Optical folding elements, camera modules and electronic devices

Abstract

The present application provides an optical folding element, a camera module and an electronic device. The optical folding element includes a first surface and a second surface arranged opposite to each other, the first surface includes an incident surface and an exit surface, the optical folding element also includes a plurality of grooves, the openings of the plurality of grooves are all formed on the second surface, and the groove surfaces of the grooves can reflect light. Among them, the first light enters the optical folding element from the incident surface, is reflected multiple times inside the optical folding element, and is emitted from the exit surface, and the second light enters the optical folding element from the incident surface, and is reflected in the direction toward the incident surface under the action of the groove surface of the groove. The optical folding element of the present application can better eliminate the influence of stray light, and the imaging quality is better.

Description

Technical Field

[0001] The present application relates to the technical field of photographing equipment, and in particular to an optical folding element, a camera module and an electronic device. Background Art

[0002] When the user takes a photo, in addition to the effective light in the shooting area that enters the camera module, there will also be stray light outside the shooting area that enters the camera module and forms an image on the image sensor, reducing the image quality. Currently, camera modules used to achieve telephoto shooting usually have a prism folding light path to increase the total length of the module's optical system to meet the long focal length requirements. However, due to the presence of the prism, in the telephoto camera module, the interference of stray light is very obvious, greatly affecting the image quality of the shot. Summary of the invention

[0003] An embodiment of the present application provides an optical folding element with good imaging quality, including a camera module of the optical folding element, and an electronic device including the camera module.

[0004] In a first aspect, an optical folding element is provided. The optical folding element includes a first surface and a second surface disposed opposite to each other, the first surface includes an incident surface and an exit surface, and the optical folding element also includes a plurality of grooves, the openings of the plurality of grooves are all formed on the second surface, and the groove surfaces of the grooves are capable of reflecting light. Among them, the first light enters the optical folding element from the incident surface, is reflected multiple times inside the optical folding element, and is emitted from the exit surface, and the second light enters the optical folding element from the incident surface, and is reflected in the direction toward the incident surface under the action of the groove surfaces of the grooves.

[0005] It is understandable that when the user takes a photo, light from the external environment can pass through the lens and enter the interior of the optical folding element from the incident surface of the optical folding element. Among them, the light entering the camera module may include a first light and a second light. The first light can be effective light in the shooting area. The second light can be stray light outside the shooting area. In a general camera module, a blocking structure is usually provided on the path of stray light propagation inside the optical folding element (for example, a groove is opened on the bottom surface of the optical folding element, and light-shielding ink is applied on the groove wall to block the light) to intercept and block the stray light, thereby reducing the impact of the stray light on the imaging quality. However, in order to prevent the blocking structure from affecting the imaging of effective light, the height of the blocking structure is limited, resulting in some stray light passing through the lens into the interior of the optical folding element without being blocked by the blocking structure, and finally being imaged on the image sensor, affecting the imaging quality.

[0006] The optical folding element in this embodiment is provided with a plurality of grooves on the bottom surface (also known as the second surface in this embodiment) of the optical folding element, and the groove surface of the groove can reflect light. In this way, when stray light enters the interior of the optical folding element, the stray light can be reflected by the groove surface of the groove and transmitted in the direction toward the incident surface. In other words, the stray light reflected by the groove surface of the groove will not be emitted from the exit surface and imaged on the image sensor, thereby effectively reducing the influence of stray light on the imaging quality, which is beneficial to improving the user's shooting experience.

[0007] In a possible implementation, the incident surface and the exit surface are arranged in a first direction, and a plurality of grooves are arranged along the first direction. In this way, the plurality of grooves are arranged along the first direction, so that the grooves can better reflect stray light incident on the second surface in a direction toward the incident surface, effectively reducing the influence of stray light on imaging quality.

[0008] In a possible implementation, the groove is in the shape of a long strip, and the length extension direction of the groove is parallel to the width extension direction of the optical folding element. In this way, the groove can better reflect stray light incident on the second surface in the direction toward the incident surface, effectively reducing the impact of stray light on imaging quality.

[0009] In a possible implementation, the groove surface of the groove includes a first groove surface and a second groove surface that are arranged opposite to each other, and the first groove surface and the second groove surface are arranged at an angle. In this way, the cross section of the groove can be roughly triangular, and stray light directed toward the second surface can be reflected in a direction toward the incident surface under the action of the first groove surface and / or the second groove surface, thereby effectively reducing the influence of stray light on the imaging quality, which is conducive to improving the user's shooting experience.

[0010] In a possible implementation, a first angle is formed between the first groove surface and the second groove surface, and the angle of the first angle is between 60° and 120°; or, the angle of the first angle is between 80° and 100°. In this way, the angle between the first groove surface and the second groove surface is more appropriate, which can better reflect stray light and prevent stray light from being imaged on the image sensor, which is conducive to improving imaging quality and enhancing user experience.

[0011] In a possible implementation, the width of the first groove surface is greater than or equal to 10 microns; and / or the width of the second groove surface is greater than or equal to 10 microns. In this way, the first groove surface and / or the second groove surface has a certain width, which can avoid excessive mechanical stress on the one hand; on the other hand, it is easy to ensure the surface shape of the groove during processing, and the processing accuracy is high.

[0012] In a possible implementation, the width of the first groove surface is equal to the width of the second groove surface. In this way, the triangle where the first groove surface and the second groove surface are located can be roughly an isosceles triangle. When stray light is emitted to the first groove surface or the second groove surface, the stray light can be reflected once and propagated in the direction toward the incident surface, or the stray light can be reflected multiple times between the first groove surface and the second groove surface and then propagated in the direction toward the incident surface, thereby effectively preventing the stray light from being emitted from the exit surface, so as to prevent the stray light from being imaged on the image sensor, which is conducive to ensuring the imaging quality.

