Optical system, camera module and electronic equipment

Abstract

The invention discloses an optical system, a camera module and electronic equipment, and relates to the technical field of optics. The optical system comprises a reflecting part, a first lens group, a zoom lens group, a focusing lens group and a photosensitive element which are sequentially arranged along a first optical axis, the first lens group has negative focal power, the zoom lens group has positive focal power, and the focusing lens group has negative focal power; wherein the reflecting part is used for reflecting light rays incident along a second optical axis and enabling the reflected light rays to be emitted along the first optical axis, and an included angle is formed between the first optical axis and the second optical axis; the zoom lens group and the focusing lens group can move in the reciprocating direction along the first optical axis so as to adjust the focal length of the optical system.

Description

Technical Field

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

[0002] With the popularity of smart terminals such as mobile phones, the camera function of smart terminals has become increasingly important and has become an important factor for consumers when choosing a device. As one of the most commonly used functions for taking photos, the telephoto lens has become a must-have function for cameras in smart terminals.

[0003] In the related art, some smart terminals have proposed a solution to use different optical modules for shooting at different focal lengths in order to further improve the shooting experience of different focal lengths during telephoto shooting. For example, a dual telephoto camera solution includes two cameras, 3X and 5X, to shoot at two different focal lengths respectively. Since different focal lengths need to be shot with independent optical modules, this method will increase the size and weight of the camera, which is not conducive to the thinness of smart terminals. Summary of the invention

[0004] The present application provides an optical system, a camera module and an electronic device, which are helpful in reducing the size and weight of the camera, thereby facilitating the thinness and lightness of the smart terminal.

[0005] In a first aspect, the present application provides an optical system, comprising a reflector, a first lens group, a zoom lens group, a focus lens group and a photosensitive element arranged in sequence along a first optical axis, wherein the first lens group has a negative optical power, the zoom lens group has a positive optical power, and the focus lens group has a negative optical power;

[0006] The reflector is used to reflect the light incident along the second optical axis and make the reflected light emerge along the first optical axis, and the first optical axis and the second optical axis are arranged at an angle;

[0007] The zoom lens group and the focus lens group can both move in a reciprocating direction along the first optical axis to adjust the focal length of the optical system.

[0008] In a second aspect, the present application provides a camera module, comprising an infrared filter and the optical system described in the first aspect, wherein the infrared filter is located between the focusing lens group and the photosensitive element.

[0009] In a third aspect, the present application provides an electronic device comprising the camera module described in the second aspect.

[0010] In the embodiment of the present application, since both the zoom lens group and the focus lens group can move in a reciprocating direction along the first optical axis to adjust the focal length of the optical system, continuous zooming of the optical system can be achieved, which is conducive to achieving shooting experience at different focal lengths. In this way, compared with the shooting method of using different optical modules to achieve different focal lengths, the optical system provided in the embodiment of the present application can achieve shooting at different focal lengths based on one optical system, which is conducive to reducing the size and weight of the camera, thereby facilitating the thinness of the smart terminal. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a schematic structural diagram of the optical system provided in Example 1 of the present application when it is at a wide-angle end;

[0012] Figure 2 is a schematic structural diagram of the optical system provided in Example 1 of the present application when it is at the telephoto end;

[0013] Figure 3 This is a schematic diagram of axial chromatic aberration at the wide-angle end in Example 1 of the present application;

[0014] Figure 4 Schematic diagram of wide-angle end through-focus MTF in Example 1 of the present application;

[0015] Figure 5 Schematic diagram of axial chromatic aberration at the telephoto end in Example 1 of the present application;

[0016] Figure 6 Schematic diagram of the telephoto end through-focus MTF in Example 1 of the present application;

[0017] Figure 7 is a schematic structural diagram of the optical system provided in Example 2 of the present application when it is at a wide-angle end;

[0018] Figure 8 is a schematic structural diagram of the optical system provided in Example 2 of the present application when it is at the telephoto end;

[0019] Fig. 9 is a schematic diagram of axial chromatic aberration at the wide-angle end in Example 2 of the present application;

[0020] Fig.10 Schematic diagram of wide-angle through-focus MTF in Example 2 of the present application;

[0021] Fig.11 Schematic diagram of axial chromatic aberration at the telephoto end in Example 2 of the present application;

[0022] Fig.12 Schematic diagram of the telephoto end through-focus MTF in Example 2 of the present application;

[0023] Fig.13is a schematic structural diagram of the optical system provided in Example 3 of the present application when it is at a wide-angle end;

[0024] Fig.14 is a schematic structural diagram of the optical system provided in Example 3 of the present application when it is at the telephoto end;

[0025] Fig.15 is a schematic diagram of axial chromatic aberration at the wide-angle end in Example 3 of the present application;

[0026] Fig.16 Schematic diagram of wide-angle end through-focus MTF in Example 3 of the present application;

[0027] Fig.17 is a schematic diagram of axial chromatic aberration at the telephoto end in Example 3 of the present application;

[0028] Fig.18 Schematic diagram of the telephoto end through-focus MTF in Example 3 of the present application;

[0029] Fig.19 is a schematic structural diagram of the optical system provided in Example 4 of the present application when it is at a wide-angle end;

[0030] Fig. 20 is a schematic structural diagram of the optical system provided in Example 4 of the present application when it is at the telephoto end;

[0031] Fig.21 Schematic diagram of axial chromatic aberration at wide-angle end in Example 4 of the present application;

[0032] Fig. 22 Schematic diagram of wide-angle end through-focus MTF in Example 4 of the present application;

