Distance detection device, imaging system, and electronic apparatus

Abstract

The embodiment of the invention provides a distance detection device, an imaging system and electronic equipment, and the device comprises a signal transmitting module and a signal receiving module, the signal transmitting module is used for transmitting light to a target object, and the signal receiving module is used for receiving reflected light reflected by the target object. And determining the position of the target object according to the transmission time of the emitted light and the reflected light. The signal transmitting module comprises a light source and a first zooming assembly, the light source and the first zooming assembly are arranged at a preset interval, the light source is used for transmitting light, a light-transmitting medium is arranged in the first zooming assembly, and the first zooming assembly is used for controlling the light-transmitting medium to rotate by a preset angle so as to transmit the received light to a target object at a preset field angle. The zoom effect can be effectively achieved by controlling rotation of the light-transmitting medium, and meanwhile the light can be controlled to be emitted to the target object at the preset field angle for distance detection.

Description

Technical Field

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

[0002] Currently, the imaging systems or camera modules of electronic devices are often equipped with time-of-flight (TOF) devices, which use time-of-flight technology to obtain the distance of a target object. A TOF device includes a signal transmitting module (also called a transmitter) and a signal receiving module (receiver). The signal transmitting module is used to transmit a light signal toward the target object. After the light signal is reflected by the target object, it can be received by the signal receiving module. The distance between the target object and the TOF device can be determined based on the flight time of the light signal between the signal transmitting module and the signal receiving module.

[0003] When used to assist mobile phone photography, the ToF system needs to be paired with different cameras, requiring the system to dynamically adjust its field of view and depth of field depending on the application scenario. Currently, most mainstream solutions employ mechanical zoom, which changes the focal point by moving the lens inside the lens, thereby changing the focal length and magnifying or reducing the image. Because electronic devices have strict power consumption and size constraints, and mechanical zoom solutions require moving parts, are complex in structure, and are large in size, mechanical zoom methods have certain spatial limitations. This can result in a suboptimal focal length, thus affecting the photographic effect. Summary of the Invention

[0004] In order to solve the aforementioned technical problems, the embodiments of the present application provide a distance detection device, an imaging system, and an electronic device that occupy a small space and can be zoomed.

[0005] In a first aspect, embodiments of the present application provide a distance detection device comprising a signal transmitting module and a signal receiving module, wherein the signal transmitting module is configured to transmit light to a target object, and the signal receiving module is configured to receive reflected light from the target object, and to determine the position of the target object based on the transmission time between the transmitted light and the reflected light. The signal transmitting module comprises a light source and a first zoom assembly, wherein the light source and the first zoom assembly are spaced apart by a preset distance, the light source is configured to transmit light, and the first zoom assembly is configured to control the light-transmitting medium to rotate by a preset angle so as to transmit the received light to the target object at a preset field of view angle.

[0006] By controlling the light-transmitting medium in the first zoom component to rotate to a preset angle, the phase of the light emitted by the light source can be adjusted, thereby adjusting the focal length of the first zoom component and the light to a preset field of view angle. That is, the first zoom component can adaptively adjust the field of view angle of the light according to the position of the target object to be detected, and is used to detect the distance to the target object through light with the optimal field of view angle.

[0007] Optionally, the first zoom component includes a zoom element, which includes a base substrate, a first electrode layer, a filter structure layer, a transparent medium layer and a second electrode layer stacked in sequence. The first electrode layer and the second electrode layer are used to form an electric field to drive the transparent medium in the transparent medium layer to rotate a preset angle, and to perform a first phase modulation on the light received from the light source and transmit the adjusted light to the filter structure layer. The filter structure layer performs a second phase modulation on the light to control the light to be emitted to the target object at a preset field of view angle.

[0008] Optionally, the light-transmitting medium layer includes multiple layers of light-transmitting media arranged in parallel, each layer of light-transmitting medium includes multiple light-transmitting media arranged parallel to each other, and the angle between two adjacent light-transmitting media is 0° or 180°. An electric field is formed between the first electrode layer and the second electrode layer to control the light-transmitting medium to rotate to a preset inclination angle and / or a preset azimuth angle, so as to perform a first phase modulation on the received light so as to adjust the phase of the received light to a first preset phase.

[0009] Voltage is applied between the first electrode layer and the second electrode layer to form an electric field to drive the light-transmitting medium to rotate at a preset angle, thereby controlling the angle change of the light when passing through the light-transmitting medium, so that a certain angle is formed between the polarization direction of the light and the optical axis. At this time, the effective refractive index of the light-transmitting medium changes with the angle of rotation, so that the light forms a phase delay after passing through the light-transmitting medium, thereby realizing phase modulation of the light, that is, the phase of the light is the first preset phase.

[0010] Optionally, the orthographic projection of the filter structure layer on the base substrate is a circular shape, and the filter structure layer includes multiple annular wave bands, and each annular wave band is provided with multiple uniform and periodically arranged microstructure units, and the microstructure units are used to receive light from the transparent medium layer and perform a second phase modulation on the received light to adjust the phase of the light to a second preset phase, so as to control the light to be emitted to the target object at a preset field of view angle.

[0011] By controlling the uniform setting and periodic arrangement of the microstructure units on the filter structure layer, the phase of the light can be modulated again, so that the light of the first preset phase is adjusted to the second preset phase. Through two phase modulations, the light emitted by the light source passes through the first zoom component and is emitted to the target object at a preset field of view angle.

[0012] Optionally, the light-transmitting medium includes a first inclination angle, a second inclination angle, and a third inclination angle, and the first inclination angle, the second inclination angle, and the third inclination angle increase sequentially; the zoom element includes a first focal length, a second focal length, and a third focal length, and the first focal length, the second focal length, and the third focal length decrease sequentially; the first electrode layer and the second electrode layer control the light-transmitting medium to rotate to the first inclination angle to control the focal length of the zoom element to be the first focal length, and the first focal length corresponds to the first field of view angle; the first electrode layer and the second electrode layer control the light-transmitting medium to rotate to the second inclination angle to control the focal length of the zoom element to be the second focal length, and the second focal length corresponds to the second field of view angle; the first electrode layer and the second electrode layer control the light-transmitting medium to rotate to the third inclination angle to control the focal length of the zoom element to be the third focal length, and the third focal length corresponds to the third field of view angle, wherein the first field of view angle, the second field of view angle, and the third field of view angle increase sequentially.