[0013] In a possible implementation, the first groove surface is connected to the second groove surface; or, a fillet is formed at the connection between the first groove surface and the second groove surface, and the radius of the fillet is less than or equal to 10% of the height of the triangle where the first groove surface and the second groove surface are located. In this way, the cross section of the groove can be roughly triangular, which can better reflect stray light directed to the second surface in the direction toward the incident surface, avoid stray light imaging, and help ensure imaging quality.

[0014] In a possible implementation, the distance between two adjacent grooves is less than or equal to 10% of the height of the triangle where the first groove surface and the second groove surface are located. In this way, the distance between the two adjacent grooves is relatively close, so that the stray light directed to the second surface can be more reflected by the groove surface of the groove, thereby reducing the impact of stray light on the imaging quality and improving the user's shooting experience.

[0015] In a possible implementation, the optical folding element further includes a light absorbing layer, which is fixed in the groove and covers at least a portion of the groove surface of the groove. In this way, when stray light is reflected by the groove surface of the groove, part of the energy of the stray light can also be absorbed by the light absorbing layer, so that the stray light incident into the optical folding element can be better eliminated, the influence of the stray light can be reduced, and the imaging quality can be improved.

[0016] In a possible implementation, the optical folding element further includes a first reflection surface and a second reflection surface, the first reflection surface and the second reflection surface are located between the first surface and the second surface, the first reflection surface and the second reflection surface are arranged at an angle, and the distance between the first reflection surface and the second reflection surface decreases along the direction toward the second surface. In this way, after the first light enters the interior of the optical folding element, it can be reflected multiple times under the action of multiple reflection surfaces until it is emitted from the exit surface, so that the light path can be effectively folded, the focal length can be extended, and the total length of the optical system can be increased, so that a large focal length can be obtained while achieving a miniaturized setting.

[0017] In one possible implementation, the optical folding element further includes a light-blocking layer, which is located between the first reflective surface and the second reflective surface. The light-blocking layer is fixedly connected to the second surface and is spaced apart from the first surface, so that a light-passing area is formed between the light-blocking layer and the first surface. In this way, effective light can pass through the light-passing area and eventually be emitted from the exit surface. A portion of stray light can be intercepted by the light-blocking layer, and a portion of stray light can be reflected by the groove surface of the groove. That is, the light-blocking layer can cooperate with the groove to jointly eliminate stray light incident on the interior of the optical folding element and reduce the influence of stray light on imaging quality.

[0018] In a second aspect, a camera module is provided. The camera module includes a lens, an image sensor, and the above-mentioned optical folding element, wherein the lens and the image sensor are located on a side of a first surface of the optical folding element facing away from a second surface, the lens is arranged opposite to the incident surface, and the image sensor is arranged opposite to the exit surface.

[0019] It can be understood that the camera module in this embodiment is provided with a plurality of grooves on the bottom surface of the optical folding element (that is, the second surface in this embodiment), and the groove surface of the groove can reflect light. In this way, when stray light enters the interior of the optical folding element from the lens, the stray light can be reflected by the groove surface of the groove and transmitted in the direction toward the incident surface. In other words, the stray light reflected by the groove surface of the groove will not be emitted from the exit surface and imaged on the image sensor, thereby effectively reducing the influence of stray light on the imaging quality, which is beneficial to improving the user's shooting experience.

[0020] In a third aspect, an electronic device is provided. The electronic device includes an image processor and the above-mentioned camera module, the image processor is communicatively connected to the camera module, and the image processor is used to obtain image data from the camera module and process the image data. The electronic device in this embodiment has good image quality when shooting. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the implementation methods of the present application or the background technology, the drawings required for use in the implementation methods of the present application or the background technology will be described below.

[0022] Figure 1 It is a structural schematic diagram of an electronic device provided in an embodiment of the present application;

[0023] Figure 2 yes Figure 1 The schematic diagram of a partial cross-sectional structure of an electronic device in one embodiment cut along AA is shown;

[0024] Figure 3 yes Figure 1 The structure diagram of the camera module shown in some embodiments;

[0025] Figure 4 yes Figure 3 The schematic diagram of the exploded structure of the camera module shown;

[0026] Figure 5 yes Figure 3 The camera module shown is a partial cross-sectional structural schematic diagram of an embodiment cut along BB;

[0027] Figure 6 This is a schematic diagram of light propagation when a general camera module is shooting;

[0028] Figure 7 yes Figure 4 The schematic diagram of the structure of the optical folding element in some embodiments is shown;

[0029] Figure 8 yes Figure 7 A schematic structural diagram of the optical folding element shown in another viewing angle;

[0030] Fig. 9 yes Figure 7 The schematic structural diagram of the optical folding element shown in yet another viewing angle;

[0031] Fig.10 yes Figure 5 The light transmission diagram of the camera module shown;

[0032] Fig.11 yes Figure 7 The schematic diagram of the structure of the optical folding element in other embodiments is shown;

[0033] Fig.12 yes Figure 7 The optical folding element shown is a partial cross-sectional structural schematic diagram of an embodiment cut along CC;

[0034] Fig.13 yes Fig.12 The shown groove is a simplified schematic cross-sectional view of another embodiment;

[0035] Fig.14 yes Fig.12 The shown groove is a simplified schematic cross-sectional view of some other embodiments;

[0036] Fig.15 yes Fig.12 The shown groove is a simplified schematic cross-sectional view in some other embodiments;

[0037] Fig.16 yes Figure 7 A schematic diagram of the preparation process of an optical folding element in some embodiments is shown;

[0038] Fig.17 yes Figure 7 Shown is a schematic diagram of the preparation process of an optical folding element in some embodiments. DETAILED DESCRIPTION

[0039] The embodiments of the present application are described below in conjunction with the accompanying drawings in the embodiments of the present application.

