Projector for large number of speckles and optical equipment

Abstract

The utility model relates to a large-scale speckle projector and optical equipment, which are characterized by comprising a light-emitting light source for projecting floodlight; the collimating lens group is positioned on an emergent light path of the light-emitting light source and is used for collimating the floodlight; the fly eye lens is located on the light emitting side of the collimating lens group and used for focusing the floodlight into speckles; a projection lens; the focal plane of the projection lens is conjugated with the fly-eye lens to form zero-order speckles; and the DOE diffraction device is positioned on the light-emitting surface of the projection lens so as to copy the zero-order speckles. According to the utility model, the problems of insufficient uniformity and quantity of projected speckles in the existing speckle projection scheme can be solved, and uniform high-density speckle projection is realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to optical technology field, specifically, relate to a large number of speckle projector and optical equipment. BACKGROUND

[0002] In face recognition equipment, floor cleaning robot, laser radar and other 3D vision optical applications, the transmitting end is often used to project speckle pattern for 3D vision modeling. The conventional scheme of the transmitting end is Vcsel+DOE speckle projector, and its principle is that Vcsel projects a zero-order speckle pattern with small divergence angle through a collimating mirror, and then the zero-order speckle pattern is copied into a projection pattern with large divergence angle through a DOE. Due to the existence of multiple light-emitting holes on the Vcsel, the brightness inconsistency is caused by the process. At the same time, due to the process limitation, the number of light-emitting holes of the Vcsel itself is difficult to achieve a large number. For large FOV or high-precision applications, it is impossible to provide sufficient number and density of speckles to achieve high enough detection precision.

[0003] The disclosure of the above background art content is only used to assist in understanding the inventive concept and technical scheme of the utility model, and it does not necessarily belong to the prior art of the present patent application. In the absence of explicit evidence that the above content has been disclosed on the filing date of the present patent application, the above background art should not be used to evaluate the novelty and inventiveness of the present application. UTILITY MODEL CONTENT

[0004] Therefore, the utility model provides a large number of speckle projection system, can overcome the existing speckle projection scheme the problem of insufficient projection speckle uniformity and quantity, realize the uniform high density speckle projection.

[0005] In the first aspect, the utility model provides a large number of speckle projector, characterized by, including:

[0006] Light-emitting source for projecting floodlight;

[0007] Collimating mirror group is located on the exit light path of the light-emitting source, for collimating the floodlight;

[0008] Compound eye lens is located on the light exit side of the collimating mirror group, for focusing the floodlight into speckle;

[0009] Projection lens;The focal plane of the projection lens is conjugated with the compound eye lens to form zero-order speckle;

[0010] DOE diffractive device is located on the light exit surface of the projection lens to copy the zero-order speckle.

[0011] Optionally, the large number of speckle projector, characterized by, further including:

[0012] 45° reflection prism, located between the collimating mirror group and the compound eye lens, to change the light path direction of the floodlight.

[0013] Optionally, the large number of speckle projector, characterized in that the 45° reflection prism is coated with a high reflection film.

[0014] Optionally, the large number of speckle projector, characterized in that the 45° reflection prism is an external reflection or an internal total reflection.

[0015] Optionally, the large number of speckle projector, characterized in that the microlens unit of the compound eye lens is a smooth curved convex lens and concave lens, a binary optical diffraction relief lens or a phase grating lens with a periodic change in refractive index.

[0016] Optionally, the large number of speckle projector, characterized in that the focal lengths of the plurality of microlens units of the compound eye lens are the same.

[0017] Optionally, the large number of speckle projector, characterized in that the plurality of microlens units of the compound eye lens are unevenly distributed.

[0018] Optionally, the large number of speckle projector, characterized in that the collimating mirror group includes two cylindrical lenses for collimating the light beams in the fast and slow axis directions of the light source.

[0019] Optionally, the large number of speckle projector, characterized in that the DOE diffraction device replicates the number of zero-order speckles by at least 5 times.

