table 11 and Table 12, wherein the definitions of the structures and parameters can be obtained from the first embodiment and will not be repeated here.

[0248] Table 11

[0249]

[0250] In addition, in the above table, three parameter values ​​are given for the effective focal length f, aperture number FNO and maximum field of view FOV of the optical zoom system 10, which, from left to right, represent the parameter values ​​of the system at the short focal end, medium focal end and long focal end respectively.

[0251] The values ​​of D1, D2 and D3 in different zoom states can be found in the following table. The value unit is millimeter (mm):

[0252]

[0253]

[0254] Table 12

[0255] Surface number K A4 A6 A8 A10 A12 A14 A16 A18 A20 4 2.023E+00 -1.440E-03 5.000E-05 -1.000E-05 0.000E+00 0 0 0 0 0 5 8.147E+00 -2.430E-03 2.900E-04 -7.000E-05 1.000E-05 0 0 0 0 0 6 9.358E+00 1.093E-02 -1.550E-03 1.400E-04 -1.000E-05 0 0 0 0 0 7 -1.225E+01 5.910E-03 -1.130E-03 1.300E-04 -1.000E-05 0 0 0 0 0 8 -4.640E+00 -2.990E-03 2.000E-04 -1.000E-05 0.000E+00 0 0 0 0 0 9 -4.476E+00 -8.100E-04 1.600E-04 -1.000E-05 0.000E+00 0 0 0 0 0 10 -3.883E+01 7.000E-05 1.000E-05 -1.000E-05 0.000E+00 0 0 0 0 0 11 4.562E+00 -8.200E-04 -7.000E-05 0.000E+00 0.000E+00 0 0 0 0 0 12 -2.838E+01 -2.500E-03 -4.000E-05 0.000E+00 0.000E+00 0 0 0 0 0 13 -5.792E+01 -6.000E-04 -1.600E-04 1.000E-05 0.000E+00 0 0 0 0 0 14 3.971E+00 -5.260E-03 1.000E-04 -5.000E-05 1.000E-05 0 0 0 0 0 15 -3.550E+00 7.700E-04 -3.800E-04 3.000E-05 0.000E+00 0 0 0 0 0 16 -3.759E+01 1.978E-02 -2.500E-03 3.200E-04 -3.000E-05 0 0 0 0 0 17 -3.462E+01 1.052E-02 -1.350E-03 1.600E-04 -1.000E-05 0 0 0 0 0

[0256] The camera module 10 in this embodiment satisfies the following relationship:

[0257] (R5-R6) / R8 1.01 f12 / (sd5*FNOc) -1.44 fc / fd 2.02 [max(D2)-min(D2)] / TTL 0.03 FOVc / ImgH 4.64 f3 / f345 0.82 TTL / (ATg2+ATg3) 33.04 f12 / f67 1.21

[0258] Fig.34 It shows the longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram when the optical zoom system in this embodiment is at the short focal end. Fig.35 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical zoom system 10 in this embodiment when it is at the mid-focus end are shown. Fig.36 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram when the optical zoom system 10 in this embodiment is at the telephoto end are reflected. Figure 34 to Figure 36 The reference wavelength of the astigmatism and distortion diagrams in is 555nm. Figure 34 to Figure 36 It can be seen that in the three zoom states of the short focal end, the medium focal end and the long focal end, the longitudinal spherical aberration, the field curvature and the distortion of the optical zoom system 10 are all well controlled, so the optical zoom system 10 has good zoom performance.

[0259] refer to Fig.37 Some embodiments of the present application further provide a camera module 20, which may include the optical zoom system 10 and the image sensor 210 of any of the above embodiments, and the image sensor 210 is arranged on the image side of the optical zoom system 10, that is, on the light-emitting side of the third lens group G3. The image sensor 210 may be a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). Generally, during assembly, the imaging surface S15 of the optical zoom system 10 overlaps with the photosensitive surface of the image sensor 210. By adopting the above optical zoom system 10, the camera module 20 can effectively control the aberration caused by the lens groups to improve the imaging quality while having the zoom capability to cope with different shooting requirements, so as to have excellent zoom performance.

