Flight-time ranging camera and detection method thereof

Abstract

The invention discloses a flight time distance measuring camera and a detection method thereof. The flight time distance measuring camera comprises a shell; the protection piece is arranged on the shell; the receiving unit is arranged in the shell; the main light source unit is arranged adjacent to the receiving unit and outputs first light; the detection light unit is arranged on the periphery of the receiving unit and outputs second light; and the processing unit is electrically connected with the receiving unit. The receiving unit receives first feedback light generated by the first light to generate depth information and receives second feedback light generated by the second light to generate luminous intensity distribution, and the processing unit judges whether the protection piece has defects or not according to the luminous intensity distribution.

Description

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 its detection method. Background Art

[0002] Time-of-flight (ToF) cameras are one of the three-dimensional (3D) sensing technologies and can be widely used in many fields such as industry, automation, logistics, monitoring, and medical. Since ToF cameras need to be dustproof and waterproof to protect internal components and circuits, they are generally covered with a housing on the outside and protective members such as glass or plastic are provided, and the light emitted and received by the ToF camera can penetrate the protective member.

[0003] However, if there are interfering objects such as dirt, scratches, water droplets, or fog on or above the protective member, the measurement results will be affected. If the ToF camera is used for personnel safety detection in human-machine collaboration, any interfering object on or above the protective member may cause damage to life and property.

[0004] In view of this, how to detect interfering objects such as dirt, scratches, water droplets, and fog on or above the protective member by a device or method without affecting the waterproof and dustproof structure of the ToF camera and without affecting the measurement of the ToF camera is actually one of the problems that need to be solved urgently at present. Summary of the Invention

[0005] The present disclosure provides a time-of-flight ranging camera and its detection method, which can detect interfering objects such as dirt, scratches, water droplets, and fog on or above the protective member and take corresponding measures, such as shutting down or issuing a warning signal, without affecting the waterproof and dustproof structure of the ToF camera and without affecting the measurement of the ToF camera.

[0006] The present disclosure provides a time-of-flight ranging camera including 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 ray in a first time period; a detection light unit disposed at a second position of the housing and outputting a second light ray in a second time period; a receiving unit disposed inside the housing, receiving a first feedback light generated by the first light ray, and generating a light intensity distribution by receiving a second feedback light generated by the second light ray incident on the protective member; a storage unit electrically connected to the receiving unit for storing the light 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 light intensity distribution.

[0007] In some embodiments, the illumination area of the second light ray on the protective member covers the field of view of the receiving unit on the protective member.

[0008] In some embodiments, the second light ray and the viewing range of the receiving unit define an overlapping area outside the protective member, and the maximum distance of the overlapping area relative to the protective member is less than the shortest working distance of the receiving unit.

[0009] In some embodiments, the second light ray does not directly enter the receiving unit.

[0010] In some embodiments, the direct reflected light or transmitted light generated by the second light ray hitting the protective member does not enter the receiving unit.

[0011] In some embodiments, the detection light unit includes a light-emitting element disposed around the receiving unit, and the second light ray is emitted jointly, and the illumination area of the second light ray on the protective member covers the viewing range of the receiving unit on the protective member.

[0012] In some embodiments, in the second time period, the main light source unit stops emitting light, and the detection light unit emits the second light ray.

[0013] In some embodiments, the first time period and the second time period partially overlap.

[0014] In some embodiments, the wavelength range of the first light ray is substantially the same as the wavelength range of the second light ray.

[0015] The present disclosure provides a time-of-flight ranging camera including a housing; a protective member disposed on the housing; a receiving unit disposed inside the housing; a main light source unit adjacent to the receiving unit and outputting a first light ray; a detection light unit disposed around the receiving unit and outputting a second light ray; and a processing unit electrically connected to the receiving unit; the receiving unit receives a first feedback light generated by the first light ray, and receives a second feedback light generated by the second light ray to generate a light intensity distribution, and the processing unit determines whether the protective member has a defect based on the light intensity distribution.

[0016] In some embodiments, the illumination area of the second light ray on the protective member covers the viewing range of the receiving unit on the protective member.

[0017] In some embodiments, the second light ray and the viewing range of the receiving unit define an overlapping area outside the protective member, and the maximum distance of the overlapping area relative to the protective member is less than the shortest working distance of the receiving unit.

[0018] In some embodiments, the second light ray does not directly enter the receiving unit.

[0019] In some embodiments, the direct reflected light or transmitted light generated by the second light ray hitting the protective member does not enter the receiving unit.

[0020] In some embodiments, the detection light unit includes light emitting elements disposed around the receiving unit and emitting a second light together, 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.

[0021] In some embodiments, the time-of-flight ranging camera further includes a storage unit electrically connected to the receiving unit and the processing unit to store the luminous intensity distribution.

[0022] The present disclosure provides a detection method for a time-of-flight rangefinder 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 in a second time period to a protective member and generating a second feedback light; receiving the second feedback light and generating a luminous intensity distribution; and determining whether the protective member has a defect according to the luminous intensity distribution.

[0023] In some embodiments, the detection method further includes outputting a warning signal if it is determined that the protective element has a defect.

[0024] In some embodiments, emitting the second light to the protective element in the second time period and generating the second feedback light further includes stopping emitting the first light and emitting the second light in the second time period.

[0025] In some embodiments, the first time period partially overlaps with the second time period.

