Optical Component, Light Emission Module, Depth Camera and Electronic Device

Abstract

The present application discloses an optical component, a light emitting module, a depth camera and an electronic device. The optical component includes a diffraction optical element, an anti-reflection film and a detection element. The diffraction optical element includes a first area and a second area surrounding the first area. The anti-reflection film is provided in the first area of the diffraction optical element, and the anti-reflection film is used to reduce the reflectivity of the light received by the diffraction optical element in the first area. The detection element is used to detect the diffraction optical element and is located in the second area of the diffraction optical element. The present application sets an anti-reflection film and a detection element on the diffraction optical element, which can not only reduce the reflectivity of the light and reduce stray light interference, but also detect the diffraction optical element through the detection element to avoid users using abnormal diffraction optical elements, thereby improving the safety of users using optical components. In addition, since the anti-reflection film and the detection element are provided in different areas of the diffraction optical element, it is beneficial to further reduce stray light interference and reduce the difficulty of manufacturing the optical component.

Description

Technical Field

[0001] The present application relates to the field of laser ranging technology, and more specifically, to an optical component, a light emitting module, a depth camera and an electronic device. Background Art

[0002] Depth cameras typically consist of a transmitter and a receiver. The transmitter is used to emit laser light toward the object under test, while the receiver is used to receive the laser light reflected from the object. The surface of the diffractive optical element in the transmitter, such as glass, can easily reflect part of the light beam, creating stray light interference that affects the quality of the laser beam projection and, in turn, interferes with the signal received by the receiver. Furthermore, if the substrate of the diffractive optical element in the transmitter breaks, the laser light emitted by the transmitter could directly enter the human eye, causing damage to the eye. Summary of the Invention

[0003] Embodiments of the present application provide an optical component, a light emission module, a depth camera, and an electronic device.

[0004] An optical assembly according to an embodiment of the present application includes a diffractive optical element, an antireflection film, and a detection element. The diffractive optical element includes a first region and a second region surrounding the first region. The antireflection film is disposed on the first region of the diffractive optical element and is configured to reduce the reflectivity of light received by the diffractive optical element in the first region. The detection element is configured to detect the diffractive optical element and is located in the second region.

[0005] The light emission module of an embodiment of the present application includes a light source and an optical component. The light source is used to emit light, and the optical component is arranged in the light output path of the light source. The optical component includes a diffractive optical element, an anti-reflection film, and a detection element. The diffractive optical element includes a first region and a second region surrounding the first region. The anti-reflection film is arranged in the first region of the diffractive optical element and is used to reduce the reflectivity of light received by the diffractive optical element in the first region. The detection element is used to detect the diffractive optical element and is located in the second region.

[0006] The depth camera of the embodiment of the present application includes a light emitting module and a light receiving module, wherein the light emitting module is used to emit light, and the light receiving module is used to receive light reflected at least partially by an object and convert it into an electrical signal. The light emitting module includes a light source and an optical component. The light source is used to emit light, and the optical component is arranged on the light output path of the light source. The optical component includes a diffraction optical element, an anti-reflection film and a detection element. The diffraction optical element includes a first area and a second area surrounding the first area. The anti-reflection film is provided in the first area of the diffraction optical element, and the anti-reflection film is used to reduce the reflectivity of the light received by the diffraction optical element in the first area. The detection element is used to detect the diffraction optical element and is located in the second area.

[0007] The electronic device of the embodiment of the present application includes a housing and a depth camera, and the housing is combined with the depth camera. The depth camera includes a light emitting module and a light receiving module, the light emitting module is used to emit light, and the light receiving module is used to receive light reflected at least partially by an object and convert it into an electrical signal. The light emitting module includes a light source and an optical component. The light source is used to emit light, and the optical component is arranged on the light output path of the light source. The optical component includes a diffraction optical element, an anti-reflection film and a detection element. The diffraction optical element includes a first area and a second area surrounding the first area. The anti-reflection film is provided in the first area of the diffraction optical element, and the anti-reflection film is used to reduce the reflectivity of the light received by the diffraction optical element in the first area. The detection element is used to detect the diffraction optical element and is located in the second area.

[0008] The optical assembly, light emission module, depth camera, and electronic device disclosed herein, by providing an anti-reflection film and a detection element on a diffractive optical element, can reduce the reflectivity of light and stray light interference. Furthermore, the detection element can detect the diffractive optical element, thereby preventing users from using abnormal diffractive optical elements and improving safety when using the optical assembly. Furthermore, because the anti-reflection film is located in a first zone at the center of the diffractive optical element and the detection element is located in a second zone at the edge of the diffractive optical element, i.e., no detection element is provided in the central region of the diffractive optical element, the majority of light is emitted after passing through the anti-reflection film, further reducing stray light interference.

