Projector for large number of speckles, depth camera and electronic equipment

Abstract

The utility model relates to a large-scale speckle projector, a depth camera and electronic equipment, which are characterized in that a light source is used for projecting floodlight; the collimating lens group is positioned on an emergent light path of the light source and is used for collimating the floodlight; the dynamic speckle generator is positioned on the light emitting side of the collimating lens group and can generate different speckles from the floodlight; an adaptive projection lens; the focal plane of the self-adaptive projection lens is conjugated with the dynamic speckle generator so as to automatically adjust the focal length according to the change of the size of the speckle and ensure that a zero-order speckle is formed; and the DOE diffraction device is positioned on the light-emitting surface of the adaptive projection lens so as to copy the zero-order speckles. According to the utility model, the problems of insufficient flexibility and insufficient projection speckle uniformity and quantity existing in a speckle projection scheme in the prior art can be solved, and uniform high-density speckle projection is realized.

Description

Technical Field

[0001] This utility model relates to the field of optical technology, specifically to a large speckle projector, a depth camera, and electronic equipment. Background Technology

[0002] In numerous optical applications, such as 3D imaging, structured light measurement, and lidar, there is a widespread and ever-growing demand for speckle projection. However, traditional speckle projection methods often have many limitations.

[0003] Traditional speckle generation equipment struggles to flexibly generate speckle patterns of varying shapes, failing to meet the demands of diverse application scenarios. For instance, in situations requiring high-precision 3D reconstruction, fixed-pattern speckle cannot provide sufficient information for accurate measurements. Furthermore, conventional projection devices cannot automatically adjust to changes in speckle size, making it difficult to stably generate zero-order speckle in practical applications, thus impacting measurement accuracy and image quality.

[0004] Moreover, traditional solutions fall short in achieving efficient projection of a large number of speckles, failing to meet the demands of mass production and rapid testing. Therefore, developing a large speckle projector capable of projecting floodlight and generating different speckles, while automatically adjusting the focal length to ensure zero-order speckle formation and effectively replicating speckles, is particularly necessary. This is of great significance for promoting the development of optical measurement, imaging, and related fields.

[0005] The above background information is provided only to aid in understanding the inventive concept and technical solution of this utility model. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above information was disclosed on the filing date of this patent application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Utility Model Content

[0006] To address this issue, this invention proposes a large-scale speckle projection system that overcomes the problems of poor flexibility, insufficient uniformity and quantity of projected speckles in existing speckle projection schemes, thereby achieving uniform high-density speckle projection.

[0007] In a first aspect, this utility model provides a large speckle projector, characterized in that it comprises:

[0008] Light source, used to project floodlight;

[0009] A collimating lens group, located in the output light path of the light source, is used to collimate the floodlight;

[0010] A dynamic speckle generator, located on the light-emitting side of the collimating lens group, can generate different speckles from the floodlight;

[0011] An adaptive projection lens; the focal plane of the adaptive projection lens is conjugate with the dynamic speckle generator to automatically adjust the focal length according to changes in the size of the speckle, ensuring the formation of zero-order speckle;

[0012] A DOE diffraction device is located on the light-emitting surface of the adaptive projection lens to replicate the zero-order speckle.

[0013] Optionally, the aforementioned large speckle projector is characterized by further comprising:

[0014] A total internal reflection prism is located between the collimating lens group and the dynamic speckle generator to change the optical path direction of the floodlight.

[0015] Optionally, the large speckle projector is characterized in that the inclined surface of the total internal reflection prism is coated with a high-reflectivity film.

[0016] Optionally, the large speckle projector is characterized in that the total internal reflection prism is either externally reflective or internally totally reflective.

[0017] Optionally, the aforementioned speckle projector is characterized in that the dynamic speckle generator is a programmable liquid crystal spatial light modulator that dynamically adjusts the phase or amplitude of the light wave to generate different speckles from the floodlight.

