Novel speckle projector and optical equipment

Abstract

A novel speckle projector and optical equipment are characterized in that the novel speckle projector comprises an array laser used for projecting array laser; a projection lens; the distance between the light-emitting surface of the array laser and the focal plane of the projection lens is smaller than 1 / 10 of the focal length of the projection lens. According to the utility model, the problems of speckle FOV, insufficient uniformity and distortion existing in the existing speckle projection scheme can be overcome, large FOV, high uniformity and low distortion speckle projection can be realized, and speckle projection with flexible pattern distribution can also be realized.

Description

Technical Field

[0001] This utility model relates to the field of optical technology, specifically to a novel speckle projector and optical device. Background Technology

[0002] In today's optical technology field, speckle projectors play a crucial role in numerous applications, such as 3D vision perception, structured light measurement, and lidar. Among these, 3D vision perception technology, as an important component of artificial intelligence and robotics, places increasingly higher demands on the performance of speckle projectors.

[0003] Traditional speckle projectors typically employ a single laser or a simple laser array, which presents several limitations. Firstly, the speckle pattern projected by a single laser struggles to meet the spatial coverage and uniformity requirements of complex scenes. In practical applications, such as 3D modeling large objects, the speckle projected by a single laser may not completely cover the object's surface, leading to missing measurement data and affecting the accuracy and completeness of the 3D model.

[0004] On the other hand, while simple laser arrays can expand the projection range to some extent, the poor consistency between the lasers within them leads to problems such as uneven intensity and unstable speckle patterns. This is a fatal flaw for high-precision 3D vision perception and measurement, as uneven speckle patterns complicate subsequent image analysis and processing, reducing the accuracy and reliability of measurements.

[0005] Furthermore, in traditional speckle projectors, the coordination between the projection lens and the laser is often not optimized. Because the focal plane of the projection lens is not conjugate with the light-emitting surface of the laser, the laser beam cannot form a clear and stable speckle pattern in the target area after being projected through the lens. This not only leads to reduced energy utilization but also affects the quality of the speckle pattern, thereby impacting the performance of the entire system.

[0006] To meet the demand for high-precision and high-reliability speckle projection in fields such as 3D vision perception, there is an urgent need for a new type of speckle projector that can overcome the aforementioned shortcomings of traditional speckle projectors.

[0007] 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

[0008] To address this, the novel speckle projector employs an array laser to project an array of laser beams. By rationally designing the projection lens, its focal plane is made close to the emitting surface of the array laser, thus effectively solving the problems existing in traditional speckle projectors, improving the uniformity, stability, and energy utilization of speckle projection, and providing more reliable technical support for applications such as 3D visual perception.

[0009] In a first aspect, this utility model provides a novel speckle projector, characterized in that it comprises:

[0010] Array laser, used to project array laser beams;

[0011] The distance between the emitting surface of the array laser and the focal plane of the projection lens is less than 1 / 10 of the focal length of the projection lens.

[0012] Optionally, the novel speckle projector is characterized in that the array laser has at least 200 light-emitting aperture units.

[0013] Optionally, the novel speckle projector is characterized in that the projection lens is an object-side telecentric lens, and the object-side principal ray angle is 0°.

[0014] Optionally, the novel speckle projector is characterized in that the object-side beam angle of the projection lens is greater than the output beam angle of the array laser, and the margin on one side does not exceed 5°.

[0015] Optionally, the novel speckle projector is characterized in that the emitting surface of the array laser coincides with the focal plane of the projection lens.

[0016] Optionally, the novel speckle projector is characterized in that the object-side beam angle of the projection lens is ≥ ±10°.

[0017] Optionally, the novel speckle projector is characterized in that the object-side beam angle of the projection lens is ≤ ±15°.

[0018] Optionally, the novel speckle projector is characterized in that the projection lens is a conventional optical lens, a diffractive optical device, or a metasurface optical device.

[0019] Optionally, the novel speckle projector is characterized in that the conventional optical lenses, along the optical axis from the projection space side to the light source side, are arranged as follows:

[0020] The first lens has a negative optical power, and the projection space side of the first lens is convex, while the light source side is concave.

[0021] The second lens has a positive optical power, and its projection space side is concave while its light source side is convex.

[0022] The third lens has a positive optical power, and its projection space side is convex, as is its light source side.

[0023] Secondly, this utility model provides a telecentric projection lens assembly, characterized in that, along the optical axis from the projection space side to the light source side, the assembly consists of:

[0024] The first lens has a negative optical power, and the projection space side of the first lens is convex, while the light source side is concave.

[0025] The second lens has a positive optical power, and its projection space side is concave while its light source side is convex.

[0026] The third lens has a positive optical power, and its projection space side is convex, as is its light source side.

