Active alignment system and alignment method thereof, point floodlight projection module and depth camera

Abstract

The application provides an active alignment system and an alignment method thereof, a point-flood projection module and a depth camera. The active alignment system comprises a motion adjustment assembly, a first camera and a controller. The motion adjustment assembly is used to move a light emitting assembly and / or a light modulation assembly, so that the optical center of the light modulation assembly corresponds to the optical axis of a first light source before a first alignment stage, and the light emitting assembly and the light modulation assembly are located at a preset position before a second alignment stage. The first camera is used to collect a first speckle pattern in the first alignment stage and a second speckle pattern in the second alignment stage. The controller is used to control the motion adjustment assembly to move according to the first speckle pattern in the first alignment stage, and control the motion adjustment assembly to move according to the second speckle pattern in the second alignment stage. The application can realize alignment of the light emitting assembly and the light modulation assembly in the point-flood projection module, and has high efficiency and precision.

Description

[Technical Field]

[0001] This application relates to the field of depth camera technology, and in particular to an active alignment system and alignment method thereof, a point floodlight projection module and a depth camera. [Background Technology]

[0002] Structured light depth cameras typically include a speckle projection module, a floodlight projection module, and a receiving module. The speckle projection module projects a speckle beam onto the target object, the floodlight projection module projects a floodlight beam onto the target object, and the receiving module acquires the speckle beam to obtain a depth image of the target object and the floodlight beam to obtain an infrared image of the target object. The speckle projection module typically includes a light source, a collimating element, and a diffractive optical element. The light source generates the beam, which passes sequentially through the collimating element and the diffractive optical element before being projected onto the target object, with the optical axis of the light source corresponding to the optical center of the collimating element; the same applies to the floodlight projection module.

[0003] To reduce the size of depth cameras, Chinese Patent Application No. 201810036240.5 provides an illumination module, and Chinese Patent Application No. 202210433022.1 provides a multi-functional illumination module. These two patents propose a technical solution that integrates a speckle projection module and a floodlight projection module into a single module to obtain a point floodlight projection module.

[0004] A typical point floodlight projection module includes a first light source, a second light source, a collimating element, and a diffractive optical element. For example, in a point floodlight projection module provided in Chinese Patent Application No. 202222184650.9, the first and second light sources are respectively distributed on opposite sides of the optical center of the collimating element. That is, the optical axes of the first and second light sources do not correspond to the optical center of the collimating element. Taking the first light source as an example, the emitted first beam is incident off-axis onto the collimating element. After passing through the collimating element, the optical axis of the first beam will have a certain angle with the optical axis of the collimating element. As a result, the first beam is incident obliquely onto the diffractive optical element, causing the speckle pattern projected by the diffractive optical element to shift to one side and the speckle distribution to be different from that of a normal speckle projection module. This makes the active alignment scheme in the original speckle projection module / floodlight projection module manufacturing process unsuitable for point floodlight projection modules. [Summary of the Invention]

[0005] This application provides an active alignment system and alignment method thereof, a point floodlight projection module and a depth camera, aiming to solve the problem of how to actively align the point floodlight projection module.

[0006] To address the aforementioned technical problems, a first aspect of this application provides an active alignment system for actively aligning a point floodlight projection module. The point floodlight projection module includes a light emitting component and a light modulation component. The light emitting component includes a first light source and a second light source, with the optical axes of the first and second light sources located on opposite sides of the optical center of the light modulation component. The active alignment system includes a motion adjustment component, a first camera, and a controller. The motion adjustment component is used to move the light emitting component and / or the light modulation component, aligning the optical center of the light modulation component with the optical axis of the first light source before a first alignment stage, and positioning the light emitting component and the light modulation component at preset positions before a second alignment stage. The first camera is used to acquire a first speckle pattern generated by the first light source during the first alignment stage and a second speckle pattern generated by the first light source during the second alignment stage. The controller is used to control the movement of the motion adjustment component according to the first speckle pattern during the first alignment stage, so that the first speckle pattern meets a first preset specification; and to control the movement of the motion adjustment component according to the second speckle pattern during the second alignment stage, so that the second speckle pattern conforms to a second preset specification.

[0007] A second aspect of this application provides an active alignment method for actively aligning a point floodlight projection module. The active alignment method includes: moving a light emitting component and / or a light modulation component so that the optical center of the light modulation component corresponds to a first light source; controlling the first light source to emit light to generate a first speckle pattern; moving the light emitting component and / or the light modulation component according to the first speckle pattern so that the first speckle pattern conforms to a first preset specification; moving the light emitting component and / or the light modulation component so that the light emitting component and the light modulation component are located at preset positions; controlling the first light source to emit light to generate a second speckle pattern; and moving the light emitting component and / or the light modulation component according to the second speckle pattern so that the second speckle pattern conforms to a second preset specification.

[0008] A third aspect of this application provides a point floodlight projection module, including a light emitting component and a light modulation component. The light emitting component includes a first light source and a second light source, with the optical axes of the first and second light sources located on opposite sides of the optical center of the light modulation component. The beam emission surface of the first light source is lower than that of the second light source. The light modulation component is used to modulate the beam emitted by the first or second light source. In some embodiments, the light emitting component and the light modulation component are actively aligned using the active alignment system described in the first aspect of this application. In some embodiments, the light emitting component and the light modulation component are actively aligned using the active alignment method described in the second aspect of this application.

[0009] A fourth aspect of this application provides a depth camera, including a point floodlight projection module and a acquisition module as described in the third aspect of this application. The point floodlight projection module is used to project a speckle beam onto a target area in speckle mode and to project a floodlight beam onto the target area in floodlight mode. The acquisition module is used to acquire the speckle beam reflected back from the target area and the floodlight beam reflected back from the target area.