[0013] By setting the rotation angle of the light-transmitting medium corresponding to the focal length of the zoom element, when the distance detection device needs to be adjusted to the first focal length, the light-transmitting medium can be directly controlled to rotate to the corresponding angle through the electric field between the first electrode layer and the electrode layer, thereby achieving adjustment of the focal length and field of view angle, which is used to provide other cameras with a more adapted field of view angle when assisting other cameras in shooting.

[0014] Optionally, the first electrode layer and the second electrode layer control the light-transmitting medium to continuously rotate from the first inclination angle to the second inclination angle to control the focal length of the zoom element to continuously change from the first focal length to the second focal length, and the first electrode layer and the second electrode layer control the light-transmitting medium to continuously rotate from the second inclination angle to the third inclination angle to control the focal length of the zoom element to continuously change from the second focal length to the third focal length.

[0015] By controlling the change of the electric field, the light-transmitting medium is caused to rotate continuously, and the zoom element can be controlled to achieve a continuous zoom effect.

[0016] Optionally, the first zoom assembly further includes a dimming element, the dimming element and the zoom element being stacked in a direction facing the light source, the zoom element being spaced a preset distance from the light source, and the dimming element being disposed on a side of the zoom element away from the light source. The dimming element is configured to adjust the energy distribution of light emitted by the zoom element to control the light emitted by the zoom element to form a light field with a preset energy distribution. Adjusting the energy distribution of light or performing uniform light processing by the dimming element can prevent localized light power from being too low or too high, thereby avoiding distortion of the final image.

[0017] Optionally, the signal receiving module includes a second zoom component and a sensing component. The sensing component and the second zoom component are set at a preset distance. A plurality of light-transmitting media are provided in the second zoom component. The second zoom component is used to control the rotation of the light-transmitting medium to receive reflected light with a preset field of view angle, and converge the received light to the sensing component. The sensing component determines the distance information of the target object based on the received reflected light.

[0018] By setting a second zoom component in the signal receiving module, the signal receiving module can also achieve zoom, thereby selectively receiving light with a preset field of view angle, which is the same as the field of view angle of the light emitted by the signal transmitting module, effectively improving the detection accuracy of the distance detection device.

[0019] In a second aspect, an embodiment of the present application further provides an imaging system, comprising at least one camera and the aforementioned distance detection device, wherein the distance detection device is used to adjust to a preset field of view angle to cooperate with the camera to capture images.

[0020] In a third aspect, an embodiment of the present application further provides an electronic device, comprising a processor and the aforementioned imaging system, wherein the processor is electrically connected to the imaging system, and forms an image of a target object based on a signal output by the imaging system.

[0021] Compared with the problems of the existing technology, the embodiment of the present application sets a zoom element in the signal transmission module, and controls the rotation of the transparent medium in the zoom element through the electric field to modulate the phase of the light emitted by the light source, thereby realizing the adjustment of the field of view angle of the light emitted by the signal transmission module. Since the zoom element does not require a mechanical zoom device, it effectively reduces the space occupancy compared to the traditional mechanical zoom lens, and avoids the limitation of the focal length change due to the mechanical structure.

[0022] It should be understood that the beneficial effects achieved by the technical solutions of the second to third aspects of the embodiments of the present application can be referred to the technical effects of the first aspect and its corresponding possible implementation methods mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0024] Figure 1 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application;

[0025] Figure 2 Schematic diagram of the camera's field of view principle;

[0026] Figure 3 This is a structural diagram of a signal transmission module of a distance detection device in the related art;

[0027] Figure 4 A schematic diagram of the zoom principle of a camera module in another related technology;

[0028] Figure 5 A schematic structural diagram of a distance detection device provided in an embodiment of the present application;

[0029] Figure 6 for Figure 5 Schematic diagram of the layer structure of the mid-zoom component;

[0030] Figure 7 for Figure 6 Schematic diagram of the structure of the light-transmitting medium layer;

[0031] Figure 8 for Figure 6 A schematic top view of the middle filter structure layer;

[0032] Figure 9 for Figure 8 Schematic diagram of the structure of the mesostructure unit;

[0033] Figure 10 is a schematic diagram of the change of the focal length of the zoom component;

[0034] Figure 11 Schematic diagram of the relationship between focal length and tilt angle. DETAILED DESCRIPTION

[0035] To facilitate the clear description of the technical solutions of this application, the words "first" and "second" are used to distinguish between identical or similar items with substantially the same functions and effects. Those skilled in the art will understand that the words "first" and "second" do not limit the quantity or order of execution, and the words "first" and "second" do not necessarily mean different.

[0036] References to "one embodiment" or "some embodiments" in this specification mean that one or more embodiments of the present application include a particular feature, structure, or characteristic described in conjunction with that embodiment. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in other embodiments" appearing in different places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.

[0037] Before explaining the distance detection device provided by the embodiment of the present application in detail, the application scenario of the embodiment of the present application is first described. The embodiment of the present application provides an electronic device that is a type of electronic device with a camera, which can specifically include a handheld device with image processing function, a vehicle-mounted device, etc. For example, some electronic devices include: mobile phones, tablet computers, PDAs, laptop computers, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote FSdical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes (smart hoFS), cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to wireless modems, in-vehicle devices, terminal devices in 5G networks or future evolved public land mobile communication networks (PLMNs), and so on. The terminal equipment in the network (PLMN), etc., is not limited to this in the embodiments of the present application.

[0038] As an example and not a limitation, in the embodiments of the present application, the electronic device may also be a wearable device. Wearable devices may also be referred to as wearable smart devices, which are a general term for wearable devices that are intelligently designed and developed using wearable technology for daily wear, such as glasses, gloves, watches, clothing, and shoes. A wearable device is a portable device that is worn directly on the body or integrated into the user's clothes or accessories. Wearable devices are not only hardware devices, but also achieve powerful functions through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include those that are fully functional, large in size, and can achieve complete or partial functions without relying on smartphones, such as smart watches or smart glasses, as well as those that only focus on a certain type of application function and need to be used in conjunction with other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0039] In addition, in the embodiments of the present application, the electronic device can also be a terminal device in the Internet of Things (IoT) system. IoT is an important part of the future development of information technology. Its main technical feature is to connect objects to the network through communication technology, thereby realizing an intelligent network of human-machine interconnection and object-to-object interconnection.