[0260] refer to Fig.38, some embodiments of the present application further provide an electronic device 30. The electronic device 30 includes a fixing part 310, and the camera module 20 is installed on the fixing part 310. The fixing part 310 may be a display screen, a circuit board, a middle frame, a back cover and other components. The electronic device 30 may be, but is not limited to, a smart phone, a smart watch, smart glasses, an e-book reader, a vehicle-mounted camera device, a monitoring device, a drone, a medical device (such as an endoscope), a tablet computer, a biometric device (such as a fingerprint recognition device, a pupil recognition device, a face recognition device, etc.), a PDA (Personal Digital Assistant), etc. By adopting the above-mentioned camera module 20, the electronic device 30 can still have excellent imaging quality under zoom adjustment, and thus has excellent zoom performance, so that the device can better cope with different camera requirements.

[0261] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0262] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An optical zoom system, characterized in that: There are seven lenses with refractive power, including: A first lens group with negative refractive power, comprising a first lens and a second lens; a second lens group having positive refractive power, comprising a third lens, a fourth lens and a fifth lens; and a third lens group having negative refractive power, comprising a sixth lens and a seventh lens; The first lens has refractive power; The second lens has negative refractive power, and the image side surface of the second lens is concave at the paraxial position; The third lens has positive refractive power, the object side surface of the third lens is convex at the paraxial position, and the image side surface of the third lens is convex at the paraxial position; The fourth lens has negative refractive power, and the image side surface of the fourth lens is concave at the paraxial position; The fifth lens has positive refractive power; The sixth lens has refractive power, the object side surface of the sixth lens is concave at the paraxial position, and the image side surface of the sixth lens is convex at the paraxial position; The seventh lens has refractive power; During the zooming process of the optical zoom system from the short focal end to the long focal end, the distance between the first lens group and the second lens group decreases, and the distance between the third lens group and the imaging plane of the optical zoom system increases; The optical zoom system satisfies the relationship: 0.2<(R5-R6) / R8≤1.7; 2.02≥fc / fd>1.6; R5 is the curvature radius of the object side of the third lens at the optical axis, R6 is the curvature radius of the image side of the third lens at the optical axis, R8 is the curvature radius of the image side of the fourth lens at the optical axis, fc is the effective focal length of the optical zoom system at the telephoto end, and fd is the effective focal length of the optical zoom system at the short focal end.

2. The optical zoom system according to claim 1, characterized in that: The optical zoom system satisfies the relationship: 26.11≤TTL / (ATg2+ATg3)<45; TTL is the distance from the object side of the first lens to the imaging surface of the optical zoom system on the optical axis, ATg2 is the sum of the distances between adjacent lenses in the second lens group on the optical axis, and ATg3 is the sum of the distances between adjacent lenses in the third lens group on the optical axis.

3. The optical zoom system according to claim 1, wherein: The optical zoom system satisfies the relationship: 4° / mm<FOVc / ImgH<6° / mm; FOVc is the maximum field of view of the optical zoom system at the telephoto end, and ImgH is half of the image height corresponding to the maximum field of view of the optical zoom system.

4. The optical zoom system according to claim 1, wherein: The optical zoom system satisfies the relationship: 0.82≤f3 / f345<1.5; f3 is the effective focal length of the third lens, and f345 is the effective focal length of the second lens group.

5. The optical zoom system according to claim 1, wherein: The optical zoom system satisfies the relationship: 0.4<f12 / f67≤1.51; f12 is the effective focal length of the first lens group, and f67 is the effective focal length of the third lens group.

6. The optical zoom system according to claim 1, wherein: The optical zoom system satisfies the relationship: -3<f12 / (sd5 FNOc)≤-1.44; f12 is the effective focal length of the first lens group, sd5 is the maximum effective radius of the object side of the third lens, and FNOc is the aperture number of the optical zoom system at the telephoto end.

7. The optical zoom system according to claim 1, wherein: The optical zoom system satisfies the relationship: [max(D2)-min(D2)] / TTL<0.1; max(D2) is the maximum distance from the image side surface of the fifth lens to the object side surface of the sixth lens on the optical axis, min(D2) is the minimum distance from the image side surface of the fifth lens to the object side surface of the sixth lens on the optical axis, and TTL is the distance from the object side surface of the first lens to the imaging plane of the optical zoom system on the optical axis.

8. The optical zoom system according to claim 1, wherein: The optical zoom system includes a reflective element disposed on the light incident side of the first lens group, and the reflective element is used to reflect incident light to the first lens group.

9. A camera module, characterized in that: The optical zoom system comprises an image sensor and any one of claims 1 to 8, wherein the image sensor is arranged on the light-exiting side of the third lens group.

10. An electronic device, characterized in that: It comprises a fixing part and the camera module as claimed in claim 9, wherein the camera module is arranged on the fixing part.

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