Area light source projection device

Abstract

The present application provides a kind of surface light source projection device, comprising: light emitting module and diffraction optical component module. Wherein, the diffraction optical component module has two micron diffraction layers, the multiple micron diffraction layers contain multiple micron structures, the shape of the multiple micron structures is set as conical, discoid or the combination of the above shape, the multiple micron structures have an outer diameter, and the outer diameter of the multiple micron structures is between 5 times and 200 times of the narrow half-wave width of the incident wavelength of the light beam output by the light emitting module. Therefore, a surface light source projection device with heat accumulation generated after high-energy laser continuous irradiation is provided, to facilitate long-time irradiation and long-distance sensing surface light source projection device.

Description

Technical Field

[0001] This invention relates to a surface light source projection device for use in time-of-flight (ToF) ranging devices. More particularly, this invention relates to a surface light source projection device comprising a micron-diffraction layer having multiple micron-sized structures. Background Technology

[0002] In recent years, with the evolution of the electronics industry and the booming development of industrial technology, various electronic devices have been developed and designed to be lightweight and portable, facilitating mobile business or entertainment anytime, anywhere. Among them, 3D sensing technology has gradually gained popularity due to the success of interactive game consoles. 3D sensing technology can also be applied to close-range face or object recognition, mid-range AR / VR applications, indoor building inspection and optical radar required for autonomous driving, as well as long-range object telemetry, leading to the vigorous development of various 3D sensing technologies. Currently, the well-known 3D technologies are stereoscopic vision sensing, time-of-flight ranging sensing, and structured light sensing.

[0003] Time-of-flight (TOF) ranging technology uses the time difference between the emission time of a light source and the time of receiving the returned light to obtain multiple distance value distributions and establish a 3D scanning result. Currently, the mainstream emission light sources used in TOF ranging technology can be divided into collimated light systems and surface light source systems, such as Vertical Cavity Surface Emitting Lasers (VCSELs). However, since collimated light systems form collimated light from a light source through a collimating lens group consisting of at least two lenses, and then project hundreds to tens of thousands of light spots through a diffraction component, the projection distance of these light spots is proportional to the luminous power of the light source. This is suitable for short to long distance applications, but it will increase the thickness of the surface light source projection device, which is not suitable for the thinness of mobile devices. Surface light source systems are the most suitable emission light sources for mobile devices, but their projection distance is limited by their luminous power, and their application is limited to short to medium distances.

[0004] However, the light emitted by a surface light source projection device needs to be diffused and scattered by a diffuser or diffractor to increase the angle range of the light projection and cover the field of view of the 3D scanning device. Currently, diffusers or diffractors are made by imprinting polymer materials. When used with the laser light source in the surface light source projection device, there is a problem of heat accumulation. Especially in some special environments where short-wavelength lasers (blue lasers or violet lasers) are required, polymer materials are more likely to absorb these wavelengths, causing material structure deterioration and deformation, thus losing the disadvantage of light diffusion or diffraction function. At the same time, due to the high beam concentration and strong light energy of the laser light source, if it is continuously irradiated on the adhesive structure, it may cause the adhesive structure to accumulate heat and cause fire. Moreover, these problems are difficult to prevent and monitor through changes in physical properties. Therefore, how to provide a diffuser or diffractor component that can stably, safely and effectively diffuse the light beam is an urgent problem to be solved.

[0005] However, while diffusers can uniformly project a beam of light and do not require high collimation of the light source, they have three drawbacks: 1. They disrupt the polarization of the light; 2. They have poor light utilization efficiency; and 3. They disrupt the directivity of the light, making them only suitable for short to medium distance projection and general sensing. On the other hand, diffraction components project a beam of light into hundreds to tens of thousands of spots. Therefore, diffraction components require high light source collimation, and poorly designed diffraction components can have severe zero-order spots. However, diffraction components have advantages such as high light utilization efficiency and the ability to maintain the polarization and directivity of the light, making them suitable for short to long distance sensing and special sensing needs that require maintaining light polarization.

[0006] In view of the above-mentioned shortcomings, the inventors conducted research and improvements to address these shortcomings, and finally the present invention was produced. Summary of the Invention

[0007] The purpose of this invention is to provide a surface light source projection device having a diffraction optical component module with two micron-level diffraction layers. Each micron-level diffraction layer contains multiple micron-level structures, the outer diameter of which is set to between 5 and 200 times the incident wavelength of the narrow half-width of the light beam emitted by the light-emitting module. This allows the diffracted light generated after the light beam passes through the diffraction optical component module to achieve a diffraction pattern with a high-density point matrix and low zero-order diffraction intensity. Therefore, this invention provides a surface light source projection device suitable for time-of-flight ranging sensing technology and resistant to heat accumulation after high-energy laser irradiation, facilitating long-term irradiation and long-distance sensing. It is also suitable for image sensing in special environments with light degradation caused by short-wavelength laser irradiation.

