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. The problems of speckle FOV, insufficient uniformity and distortion existing in an existing speckle projection scheme can be solved, large-FOV, high-uniformity and low-distortion speckle projection is achieved, and speckle projection with flexible pattern distribution can also be achieved.

Description

Technical Field

[0001] The present invention relates to the field of optical technology, and in particular to a novel speckle projector and optical equipment. Background Art

[0002] In today's optical technology field, speckle projectors play a key role in many application scenarios, such as 3D visual perception, structured light measurement, laser radar, etc. Among them, 3D visual perception technology, as an important part of the field of artificial intelligence and robotics, has put forward higher and higher requirements on the performance of speckle projectors.

[0003] Traditional speckle projectors usually use a single laser or a simple laser array, which has many limitations. On the one hand, the speckle pattern projected by a single laser is difficult to meet the needs of complex scenes in terms of spatial coverage and uniformity. In practical applications, such as when performing 3D modeling of large-sized objects, the speckle projected by a single laser may not be able to completely cover the surface of the object, resulting in missing measurement data and affecting the accuracy and integrity of the 3D model.

[0004] On the other hand, although the simple laser array expands the projection range to a certain extent, the poor consistency between the lasers inside it will cause the projected speckle pattern to have problems such as uneven intensity and unstable pattern. This is a fatal flaw for high-precision 3D visual perception and measurement, because the uneven intensity speckle pattern will complicate subsequent image analysis and processing, reducing the accuracy and reliability of the measurement.

[0005] In addition, in traditional speckle projectors, the coordination between the projection lens and the laser is often not optimized. Since the focal plane of the projection lens is not conjugated 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 will not only reduce energy utilization, but also affect the quality of the speckle pattern, and thus affect the performance of the entire system.

[0006] In order to meet the demand for high-precision and high-reliability speckle projection in fields such as 3D visual perception, a new type of speckle projector is urgently needed that can overcome the above-mentioned shortcomings of traditional speckle projectors.

[0007] The disclosure of the above background technology content is only used to assist in understanding the inventive concept and technical solution of the present invention. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above content has been disclosed on the filing date of this patent application, the above background technology should not be used to evaluate the novelty and creativity of the present application. Summary of the invention

[0008] To this end, this new speckle projector uses an array laser to project array lasers. By rationally designing the projection lens, its focal plane is close to the light-emitting surface of the array laser, thereby 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, the present invention provides a novel speckle projector, characterized in that it comprises:

[0010] An array laser, used for projecting array lasers;

[0011] Projection lens; 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.

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

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

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

[0015] Optionally, the novel speckle projector is characterized in that the light 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 light beam angle of the projection lens is ≥±10°.

[0017] Optionally, the novel speckle projector is characterized in that the object 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 are sequentially:

[0020] A first lens, wherein the optical power of the first lens is negative, the projection space side of the first lens is a convex surface, and the light source side is a concave surface;

[0021] A second lens, wherein the optical power of the second lens is positive, the projection space side of the second lens is a concave surface, and the light source side is a convex surface;

[0022] The third lens has a positive optical focal length, a convex side surface of the projection space of the third lens, and a convex side surface of the light source.

[0023] In a second aspect, the present invention provides a telecentric projection lens assembly, characterized in that the optical axis from the projection space side to the light source side is as follows:

[0024] A first lens, wherein the optical power of the first lens is negative, the projection space side of the first lens is a convex surface, and the light source side is a concave surface;

[0025] A second lens, wherein the optical power of the second lens is positive, the projection space side of the second lens is a concave surface, and the light source side is a convex surface;

[0026] The third lens has a positive optical focal length, a convex side surface of the projection space of the third lens, and a convex side surface of the light source.

[0027] Optionally, the telecentric projection lens set is characterized in that the axial distance TTL from the projection space side of the first lens to the light source light-emitting surface and the diagonal length RL of the light source light-emitting area meet the following conditions: 1.85 <TTL / RL<2.38。

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

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

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

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

[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 curvature radius of the projection space side of the first lens is greater than the curvature radius 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 third lens on the projection space side is greater than the radius of curvature of the second lens on the projection space side.