[0010] As can be seen from the above description, compared with related technologies, the beneficial effects of this application are as follows:

[0011] First, the light emitting component and / or light modulation component are moved so that the optical axis of the first light source aligns with the optical center of the light modulation component. Then, the first light source is controlled to emit light and project a first speckle pattern. Based on the first speckle pattern, the light emitting component and / or light modulation component are moved to make the first speckle pattern conform to a first preset specification. Next, the light emitting component and / or light modulation component are moved to a preset position, and the first light source is controlled to emit light and project a second speckle pattern. Based on the second speckle pattern, the light emitting component and / or light modulation component are moved to make the second speckle pattern conform to a second preset specification. This achieves active alignment of the light emitting component and light modulation component. Furthermore, because the first alignment stage is performed by aligning the optical axis of the first light source with the optical center of the light modulation component, and then the components are moved to a preset position for the second alignment stage, the alignment efficiency and accuracy are high. [Attached Image Description]

[0012] To more clearly illustrate the related technologies or the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the related technologies or the embodiments of this application will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application, and not all embodiments. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of the structure of a depth camera provided in an embodiment of this application;

[0014] Figure 2 This is a schematic diagram of the structure of the point floodlight projection module provided in the embodiments of this application;

[0015] Figure 3 This is a schematic diagram of the active alignment system provided in an embodiment of this application;

[0016] Figure 4 This is a flowchart illustrating the active alignment method provided in an embodiment of this application.

Detailed Implementation Methods

[0017] To make the objectives, technical solutions, and advantages of this application more apparent and understandable, the application will be clearly and completely described below in conjunction with the embodiments and corresponding drawings. Throughout, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. It should be understood that the various embodiments of this application described below are merely illustrative and not intended to limit the application. That is, all other embodiments obtained by those skilled in the art based on the various embodiments of this application without creative effort are within the scope of protection of this application. Furthermore, the technical features involved in the various embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0018] Figure 1 This is a schematic diagram of the structure of a depth camera provided in an embodiment of this application. The depth camera includes a point floodlight projection module 1 and a data acquisition module 2. The point floodlight projection module 1 is used to project a speckle beam onto the target area in speckle mode and a floodlight beam onto the target area in floodlight mode. The data acquisition module 2 is used to acquire the speckle beam reflected back from the target area to generate a speckle image and to acquire the floodlight beam reflected back from the target area to generate an infrared image. A depth image can be further obtained from the speckle image. Combining the depth image and the infrared image can enable applications such as face recognition, 3D reconstruction, pose recognition, and gesture recognition.

[0019] In some embodiments, the depth camera may further include a controller and processor 3, which is connected to the point floodlight projection module 1 and the acquisition module 2, respectively. The controller and processor 3 is used to control the point floodlight projection module 1 and the acquisition module 2. The controller and processor 3 is also used to receive a speckle image and calculate a depth image based on the speckle image. Specifically, it performs matching calculations between the speckle image and a preset reference speckle image to obtain the deviation value of a pixel in the current speckle image relative to the corresponding pixel in the reference speckle image. Based on the deviation value, the depth value can be calculated, and the depth values ​​of multiple pixels constitute the depth image. In other embodiments, the depth camera may not include a controller and processor 3, and the depth image may be generated by an external device or cloud platform based on the speckle image.

[0020] Figure 2This is a schematic diagram of the structure of a point floodlight projection module provided in an embodiment of this application. The point floodlight projection module 1 includes a light emitting component 10 and a light modulation component 20 disposed on the optical path of the light emitting component 10. The light emitting component 10 includes a first light source 11 and a second light source 12. The optical axes of the first light source 11 and the second light source 12 are located on opposite sides of the optical center of the light modulation component 20, and the beam emitting surface of the first light source 11 is lower than that of the second light source 12. The light modulation component 20 is used to modulate the beam emitted by the first light source 11 or the second light source 12. Specifically, in speckle mode, the first light source 11 is turned on, and the point floodlight projection module projects a speckle light field; in floodlight mode, the second light source 12 is turned on, and the point floodlight projection module projects a floodlight light field. In manufacturing the point floodlight projection module, it can be achieved through methods such as... Figure 3 The active alignment system shown aligns the light emitting component 10 and the light modulation component 20.

[0021] In this embodiment, the beam emitting surface of the first light source 11 is lower than that of the second light source 12, meaning there is a height difference between the first light source 11 and the second light source 12. The first light source 11 is farther from the optical modulation assembly 20 than the second light source 12. For example, the beam emitting surface of the first light source 11 is located at the back focal point of the optical modulation assembly 20, so it projects speckle light after passing through the optical modulation assembly 20. Since the beam emitting surface height of the second light source 12 is different from that of the first light source 11, the beam emitted by the second light source 12 will be out of focus and become floodlight when passing through the optical modulation assembly 20. Furthermore, both the first light source 11 and the second light source 12 can be a series of active optical devices capable of emitting infrared or other wavelengths, such as VCSEL (Vertical-Cavity Surface-Emitting Laser), EEL (Edge Emitting Laser), and LED (Light-Emitting Diode).

[0022] Furthermore, the light emitting assembly 10 also includes a circuit board 13 and a control circuit (not shown in the figure) disposed on the circuit board 13. The circuit board 13 has a target side A close to the light modulation assembly 20. The first light source 11, the second light source 12 and the control circuit are all disposed on the target side A, and the first light source 11 and the second light source 12 are spaced apart from each other.

[0023] As one implementation method, please refer to Figure 2A mounting platform 14 extending toward the light modulation assembly 20 is formed on the target side A. In this case, the first light source 11 is located at a position where the mounting platform 14 is not formed on the target side A, and the second light source 12 is mounted on the mounting platform 14 to ensure that the beam emission surface of the first light source 11 is lower than that of the second light source 12. In this embodiment, the mounting platform 14 can be configured to telescopically engage with the circuit board 13. This design allows for height adjustment of the beam emission surface of the second light source 12 by telescopically extending the mounting platform 14.

