Time-of-flight camera and detection method therefor

Abstract

A time-of-flight camera (1) and a detection method therefor. The time-of-flight camera (1) comprises: a housing (11); a protective member (111) arranged on the housing (11); a receiving unit (12) arranged in the housing (11); a main light source unit (13) which is arranged adjacent to the receiving unit (12) and outputs first light (13L); a detection light unit (14) which is arranged in the periphery of the receiving unit (12) and outputs second light (14L); and a processing unit (15) electrically connected to the receiving unit (12). The receiving unit (12) receives first feedback light (B1) generated by the first light (13L) to generate depth information, and receives second feedback light (B2) generated by the second light (14L) to generate a luminous intensity distribution, and on the basis of the luminous intensity distribution, the processing unit (15) determines whether the protective member (111) has a defect.

Description

Time-of-flight ranging camera and detection method thereof Technical Field

[0001] The present disclosure relates to a time-of-flight ranging camera, and more particularly to a time-of-flight ranging camera and a detection method thereof. Background Art

[0002] Time-of-flight (ToF) cameras are a type of three-dimensional (3D) sensing technology widely used in a variety of fields, including industry, automation, logistics, surveillance, and healthcare. Because ToF cameras require dust and water resistance to protect their internal components and circuitry, they are typically enclosed in a housing and protected by a protective element such as glass or plastic. Both the light emitted and received by the ToF camera can pass through the protective element.

[0003] However, any interfering objects such as dirt, scratches, water droplets, and fog on or above the protective element can affect the measurement results. If the time-of-flight rangefinder camera is used for personnel safety testing in human-machine collaboration, any interfering objects on or above the protective element may cause damage to life and property.

[0004] Therefore, one of the most pressing issues is how to detect interfering objects such as dirt, scratches, water droplets, and fog on or above the protective element through a device or method, without affecting the waterproof and dustproof structure of the time-of-flight rangefinder camera or its measurement performance.

[0005] Summary of the Invention

[0006] The present disclosure provides a time-of-flight (TOF) camera and its detection method. These methods can detect interference objects such as dirt, scratches, water droplets, and fog on or above a protective element without affecting the camera's waterproof and dustproof structure or its measurement performance, and take appropriate measures, such as shutting down the camera or issuing a warning signal.

[0007] The present disclosure provides a time-of-flight rangefinder camera comprising a housing; a protective member disposed on the housing; a main light source unit disposed at a first position of the housing and outputting a first light beam during a first time period; a detection light unit disposed at a second position of the housing and outputting a second light beam during a second time period; a receiving unit disposed within the housing and receiving first feedback light generated by the first light beam and second feedback light generated by the second light beam striking the protective member to generate a luminous intensity distribution; a storage unit electrically connected to the receiving unit and storing the luminous intensity distribution; and a processing unit electrically connected to the receiving unit and the storage unit and determining whether the protective member has a defect based on the luminous intensity distribution.

[0008] In some embodiments, the illumination area of ​​the second light on the protective member covers the field of view of the receiving unit on the protective member.

[0009] In some embodiments, the second light and the field of view of the receiving unit define an overlapping area outside the protective member, and a maximum distance of the overlapping area relative to the protective member is smaller than a shortest working distance of the receiving unit.

[0010] In some embodiments, the second light does not directly enter the receiving unit.

[0011] In some embodiments, the direct reflected light or transmitted light generated by the second light hitting the protective element does not enter the receiving unit.

[0012] In some embodiments, the detection light unit includes light emitting elements disposed around the receiving unit and jointly emitting a second light beam, and an illumination area of ​​the second light beam on the protective member covers a field of view of the receiving unit on the protective member.

[0013] In some embodiments, during the second time period, the main light source unit stops emitting light, and the detection light unit emits a second light.

[0014] In some embodiments, the first time period partially overlaps with the second time period.

[0015] In some embodiments, the wavelength range of the first light and the wavelength range of the second light are substantially the same.

[0016] The present disclosure provides a time-of-flight rangefinder camera comprising a housing; a protective member disposed on the housing; a receiving unit disposed within the housing; a main light source unit disposed adjacent to the receiving unit and outputting a first light beam; a detection light unit disposed around the receiving unit and outputting a second light beam; and a processing unit electrically connected to the receiving unit. The receiving unit receives first feedback light generated by the first light beam and second feedback light generated by the second light beam to generate a luminous intensity distribution. The processing unit determines whether the protective member has a defect based on the luminous intensity distribution.

[0017] In some embodiments, the illumination area of ​​the second light on the protective member covers the field of view of the receiving unit on the protective member.

[0018] In some embodiments, the second light and the field of view of the receiving unit define an overlapping area outside the protective member, and a maximum distance of the overlapping area relative to the protective member is smaller than a shortest working distance of the receiving unit.

[0019] In some embodiments, the second light does not directly enter the receiving unit.

[0020] In some embodiments, the direct reflected light or transmitted light generated by the second light hitting the protective element does not enter the receiving unit.

[0021] In some embodiments, the detection light unit includes light emitting elements disposed around the receiving unit and jointly emitting a second light beam, and an illumination area of ​​the second light beam on the protective member covers a field of view of the receiving unit on the protective member.

[0022] In some embodiments, the time-of-flight camera further includes a storage unit electrically connected to the receiving unit and the processing unit for storing the luminous intensity distribution.

[0023] The present disclosure provides a time-of-flight camera inspection method, comprising emitting a first light beam during a first time period to generate a first feedback light; receiving the first feedback light to generate depth information; emitting a second light beam during a second time period to illuminate a protective member and generate a second feedback light; receiving the second feedback light to generate a luminous intensity distribution; and determining whether the protective member has a defect based on the luminous intensity distribution.

[0024] In some embodiments, the detection method further includes outputting a warning signal if it is determined that the protective element has a defect.

[0025] In some embodiments, emitting the second light to strike the protective element during the second time period and generating the second feedback light further includes stopping emitting the first light and emitting the second light during the second time period.

[0026] In some embodiments, the first time period partially overlaps with the second time period.

[0027] As described above, the disclosed time-of-flight camera and its detection method can generate a luminous intensity distribution by detecting a second light beam emitted by a light detection unit before, during, or after distance measurement. A receiving unit then receives second feedback light generated by the second light beam to determine whether the protective member has defects, such as whether an object (not the object to be measured, such as dust) is located within a predetermined range of the protective member. Therefore, at any point in time during distance measurement, the disclosed time-of-flight camera and its detection method can also simultaneously determine whether there is interference from objects on or above the protective member, such as dust, dirt, fog, water droplets, oil, fingers, flies, mechanical objects, circuit components, or scratches on the protective member. Thus, the disclosed time-of-flight camera and its detection method can determine whether objects on the protective member could interfere with distance measurement without affecting the waterproof and dustproof structure of the time-of-flight camera or the time-of-flight camera's measurement. In certain distance measurement scenarios, it is important to ensure that the distance measurement is not interfered with by objects. For example, when a time-of-flight ranging camera is used for personnel safety monitoring in human-machine collaboration, or when measuring the distance between a car and an obstacle, interference from any object above the protective part may cause damage to life and property.