[0008] To achieve the above objectives, the present invention provides a surface light source projection device, comprising: a diffraction optical component module having an incident light surface and an exit light surface, and the diffraction optical component module having two micron-level diffraction layers; and a light-emitting module for outputting a collimated light beam having a narrow half-wavelength incident wavelength, the light beam entering the diffraction optical component module from the incident light surface, and sequentially passing through the two micron-level diffraction layers of the diffraction optical component module before being output as diffracted light from the exit light surface; wherein the plurality of micron-level diffraction layers include a plurality of micron-level structures, the shape of the plurality of micron-level structures being a combination of conical, disk-shaped, or higher shapes, the plurality of micron-level structures having an outer diameter, and the outer diameter of the plurality of micron-level structures being between 5 times and 200 times the narrow half-wavelength incident wavelength, which affects the size of the diffracted light spot.

[0009] Preferably, in the diffraction component of the surface light source projection device according to the invention, the height of the plurality of microstructures is between 0.05 and 0.2 times the outer diameter.

[0010] Preferably, in the diffraction component of the surface light source projection device according to the invention, the spacing between each pair of the plurality of microstructures is between 0.5 and 5 times the outer diameter.

[0011] Preferably, in the diffraction component of the surface light source projection device according to the invention, the surface roughness (Ra) of the plurality of micron-structures is between 0.5 nm and 50 nm.

[0012] Preferably, in the surface light source projection device according to the present invention, the plurality of micron diffraction layers are respectively a first micron diffraction layer and a second micron diffraction layer.

[0013] Preferably, in the surface light source projection device according to the present invention, the first micron diffraction layer is disposed on the light-incident surface of the diffraction optical component module, and the second micron diffraction layer is disposed on the light-exit surface of the diffraction optical component module.

[0014] Preferably, in the surface light source projection device according to the present invention, the diffraction optical component module includes: a first diffraction optical component having a first upper surface and a first lower surface; and a second diffraction optical component having a second upper surface and a second lower surface; wherein the first micron diffraction layer is disposed on the first upper surface of the first diffraction optical component, the second micron diffraction layer is disposed on the second diffraction optical component, the light beam is incident on the diffraction optical component module from the first lower surface, and after passing through the diffraction optical component module, the diffracted light is output from the second upper surface.

[0015] Preferably, in the surface light source projection device according to the present invention, the second micron diffraction layer is disposed on the second lower surface.

[0016] Preferably, in the surface light source projection device according to the present invention, the second micron diffraction layer is disposed on the second upper surface.

[0017] Preferably, in the surface light source projection device according to the present invention, the first micron diffraction layer has a first direction parallel to the vertical bisector of the center of the first micron diffraction layer, the second micron diffraction layer has a second direction parallel to the vertical bisector of the center of the second micron diffraction layer, and the first direction and the second direction have a relative angle between 5 degrees and 90 degrees.

[0018] Preferably, in the surface light source projection device according to the invention, the relative angle is between 19 and 21 degrees, with a cycle of 60 degrees.

[0019] Preferably, in the surface light source projection device according to the present invention, the plurality of micron structures of the micron diffraction layer are arranged in a hexagonal, densest configuration.

[0020] Preferably, in the surface light source projection device according to the present invention, the plurality of micron-sized diffraction layers are respectively disposed on the light-incident surface and the light-exit surface of the diffraction optical component module.

[0021] Preferably, in the surface light source projection device according to the present invention, the diffraction optical component module may further include a substrate, the substrate, the micron diffraction layer, and the plurality of micron structures are formed by dry etching, and the material of the diffraction optical component module is transparent crystal or glass.

[0022] The surface light source projection device provided by this invention mainly utilizes the outer diameter of the micron structure of two micron-layer diffraction layers, which is set to be between 5 and 200 times the incident wavelength of the narrow half-width of the light beam emitted by the light-emitting module. This allows the light beam to generate diffracted light with a high-density dot matrix after passing through the diffraction optical component module. Furthermore, by adjusting the height range to control the light intensity and zero-order diffraction intensity of the diffracted spot, adjusting the spacing range to control the distance and range of the spot, and adjusting the surface roughness range to control the light utilization efficiency and zero-order diffraction intensity, the diffracted light generated after passing through the diffraction optical component module achieves a diffraction pattern with a high-density dot matrix and low zero-order diffraction intensity. In addition, the two micron-layer diffraction layers of this invention are formed by dry etching, and the material of the diffraction optical component module is transparent crystal or glass. This allows the surface light source projection device provided by this invention to be applicable to time-of-flight ranging sensing technology and to withstand the heat accumulation after high-energy laser irradiation, which is beneficial for long-term irradiation and long-distance sensing. It is also suitable for image sensing in special environments with light degradation caused by short-wavelength laser irradiation, and has the advantages of wide applicability and high stability.

