Camera module and electronic equipment

Abstract

The invention provides a camera module and electronic equipment. The camera module comprises an optical lens group, an optical waveguide and a photosensitive element. The optical lens group and the photosensitive element are located on the same side of the optical waveguide, or the optical lens group and the photosensitive element are located on two opposite sides of the optical waveguide, and the optical lens group is located on the object side of the optical waveguide. The optical waveguide comprises a substrate, a coupling-in element and a coupling-out element, the coupling-in element and the coupling-out element are arranged on the substrate, the coupling-in element is arranged opposite to the optical lens group, and the coupling-out element is arranged opposite to the photosensitive element. After passing through the optical lens group, light enters the substrate through the coupling-in element, is reflected for multiple times in the substrate, is emitted out of the substrate through the coupling-out element, and is imaged on the photosensitive element. The light is transmitted in the substrate in a total reflection mode. The camera module can realize long focal length and large target surface, and the size of the camera module in the thickness direction is small. The electronic equipment can be miniaturized, light and thin, and the imaging effect is good.

Description

Technical Field

[0001] The present application relates to the field of lenses, and particularly to an imaging module and an electronic device. Background Art

[0002] The telephoto lenses in smart phones have greatly improved the user's telephoto photography experience and become an essential part of smart phones. With the increasing popularity of telephoto photography in smart phones, consumers have higher and higher requirements for telephoto photography, such as clearer images, better night shooting experience, etc.

[0003] However, traditional telephoto solutions all have the problem of excessive size, which is not conducive to the miniaturization and thinness of mobile phones. And due to the limitation of the mobile phone size, the aperture of the telephoto lens is small and the target surface is small. Summary of the Invention

[0004] The present application provides an imaging module and an electronic device. Through the design of combining an optical lens group and an optical waveguide, a long focal length and a large target surface can be achieved, and the size of the imaging module in the thickness direction is small. The imaging module can take into account both a large aperture and miniaturization. When the imaging module is applied to an electronic device, the miniaturization and thinness design of the electronic device can be realized, and the imaging effect is good.

[0005] In a first aspect, an embodiment of the present application provides an imaging module, which includes an optical lens group, an optical waveguide, and a photosensitive element; the optical lens group and the photosensitive element are located on the same side of the optical waveguide, or the optical lens group and the photosensitive element are located on opposite sides of the optical waveguide, and the optical lens group is located on the object side of the optical waveguide; the optical waveguide includes a substrate, a coupling-in element, and a coupling-out element, the substrate includes a coupling-in region and a coupling-out region, the coupling-in element is disposed in the coupling-in region, the coupling-out element is disposed in the coupling-out region, the coupling-in element is disposed opposite to the optical lens group, and the coupling-out element is disposed opposite to the photosensitive element; wherein, after the light passes through the optical lens group, it enters the substrate through the coupling-in element from the coupling-in region, undergoes multiple reflections inside the substrate, and then exits through the coupling-out element from the coupling-out region to form an image on the photosensitive element; the light propagates inside the substrate in a total reflection manner.

[0006] It can be understood that in the camera module of the present application, by providing an optical waveguide, the optical lens group and the photosensitive element are located on the same side of the optical waveguide, or the optical lens group and the photosensitive element are located on opposite sides of the optical waveguide. In this way, the light refracted from the optical lens group can enter the substrate from the light coupling region of the optical waveguide, propagate in the substrate, and then exit the substrate from the light extraction region of the optical waveguide. When the diameter of the optical lens group increases, the optical waveguide does not need to increase its thickness dimension (the dimension in the Z-axis direction), and the light can still be coupled into the substrate and totally reflected and propagated in the substrate before reaching the photosensitive element. That is to say, the optical waveguide can achieve a large target surface without increasing the thickness dimension (the dimension in the Z-axis direction), so that the camera module can achieve a large aperture effect and miniaturization.

[0007] Compared with the prism solution, the camera module of the present application uses an optical waveguide to deflect and propagate the light collected by the optical lens group. The optical waveguide can increase the diameter of the optical lens group without increasing the thickness, achieving a large target surface, and the camera module has a large aperture effect. The camera module of the present application can balance large aperture, miniaturization, and thinness.

[0008] In addition, the optical lens group can move away from the optical waveguide along the first optical axis to change the effective focal length, thereby achieving super macro. Since the thickness of the optical waveguide in the Z-axis direction is small, under the condition that the size of the camera module is fixed, the moving stroke of the first lens group in the Z-axis direction is long, and the change range of the effective focal length is large, so that super macro in more scenarios can be satisfied.

[0009] In a possible implementation, the camera module further includes an optical element, and the optical element is located between the light extraction element and the photosensitive element; the optical element is used to focus the multiple light rays emitted from the light extraction element onto the photosensitive element.

[0010] It can be understood that the camera module includes an optical element, and the optical element is used to focus the light rays coupled out by the light extraction element onto the photosensitive element. After passing through the optical element, the coupled-out light forms a smaller focused spot on the photosensitive element, thereby improving the imaging clarity, that is, improving the imaging effect of the camera module.

[0011] In a possible implementation, the camera module further includes a motor, and the optical element is mounted on the motor. The motor is used to drive the optical element to move along the optical axis direction of the photosensitive element. In this way, the motor can drive the optical element to move along the optical axis direction of the photosensitive element for focusing, enabling the camera module to achieve autofocus when focusing on objects with different object distances, and improving the imaging quality of the camera module.

[0012] In a possible implementation, the thickness of the substrate is in the range of 1 to 3 mm.

[0013] It can be understood that the thickness of the substrate of the optical waveguide is small, which can reduce the size of the imaging module in the thickness direction (i.e., in the Z-axis direction), thereby facilitating the miniaturization and thinness of the electronic device.

[0014] In a possible implementation, both the coupling-in element and the coupling-out element are diffraction gratings. The substrate includes a first surface and a second surface arranged back to back. The first surface faces the optical lens group and the photosensitive element. The second surface is located on the side of the first surface facing away from the optical lens group and the photosensitive element. The coupling-in element and the coupling-out element are arranged on the first surface, and the coupling-in element and the coupling-out element are arranged at intervals; or, the first surface faces the optical lens group, the second surface is located on the side of the first surface facing away from the optical lens group, the second surface faces the photosensitive element, the coupling-in element is arranged on the first surface, and the coupling-out element is arranged on the second surface.

[0015] It can be understood that both the coupling-in element and the coupling-out element are diffraction gratings. The imaging module can design the relevant parameters of the diffraction grating (for example, the refractive index of the grating material, the working order of the grating, and the period of the grating) so that when light rays with different incident angles irradiate the coupling-in element, they can be diffracted by the coupling-in element and turned, and the diffraction angle of the light rays meets the total internal reflection condition of the optical waveguide. At this time, the light rays can be coupled into the substrate and propagate in the substrate in the form of total internal reflection. Subsequently, the light rays after multiple total internal reflections in the substrate can be irradiated onto the photosensitive element through the diffraction of the coupling-in element.

[0016] In a possible implementation, the incident angle θ of the light ray incident on the coupling-in element i and the diffraction angle θ of the light ray after passing through the coupling-in element A satisfy the formula:

[0017]

[0018] where n i is the refractive index of the propagation medium of the light ray before it is incident on the coupling-in element, n C1 is the refractive index of the diffraction grating, λ k is the wavelength of the light ray, m k is the working order of the diffraction grating, Ф k is the period of the diffraction grating.

[0019] It can be understood that when the incident angle θ of the light ray incident on the coupling-in element i and the diffraction angle θ of the light ray after passing through the coupling-in element A satisfy the above formula, the light rays diffracted by the diffraction grating can be coupled into the substrate and propagate in the substrate in the form of total reflection.

[0020] In a possible implementation, both the coupling-in element and the coupling-out element are embedded in the substrate; the coupling-in element includes a coupling-in sub-element, and the coupling-in sub-element has a semi-transmissive and semi-reflective incident surface; the coupling-out element includes a coupling-out sub-element, and the coupling-out sub-element has a semi-transmissive and semi-reflective exit surface; the substrate includes a first surface and a second surface arranged back to back, the first surface faces the optical lens group and the photosensitive element, the second surface is on the side of the first surface facing away from the optical lens group and the photosensitive element, the angle formed between the incident surface and the second surface is an obtuse angle, and the angle formed between the exit surface and the second surface is an obtuse angle; or, the first surface faces the optical lens group, the second surface is on the side of the first surface facing away from the optical lens group, the second surface faces the photosensitive element, the angle formed between the incident surface and the second surface is an obtuse angle, and the angle formed between the exit surface and the second surface is an acute angle.

[0021] It can be understood that the coupling-in element includes a coupling-in sub-element, and the coupling-in sub-element has a semi-transmissive and semi-reflective incident surface; the coupling-out element includes a coupling-out sub-element, and the coupling-out sub-element has a semi-transmissive and semi-reflective exit surface. The imaging module can design the angle array of the incident surface so that after reflection by the incident surface, the angles of at least part of the light rays satisfy the total internal reflection condition of the geometric optical waveguide and propagate in the substrate in the form of total internal reflection; the imaging module can design the angle array of the exit surface so that after reflection by the exit surface, at least part of the light rays exit the substrate and irradiate the photosensitive element.

[0022] When the optical lens group and the photosensitive element are on the same side of the optical waveguide, the angle formed between the incident surface and the second surface is an obtuse angle. After reflection by the incident surface, the angles of at least part of the light satisfy the total internal reflection condition of the geometric optical waveguide and propagate in the substrate in the form of total internal reflection; the angle formed between the exit surface and the second surface is an obtuse angle. After reflection by the exit surface, at least part of the light rays exit the optical waveguide and irradiate the photosensitive element.

[0023] When the optical lens group and the photosensitive element are on opposite sides of the optical waveguide, the angle formed between the incident surface and the second surface is an obtuse angle. After reflection by the incident surface, the angles of at least part of the light satisfy the total internal reflection condition of the geometric optical waveguide and propagate in the substrate in the form of total internal reflection; the angle formed between the exit surface and the second surface is an acute angle. After reflection by the exit surface, at least part of the light rays exit the optical waveguide and irradiate the photosensitive element.

[0024] In a possible implementation, the number of the coupling-in sub-elements is multiple, and the multiple coupling-in sub-elements are arranged at intervals along the length extension direction of the substrate.

[0025] It can be understood that the incident surfaces of multiple incident sub-elements are arranged at intervals along the length extension direction of the substrate. Through the semi-transmissive and semi-reflective incident surfaces arranged in multiple arrays, the camera module can extend the path of light in the substrate, extend the total optical length of the camera module, and achieve a long focal length.

[0026] In a possible implementation, the number of the outgoing sub-elements is multiple, and the multiple outgoing sub-elements are arranged at intervals along the length extension direction of the substrate.

[0027] It can be understood that the incident surfaces of multiple outgoing sub-elements are arranged at intervals along the length extension direction of the substrate. Through the semi-transmissive and semi-reflective outgoing surfaces arranged in multiple arrays, the camera module can extend the path of light in the substrate, extend the total optical length of the camera module, and achieve a long focal length.

[0028] In a possible implementation, the substrate includes a first surface and a second surface arranged back to back. The first surface faces the optical lens group and the photosensitive element, and the second surface is located on the side of the first surface facing away from the optical lens group and the photosensitive element. The first surface includes an incident surface, a first total reflection surface, and an outgoing surface connected in sequence. The incident surface faces the optical lens group, and the outgoing surface of the first surface faces the photosensitive element. The second surface is a total reflection surface. After the light enters the optical waveguide from the incident surface, it is reflected multiple times between the second surface and the first total reflection surface and then exits from the outgoing surface of the first surface; or, the first surface faces the optical lens group, the second surface is located on the side of the first surface facing away from the optical lens group, the second surface faces the photosensitive element, the first surface includes an incident surface and a first total reflection surface connected to each other, the incident surface faces the optical lens group, the second surface includes a second total reflection surface and an outgoing surface connected to each other, and the outgoing surface of the second surface faces the photosensitive element. After the light enters the optical waveguide from the incident surface, it is reflected multiple times between the first total reflection surface and the second total reflection surface and then exits from the outgoing surface of the second surface.

