Optical lens, lens module and electronic device

Abstract

The present application provides an optical lens, a lens module and an electronic device. The optical lens comprises a first lens group, a first prism, a second lens group and a second prism which are sequentially arranged from an object side to an image side. The first lens group has positive focal power and is used for receiving light and converging the light; the first prism comprises a first incident surface, a first reflecting surface and a first exit surface, a first included angle between the first incident surface and the first reflecting surface is less than 45°, and the optical axis of the first exit surface coincides with the optical axis of the second lens group; the second lens group has negative focal power; and the second prism comprises a second incident surface, a second reflecting surface and a second exit surface, a second included angle between the second reflecting surface and the second exit surface is less than 45°, the first included angle is equal to the second included angle, and the optical axis of the second incident surface coincides with the optical axis of the second lens group. According to the present application, the second lens group is provided between the first prism and the second prism, so that the optical lens has relatively strong focusing capability and macro effect, and has relatively high imaging quality.

Description

Optical lenses, lens modules and electronic devices

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on December 22, 2023, with application number 202311794115.8 and application name “Optical lens, lens module and electronic device”, the entire contents of which are incorporated by reference into this application.

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on April 30, 2024, with application number 202410539857.4 and application name “Optical lens, lens module and electronic device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of lenses, and more specifically, to an optical lens, a lens module and an electronic device. Background Art

[0004] With the continuous development of electronic devices, camera functionality has become a key feature and a primary indicator for evaluating their performance. However, current lens modules typically require a long focusing stroke to achieve focus during the shooting process. This movement of the lens position also causes drastic changes in system aberrations. Compared to distant objects, image quality deteriorates significantly at close distances (e.g., 2 meters). As a result, the lens's focusing ability is weak, resulting in poor image quality.

[0005] Summary of the Invention

[0006] The present application provides an optical lens, a lens module and an electronic device that have strong focusing capabilities and high imaging quality.

[0007] In a first aspect, an optical lens is provided, comprising a first lens group, a first prism, a second lens group, and a second prism, arranged in sequence from the object side to the image side, wherein the first lens group comprises at least one lens, the first lens group has positive optical power, and the first lens group is used to receive light and converge the light; the first prism comprises a first incident surface, a first reflection surface, and a first exit surface, a first angle between the first incident surface and the first reflection surface is less than 45°, and the optical axis of the first exit surface coincides with the optical axis of the second lens group; the second lens group comprises at least one lens, the second lens group has negative optical power; the second prism comprises a second incident surface, a second reflection surface, and a second exit surface, a second angle between the second reflection surface and the second exit surface is less than 45°, and the second angle is equal to the first angle, and the optical axis of the second incident surface coincides with the optical axis of the second lens group.

[0008] In the embodiment of the present application, by arranging a second lens group between the first prism and the second prism, the first lens group and the second lens group are separated, so that the optical lens has a strong focusing capability, which can not only shoot long-range scenes, but also shoot close-range scenes (for example, macro scenes), with high image quality and high image clarity. In addition, by setting the first angle of the first prism and the second angle of the second prism to be less than 45 degrees, a large aperture, large target area, and small size design of the optical lens can be achieved.

[0009] In addition, the embodiments of the present application use a coaxial system. That is, the optical axis of the first exit surface of the first prism coincides with the optical axis of the second lens group, and the optical axis of the second incident surface of the second prism coincides with the optical axis of the second lens group. By using a coaxial system, the optical lens does not produce off-axis aberrations compared to off-axis systems. The prisms and lenses in the coaxial system can all adopt a centrally symmetrical structure, which is easy to manufacture and has strong feasibility. In addition, compared to off-axis systems, the prisms and lenses in the coaxial system are easier to find the center point, which facilitates the assembly of the lenses and prisms in the optical lens.

[0010] In one possible implementation, the first lens group may include three lenses (e.g., first lens L1, second lens L2, and third lens L3), and the second lens group may include two lenses (e.g., fourth lens L4 and fifth lens L5). In one example, L1 may have positive optical power, and at least one of L2 and L3 may have negative optical power. It should be understood that this configuration facilitates aberration correction of the optical lens, thereby achieving better imaging quality. It should be understood that from an engineering implementation perspective, a design in which L1 has positive optical power, L2 has positive optical power, and L3 has negative optical power may be employed.

[0011] Exemplarily, L4 has positive optical power and L5 has negative optical power, or L4 has negative optical power and L5 has positive optical power, and L4 and L5 as a whole (i.e., the second lens group) have negative optical power. In this example, by setting the optical power of the two lenses in the second lens group to one positive and one negative, it is beneficial to correct aberrations, so that the optical lens has better imaging quality.

[0012] In another possible implementation, the first lens group may include two lenses (e.g., a first lens L1 and a second lens L2), and the second lens group may include three lenses (e.g., a third lens L3, a fourth lens L4, and a fifth lens L5). In one example, L1 may have positive optical power, L2 may have negative optical power, and L1 and L2 as a whole (i.e., the first lens group) have positive optical power. In this example, by setting L1 to have positive optical power and L2 to have negative optical power, it is beneficial to control the aberrations of the light beam passing through the first lens group, making it easier to correct aberrations in the first lens group, and the optical lens has better imaging quality. In other examples, L1 may have positive optical power, and L2 may also have positive optical power, which is not limited in this application.

[0013] In this implementation, at least one of the three lenses in the second lens group has positive power, and at least one has negative power. The specific power of L3, L4, and L5 is not limited. For example, L3 can have positive power, L4 can have negative power, and L5 can have negative power (or positive power), and the entire group formed by L3, L4, and L5 (i.e., the second lens group) has negative power.

[0014] In this implementation, compared with the solution in which the first lens group includes three lenses, two lenses are provided in the first lens group. On the one hand, aberrations can be corrected well, and on the other hand, the size of the optical lens can be reduced.

[0015] It should be understood that the entire optical lens has positive optical power, i.e., it has a converging effect on light beams. In other words, the entire lens system formed by the first and second lens groups has positive optical power, i.e., the absolute value of the optical power of the first lens group is greater than the absolute value of the optical power of the second lens group.

[0016] In combination with the first aspect, in certain implementations of the first aspect, the first angle θ1 and the refractive index n1 of the first prism satisfy: n1 ≥ 1 / sin(2*θ1).

[0017] Exemplarily, the value of the first angle is related to the refractive index of the first prism, and the value of the first angle may be between 22° and 28°.

[0018] It should be understood that by setting the relationship between the first angle and the refractive index of the first prism, total reflection can occur at the first incident surface of the first prism, that is, transmission and total reflection can occur at the first incident surface.

[0019] In combination with the first aspect, in certain implementations of the first aspect, the second angle θ2 and the refractive index n2 of the second prism satisfy: n2≥1 / sin(2*θ2).

[0020] Exemplarily, the value of the second angle is related to the refractive index of the second prism, and the second angle is equal to the first angle. The value of the second angle may also be between 22° and 28°.

[0021] It should be understood that by setting the relationship between the second angle and the refractive index of the second prism, total reflection can occur at the second exit surface of the second prism, that is, transmission and total reflection can occur at the second exit surface.

[0022] In combination with the first aspect, in certain implementations of the first aspect, the first lens group is a movable lens group, and during the focusing process of the optical lens switching from a distant view to a near view, the first lens group moves along the optical axis toward the object side.

[0023] In this implementation, the optical lens can move the first lens group during the focusing process, so that the optical lens has a better macro effect and high-quality imaging with a long focusing stroke.

[0024] In combination with the first aspect, in certain implementations of the first aspect, the first lens group includes at least one variable lens, and during the focusing process of the optical lens switching from a distant view to a near view, the optical focal length of the variable lens in the first lens group increases.

[0025] It should be understood that a variable lens refers to a lens whose surface shape can be changed by electrical, acoustic or magnetic driving methods.

[0026] In the optical lens provided in the present application, the first lens group includes at least one variable lens. Therefore, a closer focusing object distance can be achieved without moving the first lens group (i.e., while ensuring that the total height of the system remains unchanged).

[0027] In combination with the first aspect, in some implementations of the first aspect, the second mirror group includes at least one variable lens, and the variable lens in the second mirror group is used to correct the additional aberration caused by the variable lens in the first mirror group.

[0028] Exemplarily, during the focusing process of the optical lens switching from a distant view to a near view, the optical power of the variable lens in the second lens group decreases.

[0029] In combination with the first aspect, in certain implementations of the first aspect, the first exit surface is a plane, the second lens group includes a first lens, the object side surface of the first lens is a plane, and the first lens is fixedly connected to the first exit surface of the first prism by a gluing process.

[0030] The optical lens provided in the present application can glue the lens in the second lens group to the first exit surface of the first prism, so that the first exit surface of the first prism has optical focal length. Compared with the one-piece molded first prism with optical focal length, this method is simpler to process and manufacture, and can improve the production efficiency of the first prism.

[0031] In combination with the first aspect, in certain implementations of the first aspect, the second incident surface is a plane, the second lens group includes a second lens, the image side surface of the second lens is a plane, and the second lens is fixedly connected to the second incident surface of the second prism by a gluing process.

[0032] The optical lens provided in the present application can glue the lens in the second lens group to the second incident surface of the second prism, so that the second incident surface of the second prism has optical focal length. Compared with the one-piece molded second prism with optical focal length, this method is simpler to process and manufacture, and can improve the production efficiency of the second prism.

[0033] In combination with the first aspect, in some implementations of the first aspect, the second lens group may include a first lens and a second lens, the first prism may be cemented together with the first lens in the second lens group to form a surface with optical focal length, and the second prism may also be cemented together with the second lens in the second lens group to form a surface with optical focal length.

[0034] In combination with the first aspect, in some implementations of the first aspect, the optical lens further includes an aperture stop, and the aperture stop is located on the object side of the first lens group, or the aperture stop is located between the first lens group and the first prism, or the aperture stop is located between the first prism and the second lens group, or the aperture stop is located between the second lens group and the second prism.

[0035] The optical lens provided herein may also be provided with an aperture stop. The position of the aperture stop can be adjusted according to actual needs to better adjust the aperture and filter out stray light, thereby improving the imaging quality of the optical lens. Furthermore, by placing the aperture stop on the object side of the first lens group, the overall height of the optical lens system can be reduced.

[0036] In combination with the first aspect, in some implementations of the first aspect, the optical lens further includes an infrared filter, and the infrared filter is located on the image side of the second prism.

[0037] For example, in some implementations, an infrared cutoff film layer may be provided on the surface of the second exit surface of the second prism.

[0038] The optical lens provided in the present application may also be provided with an infrared filter or an infrared cut-off film layer to filter out unnecessary light signals.

[0039] In conjunction with the first aspect, in certain implementations of the first aspect, the optical lens further includes a third lens group, the third lens group including at least one lens, and the third lens group is located on the image side of the second prism. Exemplarily, the third lens group may be located between the second prism and the infrared filter.

[0040] Illustratively, the first lens group may include a first lens having positive optical power; the second lens group may include a second lens having negative optical power; and the third lens group may include a third lens having positive optical power or negative optical power.

[0041] It should be understood that the entire optical lens has positive optical power, that is, it has a converging effect on light beams. In other words, the entirety formed by the first lens group, the second lens group, and the third lens group has positive optical power.

[0042] In a second aspect, an optical lens is provided, comprising a first lens group, a first prism, and a second prism, which are arranged in sequence from the object side to the image side, wherein the first lens group comprises at least one lens, the first lens group has positive optical power, and the first lens group is used to receive light and converge the light; the first prism comprises a first incident surface, a first reflection surface, and a first exit surface, and a first angle between the first incident surface and the first reflection surface is less than 45°; the second prism comprises a second incident surface, a second reflection surface, and a second exit surface, and a second angle between the second reflection surface and the second exit surface is less than 45°, and the second angle is the same as the first angle, and the optical axis of the second incident surface coincides with the optical axis of the first exit surface; wherein the first exit surface has optical power, the second incident surface has optical power, and the optical power of the second incident surface is opposite to that of the first exit surface, and the first prism and the second prism as a whole have negative optical power.

[0043] The optical lens provided by the present application, by setting the exit surface of the first prism and the incident surface of the second prism to surfaces with optical power, has a strong focusing ability, enabling not only long-range shooting but also close-up shooting (for example, macro scenes), with high imaging quality and high image clarity. In addition, by setting the first angle of the first prism and the second angle of the second prism to be less than 45°, a large aperture, large target area, and small size design of the optical lens can be achieved.

[0044] It should be understood that the optical lens provided in this application adopts a coaxial system, that is, the optical axis of the second incident surface coincides with the optical axis of the first exit surface. By using a coaxial system, the optical lens does not produce off-axis aberrations compared to an off-axis system. The prisms and lenses in the coaxial system can all adopt a centrally symmetrical structure, which is easy to manufacture and has strong feasibility. In addition, compared to an off-axis system, the prisms and lenses in the coaxial system are easier to find the center point, which facilitates the assembly of the lenses and prisms in the optical lens.

[0045] Exemplarily, the first lens group may include four lenses, such as a first lens L1, a second lens L2, a third lens L3 and a fourth lens L4, wherein L1 has a positive optical focal length, and at least one of L2, L3 and L4 has a negative optical focal length. It should be understood that this arrangement is beneficial for correcting aberrations of the optical lens, thereby achieving better imaging quality.

[0046] In combination with the second aspect, in certain implementations of the second aspect, the first angle θ1 and the refractive index n1 of the first prism satisfy: n1 ≥ 1 / sin(2*θ1).

[0047] Exemplarily, the value of the first angle is related to the refractive index of the first prism, and the value of the first angle may be between 22° and 28°.

[0048] It should be understood that by setting the relationship between the first angle and the refractive index of the first prism, total reflection can occur at the first incident surface of the first prism, that is, transmission and total reflection can occur at the first incident surface.

[0049] In combination with the second aspect, in certain implementations of the second aspect, the second angle θ2 and the refractive index n2 of the second prism satisfy: n2≥1 / sin(2*θ2).

[0050] Exemplarily, the value of the second angle is related to the refractive index of the second prism, and the second angle is equal to the first angle. The value of the second angle may also be between 22° and 28°.

[0051] It should be understood that by setting the relationship between the second angle and the refractive index of the second prism, total reflection can occur at the second exit surface of the second prism, that is, transmission and total reflection can occur at the second exit surface.

[0052] In combination with the second aspect, in certain implementations of the second aspect, the first lens group is a movable lens group, and during the focusing process of the optical lens switching from a distant view to a near view, the first lens group moves along the optical axis toward the object side.

[0053] In this implementation, the optical lens can move the first lens group during the focusing process, so that the optical lens has a better macro effect and high-quality imaging with a long focusing stroke.

[0054] In combination with the second aspect, in certain implementations of the second aspect, the first lens group includes at least one variable lens, and during the focusing process of the optical lens switching from a distant view to a near view, the optical focal length of the variable lens in the first lens group increases.

[0055] It should be understood that a variable lens refers to a lens whose surface shape can be changed by electrical, acoustic or magnetic driving methods.

[0056] In the optical lens provided in the present application, the first lens group includes at least one variable lens. Therefore, a closer focusing object distance can be achieved without moving the first lens group (i.e., while ensuring that the total height of the system remains unchanged).

[0057] In combination with the second aspect, in some implementations of the second aspect, the optical lens further includes a first lens, and the first lens is fixedly connected to the first exit surface through a gluing process to form a surface with optical power.