[0040] The electronic devices in the embodiments of the present application may also be referred to as: terminal equipment, user equipment (user equipFSnt, UE), mobile station (mobile station, MS), mobile terminal (mobile terminal, MT), access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication equipment, user agent or user device, etc.

[0041] See also Figure 1 , Figure 1 A schematic structural diagram of an electronic device 100 provided in an embodiment of the present application.

[0042] The electronic device 100 may be an electronic device 100 having a video or photo recording function. For ease of understanding, the present application embodiment is described by taking the electronic device 100 as a mobile phone as an example. Figure 1 The diagram shows the structure of the electronic device from two perspectives: the entire front and the back.

[0043] like Figure 1 As shown, the electronic device 100 may include a display screen 10 and a housing 20. The housing 20 may include a frame 21 and a back cover 22. The display screen 10 and the back cover 22 are respectively located on both sides of the frame 21. The frame 21 may surround the periphery of the display screen 10, and the frame 21 may surround the periphery of the back cover 22. The display screen 10, the frame 21 and the back cover 22 may be together to form an inner cavity of the entire machine. The frame 21 and the back cover 22 may be assembled to form an integrated structure, or may be an integrally molded structure. The display screen 10 may include a glass cover plate and a display panel fixed to the glass cover plate, and the display panel is used to display images.

[0044] Among them, the electronic device 100 can also include a front camera module 30, an earpiece module 40, a rear camera module 50, a processor 60, etc. housed in the inner cavity of the entire machine, and the processor 60 is electrically connected to the display screen 10, the front camera module 30, the earpiece module 40 and the rear camera module 50.

[0045] like Figure 1As shown in the left figure, for example, the front camera module 30 and the earpiece module 40 can be installed in the upper middle part of the display screen 10. The display screen 10 can be provided with a front camera hole and an earpiece hole. The front camera module 30 can collect external light of the electronic device 100 through the front camera hole to take selfies, and the earpiece module 40 can output sound through the earpiece hole so that the user can answer calls, voice, etc.

[0046] like Figure 1 As shown in the right figure in FIG, the rear camera module 50 can be installed in the upper middle portion of the rear cover 22. The electronic device 100 can also include a camera decoration 70, which is installed on the rear cover 22 and has multiple light holes. The rear camera module 50 can collect external light through the light holes in the camera decoration 70 to capture the scene around the electronic device 100.

[0047] Understandably, Figure 1 The installation positions of the front camera module 30 and the rear camera module 50 shown are merely schematic, and the present application does not limit the installation positions of the camera modules. In some other embodiments, the front camera module 30 and the rear camera module 50 may also be installed at other positions on the electronic device 100. For example, the front camera module 30 may be installed at the upper left or upper right portion of the display screen 10. For another example, the rear camera module 50 may be installed at the upper left or upper right portion of the back cover 22. For another example, the front camera module 30 or the rear camera module 50 may be set on a movable component inside the electronic device 100. By moving the movable component, the movable component can be hidden inside the electronic device 100, or can be extended outside the electronic device 100.

[0048] Understandably, Figure 1 The number of front camera modules 30 and rear camera modules 50 shown is merely illustrative, and the present application does not impose a limitation on the number of camera modules. The electronic device 100 may include a greater or lesser number of camera modules.

[0049] The rear camera module 50 includes a first camera 51, a second camera 52, a third camera 53 and a distance detection device 54. The first camera 51 can be a telephoto camera with a longer focal length and can be used to shoot objects at a farther distance.

[0050] The second camera 52 can be a wide-angle camera or a main camera, which has the characteristics of large light input, high resolution, and a central field of view. It is generally used as the default camera of the electronic device 100, that is, it is used to respond to the user's operation of starting the "Camera" application. The main camera can be started by default and the image captured by the main camera can be displayed on the preview interface.

[0051] The third camera 53 can be an ultra-wide-angle camera, which is used to shoot wide scenes at a close distance, and to shoot larger objects (such as buildings or scenery). That is, the focal lengths of the first camera 51, the second camera 52 and the third camera 53 decrease in sequence.

[0052] The distance detection device 54 is used to measure the object distance of the object to be photographed, or in other words, to measure the depth information of the object to be photographed, to assist the first camera 51, the second camera 52, and the third camera 53 in shooting. The distance detection device 54 may include a signal transmitting module and a signal receiving module. The signal transmitting module may be located near the signal receiving module. The signal transmitting module may emit infrared light. The signal receiving module may be a lens capable of detecting (capturing, receiving) infrared light. The infrared light emitted by the signal transmitting module is transmitted to the target object and reflected by the target object. The signal receiving module is used to receive the infrared light reflected by the target object, thereby measuring the distance to the target object.

[0053] It can be understood that the rear camera module 50 in the embodiment of the present application can be an imaging system, and the first camera 51, the second camera 52 and the third camera 53 are used to shoot and form images with the cooperation of the distance detection device 54.

[0054] For example, the rear camera module 50 may further include a flash 55, which may be located near the main camera and the wide-angle camera to provide illumination for the main camera or the wide-angle camera when the main camera or the wide-angle camera is shooting. For example, at night or in low light, the light emitted by the flash 55 may illuminate the subject being shot by the main camera or the wide-angle camera, allowing the main camera or the wide-angle camera to capture the subject.

[0055] In other embodiments, the rear camera module 50 may also include a macro camera, a fisheye camera, an infrared camera, a black and white camera, etc.

[0056] A macro camera is a specialized lens used for close-up photography, primarily for capturing extremely fine objects such as flowers and insects. Using a macro lens to capture small natural scenes allows you to capture microscopic scenes that are normally invisible to humans. A fisheye camera is an auxiliary lens with a focal length of 16mm or less and a field of view approaching or equal to 180°.