[0028] Furthermore, the disclosed time-of-flight camera and its detection method can be configured so that the second light output by the detection light unit does not directly enter the receiving unit, and the directly reflected or transmitted light generated by the second light hitting the protective element does not enter the receiving unit. This prevents other light from affecting the processing unit's interpretation, thereby increasing the accuracy of interfering object detection. Furthermore, the disclosed time-of-flight camera and its detection method can expand the range of interfering object detection by illuminating the protective element with the second light, encompassing the field of view of the receiving unit on the protective element. Furthermore, the disclosed time-of-flight camera and its detection method can define an overlapping region (a region above the surface of the protective element) outside the protective element by using the second light and the field of view of the receiving unit. The maximum distance of the overlapping region relative to the protective element is less than the minimum working distance of the receiving unit, meaning that the range of interfering objects is not within the range of distance measurement, thereby preventing the object being misidentified as an interfering object. Furthermore, the disclosed time-of-flight camera and its detection method can ensure that the wavelength range of the first light and the wavelength range of the second light are substantially the same, using the same light-emitting element to reduce the complexity of material control. In addition, the time-of-flight camera and detection method disclosed herein can avoid the influence of different feedback lights on each other by emitting the first light and the second light at different time periods, thereby increasing the accuracy of the interpretation.

[0029] The detection light unit of the time-of-flight camera disclosed herein may further include a plurality of light-emitting elements disposed around the receiving unit to jointly emit a second light beam to expand the range of detecting interference objects and make the brightness of the second light beam on the protective element more uniform, thereby increasing the accuracy of the interpretation. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The details of one or more embodiments of the subject matter described in this specification are set forth in the following drawings and description. Other features, embodiments, and advantages of the subject matter of this specification will be apparent from the description, drawings, and claims, including:

[0031] FIG1 is a schematic diagram of a time-of-flight camera according to a first embodiment of the present disclosure;

[0032] FIG2 is a schematic diagram of an optical path of a second light beam of a detection light unit;

[0033] FIG3 is a schematic diagram of the optical path of the second light of another detection light unit;

[0034] FIG4 is a timing diagram of the time-of-flight ranging between time-of-flight ranging cameras;

[0035] FIG5 is a timing diagram of the time-of-flight ranging camera of this embodiment;

[0036] FIG6 is a schematic diagram of a time-of-flight camera according to a second embodiment of the present disclosure;

[0037] FIG7 is a schematic diagram of a time-of-flight camera according to a third embodiment of the present disclosure;

[0038] FIG8 is a schematic diagram of a time-of-flight camera according to a fourth embodiment of the present disclosure;

[0039] FIG9 is a schematic diagram of the field of view and the illumination area on the protective member of the present disclosure;

[0040] FIG10 is a schematic diagram of a time-of-flight camera according to the present disclosure detecting water drops;

[0041] FIG11 is a schematic diagram of the time-of-flight ranging camera of the present disclosure detecting the position of a water droplet;

[0042] 12A to 12I are simulation diagrams of the light spot effect of the time-of-flight camera disclosed herein;

[0043] FIG13 is a schematic diagram of dust detection of the time-of-flight camera disclosed herein;

[0044] FIG14 is a schematic diagram of the detection position of dust by the TOF camera disclosed herein;

[0045] 15A to 15I are simulation diagrams of the light spot effect of the time-of-flight camera disclosed herein;

[0046] FIG16 is a schematic diagram of a time-of-flight camera according to the present disclosure detecting scratches;

[0047] 17A and 17B are schematic diagrams of the detection position of a scratch by the TOF camera of the present disclosure;

[0048] 18A and 18B are simulation diagrams of the light spot effect of the time-of-flight camera disclosed herein;

[0049] FIG19 is a schematic diagram of a time-of-flight camera detecting a finger according to the present disclosure;

[0050] FIG20 is a flowchart illustrating a detection method for a time-of-flight (TOF) camera according to an embodiment of the present disclosure;

[0051] FIG. 21 is a flowchart illustrating a method for detecting a time-of-flight camera according to another embodiment of the present disclosure.

[0052] Description of Figure Numbers:

[0053] 1,1A,1B,1C: Time-of-flight cameras

[0054] 11: Shell

[0055] 111: Protective parts

[0056] 12: Receiving unit

[0057] 121:Sensor

[0058] 122: Lens

[0059] 13: Main light source unit

[0060] 13L: First Light

[0061] 14: Detection light unit

[0062] 141: Light-emitting element

[0063] 14L: Second light

[0064] 15: Processing unit

[0065] 16: Storage unit

[0066] 91:Object

[0067] 91A: Water Drops

[0068] 91B: Dust

[0069] 91C: Scratches

[0070] 91D:Fingers

[0071] 92: Object to be tested

[0072] A: Lighting area

[0073] B1: First feedback light

[0074] B2: Second feedback light

[0075] Dmax: Maximum distance

[0076] OL, OL1: overlapping area

[0077] P: Preset range

[0078] P1: First position

[0079] P2: Second position

[0080] φ: Phase difference

[0081] Q1~Q4: Accumulated charge

[0082] R: Direct reflected light

[0083] S: Light spot

[0084] S01~S05, S11~S16: Steps

[0085] T: Transmitted light

[0086] T1: The first time period

[0087] T2: The second time period

[0088] V: Field of view

[0089] Wmin: Shortest working distance DETAILED DESCRIPTION

[0090] The detailed description and technical contents of the present disclosure are described below with reference to the accompanying drawings. However, the accompanying drawings are only provided for reference and explanation and are not intended to limit the present disclosure.

[0091] As used herein, terms such as "first," "second," and the like describe various elements, components, regions, layers, and / or sections, and these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, or section from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and the like as used herein do not imply a sequence or order.

[0092] FIG1 is a schematic diagram of a time-of-flight camera according to a first embodiment of the present disclosure. Referring to FIG1 , the time-of-flight camera 1 according to this embodiment includes, for example, a housing 11 , a protective member 111 , a receiving unit 12 , a main light source unit 13 , a detection light unit 14 , and a processing unit 15 .

[0093] The housing 11 may be shaped like a cuboid, a cube, or other three-dimensional structure. The housing 11 may be made of, for example, plastic or metal, but this is not limiting. The housing 11 may be used to support and protect other components and allows the user to easily grasp the housing 11 while operating the time-of-flight camera 1.

[0094] A protective member 111 is disposed on the housing 11. The shape of the protective member 111 can be, for example, a rectangular parallelepiped, a cube, a spherical solid structure, a parabolic solid structure, or any other solid shape. The protective member 111 can be made of, for example, glass or plastic, although this is not limiting. The protective member 111 protects other components from external forces or contamination while allowing light to pass through to the time-of-flight rangefinder camera 1. In some embodiments, the protective member 111 may neither converge nor diverge light. In other embodiments, the protective member 111 may converge or diverge light, although this is not intended to limit the present disclosure.

