Control circuit for depth camera image acquisition module and depth camera
By designing a timing control module and control signals through hardware control, the problem of staggered activation of different projection lenses in the depth camera was solved, ensuring the stability and speed of depth measurement and AI recognition algorithms, and avoiding image frame confusion.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHENZHEN GUANGJIAN TECH CO LTD
- Filing Date
- 2026-01-14
- Publication Date
- 2026-04-10
AI Technical Summary
How to accurately and stably achieve staggered activation of different projection lenses in a depth camera to avoid confusion between floodlight image frames and structured light image frames, which would affect the operation of depth measurement and AI recognition algorithms.
The system employs a hardware control approach, using a timing control module and control signal design to ensure staggered operation of the floodlight projection lens and the structured light projection lens, preventing simultaneous light projection. It generates floodlight control signals using exposure signals and structured light status signals, enabling precise control of both lenses.
It achieves precise and stable staggered activation of different projection lenses, prevents image frame confusion, improves the operational stability and speed of depth measurement and AI recognition algorithms, and enhances the long-term stability of the algorithms.
Smart Images
Figure CN121842500A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of depth measurement, in particular to a control circuit for a depth camera image acquisition module and a depth camera. BACKGROUND
[0002] A depth camera is a special camera that can obtain the distance information of objects in a scene to the camera, and can measure the depth value of each pixel point to form a depth map. This technology is widely used in computer vision, robots, augmented reality, virtual reality, 3D scanning and other fields.
[0003] With the maturity of depth camera technology, the functions of depth cameras have gradually expanded. In addition to measuring the distance of target space objects through depth measurement algorithms, the types of target space objects can also be determined through artificial intelligence (AI) recognition algorithms. However, depth measurement algorithms and AI recognition algorithms require image frame data generated by different light sources for calculation, so different projection lenses are needed, and different projection lenses need to be opened in staggered peaks. How to accurately and stably realize the timing control of different projection lenses is a problem to be solved in the field of depth cameras. SUMMARY
[0004] The purpose of the present application is to provide a control circuit for a depth camera image acquisition module and a depth camera to solve the technical problem of how to accurately and stably realize the staggered peak opening of different projection lenses.
[0005] In order to achieve the above purpose, the present application provides the following technical solutions: The first aspect of the present application provides a control circuit for a depth camera image acquisition module, comprising: a main control module, the main control module is connected with a timing control module, a structured light control module, an interface and a reflected light receiving lens; a timing control module, configured to receive an exposure signal of the reflected light receiving lens and a structured light state signal from the main control module, and generate a floodlight control signal according to the exposure signal of the reflected light receiving lens and the structured light state signal; a floodlight control module, configured to receive the floodlight control signal from the timing control circuit, and control the floodlight projection lens according to the floodlight control signal; a structured light control module, configured to send a structured light state signal of the structured light projection lens to the main control module, and control the structured light projection lens according to the structured light control signal received from the main control module; The floodlight projection lens is used to emit floodlight to the target space; the structured light projection lens is used to emit structured light to the target space; the interface is used to transmit the reflection light signal generated by the structured light reflection light and the floodlight reflection light to the external processor according to the main control module; and the reflection light receiving lens is used to receive the structured light reflection light and the floodlight reflection light of the object in the target space and transmit the structured light reflection light and the floodlight reflection light to the main control module.
[0006] Further, the timing control module comprises: An exposure signal acquisition unit is configured to receive an exposure signal of the reflection light receiving lens; the exposure signal is used to represent whether the reflection light receiving lens is in an exposure state; when the reflection light receiving lens is in the exposure state, the exposure signal is high; and when the reflection light receiving lens is in a non-exposure state, the exposure signal is low. A state signal acquisition unit is configured to receive the structured light state signal; the structured light state signal is used to represent the working state of the structured light projection lens; when the structured light projection lens projects structured light, the structured light state signal is low. A control signal output unit is configured to generate a floodlight control signal; when the exposure signal and the structured light state signal are both high, the floodlight control signal is high; and when at least one of the exposure signal and the structured light state signal is low, the floodlight control signal is low. When the floodlight control signal is high, the floodlight control module controls the floodlight projection lens to emit floodlight to the target space.
[0007] Further, the timing control module comprises two diodes and one resistor, and the timing control module is designed by using discrete components or an integrated chip.