[0040] In the description of the implementation mode of the present application, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installation" and "connection" should be understood in a broad sense. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. Among them, "fixed connection" means that the two are connected to each other and the relative position relationship after the connection remains unchanged. The directional terms mentioned in the implementation mode of the present application, such as "upper", "lower", "inner", "outer", etc., are only referenced to the directions of the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the implementation mode of the present application, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the implementation mode of the present application. "Multiple" means at least two.

[0041] In the embodiments of the present application, the terms "first", "second", "third", and "fourth" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first", "second", "third", and "fourth" may explicitly or implicitly include one or more of the features.

[0042] In the implementation manner of the present application, "and / or" is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0043] References to "one embodiment" or "some embodiments" etc. described in this specification mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Thus, the phrases "in one embodiment", "in some embodiments", "in some other embodiments", "in another embodiment", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0044] Figure 1 It is a structural diagram of an electronic device 1000 provided in an embodiment of the present application. Figure 2 yes Figure 1 The illustrated diagram is a partial cross-sectional structural diagram of an electronic device 1000 in one embodiment cut along AA.

[0045] like Figure 1 and Figure 2 As shown, the electronic device 1000 may be a device with a camera module, such as a mobile phone, a tablet personal computer, a laptop computer, a personal digital assistant (PDA), a camera, a personal computer, a notebook computer, a vehicle-mounted device, a wearable device, augmented reality (AR) glasses, an AR helmet, virtual reality (VR) glasses or a VR helmet. Figure 1 The electronic device 1000 in the illustrated embodiment is described by taking a mobile phone as an example.

[0046] like Figure 1 and Figure 2 As shown, the electronic device 1000 may include a camera module 100, a device housing 200, a screen 300, and an image processor (not shown). The camera module 100 may be a rear camera module or a front camera module. It should be noted that Figure 1 The following figures and the related drawings only schematically illustrate some components of the electronic device 1000, and the actual shapes, sizes, positions and structures of these components are not subject to Figure 1 In addition, when the electronic device 1000 is a device of some other form, the electronic device 1000 may not include the screen 300 .

[0047] For ease of description, the width direction of the electronic device 1000 is defined as the X axis. The length direction of the electronic device 1000 is defined as the Y axis. The thickness direction of the electronic device 1000 is defined as the Z axis. It is understood that the coordinate system setting of the electronic device 1000 can be flexibly set according to specific actual needs.

[0048] Exemplarily, the device housing 200 may include a frame 201 and a back cover 202. The back cover 202 is fixed to the frame 201. Exemplarily, the back cover 202 may be fixedly connected to the frame 201 by adhesive. The back cover 202 may also be an integrally formed structure with the frame 201, that is, the back cover 202 and the frame 201 are an integral structure.

[0049] In addition, the screen 300 may be located on a side of the frame 201 away from the back cover 202. In this case, the screen 300 and the back cover 202 are located on both sides of the frame 201. The screen 300, the frame 201 and the back cover 202 together enclose the interior of the electronic device 1000. The interior of the electronic device 1000 may be used to place components of the electronic device 1000, such as a battery, a receiver or a microphone. The screen 300 may be a flat screen or a curved screen.

[0050] For example, the camera module 100 may be located inside the electronic device 1000. The camera module 100 may be fixed to the side of the screen 300 facing the back cover 202. The back cover 202 may be provided with a light-transmitting hole 203. The shape of the light-transmitting hole 203 is not limited to the shape of the light-transmitting hole 203. Figure 1 The light-transmitting hole 203 connects the inside of the electronic device 1000 to the outside of the electronic device 1000. Light outside the electronic device 1000 can enter the inside of the electronic device 1000 through the light-transmitting hole 203. The camera module 100 can collect ambient light entering the inside of the electronic device 1000. Exemplarily, the camera module 100 can be a periscope camera module. The camera module 100 can be used for telephoto shooting.

[0051] Exemplarily, the image processor can be connected to the camera module 100 for communication. The image processor can be used to obtain image data from the camera module 100 and process the image data. The communication connection between the camera module 100 and the image processor can include data transmission through electrical connection methods such as wiring, and data transmission can also be achieved through coupling and other methods. It is understandable that the camera module 100 and the image processor can also be connected to each other for communication through other methods that can achieve data transmission.

[0052] The function of the image processor is to optimize the digital image signal through a series of complex mathematical algorithms, and finally transmit the processed signal to the display. The image processor can be an image processing chip or a digital signal processing chip.

[0053] Understandably, Figure 1 The installation position of the camera module 100 in the electronic device 1000 of the illustrated embodiment is merely illustrative, and the present application does not strictly limit the installation position of the camera module 100. In some embodiments, the camera module 100 may also be installed at other positions of the electronic device 1000, for example, the camera module 100 may also be installed at the upper middle part or the upper right corner of the back of the electronic device 1000. In other embodiments, the electronic device 1000 may include a device body and an auxiliary component that can be rotated, moved or disassembled relative to the device body. In this case, the camera module 100 may also be set on the auxiliary component.

[0054] Figure 3 yes Figure 1 The structure diagram of the camera module 100 in some embodiments is shown. Figure 4 yes Figure 3 The exploded structural diagram of the camera module 100 is shown. Figure 5 yes Figure 3 The camera module 100 shown is a partial cross-sectional structural schematic diagram of an embodiment cut along line BB.

[0055] like Figures 3 to 5 As shown, the camera module 100 may include a motor 10, a lens 20, an optical folding element 30, a bracket 40, an image sensor 50, and a circuit component 60. The image sensor 50 may also be referred to as a photosensitive chip or a photosensitive element. The image sensor 50 may be used to collect ambient light and convert the image information carried by the ambient light into an electrical signal.

[0056] Exemplarily, the optical folding element 30 can be fixed to the inner side of the bracket 40. The motor 10 and the image sensor 50 can be located on the same side of the optical folding element 30, and both can be fixedly connected to the bracket 40. The lens 20 can be installed on the inner side of the motor 10. The motor 10 can drive the lens 20 to move in a direction close to or away from the prism to achieve optical focus. In some embodiments, the motor 10 can also have an optical image stabilization function. That is, the motor 10 can be an integrated motor that takes into account both optical image stabilization and focusing functions.

