Folded optical lens, folded optical lens camera module and camera module array

Abstract

This application provides a folding optical lens, which sequentially includes a lens group and a folding element along the optical path. The folding element has at least three reflecting surfaces that reflect light an odd number of times. The folding element has a first transmission surface and a second transmission surface. The folding element is configured to transmit light passing through the lens group into the folding element via the first transmission surface, and the light reaches the imaging surface via the second transmission surface. The length of the lens group in the height direction relative to the imaging surface is the convex length denoted as ttlt, and the length of the folding element in the height direction relative to the imaging surface is the shoulder length denoted as ttlj, satisfying the following relationship: 0.768≤ttlt / ttlj≤1.1, thereby realizing a compact folding optical lens with multiple reflections.

Description

Technical Field

[0001] This application relates to folding optical lenses, and more particularly to a folding optical lens and a folding optical lens camera module that achieves optical path folding by reflecting light multiple times. Background Technology

[0002] Telephoto camera modules typically have a relatively long focal length, making them ideal for shooting photos at long distances. The long-distance shooting capabilities of telephoto camera modules offer users a unique experience, which is why they are now commonly found in smartphones, especially flagship models from various manufacturers. However, small mobile devices such as smartphones, tablets, and wearable devices require a slimmer overall size, creating an industry demand for high-resolution, compact camera modules for easy integration. The miniaturization of telephoto camera modules is limited by their long focal length. More specifically, only optical designs that combine a small form factor with high-quality imaging can create telephoto camera modules that are both compact and deliver high-quality images.

[0003] In existing technology, the distance from the upper surface of the shoulder structure of the camera module to the bottom of the camera module is called the shoulder height of the camera module. The shoulder height of the camera module determines the shoulder height of the camera module and also determines the thickness of the backplate of the area where the camera module array is mounted on the phone. In order to effectively reduce the overall thickness of the phone and thus make the phone thinner, the industry now needs an optical lens design that can achieve telephoto shooting and a low shoulder height. Summary of the Invention

[0004] To address the aforementioned problems, this application provides a folding optical lens, which sequentially includes a lens group and a folding element along the optical path. The lens group includes at least four optical elements, and the folding element has at least three reflecting surfaces. These at least three reflecting surfaces reflect light an odd number of times. The folding element has a first transmission surface and a second transmission surface. The folding element is configured to transmit light passing through the lens group via the first transmission surface into the folding element. The three reflecting surfaces are a first reflecting surface, a second reflecting surface, and a third reflecting surface. The first reflecting surface reflects the light transmitted via the first transmission surface, and the second... The reflective surface reflects the light reflected by the first reflective surface, the third reflective surface reflects the light reflected by the second reflective surface, and the light reaches the imaging surface through the second transmission surface. The length of the lens group in the height direction relative to the imaging surface is the convex length denoted as ttlt, and the length of the folding element in the height direction relative to the imaging surface is the shoulder length denoted as ttlj. The following condition is satisfied: 0.768≤ttlt / ttlj≤1.1. By reasonably allocating the optical length, the folding optical lens has a low shoulder and a less prominent convex part, resulting in a folding optical lens with a more reasonable size.

[0005] This application also provides a folding optical lens camera module, wherein the folding optical lens camera module includes a folding optical lens, the folding optical lens camera module has a protrusion and a shoulder, wherein the height of the protrusion is ttltm, and the height of the shoulder is ttljm, satisfying the following relationship: 1.061<ttltm / ttljm<1.514. By reasonably allocating the optical length, a folding optical lens camera module with a relatively reasonable size is obtained.

[0006] This application provides a camera module array, including a first camera module with a first light-transmitting hole that is circular, and a folding optical lens camera module with a folding optical lens and a folding optical lens light-transmitting hole that is circular. The diameter of the first light-transmitting hole is R1, and the diameter of the folding optical lens light-transmitting hole is R2. The shoulder height of the first camera module is ttl1m, and the shoulder height of the folding optical lens camera module is ttlzm, satisfying the following relationship: ttl1m≤7.5mm, ttlzm≤7.5mm, 0.7<R2 / R1<1.5. This provides a camera module array where all light-transmitting holes are circular, and the diameter of the light-transmitting holes in each camera module is relatively consistent, resulting in a unified and harmonious aesthetic.

[0007] The further objectives and advantages of this application will become fully apparent from the following description and accompanying drawings. Attached Figure Description

[0008] The above and other objects, features, and advantages of this application will become more apparent from the more detailed description of the embodiments of this application in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same components or steps.

[0009] Figure 1 A structural diagram of an optical system according to an embodiment of this application is shown.

[0010] Figure 2 A schematic diagram of the structure of a superlens according to an embodiment of this application is shown.

[0011] Figure 3 A schematic diagram comparing the structure of an embodiment of this application with that of the prior art is shown.

[0012] Figure 4 A schematic diagram of an embodiment of this application mounted on a terminal is shown.

[0013] Figure 5 A structural diagram of an optical system according to another embodiment of this application is shown.

[0014] Figure 6 A structural diagram of an optical system according to another embodiment of this application is shown.

[0015] Figure 7 A structural diagram of an optical system according to another embodiment of this application is shown.

[0016] Figure 8 A structural diagram of an optical system according to another embodiment of this application is shown.

[0017] Figure 9 A structural diagram of an optical system according to another embodiment of this application is shown.

[0018] Figure 10 A schematic diagram comparing the structure of a terminal equipped with an embodiment of this application with that of a prior art terminal is shown. Detailed Implementation

[0019] Hereinafter, exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments of the present invention. It should be understood that the present invention is not limited to the exemplary embodiments described herein.

[0020] In the description of this invention, it should be noted that directional terms such as "center," "lateral," "longitudinal," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limiting the specific protection scope of this invention.

[0021] It should be noted that the terms "first," "second," etc., in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0022] The terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0023] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection, a contact connection, or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0024] Appendix Figure 1 The illustration shows a folding optical lens 1 according to this application. The folding optical lens 1 includes, sequentially along the optical path, a lens group 10 and a folding element 20. The lens group 10 includes at least four optical elements, and the folding element 20 has at least three reflective surfaces that reflect light a total of an odd number of times. (See attached diagram.) Figure 1 As shown, this application employs at least three reflective surfaces, increasing the reflective surface utilization rate of the folding element 20 and utilizing multiple physical surfaces of the folding element 20, thereby reducing the required optical size of the folding element 20. This application also employs a method of reflecting light an odd number of times, making it easier to position the imaging surface 30 on the same side of the folding element 20 opposite to the lens group 10, thereby achieving the effect of reducing the size of the folding optical lens 1.

[0025] The folding element 20 has a first transmission surface and a second transmission surface. The folding element 20 is configured to transmit light passing through the lens group 10 via the first transmission surface. The three reflecting surfaces are a first reflecting surface, a second reflecting surface, and a third reflecting surface. The first reflecting surface reflects the light transmitted via the first transmission surface, the second reflecting surface reflects the light reflected by the first reflecting surface, and the third reflecting surface reflects the light reflected by the second reflecting surface. The folding element 20 also has a second transmission surface through which light reaches the imaging surface 30. This design allows the folding element 20 to reflect light at least three times, and both transmission surfaces of the folding element 20 can be disposed on the folding element 20, reducing its compactness. Furthermore, it is relatively easy to place the imaging surface 30 on the side of the folding element 20 opposite to the lens group 10, thereby reducing the size of the folding optical lens 1.

[0026] The lens group 10 positioned in front of the folding element 20 has a convex length (denoted as ttlt) relative to the imaging surface 30 in the height direction, and the folding element 20 has a shoulder length (denoted as ttlj) relative to the imaging surface 30 in the height direction, satisfying the following condition: 0.768 ≤ ttlt / ttlj ≤ 1.1. Generally, the more times light is folded, the more effectively the unidirectional light length of the telephoto optical system can be distributed in different directions, thereby reducing the overall size of the optical system. This application employs at least three reflecting surfaces, enabling at least three light reflections, thus distributing the unidirectional light length in different directions and reducing the size of the folding optical lens 1. In addition, the optical path design that uses at least three reflective surfaces to reflect light an odd number of times ensures that the light is reflected an odd number of times inside the folding element 20. This aims to position the light rays that ultimately exit the folding element 20 as close as possible to the lens group 10. In simpler terms, it aims to position the light rays that ultimately exit the folding element 20 as high as possible on the upper side of the folding element 20, so that the imaging surface 30 and the lens group 10 are located on the same side of the folding element 20, thereby reducing the height of the folding optical lens 1.