[0020] In a second aspect, the utility model provides a kind of optical equipment, characterized in that, including the large number of speckle projector of any one of the above.

[0021] Compared with prior art, the utility model has the beneficial effects as follows:

[0022] The utility model first forms the light beam emitted by light source into collimating and uniform rectangular light field by collimating mirror group, then focuses to form zero-order speckle pattern by compound eye lens, finally replicates zero-order speckle by DOE diffraction device, realizes the multiplication of speckle number and the expansion of projection angle.Compared with prior art, the number of speckles that can be projected by the utility model can be increased by tens of times, and higher speckle number provides hardware conditions for more accurate 3D visual modeling.

[0023] The number of speckles is affected by Vcsel technology in the speckle projection scheme used in the industry at present, and the number of zero-order speckles is usually several hundred, and more number has certain influence on mass production yield.The utility model uses compound eye lens to focus to form zero-order speckle, and the number of zero-order speckles can reach tens of thousands of points, greatly improving the density of speckle. Attached Figure Description

[0024] 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:

[0025] Figure 1 This is a schematic diagram of the optical path of a large speckle projector in an embodiment of this utility model;

[0026] Figure 2 This is a schematic diagram of the optical path of another large speckle projector in an embodiment of this utility model;

[0027] Figure 3 This is a schematic diagram of the optical path of another large speckle projector in an embodiment of this utility model;

[0028] Figure 4 This is a schematic diagram of the structure of a compound eye lens in an embodiment of this utility model;

[0029] Figure 5 This is a schematic diagram of the projection effect of a DOE diffraction device in an embodiment of this utility model.

[0030] 1-Light source;

[0031] 2-Collimating lens group;

[0032] 3-45° reflecting prism;

[0033] 4-Compound eye lens;

[0034] 5-Projection lens;

[0035] 6-DOE diffraction device; Detailed Implementation

[0036] 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.

[0037] The terms "first", "second", "third", "fourth" etc. (if any) in the description and claims of the present application and the above drawings are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "comprise" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0038] The embodiment of the present application provides a large number of speckle projectors, and aims to solve the problems in the prior art.

[0039] The technical scheme of the present application and how the technical scheme of the present application solves the above technical problems will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes can not be described again in some embodiments. The embodiments of the present application will be described below with reference to the drawings.

[0040] The present application first forms the light beam emitted by the light source into a collimated and uniform rectangular light field through the collimating mirror group, then focuses the light field into a zero-order speckle pattern through the compound eye lens, and finally replicates the zero-order speckle through the DOE diffraction device to realize the multiplication of the number of speckles and the expansion of the projection angle. Compared with the prior art, the number of speckles that can be projected by the present application can be increased by tens of times, and the higher number of speckles provides a hardware condition for more accurate 3D visual modeling.

[0041] Figure 1 The present application is a schematic diagram of the optical path of a large number of speckle projectors in the embodiment of the present application. As shown in Figure 1 The large number of speckle projectors in the embodiment of the present application comprises:

[0042] The light source is used for projecting floodlight.

[0043] Specifically, the light source can be a high-brightness light-emitting diode (LED) or a laser diode as a light source.

[0044] For LED light sources, choose products with appropriate wavelength range (such as visible light band or near-infrared band) to meet the specific application requirements. At the same time, consider its power characteristics, according to the intensity and range of the required speckle projection, select the appropriate power level, for example, for short distance speckle projection, only a few watts of power may be needed, while for long distance, large scene applications, may need tens of watts or even higher power.

[0045] For laser diodes, the coherence and directionality need to be considered. Choose the appropriate laser type, such as continuous wave or pulsed laser, different types will affect the characteristics of speckle. For example, the speckle produced by continuous wave laser is more stable in time, while pulsed laser can achieve different speckle dynamic effects by adjusting the pulse frequency and width. Laser diode can be EEL laser. EEL laser, as an edge-emitting semiconductor laser, has different divergence angles in fast and slow axes, and the light beam emitted by the laser is projected to the right of the collimating mirror.