[0027] Optionally, the telecentric projection lens group is characterized in that the axial distance TTL from the projection space side of the first lens to the light-emitting surface of the light source satisfies a relationship of 1.85 with the diagonal length RL of the light-emitting area of ​​the light source. <TTL / RL<2.38。

[0028] Optionally, the telecentric projection lens group is characterized in that the effective focal length f1 of the first lens and the effective focal length f2 of the second lens satisfy the following relationship: -1.2 <f2 / f1<-0.85。

[0029] Optionally, the telecentric projection lens group is characterized in that the angle of the emitted principal ray on the projection space side is 0°.

[0030] Optionally, the telecentric projection lens group is characterized in that the radius of curvature of the projection space side of the first lens is greater than the radius of curvature of the light source side of the first lens.

[0031] Optionally, the telecentric projection lens group is characterized in that the radius of curvature of the projection space side of the second lens is smaller than the radius of curvature of the light source side of the second lens.

[0032] Optionally, the telecentric projection lens group is characterized in that the radius of curvature of the light source side of the third lens is greater than the radius of curvature of the projection space side of the third lens.

[0033] Optionally, the telecentric projection lens group is characterized in that the radius of curvature of the projection space side of the first lens is greater than the radius of curvature of the light source side of the first lens.

[0034] Optionally, the telecentric projection lens group is characterized in that the radius of curvature of the third lens on the light source side is greater than the radius of curvature of the first lens on the projection space side.

[0035] Optionally, the telecentric projection lens group is characterized in that the radius of curvature of the projection space side of the third lens is greater than the radius of curvature of the projection space side of the second lens.

[0036] Thirdly, this utility model provides a telecentric projection lens assembly, characterized in that, along the optical axis from the projection space side to the light source side, the assembly consists of:

[0037] The first lens has a negative optical power, and the projection space side of the first lens is convex, while the light source side is concave.

[0038] The second lens has a negative optical power and the side of the light source is concave.

[0039] The third lens has a positive optical power, and its projection space side is concave while its light source side is convex.

[0040] The fourth lens has a positive optical power and a convex light source side.

[0041] Optionally, the telecentric projection lens group is characterized in that the axial distance TTL from the projection space side surface of the first lens to the light-emitting surface of the light source satisfies a relationship of 1.9 with respect to the diagonal length RL of the light-emitting area of ​​the light source. <TTL / RL<2.45。

[0042] Optionally, the telecentric projection lens group is characterized in that the effective focal length f1 of the first lens and the effective focal length f2 of the second lens satisfy the following relationship: 2.05 <f2 / f1<2.7。

[0043] Optionally, the telecentric projection lens group is characterized in that the angle of the emitted principal ray on the projection space side is 0°.

[0044] Optionally, the telecentric projection lens group is characterized in that the radius of curvature of the projection space side of the first lens is greater than the radius of curvature of the light source side of the first lens.

[0045] Optionally, the telecentric projection lens group is characterized in that the radius of curvature of the projection space side of the second lens is greater than the radius of curvature of the light source side of the second lens;

[0046] Optionally, the telecentric projection lens group is characterized in that the radius of curvature of the projection space side of the third lens is greater than the radius of curvature of the light source side of the third lens;

[0047] Optionally, the telecentric projection lens group is characterized in that the radius of curvature of the projection space side of the fourth lens is greater than the radius of curvature of the light source side of the fourth lens;

[0048] Optionally, the telecentric projection lens group is characterized in that the radius of curvature of the first lens on the light source side is smaller than the radius of curvature of the second lens on the light source side;

[0049] Optionally, the telecentric projection lens group is characterized in that the radius of curvature of the projection space side of the third lens is greater than the radius of curvature of the projection space side of the fourth lens.

[0050] Optionally, the telecentric projection lens group is characterized in that the radius of curvature of the projection space side of the second lens is greater than the radius of curvature of the projection space side of the fourth lens.

[0051] Fourthly, this utility model provides a telecentric projection lens assembly, characterized in that, along the optical axis from the projection space side to the light source side, the assembly consists of:

[0052] The first lens has a negative optical power, and the projection space side of the first lens is convex, while the light source side is concave.

[0053] The second lens has a negative optical power and the side of the light source is concave.

[0054] The third lens has a positive optical power, and its projection space side is concave while its light source side is convex.

[0055] The fourth lens has a positive optical power, and its projection space side is convex, as is its light source side.

[0056] The fifth lens has a positive optical power.

[0057] Optionally, the telecentric projection lens group is characterized in that the axial distance TTL from the projection space side surface of the first lens to the light-emitting surface of the light source satisfies a relationship of 1.9 with respect to the diagonal length RL of the light-emitting area of ​​the light source. <TTL / RL<2.45。

[0058] Optionally, the telecentric projection lens group is characterized in that the effective focal length f1 of the first lens and the effective focal length f2 of the second lens satisfy the following condition: 2.1 <f2 / f1<2.75。

[0059] Optionally, the telecentric projection lens group is characterized in that the angle of the emitted principal ray on the projection space side is 0°.