[0027] Reference Appendix Figure 2 As shown, the folding element 20 in this application can be designed, for example, as a polygonal prism. The three reflective surfaces inside the polygonal prism fold the light multiple times, allowing the light to be folded more than three times within the prism before reaching the imaging surface 30. Since a polygonal prism can have multiple surfaces, for example, at least six, a quadrilateral prism can be designed to have a thin thickness. Specifically, one embodiment of this application can use a prism with a parallelogram cross-section. The length between the first structural surface 21 and the third structural surface 23 of the prism can have a small value, enabling multiple folds of the light. In this way, the prism can be reduced at least in the height direction (the height along the optical axis or Z-axis of the lens group 10), and thus the overall size of the folding optical lens 1 can be reduced.

[0028] Still refer to the appendix Figure 1As shown, in the present application, the lens group 10 includes at least four plastic lenses, namely the first lens 11, the second lens 12, the third lens 13, and the fourth lens 14. The lens group 10 has an optical axis O. The relative distance in the optical axis direction between the object-side surface L1S1 of the first lens 11 and the image-side surface of the last lens is L, satisfying the following relationship: 4.35 < L < 5.78. When this condition is met, it helps to reduce the total optical system length of the folded optical lens 1, making the structure of the folded optical lens 1 more compact. Additionally, in the present application, using lenses formed of plastic materials helps to reduce the manufacturing cost of the folded optical lens 1. Additionally, more simply, the present application can use 1 cuboid and 2 triangular bodies to assemble into a polygonal prism.

[0029] In the present application, the focal length of the folded optical lens 1 is f, and the entrance pupil diameter of the folded optical lens 1 is EPD, satisfying the following relationship: 2.04 < f / EPD < 2.97, which can make the optical system of the folded optical lens 1 have a larger aperture number, is beneficial to increasing the light input amount, and thus improving the imaging quality.

[0030] In the present application, the total optical system length of the folded optical lens 1 is TTL, satisfying the following relationship: 7.3 < TTL < 11.5. Referring to the appendix Figure 1 shown, TTL represents the length from the object-side surface of the first lens 11 to the bottom surface of the folding element 20 as TTL. Meeting this relationship helps to compress the total optical system length of the folded optical lens 1, making the structure of the folded optical lens 1 more compact.

[0031] In the present application, the distance of the folding element 20 in the height direction is the thickness of the folding element 20 denoted as Lj, satisfying the following relationship: 2.92 < Lj < 3.88, which helps to compress the total optical system length of the folded optical lens 1, making the structure of the folded optical lens 1 more compact.

[0032] In this application, the structural surface of the folding element 20 close to the lens group 10 is the first structural surface 21, the structural surface of the folding element 20 that intersects with the first structural surface 21 but is far from the imaging surface 30 is the second structural surface 22, the structural surface of the folding element 20 that intersects with the second structural surface 22 but is parallel to the first structural surface 21 is the third structural surface 23, and the structural surface of the folding element 20 that intersects with the first structural surface 21 but is close to the imaging surface 30 is the fourth structural surface 24. The included angle between the first structural surface 21 and the second structural surface 22 is θ1, and the included angle between the first structural surface 21 and the fourth structural surface 24 is θ2, satisfying the following relational expressions: 28.6 < θ1 < 35.7, θ1 = θ2. Thus, the light incident on the folding element 20 can undergo multiple total internal reflections in the folding element 20, which helps to shorten the total optical system length of the folding optical lens 1. On the other hand, in some embodiments, the folding element 20 uses a quadrilateral prism, and the manufacturing process is relatively simple. The quadrilateral prism uses the four structural surfaces on the top, bottom, left, and right as optical surfaces to achieve the reflection and transmission of the optical path, and reflection can be performed on the four structural surfaces on the top, bottom, left, and right, thereby shortening the total optical system length of the folding optical lens 1.

[0033] The first transmission surface is disposed on the region of the first structural surface 21 corresponding to the lens group 10. The second transmission surface is disposed on the region of the first structural surface 21 corresponding to the imaging surface 30.

[0034] In this application, the length of the folding element 20 in the height direction relative to the imaging surface 30 is the shoulder length denoted as ttlj. The ttlj is equivalent to the maximum distance in the height direction between the third structural surface 23 and the imaging surface 30. The total optical system length of the folding optical lens 1 is TTL, satisfying the following relational expression: 0.43 < ttlj / TTL < 0.53. Since the third structural surface 23 serves as the bottom surface of the folding element 20, the height between the third structural surface 23 and the imaging surface 30 is equivalent to the height of the back focal length provided by the folding element 20 to the lens group 10 to the imaging surface 30 in optical design. This height can allocate the optical path length of the folding optical lens 1 in this application, which helps to compress the total optical system length of the folding optical lens 1 and makes the structure of the folding optical lens 1 more compact.

[0035] In this application, the total optical system length of the folding optical lens 1 is TTL. TTL is equivalent to the sum of the convex part distance and the shoulder distance of the folding optical lens 1, that is, TTL = ttlt + ttlj. The height difference in the vertical direction between the optical axis of the lens group 10 and the center of the imaging surface 30 is H, satisfying the following relationship: 0.81 < H / TTL < 1.36. When this condition is met, it helps to compress the total optical system length of the folding optical lens 1, reduce the height of the folding optical lens 1, and make the structure of the folding optical lens 1 more compact.

[0036] In this application, the total optical system length of the folding optical lens 1 is TTL, and the focal length of the folding optical lens 1 is f, satisfying the following relationship: 0.51 < f / TTL < 0.64. When this condition is met, it helps to reduce the total optical system length of the folding optical lens 1 and obtain a longer focal length.

[0037] Attached Figure 3 Schematically shows the size range diagram of a camera module of this application. The imaging surface 30 of the folding optical lens camera module 100 of this application is arranged in the side direction of the folding element 20 close to the lens group 10. Briefly speaking, in this application, both the imaging surface 30 and the lens group 10 are arranged above the folding element 20, and the imaging surface 30 corresponds to the photosensitive chip in the actual camera module structure. In the camera module, the photosensitive chip structure part will include the photosensitive chip and the circuit board assembled by the photosensitive chip, etc. The overall height of the photosensitive chip structure depends on the thickness of the circuit board, the thickness of the photosensitive chip, etc. Those skilled in the art should know that because the assembly method of the photosensitive chip determines that the backside structure part of the photosensitive chip can include the circuit board and / or steel sheet, or glue etc. set between the photosensitive chip and the circuit board. From the overall perspective of optical design to camera module manufacturing, since the thickness of the color filter and the gap between the color filter and the photosensitive chip will also be determined when the optical design is determined, therefore, in this application, the thickness of the circuit board, the thickness of the photosensitive chip, and the glue between the photosensitive chip and the circuit board will constitute the overall thickness of the photosensitive component. In this application, the structure of arranging the imaging surface 30 above the folding element 20 will increase the shoulder height of the camera module when manufacturing the camera module. However, since the thickness of the folding element 20 of this application can be made small, the overall shoulder height can still meet the requirements. This application is based on reducing the size of the camera module and can adapt to the design requirements of compact terminals. Those skilled in the art should know that the shoulder height part of the camera module refers to the structure part that can be accommodated under the terminal backplane when the camera module is mounted on the terminal. For example, when the terminal is a mobile phone, the shoulder height part of the camera module refers to the shoulder height structure where the camera module can be accommodated under the backplane. The height of the shoulder height part determines the thickness of the backplane where the camera module is placed on the mobile phone, and generally also determines the overall thickness of the mobile phone. Therefore, the lower the height of the shoulder height part, the smaller the thickness of the mobile phone.