[0036] In a third aspect, the present invention provides a telecentric projection lens assembly, characterized in that the optical axis from the projection space side to the light source side is as follows:

[0037] A first lens, wherein the optical power of the first lens is negative, the projection space side of the first lens is a convex surface, and the light source side is a concave surface;

[0038] A second lens, wherein the optical power of the second lens is negative and the light source side is concave;

[0039] A third lens, wherein the third lens has a positive optical power, a projection space side of the third lens is a concave surface, and a light source side is a convex surface;

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

[0041] Optionally, the telecentric projection lens set is characterized in that the axial distance TTL from the projection space side of the first lens to the light source light-emitting surface and the diagonal length RL of the light source light-emitting area satisfy: 1.9 <TTL / RL<2.45。

[0042] Optionally, the telecentric projection lens set 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 main light emitted on the projection space side is 0°.

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

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

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

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

[0048] Optionally, the telecentric projection lens set 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 curvature radius of the third lens projection space side is greater than the curvature radius of the fourth lens projection space side;

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

[0051] In a fourth aspect, the present invention provides a telecentric projection lens assembly, characterized in that, along the optical axis from the projection space side to the light source side, it is:

[0052] A first lens, wherein the optical power of the first lens is negative, the projection space side of the first lens is a convex surface, and the light source side is a concave surface;

[0053] A second lens, wherein the optical power of the second lens is negative and the light source side is concave;

[0054] A third lens, wherein the third lens has a positive optical power, a projection space side of the third lens is a concave surface, and a light source side is a convex surface;

[0055] A fourth lens, wherein the fourth lens has a positive optical power, a projection space side of the fourth lens is a convex surface, and a light source side is a convex surface;

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

[0057] Optionally, the telecentric projection lens set is characterized in that the axial distance TTL from the projection space side of the first lens to the light source light-emitting surface and the diagonal length RL of the light source light-emitting area satisfy: 1.9 <TTL / RL<2.45。

[0058] Optionally, the telecentric projection lens set 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: 2.1 <f2 / f1<2.75。

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

[0060] Optionally, the telecentric projection lens set 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 curvature radius of the projection space side of the first lens is smaller than the curvature radius of the projection space side of the second lens;

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

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

[0066] Optionally, the telecentric projection lens group is characterized in that the curvature radius of the projection space side of the first lens is smaller than the curvature radius 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] In a fifth aspect, the present invention provides a novel speckle projector, characterized in that it comprises any of the telecentric projection lens groups described above.

[0069] In a sixth aspect, the present invention provides an optical device, characterized in that it comprises any one of the novel speckle projectors described above.

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

[0071] The array laser direct projection adopted in the present invention overcomes the defect of inconsistent brightness between the zero-order and the high-order in the replicated light spot of the DOE device.

[0072] The array laser used in the present invention is directly projected, and the number and arrangement of light outlets can be designed and customized according to the application scenario requirements, overcoming the limitation of the traditional Vcsel+DOE solution that the array laser must be designed into a standard shape so that it can be connected after replication.

[0073] The present invention adopts object-side telecentric lens projection, which overcomes the disadvantage of large high-order distortion of the projected light field of the traditional Vcsel+DOE solution. The speckle can be concentrated in the effective area, reducing energy loss.

[0074] The light emitted by the array laser in the present invention is directly emitted through the projection lens without the need for complicated optical path processing, which greatly reduces the light loss of the laser during propagation. It has higher energy density and clarity than existing speckle projectors, a longer detection distance, and stronger anti-interference ability, and has good adaptability to various application scenarios.

[0075] In the present invention, the focal plane of the projection lens is close to the light-emitting surface of the array laser, and this relationship has been carefully designed and calculated, so that the light beam of the array laser can be focused near the focal plane of the projection lens, forming a clear, stable zero-order speckle with intensity distribution that meets the requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings in the following descriptions are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without creative work. By reading the detailed description of the non-limiting embodiments with reference to the following drawings, other features, purposes and advantages of the present invention will become more obvious:

[0077] Figure 1 Schematic diagram of the optical path of a novel speckle projector in an embodiment of the present invention;

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

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

[0080] Figure 4 A schematic diagram of the optical path of a telecentric projection lens assembly according to an embodiment of the present invention;

[0081] Figure 5 A schematic diagram of the optical path of another telecentric projection lens assembly according to an embodiment of the present invention;