[0060] Optionally, the telecentric projection lens group is characterized in that the radius of curvature of the first lens on the light source side is smaller than the radius of curvature of the second lens on the light source side;

[0061] Optionally, the telecentric projection lens group is characterized in that the radius of curvature of the first lens on the light source side is smaller than the radius of curvature of the fourth lens on the light source side.

[0062] Optionally, the telecentric projection lens group is characterized in that the radius of curvature of the first lens on the light source side is smaller than the radius of curvature of the fifth lens on the light source side;

[0063] Optionally, the telecentric projection lens group is characterized in that the radius of curvature of the projection space side of the first lens is smaller than the radius of curvature of the projection space side of the second lens;

[0064] Optionally, the telecentric projection lens group is characterized in that the radius of curvature of the projection space side of the first lens is smaller than the radius of curvature of the projection space side of the third lens.

[0065] Optionally, the telecentric projection lens group is characterized in that the radius of curvature of the projection space side of the first lens is smaller than the radius of curvature of the projection space side of the fourth lens.

[0066] Optionally, the telecentric projection lens group is characterized in that the radius of curvature of the projection space side of the first lens is smaller than the radius of curvature of the projection space side of the fifth lens.

[0067] Optionally, the telecentric projection lens group is characterized in that the radius of curvature of the second lens on the light source side is greater than the radius of curvature of the third lens on the light source side;

[0068] Fifthly, this utility model provides a novel speckle projector, characterized in that it includes the telecentric projection lens group described in any of the above claims.

[0069] Sixthly, this utility model provides an optical device, characterized in that it includes the novel speckle projector described in any of the above claims.

[0070] Compared with the prior art, the present invention has the following beneficial effects:

[0071] This invention uses an array laser for direct projection, overcoming the defect of inconsistent brightness between the zeroth and higher orders in the replicated spot of DOE devices.

[0072] This invention utilizes an array laser for direct projection, and the number and arrangement of the output ports can be customized according to application requirements. This overcomes the limitation of traditional VCSEL+DOE solutions, where the array laser must be designed in a specific shape to ensure seamless integration after replication.

[0073] This invention employs a telecentric lens for object-side projection, overcoming the drawback of large high-order distortion in the projected light field of the traditional VCSEL+DOE scheme. The speckle pattern is concentrated in the effective area, reducing energy loss.

[0074] In this invention, the light emitted by the array laser is directly emitted through the projection lens, eliminating the need for complex optical path processing. This greatly reduces light loss during laser propagation, resulting in higher energy density and clarity than existing speckle projectors. It also has a longer detection range, stronger anti-interference capabilities, and good adaptability to various application scenarios.

[0075] In this invention, the focal plane of the projection lens is close to the emitting surface of the array laser, a relationship carefully designed and calculated. This allows the beam of the array laser to be focused near the focal plane of the projection lens, forming a clear, stable, and zero-order speckle pattern with the required intensity distribution. Attached Figure Description

[0076] 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:

[0077] Figure 1 This is a schematic diagram of the optical path of a novel speckle projector according to an embodiment of the present invention;

[0078] Figure 2 This is a schematic diagram of an array laser and the arrangement of light-emitting holes in an embodiment of the present invention;

[0079] Figure 3 This is a schematic diagram of a speckle distribution in an embodiment of the present invention;

[0080] Figure 4 This is a schematic diagram of the optical path of a telecentric projection lens group in an embodiment of this utility model;

[0081] Figure 5 This is a schematic diagram of the optical path of another telecentric projection lens group in an embodiment of this utility model;

[0082] Figure 6 This is a schematic diagram of the optical path of another telecentric projection lens group in an embodiment of this utility model;

[0083] Figure 7This is a schematic diagram of the optical path of a diffractive optical lens projection lens in an embodiment of this utility model;

[0084] Figure 8 This is a schematic diagram of the texture of a projection lens for a diffractive optical lens in an embodiment of this utility model;

[0085] Figure 9 This is a schematic diagram of the optical path of a metasurface optical lens projection lens in an embodiment of this utility model;

[0086] Figure 10 This is a schematic diagram of the texture of a metasurface optical lens in an embodiment of the present invention.

[0087] 1-Array laser;

[0088] 2-Projection lens;

[0089] 3-Microstructure; Detailed Implementation

[0090] 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.

[0091] 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.

[0092] This utility model provides a novel speckle projector, which aims to solve the problems existing in the prior art.

[0093] 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.

[0094] like Figure 1 As shown, a novel speckle projector in this embodiment of the present invention includes:

[0095] Array laser 1, used to project array laser.