[0026] As described above, the time-of-flight rangefinder camera and its detection method disclosed herein can generate a luminous intensity distribution by outputting a second light beam through the detection light unit before, during or after measuring the distance, and the receiving unit receives the second feedback light generated by the second light beam, and judges whether the protective member has defects through the processing unit, such as whether there is an object (not the object to be measured, such as dust, etc.) and other defects located within the preset range of the protective member. Therefore, the time-of-flight rangefinder camera and its detection method disclosed herein can also simultaneously judge whether there is interference by objects such as dust, dirt, fog, water droplets, oil, fingers, flies, machinery, circuit components or scratches on the protective member located on or above the protective member at any time point when measuring the distance. Therefore, the time-of-flight rangefinder camera and its detection method disclosed herein can judge whether there is an object on the protective member that will interfere with the distance measurement without affecting the waterproof and dustproof structure of the time-of-flight rangefinder camera and without affecting the measurement of the time-of-flight rangefinder camera. 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 detection in human-machine collaboration, or when detecting the distance between a car and an obstacle, for example. Interference from any object on the protective part may cause damage to life and property.

[0027] Furthermore, the time-of-flight ranging camera and its detection method according to the present disclosure can be set such that the second light ray output by the detection light unit does not directly enter the receiving unit, and the direct reflection light or transmitted light generated when the second light ray hits the protection member does not enter the receiving unit, so as to avoid the influence of other light rays on the interpretation by the processing unit and increase the accuracy of the interpretation of interfering objects. In addition, the time-of-flight ranging camera and its detection method according to the present disclosure can expand the range of detecting interfering objects by covering the field of view range of the receiving unit on the protection member with the illumination area of the second light ray on the protection member. Furthermore, the time-of-flight ranging camera and its detection method according to the present disclosure can define an overlapping area (the area above the surface of the protection member) outside the protection member by the second light ray and the field of view range of the receiving unit. The maximum distance of the overlapping area relative to the protection member is less than the shortest working distance of the receiving unit, that is, the range of judging interfering objects will not be within the range of distance measurement, thereby avoiding the situation where the object to be measured is misjudged as an interfering object. Also, the time-of-flight ranging camera and its detection method according to the present disclosure can make the wavelength range of the first light ray substantially the same as the wavelength range of the second light ray, that is, use the same light-emitting element to reduce the complexity of material control. In addition, the time-of-flight ranging camera and its detection method according to the present disclosure can avoid the mutual influence of different feedback lights by emitting the first light ray and the second light ray at different time periods, thereby increasing the accuracy of the interpretation.

[0028] The detection light unit of the time-of-flight ranging camera according to the present disclosure may further include a plurality of light-emitting elements disposed around the receiving unit to jointly emit the second light ray to expand the range of detecting interfering objects, and make the brightness of the second light ray on the protection member more uniform, thereby increasing the accuracy of the interpretation. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] 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 become apparent from the description, drawings, and claims, wherein:

[0030] Figure 1 is a schematic diagram of a time-of-flight ranging camera according to the first embodiment of the present disclosure;

[0031] Figure 2 is a schematic diagram of the optical path of the second light ray of a detection light unit;

[0032] Figure 3 is a schematic diagram of the optical path of the second light ray of another detection light unit;

[0033] Figure 4 is a timing diagram of indirect time-of-flight ranging between time-of-flight ranging cameras;

[0034] Figure 5 is a timing diagram of the time-of-flight ranging camera of this embodiment;

[0035] Figure 6 Schematic diagram of a time-of-flight ranging camera according to the second embodiment of the present disclosure;

[0036] Figure 7 Schematic diagram of a time-of-flight ranging camera according to the third embodiment of the present disclosure;

[0037] Figure 8 Schematic diagram of a time-of-flight ranging camera according to the fourth embodiment of the present disclosure;

[0038] Figure 9 Schematic diagram of the field of view range and illumination area on the protective member of the present disclosure;

[0039] Figure 10 Schematic diagram of a time-of-flight ranging camera of the present disclosure for detecting water droplets;

[0040] Figure 11 Schematic diagram of the position of water droplets detected by a time-of-flight ranging camera of the present disclosure;

[0041] Figures 12A to 12I Effect simulation diagram of the light spot of a time-of-flight ranging camera of the present disclosure;

[0042] Figure 13 Schematic diagram of a time-of-flight ranging camera of the present disclosure for detecting dust;

[0043] Figure 14 Schematic diagram of the position of dust detected by a time-of-flight ranging camera of the present disclosure;

[0044] Figures 15A to 15I Effect simulation diagram of the light spot of a time-of-flight ranging camera of the present disclosure;

[0045] Figure 16 Schematic diagram of a time-of-flight ranging camera of the present disclosure for detecting scratches;

[0046] Figure 17A and Figure 17B Schematic diagram of the position of scratches detected by a time-of-flight ranging camera of the present disclosure;

[0047] Figure 18A and Figure 18B Effect simulation diagram of the light spot of a time-of-flight ranging camera of the present disclosure;

[0048] Figure 19 Schematic diagram of a time-of-flight ranging camera of the present disclosure for detecting fingers;

[0049] Figure 20 Step diagram of a detection method for a time-of-flight ranging camera according to an embodiment of the present disclosure;

[0050] Figure 21It is a step diagram of the detection method of the time-of-flight ranging camera according to another embodiment of the present disclosure.