[0033] Fig.23 Schematic diagram of axial chromatic aberration at the telephoto end in Example 4 of the present application;

[0034] Fig.24 Schematic diagram of the telephoto end through-focus MTF in Example 4 of the present application;

[0035] Fig.25 is a schematic structural diagram of the optical system provided in Example 5 of the present application when it is at a wide-angle end;

[0036] Fig.26 is a schematic structural diagram of the optical system provided in Example 5 of the present application when it is at the telephoto end;

[0037] Fig. 27 is a schematic diagram of axial chromatic aberration at the wide-angle end in Example 5 of the present application;

[0038] Fig.28 Schematic diagram of wide-angle end through-focus MTF in Example 5 of the present application;

[0039] Fig.29is a schematic diagram of axial chromatic aberration at the telephoto end in Example 5 of the present application;

[0040] Fig.30 It is a schematic diagram of the telephoto end defocus MTF in Example 5 of the present application. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0042] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0043] In the following, in combination with the accompanying drawings, an optical system, a camera module and an electronic device provided in an embodiment of the present application are described in detail through specific embodiments and their application scenarios.

[0044] For ease of understanding, firstly, the relevant technical terms involved in the embodiments of the present application are explained and illustrated:

[0045] Focal length (Effective Focal Length, EFL) is a measure of the ability of optical systems to gather or disperse light. It refers to the vertical distance from the optical center of a lens or lens group to the focal plane when an infinitely distant scene forms a clear image on the focal plane through a lens or lens group. From a practical point of view, it can be understood as the distance from the center of the lens (lens assembly) to the imaging plane.

[0046] Optical power represents the ability of a lens to refract an incident parallel light beam.

[0047] The field of view (FOV) is the angle formed by the two edges of the lens with the lens as the vertex and the maximum range of the image of the object passing through the lens. The size of the field of view determines the field of view of the lens. The larger the field of view, the larger the field of view. The half field of view (HFOV) refers to half of the field of view.

[0048] The aperture is a device used to control the amount of light that passes through the lens into an electronic device. It is usually inside the lens, and the aperture size is expressed in F# values.

[0049] The aperture number F# is a relative value obtained by dividing the focal length of the lens by the diameter of the lens (the inverse of the relative aperture). The smaller the aperture number F#, the more light enters in the same unit time, the smaller the depth of field, and the background content of the photo will be blurred, producing an effect similar to that of a telephoto lens.

[0050] Object side: the side of the lens facing the subject is the object side, and the side of the lens facing the object side is the object side of the lens.

[0051] Image side: the side where the image of the object in the lens is located is the image side, and the side of the lens facing the image side is the image side.

[0052] Infrared cut-off filter: The substrate is flat glass, and the surface is coated with AR anti-reflection film and IR cut-off film to filter near-infrared light;

[0053] Chip: that is, the imaging surface, the light receiver. The object light is refracted by the imaging lens and imaged on the chip.

[0054] See also Figure 1 , Figure 1 A schematic diagram of the structure of an optical system provided in an embodiment of the present application, wherein the optical system comprises a reflector 100, a first lens group 200, a zoom lens group 300, a focus lens group 400 and a photosensitive element 500 arranged in sequence along a first optical axis 700, wherein the first lens group 200 has a negative optical power, the zoom lens group 300 has a positive optical power, and the focus lens group 400 has a negative optical power;

[0055] The reflector 100 is used to reflect the light incident along the second optical axis 800 and make the reflected light emitted along the first optical axis 700. The first optical axis 700 and the second optical axis 800 are arranged at an angle.

[0056] The zoom lens group 300 and the focus lens group 400 can both move in a reciprocating direction along the first optical axis 700 to adjust the focal length of the optical system.

[0057] The above optical system can be used as an optical system in various periscope cameras, and specifically can be used as an optical system in various periscope cameras with telephoto shooting functions. In some embodiments of the present application, the optical system can be applied to cameras of mobile terminals such as mobile phones and tablet computers. When the optical system is applied to a mobile terminal, the extension direction of the above first optical axis 700 can be a direction perpendicular to the thickness direction of the mobile terminal, and the extension direction of the second optical axis 800 can be the thickness direction of the mobile terminal. In this way, it is conducive to realizing a telephoto shooting function with continuous zoom in a mobile terminal.

[0058] It can be understood that in the process of shooting based on the optical system, external light can be incident on the reflector 100 along the second optical axis 800, and the light reflected by the reflector 100 can be transmitted in sequence along the following path: reflector 100, first lens group 200, zoom lens group 300, focus lens group 400 and photosensitive element 500 for imaging.

[0059] The above-mentioned reflector 100 can be any reflector 100 with a reflective surface in an optical system, for example, it can be a prism, a plane mirror or a component including a reflective surface. In this process, the reflector 100 mainly functions to fold the light path. In addition, in some embodiments of the present application, the reflector 100 can also form an anti-shake component with a mechanical structure such as a motor. For example, the anti-shake component can drive the reflector 100 to perform at least one of the following movements to achieve optical anti-shake: rotate around the first optical axis 700, rotate around the second optical axis 800, and swing around the intersection of the first optical axis 700 and the second optical axis 800 in the plane formed by the first optical axis 700 and the second optical axis 800.