[0023] To enable those skilled in the art to understand the purpose, features and effects of the present invention, the present invention will be described in detail below with reference to the following specific embodiments and accompanying drawings. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the surface light source projection device of the present invention;

[0025] Figure 2 This is a schematic diagram illustrating how the light-emitting module of the present invention emits incident light to the diffraction optical component module;

[0026] Figure 3 This is a schematic diagram of the micron-diffraction layer of the present invention;

[0027] Figure 4 This is a schematic diagram of the surface light source projection device according to the first embodiment of the present invention;

[0028] Figure 5 This is a schematic diagram of the diffraction optical component module according to the first embodiment of the present invention;

[0029] Figure 6 This is a schematic diagram of the micron structure of the first embodiment of the present invention;

[0030] Figure 7 This is an enlarged schematic diagram of the micron structure of the first embodiment of the present invention;

[0031] Figure 8 A schematic diagram illustrating the included angle between the first diffraction optical component and the second diffraction optical component is provided as an example.

[0032] Figure 9 This is a schematic diagram of the diffraction optical component module according to the second embodiment of the present invention;

[0033] Figure 10 This is a schematic diagram of the diffraction optical component module according to the third embodiment of the present invention.

[0034] Explanation of reference numerals in the attached figures:

[0035] 100, 100A, 100B: Surface light source projection device;

[0036] 11, 11A, 11B: Light-emitting modules;

[0037] 12, 12A, 12B: Diffraction optical component modules;

[0038] 121, 121B: First diffractive optical components;

[0039] 1211, 1211B: First upper surface;

[0040] 1212, 1212B: First lower surface;

[0041] 122, 122B: Second diffractive optical components;

[0042] 1221, 1221B: Second upper surface;

[0043] 1222, 1222B: Second lower surface;

[0044] 21, 21A: Incident surface;

[0045] 22, 22A: Light-emitting surface;

[0046] 31, 31A: Micrometer-level diffraction layer;

[0047] 311, 311B: First micrometer diffraction layer;

[0048] 312, 312B: Second micrometer diffraction layer;

[0049] 32, 32-1, 32-2: Micrometer structure;

[0050] 33: Substrate;

[0051] 41: First direction;

[0052] 42: Second direction;

[0053] d: Spacing;

[0054] h: height;

[0055] L: Beam;

[0056] Ld: diffracted light;

[0057] :Outer diameter;

[0058] θ: Relative angle. Detailed Implementation

[0059] The inventive concept will now be more fully described below with reference to the accompanying drawings, which illustrate exemplary embodiments of the inventive concept. The advantages and features of the inventive concept, as well as methods of achieving it, will become apparent from the exemplary embodiments described in more detail below with reference to the accompanying drawings. However, it should be noted that the inventive concept is not limited to the exemplary embodiments described below, but can be implemented in various forms. Therefore, exemplary embodiments are provided only to disclose the inventive concept and to enable those skilled in the art to understand the category of the inventive concept. In the drawings, exemplary embodiments of the inventive concept are not limited to the specific instances provided herein and are exaggerated for clarity.

[0060] The terminology used herein is for illustrative purposes only and is not intended to limit the invention. Unless the context clearly indicates otherwise, the singular forms of the terms “a” and “the” as used herein are intended to include the plural forms as well. The term “and / or” as used herein includes any and all combinations of one or more of the associated listed items. It should be understood that when a component is referred to as “connected” or “coupled” to another component, the component may be directly connected or coupled to the other component or there may be intermediate components.

[0061] Similarly, it should be understood that when a component (e.g., a layer, region, or substrate) is said to be "on" another component, the component may be directly on the other component, or there may be intermediate components. In contrast, the term "directly" implies the absence of intermediate components. Furthermore, it should be understood that when the terms "comprising" or "including" are used herein, they indicate the presence of the stated features, integers, steps, operations, components, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, components, and / or groups thereof.

[0062] Furthermore, exemplary embodiments in the detailed description will be illustrated by cross-sectional views of idealized exemplary drawings that serve as concepts of the invention. Accordingly, the shapes of the exemplary drawings may be modified according to manufacturing techniques and / or tolerable errors. Therefore, exemplary embodiments of the concepts of the invention are not limited to the specific shapes shown in the exemplary drawings, but may include other shapes that may be produced according to the manufacturing process. The areas illustrated in the drawings have general characteristics and are used to illustrate specific shapes of components. Therefore, this should not be considered as limiting the scope of the concepts of the invention.

[0063] It should also be understood that although terms such as "first," "second," and "third" may be used herein to describe various components, these components should not be limited to these terms. These terms are only used to distinguish the various components. Therefore, a first component in some embodiments may be referred to as a second component in other embodiments, without departing from the teachings of the invention. Exemplary embodiments of the inventive concepts illustrated and described herein include their complementary counterparts. Throughout this specification, the same reference numerals or the same indicators denote the same components.

[0064] Furthermore, exemplary embodiments are illustrated herein with reference to sectional views and / or plan views, which are idealized exemplary illustrative diagrams. Therefore, deviations from the illustrated shapes are expected due to factors such as manufacturing techniques and / or tolerances. Thus, exemplary embodiments should not be construed as limited to the shapes of the areas shown herein, but are intended to include shape deviations caused, for example, by manufacturing processes. Therefore, the areas shown in the figures are schematic, and their shapes are not intended to illustrate the actual shapes of the areas of the device, nor are they intended to limit the scope of the exemplary embodiments.

[0065] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the surface light source projection device of the present invention. Figure 1 As shown, the surface light source projection device 100 of the present invention includes: a light-emitting module 11 and a diffraction optical component module 12.