[0018] Optionally, the aforementioned speckle projector is characterized in that the collimating lens group further shapes the floodlight into a rectangle.

[0019] Optionally, the aforementioned speckle projector is characterized by further comprising a first controller;

[0020] The first controller is used to control the dynamic speckle generator and the adaptive projection lens.

[0021] Optionally, the aforementioned speckle projector is characterized in that the collimating lens group comprises two cylindrical surfaces, which respectively collimate the fast and slow axis beams of the light source.

[0022] Secondly, this utility model provides a depth camera, characterized in that it includes a large number of speckle projectors, an image sensor, and a second controller as described in any one of the above-mentioned claims;

[0023] The image sensor is used to receive the reflection signal of the zero-order speckle and generate an image;

[0024] The second controller is used to adjust the speckle projected by the large speckle projector according to the image.

[0025] Thirdly, this utility model provides an electronic device, characterized in that it includes a large number of speckle projectors as described in any one of the above claims.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] This invention first uses a collimating lens group to shape the light beam emitted from the light source into a collimated and uniform rectangular light field. Then, a dynamic speckle generator and an adaptive projection lens focus the light to form a zero-order speckle pattern. Finally, a DOE diffractometer replicates the zero-order speckle, achieving a multiplication of the number of speckles and an expansion of the projection angle. Compared to existing technologies, this invention can project a number of speckles that can be increased by tens of times, and the higher number of speckles provides the hardware conditions for more accurate 3D visual modeling.

[0028] Currently used speckle projection schemes in the industry have speckle numbers that are affected by the VCSEL process, with zero-order speckle numbers typically numbering in the hundreds. A higher number of speckles can negatively impact mass production yield. This invention uses a dynamic speckle generator to focus and form zero-order speckles, achieving tens of thousands of zero-order speckle points, significantly increasing speckle density.

[0029] This invention incorporates a dynamic speckle generator, capable of generating different speckles from the floodlight projected by the light source. This feature allows the projector to meet the needs of various diverse application scenarios. Whether in 3D imaging in complex environments or in structured light measurement of different objects, it can provide rich and accurate information by generating suitable speckles, greatly expanding the application range of the device.

[0030] In this invention, the focal plane of the adaptive projection lens is conjugate with the dynamic speckle generator, enabling it to automatically adjust the focal length according to changes in speckle size, ensuring the formation of zero-order speckle. This advantage effectively overcomes the drawbacks of traditional projection devices, greatly improving measurement accuracy and imaging quality. In practical applications, such as lidar detection of distant targets, stable zero-order speckle ensures the accuracy of the echo signal, thereby enhancing the overall system performance. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort. Other features, objects, and advantages of this utility model will become more apparent by reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0032] Figure 1 This is a schematic diagram of the optical path of a large speckle projector in an embodiment of this utility model;

[0033] Figure 2 This is a schematic diagram of the optical path of another large speckle projector in an embodiment of this utility model;

[0034] Figure 3 This is a schematic diagram of the optical path of another large speckle projector in an embodiment of this utility model;

[0035] Figure 4 This is a schematic diagram of the projection effect of a DOE diffraction device in an embodiment of this utility model.

[0036] 1-Light source;

[0037] 2-Collimating lens group;

[0038] 3-Total internal reflection prism;

[0039] 4-Dynamic speckle generator;

[0040] 5-Adaptive projection lens;

[0041] 6-DOE diffraction device; Detailed Implementation

[0042] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any way. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0043] The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the utility model described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0044] This utility model provides a large speckle projector, which aims to solve the problems existing in the prior art.

[0045] The technical solutions of this utility model and this application solve the above-mentioned technical problems in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this utility model will now be described with reference to the accompanying drawings.