[0057] A fisheye camera can be considered an extreme wide-angle camera. Its front lens is very short and bulges outward in a parabolic shape, resembling a fish's eye. Therefore, fisheye cameras are often used to achieve special photographic effects because the images they capture differ significantly from how people perceive the real world.

[0058] Infrared cameras have a wide spectral range. For example, they can sense not only visible light but also infrared light. In low-light conditions (i.e., low visible light), using infrared cameras to capture images can improve image quality.

[0059] Black and white cameras lack filters. Therefore, they allow in more light than color cameras. However, the images they capture can only be displayed in varying shades of gray, not the true colors of the subject.

[0060] See also Figure 2 , Figure 2 Schematic diagram of the camera's field of view principle.

[0061] like Figure 2 As shown, the camera's field of view (FOV) is determined by the camera's field of view (FOV). The larger the camera's FOV, the larger its field of view. The FOV refers to the angle formed by the two edges of the optical instrument's lens, with the lens as the vertex, and the maximum range through which the image of the target can pass through the lens. This is called the FOV. The size of the FOV determines the optical instrument's field of view. The larger the FOV, the larger the field of view, and the smaller the optical magnification, or the shorter the focal length. Therefore, the field of view of the first camera 51, the second camera 52, and the third camera 53 increases. In other words, the target object will not be captured by the lens if it exceeds this angle. For optical devices such as cameras and camcorders, since their photosensitive surfaces are rectangular, the FOV is often calculated based on the diameter of the imaged object at the diagonal of the rectangular photosensitive surface. Of course, the FOV can also be calculated based on the long side of the rectangle.

[0062] The relevant technologies of this application are described below.

[0063] See also Figure 3 , Figure 3 Schematic diagram of the structure of the signal transmission module in the related art.

[0064] like Figure 3 As shown, the signal transmitting module 541 is used to transmit infrared light to the target object, wherein the signal transmitting module 541 includes a light source 5411, a lens 5413 and a motor assembly 5414, wherein the light source 5411 is used to emit infrared light, the lens 5413 is fixed to the motor assembly, and the motor assembly 5414 is a movable component, used to drive the lens 5413 to move in the optical axis direction to achieve zoom of the lens 5413.

[0065] However, as the imaging quality requirements of mobile phone camera modules become higher and higher, the size and weight of the lens 5413 are getting larger and larger, and the driving force requirements for the motor assembly 5414 are also getting higher and higher. Current electronic devices (such as mobile phones) also have great restrictions on the size of the camera module. The volume occupied by the motor assembly 5414 increases accordingly with the increase of the lens 5413. In other words, as the lens 5413 tends to develop towards a larger size and heavier weight, the driving force that the motor assembly 5414 can provide is difficult to increase accordingly. Under the premise of limited driving force, the heavier the lens 5413, the shorter the stroke that the motor assembly 5414 can drive the lens 5413 to move, which seriously affects the zoom range. Moreover, the heavier the lens 5413, the slower the speed at which the motor assembly 5414 can drive the lens 5413 to move, and the longer it takes for the lens 5413 to reach the predetermined compensation position, resulting in a slower focusing of the lens 5413, thereby affecting the user experience.

[0066] See also Figure 4 , Figure 4 This is a schematic diagram of the zoom principle of a camera module in another related technology.

[0067] like Figure 4 As shown in the middle left figure, the distance detection device 54 includes a signal transmitting module 541 and a signal receiving module 542, wherein the signal transmitting module 541 is used to transmit light, and the signal receiving module 542 is used to receive the reflected light of the light emitted outward by the signal transmitting module 541. The signal transmitting module 541 includes a first light emitting area A1 and a second light emitting area A2, the first light emitting area A1 is rectangular, and the second light emitting area A2 is arranged around the first light emitting area A1, the first light emitting area A1 is used to emit light corresponding to the first field of view angle, and the second light emitting area A2 is used to emit light corresponding to the second field of view angle, wherein the first field of view angle is smaller than the second field of view angle. Figure 4 As shown in the middle right figure, the signal receiving module 542 includes a first light receiving area B1 and a second light receiving area B2. The first light receiving area B1 is used to receive light of a first viewing angle, and the second light receiving area B2 is used to receive light of a second viewing angle.

[0068] By controlling the first light emitting area A1 and the second light emitting area A2 to emit light respectively, it is possible to emit light with different field angles, and then respectively receive reflected light in different ranges through the first light receiving area B1 and the second light receiving area B2, so as to cooperate with the lens to achieve zoom. However, this method cannot achieve continuous zoom, and because it only changes the area of ​​the light emitting area and the light receiving area, the zoom error is large, and the light power and the ability to receive light in different modes vary greatly, resulting in poor depth detection capability.

[0069] Based on this, the present application provides a distance detection device that can effectively reduce space occupancy and is capable of continuous zoom.

[0070] See also Figure 5 , Figure 5 This is a structural diagram of a distance detection device 54 provided in an embodiment of the present application.

[0071] like Figure 5 As shown, the distance detection device 54 includes a signal transmitting module 541 and a signal receiving module 542. The signal transmitting module 541 is used to transmit light, and the signal receiving module 542 is used to receive the reflected light emitted outward by the signal transmitting module 541, and detect the distance of the photographed object based on the flight time of the light.

[0072] The signal transmission module 541 includes a light source 5411 and a first zoom assembly 5412. The light source 5411 is configured to emit light, such as infrared light or other invisible light. The first zoom assembly 5412 is spaced a preset distance from the light source 5411. The first zoom assembly 5412 is configured to receive light emitted by the light source 5411 and adjust the field of view to suit the field of view required by different cameras (wide-angle, ultra-wide-angle, telephoto), that is, to adjust the focal length to suit the focal length required by different cameras.

[0073] In this embodiment, the light source 5411 can be, but is not limited to, any one of a vertical-cavity surface-emitting laser (VCSEL), a laser diode (LD), and a light-emitting diode (LED).