[0029] It can be understood that when the optical lens group and the photosensitive element are on the same side of the optical waveguide, the part of the first surface of the substrate between the incident area and the outgoing area is a total reflection surface (i.e., the first total reflection surface). The second surface of the substrate is a total reflection surface. When the light in the substrate irradiates on the part of the first surface between the incident area and the outgoing area and the second surface, it can be reflected back into the substrate 21 at the part of the first surface between the incident area and the outgoing area and the second surface.

[0030] When the optical lens group and the photosensitive element are located on opposite sides of the optical waveguide, the portion of the first surface of the substrate that is offset from the optical lens group is a total reflection surface (i.e., the first total reflection surface). The portion of the second surface of the substrate that is offset from the photosensitive element is a total reflection surface (i.e., the second total reflection surface). After the light enters the substrate from the incident surface, it is reflected back into the substrate at the first total reflection surface and the second total reflection surface.

[0031] In a possible implementation, the substrate further includes a first end face and a second end face disposed opposite to each other, and the first end face and the second end face are connected between the first surface and the second surface; both the first end face and the second end face are light absorption layers.

[0032] It can be understood that both the first end face and the second end face of the substrate are light absorption layers, which can be used to absorb stray light, avoid stray light imaging on the photosensitive element, and eliminate the influence of stray light on the image quality.

[0033] In a possible implementation, the incident angle θ of the light entering the optical waveguide A satisfies the formula:

[0034]

[0035] where θ B is the total reflection critical angle of the optical waveguide, and n C is the refractive index parameter of the coupling element.

[0036] It can be understood that when the incident angle θ of the light entering the optical waveguide A satisfies the above formula, the light can be coupled into the substrate and propagate in the substrate in the form of total internal reflection.

[0037] In a second aspect, an embodiment of the present application provides an electronic device, which includes a housing and the above-described camera module, and the camera module is installed in the housing.

[0038] It can be understood that when the camera module is applied to an electronic device, miniaturization and thinning design of the electronic device can be achieved, and the imaging effect of the electronic device is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the background art, the following will describe the drawings required to be used in the embodiments of the present application or the background art.

[0040] Figure 1 is a schematic structural diagram of the electronic device provided by an embodiment of the present application;

[0041] Figure 2 is Figure 1 a partial cross-sectional schematic view of the electronic device shown at line A-A;

[0042] Figure 3 is Figure 2 a schematic structural diagram of the camera module shown;

[0043] Figure 4 is Figure 3 a schematic diagram of total internal reflection transmission of the optical path of the optical waveguide shown;

[0044] Figure 5 is a schematic structural diagram of a camera module that uses a prism system for imaging;

[0045] Figure 6 is Figure 2 a schematic structural diagram of the camera module shown in one embodiment;

[0046] Figure 7 is Figure 2 a schematic structural diagram of the camera module shown in another embodiment;

[0047] Figure 8 is Figure 6 an optical path diagram of the optical waveguide shown in one embodiment;

[0048] Figure 9 is Figure 6 a partial enlarged view of the optical waveguide shown in one embodiment at A;

[0049] Figure 10 is Figure 2 an optical path diagram of the camera module shown;

[0050] Figure 11 is Figure 2 a schematic structural diagram of the camera module shown in another embodiment;

[0051] Figure 12 is Figure 11 an optical path diagram of the optical waveguide shown in one embodiment;

[0052] Figure 13 is Figure 2 a schematic structural diagram of the camera module shown in another embodiment. Detailed implementation manners

[0053] To facilitate understanding of the optical lens provided in the embodiments of the present application, the relevant terms involved in the present application are explained:

[0054] The optical axis is an axis that vertically passes through the center of the lens. The lens optical axis is the axis that passes through the centers of the various lenses of the lens. When light rays parallel to the optical axis enter a convex lens, an ideal convex lens should be such that all the light rays converge at a point behind the lens, and this point where all the light rays converge is the focal point.

[0055] Taking the lens as the boundary, the side where the object to be photographed is located is the object side, and the surface of the lens close to the object side is called the object side surface.

[0056] Taking the lens as the boundary, the side where the image of the object to be photographed is located is the image side, and the surface of the lens close to the image side is called the image side surface.

[0057] The focal power, expressed as the reciprocal of the image-side focal length (assuming the refractive index of air is approximately 1), characterizes the ability of an optical lens to deflect light rays. A lens or lens group with positive focal power has a positive focal length and has the effect of converging light rays. A lens or lens group with negative focal power has a negative focal length and has the effect of diverging light rays.

[0058] Positive focal power, also known as positive refractive power, indicates that the lens has a positive focal length.

[0059] Negative focal power, also known as negative refractive power, indicates that the lens has a negative focal length.

[0060] The focal length, also known as the focal distance, is a measure of the convergence or divergence of light in an optical system. It refers to the perpendicular distance from the optical center of a lens or lens group to the focal plane when an infinitely distant scene forms a clear image through the lens or lens group on the focal plane. From a practical perspective, it can be understood as the distance from the center of the lens to the imaging plane. For a fixed-focus lens, the position of its optical center remains fixed.

[0061] The effective focal length (EFL) of a lens is the distance from the center of the lens to the focus.

[0062] The principal plane of a lens (lens group), also known as the principal surface, includes the image-side principal surface and the object-side principal surface. When parallel light shines on the lens (lens group), after refraction, the light rays will pass through the image-side focus. The reverse extension of the refracted light rays intersects the incident light rays at a point. The plane perpendicular to the optical axis passing through this point is the image-side principal surface. The intersection of the image-side principal surface and the optical axis of the optical lens is the image-side focus; similarly, the light rays emitted from the object-side focus become parallel light after passing through the lens. The extension of the incident light rays intersects the parallel light at a point. The plane perpendicular to the optical axis passing through this point is the object-side principal surface. The intersection of the object-side principal surface and the optical axis of the optical lens is the object-side focus.

[0063] The object distance is the distance from the target scene to be photographed to the object-side principal surface of the optical system, represented by the English letter U; among them, the optical system can be a single lens or a lens group formed by multiple lenses.

[0064] The image distance refers to the distance from the image formed by an optical system to the image-side principal plane, which is represented by the English letter V. Among them, the optical system can be a single lens or a lens group formed by multiple lenses.

[0065] Focusing specifically refers to adjusting the position of the lens group (i.e., the focusing lens group) in an optical lens to control the image distance, so that the image plane of the optical lens falls on the photosensitive element, making the imaging of the optical lens the clearest.

[0066] The focusing stroke refers to the moving stroke of the focusing lens group during the focusing process of an optical lens. For example, during the process of the optical lens switching from focusing on a distant view to focusing on a near view, the moving stroke of the focusing lens group is the focusing stroke.

[0067] The field of view (FOV) in an optical instrument is the angle formed by two edges of the maximum range through which the image of the measured target can pass through the lens with the vertex of the lens of the optical instrument as the vertex. The size of the field of view determines the viewing range of the optical instrument. The larger the field of view, the larger the viewing field, and the smaller the optical magnification.

[0068] The aperture is a device used to control the amount of light passing through the lens, and it is usually inside the lens. The aperture size can be expressed by the F-number (symbol: Fno). The aperture F-number is the relative value obtained by dividing the focal length of the lens by the clear aperture diameter of the lens (the reciprocal of the relative aperture). The smaller the aperture F-number, the more light enters in the same unit time. The larger the aperture F-number, the smaller the depth of field, and the background content of the photo will be blurred, similar to the effect of a telephoto lens.

[0069] The target surface refers to the size of the camera sensor, that is, the maximum picture size that the camera can capture. The larger the target surface of the camera, the larger the viewing range that can be obtained.

[0070] The total track length (TTL) of an optical lens refers to the distance from the object-side surface of the first lens of the optical lens to the imaging surface in the direction from the object side to the image side.

[0071] Distortion, also known as aberration, is the degree of distortion of the image formed by an optical system of an object relative to the object itself. Distortion is due to the influence of spherical aberration of the aperture stop. The height of the chief ray of different fields of view passing through the optical system and intersecting with the Gaussian image plane is not equal to the ideal image height, and the difference between the two is the distortion. Therefore, distortion only changes the imaging position of off-axis object points on the ideal plane, causing the shape of the image to be distorted, but does not affect the clarity of the image.

[0072] Next, the technical solutions in some embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings.

[0073] Figure 1Schematic diagram of the structure of the electronic device 1000 provided by the embodiments of the present application.

[0074] As Figure 1 shown, the electronic device 1000 can be 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, or other devices with photo-taking and video-recording functions. Figure 1 The electronic device 1000 in the illustrated embodiment is described by taking a mobile phone as an example.

[0075] Figure 2 For Figure 1 shown, partial cross-sectional view of the electronic device 1000 at the A-A line.

[0076] As Figure 1 and Figure 2 shown, the electronic device 1000 includes a housing 200, a screen 300, and a camera module 100. The camera module 100 is installed on the housing 200. The camera module 100 can be used for photo-taking and video-recording. It can be understood that Figure 1 and Figure 2 only schematically show some components included in the electronic device 1000. The actual shapes, actual sizes, actual positions, and actual structures of these components are not limited by Figure 1 and Figure 2 defined. In addition, when the electronic device 1000 is other devices, the electronic device 1000 may not include the screen 300. For the convenience 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 can be understood that the coordinate system setting of the electronic device 1000 can be flexibly set according to specific actual needs.

[0077] In this embodiment, the housing 200 may include a frame 201 and a rear cover 202. The rear cover 202 is fixed to the frame 201. Exemplarily, the rear cover 202 may be fixedly connected to the frame 201 by adhesive. The rear cover 202 may also be an integrally formed structure with the frame 201, that is, the rear cover 202 and the frame 201 are a single integral structure. The housing 200 can be used to support the screen 300. The screen 300 may be located on a side of the frame 201 away from the rear cover 202. At this time, the screen 300 and the rear cover 202 are respectively located on two sides of the frame 201. The screen 300, the frame 201 and the rear cover 202 jointly enclose the interior of the electronic device 1000. The interior of the electronic device 1000 can be used to place components of the electronic device 1000, such as a battery, a receiver or a microphone, etc.

[0078] In this embodiment, the screen 300 can be used to display images, texts, etc. The screen 300 can be a flat screen or a curved screen. In addition, the screen 300 may include a protective cover plate 301 and a display screen 302. The protective cover plate 301 is laminated on the display screen 302. The protective cover plate 301 can be disposed closely to the display screen 302, and can be mainly used to protect the display screen 302 and prevent dust. The material of the protective cover plate 301 can be, but is not limited to, glass. The display screen 302 can adopt an organic light-emitting diode (OLED) display screen, an active-matrix organic light-emitting diode (AMOLED) display screen, a quantum dot light emitting diodes (QLED) display screen, etc.

[0079] As Figure 2 shown, the camera module 100 is fixed inside the electronic device 1000. Figure 2 Schematically shows that the camera module 100 is fixed on the surface of the screen 300 facing the rear cover 202. In some embodiments, the housing 200 may include a middle plate. The middle plate is connected to the inner surface of the frame 201, and the middle plate is located between the screen 300 and the rear cover 202. At this time, the camera module 100 can be fixed on the surface of the middle plate facing the rear cover 202.

[0080] The number of camera modules 100 is not limited to Figure 1 and Figure 2The number of camera modules 100 given can also be two, or more than two. Exemplarily, the camera module 100 can be a periscope camera module. The camera module 100 can be located inside the electronic device 1000. The camera module 100 can be fixed to the side of the screen 300 facing the rear cover 202. The rear cover 202 has a light-transmitting portion 203. The light-transmitting portion 203 can allow ambient light to enter the interior of the electronic device 1000. The camera module 100 can collect the ambient light entering the interior of the electronic device 1000. The shape of the light-transmitting portion 203 is not limited to Figure 1 and Figure 2 the circular shape shown. For example, the shape of the light-transmitting portion 203 can also be oval or an irregular shape.