[0046] This invention first uses a collimating lens group to shape the light beam emitted from the light source into a collimated and uniform rectangular light field. Then, a dynamic speckle generator and an adaptive projection lens focus the light to form a zero-order speckle pattern. Finally, a DOE diffractometer replicates the zero-order speckle, achieving a multiplication of the number of speckles and an expansion of the projection angle. Compared to existing technologies, this invention can project a number of speckles that can be increased by tens of times, and the higher number of speckles provides the hardware conditions for more accurate 3D visual modeling.

[0047] Figure 1 This is a schematic diagram of the optical path of a large speckle projector according to an embodiment of this utility model. Figure 1 As shown, an embodiment of this utility model includes a large speckle projector comprising:

[0048] A light source used to project floodlight.

[0049] Specifically, as the initial light source of the entire speckle projector, the primary function of the light source is to project floodlight. Floodlight is characterized by its relatively uniform light distribution and wide coverage, providing the basic illumination conditions for the subsequent generation of stable and uniformly distributed speckles. Common types include light-emitting diodes (LEDs) and laser diodes (LDs). LEDs have advantages such as low cost, long lifespan, and low power consumption, and can produce a relatively broad spectrum, making them suitable for floodlight projection where spectral requirements are not particularly high. Laser diodes, on the other hand, can produce high-brightness, highly directional beams, and through specific optical design, can also be converted into uniform floodlight. Uniform floodlight ensures consistent speckle generation across the entire projection area, avoiding inconsistent speckle quality caused by uneven light source distribution, thus guaranteeing the stability and reliability of the entire projection system.

[0050] The collimating lens group is located in the output light path of the light source and is used to collimate the floodlight.

[0051] Specifically, the collimating lens group is located in the output light path of the light source and collimates the floodlight projected by the light source. It adjusts the originally divergent light rays into parallel light rays, making the light rays more orderly during propagation and reducing light scattering and energy loss. It is generally composed of multiple different types of lenses, such as a combination of convex and concave lenses. The convex lens is used to converge the light rays, and the concave lens is used to diverge the light rays. By reasonably designing the radius of curvature, focal length and relative position of the two, the divergent light rays can be collimated into parallel light rays. A common type is the cemented doublet lens group, which cements lenses with different refractive indices together to reduce chromatic aberration and aberrations. The collimated light rays are more conducive to subsequent processing by the dynamic speckle generator, which can generate more stable and high-quality speckles. The collimated parallel light rays can ensure that the speckles generated at different positions have the same characteristics and accuracy, providing a reliable foundation for subsequent applications. When the light source is an EEL laser, it includes two directions: fast axis and slow axis. In this case, the collimating lens group contains two cylindrical surfaces to collimate the light beams in the fast and slow axis directions of the light source, respectively.

[0052] In some embodiments, the collimating lens group further shapes the floodlight into a rectangle. The collimating lens group also includes a special cylindrical lens or a shaping aperture. The cylindrical lens possesses focusing or diverging capabilities in a specific direction. By rationally designing its combination with other lenses, their relative positions, and various optical parameters such as radius of curvature and focal length, it can not only collimate diverging light into parallel light but also perform differential processing on the light in the horizontal and vertical directions, thereby shaping the floodlight into a rectangle. The shaping aperture has a rectangular opening. By precisely adjusting its position and opening size in the optical path, light that does not conform to the rectangular outline can be blocked, ensuring that the output floodlight is rectangular.

[0053] A dynamic speckle generator, located on the light-emitting side of the collimating lens group, can generate different speckles from the floodlight.

[0054] Specifically, the dynamic speckle generator is located on the light-emitting side of the collimating lens assembly. Its core function is to generate different speckles from the collimated floodlight. Through special internal optical structures or technologies, it can change the phase, amplitude, and other characteristics of the light, thereby producing randomly distributed speckle patterns. The spatial light modulator (SLM) is one of the core components; it can control the orientation of liquid crystal molecules through electrical or optical signals, thereby changing the phase and amplitude of the light. By loading different patterns or data onto the SLM, the incident light can be modulated to generate various speckle patterns. The dynamic speckle generator can generate diverse speckles to meet the needs of various complex application scenarios. In 3D imaging, it can generate suitable speckle patterns based on the shape, material, and other characteristics of different objects, providing richer information and improving imaging accuracy and resolution. In structured light measurement, different speckles can be used to measure objects of different shapes and sizes, greatly expanding the application range of the equipment.