[0038] In general, from the overall process of optical design to camera module manufacturing, the lens shoulder height in the optical design affects the shoulder height of the camera module. The lower the shoulder height in the optical design, the smaller the shoulder height of the camera module will be. When the optically designed lens is manufactured into a camera module, the shoulder height of the camera module is equivalent to adding, for example, the thickness of the lens barrel, and / or the thickness of the motor in the camera module, and / or the thickness of the structural components, and / or the thickness of the lens wall, and / or the clearance dimensions, etc., to the lens shoulder height of the optical design. These dimensions can all cause the shoulder height of the camera module to increase. In this application, the imaging surface 30 is positioned on the upper side of the folding element 20, so that in the camera module state, the photosensitive chip and the lens group 10 are located on the same side of the folding element 20, thereby achieving that the height dimension of the lens group 10 covers the height dimension of the photosensitive chip in the height direction of the camera module structure, thus reducing the total height of the camera module. (See attached document) Figure 3 As shown, when the photosensitive chip is positioned on the underside of the folding element 20, the actual manufactured camera module will extend downwards due to the thickness of the photosensitive chip, and the dimensions of the photosensitive chip and its related structures will also extend downwards, thus increasing the overall height of the camera module. Therefore, by positioning the imaging surface 30 and the lens group 10 on the same side of the folding element 20 in this application, the overall height of the camera module can be reduced.

[0039] Specifically, attached Figure 3 The diagram illustrates a folding optical lens camera module 100 of this application and a prior art. In the prior art camera module 100A, the total thickness of the photosensitive chip, color filter, gap between the color filter and the photosensitive chip, and circuit board thickness is 0.7-0.9mm. Generally, in the industry, components made of photosensitive chips, color filters, and circuit boards are referred to as color filter components, IR components, photosensitive chip components, etc. Generally, in the industry, the thickness of IR components (components made of photosensitive chips, color filters, and circuit boards) is considered to be approximately 0.7-0.9mm. This thickness is higher than the structural thickness added by manufacturing the folding element 20 of this application into a camera module. Generally, when the folding element 20 of this application is manufactured into a camera module, the structural wall thickness of the lens barrel in the lens is increased by 0.2mm. In this embodiment, since the folding element 20 does not require a motor for driving, the folding element 20 is directly mounted on the structural surface of the camera module. The lens barrel structural thickness of this application is 0.2-0.3mm. Therefore, the method of setting a photosensitive chip on the folding element 20 in this application can reduce the height of the folding optical lens 1 when it is manufactured into a camera module, and compared with the attached... Figure 3 Compared to existing technologies, this can reduce the overall height by 0.4-0.7mm. (See attached diagram) Figure 3The total height (ttl1) of the folding optical lens 1 of this application when manufactured into a camera module is equivalent to the TTL height of the optical design of the folding optical lens 1 plus the structural thickness, while the prior art reference appendix... Figure 3 The total height (ttl2) of the camera module 100A is equivalent to the TTL height of the optical design of the folding optical lens 1 plus the thickness of the IR component. Obviously, ttl1 < ttl2. Therefore, when the folding optical lens 1 of this application is used to manufacture a camera module, the total height of the camera module can be reduced, thereby reducing the thickness of the mobile phone when the camera module manufactured by the folding optical lens 1 of this application is mounted on the mobile phone terminal.

[0040] Appendix Figure 4 This illustration depicts a folding optical lens camera module 100, which includes a camera module protrusion A and a camera module shoulder B. The camera module protrusion A is the raised portion of the folding optical lens camera module 100, corresponding to the portion of the camera module exposed outside the phone cover C. The camera module shoulder B is the bottom portion of the folding optical lens camera module 100, corresponding to the portion of the folding optical lens camera module 100 housed within the phone cover C. In this application, the camera module shoulder B and the camera module protrusion A of the folding optical lens camera module 100 have different thicknesses to achieve various designs. When manufacturing the optical design in the camera module, it is still necessary to ensure the gap between the lens optical surfaces. During lens manufacturing, structural surfaces are extended outside the lens optical surfaces to add structural parts for shaping. In addition, structural parts such as motors or structural components are needed in the camera module to support the optical lens, etc. Therefore, in this application, the camera module will have structures added for avoidance and / or resting, increasing the overall height in the module state. In this application, the thickness of the protrusion of the folding optical lens camera module is ttltm, and the thickness of the shoulder of the camera module is ttljm. The height of the protrusion and the height of the shoulder of the camera module are designed to satisfy the following relationship: 1.061 < ttltm / ttljm < 1.514, so that the folding optical lens camera module 100 has an appropriate structural proportion, thereby reducing the thickness of the miniaturized terminal.

[0041] More readily understood, if the ratio of the camera module shoulder to the camera module protrusion is too small, the folding element 20 may be too large. Furthermore, since the folding element 20 in this application is made of glass, it may also be too heavy and may not effectively reduce the optical size of the folding optical lens 1. Additionally, the lens group 10 may be too short and too thin, potentially failing to achieve good optical performance. Alternatively, if the ratio of the camera module shoulder to the camera module protrusion is too large, the folding element 20 may be too thin and may not be able to capture enough light from the entire field of view (FOV), potentially causing a reduction in luminous flux and significantly impacting optical imaging performance. Therefore, in this application, the optical system of the folding optical lens 1 is designed with appropriate parameters to reduce at least a portion of the height and / or the total height of the folding optical lens 1 while still maintaining high-quality optical performance. In some embodiments of this application, reducing the height of the optical system's total track length (TTL) can correspondingly reduce the size of the optical system, and thus benefit a telephoto camera module with the folding optical lens 1 that achieves a miniaturized design.

[0042] In some embodiments, all lenses in lens group 10 may be aspherical lenses. In some embodiments, all lenses in lens group 10 may be spherical lenses. In some embodiments, lens group 10 may include a combination of aspherical and spherical lenses. A spherical lens may refer to a lens having the same curvature with a similar spherical shape on at least one surface, while an aspherical lens may refer to a lens having a surface whose curvature gradually changes from the center of the lens outwards to the edge. In some embodiments, aspherical lenses can help the folding optical lens 1 achieve a low aperture number. For a given focal length, a lower aperture number means that the optical system can use a larger aperture stop, which has a greater light-gathering capacity, thereby enabling the camera module to receive more light per unit time, so that the camera module can have a fast shutter speed.

[0043] Appendix Figure 2An exemplary embodiment of a mask in folding element 20 is shown. In some embodiments, providing a mask 40 in folding element 20 can reduce or mitigate glare. In this embodiment, the folding element 20 is implemented as a prism. For optical systems, stray light from the environment (especially stray light brighter than the light from the scene or subject to be captured by the camera module) can cause glare when it enters the optical system. Stray light from the environment can enter the optical system from various directions of the camera and / or other components (e.g., the sidewalls of the camera module housing) and eventually enter the image. Stray light can enter the prism, for example, from the surface of the prism (e.g., the top surface of the prism, the bottom surface of the prism). In some embodiments, the prism may include one or more masks 40 located inside the prism and / or on the prism surface to reduce glare. In this embodiment, the mask 40 may include a first mask 401 and a second mask 402 located inside the prism. Those skilled in the art will understand that in some embodiments, the first mask 401 and the second mask 402 may be designed in various spatial locations and may have various shapes and / or sizes. As long as the first mask 401 and the second mask 402 can cover areas of unintended light paths, such as areas illuminated by stray light from the environment, or areas of unintended reflection from the folding element 20, and as long as the first mask 401 and the second mask 402 are set sequentially, the scheme of reducing some stray light using the first mask 401 and the second mask 402, utilizing the mask's ability to intercept and absorb stray light, can achieve the effect of reducing glare.