[0058] The optical lens provided in the present application can adopt a method of gluing the first lens and the first prism together so that the first exit surface of the first prism has optical focal length. Compared with the one-piece molded first prism with optical focal length, this method is simpler to process and manufacture, and can improve the production efficiency of the first prism.

[0059] In combination with the second aspect, in certain implementations of the second aspect, the optical lens further includes a second lens, and the second lens is fixedly connected to the second incident surface through a gluing process to form a surface with optical power.

[0060] The optical lens provided in the present application can adopt a method of gluing the second lens and the second prism so that the second incident surface of the second prism has optical focal length. Compared with the one-piece molded second prism with optical focal length, this method is simpler to process and manufacture, and can improve the production efficiency of the second prism.

[0061] In conjunction with the second aspect, in certain implementations of the second aspect, the first prism and / or the second prism are prisms having optical power formed by an integral process. That is, the first prism and / or the second prism may be formed by an integral molding process, and at least one surface of the formed prism has optical power.

[0062] In combination with the second aspect, in some implementations of the second aspect, the optical lens further includes an aperture stop, and the aperture stop is located on the object side of the first lens group, or the aperture stop is located between the first lens group and the first prism, or the aperture stop is located between the first prism and the second prism.

[0063] The optical lens provided herein may also be provided with an aperture stop. The position of the aperture stop can be adjusted according to actual needs to better adjust the aperture and filter out stray light, thereby improving the imaging quality of the optical lens. Furthermore, by placing the aperture stop on the object side of the first lens group, the overall height of the optical lens system can be reduced.

[0064] In combination with the second aspect, in some implementations of the second aspect, the optical lens further includes an infrared filter, and the infrared filter is located on the image side of the second prism.

[0065] For example, in some implementations, an infrared cutoff film layer may be provided on the surface of the second exit surface of the second prism.

[0066] The optical lens provided in the present application may also be provided with an infrared filter or an infrared cut-off film layer to filter out unnecessary light signals.

[0067] In conjunction with the second aspect, in certain implementations of the second aspect, the optical lens further includes a third lens group, the third lens group including at least one lens, and the third lens group is located on the image side of the second prism. Exemplarily, the third lens group may be located between the second prism and the infrared filter.

[0068] Exemplarily, the third lens group may include a third lens, and the third lens may have positive or negative optical power. The third lens group may be used to further correct aberrations.

[0069] In a third aspect, an optical lens is provided, comprising a first lens group, a first prism, a second lens group and a third prism, arranged in sequence from the object side to the image side, wherein the first lens group includes at least one lens, the first lens group has positive optical power, and the first lens group is used to receive light and converge the light; the first prism includes a first incident surface, a first reflection surface and a first exit surface, a first angle between the first incident surface and the first reflection surface is less than 45°, and the optical axis of the first exit surface coincides with the optical axis of the second lens group; the second lens group includes at least one lens, the second lens group has negative optical power; the third prism includes a third incident surface, a third reflection surface and a third exit surface, the angle between the third incident surface and the third reflection surface is equal to the angle between the third exit surface and the third reflection surface, and a third angle formed between the third incident surface and the third reflection surface is twice the first angle, the third angle is less than 90° and greater than 40°, and the optical axis of the third incident surface coincides with the optical axis of the second lens group.

[0070] The first prism may be configured to fold the optical axis of the optical system twice, and the third prism may be configured to fold the optical axis of the optical system three times.

[0071] In an embodiment of the present application, by arranging a second lens group between the first prism and the third prism, the first lens group and the second lens group are separated, so that the optical lens has a strong focusing ability, which can not only shoot distant scenes, but also shoot close scenes (for example, macro scenes), with high imaging quality and high imaging clarity. In addition, by setting the angle between the third incident surface and the third reflection surface to be equal to the angle between the third exit surface and the third reflection surface, and the third angle formed between the third incident surface and the third reflection surface to be twice the first angle, the light can be reflected three times in the third prism, the light path is folded more times in the third prism, the space utilization rate is higher, and it is more conducive to the design of a telephoto lens. In addition, the light incident on the third prism turns upward when it undergoes the second reflection, so that the optical axis of the exit light of the third prism can be raised upward, thereby further reducing the length of the optical system.

[0072] It should be understood that the embodiments of the present application use a coaxial system. That is, the optical axis of the first exit surface of the first prism coincides with the optical axis of the second lens group, and the optical axis of the third incident surface of the third prism coincides with the optical axis of the second lens group. By using a coaxial system, the optical lens does not produce off-axis aberrations compared to an off-axis system. The prisms and lenses in the coaxial system can all adopt a centrally symmetrical structure, which is easy to manufacture and has strong feasibility. In addition, compared to an off-axis system, the prisms and lenses in the coaxial system are easier to find the center point, which facilitates the assembly of the lenses and prisms in the optical lens.

[0073] In one possible implementation, the first lens group may include three lenses (e.g., first lens L1, second lens L2, and third lens L3), and the second lens group may include two lenses (e.g., fourth lens L4 and fifth lens L5). In one example, L1 may have positive optical power, and at least one of L2 and L3 may have negative optical power. It should be understood that this configuration facilitates aberration correction of the optical lens, thereby achieving better imaging quality. It should be understood that from an engineering implementation perspective, a design in which L1 has positive optical power, L2 has positive optical power, and L3 has negative optical power may be employed.

[0074] Exemplarily, L4 has positive optical power and L5 has negative optical power, or L4 has negative optical power and L5 has positive optical power, and L4 and L5 as a whole (i.e., the second lens group) have negative optical power. In this example, by setting the optical power of the two lenses in the second lens group to one positive and one negative, it is beneficial to correct aberrations, so that the optical lens has better imaging quality.

[0075] In one possible implementation, the first lens group may include two lenses (e.g., a first lens L1 and a second lens L2), and the second lens group may include three lenses (e.g., a third lens L3, a fourth lens L4, and a fifth lens L5). In one example, L1 may have positive optical power, L2 may have negative optical power, and L1 and L2 as a whole (i.e., the first lens group) have positive optical power. In this example, by setting L1 to have positive optical power and L2 to have negative optical power, it is beneficial to control the aberration of the light beam passing through the first lens group, making it easier to correct aberrations in the first lens group, and the optical lens has better imaging quality. In other examples, L1 may have positive optical power, and L2 may also have positive optical power, which is not limited in this application.

[0076] In this implementation, at least one of the three lenses in the second lens group has positive power, and at least one has negative power. The specific power of L3, L4, and L5 is not limited. For example, L3 can have positive power, L4 can have negative power, and L5 can have negative power (or positive power), and the entire group formed by L3, L4, and L5 (i.e., the second lens group) has negative power.

[0077] In this implementation, compared with the solution in which the first lens group includes three lenses, two lenses are provided in the first lens group. On the one hand, aberrations can be corrected well, and on the other hand, the size of the optical lens can be reduced.

[0078] It should be understood that the entire optical lens has positive optical power, i.e., it has a converging effect on light beams. In other words, the entire lens system formed by the first and second lens groups has positive optical power, i.e., the absolute value of the optical power of the first lens group is greater than the absolute value of the optical power of the second lens group.

[0079] In combination with the third aspect, in certain implementations of the third aspect, the first angle θ1 and the refractive index n1 of the first prism satisfy: n1 ≥ 1 / sin(2*θ1).

[0080] Exemplarily, the value of the first angle is related to the refractive index of the first prism, and the value of the first angle may be between 22° and 28°.

[0081] It should be understood that by setting the relationship between the first angle and the refractive index of the first prism, total reflection can occur at the first incident surface of the first prism, that is, transmission and total reflection can occur at the first incident surface.

[0082] In combination with the third aspect, in certain implementations of the third aspect, the first lens group is a movable lens group, and during the focusing process of the optical lens switching from a distant view to a near view, the first lens group moves along the optical axis toward the object side.

[0083] In this implementation, the optical lens can move the first lens group during the focusing process, so that the optical lens has a better macro effect and high-quality imaging with a long focusing stroke.

[0084] In combination with the third aspect, in certain implementations of the third aspect, the first lens group includes at least one variable lens, and during the focusing process of the optical lens switching from a distant view to a near view, the optical focal length of the variable lens in the first lens group increases.

[0085] It should be understood that a variable lens refers to a lens whose surface shape can be changed by electrical, acoustic or magnetic driving methods.

[0086] In the optical lens provided in the present application, the first lens group includes at least one variable lens. Therefore, a closer focusing object distance can be achieved without moving the first lens group (i.e., while ensuring that the total height of the system remains unchanged).

[0087] In combination with the third aspect, in some implementations of the third aspect, the second mirror group includes at least one variable lens, and the variable lens in the second mirror group is used to correct the additional aberration caused by the variable lens in the first mirror group.

[0088] Exemplarily, during the focusing process of the optical lens switching from a distant view to a near view, the optical power of the variable lens in the second lens group decreases.

[0089] In combination with the third aspect, in certain implementations of the third aspect, the first exit surface is a plane, the second lens group includes a first lens, the object side surface of the first lens is a plane, and the first lens is fixedly connected to the first exit surface of the first prism by a gluing process.

[0090] The optical lens provided in the present application can glue the lens in the second lens group to the first exit surface of the first prism, so that the first exit surface of the first prism has optical focal length. Compared with the one-piece molded first prism with optical focal length, this method is simpler to process and manufacture, and can improve the production efficiency of the first prism.

[0091] In combination with the third aspect, in some implementations of the third aspect, the optical lens further includes an aperture stop, and the aperture stop is located on the object side of the first lens group, or the aperture stop is located between the first lens group and the first prism, or the aperture stop is located between the first prism and the second lens group, or the aperture stop is located between the second lens group and the third prism.

[0092] The optical lens provided herein may also be provided with an aperture stop. The position of the aperture stop can be adjusted according to actual needs to better adjust the aperture and filter out stray light, thereby improving the imaging quality of the optical lens. Furthermore, by placing the aperture stop on the object side of the first lens group, the overall height of the optical lens system can be reduced.

[0093] In combination with the third aspect, in some implementations of the third aspect, the optical lens further includes an infrared filter, and the infrared filter is located on the image side of the third prism.

[0094] For example, in some implementations, an infrared cut-off film layer may be provided on the surface of the third exit surface of the third prism.

[0095] The optical lens provided in the present application may also be provided with an infrared filter or an infrared cut-off film layer to filter out unnecessary light signals.

[0096] In combination with the third aspect, in certain implementations of the third aspect, the optical lens further includes a third lens group, the third lens group includes at least one lens, and the third lens group is located on the image side of the third prism.

[0097] Exemplarily, the third mirror group may be located between the third prism and the infrared filter.

[0098] Illustratively, the first lens group may include a first lens having positive optical power; the second lens group may include a second lens having negative optical power; and the third lens group may include a third lens having positive optical power or negative optical power.

[0099] It should be understood that the entire optical lens has positive optical power, that is, it has a converging effect on light beams. In other words, the entirety formed by the first lens group, the second lens group, and the third lens group has positive optical power.

[0100] In a fourth aspect, a lens module is provided, comprising an image sensor and the optical lens described in the first aspect and any one of the first aspects, or comprising an image sensor and the optical lens described in the second aspect and any one of the second aspects, wherein the optical lens is used to image the scene on the object side onto the image sensor.

[0101] In one possible implementation, the image sensor is located on the image side of the optical lens and is arranged parallel to the second exit surface. In this implementation, the image sensor is arranged vertically, that is, the image sensor is arranged perpendicular to the thickness direction of the electronic device.

[0102] In one possible implementation, the image sensor is located on the image side of the optical lens and is arranged parallel to the second reflective surface. In this implementation, the image sensor is arranged at an angle, thereby reducing the overall height of the electronic device to a certain extent.

[0103] In a fifth aspect, a lens module is provided, comprising an image sensor and the optical lens described in the third aspect and any one of the third aspects, wherein the optical lens is used to image the scene on the object side onto the image sensor.

[0104] In one possible implementation, the image sensor is located on the image side of the optical lens and is arranged parallel to the third exit surface. In this implementation, the image sensor is arranged vertically, that is, the image sensor is arranged perpendicular to the thickness direction of the electronic device.

[0105] In the sixth aspect, an electronic device is provided, comprising an image processor and the lens module described in the fourth aspect and any one of the fourth aspects, or comprising an image processor and the lens module described in the fifth aspect and any one of the fifth aspects, the image processor being communicatively connected to the lens module, and the image processor being used to obtain image data from the lens module and process the image data.

[0106] Among them, the beneficial effects of the fourth to sixth aspects can refer to the beneficial effects of the first to third aspects, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0107] FIG1 is a schematic diagram of an electronic device provided in an embodiment of the present application.

[0108] FIG2 is a schematic structural diagram of a lens module provided in an embodiment of the present application.

[0109] FIG3 and FIG4 are schematic diagrams of the modulation transfer function of the lens module shown in FIG2 at an infinite object distance and an object distance of 200 mm.

[0110] FIG5 is a schematic structural diagram of another lens module provided in an embodiment of the present application.

[0111] FIG6 and FIG7 are schematic diagrams of the modulation transfer function of the lens module shown in FIG5 at an infinite object distance and an object distance of 60 mm.

[0112] FIG8 is a schematic structural diagram of another lens module provided in an embodiment of the present application.

[0113] FIG9 and FIG10 are schematic diagrams of the modulation transfer function of the lens module shown in FIG8 at an infinite object distance and an object distance of 200 mm.

[0114] FIG11 is a schematic structural diagram of another lens module provided in an embodiment of the present application.

[0115] FIG12 and FIG13 are schematic diagrams of the modulation transfer function of the lens module shown in FIG11 at an infinite object distance and an object distance of 200 mm.

[0116] FIG14 is a schematic structural diagram of another lens module provided in an embodiment of the present application.

[0117] FIG15 and FIG16 are schematic diagrams of the modulation transfer function of the lens module shown in FIG14 at an infinite object distance and an object distance of 200 mm.

[0118] FIG17 is a schematic structural diagram of another lens module provided in an embodiment of the present application.

[0119] FIG18 is a schematic structural diagram of another lens module provided in an embodiment of the present application. DETAILED DESCRIPTION

[0120] The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings.

[0121] The terms used in the following embodiments are only for the purpose of describing specific embodiments and are not intended to limit the present application. In the following embodiments of the present application, "first", "second" and various digital numbers are only for the convenience of description and are not used to limit the scope of the embodiments of the present application. The character " / " generally indicates that the objects before and after are in an "or" relationship. The size of the sequence number of each process below does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. For example, in the embodiments of the present application, words such as "10", "20", and "30" are only used for the convenience of description and are not used to limit the order of execution of the steps.

[0122] References to "one embodiment" or "some embodiments" described in this embodiment mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. In this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described in this application as "exemplary" or "for example" should not be interpreted as being more preferred or more advantageous than other embodiments or design. Specifically, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete way. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized. In the embodiments of the present application, descriptions such as "when...", "in the case of...", "if" and "if" all mean that the device will perform corresponding processing under certain objective circumstances, and do not limit the time, nor do they require the device to perform judgment actions when implemented, nor do they mean that there are other limitations.

[0123] For ease of understanding, the technical terms involved in this application are explained and described below.

[0124] Lens: A component that uses the refraction principle of the lens to allow the light beam of the scene to pass through the lens and form a clear image on the focal plane.

[0125] Lens group: is a combination of one or more lenses. The lens group can move as a whole, or at least one lens in the lens group can move. In this application, the lens group can also be understood as a lens group or a lens group.