[0060] In some embodiments of the present application, when the optical system is applied to a camera module, the camera module may include a shell, a first drive component, a second drive component, a third drive component and the above-mentioned optical system, wherein the optical system, the first drive component, the second drive component and the third drive component may be respectively arranged in the shell, the first drive component may be connected to the zoom lens group 300 to drive the zoom lens group 300 to move in a reciprocating direction along the first optical axis 700, the second drive component may be connected to the focus lens group 400 to drive the focus lens group 400 to move in a reciprocating direction along the first optical axis 700, and the third drive component may be connected to the reflector 100 to drive the reflector 100 to perform the above-mentioned optical anti-shake action.

[0061] The first driving component, the second driving component and the third driving component may be various driving components applied to cameras in the related art, for example, various electromagnetic driving motors.

[0062] Specifically, when the focal length of the optical system needs to be increased, the zoom lens group 300 and the focus lens group 400 can be controlled to move along the first optical axis 700 toward the telephoto end, that is, the zoom lens group 300 and the focus lens group 400 can be controlled to move along the first optical axis 700 toward the reflector 100. Correspondingly, when the focal length of the optical system needs to be reduced, the zoom lens group 300 and the focus lens group 400 can be controlled to move along the first optical axis 700 toward the wide-angle end, that is, the zoom lens group 300 and the focus lens group 400 can be controlled to move along the first optical axis 700 toward the photosensitive element 500.

[0063] The photosensitive element 500 may be a photosensitive chip. The photosensitive element 500 may be used as a light receiver. The object light is refracted by an imaging lens and imaged on the photosensitive element 500.

[0064] In this embodiment, since both the zoom lens group 300 and the focus lens group 400 can move in a reciprocating direction along the first optical axis 700 to adjust the focal length of the optical system, continuous zooming of the optical system can be achieved, which is conducive to achieving shooting experience at different focal lengths. In this way, compared with the shooting method of using different optical modules to achieve different focal lengths, the optical system provided by the embodiment of the present application can achieve shooting at different focal lengths based on one optical system, which is conducive to reducing the size and weight of the camera, thereby facilitating the thinness of the smart terminal.

[0065] In addition, compared with the scheme of using different optical modules to shoot in related technologies to achieve shooting at different focal lengths, since the scheme of using different optical modules to shoot is not physical optical zoom, but digital "relay" zoom using different cameras, different cameras bear the photography requirements of different focal lengths, which loses image quality. However, the optical system provided by the embodiment of the present application realizes zoom by controlling the zoom lens group 300 and the focus lens group 400 to move in the reciprocating direction along the first optical axis 700, so that physically continuous optical lossless zoom at different focal lengths can be achieved, thereby improving image quality, zoom continuity, and user experience.

[0066] Optionally, the focal length adjustment range of the optical system is between a first focal length ft and a second focal length fw, wherein a≤|f1 / f|≤b, c≤|f2 / fw|≤d, a, b, c, d are all positive numbers, and c<a<d<b, f1 is the focal length of the first lens group 200, and f2 is the focal length of the zoom lens group 300.

[0067] The values ​​of a, b, c and d can be set as needed. In some embodiments of the present application, the value of a is 0.8, the value of b is 2.0, the value of c is 0.5, and the value of d is 1.0. In other embodiments of the present application, the value of a is 0.9, the value of b is 2.0, the value of c is 0.5, and the value of d is 1.0.

[0068] The first focal length may be the telephoto focal length of the optical system, and the second focal length may be the wide-angle focal length of the optical system. It is understood that by controlling the zoom lens group 300 and the focus lens group 400 to move along the first optical axis 700, the focal length of the optical system may be adjusted to any focal length value between the telephoto focal length and the wide-angle focal length. The focal length segment between the first focal length and the second focal length may be a longer focal length segment, for example, 3X to 5X.

[0069] In this embodiment, by making 0.8≤|f1 / ft|≤2.0, 0.5≤|f2 / fw|≤1, the optical system can be focused within a longer focal length range, thereby reducing the size of the optical system while increasing the range of the focal length range.

[0070] Optionally, the optical system further includes an object side, and the second optical axis 800 is an optical axis of light from the object side to the reflector 100;

[0071] The distance from the end surface of the first lens group 200 facing one end of the reflector 100 to the object side along the optical path is a first distance TTL, and the optical path is an optical path formed by connecting the first optical axis 700 and the second optical axis 800;

[0072] Among them, e≤ft / fw≤g, h≤TTL / ft≤j, e, f, g, h, j are all positive numbers, and h<e<j<g.

[0073] The values ​​of e, g, h and j can be set as needed. In some embodiments of the present application, the value of e is 1.2, the value of g is 2.0, the value of h is 0.7, and the value of g is 1.3. In other embodiments of the present application, the value of e is 1.2, the value of g is 1.9, the value of h is 0.7, and the value of g is 1.3.

[0074] Specifically, the object side of the optical system refers to the side of the lens of the optical system facing the object, which can be the surface of the lens for receiving light. In addition, the optical system can also include an image side, which can be the photosensitive surface of the photosensitive element 500.

[0075] In this implementation, by making 1.2≤ft / fw≤2.0 and 0.7≤TTL / ft≤1.3, it is possible to ensure that the optical system has a suitable zoom ratio and achieve excellent imaging effects.

[0076] Optionally, the first lens group 200 may move in a reciprocating direction along the first optical axis 700 .

[0077] In some embodiments of the present application, when the optical system is applied to a camera module, the camera module may further include a fourth driving component, which may be connected to the first lens group 200 to drive the first lens group 200 to move in a reciprocating direction along the first optical axis 700. The fourth driving component may be any driving component applied to a camera in the related art, for example, any electromagnetic driving motor.