[0074] The first zoom assembly 5412 includes a zoom element 5412a and a dimming element 5412b. The zoom element 5412a and the dimming element 5412b are stacked in a direction facing the light source 5411. The zoom element 5412a is adjacent to the light source 5411, and the dimming element 5412b is located on the side of the zoom element 5412a away from the light source 5411. The zoom element 5412a is used to phase modulate the incident light emitted by the light source 5411. This phase modulation of the incident light adjusts the focal length and field of view. In other words, the zoom element 5412a acts as a lens with automatic focal length adjustment. The dimming element 5412b is used to adjust the energy distribution of the light emitted by the light source 5411 to obtain a light field with a predetermined energy distribution. The predetermined energy distribution can be a uniform distribution or a batwing distribution. By uniforming the light emitted by the light source 5411, localized light power can be prevented from being too low or too high, thereby avoiding distortion in the final image.

[0075] In an exemplary embodiment, the dimming element 5412b may be a diffractive optical element (DOE) configured to shape the light beam emitted by the light source 5411 into a more uniform light. Specifically, the DOE may be configured to shape the light beam emitted by the light source 5411 into a uniform square light source or a uniform rectangular light source having a certain field of view (FOV) (e.g., a 5°×5° FOV).

[0076] The diffraction optical element can make the light emitted by the signal transmission module 541 more uniform, and since the optical diffraction element can shape the light beam into a uniform shape with a certain field angle, the light emitted by the signal transmission module 541 can be more accurately aligned with the object to be detected.

[0077] In other embodiments, the dimming element 5412b can also be a microlens diffuser. The microlens array can achieve uniform light based on geometric optics, with a high transmission efficiency of over 80%. It is composed of a series of microlenses distributed in an array. The microlens array is used to shape the light emitted by the light source 5411, making the shaped light beam more uniform, thereby making the light emitted by the signal transmission module 541 more uniform. The individual microlenses in the microlens array can be distributed in a regular array, for example, the individual microlenses can be distributed in a rectangular, circular, regular polygonal, or linear array, with the distance between each adjacent microlens being equal. Alternatively, the individual microlenses in the microlens array can be distributed in an irregular array, for example, the individual microlenses can be distributed in an asymmetric pattern array, with the distance between each adjacent microlens being unequal. This application does not limit the specific distribution method of the microlens array. Of course, the dimming element 5412b can also be other devices that can make the light beam more uniform, and this application does not limit this.

[0078] The signal receiving module 542 includes a sensing component 5421 and a second zoom component 5422, wherein the sensing component 5421 and the second zoom component 5422 are set at a preset distance. The light emitted by the signal transmitting module 541 is reflected by the target object and transmitted to the second zoom component 5422. The second zoom component 5422 is used to adjust the field of view angle receiving range to receive the reflected light of the preset field of view angle, and converge the received reflected light and transmit it to the sensing component 5421. The sensing component 5421 determines the distance information of the target object based on the received reflected light.

[0079] In this embodiment, the sensing component 5421 can be a semiconductor chip. Hundreds of thousands to millions of photodiodes are provided on the photosensitive surface of the sensing component 5421. The photodiode can be, for example, a single photon avalanche diode (SPAD). The photodiode generates an electric charge when irradiated by light, thereby converting the optical signal into an electrical signal. The sensing component 5421 can be a charge coupled device (CCD), a complementary metal-oxide semiconductor (CMOS), etc. The second zoom component 5422 can be an automatically zooming lens, which is used to converge the reflected light emitted by the signal transmitting module 541, thereby receiving light with different field angles.

[0080] In other embodiments, the signal receiving module 542 may further include a filter, which is arranged between the second zoom component 5422 and the sensor component 5421, and is used to filter light of other wavelengths except infrared light in the received reflected light. Since the light emitted by the signal transmitting module 541 is usually infrared light, the filter is used to reduce the interference of ambient light on the detection structure to improve the detection accuracy.

[0081] Among them, the second zoom component 5422 includes a zoom element, which has the same structure as the zoom element 5412a in the first zoom component 5412, that is, the second zoom component 5422 is also a lens that can automatically adjust the focal length. The second zoom component 5422 can selectively receive light of different field of view angles to adapt to the light of different field of view angles emitted by the signal transmission module 541. For example, when the signal transmission module 541 emits light of the first field of view angle FOV1, the second zoom component 5422 controls the reception of reflected light within the range of the first field of view angle FOV1; when the signal transmission module 541 emits light of the second field of view angle FOV2, the second zoom component 5422 receives reflected light within the range of the second field of view angle FOV2; when the signal transmission module 541 emits light of the third field of view angle FOV3, the second zoom component 5422 receives reflected light within the range of the third field of view angle FOV3. That is, by simultaneously controlling the field of view adaptation of the zoom element 5412a and the second zoom component 5422, the distance detection device 54 can assist cameras with different field of view angles to perform shooting.

[0082] For example, when the first camera 51 is shooting, the signal transmitting module 541 transmits light with a first field of view angle FOV1 to the target object for distance detection, and simultaneously controls the signal receiving module 542 to receive reflected light within the first field of view angle FOV1, thereby providing depth information or distance information to the first camera 51, i.e., adjusting the focal length to facilitate shooting with the first camera 51. When the second camera 52 is shooting, the signal transmitting module 541 transmits light with a second field of view angle FOV2 to the target object for distance detection, and simultaneously controls the signal receiving module 542 to receive reflected light within the second field of view angle FOV2, thereby providing depth information or distance information to the second camera 52, i.e., adjusting the focal length to facilitate shooting with the second camera 52. When the third camera 53 is shooting, the signal transmitting module 541 transmits light with a third field of view angle FOV3 to the target object for distance detection, and simultaneously controls the signal receiving module 542 to receive reflected light within the third field of view angle FOV3, thereby providing depth information or distance information to the third camera 53, i.e., adjusting the focal length to facilitate shooting with the third camera 53.

[0083] See also Figure 6 , Figure 6 for Figure 5 Schematic diagram of the layer structure of the middle zoom element 5412a.

[0084] like Figure 6 As shown, the zoom element 5412a includes a substrate sub, a first electrode layer E1, a filter structure layer FS, a transparent medium layer DL and a second electrode layer E2 stacked in sequence along the thickness direction, wherein the first electrode layer E1 and the second electrode layer E2 are used to form an electric field to drive the transparent medium in the transparent medium layer DL to rotate, so as to adjust the phase of the incident light to a first preset phase.