[0096] Specifically, a laser is a device capable of generating stimulated emission of light, while an array laser is an assembly of multiple laser units arranged according to a certain rule. In this novel speckle projector, each laser unit of the array laser can generate a laser beam, and these laser beams are combined to form an array laser. Laser light is a type of light with high coherence, directionality, and monochromaticity, which gives it unique advantages in many applications. For speckle projectors, the coherence of laser light is utilized to generate specific speckle patterns.

[0097] As the light source of a speckle projector, the array laser is responsible for projecting an array of laser beams, providing the basic optical signal for the subsequent generation of speckle patterns. By precisely controlling parameters such as the luminous intensity and frequency of each laser unit, the characteristics of the output array laser can be adjusted, thereby affecting the properties of the final speckle pattern to meet the needs of different application scenarios, such as in 3D imaging and LiDAR.

[0098] The arrangement of the laser units in an array laser can affect the laser's output characteristics and speckle pattern distribution. Common arrangements include linear, rectangular, and circular arrays. Furthermore, each laser unit may be equipped with its own drive circuitry and control module to achieve precise control over its emission state. The divergence angle of an array laser is <±10°. Figure 2 As shown, the array laser consists of multiple pre-designed independent light-emitting units, each with multiple light-emitting apertures. It should be noted that... Figure 2 The quantity and distribution shown are merely illustrative and do not represent the number and arrangement of light-emitting units in the array laser in this embodiment. Figure 2 The state shown in the image.

[0099] In some embodiments, the array laser has at least 200 light-emitting aperture units. The number of light-emitting aperture units in the array laser is matched to the projection lens. When the array laser has at least 200 light-emitting aperture units, the number of emitted light spots can form a speckle image, which can be used for measurement, etc.

[0100] Projection lens 2; the distance between the light-emitting surface of the array laser and the focal plane of the projection lens is less than 1 / 10 of the focal length of the projection lens.

[0101] Specifically, a projection lens is an optical element that uses the principle of refraction to change the propagation direction and focusing state of light. In an optical system, the main function of a lens is to converge or diverge the light emitted by a light source so that a clear image or a specific light distribution can be formed at a specific position.

[0102] The projection lens focuses and shapes the array laser light projected by the array laser so that a desired speckle pattern can be formed at the target position. The distance between the light-emitting surface of the array laser and the focal plane of the projection lens is less than 1 / 10 of the focal length of the projection lens. Let the distance between the light-emitting surface of the array laser and the focal plane of the projection lens be represented by d, and the focal length of the projection lens be represented by f, then d < f * 0.1. 1 / 10 is a better range obtained by the inventors of this solution through testing. Through this relationship, it can be ensured that the energy distribution and spatial position relationship of the laser beam are precisely controlled after passing through the projection lens, thereby forming a stable and repeatable speckle pattern.

[0103] The light rays emitted from the array laser 1 are symmetric and all vertically emitted. Each beam of light emitted by the array laser 1 is uniformly emitted after passing through the projection lens 2. The optical path in the middle of the array laser 1 is the 0 field of view, and finally diffuses out after passing through the projection lens 2. The exit angle of the main field of view in the middle of the optical path emitted from the projection lens 2 is 0°, and the others are obliquely emitted.

[0104] In some embodiments, the focal plane of the projection lens is conjugate to the light-emitting surface of the array laser. The projection lens focuses and images the light rays on the focal plane, and finally forms a speckle pattern at a specific position. The projection lens is a conventional optical lens, DOE (diffractive optical element) or Metalens (metasurface optical device). When the projection lens is a conventional optical lens, the projection lens is an object-side telecentric lens. The projection lens is usually composed of multiple optical lenses, and these lenses may have different parameters such as curvature radius, material, and refractive index. The main ray angles of each field of view on the object side of the lens are all 0°, and the beam divergence angle satisfies: ±10° ≤ divergence angle ≤ ±15°. Such a design enables most of the light rays emitted by the array laser to enter the lens for uniform projection. As Figure 3 As shown, the projected speckles have the same speckle pattern as the array laser, uniform intensity distribution, and small distortion.

[0105] In some embodiments, the object-side beam angle of the projection lens is larger than the output beam angle of the array laser, and the margin on one side does not exceed 5°. Beam angle is a physical quantity describing the degree of beam divergence; it represents the range of angles by which the beam deviates from the central axis during propagation. For the output beam angle of the array laser, it reflects the degree of divergence when the laser beams emitted from the individual light-emitting units of the array laser converge; while the object-side beam angle of the projection lens refers to the range of divergence angles of the beam that can be effectively received and processed by the lens within the object-side space of the projection lens.

[0106] Having a larger beam angle on the object side of the projection lens than the beam angle emitted by the array laser can improve light energy utilization and allow for better shaping.