[0078] In this embodiment, by enabling the first lens group 200 to move in a reciprocating direction along the first optical axis 700, during the focusing process, the first lens group 200, the zoom lens group 300 and the focus lens group 400 can be controlled to move along the first optical axis 700 respectively, which is beneficial to further increase the focusing range of the optical system.

[0079] In some other embodiments of the present application, the first lens group 200 is a fixed group, that is, the position of the first lens group 200 cannot be moved, and only the zoom lens group 300 and the focus lens group 400 can move in the reciprocating direction along the first optical axis 700.

[0080] Optionally, the first lens group 200 includes a first lens 210 and a second lens 220, the first lens 210 is located between the reflector 100 and the second lens 220, the first lens 210 has positive optical power, the second lens 220 has negative optical power, the Abbe number of the first lens 210 is less than 30, and the Abbe number of the second lens 220 is greater than 50.

[0081] The first lens 210 and the second lens 220 may be two aspherical lenses.

[0082] It can be understood that after the first lens 210 and the second lens 220 are combined, the whole has negative optical power.

[0083] In this embodiment, since the combination of positive and negative optical power can effectively eliminate the spherical aberration of the system, by making the first lens 210 have positive optical power and the second lens 220 have negative optical power, the Abbe number of the first lens 210 is less than 30, and the Abbe number of the second lens 220 is greater than 50, it is helpful to eliminate the spherical aberration of the light system.

[0084] Optionally, the zoom lens group 300 includes at least 3 lenses, and the focus lens group 400 includes at least 2 lenses.

[0085] The number of lenses included in the zoom lens group 300 and the focus lens group 400 and the type of each lens can be set as needed.

[0086] In this embodiment, the zoom lens group 300 includes at least 3 lenses, and the focus lens group 400 includes at least 2 lenses, which is beneficial to realize the zoom and focus functions of the optical system.

[0087] Optionally, the optical system satisfies at least one of the following conditions:

[0088] The travel of the zoom lens group 300 in the reciprocating direction along the first optical axis 700 is a first travel D1, 0.3*(ft-fw)≤D1≤0.8*(ft-fw);

[0089] The travel of the focusing lens group 400 in the reciprocating direction along the first optical axis 700 is a first travel D2, and 0.7*(ft-fw)≤D2≤1.2*(ft-fw).

[0090] In this embodiment, by making 0.3*(ft-fw)≤D1≤0.8*(ft-fw), on the one hand, it is helpful to reduce the zoom stroke of the zoom lens group 300 and reduce the demand for a large-stroke motor. On the other hand, it is also helpful to ensure that the zoom lens group 300 has a suitable sensitivity, reduce the demand for motor stroke accuracy, and ensure that the optical system can achieve fast and accurate zooming. In addition, by making 0.7*(ft-fw)≤D2≤1.2*(ft-fw), on the one hand, it is helpful to reduce the focus stroke of the focus lens group 400 and reduce the demand for a large-stroke motor. On the other hand, it is also helpful to ensure that the focus lens group 400 has a suitable sensitivity, reduce the demand for motor stroke accuracy, and ensure that the optical system can achieve fast and accurate focusing.

[0091] Optionally, the zoom lens group 300 includes a third lens 310, a fourth lens 320, a fifth lens 330 and a sixth lens 340 arranged in sequence along the first optical axis 700, the third lens 310 is opposite to the first lens group 200, and the surface of the third lens 310 facing the first lens group 200 is a convex surface, the fourth lens 320 is a biconvex lens, the fifth lens 330 is a biconcave lens, and the surface of the sixth lens 340 facing the focusing lens group 400 is a convex surface;

[0092] The travel of the zoom lens group 300 in the reciprocating direction along the first optical axis 700 is a first travel D1, and 0.3*(ft-fw)≤D1≤0.8*(ft-fw).

[0093] It is understandable that the shape of the surface of the third lens 310 facing away from the first lens group 200 can be set as needed, for example, it can be a convex surface or a concave surface. The shape of the surface of the sixth lens 340 facing away from the focusing lens group 400 can be set as needed, for example, it can be a convex surface or a concave surface.

[0094] During the movement of the zoom lens group 300 in the reciprocating direction along the first optical axis 700, the relative positions of the lenses included in the zoom lens group 300 remain unchanged, that is, the zoom lens group 300 as a whole moves in the reciprocating direction along the first optical axis 700 during this process.

[0095] The four lenses included in the zoom lens group 300 are all aspherical lenses. When the optical system zooms from the wide-angle end to the telephoto end, the zoom lens group 300 moves toward the object side along the first optical axis 700. When the optical system zooms from the telephoto end to the wide-angle end, the zoom lens group 300 moves toward the image side along the first optical axis 700. The movement distance of the zoom lens group 300 from the wide-angle end to the telephoto end is D1, which satisfies the relationship: 0.3*(ft-fw)≤D1≤0.8*(ft-fw).

[0096] In this embodiment, the zoom lens group 300 includes a third lens 310, a fourth lens 320, a fifth lens 330 and a sixth lens 340 arranged in sequence along the first optical axis 700, which is conducive to realizing the zoom function of the optical system. At the same time, by making 0.3*(ft-fw)≤D1≤0.8*(ft-fw), on the one hand, it is conducive to reducing the zoom stroke of the zoom lens group 300 and reducing the demand for a large stroke motor. On the other hand, it is also conducive to ensuring that the zoom lens group 300 has a suitable sensitivity, reducing the demand for motor stroke accuracy, and ensuring that the optical system can achieve fast and accurate zooming.