[0085] The filter structure layer FS is fabricated on the side of the first electrode layer E1 adjacent to the transparent dielectric layer DL. It is used to receive light with a first preset phase from the zoom element 5412a and adjust the phase of the light to a second preset phase, thereby adjusting the light emitted by the light source 5411 to a preset field of view (FOV1, FOV2, or FOV3). In other words, light emitted by the light source 5411 passes through the transparent dielectric layer DL and the filter structure layer FS in sequence, adjusting the phase of the light emitted by the light source 5411 to the second preset phase, thereby controlling the light emitted by the signal transmission module 541 to adjust to the preset field of view. The filter structure layer FS is used to adjust the wavefront phase of the light. The wavefront refers to the surface formed by the particles that have just begun to displace at a certain moment when the wave propagates in a medium, or the surface formed by the points with the same phase during the propagation of the light wave. Light waves are transverse waves with a vibration plane perpendicular to the propagation direction. The wavefront is a plane formed by electromagnetic vibrations. The wavefront of the entire light wave is composed of points with the same phase within different wavefronts.

[0086] See also Figure 7 , Figure 7 for Figure 6 Schematic diagram of the structure of the light-transmitting medium layer DL.

[0087] like Figure 7 As shown, the light-transmitting medium layer DL is a liquid crystal layer. The structure of the liquid crystal layer can be smectic liquid crystal (a), cholesteric liquid crystal (b), or nematic liquid crystal (c). Smectic liquid crystal is composed of rod-shaped or strip-shaped liquid crystal molecules arranged in layers. The long axes of the molecules within the layers are parallel to each other and can be perpendicular or inclined to the layers, resulting in two-dimensional order. The molecular center of mass is disordered within the layers and can freely translate, resulting in fluidity. The attractive forces and intermolecular forces within the smectic liquid crystal layer are very weak, so the liquid crystal molecules can slide back and forth, left and right, but cannot move between layers. Cholesteric liquid crystal has asymmetric carbon atoms, and the liquid crystal molecules are flat and arranged in layers. The molecules within the layers are often arranged parallel to each other in a nematic texture, with the long axes parallel to the layers. The molecules in each layer are stacked up and down in a periodic twist or spiral pattern, forming a certain angle between the orientation directions of the molecules in adjacent layers. When the orientation angle between adjacent molecules in the cholesteric liquid crystal is 0° or 180°, it is a nematic liquid crystal. The liquid crystal layer in this embodiment uses nematic liquid crystal. Of course, other types of liquid crystals can be used according to specific needs, and this application does not limit this.

[0088] In this embodiment, an electric field is formed between the first electrode layer E1 and the second electrode layer E2 to control the tilt angle θ or azimuth angle of the liquid crystal molecules. To obtain a specific phase delay and thus realize the control of the incident light field, the specific principle is as follows: when the polarization direction of the incident light forms a certain angle with the optical axis, the effective refractive index at this time is:

[0089]

[0090] Where θ is the angle between the polarization direction of the incident light and the optical axis, n0 is the ordinary light refractive index of the liquid crystal material, and n e is the extraordinary refractive index of the liquid crystal material. Therefore, for incident linearly polarized light, the phase delay after passing through the liquid crystal layer is:

[0091]

[0092] Here, d is the thickness of the liquid crystal layer, and λ is the wavelength of the incident light in a vacuum. The phase introduced by the optical path difference during propagation is called propagation phase, also known as "dynamic phase." It is closely related to the refractive index and thickness of the propagation medium. By adjusting the voltage, the phase delay of the incident light after passing through the liquid crystal layer can be altered, thereby shaping the incident light wavefront.

[0093] Similarly, by controlling the arrangement of the liquid crystal molecule director in the plane, that is, the azimuth angle It is also possible to achieve dynamic control of liquid crystal molecules. The effective refractive index of liquid crystal chips arranged along different azimuth angles for the same linear polarization is different. When the polarization direction of the incident light is parallel to the direction of the liquid crystal director, the refractive index is n e , when the polarization direction is perpendicular to the direction of the director, the refractive index is n0. When there is a certain angle between the two When , its effective birefringence is:

[0094]

[0095] Therefore, there is a phase difference ΔΓ=2πdΔn between the incident light and different liquid crystal domains. eff By controlling the local pointing direction of the liquid crystal chips in the liquid crystal layer, the phase modulation of the incident light can be achieved.

[0096] That is to say, in this embodiment, the tilt angle θ and the azimuth angle of the liquid crystal molecules in the liquid crystal layer are adjusted by the electric field formed between the first electrode layer E1 and the second electrode layer E2. This can achieve phase modulation of the light emitted by the light source 5411, thereby achieving adjustment of the field of view angle.

[0097] Please also refer to Figure 8 and Figure 9 , Figure 8 for Figure 6 Schematic top view of the middle filter structure layer, Figure 9 for Figure 8 Schematic diagram of the structure of the mesostructure unit.

[0098] like Figure 8 and Figure 9 As shown, in this embodiment, the filter structure layer FS is a metasurface, disposed within the liquid crystal layer. A metasurface is an artificial material composed of an ultra-thin two-dimensional array of sub-wavelength macroscopic units with a specific geometric shape, arranged periodically or aperiodically. Composed of multiple metamaterial structural units, the wavefront phase, amplitude, and polarization of an optical beam can be flexibly adjusted by controlling the structure and arrangement period of the metamaterial structural units.

[0099] Among them, the filtering structure layer FS (metasurface) includes multiple 2π wave bands, that is, it includes multiple annular wave bands SW, each annular wave band SW includes multiple sub-wave bands SW1, and one or more microstructure units na can be set in each sub-wave band SW1, that is, the filtering structure layer FS is provided with multiple microstructure units na, and the multiple microstructure units na located on the same annular wave band S2 are periodically arranged, wherein the microstructure unit na can be a nanocolumn.

[0100] Among them, the distance between the microstructure units na is subwavelength, and the microstructure units na can be set to different geometric parameters, including shape, size and direction, etc. Therefore, due to the subwavelength size characteristics and ultra-thin characteristics, the metasurface can be equivalent to an interface. By adjusting the phase arrangement on the interface, the propagation direction of the transmitted and reflected light beams can be modulated. In other words, by adjusting the shape parameters and arrangement period of the nanocolumns na, the phase distribution of the filter structure layer FS can be adjusted, and then the speed of the light beam passing through the filter structure layer FS can be adjusted, and the time delay of the light speed passing through the microstructure unit na can be adjusted, that is, the phase delay of the light emitted by the light source 5411 can be adjusted.