[0044] In this embodiment, the first mask 401 and the second mask 402 can be parallel to each other and arranged on the opposite inner sides of the folding element 20, so as to reduce the glare caused by stray light from the opposite sides of the folding element 20. Those skilled in the art should know that in some other embodiments, the first mask 401 and the second mask 402 can have the same or different shapes. The first mask 401 and the second mask 402 can have different shapes. For example, some frayed edges or serrated patterns can be made near the light-transmitting area of the first mask 401, which can enhance the effect of blocking stray light, and the second mask 402 can be without frayed edges. However, it is worth mentioning that in this application, the first mask 401 and the second mask 402 can be separately provided with structures for enhancing the reduction of stray light. For example, an anti-glare coating, a dark (black) mask, a dark (black) paint, a change in the flange shape, etc. can be provided on the first mask 401 and the second mask 402, which can reduce the influence of stray light. Because multiple reflections of light occur inside the folding element 20 of this application, the light is more likely to be deflected or have undesired reflections, which may cause the light to have an undesired optical path and have a certain regionality, and it is easy to cause the folding optical lens 1 to be affected by stray light.

[0045] In this application, the folding element 20 can adopt an integral prism. In some embodiments, the folding element 20 can also adopt a split prism. For example, several prisms can be joined together with an optically transparent adhesive to form a prism. In some embodiments, an aperture stop can be formed on the split prism by bonding a mask, such as Figure 2 As shown, it can be formed by using a rectangular prism and two triangular prisms. The first mask 401 and the second mask 402 can be first formed on the corresponding surfaces of the rectangular prism. The first mask 401 can be formed on two opposite parallel surfaces of the rectangular prism, and then the rectangular prism can be bonded to the first triangular prism and the second triangular prism, so that the first mask 401 and the second mask 402 are formed at the corresponding surfaces, thereby realizing the setting of the aperture stop of the folding element 20 to achieve the effect of reducing stray light. <000...​​​​As can be seen from the remaining figures, in some embodiments, the folding element 20 reflects the incident light three times. The first reflection is total internal reflection of the incident light on the second structural surface 22 of the folding element 20. Since total internal reflection occurs on the second structural surface 22, the second reflection is the light from the first reflection being reflected onto the first structural surface 21 after passing through the second structural surface 22. The third reflection is the light from the second reflection being reflected onto the third structural surface 23 after passing through the first structural surface 21.

[0048] In some other embodiments, the folding element 20 reflects the incident light five times. The first reflection is a total internal reflection of the incident light from the second structural surface 22 of the folding element 20 to the first structural surface 21. The second reflection is a total internal reflection of the light from the first reflection from the first structural surface 21 to the third structural surface 23. The third reflection is a total internal reflection of the light from the second reflection from the third structural surface 23 to the first structural surface 21. The fourth reflection is a total internal reflection of the light from the third reflection from the first structural surface 21 to the fourth structural surface 24. The fifth reflection is a total internal reflection of the light from the fourth reflection from the fourth structural surface 24 to the first structural surface 21.

[0049] In some other embodiments, the folding element 20 reflects the incident light seven times. The first reflection is a total internal reflection of the incident light from the second structural surface 22 of the folding element 20 to the first structural surface 21. The second reflection is a total internal reflection of the light from the first reflection from the first structural surface 21 to the third structural surface 23. The third reflection is a total internal reflection of the light from the second reflection from the third structural surface 22 to the first structural surface 21. The fourth reflection is a total internal reflection of the light from the third reflection from the first structural surface 21 to the third structural surface 23. The fifth reflection is a total internal reflection of the light from the fourth reflection from the third structural surface 23 to the first structural surface 21. The sixth reflection is a total internal reflection of the light from the fifth reflection from the first structural surface 21 to the fourth structural surface 24. The seventh reflection is a total internal reflection of the light from the sixth reflection from the fourth structural surface 24 to the first structural surface 21.

[0050] It is worth mentioning that in this application, the folding element 20, through an odd number of internal reflections, ultimately makes the light emitted from the folding element 20 the light reflected from the fourth structural surface 24 to the first structural surface 21. This makes it easier to set the imaging surface 30 on the upper side of the folding element 20. As described above, by setting the imaging surface 30 on the same side of the folding element 20 and the lens group 10, the total height of the folding optical lens 1 can be reduced.

[0051] Table 1 below shows the numerical range of each conditional expression in this application and the actual values ​​of each embodiment:

[0052]

[0053]

[0054] <Example 1>

[0055] Appendix Figure 5 The illustration shows a first embodiment of the folding optical lens 1 of this application. In this embodiment, the folding optical lens 1 includes a lens group 10 and a folding element 20 in sequence along the optical path. The lens group 10 includes a first lens 11, a second lens 12, a third lens 13 and a fourth lens 14 in sequence along the optical path from the object side to the image side. Each lens includes an object-side surface near the object side and an image-side surface near the image side.

[0056] The object-side surface (L1S1) of the first lens 11 has a positive radius of curvature, and the image-side surface (L1S2) of the first lens 11 has a positive radius of curvature. The first lens 11 converges the light rays, thereby reducing the aperture of the incident light rays and reducing the size.

[0057] The object-side surface (L2S1) of the second lens 12 has a negative radius of curvature, and the image-side surface (L2S2) of the second lens 12 has a negative radius of curvature. The second lens 12 can share the required radius of curvature and reduce optical distortion.

[0058] The object-side surface (L3S1) of the third lens 13 has a negative radius of curvature, and the image-side surface (L3S2) of the third lens 13 has a negative radius of curvature. The third lens 13 can share the required radius of curvature and reduce optical distortion.

[0059] The fourth lens 14 has a positive radius of curvature on its object-side surface (L4S1) and a positive radius of curvature on its image-side surface (L4S2). The fourth lens 14 can share the required radius of curvature and reduce optical distortion.

[0060] More specifically, the object-side surface (L1S1) of the first lens 11 is convex, and the image-side surface (L1S2) of the first lens 11 is concave, thereby reducing the aperture of the incident light and reducing the size.

[0061] The object-side surface (L2S1) of the second lens 12 is concave, and the image-side surface (L2S2) of the second lens 12 is convex. This can share the required optical power and reduce optical distortion.

[0062] The object-side surface (L3S1) of the third lens 13 is concave, and the image-side surface (L3S2) of the third lens 13 is convex. This shares the optical power required and can also reduce optical distortion.

[0063] The object-side surface (L4S1) of the fourth lens 14 is convex, and the image-side surface (L4S2) of the fourth lens 14 is concave, which concentrates the light rays, thereby reducing the aperture of the incident light rays and reducing the size.

[0064] The first lens 11 has a focal length of 14.1653 mm, the second lens 12 has a focal length of 14.94 mm, the third lens has a focal length of 498 mm, and the fourth lens has a focal length of -10.67 mm.

[0065] In this embodiment, the first lens 11, the second lens 12, the third lens 13 and the fourth lens 14 are all made of plastic material, thereby reducing the manufacturing cost of the lens group 10.

[0066] In this embodiment, the dimensions of the folding optical lens 1 are shown in Table 1 below, where Y represents the spacing between two adjacent surfaces in the Y direction, Z represents the spacing between two surfaces in the Z direction, and the angle represents the included angle between two planes. Prism S1 represents the aforementioned first structural surface, prism S2 represents the aforementioned second structural surface, prism S3 represents the aforementioned third structural surface, and prism S4 represents the aforementioned fourth structural surface.