[0097] Optionally, the focusing lens group 400 includes a seventh lens 410, an eighth lens 420 and a ninth lens 430 sequentially arranged along the first optical axis 700, the seventh lens 410 is opposite to the zoom lens group 300, and a surface of the seventh lens 410 facing the zoom lens group 300 is a convex surface, the eighth lens 420 has a positive optical power, and the ninth lens 430 has a negative optical power;

[0098] The travel of the focusing lens group 400 in the reciprocating direction along the first optical axis 700 is a first travel D2, and 0.7*(ft-fw)≤D2≤1.2*(ft-fw).

[0099] The shape of the surface of the seventh lens 410 facing away from the zoom lens group 300 can be set as needed, for example, it can be a convex surface or a concave surface. In addition, the seventh lens 410 can have positive or negative optical power, and it is only necessary to ensure that the focusing lens group 400 as a whole has negative optical power. The eighth lens 420 and the ninth lens 430 can be various types of aspherical lenses.

[0100] Specifically, when focusing on a distant object, the focusing lens group 400 moves toward the object side along the first optical axis 700, and when focusing on a close object, the focusing lens group 400 moves toward the image side along the first optical axis 700. The moving distance of the focusing lens group 400 from the wide-angle end to the telephoto end is D2, satisfying the relationship: 0.7*(ft-fw)≤D2≤1.2*(ft-fw).

[0101] In this embodiment, the focusing lens group 400 includes the seventh lens 410, the eighth lens 420 and the ninth lens 430 arranged in sequence along the first optical axis 700, which is conducive to achieving the focusing function of the optical system. At the same time, by making 0.7*(ft-fw)≤D2≤1.2*(ft-fw), on the one hand, it is conducive to reducing the focusing stroke of the focusing lens group 400 and reducing the demand for a large stroke motor. On the other hand, it is also conducive to ensuring that the focusing lens group 400 has appropriate sensitivity, reducing the demand for motor stroke accuracy, and ensuring that the optical system can achieve fast and accurate focusing.

[0102] In some other embodiments of the present application, the focusing lens group 400 includes two aspherical lenses, which are the tenth lens and the eleventh lens from the object side to the image side along the first optical axis 700, wherein the tenth lens has positive optical power and the tenth lens has negative optical power.

[0103] The aspheric lens in the above embodiment is an even aspheric surface and satisfies the aspheric surface formula describing the aspheric surface:

[0104]

[0105] Where Z is the sag of the surface parallel to the Z axis, which coincides with the optical axis, C is the curvature of the surface, which is the inverse of the radius of curvature of the surface, K is the conic constant, A, B, C, D, E, F, G, and H are the aspheric coefficients, and r is the radius.

[0106] According to the above formula, some implementation examples of its conditional boundaries are as follows:

[0107] Embodiment 1:

[0108] See also Figure 1 , is a diagram showing the positional relationship between the lenses within the optical system when the light system is at the wide-angle end in the embodiment of the present application, see Figure 2 , is a positional relationship diagram of the lenses inside the optical system when the optical system is at the telephoto end in the embodiment of the present application. Wherein, the reflector 100 is a prism, and the light is incident along the second optical axis 800, reflected by the reflective surface, and then emitted along the first optical axis 700.

[0109] The first lens group 200 is the first lens group 200, which includes two aspheric lenses, which include two aspheric lenses. Along the first optical axis 700 from the object side to the image side, they are the first lens 210 and the second lens 220. The first lens 210 has positive optical power, and its Abbe number satisfies Vd1 equal to 19.3. The second lens 220 has negative optical power, and its Abbe number satisfies Vd equal to 55.7. The combination of positive and negative optical power can effectively eliminate the system spherical aberration.

[0110] The zoom lens group 300 includes 4 lenses, all of which are aspherical lenses. Specifically, along the first optical axis 700, it includes a third lens 310 with positive optical power, a fourth lens 320 with positive optical power, a fifth lens 330 with negative optical power, and a sixth lens 340 with positive optical power. From the wide-angle end to the telephoto end, the zoom group moves 4.32 mm from the image side to the object side along the first optical axis 700 to achieve optical zoom.

[0111] The third lens 310 is made of ultra-low dispersion glass material, whose refractive index Nd is equal to 1.5 and Abbe number Vd is equal to 81.6. The use of ultra-low dispersion material here can well reduce system chromatic aberration.

[0112] The focusing lens group 400 includes three lenses, all of which are aspherical. Specifically, along the first optical axis 700, the focusing lens group 400 includes a seventh lens 410 with negative optical power, an eighth lens 420 with positive optical power, and a ninth lens 430 with negative optical power. From the wide-angle end to the telephoto end, the focusing lens group 400 moves 7.79 mm from the image side to the object side along the first optical axis 700 to achieve the focusing function.