[0066] Please refer to the following at the same time. Figure 2 , Figure 2 This is a schematic diagram illustrating how the light-emitting module of the present invention emits incident light to the diffraction optical component module. (See attached diagram.) Figure 2 As shown, the light-emitting module 11 of the present invention is used to output a light beam L, which has a specific narrow half-width incident wavelength (not shown), and the light beam L can be a highly directional light beam. In some embodiments, the light-emitting module 11 can be a vertical-cavity surface-emitting laser (VCSEL) module capable of simultaneously emitting multiple light beams. In other embodiments, the light-emitting module 11 can also be an edge-emitting laser diode module capable of emitting a single light beam, a collimated light-emitting diode (LED) module, or other suitable light sources, and the number of light sources can be one or more; however, the present invention is not limited thereto.

[0067] Please refer to Figure 2 and Figure 3 As shown, Figure 3 This is a schematic diagram of the micron-diffraction layer of the present invention. According to the diffraction optical component module 12 of the present invention, a light beam L passes through to form an outwardly projected diffracted light Ld. The diffraction optical component module 12 has an incident surface 21 and an exit surface 22. The incident surface 21 receives the light beam L, and the exit surface 22 outputs the diffracted light Ld. The diffraction optical component module 12 has two micron-diffraction layers 31, and the plurality of micron-diffraction layers 31 have a plurality of micron-structures 32, the outer diameter of which is... The wavelength is between 5 and 200 times the narrow half-width of the incident wavelength of the beam L. It should be further noted that the outer diameter of the micrometer structure 32... Users can adjust the spot density of the diffraction pattern formed by the diffracted light Ld, when the outer diameter The larger the diameter, the lower the spot density of the diffraction pattern formed by the diffracted light Ld. The advantage is that the diffraction pattern formed by the diffracted light Ld covers a larger area, enabling 3D sensing on a smaller surface light source projection device 100. However, the disadvantage is that low spot density makes long-distance sensing difficult. Conversely, when the outer diameter is larger... The smaller the diameter, the higher the spot density of the diffraction pattern formed by the diffracted light Ld. Its advantages are high 3D sensing accuracy and the ability to achieve long-distance sensing, but its disadvantage is the small outer diameter. This would result in a diffraction pattern that is too small, making it difficult to reduce the size of the surface light source projection device 100, which does not meet the needs of practical applications.

[0068] Therefore, the surface light source projection device 100 of the present invention converts the original light beam L into diffracted light Ld by the diffraction optical component module 12, and at the same time, it is combined with the outer diameter of the micron structure 32. The beam is set to a width between 5 and 200 times the incident wavelength of the narrow half-width of the beam L, resulting in a diffraction pattern with a high-density dot matrix. The light spot of the diffraction pattern has advantages such as uniform light intensity and high density, so as to achieve the effect of long-distance sensing.

[0069] It is worth noting that the diffraction optical component module 12 of the present invention must have two micron-level diffraction layers 31. This is because when only a single micron-level diffraction layer is used as the diffraction optical component module 12, the spot density of the diffraction pattern formed by the diffracted light Ld on the small-sized surface light source projection device 100 is insufficient to cover a large projection area. As mentioned above, low spot density makes long-distance sensing difficult and significantly reduces the accuracy of long-distance sensing. Therefore, the present invention uses two micron-level diffraction layers 31 in combination to form a diffraction pattern with a high-density dot matrix of diffracted light Ld. It should be noted that the combination of micron-level diffraction layers 31 is not limited to two layers; the above-described actual process is for illustrative purposes only and is not intended to limit the present invention.

[0070] Specifically, in some embodiments, the shape of the microstructure 32 of the present invention can be configured as conical, disk-shaped, or a combination of these shapes. It should be further noted that the outer diameter referred to herein... It can represent the width of any micrometer structure 32. When the micrometer structure 32 is disk-shaped, the outer diameter... The outer diameter can be 32 micrometers. When the microstructure 32 is not disk-shaped, the outer diameter The outer diameter can be represented by the cylindrical structure that is closest to the micron structure 32; however, the invention is not limited thereto.

[0071] Specifically, in some embodiments, the height h of the plurality of microstructures 32 is between the outer diameter and the outer diameter. The difference is between 0.05 and 0.2 times. It should be further explained that the height h of the micron structure 32 allows the user to adjust the uniformity of the light intensity of the diffraction pattern formed by the diffracted light Ld. This is because the height h of the micron structure 32 is related to the outer diameter of the beam L. The combination of these factors will affect the diffraction factor and interference factor of the diffracted light Ld, causing changes in the uniformity of the light intensity of the diffracted pattern. It is understandable that if the height h of the micron structure 32 is too small, the light beam L will not be able to form diffracted light Ld after passing through the diffraction optical component module 12. Furthermore, in actual manufacturing processes, the higher the height h of the micron structure 32, the lower the uniformity of the crystal in the micron structure 32 will be, further affecting the uniformity of the light intensity of the diffracted pattern formed by the diffracted light Ld. It is worth noting that the above-described actual manufacturing process is for illustrative purposes only and is not intended to limit the invention.