[0009] In addition, in the embodiments of the present application, additional aspects and advantages of the embodiments of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be understood through the practice of the embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0011] Figure 1 is a schematic structural diagram of an optical assembly in certain embodiments of the present application;

[0012] Figure 2 is a schematic plan view of an optical assembly in certain embodiments of the present application;

[0013] Figure 3 and Figure 4 is a schematic diagram of a cross section of an optical component in certain embodiments of the present application;

[0014] Figure 5a is a schematic diagram of light passing through a diffractive optical element without an anti-reflection film;

[0015] Figure 5b Schematic diagram of light passing through a diffractive optical element with an anti-reflection film;

[0016] Figure 6a It is the speckle pattern that the light receiving module can obtain after the light passes through the diffractive optical element without anti-reflection film;

[0017] Figure 6b It is the speckle pattern that can be obtained by the light receiving module after the light passes through the optical component in certain embodiments of the present application;

[0018] Figure 7 is a schematic diagram of an anti-reflection film in an optical component according to certain embodiments of the present application;

[0019] Figure 8 is a schematic diagram of a partial cross-section of an optical component in certain embodiments of the present application;

[0020] Figure 9 is a schematic diagram of the structure of a depth camera in certain embodiments of the present application;

[0021] Figure 10 is a schematic structural diagram of a light emission module in certain embodiments of the present application;

[0022] Figure 11 It is a schematic structural diagram of an electronic device in some embodiments of the present application. DETAILED DESCRIPTION

[0023] The following further describes the embodiments of the present application in conjunction with the accompanying drawings. The same or similar reference numerals in the accompanying drawings represent the same or similar elements or elements with the same or similar functions.

[0024] In addition, the embodiments of the present application described below in conjunction with the accompanying drawings are exemplary and are only used to explain the embodiments of the present application and should not be understood as limiting the present application.

[0025] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0026] Laser ranging modules typically consist of a transmitter and a receiver. The transmitter is used to emit laser light toward an object, while the receiver receives the laser light reflected from the object. The substrate of the diffractive optical element in the transmitter, such as glass, polyvinyl chloride (PVC), or acrylic, can easily reflect part of the light beam, creating stray light interference that affects the quality of laser beam projection and, in turn, interferes with the signal received by the receiver. Furthermore, if the substrate of the diffractive optical element in the transmitter breaks, the laser light emitted by the transmitter could directly enter the human eye, causing damage to the eye.

[0027] To solve the above problem, please refer to Figures 1 to 3 , an embodiment of the present application provides an optical component 100. The optical component 100 includes a diffractive optical element 10, an anti-reflection film 20 and a detection element 30. The diffractive optical element 10 includes a first area 11 and a second area 12 surrounding the first area 11. The anti-reflection film 20 is located in the first area 11 of the diffractive optical element 10, and the anti-reflection film 20 is used to reduce the reflectivity of the light received by the diffractive optical element 10 in the first area 11. The detection element is used to detect the diffractive optical element and is located in the second area 12 of the diffractive optical element 10. It should be noted that, Figure 4 As shown, the first area 11 and the second area 12 of the diffractive optical element 10 are a three-dimensional structure, not just a plane. In addition, the volume and cross-section of the first area 11 and the second area 12 are not limited here.

[0028] The optical component 100 of the present application, on the one hand, can reduce the reflectivity of the light received by the diffractive optical element 10 in the first area 11 by providing the anti-reflection film 20 on the diffractive optical element 10, thereby reducing stray light interference and improving the optical transmission module 200 (such as Figure 9 As shown in FIG) , the quality of the emitted light beam is improved, thereby improving the depth camera 400 (as shown) using the optical component 100 Figure 9 on the other hand, by providing a detection element 30 capable of detecting the diffractive optical element 10 in the diffractive optical element 10, it is possible to prevent users from using abnormal diffractive optical elements, thereby improving the safety of users using optical components.