[0126] Optical axis: This is an axis running perpendicularly through the center of the lens. The optical axis of a lens is the axis running through the centers of each lens element. When a beam of light parallel to the optical axis enters a convex lens, the ideal convex lens should have all the light beams converge at a single point behind the lens. This point is the focal point.

[0127] Object side and image side: With the lens as the boundary, the side where the object is located is the object side, and the surface of the lens close to the object side can be called the object side side; with the lens as the boundary, the side where the image of the object is located is the image side, and the surface of the lens close to the image side can be called the image side side.

[0128] Focal length, also known as focal length, is a measure of the convergence or divergence of light in an optical system. It refers to the distance from the optical center of a lens or lens group to the focal point when an infinitely distant object is formed through the lens or lens group in the focal plane. It can also be understood as the perpendicular distance from the optical center of the lens or lens group to the focal plane. From a practical perspective, it can be understood as the distance from the center of the lens to the imaging plane. For fixed-focus lenses, the position of the optical center is fixed; for lens modules, changes in the optical center of the lens result in changes in the focal length.

[0129] Focal power: Equal to the difference between the image-side and object-side convergence of the beam, it characterizes the ability of an optical system to deflect a beam. A lens or lens group with positive focal power (i.e., a positive focal length) converges a beam. A lens or lens group with negative focal power (i.e., a negative focal length) diverges a beam.

[0130] Diaphragm: refers to the edge, frame or specially designed barrier with holes in an optical assembly used to limit the size of the imaging beam or the imaging spatial unit.

[0131] Aperture stop (STO): It is an aperture that limits the maximum inclination angle of the marginal beam in the on-axis point imaging beam, that is, the aperture with the smallest incident aperture angle.

[0132] Aperture: Aperture is a device used to control the amount of light that passes through the lens and reaches the camera's photosensitive surface. It is usually located within the lens. The aperture size is expressed as a value of F / .

[0133] Aperture F-number (F#): Equal to the lens focal length divided by the entrance pupil diameter. With the lens focal length unchanged, a larger entrance pupil diameter results in a larger aperture and a smaller F-number, allowing more light to enter, resulting in a brighter image and a more blurred background. Conversely, a smaller entrance pupil diameter results in a smaller aperture and a larger F-number, allowing less light to enter, resulting in a darker image and sharper backgrounds in the foreground and background of the subject.

[0134] Total track length (TTL): refers to the total length from the lens barrel to the imaging surface, which is the main factor in determining the height of the camera.

[0135] IMH (Image Hight) represents half of the diagonal length of the effective pixel area on the photosensitive chip, that is, the image height of the imaging surface.

[0136] Field of view (FOV): In optical instruments, the angle formed by the two edges of the maximum range through which the image of the object can pass through the lens, with the lens as the vertex, is called the field of view. The field of view angle determines the visual range of the optical instrument. The larger the field of view angle, the greater the field of view and the smaller the optical magnification. The shorter the focal length, the wider the horizontal field of view, and therefore the smaller the image. The horizontal field of view narrows as the focal length increases, and the subject becomes larger.

[0137] The Abbe number, also known as the dispersion coefficient, is the difference ratio of the refractive index of an optical material at different wavelengths, representing the degree of dispersion of the material.

[0138] Aberrations: The paraxial region of an optical system exhibits the properties of an ideal optical system, where a paraxial beam emitted from a point on the object intersects the image plane at a single point. In reality, beams of light passing through different lens apertures rarely intersect perfectly at a single point, but rather deviate from the paraxial image point by a certain amount. These differences are collectively referred to as aberrations.

[0139] Meridian plane: The plane formed by the main beam (main beam) of the object point outside the optical axis and the optical axis is called the meridian plane.

[0140] The sagittal plane is the plane that passes through the main beam (main beam) of the object point outside the optical axis and is perpendicular to the meridian plane.

[0141] The main trend in the future is the large-bottom, large-aperture, and high-pixel telephoto lenses for mobile phones. Large pixel size can bring a higher full-well capacity (that is, the limit on the number of electrons that a pixel can collect and accommodate), thereby achieving a larger dynamic range; at the same time, it has a lower Nyquist frequency, which can bring better focusing and anti-shake effects. The large aperture can bring in more light and a higher diffraction limit.

[0142] Existing telephoto lenses suffer from poor image quality in extremely low-light conditions, with focusing performance limited by the signal-to-noise ratio. To increase the amount of light entering the lens and image clarity, larger lens diameters and longer, more complex optical paths are required to correct for aberrations. While maintaining the same equivalent focal length, the larger lens base also results in a longer effective focal length, and therefore a longer TTL, further increasing the lens size. For smartphones, size is a significant constraint, and therefore a larger base has led to the emergence of various approaches in recent years that utilize prisms to fold the optical path (such as the 45° prism solution). The prism size in existing 45° prism solutions is limited by the target surface size, which in turn limits the overall module height. Consequently, the module protrudes significantly when using a larger base. Furthermore, these approaches suffer from low optical path folding efficiency. For telephoto modules with larger bases, a 45° prism folding solution still cannot meet the physical requirements of smartphones. Consequently, some anisotropic prism solutions have emerged, breaking the symmetry of the 45° prism to achieve higher folding efficiency. However, these approaches struggle to achieve excellent macro focus quality.

[0143] Therefore, based on the demand for large aperture, large target area, compact size, and high-quality mobile phone image capture, this application provides a large aperture, special-shaped prism refractive telephoto lens, which can be applied to future mobile phones and other small smart devices. By rationally adjusting the number, focal length, material, and position of each optical element in the lens group, high-quality imaging with large aperture, large target area, compact size, and long focus range can be achieved.

[0144] It should be noted that the electronic devices involved in the embodiments of the present application may include handheld devices, vehicle-mounted devices, wearable devices, computing devices, or other processing devices connected to a wireless modem. For example, a cellular phone, a mobile phone, a smart phone, a tablet computer, a laptop computer, a video camera, a video recorder, a still camera, a smart watch, a smart wristband, or other devices with photo or video recording capabilities. The embodiments of the present application do not impose any particular restrictions on the specific type of electronic device.

[0145] Figure 1 is a schematic diagram of an electronic device provided in an embodiment of the present application. This embodiment of the present application is described by taking the electronic device 100 as a mobile phone as an example.

[0146] The electronic device 100 includes a housing 10, a display screen 20, an image processor 30, and a lens module 40. In some embodiments, the housing 10 includes a frame 101 and a back cover 102. The frame 101 and the back cover 102 can be an integrally formed structure, or they can be assembled to form an integral structure. The display screen 20 and the back cover 102 are respectively mounted on both sides of the frame 101, and together enclose the inner cavity of the entire device. The display screen 20 can be a liquid crystal display (LCD) screen, an organic light emitting diode (OLED) display screen, etc., wherein the OLED display screen can be a flexible display screen or a rigid display screen.

[0147] The image processor 30 and lens module 40 are housed within the interior of the device. The image processor 30 is communicatively coupled to the lens module 40, and is used to acquire and process image data from the lens module 40. The communication between the lens module 40 and the image processor 30 can include data transmission via electrical connections such as wiring, or data transmission can be achieved through coupling or other methods. It is understood that the lens module 40 and the image processor 30 can also be communicated via other methods capable of achieving data transmission.

[0148] Image processor 30 optimizes and processes the digital image signal and transmits the processed signal to the display. Image processor 30, which can be an image processing chip or a digital signal processing chip, promptly and quickly transmits data obtained by the photosensitive chip to the central processing unit and refreshes the photosensitive chip. Therefore, the quality of image processor 30 directly affects image quality (such as color saturation and clarity).

[0149] The lens module 40 can be set only on the front of the electronic device 100 to shoot the scene on the front side of the electronic device 100. In some embodiments, it can be called a front lens module; it can also be set only on the back of the electronic device 100 to shoot the scene on the back side of the electronic device 100. In some embodiments, it can be called a rear lens module; it can also be set on the front and back of the electronic device 100. As shown in Figure 1, the lens module 40 is set on the front of the electronic device 100, and the lens module 40 is also set on the back of the electronic device 100. It can shoot both the scene on the front side of the electronic device 100 and the scene on the back side of the electronic device 100, as long as the corresponding lens module is used when shooting.

[0150] It should be understood that the mounting location of the lens module 40 is merely illustrative. In some embodiments, when the lens module 40 functions as a front-facing lens module, it may also be mounted elsewhere on the electronic device 100, such as to the left of the earpiece, in the upper center of the electronic device 100, at the bottom of the electronic device 100, or at one of the four corners of the electronic device 100. When the lens module 40 functions as a rear-facing lens module, it may be mounted in the upper center or upper right corner of the back of the electronic device 100. In other embodiments, the lens module 40 may not be mounted on the main body of the electronic device 100, but may be mounted on an edge protruding from the main body of the electronic device 100, or on a component that is movable or rotatable relative to the electronic device 100, such as a component that can extend, retract, or rotate from the main body of the electronic device 100. When the lens module 40 is rotatable relative to the electronic device 100, the lens module 40 functions as both a front-facing lens module and a rear-facing lens module. That is, by rotating the same lens module 40, it can capture both the front and back views of the electronic device 100. In other embodiments, when the display screen 20 can be folded, the lens module 40 can be used as either a front lens module or a rear lens module. The lens module 40 is used to shoot the scene on the front side of the electronic device 100 or the scene on the back side of the electronic device 100 as the display screen 20 is folded.

[0151] The embodiment of the present application does not limit the number of lens modules 40 provided, and can be one, two, four, or even more. For example, the electronic device 100 can be provided with one or more lens modules 40 on the front, and one or more lens modules 40 on the back. The embodiment of the present application does not impose any restrictions on the number of lens modules provided, nor does it impose any restrictions on the relative positions of multiple lens modules when provided. When multiple lens modules 40 are provided, the multiple lens modules 40 can be exactly the same or different, for example, the multiple lens modules 40 include different numbers of lenses, or different optical parameters of the lenses, or different settings of the lenses, etc.

[0152] The lens module 40 can be used to shoot videos and / or photos, and can be used to shoot scenes at different distances, for example, the lens module 40 can be used to shoot distant scenes, can be used to shoot close scenes, and can also be used to shoot macro scenes.

[0153] Optionally, the electronic device 100 may further include a lens protection lens 103 for protecting the lens module 40. The lens protection lens 103 is arranged on the housing 10 to cover the lens module 40. When the lens protection lens 103 is used to protect the front lens module, the lens protection lens 103 may only cover the front lens module or cover the entire front of the electronic device 100, wherein when the lens protection lens 103 covers the entire front of the electronic device 100, it can be used to protect the front lens module and the display screen 20 at the same time, and the lens protection lens 103 is a cover glass (cover glass, CG). When the lens protection lens 103 is used to protect the rear lens module, the lens protection lens 103 may cover the entire back of the electronic device 100, or it may be only arranged at a position corresponding to the rear lens module to protect the rear lens module. The material of the lens protection lens 103 may be glass, sapphire, ceramic, etc., and is not specifically limited in the embodiments of the present application. In some embodiments, the lens protection lens 103 is transparent, so that a light beam outside the electronic device 100 can pass through the lens protection lens 103 and enter the lens module 40 .

[0154] It should be noted that the front of the electronic device 100 described in the embodiment of the present application can be understood as the side surface of the electronic device 100 facing the user when the user uses the electronic device 100, and the back of the electronic device 100 can be understood as the side surface of the electronic device 100 facing away from the user when the user uses the electronic device 100.

[0155] It should be understood that the electronic device 100 shown in Figure 1 is not limited to including the above devices, but may also include other devices, such as a battery, a flash, a fingerprint recognition module, an earpiece, buttons, sensors, etc. The embodiment of the present application only uses the electronic device equipped with a lens module 40 as an example for illustration, but the components installed on the electronic device 100 are not limited to this.

[0156] In some embodiments, the electronic device 100 may further include an analog-to-digital converter (also referred to as an A / D converter, not shown). The analog-to-digital converter is connected between the lens module 40 and the image processor 30. The analog-to-digital converter is used to convert the signal generated by the lens module 40 into a digital image signal and transmit it to the image processor 30. The image processor 30 then processes the digital image signal and ultimately displays the image or video on the display screen 20.

[0157] In some embodiments, the electronic device 100 may further include a memory (not shown), which is communicatively connected to the image processor 30. The image processor 30 processes the digital image signal and then transfers the image to the memory, so that the image can be retrieved from the memory and displayed on the display screen 20 at any time when the image is needed. In some embodiments, the image processor 30 also compresses the processed digital image signal before storing it in the memory to save memory space.

[0158] In some embodiments, the lens module 40 may include an optical lens and a photosensitive element. The photosensitive element is located on the image side of the optical lens. The lens module 40 may also include a circuit board (not shown in the figure), and the photosensitive element may be fixed to the circuit board. The filter may be located between the optical lens and the photosensitive element. The light beam can pass through the optical lens and illuminate the photosensitive surface of the photosensitive element. Exemplarily, the working principle of the lens module 40 is as follows: the light beam reflected by the photographed scene generates an optical image through the optical lens and is projected onto the photosensitive surface of the photosensitive element. The photosensitive element converts the optical image into an electrical signal, i.e., an analog image signal, and transmits it to the analog-to-digital converter, so as to be converted into a digital image signal through the analog-to-digital converter and given to the image processor 30.

[0159] The photosensitive element (also known as an image sensor) is a semiconductor chip with hundreds of thousands to millions of photodiodes on its surface. When exposed to light, these diodes generate an electrical charge. The photosensitive element can be a charge-coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS). A CCD is made of a highly sensitive semiconductor material that converts light into electrical charge. A CCD consists of many photosensitive units, typically measured in megapixels. When a beam of light hits the CCD's surface, each unit reflects an electrical charge on the component. The signals generated by all these units are combined to form a complete image. CMOS primarily utilizes semiconductors made of silicon and germanium, allowing the coexistence of semiconductors with N (negative) and P (positive) polarizations within the CCD. These two complementary effects generate currents that are recorded and interpreted by the processing chip as an image.

[0160] Among them, the optical lens mainly uses the refraction principle of the lens to form an image, that is, the light beam of the scene passes through the optical lens, forming a clear image on the focal plane, and the image of the scene is recorded by the photosensitive element located on the focal plane.

[0161] Figure 2 is a structural schematic diagram of another example of a lens module 40 provided in an embodiment of the present application, wherein (a) in Figure 2 is the state of the lens module 40 when shooting a distant object, and (b) in Figure 2 is the state of the lens module when shooting a close object.

[0162] The lens module 40 may include a first lens group G1, a first prism P1, a second lens group G2, a second prism P2, and an image sensor 43 along the optical axis from the object side to the image side. It should be understood that the first lens group G1, the first prism P1, the second lens group G2, and the second prism P2 may constitute an optical lens, with the image sensor 43 located on the image side of the optical lens. The first lens group G1 includes at least one optical lens having positive optical power for receiving and converging light beams. For example, the first lens group G1 may include a first lens L1, a second lens L2, and a third lens L3. The second lens group G2 includes at least one optical lens having negative optical power. For example, the second lens group G2 may include a fourth lens L4 and a fifth lens L5.

[0163] The first lens group G1 is capable of focusing and imaging objects at different object distances. It is a movable lens group. That is, the first lens group G1 is capable of moving at least one optical lens in the first lens group G1 under the drive of a motor or other driving element. For example, the first lens group G1 may be enclosed by a mechanical actuator (such as a motor) that can change the relative position of the first lens group G1 and the first prism P1 to image objects at different object distances.