[0067]

[0068]

[0069] Table 2 below illustrates the surface coefficients of each surface in this embodiment:

[0070] Table 2 L1S1 L1S2 L2S1 L2S2 L3S1 L3S2 L4S1 L4S2 radius of curvature 5.1924 14.01 -7.6539 -4.0464 -6.0387 -6.1972 2.962 1.9435 K conic coefficient 0 0 0 -5.7122 1.3026 2.0318 -3.5873 -1.7617 Level 4 0.0003 0.0024 0.0129 0.064 -0.0093 -0.0097 -0.0023 -0.0089 Level 6 5.199e-5 0.0007 0.0003 0.0012 0.005 0.0076 -0.0013 -0.0053 Level 8 -9.484e-6 -0.0001 -0.0005 -0.0012 -0.0008 -0.0019 0.0023 0.0065 Level 10 9.13e-7 -2.305E-5 7.4628E-5 0.0003 4.418E-5 0.0002 -0.0014 -0.0036 Level 12 -1.184e-7 7.213E-6 -1.60E-6 -5.188E-5 7.068E-6 -7.4593E-6 0.0014 0.0012 Level 14 1.324e-8 -7.929E-7 -4.521E-7 -5.079E-6 -1.464E-6 1.689E-6 -7.568E-5 -0.0002 .16th level -7.997e-10 4.5477E-8 4.479E-8 3.054.E-7 1.145E-7 2.458E-7 7.773E-6 2.839E-5 Level 18 1.708e-11 -1.365E-9 -1.712E-9 1.016E-8 -4.351E-9 -1.375E-8 -4.362E-7 -1.946E-6 Level 20 0 1.70e-11 2.47e-11 -1.419E-10 6.66E-11 -2.99E-10 1.036E-8 5.747E-8

[0071] In the embodiments of this application that conform to the above-described implementation, the aspherical curve equations of each lens are expressed as follows:

[0072] X(Y)=(Y 2 / R) / (1+sqrt(1-(1+k)×(Y / R) 2 ))+Σ(A i )×(Y i )

[0073] Where X: the distance from a point on the aspherical surface at a distance Y from the optical axis, and the relative distance between the point and the tangent plane at the intersection point on the optical axis of the aspherical surface;

[0074] Y: The perpendicular distance between a point on the aspherical curve and the optical axis;

[0075] R: Radius of curvature;

[0076] k: Conical coefficient;

[0077] Ai: The i-th order aspherical coefficient;

[0078] Table 3 below illustrates the optical parameters of each optical element in this embodiment, including refractive index Nd, dispersion coefficient Vd, and material.

[0079] Table 3 L1 L2 L3 L4 Prism Nd 1.536 1.544 1.641 1.67 1.773 Vd 50.69 55.9 22.24 19.4 49.6 Material plastic plastic plastic plastic Glass

[0080] <Example 2>

[0081] Appendix Figure 6 The illustration shows a second embodiment of the folding optical lens 1 of this application. In this embodiment, the folding optical lens 1 includes a lens group 10 and a folding element 20 in sequence along the optical path. The lens group 10 includes a first lens 11, a second lens 12, a third lens 13 and a fourth lens 14 in sequence along the optical path from the object side to the image side.

[0082] The object-side surface (L1S1) of the first lens 11 has a positive radius of curvature, and the image-side surface (L1S2) of the first lens 11 has a negative radius of curvature. The first lens 11 converges the light rays, thereby reducing the aperture of the incident light rays and reducing the size.

[0083] The object-side surface (L2S1) of the second lens 12 has a negative radius of curvature, and the image-side surface (L2S2) of the second lens 12 has a negative radius of curvature. The second lens 12 can share the required radius of curvature and reduce optical distortion.

[0084] The object-side surface (L3S1) of the third lens 13 has a negative radius of curvature, and the image-side surface (L3S2) of the third lens 13 has a negative radius of curvature. The third lens 13 can share the required radius of curvature and reduce optical distortion.

[0085] The object-side surface (L4S1) of the fourth lens 14 has a positive radius of curvature, and the image-side surface (L4S2) of the fourth lens 14 has a positive radius of curvature. The fourth lens 14 can share the required radius of curvature and reduce optical distortion.

[0086] More specifically, the object-side surface (L1S1) of the first lens 11 is convex, and the image-side surface (L1S2) of the first lens 11 is concave, thereby reducing the aperture of the incident light and reducing the size.

[0087] The object-side surface (L2S1) of the second lens 12 is concave near the optical axis, and the image-side surface (L2S2) of the second lens 12 is convex near the optical axis. This can share the required optical power and reduce optical distortion.

[0088] The object-side surface (L3S1) of the third lens 13 is concave, and the image-side surface (L3S2) of the third lens 13 is convex. This shares the optical power required and can also reduce optical distortion.

[0089] The object-side surface (L4S1) of the fourth lens 14 is convex, and the image-side surface (L4S2) of the fourth lens 14 is concave, which concentrates the light rays, thereby reducing the aperture of the incident light rays and reducing the size.

[0090] In this embodiment, the first lens 11, the second lens 12, the third lens 13 and the fourth lens 14 are all made of plastic material, thereby reducing the manufacturing cost of the lens group 10.

[0091] The first lens 11 has a focal length of 10.568 mm, the second lens 12 has a focal length of 25.9418 mm, the third lens has a focal length of 59.23 mm, and the fourth lens has a focal length of -7.33 mm.

[0092] In this embodiment, the dimensions of the folding optical lens 1 are shown in Table 4 below, where Y represents the dimension in the Y direction, Z represents the dimension in the Z direction, and the angle represents the angle between the two planes:

[0093] Table 4 Y Z angle L1S1 0 0 0 L1S2 0 2.8 0 L2S1 0 2.91 0 L2S2 0 4.18 0 L3S1 0 4.47 0 L3S2 0 5.34 0 L4S1 0 5.37 0 L4S2 0 5.77 0 Prism S1 -2.54 6.98 0 Prism S2 0 8.62 28.6 Prism S3 -7.2 10.54 0 Prism S4 -14.37 8.62 -28.6 IR1 14.37 6.24 0 IR2 -14.37 6.04 0 Image plane -14.37 5.96 0

[0094] Table 5 below illustrates the surface coefficients of each surface in this embodiment:

[0095] Table 5 L1S1 L1S2 L2S1 L2S2 L3S1 L3S2 L4S1 L4S2 radius of curvature 6.4396 -97.747 -15.755 -7.673 -21.201 -14.104 3.297 1.8841 K conic coefficient 0 0 0 -3.8594 1.3026 3.3812 -6.232 -2.3828 Level 4 4.788E-5 -0.0032 -0.002 0.0047 -0.0022 0.0064 -0.0127 -0.0253 Level 6 4.789E-5 0.0022 0.0026 -0.0003 0.003 -0.0031 0.0046 -0.00134 Level 8 -9.918E-6 -0.0004 -0.0004 0.0001 -0.0002 0.0007 -0.0016 -0.0051 Level 10 6.697E-7 3.188E-5 4.511E-5 -2.629E-5 7.0412E-5 -7.6144E-5 0.0004 0.0014 Level 12 -2.108E-8 -1.627E-6 -3.015E-6 4.071E-6 -1.1258E-5 4.991E-6 -4.709E-5 -0.0002 Level 14 -1.205E-10 5.171E-8 1.419E-7 -3.783E-7 1.009E-6 -2.705E-7 2.173E-6 2.779E-5 .16th level 2.005E-11 -9.828E-10 4.751E-9 1.995E-8 -5.2495E-8 1.827E-8 1.454E-7 -2.047E-6 Level 18 -2.803E-13 9.691E-12 1.033E-10 -5.554E-10 1.486E-9 -9.609E-10 -2.062E-8 9.022E-8 Level 20 0 -3.140E-14 -1.081e-12 6.379E-12 -1.781E-11 -2.154E-11 6.629E-10 -1.903E-9

[0096] Table 6 below illustrates the optical parameters of each optical element in this embodiment, including refractive index Nd, dispersion coefficient Vd, and material.

[0097] Table 6 L1 L2 L3 L4 Prism Nd 1.575 1.544 1.67 1.67 1.883 Vd 37.52 55.9 19.4 19.4 39.2 Material plastic plastic plastic plastic Glass

[0098] <Example 3>

[0099] Appendix Figure 7 The third embodiment of the folding optical lens 1 of this application is illustrated. In this embodiment, the folding optical lens 1 includes a lens group 10 and a folding element 20 in sequence along the optical path. The lens group 10 includes a first lens 11, a second lens 12, a third lens 13 and a fourth lens 14 in sequence along the optical path from the object side to the image side.

[0100] The object-side surface (L1S1) of the first lens 11 has a positive radius of curvature, and the image-side surface (L1S2) of the first lens 11 has a positive radius of curvature. The object-side surface of the first lens 11 can converge the light rays, thereby reducing the aperture of the incident light rays and reducing the size.

