Optical recognition device and three-dimensional image acquisition method

Abstract

The application provides an optical recognition device, which comprises: a light emitting device for emitting a probe light, the probe light generating reflected light after encountering an external object; a receiving device comprising a plurality of photoelectric conversion elements, each of the photoelectric conversion elements being used for receiving a bundle of the reflected light to generate a sensing electric signal; a control device electrically connected with the light emitting device, used for modulating the probe light; and a gating switch, used for controlling the plurality of photoelectric conversion elements to be electrically connected with the control device in sequence in a recognition time period, so that the control device is used for receiving the sensing electric signals generated by the plurality of photoelectric conversion elements in sequence in the recognition time period, and is used for obtaining a three-dimensional image of the external object in the recognition time period according to the sensing electric signals. The application also provides a three-dimensional image acquisition method.

Description

Technical Field

[0001] This application relates to the field of optical detection, and more particularly to an optical recognition device and a method for acquiring three-dimensional images. Background Technology

[0002] With the widespread use of smart terminals, object recognition has gradually become one of the important ways for users to interact with smart terminals, such as gesture recognition, body movement recognition, or facial recognition. Among these, gesture recognition is applied to various smart scenarios due to its convenience and versatility. As application scenarios increase, users' gestures are becoming more and more diverse, and the requirements for the recognition accuracy of interactive devices are also getting higher and higher.

[0003] Traditional gesture recognition methods, such as those using cameras, can only acquire surface information of objects and cannot obtain depth information, leading to inaccurate image recognition. While the Time-of-Flight (ToF) method can measure the three-dimensional contours of objects, ToF recognition devices using area array optoelectronic devices such as charge-coupled devices (CCDs) require significant computation, especially in dynamic scenes, thus hindering the rapid determination and recognition of object motion trends. Summary of the Invention

[0004] This application provides an optical recognition device, which includes:

[0005] A light-emitting device for emitting a detection light, which is reflected when it encounters an external object;

[0006] The receiving device includes a plurality of photoelectric conversion elements, each of which is used to receive a beam of reflected light to generate a sensing electrical signal;

[0007] A control device, electrically connected to the light-emitting device, is used to modulate the detection light; and

[0008] A gating switch is used to control the plurality of photoelectric conversion elements to be electrically connected to the control device in sequence during the recognition period, so that the control device can receive the sensing electrical signals generated by the plurality of photoelectric conversion elements in sequence during the recognition period, and obtain a three-dimensional image of the external object during the recognition period based on the plurality of sensing electrical signals.

[0009] In one embodiment, the control device is further configured to calculate and store three-dimensional images of the external object during multiple recognition time periods, thereby obtaining the motion trend of the external object.

[0010] In one embodiment, the control device further includes: a modulator connected to the light-emitting device for outputting a modulation signal to modulate the detection light; a phase shifter connected to the modulator and the receiving device for converting the modulation signal into a reference electrical signal and transmitting it to the receiving device; a demodulator connected to the receiving device for comparing the sensing electrical signal and the reference electrical signal and calculating the difference electrical signal; an analog-to-digital converter connected to the demodulator for converting the difference electrical signal into a digital signal; and a processing unit connected to the analog-to-digital converter, the modulator, and the gating switch for controlling the modulator to output the modulation signal and calculating a three-dimensional image of the external object based on the digital signal.

[0011] In one embodiment, the light-emitting device includes: a laser source for emitting the detection light; a driver connected to the control device for driving the laser source to emit light; and a lens disposed in the optical path of the detection light for adjusting the beam angle of the detection light.

[0012] In one embodiment, the receiving device further includes a filter disposed on the side of the plurality of photoelectric conversion elements used to receive the reflected light, for shielding light other than the reflected light.

[0013] In one embodiment, each of the photoelectric conversion elements has a field of view, and the field of view of the plurality of photoelectric conversion elements are coupled to each other, such that the receiving device has a continuous field of view, and the reflected light generated in any region within the field of view is received by at least one of the photoelectric conversion elements.

[0014] In one embodiment, the field of view of the receiving device is equal to the field of view of the probe light.