[0024] As another implementation method, analogy Figure 2 A first mounting platform and a second mounting platform (equivalent to mounting platform 14 in the aforementioned embodiment) extending towards the light modulation component 20 and spaced apart from each other are formed on the target side A. In this case, the first light source 11 is disposed on the first mounting platform, the second light source 12 is disposed on the second mounting platform, and the height of the first mounting platform is lower than that of the second mounting platform, so as to ensure that the beam emission surface of the first light source 11 is lower than that of the second light source 12.

[0025] As another implementation method, it is still analogous to Figure 2 On the target side A, there are a first mounting platform and a second mounting platform (similar to mounting platform 14 in the aforementioned embodiment) that are spaced apart from each other and both telescopically cooperate with the circuit board 13. In this case, the first light source 11 is mounted on the first mounting platform, and the second light source 12 is mounted on the second mounting platform. In this embodiment, the height of the beam emitting surface of the first light source 11 and / or the second light source 12 can be adjusted by telescopically extending and retracting the first mounting platform and / or the second mounting platform. During the adjustment process, it is necessary to ensure that the beam emitting surface of the first light source 11 is lower than that of the second light source 12.

[0026] It should be noted that the above three implementation methods are only preferred implementations of the embodiments of this application, and are not the only limitation on the height adjustment method of the beam emitting surface of the first light source 11 and / or the second light source 12 in the embodiments of this application; those skilled in the art can make flexible settings based on the embodiments of this application and according to the actual application scenario.

[0027] As one implementation method, please refer to Figure 2 The optical modulation assembly 20 includes a support frame 21, a collimating element 22, and a diffractive optical element 23. The collimating element 22 and the diffractive optical element 23 are both mounted on the target side A of the circuit board 13 via the support frame 21, and the collimating element 22 is located between the diffractive optical element 23 and the first light source 11 and the second light source 12.

[0028] Specifically, the light beam emitted by the first light source 11 is first collimated by the collimating element 22, and then modulated by the diffractive optical element 23, ultimately forming a corresponding speckle light field on the target area. Similarly, the light beam emitted by the second light source 12 is first collimated by the collimating element 22, and then modulated by the diffractive optical element 23, ultimately forming a corresponding floodlight light field on the target area. In practical applications, since the first light source 11 and the second light source 12 are located on opposite sides of the optical center of the collimating element 22, and the distances between the first light source 11 and the second light source 12 and the collimating element 22 are different, the floodlight projection module generates a speckle light field when the first light source 11 emits light, while the floodlight projection module generates a floodlight light field when the second light source 12 emits light.

[0029] In this embodiment, collimating element 22 generally refers to a series of devices that can adjust the beam divergence angle, such as traditional optical lenses and collimating lenses; diffractive optical element 23 can be a DOE (Diffractive Optical Elements). Furthermore, collimating element 22 and diffractive optical element 23 are not limited to separate forms. In other embodiments, collimating element 22 and diffractive optical element 23 can be integrated into a single element using the principle of phase superposition. All of the above descriptions can be reasonably selected according to the actual application scenario, and this embodiment does not impose a unique limitation on them.

[0030] It can be observed that the optical axes of the first light source 11 and the second light source 12 in the aforementioned spot floodlight projection module 1 are misaligned with the optical center of the light modulation component 20. Therefore, the active alignment scheme used in the manufacturing process of the original speckle projection module or floodlight projection module is no longer applicable to the aforementioned spot floodlight projection module. To address this, this application embodiment also provides an active alignment system, which is actually used to actively align the light emitting component 10 and the light modulation component 20 during the manufacturing process of the spot floodlight projection module.

[0031] Figure 3 This is a schematic diagram of the framework of an active alignment system provided in an embodiment of this application. The active alignment system includes a first camera 100, a motion adjustment component 200, and a controller 300. The controller 300 is connected to both the first camera 100 and the motion adjustment component 200, and can control both the first camera 100 and the motion adjustment component 200. For example, the controller 300 can transmit specific movement commands to the motion adjustment component 200, and the motion adjustment component 200 can then move according to the movement commands. The controller 300 can also transmit image acquisition commands to the first camera 100, and when the first camera 100 receives the image acquisition command, it acquires images (e.g., a first speckle pattern and a second speckle pattern) and transmits the acquired images to the controller 300.

[0032] The motion adjustment component 200 is used to move the light emitting component 10 and / or the light modulation component 20. Upon receiving a movement command from the controller 300, the motion adjustment component 200 can correspondingly move the light emitting component 10 and / or the light modulation component 20. For example, moving the light emitting component 10 and / or the light modulation component 20 so that the optical center of the light modulation component aligns with the optical axis of the first light source, facilitating subsequent alignment in the first alignment stage; or, for another example, moving the light emitting component 10 and / or the light modulation component 20 so that they are located at a preset position, facilitating subsequent alignment in the second alignment stage. The motion adjustment component 200 can move the light emitting component 10 or the light modulation component 20, or it can move both the light emitting component 10 and the light modulation component 20. For example, the motion adjustment component 200 includes a first moving member 210 and a second moving member 220. The first moving member 210 is used to move the light emitting component 10, and the second moving member 220 is used to move the light modulation component 20. The motion adjustment component 200 can be a robot, a motion platform, a fixture, etc., and there are no restrictions here. The movement includes translation and rotation.

[0033] The first camera 100 is used to capture the speckle or floodlight generated by the point floodlight projection module 1 during the active alignment process. Specifically, the first camera 100 is used to capture the first speckle pattern generated by the first light source 11 emitting light during the first alignment stage, and the second speckle pattern generated by the first light source 11 emitting light during the second alignment stage. It can be understood that the first camera 100 can capture the light beams emitted by the first light source 11 and the second light source 12.