[0101] In other embodiments, the filter structure layer FS can also be a structure or material with filtering properties such as photonic crystals, multilayer films, quantum dots, micro-electro-mechanical systems (MEMS), cavity layers, waveguide layers (WAVEGUIDE), diffraction elements, etc., and this application does not impose any restrictions on this.

[0102] Furthermore, one arrangement period includes at least two microstructure units na, for example, Figure 9 In the embodiment, an arrangement period includes adjacent first and second microstructure units na1 and na2. The first and second microstructure units na1 and na2 are rectangular parallelepiped structures. The first microstructure unit na1 has a first width w1 and a first height h1, and the second microstructure unit na2 has a second width w2 and a second height h2. A first distance d1 exists between the first and second microstructure units na1 and na2. By adaptively adjusting parameters such as the shape, width, and height of the first and second microstructure units na1 and na2, the phase distribution at the location of the microstructure unit na can be adjusted, thereby adjusting the time delay of the light beam passing through the microstructure unit na.

[0103] The material of the microstructure units na is one or more of Si, GaN, TiO2, and Si3N4. Each microstructure unit na can also be a cylindrical pillar structure or a pillar structure with other cross-sectional shapes as needed. The height of the nanopillars can be set between 400nm and 2000nm, or other values ​​can be selected based on actual conditions. Each microstructure unit na can be arranged in a square, hexagonal, or circular periodic arrangement, with varying period sizes, such as P = 300nm / 400nm.

[0104] It is understandable that the wide range of design possibilities of the metasurface's micro-unit structure makes it highly flexible in terms of wavelength and polarization response. This allows the metasurface to flexibly adjust the amplitude and phase distribution at the interface, enabling arbitrary control of the wavefront according to the Huygens principle. At the same time, to achieve 360-degree phase control, the dimensional parameters of the nanopillars and the rotation angles of the liquid crystal molecules on the metasurface can be scanned, and a model library with a direct correspondence to the phase difference of the incident light can be established. This allows the phase modulation of the incident light to be achieved by adjusting the tilt and azimuth angles of the liquid crystal molecules.

[0105] That is to say, in this embodiment, a metasurface is provided on the side of the liquid crystal layer DL adjacent to the substrate sub, and the size and arrangement period of the nanocolumns on the metasurface are adjusted to adjust the light emitted by the light source 5411 to a preset wavefront phase, wherein the adjustment of the wavefront phase by the metasurface is fixed, that is, the phase modulation of the structural unit n at each position of the metasurface for the light beam of the same wavelength is fixed. After the metasurface performs the first phase modulation on the incident light, an electric field is applied on both sides of the liquid crystal layer to control the rotation of the liquid crystal molecules in the liquid crystal layer, thereby performing the second phase modulation on the incident light, thereby adjusting the light emitted by the signal transmission module 541 to a preset field of view angle, or adjusting the focal length to a preset value.

[0106] Furthermore, in this embodiment, by applying a bias voltage, that is, applying a voltage to the first electrode layer E1 and the second electrode layer E2, the tilt angle θ of the liquid crystal molecules can be continuously changed, thereby controlling the first zoom component 5412 to achieve continuous zoom within a certain angle range, wherein the phase delay function of the continuous zoom is:

[0107]

[0108] Where r is the radial distance from the center of the lens (zoom element) and f is the focal length.

[0109] In this embodiment, the focal length f changes linearly with the tilt angle θ of the liquid crystal molecules, and the change function is:

[0110]

[0111] Where δf = f on -f off ,δθ=θ on -θ off , f on is the current focal length, f off is the initial focal length, θ on is the current tilt angle of the liquid crystal molecules, θ off is the initial tilt angle of the liquid crystal molecules.

[0112] At this time, the phase distribution of the lens is

[0113] in,

[0114] From this we can see that the desired That is, in this embodiment, the light emitted by the light source 5411 is modulated by the uniform tilt angle of the liquid crystal molecules, and the microstructure units na on the metasurface can produce phases with approximately uniform intervals, thereby achieving the effect of continuous change of the focal length with the tilt angle, that is, achieving continuous change in the control of the field of view angle.

[0115] For example, Figure 10 and Figure 11 As shown, Figure 10 is a schematic diagram of the change in focal length of the zoom element 5412a, Figure 11 Schematic diagram of the relationship between focal length and tilt angle.

[0116] The tilt angles of the liquid crystal molecules include a first tilt angle θ1, a second tilt angle θ2 and a third tilt angle θ3. The first tilt angle θ1, the second tilt angle θ2 and the third tilt angle θ3 increase successively, wherein the first tilt angle θ1 corresponds to the first focal length f1, the second tilt angle θ2 corresponds to the second focal length f2, and the third tilt angle θ3 corresponds to the third focal length f3. The first focal length f1, the second focal length f2 and the third focal length f3 decrease successively, that is, the change in the tilt angle is inversely proportional to the change in the focal length.

[0117] In this embodiment, the first focal length f1 may correspond to a first field of view FOV1. That is, when the focal length of the zoom element 5412a is the first focal length f1, the light received and adjusted by the zoom element 5412a has the first field of view FOV1, which can be used to assist the first camera 51 in capturing images. The second focal length f2 may correspond to a second field of view FOV2, which can be used to assist the second camera 52 in capturing images. The third focal length f3 may correspond to a third field of view FOV3, which can be used to assist the third camera 53 in capturing images. When the liquid crystal molecules are controlled to uniformly and continuously change from the first tilt angle θ1 to the second tilt angle θ2, the focal length of the zoom element 5412a continuously changes from the first focal length f1 to the second focal length f2. When the liquid crystal molecules are controlled to uniformly and continuously change from the second tilt angle θ2 to the third tilt angle θ3, the zoom element 5412a continuously changes from the second focal length f2 to the third focal length f3.