[0015] The optical recognition device proposed in this application can sequentially calculate a segment of sensing electrical signal generated by each photoelectric conversion element within the recognition time period by setting a gating switch, thereby obtaining a three-dimensional image of the external object as a whole within the recognition time period. Since it is not necessary to process the full band of the sensing electrical signal converted by each photoelectric conversion element within the recognition time period, the three-dimensional image of the external object within the recognition time period can be obtained at a faster speed while reducing the amount of computation, thus improving the processing speed and reducing power consumption.

[0016] Another aspect of this application proposes a method for acquiring three-dimensional images, which includes:

[0017] A detection beam is emitted, which generates multiple reflected beams upon encountering an external object;

[0018] The multiple reflected beams are received respectively, and each of the reflected beams generates a sensing electrical signal;

[0019] During the recognition period, each of the sensed electrical signals is processed sequentially to obtain a three-dimensional image of the external object during the recognition period.

[0020] In one embodiment, the three-dimensional image acquisition method further includes: calculating and storing three-dimensional images of the external object during multiple recognition time periods to obtain the motion trend of the external object; and analyzing and comparing the data of the three-dimensional images and / or motion trends of the external object.

[0021] In one embodiment, the analysis and comparison of the three-dimensional image and / or motion trend data of the external object specifically involves comparing the three-dimensional image and / or motion trend data of the external object with multiple pre-stored data to determine the type of the three-dimensional image or motion trend of the external object.

[0022] The three-dimensional image acquisition method provided in this application processes each of the sensing electrical signals sequentially within a recognition time period and obtains a three-dimensional image of the external object as a whole within the recognition time period. Since it is not necessary to process all bands of each sensing electrical signal within the recognition time period, the three-dimensional image of the external object within the recognition time period can be obtained at a faster speed while reducing the amount of computation, thereby improving the processing speed and reducing power consumption. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the system structure of an optical recognition device in one embodiment of this application.

[0024] Figure 2 This is a schematic diagram of the electrical connections of an optical recognition device in one embodiment of this application.

[0025] Figure 3 This is a schematic diagram of the structure of a light-emitting device in one embodiment of this application.

[0026] Figure 4 This is a schematic diagram of the structure of an optical recognition device in one embodiment of this application.

[0027] Figure 5 This is a schematic diagram of the field of view of an optical recognition device in one embodiment of this application.

[0028] Figure 6 This is a schematic diagram of the field of view of the receiving device in one embodiment of this application.

[0029] Figure 7 This is a schematic diagram of a numerical array in one embodiment of this application.

[0030] Figure 8 This is a schematic diagram of a three-dimensional image in one embodiment of this application.

[0031] Explanation of main component symbols

[0032] Optical recognition device 100

[0033] Control device 10

[0034] Modulator 11

[0035] Phase shifter 13

[0036] Demodulator 15

[0037] Analog-to-digital converter 17

[0038] Processing Unit 19

[0039] Light-emitting device 30

[0040] Driver 31

[0041] Laser source 33

[0042] Lens 35

[0043] Receiver 50

[0044] Photosensitive element 51

[0045] Photoelectric conversion element 510

[0046] Filter 53

[0047] strobe switch 70

[0048] Detector light L

[0049] Reflected light R1, R2

[0050] External object A

[0051] Reception range B, B1

[0052] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this application. Detailed Implementation

[0053] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0054] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this application's specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0055] To further illustrate the technical means and effects adopted by this application in achieving its intended purpose, the following detailed description of this application is provided in conjunction with the accompanying drawings and preferred embodiments.

[0056] Please refer to the following: Figure 1 and Figure 5 This application provides an optical recognition device 100, comprising: a control device 10, a light-emitting device 30, a receiving device 50, and a selection switch 70. The light-emitting device 30 emits a detection light, which is reflected by an external object. The light reflected by the external object is defined as reflected light. In this embodiment, the external object reflects multiple beams of reflected light. The receiving device 50 includes a photosensitive element 51, on which multiple photoelectric conversion elements 510 are provided. Each photoelectric conversion element 510 receives a beam of reflected light to generate a sensing electrical signal. The control device 10 is electrically connected to the light-emitting device 30 and the receiving device 50, and is used to modulate the detection light. The selection switch 70 controls the multiple photoelectric conversion elements 510 to be sequentially electrically connected to the control device 10 during a recognition time period, so that the control device 10 sequentially receives the sensing electrical signals generated by the multiple photoelectric conversion elements 510 during the recognition time period, and obtains a three-dimensional image of the external object during the recognition time period based on the multiple sensing electrical signals. The control device 10 is also used to calculate and store three-dimensional images of the external object in multiple recognition time periods. The multiple recognition time periods do not overlap, and each recognition time period is arranged in the order of its appearance, so that the movement trend of the external object in multiple recognition time periods can be obtained.