[0057] Exemplarily, the motor 10 can be electrically connected to the image sensor 50 via the circuit assembly 60. In some embodiments, the circuit assembly 60 can also include a connector (not shown), such as a board-to-board connector. The circuit assembly 60 can be electrically connected to a mainboard (not shown) of the electronic device 1000 via the connector.

[0058] For example, light can be incident on the optical folding element 30 through the lens 20, and be reflected multiple times inside the optical folding element 30, and then be emitted from the optical folding element 30, and finally imaged on the image sensor 50. In this way, before being imaged on the image sensor 50, the light can be reflected multiple times inside the optical folding element 30, so that the light path can be folded, effectively increasing the focal length of the camera module 100 and the total track length (TTL) of the optical system.

[0059] Figure 6 is a schematic diagram of light propagation of a general camera module 400 during shooting. Figure 6 (a) and (b) are schematic diagrams of light transmission when stray light at different angles enters the prism 410.

[0060] like Figure 6 As shown, it can be understood that when the user is shooting, there will usually be light outside the shooting area (i.e. stray light) passing through the lens and finally forming an image on the image sensor, which affects the image quality. In a general camera module 400, a blocking structure 420 is usually provided on the path of stray light propagation inside the prism 410 (for example, a groove is made on the bottom surface of the prism 410, and light-shielding ink is applied on the groove wall to block the light), intercepting and blocking stray light, thereby reducing the effect of stray light on the image quality. However, in order to prevent the blocking structure 420 from affecting the effective light imaging, the height of the blocking structure 420 is limited, resulting in some stray light still passing through the lens 440 and entering the prism 410. After that, it is not blocked by the blocking structure 420 and finally formed on the image sensor 430, affecting the image quality. The camera module 100 in this embodiment can effectively eliminate stray light by improving the optical folding element 30, and at the same time will not affect the effective light imaging, and the image quality is high.

[0061] The optical folding element 30 will be described in detail below in conjunction with the relevant drawings.

[0062] Figure 7 yes Figure 4 The illustrated structure of the optical folding element 30 in some embodiments. Figure 8 yes Figure 7 The structure of the optical folding element 30 shown is schematically shown at another viewing angle. Fig. 9 yes Figure 7 The optical folding element 30 shown is a schematic structural diagram at another viewing angle.

[0063] like Figures 7 to 9 As shown, the optical folding element 30 may be a prism. The optical folding element 30 may include a first surface 31 and a second surface 32 that are disposed opposite to each other. The first surface 31 may be parallel to the second surface 32, and arranged with the second surface 32 in the height direction of the optical folding element 30 (that is, the Z-axis direction in this embodiment). The first surface 31 may be disposed closer to the lens 20 than the second surface 32. At this time, the first surface 31 may constitute the top surface of the optical folding element 30. The second surface 32 may constitute the bottom surface of the optical folding element 30. Exemplarily, in the length direction of the optical folding element 30 (that is, the X-axis direction in this embodiment), the size of the first surface 31 may be greater than the size of the second surface 32.

[0064] Exemplarily, the optical folding element 30 may further include a first side surface 33, a second side surface 34, a third side surface 35 and a fourth side surface 36. The first side surface 33 may be arranged opposite to the second side surface 34. The third side surface 35 may be arranged opposite to the fourth side surface 36. The first side surface 33, the third side surface 35, the second side surface 34 and the fourth side surface 36 may be connected end to end in sequence. The first side surface 33, the second side surface 34, the third side surface 35 and the fourth side surface 36 may all be connected between the first surface 31 and the second surface 32. The first side surface 33 and the second side surface 34 may be arranged in the length direction of the optical folding element 30 (i.e., the X-axis direction in this embodiment).

[0065] Exemplarily, the optical folding element 30 may have an incident surface 30a and an exit surface 30b. Both the incident surface 30a and the exit surface 30b may be formed on the first surface 31 of the optical folding element 30. That is, the first surface 31 may include the incident surface 30a and the exit surface 30b. The incident surface 30a and the exit surface 30b may be located on the same side of the optical folding element 30. The incident surface 30a and the exit surface 30b may be arranged in a first direction. The first direction X may be parallel to the X-axis direction, that is, the length extension direction of the optical folding element 30. After the light enters the interior of the optical folding element 30 from the incident surface 30a, the light may be reflected multiple times inside the optical folding element 30 and finally emitted from the exit surface 30b. In other words, the incident surface 30a and the exit surface 30b may be transmission surfaces for optical signal transmission in the optical folding element 30. Among them, the reflection of the light inside the optical folding element 30 may be ordinary reflection or total reflection. Exemplarily, when the incident angle of the light is close to or greater than the critical angle of the optical folding element 30, the light may be totally reflected (TIR) ​​inside the optical folding element 30. It should be noted that, Figure 7 In the following figures, the incident surface 30a and the exit surface 30b are indicated by dotted lines.

[0066] Exemplarily, the optical folding element 30 may include at least two reflective surfaces. The reflective surface may be formed by providing a reflective material on the surface of the optical folding element 30 (for example, by coating a reflective coating / adhering a reflective film, etc.). In the present embodiment, the number of reflective surfaces may be three, for example, including a first reflective surface 371, a second reflective surface 372, and a third reflective surface 373. Among them, the first reflective surface 371 may be formed on the first side surface 33. The second reflective surface 372 may be formed on the second side surface 34. The third reflective surface 373 may be formed on the first surface 31 and located between the incident surface 30a and the exit surface 30b. At this time, both the first reflective surface 371 and the second reflective surface 372 may be located on the image side of the incident surface 30a. The third reflective surface 373 and the incident surface 30a may be located on the same side of the optical folding element 30.