[0107] The projection lens can collect a more divergent beam than the laser array emits, meaning it can capture more light energy. In a speckle projector, more light energy helps increase the brightness of the speckle pattern, making it easier to detect and analyze in imaging or other applications. For example, in some 3D imaging systems that require high-contrast speckle patterns, sufficient light energy can improve image quality and resolution.

[0108] A larger object-side beam angle provides greater operational flexibility for the projection lens to further shape and focus the beam. By expanding the relatively narrow beam emitted from the array laser before processing, the projection lens can more precisely control the beam's propagation direction and focusing position, thereby more accurately forming the desired speckle pattern on the focal plane. This beam-shaping capability is crucial for meeting the specific speckle pattern requirements of different applications.

[0109] The beam angle is between ±10° and ±15°, which ensures the controllability of the beam and enhances the irradiation range and intensity of the speckle.

[0110] If the object-side beam angle is too large, the beam will diverge rapidly during propagation, making precise control and focusing difficult. Limiting it to no more than ±15° ensures that the beam remains relatively focused under the projection lens, facilitating effective beam processing and adjustment to form a stable and repeatable speckle pattern. For example, in lidar applications, stable beam propagation is crucial for accurately measuring target distance and position; an excessively large beam angle can lead to increased measurement errors.

[0111] This angular constraint is determined based on the overall system design and performance requirements of the speckle projector. It is matched with the emission characteristics of the array laser, the optical parameters of the projection lens, and the speckle pattern requirements of subsequent applications. During the design and manufacturing process, by controlling the relevant parameters of the array laser and the projection lens to ensure that the object-side beam angle meets this constraint, the overall performance and stability of the system can be guaranteed, avoiding various problems caused by excessive beam angle, such as increased aberrations and uneven energy distribution.

[0112] In some embodiments, the beam angle generated by the array laser is <±10°. The beam angle is a physical quantity that measures the degree to which a light beam deviates from its initial propagation direction during propagation. For an array laser, the beam angle represents the range of angles by which the laser beams emitted from the individual light-emitting units of the array laser spread outwards as the propagation distance increases. A smaller beam angle means that the beam can remain relatively concentrated during propagation, while a larger beam angle means that the beam spreads out more quickly.

[0113] A beam angle of less than ±10° allows for energy concentration and matching with the projection lens.

[0114] When the beam angle generated by an array laser is less than ±10°, the beam energy remains relatively concentrated during propagation. This is crucial for speckle projectors because the concentrated energy allows for higher brightness and contrast in the projected speckle pattern. For example, in 3D imaging applications, high-brightness and high-contrast speckle patterns are captured more clearly by imaging devices, thus improving imaging accuracy and quality. In applications requiring long-range detection, such as lidar, the concentrated energy beam can propagate over greater distances without becoming too dispersed, ensuring the system's detection range and sensitivity.

[0115] Considering the previously mentioned object-side beam angle characteristics of the projection lens (the object-side beam angle of the projection lens is larger than the output beam angle of the array laser, and the margin on one side does not exceed 5°), a smaller array laser beam angle (<±10°) is beneficial for better coordination with the projection lens. This allows the projection lens to more effectively collect and process the beam, further expanding and shaping it to form an accurate speckle pattern on the focal plane. If the array laser beam angle is too large, it may exceed the processing capacity of the projection lens, resulting in inaccurate beam focusing and affecting the quality of the speckle pattern.

[0116] Furthermore, a smaller beam angle contributes to improved stability of the entire speckle projector system. Because the beam remains relatively focused during propagation, uncertainties and interference caused by beam diffusion are reduced. This allows the system to operate more stably under different environmental conditions (such as temperature variations and vibrations), resulting in better repeatability and consistency of the speckle pattern, thereby improving the system's reliability and repeatability.

[0117] In some embodiments, the object-side beam angle of the projection lens is ≥ ±10°. This embodiment ensures that the emitted beam angle is ≥ ±10°, thereby guaranteeing the divergence angle of the speckle projector and ensuring the emission angle of the speckle, thus giving the speckle projector a sufficient projection range.

[0118] In some embodiments, the object-side beam angle of the projection lens is ≤ ±15°. This embodiment ensures that the emitted beam angle is ≤ ±15°, thereby guaranteeing that the divergence angle of the speckle projector is within a certain range, avoiding the problem of excessively large divergence angles leading to excessively low speckle density or speckle intensity.

[0119] Figure 4 This is a schematic diagram of the optical path of a telecentric projection lens group according to an embodiment of this utility model. Figure 4 As shown, the telecentric projection lens group provided by this utility model consists of the following components along the optical axis from the projection space side to the light source side:

[0120] The first lens 231 has a negative optical power, and the projection space side of the first lens 231 is convex, while the light source side is concave.