[0057] In one embodiment, please refer to the following: Figure 2 and Figure 3The control device 10 includes a modulator 11, a phase shifter 13, a demodulator 15, an analog-to-digital converter 17, and a processing unit 19. The light-emitting device 30 includes a driver 31, a laser source 33, and a lens 35. The modulator 11 is connected to the driver 31 of the light-emitting device 30 and outputs a modulation signal to modulate the detection light. The phase shifter 13 is connected to the modulator 11 and the photosensitive element 51 and converts the modulation signal into a reference electrical signal and transmits it to the photosensitive element 51. The demodulator 15 is connected to the photosensitive element 51 via a gating switch 70 and compares the sensing electrical signal and the reference electrical signal to calculate a difference electrical signal, which is used to record the phase difference or time difference between the sensing electrical signal and the reference electrical signal. The analog-to-digital converter 17 is connected to the demodulator 15 and converts the difference electrical signal into a digital signal. The processing unit 19 is connected to the analog-to-digital converter 17, the gating switch 70, and the modulator 11 and controls the modulator 11 to output the modulation signal and calculates a three-dimensional image of the external object based on the digital signal. The driver 31 drives the laser source 33 to emit the detection light, and the lens 35 is disposed in the optical path of the detection light to adjust the beam angle of the detection light.

[0058] In one embodiment, please refer to Figure 2 The processing unit 19 sends a command to the modulator 11, causing the modulator 11 to start outputting a modulation signal. The modulation signal can be a sine wave, pulse signal, or square wave signal, etc. Within one period, the modulation signal has a certain frequency or amplitude to generate a specific waveform, so that when any segment of the signal is intercepted within the period, the phase of the signal can be determined. After the modulator 11 outputs the modulation signal to the driver 31, the driver 31 can make the probe light emitted by the laser source 33 have the same waveform as the modulation signal, thereby achieving modulation of the probe light.

[0059] In one embodiment, the phase shifter 13 receives the modulation signal output by the modulator 11, converts it into a reference electrical signal, and outputs it to the photosensitive element 51. Specifically, the phase shifter 13 can adjust the phase of the modulation signal waveform so that the reference electrical signal received by the photosensitive element 51 and the optical signal of the probe light emitted by the laser source 33 are in the same phase at the same time, thereby serving as a reference. When the reflected light carrying the modulation signal is received by the photosensitive element 51, since the photosensitive element 51 simultaneously receives the reference electrical signal, it can obtain the output waveform of the laser source 33 when the reflected light is received more accurately, thereby eliminating the time difference generated during the process of the electrical signal traveling from the modulator 11 through the driver 31 to the laser source 33 emitting the probe light.

[0060] In one embodiment, the demodulator 15 simultaneously receives a reference electrical signal and a sensing electrical signal, and compares the reference electrical signal and the sensing electrical signal to obtain a difference electrical signal. Specifically, after removing interference from ambient light and light loss due to reflection, the sensing electrical signal and the reference electrical signal have the same but different waveforms. By comparing the sensing electrical signal and the reference electrical signal, the demodulator 15 can obtain the phase difference between the sensing electrical signal and the reference electrical signal, and output a difference electrical signal waveform based on the phase difference. Since the period and frequency of the modulation signal are preset values, the distance traveled by the probe light after it is emitted from the laser source 33, encounters an external object, and is reflected back to the photosensitive element 51 can be calculated using the phase difference, thereby obtaining the distance between the external object and the optical recognition device 100.