[0055] In some embodiments, the dynamic speckle generator is a programmable liquid crystal spatial light modulator (PLM) that dynamically adjusts the phase or amplitude of the light wave to generate different speckles from the floodlight. The PLM mainly consists of a liquid crystal array and an electrode structure. The liquid crystal array is composed of a large number of liquid crystal pixels, each of which can change the orientation of its liquid crystal molecules under the control of an electrical signal. In this way, the phase or amplitude of the light wave passing through that pixel can be precisely and dynamically adjusted. Liquid crystal materials have the characteristics of fast response speed and adjustable optical properties, which can meet the need for rapid generation of different speckle patterns. The electrode structure is used to apply electrical signals to the liquid crystal pixels to achieve precise control of the orientation of the liquid crystal molecules. The electrode structure is ingeniously designed to ensure that each pixel can independently receive an accurate electrical signal, thereby achieving diversified modulation of the phase or amplitude of the light wave. By applying different voltage modes to the electrodes, different modulation states can be quickly switched, thereby generating various speckle patterns.

[0056] An adaptive projection lens; the focal plane of the adaptive projection lens is conjugate with the dynamic speckle generator to automatically adjust the focal length according to changes in the size of the speckle, ensuring the formation of zero-order speckle.

[0057] Specifically, the focal plane of the adaptive projection lens is conjugate with the dynamic speckle generator, enabling it to monitor changes in speckle size in real time and automatically adjust its focal length accordingly. This precise focal length adjustment ensures the consistent formation of zero-order speckle, effectively solving the problem of unstable zero-order speckle formation in traditional projection devices. In practical applications, such as the detection of distant targets, changes in target distance can alter speckle size. The adaptive projection lens can adjust its focal length promptly to guarantee the stable formation of zero-order speckle, thereby ensuring the accuracy of the echo signal and improving the overall system performance and measurement precision.

[0058] In some embodiments, the adaptive projection lens includes a variable focal length lens and a displacement drive mechanism.

[0059] Variable focus lenses are key components for achieving automatic focus adjustment; common types include liquid lenses and electrostrictive lenses. Taking liquid lenses as an example, by changing the distribution or pressure of the liquid inside the lens, the radius of curvature of the lens can be changed, thereby achieving continuous focus adjustment.

[0060] The displacement drive mechanism is used to precisely control the position of the variable focal length lens to achieve conjugate matching with the dynamic speckle generator. The displacement drive mechanism can employ piezoelectric ceramic drives, voice coil motor drives, or other methods, and features fast response speed and high precision.

[0061] A DOE diffraction device is located on the light-emitting surface of the adaptive projection lens to replicate the zero-order speckle.

[0062] Specifically, the DOE diffracting device is located on the light-emitting surface of the adaptive projection lens, and its main function is to replicate zero-order speckle. It utilizes the principle of diffraction to replicate the zero-order speckle after it has been processed by the adaptive projection lens, thereby achieving efficient projection of a large number of speckles. The diffractive optical element is the core component of the DOE diffracting device, and it is typically fabricated on a substrate material using photolithography to create a structure with a specific diffraction pattern. For example, a blazed grating structure fabricated using binary optics can diffract the incident zero-order speckle according to a specific angle and intensity distribution, thus replicating the speckle.