[0067] Exemplarily, the first side surface 33 may be entirely provided with a reflective material to form a first reflective surface 371. That is, the first reflective surface 371 may completely overlap with the first side surface 33. The second side surface 34 may also be entirely provided with a reflective material to form a second reflective surface 372. That is, the second reflective surface 372 may completely overlap with the second side surface 34. In other embodiments, the first side surface 33 may also be provided with a reflective material only in a partial area (e.g., a central area of ​​the first side surface 33) to form the first reflective surface 371. At this time, a portion of the first side surface 33 that does not overlap with the first reflective surface 371 may also be provided with light-absorbing ink to absorb stray light and improve imaging quality.

[0068] like Figures 7 to 9 As shown, the first reflective surface 371 and the incident surface 30a may form an angle less than 90° (that is, the first surface 31 and the first side surface 33 may form an angle less than 90°). The projection of the first reflective surface 371 on the plane where the first surface 31 is located may overlap with at least a portion of the incident surface 30a. The projection of the second reflective surface 372 on the plane where the first surface 31 is located may overlap with at least a portion of the exit surface 30b. In this way, after the light enters the interior of the optical folding element 30 from the incident surface 30a, it may be reflected by one or more of the first reflective surface 371, the second reflective surface 372, and the third reflective surface 373, and finally imaged on the image sensor 50.

[0069] Exemplarily, the optical folding element 30 may further include a light blocking layer 38. The light blocking layer 38 may be located between the first side surface 33 and the second side surface 34, that is, between the first reflective surface 371 and the second reflective surface 372. The light blocking layer 38 may be connected to the second surface 32 and spaced apart from the first surface 31. A light passing area 30c (combined with the light blocking layer 38) may be formed between the light blocking layer 38 and the first surface 31. Figure 5 Thus, by providing a light blocking layer 38 inside the optical folding element 30 to block the light, it is possible to prevent stray light outside the light passing area 30c from passing through and being imaged on the image sensor 50, thereby affecting the imaging quality.

[0070] In some embodiments, the optical folding element 30 may also have a light-blocking groove 381. The opening of the light-blocking groove 381 may be formed on the second surface 32, the third side surface 35, and the fourth side surface 36. At this time, the light-blocking groove 381 may be recessed toward the inside of the optical folding element 30. The groove wall of the light-blocking groove 381 may be subjected to a light-shielding treatment to form a light-blocking layer 38. For example, the light-blocking layer 38 may be formed by coating / pasting a light-shielding material on the groove wall of the light-blocking groove 381. In other embodiments, the optical folding element 30 may also be a glued prism. At this time, the optical folding element 30 may include a first sub-section (not shown) and a second sub-section (not shown) that are independent of each other. The first sub-section may be fixed to the second sub-section by gluing. In this way, the light-blocking layer 38 may be formed by coating / pasting a light-shielding material on the gluing surface of the first sub-section and / or the second sub-section. In some other embodiments, the optical folding element 30 may not have a light-blocking layer 38.

[0071] See again Figures 7 to 9 , the optical folding element 30 may have a plurality of grooves 39. The openings of the plurality of grooves 39 may all be formed on the second surface 32. The plurality of grooves 39 may be arranged along the first direction X. The shapes and sizes of the plurality of grooves 39 may be completely the same. Exemplarily, the groove 39 may be in the shape of a long strip. The length extension direction of the groove 39 may be parallel to the width extension direction of the optical folding element 30 (that is, the Y-axis direction in this embodiment). The plurality of grooves 39 may be evenly distributed on the second surface 32. In other embodiments, the shapes and sizes of the plurality of grooves 39 may not be completely the same.

[0072] Exemplarily, the groove 39 may have a first groove surface 391 and a second groove surface 392 that are arranged opposite to each other. Both the first groove surface 391 and the second groove surface 392 may be reflective surfaces, for example, by coating / pasting reflective materials on two groove walls that are arranged opposite to each other in the groove 39 to form the first groove surface 391 and the second groove surface 392. That is, both the first groove surface 391 and the second groove surface 392 may reflect light. At this time, when light is transmitted to the first groove surface 391 or the second groove surface 392, the light may be reflected by the first groove surface 391 or the second groove surface 392. Among them, the first groove surface 391 of one of the two adjacent grooves 39 may be connected to the second groove surface 392 of the other groove 39, that is, a plurality of grooves 39 may be arranged close to each other. At this time, a plurality of grooves 39 may form a sawtooth structure together.

[0073] Exemplarily, a first angle α may be formed between the first groove surface 391 and the second groove surface 392. The angle of the first angle α may be in the range of 60° to 120°. Among them, the width of the first groove surface 391 may be a first width D1. The width of the second groove surface 392 may be a second width D2. Both the first width D1 and the second width D2 may be greater than or equal to 10 microns. In this way, the first groove surface 391 and the second groove surface 392 may have a certain width, which may avoid excessive mechanical stress on the one hand, and on the other hand, it is easy to ensure the surface shape of the first groove surface 391 and the second groove surface 392 when machining the groove 39, and the machining accuracy is high. It should be noted that the width extension direction of the first groove surface 391 may intersect with the width extension direction of the second groove surface 392, and both may intersect with the length extension direction of the groove 39.

[0074] Exemplarily, the optical folding element 30 may further include a light absorbing layer (not shown). The light absorbing layer may be fixed in the groove 39 and cover the first groove surface 391 and / or the second groove surface 392. For example, the light absorbing layer may be formed by coating a light absorbing ink on the first groove surface 391 and / or the second groove surface 392 or by providing a light absorbing film layer. In this way, when light is transmitted to the first groove surface 391 or the second groove surface 392, at least part of the energy of the light may be absorbed by the light absorbing layer, thereby reducing the light intensity.

[0075] Fig.10 yes Figure 5 The light transmission diagram of the camera module 100 is shown in FIG. Fig.10 (a) and (b) are schematic diagrams of light transmission when stray light at different angles enters the optical folding element 30.