[0034] The controller 300 is configured to: during the first alignment stage, control the movement of the motion adjustment component 200 according to the first speckle pattern to make the first speckle pattern meet a first preset specification; and during the second alignment stage, control the movement of the motion adjustment component 200 according to the second speckle pattern to make the second speckle pattern meet a second preset specification. It is understood that the active alignment of the light emitting component 10 and the light modulating component 20 mainly includes a first alignment stage and a second alignment stage. To enable the motion adjustment component 200 to accurately move the light emitting component 10 and / or the light modulating component 20, the controller 300 is further configured to: before the first alignment stage, send a first movement command to the motion adjustment component 200; and before the second alignment stage, send a second movement command to the motion adjustment component 200.

[0035] In some embodiments, the active alignment system further includes a second camera 400 connected to the controller 200. When active alignment begins, the controller 300 sends a positioning command to the second camera 400, which then images the light emitting component 10 and / or the light modulation component 20 to acquire a positioning image. Specifically, the controller 300 can be used to: determine the initial relative position between the light emitting component 10 and the light modulation component 20 based on the positioning image; obtain the specific position of the first light source 11 within the light emitting component 10; calculate the coordinate difference between the optical axis of the first light source 11 and the optical center of the light modulation component 20 based on the initial relative position and the specific position; generate a first movement command based on the coordinate difference and send the first movement command to the motion adjustment component 200, which can then move the light emitting component 10 and / or the light modulation component 20 according to the first movement command. The specific location refers to the actual position of the first light source 11 in the light emitting component 10 in the design drawing of the point floodlight projection module 1. The optical center of the light modulation component 20 corresponds to the optical axis of the first light source 11, which means that the optical center of the light modulation component 20 is located on the optical axis of the first light source 11 or the deviation is less than the threshold, and the light modulation component 20 is located in the optical path of the first light source 11.

[0036] In one embodiment, the relative position between the light modulation component 20 and the second camera 400 remains fixed. Only the current relative position of the light emitting component 10 and the second camera 400 needs to be determined, and then combined with the fixed relative position to obtain the initial relative position between the light emitting component 10 and the light modulation component 20. For example, multiple mark points (i.e., position identification points) are set within the light emitting component 10. Then, the second camera 400 acquires images of the light emitting component 10, and the controller 300 identifies these mark points to calculate the relative position between the light emitting component 10 and the second camera 400, thereby obtaining the initial relative position between the light emitting component 10 and the light modulation component 20.

[0037] Furthermore, the specific position of the first light source 11 in the light emitting component 10 can be obtained from the design drawings of the point floodlight projection module 1. Based on the specific position of the first light source 11 in the light emitting component 10 and the initial relative position of the light emitting component 10 and the light modulation component 20, the controller 300 can calculate the coordinate difference between the optical axis of the first light source 11 and the optical center of the light modulation component 20. Then, based on the coordinate difference, the specific moving direction and moving distance can be calculated to generate a first moving command. Subsequently, the motion adjustment component 200 executes the first moving command to move the light emitting component 10. After the movement is completed, the optical center of the light modulation component 20 corresponds to the optical axis of the first light source 11, so as to facilitate the smooth progress of the subsequent active alignment process.

[0038] After the optical center of the light modulation component 20 aligns with the optical axis of the first light source 11, the first alignment stage can be performed. Specifically, the controller 300 controls the first light source 11 to emit light, and the light beam emitted by the first light source 11 is modulated by the light modulation component 20 to project a first speckle pattern. In some embodiments, the active alignment system may include a plate 101, which may be located on the light-emitting side of the point floodlight projection module 1. The light beam emitted by the first light source 11 is modulated by the light modulation component 20 and projected onto the plate 101, generating a first speckle pattern on the plate 101. The controller 300 may control the first camera 100 to acquire the first speckle pattern on the plate 101, and then, based on the difference between the first speckle pattern and a first preset specification, control the motion adjustment component 200 to move the light emitting component 10 and / or the light modulation component 20 to make the first speckle pattern conform to the first preset specification.

[0039] More specifically, in the first alignment stage, the controller 300 is used to: (1) control the motion adjustment component 200 to translate the light emitting component 10 and / or the light modulation component 20 along the x-axis and / or y-axis of the spot floodlight projection module, so that the zero-order position of the first speckle pattern projected after the movement is at a first preset position; for example, the controller 300 can calculate the specific moving direction and moving distance of the light emitting component 10 and / or the light modulation component 20 according to the deviation between the zero-order position of the first speckle pattern and the first preset position, and then send it to the motion adjustment component 200 for execution. (2) control the motion adjustment component 200 to rotate the light emitting component 10 and / or the light modulation component 20 around the z-axis, so that there is no overlap between the speckles in the first speckle pattern projected after the movement; for example, the controller 300 can identify the overlapping speckles in the first speckle pattern, then calculate the rotation direction and angle around the z-axis, and then send it to the motion adjustment component 200 for execution. (3) The motion adjustment component 200 is controlled to translate the light emitting component 10 and / or the light modulation component 20 along the z-axis so that the clarity of the first speckle pattern projected after the movement meets the preset requirements. For example, the first speckle pattern and the preset speckle pattern can be compared to calculate the z-axis movement distance of the light emitting component 10 and / or the light modulation component 20, and then sent to the motion adjustment component 200 for execution. In this first alignment stage, when the light emitting component 10 and / or the light modulation component 20 are moved, the first light source 11 can be kept on, and the first camera 100 can acquire the first speckle pattern in real time to continuously calculate the movement direction and movement distance. Here, the x-axis refers to the line connecting the center of the first light source 11 and the center of the second light source 12, the y-axis is perpendicular to the x-axis in the horizontal plane, and the z-axis is the optical axis direction.

[0040] In one embodiment, in process (1), the motion adjustment component 200 translates the light emitting component 10 only along the x-axis and / or y-axis; in process (2), the motion adjustment component 200 rotates the light modulation component 20 only around the z-axis; and in process (3), the motion adjustment component 200 translates the light emitting component 10 only along the z-axis.