[0164] For example, as shown in (a) and (b) of Figure 2, during the focusing process of the lens module 40 switching from a distant view to a close view, the first lens L1, the second lens L2 and the third lens L3 can be driven by a driving element such as a motor to move along the optical axis toward the object side to achieve focusing.

[0165] The first prism P1 is located on the image side of the first mirror group G1. The first prism P1 may include at least three characteristic surfaces. For example, the first prism P1 includes a first surface S1-1, a second surface S1-2, and a third surface S1-3. A light beam can enter the first prism P1 from the first surface S1-1 and exit the first prism P1 from the third surface S1-3. The first surface S1-1 is an incident surface (which may be referred to as a first incident surface) and is also a transmission and total internal reflection (TIR) ​​surface. It transmits light received from the first mirror group G1 and reflects light received from the second surface S1-2 of the prism to the third surface S1-3 through TIR. The second surface S1-2 is a reflective surface (which may be referred to as a first reflective surface) and is also a reflective surface coated with a mirror coating. It reflects light received through the first surface S1-1 back to the first surface S1-1 in the prism. The third surface S1-3 is an exit surface (which may be referred to as a first exit surface) and is also a transmission surface that transmits light received from the first surface S1-1. In short, the light beam enters the first prism P1 from the first surface S1-1, is reflected by the second surface S1-2 to the first surface S1-1, and undergoes total internal reflection on the first surface S1-1. The reflected light finally passes through the third surface S1-3 and exits the first prism P1.

[0166] It should be understood that the first angle θ1 between the first surface S1-1 and the second surface S1-2 (i.e., the first incident surface S1-1 and the first reflective surface S1-2) is less than 45° (e.g., θ1 is 25°). Exemplarily, the range of θ1 can be: 0°<θ1<10°, 10°≤θ1<20°, 20°≤θ1<25°, 25°≤θ1<30°, 30°≤θ1<35°, 35°≤θ1<40°, 40°≤θ1<45°. Exemplarily, the range of θ1 can be: 22°<θ1<28°.

[0167] It should be noted that the value of the first angle θ1 is related to the refractive index of the first prism P1. In order to satisfy total reflection, the first angle θ1 and the refractive index n1 of the first prism P1 can satisfy the following relationship: n1 ≥ 1 / sin(2*θ1). In a conventional folding lens system, the angle between the first surface of the first prism and the second surface of the first prism is usually 45°. The present application sets the angle between the first surface S1-1 and the second surface S1-2 of the first prism P1 to be less than 45°, that is, reducing the angle between the first surface S1-1 and the second surface S1-2 of the first prism P1, thereby helping to reduce the height of the lens module in the Z direction (that is, the thickness direction of the electronic device), thereby helping to reduce the size of the lens module 40.

[0168] The second prism P2 is located on the image side of the first prism P1. The second prism P2 may include at least three characteristic surfaces. For example, the second prism P2 includes a fourth surface S2-1, a fifth surface S2-2, and a sixth surface S2-3. The fourth surface S2-1 is an incident surface (which may be referred to as a second incident surface) and is also a transmissive surface, which transmits the light received from the first prism P1 to the fifth surface S2-2 in the prism. The fifth surface S2-2 is an exit surface (which may be referred to as a second exit surface) and is also a transmissive and TIR surface, which reflects the light received through the fourth surface S2-1 to the sixth surface S2-3 in the prism by TIR, and transmits the light received from the sixth surface S2-3 in the prism to form an image in the image sensor 43. The sixth surface S2-3 is a reflective surface coated with a mirror coating (which may be referred to as a second reflective surface), which reflects the light received from the fifth surface S2-2 back to the fifth surface S2-2. In short, the light beam enters the second prism P2 from the fourth surface S2-1, is then totally reflected by the fifth surface S2-2, is then reflected by the sixth surface S2-3 to the fifth surface S2-2, and finally exits the second prism P2 from the fifth surface S2-2.

[0169] It should be understood that the second angle θ2 between the fifth surface S2-2 and the sixth surface S2-3 (i.e., the second exit surface S2-2 and the second reflection surface S2-3) is less than 45°, for example, θ2 is 25°, and the second angle θ2 is equal to the first angle θ1. Exemplarily, the range of θ2 can be: 0°<θ2<10°, 10°≤θ2<20°, 20°≤θ2<25°, 25°≤θ2<30°, 30°≤θ2<35°, 35°≤θ2<40°, 40°≤θ2<45°. Exemplarily, the range of θ2 can be: 22°<θ3<28°.

[0170] It should be noted that the value of the second angle θ2 is related to the refractive index of the second prism P2. In order to achieve total internal reflection, the second angle θ2 and the refractive index n2 of the second prism P2 satisfy the following relationship: n2 ≥ 1 / sin(2*θ2). The present application sets the angle between the fifth surface S2-2 and the sixth surface S2-3 of the second prism P2 to be less than 45°, that is, reducing the angle between the fifth surface S2-2 and the sixth surface S2-3 of the second prism P2, which helps to reduce the height of the lens module in the Z direction (i.e., the thickness direction of the electronic device), thereby helping to reduce the size of the lens module 40.

[0171] It should be noted that the prism material of the first prism P1 and the second prism P2 preferably has a higher refractive index and a lower dispersion coefficient, as the higher the refractive index, the more likely it is to cause total internal reflection. The refractive index of the first prism P1 and the refractive index of the second prism P2 are both greater than 1.5, and the Abbe number is greater than 40.

[0172] It should be understood that by disposing the second lens group G2 between the first prism P1 and the second prism P2, the lens module 40 can have good macro performance, achieving an optical magnification of 0.1 times or more and a macro focusing distance of less than 20 cm.

[0173] It should be understood that the optical axis of the third surface S1-3 of the first prism P1 coincides with the optical axis of the second lens group G2, and the optical axis of the fourth surface S2-1 of the second prism P2 coincides with the optical axis of the second lens group G2. In other words, the present application employs a coaxial system. By using a coaxial system, the optical lens does not produce off-axis aberrations compared to an off-axis system. The prisms and lenses in the coaxial system can all adopt a centrally symmetrical structure, which is easy to manufacture and has high feasibility. In addition, compared to an off-axis system, the prisms and lenses in the coaxial system are easier to find the center point, which facilitates the assembly of the lenses and prisms in the optical lens.

[0174] In some embodiments, as shown in FIG2 , the first surface S1-1, the second surface S1-2, and the third surface S1-3 of the first prism P1 may all be planes, and the fourth surface S2-1, the fifth surface S2-2, and the sixth surface S2-3 of the second prism P2 may all be planes.

[0175] In some other embodiments, the first surface S1-1 of the first prism P1 is a plane, the second surface S1-2 of the first prism P1 and / or the third plane S1-3 of the first prism P1 can be surfaces with optical focal length; the fifth surface S2-2 of the second prism P2 is a plane, the fourth surface S2-1 and / or the sixth surface S2-3 can be surfaces with optical focal length. This application does not limit this.

[0176] Illustratively, in order to form a surface with optical power of the first prism P1, the lenses in the second lens group G2 may be fixedly connected to the first exit surface (ie, the third plane S1-3) of the first prism P1 through a gluing process.

[0177] Illustratively, in order to form a surface with optical power of the second prism P2, the lenses in the second lens group G2 may be fixedly connected to the second incident surface (ie, the fourth surface S2-1) of the second prism P2 through a gluing process.

[0178] In the lens module 40 shown in FIG2 , the image sensor 43 is located on the image side of the optical lens and is arranged parallel to the fifth surface S2-2 (i.e., the second exit surface), so that the first prism P1 and the second prism P2 can fold the optical axis four times. The second surface S1-2 of the first prism P1 folds the optical axis once; then, the first surface S1-1 of the first prism P1 folds the optical axis a second time; then, the fifth surface S2-2 of the second prism P2 folds the optical axis again; then, the sixth surface S2-3 of the second prism P2 folds the optical axis a fourth time; and the light beam finally impinges on the image sensor 43. The present application can better correct aberrations by setting a longer and more complex optical path.

[0179] In some other embodiments, by tilting the image sensor 43, that is, the image sensor 43 is located on the image side of the optical lens and parallel to the sixth surface S2-3 (i.e., the second reflective surface), the first prism P1 and the second prism P2 fold the optical axis three times. The second surface S1-2 of the first prism P1 folds the optical axis once; then, the first surface S1-1 of the first prism P1 folds the optical axis again; then, the fifth surface S2-2 of the second prism P2 folds the optical axis a third time; and the light beam finally impinges on the image sensor 43.

[0180] It should be understood that the entire optical lens has a positive optical power, that is, the absolute value of the optical power of the first lens group G1 is greater than the absolute value of the optical power of the second lens group G2.

[0181] In one example, L1 can have positive optical power, and at least one of L2 and L3 can have negative optical power. It should be understood that this configuration facilitates aberration correction in the optical lens, thereby achieving better imaging quality. It should be understood that from an engineering implementation perspective, a design in which L1 has positive optical power, L2 has positive optical power, and L3 has negative optical power can be employed.

[0182] Exemplarily, L4 has positive optical power and L5 has negative optical power, or L4 has negative optical power and L5 has positive optical power, and L4 and L5 as a whole (i.e., the second lens group G2) have negative optical power. In this example, by setting the optical power of the two lenses in the second lens group to one positive and one negative, it is beneficial to correct aberrations, so that the optical lens has better imaging quality.

[0183] Optionally, the optical lens may further include a third lens group, which may include at least one optical lens. The third lens group is located on the image side of the second prism P2, specifically between the second prism P2 and the image sensor 43. The third lens group can be used to correct aberrations and improve imaging quality.

[0184] It should be understood that the entire optical lens has positive optical power, meaning it has a converging effect on light beams. In other words, when a third lens group is included, the entire first, second, and third lens groups have positive optical power. The third lens group can have either positive or negative optical power, and this application does not limit this.

[0185] It should be noted that, in order to better correct aberrations, the more lenses provided in the optical lens, the better. However, due to the overall height of the optical lens system and the size limitations of the electronic device, the number of lenses included in the optical lens in the embodiment of the present application can range from 3 to 5. For example, the first lens group G1 can include 1 lens, and the second lens group G2 can include 4 lenses. For another example, the first lens group G1 can include 2 lenses, and the second lens group G2 can include 3 lenses. This example will be described in detail in conjunction with Figure 5. For another example, the first lens group G1 can include 1 lens, the second lens group G2 can include 1 lens, and the third lens group G3 can include 1 lens. This example will be described in detail in conjunction with Figure 8.

[0186] Optionally, the optical lens may further include an infrared filter 42, which is located on the image side of the second prism P2, specifically between the second prism P2 and the image sensor 43. More specifically, the infrared filter 42 is located between the fifth surface S2-2 of the second prism P2 and the image sensor 43. The infrared filter 42 can be used to filter out unnecessary light signals. In some other embodiments, the optical lens may not be provided with a separate infrared filter. For example, an infrared cutoff film layer may be provided on the light-emitting surface of the fifth surface S2-2 of the second prism P2 to filter out unnecessary light signals. Alternatively, an absorbent material may be added to the light-emitting surface of the fifth surface S2-2 of the second prism P2 to filter out unnecessary light signals.

[0187] Optionally, the optical lens may further include an aperture stop STO. As shown in FIG2 , the aperture stop STO may be disposed between the first lens group G1 and the first prism P1. Specifically, the aperture stop STO may be disposed between the fourth lens L4 and the first surface S1-1 of the first prism P1. In other embodiments, the aperture stop STO may also be located on the object side of the first lens group G1, thereby reducing the overall system height of the optical lens. In other embodiments, the aperture stop STO may also be located between the first prism P1 and the second lens group G2, or between the second lens group G2 and the second prism P2. It should be understood that the aperture stop STO may be used to adjust the aperture, filter out stray light, and improve the imaging quality of the lens module 40.

[0188] The aperture stop STO may be a spacer ring structure or a variable fan blade structure; alternatively, the aperture stop STO may be implemented through a surface spraying process, for example, by spraying a light-shielding material onto a lens to form the aperture stop STO. The position of the aperture stop STO may be fixed or variable. For example, the position of the aperture stop STO may be variable, and the aperture stop STO may be adjusted according to the focusing condition so as to be positioned between different lenses.

[0189] The following presents a possible design approach for the lens module 40 shown in FIG. 2 in combination with parameter data and simulation results.

[0190] As shown in FIG2 , the lens module 40 includes, for example, a first lens group G1, a first prism P1, a second lens group G2, a second prism P2, an infrared filter 42, and an image sensor 43, arranged sequentially from the object side to the image side. The first lens group G1 includes a first lens L1, a second lens L2, and a third lens L3, while the second lens group includes a fourth lens L4 and a fifth lens L5. The refractive index n1 of the first prism P1 is 1.70, and the first angle θ1 between its first surface S1-1 and second surface S1-2 is 25°. The refractive index n2 of the second prism P2 is 1.69, and the angle θ2 between its fifth surface S2-2 and sixth surface S2-3 is 25°.

[0191] The first lens group G1 can be enclosed by a mechanical actuator (e.g., a motor). By varying the relative position of the first lens group G1 and the first prism P1, images can be captured at various distances, with a minimum focusing distance of 20 cm. The following describes the relevant parameters of the lens module 40 shown in FIG2 , in conjunction with Tables 1A and 1B.

[0192] Table 1A Basic parameters of lens module

[0193] It should be noted that when the image sensor 43 is set vertically, the "system total height" in Table 1A is the vertical distance between the first surface of the first lens (i.e., L1) and the image sensor 43, the "system shoulder height" is the vertical distance between the first surface S1-1 of the first prism P1 and the image sensor 43, and the "system length" is the longest distance of the lens module 40 along the length direction of the electronic device, that is, the vertical distance between the top end of the first lens L1 and the bottom end of the image sensor 43.

[0194] As can be seen from Table 1A, using the lens module 40 shown in Figure 2, the system's total height is 8.09mm, the system's shoulder height is 3.89mm, and the system length is 13.4mm. These are all significantly reduced compared to the 45° prism solution, thereby reducing the size of the lens module. Furthermore, using the lens module 40 shown in Figure 2, the minimum focusing distance can reach 200mm, providing excellent macro effects.

[0195] Table 1B Lens module moving parts parameters at different object distances

[0196] As can be seen from Table 1B, at an object distance of infinite, the distance between the second surface S1-2 of the third lens L3 of the first lens group G1 and the first surface S1-1 of the first prism P1 is 0.569 mm. This second surface S1-2 is the surface of the third lens L3 closest to the first prism P1. When the lens module 40 is adjusted from an object distance of infinite to an object distance of 200 mm, the first lens group G1 moves away from the first prism P1 (i.e., toward the object side). At an object distance of 200 mm, the distance between the second surface S1-2 of the third lens L3 and the first surface S1-1 of the first prism P1 is 1.253 mm.