[0076] like Figure 5 , Figure 7 as well as Fig.10As shown, when the user takes a photo, light from the external environment can pass through the lens 20 and enter the interior of the optical folding element 30 from the incident surface 30a of the optical folding element 30. Among them, the light entering the camera module 100 may include a first light and a second light. The first light can be effective light in the shooting area. The second light can be stray light outside the shooting area. After the first light enters the interior of the optical folding element 30 from the incident surface 30a, it can be reflected multiple times between multiple reflection surfaces, and finally emitted from the optical folding element 30 from the exit surface 30b and imaged on the image sensor 50. After the second light enters the interior of the optical folding element 30 from the incident surface 30a, it will be reflected by the reflection surface to the bottom surface of the optical folding element 30 (that is, the second surface 32 in this embodiment), or directly transmitted to the bottom surface of the optical folding element 30. When the second light is transmitted to the first groove surface 391 or the second groove surface 392 of the groove 39, the stray light can be reflected in the direction toward the incident surface 30a under the action of the first groove surface 391 and / or the second groove surface 392 of the groove 39, and finally emitted from the incident surface 30a.

[0077] It can be understood that the optical folding element 30 in this embodiment is provided with a plurality of grooves 39 on the bottom surface of the optical folding element 30 (i.e., the second surface 32 in this embodiment), and the groove 39 may have a first groove surface 391 and a second groove surface 392 arranged at an angle, and the first groove surface 391 and the second groove surface 392 may both be reflective surfaces. In this way, when stray light is reflected to the second surface 32, the stray light may be reflected by the first groove surface 391 and / or the second groove surface 392, and transmitted in a direction toward the incident surface 30a. That is, the stray light reflected by the first groove surface 391 and / or the second groove surface 392 of the groove 39 will not be emitted by the exit surface 30b in the end, and imaged on the image sensor 50, thereby effectively reducing the influence of stray light on the imaging quality, which is beneficial to improving the user's shooting experience.

[0078] Secondly, the optical folding element 30 in this embodiment may further include a light absorbing layer. The light absorbing layer may be provided on the first groove surface 391 and / or the second groove surface 392. In this way, when stray light is reflected to the first groove surface 391 or the second groove surface 392, at least part of the energy of the stray light may also be absorbed by the light absorbing layer, thereby effectively reducing the energy of the stray light and reducing the influence of the stray light on the imaging quality, which is beneficial to improving the user's shooting experience.

[0079] In addition, the angle between the first groove surface 391 and the second groove surface 392 of the groove 39 in this embodiment can be in the range of 60° to 120°. In this way, the angle between the first groove surface 391 and the second groove surface 392 is appropriate, so that the first groove surface 391 and the second groove surface 392 can better reflect the stray light directed to the second surface 32, and avoid the stray light from imaging on the image sensor 50, which is conducive to improving the imaging quality and enhancing the user experience.

[0080] In other embodiments, see Fig.11 Combined with Figure 7 As shown, Fig.11 yes Figure 7 The optical folding element 30 shown is a schematic diagram of the structure in other embodiments. The light blocking layer 38 can divide the second surface 32 into a first area 321 and a second area 322. The first area 321 can be arranged closer to the first side surface 33 than the second area 322. The multiple grooves 39 located in the first area 321 can constitute a first group of grooves 39a. The grooves 39 located in the second area 322 can constitute a second group of grooves 39b. At this time, the first group of grooves 39a and the second group of grooves 39b can be located on opposite sides of the light blocking layer 38. Exemplarily, the first group of grooves 39a and the second group of grooves 39b can both be spaced apart from the light blocking layer 38. In this way, when stray light is reflected to the second surface 32, a part of the stray light can be reflected to the first groove surface 391 or the second groove surface 392 of the groove 39, and under the action of the first groove surface 391 and / or the second groove surface 392, it is reflected in the direction toward the incident surface 30a. Part of the stray light can also be reflected between the first group of grooves 39a and the light blocking layer 38 or between the second group of grooves 39b and the light blocking layer 38. This part of the stray light can be reflected by the second surface 32 to the light blocking layer 38, that is, blocked by the light blocking layer 38, and will not be emitted from the exit surface 30b.

[0081] It should be noted that the spacing distance between the first group of grooves 39a and the light blocking layer 38 and the distance between the second group of grooves 39b and the light blocking layer 38 can be determined according to the height of the light blocking layer 38 and the size parameters of the optical folding element 30.

[0082] The above specifically introduces the structure of the optical folding element. The shape structure of the groove 39 of the optical folding element 30 will be specifically introduced below in conjunction with the relevant drawings.

[0083] Fig.12 yes Figure 7 The illustrated diagram is a partial cross-sectional structural diagram of an optical folding element 30 in one embodiment cut along CC.

[0084] like Figure 7 and Fig.12As shown, a light absorbing layer 393 may be provided in the groove 39. The first groove surface 391 may be connected to the second groove surface 392. The first width D1 of the first groove surface 391 may be equal to the second width D2 of the second groove surface 392. At this time, the cross section of the groove 39 in the XZ plane may be approximately an isosceles triangle. The angle between the first groove surface 391 and the second surface 32 may be equal to the angle between the second groove surface 392 and the second surface 32.

[0085] Exemplarily, the first groove surface 391 may be perpendicular to the second groove surface 392. The first angle α may be 90°. The first groove surface 391 and the second groove surface 392 may be completely perpendicular or approximately perpendicular within the range allowed by the processing error. For example, when the first angle α is between 80° and 100°, the first groove surface 391 and the second groove surface 392 may be considered perpendicular. At this time, the cross section of the groove 39 in the XZ plane may be roughly an isosceles right triangle.