[0082] Figure 6 A schematic diagram of the optical path of another telecentric projection lens assembly according to an embodiment of the present invention;

[0083] Figure 7 A schematic diagram of the optical path of a diffractive optical lens projection lens in an embodiment of the present invention;

[0084] Figure 8 A schematic diagram of the texture of a diffractive optical lens projection lens in an embodiment of the present invention;

[0085] Fig. 9 This is a schematic diagram of the optical path of a metasurface optical lens projection lens in an embodiment of the present invention;

[0086] Fig.10 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 DESCRIPTION

[0090] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0091] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein, for example, can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0092] A novel speckle projector provided in an embodiment of the present invention is intended to solve the problems existing in the prior art.

[0093] The following specific embodiments are used to describe in detail the technical solutions of the present invention and how the technical solutions of the present application solve the above-mentioned technical problems. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present invention will be described below in conjunction with the accompanying drawings.

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

[0095] The array laser 1 is used for projecting array laser.

[0096] Specifically, a laser is a device that can generate stimulated radiation light, and an array laser is a collection of multiple laser units arranged according to certain rules. In this new 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 is a kind of light with high coherence, directionality and monochromaticity, which gives it unique advantages in many applications. For the speckle projector, the coherence of the laser is used to generate a specific speckle pattern.

[0097] As the light source of the speckle projector, the array laser is responsible for projecting the array laser and providing the basic optical signal for the subsequent generation of the speckle pattern. By precisely controlling the luminous intensity, frequency and other parameters 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 applications in 3D imaging, LiDAR and other fields.

[0098] The arrangement of the laser units in the array laser may affect the output characteristics of the laser and the distribution of the speckle pattern. Common arrangements include linear arrangement, rectangular array arrangement, circular array arrangement, etc. In addition, each laser unit may also be equipped with a corresponding drive circuit and control module to achieve precise control of its light-emitting state. The divergence angle of the array laser is <±10°. Figure 2 As shown, the array laser is a plurality of pre-designed independent light-emitting units with a plurality of light-emitting holes. Figure 2 The number and distribution in the figure are only exemplary, and do not mean that the number and arrangement of the light-emitting units of the array laser in this embodiment can only be Figure 2 The status shown in .

[0099] In some embodiments, the number of light-emitting aperture units of the array laser is at least 200. The number of light-emitting aperture units of the array laser matches the projection lens. When the number of light-emitting aperture units of the array laser is at least 200, the number of emitted light spots can form a speckle image 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 it can form a clear image or a specific light distribution at a specific location.

[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 the 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 reproducible speckle pattern.

[0103] The light rays emitted from the array laser 1 are symmetric and all vertically emitted. Each beam of light emitted from 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 exiting 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 element). When the projection lens is a conventional optical lens, the projection lens is an object-side telecentric lens. The projection lens usually consists 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 speckle has the same speckle pattern as the array laser, uniform intensity distribution, and small distortion.

[0105] In some embodiments, the object-side beam divergence angle of the projection lens is greater than the beam divergence angle of the light emitted by the array laser, and the unilateral margin does not exceed 5°. The beam divergence angle is a physical quantity describing the degree of divergence of the beam, which represents the angular range in which the beam deviates from the central axis during propagation. For the beam divergence angle of the light emitted by the array laser, it reflects the degree of divergence when the laser beams emitted from each light-emitting unit of the array laser are combined together; while the object-side beam divergence angle of the projection lens refers to the divergence angle range of the beam that can be effectively received and processed by the lens in the object-side space of the projection lens.

[0106] The object-side beam divergence angle of the projection lens being greater than the beam divergence angle of the light emitted by the array laser can improve the light energy utilization rate and can better shape the light.

[0107] The projection lens is able to collect a more divergent beam than the array laser emits, which means 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] The larger object beam angle provides a larger operating space for the projection lens to further shape and focus the beam. By expanding the relatively narrow array laser output beam before processing, the projection lens can more accurately control the propagation direction and focus position of the beam, thereby more accurately forming the desired speckle pattern on the focal plane. This beam shaping capability is crucial to meeting the specific requirements of speckle patterns in different application scenarios.

[0109] The object beam angle is between ±10° and ±15°, which can ensure the controllability of the beam and enhance the irradiation range and intensity of the speckle.