[0008] Further, the structured light control module is arranged adjacent to the structured light projection lens.
[0009] Further, the exposure signal adopts a timing design mode of a large cycle nested in a small cycle; the large cycle is determined by the frame rate of the depth camera, and the small cycle is greater than 0.8 milliseconds and less than 1.2 milliseconds. The small cycle is the time interval between adjacent exposure signals.
[0010] Further, the large cycle is a constant value, and the small cycle is a variable value.
[0011] Further, the number of small cycles in the large cycle is between 3 and 25.
[0012] Further, the duration of the exposure signal being high is less than the time of the small cycle.
[0013] Further, the floodlight control signal in each of the large periods includes a small period in which the floodlight control signal is high.
[0014] The second aspect of the present application provides a depth camera, comprising: a floodlight projection lens for emitting floodlight to a target space; a structured light projection lens for emitting structured light to the target space; a reflected light receiving lens for receiving structured light reflected light and floodlight reflected light of an object in the target space; a control circuit for controlling other elements in the depth camera and generating a reflected light signal according to the structured light reflected light and the floodlight reflected light, the control circuit having the structure of the control circuit for the depth camera image acquisition module as described in the first aspect; an interface for transmitting the reflected light signal to a processor; a processor for calculating depth information of the object in the target space by a structured light algorithm and a time-of-flight (ToF) algorithm respectively according to the received reflected light signal.
[0015] The present application has at least the following advantages or benefits: the embodiment designs a control circuit for a depth camera image acquisition module, solves the technical problem of how to accurately and stably enable different projection lenses to open staggeredly, and achieves the technical effects of preventing different projection lenses from projecting floodlight and structured light at the same time by using a hardware control method, and preventing the confusion of floodlight image frames and structured light image frames. In addition, compared with the software control method of projecting floodlight and structured light, the present application has faster speed and higher stability, thereby effectively improving the long-term stability of the operation of the depth measurement algorithm and the AI recognition algorithm. BRIEF DESCRIPTION OF DRAWINGS
[0016] In order to more clearly illustrate the technical solutions in the specific embodiments or prior art of the present application, the following will briefly introduce the drawings needed to be used in the specific embodiments or prior art description. Obviously, the drawings described below are some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without any creative effort.
[0017] Figure 1 FIG. 1 is a structural schematic diagram of a depth camera image acquisition module according to an embodiment of the present application; Figure 2A FIG. 2 is a schematic diagram of floodlight; Figure 2B FIG. 3 is a schematic diagram of speckle structured light; Figure 3 FIG. 4 is a structural schematic diagram of a timing control module; Figure 4AThis is an input / output timing diagram for a timing control module; Figure 4B for Figure 4A Enlarged view of region C in the middle; Figure 5 This is a schematic diagram of a depth camera.
[0018] Reference numerals: 10-Main control module; 20-Timing control module; 30-Floodlight control module; 40-Structured light control module; 50-Interface; 60-Reflected light receiving lens; 70-Floodlight projection lens; 80-Structured light projection lens; 21-Exposure signal acquisition unit; 22-Status signal acquisition unit; 23-Control signal output unit. Detailed Implementation
[0019] The technical solutions of this application will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0020] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0021] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0022] Furthermore, terms such as "horizontal" and "vertical" do not imply that the component must be absolutely horizontal or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," not that the structure must be completely horizontal, but can be slightly tilted. Similarly, terms such as "front," "back," "left," and "right" do not imply that the component must be absolutely front, back, left, or right, but can be slightly tilted.
[0023] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0024] Example 1 The control circuit for the depth camera image acquisition module provided in this application can realize the orderly control of the floodlight projection lens and the structured light projection lens on the depth camera image acquisition module. The hardware control method prevents the floodlight projection lens and the structured light projection lens from projecting floodlight and structured light at the same time, and prevents subsequent floodlight image frames from being confused with structured light image frames, which would affect the operation of the depth measurement algorithm and the AI recognition algorithm.
[0025] Figure 1 This is a schematic diagram of the structure of the depth camera image acquisition module described in Embodiment 1 of this application. Figure 1 As shown, the depth camera image acquisition module 1 includes: a main control module 10, a timing control module 20, a flood illuminator control module 30, a structured light control module 40, an interface 50, a reflected light receiving lens 60, a flood illuminator projection lens 70, and a structured light projection lens 80. The main control module 10, timing control module 20, flood illuminator control module 30, and structured light control module 40 constitute the control circuit of the depth camera image acquisition module 1; while the interface 50, reflected light receiving lens 60, flood illuminator projection lens 70, and structured light projection lens 80 are controlled by the control circuit to achieve their respective functions. The depth camera image acquisition module 1 described in this embodiment may also include other components to achieve more detailed functions, which are not listed here.