[0046] Equipped with corresponding heat dissipation devices, because high-power light sources will generate a lot of heat when working. For LED, heat sinks or air cooling devices can be used; for laser diodes, more advanced cooling measures such as liquid cooling may be needed to ensure that their working temperature is within a safe range and avoid performance degradation or damage due to overheating. For EEL lasers, they can be attached to a heat sink.

[0047] The collimating mirror group is located on the light path of the light-emitting light source and is used for collimating the floodlight.

[0048] Specifically, the collimating mirror group can use multiple lens combinations to achieve precise collimation. Choose lenses with appropriate focal length and radius of curvature. For example, a combination of convex and concave mirrors can be used to perform preliminary collimation of the floodlight emitted from the light-emitting light source by accurately calculating the distance and curvature between them. Consider using aspherical lenses to reduce aberrations and improve collimation. Aspherical lenses can better correct spherical aberrations, making the light more parallel, thereby providing a higher quality input beam for subsequent compound eye lenses and speckle formation. The lenses of the collimating mirror group are coated, such as anti-reflective coating, to reduce reflection loss and improve light energy utilization. The choice of coating is optimized according to the wavelength of the light source to achieve the maximum transmittance at that wavelength.

[0049] When the light-emitting light source has fast and slow axes, the collimating mirror group contains two cylinders, which collimate the light beams in the fast and slow axis directions of the light-emitting light source respectively, so that both the fast and slow axis directions are collimated, making the rectangular light field more uniform.

[0050] The compound eye lens is located on the light-emitting side of the collimating mirror group and is used to focus the floodlight into speckles.

[0051] Specifically, the design of the compound eye lens is a key part, which focuses the collimated floodlight into speckles. The compound eye lens can be composed of multiple micro-lens units, the size, shape and arrangement of which will affect the characteristics of the speckles. The size of the micro-lens units is optimized, and the diameter and pitch of the units are adjusted according to the size and density of the required speckles. Smaller unit size will produce smaller and denser speckles; larger unit size will form larger and sparser speckles. In order to form a uniform dot matrix, the focal length of the micro-lens units is the same, so that the generated dot matrix is uniform.

[0052] Considering the material of the compound eye lens, high refractive index and low dispersion optical materials are selected to ensure good focusing performance. For example, optical glass or certain transparent polymers can be used, which have stable optical performance and certain mechanical strength, and can withstand certain thermal and environmental stresses. The surface of the compound eye lens is finely processed to ensure its surface quality and reduce surface roughness, avoiding light scattering and speckle quality degradation caused by surface defects.

[0053] A projection lens; the focal plane of the projection lens is conjugate with the compound eye lens to form zero-order speckles.

[0054] Specifically, the focal plane of the projection lens is conjugate with the compound eye lens to form clear zero-order speckles. A complex lens group structure is used, such as a combination of multiple positive and negative lenses, and the conjugate relationship with the compound eye lens is ensured by accurately adjusting the pitch and focal length of the lenses. The projection lens is designed to be achromatic to overcome the chromatic aberration problem of different color lights, ensuring the consistency of the position and shape of the speckles under different color components, which is more important for wide-spectrum light sources. Consider using a zoom lens to adjust the focal length according to different actual application scenarios, to achieve clear imaging of speckles at different projection distances. Similarly, the lenses of the projection lens are coated with high-quality coating to improve light transmittance and reduce reflection loss.

[0055] A DOE diffraction device is located at the light exit surface of the projection lens to replicate the zero-order speckles.