[0110] If the object beam angle is too large, the beam will diverge rapidly during propagation, making it difficult to accurately control and focus. Limiting it to no more than ±15° ensures that the beam can remain relatively concentrated under the action of the projection lens, facilitating effective processing and adjustment of the beam to form a stable and repeatable speckle pattern. For example, in LiDAR applications, stable beam propagation is critical for accurately measuring target distance and position, and excessive beam angles may lead to increased measurement errors.

[0111] This angle limit is determined based on the system design and performance requirements of the entire speckle projector. It matches the emission characteristics of the array laser, the optical parameters of the projection lens, and the requirements of the subsequent application for the speckle pattern. During the design and manufacturing process, by controlling the relevant parameters of the array laser and the projection lens, the object beam angle meets this restriction condition, which can ensure the overall performance and stability of the system and avoid various problems caused by excessive beam angles, 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 angle range over which the light beam diffuses outward as the propagation distance increases after the laser beams emitted from the various light-emitting units of the array laser are combined. A smaller beam angle means that the light beam can remain relatively concentrated during propagation, while a larger beam angle means that the light beam will diffuse faster.

[0113] The beam angle <±10° can focus the energy and match the projection lens.

[0114] When the beam angle generated by the array laser is <±10°, the energy of the beam can remain relatively concentrated during propagation. This is very important for speckle projectors, because concentrated energy can make the projected speckle pattern have higher brightness and contrast. For example, in three-dimensional imaging applications, high-brightness and high-contrast speckle patterns can be captured more clearly by imaging devices, thereby improving the accuracy and quality of imaging. In applications such as LiDAR that require long-distance detection, a beam with concentrated energy can propagate a longer distance without being too dispersed, ensuring the detection range and sensitivity of the system.

[0115] Combined with the previously mentioned object beam angle characteristics of the projection lens (the object beam angle of the projection lens is larger than the output beam angle of the array laser, and the single-side margin does not exceed 5°), a smaller array laser beam angle (<±10°) is conducive to better cooperation with the projection lens. It enables the projection lens to collect and process the beam more effectively, further expand and shape the beam to form an accurate speckle pattern on the focal plane. If the beam angle of the array laser is too large, it may exceed the processing capacity of the projection lens, resulting in the inability to accurately focus the beam and the quality of the speckle pattern will also be affected.

[0116] In addition, a smaller beam angle helps improve the stability of the entire speckle projector system. Since the beam remains relatively concentrated during propagation, the uncertainty and interference factors caused by beam diffusion are reduced. This enables the system to work more stably under different environmental conditions (such as temperature changes, vibrations, etc.), and the repeatability and consistency of the speckle pattern are better, thereby improving the reliability and repeatability of the system.

[0117] In some embodiments, the projection lens object side beam angle is ≥±10°. This embodiment makes the angle of the emitted light beam ≥±10°, thereby ensuring the divergence angle of the speckle projector and the emission angle of the speckle, so that the speckle projector has a sufficient projection range.

[0118] In some embodiments, the object side beam angle of the projection lens is ≤±15°. This embodiment makes the angle of the emitted light beam ≤±15°, thereby ensuring that the divergence angle of the speckle projector is within a certain range, avoiding the problem of too low speckle density or too low speckle intensity due to too large divergence angle.

[0119] Figure 4 FIG. 1 is a schematic diagram of the optical path of a telecentric projection lens assembly according to an embodiment of the present invention. Figure 4 As shown, a telecentric projection lens assembly provided by the present invention is as follows from the projection space side to the light source side along the optical axis:

[0120] A first lens 231, wherein the optical power of the first lens 231 is negative, the projection space side of the first lens 231 is a convex surface, and the light source side is a concave surface;

[0121] A second lens 232, the optical power of the second lens 232 is positive, the projection space side of the second lens 232 is a concave surface, and the light source side is a convex surface;

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

[0123] The axial distance TTL from the side of the projection space of the first lens 231 to the light source emitting surface and the diagonal length RL of the light source emitting area meet the following conditions: 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: -1.2 <f2 / f1<-0.85。

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

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

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

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

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

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

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

[0132] The telecentric projection lens group in this embodiment can realize all the functions of the projection lens in the above-mentioned embodiments, and only requires three lenses, which has the advantage of low cost.