[0081] As Figure 2 shown, the light-transmitting portion 203 is a through-hole. The through-hole connects the interior of the electronic device 1000 to the outside of the electronic device 1000. In addition, the electronic device further includes a decorative member 204 and a cover plate 205. Part of the decorative member 204 can be fixed to the inner surface of the rear cover 202. Part of the decorative member 204 contacts the hole wall of the through-hole. In addition, the cover plate 205 is fixedly connected to the inner surface of the decorative member 204. The cover plate 205 can prevent external water or dust from entering the interior of the electronic device 1000. The cover plate 205 can be made of glass material or plastic. Figure 2 Schematically shows a setting manner of the light-transmitting portion 203. Of course, the light-transmitting portion 203 can also adopt other setting manners. For example, the material of the rear cover 202 is a transparent material. A partial area of the rear cover 202 forms the light-transmitting portion 203.

[0082] Figure 3 is Figure 2 a schematic structural diagram of the camera module 100 shown.

[0083] As Figure 2 and Figure 3As shown in the figure, the camera module 100 includes an optical lens group 10, an optical waveguide 20, and a photosensitive element 30. The optical lens group 10 is located on the object side of the optical waveguide 20. The optical lens group 10 and the photosensitive element 30 are located on the same side of the optical waveguide 20 and are spaced apart. In another embodiment, the optical lens group 10 and the photosensitive element 30 may also be located on opposite sides of the optical waveguide 20. Among them, the optical lens group 10 mainly uses the refraction principle of the lens to form an image, that is, the scene light passes through the optical lens group 10, forms a clear image on the imaging surface, and the photosensitive element 30 located on the imaging surface records the image of the scene. The optical lens group 10 may be an upright lens group or a periscope lens. In this application, light can pass through the optical lens group 10 along the first optical axis O1 - O1 (negative Z-axis direction) and irradiate onto the optical waveguide 20, and propagate in the optical waveguide 20 along the second optical axis O2 - O2 direction (positive X-axis direction), and finally emit from the optical waveguide 20 along the third optical axis O3 - O3 (positive Z-axis direction) and irradiate onto the photosensitive surface of the photosensitive element 30. Among them, the first optical axis O1 - O1 and the third optical axis O3 - O3 can be perpendicular to the plane where the optical waveguide 20 is located. The photosensitive element 30 converts the optical image into an electrical signal and transmits it to the processor, and the processor transmits the electrical signal to the screen to display the image of the photographed scene on the screen. The photosensitive element 30 (also called an image sensor) is a semiconductor chip with hundreds of thousands to millions of photodiodes on its surface. When irradiated by light, it generates electric charges. The photosensitive element 30 can be a charge-coupled device (CCD) or a complementary metal-oxide semiconductor device (CMOS), which is not specifically limited here.

[0084] Exemplarily, the camera module 100 further includes a filter 40. The filter 40 can be located between the optical waveguide 20 and the photosensitive element 30. The filter 40 is used to filter out the unnecessary bands in the light and make the filtered ambient light project onto the photosensitive element 30, thereby preventing the photosensitive element 30 from generating false colors or ripples and improving its effective resolution and color reducibility. The filter 40 can be, but is not limited to, a blue glass filter. For example, the filter 40 can also be a reflective infrared filter, or a dual-pass filter (the dual-pass filter can allow both visible light and infrared light in the ambient light to pass through, or allow both visible light and other specific wavelength lights (such as ultraviolet light) in the ambient light to pass through, or allow infrared light and other specific wavelength lights (such as ultraviolet light) to pass through.

[0085] As Figure 2 and Figure 3As shown, the optical lens group 10 includes at least one lens. Among them, at least one lens has a positive optical power. Exemplarily, the optical lens group 10 may include a first lens 11, a second lens 12, a third lens 13, and a fourth lens 14 arranged from the object side to the image side (i.e., along the negative direction of the Z axis). The first lens 11, the second lens 12, the third lens 13, and the fourth lens 14 all have positive optical powers, and there is a gap between two adjacent ones of the first lens 11, the second lens 12, and the third lens 13. With such an arrangement, not only the number of lens surfaces in the optical lens group 10 is increased, the design freedom of the optical lens group 10 is increased, which is beneficial to correcting the aberration of the optical lens group 10, but also the number of lenses in the optical lens group 10 is avoided from being too large, thus being beneficial to reducing the weight of the optical lens group 10.

[0086] Of course, at least one of the above-mentioned second lens 12 and third lens 13 may also have a negative optical power. With such an arrangement, the optical powers of the lenses in the optical lens group 10 are arranged in a positive, negative, and positive combination, which is more beneficial to correcting the aberration of the optical lens group 10.

[0087] The above-mentioned optical lens group 10 is not limited to the above structure. The optical lens group 10 may include one lens, two lenses, three lenses, or more than four lenses. It can be understood that when the optical lens group 10 includes multiple lenses, the multiple lenses are arranged from the object side to the image side (i.e., along the negative direction of the Z axis). There is a gap between two adjacent ones of the multiple lenses.

[0088] At least one of the first lens 11 to the fourth lens 14 may be a spherical or aspherical glass lens. At least one of the first lens 11 to the fourth lens 14 may be a fully plastic lens. That is, the optical lens group 10 may include a spherical glass lens, an aspherical glass lens, or a fully plastic lens. The present application does not make specific limitations on this.

[0089] In one embodiment, the optical lens group 10 may further include a lens barrel, and the first lens 11 to the fourth lens 14 may be arranged in the lens barrel. A spacer ring may be provided between two adjacent ones of the first lens 11, the second lens 12, the third lens 13, and the fourth lens 14. A light shielding ring is provided at the edge of at least one of the first lens 11 to the fourth lens 14. The light shielding ring may be annular, so that light can enter from the central region of at least one of the first lens 11 to the fourth lens 14 to eliminate stray light at the edge of the optical lens group 10. The light shielding rings may be respectively provided at the edges of the first lens 11, the second lens 12, the third lens 13, and the fourth lens 14.

[0090] In other embodiments, the optical lens group 10 may not include a lens barrel. At this time, the optical lens group 10 may be installed in the housing 200 of the camera module 100.

[0091] As Figure 2 and Figure 3 shown, the optical lens group 10 and the optical waveguide 20 are separately arranged. It can be understood that the optical lens group 10 and the optical waveguide 20 are arranged in a grouped manner. During the focusing process of the imaging module 100, the distance between the optical lens group 10 and the optical waveguide 20 can change, thereby enabling long focusing.

[0092] In one embodiment, the optical lens group 10 can be a focusing lens group. The optical lens group 10 can move relative to the optical waveguide 20 along the Z-axis direction for focusing. In other words, the optical lens group 10 can move parallel to the first optical axis O1 - O1 relative to the optical waveguide 20 to approach or move away from the optical waveguide 20, thereby achieving focusing. For example, by moving the optical lens group 10 away from the optical waveguide 20 to change the effective focal length (EFL), super macro of the imaging module 100 can be achieved. In addition, the optical lens group 10 is located on the object side of the optical waveguide 20, increasing the movable optical path space, which is conducive to reducing the light turning angle, reducing aberration, and improving the imaging quality.

[0093] In one embodiment, during the focusing process of the optical lens group 10, the first lens 11 and the second lens 12 can form a first lens group, and the third lens 13 and the fourth lens 14 can form a second lens group. The distance between the first lens group and the second lens group can change, thereby enabling super macro. The optical lens group 10 can adopt a single-group focusing method, which simplifies the movement mode of the focusing structure and the focusing method. For example, when the second lens group remains stationary and the first lens group is moved for focusing, the movement mode of the focusing structure of the telephoto lens can be simplified, thereby simplifying the focusing method. In addition, the first lens group is located on the object side of the second lens group, increasing the movable optical path space, which is conducive to reducing the light turning angle, reducing aberration, and improving the imaging quality. The optical lens group 10 can also adopt a double-group focusing method, and both the first lens group and the second lens group can move to change the distance between the first lens group and the second lens group to achieve super macro.

[0094] In one embodiment, the optical lens group 10 can be an anti-shake compensation lens group. Relative to the first optical axis O1-O1, the optical lens group 10 can be laterally displaced or tilted to achieve optical anti-shake. That is, the optical lens group 10 can move relative to the first optical axis O1-O1 so as to be able to compensate for the unwanted, accidental or undesired movement of the device where the imaging module 100 is located due to movement or the like. For example, the optical lens group 10 can move laterally relative to the first optical axis O1-O1 (i.e., move along the second optical axis O2-O2), and can compensate for accidental or unnecessary lateral system movement, thereby achieving optical anti-shake. The optical lens group 10 can be tilted relative to the first optical axis O1-O1 to compensate for the angular rotation or swing of the device where the system is located. It can be understood that there are two types of movements for the optical lens group 10 to achieve optical anti-shake: eccentricity (X-Y displacement) and tilt, which can be applied alone or in combination. Relative to the first optical axis O1-O1, eccentricity movement and tilt can be used to compensate for X-Y displacement and rotation under exposure conditions.

[0095] In one embodiment, the imaging module 100 can further include an actuator (not shown in the figure), and the optical lens group 10 can be coupled to the actuator. The actuator can drive the optical lens group 10 to achieve Z-axis movement relative to the first optical axis O1-O1 to achieve focusing; the actuator can drive the optical lens group 10 to perform tilt and eccentricity movements relative to the first optical axis O1-O1 to achieve optical anti-shake.

[0096] In one embodiment, relative to the third optical axis O3-O3, the photosensitive element 30 can be laterally displaced (move along the X-axis direction) to achieve optical anti-shake. That is, the photosensitive element 30 can move relative to the third optical axis O3-O3 so as to be able to compensate for the unwanted, accidental or undesired movement of the device where the imaging module 100 is located due to movement or the like.

[0097] As Figure 3 shown, the optical waveguide 20 has a light-coupling region 210 and a light-output region 220. The light-coupling region 210 is disposed opposite to the optical lens group 10, and the light-output region 220 is disposed opposite to the photosensitive element 30. It can be understood that the light-coupling region 210 can be a partial physical region of the optical waveguide 20 that is disposed opposite to the optical lens group 10 ( Figure 3 the light-coupling region 210 is schematically shown by a dashed line box), and the light-output region 220 can be a partial physical region of the optical waveguide 20 that is disposed opposite to the photosensitive element 30 ( Figure 3The coupling-in region 210 is schematically shown by a dashed box. The coupling-in region 210 of the optical waveguide 20 is provided with a coupling-in element 22, and the coupling-in element 22 faces the optical lens group 10. The coupling-out region 220 of the optical waveguide 20 is provided with a coupling-out element 23, and the coupling-out element 23 faces the photosensitive element 30. It can be understood that the coupling-in element 22 facing the optical lens group 10 means that at least half of the region of the coupling-in element 22 in the X-axis direction is directly opposite to the optical lens group 10. The coupling-out element 23 facing the photosensitive element 30 means that at least half of the region of the coupling-out element 23 in the X-axis direction is directly opposite to the photosensitive element 30. Exemplarily, the coupling-in element 22 can be directly opposite to the optical lens group 10, and the coupling-out element 23 can be directly opposite to the photosensitive element 30. In the embodiment of the present application, the light refracted by the optical lens group 10 irradiates the coupling-in element 22 in the coupling-in region 210, is coupled into the interior of the optical waveguide 20 through the coupling-in element 22, and propagates in the optical waveguide 20 in the form of total internal reflection (TIR). Subsequently, the light irradiates the coupling-out element 23 in the coupling-out region 220, and the optical waveguide 20 is coupled out through the coupling-out element 23 in the coupling-out region 220 and irradiates the photosensitive element 30. It can be understood that the scene light can be received by the photosensitive element 30 after being refracted by the optical lens group 10 and reflected by the optical waveguide 20.

[0098] Figure 4 is Figure 3 the schematic diagram of the total internal reflection transmission principle of the optical path of the optical waveguide 20 shown in the figure.

[0099] As Figure 3 and Figure 4 shown, the reason why light can propagate in the optical waveguide 20 in the form of total internal reflection is that: there is a total reflection effect when light propagates from a high refractive index medium n1 to a low refractive index medium n2 (for example, light enters air from glass). Total internal reflection refers to the phenomenon that when light enters a low refractive index medium n2 from a high refractive index medium n1, the incident angle or diffraction angle of the light exceeds a certain critical angle, and the refracted light completely disappears, leaving only the reflected light. Since the material of the optical waveguide 20 generally uses glass, whose refractive index is greater than that of air, therefore, when light enters the optical waveguide 20 at an angle θ A (that is, the incident angle θ A of the light satisfies the following formula), the light can achieve total internal reflection propagation in the optical waveguide 20.