[0113] The basic specifications achieved in Example 1 are shown in Table 1-1 below:

[0114]

[0115] Where efl is the system focal length, F# is the system aperture, DFOV is the field of view, f1 is the 200 focal length of the first lens group, f2 is the 300 focal length of the zoom lens group, and f3 is the 400 focal length of the focus lens group

[0116] Table 1-2 shows the surface type, curvature radius, thickness, refractive index and Abbe number of each lens in the optical imaging system of Example 1;

[0117]

[0118]

[0119] Among them, the above S1 is the object side surface of the first lens 210, and S2 is the image side surface of the first lens 210; the above S3 is the object side surface of the second lens 220, and S4 is the image side surface of the second lens 220; the above S5 is the object side surface of the third lens 310, and S6 is the image side surface of the third lens 310; the above S7 is the object side surface of the fourth lens 320, and S8 is the image side surface of the fourth lens 320; the above S9 is the object side surface of the fifth lens 330, and S10 is the image side surface of the fifth lens 330; the above S11 is the object side surface of the sixth lens 340, and S12 is the image side surface of the third lens 340. The image side surface of the sixth lens 340; the above-mentioned S13 is the object side surface of the seventh lens 410, and S14 is the image side surface of the seventh lens 410; the above-mentioned S15 is the object side surface of the eighth lens 420, and S16 is the image side surface of the eighth lens 420; the above-mentioned S17 is the object side surface of the ninth lens 430, and S18 is the image side surface of the ninth lens 430; the above-mentioned S19 is the object side surface of the infrared filter 600, and S20 is the image side surface of the infrared filter 600; S21 is the image surface of the photosensitive element 500, that is, the surface of the photosensitive element 500 facing the infrared filter 600.

[0120] Table 1-3 shows the aspheric high-order coefficients of each lens surface in Example 1;

[0121]

[0122]

[0123] See also Figure 3-6 From the five solid curves in the chromatic aberration diagram, which are the color lights with wavelengths of 650nm, 610nm, 555nm, 510nm, and 470nm, it can be seen that the axial chromatic aberration of the lens of this embodiment is controlled within a very small range at the wide-angle end and the telephoto end, and the chromatic aberration converges well. From the defocus modulation transfer function (MTF) curve, it can be seen that at a spatial frequency of 100lp / mm, the full-field MTF is greater than 0.5, which has extremely high resolution.

[0124] Embodiment 2:

[0125] See also Figure 7, is a diagram showing the positional relationship between the lenses within the optical system when the light system is at the wide-angle end in the embodiment of the present application, see Figure 8 , is a positional relationship diagram of the lenses inside the optical system when the optical system is at the telephoto end in the embodiment of the present application. The main difference between embodiment 2 and embodiment 1 is that the focal lengths at the wide-angle end and the telephoto end are longer.

[0126] The basic specifications achieved in Example 2 are shown in Table 2-1 below:

[0127]

[0128] Where efl is the system focal length, F# is the system aperture, DFOV is the field of view, f1 is the 200 focal length of the first lens group, f2 is the 300 focal length of the zoom lens group, and f3 is the 400 focal length of the focus lens group

[0129] Table 2-2 shows the surface type, curvature radius, thickness, refractive index and Abbe number of each lens in the optical imaging system of Example 3;

[0130]

[0131]

[0132] Among them, the above S1 is the object side surface of the first lens 210, and S2 is the image side surface of the first lens 210; the above S3 is the object side surface of the second lens 220, and S4 is the image side surface of the second lens 220; the above S5 is the object side surface of the third lens 310, and S6 is the image side surface of the third lens 310; the above S7 is the object side surface of the fourth lens 320, and S8 is the image side surface of the fourth lens 320; the above S9 is the object side surface of the fifth lens 330, and S10 is the image side surface of the fifth lens 330; the above S11 is the object side surface of the sixth lens 340, and S12 is the image side surface of the third lens 340. The image side surface of the sixth lens 340; the above-mentioned S13 is the object side surface of the seventh lens 410, and S14 is the image side surface of the seventh lens 410; the above-mentioned S15 is the object side surface of the eighth lens 420, and S16 is the image side surface of the eighth lens 420; the above-mentioned S17 is the object side surface of the ninth lens 430, and S18 is the image side surface of the ninth lens 430; the above-mentioned S19 is the object side surface of the infrared filter 600, and S20 is the image side surface of the infrared filter 600; S21 is the image surface of the photosensitive element 500, that is, the surface of the photosensitive element 500 facing the infrared filter 600.

[0133] Table 2-3 shows the aspheric high-order coefficients of each lens surface in Example 3;

[0134]

[0135]

[0136] See also Figure 9-12 From the five solid curves in the chromatic aberration diagram, which are the color lights of 650nm, 610nm, 555nm, 510nm, and 470nm wavelengths, it can be seen that the axial chromatic aberration of the lens of this embodiment is controlled within a very small range at the wide-angle end and the telephoto end, and the chromatic aberration converges well. From the defocus MTF diagram, it can be seen that at a spatial frequency of 100lp / mm, the full-field MTF is greater than 0.5, which has extremely high resolution.

[0137] Embodiment 3:

[0138] See also Fig.13 , is a diagram showing the positional relationship between the lenses within the optical system when the light system is at the wide-angle end in the embodiment of the present application, see Fig.14 , is a positional relationship diagram of the lenses inside the optical system when the light system is at the telephoto end in the embodiment of the present application. The main difference between Embodiment 3 and Embodiment 2 is that the aperture of the system at the wide-angle end and the telephoto end is increased, and the material of the fourth lens 320 is optimized from plastic to glass aspheric surface to improve the imaging quality.