[0072] Specifically, in some embodiments, the spacing d between each pair of the plurality of microstructures 32 allows the user to adjust the range of the diffraction pattern formed by the diffracted light Ld. A larger spacing d results in a larger range of the diffraction pattern formed by the diffracted light Ld, and vice versa. It is understood that the user can choose which spacing d to match the outer diameter of the aforementioned microstructures 32 according to their needs. This is quite appropriate. It is worth mentioning that, in a preferred embodiment of the present invention, the spacing d between each pair of the plurality of micron-structures 32 must be within the outer diameter. The difference is between 0.5 and 5 times, because the spacing d between each pair of the multiple micrometer structures 32 is smaller than the outer diameter. When the distance is increased to 0.5 times the diameter, the range of the diffraction pattern formed by the diffracted light Ld will be too small, which does not meet the requirements of practical applications. Conversely, when the distance d is increased to improve the range of the diffraction pattern formed by the diffracted light Ld, the outer diameter will be too large. If the beam is too small, it will prevent the beam L from forming a diffracted beam Ld after passing through the diffraction optical component module 12.

[0073] Specifically, in some embodiments, the surface roughness (Ra) of the plurality of microstructures 32 affects the zero-order diffraction intensity and light utilization efficiency of the diffraction pattern formed by the diffracted light Ld. Specifically, a larger Ra results in lower light utilization efficiency and a weaker zero-order diffraction intensity, which may even fall below the first-order diffraction intensity. Conversely, a smaller Ra results in higher light utilization efficiency and a stronger zero-order diffraction intensity. It is understood that users can choose the appropriate spacing d to match the surface roughness Ra of the microstructures 32 according to their needs. It is worth noting that in a preferred embodiment of the present invention, the surface roughness Ra of the microstructures 32 must be between 0.5 nm and 50 nm. This is because if the Ra of the microstructures 32 is less than 0.5 nm, its zero-order diffraction will be too strong, which does not meet the requirements of practical applications. Conversely, if Ra is increased to reduce the zero-order diffraction intensity formed by the diffracted light Ld, a Ra exceeding 50 nm will result in low effective light utilization and insufficient diffraction spot intensity after the light beam L passes through the diffraction optical component module 12.

[0074] Therefore, the surface light source projection device 100 of the present invention further enhances the intensity uniformity and spot density of the diffraction pattern formed by the diffracted light Ld by adjusting the height h and spacing d of the micron structure 32, thereby improving the stability and accuracy of long-distance sensing and realizing a diffraction pattern with a large range and high light intensity uniformity. At the same time, the micron structure 32 also has good optical characteristics that meet the needs of practical applications.

[0075] It is worth mentioning again that in some embodiments, the plurality of microstructures 32 of the micron diffraction layer 31 of the present invention are arranged in a hexagonal densest arrangement. The hexagonal densest arrangement is the arrangement with the highest space utilization. In this way, by arranging the microstructures 32 in a hexagonal densest arrangement, the light spot density of the diffraction pattern formed by the diffraction light Ld is further improved, and the accuracy of long-distance sensing is greatly improved. However, the present invention is not limited to this.

[0076] Specifically, the microstructure 32 of the micron-diffraction layer 31 of the present invention can be formed from a single material via dry etching. This allows for effective control over the appearance and shape of the microstructure 32. Compared to optical structures formed from organic materials in the prior art, the microstructure 32 of the embodiments of the present invention is less prone to cracking or pyrolysis and is also resistant to physical friction. Therefore, the micron-diffraction layer 31 can possess stable optical properties. Furthermore, in some embodiments, the material of the micron-diffraction layer 31 may include transparent crystals or glass, such as sapphire or quartz. Specifically, sapphire possesses multiple characteristics including high hardness, high melting point, and high refractive index. With a Mohs hardness of 9, sapphire is a hard and wear-resistant material, thus making the microstructure 32 of the micron-diffraction layer 31 less susceptible to damage. Moreover, sapphire has a melting point greater than 2000 degrees Celsius and excellent thermal conductivity, so even when exposed to light for extended periods, it is not prone to deformation, contributing to the stable optical properties of the micron-diffraction layer 31. Furthermore, since the lattice stacking of sapphire is also a hexagonal system, in some embodiments it can be paired with micron structures 32 arranged in the densest hexagonal pattern to further enhance the spot density of the diffraction pattern formed by the diffracted light Ld; however, the present invention is not limited thereto.

[0077] Specifically, in some embodiments, the micron-level diffraction layer 31 can be disposed on the light-incident surface 21 and the light-exit surface 22 of the diffraction optical component module 12, respectively. In other embodiments, the diffraction optical component module 12 can further include a first diffraction optical component 121 and a second diffraction optical component 122, wherein the first diffraction optical component 121 is provided with a first micron-level diffraction layer 311, and the second diffraction optical component 122 is provided with a second micron-level diffraction layer 312. In this way, by setting up a double-layer optical component, the user can adjust the angle between the optical components according to their own needs to control the diffraction pattern and light spot density formed by the diffracted light Ld, which greatly improves the application range of the surface light source projection device 100 of the present invention, making the present invention widely applicable; however, the present invention is not limited thereto.