[0100]

[0101] where θ A is the incident angle of the light entering the optical waveguide 20, θ B is the total reflection critical angle of the optical waveguide 20, and n C is the refractive index parameter of the coupling-in element 22.

[0102] As shown Figure 3 After the light rays collected by the optical lens group 10 are coupled into the optical waveguide 20, they are transmitted in the optical waveguide 20 in the form of total internal reflection, and finally coupled out of the optical waveguide 20 and focused on the photosensitive element 30. In the embodiment of the present application, the optical waveguide 20 is used to deflect and propagate the light rays collected by the optical lens group 10. The light rays refracted from the optical lens group 10 can enter the interior of the optical waveguide 20 through the coupling element 22 from the coupling region 210. After total internal reflection propagation in the optical waveguide 20, they are emitted from the optical waveguide 20 through the coupling element 23 from the coupling-out region 220. In the present application, when the diameter of the optical lens group 10 increases, the optical waveguide 20 does not need to increase the thickness dimension (the dimension in the Z-axis direction). The light rays refracted from the optical lens group 10 can still enter the interior of the optical waveguide 20 through the coupling element 22 from the coupling region 210. After total internal reflection propagation in the optical waveguide 20, they are emitted from the optical waveguide 20 through the coupling element 23 from the coupling-out region 220. The optical lens group 10 can achieve a large target surface, so that the imaging module 100 can achieve a large aperture effect. In other words, the imaging module 100 of the present application uses the optical waveguide 20 to deflect and propagate the light rays collected by the optical lens group 10. After the diameter of the optical lens group 10 increases, the dimension of the optical waveguide 20 in the Z-axis direction does not need to increase. The imaging module 100 has a large target surface and a small thickness. The imaging module 100 can achieve both large aperture, miniaturization and thinness and lightness.

[0103] Figure 5 FIG. is a schematic structural diagram of an imaging module 100a using a prism system for imaging. Exemplarily, Figure 5 illustrates a solution in which the imaging module 100a uses a prism 20a to deflect and propagate the light rays collected by the optical lens group 10a.

[0104] As Figure 5As shown, the prism 20a includes at least four surfaces, namely the first surface S1, the second surface S2, the third surface S3, and the fourth surface S4. Among them, the first surface S1 can face the optical lens group 10a and the photosensitive element 30a, and the third surface S3 is arranged opposite to the first surface S1. The second surface S2 and the fourth surface S4 are connected between the first surface S1 and the third surface S3, and the second surface S2 and / or the fourth surface S4 can individually include a reflective coating (or reflector). Therefore, the second surface S2 and the fourth surface S4 of the prism 20a can reflect light at the corresponding surfaces. The first surface S1 and the third surface S3 of the prism 20a can transmit light or allow light to pass through the corresponding surfaces. The prism 20a can guide the light from the optical lens group 10a through the prism 20a to reach the photosensitive element 30a. For example, the light from the optical lens group 10a can pass through the first surface S1 of the prism 20a and enter the prism 20a. At least some of the light can reach the second surface S2 of the prism 20a and then be reflected at the second surface S2. At least some of the light reflected from the second surface S2 of the prism 20a can be reflected to the first surface S1 of the prism 20a and be reflected at the first surface S1. Finally, at least some of the light reflected from the first surface S1 of the prism 20a can reach the fourth surface S4 of the prism 20a, be reflected at the fourth surface S4, and leave the prism 20a to be focused on the photosensitive element 30a.

[0105] It can be understood that Figure 5 For the shown imaging module 100a, the diameter of the optical lens group 10a (i.e., the dimension in the X-axis direction) is limited by the thickness of the prism 20a (i.e., the dimension in the Z-axis direction). When the diameter of the optical lens group 10a increases, the dimensions of the second surface S2 in the X-axis and Y-axis directions also need to increase accordingly, and the dimension of the second surface S2 in the Z-axis direction will also increase, resulting in an increase in the thickness of the prism 20a. In this way, the dimension of the imaging module 100a in the Z-axis direction increases, which is not conducive to the miniaturization and thinning of the imaging module 100a. To achieve a large target surface for the imaging module 100a, it is necessary to increase the dimension of the imaging module 100a in the Z-axis direction. In addition, due to the limitation of the total optical length, the light in the prism 20a needs to be reflected a certain number of times to meet the total optical length. Therefore, under the condition of a certain total optical length, the dimensions of the prism 20a in the X-axis and Y-axis directions are relatively large, which is not conducive to the miniaturization of the imaging module 100a. Therefore, the imaging module 100a using a prism system cannot achieve both a large aperture and miniaturization.

[0106] As Figure 3As shown, in the present application, the light refracted from the optical lens group 10 can enter the interior of the optical waveguide 20 from the light coupling-in region 210 through the light coupling-in element 22. After propagating within the optical waveguide 20, it exits the optical waveguide 20 through the light coupling-out region 220 via the light coupling-out element 23. When the diameter of the optical lens group 10 increases, the optical waveguide 20 does not need to increase its thickness dimension (dimension in the Z-axis direction), and the light can still be coupled into the optical waveguide 20 and totally reflected and propagated within the optical waveguide 20 before being incident on the photosensitive element 30. That is to say, the optical waveguide 20 can achieve a large target surface without increasing its thickness dimension (dimension in the Z-axis direction), so that the imaging module 100 can achieve a large aperture effect and miniaturization. Compared with Figure 5 the prism solution shown, the imaging module 100 of the present application uses the optical waveguide 20 to deflect and propagate the light collected by the optical lens group 10. Without increasing the thickness of the optical waveguide 20, the diameter of the optical lens group 10 can be increased, achieving a large target surface, and the imaging module 100 has a large aperture effect. The imaging module 100 of the present application can balance large aperture, miniaturization, and thinness. In addition, the optical lens group 10 can move away from the optical waveguide 20 along the first optical axis O1 - O1 to change the effective focal length (EFL), thereby achieving super macro shooting. Since the thickness of the optical waveguide 20 in the Z-axis direction is small, under the condition that the size of the imaging module 100 is fixed, the moving stroke of the first lens 11 of the optical lens group 10 in the Z-axis direction is long, and the change range of the effective focal length is large, so that super macro shooting in more scenarios can be satisfied.

[0107] Figure 6 Figure Figure 2 6 is a schematic structural diagram of the imaging module 100 in an embodiment.

[0108] As shown in Figure 6As shown, the optical waveguide 20 can be an integrated optical waveguide, such as a diffractive optical waveguide, a geometric optical waveguide, etc. The optical waveguide 20 includes a substrate 21, an input coupling element 22, and an output coupling element 23. Among them, the substrate 21 can be glass, resin, plastic, etc., such as K9 glass. Among them, the length extension direction of the substrate 21 can be the X-axis direction. The thickness extension direction of the substrate 21 can be the Z-axis direction. At this time, the first optical axis O1 - O1 and the third optical axis O3 - O3 can be perpendicular to the length extension direction of the substrate 21. The second optical axis O2 - O2 can be parallel to the length extension direction of the substrate 21. The thickness of the substrate 21 (i.e., the dimension in the Z-axis direction) is in the range of 1 to 3 mm, such as 1 mm, 2 mm, 3 mm, etc. The length of the substrate 21 (i.e., the dimension in the X-axis direction) is 18 - 28 mm, such as 18 mm, 20 mm, 25 mm, 28 mm, etc. It can be understood that the small thickness of the substrate 21 of the optical waveguide 20 can reduce the size of the imaging module 100 in the thickness direction (i.e., in the Z-axis direction), which is beneficial to the miniaturization and thinness of the electronic device 1000. It can be understood that the input coupling region 210 can be a partial solid region of the substrate 21 facing the optical lens group 10, and the output coupling region 220 can be a partial solid region of the substrate 21 facing the photosensitive element 30. The input coupling element 22 is disposed in the input coupling region 210 and is used to couple the light irradiated from outside the optical waveguide 20 to the input coupling region 210 into the substrate 21. The output coupling element 23 is disposed in the output coupling region 220 and is used to couple the light irradiated from inside the substrate 21 to the output coupling region 220 out of the substrate 21. Specifically, when the light irradiates the optical lens group 10 and is refracted by the optical lens group 10 and then irradiates the input coupling region 210, it can enter the substrate 21 through the input coupling element 22 from the input coupling region 210. Subsequently, the light propagates in the substrate 21 in the form of total internal reflection, and finally irradiates the output coupling region 220. It is emitted from the substrate 21 through the output coupling element 23 of the output coupling region 220 and is received by the photosensitive element 30, and an image is formed on the photosensitive element 30. Among them, the input coupling element 22 can be disposed on the surface of the substrate 21 facing the optical lens group 10 or inside the substrate 21. The output coupling element 23 can be disposed on the surface of the substrate 21 facing the photosensitive element 30 or inside the substrate 21.

[0109] In one embodiment, the camera module 100 may further include an optical element 60. The optical element 60 may be located between the light-coupling element 23 and the photosensitive element 30. It can be understood that the optical element 60 is used to focus the light coupled out by the light-coupling element 23 onto the photosensitive element 30. After passing through the optical element 60, the coupled-out light can form a smaller focused spot on the photosensitive element 30, thereby improving the imaging clarity, that is, improving the imaging effect of the camera module 100. The optical element 60 may include one or more lenses. By changing the refractive index parameters and / or curvature radii of one or more lenses in the optical element 60, multiple light rays emitted from the light-coupling element 23 can be focused onto the photosensitive element 30 after passing through the optical element 60. For example, one or more lenses in the optical element 60 may be lenses with a relatively large curvature. In this way, after multiple light rays in the substrate 21 of the optical waveguide 20 are emitted from the light-coupling element 23 and refracted by one or more lenses in the optical element 60, the multiple light rays can be focused onto the photosensitive element 30, thereby improving the imaging clarity and the imaging quality of the camera module 100.

[0110] In addition, the camera module 100 may further include a motor (not shown in the figure). The optical element 60 may be mounted on the motor. The motor may be used to drive the optical element 60 to move along the optical axis direction of the photosensitive element 30 (that is, the third optical axis O3 - O3 direction). The motor may be connected to the lens barrel of one or more lenses in the optical element 60. The motor can drive one or more lenses in the optical element 60 to move along the third optical axis O3 - O3 direction (that is, the optical axis direction of the photosensitive element 30) for focusing, so that the camera module 100 can achieve autofocus when focusing on objects with different object distances. The motor can also drive one or more lenses in the optical element 60 to move in a direction perpendicular to the third optical axis O3 - O3 direction (that is, the X-axis direction) to compensate for the displacement of the camera module 100 in the X-axis direction, thereby realizing the anti-shake function of the camera module 100. It should be noted that the thicknesses of the optical element 60 and the photosensitive element 30 in the Z-axis direction are less than or equal to the thickness of the optical lens group 10 in the Z-axis direction. In this way, in the Z-axis direction, the distance between the photosensitive element 30 and the surface of the substrate 21 facing the photosensitive element 30 is less than or equal to the distance between the optical lens group 10 and the surface of the substrate 21 facing the optical lens group 10, and the thickness of the camera module 100 in the Z-axis direction will not increase.

[0111] Exemplarily, the light-coupling element 22 may be disposed on the surface of the substrate 21 facing the optical lens group 10. At this time, the light-coupling element 22 may be located on the optical path between the optical lens group 10 and the optical waveguide 20. The refractive index of the substrate 21 may be the same as that of the light-coupling element 22. The refractive index of the substrate 21 may also be less than that of the light-coupling element 22. The light refracted by the optical lens group 10 may be coupled into the substrate 21 of the optical waveguide 20 via the light-coupling element 22 and be guided to propagate by total internal reflection within the substrate 21. The light-coupling element 22 may include a plurality of turning features configured to turn the light incident thereon at a specific angle into the substrate 21 of the optical waveguide 20 to be guided within the substrate 21 of the optical waveguide 20 by total internal reflection. The light-coupling element 22 may be transmissive or reflective and may propagate light in a transmissive or reflective manner. For example, the light-coupling element 22 may include a transmissive or reflective diffractive optical element (e.g., a grating) or a holographic optical element that works in a transmissive or reflective manner respectively, so that the light transmitted through or reflected from it is turned, and the incident angle of the turned light satisfies the total internal reflection condition of the optical waveguide 20. For example, the light-coupling element 22 may include a reflective optical element (e.g., a lens), so that the light reflected from it is turned, and the incident angle of the turned light satisfies the total internal reflection condition of the optical waveguide 20.