[0056] Specifically, the design of the DOE diffraction device is crucial for replicating the zero-order speckle. The diffraction structure of the DOE is designed according to the replication multiple and distribution characteristics of the required speckle. Binary optical technology can be used to manufacture the DOE with a specific diffraction pattern through micro-nano processing means. Considering the diffraction efficiency of the DOE, the structure parameters are optimized to make more light energy diffract according to the required diffraction order, thereby improving the efficiency of speckle replication. The material of the DOE is selected, and quartz, silicon and other materials can be used. These materials have high optical uniformity and low absorption loss, which can ensure the quality of the diffracted light. The DOE is packaged and protected to avoid surface contamination and scratches, because minor damage to the surface can affect the diffraction effect and thus the replication effect of the speckle.

[0057] Figure 2 The utility model discloses another kind of massive speckle projector's optical path schematic view in another embodiment of the utility model. As shown in Figure 2 Compared with the foregoing embodiment, another kind of massive speckle projector in another embodiment of the utility model further comprises:

[0058] 45° reflecting prism is located between the collimating lens group and the compound eye lens to change the light path direction of the floodlight.

[0059] Specifically, the 45° reflecting prism usually selects optical glass as the material of the prism, such as BK7 or quartz, and these materials have good optical properties, such as high transparency, low absorption and low scattering. The surface of the 45° reflecting prism is polished with high precision to ensure the flatness and smoothness of the surface, so as to ensure the quality of the reflected light. Generally, the surface roughness is required to be in nanometer level to reduce the scattering and energy loss of the reflected light.

[0060] High reflectivity film is coated on the reflecting surface, and according to the wavelength of the light source, the appropriate coating material and thickness are selected to make the reflectivity reach a high level. For example, for the visible light band, multilayer dielectric film can be used to make the reflectivity reach more than 99%. At the same time, antireflection film can be coated on other non-reflecting surfaces to reduce the interference of stray light.

[0061] As shown in Figure 2 The 45° reflecting prism is externally reflected. The reflecting surface of the prism is coated to form reflection, so that the light is turned by 90 degrees. Figure 2 The light path direction is changed from horizontal to vertical.

[0062] As shown in Figure 3As shown, the 45° reflecting prism exhibits total internal reflection. Based on the critical angle formula for 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°, satisfying the condition for total internal reflection when light is incident at 45° onto the prism's internal interface. 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, resulting in total internal reflection 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 total internal reflection does not occur, an anti-reflection coating can be applied to reduce stray light reflection and improve light transmission efficiency.

[0063] Figure 4 This is a schematic diagram of a compound eye lens according to an embodiment of the present invention. The compound eye lens comprises many microlenses with the same focal length. When parallel light is incident on the compound eye lens, each microlens focuses the light onto the same plane, forming a dot matrix. The arrangement of the compound eye lenses is not limited to a regular rectangle or hexagon; it can be any pattern. The microlens units of the compound eye lens can be... Figure 4 The smooth curved surface shown in a convex lens and concave lens can also be... Figure 4 The binary optical diffraction relief lens shown in b or Figure 4 Figure c shows a phase grating lens with a periodically changing refractive index. Depending on the design requirements of the light spot, multiple microlens units can be non-uniformly distributed, thereby achieving different densities of the light spot in different regions.

[0064] Figure 5 This is a schematic diagram illustrating the projection effect of a DOE diffraction device according to an embodiment of this utility model. Figure 5 In the diagram, D represents the actual range of the pattern projected by the 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 compound eye lens is X, and the number of speckles projected by the compound eye microlens through the projection lens is the same as the number of microlens units, also X. After DOE diffraction, the number of speckles projected by the entire system is...

[0065] Number of speckles = X × N

[0066] 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.

[0067] The utility model still provides an optical equipment, contains the large amount of speckle projector of any preceding description. This optical equipment can various types, the following is with depth camera as an example to explain. It needs to explain, this embodiment is only illustratively explained, to make the person skilled in the art have more clear cognition to optical equipment, and should not constitute the restriction to the protection scope of the utility model.

[0068] Depth camera is an integrated system, mainly contains above-mentioned large amount of speckle projector, and the key components such as image sensor, image processing unit matched with it. Through speckle projector, speckle pattern is projected to target object, and the speckle information reflected back is received using image sensor, then the information is processed by image processing unit, to realize the measurement and extraction of depth information.