[0061] In one embodiment, the analog-to-digital converter 17 receives the difference electrical signal and converts it from an analog electrical signal to a digital signal. Specifically, the modulation signal output by the modulator 11, the reference electrical signal output by the phase shifter 13, the sensing electrical signal converted by the photosensitive element 51, and the difference electrical signal output by the demodulator 15 are all analog electrical signals. If subsequent calculations or storage processing are to be performed, the analog electrical signals need to be converted into digital signals in order to generate a three-dimensional image of the external object.

[0062] In one embodiment, the processing unit 19 is used to control the modulator 11 to output a modulated signal and to receive the digital signal converted by the analog-to-digital converter 17, and to perform operations such as storage and arrangement of the digital signal to generate a three-dimensional image and / or motion trend of an external object.

[0063] In one embodiment, the control device 10 may include one or a combination of chips such as a microcontroller unit (MCU), a central processing unit, or a single-chip microcomputer. For example, the modulator 11, phase shifter 13, demodulator 15, analog-to-digital converter 17, and processing unit 19 may all be parts of the MCU chip. In other embodiments, the control device 10 may also be a circuit board composed of multiple chips connected by circuit traces; this application does not impose any limitations on this.

[0064] In one embodiment, please continue to refer to Figure 3The driver 31 can be a driving device for a vertical cavity surface-emitting laser (VCSEL), and the laser source 33 can be the laser source of the VCSEL. That is, the VCSEL laser includes both the driver 31 and the laser source 33. In other embodiments, the driver 31 and the laser source 33 can also be provided separately. The VCSEL laser used in this application embodiment has the characteristics of small size, high power, and fast switching speed, which can reduce the size while outputting modulated probe light well, thereby improving the accuracy of identification.

[0065] In one embodiment, the detection light is near-infrared light, with a selectable wavelength range of 850nm-940nm. Specifically, depending on the usage scenario, such as the different brightness of the surrounding light environment, different detection light wavelengths can be selected to minimize the impact on the optical recognition device 100.

[0066] In one embodiment, lens 35 is disposed in the optical path of the probe light to adjust the beam angle of the probe light. Specifically, lens 35 can be disposed at the light outlet of laser source 33 to facilitate adjustment of all probe light. Lens 35 can be a single lens or a lens group composed of multiple lenses. The adjustment of the beam angle of the probe light by lens 35 can specifically be beam expansion, shaping, or focusing, so that the probe light can illuminate the target area to improve the utilization rate of the probe light.

[0067] In one embodiment, please refer to the following: Figure 4 and Figure 5 The receiving device 50 includes a photosensitive element 51 and a filter 53. The photosensitive element 51 includes multiple photoelectric conversion elements 510 arranged in an array, each photoelectric conversion element 510 being used to receive a beam of reflected light. Specifically, after the detection light L illuminates the external object A, it generates multiple beams of reflected light, such as reflected light R1 and reflected light R2. Different reflected lights correspond to different photoelectric conversion elements 510, that is, reflected light R1 and reflected light R2 are received by different photoelectric conversion elements 510 and converted into electrical signals. Since the distance between different parts of the external object A and the optical recognition device 100 is different, the optical paths of reflected light R1 and reflected light R2 are also different. Different photoelectric conversion elements 510 convert reflected light R1 and reflected light R2 into two different sensing electrical signals, and transmit the two sensing electrical signals to the control device 10 respectively. The distance between each part of the external object A and the optical recognition device 100 can be calculated respectively, thereby obtaining a three-dimensional image of the entire external object A.

[0068] In one embodiment, the filter 53 is used to shield and filter out light other than reflected light, thereby reducing interference. Depending on the external light environment, the filtering band of the filter 53 can be adjusted accordingly to make the measurement results more accurate.

[0069] In one embodiment, the photosensitive element 51 can be a CCD array, which includes photoelectric conversion elements 510 arranged in an 8*8 array (that is, the photosensitive element 51 includes 64 photoelectric conversion elements 510, arranged in a two-dimensional array of 8 in each row and 8 in each column). In other embodiments, the photosensitive element 51 can also be a complementary metal-oxide-semiconductor (CMOS) chip or other elements used to convert optical signals into electrical signals. The number of photoelectric conversion elements 510 can also vary according to the required detection accuracy, such as 16*16, 64*64 or 1080*720, etc., and this application does not limit it in this regard.