[0063] In some embodiments, a large speckle projector further includes a first controller; the first controller controls the dynamic speckle generator and the adaptive projection lens. As the core hub, the first controller integrates feedback signals from the image sensor, external input commands, and system-preset algorithms. Through comprehensive analysis and computation of this information, it sends commands to the controller of the dynamic speckle generator to generate suitable speckle patterns, and sends signals to the displacement drive mechanism of the adaptive projection lens to adjust the lens focal length and position, ensuring that zero-order speckle is always formed to meet the speckle projection requirements of different application scenarios. For example, the first controller controls the operating state of the spatial light modulator, including switching the loaded pattern and setting modulation parameters. Based on system requirements and received external commands, the first controller sends pattern switching commands and detailed modulation parameters, such as phase modulation depth and amplitude modulation coefficients. The dynamic speckle generator precisely controls the orientation of liquid crystal molecules within the SLM, thereby generating a speckle pattern that meets the requirements.

[0064] Figure 2 This is a schematic diagram of the optical path of another type of speckle projector in an embodiment of this utility model. Figure 2 As shown, compared to the aforementioned embodiments, another type of large speckle projector in this embodiment of the present invention further includes:

[0065] A total internal reflection prism is located between the collimating lens group and the dynamic speckle generator to change the optical path direction of the floodlight.

[0066] Specifically, the main body of the optical glass is usually made of glass materials with excellent optical properties, such as K9 glass. This type of glass has a high refractive index, which can meet the conditions for total internal reflection, and it has low absorption and scattering of light, ensuring low energy loss when light propagates inside the prism.

[0067] The reflecting surface of the prism undergoes high-precision grinding and polishing, achieving a surface flatness at the nanometer level. This ensures that light is reflected precisely at a predetermined angle, reducing deviations and scattering of the reflected light. Some total internal reflection prisms also have an anti-reflection coating applied to the reflecting surface to further improve light reflection efficiency.

[0068] In some embodiments, the inclined surfaces of the total internal reflection prism are coated with a high-reflectivity film. This film is deposited using vacuum deposition technology from materials with high reflectivity, such as metallic silver or aluminum. It significantly enhances the reflectivity of the inclined surfaces, greatly increasing the reflectivity when light is reflected, thus further reducing light loss. Furthermore, the coating process precisely controls the film thickness to suit specific wavelengths of light, ensuring the stability and consistency of the reflection effect.

[0069] like Figure 2 As shown, a total internal reflection prism is an external reflection. When light from a medium outside the prism (such as air) is incident at a suitable angle onto the surface of a 45° reflecting prism, the light will be reflected at the prism surface. In this case, special treatment is needed on the prism surface to improve reflection efficiency and reduce light loss. For example, by coating the prism surface with a high-reflectivity metal film or a multilayer dielectric film, the light can be reflected efficiently, thus changing its propagation direction by 90°. This external reflection method is advantageous in scenarios where the intensity of reflected light is required and the complexity of the prism's internal structure is relatively low.

[0070] like Figure 3 As shown, the total internal reflection prism exhibits internal total internal reflection. Based on the critical angle formula for internal total internal reflection, the critical angle is calculated for the selected optical glass. For BK7 glass (refractive index approximately 1.517), the critical angle is approximately 41.2°. When light is incident at 45° onto the internal interface of the prism, the condition for internal total internal reflection is met. The prism is designed as a right-angle prism, with one face being a 45° inclined surface. Light enters the prism from the collimating lens group at an appropriate angle, and internal total internal reflection occurs at the 45° inclined surface. The prism's angular accuracy is ensured to be on the order of seconds, which can be guaranteed through precision machining and angle measurement instruments. All surfaces of the prism are ultra-smoothly polished, with surface roughness controlled at the nanometer level to avoid the influence of surface defects on light propagation. On the surfaces where internal total internal reflection does not occur, an anti-reflection coating can be deposited to reduce stray light reflection and improve light transmission efficiency.