[0095] The receiving unit 12 is disposed within the housing 11. In certain embodiments, the receiving unit 12 may include, for example, a sensor 121 and a lens 122, although this is not limiting. The sensor 121 may be, for example, a complementary metal oxide semiconductor (CMOS) sensor or a charge coupled device (CCD) sensor, although this is not limiting. The sensor 121 is configured to convert light into an electrical signal, which may be, for example, an analog signal or a digital signal, although this is not limiting. The lens 122 may include, for example, one or more lenses, which may refract light onto the sensor 121.

[0096] The main light source unit 13 is arranged at a first position P1 of the shell 11, and outputs a first light 13L. The first position P1 is, for example, adjacent to the receiving unit 12. The main light source unit 13 can be arranged at any location on the shell 11, inside the shell 11, or outside the shell 11. The main light source unit 13 being adjacent to the receiving unit 12 means, for example, that the main light source unit 13 and the receiving unit 12 are close to each other in physical space, or adjacent and in direct contact. In some embodiments, the main light source unit 13 and the receiving unit 12 are configured so that the main light source unit 13 outputs a first light 13L to illuminate the object to be measured 92, and the reflected light or scattered light generated thereby can be received by the receiving unit 12. It is worth mentioning that the main light source unit 13 can be fixed directly through the shell 11, or can be fixed through other components.

[0097] The main light source unit 13 may comprise, for example, a light-emitting diode, a light bulb, or a fluorescent tube, though these are non-limiting examples. The first light 13L emitted by the main light source unit 13 may comprise, for example, infrared light, visible light, or other electromagnetic waves. In certain embodiments, the main light source unit 13 may comprise, for example, a light-emitting diode emitting infrared light with a wavelength of 850 to 940 nanometers, though these are non-limiting examples. In certain embodiments, the relationship between the amplitude and time of the first light 13L may comprise, for example, a single pulse wave or a periodic wave, with the period of the periodic wave being, for example, 1 / 240 second, 2 / 240 second, 1 / 400 second, 1 / 480 second, or 1 / 576 second.

[0098] The detection light unit 14 is disposed at a second position P2 of the housing 11 and outputs a second light beam 14L. The second position P2 is, for example, disposed around the receiving unit 12. The detection light unit 14 can be disposed anywhere on, within, or outside the housing 11. It should be noted that the second position P2 is different from the first position P1. In this embodiment, the detection light unit 14 is disposed closer to the receiving unit 12 than the main light source unit 13 and is located at the edge of the receiving unit 12. In some embodiments, the detection light unit 14 may include a single light-emitting element 141, but this is not limiting. In other embodiments, the detection light unit 14 may include multiple light-emitting elements 141, which are arranged equidistantly or unequally around the periphery of the receiving unit 12, depending on the shape of the receiving unit 12. The light-emitting elements 141 may include, for example, light-emitting diodes, light bulbs, or fluorescent tubes, but this is not limiting. It is worth noting that the detection light unit 14 may be secured directly to the housing 11 or via other elements.

[0099] In some embodiments, the detection light unit 14 can output a second light beam 14L to illuminate the object 91 (i.e., a defect), generating feedback light based on the surface of the object 91. The second light beam 14L can be, for example, infrared light, visible light, or other electromagnetic waves. The feedback light can be, for example, reflected light or scattered light. The object 91 can be, for example, dust, dirt, mist, water droplets, oil, fingers, flies, machinery, circuit components, or scratches on the outside, inside, or inside (inside or outside) of the protective member 111. All of these can be considered defects and may affect the distance measurement of the time-of-flight camera 1.

[0100] In some embodiments, the detection light unit 14 may emit electromagnetic waves of the same wavelength as the main light source unit 13, such as infrared light with a wavelength of 850 to 940 nanometers, but this is not limiting. The relationship between the amplitude and time of the second light 14L may be the same as that of the first light 13L. For example, the relationship between the amplitude and time of the second light 14L may also be a single pulse wave or a periodic wave, and the period of the periodic wave may be, for example, 1 / 240 second, 2 / 240 second, 1 / 400 second, 1 / 480 second, or 1 / 576 second. Of course, the relationship between the amplitude and time of the second light 14L may be different from that of the first light 13L, such as a constant value.

[0101] It is worth mentioning that the wavelength range of the second light 14L can be substantially the same as the wavelength range of the first light 13L. For example, the wavelength range of the first light 13L is 850 nanometers to 940 nanometers, and the wavelength of the second light 14L is 850 nanometers to 940 nanometers, but this is not restrictive. Thus, the main light source unit 13 and the detection light unit 14 can use the same light-emitting element 141, and a certain degree of wavelength error can be accepted to reduce the complexity of material management. Of course, the wavelength range of the second light 14L can also be different from the wavelength range of the first light 13L. For example, the wavelength range of the first light 13L is 850 nanometers to 940 nanometers, and the wavelength of the second light 14L is 773 nanometers to 1034 nanometers, but this is not restrictive.

[0102] It is worth noting that the detection light unit 14 is preferably positioned at an angle so that the emitted second light 14L does not directly enter the receiving unit 12. Figure 2 is a schematic diagram of the optical path of the second light from the detection light unit. As shown in Figure 2, if the second light 14L directly enters the receiving unit 12, it may produce a strong light spot on the receiving unit 12. If the position of this light spot on the sensor 121 of the receiving unit 12 coincides with or partially overlaps with the image position of the object 91 on the sensor 121 of the receiving unit 12, it may affect the interpretation of the processing unit 15. Therefore, referring again to Figure 1, in this embodiment, the second light 14L can be prevented from directly entering the receiving unit 12 by, for example, adjusting the emission angle range of the detection light unit 14, adjusting the design of the housing 11, adjusting the position of the detection light unit 14 within the housing 11, or adjusting the relative position of the receiving unit 12 and the protective member 111. This prevents the second light 14L from directly entering the receiving unit 12 and affecting the interpretation of the processing unit 15, thereby improving the accuracy of the interpretation.