[0197] 3 and 4 show the modulation transfer function (MTF) of the lens module 40 of FIG2 at an infinite object distance and at an object distance of 200 mm. Among them, FIG3 is the defocus MTF curve of this embodiment when the spatial frequency is 125 lp / mm at an infinite object distance. As can be seen from FIG3, the modulation transfer function (MTF) under different fields of view at an infinite object distance is greater than 0.4 in the sagittal and tangential directions. This result shows that the lens module 40 of FIG2 can achieve high-quality imaging at an infinite object distance. FIG4 is the defocus MTF curve of this embodiment when the spatial frequency is 89 lp / mm at an object distance of 200 mm. As can be seen from FIG4, the modulation transfer function (MTF) under different fields of view at a macro distance of 200 mm is greater than 0.5 in the sagittal and tangential directions. This result shows that the lens module 40 of FIG2 can achieve high-quality macro imaging.

[0198] Figure 5 is a structural schematic diagram of another example of a lens module 40 provided in an embodiment of the present application, wherein (a) in Figure 5 is the state of the lens module 40 when shooting a distant object, and (b) in Figure 5 is the state of the lens module when shooting a close object.

[0199] It should be noted that the lens module shown in Figure 5 is similar in structure to the lens module shown in Figure 2 , with the primary difference between the two being the number of lenses included in the first lens group G1 and the number of lenses included in the second lens group G2. Therefore, for other related descriptions of the first lens group G1, the second lens group G2, the first prism P1, and the second prism P2, refer to the relevant description in Figure 2 and will not be repeated here. The following will focus on the differences.

[0200] As shown in Figure 5, the lens module 40 may include a first lens group G1, a first prism P1, a second lens group G2, a second prism P2, an infrared filter 42, and an image sensor 43 along the optical axis from the object side to the image side. It should be understood that the first lens group G1, the first prism P1, the second lens group G2, and the second prism P2 may constitute an optical lens, with the image sensor 43 located on the image side of the optical lens. The first lens group G1 includes at least one optical lens with positive optical power for receiving and converging light beams. For example, the first lens group G1 may include a first lens L1 and a second lens L2. The second lens group G2 includes at least one optical lens with negative optical power. For example, the second lens group G2 may include a third lens L3, a fourth lens L4, and a fifth lens L5.

[0201] In one example, L1 can have positive optical power, L2 can have negative optical power, and L1 and L2 as a whole (i.e., the first lens group G1) have positive optical power. In this example, by setting L1 to have positive optical power and L2 to have negative optical power, it is beneficial to control the aberrations of the light beam passing through the first lens group G1, making it easier to correct aberrations in the first lens group G1, and the optical lens has better imaging quality. In other examples, L1 can have positive optical power, and L2 can also have positive optical power, which is not limited in this application.

[0202] It should be understood that at least one of the three lenses in the second lens group G2 has positive power and at least one has negative power, and the specific power of L3, L4, and L5 is not limited. For example, L3 can have positive power, L4 can have negative power, and L5 can have negative power (or positive power), and the entire lens group formed by L3, L4, and L5 (i.e., the second lens group G2) has negative power.

[0203] In the lens module shown in FIG5 , compared with the solution in which the first lens group G1 includes three lenses (the lens module shown in FIG2 ), two lenses are provided in the first lens group G1. On the one hand, this can correct aberrations well, and on the other hand, it can also reduce the size of the optical lens.

[0204] The following presents a possible design approach for the lens module 40 shown in FIG5 , in combination with parameter data and simulation results.

[0205] For example, as shown in FIG5 , the lens module 40 includes a first lens group G1, a first prism P1, a second lens group G2, a second prism P2, an infrared filter 42, and an image sensor 43, arranged sequentially from the object side to the image side. The first lens group G1 includes a first lens L1 and a second lens L2, and the second lens group includes a third lens L3, a fourth lens L4, and a fifth lens L5. The refractive index n1 of the first prism P1 is 1.74, and the first angle θ1 between its first surface S1-1 and the second surface S1-2 is 25°. The refractive index n2 of the second prism P2 is 1.70, and the angle θ2 between its fifth surface S2-2 and the sixth surface S2-3 is 25°.

[0206] The first lens group G1 can be enclosed by a mechanical actuator (e.g., a motor). By varying the relative position of the first lens group G1 and the first prism P1, the lens can be used to image objects at varying distances, with a minimum focusing distance of 6 cm. The following describes the relevant parameters of the lens module 40 shown in FIG5 , in conjunction with Tables 2A and 2B.

[0207] Table 2A Basic parameters of lens module

[0208] As can be seen from Table 2A, using the lens module 40 shown in Figure 5, the system's total height is 8.22mm, the system's shoulder height is 4.3mm, and the system length is 13.0mm. These are all significantly reduced compared to the 45° prism solution, thereby reducing the size of the lens module. Furthermore, using the lens module 40 shown in Figure 2, the minimum focusing distance can reach 60mm, providing excellent macro effects.

[0209] Table 2B Lens module moving parts parameters at different object distances

[0210] As can be seen from Table 2B, at an object distance of infinite, the distance between the second surface S1-2 of the second lens L2 of the first lens group G1 and the first surface S1-1 of the first prism P1 is 0.403 mm. This second surface S1-2 is the surface of the second lens L2 closest to the first prism P1. When the lens module 40 is adjusted from an object distance of infinite to an object distance of 200 mm, the first lens group G1 moves away from the first prism P1 (i.e., toward the object side). At an object distance of 60 mm, the distance between the second surface S1-2 of the second lens L2 and the first surface S1-1 of the first prism P1 is 0.896 mm.

[0211] Figures 6 and 7 show the modulation transfer function MTF of the lens module 40 of Figure 5 at infinite object distance and at an object distance of 60mm. Among them, Figure 6 is the defocus MTF curve of this embodiment when the spatial frequency is 125lp / mm at infinite object distance. It can be seen from Figure 6 that the modulation transfer function (MTF) under different fields of view at infinite object distance is greater than 0.45 in the sagittal direction and the meridional direction. This result shows that the lens module 40 of Figure 5 can achieve high-quality imaging at infinite object distance. Figure 7 is the defocus MTF curve of this embodiment when the spatial frequency is 89lp / mm at an object distance of 60mm. It can be seen from Figure 7 that the modulation transfer function (MTF) under different fields of view at 60mm macro is greater than 0.5 in the sagittal direction and the meridional direction. This result shows that the lens module 40 of Figure 5 can achieve high-quality macro imaging.

[0212] Figure 8 is a structural schematic diagram of another example of a lens module 40 provided in an embodiment of the present application, wherein (a) in Figure 8 shows the state of the lens module 40 when shooting a distant object, and (b) in Figure 8 shows the state of the lens module when shooting a close object.

[0213] It should be noted that the lens module shown in Figure 8 has a similar structure to the lens module shown in Figure 2 , with the primary difference between the two being the number of lenses included in the first lens group G1 and the number of lenses included in the second lens group G2. Therefore, for other related descriptions of the first lens group G1, the second lens group G2, the first prism P1, and the second prism P2, refer to the relevant description in Figure 2 and will not be repeated here. The following will focus on the differences.

[0214] As shown in FIG8 , the lens module 40 may include, along the optical axis from the object side to the image side, a first lens group G1, a first prism P1, a second lens group G2, a second prism P2, a third lens group G3, an infrared filter 42, and an image sensor 43. It should be understood that the first lens group G1, the first prism P1, the second lens group G2, the second prism P2, and the third lens group G3 may constitute an optical lens, and the image sensor 43 is located on the image side of the optical lens.

[0215] The first lens group G1 may include a first lens L1, the second lens group G2 may include a second lens L2, and the third lens group G3 may include a third lens L3. Furthermore, the first lens L1 has positive refractive power, and is used to receive and converge light; the second lens L2 has negative refractive power; and the third lens L3 may have either positive or negative refractive power, and may be used to correct aberrations and improve image quality.

[0216] It should be understood that the entire optical lens has positive refractive power, that is, it has a converging effect on light beams. In other words, the entire lens formed by the first lens group G1, the second lens group G2 and the third lens group G3 has positive refractive power.

[0217] In the lens module 40 shown in FIG8 , the aperture stop STO can be disposed on the object side of the first lens group G1. In other embodiments, the aperture stop STO can be disposed between the first lens group G1 and the first prism P1, or between the first prism P1 and the second lens group G2, or between the second lens group G2 and the second prism P2, or between the second prism P2 and the third lens group G3, and this application does not limit this.

[0218] The following presents a possible design of the lens module 40 shown in FIG8 in combination with parameter data and simulation results.

[0219] For example, as shown in FIG8 , the lens module 40 includes a first lens group G1, a first prism P1, a second lens group G2, a second prism P2, a third lens group G3, an infrared filter 42, and an image sensor 43, arranged in order from the object side to the image side. The first lens group G1 includes a first lens L1, the second lens group G2 includes a second lens L2, and the third lens group G3 includes a third lens L3. The refractive index n1 of the first prism P1 is 1.67, and the first angle θ1 between its first surface S1-1 and the second surface S1-2 is 25°. The refractive index n2 of the second prism P2 is 1.67, and the angle θ2 between its fifth surface S2-2 and the sixth surface S2-3 is 25°.

[0220] The first lens group G1 can be enclosed by a mechanical actuator (e.g., a motor). By varying the relative position of the first lens group G1 and the first prism P1, the lens can be used to image objects at varying distances, with a minimum focusing distance of 20 cm. The following describes the relevant parameters of the lens module 40 shown in FIG8 , in conjunction with Tables 3A and 3B.

[0221] Table 3A Basic parameters of lens module

[0222] As can be seen from Table 3A, using the lens module 40 shown in Figure 8, the system's total height is 9.39mm, the system's shoulder height is 6.3mm, and the system length is 14.1mm. These are all significantly reduced compared to the 45° prism solution, thereby reducing the size of the lens module. Furthermore, using the lens module 40 shown in Figure 8, the minimum focusing distance can reach 200mm, providing excellent macro effects.

[0223] Table 3B Lens module moving parts parameters at different object distances

[0224] As can be seen from Table 4B, at an object distance of infinite, the distance between the second surface S1-2 of first lens L1 of first lens group G1 and the first surface S1-1 of first prism P1 is 0.35 mm. Second surface S1-2 is the surface of first lens L1 closest to first prism P1. When lens module 40 is adjusted from an object distance of infinite to an object distance of 200 mm, first lens L1 moves away from first prism P1 (i.e., toward the object side). At an object distance of 200 mm, the distance between second surface S1-2 of first lens L1 and first surface S1-1 of first prism P1 is 0.895 mm.

[0225] Figures 9 and 10 show the modulation transfer function MTF of the lens module 40 of Figure 8 at infinite object distance and at an object distance of 200mm. Among them, Figure 9 is the defocus MTF curve of this embodiment when the spatial frequency is 125lp / mm at infinite object distance. It can be seen from Figure 9 that the modulation transfer function (MTF) under different fields of view at infinite object distance is greater than 0.6 in the sagittal direction and the meridional direction. This result shows that the lens module 40 of Figure 8 can achieve high-quality imaging at infinite object distance. Figure 10 is the defocus MTF curve of this embodiment when the spatial frequency is 89lp / mm at an object distance of 200mm. It can be seen from Figure 10 that the modulation transfer function (MTF) under different fields of view at 200mm macro is greater than 0.6 in the sagittal direction and the meridional direction. This result shows that the lens module 40 of Figure 8 can achieve high-quality macro imaging.

[0226] Figure 11 is a structural schematic diagram of another example of a lens module 40 provided in an embodiment of the present application, wherein (a) in Figure 11 is the state of the lens module 40 when shooting a distant object, and (b) in Figure 11 is the state of the lens module when shooting a close object.

[0227] It should be noted that the lens module shown in Figure 11 has a similar structure to the lens module shown in Figure 2 . Therefore, other related descriptions of the first lens group G1, the second lens group G2, the first prism P1, and the second prism P2 can be referred to in the relevant description in Figure 2 , and will not be repeated here. The following mainly describes the differences.

[0228] The lens module 40 may include a first lens group G1, a first prism P1, a second lens group G2, a second prism P2, and an image sensor 43 along the optical axis from the object side to the image side. It should be understood that the first lens group G1, the first prism P1, the second lens group G2, and the second prism P2 may constitute an optical lens, and the image sensor 43 is located on the image side of the optical lens.

[0229] Exemplarily, the first lens group G1 may include at least one variable lens. During the focusing process of the optical lens switching from a distant view to a near view, the optical power of the variable lens in the first lens group G1 increases.

[0230] Exemplarily, the second lens group G2 may also include at least one variable lens, and the variable lens in the second lens group G2 is used to correct the additional aberration caused by the variable lens in the first lens group G1.

[0231] In some embodiments, as shown in Figure 11, the first lens group G1 may include a first variable lens LF1, a second lens L2, and a third lens L3, and the second lens group G2 may include a fourth variable lens LF4, a fifth lens L5, and a sixth lens L6. It should be understood that a variable lens refers to a lens whose surface shape can be changed by electrical, acoustic, or magnetic means.

[0232] The first variable lens LF1 in the first lens group G1 and the fourth variable lens LF4 in the second lens group G2 can change their surface shape and thickness under electrical, acoustic or magnetic drive, so as to image objects at different object distances.

[0233] It should be noted that in the structure shown in Figure 11, the lens module 40 achieves focusing by adjusting the optical power, curvature radius, refractive index, etc. of the variable lens. In other embodiments, the lens module 40 may achieve focusing by moving the first lens group G1.

[0234] The following presents a possible design approach for the lens module 40 shown in FIG11 in combination with parameter data and simulation results.

[0235] For example, as shown in FIG11 , the lens module 40 includes a first lens group G1, a first prism P1, a second lens group G2, a second prism P2, and an image sensor 43, arranged sequentially from the object side to the image side. The first lens group G1 may include a first variable lens LF1, a second lens L2, and a third lens L3, and the second lens group G2 may include a fourth variable lens LF4, a fifth lens L5, and a sixth lens L6. The refractive index n1 of the first prism P1 is 1.75, and the first angle θ1 between its first surface S1-1 and the second surface S1-2 is 25°. The refractive index n2 of the second prism P2 is 1.73, and the angle θ2 between its fifth surface S2-2 and the sixth surface S2-3 is 25°.

[0236] The first variable lens LF1 in the first lens group G1 and the fourth variable lens LF4 in the second lens group G2 can change their surface shape and thickness under electrical, acoustic, or magnetic actuation, enabling imaging of objects at varying distances. Their minimum focusing distance is 20 cm. The following describes the relevant parameters of the lens module 40 shown in Figure 11, in conjunction with Table 4A.

[0237] Table 4A Basic parameters of lens module

[0238] As can be seen from Table 4A, using the lens module 40 shown in Figure 11, the system's total height is 10.59mm, the system's shoulder height is 6.69mm, and the system length is 25.05mm. These are all significantly reduced compared to the 45° prism solution, thereby reducing the size of the lens module. Furthermore, using the lens module 40 shown in Figure 11, the minimum focusing distance can reach 200mm, providing excellent macro effects.

[0239] In the embodiment of the present application, all even-order aspheric surface types z can be defined using, but not limited to, the following aspheric curve equations:

[0240] Wherein, z is the relative distance between a point on the aspheric surface that is r away from the optical axis and the tangent plane of the intersection point on the aspheric surface optical axis; r is the vertical distance between a point on the aspheric curve and the optical axis; c is the curvature; k is the cone coefficient; and is the i-th order aspheric coefficient. Table 4B and Table 4C show the cone constant k and aspheric coefficient corresponding to the surface of the variable lens in Table 1, where A4, A6, A8, ..., A 30 They represent the 4th, 6th, 8th, ..., and 30th order aspheric coefficients respectively.