[0026] like Figure 1 As shown, the main control module 10 is connected to the timing control module 20, the structured light control module 40, the interface 50, and the reflected light receiving lens 60. The main control module 10 is the core control chip of the depth camera image acquisition module 1. It has functions such as drive output and image acquisition, and can coordinate the operation of the entire depth camera image acquisition module. It is the core module in the control circuit of the depth camera image acquisition module.
[0027] The floodlight projection lens 70 is used to project floodlight into the target space. Figure 2A This is a schematic diagram of floodlight, as shown below. Figure 2AAs shown, the floodlight can illuminate the target space more evenly, without obvious light and dark contrast. The floodlight projection lens can generate floodlight by combining a vertical-cavity surface-emitting laser (VCSEL) with an optical diffuser, or by using a light emitting diode (LED). In this application, an LED with a simpler structure is used as the floodlight projection lens.
[0028] The structured light projection lens 80 is used to emit structured light to the target space. There are many types of structured light, such as speckle structured light or stripe structured light, etc. Figure 2B The speckle structured light is a schematic diagram, which includes a plurality of irregularly distributed structured light spots, Figure 2B The speckle structured light is a schematic structure, and the number and shape of the light spots can be designed according to the situation. The structured light projection lens 80 can include lasers, conventional optical lens devices, diffractive optical devices, and metasurface optical devices, etc. The structured light projection lens 80 described in this application includes a VCSEL and a conventional optical lens device to reduce the volume of the structured light projection lens 80.
[0029] The reflected light receiving lens 60 is used to receive the structured light reflection and the floodlight reflection of the objects in the target space. After the floodlight projection lens 70 and the structured light projection lens 80 project the floodlight or the structured light to the target space, the objects in the target space will reflect the floodlight or the structured light. The reflected light receiving lens 60 can capture the structured light reflection or the floodlight reflection for subsequent processing.
[0030] Since there is no processor on the depth camera image acquisition module 1 to analyze and process the reflected light signal, it is necessary to transmit the structured light reflection and the floodlight reflection received by the reflected light receiving lens 60 to an external processor for processing, so as to obtain the distance and type of the objects in the target space through depth measurement algorithm and AI recognition algorithm. After the reflected light receiving lens 60 receives the structured light reflection and the floodlight reflection, it transmits the structured light reflection and the floodlight reflection to the main control module 10. The main control module 10 generates a reflected light signal according to the structured light reflection and the floodlight reflection, and transmits the reflected light signal to the interface 50, which is further transmitted to an external processor through the interface 50.
[0031] The control circuit for the depth camera image acquisition module comprises a floodlight control module 30 and a structured light control module 40. The floodlight control module 30 is used to receive a floodlight control signal from the timing control circuit 20 and control the floodlight projection lens 70 according to the floodlight control signal. The structured light control module 40 is used to send a structured light state signal of the structured light projection lens 80 to the master control module 10 and control the structured light projection lens 80 according to the structured light control signal received from the master control module 10. As shown in Figure 1 To turn on or off the floodlight projection lens 70, the corresponding floodlight control module 30 is provided, which is a circuit serving the floodlight projection lens 70 and used to control the floodlight projection lens 70 by changing the output level. Similarly, the structured light control module 40 is a circuit serving the structured light projection lens 80 and used to control the structured light projection lens 80 by changing the output level. The turning on of the floodlight projection lens 70 and the structured light projection lens 80 needs to consider the current state of the reflected light receiving lens 60, that is, the floodlight projection lens 70 and the structured light projection lens 80 are not always turned on, but are turned on when the reflected light receiving lens 60 receives the floodlight reflected light or the structured light reflected light. The simultaneous turning on of the projection lens and the receiving lens realizes the technical effect of energy saving. The turning on state of the reflected light receiving lens 60 is directly or indirectly transmitted to the floodlight control module 30 and the structured light control module 40 by the master control module 10.