[0103] Furthermore, the detection light unit 14 is preferably positioned at an angle such that the directly reflected light R generated by the second light beam 14L striking the protective member 111 does not enter the receiving unit 12. FIG3 is a schematic diagram of the optical path of the second light beam from another detection light unit. As shown in FIG3 , if the directly reflected light R generated by the second light beam 14L striking the protective member 111 enters the receiving unit 12, the second light beam 14L may generate a strong light spot on the receiving unit 12. If the position of this light spot on the sensor 121 of the receiving unit 12 coincides with or partially overlaps with the image position of the object 91 on the sensor 121 of the receiving unit 12, it may affect the interpretation of the processing unit 15. Therefore, referring again to FIG1 , in this embodiment, the directly reflected light R generated by the second light beam 14L striking the protective member 111 does not enter the receiving unit 12 by adjusting the emission angle range of the detection light unit 14, adjusting the design of the housing 11, adjusting the position of the detection light unit 14 within the housing 11, or adjusting the relative positions of the receiving unit 12 and the protective member 111. This prevents the direct reflected light R generated by the second light 14L striking the protective member 111 from entering the receiving unit 12 and affecting the interpretation by the processing unit 15, thereby improving the accuracy of the interpretation. It should be noted that the direct reflected light R herein refers to the light R directly reflected from the protective member 111 by the second light 14L before it strikes the object 91 (e.g., dust or a flaw on the protective member).

[0104] In some embodiments, the output angle of the detection light unit 14 can be set within a specific angle range to ensure that the second light 14L does not directly enter the receiving unit 12, and that the directly reflected light R generated by the second light 14L hitting the protective member 111 does not enter the receiving unit 12. For example, the relative positions of the housing 11, protective member 111, detection light unit 14, and receiving unit 12 can be adjusted to achieve the above-mentioned specific angle. This prevents the second light 14L from directly entering the receiving unit 12, and the directly reflected light R generated by the second light 14L hitting the protective member 111 from entering the receiving unit 12 and affecting the interpretation of the processing unit 15, thereby improving the accuracy of the interpretation.

[0105] It should be noted that, as shown in FIG1 , in some embodiments, the illumination area A of the second light beam 14L on the protective member 111 encompasses the field of view V of the receiving unit 12 on the protective member 111. The field of view V (FOV) of the receiving unit 12 can be, for example, pyramidal or conical, though this is not limiting. The apex of the cone, for example, lies within the receiving unit 12. Here, "covering" means that the area of ​​the illumination area A is greater than or equal to the area of ​​the FOV V of the receiving unit 12 on the protective member 111, and that the FOV V of the receiving unit 12 on the protective member 111 lies within the illumination area A. This ensures that the entire FOV V on the protective member 111 is fully illuminated by the second light beam 14L. Therefore, even if only a portion of the object 91 lies within the FOV V of the receiving unit 12, as long as the object 91 is within the illumination area A of the second light beam 14L, the object 91 will still be illuminated by the second light beam 14L, and the reflected or scattered light of the second light beam 14L will be received by the receiving unit 12, ensuring that the receiving unit 12 can detect the object 91.

[0106] Furthermore, in certain embodiments, the second light 14L and the field of view V of the receiving unit 12 define an overlapping region OL1 outside the protective member 111. The maximum distance Dmax of the overlapping region OL1 relative to the protective member 111 is less than the shortest working distance Wmin of the receiving unit 12. The overlapping region OL1 refers to the overlapping region outside the housing 11 created by the second light 14L and the field of view V of the receiving unit 12. The overlapping region OL1 is a three-dimensional spatial range within which the shortest distance or perpendicular distance from any position to the protective member 111 is less than the shortest working distance Wmin of the receiving unit 12. The shortest working distance Wmin refers to the distance within which the time-of-flight camera 1 cannot measure the distance when the object under test 92 is located. Therefore, the range of the interference object 91 is determined to be outside the range of distance measurement, thereby preventing the object under test 92 from being misidentified as the interference object 91.

[0107] The processing unit 15 is electrically connected to the receiving unit 12. The processing unit 15 may be, for example, a programmable logic controller (PLC), a central processing unit (CPU), a microcontroller (MCU), a field programmable gate array (FPGA), or a system on a chip (SoC), but these are not limiting. The processing unit 15 is electrically connected to the receiving unit 12. After the receiving unit 12 converts the light signal into an electrical signal, the electrical signal is transmitted to the processing unit 15 via the electrical connection, and the processing unit 15 performs signal processing.

[0108] Here, we briefly explain the working principle of a time-of-flight camera. For example, a time-of-flight camera can obtain depth (e.g., distance) through direct time-of-flight (dTOF) or indirect time-of-flight (iTOF).

[0109] When measuring depth using direct time-of-flight (TOF), the relationship between the amplitude and time of the light emitted by the light source unit is, for example, a single pulse. After the object reflects or scatters the single pulse, the light is received by the sensor. The interval between the time the light source emits the single pulse and the time the sensor receives it is calculated as a time interval. The following formula can be used to calculate the depth information (e.g., distance) from the TOF camera to the object.

[0110] Where d is the depth (e.g., distance) and c is the speed of light.

[0111] Figure 4 is a timing diagram of indirect time-of-flight (TOF) ranging using a TOF camera. As shown in Figure 4, when a TOF camera measures depth using indirect TOF, the relationship between the amplitude and time of the light emitted by the light source unit is, for example, a periodic wave. After the periodic wave is reflected or scattered by the object under test, the light is received by a sensor, such as a metal oxide semiconductor (CMOS) sensor. The sensor receives the reflected or scattered periodic wave and accumulates charge through the photoelectric effect. If the sensor is divided into four integration periods, such as phase 0, 90, 180, and 270 degrees, and the accumulated charges are defined as Q1, Q2, Q3, and Q4, the phase difference and depth (e.g., distance) can be derived using the following formula.

[0112] Where φ is the phase difference, Q1, Q2, Q3, and Q4 are the accumulated charges, d is the depth (e.g., distance), c is the speed of light, and f is the frequency.

[0113] In other words, referring to FIG. 1 again, if the sensor 121 of the receiving unit 12 of this embodiment utilizes indirect time-of-flight measurement, it can receive the first feedback light B1 generated by the first light 13L in the above manner to generate depth information.

[0114] FIG5 is a timing diagram of the time-of-flight camera according to this embodiment. Referring to FIG1 and FIG5 , in this embodiment, the main light source unit 13 outputs a first light beam 13L during a first time period T1, and the detection light unit 14 outputs a second light beam 14L during a second time period T2. The first time period T1 can be a time range, such as 0 / 60 to 59 / 60 seconds, 0 / 60 to 58 / 60 seconds, 0 / 100 to 99 / 100 seconds, 0 / 120 to 119 / 120 seconds, or 0 / 144 to 143 / 144 seconds, though this is not limiting. In certain embodiments, the second time period T2 can also be a time range, such as 0 / 60 to 1 / 60 seconds, 0 / 60 to 2 / 60 seconds, 0 / 100 to 1 / 100 seconds, 0 / 120 to 1 / 120 seconds, or 0 / 144 to 1 / 144 seconds.

[0115] During a first time period T1, the main light source unit 13 emits a first light beam 13L, while the detection light unit 14 stops emitting light. During a second time period T2, the main light source unit 13 stops emitting light, and the detection light unit 14 emits a second light beam 14L. The second time period T2 can occur before, during, or after the first time period T1. The detection light unit 14 emits the second light beam 14L during the second time period T2, ensuring that the emission times of the second light beam 14L and the first light beam 13L do not overlap at all. In other words, by dividing the time periods, the sensor 121 of the receiving unit 12 receives the first feedback light B1 generated by the first light beam 13L and the second feedback light B2 generated by the second light beam 14L during different time periods, preventing the sensor 121 from receiving both the first feedback light B1 and the second feedback light B2 simultaneously, which could affect the interpretation of the processing unit 15.