[0041] It is understood that in this embodiment, the first preset specification includes three different limitations on the first speckle pattern: the zero-order position of the speckle pattern is at a first preset position; there is no overlap between the speckles in the first speckle pattern; and the clarity of the first speckle pattern meets the preset requirements. Therefore, when the first speckle pattern simultaneously meets these three limitations, it conforms to the first preset specification. If, after moving the light emitting component 10 and / or the light modulation component 20, the first speckle pattern still cannot conform to the first preset specification, it can be considered that there is a problem with the light emitting component 10 or the light modulation component 20, and a new light emitting component 10 or light modulation component 20 can be selected for re-alignment.

[0042] Once the first speckle pattern of the projection meets the first preset specification, since the optical axis of the first light source 11 in the actual spot floodlight projection module 1 does not correspond to the optical center of the light modulation component 20, it is necessary to move the light emitting component 10 and / or the light modulation component 20 to place them in a preset position to facilitate alignment in the second alignment stage. The preset relative position can be understood as the actual position between the light emitting module 10 and the light modulation module 20 in the spot floodlight projection module, that is, the relative position between the light emitting module 10 and the light modulation module 20 is as follows: Figure 2 As shown. Specifically, the controller 300 can obtain the target deviation between the optical axis of the first light source 11 and the optical center of the light modulation component 20 in the point floodlight projection module 1, calculate the movement parameters of the light emitting component 10 and / or the light modulation component 20 based on the target deviation, generate a second movement command based on the movement parameters and send it to the motion adjustment component 200, and the motion adjustment component 200 executes the second movement command to move the light emitting component 10 and / or the light modulation component 20. The movement parameters specifically include the movement direction and the movement distance.

[0043] When the moved light emitting component 10 and light modulation component 20 are in a preset position, the second alignment stage begins. The controller 300 can control the first light source 11 to emit light; at this time, the light beam emitted by the first light source 11 (e.g., Figure 3 (As shown by the solid arrow pointing outwards) After being modulated by the light modulation component 20, it is projected onto the flat plate 101 to generate a second speckle pattern. The controller 300 can control the first camera 100 to acquire the second speckle pattern on the flat plate 101 and transmit it to the controller 300. The controller 300 can control the motion adjustment component 200 to move the light emitting component 10 and / or the light modulation component 20 according to the difference between the second speckle pattern and the second preset specification.

[0044] In some embodiments, during the second alignment stage, the controller 300 is specifically configured to: control the motion adjustment component 200 to translate the light emitting component 10 and / or the light modulation component 20 along the x-axis and / or y-axis of the dot-matrix switching module, so that the zero-order position of the speckle pattern projected after the movement is at a second preset position; and control the motion adjustment component 200 to translate the light emitting component 10 and / or the light modulation component 20 along the z-axis, so that the clarity of the second speckle pattern projected after the movement meets a preset requirement. When the second speckle pattern projected after the movement meets the second preset specification, it indicates that the second alignment stage has been completed between the light emitting component 10 and the light modulation component 20. During the second alignment stage, the first light source 11 can remain on, and the first camera 100 can acquire the second speckle pattern in real time. In one embodiment, during the second alignment stage, the light modulation component 20 is fixed, and the motion adjustment component 200 translates only the light emitting component 10 along the x-axis and / or y-axis, and only along the z-axis.

[0045] Since the constraint of "no overlap between speckles in the speckle pattern" has been achieved in the first alignment stage and the constraint of moving to the preset position will not change, it is not necessary to rotate the light emitting component 10 and / or the light modulation component 20 around the z-axis in the second alignment stage. This is because the first light source 11 is the defocused incident light modulation component 20 in the second alignment stage. If the light emitting component 10 and / or the light modulation component 20 are rotated around the z-axis, it will easily have a significant impact on the position and distribution of the speckles, which will require re-translation along the x-axis and y-axis. Therefore, in this embodiment, the absence of overlap between speckles in the speckle pattern is achieved through the first alignment stage, which can improve the efficiency and accuracy of active alignment.

[0046] It is understood that in this embodiment, the second preset specification includes two different restrictions on the second speckle pattern: the zero-order position of the second speckle pattern is at a second preset position; and the sharpness of the second speckle pattern meets preset requirements. Therefore, when the second speckle pattern simultaneously meets both restrictions, it conforms to the second preset specification. The second preset position differs from the first preset position and can be specifically obtained through simulation, experimentation, etc.

[0047] Furthermore, after the second alignment stage is completed, it is also necessary to verify whether the point floodlight projection module is a qualified product. Specifically, the controller 300 controls the second light source 12 to operate, and the beam generated by the second light source 12 (e.g., Figure 3(As indicated by the dashed arrow) After modulation by the light modulation component 20, the light can be projected onto the flat plate 101 to generate a floodlight field. The controller 300 controls the first camera 100 to capture the floodlight pattern on the flat plate 101. The first camera 100 transmits the floodlight pattern to the controller 300. The controller 300 can determine whether the point floodlight projection module is a qualified product based on the floodlight pattern, thus avoiding the production and shipment of unqualified point floodlight projection modules. Specifically, the controller 300 can determine whether the point floodlight projection module is a qualified product based on whether the size and position parameters of the floodlight pattern meet preset requirements. When the size and position parameters of the floodlight pattern meet the preset requirements, the point floodlight projection module is determined to be a qualified product; when the size and position parameters of the floodlight pattern do not meet the preset requirements, the point floodlight projection module is determined to be an unqualified product.

[0048] The active alignment system also includes a gripping component and a fixing component (not shown in the figure). When the spot floodlight projection module 1 is a qualified product, the controller 300 controls the fixing component to fix the light emitting component 10 and the light modulation component 20. When the spot floodlight projection module 1 is a defective product, the controller 300 controls the gripping component to grip the light emitting component 10 to the defective product area, and to re-grip a light emitting component 10 and the light modulation component 20 for active alignment until it is determined to be a qualified product, then it is fixed and placed in the qualified product area. The fixing component can be used to fix the light emitting component 10 and the light modulation component 20 by means of dispensing, welding, etc., and the gripping component can be a robotic arm or other device. When the floodlight field cannot meet the requirements, since the first and second speckle patterns in the early stage meet the requirements, it indicates that the light modulation component 20 is not the problem. Therefore, the problem lies in the assembly of the light emitting component 10 or the second light source 12 within the light emitting component 10. Therefore, a new light emitting component 10 can be replaced for realignment.