[0032] The control circuit for the depth camera image acquisition module comprises a timing control module 20, which is used to receive an exposure signal of the reflected light receiving lens 60 and a structured light state signal from the master control module 10 and generate a floodlight control signal according to the exposure signal of the reflected light receiving lens 60 and the structured light state signal. As shown in Figure 1As shown, since the depth camera image acquisition module described in the present application includes two different light sources, namely the floodlight projection lens 70 and the structured light projection lens 80, and the two light sources respectively project different types of light, the two types of light are respectively used for different algorithms, therefore it is necessary to ensure that the floodlight projection lens 70 and the structured light projection lens 80 work staggeredly, that is, when the floodlight projection lens 70 projects floodlight, the structured light projection lens 80 stops working, and when the structured light projection lens 80 projects structured light, the floodlight projection lens 70 stops working. In the prior art, the realization of the alternate working of different projection lenses usually depends on pure software control, that is, the working time sequence of different projection lenses is controlled through a program, but the program running has a certain uncertainty and is easily disturbed by the running of other programs. In the case that the floodlight projection lens 70 and the structured light projection lens 80 cannot be ensured to work staggeredly, the same frame of reflected light received by the reflected light receiving lens 60 may include both floodlight reflected light and structured light reflected light, and the reflected light signal generated thereby will not meet the requirements of the depth measurement algorithm and the AI recognition algorithm after being transmitted to the external processor, thereby the distance and the type of the object in the target space are calculated incorrectly. The floodlight projection lens 70 described in the embodiment of the present application decides whether to turn on or off according to the state of the structured light projection lens 80, therefore the timing control module 20 is connected to the floodlight control module 30, so as to realize the control of the floodlight projection lens 70 through the floodlight control module 30. The state of the structured light projection lens 80 is not directly transmitted to the timing control module 20 by the structured light projection lens 80 or the structured light control module 40, but is first transmitted to the main control module 10 by the structured light control module 40, and then transmitted to the timing control module 20 by the main control module 10, that is, the timing control module 20 receives the structured light state signal from the main control module 10.
[0033] The embodiment of the present application solves the technical problem of how to make different projection lenses accurately and stably realize staggered opening, achieves the technical effect of preventing different projection lenses from projecting floodlight and structured light at the same time by using a hardware control mode, and preventing the floodlight image frame and the structured light image frame from being confused, and has faster speed and higher stability compared with the software control mode of projecting floodlight and structured light, thereby effectively improving the long-term stability of the depth measurement algorithm and the AI recognition algorithm.
[0034] Optionally, the timing control module 20 includes an exposure signal acquisition unit 21, a state signal acquisition unit 22 and a control signal output unit 23. The exposure signal acquisition unit 21 is used for receiving the exposure signal of the reflected light receiving lens 60; the exposure signal is used for representing whether the reflected light receiving lens 60 is in an exposure state, the exposure signal is high level when the reflected light receiving lens 60 is in the exposure state, and the exposure signal is low level when the reflected light receiving lens 60 is in a non-exposure state.
[0035] Figure 3 The structural diagram of the timing control module is shown in the figure. The exposure signal collection unit 21 receives the exposure signal A of the reflection light receiving lens. As shown in the figure, the exposure signal A is transmitted by the main control module 10 to the exposure signal collection unit 21, which is used to indicate whether the reflection light receiving lens 60 is in the exposure state, i.e. the opening state at this time. When the reflection light receiving lens 60 is in the exposure state, the exposure signal A is high. When the reflection light receiving lens 60 is in the non-exposure state, the exposure signal A is low. The specific values of the high and low levels of the exposure signal A can be selected according to the circuit design. Figure 1
[0036] The state signal collection unit 22 is used to receive the structured light state signal. The structured light state signal is used to represent the working state of the structured light projection lens 80. When the structured light projection lens 80 projects structured light, the structured light state signal is low. As shown in the figure, the state signal collection unit 22 receives the structured light state signal B. As shown in the figure, the structured light state signal B is transmitted by the main control module 10 to the state signal collection unit 22, which is used to indicate whether the structured light projection lens 80 is in the opening state, i.e. whether it is projecting structured light at this time. When the structured light projection lens 80 is in the opening state, the structured light state signal B is low. When the structured light projection lens 80 is in the closing state, the structured light state signal B is high. The specific voltage values of the high and low levels of the structured light state signal B can be selected according to the circuit design. Figure 3 Figure 1 The control signal output unit 23 is used to generate the flood light control signal Y. When the exposure signal A and the structured light state signal B are both high, the flood light control signal Y is high. When at least one of the exposure signal A and the structured light state signal B is low, the flood light control signal Y is low. When the flood light control signal Y is high, the flood light control module 30 controls the flood light projection lens 70 to emit flood light to the target space. Table 1 is the input and output logic diagram of the timing control module 20, where "1" represents high and "0" represents low. The timing control module 20 is equivalent to an AND gate circuit. Only when the input values A and B are both 1, the output value Y is 1. In this application, only when the reflection light receiving lens 60 is in the exposure state and the structured light projection lens 80 is in the closing state, the flood light projection lens 70 is opened. The advantage of this setting is that through the AND gate circuit, it is forced to avoid the flood light projection lens 70 and the structured light projection lens 80 from being opened at the same time. Considering the energy saving problem, the flood light projection lens 70 is only opened when the reflection light receiving lens 60 is exposed, preventing the projection lens from being opened for a long time without receiving reflected light.