[0112] Exemplarily, the light-extracting element 23 may be disposed on the surface of the substrate 21 facing the photosensitive element 30. At this time, the light-extracting element 23 may be located on the optical path between the optical waveguide 20 and the photosensitive element 30. The light within the substrate 21 of the optical waveguide 20 may be extracted from the substrate 21 of the optical waveguide 20 via the light-extracting element 23 and irradiate on the photosensitive element 30. The light-extracting element 23 may include a plurality of turning features configured to turn the light incident thereon at a specific angle into the substrate 21 of the optical waveguide 20 to be guided within the substrate 21 of the optical waveguide 20 by total internal reflection. The light-extracting element 23 may be transmissive or reflective and may propagate light in a transmissive or reflective manner. For example, the light-extracting element 23 may include a transmissive or reflective diffractive optical element (e.g., a grating) or a holographic optical element that works in a transmissive or reflective manner respectively, so that the light transmitted through or reflected from it is turned, and the incident angle of the turned light satisfies the total internal reflection condition of the optical waveguide 20. For example, the light-extracting element 23 may include a reflective optical element (e.g., a lens), so that the light reflected from it is turned, and the incident angle of the turned light satisfies the total internal reflection condition of the optical waveguide 20.

[0113] As Figure 6As shown, the substrate 21 of the optical waveguide 20 includes a first surface 211 and a second surface 212 disposed back to back, and a first end face 213 and a second end face 214 disposed back to back. Among them, the first end face 213 and the second end face 214 are connected between the first surface 211 and the second surface 212. The optical lens group 10 and the photosensitive element 30 can be located on the same side of the optical waveguide 20 and are spaced apart. The first surface 211 faces the optical lens group 10 and the photosensitive element 30, and the second surface 212 is located on the side of the first surface 211 facing away from the optical lens group 10 and the photosensitive element 30.

[0114] Exemplarily, both the coupling-in element 22 and the coupling-out element 23 can be disposed on the first surface 211. The light refracted by the optical lens group 10 can be coupled into the substrate 21 of the optical waveguide 20 by the coupling-in element 22 from the first surface 211. Subsequently, after the light undergoes multiple total internal reflections in the substrate 21 of the optical waveguide 20, it can be coupled out of the optical waveguide 20 by the coupling-out element 23 from the first surface 211 and irradiate onto the photosensitive element 30. In another implementation, both the coupling-in element 22 and the coupling-out element 23 can be disposed on the second surface 212. The light refracted by the optical lens group 10 can be coupled into the substrate 21 by the coupling-in element 22 from the second surface 212. Subsequently, after the light undergoes multiple total internal reflections in the substrate 21, it can be coupled out of the substrate 21 by the coupling-out element 23 from the second surface 212 and irradiate onto the photosensitive element 30.

[0115] Exemplarily, the first surface 211 includes an incident surface 2111, a first total reflection surface 2112, and an exit surface 2113 that are sequentially connected. The incident surface 2111 faces the optical lens group 10. The exit surface 2113 of the first surface 211 faces the photosensitive element 30. At this time, the coupling-in element 22 can be disposed on the incident surface 2111 of the first surface 211 or in the substrate 21 facing the incident surface 2111. The coupling-out element 23 can be disposed on the exit surface 2113 of the first surface 211 or in the substrate 21 facing the exit surface 2113 of the first surface 211. The second surface 212 is a total reflection surface. After the light enters the substrate 21 of the optical waveguide 20 from the incident surface 2111, it is reflected multiple times between the second surface 212 and the first total reflection surface 2112, and then exits from the exit surface 2113 of the first surface 211. It can be understood that the portion of the first surface 211 of the substrate 21 located between the coupling-in region 210 and the coupling-out region 220 is a total reflection surface (i.e., the first total reflection surface 2112). The second surface 212 of the substrate 21 is a total reflection surface (i.e., the first total reflection surface 2112). When the light in the substrate 21 of the optical waveguide 20 irradiates the portion of the first surface 211 located between the coupling-in region 210 and the coupling-out region 220, and the second surface 212, it can be reflected back into the substrate 21 of the optical waveguide 20 at the portion of the first surface 211 located between the coupling-in region 210 and the coupling-out region 220, and at the second surface 212.

[0116] In one embodiment, both the first end face 213 and the second end face 214 are light absorption layers, which are used to absorb stray light, prevent the stray light from imaging on the photosensitive element 30, and eliminate the influence of the stray light on the image quality. Both the first end face 213 and the second end face 214 can be subjected to an ink coating and blackening treatment.

[0117] Figure 7 For Figure 2 the structural schematic diagram of the imaging module 100 shown in another embodiment.

[0118] As Figure 7As shown, in another embodiment, the optical lens group 10 and the photosensitive element 30 can be located on opposite sides of the optical waveguide 20. The first surface 211 of the substrate 21 is disposed facing the optical lens group 10. The second surface 212 of the substrate 21 is located on the side of the first surface 211 facing away from the optical lens group 10 and is disposed facing the photosensitive element 30. The first surface 211 may include an incident surface 2111 and a first total reflection surface 2112 that are connected to each other. Among them, the incident surface 2111 faces the optical lens group 10 directly. The portion of the first surface 211 of the substrate 21 that is offset from the optical lens group 10 is a total reflection surface (i.e., the first total reflection surface 2112). The second surface 212 may include a second total reflection surface 2121 and an exit surface 2122 that are connected to each other. Among them, the exit surface 2122 of the second surface 212 faces the photosensitive element 30 directly. The portion of the second surface 212 of the substrate 21 that is offset from the photosensitive element is a total reflection surface (i.e., the second total reflection surface 2121). At this time, the coupling-in element 22 can be disposed on the incident surface 2111 of the first surface 211 or in the substrate 21 facing the incident surface 2111 directly. The coupling-out element 23 can be disposed on the exit surface 2122 of the second surface 212 or in the substrate 21 facing the exit surface 2122 of the second surface 212 directly. After the light enters the substrate 21 of the optical waveguide 20 from the incident surface 2111, it undergoes multiple reflections between the first total reflection surface 2112 and the second total reflection surface 2121 and then exits from the exit surface 2122 of the second surface 212.

[0119] Figure 8 For Figure 6 the optical path diagram of the optical waveguide 20 shown in one embodiment.

[0120] As Figure 8 shown, in one embodiment, the optical waveguide 20 is a diffractive optical waveguide. The diffractive optical waveguide utilizes the diffraction effect of micro-nano optical elements on light to achieve the coupling-in and coupling-out of light. Both the coupling-in element 22 and the coupling-out element 23 of the diffractive optical waveguide can be diffraction gratings. The refractive index of the diffraction grating has a periodic change, which can deflect light so that the incident angle of the light entering the substrate 21 of the optical waveguide 20 is greater than the total reflection critical angle of the optical waveguide 20. At this time, the light satisfies the total reflection condition and can propagate in the substrate 21 of the optical waveguide 20 in the form of total internal reflection.

[0121] Diffractive optical waveguides include surface relief grating waveguides (Diffractive Waveguide with Surface Relief Grating) fabricated using lithography techniques and volumetric holographic waveguides (Diffractive Waveguide with Volumetric Holographic) fabricated based on holographic interference techniques, etc. Among them, surface relief gratings have a large refractive index difference and can diffract light beams in a larger wavelength range. Surface relief gratings can be mass-produced by nanoimprinting. Holographic gratings have good incident light wavelength selectivity and incident angle selectivity. When the incident light angle and wavelength satisfy the Bragg condition, the diffraction efficiency of the holographic grating is relatively high. In the embodiments of this application, no limitation is imposed on the specific structure of the grating, and it can be one of a surface relief grating and a holographic grating. Those skilled in the art can make a choice according to the actual situation. Below, the structure and related optical principles of the diffractive optical waveguide will be specifically introduced in conjunction with relevant drawings.

[0122] Exemplarily, the coupling-in element 22 can be formed on the first surface 211 of the substrate 21. For example, a surface holographic or diffractive optical element (such as a surface relief grating) can be fabricated by patterning (such as etching) the first surface 211 of the substrate 21. The holographic or diffractive optical element can also be formed by changing the refractive index of the material of the substrate 21. Exemplarily, the diffraction grating is disposed opposite to the optical lens group 10. The light rays refracted by the optical lens group 10 can be redirected after diffraction by the diffraction grating, and thus can be coupled into the substrate 21 and propagate in a total internal reflection manner.

[0123] It can be understood that since the light rays are incident on the coupling-in element 22 at an oblique incident angle, the required diffraction coupling condition can be achieved by controlling the diffraction coupling of the incident light into the substrate 21, so that the light rays can propagate in the substrate 21 of the optical waveguide 20 in a total internal reflection manner to the coupling-out element 23 and be emitted from the coupling-out element 23 out of the substrate 21 of the optical waveguide 20. By designing the relevant parameters of the diffraction grating (such as the refractive index of the material, the shape, thickness, duty cycle, etc. of the grating), the diffraction efficiency of a certain diffraction order (i.e., a certain direction) can be optimized to the highest, so that most of the light mainly propagates in this direction after diffraction. For example, by selecting the incident angle of the light rays entering the substrate 21 and the grating period to make the light rays satisfy the total internal reflection condition of the optical waveguide 20.

[0124] Figure 9 For Figure 6 A partial enlarged view of an embodiment of the optical waveguide 20 shown at A.

[0125] As Figure 9As shown, in one embodiment, the coupling element 22 may be a surface relief grating. At this time, the diffraction grating is a relief structure with periodic changes. Specifically, the relief structure may include alternately arranged protrusions 221 and grooves 222. The refractive index of the diffraction grating is different at the positions of the protrusions 221 and the grooves 222, so that the refractive index of the coupling element 22 has periodic changes. By designing the relevant parameters of the diffraction grating (such as the refractive index of the material, the shape, thickness, duty cycle, etc. of the grating), the diffraction efficiency of a certain diffraction order (i.e., a certain direction) can be optimized to the highest, so that most of the light mainly propagates in this direction after diffraction. For example, by selecting the incident angle of the light entering the substrate 21 and the grating period so that the light satisfies the total reflection condition of the optical waveguide 20.

[0126] Figure 10 is Figure 2 the optical path diagram of the camera module 100 shown in the figure.

[0127] As Figures 8 to 10 shown, the light irradiated onto the diffraction grating at different incident angles θ i after being refracted by the optical lens group 10 can be diffracted by the diffraction grating to a certain specific angle θ A1 , and make this angle θ A1 meet the total reflection condition of the optical waveguide 20 (that is, θ A1 is greater than θ B1 , where θ B1 is the total emission critical angle of the diffractive optical waveguide). At this time, the light can propagate in the substrate 21 of the diffractive optical waveguide in the form of total internal reflection. Among them, the angle θ A1 of the light passing through the diffraction grating satisfies the following formula:

[0128]

[0129] In the above formula, θ i is the incident angle of the light incident on the coupling element 22, n i is the refractive index of the propagation medium of the light before it is incident on the coupling element 22, θ A1 is the diffraction angle of the light diffracted by the diffraction grating, n C1 is the refractive index of the medium after incidence (i.e., the refractive index of the diffraction grating), λ k is the wavelength of the light, m k is the working order of the diffraction grating, Ф kis the period of the diffraction grating. Herein, the working order of the diffraction grating, also known as the working series of the diffraction grating, refers to the order to which the diffraction grating diffracts the incident light. After passing through the diffraction grating, the incident light will be diffracted into +-1 order light, +-2 order light, +-3 order light, etc. By setting information such as the refractive index, period, step height of the grating, and the angle and wavelength of the incident light, it is ultimately determined to which order the diffracted light will be diffracted. For example, if the working order of the diffraction grating is 2, then the main energy after diffraction will be concentrated in the +2 order light, and the energy of the light of other orders is relatively low. The working order of the diffraction grating is related to information such as the refractive index, period, step height of the diffraction grating, and the angle and wavelength of the incident light. Information such as the refractive index, period, step height of the diffraction grating, and the angle and wavelength of the incident light determines to which order the incident light will be diffracted. Regarding the period Ф of the diffraction grating k : The diffraction grating is composed of periodically repeating unit structures, and the length of one repeating unit structure is called the period of the diffraction grating. For example, Figure 9 in, the width of an adjacent protrusion 221 and the width of a groove 222 together form a period. It should be noted that in an actual diffraction grating, the period of the diffraction grating may not simply be composed of the width of a protrusion 221 and the width of a groove 222.