[0069] Light source:

[0070] Considering matching with the working mode of depth camera, according to different measurement range and accuracy requirement, the power and wavelength of light source are reasonably selected. For example, for close-range high-precision measurement, low-power but more accurate wavelength laser diode can be selected as light source to improve the resolution of depth measurement; for long-distance measurement, the power of light source is appropriately increased to ensure that the speckle is still clear and can be accurately detected at a long distance.

[0071] The modulation function of light source can be integrated to realize accurate modulation of light pulse. Through time-of-flight (ToF) principle, the emission time and period of light pulse are accurately controlled to provide time reference for depth measurement. For example, high-frequency modulation signal can be used to drive light source to improve the accuracy and response speed of depth measurement.

[0072] Combined with power management module, the power of light source is dynamically adjusted according to the working state of depth camera and environmental light conditions. When the environmental light is strong, the power of light source is appropriately increased to enhance the contrast of speckle; in low-light environment, the power can be appropriately reduced to save energy, while avoiding excessive exposure.

[0073] Collimating lens group:

[0074] The collaborative work of collimating lens group and speckle projector is optimized to ensure that its collimating effect matches the field of view angle and working distance of depth camera. According to the focal length of depth camera and the desired working distance range, the parameters of collimating lens group are adjusted to ensure that the projected speckle uniformly covers the target object at different distances.

[0075] In order to improve the stability and anti-interference ability of the system, the collimating lens group is designed to be anti-vibration. Elastic support structure or damping material is used to avoid changes in optical parameters of collimating lens group caused by mechanical vibration of camera or external environmental vibration, thereby affecting the collimating effect of speckle.

[0076] Increase the self-calibration function of the collimating lens group. Through the built-in calibration sensor, the quality of the collimated beam is monitored in real time, such as the shape of the spot, the energy distribution, etc. According to the monitoring results, the position or focal length of the lens group is automatically adjusted to maintain the best collimation state.

[0077] 45° reflecting prism (internal total reflection):

[0078] Coordinate with the overall optical layout of the depth camera to ensure the accuracy of the position and angle of the reflecting prism. During assembly, use high-precision positioning and adjustment mechanisms to ensure the 45° angle and the position of the reflecting surface of the reflecting prism to ensure that the light accurately changes direction and is transmitted to the subsequent components.

[0079] Consider designing optical isolation structures around the prism to prevent external stray light from interfering with the reflection process. Use light shields or diaphragms to block unnecessary light from entering the reflection path, improve the purity of the light signal of the speckle projection, and thus improve the accuracy of depth measurement.

[0080] To cope with different environmental conditions, add anti-fog and anti-corrosion coatings to the prism surface. Especially in high humidity or harsh environments, these coatings can prevent water vapor condensation and chemical erosion of the prism surface, ensuring the stability and reliability of internal total reflection.

[0081] Compound eye lens:

[0082] Optimize the parameters of the microlens unit of the compound eye lens according to the resolution and measurement range of the depth camera. According to the required depth resolution, adjust the size and arrangement of the microlens unit to make the generated speckle more suitable for the needs of depth measurement. Smaller microlens units can provide higher spatial resolution, helping to more accurately measure the tiny details of the target object; while larger unit sizes may be suitable for measuring large-sized objects or large field of view ranges.

[0083] To realize flexible switching of different measurement scenarios, the compound eye lens can be designed as a replaceable module. By replacing compound eye lenses of different specifications, the measurement performance of the depth camera can be quickly adjusted, such as switching from a near-range high-resolution measurement mode to a long-range large-range measurement mode.

[0084] Combined with the mechanical fine-tuning mechanism, fine position adjustment of the compound eye lens is realized. During the calibration process of the depth camera, by fine-tuning the position of the compound eye lens, the focus position of the speckle can be accurately adjusted, improving the accuracy and accuracy of depth measurement.