[0049] In some embodiments, such as Figure 3As shown, the active alignment system also includes an alignment stage 600, which is connected to the motion adjustment component 200 for placing the light emitting component 10 and can be electrically connected to the light emitting component 10 so that the controller 300 can control the light emitting component 10 to emit light. The motion adjustment component 200 moves the alignment stage 600, and the gripping component is used to grip the light emitting component 10 and / or the light modulation component 20. In one embodiment, when it is necessary to align the light emitting component 10 and the light modulation component 20, the light emitting component 10 can be first grasped onto the alignment stage 600 by the grasping component, and then the light modulation component 20 can be grasped above the light emitting component 10. Then, the positioning images of the light modulation component 10 and / or the light emitting component 20 can be acquired by the second camera 400 to obtain the initial relative position between the light modulation component 10 and the light emitting component 20. The controller 300 controls the first moving component 210 to move the alignment stage 600 and move the light emitting component 10, and the controller 300 controls the second moving component 220 to move the light modulation component 20, thereby realizing the alignment between the light emitting component 10 and the light modulation component 20.

[0050] As can be seen from the above, the embodiments of this application provide an active alignment system for manufacturing a point floodlight projection module 1. Through the cooperation between the first camera 100, the motion adjustment component 200, and the controller 300, active alignment of the light emitting component 10 and the light modulation component 20 in the point floodlight projection module 1 can be achieved. Furthermore, considering that the first light source 11 in the point floodlight projection module 1 is off-axis incident and the emitted speckle pattern is irregular, direct alignment is difficult and there are many variables during alignment, resulting in low alignment efficiency. Therefore, the active alignment system of this application first moves the first light source 11 to correspond to the optical center of the light modulation component 20. At this time, the first speckle pattern projected is relatively regular, and the alignment difficulty in the first alignment stage is relatively small. After determining some variables in the first alignment stage, it moves to a preset position for the second alignment stage. There are fewer variables in the second alignment stage, so the difficulty is also relatively small. Therefore, the active alignment system of this application has high alignment efficiency and accuracy.

[0051] To better understand the above-described active alignment system, this application also provides an active alignment method that applies the above-described active alignment system. Figure 4 This is a flowchart illustrating the active alignment method provided in an embodiment of this application, as shown below. Figure 4 As shown, the active alignment method includes steps 401 to 404.

[0052] Step 401: Move the light emitting component and / or the light modulation component so that the optical center of the light modulation component corresponds to the optical axis of the first light source.

[0053] In some embodiments, step 401 may include: acquiring a positioning image of the light emitting component 10 and / or the light modulation component 20, and determining the initial relative position between the light emitting component 10 and the light modulation component 20 based on the positioning image; acquiring the specific position of the first light source 11 in the light emitting component 10; calculating the coordinate difference between the optical axis of the first light source 11 and the optical center of the light modulation component 20 based on the initial relative position and the specific position; and moving the light emitting component 10 and / or the light modulation component 20 according to the coordinate difference. The positioning image may be acquired by the second camera 400 in the aforementioned active alignment system, and the acquisition command may be issued by the controller 300 to the second camera 400.

[0054] Step 402: Control the first light source to emit light to generate a first speckle pattern, and move the light emitting component and / or light modulation component according to the first speckle pattern to make the first speckle pattern conform to the first preset specification.

[0055] The first speckle pattern can be acquired by the first camera 100 in the active alignment system described above, and the acquisition command can be sent to the first camera 100 by the controller 300. In some embodiments, step 402 may specifically include: translating the light emitting component 10 and / or the light modulation component 20 along the x-axis and / or y-axis of the point flood illuminator 1, so that the zero-order position of the speckle pattern in the first speckle pattern is at a first preset position; rotating the light emitting component 10 and / or the light modulation component 20 around the z-axis of the point flood illuminator 1, so that there is no overlap between the speckles in the first speckle pattern; and translating the light emitting component 10 and / or the light modulation component 20 along the z-axis, so that the clarity of the first speckle pattern meets the preset requirements. It can be understood that step 402 is the first alignment stage in the active alignment system described above.

[0056] Step 403: Move the light emitting component and / or the light modulation component to a preset position.

[0057] In some embodiments, step 403 may specifically include: obtaining the target deviation between the optical axis of the first light source 11 and the optical center of the light modulation component 20 in the point floodlight projection module 1; calculating the movement parameters of the light emitting component 10 and / or the light modulation component 20 based on the target deviation; and moving the light emitting component 10 and / or the light modulation component 20 based on the movement parameters.

[0058] Step 404: Control the first light source to emit light to obtain a second speckle pattern projected by the light modulation component, and move the light emitting component and / or the light modulation component according to the second speckle pattern so that the second speckle pattern conforms to the second preset specification.

[0059] The second speckle pattern can be acquired by the first camera 100 in the active alignment system described above, and the acquisition command can be sent to the first camera 100 by the controller 300. In some embodiments, step 404 may include: translating the light emitting component 10 and / or the light modulation component 20 along the x-axis and / or y-axis of the point floodlight projection module 1, so that the zero-order position of the speckle pattern in the second speckle pattern is at a second preset position; translating the light emitting component 10 and / or the light modulation component 20 along the z-axis of the point floodlight projection module 1, so that the clarity of the second speckle pattern meets a preset requirement. It can be understood that step 404 is the second alignment stage in the active alignment system described above.