[0086] For example, the light may be incident on the first groove surface 391 or the second groove surface 392 along the first propagation direction T1. The first propagation direction T1 may intersect with the normal direction of the second surface 32. After being reflected once on the first groove surface 391 or the second groove surface 392, the light may be transmitted along the second propagation direction T2 and toward the incident surface 30a (see Fig.12 (a) and (b) in FIG. 1 ). The second propagation direction T2 may intersect with the first propagation direction T1 or coincide with the first propagation direction T1.

[0087] For example, the light may be incident on the first groove surface 391 or the second groove surface 392 along the third propagation direction T3. The third propagation direction T3 may intersect with the normal direction of the second surface 32. The light may be reflected twice on the first groove surface 391 and the second groove surface 392, and then transmitted along the fourth propagation direction T4 toward the incident surface 30a (see Fig.12 (c) and (d) in FIG. 4 . The fourth propagation direction T4 may be parallel to the third propagation direction T3. Alternatively, the light may also be incident on the first groove surface 391 or the second groove surface 392 along the fifth propagation direction T5. The fifth propagation direction T5 may be parallel to the normal direction of the second surface 32. At this time, the light may be reflected twice on the first groove surface 391 and the second groove surface 392, and then transmitted along the sixth propagation direction T6 toward the first surface 31 (see FIG. 4 ). Fig.12 (e) in FIG. 5 ). The sixth propagation direction T6 may be parallel to the fifth propagation direction T5, that is, the sixth propagation direction T6 may be parallel to the normal direction of the second surface 32. In other words, the light may be reflected twice on the first groove surface 391 and the second groove surface 392, and return to the first surface 31 along the propagation direction parallel to the first groove surface 391 or the second groove surface 392, and will not be transmitted to the exit surface 30b.

[0088] It can be understood that the angle of the first angle α formed between the first groove surface 391 and the second groove surface 392 of the groove 39 in this embodiment can be 90°, and the width of the first groove surface 391 can be equal to the width of the second groove surface 392. In this way, stray light at any angle directed to the second surface 32 of the optical folding element 30 can be returned to the first surface 31 under the effect of one or two reflections of the first groove surface 391 and / or the second groove surface 392 of the groove 39, thereby effectively avoiding stray light from being imaged on the image sensor 50, which is beneficial to reducing the influence of stray light and improving the imaging quality of the camera module 100.

[0089] In other embodiments, see Fig.13 , Fig.13 yes Fig.12 The simplified schematic diagram of the cross section of the groove 39 in other embodiments is shown. During the preparation process of the groove 39, there are certain processing and preparation errors. Exemplarily, the connection between the first groove surface 391 and the second groove surface 392 of the groove 39 may also have a rounded corner. At this time, the height of the triangle where the first groove surface 391 and the second groove surface 392 are located is H1. Among them, the radius of the rounded corner can be less than or equal to 10% of the height H1 of the triangle where the first groove surface 391 and the second groove surface 392 are located. In this way, the cross section of the groove 39 can be roughly triangular, which can better reflect the stray light directed to the second surface 32 in the direction toward the incident surface 30a, avoid stray light imaging, and help to ensure imaging quality.

[0090] Exemplarily, two adjacent grooves 39 may be spaced apart along their arrangement direction. Among them, the spacing distance H2 between two adjacent grooves 39 may be less than or equal to 10% of the height H1 of the triangle where the first groove surface 391 and the second groove surface 392 are located. At this time, the two adjacent grooves 39 can still be regarded as being arranged closely. Exemplarily, the height H1 of the triangle where the first groove surface 391 and the second groove surface 392 are located may be the distance between the intersection of the first groove surface 391 and the second groove surface 392 and the opening of the groove 39. In this way, the distance between the two adjacent grooves 39 is relatively close, so that the stray light directed toward the second surface 32 can be more reflected by the groove surface of the groove 39, thereby reducing the influence of stray light on the imaging quality and improving the user's shooting experience.

[0091] Fig.14 yes Fig.12 The shown grooves 39 are simplified schematic cross-sectional views of other embodiments.

[0092] In other embodiments, Figure 7 and Fig.14 As shown, the first angle α can also be 60°. In this case, the cross section of the groove 39 in the XZ plane can be roughly an equilateral triangle. Fig.14 As shown in (a), (b), and (c) in FIG. 1 , when light enters the first groove surface 391 or the second groove surface 392, the light may be reflected once or multiple times on the first groove surface 391 or the second groove surface 392 and transmitted in a direction toward the first surface 31 to avoid stray light from being reflected on the image sensor 50 (see FIG. 1 ). Figure 5 Imaged as shown).

[0093] Fig.15 yes Fig.12 The shown grooves 39 are simplified schematic cross-sectional views of further embodiments.

[0094] In some other embodiments, Figure 7 and Fig.15 As shown, the first angle α can also be 120°. In this case, the cross section of the groove 39 in the XZ plane can be roughly an isosceles triangle. Fig.15 As shown in (a), (b), and (c), when light is incident on the first groove surface 391 or the second groove surface 392, the light may be reflected once or twice on the first groove surface 391 or the second groove surface 392 in total, and transmitted in the direction toward the first surface 31 to avoid stray light from being imaged on the image sensor 50.

[0095] Fig.16 yes Figure 7 The illustrated diagram is a schematic diagram of the preparation process of the optical folding element 30 in some embodiments. Fig.17 yes Figure 7 The illustrated diagram is a schematic diagram of the preparation process of the optical folding element 30 in some embodiments.

[0096] In some embodiments, Fig.16 As shown, the groove 39 in the optical folding element 30 can be prepared by laser shaping. For example, according to the material of the optical folding element 30, the size of the groove 39 and other parameters, the wavelength, surface shape, processing depth of the laser and the moving speed of the carrier carrying the initial prism can be selected to laser engrave the bottom surface of the optical folding element 30 (that is, the second surface 32 in this embodiment) to form a plurality of grooves 39 arranged in an array. Then, the groove surface in the groove 39 can be coated with light-absorbing ink to form a light-absorbing layer 393. Among them, the light-absorbing layer 393 can completely cover the groove surface of the groove 39.