[0101] The object-side surface (L2S1) of the second lens 12 has a positive radius of curvature, and the image-side surface (L2S2) of the second lens 12 has a positive radius of curvature. The second lens 12 can share the required radius of curvature and reduce optical distortion.

[0102] The object-side surface (L3S1) of the third lens 13 has a positive radius of curvature, and the image-side surface (L3S2) of the third lens 13 has a positive radius of curvature. The third lens 13 can share the required radius of curvature and reduce optical distortion.

[0103] The object-side surface (L4S1) of the fourth lens 14 has a positive radius of curvature, and the image-side surface (L4S2) of the fourth lens 14 has a positive radius of curvature. The fourth lens 14 can share the required radius of curvature and reduce optical distortion.

[0104] More specifically, the object-side surface (L1S1) of the first lens 11 is convex, and the image-side surface (L1S2) of the first lens 11 is concave, thereby reducing the aperture of the incident light and reducing the size.

[0105] The object-side surface (L2S1) of the second lens 12 is convex, and the image-side surface (L2S2) of the second lens 12 is concave, which shares the optical power required and can also reduce optical distortion.

[0106] The object-side surface (L3S1) of the third lens 13 is convex, and the image-side surface (L3S2) of the third lens 13 is concave. This design shares the required optical power and reduces optical distortion.

[0107] The object-side surface (L4S1) of the fourth lens 14 is convex, and the image-side surface (L4S2) of the fourth lens 14 is concave, which concentrates the light rays, thereby reducing the aperture of the incident light rays and reducing the size.

[0108] In this embodiment, the first lens 11, the second lens 12, the third lens 13 and the fourth lens 14 are all made of plastic material, thereby reducing the manufacturing cost of the lens group 10.

[0109] The first lens 11 has a focal length of 22.51 mm, the second lens 12 has a focal length of 16 mm, the third lens has a focal length of -14.72 mm, and the fourth lens has a focal length of -85.15 mm.

[0110] In this embodiment, the dimensions of the folding optical lens 1 are shown in Table 7 below, where Y represents the dimension in the Y direction, Z represents the dimension in the Z direction, and the angle represents the angle between the two planes:

[0111]

[0112]

[0113] Table 8 below illustrates the surface coefficients of each surface in this embodiment:

[0114] Table 8 L1S1 L1S2 L2S1 L2S2 L3S1 L3S2 L4S1 L4S2 radius of curvature 8.557 26.4545 4.8673 9.9025 4.9313 3.1392 4.8614 4.1835 K conic coefficient 0 0 0 -90 1.0655 -11.2931 -5.5146 -1.0062 Level 4 -0.0014 -0.0077 0.0014 0.0268 -0.024 -0.0247 0.0394 0.0227 Level 6 0.0004 0.0026 -0.0001 -0.0038 0.0157 -0.0069 -0.0138 -0.0101 Level 8 -2.417E-5 -0.0004 -6.307E-5 -0.0011 -0.0063 0.0023 0.0019 0.0033 Level 10 -2.570E-6 4.036E-5 4.064E-5 0.0006 0.0015 -0.0005 0.0009 -0.0005 Level 12 5.576E-7 -2.244E-6 -1.052E-5 -0.0001 -0.0002 5.687E-6 -0.0006 -7.351E-5 Level 14 -4.277E-8 6.951E-8 1.487E-6 -1.084E-5 2.287E-5 1.645E-5 0.0001 3.875E-5 Level 16 -1.567E-9 -9.199E-10 -1.229E-7 -5.600E-7 -1.403E-6 -2.972E-6 -1.697E-5 -6.191E-6 Level 18 -2.253E-11 0 5.563E-9 1.184E-8 -4.819E-8 2.128E-7 1.097E-6 4.554E-7 Level 20 0 0 -1.060E-10 0 -7.067E-10 -5.627E-9 -2.914E-8 -1.299E-8

[0115] Table 9 below illustrates the optical parameters of each optical element in this embodiment, including refractive index Nd, dispersion coefficient Vd, and material.

[0116]

[0117]

[0118] <Example 4>

[0119] Appendix Figure 8 The fourth embodiment of the folding optical lens 1 of this application is illustrated. In this embodiment, the folding optical lens 1 includes a lens group 10 and a folding element 20 in sequence along the optical path. The lens group 10 includes a first lens 11, a second lens 12, a third lens 13, a fourth lens 14 and a fifth lens 15 in sequence along the optical path from the object side to the image side.

[0120] The object-side surface (L1S1) of the first lens 11 has a positive radius of curvature, and the image-side surface (L1S2) of the first lens 11 has a negative radius of curvature. The object-side surface of the first lens 11 can converge the light rays, thereby reducing the aperture of the incident light rays and reducing the size.

[0121] The object-side surface (L2S1) of the second lens 12 has a positive radius of curvature, and the image-side surface (L2S2) of the second lens 12 has a positive radius of curvature. The second lens 12 can share the required radius of curvature and reduce optical distortion.

[0122] The object-side surface (L3S1) of the third lens 13 has a positive radius of curvature, and the image-side surface (L3S2) of the third lens 13 has a negative radius of curvature. The third lens 13 can share the required radius of curvature and reduce optical distortion.

[0123] The fourth lens 14 has a negative radius of curvature on its object-side surface (L4S1) and a negative radius of curvature on its image-side surface (L4S2). The fourth lens 11 converges the light rays, thereby reducing the aperture of the incident light rays and thus reducing the size.

[0124] The object-side surface (L5S1) of the fifth lens 15 has a positive radius of curvature, and the image-side surface (L5S2) of the fifth lens 15 has a positive radius of curvature. The fifth lens 11 can also reduce optical distortion by sharing the radius of curvature it needs to bear.

[0125] More specifically, the object-side surface (L1S1) of the first lens 11 is convex, and the image-side surface (L1S2) of the first lens 11 is concave, thereby reducing the aperture of the incident light and thus reducing the size.

[0126] The object-side surface (L2S1) of the second lens 12 is convex, and the image-side surface (L2S2) of the second lens 12 is concave, which shares the optical power required and can also reduce optical distortion.

[0127] The object-side surface (L3S1) of the third lens 13 is convex, and the image-side surface (L3S2) of the third lens 13 is concave. This design shares the required optical power and reduces optical distortion.

[0128] The object-side surface (L4S1) of the fourth lens 14 is concave, and the image-side surface (L4S2) of the fourth lens 14 is convex, which corrects optical aberrations and thus improves resolution.

[0129] The fourth lens 15 has a convex surface near the optical axis on its object-side surface (L5S1), and the fifth lens 15 has a concave surface near the optical axis on its image-side surface (L5S2). This corrects optical aberrations and improves resolution.

[0130] In this embodiment, the first lens 11, the second lens 12, the third lens 13, the fourth lens 14 and the fifth lens 15 are all made of plastic material, thereby reducing the manufacturing cost of the lens group 10.

[0131] The first lens 11 has a focal length of 10.69 mm, the second lens 12 has a focal length of -17.81 mm, the third lens has a focal length of 14.31 mm, the fourth lens has a focal length of 45.59 mm, and the fifth lens has a focal length of -11.05 mm.