[0118] For example, the first inclination angle θ1 can be set to 0°, the second inclination angle θ2 can be set to 45°, and the third inclination angle θ3 can be set to 90°. When an electric field is applied between the first electrode layer E1 and the second electrode layer E2 to control the inclination angle of the liquid crystal molecules to 0°, the focal length of the zoom element 5412a is approximately 15 mm. When an electric field is applied between the first electrode layer E1 and the second electrode layer E2 to control the inclination angle of the liquid crystal molecules to 45°, the focal length of the zoom element 5412a is approximately 8.2 mm. When an electric field is applied between the first electrode layer E1 and the second electrode layer E2 to control the inclination angle of the liquid crystal molecules to 90°, the focal length of the zoom element 5412a is approximately 2.5 mm.

[0119] When the liquid crystal molecules are controlled to change uniformly and continuously from 0° to 45°, the focal length of the zoom element 5412a changes uniformly and continuously from approximately 15 mm to 8.2 mm. When the liquid crystal molecules are controlled to change uniformly and continuously from 45° to 90°, the focal length f changes uniformly and continuously from approximately 8.2 mm to approximately 2.5 mm.

[0120] The above disclosure is only part of the embodiments of the present application, and it is certainly not intended to limit the scope of the rights of the present application. Ordinary technicians in this field can understand that all or part of the processes of the above embodiments and equivalent changes made in accordance with the claims of the present application are still within the scope covered by the present application.

Claims

1. A distance detection device comprising a signal transmitting module and a signal receiving module, wherein the signal transmitting module is configured to transmit light to a target object, and the signal receiving module is configured to receive light reflected from the target object, and determine the position of the target object based on the transmission time between the transmitted light and the reflected light; It is characterized by: The signal transmission module includes a light source and a first zoom component, the light source and the first zoom component are set at a preset distance, the light source is used to emit light, and a light-transmitting medium is provided in the first zoom component. The first zoom component is used to control the light-transmitting medium to rotate a preset angle so as to transmit the received light to the target object at a preset field of view angle.

2. The distance detection device according to claim 1, wherein The first zoom component includes a zoom element, which includes a base substrate, a first electrode layer, a filter structure layer, a transparent medium layer and a second electrode layer stacked in sequence. The first electrode layer and the second electrode layer are used to form an electric field to drive the transparent medium in the transparent medium layer to rotate the preset angle, and to perform a first phase modulation on the light received from the light source and transmit the adjusted light to the filter structure layer. The filter structure layer performs a second phase modulation on the light to control the light to be emitted to the target object at the preset field of view angle.

3. The distance detection device according to claim 2, wherein: The light-transmitting medium layer includes multiple layers of light-transmitting media arranged in parallel, each layer of the light-transmitting medium includes multiple light-transmitting media arranged in parallel with each other, and the angle between two adjacent light-transmitting media is 0° or 180°. An electric field is formed between the first electrode layer and the second electrode layer to control the light-transmitting medium to rotate to a preset inclination angle and / or a preset azimuth angle, so as to perform a first phase modulation on the received light so as to adjust the phase of the received light to a first preset phase.

4. The distance detection device according to claim 3, wherein: The orthographic projection of the filter structure layer on the base substrate is a circular shape. The filter structure layer includes a plurality of annular wave bands, and a plurality of uniformly and periodically arranged microstructure units are arranged on each of the annular wave bands. The microstructure units are used to receive light from the transparent medium layer and perform a second phase modulation on the received light to adjust the phase of the light to a second preset phase, so as to control the light to be emitted to the target object at the preset field of view angle.

5. The distance detection device according to claim 4, wherein: The light-transmitting medium includes a first inclination angle, a second inclination angle, and a third inclination angle, wherein the first inclination angle, the second inclination angle, and the third inclination angle increase sequentially; the zoom element includes a first focal length, a second focal length, and a third focal length, wherein the first focal length, the second focal length, and the third focal length decrease sequentially; the first electrode layer and the second electrode layer control the light-transmitting medium to rotate to the first inclination angle, so as to control the focal length of the zoom element to be the first focal length, and the first focal length corresponds to a first field of view angle; The first electrode layer and the second electrode layer control the light-transmitting medium to rotate to the second tilt angle, so as to control the focal length of the zoom element to be the second focal length, and the second focal length corresponds to a second field of view angle; The first electrode layer and the second electrode layer control the light-transmitting medium to rotate to the third inclination angle to control the focal length of the zoom element to be the third focal length, and the third focal length corresponds to a third field of view angle, wherein the first field of view angle, the second field of view angle and the third field of view angle increase sequentially.

6. The distance detection device according to claim 5, wherein: The first electrode layer and the second electrode layer control the light-transmitting medium to continuously rotate from the first inclination angle to the second inclination angle, so as to control the focal length of the zoom element to continuously change from the first focal length to the second focal length. The first electrode layer and the second electrode layer control the light-transmitting medium to continuously rotate from the second inclination angle to the third inclination angle, so as to control the focal length of the zoom element to continuously change from the second focal length to the third focal length.

7. The distance detection device according to any one of claims 1 to 6, characterized in that: The first zoom component also includes a dimming element, which is stacked with the zoom element in a direction facing the light source. The zoom element and the light source are spaced apart by a preset distance. The dimming element is arranged on the side of the zoom element away from the light source. The dimming element is used to adjust the energy distribution of the light emitted by the zoom element to control the light emitted by the zoom element to form a light field with a preset energy distribution.

8. The distance detection device according to claim 7, wherein: The signal receiving module includes a second zoom component and a sensing component. The sensing component and the second zoom component are set at a preset distance. A plurality of the light-transmitting media are provided in the second zoom component. The second zoom component is used to control the rotation of the light-transmitting medium to receive the reflected light of the preset field of view angle and converge the received light to the sensing component. The sensing component determines the distance information of the target object based on the received reflected light.

9. An imaging system, characterized in that: It comprises at least one camera and the distance detection device according to any one of claims 1 to 8, wherein the distance detection device is used to adjust to the preset field of view angle to cooperate with the camera to capture images.

10. An electronic device, characterized in that: The imaging system comprises a processor and the imaging system as claimed in claim 9, wherein the processor is electrically connected to the imaging system and forms an image of a target object according to a signal output by the imaging system.

Images