[0085] Projection lens:

[0086] Ensure that the focal plane of the projection lens is conjugate with the compound eye lens to form a clear zero-order speckle, while making its optical parameters compatible with the imaging system of the depth camera. According to the pixel size, pixel number and field of view angle of the depth camera, design the focal length and aperture of the projection lens to match the receiving range of the image sensor with the projected speckle pattern.

[0087] Integrate automatic focusing and automatic aperture control functions to automatically adjust the focal length and aperture size according to the distance of the target object and the environmental lighting conditions. Automatic focusing can be achieved by analyzing the clarity of the speckle image received by the image sensor, and using a feedback control algorithm to drive the focusing mechanism of the projection lens; automatic aperture can automatically adjust the aperture size according to the environmental light intensity and the contrast of the speckle, to optimize the imaging quality of the speckle.

[0088] Aberration correction for the projection lens, considering the working requirements of the depth camera at different wavelengths, carrying out aberration correction such as achromatism and spherical aberration correction, to ensure that the projected speckle image is clear and distortion-free under different depths and lighting conditions, and to improve the accuracy of depth measurement.

[0089] DOE diffraction device:

[0090] Combine with the depth measurement algorithm to design the diffraction structure of the DOE diffraction device. According to different depth measurement algorithms and application scenarios, design the DOE with specific diffraction characteristics to make the copied speckle pattern more conducive to the extraction of depth information. For example, according to the principle of triangulation, a DOE that can generate a speckle pattern with a specific angle distribution can be designed to improve the accuracy of depth measurement.

[0091] In order to improve the performance and stability of the DOE, it is combined with a temperature control system. Since the diffraction performance of the DOE may be affected by temperature, by precisely controlling the temperature of the DOE, the diffraction efficiency and stability of the diffraction pattern can be guaranteed, thereby improving the reliability of depth measurement.

[0092] Consider designing the DOE as a replaceable or adjustable component, which can quickly replace or adjust the parameters of the DOE under different depth measurement tasks or environmental conditions, to achieve different speckle replication effects and enhance the adaptability of the depth camera.

[0093] Image sensor

[0094] Select a suitable image sensor, considering its resolution, sensitivity, frame rate and spectral response range, etc. For high-resolution depth measurement, select an image sensor with high pixel density; for measurement of fast-moving objects, select a high-frame-rate sensor; according to the wavelength of the light source, select a sensor with corresponding spectral response range to ensure that it can effectively receive and detect speckle reflected light.

[0095] To improve the performance of image sensors, back-illuminated sensor technology can be used to increase quantum efficiency and enhance the ability to detect weak light signals. At the same time, noise reduction processing can be performed on the image sensor, such as integrating noise suppression circuits in the sensor or using filtering algorithms in the image processing unit, to reduce the impact of noise on depth measurement.

[0096] Image processing unit

[0097] This unit is the core part of the depth camera, responsible for processing the speckle images collected by the image sensor and extracting depth information.

[0098] Advanced image processing algorithms such as structured light, binocular vision, or ToF are used to calculate the depth of the target object based on speckle deformation, disparity, or time-of-flight information. For structured light algorithms, the difference between the projected speckle pattern and the reflected speckle pattern is analyzed to calculate the depth information of the object surface; for binocular vision algorithms, the speckle images from the left and right image sensors are combined to calculate the depth using disparity information; for ToF algorithms, the depth is calculated based on the time-of-flight information of the light pulse.

[0099] Optimization and acceleration of image processing algorithms can be achieved using hardware acceleration techniques such as GPU acceleration or dedicated image processing chips to improve the speed and efficiency of depth information processing. This is particularly important for real-time depth measurement and dynamic scene applications, ensuring that the depth camera can quickly and accurately output depth information.

[0100] Error correction and compensation are performed to consider the impact of environmental light interference, system aberration, speckle noise, and other factors on depth measurement. Error correction and compensation algorithms are added to the image processing process. For example, an ambient light model is established to compensate for the impact of ambient light; by calibrating the system, aberration and speckle noise are corrected to improve the accuracy and stability of depth measurement.