[0139] The basic specifications achieved in Example 3 are shown in Table 3-1 below:

[0140]

[0141] Where efl is the system focal length, F# is the system aperture, DFOV is the field of view, f1 is the 200 focal length of the first lens group, f2 is the 300 focal length of the zoom lens group, and f3 is the 400 focal length of the focus lens group

[0142] Table 3-2 shows the surface type, curvature radius, thickness, refractive index and Abbe number of each lens in the optical imaging system of Example 3;

[0143]

[0144]

[0145] Among them, the above S1 is the object side surface of the first lens 210, and S2 is the image side surface of the first lens 210; the above S3 is the object side surface of the second lens 220, and S4 is the image side surface of the second lens 220; the above S5 is the object side surface of the third lens 310, and S6 is the image side surface of the third lens 310; the above S7 is the object side surface of the fourth lens 320, and S8 is the image side surface of the fourth lens 320; the above S9 is the object side surface of the fifth lens 330, and S10 is the image side surface of the fifth lens 330; the above S11 is the object side surface of the sixth lens 340, and S12 is the image side surface of the third lens 340. The image side surface of the sixth lens 340; the above-mentioned S13 is the object side surface of the seventh lens 410, and S14 is the image side surface of the seventh lens 410; the above-mentioned S15 is the object side surface of the eighth lens 420, and S16 is the image side surface of the eighth lens 420; the above-mentioned S17 is the object side surface of the ninth lens 430, and S18 is the image side surface of the ninth lens 430; the above-mentioned S19 is the object side surface of the infrared filter 600, and S20 is the image side surface of the infrared filter 600; S21 is the image surface of the photosensitive element 500, that is, the surface of the photosensitive element 500 facing the infrared filter 600.

[0146] Table 3-3 shows the aspheric high-order coefficients of each lens surface in Example 3;

[0147]

[0148]

[0149] See also Figure 15-18 From the five solid curves in the chromatic aberration diagram, which are the color lights of 650nm, 610nm, 555nm, 510nm, and 470nm wavelengths, it can be seen that the axial chromatic aberration of the lens of this embodiment is controlled within a very small range at the wide-angle end and the telephoto end, and the chromatic aberration converges well. From the defocus MTF diagram, it can be seen that at a spatial frequency of 100lp / mm, the full-field MTF is greater than 0.5, which has extremely high resolution.

[0150] Embodiment 4:

[0151] See also Fig.19 , is a diagram showing the positional relationship between the lenses within the optical system when the light system is at the wide-angle end in the embodiment of the present application, see Fig. 20 , is a diagram showing the positional relationship between the lenses in the optical system when the optical system is at the telephoto end in the embodiment of the present application. The main difference between Embodiment 4 and Embodiment 3 is that the first lens group 200 uses two glass aspherical surfaces, which can reduce the molding and reliability risks caused by the trimming of the plastic aspherical surface.

[0152] The basic specifications achieved in Example 4 are shown in Table 4-1 below:

[0153]

[0154] Where efl is the system focal length, F# is the system aperture, DFOV is the field of view, f1 is the 200 focal length of the first lens group, f2 is the 300 focal length of the zoom lens group, and f3 is the 400 focal length of the focus lens group

[0155] Table 4-2 shows the surface type, curvature radius, thickness, refractive index and Abbe number of each lens in the optical imaging system of Example 4;

[0156]

[0157]

[0158] Among them, the above S1 is the object side surface of the first lens 210, and S2 is the image side surface of the first lens 210; the above S3 is the object side surface of the second lens 220, and S4 is the image side surface of the second lens 220; the above S5 is the object side surface of the third lens 310, and S6 is the image side surface of the third lens 310; the above S7 is the object side surface of the fourth lens 320, and S8 is the image side surface of the fourth lens 320; the above S9 is the object side surface of the fifth lens 330, and S10 is the image side surface of the fifth lens 330; the above S11 is the object side surface of the sixth lens 340, and S12 is the image side surface of the third lens 340. The image side surface of the sixth lens 340; the above-mentioned S13 is the object side surface of the seventh lens 410, and S14 is the image side surface of the seventh lens 410; the above-mentioned S15 is the object side surface of the eighth lens 420, and S16 is the image side surface of the eighth lens 420; the above-mentioned S17 is the object side surface of the ninth lens 430, and S18 is the image side surface of the ninth lens 430; the above-mentioned S19 is the object side surface of the infrared filter 600, and S20 is the image side surface of the infrared filter 600; S21 is the image surface of the photosensitive element 500, that is, the surface of the photosensitive element 500 facing the infrared filter 600.

[0159] Table 4-3 shows the aspheric high-order coefficients of each lens surface in Example 4;

[0160]

[0161]

[0162] See also Figure 21-24 From the five solid curves in the chromatic aberration diagram, which are the color lights of 650nm, 610nm, 555nm, 510nm, and 470nm wavelengths, it can be seen that the axial chromatic aberration of the lens of this embodiment is controlled within a very small range at the wide-angle end and the telephoto end, and the chromatic aberration converges well. From the defocus MTF diagram, it can be seen that at a spatial frequency of 100lp / mm, the full-field MTF is greater than 0.5, which has extremely high resolution.

[0163] Embodiment 5:

[0164] See also Fig.25 , is a diagram showing the positional relationship between the lenses within the optical system when the light system is at the wide-angle end in the embodiment of the present application, see Fig.26 , is a diagram showing the positional relationship between the lenses in the optical system when the optical system is at the telephoto end in the embodiment of the present application. The main difference between the embodiment 5 and other embodiments is that the focus group uses two aspherical lenses.