[0132] In this embodiment, the dimensions of the folding optical lens 1 are shown in Table 10 below, where Y represents the dimension in the Y direction, Z represents the dimension in the Z direction, and the angle represents the angle between the two planes:

[0133] Table 10 Y Z angle L1S1 0 0 0 L1S2 0 1.19 0 L2S1 0 1.22 0 L2S2 0 1.92 0 L3S1 0 2.62 0 L3S2 0 3.93 0 L4S1 0 4.43 0 L4S2 0 5.06 0 L5S1 0 5.09 0 L5S2 0 5.47 0 Prism S1 -4.12 6.23 0 Prism S2 0 8.68 30.6 Prism S3 -4.12 10.37 0 Prism S4 -8.42 8.68 -30.6 IR1 -8.42 5.68 0 IR2 -8.42 5.47 0 Image plane -8.42 5.29 0

[0134] Tables 11-1 and 11-2 below illustrate the surface coefficients of the various surfaces in this embodiment:

[0135] Table 11-1 L1S1 L1S2 L2S1 L2S2 L3S1 L3S2 L4S1 L4S2 radius of curvature 6.478 -76.517 3.855 2.705 9.088 -52.779 -3.516 -3.2938 K conic coefficient -15.235 90 -0.1014 -1.488 -37.503 90 0.153 -0.649 Level 4 0.0077 0.0061 -0.0035 -0.0028 0.0102 -0.0036 0.0116 -0.026 Level 6 -0.0016 -0.0019 0.0013 0.0053 0.0019 0.0066 0.0094 -0.0007 Level 8 0.0005 0.0008 -0.0012 -0.004 -0.0017 -0.0031 -0.0073 -0.0027 Level 10 -0.0001 -0.0002 0.0005 0.0017 0.0005 0.0005 0.003 0.0015 Level 12 -2.848E-5 3.984E-5 -0.0001 -0.0004 -7.021E-5 0.0001 -0.0007 -0.0004 Level 14 -3.602E-6 -4.790E-6 1.764E-5 6.378E-5 5.492E-7 -7.36E-5 0.0001 6.374E-5 .16th level 2.831E-7 3.652E-7 -1.540E-6 -5.951E-6 9.696E-7 1.412E-5 -8.0461E-6 -5.048E-6 Level 18 1.249E-8 -1.608E-8 7.414E-8 3.107E-7 -1.064E-7 -1.248E-6 3.058E-7 1.4922E-7 Level 20 2.347E-10 -3.103E-10 -1.517E-9 -7.013E-9 3.669E-9 4.25E-8 -3.741E-9 -1.330E-9

[0136] Table 11-2 L5S1 L5S2 radius of curvature 5.573 2.9543 K conic coefficient -1.595 -0.2165 Level 4 -0.0534 -0.0781 Level 6 0.0207 0.0329 Level 8 -0.0079 -0.0136 Level 10 0.0022 0.0043 Level 12 -0.0003 -0.001 Level 14 1.442E-5 0.0002 .16th level 4.402E-6 -1.486E-5 Level 18 -7.228E-7 8.318E-7 Level 20 3.391E-8 -2.014E-8

[0137] Table 12 below illustrates the optical parameters of each optical element in this embodiment, including refractive index Nd, dispersion coefficient Vd, and material.

[0138] Table 12 L1 L2 L3 L4 L5 Prism Nd 1.56 1.67 1.544 1.56 1.60 1.744 Vd 44.75 19.4 56.0 42.52 28.3 44.85 Material plastic plastic plastic plastic plastic Glass

[0139] <Example 5>

[0140] Appendix Figure 9The fifth embodiment of the folding optical lens 1 of this application is illustrated. In this embodiment, the folding optical lens 1 includes a lens group 10 and a folding element 20 in sequence along the optical path. The lens group 10 includes a first lens 11, a second lens 12, a third lens 13 and a fourth lens 14 in sequence along the optical path from the object side to the image side.

[0141] The object-side surface (L1S1) of the first lens 11 has a positive radius of curvature, and the image-side surface (L1S2) of the first lens 11 has a positive radius of curvature. The object-side surface of the first lens 11 can converge the light rays, thereby reducing the aperture of the incident light rays and reducing the size.

[0142] The object-side surface (L2S1) of the second lens 12 has a negative radius of curvature, and the image-side surface (L2S2) of the second lens 12 has a negative radius of curvature. The second lens 12 can share the required radius of curvature and reduce optical distortion.

[0143] The object-side surface (L3S1) of the third lens 13 has a negative radius of curvature, and the image-side surface (L3S2) of the third lens 13 has a negative radius of curvature. The third lens 13 can share the required radius of curvature and reduce optical distortion.

[0144] The fourth lens 14 has a positive radius of curvature on its object-side surface (L4S1) and a positive radius of curvature on its image-side surface (L4S2). The first lens 11 converges the light rays, thereby reducing the aperture of the incident light rays and thus reducing the size.

[0145] More specifically, the object-side surface (L1S1) of the first lens 11 is convex, and the image-side surface (L1S2) of the first lens 11 is concave, thereby reducing the aperture of the incident light and thus reducing the size.

[0146] The object-side surface (L2S1) of the second lens 12 is concave, and the image-side surface (L2S2) of the second lens 12 is convex. This shares the optical power required and can also reduce optical distortion.

[0147] The object-side surface (L3S1) of the third lens 13 is concave, and the image-side surface (L3S2) of the third lens 13 is convex. This design shares the required optical power and reduces optical distortion.

[0148] The object-side surface (L4S1) of the fourth lens 14 is convex, and the image-side surface (L4S2) of the fourth lens 14 is concave, which corrects optical aberrations and thus improves resolution.

[0149] In this embodiment, the first lens 11, the second lens 12, the third lens 13 and the fourth lens 14 are all made of plastic material, thereby reducing the manufacturing cost of the lens group 10.

[0150] The first lens 11 has a focal length of 13.78 mm, the second lens 12 has a focal length of 15.84 mm, the third lens has a focal length of 341.85 mm, and the fourth lens has a focal length of -10.44 mm.

[0151] In this embodiment, the dimensions of the folding optical lens 1 are shown in Table 13 below, where Y represents the dimension in the Y direction, Z represents the dimension in the Z direction, and the angle represents the angle between the two planes:

[0152] Table 13 Y Z angle L1S1 0 0 0 L1S2 0 2.270 0 L2S1 0 2.88 0 L2S2 0 3.623 0 L3S1 0 3.914 0 L3S2 0 4.613 0 L4S1 0 4.664 0 L4S2 0 5.341 0 Prism S1 -5.735 6.32 0 Prism S2 0 8.25 35.7 Prism S3 -5.735 10.65 0 Prism S4 -11.263 8.25 -35.7 IR1 -11.263 5.82 0 IR2 -11.263 5.61 0 Image plane -11.263 5.60 0

[0153] Table 14 below illustrates the surface coefficients of each surface in this embodiment:

[0154]

[0155]

[0156] Table 15 below illustrates the optical parameters of each optical element in this embodiment, including refractive index Nd, dispersion coefficient Vd, and material.

[0157] Table 15 L1 L2 L3 L4 Prism Nd 1.533 1.53 1.625 1.67 1.77 Vd 52.4 55.0 24.28 19.48 49.60 Material plastic plastic plastic plastic Glass

[0158] According to the aforementioned folding optical lenses, this application provides a folding optical lens structure in which the first lens object side is convex, the first lens image side is concave, the third lens object side is concave, the third lens image side is convex, the fourth lens object side is convex, and the fourth lens image side is concave, thereby reducing the size of the folding optical lens.

[0159] In addition, according to the folding optical lenses of the foregoing embodiments, this application also provides another folding optical lens structure, the lens group further including a fifth lens, the object-side surface of the first lens is convex, the image-side surface of the first lens is concave, the object-side surface of the third lens is convex, the image-side surface of the third lens is concave, the object-side surface of the fourth lens is concave, the image-side surface of the fourth lens is convex, the object-side surface of the fifth lens is convex near the optical axis, and the image-side surface of the fifth lens is concave near the optical axis, thereby reducing the size of the folding optical lens.

[0160] Reference Appendix Figure 10As shown, in this embodiment, the folding optical lens 1 is manufactured as a folding optical lens camera module 100. In this embodiment, the folding optical lens camera module 100 is a telephoto camera module, and a main camera module 200 is arranged next to the telephoto camera module. The main camera module 200 is generally the one with larger pixels in the mobile phone camera module array. In this application, in order to reduce the overall height of the camera module array, the shoulder height of the main camera module 200 is similar to that of the telephoto camera module. The shoulder height of the main camera module is ttljz, and the shoulder height of the telephoto camera module is ttljc, satisfying the following relationship: 1≤ttljzm / ttlcm≤1.2.