[0241] Table 4B Lens module moving parts parameters at different object distances

[0242] As can be seen from Table 4B, when the lens module 40 is adjusted from an object distance of infinity to an object distance of 200 mm, the first lens group G1 and the second lens group G2 do not move, but the curvature radius of the first variable lens LF1 in the first lens group G1 and the fourth variable lens LF4 in the second lens group G2 can change, and the optical focal length changes, thereby achieving focusing.

[0243] Table 4C Aspheric coefficients of variable lenses

[0244] Figures 12 and 13 show the modulation transfer function MTF of the lens module 40 of Figure 11 at infinite object distance and 200mm object distance. Among them, Figure 12 is the defocus MTF curve of this embodiment when the spatial frequency is 125lp / mm at infinite object distance. It can be seen from Figure 12 that the modulation transfer function (MTF) under different fields of view at infinite object distance is greater than 0.4 in the sagittal direction and the meridional direction. This result shows that the lens module 40 of Figure 11 can achieve high-quality imaging at infinite object distance. Figure 13 is the defocus MTF curve of this embodiment when the spatial frequency is 89lp / mm at 200mm object distance. It can be seen from Figure 13 that the modulation transfer function (MTF) under different fields of view at 200mm macro is greater than 0.5 in the sagittal direction and the meridional direction. This result shows that the lens module 40 of Figure 11 can achieve high-quality macro imaging.

[0245] Figure 14 is a structural schematic diagram of a lens module 40 provided in an embodiment of the present application, wherein (a) in Figure 14 shows the state of the lens module 40 when shooting a distant object, and (b) in Figure 14 shows the state of the lens module when shooting a close object.

[0246] The lens module 40 may include a first lens group G1, a first prism P1, a second prism P2, and an image sensor 43 along the optical axis from the object side to the image side. It should be understood that the first lens group G1, the first prism P1, and the second prism P2 may constitute an optical lens, and the image sensor 43 is located on the image side of the optical lens.

[0247] The first mirror group G1 includes at least one optical lens, and the first mirror group G1 has positive optical power and is used to receive and converge the light beam. It should be understood that the first mirror group G1 is capable of focusing and imaging objects at different object distances. The first mirror group G1 is a movable mirror group, that is, the first mirror group G1 is capable of moving at least one optical lens in the first mirror group G1 under the drive of a motor or other driving element. For example, the first mirror group G1 may be surrounded by a mechanical moving element (such as a motor), which can change the relative position of the first mirror group G1 and the first prism P1 to image objects at different object distances.

[0248] For example, as shown in (a) and (b) of Figure 14, during the focusing process of the lens module 40 switching from a distant view to a close view, the first lens group G1 can move along the optical axis toward the object side, that is, the first lens group G1 can move along the optical axis in a direction away from the first prism P1.

[0249] In some embodiments, as shown in FIG14 , the first lens group G1 may include a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4. During the focusing process of the lens module 40 switching from a telephoto view to a close-up view, the first lens L1, the second lens L2, the third lens L3, and the fourth lens L4 can be driven by a motor or other driving element to move along the optical axis toward the object side to achieve focusing.

[0250] In some other embodiments, the first lens group G1 includes at least one variable lens. During the focusing process of the optical lens from a distant view to a near view, the optical power of the variable lens in the first lens group G1 increases. It should be understood that a variable lens is a lens whose surface shape can be changed by electrical, acoustic, or magnetic means.

[0251] The first prism P1 is located on the image side of the first mirror group G1. The first prism P1 may include at least three characteristic surfaces. For example, the first prism P1 includes a first surface S1-1, a second surface S1-2, and a third surface S1-3. A light beam can enter the first prism P1 from the first surface S1-1 and exit the first prism P1 from the third surface S1-3. The first surface S1-1 is an incident surface (which may be referred to as a first incident surface) and is also a transmission and total internal reflection (TIR) ​​surface. It transmits light received from the first mirror group G1 and reflects light received from the second surface S1-2 of the prism to the third surface S1-3 through TIR. The second surface S1-2 is a reflective surface (which may be referred to as a first reflective surface) and is also a reflective surface coated with a mirror coating. It reflects light received through the first surface S1-1 back to the first surface S1-1 in the prism. The third surface S1-3 is an exit surface (which may be referred to as a first exit surface) and is also a transmission surface that transmits light received from the first surface S1-1. In short, the light beam enters the first prism P1 from the first surface S1-1, is reflected by the second surface S1-2 to the first surface S1-1, and undergoes total internal reflection on the first surface S1-1. The reflected light finally passes through the third surface S1-3 and exits the first prism P1.

[0252] It should be understood that the first angle θ1 between the first surface S1-1 and the second surface S1-2 (i.e., the first incident surface S1-1 and the first reflective surface S1-2) is less than 45° (e.g., θ1 is 25°). Exemplarily, the range of θ1 can be: 0°<θ1<10°, 10°≤θ1<20°, 20°≤θ1<25°, 25°≤θ1<30°, 30°≤θ1<35°, 35°≤θ1<40°, 40°≤θ1<45°. Exemplarily, the range of θ1 can be: 22°<θ1<28°.

[0253] It should be noted that the value of the first angle θ1 is related to the refractive index of the first prism P1. In order to satisfy total reflection, the first angle θ1 and the refractive index n1 of the first prism P1 can satisfy the following relationship: n1 ≥ 1 / sin(2*θ1). In a conventional folding lens system, the angle between the first surface of the first prism and the second surface of the first prism is usually 45°. The present application sets the angle between the first surface S1-1 and the second surface S1-2 of the first prism P1 to be less than 45°, that is, reducing the angle between the first surface S1-1 and the second surface S1-2 of the first prism P1, thereby helping to reduce the height of the lens module in the Z direction (that is, the thickness direction of the electronic device), thereby helping to reduce the size of the lens module 40.

[0254] The second prism P2 is located on the image side of the first prism P1. The second prism P2 may include at least three characteristic surfaces. For example, the second prism P2 includes a fourth surface S2-1, a fifth surface S2-2, and a sixth surface S2-3. The fourth surface S2-1 is an incident surface (which may be referred to as a second incident surface) and is also a transmissive surface, which transmits the light received from the first prism P1 to the fifth surface S2-2 in the prism. The fifth surface S2-2 is an exit surface (which may be referred to as a second exit surface) and is also a transmissive and TIR surface, which reflects the light received through the fourth surface S2-1 to the sixth surface S2-3 in the prism by TIR, and transmits the light received from the sixth surface S2-3 in the prism to form an image in the image sensor 43. The sixth surface S2-3 is a reflective surface coated with a mirror coating (which may be referred to as a second reflective surface), which reflects the light received from the fifth surface S2-2 back to the fifth surface S2-2. In short, the light beam enters the second prism P2 from the fourth surface S2-1, is then totally reflected by the fifth surface S2-2, is then reflected by the sixth surface S2-3 to the fifth surface S2-2, and finally exits the second prism P2 from the fifth surface S2-2.

[0255] It should be understood that the second angle θ2 between the fifth surface S2-2 and the sixth surface S2-3 (i.e., the second exit surface S2-2 and the second reflection surface S2-3) is less than 45°, for example, θ2 is 25°, and the second angle θ2 is equal to the first angle θ1. Exemplarily, the range of θ2 can be: 0°<θ2<10°, 10°≤θ2<20°, 20°≤θ2<25°, 25°≤θ2<30°, 30°≤θ2<35°, 35°≤θ2<40°, 40°≤θ2<45°. Exemplarily, the range of θ2 can be: 22°<θ3<28°.

[0256] It should be noted that the value of the second angle θ2 is related to the refractive index of the second prism P2. To achieve total internal reflection, the second angle θ2 and the refractive index n2 of the second prism P2 can satisfy the following relationship: n2 ≥ 1 / sin(2*θ2). The present application sets the angle between the fifth surface S2-2 and the sixth surface S2-3 of the second prism P2 to be less than 45°, which helps to reduce the height of the lens module in the Z direction (i.e., the thickness direction of the electronic device), thereby helping to reduce the size of the lens module 40.

[0257] In the lens module 40 shown in FIG14 , the optical axis can be folded four times by providing the first prism P1 and the second prism P2. The second surface S1-2 of the first prism P1 folds the optical axis once; then, the first surface S1-1 of the first prism P1 folds the optical axis a second time; then, the fifth surface S2-2 of the second prism P2 folds the optical axis again; and then, the sixth surface S2-3 of the second prism P2 folds the optical axis a fourth time. By providing a longer and more complex optical path, the present application can better correct aberrations.

[0258] It should be understood that the optical axis of the fourth surface S2-1 of the second prism P2 coincides with the optical axis of the third surface S1-3 of the first prism P1. In other words, the present application adopts a coaxial system. By using a coaxial system, the optical lens does not produce off-axis aberrations compared to an off-axis system. The prisms and lenses in the coaxial system can all adopt a centrally symmetrical structure, which is easy to manufacture and has strong feasibility. In addition, compared to an off-axis system, the prisms and lenses in the coaxial system are easier to find the center point, which facilitates the assembly of the lenses and prisms in the optical lens.

[0259] In some embodiments, as shown in FIG14 , the first surface S1-1 and the second surface S1-2 of the first prism P1 are both planes, and the third surface S1-3 is a surface having optical power; the fifth surface S2-2 and the sixth surface S2-3 of the second prism P2 are both planes, and the fourth surface S2-1 is a surface having optical power. In other embodiments, the first surface S1-1 of the first prism P1 is a plane, and the second surface S1-2 and the third surface S1-3 of the first prism P1 may also be surfaces having optical power; the fifth surface S2-2 of the second prism P2 is a plane, and the fourth surface S2-1 and the sixth surface S2-3 are both surfaces having optical power.

[0260] Exemplarily, in order to form a surface with optical power in the first prism P1, a lens may be fixedly connected to the first exit surface (ie, the third plane S1-3) of the first prism P1 through a gluing process to form a surface with optical power.

[0261] Exemplarily, in order to form a surface with optical power in the second prism P2, a lens may be fixedly connected to the second incident surface (ie, the fourth surface S2-1) of the second prism P2 through a gluing process to form a surface with optical power.

[0262] In other embodiments, the first prism P1 and / or the second prism P2 can be a special-shaped prism formed by integral processing. That is, when manufacturing the first prism P1 and the second prism P2, one surface of the first prism P1 (i.e., the third surface S1-3) can be set as a surface with optical focal length, and one surface of the second prism P2 (i.e., the fourth surface S2-1) can be set as a surface with optical focal length.

[0263] It should be noted that the optical power of the third surface S1-3 of the first prism P1 is opposite to the optical power of the fourth surface S2-1 of the second prism P2, and the absolute value of the optical power of the third surface S1-3 of the first prism P1 is different from the absolute value of the optical power of the fourth surface S2-1 of the second prism P2. The first prism P1 and the second prism P2 have a negative optical power. It is understood that the first prism P1 and the second prism P2 cannot be spliced ​​together to form a parallelogram prism.

[0264] For example, the third surface S1-3 of the first prism P1 has positive optical power, the fourth surface S2-1 of the second prism P2 has negative optical power, and the absolute value of the optical power of the third surface S1-3 of the first prism P1 is different from the absolute value of the optical power of the fourth surface S2-1 of the second prism P2. For another example, the third surface S1-3 of the first prism P1 has negative optical power, the fourth surface S2-1 of the second prism P2 has positive optical power, and the absolute value of the optical power of the third surface S1-3 of the first prism P1 is different from the absolute value of the optical power of the fourth surface S2-1 of the second prism P2. It should be understood that by setting the third surface S1-3 of the first prism P1 and the fourth surface S2-1 of the second prism P2 as surfaces with optical power, the lens module 40 has good macro performance and can achieve an optical magnification of 0.1 times or more and a macro focusing distance of less than 20 cm.

[0265] In the lens module 40 shown in FIG14 , the first lens group G1 has positive optical power, the first prism P1 has positive optical power, the second prism P2 has negative optical power, and the absolute value of the optical power of the first prism P1 is smaller than the absolute value of the optical power of the second prism P2. In other embodiments, the first lens group G1 has positive optical power, the first prism P1 has negative optical power, the second prism P2 has positive optical power, and the absolute value of the optical power of the first prism P1 is larger than the absolute value of the optical power of the second prism P2.

[0266] Optionally, the optical lens may further include a third lens group, which may include at least one optical lens. The third lens group is located on the image side of the second prism P2, specifically between the second prism P2 and the image sensor 43. The third lens group can be used to correct aberrations and improve imaging quality.

[0267] It should be understood that the entire optical lens has positive optical power, meaning it has a converging effect on light beams. In other words, when a third lens group is included, the entire structure formed by the first lens group, the first prism, the second prism, and the third lens group has positive optical power. The third lens group can have positive or negative optical power, which is not limited in this application.

[0268] Optionally, the optical lens may further include an infrared filter 42, which is located on the image side of the second prism P2, specifically between the second prism P2 and the image sensor 43. More specifically, the infrared filter 42 is located between the fifth surface S2-2 of the second prism P2 and the image sensor 43. The infrared filter 42 can be used to filter out unnecessary light signals. In some other embodiments, the optical lens may not be provided with a separate infrared filter. For example, an infrared cutoff film layer may be provided on the light-emitting surface of the fifth surface S2-2 of the second prism P2 to filter out unnecessary light signals. Alternatively, an absorbent material may be added to the light-emitting surface of the fifth surface S2-2 of the second prism P2 to filter out unnecessary light signals.

[0269] Optionally, the optical lens may further include an aperture stop STO. As shown in FIG14 , the aperture stop STO may be disposed on the object side of the first lens group G1. In other embodiments, the aperture stop STO may also be located between the first lens group G1 and the first prism P1. Specifically, the aperture stop STO may be disposed between the fourth lens L4 and the first surface S1-1 of the first prism P1. Alternatively, the aperture stop STO may also be located between the first prism P1 and the second prism P2. Specifically, the aperture stop STO may be disposed between the third surface S1-3 of the first prism P1 and the fourth surface S2-1 of the second prism P2. This is not limited in this application. It should be understood that the aperture stop STO can be used to adjust the aperture, filter out stray light, and improve the imaging quality of the lens module 40.

[0270] The aperture stop STO may be a spacer ring structure or a variable fan blade structure; alternatively, the aperture stop STO may be implemented through a surface spraying process, for example, by spraying a light-shielding material onto a lens to form the aperture stop STO. The position of the aperture stop STO may be fixed or variable. For example, the position of the aperture stop STO may be variable, and the aperture stop STO may be adjusted according to the focusing condition so as to be positioned between different lenses.

[0271] The following presents a possible design of the lens module 40 shown in FIG. 14 in combination with parameter data and simulation results.

[0272] As shown in Figure 14, the lens module 40 includes a first lens group G1, a first prism P1, a second prism P2, an infrared filter 42, and an image sensor 43, arranged in order from the object side to the image side. The first lens group G1 includes a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4. The refractive index n1 of the first prism P1 is 1.62, and the first angle θ1 between its first surface S1-1 and the second surface S1-2 is 25°. The refractive index n2 of the second prism P2 is 1.54, and the angle θ2 between its fifth surface S2-2 and the sixth surface S2-3 is 25°.

[0273] The first lens group G1 can be enclosed by a mechanical actuator (e.g., a motor). By varying the relative position of the first lens group G1 and the first prism P1, the lens can be used to image objects at varying distances, with a minimum focusing distance of 20 cm. The following describes the relevant parameters of the lens module 40 shown in FIG14 , in conjunction with Tables 5A and 5B.