[0133] Figure 5 FIG. 1 is a schematic diagram of the optical path of another telecentric projection lens assembly according to an embodiment of the present invention. Figure 5 As shown, another telecentric projection lens group in the embodiment of the present invention is as follows from the projection space side to the light source side along the optical axis:

[0134] A first lens 241, wherein the optical power of the first lens 241 is negative, the projection space side of the first lens 241 is a convex surface, and the light source side is a concave surface;

[0135] A second lens 242, wherein the optical power of the second lens 242 is negative and the light source side surface is concave;

[0136] A third lens 243, the optical power of the third lens 243 is positive, the projection space side of the third lens 243 is a concave surface, and the light source side is a convex surface;

[0137] The fourth lens 244 has a positive focal length and a convex side surface of the fourth lens 244 .

[0138] The axial distance TTL from the side of the projection space of the first lens 241 to the light source light-emitting surface and the diagonal length RL of the light source light-emitting area satisfy: 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: 2.05 <f2 / f1<2.7。

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

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

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

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

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

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

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

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

[0148] The telecentric projection lens group in this embodiment can realize all the functions of the projection lens in the aforementioned embodiments and has the advantage of good stability.

[0149] Figure 6 FIG. 1 is a schematic diagram of the optical path of another telecentric projection lens assembly according to an embodiment of the present invention. Figure 6 As shown, another telecentric projection lens group in the embodiment of the present invention is as follows from the projection space side to the light source side along the optical axis:

[0150] A first lens 251, wherein the optical power of the first lens 251 is negative, the projection space side of the first lens 251 is a convex surface, and the light source side is a concave surface;

[0151] A second lens 252, wherein the optical power of the second lens 252 is negative and the light source side surface is concave;

[0152] A third lens 253, the optical power of the third lens 253 is positive, the projection space side of the third lens 253 is a concave surface, and the light source side is a convex surface;

[0153] A fourth lens 254, wherein the optical power of the fourth lens 254 is positive, the projection space side of the fourth lens 254 is a convex surface, and the light source side is a convex surface;

[0154] The fifth lens 255 has a positive optical power.

[0155] The axial distance TTL from the side of the projection space of the first lens 251 to the light source light-emitting surface and the diagonal length RL of the light source light-emitting area satisfy: 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: 2.1 <f2 / f1<2.75。

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

[0173] The curvature radius of the fourth lens 254 on the light source side is greater than the curvature radius 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 aforementioned embodiments, and has the advantages of good stability and good uniformity.

[0175] Figure 7 The figure is a schematic diagram of the optical path of a diffractive optical lens projection lens in an embodiment of the present invention. Compared with the previous embodiment, the projection lens uses a DOE diffraction device to replace the optical lens. The main ray angle of each field of view of the object side of the DOE projection lens is 0°, and the opening 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] Fig. 9The figure is a schematic diagram of the optical path of a metasurface optical lens projection lens in an embodiment of the present invention. Compared with the previous embodiment, the projection lens in this embodiment replaces the optical lens with a metasurface optical device. The main ray angle of each field of view of the metasurface projection lens is 0°, and the opening 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: Fig. 9 As shown, it can be located on the outer surface or the inner surface of the lens.

[0177] The present invention further 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 has a new speckle projector as a key component. The array laser in the new speckle projector is responsible for emitting array lasers with specific characteristics. Its beam divergence angle is <±10°, which can ensure that the energy of the output beam is relatively concentrated. The projection lens plays a crucial role in beam processing. Its object beam angle is ≥±10°, which is larger than the output beam angle of the array laser and the single-side margin does not exceed 5° (combined with the previous conditions). It can effectively collect and further expand and shape the beam from the array laser to form the required speckle pattern on its focal plane. These speckle patterns are the basic optical signals for the optical device to realize its function.

[0179] Functional characteristics of optical equipment:

[0180] High-precision 3D imaging: Based on the speckle pattern projected by the speckle projector, optical equipment can be used for high-precision 3D imaging. When the speckle pattern is projected onto the surface of the target object, the shape and texture of the surface will cause the speckle pattern to deform. The deformed speckle pattern is captured and processed by subsequent imaging and analysis equipment (such as high-resolution cameras and image processors), and the 3D coordinate information of each point on the surface of the object can be accurately calculated using methods such as the principle of optical triangulation, thereby achieving 3D modeling and imaging of the object. Since the speckle projector can provide stable and high-quality speckle patterns, the accuracy and resolution of 3D imaging are effectively improved.