[0051] Explanation of reference numerals in the drawings:

[0052] 1, 1A, 1B, 1C: Time-of-flight ranging cameras

[0053] 11: Housing

[0054] 111: Protective member

[0055] 12: Receiving unit

[0056] 121: Sensor

[0057] 122: Lens

[0058] 13: Main light source unit

[0059] 13L: First light ray

[0060] 14: Detection light unit

[0061] 141: Light-emitting element

[0062] 14L: Second light ray

[0063] 15: Processing unit

[0064] 16: Storage unit

[0065] 91: Object

[0066] 91A: Water droplet

[0067] 91B: Dust

[0068] 91C: Scratch

[0069] 91D: Finger

[0070] 92: Object to be measured

[0071] A: Illumination area

[0072] B1: First feedback light

[0073] B2: Second feedback light

[0074] Dmax: Maximum distance

[0075] OL, OL1: Overlapping area

[0076] P: Preset range

[0077] P1: First position

[0078] P2: Second position

[0079] φ: Phase difference

[0080] Q1 to Q4: Cumulative charge

[0081] R: Directly reflected light

[0082] S: Light spot

[0083] S01 to S05, S11 to S16: Steps

[0084] T: Transmitted light

[0085] T1: First time period

[0086] T2: Second time period

[0087] V: Field of view

[0088] Wmin: Shortest working distance Detailed implementation manners

[0089] The detailed description and technical content of the present disclosure are described below in conjunction with the accompanying drawings. However, the accompanying drawings are only provided for reference and illustration purposes and are not used to limit the present disclosure.

[0090] As used herein, terms such as "first", "second", etc. describe various elements, components, regions, layers, and / or parts, and these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, or part from another. Unless the context clearly indicates otherwise, terms such as "first", "second" used herein do not imply order or sequence.

[0091] Figure 1 For a schematic diagram of a time-of-flight ranging camera according to a first embodiment of the present disclosure, please refer to Figure 1 As shown, the time-of-flight ranging camera 1 of this embodiment, for example, includes 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.

[0092] The shape of the housing 11 can be, for example, a cuboid, a cube, or other three-dimensional structures. The material of the housing 11 can be, for example, plastic or metal, but it is not limited thereto. The housing 11 can be used to provide support and protection for other components, and allow the user to easily hold the housing 11 to use the time-of-flight ranging camera 1.

[0093] The protection member 111 is disposed on the housing 11. The shape of the protection member 111 can be, for example, a cuboid, a cube, a three-dimensional structure with a spherical shape, a three-dimensional structure with a paraboloid shape, or a three-dimensional structure with other shapes. The material of the protection member 111 can be, for example, glass or plastic, but it is not limited thereto. The protection member 111 can allow light to pass through and irradiate into the time-of-flight distance measuring camera 1 while protecting other components from external forces or dirt interference. In some embodiments, the protection member 111 may neither converge nor diverge light. In some other embodiments, the protection member 111 may also converge or diverge light, which is not intended to limit the present disclosure.

[0094] The receiving unit 12 is disposed in the housing 11. In some embodiments, the receiving unit 12 can include, for example, a sensor 121 and a lens 122, but it is not limited thereto. The sensor 121 can be, for example, a complementary metal oxide semiconductor (CMOS) sensor or a charge-coupled device (CCD) sensor, but it is not limited thereto. The sensor 121 is used to convert light into an electrical signal, and the electrical signal can be, for example, an analog signal or a digital signal, but it is not limited thereto. The lens 122 can include, for example, one or more groups of lenses, and the lenses can refract light onto the sensor 121.

[0095] The main light source unit 13 is disposed at the first position P1 of the housing 11 and outputs the first light 13L. The first position P1 is, for example, adjacent to the receiving unit 12. The main light source unit 13 can be disposed anywhere on the housing 11, inside the housing 11, or outside the housing 11. The main light source unit 13 being adjacent to the receiving unit 12 means that, for example, the main light source unit 13 and the receiving unit 12 are close to each other, adjacent, and in direct contact in the physical space. In some embodiments, the main light source unit 13 and the receiving unit 12 are configured such that the main light source unit 13 outputs the first light 13L to irradiate 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 directly fixed by the housing 11 or can also be fixed by other components.

[0096] The main light source unit 13 can include, for example, a light-emitting diode, a light bulb, or a fluorescent lamp for emitting light, but it is not limited thereto. The first light 13L emitted by the main light source unit 13 can be, for example, infrared light, visible light, or other electromagnetic waves. In some embodiments, the main light source unit 13 can include, for example, a light-emitting diode that emits infrared light with a wavelength of 850 nanometers to 940 nanometers, but it is not limited thereto. In some embodiments, the relationship between the amplitude and time of the first light 13L can be, for example, a single pulse wave or a periodic wave, and the period of the periodic wave can be, for example, 1 / 240 second, 2 / 240 second, 1 / 400 second, 1 / 480 second, or 1 / 576 second, etc.

[0097] The detection light unit 14 is disposed at the 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 the housing 11, inside the housing 11, 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 have a light emitting element 141, but this is not restrictive. In some other embodiments, the detection light unit 14 may also have a plurality of light emitting elements 141, and these light emitting elements 141 are arranged around the periphery of the receiving unit 12 at equal or unequal distances according to the shape of the receiving unit 12. The light emitting element 141 may, for example, include a light emitting diode, a light bulb, or a fluorescent lamp, etc., but this is not restrictive. It is worth mentioning that the detection light unit 14 can be directly fixed by the housing 11 or can also be fixed by other elements.