[0274] Table 5A Basic parameters of lens module

[0275] As shown in Table 5A, using the lens module 40 shown in Figure 14, the system's total height is 7.04mm, the system's shoulder height is 3.53mm, and the system length is 13.1mm. These are all significantly reduced compared to the 45° prism solution, thereby reducing the size of the lens module. Furthermore, using the lens module 40 shown in Figure 14, the minimum focusing distance can reach 200mm, providing excellent macro effects.

[0276] Table 5B Lens module moving parts parameters at different object distances

[0277] As can be seen from Table 5B, at an object distance of infinite, the distance between the second surface S1-2 of the fourth lens L4 of the first lens group G1 and the first surface S1-1 of the first prism P1 is 0.513 mm. This second surface S1-2 is the surface of the fourth lens L4 closest to the first prism P1. When the lens module 40 is adjusted from an object distance of infinite to an object distance of 200 mm, the first lens group G1 moves away from the first prism P1 (i.e., toward the object side). At an object distance of 200 mm, the distance between the second surface S1-2 of the fourth lens L4 and the first surface S1-1 of the first prism P1 is 1.442 mm.

[0278] Figures 15 and 16 show the modulation transfer function MTF of the lens module 40 of Figure 14 at infinite object distance and 200mm object distance. Among them, Figure 15 is the defocus MTF curve of this embodiment when the spatial frequency is 125lp / mm at infinite object distance. It can be seen from Figure 15 that the modulation transfer function (MTF) under different fields of view at infinite object distance is greater than 0.55 in the sagittal direction and the meridional direction. This result shows that the lens module 40 of Figure 14 can achieve high-quality imaging at infinite object distance. Figure 16 is the defocus MTF curve of this embodiment when the spatial frequency is 89lp / mm at 200mm object distance. It can be seen from Figure 16 that the modulation transfer function (MTF) under different fields of view at 200mm macro is greater than 0.65 in the sagittal direction and the meridional direction. This result shows that the lens module 40 of Figure 14 can achieve high-quality macro imaging.

[0279] Figure 17 is a structural schematic diagram of another example of a lens module 40 provided in an embodiment of the present application, wherein (a) in Figure 17 is the state of the lens module 40 when shooting a distant object, and (b) in Figure 17 is the state of the lens module when shooting a close object.

[0280] It should be noted that the lens module shown in Figure 17 is similar in structure to the lens module shown in Figure 14 , with the primary difference between the two being the placement of image sensor 43. Therefore, the description of the first lens group G1, second lens group G2, first prism P1, and second prism P2 can be found in Figure 14 , and will not be repeated here. The following will focus on the differences.

[0281] As shown in Figure 17, the lens module 40 includes a first lens group G1, a first prism P1, a second prism P2, and an image sensor 43 along the optical axis from the object side to the image side. It should be understood that the first lens group G1, the first prism P1, and the second prism P2 can form an optical lens, and the image sensor 43 is located on the image side of the optical lens. The image sensor 43 is arranged parallel to the sixth surface S2-3 (i.e., the second reflective surface S2-3) of the second prism P2.

[0282] It should be understood that the optical path change that occurs in the first prism P1 is the same as that of the lens module shown in Figure 14, and the optical path change that occurs in the second prism P2 is different from that of the lens module shown in Figure 14. Specifically, in the lens module 40 shown in Figure 17, the optical axis can be folded three times by setting the first prism P1 and the second prism P2. The second surface S1-2 of the first prism P1 folds the optical axis once; then, the first surface S1-1 of the first prism P1 folds the optical axis again; then, the fifth surface S2-2 of the second prism P2 folds the optical axis for the third time. The present application can better correct aberrations by setting a longer and more complex optical path.

[0283] It should be noted that in the specific module 40 shown in Figure 17, the image sensor 43 can be set at an angle. Specifically, the image sensor 43 can be set parallel to the sixth surface S2-3 of the second prism P2 (i.e., the second reflective surface S2-3). The light beam can form an image in the image sensor 43, thereby reducing the total system height of the electronic device to a certain extent, and at the same time further reducing the Z-direction (i.e., the thickness direction of the electronic device) size, thereby further reducing the size of the lens module 40.

[0284] The following presents a possible design of the lens module 40 shown in FIG17 in combination with parameter data and simulation results.

[0285] As shown in FIG17 , the lens module 40 includes a first lens group G1, a first prism P1, a second prism P2, and an image sensor 43, arranged in order from the object side to the image side. The first lens group G1 includes a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4. The refractive index n1 of the first prism P1 is 1.62, and the first angle θ1 between its first surface S1-1 and second surface S1-2 is 25°. The refractive index n2 of the second prism P2 is 1.54, and the angle θ2 between its fifth surface S2-2 and sixth surface S2-3 is 25°.

[0286] The first lens group G1 can be enclosed by a mechanical actuator (e.g., a motor). By varying the relative position of the first lens group G1 and the first prism P1, the lens can be used to image objects at varying distances, with a minimum focusing distance of 20 cm. The following describes the relevant parameters of the lens module 40 shown in FIG. 17 , in conjunction with Tables 6A and 6B.

[0287] Table 6A Basic parameters of lens module

[0288] It should be noted that when the image sensor 43 is tilted, the "system total height" in Table 6A is the vertical distance between the first surface of the first lens (i.e., L1) and the fifth surface S2-2 of the second prism P2, the "system shoulder height" is the maximum vertical distance between the fifth surface S2-2 of the second prism P2 and the image sensor 43, and the "system length" is the longest distance of the lens module 40 along the length direction of the electronic device, that is, the vertical distance between the top of the first lens L1 and the bottom of the image sensor 43.

[0289] As shown in Table 6A, using the lens module 40 shown in Figure 17, the system's total height is 6.27mm, the system's shoulder height is 4.57mm, and the system length is 15.7mm. These are all significantly reduced compared to the 45° prism solution, thereby reducing the size of the lens module. Furthermore, using the lens module 40 shown in Figure 17, the minimum focusing distance can reach 200mm, providing excellent macro effects.

[0290] Table 6B Lens module moving parts parameters at different object distances

[0291] As can be seen from Table 6B, at an object distance of infinite, the distance between the second surface S1-2 of the fourth lens L4 of the first lens group G1 and the first surface S1-1 of the first prism P1 is 0.513 mm. This second surface S1-2 is the surface of the fourth lens L4 closest to the first prism P1. When the lens module 40 is adjusted from an object distance of infinite to an object distance of 200 mm, the first lens group G1 moves away from the first prism P1 (i.e., toward the object side). At an object distance of 200 mm, the distance between the second surface S1-2 of the fourth lens L4 and the first surface S1-1 of the first prism P1 is 1.442 mm.

[0292] Figure 18 is a structural schematic diagram of another example of a lens module 40 provided in an embodiment of the present application, wherein (a) in Figure 18 is the state of the lens module 40 when shooting a distant object, and (b) in Figure 18 is the state of the lens module when shooting a close object.

[0293] The lens module 40 may include a first lens group G1, a first prism P1, a second lens group G2, a third prism P3, and an image sensor 43 along the optical axis from the object side to the image side. It should be understood that the first lens group G1, the first prism P1, the second lens group G2, and the third prism P3 may constitute an optical lens, with the image sensor 43 located on the image side of the optical lens. The first lens group G1 includes at least one optical lens having positive optical power for receiving and converging light beams. For example, the first lens group G1 may include a first lens L1 and a second lens L2. The second lens group G2 includes at least one optical lens having negative optical power. For example, the second lens group G2 may include a third lens L3, a fourth lens L4, and a fifth lens L5.

[0294] The first lens group G1 is capable of focusing and imaging objects at different object distances. It is a movable lens group. That is, the first lens group G1 can be driven by a motor or other driving element to move the entire first lens group G1 or at least one optical lens within the first lens group G1. For example, the first lens group G1 can be enclosed by a mechanical actuator (such as a motor) that can change the relative position of the first lens group G1 and the first prism P1 to image objects at different object distances.

[0295] For example, as shown in (a) and (b) of Figure 18, during the focusing process of the lens module 40 switching from a distant view to a close view, the first lens L1 and the second lens L2 can be driven by a driving element such as a motor to move along the optical axis toward the object side to achieve focusing.

[0296] The first prism P1 is located on the image side of the first mirror group G1. The first prism P1 may include at least three characteristic surfaces. For example, the first prism P1 includes a first surface S1-1, a second surface S1-2, and a third surface S1-3. A light beam can enter the first prism P1 from the first surface S1-1 and exit the first prism P1 from the third surface S1-3. The first surface S1-1 is an incident surface (which may be referred to as a first incident surface), a transmissive surface, and a total internal reflection (TIR) ​​surface. It transmits light received from the first mirror group G1 and totally reflects light received from the second surface S1-2 to the third surface S1-3 through TIR. The second surface S1-2 is a reflective surface (which may be referred to as a first reflective surface), and is also a reflective surface coated with a mirror coating. It reflects light received through the first surface S1-1 back to the first surface S1-1 in the prism. The third surface S1-3 is an exit surface (which may be referred to as a first exit surface), and is also a transmissive surface that transmits light received from the first surface S1-1. In short, a light beam enters the first prism P1 from the first surface S1-1, is reflected by the second surface S1-2 back to the first surface S1-1, undergoes total internal reflection there, and finally exits the first prism P1 through the third surface S1-3. In other words, the first prism P1 can be configured to fold the optical axis of the optical system twice.

[0297] It should be understood that the first angle θ1 between the first surface S1-1 and the second surface S1-2 (i.e., the first incident surface and the first reflective surface) is less than 45° (e.g., θ1 is 25°). Exemplarily, the range of θ1 may be: 0°<θ1<10°, 10°≤θ1<20°, 20°≤θ1<25°, 25°≤θ1<30°, 30°≤θ1<35°, 35°≤θ1<40°, and 40°≤θ1<45°. Exemplarily, the range of θ1 may be: 22°<θ1<28°.

[0298] It should be noted that the value of the first angle θ1 is related to the refractive index of the first prism P1. In order to satisfy total reflection, the first angle θ1 and the refractive index n1 of the first prism P1 can satisfy the following relationship: n1 ≥ 1 / sin(2*θ1). In a conventional folding lens system, the angle between the first surface of the first prism and the second surface of the first prism is usually 45°. The present application sets the angle between the first surface S1-1 and the second surface S1-2 of the first prism P1 to be less than 45°, that is, reducing the angle between the first surface S1-1 and the second surface S1-2 of the first prism P1, thereby helping to reduce the height of the lens module in the Z direction (that is, the thickness direction of the electronic device), thereby helping to reduce the size of the lens module 40.

[0299] The third prism P3 is located on the image side of the first prism P1 or the second lens group G2. The third prism P3 may include at least three characteristic surfaces. For example, the third prism P3 includes a seventh surface S3-1, an eighth surface S3-2, and a ninth surface S3-3. The seventh surface S3-1 is an incident surface (which may be referred to as a third incident surface) and is also a transmissive surface. It transmits the light received from the first prism P1 to the eighth surface S3-2 in the prism. The seventh surface S3-1 is also a total internal reflection (TIR) ​​surface. The light received from the ninth surface S3-3 is totally reflected to the eighth surface S3-2 through the TIR surface. The eighth surface S3-2 is an exit surface (which may be referred to as a third exit surface) and is also a total internal reflection surface. It totally reflects the light received from the seventh surface S3-1 to the ninth surface S3-3. The eighth surface S3-2 is also a transmissive surface. It can transmit the light from the seventh surface S3-1 to form an image in the image sensor 43. The ninth surface S3 - 3 is a reflective surface coated with a mirror coating (may be referred to as a third reflective surface), which reflects the light received from the eighth surface S3 - 2 back to the seventh surface S3 - 1 .

[0300] In short, the light beam enters the third prism P3 from the seventh surface S3-1 (i.e., the third incident surface), is then totally reflected by the eighth surface S3-2 (i.e., the third exit surface) to the ninth surface S3-3 (i.e., the third reflection surface), is then reflected by the ninth surface S3-3 (i.e., the third reflection surface) to the seventh surface S3-1 (i.e., the third incident surface), is then totally reflected by the seventh surface S3-1 (i.e., the third incident surface) to the eighth surface S3-2 (i.e., the third exit surface), and finally exits the third prism P3 from the eighth surface S3-2 (i.e., the third exit surface). In other words, the third prism P3 can be configured to fold the optical axis of the optical system three times.

[0301] It should be noted that the light is reflected three times in the third prism P3 (in the above-described embodiment, it is reflected once or twice), and the optical path is bent more times in the third prism P3, which improves space utilization and is more conducive to the design of a telephoto lens. In addition, as shown by the direction of the light arrows in Figure 18, the light incident on the third prism P3, when it undergoes the second reflection, that is, when it is reflected on the ninth surface S3-3 (i.e., the third reflective surface), turns upward. This can cause the optical axis of the light emitted from the third prism P3 to be raised, thereby further reducing the length of the optical system.

[0302] It should be understood that the included angle between the seventh surface S3-1 and the ninth surface S3-3 (i.e., the third incident surface and the third reflective surface) is equal to the included angle between the eighth surface S3-2 and the ninth surface S3-3 (i.e., the third exit surface and the third reflective surface). The included angle formed between the seventh surface S3-1 and the ninth surface S3-3 (i.e., the third incident surface and the third reflective surface) or between the eighth surface S3-2 and the ninth surface S3-3 (i.e., the third exit surface and the third reflective surface) is denoted as the third included angle θ3. The third included angle θ3 is twice the first included angle θ1, i.e., θ3=2θ1. The third included angle θ3 is less than 90° and greater than 40°.

[0303] It should be noted that the prism material of the first prism P1 and the third prism P3 preferably has a higher refractive index and a lower dispersion coefficient. Prisms with higher refractive indices are more likely to undergo total internal reflection. For example, the refractive index of the first prism P1 and the refractive index of the third prism P3 are both greater than 1.5, and the Abbe number is greater than 40.

[0304] It should be understood that by disposing the second lens group G2 between the first prism P1 and the third prism P3, the lens module 40 can have good macro performance, achieving an optical magnification of 0.1 times or more and a macro focusing distance of less than 20 cm.

[0305] It should be understood that the optical axis of the third surface S1-3 of the first prism P1 coincides with the optical axis of the second lens group G2, and the optical axis of the seventh surface S3-1 of the third prism P3 coincides with the optical axis of the second lens group G2. In other words, the present application employs a coaxial system. By using a coaxial system, the optical lens does not produce off-axis aberrations compared to an off-axis system. The prisms and lenses in the coaxial system can all adopt a centrally symmetrical structure, which is easy to manufacture and has high feasibility. In addition, compared to an off-axis system, the prisms and lenses in the coaxial system are easier to find the center point, which facilitates the assembly of the lenses and prisms in the optical lens.

[0306] In some embodiments, as shown in FIG18 , the first surface S1-1, the second surface S1-2, and the third surface S1-3 of the first prism P1 may all be planes, and the seventh surface S3-1, the eighth surface S3-2, and the ninth surface S3-3 of the third prism P3 may all be planes.

[0307] In some other embodiments, the first surface S1 - 1 of the first prism P1 is a plane, and the second surface S1 - 2 of the first prism P1 and / or the third plane S1 - 3 of the first prism P1 may be surfaces having optical power.