[0071] Figure 4 This is a schematic diagram illustrating the projection effect of a DOE diffraction device according to an embodiment of this utility model. Figure 4In the diagram, D represents the actual projection pattern range of the adaptive projection lens, and E, F, G, H, J, K, L, and M are the images reproduced by DOE diffraction, respectively. Through diffraction optics design, the diffraction pattern ranges in different directions can be seamlessly stitched together. The DOE replication factor is N, the number of microlens units in the dynamic speckle generator is X, and the number of speckles projected by the compound eye microlens through the adaptive projection lens is the same as the number of microlens units, also X. After DOE diffraction, the total number of speckles projected by the entire system is [missing value].

[0072] Number of speckles = X × N

[0073] The number of speckle elements is increased N times compared to the original number of microlens units in a compound eye, significantly increasing the number of speckle patterns projected by the system. With the same projection FOV, the increased speckle density greatly contributes to improving the accuracy of subsequent algorithms. The DOE diffraction device replicates the number of zero-order speckles by at least 5 times.

[0074] This utility model also provides a depth camera, which includes a large number of speckle projectors, an image sensor and a second controller as described in any of the preceding claims;

[0075] The image sensor is used to receive the reflection signal of the zero-order speckle and generate an image;

[0076] The second controller is used to adjust the speckle projected by the large speckle projector according to the image. The following is a detailed description. It should be noted that this embodiment is exemplary in nature and should not be construed as limiting the scope of the claims of this utility model.

[0077] A depth camera, as an important device for acquiring three-dimensional information of an object, mainly consists of a large number of speckle projectors, an image sensor, and a second controller. These components work closely together to achieve accurate depth imaging.

[0078] Large speckle projectors are an important component of depth cameras, used to project specific speckle patterns onto a target object, providing the basis for depth calculations. Large speckle projectors include:

[0079] Light source: LEDs or laser diodes are commonly used to produce uniform floodlight and provide a stable light source for subsequent optical paths.

[0080] Collimating lens group: Composed of multiple lenses, including cylindrical lenses, it can collimate and shape floodlight into a rectangle, ensuring that the light is uniform and regularly shaped.

[0081] Total internal reflection prism: Choose between external reflection or internal total internal reflection type according to requirements, and change the direction of light path through high reflectivity film or its own characteristics.

[0082] Dynamic speckle generator: It adopts a programmable liquid crystal spatial light modulator and generates different speckles by adjusting the phase and amplitude of the light wave under the control of the first controller.

[0083] Adaptive projection lens: The focal plane is conjugate with the dynamic speckle generator, which can automatically adjust the focal length according to the speckle changes to ensure the formation of zero-order speckle.

[0084] DOE diffraction device: Located on the light-emitting surface of the projection lens, it is used to replicate zero-order speckle and achieve a large number of speckle projections.

[0085] First controller: controls the dynamic speckle generator and the adaptive projection lens, coordinating their operation to produce appropriate speckle.

[0086] An image sensor is responsible for receiving zero-order speckle signals reflected from the surface of an object and converting them into image data. An image sensor includes:

[0087] Image sensor: Mostly uses CMOS or CCD technology, and the number and size of pixels determine the camera's resolution and sensitivity.

[0088] Optical filters: filter specific wavelengths of light to improve image clarity and accuracy.

[0089] Signal amplification and processing circuit: amplifies, denoises, and performs analog-to-digital conversion on the weak electrical signal output from the photosensitive chip.

[0090] The second controller, acting as the "brain" of the depth camera, performs depth analysis and processing on the image data transmitted from the image sensor. The second controller includes:

[0091] Main processor: Generally a high-performance DSP or GPU, with powerful image algorithm computing capabilities.

[0092] Storage unit: including RAM and flash memory, used to store image data, algorithms and configuration information.

[0093] Communication interface: Communicates with the first controller and external devices through a high-speed interface to achieve speckle adjustment and data interaction.

[0094] Algorithm library: Built-in algorithms such as stereo matching and phase unwrapping are used to calculate the depth information of objects and adjust the working state of the speckle projector based on the results.