[0121] The second lens 232 has a positive optical power, and the projection space side of the second lens 232 is concave, while the light source side is convex.

[0122] The third lens 233 has a positive optical power, and the projection space side of the third lens 233 is convex, as is the light source side.

[0123] The axial distance TTL from the projection side of the first lens 231 to the light-emitting surface of the light source satisfies the following relationship with the diagonal length RL of the light-emitting area: 1.85 <TTL / RL<2.38。

[0124] The effective focal length f1 of the first lens 231 and the effective focal length f2 of the second lens 232 satisfy the following condition: -1.2 <f2 / f1<-0.85。

[0125] The angle of the principal ray emitted from the projection space side of the telecentric projection lens group is 0°.

[0126] The radius of curvature on the projection space side of the first lens 231 is greater than the radius of curvature on the light source side of the first lens 231.

[0127] The radius of curvature on the projection space side of the second lens 232 is smaller than the radius of curvature on the light source side of the second lens 232.

[0128] The radius of curvature on the light source side of the third lens 233 is greater than the radius of curvature on the projection space side of the third lens 233.

[0129] The radius of curvature on the projection space side of the first lens 231 is greater than the radius of curvature on the light source side of the first lens 231.

[0130] The radius of curvature of the third lens 233 on the light source side is greater than the radius of curvature of the first lens 231 on the projection space side.

[0131] The radius of curvature of the third lens 233 on the projection space side is greater than the radius of curvature of the second lens 232 on the projection space side.

[0132] The telecentric projection lens group in this embodiment can achieve all the functions of the projection lens in the previous embodiment, and only requires 3 lenses, which has the advantage of low cost.

[0133] Figure 5 This is a schematic diagram of the optical path of another telecentric projection lens group in an embodiment of this utility model. Figure 5 As shown, in another embodiment of this utility model, the telecentric projection lens group, along the optical axis from the projection space side to the light source side, is as follows:

[0134] The first lens 241 has a negative optical power, and the projection space side of the first lens 241 is convex, while the light source side is concave.

[0135] The second lens 242 has a negative optical power and the side of the light source is concave.

[0136] The third lens 243 has a positive optical power, and the projection space side of the third lens 243 is concave, while the light source side is convex.

[0137] The fourth lens 244 has a positive optical power and the light source side of the fourth lens 244 is convex.

[0138] The axial distance TTL from the projection side of the first lens 241 to the light-emitting surface of the light source satisfies the following relationship with the diagonal length RL of the light-emitting area: 1.9 <TTL / RL<2.45。

[0139] The effective focal length f1 of the first lens 241 and the effective focal length f2 of the second lens 242 satisfy the following condition: 2.05 <f2 / f1<2.7。

[0140] The angle of the principal ray emitted from the projection space side of the telecentric projection lens group is 0°.

[0141] The radius of curvature on the projection space side of the first lens 241 is greater than the radius of curvature on the light source side of the first lens 241.

[0142] The radius of curvature on the projection space side of the second lens 242 is greater than the radius of curvature on the light source side of the second lens 242.

[0143] The radius of curvature on the projection space side of the third lens 243 is greater than the radius of curvature on the light source side of the third lens 243.

[0144] The radius of curvature on the projection space side of the fourth lens 244 is greater than the radius of curvature on the light source side of the fourth lens 244.

[0145] The radius of curvature of the first lens 241 on the light source side is smaller than the radius of curvature of the second lens 242 on the light source side.

[0146] The radius of curvature of the third lens 243 on the projection space side is greater than the radius of curvature of the fourth lens 244 on the projection space side.

[0147] The radius of curvature of the second lens 242 on the projection space side is greater than the radius of curvature of the fourth lens 244 on the projection space side.

[0148] The telecentric projection lens group in this embodiment can achieve all the functions of the projection lens in the previous embodiment, and has the advantage of good stability.

[0149] Figure 6 This is a schematic diagram of the optical path of another telecentric projection lens group in an embodiment of this utility model. Figure 6 As shown, in another embodiment of this utility model, the telecentric projection lens group, along the optical axis from the projection space side to the light source side, is as follows:

[0150] The first lens 251 has a negative optical power, and the projection space side of the first lens 251 is convex, while the light source side is concave.

[0151] The second lens 252 has a negative optical power and the side of the light source is concave.

[0152] The third lens 253 has a positive optical power, and the projection space side of the third lens 253 is concave, while the light source side is convex.

[0153] The fourth lens 254 has a positive optical power, and the projection space side of the fourth lens 254 is convex, as is the light source side.

[0154] The fifth lens is 255, and the optical power of the fifth lens 255 is positive.