[0098] In some embodiments, the detection light unit 14 can output the second light beam 14L to irradiate an object 91 (i.e., a defect), and generate feedback light according to 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 is, for example, reflected light or scattered light. The object 91 is, for example, dust, dirt, fog, water droplets, oil stains, fingers, flies, machinery, circuit elements, or scratches on them on the outer side, inner side, or on the protection member 111 (inner surface or outer surface), all of which can be referred to as defects and all of which may affect the distance measurement of the time-of-flight distance camera 1.

[0099] In some embodiments, the detection light unit 14 can select to emit electromagnetic waves with the same wavelength as the main light source unit 13. For example, it can emit infrared light with a wavelength of 850 nanometers to 940 nanometers, but this is not restrictive. The relationship between the amplitude and time of the second light beam 14L can be the same as the relationship between the amplitude and time of the first light beam 13L. For example, the relationship between the amplitude and time of the second light beam 14L is also a single pulse wave or a periodic wave. The period of the periodic wave can be, for example, 1 / 240 second, 2 / 240 second, 1 / 400 second, 1 / 480 second, or 1 / 576 second, etc. Of course, the relationship between the amplitude and time of the second light beam 14L can be different from the relationship between the amplitude and time of the first light beam 13L. For example, the relationship between the amplitude and time of the second light beam 14L is a constant value.

[0100] It is worth mentioning that the wavelength range of the second light ray 14L can be substantially the same as that of the first light ray 13L. For example, the wavelength range of the first light ray 13L is from 850 nanometers to 940 nanometers, and the wavelength of the second light ray 14L is from 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 can accept a certain degree of wavelength error to reduce the complexity of material control. Of course, the wavelength range of the second light ray 14L can also be different from that of the first light ray 13L. For example, the wavelength range of the first light ray 13L is from 850 nanometers to 940 nanometers, and the wavelength of the second light ray 14L is from 773 nanometers to 1034 nanometers, but this is not restrictive.

[0101] It is worth mentioning that the setting angle of the detection light unit 14 is preferably such that the emitted second light ray 14L does not directly enter the receiving unit 12. Figure 2 It is a schematic diagram of the optical path of the second light ray of a detection light unit. As Figure 2 shown, if the second light ray 14L directly enters the receiving unit 12, the second light ray 14L may produce a strong light spot in the receiving unit 12. If the position of this light spot on the sensor 121 of the receiving unit 12 exactly overlaps or partially overlaps with the imaging 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 shown, in this embodiment, for example, by adjusting the light-emitting angle range of the detection light unit 14, adjusting the design of the housing 11, adjusting the position of the detection light unit 14 disposed in the housing 11, or adjusting the relative positions of the receiving unit 12 and the protective member 111, the second light ray 14L is not directly allowed to enter the receiving unit 12. Thus, it is possible to prevent the second light ray 14L from directly entering the receiving unit 12 and affecting the interpretation of the processing unit 15, and to increase the accuracy of the interpretation.

[0102] Furthermore, the setting angle of the detection light unit 14 is also preferably such that the direct reflected light R generated by the second light ray 14L hitting the protective member 111 does not enter the receiving unit 12. Figure 3 It is a schematic diagram of the optical path of the second light ray of another detection light unit. As Figure 3 shown, if the direct reflected light R generated by the second light ray 14L hitting the protective member 111 enters the receiving unit 12, the second light ray 14L may produce a strong light spot in the receiving unit 12. If the position of this light spot on the sensor 121 of the receiving unit 12 exactly overlaps or partially overlaps with the imaging 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 1As shown, in the present embodiment, for example, 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 disposed in the housing 11, or adjusting the relative positions of the receiving unit 12 and the protective member 111, the direct reflection light R generated when the second light beam 14L hits the protective member 111 is prevented from entering the receiving unit 12. Thereby, it is possible to avoid the direct reflection light R generated when the second light beam 14L hits the protective member 111 from entering the receiving unit 12 and affecting the interpretation of the processing unit 15, and to increase the accuracy of the interpretation. It should be noted that here, the direct reflection light R refers to the reflection light R directly generated on the protective member 111 before the second light beam 14L hits the object 91 (for example, dust or a flaw on the protective member).

[0103] In some embodiments, the emission light angle of the detection light unit 14 can be set between specific angles to meet the conditions that the second light beam 14L does not directly enter the receiving unit 12 and the direct reflection light R generated when the second light beam 14L hits the protective member 111 does not enter the receiving unit 12. For example, the relative positions of the housing 11, the protective member 111, the detection light unit 14, and the receiving unit 12 can be adjusted to make the emission light angle of the detection light unit 14 the above-mentioned specific angle. Thereby, it is possible to avoid the second light beam 14L directly entering the receiving unit 12 and the direct reflection light R generated when the second light beam 14L hits the protective member 111 from entering the receiving unit 12 and affecting the interpretation of the processing unit 15, so as to increase the accuracy of the interpretation.

[0104] It should be noted that as Figure 1 shown, in some embodiments, 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 field of view V (field of view, FOV) of the receiving unit 12 is, for example, conical or pyramidal, but it is not limited thereto. The apex of the cone is, for example, located inside the receiving unit 12. Here, "covers" means that the area of the illumination area A 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 inside the illumination area A. Thereby, all the field of view V on the protective member 111 can be fully illuminated by the second light beam 14L. Therefore, even if only a part of the object 91 is located within the field of view V of the receiving unit 12, as long as the object 91 is located 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 light or scattered light of the second light beam 14L will be received by the receiving unit 12 to ensure the range for the receiving unit 12 to detect the object 91.