[0029] Furthermore, a diffractive optical element typically includes a glass substrate and a microstructure, with the microstructure disposed on one surface of the glass substrate. Since the microstructure is disposed on one surface of the glass substrate, if an anti-reflection film and a detection element are to be disposed simultaneously on the diffractive optical element, the anti-reflection film and the detection element can only be stacked on the other surface of the glass substrate, i.e., the surface of the glass substrate without the microstructure. However, if the anti-reflection film is first disposed on the diffractive optical element and the detection element is then disposed on the side of the anti-reflection film away from the diffractive optical element, the detection element and the diffractive optical element are not in direct contact, and thus, it is not possible to detect whether the diffractive optical element is abnormal based on the electrical signal from the detection element. Furthermore, if the detection element is first disposed on the diffractive optical element and the anti-reflection film is then disposed on the side of the detection element away from the diffractive optical element, this is not only more difficult to process, but also, since the anti-reflection film is not in direct contact with the diffractive optical element, light passing through the diffractive optical element does not directly enter the anti-reflection film. This increases the reflectivity of the light compared to when light passing through the diffractive optical element directly enters the anti-reflection film, which is not conducive to reducing stray light interference. Therefore, in the embodiment of the present application, the anti-reflection film 20 and the detection element 30 are disposed in different areas of the diffractive optical element 10, allowing them to be placed on the same layer and directly on the diffractive optical element 10. This not only reduces the thickness of the optical assembly 100, but also enables the detection element 30 to detect whether the diffractive optical element 10 is abnormal. It also reduces the reflectivity of light, thereby reducing stray light interference. In addition, this eliminates the need to dispose the anti-reflection film on the side of the detection element away from the diffractive optical element, which reduces the difficulty of manufacturing the optical assembly.

[0030] Furthermore, in the light emitting module 200, the light source 201 ( Figure 10 The central region 11 of the diffractive optical element 10 (as shown) typically corresponds to the central region of the diffractive optical element 10. That is, the central region of the diffractive optical element 10 receives more light than the peripheral regions. Therefore, in the present embodiment, the anti-reflection film 20 is located in the first region 11 at the center of the diffractive optical element 10, and the detection element 30 is located in the second region 12 at the edge of the diffractive optical element 10. This allows the majority of light to pass through the anti-reflection film 20 before exiting. This helps reduce the reflectivity of light and thus minimizes stray light interference.

[0031] Specifically, the diffractive optical element 10 includes a microstructure 13, which is used to receive light and replicate the received light before emitting it. That is, the amount of light increases after being replicated by the microstructure 13. In some embodiments, the diffractive optical element 10 includes multiple microstructures 13, and all of the microstructures 13 are located in the first region 11. Because all of the microstructures 13 are located in the first region 11, after light is replicated by the microstructures 13, more light is emitted from the first region 11 than from the second region 12. This allows the majority of light to be emitted by the anti-reflection film 20 located in the first region 11, which helps reduce the reflectivity of light received by the diffractive optical element 10 in the first region 11, thereby reducing stray light interference. In addition, since all the microstructures 13 are arranged in the first zone 11, that is, no microstructure 13 is set in the second zone 12, the detection element 30 is located in the second zone 12 where no microstructure 13 is set, which can reduce the obstruction of light by the detection element 30, and can detect whether the diffraction optical element 10 is abnormal while facilitating the light emission of the light emitting module 200.

[0032] Of course, in some embodiments, when the diffractive optical element 10 includes a plurality of microstructures 13, both the first region 11 and the second region 12 may be provided with microstructures 13, but the number of microstructures 13 in the first region 11 is greater than the number of microstructures 13 in the second region 12. In this way, more light is emitted from the first region 11 than from the second region 12, allowing most of the light to be emitted from the anti-reflection film 20 located in the first region 11, thereby reducing the reflectivity of the light received by the diffractive optical element 10 in the first region 11, thereby reducing stray light interference.

[0033] See also Figure 3 In some embodiments, the diffractive optical element 10 includes a substrate 14, an anti-reflection film 20 and a detection element 30 are located on the same surface of the substrate 14, and the microstructure 13 is located on a surface opposite to the anti-reflection film 20 and the detection element 30. Specifically, the substrate 14 includes a first surface 1401 and a second surface 1402 opposite to each other. The first surface 1401 of the first substrate 14 is the first side 101 of the diffractive optical element 10. The microstructure 13 is provided on the second surface 1402 of the substrate 14, and the anti-reflection film 20 and the detection element 30 are both provided on the first surface 1401 of the substrate 14. The anti-reflection film 20 is provided on the first surface 1401 and is located in the first area 11, and the detection element 30 is provided on the first surface 1401 and is located in the second area 12. In this manner, the detection element 30 and the anti-reflection film 20 can be placed on the same layer and directly disposed on the diffractive optical element 10, thereby reducing the thickness of the optical assembly 100. Furthermore, the detection element 30 can be used to detect whether the diffractive optical element 10 is abnormal, and the reflectivity of light can be reduced, thereby reducing stray light interference. In some embodiments, the substrate 14 can be made of glass.