[0155] The axial distance TTL from the projection side of the first lens 251 to the light-emitting surface of the light source satisfies the following relationship with the diagonal length RL of the light-emitting area: 1.9 <TTL / RL<2.45。

[0156] The effective focal length f1 of the first lens 251 and the effective focal length f2 of the second lens 252 satisfy the following condition: 2.1 <f2 / f1<2.75。

[0157] The angle of the principal ray emitted from the projection space side of the telecentric projection lens group is 0°.

[0158] The radius of curvature of the first lens 251 on the light source side is smaller than the radius of curvature of the second lens 252 on the light source side.

[0159] The radius of curvature of the first lens 251 on the light source side is smaller than the radius of curvature of the fourth lens 254 on the light source side.

[0160] The radius of curvature of the first lens 251 on the light source side is smaller than the radius of curvature of the fifth lens 255 on the light source side.

[0161] The radius of curvature of the first lens 251 on the projection space side is smaller than the radius of curvature of the second lens 252 on the projection space side.

[0162] The radius of curvature of the first lens 251 on the projection space side is smaller than the radius of curvature of the third lens 253 on the projection space side.

[0163] The radius of curvature of the first lens 251 on the projection space side is smaller than the radius of curvature of the fourth lens 254 on the projection space side.

[0164] The radius of curvature of the first lens 251 on the projection space side is smaller than the radius of curvature of the fifth lens 255 on the projection space side.

[0165] The radius of curvature of the second lens 252 on the light source side is greater than the radius of curvature of the third lens 253 on the light source side.

[0166] The radius of curvature of the second lens 252 on the light source side is greater than the radius of curvature of the fifth lens 255 on the light source side.

[0167] The radius of curvature of the second lens 252 on the projection space side is greater than the radius of curvature of the fourth lens 254 on the projection space side.

[0168] The radius of curvature of the second lens 252 on the projection space side is greater than the radius of curvature of the fifth lens 255 on the projection space side.

[0169] The radius of curvature of the third lens 253 on the projection space side is greater than the radius of curvature of the fourth lens 254 on the projection space side.

[0170] The radius of curvature of the third lens 253 on the projection space side is greater than the radius of curvature of the fifth lens 255 on the projection space side.

[0171] The radius of curvature of the third lens 253 on the light source side is smaller than the radius of curvature of the fourth lens 254 on the light source side.

[0172] The radius of curvature of the third lens 253 on the light source side is smaller than the radius of curvature of the fifth lens 255 on the light source side.

[0173] The radius of curvature of the fourth lens 254 on the light source side is greater than the radius of curvature of the fifth lens 255 on the light source side.

[0174] The telecentric projection lens group in this embodiment can realize all the functions of the projection lens in the previous embodiment, and has the advantages of good stability and good uniformity.

[0175] Figure 7 This is a schematic diagram of the optical path of a projection lens using a diffractive optical lens in an embodiment of this utility model. Compared to the previous embodiments, the projection lens uses a DOE diffraction device instead of an optical lens. The principal ray angle of each field of view on the object side of the DOE projection lens is 0°, and the divergence angle is ≥±10°. The lens has a thinner thickness than the telecentric projection lens group, but the divergence angle is slightly smaller and the distortion is slightly larger. The texture of the DOE lens surface is as follows... Figure 8 As shown, it can be located on the outer surface or the inner surface of the lens.

[0176] Figure 9 This is a schematic diagram of the optical path of a metasurface optical lens projection lens according to an embodiment of this utility model. Compared with the previous embodiments, the projection lens in this embodiment uses a metasurface optical device instead of an optical lens. The principal ray angle of each field of view on the object side of the metasurface projection lens is 0°, and the divergence angle is ≥±10°. The lens has a thinner thickness than the telecentric projection lens group and can achieve a larger divergence angle and low distortion. The texture of the metalens surface is as follows: Figure 9 As shown, it can be located on the outer surface or the inner surface of the lens.

[0177] This utility model also provides an optical device. It should be noted that the description in this embodiment is only for the convenience of those skilled in the art and should not constitute any limitation on the optical device.

[0178] The optical device uses a novel speckle projector as a key component. The array laser in this projector emits an array of laser beams with specific characteristics, a divergence angle of <±10°, ensuring a relatively concentrated output beam. The projection lens plays a crucial role in beam processing; its object-side beam angle is ≥±10°, greater than the output beam angle of the array laser, with a single-sided margin not exceeding 5° (considering the previous conditions). This allows it to effectively collect, further expand, and shape the beam from the array laser, forming the desired speckle pattern on its focal plane. These speckle patterns are the fundamental optical signals that enable the optical device to function.