[0105] Furthermore, in some embodiments, the second light ray 14L and the field of view V of the receiving unit 12 define an overlapping region OL1 outside the protective member 111, and 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 generated by the second light ray 14L and the field of view V of the receiving unit 12 outside the housing 11. The overlapping region OL1 is a three-dimensional spatial range, and the shortest distance or the perpendicular distance from any position in this spatial range to the protective member 111 is less than the shortest working distance Wmin of the receiving unit 12. The shortest working distance Wmin means that when the object to be measured 92 is within this distance, the time-of-flight distance measuring camera 1 cannot measure the distance. Thus, it is determined that the range of the interfering object 91 will not be within the distance measurement range, thereby avoiding the situation where the object to be measured 92 is misjudged as the interfering object 91.

[0106] The processing unit 15 is electrically connected to the receiving unit 12. The processing unit 15 can be, for example, a Programmable Logic Controller (PLC), a Central Process Unit (CPU), a Micro Control Unit (MCU), a Field Programmable Gate Array (FPGA), or a System on Chip (SoC), etc., but it is not limited thereto. 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 through the electrical connection, and the processing unit 15 performs signal processing.

[0107] Here, the working principle of the time-of-flight distance measuring camera will be briefly described. The time-of-flight distance measuring camera can obtain depth (such as distance) through, for example, direct time-of-flight (dTOF) or indirect time-of-flight (iTOF).

[0108] When measuring the depth by direct time-of-flight, the relationship between the amplitude and time of the light ray emitted by the light source unit is, for example, a single pulse wave. After the object to be measured reflects or scatters the single pulse wave, the light ray is received by the sensor. The time interval from the time point when the light source unit emits the single pulse wave to the time point when the sensor receives the single pulse wave can be obtained, and the depth information (such as distance) from the time-of-flight distance measuring camera to the object to be measured can be obtained through the following formula.

[0109]

[0110] Where d is the depth (such as distance) and c is the speed of light.

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

[0112]

[0113] Among them, φ is the phase difference, Q1, Q2, Q3, and Q4 are the accumulated charges, d is the depth (such as distance), c is the speed of light, and f is the frequency.

[0114] In other words, please refer to Figure 1 shown. If the sensor 121 of the receiving unit 12 in this embodiment uses indirect time-of-flight ranging, it can receive the first feedback light B1 generated by the first light 13L in the above manner to generate depth information.

[0115] Figure 5 It is the timing diagram of the time-of-flight camera in this embodiment. Please refer to Figure 1 and Figure 5 shown. In this embodiment, the main light source unit 13 outputs the first light 13L in the first time period T1, and the detection light unit 14 outputs the second light 14L in the 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, but it is not limited thereto. In some 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.

[0116] During the first time period T1, the main light source unit 13 emits the first light ray 13L, while the detection light unit 14 stops emitting light. During the second time period T2, the main light source unit 13 stops emitting light, and the detection light unit 14 emits the second light ray 14L. The second time period T2 can be before, during, or after the first time period T1. The detection light unit 14 emits the second light ray 14L during the second time period T2 such that the emission time of the second light ray 14L does not overlap with that of the first light ray 13L 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 ray 13L and the second feedback light B2 generated by the second light ray 14L during different time periods, preventing the sensor 121 from receiving the first feedback light B1 and the second feedback light B2 simultaneously, which may affect the interpretation by the processing unit 15.

[0117] In some embodiments, as Figure 5 shown, 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 - 59 / 60 seconds, and the second time period T2 is set to 59 / 60 - 60 / 60 seconds; or the first time period T1 is set to 0 / 100 - 99 / 100 seconds, and the second time period T2 is set to 99 / 100 - 100 / 100 seconds; or the first time period T1 is set to 0 / 120 - 119 / 120 seconds, and the second time period T2 is set to 119 / 120 - 120 / 120 seconds; or the first time period T1 is set to 0 / 144 - 143 / 144 seconds, and the second time period T2 is set to 143 / 144 - 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 before the first time period T1. For example: the second time period T2 is set to 0 / 60 - 1 / 60 seconds, and the first time period T1 is set to 1 / 60 - 60 / 60 seconds; or the second time period T2 is set to 0 / 100 - 1 / 100 seconds, and the first time period T1 is set to 1 / 100 - 100 / 100 seconds; or the second time period T2 is set to 0 / 120 - 1 / 120 seconds, and the first time period T1 is set to 1 / 120 - 120 / 120 seconds; or the second time period T2 is set to 0 / 144 - 1 / 144 seconds, and the first time period T1 is set to 1 / 144 - 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.

[0119] In some other embodiments, although not shown in the figures, the second time period T2 may be set in the middle of the first time period T1. For example, the first time period T1 is set to 0 / 60 - 30 / 60 seconds and 33 / 60 - 60 / 60 seconds, and the second time period T2 is set to 31 / 60 - 32 / 60 seconds; or the first time period T1 is set to 0 / 100 - 50 / 100 seconds and 53 / 100 - 100 / 100 seconds, and the second time period T2 is set to 51 / 100 - 52 / 100 seconds; or the first time period T1 is set to 0 / 120 - 60 / 120 seconds and 63 / 120 - 120 / 120 seconds, and the second time period T2 is set to 61 / 120 - 62 / 120 seconds; or the first time period T1 is set to 0 / 144 - 72 / 144 seconds and 75 / 144 - 144 / 144 seconds, and the second time period T2 is set to 73 / 144 - 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.