[0130] It can be understood that from the above formula, when the incident angle θ of the light incident on the coupling element 22 i and the wavelength λ of the light k are determined, the diffraction angle θ of the light after being diffracted by the grating A1 is related to the refractive index n of the material of the grating C1 the working order m of the grating k and the period Ф of the grating k By designing the refractive index of the material of the grating, the working order m of the grating k and the period Ф of the grating k , the diffraction angle θ of the light after being diffracted by the grating A1 meets the total reflection condition of the optical waveguide 20 (that is, θ A1 is greater than θ B1 , where θ B1 is the total reflection critical angle of the diffracted optical waveguide), then the light can be coupled into the substrate 21 of the optical waveguide 20 and totally reflected and propagated in the substrate 21. Specifically, by changing the refractive index of the material of the diffraction grating, the shape, thickness, duty cycle, etc. of the grating, the refractive index of the material of the grating, the working order m of the grating k and the period Ф of the grating k etc. can be changed, thereby changing the diffraction angle θ of the light A1 , so that the angle θ A1It meets the total internal reflection condition of the optical waveguide 20, enabling light to propagate in the diffractive optical waveguide in the form of total internal reflection.

[0131] In addition, through the above formula, the design of the diffraction grating can also be carried out based on the angle distribution matrix of the outgoing light rays of the optical lens group 10. For example, by obtaining the angle distribution matrix of the outgoing light rays of the optical lens group 10, specifically, it can be the angle distribution matrix of the outgoing light rays of the fourth lens 14, and substituting the incident angle θ of each matrix obtained into the light incident coupling element 22 i into the above formula, the refractive index n of the material of the diffraction grating can be obtained by conversion C1 , the working order m of the grating k and the period Ф of the grating k . Thus, the design parameters of the diffraction grating (such as the refractive index of the material of the diffraction grating, the shape, thickness, duty cycle, etc. of the grating) can be obtained, enabling the light to be coupled into the substrate 21 of the optical waveguide 20 after being diffracted by the diffraction grating and propagate in the substrate 21 of the geometric optical waveguide in the form of total internal reflection. It should be understood that when the diameter of the optical lens group 10 increases, the angle matrix of the light rays refracted by the optical lens group 10 will also change accordingly, and then the relevant parameter design of the coupling element 22 of the optical waveguide 20 also needs to be changed accordingly.

[0132] Exemplarily, the coupling-out element 23 can be formed on the first surface 211 of the substrate 21. For example, a surface holographic or diffractive optical element (such as a surface relief grating) can be fabricated by patterning (such as etching) the first surface 211 of the substrate 21. The holographic or diffractive optical element can also be formed by changing the refractive index of the material of the substrate 21. Exemplarily, the diffraction grating is disposed opposite to the photosensitive element 30. The light rays after multiple total internal reflections in the substrate 21 of the optical waveguide 20 can be diffracted out of the substrate 21 by the diffraction grating and irradiated onto the photosensitive element 30 to be received by the photosensitive element 30.

[0133] Exemplarily, the coupling-out element 23 can be a surface relief grating. At this time, the diffraction grating can be a relief structure with periodic changes. Specifically, the relief structure can include alternately arranged protrusions 221 and grooves 222. The refractive index of the diffraction grating is different at the positions of the protrusions 221 and the grooves 222, making the refractive index of the coupling-out element 23 have periodic changes. By designing the relevant parameters of the diffraction grating (such as the refractive index of the material, the shape, thickness, duty cycle, etc. of the grating), the diffraction efficiency of a certain diffraction order (i.e., a certain direction) can be optimized to the highest, so that most of the light mainly propagates in this direction after diffraction. For example, by selecting the grating period of the coupling-out element 23, the light rays propagated through the optical waveguide 20 can be received by the photosensitive element 30 and imaged on the photosensitive element 30.

[0134] In this embodiment, both the coupling-in element 22 and the coupling-out element 23 are diffraction gratings. The imaging module 100 can be designed by adjusting relevant parameters of the diffraction grating (e.g., the refractive index of the grating material, the working order of the grating, and the period of the grating) such that when light rays with different incident angles θ i shine on the coupling-in element 22, they can be diffracted by the coupling-in element 22 and redirected, and the diffraction angle θ A1 of the light rays meets the total internal reflection condition of the optical waveguide 20. At this time, the light rays can be coupled into the substrate 21 of the optical waveguide 20 and propagate in the substrate 21 of the optical waveguide 20 in the form of total internal reflection. Subsequently, the light rays that have undergone multiple total internal reflections in the substrate 21 of the optical waveguide 20 can be irradiated onto the photosensitive element 30 through the diffraction of the coupling-out element 23.

[0135] In addition, since the angles θ i of the light rays diffracted by the diffraction grating satisfy the following formula:

[0136]

[0137] where θ i is the incident angle of the light rays on the coupling-in element 22, n i is the refractive index of the propagation medium of the light rays before they enter the coupling-in element 22, θ A1 is the diffraction angle of the light rays after being diffracted by the diffraction grating, n C1 is the refractive index of the medium after incidence (i.e., the refractive index of the diffraction grating), λ k is the wavelength of the light rays, m k is the working order of the diffraction grating, Ф k is the period of the diffraction grating. When the parameters of the optical waveguide 20 are set (e.g., the period Ф k of the diffraction grating, the refractive index n C1 , the working order m k ), and the wavelength λ k of the light rays are determined, the incident angle θ A1 of the light rays that can be coupled into the optical waveguide 20 can be obtained according to the above formula, thereby determining the field of view angle of the imaging module 100.

[0138] It can be understood that the diffraction grating has high color selectivity. When light of different wavelengths (colors) is incident on the optical waveguide 20 at the same angle, the diffraction angles of light of different wavelengths (colors) may be different, and chromatic dispersion is likely to occur, and the imaging shows a rainbow phenomenon. In this embodiment, by designing the angular parameters of the coupling-in element 22 (corresponding to the grating size, refractive index, and working order of the diffractive optical waveguide) through the above formula, light rays with different incident angles θ i can be specifically diffracted to a certain angle θ A1, and make it meet the total reflection requirements of the optical waveguide 20. In this way, when lights of different wavelengths (colors) are incident on the optical waveguide 20 at the same angle, their diffraction angles are the same, and when lights of different wavelengths (colors) are emitted from the optical waveguide 20 at the same angle, their diffraction angles are also the same. Thus, the dispersion problem caused by different diffraction angles of lights of different wavelengths can be eliminated, ensuring the imaging effect of the electronic device 1000.

[0139] It can be understood that the diffraction grating has high selectivity for angles. When a single wavelength is incident on the optical waveguide 20 at different angles, its diffraction angles are different, and there is easily a distortion problem. The imaging shows that there are differences in the distortion / enlargement magnification corresponding to objects in different fields of view (different incident cone angles). In this embodiment, the angle parameters of the coupling element 22 (corresponding to the grating size, refractive index, and working order of the diffraction optical waveguide) are designed through the above formula, so that when a single-wavelength light is incident on the optical waveguide 20 at different angles, its diffraction angles are the same. Thus, the distortion problem caused by different diffraction angles of the single-wavelength light can be eliminated, ensuring the imaging effect of the electronic device 1000.

[0140] In one embodiment, by adjusting the optical power of the optical lens group 10, for example, reducing the curvature of at least one lens in the optical lens group 10, the light rays refracted by the optical lens group 10 can form parallel light, thereby improving the coupling efficiency of the coupling element 22 and enhancing the imaging quality of the electronic device 1000. In addition, a lens with a larger curvature can also be arranged between the photosensitive element 30 and the optical waveguide 20 to improve the imaging quality of the electronic device 1000.

[0141] Another embodiment of the present application provides an imaging module 100. The imaging module 100 in another embodiment of the present application is similar to the imaging module 100 in the above embodiment. The difference lies in that the structure of the optical waveguide 20 in the imaging module 100 in another embodiment of the present application is different. The following mainly describes the difference solutions here. For the other structures of the imaging module 100 in another embodiment of the present application and the setting manners of each structure, reference can be made to the relevant descriptions of any possible implementation manner in the above embodiment, and specifically, it will not be elaborated here. For example, for the structures and setting manners of the optical lens group 10 and the photosensitive element 30, as well as the relative position relationship between the optical lens group 10, the photosensitive element 30, and the optical waveguide 20, etc., reference can be made to the relevant descriptions of any possible implementation manner in the above embodiment, and specifically, it will not be elaborated here.

[0142] Figure 11 is Figure 2 a schematic structural diagram of the imaging module 100 in another embodiment. For ease of understanding, Figure 11 the coupling element 22 and the coupling-out element 23 are schematically framed by a narrow dashed line, and the coupling-in area 210 and the coupling-out area 220 are also schematically framed by a wide dashed line.

[0143] As Figure 11 shown, in another embodiment, the optical waveguide 20 may be a geometric optical waveguide. The geometric optical waveguide is also called an array optical waveguide, which is formed by stacking semi-transmissive and semi-reflective array mirrors. The structure and related optical principles of the geometric optical waveguide will be specifically introduced below in conjunction with the relevant drawings.

[0144] The geometric optical waveguide includes a substrate 21, an input coupling element 22, and an output coupling element 23. It can be understood that the input coupling region 210 may be a partial solid region of the substrate 21 facing the optical lens group 10, and the output coupling region 220 may be a partial solid region of the substrate 21 facing the photosensitive element 30. Among them, the input coupling element 22 is embedded in the substrate 21 facing the optical lens group 10. That is, the input coupling element 22 is disposed in the input coupling region 210 and is used to couple the light irradiated from the outside of the optical waveguide 20 to the input coupling region 210 into the substrate 21. The output coupling element 23 may be embedded in the substrate 21 facing the photosensitive element 30. That is, the output coupling element 23 is disposed in the output coupling region 220 and is used to couple the light irradiated from the substrate 21 to the output coupling region 220 out of the substrate 21. Among them, the refractive index of the substrate 21 is less than the refractive index of the input coupling element 22.

[0145] Exemplarily, the substrate 21 of the optical waveguide 20 includes a first surface 211 and a second surface 212 arranged back to back, and a first end face 213 and a second end face 214 arranged back to back. The first end face 213 and the second end face 214 are connected between the first surface 211 and the second surface 212. The optical lens group 10 and the photosensitive element 30 may be located on the same side of the optical waveguide 20 and are spaced apart. The first surface 211 faces the optical lens group 10 and the photosensitive element 30, and the second surface 212 is located on the side of the first surface 211 facing away from the optical lens group 10 and the photosensitive element 30.

[0146] Exemplarily, the first surface 211 includes an incident surface 2111, a first total reflection surface 2112, and an exit surface 2113 that are sequentially connected. At this time, the coupling-in element 22 can be disposed in the substrate 21 facing the incident surface 2111. The coupling-out element 23 can be disposed in the substrate 21 facing the exit surface 2113 of the first surface 211. The second surface 212 is a total reflection surface. After the light enters the substrate 21 of the optical waveguide 20 from the incident surface 2111, it is reflected multiple times between the second surface 212 and the first total reflection surface 2112, and then exits from the exit surface 2113 of the first surface 211. It can be understood that the portion of the first surface 211 of the substrate 21 between the coupling-in region 210 and the coupling-out region 220 is a total reflection surface (i.e., the first total reflection surface 2112). The second surface 212 of the substrate 21 is a total reflection surface. When the light in the substrate 21 of the optical waveguide 20 irradiates the portion of the first surface 211 between the coupling-in region 210 and the coupling-out region 220, and the second surface 212, it can be reflected back into the substrate 21 of the optical waveguide 20 at the portion of the first surface 211 between the coupling-in region 210 and the coupling-out region 220 and at the second surface 212.