[0095] When the depth camera is working, numerous speckle projectors project zero-order speckle patterns, which are reflected from the object's surface and received by the image sensor, converted into image data, and transmitted to the second controller. The second controller analyzes the data to determine if the speckle pattern is appropriate. If adjustment is needed, it sends a command to the first controller to adjust the speckle projection of the projectors, ultimately achieving efficient and accurate depth imaging.

[0096] This invention also provides an electronic device comprising the numerous speckle projectors described in any of the foregoing claims. This optical device can be of various types. It should be noted that this embodiment is merely illustrative to provide those skilled in the art with a clearer understanding of the optical device and should not constitute a limitation on the scope of protection of this invention.

[0097] Based on the unique functionality of the aforementioned large number of speckle projectors, many electronic devices incorporate them as core components to achieve diverse and practical functions. In addition to the aforementioned large number of speckle projectors, such electronic devices also include other key components to work in concert with the large number of speckle projectors to complete specific tasks.

[0098] As mentioned above, a large number of speckle projectors include:

[0099] Light source: LEDs or laser diodes are commonly used to generate uniform floodlight, providing a stable light source for the subsequent optical path and ensuring the stability and reliability of speckle projection.

[0100] Collimating lens group: It is a clever combination of multiple lenses, including cylindrical lenses, which can collimate and shape the floodlight into a rectangle, providing a regular and uniform light basis for subsequent speckle generation.

[0101] Total internal reflection prism: Depending on actual needs, external reflection or internal total internal reflection types can be flexibly selected. Through high reflectivity film or its own special optical properties, the direction of light path can be precisely changed to meet the requirements of different structural designs and optical path layouts.

[0102] Dynamic speckle generator: Employing an advanced programmable liquid crystal spatial light modulator, under the precise control of the first controller, it rapidly generates various speckle patterns by finely adjusting the phase and amplitude of the light waves to adapt to different application scenarios.

[0103] Adaptive projection lens: Its focal plane is conjugate with the dynamic speckle generator, which can keenly sense changes in speckle and automatically adjust the focal length to always ensure the formation of zero-order speckle, thus guaranteeing high-quality speckle projection.

[0104] DOE diffraction device: Located on the light-emitting surface of the projection lens, it can efficiently replicate zero-order speckle and achieve stable projection of a large number of speckles, providing sufficient speckle resources for the function realization of electronic devices.

[0105] The first controller is responsible for controlling the dynamic speckle generator and the adaptive projection lens, coordinating their work, and producing the most suitable speckle projection effect according to the equipment requirements.

[0106] Other key components include:

[0107] Data processing unit: Similar to the second controller in a depth camera, it is equipped with a high-performance processor, such as a powerful central processing unit (CPU) or a dedicated graphics processing unit (GPU). It can not only quickly process large amounts of speckle data generated by the speckle projector, but also perform comprehensive analysis of data from other related sensors. For example, in a 3D modeling device, the data processing unit combines speckle information with position sensor data to construct an accurate 3D model.

[0108] Storage module: Includes random access memory (RAM) for temporary storage of speckle data being processed and intermediate calculation results to ensure efficient data processing; and high-capacity flash memory or hard disk drive for long-term storage of programs, algorithms, and important processed data required for device operation, such as storing test results and historical data in industrial testing equipment for subsequent analysis.

[0109] Display Unit: In electronic devices that require a visual representation of speckle projection effects or results generated based on speckle data, a high-resolution display is provided. For example, in virtual reality (VR) / augmented reality (AR) devices, the display unit presents a 3D scene calculated based on speckle data to the user, providing an immersive experience.

[0110] Power supply system: Provides stable power support for the entire electronic device, including rechargeable batteries or external power adapters. The power supply system has overvoltage protection, overcurrent protection, and voltage regulation functions to ensure stable operation of the device under different power supply conditions and avoid the normal operation of the speckle projector and other components due to power problems.