[0037]
[0038] Table 1 timing control module input and output logic diagram
[0039] Optionally, the timing control module 20 includes two diodes and a resistor, and the timing control module 20 is designed by discrete components or integrated chips. As shown in the figure, the embodiment gives a discrete component design scheme of the timing control module 20, which includes two diodes and a resistor. In this application, the diodes can be conventional Schottky diodes. The specific selection of diodes and resistors needs to be adjusted according to the overall requirements of the depth camera image acquisition module. In addition to the way of building the timing control module 20 by discrete components, an integrated chip with the same function as the timing control module 20 in this application can also be directly used. The use of integrated chips can reduce the space occupied by the timing control module 20 and simplify the design process. Figure 3
[0040] Optionally, the structured light control module 40 is arranged adjacent to the structured light projection lens 80; wherein the driving frequency of the structured light projection lens 80 is greater than 50MHz. As shown in the figure, the structured light control module 40 is composed of high-frequency driving elements, which are used to drive the structured light projection lens 80. The driving frequency is greater than 50MHz, and the high-frequency structured light projection lens 80 can make the depth value calculated by the subsequent depth measurement algorithm more accurate. The high-frequency driving elements are arranged adjacent to the structured light projection lens 80, which reduces the corresponding wiring length and reduces the integrated inductance between the high-frequency driving elements and the structured light projection lens 80. Figure 1
[0041] Embodiment two Embodiment one realizes stable control of the timing of the floodlight projection lens 70 and the structured light projection lens 80 through the timing control module 20. Figure 4A Figure 1 is an input and output timing diagram of a timing control module, Figure 4B Figure 2 is a schematic diagram of a timing control module, Figure 4A Figure 3 is an enlarged view of region C in Figure 2.
[0042] Figure 4 is a schematic diagram of a timing control module, Figure 4A and Figure 4B As shown, the exposure signal A adopts a timing design mode of a large period H1 set with a small period H2, the large period H1 is determined by the frame rate of the depth camera, the small period H2 is greater than 0.8 milliseconds and less than 1.2 milliseconds; wherein, the small period H2 is the time interval between adjacent exposure signals. The picture generated in the large period H1 can be generated by picture fusion of multiple small frames, so the value of the large period H1 corresponds to the frame rate of the depth camera, the large period H1 is greater than 80 milliseconds and less than 120 milliseconds, which can meet the requirement of the frame rate of the depth camera, and at the same time, the above value of the large period H1 can reduce the data acquisition times as much as possible, thereby reducing the computing power consumption. The small period H2 is about 1 millisecond, which can meet the requirement of Mobile Industry Processor Interface (MIPI) and minimize the impact of motion blur.
[0043] Optionally, the number of small periods H2 included in the large period H1 is between 3 and 25. Figure 4A and Figure 4B As shown, the example given by the embodiment includes 15 small periods H2 in the large period H1, in order to accurately run the subsequent depth measurement algorithm and AI recognition algorithm, the picture generated in the large period H1 can be generated by picture fusion of multiple small frames, wherein each small period H2 corresponds to a small frame, too few small frames will cause difficulty in running the subsequent algorithm, and the accuracy of the obtained large frame is reduced, and too many small frames will increase the operation amount of the subsequent algorithm, increase the computing power consumption and cause time delay. Therefore, it is preferred that 10-20 small frames are included in a large frame, which can balance the contradiction between the algorithm calculation accuracy and the operation amount.