[0070] In one embodiment, the light outlet of the laser source 33 and the side of the photosensitive element 51 used to receive reflected light are coplanar. Therefore, the distance from the emission of the probe light L to the encounter with the external object A is equal to the distance from the external object A to the photosensitive element 51 of the reflected light. Thus, the difference in distance between the two paths of the light from emission to reception does not need to be considered during the calculation, which helps to reduce errors and improve calculation accuracy.

[0071] In one embodiment, please refer to the following: Figure 5 and Figure 6 Each photoelectric conversion element 510 has a receiving range B1. By adjusting the angle of each photoelectric conversion element 510 on the photosensitive element 51, the receiving ranges B1 of multiple photoelectric conversion elements 510 can be coupled (i.e., spliced ​​together), so that the photosensitive element 51 has a continuous receiving range B. Reflected light generated in any area within the receiving range B is received by at least one photoelectric conversion element 510. Specifically, each photoelectric conversion element 510 is used to receive reflected light within its receiving range B1, and the control device 10 calculates the distance between the external object A and the optical recognition device 100 within the corresponding area. By calculating the distance between the external object A and the optical recognition device 100 within different receiving ranges B1, a three-dimensional image of the external object A in the receiving range B can be obtained.

[0072] In one embodiment, the photosensitive element 51 is also used to receive a reference electrical signal emitted by the phase shifter 13, which can be transmitted to the control device 10 simultaneously with the sensing electrical signal generated by each photoelectric conversion element 510.

[0073] In one embodiment, the field of view of the probe light L is equal to that of the receiving range B. Specifically, the probe light L emitted after adjustment by the lens 35 covers a range that coincides with the receiving range B. That is, the probe light L is fully utilized within the receiving range B. While avoiding waste, the lens 35 concentrates the energy of the probe light L within the receiving range B, ensuring that the probe light L does not diverge at a greater distance, thus achieving detection at a longer distance.

[0074] In one embodiment, a selector switch 70 is used to control the connection state between each photoelectric conversion element 510 and the control device 10. Specifically, when the selector switch 70 controls a photoelectric conversion element 510 to connect to the control device 10, the sensing electrical signal generated by the photoelectric conversion element 510 can be transmitted to the control device 10 along with a reference electrical signal. When the selector switch 70 controls a photoelectric conversion element 510 to disconnect from the control device 10, the sensing electrical signal generated by the photoelectric conversion element 510 and the reference electrical signal cannot be transmitted to the control device 10. Since the photosensitive element 51 includes multiple photoelectric conversion elements 510, the computational load required to process multiple sensing electrical signals simultaneously is large. Therefore, this embodiment sets a selector switch 70 so that the selector switch 70 controls multiple photoelectric conversion elements 510 to be electrically connected to the control device 10 in sequence. The control device 10 can receive and process the sensing electrical signals generated by each photoelectric conversion element 510 in sequence, thereby reducing the computational load.

[0075] Specifically, during the recognition period, the detection light continuously illuminates the external object and generates multiple beams of reflected light. The photosensitive element 51 continuously receives these multiple beams of reflected light and generates a sensing electrical signal. The selection switch 70 sequentially connects each photoelectric conversion element 510 to the control device 10, and connects all photoelectric conversion elements 510 to the control device 10 during the recognition period, thus obtaining a static three-dimensional image. If the recognition period is short, the external object is approximately stationary during the recognition period, therefore the three-dimensional image obtained by the control device 10 can be approximated as a three-dimensional image of the external object during the recognition period.

[0076] In one embodiment, the duration of the identification time period can be 50-100ms. In other embodiments, it can also be 1-50ms, 100-200ms, 200-500ms, etc. The duration of the identification time period can be set according to the different external objects to be measured, or it can be adjusted by the control device 10. This application does not limit it in this regard.

[0077] In one embodiment, the gating switch 70 can be a circuit element disposed on the MCU, located on the same chip as the control device 10. In other embodiments, the gating switch 70 can also be a separate chip disposed on a circuit board, connected to the control device 10 and the receiving device 50 through circuit traces, and this application does not limit this.