[0097] In some embodiments, Fig.17As shown, the grooves 39 of the optical folding element 30 can also be prepared by grinding and polishing (including grinding and polishing). For example, according to the size of the grooves 39, a grinding wheel with a suitable surface shape can be selected to grind the bottom surface (i.e., the second surface 32 in this embodiment) of the optical folding element 30, so as to form a plurality of grooves 39 arranged in an array. Then, light-absorbing ink can be coated on the groove surface in the groove 39 to form a light-absorbing layer 393.

[0098] It should be noted that, in the absence of conflict, the features in the embodiments of the present application can be combined with each other, and any combination of features in different embodiments is also within the protection scope of the present application. That is to say, the multiple embodiments described above can also be arbitrarily combined according to actual needs.

[0099] It should be noted that all the above drawings are illustrative illustrations of the present application and do not represent the actual size of the product. Moreover, the size ratio relationship between the components in the drawings is not intended to limit the actual product of the present application.

[0100] The above are only some implementation methods of the present application, and the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by any person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An optical folding element (30), characterized in that: The optical folding element (30) comprises a first surface (31) and a second surface (32) arranged opposite to each other, the first surface (31) comprising an incident surface (30a) and an exit surface (30b), the optical folding element (30) further comprising a plurality of grooves (39), the openings of the plurality of grooves (39) are all formed on the second surface (32), and the groove surfaces of the grooves (39) are capable of reflecting light; Wherein, a first light ray enters the optical folding element (30) from the incident surface (30a), is reflected multiple times inside the optical folding element (30), and is then emitted from the exit surface (30b); a second light ray enters the optical folding element (30) from the incident surface (30a), and is reflected in a direction toward the incident surface (30a) under the action of the groove surface of the groove (39); The groove (39) is formed on the second surface (32) by laser engraving; The optical folding element (30) further comprises a light-blocking layer (38), the light-blocking layer (38) being fixedly connected to the second surface (32) and spaced apart from the first surface (31), a light-transmitting area (30c) being formed between the light-blocking layer (38) and the first surface (31); The light-blocking layer (38) divides the second surface (32) into a first area (321) and a second area (322); the plurality of grooves (39) located in the first area (321) constitute a first group of grooves (39a); the plurality of grooves (39) located in the second area (322) constitute a second group of grooves (39b); and the first group of grooves (39a) and the second group of grooves (39b) are both spaced apart from the light-blocking layer (38).

2. The optical folding element (30) according to claim 1, characterized in that The incident surface (30a) and the exit surface (30b) are arranged in a first direction (X), and a plurality of the grooves (39) are arranged along the first direction (X).

3. The optical folding element (30) according to claim 1, characterized in that The groove (39) is in the shape of an elongated strip, and the length extension direction of the groove (39) is parallel to the width extension direction of the optical folding element (30).

4. The optical folding element (30) according to any one of claims 1 to 3, characterized in that The groove surface of the groove (39) comprises a first groove surface (391) and a second groove surface (392) which are arranged opposite to each other, and the first groove surface (391) and the second groove surface (392) are arranged at an angle.

5. The optical folding element (30) according to claim 4, characterized in that A first angle (α) is formed between the first groove surface (391) and the second groove surface (392), and the angle of the first angle (α) is in the range of 60° to 120°; Alternatively, the first angle (α) is in the range of 80° to 100°.

6. The optical folding element (30) according to claim 4, characterized in that The width of the first groove surface (391) is greater than or equal to 10 microns; And / or, the width of the second groove surface (392) is greater than or equal to 10 microns.

7. The optical folding element (30) according to claim 4, characterized in that The width of the first groove surface (391) is equal to the width of the second groove surface (392).

8. The optical folding element (30) according to claim 4, characterized in that The first groove surface (391) is connected to the second groove surface (392); Alternatively, a fillet is formed at the connection between the first groove surface (391) and the second groove surface (392), and the radius of the fillet is less than or equal to 10% of the height (H1) of the triangle where the first groove surface (391) and the second groove surface (392) are located.

9. The optical folding element (30) according to claim 4, characterized in that The distance between two adjacent grooves (39) is less than or equal to 10% of the height (H1) of the triangle where the first groove surface (391) and the second groove surface (392) are located.

10. The optical folding element (30) according to any one of claims 1 to 3, characterized in that The optical folding element (30) further comprises a light absorbing layer (393), wherein the light absorbing layer (393) is fixed in the groove (39) and covers at least a portion of the groove surface of the groove (39).

11. The optical folding element (30) according to any one of claims 1 to 3, characterized in that The optical folding element (30) further comprises a first reflecting surface (371) and a second reflecting surface (372), wherein the first reflecting surface (371) and the second reflecting surface (372) are located between the first surface (31) and the second surface (32), the first reflecting surface (371) and the second reflecting surface (372) are arranged at an angle, and the distance between the first reflecting surface (371) and the second reflecting surface (372) decreases in a direction toward the second surface (32).

12. The optical folding element (30) according to claim 11, characterized in that The light blocking layer (38) is located between the first reflecting surface (371) and the second reflecting surface (372).

13. A camera module (100), characterized in that: The optical folding element (30) comprises a lens (20), an image sensor (50), and the optical folding element (30) according to any one of claims 1 to 12, wherein the lens (20) and the image sensor (50) are located on the side of the first surface (31) of the optical folding element (30) facing away from the second surface (32), the lens (20) is arranged opposite to the incident surface (30a), and the image sensor (50) is arranged opposite to the exit surface (30b).

14. An electronic device (1000), characterized in that: It comprises an image processor and the camera module (100) according to claim 13, wherein the image processor is communicatively connected to the camera module (100), and the image processor is used to obtain image data from the camera module (100) and process the image data.

Images