[0034] See also Figure 2 and Figure 4 In some embodiments, the diffractive optical element 10 includes a substrate 14, which includes a first layer 141 and a second layer 142. The side of the first layer 141 away from the second layer 142 is the first side 101 of the diffractive optical element 10. A sealed cavity 143 is formed between the first layer 141 and the second layer 142, and the microstructure 13 is located within the sealed cavity 143. The anti-reflection film 20 is disposed on the side of the first layer 141 away from the second layer 142 and is located in the first region 11. The detection element 30 is disposed on the side of the first layer 141 away from the second layer 142 and is located in the second region 12. In this way, the detection element 30 and the anti-reflection film 20 are placed on the same layer and can both be directly disposed on the diffractive optical element 10, thereby reducing the thickness of the optical component 100. The detection element 30 can be used to detect whether the diffractive optical element 10 is abnormal. Furthermore, the reflectivity of light can be reduced, thereby reducing stray light interference. Furthermore, because the microstructure 13 is located within the sealed cavity 143 between the first layer 141 and the second layer 142, the microstructure 13 is protected from scratches and moisture, thereby extending the service life of the diffractive optical element 10. In some embodiments, both the first layer 141 and the second layer 142 may be made of glass.

[0035] Of course, in some embodiments, the detection element 30 can also be arranged on the side of the second layer 142 away from the first layer 141, and the detection element 30 and the anti-reflection film 20 can also be directly arranged on the diffraction optical element 10, so that the detection element 30 can be used to detect whether the diffraction optical element 10 is abnormal, and the reflectivity of the light can be reduced, thereby reducing stray light interference.

[0036] Furthermore, in some embodiments, a detection element 30 is provided on the side of the first layer 141 away from the second layer 142, and on the side of the second layer 142 away from the first layer 141. Since the detection elements 30 are provided on the opposite sides of the diffraction optical element 10, whether the first layer 141 or the second layer 142 is broken, it can be detected in time by the detection element 30, which can further improve the safety of user use.

[0037] It should be noted that, in some embodiments, when the optical component 100 and the light source 201 cooperate to form the light emission module 200, the first side 101 of the optical component 100 is away from the light source 201 (eg Figure 10(as shown). After passing through the microstructures 13, light is emitted from the first side 101 of the diffractive optical element 10. At this point, light corresponding to the first region 11, after emitting from the first side 101, can be incident on the anti-reflection film 20, which can reduce the reflectivity of the incident light. In other words, this prevents light emitted from the first side 101 from being reflected within the diffractive optical element 10 and then reflected a second time by other components (e.g., the structure of the diffractive optical element 10 itself, or other devices in the light emission module 200) before being emitted again to the outside world from a different location from the previous exit position, thereby reducing the generation of stray light.

[0038] For example, the diffractive optical element 10 in which the microstructure 13 is provided in the sealed cavity 143 between the first layer 141 and the second layer 142 is taken as an example for description. Figure 5a and Figure 5b As shown (for the convenience of explanation, Figure 5a and Figure 5b Only one beam of light is drawn, and the replication effect of the microstructure 13 on the light is ignored). Figure 5a Schematic diagram of light passing through the diffractive optical element 10 without the anti-reflection film 20. Since the light passes from the first layer 141 of the substrate 14 to the ambient medium (usually air) outside the diffractive optical element 10, which is a transition from a denser medium to a less dense medium, it is easy to cause reflection. The reflected light will return to the inside of the diffractive optical element 10. A part of the reflected light will contact other components, such as Figure 5a After the reflected light hits the second layer 142 of the substrate 14 , it is reflected back and emitted from the first side 101 of the diffractive optical element 10 again. However, the emission position at this time is different from the position where it should actually be emitted, thus generating stray light. Figure 6a After the light passes through the diffractive optical element 10 without the anti-reflection film 20 , the speckle image A obtained by the light receiving module 300 can be seen. It can be seen that there is a lot of stray light in the speckle image A, which is not conducive to subsequently obtaining the depth information of the object based on the speckle image A. Figure 5b This is a schematic diagram of light passing through a diffractive optical element 10 provided with an anti-reflection film 20. After being emitted from the substrate 14, the light can be emitted to the outside of the diffractive optical element 10 through the anti-reflection film 20, thereby preventing the light from directly passing from the substrate 14 to the medium outside the diffractive optical element 10. This can reduce the reflectivity of the light received by the diffractive optical element 10 in the first zone 11, thereby reducing stray light. Figure 6b After the light passes through the diffractive optical element 10 provided with the anti-reflection film 20 , the speckle image B can be obtained in the light receiving module 300 . It can be seen that there is almost no stray light interference in the speckle image B, which is conducive to the subsequent acquisition of the depth information of the object based on the speckle image B.