[0060] In this embodiment, when the point floodlight projection module 1 meets the two conditions of "the first speckle pattern conforms to the first preset specification when the optical axis of the first light source 11 corresponds to the optical center of the light modulation component 20" and "the second speckle pattern conforms to the second preset specification when the relative position between the light emitting component 10 and the light modulation component 20 conforms to the design drawing", the active alignment process is basically completed. However, we also need to consider the floodlight projection effect of the point floodlight projection module 1. Only when the floodlight projection function of the point floodlight projection module is normal and the floodlight projection effect is good, do we consider the point floodlight projection module after steps 401 to 404 to be a qualified product. Otherwise, we consider the point floodlight projection module after steps 401 to 404 to be a defective product.

[0061] The active alignment method further includes the steps of: controlling the second light source 12 to emit light to generate floodlight and collecting the floodlight; and determining whether the point floodlight projection module 1 is a qualified product based on the collected floodlight. For example, when the light modulation component 20 cannot project a floodlight field after the second light source 12 is turned on, it is determined that the floodlight projection function of the point floodlight projection module 1 is abnormal, and the point floodlight projection module 1 is a defective product; when the floodlight field projected by the light modulation component 20 after the second light source 12 is turned on does not meet the preset requirements, it is determined that the floodlight projection effect of the point floodlight projection module 1 is poor, and the point floodlight projection module 1 is a defective product; when the floodlight field projected by the light modulation component 20 after the second light source 12 is turned on meets the preset requirements, the point floodlight projection module 1 is a qualified product.

[0062] In some embodiments, the active alignment method further includes: when the spot floodlight projection module 1 is a qualified product, fixing the light emitting component 10 and the light modulation component 20; when the spot floodlight projection module 1 is a defective product, grabbing the light emitting component 10 to the defective product area, and re-grabbing a light emitting component 10 and the light modulation component 20 for active alignment. The fixing action can be implemented by the fixing component in the above-mentioned active alignment system, and the fixing command can be issued by the controller 300; the grabbing action can be implemented by the grabbing component in the above-mentioned active alignment system, and the grabbing command can be issued by the controller 300.

[0063] As can be seen from the above, the active alignment method provided in this application embodiment can achieve alignment between the light emitting component 10 and the light modulation component 20 in the point floodlight projection module 1, and the alignment efficiency and alignment accuracy are both high.

[0064] It should be noted that the above embodiments are merely preferred implementations of the embodiments of this application, and are not the only limitation on the specific processes of steps 401, 402, 403, and 404; those skilled in the art can flexibly set them according to actual application scenarios based on the embodiments of this application. The above descriptions of the active alignment system and active alignment method each have their own emphasis. The relevant content in the active alignment system can be applied to the active alignment method, and the relevant content in the active alignment method can be applied to the active alignment system. The specific content of each step in the active alignment method can be found in the relevant descriptions in the above active alignment system, and no specific limitations are made here. The movement-related steps in the above active alignment method can be implemented by the motion adjustment component 200, the movement command can be issued to the motion adjustment component 200 by the controller 300, and the specific movement parameters in the movement command can be calculated by the controller 300.

[0065] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0066] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. A computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk).

[0067] It should be noted that the various embodiments in this application are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For product-related embodiments, since they are similar to method-related embodiments, the descriptions are relatively simple, and relevant parts can be referred to the descriptions of the method-related embodiments.

[0068] It should also be noted that, in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0069] The above description of the disclosed embodiments enables those skilled in the art to implement or use the content of this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined in this application may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An active alignment system, characterized in that, This is used for active alignment of a point floodlight projection module, which includes a light emitting component and a light modulation component. The light emitting component includes a first light source and a second light source, and the optical axes of the first light source and the second light source are located on opposite sides of the optical center of the light modulation component. The active alignment system includes: A motion adjustment component is used to move the light emitting component and / or the light modulation component, so that the optical center of the light modulation component corresponds to the optical axis of the first light source before the first alignment stage, and so that the light emitting component and the light modulation component are located at a preset position before the second alignment stage. A first camera is used to acquire a first speckle pattern generated by the first light source emitting light during the first alignment stage, and to acquire a second speckle pattern generated by the first light source emitting light during the second alignment stage. The controller is configured to, during the first alignment stage, control the movement of the motion adjustment component based on the first speckle pattern to ensure that the first speckle pattern meets a first preset specification; during the second alignment stage, control the motion adjustment component to translate the light emitting component and / or the light modulation component along the x-axis and / or y-axis of the dot flood projection module to ensure that the speckle zero-order position of the second speckle pattern is at a second preset position; and control the motion adjustment component to translate the light emitting component and / or the light modulation component along the z-axis of the dot flood projection module to ensure that the clarity of the second speckle pattern meets a preset requirement; The first alignment stage includes: controlling the first light source to emit light to generate a first speckle pattern, and moving the light emitting component and / or the light modulation component according to the first speckle pattern to make the first speckle pattern conform to a first preset specification; the second alignment stage includes: controlling the first light source to emit light to generate a second speckle pattern, and controlling the motion adjustment component to translate the light emitting component and / or the light modulation component along the x-axis and / or y-axis of the point flood projection module to make the speckle zero-order position of the second speckle pattern at a second preset position; controlling the motion adjustment component to translate the light emitting component and / or the light modulation component along the z-axis of the point flood projection module to make the clarity of the second speckle pattern meet preset requirements.

2. The active alignment system as described in claim 1, characterized in that, The active alignment system further includes a second camera, which is used to acquire positioning images of the light emitting component and / or the light modulation component and transmit them to the controller; The controller is specifically used for: The initial relative position between the light emitting component and the light modulation component is determined based on the positioning image; Obtain the specific location of the first light source within the light emitting component; Based on the initial relative position and the specific position, calculate the coordinate difference between the optical axis of the first light source and the optical center of the light modulation component; A first movement command is generated based on the coordinate difference and sent to the motion adjustment component. The first movement command is used to align the optical center of the light modulation component with the optical axis of the first light source.