[0078] Therefore, by adjusting the arrangement of the plurality of microstructures 32 in the micron diffraction layer 31, the present invention further improves the spot density of the diffraction pattern formed by the diffraction light Ld, greatly improving the accuracy of long-distance sensing. At the same time, the combination of the dual-layer optical components makes the present invention widely applicable.

[0079] First Embodiment

[0080] Hereinafter, with reference to the drawings, a first embodiment of the surface light source projection device 100 of the present invention will be described.

[0081] Please see Figure 4 and Figure 5 As shown, Figure 4 This is a schematic diagram of the surface light source projection device according to the first embodiment of the present invention; Figure 5 This is a schematic diagram of the diffraction optical component module according to the first embodiment of the present invention. Figure 4 As shown, the surface light source projection device 100 of the first embodiment of the present invention is applied to a 3D sensing system. The surface light source projection device 100 includes a light-emitting module 11 and a diffraction optical component module 12. The diffraction optical component module 12 includes a first diffraction optical component 121 and a second diffraction optical component 122. A first micron diffraction layer 311 is disposed on the first diffraction optical component 121, and a second micron diffraction layer 312 is disposed on the second diffraction optical component 122. Both the first micron diffraction layer 311 and the second micron diffraction layer 312 have multiple micron structures 32, namely micron structure 32-1 and micron structure 32-2. In this embodiment, the diffraction optical component module 12 has a substrate 33, and the substrate 33 and the micron structure 32 are integrally formed.

[0082] Specifically, such as Figure 4 As shown, in the first embodiment of the present invention, the first micron diffraction layer 311 and the second micron diffraction layer 312 of the diffraction optical component module 12 are integrally formed by etching process. The material of the diffraction optical component module 12 is crystal, such as sapphire. Since sapphire is a material with high hardness and wear resistance, it can provide the diffraction optical component module 12 with stable optical properties. As mentioned above, the lattice stacking of sapphire is also a hexagonal system, which can be matched with the micron structure 32 arranged in the hexagonal densest arrangement to further improve the spot density of the diffraction pattern formed by the diffraction light Ld. However, the present invention is not limited to this.

[0083] Specifically, such as Figure 4 and Figure 5As shown, the first diffraction optical component 121 of the first embodiment of the present invention has a first upper surface 1211 and a first lower surface 1212. In this embodiment, the first lower surface 1212 corresponds to the light-incident surface 21 of the diffraction optical component module 12, and a first micron diffraction layer 311 is disposed on the first upper surface 1211. The second diffraction optical component 122 of the first embodiment of the present invention has a second upper surface 1221 and a second lower surface 1222. In this embodiment, the second upper surface 1221 corresponds to the light-outcrystal surface 22 of the diffraction optical component module 12, and a second micron diffraction layer 312 is disposed on the second upper surface 1221. Specifically, in this embodiment, the light beam L is formed into an outwardly projected diffracted light Ld by the diffracting optical component module 12. The light beam L enters the diffracting optical component module 12 from the first lower surface 1212 and outputs the diffracted light Ld from the second upper surface 1221. However, the present invention is not limited thereto.

[0084] It is worth mentioning that in this embodiment, the microstructure 32-1 of the first micron diffraction layer 311 is exactly the same as the microstructure 32-2 of the second micron diffraction layer 312, so as to ensure that the light spot formed by the diffracted light Ld can have a consistent light intensity when they do not overlap, so as to ensure the accuracy of long-distance sensing. However, the present invention is not limited to this.

[0085] Specifically, please refer to Figure 6 and Figure 7 As shown, Figure 6 This is a schematic diagram of the micron structure of the first embodiment of the present invention; Figure 7 This is an enlarged schematic diagram of the micron-sized structure according to the first embodiment of the present invention. Figure 6 and Figure 7 As shown, the micron structure 32 of the first embodiment of the present invention is arranged in a hexagonal close-packed configuration, which is the arrangement with the highest space utilization. Furthermore, the crystal material of the first embodiment of the present invention is also hexagonal close-packed, and the micron structure 32 is cylindrical. This allows the diffraction pattern formed by the large-amplitude diffracted light Ld to possess both uniform light intensity and high light density, thereby improving the accuracy of long-distance sensing. Specifically, in this embodiment, the outer diameter of the micron structure 32... The height h of the micrometer structure 32 is between 5 and 200 times the incident wavelength, which is narrow half-width L. The spacing d between any two of these multiple micrometer structures 32 is between 0.05 and 0.2 times the outer diameter. The surface roughness Ra of the micron structure 32 is between 0.5 nm and 50 nm, which is between 0.5 nm and 5 times that of the surface light source projection device 100 of the first embodiment of the present invention. In this way, the intensity uniformity and density of the light spot of the diffraction pattern formed by the diffracted light Ld are further enhanced, thereby improving the stability and accuracy of long-distance sensing.