[0120] On the other hand, in other embodiments, the first time period T1 and the second time period T2 may also be partially overlapped. In other words, the first time period T1 and the second time period T2 are mainly non - overlapping, but there is a part that is overlapping. For example: the first time period T1 is set to 0 / 60 - 59 / 60 seconds, and the second time period T2 is set to 57 / 60 - 60 / 60 seconds; or the second time period T2 is set to 0 / 60 - 3 / 60 seconds, and the first time period T1 is set to 2 / 60 - 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 are partially overlapped.

[0121] 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, by making the first time period T1 and the second time period T2 non - overlapping, the problem of mutual interference of the feedback lights can also be avoided.

[0122] Therefore, when the second light ray 14L emitted by the detection light unit 14 irradiates the protective member 111, if there is an object 91 (such as defects like dust, dirt, fog, water droplets, oil stains, fingers, flies, machinery, circuit elements, or scratches thereon) within the preset range P, the second light ray 14L can irradiate 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, generating a luminous intensity distribution. For example, an intensity spatial distribution of infrared rays is formed on the sensor 121. In other words, information similar to that generated by an infrared thermal imager is formed. For another example, an intensity spatial distribution 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.

[0123] Furthermore, the processing unit 15 can determine whether the protective member 111 has a defect based on the light intensity distribution, for example, whether there are defects such as an object 91 within a preset range P of the protective member 111. The preset range P can be, for example, the overlapping area OL between the second light ray 14L and the visual field range V of the receiving unit 12.

[0124] Therefore, the processing unit 15 can perform image interpretation based on the light intensity distribution generated by the receiving unit 12 (for example, with the assistance of an algorithm). When the light intensity distribution conforms to a specific feature, or when the light intensity distribution exceeds a preset brightness and size, it is determined that there is an object 91 within the preset range P of the protective member 111. In some embodiments, if the processing unit 15 determines that there is an object 91 within the preset range P of the protective member 111, the processing unit 15 can output a warning signal. The warning signal can be, for example, a sound signal or an image signal. Thus, when performing detection, if the measurement distance is an invalid value due to interference by the object 91, a warning signal can be emitted and the distance measurement can be stopped to avoid obtaining incorrect distance information.

[0125] As described above, before, during, or after measuring the distance, the time-of-flight ranging camera 1 of the present disclosure outputs the second light ray 14L through the detection optical unit 14, and the receiving unit 12 receives the second feedback light B2 generated by the second light ray 14L to generate a light intensity distribution, and the processing unit 15 determines whether the protective member 111 has a defect, for example, whether there are defects such as an object 91 (not the object to be measured 92, such as dust 91B, etc.) within the preset range P of the protective member 111. Therefore, at any time point when the time-of-flight ranging camera 1 of the present disclosure is used for measuring the distance, it can also simultaneously determine whether there is interference from objects 91 such as dust 91B, dirt, fog, water droplets 91A, oil stains, fingers 91D, flies, machinery, circuit elements, or scratches 91C on the protective member 111 located on or above the protective member 111. Thus, the time-of-flight ranging camera 1 of the present disclosure can determine whether there are objects 91 above the protective member 111 that will interfere with the distance measurement without affecting the waterproof and dustproof structure of the time-of-flight ranging camera 1 and without affecting the measurement of the time-of-flight ranging camera 1. In specific distance measurement scenarios, ensuring that the distance measurement is not interfered with by objects 91 is important. For example, when the time-of-flight ranging camera 1 is used for personnel safety detection in human-machine collaboration, or for example, when detecting the distance between a vehicle and an obstacle, any interference from objects 91 above the protective member 111 may cause damage to life and property.

[0126] Figure 6 For a schematic diagram of the time-of-flight ranging camera according to the second embodiment of the present disclosure, please refer to Figure 6As shown, the time-of-flight ranging camera 1A of 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 the luminous intensity distribution. The storage unit 16 can be, for example, a non-transitory storage medium such as a flash memory, a read-only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or an optical memory, but it is not limited thereto. After the storage unit 16 stores the luminous intensity distribution, the processing unit 15 can read the storage unit 16 to analyze one or more luminous intensity distributions. In some embodiments, the luminous intensity distribution stored in the storage unit 16 can also be output as data for machine learning. In other embodiments, the training results of machine learning can also be stored in the storage unit 16 for the processing unit 15 to read. It is worth mentioning that the storage unit 16 can start storing the luminous intensity distribution only when the main light source unit 13 stops emitting light.

[0127] Thus, the time-of-flight ranging camera 1A of the second embodiment can perform more complex operations compared to the first embodiment, or output the stored luminous intensity distribution for other applications. It can also install new software through the storage device 16, such as adding new algorithms or data, so that the time-of-flight ranging camera 1A can adapt to the interference of different objects 91 or make adjustments according to the usage environment.

[0128] Figure 7 Schematic diagram of the time-of-flight ranging camera of the third embodiment of the present disclosure. Please refer to Figure 1 and Figure 7 As shown, the time-of-flight ranging camera 1B of the third embodiment is similar to the time-of-flight ranging camera 1 of the first embodiment. The difference is that in this embodiment, the detection light unit 14 is disposed outside the protection member 111, that is, the detection light unit 14 and the receiving unit 12 are respectively disposed on both sides of the protection member 111. The second light beam 14L generated by the detection light unit 14 directly irradiates to the outside of the protection member 111.