[0039] Specifically, in some embodiments, the diffractive optical element 10 is placed in an ambient medium, the substrate 14 has a first refractive index, the ambient medium has a second refractive index, and the refractive index of the anti-reflection film 20 is related to the first and second refractive indices. When the diffractive optical element 10 is placed in air for use, the ambient medium is air, and the second refractive index is the refractive index of air. If the diffractive optical element 10 is placed in another medium for use, the second refractive index is the refractive index of the medium. Because the refractive index of the anti-reflection film 20 is related to the refractive indices of the substrate 14 and the ambient medium, this can reduce the refractive index difference between the substrate 14 and the first medium, thereby reducing the reflectivity of light.

[0040] More specifically, in some embodiments, the refractive index of the anti-reflection film 20 is the square root of the product of the first refractive index and the second refractive index. That is, the refractive index of the anti-reflection film 20 can be calculated by the formula: Calculated. Among them, is the refractive index of the antireflection film 20, is the first refractive index, that is is the refractive index of the matrix 14, is the second refractive index, that is is the refractive index of the ambient medium. For example, Figure 7 As shown, Figure 7 The schematic diagram of the principle of the anti-reflection film 20 is given. In the figure, light I enters the anti-reflection film 20 from the substrate 14 with a first refractive index, and then enters the environment medium with a second refractive index from the anti-reflection film 20. Figure 7 It can be seen that although there is a small amount of reflected light R1 and R2 at the upper and lower interfaces of the anti-reflection film 20, since the refractive index of the anti-reflection film 20 is the square root of the product of the first refractive index and the second refractive index, the phases of the reflected light R1 and R2 at the upper and lower interfaces of the anti-reflection film 20 are opposite, which can offset each other, thereby reducing light reflection and reducing stray light interference.

[0041] Of course, in some embodiments, the optical component 100 and the light source 201 (such as Figure 10When the optical component 100 and the optical module 200 are combined to form the light emitting module 200, the first side 101 of the optical component 100 faces the light source 201. After passing through the anti-reflection film 20, the light enters the optical component 100 and is then emitted from the optical component 100 to the outside of the optical component 100 to reach the object to be measured. At this time, since the light is easily reflected from the substrate 14 to the surrounding medium (usually air), which is a transition from a denser medium to a less dense medium, it is easy to cause reflection. Some reflected light will be reflected back into the interior of the optical component 100 (the side where the substrate 14 is located). After the reflected light passes through the anti-reflection film 20 provided on the first side 101 of the optical component 100, the anti-reflection film 20 can prevent the reflected light from being reflected again in a direction away from the first side 101, thereby preventing the reflected light from being emitted to the outside at a position different from the previous exit position after the second reflection, thereby reducing the generation of stray light.

[0042] See also Figure 8 When the substrate 14 includes a first layer 141 and a second layer 142, and the microstructures 13 are located in the sealed cavity 143 between the first and second layers 141, in some embodiments, an anti-reflection film 20 may also be provided on the side of the second layer 142 facing away from the first layer 141. That is, the anti-reflection film 20 may be provided on both the side of the first layer 141 facing away from the second layer 142 and the side of the second layer 142 facing away from the first layer 141. Because the anti-reflection film 20 provided on the first layer 141 can prevent reflection of light emitted from the first side 101 of the diffractive optical element 10, even if a small amount of light is reflected from the first side 101, the anti-reflection film 20 provided on the second layer 142 can prevent the reflected light from being re-reflected and emitted to the outside world at a different location from the original location. Compared to providing the anti-reflection film 20 only on one side of the diffractive optical element 10, this can further reduce stray light, thereby improving the accuracy of the depth camera 400 in detecting depth information of objects.