[0116] In some embodiments, as shown in FIG5 , the second time period T2 can be set after the first time period T1. For example, the first time period T1 is set to 0 / 60 to 59 / 60 seconds, and the second time period T2 is set to 59 / 60 to 60 / 60 seconds; or the first time period T1 is set to 0 / 100 to 99 / 100 seconds, and the second time period T2 is set to 99 / 100 to 100 / 100 seconds; or the first time period T1 is set to 0 / 120 to 119 / 120 seconds, and the second time period T2 is set to 119 / 120 to 120 / 120 seconds; or the first time period T1 is set to 0 / 144 to 143 / 144 seconds, and the second time period T2 is set to 143 / 144 to 144 / 144 seconds. It should be noted that the lengths of the second time period T2 and the first time period T1 are not restrictive.

[0117] In other embodiments, although not shown in the figure, the second time period T2 can be set before the first time period T1. For example, the second time period T2 can be set to 0 / 60 to 1 / 60 seconds, and the first time period T1 can be set to 1 / 60 to 60 / 60 seconds; or the second time period T2 can be set to 0 / 100 to 1 / 100 seconds, and the first time period T1 can be set to 1 / 100 to 100 / 100 seconds; or the second time period T2 can be set to 0 / 120 to 1 / 120 seconds, and the first time period T1 can be set to 1 / 120 to 120 / 120 seconds; or the second time period T2 can be set to 0 / 144 to 1 / 144 seconds, and the first time period T1 can be set to 1 / 144 to 144 / 144 seconds. It should be noted that the lengths of the second time period T2 and the first time period T1 are not restrictive.

[0118] In other embodiments, although not shown in the figure, the second time period T2 can be set in the middle of the first time period T1. For example, the first time period T1 is set to 0 / 60 to 30 / 60 seconds and 33 / 60 to 60 / 60 seconds, and the second time period T2 is set to 31 / 60 to 32 / 60 seconds; or the first time period T1 is set to 0 / 100 to 50 / 100 seconds and 53 / 100 to 100 / 100 seconds, and the second time period T2 is set to 51 / 100 to 52 / 100 seconds; or the first time period T1 is set to 0 / 120 to 60 / 120 seconds and 63 / 120 to 120 / 120 seconds, and the second time period T2 is set to 61 / 120 to 62 / 120 seconds; or the first time period T1 is set to 0 / 144 to 72 / 144 seconds and 75 / 144 to 144 / 144 seconds, and the second time period T2 is set to 73 / 144 to 74 / 144 seconds. It should be noted that the lengths of the second time period T2 and the first time period T1 are not restrictive.

[0119] On the other hand, in other embodiments, the first time period T1 and the second time period T2 may partially overlap. In other words, the first time period T1 and the second time period T2 are primarily non-overlapping, but partially overlap. For example, the first time period T1 is set to 0 / 60 to 59 / 60 seconds, and the second time period T2 is set to 57 / 60 to 60 / 60 seconds; or the second time period T2 is set to 0 / 60 to 3 / 60 seconds, and the first time period T1 is set to 2 / 60 to 60 / 60 seconds. It should be noted that the lengths of the second time period T2 and the first time period T1 are not restrictive. Similarly, the second time period T2 may also be set in the middle of the first time period T1, and the two may partially overlap.

[0120] It is worth mentioning that when the main light source unit 13 and the detection light unit 14 both use light sources of the same wavelength, the first time period T1 and the second time period T2 do not overlap, thereby avoiding the problem of feedback light interfering with each other.

[0121] Therefore, when the second light 14L emitted by the detection light unit 14 hits the protective member 111, if an object 91 (for example, dust, dirt, fog, water droplets, oil, fingers, flies, machinery, circuit components, or scratches thereon) is located within the preset range P, the second light 14L can illuminate the object 91 and generate a second feedback light B2. Then, the receiving unit 12 can receive the second feedback light B2 and image it onto the sensor 121 through the lens 122 to generate a luminous intensity distribution. For example, a spatial distribution of the intensity of infrared light is formed on the sensor 121. In other words, information similar to that generated by an infrared thermal imager is formed. For another example, a spatial distribution of the intensity of visible light can also be formed on the sensor 121. In other words, information similar to that generated by a digital camera can also be formed.

[0122] Furthermore, the processing unit 15 can determine whether the protective member 111 has a defect based on the luminous intensity distribution, for example, whether a defect such as the object 91 is located within a predetermined range P of the protective member 111. The predetermined range P can be, for example, an overlapping area OL of the second light 14L and the field of view V of the receiving unit 12.

[0123] Therefore, the processing unit 15 can perform image interpretation (for example, with the assistance of an algorithm) based on the luminous intensity distribution generated by the receiving unit 12. When the luminous intensity distribution meets specific characteristics, or when the luminous intensity distribution exceeds the preset brightness and size, it is determined that an object 91 is located within the preset range P of the protective member 111. In some embodiments, if the processing unit 15 determines that an object 91 is located within the preset range P of the protective member 111, the processing unit 15 can output a warning signal. The warning signal is, for example, a sound signal or an image signal. Therefore, when performing a detection, if the object 91 interferes with the measured distance so that the measured distance is an invalid value, a warning signal can be issued and the distance measurement can be stopped to avoid obtaining erroneous distance information.

[0124] As described above, before, during, or after distance measurement, the time-of-flight camera 1 of the present disclosure outputs the second light 14L through the detection light unit 14. The receiving unit 12 receives the second feedback light B2 generated by the second light 14L to generate a luminous intensity distribution. The processing unit 15 then determines whether the protective member 111 has a defect, such as whether an object 91 (not the object to be measured 92, such as dust 91B) is located within a predetermined range P of the protective member 111. Therefore, at any point in time while measuring distance, the time-of-flight camera 1 of the present disclosure can also simultaneously determine whether there is interference from objects 91 located on or above the protective member 111, such as dust 91B, dirt, fog, water droplets 91A, oil, fingers 91D, flies, machinery, circuit components, or scratches 91C on the protective member 111. Thus, the disclosed time-of-flight camera 1 can determine whether an object 91 on the protective member 111 interferes with distance measurement without affecting the camera's waterproof and dustproof structure or the camera's measurement performance. In certain distance measurement scenarios, ensuring that distance measurement is not interfered with by objects 91 is crucial. For example, when the time-of-flight camera 1 is used for human safety monitoring in human-machine collaboration, or for measuring the distance between a vehicle and an obstacle, any interference from objects 91 on the protective member 111 could potentially cause damage to life or property.