[0129] It should be noted that it is preferably that the transmitted light T generated by the second light beam 14L emitted by the detection light unit 14 irradiating to the protection member 111 does not enter the receiving unit 12 (as required conditions in Figure 2 and Figure 3 ). As described in the first embodiment, for example, the luminous angle range of the detection light unit 14 can be adjusted, the design of the housing 11 can be adjusted, the position of the detection light unit 14 disposed in the housing 11 can be adjusted, or the relative positions of the receiving unit 12 and the protection member 111 can be adjusted so that the transmitted light T generated by the second light beam 14L irradiating to the protection member 111 does not enter the receiving unit 12.

[0130] Accordingly, the time-of-flight ranging camera 1B of the third embodiment can increase the different configuration modes of the time-of-flight ranging camera.

[0131] Figure 8 Schematic diagram of the time-of-flight ranging camera of the fourth embodiment of the present disclosure, Figure 9 Schematic diagram of the field of view range and illumination area on the protective member of the present disclosure. It should be noted that, for clarity of illustration, Figure 8 the main light source unit 13 is omitted in Figure 1 and Figure 8 As shown in

[0132] and Figure 8 shown, the time-of-flight ranging camera 1C of the fourth embodiment is similar to the time-of-flight ranging camera 1 of the first embodiment, and the difference is that the detection light unit 14 of the time-of-flight ranging camera 1C of the fourth embodiment includes a plurality of light-emitting elements 141 disposed around the receiving unit 12 and jointly 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 range 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 than four light-emitting elements 141. 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 area A of the second light beam 14L jointly emitted by the plurality of light-emitting elements 141 on the protective member 111 is greater than or equal to the area of the field of view range V of the receiving unit 12 on the protective member 111, and the field of view range V of the receiving unit 12 on the protective member 111 is located inside the illumination area A. For example, by adjusting the light-emitting angle range of the plurality of light-emitting elements 141, adjusting the design of the housing 11, adjusting the positions of the plurality of light-emitting elements 141 disposed in the housing 11, or adjusting the relative positions of the receiving unit 12 and the protective member 111, the illumination area A of the second light beam 14L on the protective member 111 can cover the field of view range V of the receiving unit 12 on the protective member 111.

[0132] As Figure 8 shown, in this embodiment, four light-emitting elements 141 are disposed around the receiving unit 12 at equal intervals ( Figure 8 is a cross-sectional view, so only two light-emitting elements 141 are shown), which is non-limiting. The illumination area A of the second light beam 14L generated by the four light-emitting elements 141 on the protective member 111 will cover the field of view range V of the receiving unit 12 on the protective member 111. As Figure 8 and Figure 9 shown. When a defect (such as a water droplet, scratch, dust or finger, etc.) is located within the field of view range V, it can be irradiated by the second light beam 14L of the time-of-flight ranging camera 1C of the fourth embodiment.

[0133] Thus, the time-of-flight distance measurement camera 1C of the fourth embodiment can further ensure that all the visual field ranges V on the protective member 111 can be illuminated by the second light beam 14L, so that the brightness of the second light beam 14L on the protective member 111 is more uniform, and the imaging of interfering objects is easier to interpret.

[0134] Next, the optical simulation results of detecting water droplets, dust, and scratches are described by using the time-of-flight distance measurement camera 1C of the fourth embodiment.

[0135] Figure 10 It is a schematic diagram of detecting water droplets by the time-of-flight distance measurement camera of the present disclosure. Figure 11 It is a schematic diagram of the position of detecting water droplets by the time-of-flight distance measurement camera of the present disclosure. Figures 12A to 12I It is an effect simulation diagram of the light spot of the time-of-flight distance measurement camera of the present disclosure. As Figure 10 and Figure 11 shown, here, the simulation conditions are that water droplets 91A (for example, with a diameter of 1.5 mm, which is non-limiting) are placed at 9 different positions on the protective member 111 and detected respectively. As Figure 11 and Figure 12A shown, if the water droplet 91A is located at the leftmost position in the uppermost row, the time-of-flight distance measurement camera of the present disclosure can clearly detect the light spot S image at the corresponding position. As Figure 11 and Figure 12B shown, if the water droplet 91A is located at the middle position in the uppermost row, the time-of-flight distance measurement camera of the present disclosure can clearly detect the light spot S image at the corresponding position. As Figure 11 and Figure 12C shown, if the water droplet 91A is located at the rightmost position in the uppermost row, the time-of-flight distance measurement camera of the present disclosure can clearly detect the light spot S image at the corresponding position. As Figure 11 and Figure 12D shown, if the water droplet 91A is located at the leftmost position in the middle row, the time-of-flight distance measurement camera of the present disclosure can clearly detect the light spot S image at the corresponding position. As Figure 11 and Figure 12E shown, if the water droplet 91A is located at the middle position in the middle row, the time-of-flight distance measurement camera of the present disclosure can clearly detect the light spot S image at the corresponding position. As Figure 11 and Figure 12F shown, if the water droplet 91A is located at the rightmost position in the middle row, the time-of-flight distance measurement camera of the present disclosure can clearly detect the light spot S image at the corresponding position. As Figure 11 and Figure 12G shown, if the water droplet 91A is located at the leftmost position in the lowermost row, the time-of-flight distance measurement camera of the present disclosure can clearly detect the light spot S image at the corresponding position. As Figure 11 and Figure 12H shown, if the water droplet 91A is located at the middle position in the lowermost row, the time-of-flight distance measurement camera of the present disclosure can clearly detect the light spot S image at the corresponding position. As Figure 11 and Figure 12IAs shown, if the water droplet 91A is located at the right position in the bottom row, the time-of-flight ranging camera of the present disclosure can clearly detect the image of the light spot S at the corresponding position.