[0043] In some embodiments, the detection element 30 can be powered on to generate an electrical signal. When the light emitting module 200 using the optical component 100 is working, it can be judged whether there is an abnormality in the diffraction optical element 10 (for example, the diffraction optical element 10 is broken, tilted or fallen off) based on the electrical signal of the detection element 30. In this way, it is possible to promptly detect whether there is an abnormality in the diffraction optical element 10 to avoid the light emitted by the light source 201 in the light emitting module 200 directly passing through the abnormal diffraction optical element 10 and entering the human eye, thereby improving the safety of users using the optical module.

[0044] For example, see Figure 2In some embodiments, the detection element 30 includes an input terminal 31, an output terminal 32, and a conductive portion 33. The conductive portion 33 connects the input terminal 31 and the output terminal 32. The input terminal 31 and the output terminal 32 are electrically connected to an external circuit, so that the detection element 30 and the external circuit are electrically connected to form a detection circuit. When the diffractive optical element 10 is abnormal, the detection circuit is disconnected. In this way, whether the diffractive optical element 10 is abnormal can be determined based on whether the detection circuit is disconnected.

[0045] Specifically, the input end 31 and the output end 32 are located on the same side of the second area 12, and the conductive portion 33 bends through the other side of the second area 12 to the side where the input end 31 or the output end 32 is located, and the conductive portion 33 on the other side includes two sections. Figure 2 As shown, the diffractive optical element 10 includes a first region 11 and a second region 12 surrounding the first region 11. The second region 12 includes a first side 121, a second side 122, a third side 123, and a fourth side 124, which are adjacent to each other in sequence. The output end 32 and the output end 32 are both disposed on the first side 121 of the second region 12. One end of the conductive portion 33 is connected to the input end 31, and the other end extends sequentially along the second side 122, the third side 123, and the fourth side 124. When the conductive portion 33 reaches the junction of the fourth side 124 and the first side 121, it bends back and extends sequentially along the fourth side 124, the third side 123, the second side 122, and the first side 121 until it connects to the output end 32. Thus, the sides without the output end 32, i.e., the second side 122, the third side 123, and the fourth side 124, each have two sections of the conductive portion 33. On the one hand, since the input end 31 and the output end 32 are located on the same side of the second area 12, this facilitates the electrical connection of the input end 31 and the output end 32 to the external circuit respectively, reducing the difficulty of wiring; on the other hand, since the conductive portion 33 on the other side has two sections, this can expand the coverage of the conductive portion 33 for detection, thereby being able to promptly detect whether the diffractive optical element 10 is abnormal.

[0046] It should be noted that in some embodiments, the conductive portion 33 may include conductive particles (not shown), which are disposed within the substrate 14. When the substrate 14 is intact, the conductive particles can electrically connect the input end 31 and the output end 32. Disposing the conductive portion 33 within the substrate 14, compared to disposing the conductive portion 33 directly on the surface of the substrate 14, can prevent the conductive portion 33 from being damaged by mechanical scratches or moisture, which could lead to a misjudgment of an abnormality in the diffractive optical element 10. This can thereby improve the accuracy of detection by the detection element 30.

[0047] See also Figure 4In some embodiments, at least one conductive layer 34 may be provided on the side of the input terminal 31 away from the diffractive optical element 10. This can increase the conductivity of the input terminal 31, thereby facilitating electrical connection between the input terminal 31 and an external circuit. Similarly, at least one conductive layer 34 may be provided on the side of the output terminal 32 away from the diffractive optical element 10. The conductive layer 34 may be made of chromium; or, the conductive layer 34 may be made of gold. For example, Figure 4 As shown, in some embodiments, two conductive layers 34 are provided at a layer away from the diffractive optical element 10 at the input end 31 and the output end 32 , wherein one conductive layer 34 is made of chromium and the other conductive layer 34 is made of gold.

[0048] In some embodiments, the detection element 30 further includes an insulating portion 35, which is disposed on the first side 101 of the diffractive optical element 10 and bends along with the bending shape of the conductive portion 33 to surround the conductive portion 33. This can insulate and protect the conductive portion 33. Figure 4 In some embodiments, an insulating portion 35 may be provided around the input terminal 31 and the output terminal 32 to provide insulation and protection for the input terminal 31 and the output terminal 32. In particular, when the conductive portion 33 includes conductive particles located within the substrate 14, the insulating portion 35 may be provided only around the input terminal 31 and the output terminal 32 to provide insulation and protection for the input terminal 31 and the output terminal 32. In some embodiments, the insulating portion 35 may be made of silicon dioxide.