[0078] In one embodiment, the control device 10, the light-emitting device 30, the receiving device 50, and the gating switch 70 can all be integrated on a single circuit board. In other embodiments, they can also be independent components that are electrically connected through circuit traces.

[0079] This application also provides a method for acquiring three-dimensional images, which includes:

[0080] Step S1: Emit a probe light, which generates multiple reflected beams after encountering an external object;

[0081] Step S2: Receive the multiple beams of reflected light respectively, and generate a sensing electrical signal for each beam of reflected light;

[0082] Step S3: During the recognition time period, each of the sensing electrical signals is processed sequentially to obtain a three-dimensional image of the external object during the recognition time period.

[0083] Step S4: Calculate and store three-dimensional images of the external object during multiple recognition time periods to obtain the motion trend of the external object:

[0084] Step S5: Analyze and compare the data on the motion trend of the external object.

[0085] In one embodiment, the three-dimensional image acquisition method is performed by an optical recognition device 100. Specifically, in step S1, the light-emitting device 30 emits the detection light; in step S2, the receiving device 50 receives the multiple reflected beams of light and generates a sensing electrical signal; steps S3-S5 are jointly completed by the gating switch 70 and the control device 10.

[0086] In one embodiment, step S2 specifically involves: multiple photoelectric conversion elements 510 on the photosensitive element 51 receiving reflected light within their receiving range B1 and generating multiple sensing electrical signals.

[0087] In one embodiment, step S3 specifically involves: the selection switch 70 sequentially connecting each photoelectric conversion element 510 to the control device 10; the control device 10 calculating the distance between the external object and the optical recognition device 100 within the corresponding receiving range B1 based on the sensing electrical signal; and obtaining a three-dimensional image of the external object within the receiving range B during the recognition time period by statistically analyzing the distance data within each receiving range B1.

[0088] In one embodiment, please refer to the following: Figure 7 and Figure 8 Step S3 further includes: processing the sensed electrical signal to obtain a difference electrical signal recording the phase difference or time difference; converting the difference electrical signal from an analog signal to a digital signal; and recording it in the control device 10. For example, a photosensitive element 51 including an 8*8 array of photoelectric conversion elements 510, during the identification period, transmits the sensed electrical signal of each photoelectric conversion element 510 to the control device 10 via a selection switch 70 for processing, thus obtaining... Figure 7 The numerical array diagram shown is illustrated. The numbers "0-7" are used to label the photoelectric conversion elements 510 arranged in the array, and can also represent the position of the receiving range B1 corresponding to each photoelectric conversion element 510. The numbers in the diagram represent the distance between the external object and the optical recognition device 100 recorded after conversion to digital signals; the "ADC" in the diagram indicates that the corresponding sensing signal has not yet been converted from analog to digital. A three-dimensional plot of the diagram after complete conversion to digital signals can be obtained as shown below. Figure 8 The diagram shows a three-dimensional image, where "0-3000" represents the distance between the external object and the optical recognition device 100.

[0089] In one embodiment, step S4 specifically involves: calculating and storing three-dimensional images of external objects within multiple recognition time periods, wherein each recognition time period does not overlap. Each three-dimensional image is then sorted according to the order of its recognition time period to obtain the trend of the object's three-dimensional image changing over time, i.e., the object's motion trend.

[0090] In one embodiment, the analysis and comparison of the motion trend data of the external object in step S5 specifically involves comparing the motion trend data of the external object with multiple pre-stored data to determine the type of the motion trend of the external object. For example, the control device 10 pre-records multiple three-dimensional images and related motion trend data. After obtaining the three-dimensional image or motion trend of the external object, it compares it with the pre-stored related data to determine the type of the three-dimensional image or motion trend.

[0091] The optical recognition device 100 and the three-dimensional image acquisition method provided in this application, by setting a gating switch 70, perform time-division processing on the simultaneously received sensing electrical signals. That is, a portion of each sensing electrical signal during the recognition time period is processed, which can effectively reduce the amount of computation and obtain the three-dimensional image of the external object during the recognition time period more quickly, thereby reducing power consumption. At the same time, by recording the three-dimensional images of the external object in multiple recognition time periods, the motion trend data of the external object can be obtained and analyzed for recognition.