[0181] High-sensitivity LiDAR: In LiDAR applications, this optical device uses a laser beam emitted by a speckle projector for target detection. The uniqueness and stability of the speckle pattern help improve the detection accuracy and anti-interference ability of the LiDAR system. The larger object beam angle of the projection lens enables LiDAR to cover a wider spatial angle range, increasing the probability of detecting the target object. When the laser beam encounters the target object and reflects back, by analyzing the speckle information in the reflected light, the distance, speed, and direction of the target object can be accurately measured, achieving high-sensitivity perception of the surrounding environment, which is suitable for autonomous driving, intelligent transportation and other fields.

[0182] Precision optical inspection: In precision optical inspection, this optical device can be used to detect tiny defects and changes on the surface of an object. The speckle pattern projected by the speckle projector is used as a reference. When there are defects or slight deformations on the surface of an object, the reflected speckle pattern will change accordingly. By comparing the reference speckle pattern with the deformed speckle pattern, and using optical interference, correlation analysis and other technologies, the position and degree of defects on the surface of an object can be accurately detected, which has important application value in the fields of semiconductor manufacturing, optical component inspection, etc.

[0183] Advantages and features of optical equipment:

[0184] High-performance speckle projection: The unique design of the new speckle projector, including the parameter matching of 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 performance of the device in various applications, with higher accuracy and reliability than traditional speckle projection methods.

[0185] Wide adaptability: Due to the large object beam angle of the projection lens and the appropriate beam divergence angle of the array laser, the optical device has strong adaptability to different working environments and conditions. Whether under different light intensities or in the presence of certain equipment installation errors or light source fluctuations, the device can maintain a stable working state to ensure the normal realization of speckle projection and subsequent functions.

[0186] Multifunctional integration: Based on the principle of speckle projection, this optical device can integrate multiple functions to meet the diverse needs of different fields. For example, in industrial production, it can be used for 3D quality inspection of products, as well as for position positioning and dimension measurement during the production process, thus improving the efficiency and application value of the equipment.

[0187] Expansion of equipment application areas: In addition to the above-mentioned three-dimensional imaging, laser radar and precision optical detection, this optical device also has a wider range of application potential. In the biomedical field, it can be used for cell imaging and tissue morphology analysis, and the growth and pathological conditions of cells can be studied through the changes in speckle patterns; in the scientific research field, it can be used for optical experiments and research, providing an experimental platform for the verification of optical principles and the development of new optical technologies; in the field of security monitoring, it can be used for target recognition and behavior analysis, and improve the intelligence level of security systems.

[0188] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the embodiments can be referred to each other. The above description of the disclosed embodiments enables professionals and technicians in this field to implement or use the present invention. Various modifications to these embodiments will be obvious to professionals and technicians in this field, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown in this article, but will comply with the widest range consistent with the principles and novel features disclosed herein.

[0189] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art may make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A novel speckle projector, characterized in that: include: An array laser, used for projecting array lasers; Projection lens; 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.

2. According to claim 1, the novel speckle projector is characterized in that: The number of light-emitting hole units of the array laser is at least 200.

3. According to claim 1, the novel speckle projector is characterized in that: The projection lens is an object-side telecentric lens, and the object-side chief ray angle is 0°.

4. According to claim 1, 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 single-side margin does not exceed 5°.

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

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

7. According to claim 1, the novel speckle projector is characterized in that: The object side light 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. The novel speckle projector according to claim 8, characterized in that: The conventional optical lenses are as follows from the projection space side to the light source side along the optical axis: A first lens, wherein the optical power of the first lens is negative, the projection space side of the first lens is a convex surface, and the light source side is a concave surface; A second lens, wherein the optical power of the second lens is positive, the projection space side of the second lens is a concave surface, and the light source side is a convex surface; The third lens has a positive optical focal length, a convex side surface of the projection space of the third lens, and a convex side surface of the light source.

10. An optical device, characterized in that: A new speckle projector comprising the one described in any one of claims 1-9.

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