[0147] In some embodiments, both the first end face 213 and the second end face 214 are light absorption layers, which are used to absorb stray light, avoid the imaging of stray light on the photosensitive element 30, and eliminate the influence of stray light on the image quality. Both the first end face 213 and the second end face 214 can be subjected to ink coating and blackening treatment.

[0148] It can be understood that the coupling-in element 22 can be disposed between the first surface 211 and the second surface 212. The light refracted by the optical lens group 10 can enter the substrate 21 of the optical waveguide 20 from the coupling-in region 210 and irradiate the coupling-in element 22. Subsequently, at least part of the light is reflected by the coupling-in element 22 to the portion of the first surface 211 between the coupling-in region 210 and the coupling-out region 220 (i.e., the first total reflection surface 2112). Since the portion of the first surface 211 between the coupling-in region 210 and the coupling-out region 220 is a total reflection surface, the light is reflected back into the substrate 21 of the optical waveguide 20 at the position of the first surface 211 between the coupling-in region 210 and the coupling-out region 220, irradiates the second surface 212, and then is reflected back into the substrate 21 of the optical waveguide 20.

[0149] Figure 12 For Figure 11 the optical path diagram of the optical waveguide 20 shown in one embodiment.

[0150] As Figure 11 and Figure 12As shown, the coupling element 22 is disposed obliquely with respect to the direction of the first optical axis O1 - O1, such that the light rays incident along the first optical axis O1 - O1 into the geometric optical waveguide are first changed in the incident angle by the coupling element 22, so that after being reflected by the coupling element 22, the incident angle θ of at least part of the light rays entering the substrate 21 of the geometric optical waveguide A2 (the angle formed between the light ray and the direction of the first optical axis O1 - O1) is greater than the total internal reflection critical angle θ of the geometric optical waveguide B2 , that is, the condition of total internal reflection is satisfied (as shown in the following formula). In this way, the light rays coupled into the substrate 21 of the optical waveguide 20 by the coupling element 22 can propagate in the substrate 21 in the form of total internal reflection.

[0151]

[0152] Wherein, θ A2 is the incident angle of the light ray entering the optical waveguide 20, and θ B2 is the total internal reflection critical angle of the optical waveguide 20, and n C2 is the refractive index parameter of the coupling element 22.

[0153] For the geometric optical waveguide, it is required that the light rays emitted from the optical lens group 10 enter the optical waveguide 20 at a set incident angle for total internal emission, that is, the emitted light rays of the optical lens group 10 are obliquely incident into the optical waveguide 20. In this embodiment, by disposing the coupling element 22 in the coupling region 210, the coupling element 22 is disposed obliquely with respect to the Z - axis direction, such that the light rays incident into the optical waveguide 20 are first changed in the incident angle by the coupling element 22, so that the incident angle of the light rays after passing through the coupling element 22 satisfies the condition of total internal reflection. That is, the incident angle of the light rays reflected by the coupling element 22 is greater than the total internal reflection critical angle of the optical waveguide 20, so that the light rays can propagate in the substrate 21 of the optical waveguide 20 in the form of total internal reflection.

[0154] Exemplarily, the coupling element 22 may include at least one coupling sub - element 22a. The coupling sub - element 22a is embedded in the substrate 21. Exemplarily, the number of the coupling sub - elements 22a may be two, and the two coupling sub - elements 22a are arranged in parallel. It can be understood that the number of the coupling sub - elements 22a may be one. The number of the coupling sub - elements 22a may also be greater than two, and multiple coupling sub - elements 22a may be arranged at intervals along the length extension direction of the substrate 21. That is, multiple coupling sub - elements 22a may be arranged in an array. It can be understood that the distance between two adjacent coupling sub - elements 22a may be equal. When the light ray is incident on the coupling sub - element 22a, a part of the light ray may be transmitted through the coupling sub - element 22a, and another part of the light ray may be reflected by the coupling sub - element 22a.

[0155] In one embodiment, the light-coupling sub-element 22a has an incident surface 223. When light is incident on the light-coupling sub-element 22a, a part of the light can transmit through the light-coupling sub-element 22a, and another part of the light can be reflected by the light-coupling sub-element 22a. That is to say, the incident surface 223 of the light-coupling sub-element 22a can be a semi-transmissive and semi-reflective mirror surface. It should be understood that the reflectivity of the semi-transmissive and semi-reflective mirror surface can be in the range of 50% to 95%. For example, the transmittance of the semi-transmissive and semi-reflective mirror surface can be 50%, and the reflectivity can be 50%; the transmittance of the semi-transmissive and semi-reflective mirror surface can be 30%, and the reflectivity can be 70%; the transmittance of the semi-transmissive and semi-reflective mirror surface can be 20%, and the reflectivity can be 80%; the transmittance of the semi-transmissive and semi-reflective mirror surface can be 5%, and the reflectivity can be 95%. Of course, the reflectivity of the semi-transmissive and semi-reflective mirror surface can also be other ratios. The incident surface 223 can be formed by alternately stacking a high-refractive-index material and a low-reflectivity material on the substrate 21. Among them, the high-refractive-index material can be titanium dioxide, and the low-reflectivity material can be silicon dioxide.

[0156] When light irradiates the semi-transmissive and semi-reflective incident surface 223, the incident surface 223 can reflect part of the light, so that the incident angle of this part of the light satisfies the total internal reflection condition of the optical waveguide 20; the remaining light transmits through the light-coupling sub-element 22a and continues to propagate in the substrate 21. Subsequently, this part of the light that continues to propagate reaches the second surface 212 of the optical waveguide 20. Since the second surface 212 of the optical waveguide 20 is a total reflection surface, the light is reflected back into the substrate 21 and continues to propagate until it reaches the next semi-transmissive and semi-reflective incident surface 223, and the above-mentioned "reflection-transmission" process is repeated until the incident surface 223 in the mirror array reflects all the remaining light. It can be understood that by arranging multiple semi-transmissive and semi-reflective incident surfaces 223 in an array, the path of light in the substrate 21 can be extended, the total optical length of the imaging module 100 can be extended, and a long focal length can be achieved.

[0157] In addition, according to the total internal reflection condition of the optical waveguide 20 (as shown in the following formula), the angle design of the light-coupling sub-element 22a array can also be carried out based on the angle distribution matrix of the outgoing light of the optical lens group 10. Exemplarily, by obtaining the angle distribution matrix of the outgoing light of the optical lens group 10, specifically, the angle distribution matrix of the outgoing light of the fourth lens 14, and the incident angle θ of the light of each obtained matrix entering the optical waveguide 20 A2Substituting the above formula, the angular design of the coupled-in sub-elements 22a array (the inclination angle of the coupled-in sub-elements 22a relative to the Z-axis direction) can be obtained through conversion, such that the light reflected by the incident surface 223 of the coupled-in sub-elements 22a satisfies the total internal reflection condition of the optical waveguide 20. For example, the angle formed between the incident surface 223 of the coupled-in sub-elements 22a and the second surface 212 of the substrate 21 is an obtuse angle. In this way, the light can be coupled into the substrate 21 of the optical waveguide 20 after being reflected by the incident surface 223 and propagate in the substrate 21 of the optical waveguide 20 in the form of total internal reflection.

[0158]

[0159] Among them, θ A2 is the incident angle of the light entering the optical waveguide 20, and θ B2 is the critical angle of total internal reflection of the optical waveguide 20 (geometric optical waveguide), and n C21 is the refractive index parameter of the coupled-in sub-elements 22a.

[0160] In addition, the field of view angle of the camera module 100 can be determined through the total internal reflection condition. For example, when the angle of the coupled-in sub-elements 22a array is known, the angle θ A2 range of the light that can be coupled into the optical waveguide 20 can be obtained through conversion using the above formula, thereby determining the field of view angle of the camera module 100.

[0161] Furthermore, by obtaining the relevant optical parameters of the optical lens group 10, the angular design of the coupled-in sub-elements 22a array of the geometric optical waveguide can be carried out using the total internal reflection condition (the above formula). Specifically, by obtaining the angular distribution matrix of the outgoing light rays of the fourth lens 14 and substituting the angles of each obtained matrix into the above formula, the angular design parameters of the coupled-in sub-elements 22a array of the geometric optical waveguide can be obtained through conversion, such that the light can be irradiated onto the geometric optical waveguide after being refracted by the optical lens group 10 and propagate in the geometric optical waveguide in the form of total internal reflection. It should be understood that when the diameter of the optical lens group 10 increases, the light ray matrix refracted by the optical lens group 10 will also change accordingly, so the matrix design of the coupled-in sub-elements 22a of the optical waveguide 20 also needs to be changed accordingly.

[0162] Such as Figure 11 and Figure 12As shown, the coupling-out element 23 can be located between the first surface 211 and the second surface 212. Exemplarily, the coupling-out element 23 can be located between the exit surface 2113 of the first surface 211 and the second surface 212. The coupling-out element 23 can be inclined with respect to the Z-axis direction, so that the light in the substrate 21 can be reflected by the coupling-out element 23, coupled out of the substrate 21, and irradiated onto the photosensitive element 30. That is, after the light propagates through multiple total internal reflections in the substrate 21, it irradiates onto the coupling-out element 23, and the coupling-out element 23 can reflect part of the light out of the substrate 21 and be received by the photosensitive element 30. In other words, after the light undergoes multiple total internal reflections in the substrate 21, it can be coupled out of the substrate 21 by the coupling-out element 23 from the exit surface 2113 of the first surface 211 and irradiated onto the photosensitive element 30.

[0163] The coupling-out element 23 can include at least one coupling-out sub-element 23a. The coupling-out sub-element 23a is embedded in the substrate 21. Exemplarily, the number of the coupling-out sub-elements 23a can be two, and the two coupling-out sub-elements 23a are arranged in parallel. It can be understood that the number of the coupling-out sub-elements 23a can be one. The number of the coupling-out sub-elements 23a can also be greater than two, and multiple coupling-out sub-elements 23a can be arranged at intervals along the length extension direction of the substrate 21. That is, multiple coupling-out sub-elements 23a can be arranged in an array. When the light is incident on the coupling-out sub-element 23a, a part of the light can be transmitted through the coupling-out sub-element 23a, and another part of the light can be reflected by the coupling-out sub-element 23a.

[0164] In one embodiment, the coupling-out sub-element 23a has an exit surface 231. When the light is incident on the coupling-out sub-element 23a, a part of the light can be transmitted through the coupling-out sub-element 23a, and another part of the light can be reflected by the coupling-out sub-element 23a. That is, the exit surface 231 of the coupling-out sub-element 23a can be a semi-transmissive and semi-reflective mirror surface. The exit surface 231 of the geometric optical waveguide can be formed by alternately stacking a high refractive index material and a low reflectivity material on the substrate 21. Among them, the high refractive index material can be titanium dioxide, and the low reflectivity material can be silicon dioxide.

[0165] Exemplarily, the output sub-element 23a is disposed obliquely with respect to the Z-axis direction. The included angle formed between the output surface 231 of the output sub-element 23a and the second surface 212 is an obtuse angle. During the propagation of light in the geometric optical waveguide, when the light irradiates the semi-transmissive and semi-reflective output surface 231, the light is disposed at an included angle with the output surface 231, and the mirror surface reflects part of the light out of the substrate 21 of the optical waveguide 20, and the remaining light is transmitted through the mirror and continues to propagate within the substrate 21; then this part of the light that continues to propagate reaches the second surface 212. Since the second surface 212 is a total reflection surface, the light is reflected back into the substrate 21 and continues to propagate, and then reaches the part of the first surface 211 located between the light coupling region 210 and the light output region 220. Since the part of the first surface 211 located between the light coupling region 210 and the light output region 220 is a total reflection surface (i.e., the first total reflection surface 2112), the light will be reflected back into the substrate 21 and continue to propagate until it reaches another semi-transmissive and semi-reflective output surface 231, and the above-mentioned "reflection-transmission" process is repeated until the remaining all light is reflected out of the substrate 21 of the optical waveguide 20 by the output surface 231 in the mirror array. It can be understood that by providing a plurality of semi-transmissive and semi-reflective output surfaces 231 arranged in an array, the path of the light in the substrate 21 can be extended, the total optical length of the imaging module 100 can be extended, and a long focal length can be achieved; and the light that propagates by total reflection multiple times within the substrate 21 of the optical waveguide 20 can finally be coupled out of the optical waveguide 20 through the output surface 231 and received by the photosensitive element 30.