[0101] External interfaces and data transmission

[0102] The depth camera is equipped with various external interfaces such as USB, Ethernet, HDMI, etc. to facilitate connection with external devices. Through the USB interface, the depth camera can be connected to a computer for control and data transmission; through the Ethernet interface, remote control and fast transmission of large amounts of data can be achieved, suitable for distributed measurement systems; through the HDMI interface, depth images can be displayed in real time on external displays.

[0103] Standardize data formats and output depth data in standard data formats such as point cloud data (PLY, PCD, etc.) or depth image data (such as 16-bit grayscale images representing depth information) to facilitate integration and interaction with other software and systems.

[0104] System calibration and calibration

[0105] Develop a special calibration and calibration program to calibrate and calibrate the depth camera. Including the optical axis calibration of the speckle projector, the pixel calibration of the image sensor, the geometric calibration of the system, etc. By using standard objects with known shape and size, such as chessboard calibration board, calibrate the depth camera, determine the internal and external parameters of the system, and improve the accuracy of depth measurement.

[0106] Establish an online calibration mechanism, and periodically or in real time calibrate and calibrate the depth camera during operation according to environmental changes and system performance changes, to ensure long-term stability and accuracy of depth measurement.

[0107] In summary, the depth camera uses a large number of speckle projectors as an important component, and through the optimization, integration and overall design of each component, it realizes the complete function from speckle projection, image acquisition to depth information processing. At the same time, through the functions of external interface, calibration and calibration, etc., the flexibility, reliability and compatibility with external devices of the system are improved, and it can be widely used in robot navigation, augmented reality, three-dimensional modeling, industrial detection and other fields, and provides accurate depth information for different application scenarios.

[0108] The embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. The above description of the disclosed embodiments enables a person skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

[0109] The specific embodiments of the present application are described above. It should be understood that the present application is not limited to the above specific embodiments, and those skilled in the art can make various modifications or modifications within the scope of the claims, which does not affect the essential content of the present application.

Claims

1. A bulk speckle projector, characterized by, The application relates to a large-quantity speckle projector, comprising: a light-emitting source for projecting a floodlight; a collimating lens group located on the light-emitting source's light path for collimating the floodlight; an ommatidium lens located on the light-emitting source's light path for focusing the floodlight into speckles; a projection lens; a focal plane of the projection lens is conjugated with the ommatidium lens to form zero-order speckles; a DOE diffractive device located on the projection lens's light-emitting surface to copy the zero-order speckles.

2. A bulk speckle projector according to claim 1, wherein, Further comprising: a 45-degree reflecting prism located between the collimating lens group and the ommatidium lens to change the floodlight's light path direction.

3. A bulk speckle projector according to claim 2, wherein, The 45-degree reflecting prism's inclined surface is coated with a high-reflective film.

4. A bulk speckle projector according to claim 2, wherein, The 45-degree reflecting prism is an external reflection or an internal total reflection.

5. A bulk speckle projector according to claim 1, wherein, The ommatidium lens's microlens unit is a smooth curved convex lens and concave lens, a binary optical diffraction relief lens or a refractive index periodically changed phase grating lens.

6. A bulk speckle projector according to claim 1, wherein, The ommatidium lens's multiple microlens units have the same focal length.

7. A bulk speckle projector according to claim 1, wherein, The ommatidium lens's multiple microlens units are unevenly distributed.

8. A bulk speckle projector according to claim 1, wherein, The collimating lens group contains two cylindrical lenses for collimating the light-emitting source's fast and slow axis light beams.

9. A bulk speckle projector according to claim 1, wherein, The DOE diffractive device copies the zero-order speckles' quantity by at least 5 times.

10. An optical device, characterized by The application further comprises the large-quantity speckle projector according to any one of claims 1-9.

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