[0161] Appendix Figure 10 The left half of the diagram illustrates a prior art, which is a periscope camera module 100q that selects a telephoto camera module as the first optical element and a prism as the first optical element. The folding optical lens of this application adopts a shoulder height structure of folding element 20, and the shoulder height is mainly the height of folding element 20. Compared with the lens in the prior art, the shoulder height of this camera module can be within 7mm. Since the shoulder height of this telephoto camera module is within 7mm, the shoulder height requirement in the camera module array can be reduced. Since in this embodiment, the folding element 20 does not require image stabilization or displacement, when the folding element 20 is manufactured into a camera module, the shoulder height of the camera module is mainly the height of the folding element 20 plus the height of the bottom supporting structure of the folding element 20 of the camera module. Generally speaking, the height of the bottom supporting structure of the folding element 20 of the camera module is generally 0.3-0.4mm. The camera module equipped with the folding optical lens 1 in this application can therefore have a lower shoulder height. Therefore, in the camera module array, by designing the shoulder height of the main camera module as close as possible to the shoulder height of the camera module equipped with the folding optical lens 1, the overall shoulder height of the camera module array can be reduced. Reducing the overall shoulder height of the camera module array allows the cover plate of the camera module array to have a lower size, so that the camera module array can be placed inside the mobile phone body, resulting in a lower mobile phone body size.

[0162] In addition, the front lens group 10 of the folding optical lens 1 of this application can make the exposed appearance a circular lens shape. In this application, the aperture of the lens in the front lens group 10 does not directly affect the height of the camera module, so the aperture of the lens in the lens group 10 can be increased as much as possible.

[0163] In this embodiment, in the camera module array, the total height of the camera module of the folding optical lens 1 is ttl1, and the total height of the other camera modules can be ttlz, which represents the height of the main camera module, satisfying the following relationship:

[0164] 0.8 < ttlz / ttl1 < 1.2. Within this range, the total height of the main camera module and the camera module of the folding optical lens 1 in the camera module array can be kept as close as possible, thereby ensuring that the height of each camera module in the camera module array is as consistent as possible, so that each camera module has a surface of the same height to achieve a unified visual requirement.

[0165] In existing technologies, there are certain requirements for the diameter of the exposed light-transmitting holes of each camera module in a mobile phone camera module array. Since the exposed rectangular light-transmitting holes of periscope camera modules in general existing technologies are inconsistent with circular light-transmitting holes, lacking a unified aesthetic appeal, in this embodiment, since the exposed light-transmitting hole of the camera module of the folded optical lens 1 is circular, and the exposed light-transmitting holes of the remaining camera modules in this embodiment are also circular, it can ensure that the camera module array provides consumers with a unified aesthetic. It is worth mentioning that in this embodiment, the diameter of the exposed light-transmitting hole of the camera module of the folded optical lens 1 is Rzd, and the diameter of the exposed light-transmitting hole of the main camera module is Rzy, satisfying the following relationship:

[0166] 0.7 < Rzy / Rzd < 1.5, which makes the diameter of the light-transmitting hole of the main camera module in the camera module array close to that of the light-transmitting hole of the camera module of the folding optical lens 1, thereby providing consumers with a more unified visual aesthetic.

[0167] The basic principles, main features, and advantages of this invention have been described above. Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made without departing from the spirit and scope of the invention, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection claimed by this invention is defined by the appended claims and their equivalents.

Claims

1. A folded optical lens characterized by, The folding optical lens sequentially includes a lens group and a folding element along an optical path, the lens group includes a first lens, a second lens, a third lens and a fourth lens, the first lens is positive focal length, the second lens is positive focal length, the fourth lens is negative focal length, the folding element has at least three reflecting surfaces, the at least three reflecting surfaces reflect light a total number of odd times, the folding element has a first transmission surface and a second transmission surface, the folding element is configured to transmit light passing through the lens group into the folding element via the first transmission surface, the three reflecting surfaces are a first reflecting surface, a second reflecting surface and a third reflecting surface, the first reflecting surface reflects light transmitted via the first transmission surface, the second reflecting surface reflects light reflected via the first reflecting surface, the third reflecting surface reflects light reflected via the second reflecting surface, light reaches an imaging surface via the second transmission surface, the length of the lens group arranged in front of the folding element relative to the imaging surface in the height direction is a convex length, denoted as ttlt, the length of the folding element relative to the imaging surface in the height direction is a shoulder length, denoted as ttlj, the following conditions are met: 0.768≤ttlt / ttlj≤1.

1.

2. The folded optical lens of claim 1, wherein, The lens group has an optical axis, the first lens, the second lens, the third lens and the fourth lens are all plastic lenses, wherein the relative distance of the object side surface of the first lens to the image side surface of the fourth lens on the optical axis is L, the following relationship is met: 4.35 < L < 5.78 。 3. The folded optical lens of claim 2, wherein, The focal length of the folding optical lens is f, the entrance pupil diameter of the folding optical lens is EPD, the following relationship is met: 2.04<f / EPD<2.

78.

4. The folded optical lens of claim 3, wherein, The total length of the optical system of the folding optical lens is TTL, the following relationship is met: 10.46<TTL <11.

5.

5. The folded optical lens according to claim 4, wherein, The distance of the folding element in the height direction is the folding element thickness, denoted as Lj, the following relationship is met: 2.92<Lj<3.

88.

6. The folded optical lens of claim 5, wherein, The structure surface of the folding element close to the lens group is a first structure surface, the structure surface of the folding element intersecting the first structure surface at an angle but away from the imaging surface is a second structure surface, the structure surface of the folding element intersecting the second structure surface but parallel to the first structure surface is a third structure surface, the structure surface of the folding element intersecting the first structure surface but close to the imaging surface is a fourth structure surface, the included angle between the first structure surface and the second structure surface is θ1, the included angle between the first structure surface and the fourth structure surface is θ2, the following relationship is met: 28.6 °<θ1< 35.7°, θ1=θ2.

7. The folded optical lens according to claim 6, wherein, The length of the folding element relative to the imaging surface in the height direction is a shoulder length, denoted as ttlj, the total length of the optical system of the folding optical lens is TTL, the following relationship is met: 0.43< ttlj / TTL<0.

53.

8. The folded optical lens according to claim 7, wherein, The total length of the optical system of the folded optical lens is TTL, the height difference of the optical axis of the lens group to the central axis of the imaging surface in the vertical direction is H, and the following relationship is satisfied: 0.91 < H / TTL < 1.

36.

9. The folded optical lens according to claim 8, wherein, The total length of the optical system of the folded optical lens is TTL, the focal length of the folded optical lens is f, and the following relationship is satisfied: 0.51 <f / TTL<0.

64.

10. The folded optical lens of claim 9, wherein, The maximum imaging height of the imaging surface of the folded optical lens is ImgH, the focal length of the folded optical lens is f, and the following relationship is satisfied: 0.21<ImgH / f<0.

47.

11. The folded optical lens according to claim 2, wherein the first lens object side surface is convex, and the first lens image side surface is concave, the third lens object side surface is concave, and the third lens image side surface is convex, the fourth lens object side surface is convex, and the fourth lens image side surface is concave.

12. A folded optical lens camera module, characterized in that, Comprising: The folded optical lens according to any one of claims 1 to 11, the folded optical lens camera module has a convex part and a shoulder part, wherein the height of the convex part is ttltm, the height of the shoulder part is ttljm, and the following relationship is satisfied: 1.061 < ttltm / ttljm < 1.

514.

13. An array of camera modules, the array comprising: Comprising: The first camera module has a first light passing hole, and the first light passing hole is circular; The folded optical lens camera module comprises the folded optical lens according to any one of claims 1 to 11, and the folded optical lens has a folded optical lens light passing hole, the folded optical lens light passing hole is circular, the diameter of the first light passing hole is R1, the diameter of the folded optical lens light passing hole is R2, the height of the shoulder part of the first camera module is ttl1m, the height of the shoulder part of the folded optical lens camera module is ttlzm, and the following relationship is satisfied: ttl1m≤7.5mm, ttlzm≤7.5mm, 0.7 < R2 / R1 < 1.5.

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