[0086] Please see Figure 8 As shown, Figure 8 A schematic diagram illustrating the included angle between the first diffraction optical component and the second diffraction optical component is provided as an example. Figure 8 As shown, in this embodiment, the center point of the first micrometer diffraction layer 311 is perpendicularly aligned with the center point of the second micrometer diffraction layer 312. The second micrometer diffraction layer 312 rotates relative to the first micrometer diffraction layer 311 with its center point as the center, such that there is a relative angle θ between the first direction 41 passing through the center point of the first micrometer diffraction layer 311 and the second direction 42 passing through the center point of the second micrometer diffraction layer 312. Preferably, in this embodiment, when the relative angle θ is 12 degrees, the diffracted light Ld can have the best intensity uniformity and density of the light spot; however, the present invention is not limited thereto.

[0087] It should be further noted that, in this embodiment, the relative angle θ is ideally 12 degrees. However, embodiments of the present invention may be subject to the error of the measuring instrument. Ideally, the relative angle θ between the first direction 41 and the second direction 42 measured by the measuring instrument used according to the present invention is in the range of 10 to 14 degrees. However, the user may choose a relative angle θ with a smaller error range as needed, and the measured value may be smaller. This is only an illustrative example, and the present invention is not limited thereto. In addition, the relative angle θ referred to in the present invention can be defined as measured when the light beam L is in the infrared light range (e.g., above 830 nm), and the first micron diffraction layer 311 and the second micron diffraction layer 312 are completely identical; or, for ease of explanation, the relative angle θ referred to in the present invention can be defined as measured when the light beam L is 940 nm.

[0088] Specifically, when the relative angle θ between the first direction 41 passing through the center of the first micrometer diffraction layer 311 and the second direction 42 passing through the center of the second micrometer diffraction layer 312 is adjusted to 5 degrees using the aforementioned method, the resulting diffracted light Ld spot distribution presents a hexagonal diffraction pattern. This is because the crystal material in the first embodiment of the present invention is a hexagonal close-packed structure. At the same time, due to the overlapping arrangement of some of the diffracted light Ld spots (i.e., diffraction points), the diffraction points have spots with higher light intensity covering spots with lower light intensity, resulting in poor uniformity of the intensity of the diffracted light Ld spot. On the other hand, when the relative angle θ between the first direction 41 at the center of the first micrometer diffraction layer 311 and the second direction 42 at the center of the second micrometer diffraction layer 312 is 12 degrees, the resulting diffracted light Ld spot distribution is uniform. This is because, in this embodiment, by adjusting the relative angle θ, the position of the diffracted light Ld spot is changed, reducing the overlap of the diffracted light Ld spots, thereby significantly improving the intensity uniformity and spot density of the diffracted light Ld spot. This enhances the sensing signal for long-distance sensing and strengthens the contour recognition for long-distance sensing. It is understood that users can adjust the relative angle θ according to their needs. The range of the relative angle θ can be between 0 and 90 degrees, for example, the relative angle θ can be 5 degrees, 10 degrees, and 20 degrees, to select the most suitable diffraction pattern formed by the diffracted light Ld. This invention should not be construed as limited to this.

[0089] Therefore, the surface light source projection device 100 of the first embodiment of the present invention adjusts the relative angle θ between the first micron diffraction layer 311 and the second micron diffraction layer 312 to adjust the relative position of the micron structure 32 of the first micron diffraction layer 311 and the micron structure 32 of the second micron diffraction layer 312, thereby realizing a diffraction pattern with a high density dot matrix suitable for time-of-flight ranging sensing systems.

[0090] Other examples of surface light source projection devices are provided below to enable those skilled in the art to better understand possible variations. Components indicated by the same component symbols as in the above embodiments are substantially the same as those referenced above. Figures 1 to 3 The components, features, and advantages that are the same as those of the surface light source projection device 100 will not be repeated.

[0091] Specifically, please refer to Figure 9 As shown, Figure 9This is a schematic diagram of a diffraction optical component module according to a second embodiment of the present invention. The difference between the surface light source projection device 100A of the second embodiment and the surface light source projection device 100 of the first embodiment lies in that, in this embodiment, the diffraction optical component module 12A of the surface light source projection device 100A is a single-substrate structure. The plurality of micron-sized diffraction layers 31A are respectively disposed on the light-incident surface 21A and the light-exiting surface 22A of the diffraction optical component module 12A, and the plurality of micron-sized diffraction layers 31A can have identical micron-sized structures 32. In this embodiment, the micron-sized diffraction layer 31A can first be disposed on one of the light-incident surface 21A and the light-exiting surface 22A by etching. After the first layer of micron-sized diffraction layer 31A is disposed, the diffraction optical component module 12A is rotated by a relative angle θ, and then another layer of micron-sized diffraction layer 31A is disposed on the other of the light-incident surface 21A and the light-exiting surface 22A. However, the present invention is not limited to this.