[0044] Optionally, the large period H1 is a constant value, and the small period H2 is a variable value. The value of the large period H1 corresponds to the frame rate of the depth camera, and the large period H1 is a constant value when the frame rate of the depth camera is unchanged. The small period H2 corresponds to different small frames, for example, in the present application, each large period H1 includes 15 small periods H2, which correspond to 15 small frames respectively, and each small frame corresponds to a depth measurement algorithm or an AI recognition algorithm. As shown, Figure 4BAs shown, in the first small cycle of the exposure signal A, the floodlight projection lens 70 and the structured light projection lens 80 are both in the closed state, the reflected light receiving lens 60 receives the background light, and the obtained small frame is used for the depth measurement algorithm and the AI recognition algorithm to remove background noise; in the second small cycle of the exposure signal A, the structured light state signal B is high, the structured light projection lens 80 is in the closed state, the floodlight control signal Y is high, the floodlight projection lens 70 is in the open state, and the reflected light receiving lens 60 receives the floodlight reflected light. The obtained small frame is used for the AI recognition algorithm to identify the type of target space object; in the third to fifteenth small cycles of the exposure signal A, the structured light state signal B is low, the structured light projection lens 80 is in the open state, the floodlight control signal Y is low, the floodlight projection lens 70 is in the closed state, and the reflected light receiving lens 60 receives the structured light reflected light. The obtained small frame is used for the depth measurement algorithm to identify the distance of the object in the target space. The small cycle H2 can be changed in a small range as needed, for example, fine-tuned at about 1 millisecond, and according to the actual needs of the depth measurement algorithm or the AI recognition algorithm, a suitable exposure time is selected to improve the operating efficiency of the depth camera while ensuring the accuracy of the algorithm.
[0045] Optionally, the floodlight control signal is high in each small cycle included in each large cycle. As shown, Figure 4B As shown, the floodlight control signal Y corresponding to the second small cycle H2 in each large cycle H1 is high. Since only one small frame of floodlight reflected light is needed in this application to meet the AI recognition algorithm, the floodlight control signal Y is high only for a small frame. If the frame format required by the AI recognition algorithm changes in actual application, the input and output timing of the timing control module 20 can also be adjusted accordingly.
[0046] Optionally, the duration of the exposure signal A is less than the time of the small cycle H2. As shown, Figure 4B As shown, the selection of the exposure time H3 corresponding to each small frame is related to the performance of the sensor of the reflected light receiving lens 60. The longer the exposure time H3 needs to be, the poorer the photosensitive ability of the sensor or the higher the brightness of the small frame required by the subsequent depth measurement algorithm. The exposure time H3 selected in this application is greater than 100 microseconds and less than 1 millisecond, and can be adaptively adjusted according to the algorithm needs or the environment in which the depth camera is located, so that the depth camera image acquisition module described in this application is more universal.
[0047] By designing the input and output timing of the timing control module 20, this embodiment solves the problem of how the timing control module 20 matches with the subsequent algorithm, so that the opening and closing timing of the floodlight projection lens 70 and the structured light projection lens 80 can better support the operation of the depth measurement algorithm and the AI recognition algorithm, thereby obtaining more accurate depth measurement results and object type judgment results.
[0048] Embodiment Three Figure 5 As shown in the figure, the depth camera comprises a floodlight projection lens 70, a structured light projection lens 80, a reflected light receiving lens 60, a control circuit, an interface 50 and a processor. The floodlight projection lens 70 and the structured light projection lens 80 emit floodlight and structured light to the target space in time-sharing manner, and the reflected light receiving lens 60 receives the structured light reflection light and the floodlight reflection light of the object in the target space. The control circuit has the structure of the control circuit for the depth camera image acquisition module as described in Embodiment One or Embodiment Two, is used to control other elements in the depth camera, and generates reflected light signals according to the structured light reflection light and the floodlight reflection light. After the interface 50 transmits the reflected light signals to the processor, the processor calculates the depth information of the object in the target space through the structured light algorithm and the Time of Flight (ToF) algorithm respectively according to the received reflected light signals, and identifies the category information of the object in the target space through the AI algorithm.