[0092] Those skilled in the art should recognize that the above embodiments are only used to illustrate this application and are not intended to limit this application. Any appropriate changes and variations made to the above embodiments within the essential spirit and scope of this application fall within the scope of protection claimed in this application.

Claims

1. An optical recognition device, characterized in that, include: A light-emitting device is used to emit a detection light, which produces reflected light at different times after illuminating a moving external object at different times within the identification time period. The receiving device includes multiple photoelectric conversion elements, which are used to receive the reflected light at different times in chronological order during the identification time period, and generate sensing electrical signals corresponding to the reflected light at the different times in chronological order. A control device, electrically connected to the light-emitting device, is used to modulate the detection light; as well as A selection switch is used to control the plurality of photoelectric conversion elements to be electrically connected to the control device in sequence, so that the control device can receive sensing electrical signals of reflected light generated by the plurality of photoelectric conversion elements corresponding to different times in the recognition time period, and obtain a three-dimensional image of the external object in the recognition time period based on the sensing electrical signals of reflected light corresponding to different times. The control device is also used to calculate and store the three-dimensional images of the external object in the plurality of recognition time periods arranged in the order of appearance, so as to obtain the motion trend of the external object in the plurality of recognition time periods, wherein the plurality of recognition time periods do not overlap, and the duration of the recognition time period is 50-100ms.

2. The optical recognition device as described in claim 1, characterized in that, The control device includes: A modulator, connected to the light-emitting device, is used to output a modulation signal to modulate the detection light; A phase shifter, connected to the modulator and the receiving device, is used to convert the modulated signal into a reference electrical signal and transmit it to the receiving device; A demodulator, connected to the receiving device, is used to compare the sensed electrical signal and the reference electrical signal, and to calculate the difference electrical signal; An analog-to-digital converter, connected to the demodulator, is used to convert the differential electrical signal into a digital signal; and The processing unit, connected to the analog-to-digital converter, the modulator, and the gating switch, is used to control the modulator to output the modulated signal and to calculate a three-dimensional image of the external object based on the digital signal.

3. The optical recognition device as described in claim 1, characterized in that, The light-emitting device includes: A laser source is used to emit the detection light; A driver, connected to the control device, for driving the laser source to emit light; and A lens is disposed in the optical path of the probe light and is used to adjust the beam angle of the probe light.

4. The optical recognition device as described in claim 1, characterized in that, The receiving device also includes a filter disposed on the side of the plurality of photoelectric conversion elements used to receive the reflected light, for shielding light other than the reflected light.

5. The optical recognition device as described in claim 1, characterized in that, Each of the photoelectric conversion elements has a receiving range, and the receiving ranges of the plurality of photoelectric conversion elements are coupled to each other, such that the receiving device has a continuous receiving range, and the reflected light generated in any region of the receiving range is received by at least one of the photoelectric conversion elements.

6. The optical recognition device as described in claim 5, characterized in that, The receiving range of the receiving device is equal to the field of view of the probe light.

7. A method for acquiring three-dimensional images, characterized in that, include: A detection light is emitted, which, after illuminating a moving external object at different times within the identification time period, produces multiple reflected beams of light at different times. The multiple beams of reflected light are received in chronological order during the identification period, and each beam of reflected light generates a sensing electrical signal. During the recognition time period, each of the sensing electrical signals is processed sequentially to obtain a three-dimensional image of the external object during the recognition time period, wherein the duration of the recognition time period is 50-100ms. Calculate and store three-dimensional images of the external object in multiple recognition time periods arranged in chronological order of appearance, to obtain the motion trend of the external object in the multiple recognition time periods, wherein the multiple recognition time periods do not overlap; Analyze and compare the three-dimensional images and / or motion trends of the external object.

8. The three-dimensional image acquisition method as described in claim 7, characterized in that, The specific method of analyzing and comparing the data of the three-dimensional image and / or motion trend of the external object is to compare the data of the three-dimensional image and / or motion trend of the external object with multiple pre-stored data to determine the type of the three-dimensional image or motion trend of the external object.

Images