[0092] Specifically, please refer to Figure 10 As shown, Figure 10 This is a schematic diagram of the diffraction optical component module according to the third embodiment of the present invention. The difference between the surface light source projection device 100B of the third embodiment and the surface light source projection device 100 of the first embodiment is that, in this embodiment, the diffraction optical component module 12B of the surface light source projection device 100B has a first diffraction optical component 121B and a second diffraction optical component 122B. A first micron diffraction layer 311B is disposed on the first upper surface 1211B of the first diffraction optical component 121B, and a second micron diffraction layer 312B is disposed on the second lower surface 1222B of the second diffraction optical component 122B. It is worth mentioning that, in this embodiment, the micron structure 32 of the first micron diffraction layer 311B and the second micron diffraction layer 312B is completely identical to ensure that the light spot formed by the diffracted light Ld can have a consistent light intensity when they do not overlap, thereby ensuring the accuracy of long-distance sensing.

[0093] It is understood that the placement of the second micrometer diffraction layer 312B will not significantly affect the intensity uniformity and density of the diffracted light Ld formed by the surface light source projection device 100, or the light spot of the diffraction pattern formed by the diffracted light Ld. Furthermore, those skilled in the art to which this invention pertains can make various changes and adjustments based on the above examples, which will not be listed here.

[0094] The above description of specific embodiments illustrates the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0095] The above describes the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also within the scope of protection of the present invention.

Claims

1. A surface light source projection device, characterized in that, include: A diffraction optical component module has an incident light surface and an exit light surface, and the diffraction optical component module is provided with two micron-level diffraction layers; as well as A light-emitting module is used to output a collimated light beam with a narrow half-width incident wavelength. The light beam enters the diffraction optical component module from the incident surface and passes through the two micron-level diffraction layers of the diffraction optical component module in sequence before being output from the light-emitting surface. The two micron-level diffraction layers are a first micron-level diffraction layer and a second micron-level diffraction layer, respectively. The first micron-level diffraction layer is disposed on the light-incident surface of the diffraction optical component module, and the second micron-level diffraction layer is disposed on the light-exit surface of the diffraction optical component module. The diffraction optical component module includes: A first diffractive optical component, the first diffractive optical component having a first upper surface and a first lower surface; and A second diffraction optical component, the second diffraction optical component having a second upper surface and a second lower surface; The first micron diffraction layer is disposed on the first upper surface of the first diffraction optical component, and the second micron diffraction layer is disposed on the second diffraction optical component. The light beam enters the diffraction optical component module from the first lower surface and is output from the second upper surface after passing through the diffraction optical component module. Both micron-diffraction layers contain multiple micron-structures. The shapes of these micron-structures are conical, disk-shaped, or a combination of these shapes. Each micron-structure has an outer diameter, which is between 5 and 200 times the narrow half-width incident wavelength. The height of each micron-structure is between 0.05 and 0.2 times the outer diameter. The spacing between any two micron-structures is between 0.5 and 5 times the outer diameter. The surface roughness of each micron-structure is between 0.5 nm and 50 nm. This allows the light beam to generate a high-density point matrix of diffracted light after passing through the diffraction optical component module, enabling long-distance sensing.

2. The surface light source projection device according to claim 1, characterized in that, The second micron-sized diffraction layer is disposed on the second lower surface.

3. The surface light source projection device according to claim 1, characterized in that, The second micron diffraction layer is disposed on the second upper surface.

4. The surface light source projection device according to claim 1, characterized in that, The center point of the first micrometer diffraction layer is perpendicularly aligned with the center point of the second micrometer diffraction layer. The second micrometer diffraction layer rotates relative to the first micrometer diffraction layer by a relative angle with the center point as the center, so that a first direction passing through the center point of the first micrometer diffraction layer and a second direction passing through the center point of the second micrometer diffraction layer have the relative angle, and the relative angle is between 5 degrees and 90 degrees.

5. The surface light source projection device according to claim 1, characterized in that, The multiple microstructures of the two micron-diffraction layers are arranged in a hexagonal, densest configuration.

6. A surface light source projection device, characterized in that, include: A diffraction optical component module has an incident light surface and an exit light surface, and the diffraction optical component module is provided with two micron-level diffraction layers; as well as A light-emitting module is used to output a collimated light beam with a narrow half-width incident wavelength. The light beam enters the diffraction optical component module from the incident surface and passes through the two micron-level diffraction layers of the diffraction optical component module in sequence before being output from the light-emitting surface. The diffraction optical component module includes a substrate, and the two micron-level diffraction layers are both disposed on the substrate; Both micron-diffraction layers contain multiple micron-structures. The shapes of these micron-structures are conical, disk-shaped, or a combination of these shapes. Each micron-structure has an outer diameter, which is between 5 and 200 times the narrow half-width incident wavelength. The height of each micron-structure is between 0.05 and 0.2 times the outer diameter. The spacing between any two micron-structures is between 0.5 and 5 times the outer diameter. The surface roughness of each micron-structure is between 0.5 nm and 50 nm. This allows the light beam to generate a high-density point matrix of diffracted light after passing through the diffraction optical component module, enabling long-distance sensing.

7. The surface light source projection device according to claim 6, characterized in that, The substrate and the plurality of micron-sized structures are formed by dry etching, and the material of the diffraction optical component module is transparent crystal or glass.

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