[0125] FIG6 is a schematic diagram of a time-of-flight camera according to a second embodiment of the present disclosure. Referring to FIG6 , the time-of-flight camera 1A according to the second embodiment further includes a storage unit 16 electrically connected to the receiving unit 12 and the processing unit 15. The storage unit 16 is used to store luminous intensity distributions. The storage unit 16 may be, for example, a non-transitory storage medium such as flash memory, read-only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or an optical storage device, but this is not limiting. After the storage unit 16 stores the luminous intensity distributions, the processing unit 15 can read the storage unit 16 to analyze one or more luminous intensity distributions. In some embodiments, the luminous intensity distributions stored in the storage unit 16 can also be output as data for machine learning. In other embodiments, the machine learning training results can also be stored in the storage unit 16 for reading by the processing unit 15. It is worth noting that the storage unit 16 can only begin storing the luminous intensity distributions when the main light source unit 13 stops emitting light.

[0126] Thus, the time-of-flight camera 1A of the second embodiment can perform more complex calculations than the first embodiment, or output the stored luminous intensity distribution for other applications. New software can also be installed via the storage device 16, such as adding new algorithms or data, so that the time-of-flight camera 1A can respond to interference from different objects 91 or adjust according to the usage environment.

[0127] FIG7 is a schematic diagram of a time-of-flight camera according to a third embodiment of the present disclosure. Referring to FIG1 and FIG7 , the time-of-flight camera 1B of the third embodiment is similar to the time-of-flight camera 1 of the first embodiment. The difference lies in that in this embodiment, the detection light unit 14 is disposed outside the protective member 111. Specifically, the detection light unit 14 and the receiving unit 12 are disposed on either side of the protective member 111. The second light 14L generated by the detection light unit 14 is emitted directly outside the protective member 111.

[0128] It should be noted that it is preferred that the transmitted light T generated by the second light 14L emitted by the detection light unit 14 upon striking the protective member 111 does not enter the receiving unit 12 (as required by Figures 2 and 3). As described in the first embodiment, for example, the angular range of the detection light unit 14, the design of the housing 11, the position of the detection light unit 14 within the housing 11, or the relative positions of the receiving unit 12 and the protective member 111 can be adjusted to prevent the transmitted light T generated by the second light 14L striking the protective member 111 from entering the receiving unit 12.

[0129] Therefore, the time-of-flight camera 1B of the third embodiment can add different configuration modes of the time-of-flight camera.

[0130] Figure 8 is a schematic diagram of a time-of-flight camera according to a fourth embodiment of the present disclosure, and Figure 9 is a schematic diagram of the field of view and illumination area on the protective member of the present disclosure. Note that for clarity, the main light source unit 13 is omitted in Figure 8 . Referring to Figures 1 and 8 , the time-of-flight camera 1C according to the fourth embodiment is similar to the time-of-flight camera 1 according to the first embodiment. The difference lies in the detection light unit 14 of the fourth embodiment of the time-of-flight camera 1C, which includes a plurality of light-emitting elements 141 disposed around the receiving unit 12 and collectively emits a second light beam 14L. Similarly, the illumination area A of the second light beam 14L on the protective member 111 covers the field of view V of the receiving unit 12 on the protective member 111. The plurality of light-emitting elements 141 can be, for example, two, three, four, or more. The plurality of light-emitting elements 141 can be disposed around the receiving unit 12 at equal or unequal intervals. The area of ​​the illumination region A on the protective member 111 by the second light beam 14L emitted jointly by the multiple light-emitting elements 141 is greater than or equal to the area of ​​the field of view V of the receiving unit 12 on the protective member 111, and the field of view V of the receiving unit 12 on the protective member 111 is located within the illumination region A. For example, the illumination region A on the protective member 111 by the second light beam 14L can be made to encompass the field of view V of the receiving unit 12 on the protective member 111 by adjusting the light-emitting angle range of the multiple light-emitting elements 141, adjusting the design of the housing 11, adjusting the positions of the multiple light-emitting elements 141 within the housing 11, or adjusting the relative positions of the receiving unit 12 and the protective member 111.

[0131] As shown in Figure 8 , this embodiment uses four light-emitting elements 141 equally spaced around the perimeter of the receiving unit 12 (Figure 8 is a cross-sectional view, therefore only two light-emitting elements 141 are shown). This is not limiting. The second light beams 14L generated by the four light-emitting elements 141 illuminate an area A on the protective member 111, encompassing a field of view V of the receiving unit 12 on the protective member 111. As shown in Figures 8 and 9 , any defects (such as water droplets, scratches, dust, or fingers) within the field of view V will be illuminated by the second light beams 14L of the time-of-flight camera 1C of the fourth embodiment.

[0132] Therefore, the time-of-flight camera 1C of the fourth embodiment can ensure that the entire field of view V on the protective member 111 is illuminated by the second light 14L, so that the brightness of the second light 14L on the protective member 111 is more uniform, and the image of the interfering object is easier to interpret.

[0133] Next, the optical simulation results of water droplet, dust, and scratch detection will be described using the time-of-flight camera 1C according to the fourth embodiment.

[0134] Figure 10 is a schematic diagram of a time-of-flight camera detecting a water droplet. Figure 11 is a schematic diagram of the position of the water droplet detected by the time-of-flight camera. Figures 12A-12I are simulated images of the light spot effect of the time-of-flight camera. As shown in Figures 10 and 11, the simulation conditions are as follows: a water droplet 91A (e.g., 1.5 mm in diameter, not limiting) is placed at nine different locations on the protective member 111 and detected. As shown in Figures 11 and 12A, if the water droplet 91A is located at the left position in the top row, the time-of-flight camera can clearly detect the light spot S image at the corresponding position. As shown in Figures 11 and 12B, if the water droplet 91A is located in the middle position in the top row, the time-of-flight camera can clearly detect the light spot S image at the corresponding position. As shown in Figures 11 and 12C, if the water droplet 91A is located at the right position in the top row, the time-of-flight camera can clearly detect the light spot S image at the corresponding position. As shown in Figures 11 and 12D, if the water droplet 91A is located on the left side of the middle row, the time-of-flight camera of the present disclosure can clearly detect the light spot S image at the corresponding position. As shown in Figures 11 and 12E, if the water droplet 91A is located in the middle of the middle row, the time-of-flight camera of the present disclosure can clearly detect the light spot S image at the corresponding position. As shown in Figures 11 and 12F, if the water droplet 91A is located on the right side of the middle row, the time-of-flight camera of the present disclosure can clearly detect the light spot S image at the corresponding position. As shown in Figures 11 and 12G, if the water droplet 91A is located on the left side of the bottom row, the time-of-flight camera of the present disclosure can clearly detect the light spot S image at the corresponding position. As shown in Figures 11 and 12H, if the water droplet 91A is located in the middle of the bottom row, the time-of-flight camera of the present disclosure can clearly detect the light spot S image at the corresponding position. As shown in Figures 11 and 12I, if the water droplet 91A is located on the right side of the bottom row, the time-of-flight camera of the present disclosure can clearly detect the light spot S image at the corresponding position.