3. The active alignment system as described in claim 1, characterized in that, The controller is specifically used for: In the point floodlight projection module, the target deviation between the optical axis of the first light source and the optical center of the light modulation component is obtained; The movement parameters of the optical emitting component and / or the optical modulation component are calculated based on the target deviation; A second movement command is generated based on the movement parameters and sent to the motion adjustment component. The second movement command is used to position the light emitting component and the light modulation component at a preset position.

4. The active alignment system as described in claim 1, characterized in that, During the first alignment phase, the controller is specifically configured to: The motion adjustment component is controlled to translate the light emission component and / or the light modulation component along the x-axis and / or y-axis of the point floodlight projection module, so that the speckle zero-order position of the first speckle pattern is at a first preset position. Control the motion adjustment component to rotate the light emission component and / or the light modulation component around the z-axis of the point floodlight projection module so that there is no overlap between the speckles in the first speckle pattern; The motion adjustment component is controlled to translate the light emitting component and / or the light modulation component along the z-axis so that the clarity of the first speckle pattern meets the preset requirements.

5. The active alignment system as described in claim 1, characterized in that, When the second speckle pattern meets the second preset specifications, the controller is further used to control the second light source to emit light to generate floodlight, the first camera is further used to collect the floodlight, and the controller is further used to determine whether the point floodlight projection module is a qualified product based on the floodlight collected by the first camera.

6. The active alignment system as described in claim 5, characterized in that, The active alignment system also includes: A fixing component is used to fix the light emitting component and the light modulation component when the point floodlight projection module is a qualified product. The grasping component is used to grasp the light emitting component to the defective product area when the point floodlight projection module is defective, and to re-grab one of the light emitting components and actively align it with the light modulation component.

7. An active alignment method, characterized in that, This is used for active alignment of a point floodlight projection module, which includes a light emitting component and a light modulation component. The light emitting component includes a first light source and a second light source, and the optical axes of the first light source and the second light source are located on opposite sides of the optical center of the light modulation component. The active alignment method includes: Move the light emitting component and / or the light modulation component so that the optical center of the light modulation component corresponds to the optical axis of the first light source; The first light source is controlled to emit light to generate a first speckle pattern. The light emitting component and / or the light modulation component are moved according to the first speckle pattern so that the first speckle pattern conforms to a first preset specification. Move the light emitting component and / or the light modulation component to a preset position; The first light source is controlled to emit light to generate a second speckle pattern, and the motion adjustment component is controlled to translate the light emitting component and / or the light modulation component along the x-axis and / or y-axis of the point flood projection module so that the speckle zero-order position of the second speckle pattern is at a second preset position; the motion adjustment component is controlled to translate the light emitting component and / or the light modulation component along the z-axis of the point flood projection module so that the clarity of the second speckle pattern meets the preset requirements.

8. The active alignment method as described in claim 7, characterized in that, Moving the light emitting component and / or the light modulation component so that the optical center of the light modulation component corresponds to the optical axis of the first light source includes: Acquire positioning images of the optical emitting component and / or the optical modulation component, and determine the initial relative position between the optical emitting component and the optical modulation component based on the positioning images; Obtain the specific location of the first light source within the light emitting component; Based on the initial relative position and the specific position, calculate the coordinate difference between the optical axis of the first light source and the optical center of the light modulation component; Move the light emitting component and / or the light modulation component according to the coordinate difference, so that the optical center of the light modulation component corresponds to the optical axis of the first light source.

9. The active alignment method as described in claim 7, characterized in that, Moving the light emitting component and / or the light modulation component to position them at a preset location includes: In the point floodlight projection module, the target deviation between the optical axis of the first light source and the optical center of the light modulation component is obtained; The movement parameters of the optical emitting component and / or the optical modulation component are calculated based on the target deviation; The light emitting component and / or the light modulation component are moved according to the moving parameters so that the light emitting component and the light modulation component are located at a preset position.

10. The active alignment method as described in claim 7, characterized in that, The step of moving the light emitting component and / or the light modulation component according to the first speckle pattern to make the first speckle pattern conform to a first preset specification includes: Translate the light emitting component and / or the light modulation component along the x-axis and / or y-axis of the point floodlight projection module so that the zero-order position of the first speckle pattern is at a first preset position. Rotate the light emitting component and / or the light modulation component around the z-axis of the point floodlight projection module to make the speckles in the first speckle pattern non-overlapping; The light emitting component and / or the light modulation component are translated along the z-axis to make the clarity of the first speckle pattern meet the preset requirements.

11. The active alignment method as described in claim 7, characterized in that, After the second speckle pattern conforms to the second preset specification, the active alignment method further includes: The second light source is controlled to emit light to generate floodlight, and the floodlight is collected; The point floodlight projection module is judged to be a qualified product based on the collected floodlight data.

12. The active alignment method as described in claim 11, characterized in that, The active alignment method further includes: When the point floodlight projection module is a qualified product, fix the light emitting component and the light modulation component; When the point floodlight projection module is defective, the light emitting component is picked up and moved to the defective product area, and another light emitting component is picked up and actively aligned with the light modulation component.

13. A point floodlight projection module, characterized in that, include: A light emitting component includes a first light source and a second light source, wherein the beam emitting surface of the first light source is lower than that of the second light source; An optical modulation component, wherein the optical axes of the first light source and the second light source are located on opposite sides of the optical center of the optical modulation component, and the optical modulation component is used to modulate the light beam emitted by the first light source or the second light source; The optical emitting component and the optical modulation component are actively aligned by the active alignment system as described in any one of claims 1-6, or by the active alignment method as described in any one of claims 7-12.

14. A depth camera, characterized in that, include: The dot floodlight projection module as described in claim 13 is used to project a speckle beam onto a target area in speckle mode and to project a floodlight beam onto the target area in floodlight mode. The acquisition module is used to acquire the speckle beam reflected back from the target area and the floodlight beam reflected back from the target area.

Images