[0049] It should be noted that, in some embodiments, among the input end 31, the output end 32, the conductive portion 33 and the insulating portion 35, the thickness of the insulating portion 35 is the largest. In this way, when the detection element 30 is arranged on the surface of the diffraction optical element 10, since the thickness of the insulating portion 35 is the largest, other devices in the light emitting module 200 can be prevented from directly contacting the detection element 30 and scratching the detection element 30, resulting in a misjudgment of an abnormality of the diffraction optical element 10, which is beneficial to improving the detection accuracy of the detection element 30.

[0050] See also Figure 9 The present application also provides a light emitting module 200. Light emitting module 200 includes a light source 201 and the optical assembly 100 described in any of the above embodiments. Optical assembly 100 is disposed in the light path of light source 201, so that light emitted by light source 201 can pass through optical assembly 100 and then be emitted outside of light emitting module 200.

[0051] The light emitting module 200 of the present application, by providing an anti-reflection film 20 and a detection element 30 on the diffractive optical element 10, can not only reduce the reflectivity of light and alleviate stray light interference, but also detect the diffractive optical element 10 through the detection element 30, thereby preventing users from using abnormal diffractive optical elements 10, thereby improving user safety when using the light emitting module 200. In addition, because the anti-reflection film 20 is located in the first zone 11 at the center of the diffractive optical element 10, and the detection element 30 is located in the second zone 12 at the edge of the diffractive optical element 10, that is, the detection element 30 is not provided in the central area of the diffractive optical element 10, the majority of light is emitted after passing through the anti-reflection film 20, which further helps to reduce stray light interference.

[0052] Specifically, in some embodiments, the first side 101 of the diffractive optical element 10 is provided with an anti-reflection film 20, and the first side 101 of the diffractive optical element 10 faces away from the light source 201. Light emitted by the light source 201 passes through the diffractive optical element 10 and then the anti-reflection film 20 before being emitted from the optical assembly 100 to the outside of the optical assembly 100. At this time, since the light is easily reflected from the substrate 14 to the medium outside the diffractive optical element 10 (typically air), which is a transition from a denser medium to a less dense medium, this is prone to reflection. Therefore, in this embodiment, the anti-reflection film 20 is provided on the side facing away from the light source 201 to reduce the reflectivity of the light, thereby preventing light from being reflected back into the optical assembly 100 and reducing the generation of stray light.

[0053] Of course, in some embodiments, the first side 101 of the diffractive optical element 10 is provided with an anti-reflection film 20, and the first side 101 of the diffractive optical element 10 may also face the light source 201. Light emitted by the light source 201 passes through the anti-reflection film 20, enters the diffractive optical element 10, and then exits the optical assembly 100. At this time, since the medium (typically air) outside the diffractive optical element 10 transitions from a denser medium to a less dense medium, light is prone to reflection. Some reflected light will be reflected back into the optical assembly 100. After passing through the anti-reflection film 20 provided on the first side 101 of the optical assembly 100, the anti-reflection film 20 prevents the reflected light from being reflected again into the optical assembly 100, thereby preventing the reflected light from being emitted to the outside at a different location after secondary reflection, thereby reducing the generation of stray light.

[0054] Specifically, see Figure 7 and Figure 10 In some embodiments, the thickness of the anti-reflection film 20 is one quarter of the wavelength of the light emitted by the light source 201. This helps to further reduce the reflectivity of the light, thereby improving the quality of the light emitted by the light emitting module 200. For example, the wavelength of the light emitted by the light source 201 is , the thickness of the anti-reflection film 20 is one quarter of the wavelength of the light, that is, the thickness of the anti-reflection film 20 is .

[0055] See also Figure 9 The present application also provides a depth camera 400. The depth camera 400 includes a light receiving module 300 and a light emitting module 200 as described in any of the above embodiments. The light emitting module 200 is configured to emit light, and the light receiving module 300 is configured to receive at least a portion of the light reflected by an object and generate an electrical signal. The depth camera 400 obtains depth information of the object based on the electrical signal generated by the light receiving module 300.

[0056] In the present application, the depth camera 400 is provided with an anti-reflection film 20 and a detection element 30 on the diffractive optical element 10. This not only reduces the reflectivity of light and reduces stray light interference, but also allows the detection element 30 to detect the diffractive optical element 10, thereby preventing users from using abnormal diffractive optical elements 10, thereby improving the safety of users using the depth camera 400. In addition, because the anti-reflection film 20 is located in the first zone 11 at the center of the diffractive optical element 10, and the detection element 30 is located in the second zone 12 at the edge of the diffractive optical element 10, that is, the detection element 30 is not provided in the central area of the diffractive optical element 10, most of the light can be emitted after passing through the anti-reflection film 20, which helps to further reduce stray light interference.