[0135] Figure 13 is a schematic diagram of dust detection by the time-of-flight camera of the present disclosure. Figure 14 is a schematic diagram of the locations where dust is detected by the time-of-flight camera of the present disclosure. Figures 15A-15I are simulated diagrams of the light spot effect of the time-of-flight camera of the present disclosure. As shown in Figures 13 and 14, the simulation conditions are as follows: dust 91B (e.g., 1.0 mm in diameter, not limiting) is placed at nine different locations on the protective member 111 and detected separately. As shown in Figures 14 and 15A, if dust 91B is located at the left position in the top row, the time-of-flight camera of the present disclosure can clearly detect the light spot S image at the corresponding location. As shown in Figures 14 and 15B, if dust 91B is located at the center position in the top row, the time-of-flight camera of the present disclosure can clearly detect the light spot S image at the corresponding location. As shown in Figures 14 and 15C, if dust 91B is located at the right position in the top row, the time-of-flight camera of the present disclosure can clearly detect the light spot S image at the corresponding location. As shown in Figures 14 and 15D, if dust 91B is located on the left side of the middle row, the time-of-flight camera of the present disclosure can clearly detect the light spot S image at the corresponding location. As shown in Figures 14 and 15E, if dust 91B is located in the middle of the middle row, the time-of-flight camera of the present disclosure can clearly detect the light spot S image at the corresponding location. As shown in Figures 14 and 15F, if dust 91B is located on the right side of the middle row, the time-of-flight camera of the present disclosure can clearly detect the light spot S image at the corresponding location. As shown in Figures 14 and 15G, if dust 91B is located on the left side of the bottom row, the time-of-flight camera of the present disclosure can clearly detect the light spot S image at the corresponding location. As shown in Figures 14 and 15H, if dust 91B is located in the middle of the bottom row, the time-of-flight camera of the present disclosure can clearly detect the light spot S image at the corresponding location. As shown in Figures 14 and 15I, if water droplets 91A are located on the right side of the bottom row, the time-of-flight camera of the present disclosure can clearly detect the light spot S image at the corresponding location.

[0136] Figure 16 is a schematic diagram of a time-of-flight camera of the present disclosure detecting a scratch. Figures 17A and 17B are schematic diagrams of the location of the scratch detected by the time-of-flight camera of the present disclosure. Figures 18A and 18B are simulated diagrams of the light spot effect of the time-of-flight camera of the present disclosure. As shown in Figures 16, 17A, and 17B, the simulation conditions are as follows: a scratch 91C (e.g., 0.2 mm wide, not limiting) is engraved on the protective member 111 in either the left-right or the up-down direction as shown in the figure, and the detection is performed respectively. As shown in Figures 17A and 18A, if the scratch 91C is in the left-right direction as shown in the figure, the time-of-flight camera of the present disclosure can clearly detect the light spot S image at the corresponding location. Similarly, as shown in Figures 17B and 18B, if the scratch 91C is in the up-down direction as shown in the figure, the time-of-flight camera of the present disclosure can clearly detect the light spot S image at the corresponding location.

[0137] Figure 19 is a schematic diagram of a time-of-flight (TOF) camera of the present disclosure detecting a finger. When a finger 91D is within a predetermined range P, second light 14L illuminates finger 91D and generates second feedback light B2. Similarly, the receiving unit of the TOF camera of the present disclosure receives second feedback light B2 and generates a luminous intensity distribution.

[0138] Although the above simulation is based on the structure of the fourth embodiment, any of the time-of-flight cameras of the first to fourth embodiments of the present disclosure can detect defects that may cause interference, such as water droplets, dust, scratches, or fingers.

[0139] FIG20 illustrates the steps of a time-of-flight camera inspection method according to one embodiment of the present disclosure. Referring to FIG20 , the inspection method of this embodiment includes steps S11 to S15. Step S11 emits a first light beam during a first time period and generates a first feedback light beam. Step S12 receives the first feedback light beam and generates depth information. Step S13 emits a second light beam during a second time period and directs it toward the protective member, generating a second feedback light beam. Step S14 receives the second feedback light beam and generates a luminous intensity distribution. Step S15 determines whether the protective member has a defect based on the luminous intensity distribution. The inspection method of this embodiment can be applied to the time-of-flight cameras 1, 1A, 1B, and 1C described in any of the first to fourth embodiments, but this is not intended to be limiting. The inspection method of this embodiment can also be applied to other time-of-flight cameras or other devices that require defect detection on or in protective members. The detailed inspection method has been described in detail in the above embodiments and will not be repeated here.

[0140] Figure 21 illustrates the steps of a time-of-flight camera inspection method according to another embodiment of the present disclosure. Referring to Figure 21 , the inspection method of this embodiment includes steps S11 to S16. Step S11 emits a first light beam during a first time period and generates a first feedback light beam. Step S12 receives the first feedback light beam and generates depth information. Step S13 emits a second light beam during a second time period and directs it toward the protective member, generating a second feedback light beam. Step S14 receives the second feedback light beam and generates a luminous intensity distribution. Step S15 determines whether the protective member is defective based on the luminous intensity distribution. Step S16 outputs a warning signal if the protective member is determined to be defective. The inspection method of this embodiment can also be used with the time-of-flight cameras 1, 1A, 1B, and 1C of the aforementioned embodiments, but this is not intended to be limiting. The inspection method of this embodiment can also be applied to other time-of-flight cameras or other devices that need to detect foreign objects on or above a protective member. The detailed inspection method has been described in detail in the aforementioned embodiments and will not be repeated here.

[0141] In addition, if it is determined that the protective member has no defects, the process returns to step S11 and performs depth and defect detection again.

[0142] Therefore, when performing the inspection method of the time-of-flight ranging camera, if the measured distance is interfered with by a defect and becomes an invalid value, a warning signal can be issued and the distance measurement can be stopped to avoid obtaining erroneous distance information.

[0143] In summary, the disclosed time-of-flight camera and its detection method can generate a luminous intensity distribution by detecting a second light beam emitted by a light detection unit before, during, or after distance measurement. A receiving unit then receives the second feedback light generated by the second light beam to determine whether the protective member has defects, such as whether an object (not the object to be measured, such as dust) is located within a predetermined range of the protective member. Therefore, at any point in time during distance measurement, the disclosed time-of-flight camera and its detection method can also simultaneously determine whether there is interference from objects on or above the protective member, such as dust, dirt, fog, water droplets, oil, fingers, flies, mechanical objects, circuit components, or scratches on the protective member. Thus, the disclosed time-of-flight camera and its detection method can determine whether objects on the protective member could interfere with distance measurement without affecting the waterproof and dustproof structure of the time-of-flight camera or the time-of-flight camera's measurement. In certain distance measurement scenarios, it is important to ensure that the distance measurement is not interfered with by objects. For example, when a time-of-flight ranging camera is used for personnel safety monitoring in human-machine collaboration, or when measuring the distance between a car and an obstacle, interference from any object above the protective part may cause damage to life and property.