[0308] Illustratively, in order to form a surface with optical power of the first prism P1, the lenses in the second lens group G2 may be fixedly connected to the first exit surface (ie, the third plane S1-3) of the first prism P1 through a gluing process.

[0309] In the lens module 40 shown in Figure 18, the image sensor 43 is located on the image side of the optical lens and on the image side of the third prism P3. The image sensor 43 can be arranged parallel to the eighth surface S3-2 (i.e., the third exit surface) of the third prism P3, so that the third prism P3 can fold the light beam three times, and the first prism P1 and the third prism P3 can fold the light beam five times. The second surface S1-2 of the first prism P1 folds the light beam once; then, the first surface S1-1 of the first prism P1 folds the light beam a second time; then, the eighth surface S3-2 of the third prism P3 folds the light beam again; then, the ninth surface S3-3 of the third prism P3 folds the light beam a fourth time; then, the seventh surface S3-1 of the third prism P3 folds the light beam a fifth time, so that the light beam is finally incident on the image sensor 43. The present application can better correct aberrations by setting a longer and more complex optical path, and the space utilization rate is higher, which is more conducive to the design of a telephoto lens.

[0310] It should be understood that the entire optical lens has a positive optical power, that is, the absolute value of the optical power of the first lens group G1 is greater than the absolute value of the optical power of the second lens group G2.

[0311] In one example, L1 can have positive optical power, L2 can have negative optical power, and L1 and L2 as a whole (i.e., the first lens group G1) have positive optical power. In this example, by setting L1 to have positive optical power and L2 to have negative optical power, it is beneficial to control the aberrations of the light beam passing through the first lens group G1, making it easier to correct aberrations in the first lens group G1, and the optical lens has better imaging quality. In other examples, L1 can have positive optical power, and L2 can also have positive optical power, which is not limited in this application.

[0312] It should be understood that at least one of the three lenses in the second lens group G2 has positive power and at least one has negative power, and the specific power of L3, L4, and L5 is not limited. For example, L3 can have positive power, L4 can have negative power, and L5 can have negative power (or positive power), and the entire lens group formed by L3, L4, and L5 (i.e., the second lens group G2) has negative power.

[0313] Optionally, the optical lens may further include a third lens group, which may include at least one optical lens. The third lens group may be located on the image side of the third prism P3, specifically between the third prism P3 and the image sensor 43. The third lens group may be used to correct aberrations and improve imaging quality.

[0314] It should be understood that the entire optical lens has positive optical power, meaning it has a converging effect on light beams. In other words, when a third lens group is included, the entire first, second, and third lens groups have positive optical power. The third lens group can have positive or negative optical power, which is not limited in this application.

[0315] It should be noted that, in order to better correct aberrations, the more lenses provided in the optical lens, the better. However, due to the overall height of the optical lens system and the size limitations of the electronic device, the number of lenses included in the optical lens in the embodiments of the present application can range from 3 to 5. For example, the first lens group G1 can include 1 lens, and the second lens group G2 can include 4 lenses. For another example, the first lens group G1 can include 2 lenses, and the second lens group G2 can include 3 lenses. For another example, the first lens group G1 can include 1 lens, the second lens group G2 can include 1 lens, and the third lens group G3 can include 1 lens.

[0316] Optionally, the optical lens may further include an infrared filter 42, which is located on the image side of the third prism P3, specifically between the third prism P3 and the image sensor 43. More specifically, the infrared filter 42 is located between the eighth surface S3-2 of the third prism P3 and the image sensor 43. The infrared filter 42 can be used to filter out unnecessary light signals. In some other embodiments, the optical lens may not be provided with a separate infrared filter. For example, an infrared cutoff film layer may be provided on the light-emitting surface of the eighth surface S3-2 of the third prism P3 to filter out unnecessary light signals. Alternatively, an absorbent material may be added to the light-emitting surface of the eighth surface S3-2 of the third prism P3 to filter out unnecessary light signals.

[0317] Optionally, the optical lens may further include an aperture stop STO. As shown in FIG18 , the aperture stop STO may be located on the object side of the first lens group G1, thereby reducing the overall system height of the optical lens. In other embodiments, the aperture stop STO may also be disposed between the first lens group G1 and the first prism P1. In other embodiments, the aperture stop STO may also be located between the first prism P1 and the second lens group G2, or between the second lens group G2 and the third prism P3. It should be understood that the aperture stop STO may be used to adjust the aperture, filter out stray light, and improve the imaging quality of the lens module 40.

[0318] The aperture stop STO may be a spacer ring structure or a variable fan blade structure; alternatively, the aperture stop STO may be implemented through a surface spraying process, for example, by spraying a light-shielding material onto a lens to form the aperture stop STO. The position of the aperture stop STO may be fixed or variable. For example, the position of the aperture stop STO may be variable, and the aperture stop STO may be adjusted according to the focusing condition so as to be positioned between different lenses.

[0319] The following presents a possible design of the lens module 40 shown in FIG18 in combination with parameter data and simulation results.

[0320] For example, as shown in FIG18 , the lens module 40 includes a first lens group G1, a first prism P1, a second lens group G2, a third prism P3, and an image sensor 43, which are arranged in sequence from the object side to the image side. The first lens group G1 includes a first lens L1 and a second lens L2, and the second lens group includes a third lens L3, a fourth lens L4, and a fifth lens L5. The refractive index n1 of the first prism P1 can be 1.74, and the first angle θ1 between its first surface S1-1 and the second surface S1-2 can be 25°. The refractive index n2 of the third prism P3 can be 1.70, and the angle θ3 between its seventh surface S3-1 and the ninth surface S3-3, or between its eighth surface S3-2 and the ninth surface S3-3, can be 50°.

[0321] The first lens group G1 can be enclosed by a mechanical actuator (e.g., a motor). By varying the relative position of the first lens group G1 and the first prism P1, objects at varying distances can be imaged, with a minimum focusing distance of 100 cm. The following describes the relevant parameters of the lens module 40 shown in FIG18 , in conjunction with Table 7.

[0322] Table 7 Basic parameters of lens module

[0323] It should be noted that when the image sensor 43 is set vertically, the "system total height" in Table 7 is the vertical distance between the first surface of the first lens (i.e., L1) and the image sensor 43, the "system shoulder height" is the vertical distance between the first surface S1-1 of the first prism P1 and the image sensor 43, and the "system length" is the longest distance of the lens module 40 along the length direction of the electronic device, that is, the vertical distance between the top of the first lens L1 and the bottom of the image sensor 43.

[0324] It can be seen from Table 7 that the system length of the lens module 40 shown in Figure 18 is 12.7 mm. Compared with the solution of the above embodiment, the system length of the lens module 40 shown in Figure 18 is reduced to a certain extent, thereby reducing the volume of the lens module.

[0325] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. An optical lens, characterized in that: The lens comprises a first lens group, a first prism, a second lens group and a second prism, which are arranged in sequence from the object side to the image side. The first mirror group includes at least one lens, the first mirror group has positive optical power, and the first mirror group is used to receive light and converge the light; The first prism comprises a first incident surface, a first reflection surface and a first exit surface, a first angle between the first incident surface and the first reflection surface is less than 45°, and an optical axis of the first exit surface coincides with an optical axis of the second mirror group; The second lens group includes at least one lens, and the second lens group has negative optical power; The second prism includes a second incident surface, a second reflection surface and a second exit surface, a second angle between the second reflection surface and the second exit surface is less than 45°, and the second angle is equal to the first angle, and the optical axis of the second incident surface coincides with the optical axis of the second mirror group.

2. The optical lens according to claim 1, characterized in that: The first angle θ1 and the refractive index n1 of the first prism satisfy: n1≥1 / sin(2*θ1).

3. The optical lens according to claim 1 or 2, characterized in that: The second angle θ2 and the refractive index n2 of the second prism satisfy: n2≥1 / sin(2*θ2).

4. The optical lens according to any one of claims 1 to 3, characterized in that: The first lens group is a movable lens group. When the optical lens switches from a distant view to a near view during focusing, the first lens group moves along the optical axis toward the object side.

5. The optical lens according to any one of claims 1 to 3, characterized in that: The first lens group includes at least one variable lens. During the focusing process of the optical lens switching from a distant view to a near view, the optical focal length of the variable lens in the first lens group increases.

6. The optical lens according to claim 5, wherein the second lens group comprises at least one variable lens, and the variable lens in the second lens group is used to correct additional aberrations caused by the variable lens in the first lens group.

7. The optical lens according to any one of claims 1 to 6, characterized in that: The first exit surface is a plane, the second lens group includes a first lens, the object side surface of the first lens is a plane, and the first lens is fixedly connected to the first exit surface of the first prism through a gluing process.

8. The optical lens according to any one of claims 1 to 7, characterized in that: The second incident surface is a plane, the second lens group includes a second lens, the image side surface of the second lens is a plane, and the second lens is fixedly connected to the second incident surface of the second prism by a gluing process.

9. The optical lens according to any one of claims 1 to 8, characterized in that: The optical lens also includes an aperture stop, which is located on the object side of the first lens group, or between the first lens group and the first prism, or between the first prism and the second lens group, or between the second lens group and the second prism.

10. The optical lens according to any one of claims 1 to 9, characterized in that: The optical lens further includes an infrared filter, and the infrared filter is located on the image side of the second prism.

11. The optical lens according to any one of claims 1 to 10, characterized in that: The optical lens further includes a third lens group, the third lens group includes at least one lens, and the third lens group is located on the image side of the second prism.

12. An optical lens, characterized in that: The lens comprises a first lens group, a first prism and a second prism which are arranged in sequence from the object side to the image side. The first mirror group includes at least one lens, the first mirror group has positive optical power, and the first mirror group is used to receive light and converge the light; The first prism comprises a first incident surface, a first reflecting surface and a first emitting surface, and a first angle between the first incident surface and the first reflecting surface is less than 45°; The second prism comprises a second incident surface, a second reflection surface, and a second exit surface, a second angle between the second reflection surface and the second exit surface is less than 45°, and the second angle is equal to the first angle, and an optical axis of the second incident surface coincides with an optical axis of the first exit surface; The first exit surface has optical focal length, the second incident surface has optical focal length, and the optical focal length of the second incident surface is opposite to that of the first exit surface. The first prism and the second prism as a whole have negative optical focal length.

13. The optical lens according to claim 12, characterized in that: The first angle θ1 and the refractive index n1 of the first prism satisfy: n1≥1 / sin(2*θ1).

14. The optical lens according to claim 12 or 13, characterized in that: The second angle θ2 and the refractive index n2 of the second prism satisfy: n2≥1 / sin(2*θ2).

15. The optical lens according to any one of claims 12 to 14, characterized in that: The first lens group is a movable lens group. When the optical lens switches from a distant view to a near view during focusing, the first lens group moves along the optical axis toward the object side.

16. The optical lens according to any one of claims 12 to 14, characterized in that: The first lens group includes at least one variable lens. During the focusing process of the optical lens switching from a distant view to a near view, the optical focal length of the variable lens in the first lens group increases.

17. The optical lens according to any one of claims 12 to 16, characterized in that: The optical lens also includes a first lens, and the first lens is fixedly connected to the first exit surface through a gluing process to form a surface of the first prism with optical power.

18. The optical lens according to any one of claims 12 to 17, characterized in that: The optical lens also includes a second lens, and the second lens is fixedly connected to the second incident surface through a gluing process to form a surface of the second prism with optical power.

19. The optical lens according to any one of claims 12 to 16, characterized in that: The first prism and / or the second prism are / is an integrally processed prism with optical power.

20. The optical lens according to any one of claims 12 to 19, characterized in that: The optical lens further includes an aperture stop, which is located on the object side of the first lens group, or between the first lens group and the first prism, or between the first prism and the second prism.

21. The optical lens according to any one of claims 12 to 20, characterized in that: The optical lens further includes an infrared filter, and the infrared filter is located on the image side of the second prism.

22. The optical lens according to any one of claims 12 to 21, characterized in that: The optical lens further includes a third lens group, the third lens group includes at least one lens, and the third lens group is located on the image side of the second prism.

23. An optical lens, characterized in that: The lens comprises a first lens group, a first prism, a second lens group and a third prism which are arranged in sequence from the object side to the image side. The first mirror group includes at least one lens, the first mirror group has positive optical power, and the first mirror group is used to receive light and converge the light; The first prism comprises a first incident surface, a first reflection surface and a first exit surface, a first angle between the first incident surface and the first reflection surface is less than 45°, and an optical axis of the first exit surface coincides with an optical axis of the second mirror group; The second lens group includes at least one lens, and the second lens group has negative optical power; The third prism includes a third incident surface, a third reflection surface and a third exit surface, the angle between the third incident surface and the third reflection surface is equal to the angle between the third exit surface and the third reflection surface, and a third angle formed between the third incident surface and the third reflection surface is twice the first angle, the third angle is less than 90° and greater than 40°, and the optical axis of the third incident surface coincides with the optical axis of the second mirror group.

24. The optical lens according to claim 23, characterized in that: The first angle θ1 and the refractive index n1 of the first prism satisfy: n1≥1 / sin(2*θ1).

25. The optical lens according to claim 23 or 24, characterized in that: The first lens group is a movable lens group. When the optical lens switches from a distant view to a near view during focusing, the first lens group moves along the optical axis toward the object side.

26. The optical lens according to claim 23 or 24, characterized in that: The first lens group includes at least one variable lens. During the focusing process of the optical lens switching from a distant view to a near view, the optical focal length of the variable lens in the first lens group increases.

27. The optical lens according to claim 26, wherein the second lens group comprises at least one variable lens, and the variable lens in the second lens group is used to correct additional aberrations caused by the variable lens in the first lens group.

28. The optical lens according to any one of claims 23 to 27, characterized in that: The first exit surface is a plane, the second lens group includes a first lens, the object side surface of the first lens is a plane, and the first lens is fixedly connected to the first exit surface of the first prism through a gluing process.

29. The optical lens according to any one of claims 23 to 28, characterized in that: The optical lens also includes an aperture stop, which is located on the object side of the first lens group, or between the first lens group and the first prism, or between the first prism and the second lens group, or between the second lens group and the third prism.

30. The optical lens according to any one of claims 23 to 29, characterized in that: The optical lens further includes an infrared filter, and the infrared filter is located on the image side of the third prism.

31. The optical lens according to any one of claims 23 to 30, characterized in that: The optical lens further includes a third lens group, the third lens group includes at least one lens, and the third lens group is located on the image side of the third prism.

32. A lens module, characterized in that: The optical lens comprises an image sensor and the optical lens as claimed in any one of claims 1 to 11, or comprises an image sensor and the optical lens as claimed in any one of claims 12 to 22, wherein the optical lens is used to image the scene on the object side onto the image sensor.

33. The lens module according to claim 32, characterized in that: The image sensor is located on the image side of the optical lens and is arranged parallel to the second exit surface.

34. The lens module according to claim 32, characterized in that: The image sensor is located on the image side of the optical lens and is arranged parallel to the second reflective surface.

35. A lens module, characterized in that: The optical lens comprises an image sensor and any one of claims 23 to 31, wherein the optical lens is used to image the scene on the object side onto the image sensor.

36. The lens module according to claim 35, characterized in that: The image sensor is located on the image side of the optical lens and is arranged parallel to the third exit surface.

37. An electronic device, characterized in that: It comprises an image processor and a lens module as described in any one of claims 32 to 36, wherein the image processor is communicatively connected to the lens module, and the image processor is used to obtain image data from the lens module and process the image data.

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