[0179] Functional characteristics of optical equipment:

[0180] High-precision 3D imaging: Optical equipment can be used for high-precision 3D imaging based on the speckle pattern projected by a speckle projector. When the speckle pattern is projected onto the surface of a target object, the shape and texture of the object's surface will distort the speckle pattern. Subsequent imaging and analysis equipment (such as high-resolution cameras and image processors) captures and processes the distorted speckle pattern, and using methods such as optical triangulation, the 3D coordinates of each point on the object's surface can be accurately calculated, thereby achieving 3D modeling and imaging of the object. Because the speckle projector can provide stable, high-quality speckle patterns, the accuracy and resolution of 3D imaging are effectively improved.

[0181] High-sensitivity lidar: In lidar applications, this optical device utilizes a laser beam emitted by a speckle projector for target detection. The uniqueness and stability of the speckle pattern contribute to improving the detection accuracy and anti-interference capability of the lidar system. A larger object-side beam angle of the projection lens allows the lidar to cover a wider spatial angular range, increasing the probability of detecting target objects. When the laser beam encounters a target object and reflects back, by analyzing the speckle information in the reflected light, parameters such as the target object's distance, velocity, and azimuth can be accurately measured, achieving high-sensitivity perception of the surrounding environment. This is suitable for fields such as autonomous driving and intelligent transportation.

[0182] Precision optical inspection: In precision optical inspection, this optical equipment can be used to detect minute defects and changes on the surface of objects. The speckle pattern projected by the speckle projector serves as a reference. When defects or minor deformations occur on the object's surface, the reflected speckle pattern changes accordingly. By comparing the reference speckle pattern and the deformed speckle pattern, and using techniques such as optical interferometry and correlation analysis, the location and extent of defects on the object's surface can be accurately detected. This has significant application value in fields such as semiconductor manufacturing and optical component inspection.

[0183] Advantages and characteristics of optical equipment:

[0184] High-performance speckle projection: The unique design of the new speckle projector, including parameter matching between the array laser and the projection lens, enables the optical device to project high-quality, stable, and precisely controllable speckle patterns. This provides a solid foundation for the device's performance in a variety of applications, offering higher accuracy and reliability compared to traditional speckle projection methods.

[0185] Wide adaptability: Due to the large object-side beam angle of the projection lens and the suitable beam divergence angle of the array laser, the optical equipment has strong adaptability to different working environments and conditions. Regardless of different light intensities, or even with certain installation errors or light source fluctuations, the equipment can maintain a stable working state, ensuring the normal operation of speckle projection and subsequent functions.

[0186] Multifunctional Integration: Based on the speckle projection principle, this optical device can integrate multiple functions to meet diverse needs in different fields. For example, in industrial production, it can be used for three-dimensional quality inspection of products, as well as for position positioning and dimensional measurement during the production process, thereby improving the efficiency and application value of the equipment.

[0187] Expanding Application Areas: Beyond the aforementioned fields of 3D imaging, lidar, and precision optical inspection, this optical device has broader application potential. In the biomedical field, it can be used for cell imaging and tissue morphology analysis, studying cell growth and pathological changes through variations in speckle patterns. In scientific research, it can be used for optical experiments and research, providing an experimental platform for verifying optical principles and developing new optical technologies. In security monitoring, it can be used for target recognition and behavior analysis, improving the intelligence level of security systems.

[0188] 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.

[0189] 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 novel speckle projector, characterized in that, include: Array laser, used to project array laser beams; Projection lens; The distance between the emitting surface of the array laser and the focal plane of the projection lens is less than 1 / 10 of the focal length of the projection lens.

2. The novel speckle projector according to claim 1, characterized in that, The array laser has at least 200 light-emitting aperture units.

3. The novel speckle projector according to claim 1, characterized in that, The projection lens is a telecentric lens with an object-side principal ray angle of 0°.

4. The novel speckle projector according to claim 1, characterized in that, The object-side beam angle of the projection lens is greater than the output beam angle of the array laser, and the margin on one side does not exceed 5°.

5. The novel speckle projector according to claim 1, characterized in that, The emitting surface of the array laser coincides with the focal plane of the projection lens.

6. The novel speckle projector according to claim 1, characterized in that, The object-side beam angle of the projection lens is ≥ ±10°.

7. The novel speckle projector according to claim 1, characterized in that, The object-side beam angle of the projection lens is ≤ ±15°.

8. The novel speckle projector according to claim 1, characterized in that, The projection lens is a conventional optical lens, a diffractive optical device, or a metasurface optical device.

9. A novel speckle projector according to claim 8, characterized in that, The conventional optical lenses, arranged sequentially from the projection space side to the light source side along the optical axis, are as follows: The first lens has a negative optical power, and the projection space side of the first lens is convex, while the light source side is concave. The second lens has a positive optical power, and its projection space side is concave while its light source side is convex. The third lens has a positive optical power, and its projection space side is convex, as is its light source side.

10. An optical device, characterized in that, Including the novel speckle projector as described in any one of claims 1-9.

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