[0144] Furthermore, the disclosed time-of-flight camera and its detection method can be configured so that the second light output by the detection light unit does not directly enter the receiving unit, and the directly reflected or transmitted light generated by the second light hitting the protective element does not enter the receiving unit. This prevents other light from affecting the processing unit's interpretation, thereby increasing the accuracy of interfering object detection. Furthermore, the disclosed time-of-flight camera and its detection method can expand the range of interfering object detection by illuminating the protective element with the second light, encompassing the field of view of the receiving unit on the protective element. Furthermore, the disclosed time-of-flight camera and its detection method can define an overlapping region (located on the surface of the protective element) outside the protective element by using the second light and the field of view of the receiving unit. The maximum distance of the overlapping region relative to the protective element is less than the shortest working distance of the receiving unit, meaning that the range of interfering objects is not within the range of distance measurement, thereby preventing the object being misidentified as an interfering object. Furthermore, the disclosed time-of-flight camera and its detection method can ensure that the wavelength range of the first light and the wavelength range of the second light are substantially the same, i.e., using the same light-emitting element to reduce the complexity of material control. In addition, the time-of-flight camera and detection method disclosed herein can avoid the influence of different feedback lights on each other by emitting the first light and the second light at different time periods, thereby increasing the accuracy of the interpretation.

[0145] The detection light unit of the time-of-flight camera disclosed herein may further include a plurality of light-emitting elements disposed around the receiving unit to jointly emit a second light beam to expand the range of detecting interference objects and make the brightness of the second light beam on the protective element more uniform, thereby increasing the accuracy of the interpretation.

[0146] As used herein and not otherwise defined, terms such as "substantially" and "approximately" are used to describe and describe small variations. When used in conjunction with an event or circumstance, the terms may encompass the exact moment the event or circumstance occurs, as well as a close approximation of the point at which the event or circumstance occurs.

[0147] The above summarizes the components of several embodiments so that those skilled in the art to which this disclosure belongs can better understand the concepts of the embodiments of this disclosure. Those skilled in the art to which this disclosure belongs should understand that the embodiments of this disclosure can be used as a basis to design or modify other processes and structures to achieve the same purposes and / or achieve the same benefits as the embodiments introduced herein. Those skilled in the art to which this disclosure belongs should also understand that these equivalent structures do not depart from the spirit and scope of this disclosure, and various changes, substitutions and other options can be made herein without departing from the spirit and scope of this disclosure. Therefore, the scope of protection of this disclosure shall be defined as the scope of the claims appended hereto.

Claims

1. A time-of-flight ranging camera, comprising: case; A protective member, disposed on the housing; A main light source unit is disposed at a first position of the housing and outputs a first light in a first time period; A detection light unit is disposed at a second position of the housing and outputs a second light in a second time period; a receiving unit, disposed in the housing, and receiving a first feedback light generated by the first light, and receiving a second feedback light generated by the second light irradiating the protective element to generate a luminous intensity distribution; a storage unit, electrically connected to the receiving unit, and storing the luminous intensity distribution; and The processing unit is electrically connected to the receiving unit and the storage unit, and determines whether the protection component has defects according to the luminous intensity distribution. 2 . The time-of-flight camera according to claim 1 , wherein an illumination area of ​​the second light on the protective member covers a field of view of the receiving unit on the protective member.

3. The time-of-flight camera according to claim 1, wherein the second light and the field of view of the receiving unit define an overlapping area outside the protective member, and a maximum distance of the overlapping area relative to the protective member is smaller than a shortest working distance of the receiving unit. The TOF camera according to claim 1 , wherein the second light does not directly enter the receiving unit. 5 . The time-of-flight camera according to claim 1 , wherein the direct reflected light or transmitted light generated by the second light irradiating the protective member does not enter the receiving unit.

6. The time-of-flight rangefinder camera according to claim 1, wherein the detection light unit comprises a plurality of light emitting elements disposed around the receiving unit and jointly emitting the second light, and an illumination area of ​​the second light on the protective member covers a field of view of the receiving unit on the protective member. 7 . The time-of-flight camera according to claim 1 , wherein during the second period of time, the main light source unit stops emitting light, and the detection light unit emits the second light.

8. The TOF camera of claim 1, wherein the first time period partially overlaps with the second time period. 9 . The time-of-flight camera according to claim 1 , wherein a wavelength range of the first light is substantially the same as a wavelength range of the second light.

10. A time-of-flight ranging camera, comprising: case; A protective member, disposed on the housing; A receiving unit, disposed in the housing; A main light source unit is disposed adjacent to the receiving unit and outputs a first light; A detection light unit is arranged around the receiving unit and outputs a second light; and A processing unit, electrically connected to the receiving unit; The receiving unit receives the first feedback light generated by the first light, and receives the second feedback light generated by the second light to generate a luminous intensity distribution, and the processing unit determines whether the protective element has a defect according to the luminous intensity distribution. 11 . The time-of-flight camera according to claim 10 , wherein an illumination area of ​​the second light on the protection member covers a field of view of the receiving unit on the protection member.

12. The time-of-flight camera according to claim 10, wherein the second light and the field of view of the receiving unit define an overlapping area outside the protective member, and a maximum distance of the overlapping area relative to the protective member is smaller than a shortest working distance of the receiving unit.

13. The TOF camera according to claim 10, wherein the second light does not directly enter the receiving unit. 14 . The time-of-flight range-finding camera according to claim 10 , wherein the direct reflected light or transmitted light generated by the second light irradiating the protective member does not enter the receiving unit.

15. The time-of-flight camera according to claim 10, wherein the detection light unit comprises a plurality of light emitting elements disposed around the receiving unit and jointly emitting the second light, and an illumination area of ​​the second light on the protective member covers a field of view of the receiving unit on the protective member.

16. The TOF camera according to claim 10, further comprising: The storage unit is electrically connected to the receiving unit and the processing unit, and stores the luminous intensity distribution.

17. A detection method for a time-of-flight ranging camera, comprising: Emitting a first light in a first time period and generating a first feedback light; receiving the first feedback light and generating depth information; emitting a second light beam to the protective element in a second time period and generating a second feedback light; receiving the second feedback light to generate a luminous intensity distribution; and Whether the protection member has a defect is determined based on the luminous intensity distribution.

18. The detection method according to claim 17, further comprising: If it is determined that the protective member has the defect, a warning signal is output.

19. The detection method according to claim 17, wherein emitting the second light to the protection element in the second time period and generating the second feedback light further comprises: During the second time period, the first light is stopped from being emitted, and the second light is emitted.

20. The detection method according to claim 17, wherein the first time period partially overlaps with the second time period.

Images