[0111] The main application scenarios include:

[0112] Industrial Inspection: In industrial fields such as electronic equipment manufacturing and automotive parts production, it is used to detect defects and flatness on the surface of products. A large number of speckle projectors project speckles onto the product surface. By analyzing changes in the reflected speckles, the data processing unit can quickly and accurately detect the presence of defects in the product, improving production quality control efficiency.

[0113] Virtual Reality and Augmented Reality: In VR / AR devices, numerous speckle projectors are used to acquire depth information about the user's surroundings, helping the device construct 3D scenes in real time and achieve a more realistic and immersive interactive experience. For example, when a user moves in a virtual environment, the device updates the scene display in real time through speckle projection and data processing, allowing the user to experience realistic spatial changes.

[0114] Intelligent security monitoring: Security cameras and other equipment utilize numerous speckle projectors to achieve 3D modeling and dynamic monitoring of the monitored area. By analyzing changes in speckle reflection data, intrusions by abnormal objects or the trajectories of moving objects can be detected in a timely manner, improving the accuracy and intelligence of security monitoring.

[0115] When these electronic devices are in operation, numerous speckle projectors first project zero-order speckle onto the target area. After the speckle is reflected by the object's surface, relevant sensors collect the reflection information and transmit it to the data processing unit. The data processing unit analyzes and processes the data according to its built-in algorithm, and then feeds back to the first controller as needed to adjust the working state of the speckle projectors. At the same time, the processing results are output to the display unit or used for other subsequent operations, ultimately enabling the electronic device to perform efficient functions in different application scenarios.

[0116] The various embodiments described in this specification are presented in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The above description of the disclosed embodiments enables those skilled in the art to implement or use this invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this invention. Therefore, this invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0117] The specific embodiments of this utility model have been described above. It should be understood that this utility model is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the substantive content of this utility model.

Claims

1. A large speckle projector, characterized in that, include: Light source, used to project floodlight; A collimating lens group, located in the output light path of the light source, is used to collimate the floodlight; A dynamic speckle generator, located on the light-emitting side of the collimating lens group, can generate different speckles from the floodlight; An adaptive projection lens; the focal plane of the adaptive projection lens is conjugate with the dynamic speckle generator to automatically adjust the focal length according to changes in the size of the speckle, ensuring the formation of zero-order speckle; A DOE diffraction device is located on the light-emitting surface of the adaptive projection lens to replicate the zero-order speckle.

2. A large speckle projector according to claim 1, characterized in that, Also includes: A total internal reflection prism is located between the collimating lens group and the dynamic speckle generator to change the optical path direction of the floodlight.

3. A large speckle projector according to claim 2, characterized in that, The inclined surface of the total internal reflection prism is coated with a high-reflection film.

4. A large speckle projector according to claim 2, characterized in that, The total internal reflection prism is either externally reflective or internally totally reflective.

5. A large speckle projector according to claim 1, characterized in that, The dynamic speckle generator is a programmable liquid crystal spatial light modulator that dynamically adjusts the phase or amplitude of the light wave to generate different speckles from the floodlight.

6. A large speckle projector according to claim 1, characterized in that, The collimating lens group also shapes the floodlight into a rectangle.

7. A large speckle projector according to claim 1, characterized in that, It also includes the first controller; The first controller is used to control the dynamic speckle generator and the adaptive projection lens.

8. A large speckle projector according to claim 1, characterized in that, The collimating lens group comprises two cylindrical surfaces, which collimate the light beams of the light source along the fast and slow axes, respectively.

9. A depth camera, characterized in that, Includes a large number of speckle projectors, an image sensor, and a second controller as described in any one of claims 1-8; The image sensor is used to receive the reflection signal of the zero-order speckle and generate an image; The second controller is used to adjust the speckle projected by the large speckle projector according to the image.

10. An electronic device, characterized in that, Includes a large number of speckle projectors as described in any one of claims 1-8.

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