[0049] The embodiment solves the same technical problem as the control circuit for the depth camera image acquisition module as described in Embodiment One by designing a depth camera, achieves the same technical effect as Embodiment One, and improves the accuracy of the depth value measurement of the object in the target space through the structured light algorithm and the Time of Flight algorithm.
[0050] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.
Claims
1. A control circuit for a depth camera image acquisition module, characterized in that, The application relates to a light control system, which comprises a main control module (10), a time sequence control module (20), a structured light control module (40), an interface (50) and a reflected light receiving lens (60). The time sequence control module (20) is used for receiving an exposure signal and a structured light state signal of the reflected light receiving lens (60) from the main control module (10) and generating a flood light control signal according to the exposure signal and the structured light state signal of the reflected light receiving lens (60). The flood light control module (30) is used for receiving the flood light control signal from the time sequence control circuit (20) and controlling a flood light projection lens (70) according to the flood light control signal. The structured light control module (40) is used for sending a structured light state signal of a structured light projection lens (80) to the main control module (10) and controlling the structured light projection lens (80) according to a structured light control signal received from the main control module (10). The flood light projection lens (70) is used for emitting flood light to a target space; the structured light projection lens (80) is used for emitting structured light to the target space; the interface (50) is used for transmitting a reflected light signal generated by the main control module (10) according to structured light reflection and flood light reflection to an external processor; and the reflected light receiving lens (60) is used for receiving structured light reflection and flood light reflection of an object in the target space and transmitting the structured light reflection and the flood light reflection to the main control module (10). The time sequence control module (20) comprises:
2. The control circuit for a depth camera image acquisition module of claim 1, wherein, An exposure signal acquisition unit (21) is used for receiving an exposure signal of the reflected light receiving lens (60); the exposure signal is used for representing whether the reflected light receiving lens (60) is in an exposure state; when the reflected light receiving lens (60) is in the exposure state, the exposure signal is high; when the reflected light receiving lens (60) is in a non-exposure state, the exposure signal is low; A state signal acquisition unit (22) is used for receiving the structured light state signal; the structured light state signal is used for representing a working state of the structured light projection lens (80); when the structured light projection lens (80) projects structured light, the structured light state signal is low; A control signal output unit (23) is used for generating a flood light control signal; when the exposure signal and the structured light state signal are both high, the flood light control signal is high; when at least one of the exposure signal and the structured light state signal is low, the flood light control signal is low; When the flood light control signal is high, the flood light control module (30) controls the flood light projection lens (70) to emit flood light to the target space. The time sequence control module (20) comprises two diodes and one resistor and is designed by using discrete components or an integrated chip.
3. The control circuit for a depth camera image acquisition module of claim 2, wherein, The structured light control module (40) is arranged adjacent to the structured light projection lens (80).
4. The control circuit for a depth camera image acquisition module of claim 3, wherein, 5. The control circuit for a depth camera image acquisition module of claim 3, wherein, The exposure signal adopts a timing design mode of a large period nested in a small period, the large period is determined by a frame rate of the depth camera, and the small period is greater than 0.8 milliseconds and less than 1.2 milliseconds. The small period is a time interval between adjacent exposure signals.
6. The control circuit for a depth camera image acquisition module of claim 5, wherein, The large period is a constant value, and the small period is a variable value.
7. The control circuit for a depth camera image acquisition module of claim 6, wherein, The number of small periods included in the large period is between 3 and 25.
8. The control circuit for a depth camera image acquisition module of claim 7, wherein, The exposure signal is a duration of a high level, and is less than the time of the small period.
9. The control circuit for a depth camera image acquisition module of claim 8, wherein, A floodlight control signal including one small period in each large period is a high level.
10. A depth camera, characterized by Comprise: a floodlight projection lens (70) for emitting a floodlight to a target space; a structured light projection lens (80) for emitting a structured light to the target space; a reflected light receiving lens (60) for receiving a structured light reflected light and a floodlight reflected light of an object in the target space; a control circuit for controlling other elements in the depth camera and generating a reflected light signal according to the structured light reflected light and the floodlight reflected light, the control circuit having a structure of the control circuit for a depth camera image acquisition module as claimed in any one of claims 1 to 9; an interface (50) for transmitting the reflected light signal to a processor; a processor for calculating depth information of an object in the target space through a structured light algorithm and a time of flight (ToF) algorithm respectively according to the received reflected light signal.