[0057] See also Figure 11 The present application also provides an electronic device 1000. The electronic device 1000 includes a housing 500 and a depth camera 400 as described in any of the above embodiments, wherein the depth camera 400 is combined with the housing 500. It should be noted that the terminal can be a mobile phone, a computer, a tablet computer, a smart watch, a smart wearable device, etc., and is not limited here.

[0058] The electronic device 1000 of the present application, by providing an antireflection film 20 and a detection element 30 on a diffractive optical element 10, can detect whether the diffractive optical element 10 is abnormal through the detection element 30, and can also reduce the reflectivity of light, thereby reducing stray light interference. In addition, the antireflection film 20 is located in the first zone 11 at the center of the diffractive optical element 10, and the detection element 30 is located in the second zone 12 at the edge of the diffractive optical element 10. This allows most light to pass through the antireflection film 20 before exiting, which further helps to reduce stray light interference.

[0059] Throughout this specification, reference to the terms "certain embodiments," "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0060] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "plurality" means at least two, for example, two or three, unless otherwise specifically defined.

[0061] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are illustrative and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application. The scope of the present application is defined by the claims and their equivalents.

Claims

1. An optical component, characterized in that: include: A diffractive optical element having a first region and a second region surrounding the first region, the diffractive optical element comprising a substrate and microstructures provided on the substrate, the microstructures being present in the second region, and the number of the microstructures in the first region being greater than the number of the microstructures in the second region; an anti-reflection film located on the first region of the diffractive optical element, the anti-reflection film being used to reduce the reflectivity of light received by the diffractive optical element in the first region; and The detection element is used to detect the diffractive optical element and is located in the second area of the diffractive optical element. The anti-reflection film and the detection element are located on the same surface of the substrate, and the microstructure is located on the side opposite to the anti-reflection film and the detection element.

2. The optical component according to claim 1, wherein The diffraction optical element includes a substrate and a microstructure, the substrate includes a first layer and a second layer, the microstructure is located in a sealed cavity formed by the first layer and the second layer, the anti-reflection film is arranged on the side of the first layer away from the second layer; the detection element is arranged on the side of the first layer away from the second layer.

3. The optical component according to claim 1, wherein The diffraction optical element includes a substrate and a microstructure, the substrate includes a first layer and a second layer, the microstructure is located in a sealed cavity formed by the first layer and the second layer, the anti-reflection film is arranged on the side of the first layer away from the second layer; the detection element is arranged on the side of the second layer away from the first layer.

4. The optical component according to claim 2 or 3, characterized in that The anti-reflection film is located on a side of the second layer away from the first layer.

5. The optical component according to any one of claims 1 to 3, characterized in that The diffractive optical element is placed in an ambient medium, wherein the substrate has a first refractive index, the ambient medium has a second refractive index, and the refractive index of the anti-reflection film is related to the first refractive index and the second refractive index.

6. The optical component according to claim 5, wherein: The refractive index of the anti-reflection film is a square root of a product of the first refractive index and the second refractive index.

7. The optical component according to claim 1, wherein The detection element includes an input end, an output end, and a conductive part connecting the input end and the output end. The input end and the output end are electrically connected to an external circuit respectively, so that the detection element is electrically connected to the external circuit to form a detection circuit. When the diffraction optical element is abnormal, the detection circuit is disconnected.

8. A light emitting module, characterized in that: include: a light source, the light source being used to emit light; and The optical component according to any one of claims 1 to 7, wherein the optical component is arranged on a light output path of the light source.

9. The light emitting module according to claim 8, wherein: The first side of the diffractive optical element is provided with the anti-reflection film, The first side of the diffractive optical element faces away from the light source; or A first side of the diffractive optical element faces the light source.

10. The light emitting module according to claim 8, wherein: The thickness of the anti-reflection film is one quarter of the wavelength of the light.

11. A depth camera, characterized in that include: The light emitting module according to any one of claims 8 to 10, used for emitting light; and The light receiving module is used to receive at least part of the light reflected by the object and convert it into an electrical signal.

12. An electronic device, characterized in that: include: case; and The depth camera of claim 11, wherein the housing is combined with the depth camera.

Images