[0166] Figure 13 is Figure 2 a schematic structural diagram of the imaging module 100 shown in another embodiment.

[0167] As Figure 13As shown, in another embodiment, the optical lens group 10 and the photosensitive element 30 may be located on opposite sides of the optical waveguide 20. The first surface 211 of the substrate 21 is disposed facing the optical lens group 10. The second surface 212 of the substrate 21 is on the side of the first surface 211 facing away from the optical lens group 10 and is disposed facing the photosensitive element 30. The first surface 211 may include an incident surface 2111 and a first total reflection surface 2112 that are connected to each other. Among them, the incident surface 2111 faces the optical lens group 10 directly. The portion of the first surface 211 of the substrate 21 that is offset from the optical lens group 10 is a total reflection surface (i.e., the first total reflection surface 2112). The second surface 212 may include a second total reflection surface 2121 and an exit surface 2122 that are connected to each other. Among them, the exit surface 2122 of the second surface 212 faces the photosensitive element 30 directly. The portion of the second surface 212 of the substrate 21 that is offset from the photosensitive element is a total reflection surface (i.e., the second total reflection surface 2121). At this time, the coupling element 22 may be disposed in the substrate 21 facing the incident surface 2111. After the light enters the substrate 21 of the optical waveguide 20 from the incident surface 2111, it is reflected back into the substrate 21 at the first total reflection surface 2112 and the second total reflection surface 2121.

[0168] An obtuse angle is formed between the incident surface 223 of the coupling sub-element 22a and the second surface 212 of the substrate 21. The coupling-out element 23 may be disposed in the substrate 21 facing the exit surface 2122 of the second surface 212. An acute angle is formed between the exit surface 231 of the coupling-out sub-element 23a and the second surface 212. After the light enters the substrate 21 of the optical waveguide 20 from the incident surface 2111, it is reflected multiple times between the first total reflection surface 2112 and the second total reflection surface 2121 and then exits from the exit surface 2122 of the second surface 212.

[0169] In the above embodiments, the optical lens group 10 and the optical waveguide 20 are separately arranged. The optical lens group 10 can move relative to the optical waveguide 20 to change the effective focal length, so as to achieve super macro shooting. The optical lens group 10 can also achieve super macro shooting by changing the distance between the first lens group and the second lens group. Utilizing the total internal reflection propagation principle of the optical waveguide 20, after the light collected by the optical lens group 10 is coupled into the substrate 21 of the optical waveguide 20, it is transmitted in the substrate 21 of the optical waveguide 20 in the form of total internal reflection, and finally coupled out of the substrate 21 of the optical waveguide 20 and focused on the photosensitive element 30. When the diameter of the optical lens group 10 increases, it is not necessary to increase the thickness dimension (the dimension in the Z-axis direction) of the optical waveguide 20, and the light can also be coupled into the substrate 21 of the optical waveguide 20 and totally internally reflected and propagated in the substrate 21 of the optical waveguide 20 and then emitted onto the photosensitive element 30. That is, a large target surface can be achieved without increasing the thickness dimension (the dimension in the Z-axis direction) of the optical waveguide 20, so that the imaging module 100 can achieve a large aperture effect and miniaturization. Compared with Figure 5 the prism solution shown, in the imaging module 100 of the present application, the optical waveguide 20 is used to deflect and propagate the light collected by the optical lens group 10. Without increasing the thickness of the optical waveguide 20, the diameter of the optical lens group 10 can be increased, a large target surface can be achieved, and the imaging module 100 has a large aperture effect. The imaging module 100 of the present application can take into account both large aperture and miniaturization and thinness. In addition, the optical lens group 10 can move away from the optical waveguide 20 along the Z-axis direction and change the effective focal length to achieve super macro shooting. Since the thickness of the optical waveguide 20 in the Z-axis direction is small, under the condition that the size of the imaging module 100 is fixed, the moving stroke of the optical lens group 10 along the Z-axis direction is long, and the change range of the effective focal length is large, so that super macro shooting in more scenarios can be satisfied.

[0170] Therefore, by setting the optical lens group 10 in combination with the design of the optical waveguide 20 in the embodiments of the present application, a long focal length and a large target surface can be achieved, and the size of the imaging module 100 in the thickness direction (Z-axis direction) is small. The imaging module 100 can take into account both large aperture and miniaturization. In other words, this embodiment designs a compact long focal length imaging module 100. When the imaging module 100 is applied to the electronic device 1000, the miniaturization and thinness design of the electronic device 1000 can be achieved.

[0171] It should be noted that, without conflict, the features in the embodiments of the present application can be combined with each other, and any combination of the features in different embodiments is also within the protection scope of the present application. That is to say, the above-described multiple embodiments can also be arbitrarily combined according to actual needs.

[0172] It should be noted that all the above-mentioned drawings are exemplary illustrations of the present application and do not represent the actual size of the product. Also, the dimensional proportional relationships between components in the drawings are not used as limitations on the actual products of the present application.

[0173] The above are only partial embodiments of the present application. The protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present application, and all should be covered within 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 imaging module (100), characterized in that, Comprising: An optical lens group (10), an optical waveguide (20), and a photosensitive element (30); The optical lens group (10) and the photosensitive element (30) are on the same side of the optical waveguide (20), or the optical lens group (10) and the photosensitive element (30) are on opposite sides of the optical waveguide (20), and the optical lens group (10) is located on the object side of the optical waveguide (20); The optical waveguide (20) includes a substrate (21), an input coupling element (22), and an output coupling element (23). The substrate (21) includes an input coupling region (210) and an output coupling region (220). The input coupling element (22) is disposed in the input coupling region (210), the output coupling element (23) is disposed in the output coupling region (220), the input coupling element (22) is disposed opposite to the optical lens group (10), and the output coupling element (23) is disposed opposite to the photosensitive element (30); Wherein, after passing through the optical lens group (10), light enters the substrate (21) from the input coupling region (210) through the input coupling element (22), undergoes multiple reflections inside the substrate (21), and then exits from the output coupling region (220) through the output coupling element (23) to form an image on the photosensitive element (30); the light propagates in the substrate (21) in a total internal reflection manner.

2. The camera module (100) according to claim 1, wherein The imaging module (100) further includes an optical element (60), and the optical element (60) is located between the output coupling element (23) and the photosensitive element (30); The optical element (60) is configured to focus a plurality of light rays emitted from the output coupling element (23) onto the photosensitive element (30).

3. The imaging module (100) according to claim 2, wherein The imaging module (100) further includes a motor, the optical element (60) is mounted on the motor, and the motor is configured to drive the optical element (60) to move along the optical axis direction of the photosensitive element (30).

4. The camera module (100) according to any one of claims 1 to 3, characterized in that, The thickness of the substrate (21) is in the range of 1 to 3 mm.

5. The camera module (100) according to any one of claims 1 to 4, characterized in that, Both the input coupling element (22) and the output coupling element (23) are diffraction gratings. The substrate (21) includes a first surface (211) and a second surface (212) disposed opposite to each other. The first surface (211) faces the optical lens group (10) and the photosensitive element (30). The second surface (212) is on the side of the first surface (211) facing away from the optical lens group (10) and the photosensitive element (30). The input coupling element (22) and the output coupling element (23) are disposed on the first surface (211), and the input coupling element (22) and the output coupling element (23) are spaced apart; Or, The first surface (211) faces the optical lens group (10), the second surface (212) is on the side of the first surface (211) facing away from the optical lens group (10), the second surface (212) faces the photosensitive element (30), the input coupling element (22) is disposed on the first surface (211), and the output coupling element (23) is disposed on the second surface (212).

6. The imaging module (100) according to claim 5, wherein The incident angle θ of the light incident on the coupling element (22) i and the diffraction angle θ of the light after passing through the coupling element (22) A1 satisfy the formula: where n i is the refractive index of the propagation medium before the light enters the coupling element (22), n C1 is the refractive index of the diffraction grating, λ k is the wavelength of the light, m k is the working order of the diffraction grating, Ф k is the period of the diffraction grating.

7. The camera module (100) according to any one of claims 1 to 6, characterized in that, The coupling-in element (22) and the coupling-out element (23) are both embedded in the substrate (21). The coupling-in element (22) includes a coupling-in sub-element (22a) which has a semi-transmissive and semi-reflective incident surface (223); the coupling-out element (23) includes a coupling-out sub-element (23a) which has a semi-transmissive and semi-reflective exit surface (231). The substrate (21) includes a first surface (211) and a second surface (212) which are arranged oppositely. The first surface (211) faces the optical lens group (10) and the photosensitive element (30). The second surface (212) is on the side of the first surface (211) that faces away from the optical lens group (10) and the photosensitive element (30). The angle formed between the incident surface (223) and the second surface (212) is an obtuse angle, and the angle formed between the exit surface (231) and the second surface (212) is an obtuse angle. Or The first surface (211) faces the optical lens group (10), the second surface (212) is on the side of the first surface (211) that faces away from the optical lens group (10), the second surface (212) faces the photosensitive element (30), the angle formed between the incident surface (223) and the second surface (212) is an obtuse angle, and the angle formed between the exit surface (231) and the second surface (212) is an acute angle.

8. The camera module (100) according to claim 7, characterized in that, The number of the coupling-in sub-elements (22a) is multiple, and the multiple coupling-in sub-elements (22a) are arranged at intervals along the length extension direction of the substrate (21).

9. The camera module (100) according to claim 7 or 8, characterized in that, The number of the coupling-out sub-elements (23a) is multiple, and the multiple coupling-out sub-elements (23a) are arranged at intervals along the length extension direction of the substrate (21).

10. The camera module (100) according to any one of claims 1 to 9, characterized in that, The substrate (21) includes a first surface (211) and a second surface (212) which are arranged oppositely. The first surface (211) faces the optical lens group (10) and the photosensitive element (30). The second surface (212) is on the side of the first surface (211) that faces away from the optical lens group (10) and the photosensitive element (30). The first surface (211) includes an incident surface (2111), a first total reflection surface (2112), and an exit surface (2113) which are connected in sequence. The incident surface (2111) faces the optical lens group (10) directly, and the exit surface (2113) of the first surface (211) faces the photosensitive element (30) directly. The second surface (212) is a total reflection surface; after the light enters the optical waveguide (20) from the incident surface (2111), it is reflected multiple times between the second surface (212) and the first total reflection surface (2112), and then exits from the exit surface (2113) of the first surface (211). Or The first surface (211) is disposed facing the optical lens group (10), the second surface (212) is located on the side of the first surface (211) facing away from the optical lens group (10), the second surface (212) is disposed facing the photosensitive element (30), the first surface (211) includes an incident surface (2111) and a first total reflection surface (2112) that are connected to each other, the incident surface (2111) faces the optical lens group (10) directly, the second surface (212) includes a second total reflection surface (2121) and an exit surface (2122) that are connected to each other, and the exit surface (2122) of the second surface (212) faces the photosensitive element (30) directly; after light enters the optical waveguide (20) from the incident surface (2111), it is reflected multiple times between the first total reflection surface (2112) and the second total reflection surface (2121), and then exits from the exit surface (2122) of the second surface (212).

11. The imaging module (100) according to claim 10, wherein The substrate (21) further includes a first end face (213) and a second end face (214) that are disposed facing away from each other, and the first end face (213) and the second end face (214) are connected between the first surface (211) and the second surface (212); Both the first end face (213) and the second end face (214) are light absorption layers.

12. The camera module (100) according to any one of claims 1 to 11, characterized in that, The incident angle θ of light entering the optical waveguide (20) A satisfies the formula: where θ B is the total reflection critical angle of the optical waveguide (20), and n C is the refractive index parameter of the coupling element (22).

13. An electronic device (1000), characterized in that, It includes a housing (200) and the imaging module (100) as described in claims 1 to 12, and the imaging module (100) is installed in the housing (200).

Images