[0165] The basic specifications achieved in Example 5 are shown in Table 5-1 below:

[0166]

[0167] Where efl is the system focal length, F# is the system aperture, DFOV is the field of view, f1 is the 200 focal length of the first lens group, f2 is the 300 focal length of the zoom lens group, and f3 is the 400 focal length of the focus lens group

[0168] Table 5-2 shows the surface type, curvature radius, thickness, refractive index and Abbe number of each lens in the optical imaging system of Example 5;

[0169]

[0170] Among them, the above S1 is the object side surface of the first lens 210, and S2 is the image side surface of the first lens 210; the above S3 is the object side surface of the second lens 220, and S4 is the image side surface of the second lens 220; the above S5 is the object side surface of the third lens 310, and S6 is the image side surface of the third lens 310; the above S7 is the object side surface of the fourth lens 320, and S8 is the image side surface of the fourth lens 320; the above S9 is the object side surface of the fifth lens 330, and S10 is the image side surface of the fifth lens 330; the above S1 1 is the object-side surface of the sixth lens 340, S12 is the image-side surface of the sixth lens 340; the above-mentioned S13 is the object-side surface of the seventh lens 410, S14 is the image-side surface of the seventh lens 410; the above-mentioned S15 is the object-side surface of the eighth lens 420, S16 is the image-side surface of the eighth lens 420; the above-mentioned S17 is the object-side surface of the ninth lens 430, S18 is the image-side surface of the ninth lens 430; the above-mentioned S19 is the object-side surface of the infrared filter 600, and S20 is the image-side surface of the infrared filter 600.

[0171] Table 5-3 shows the aspheric high-order coefficients of each lens surface in Example 5;

[0172]

[0173] See also Figure 27-30From the five solid curves in the chromatic aberration diagram, which are the color lights of 650nm, 610nm, 555nm, 510nm, and 470nm wavelengths, it can be seen that the axial chromatic aberration of the lens of this embodiment is controlled within a very small range at the wide-angle end and the telephoto end, and the chromatic aberration converges well. From the defocus MTF diagram, it can be seen that at a spatial frequency of 100lp / mm, the full-field MTF is greater than 0.5, which has extremely high resolution.

[0174] The embodiment of the present application further provides a camera module, which includes an infrared filter 600 and the optical system described in the above embodiment, wherein the infrared filter 600 is located between the focusing lens group 400 and the photosensitive element 500.

[0175] In this implementation, since the camera module includes the optical system described in the above embodiments, the camera module can implement each process of the optical system in the above embodiments and has the same beneficial effects. To avoid repetition, it will not be described again here.

[0176] An embodiment of the present application also provides an electronic device, comprising the camera module described in the above embodiment.

[0177] In this implementation, since the electronic device includes the camera module described in the above embodiments, the electronic device can implement each process of the camera module in the above embodiments and has the same beneficial effects. To avoid repetition, they will not be described again here.

[0178] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. An optical system, characterized in that: The invention comprises a reflector, a first lens group, a zoom lens group, a focus lens group and a photosensitive element which are sequentially arranged along a first optical axis, wherein the first lens group has a negative optical power, the zoom lens group has a positive optical power, and the focus lens group has a negative optical power; The reflector is used to reflect the light incident along the second optical axis and make the reflected light emerge along the first optical axis, and the first optical axis and the second optical axis are arranged at an angle; The zoom lens group and the focus lens group can both move in a reciprocating direction along the first optical axis to adjust the focal length of the optical system.

2. The optical system according to claim 1, characterized in that The focal length adjustment range of the optical system is between a first focal length ft and a second focal length fw, wherein a≤|f1 / f|≤b, c≤|f2 / fw|≤d, a, b, c, d are all positive numbers, and c<a<d<b, f1 is the focal length of the first lens group, and f2 is the focal length of the zoom lens group.

3. The optical system according to claim 2, characterized in that The optical system further includes an object side, and the second optical axis is an optical axis of light from the object side to the reflector; The distance from the end surface of the first lens group facing one end of the reflector to the object side along the optical path is a first distance TTL, and the optical path is an optical path formed by connecting the first optical axis and the second optical axis; Among them, e≤ft / fw≤g, h≤TTL / ft≤j, e, f, g, h, j are all positive numbers, and h<e<j<g.

4. The optical system according to claim 1, characterized in that The first lens group is movable in a reciprocating direction along the first optical axis.

5. The optical system according to claim 1, characterized in that The first lens group includes a first lens and a second lens, the first lens is located between the reflector and the second lens, the first lens has positive optical power, and the second lens has negative optical power.

6. The optical system according to claim 2, characterized in that The zoom lens group includes at least 3 lenses, and the focus lens group includes at least 2 lenses.

7. The optical system according to claim 2, characterized in that The optical system satisfies at least one of the following conditions: The travel of the zoom lens group in the reciprocating direction along the first optical axis is a first travel D1, 0.3*(ft-fw)≤D1≤0.8*(ft-fw); The stroke of the focusing lens group moving in the reciprocating direction along the first optical axis is a first stroke D2, and 0.7*(ft-fw)≤D2≤1.2*(ft-fw).

8. The optical system according to claim 7, characterized in that The zoom lens group includes a third lens, a fourth lens, a fifth lens and a sixth lens arranged in sequence along the first optical axis, the third lens is opposite to the first lens group, and the surface of the third lens facing the first lens group is a convex surface, the fourth lens is a biconvex lens, the fifth lens is a biconcave lens, and the surface of the sixth lens facing the focusing lens group is a convex surface.

9. The optical system according to claim 7, characterized in that The focusing lens group includes a seventh lens, an eighth lens and a ninth lens arranged in sequence along the first optical axis, the seventh lens is opposite to the zoom lens group, and the surface of the seventh lens facing the zoom lens group is a convex surface, the eighth lens has positive optical power, and the ninth lens has negative optical power.

10. A camera module, characterized in that: An optical system comprising an infrared filter and any one of claims 1 to 9, wherein the infrared filter is located between the focusing lens group and the photosensitive element.

11. An electronic device, characterized in that: Includes the camera module described in claim 10.

Images