[0136] Figure 13 FIG. is a schematic diagram of the detection of dust by the time-of-flight ranging camera of the present disclosure. Figure 14 FIG. is a schematic diagram of the position of the detection of dust by the time-of-flight ranging camera of the present disclosure. Figures 15A to 15I FIG. is a simulation diagram of the effect of the light spot of the time-of-flight ranging camera of the present disclosure. As Figure 13 and Figure 14 shown, here, the simulation condition is to place dust 91B (for example, with a diameter of 1.0 mm, which is non-limiting) at 9 different positions of the protection member 111 and perform detection respectively. As Figure 14 and Figure 15A shown, if the dust 91B is located at the left position in the top row, the time-of-flight ranging camera of the present disclosure can clearly detect the image of the light spot S at the corresponding position. As Figure 14 and Figure 15B shown, if the dust 91B is located at the middle position in the top row, the time-of-flight ranging camera of the present disclosure can clearly detect the image of the light spot S at the corresponding position. As Figure 14 and Figure 15C shown, if the dust 91B is located at the right position in the top row, the time-of-flight ranging camera of the present disclosure can clearly detect the image of the light spot S at the corresponding position. As Figure 14 and Figure 15D shown, if the dust 91B is located at the left position in the middle row, the time-of-flight ranging camera of the present disclosure can clearly detect the image of the light spot S at the corresponding position. As Figure 14 and Figure 15E shown, if the dust 91B is located at the middle position in the middle row, the time-of-flight ranging camera of the present disclosure can clearly detect the image of the light spot S at the corresponding position. As Figure 14 and Figure 15F shown, if the dust 91B is located at the right position in the middle row, the time-of-flight ranging camera of the present disclosure can clearly detect the image of the light spot S at the corresponding position. As Figure 14 and Figure 15G shown, if the dust 91B is located at the left position in the bottom row, the time-of-flight ranging camera of the present disclosure can clearly detect the image of the light spot S at the corresponding position. As Figure 14 and Figure 15H shown, if the dust 91B is located at the middle position in the bottom row, the time-of-flight ranging camera of the present disclosure can clearly detect the image of the light spot S at the corresponding position. As Figure 14 and Figure 15I shown, if the water droplet 91A is located at the right position in the bottom row, the time-of-flight ranging camera of the present disclosure can clearly detect the image of the light spot S at the corresponding position.

[0137] Figure 16 FIG. is a schematic diagram of the detection of scratches by the time-of-flight ranging camera of the present disclosure.Figure 17A and Figure 17B are schematic diagrams showing the positions of detected scratches of the time-of-flight ranging camera of the present disclosure, Figure 18A and Figure 18B are simulation diagrams of the spot effects of the time-of-flight ranging camera of the present disclosure. As shown in Figure 16 , Figure 17A and Figure 17B shown, herein, the simulation conditions are to detect scratches 91C in the left-right direction or up-down direction in the figure (for example, with a width of 0.2 mm, which is non-limiting) on the protective member 111 respectively. As shown in Figure 17A and Figure 18A shown, if the scratch 91C is in the left-right direction in the figure, the time-of-flight ranging camera of the present disclosure can clearly detect the spot S image at the corresponding position. Similarly, as shown in Figure 17B and Figure 18B shown, if the scratch 91C is in the up-down direction in the figure, the time-of-flight ranging camera of the present disclosure can clearly detect the spot S image at the corresponding position.

[0138] Figure 19 is a schematic diagram showing the detection of a finger by the time-of-flight ranging camera of the present disclosure. When the finger 91D is within the preset range P, the second light ray 14L can irradiate the finger 91D and similarly generate the second feedback light B2. Similarly, the receiving unit of the time-of-flight ranging camera of the present disclosure can receive the second feedback light B2 and generate a light intensity distribution.

[0139] Although the above is simulated with the structure of the fourth embodiment, the time-of-flight ranging cameras of any one of the first to fourth embodiments of the present disclosure can detect defects such as water droplets, dust, scratches, or fingers that cause interference.

[0140] Figure 20 is a step diagram of the detection method of the time-of-flight ranging camera according to an embodiment of the present disclosure. Please refer to Figure 20 shown, the detection method of this embodiment includes steps S11 to S15. Step S11 is to emit a first light ray in the first time period and generate a first feedback light. Step S12 is to receive the first feedback light and generate depth information. Step S13 is to emit a second light ray to the protective member in the second time period and generate a second feedback light. Step S14 is to receive the second feedback light and generate a light intensity distribution. Step S15 is to judge whether the protective member has defects according to the light intensity distribution. The detection method of the time-of-flight ranging camera of this embodiment can be applied to the time-of-flight ranging cameras 1, 1A, 1B, 1C of any one of the first to fourth embodiments as described above, but it is non-limiting. The detection method of the time-of-flight ranging camera of this embodiment can also be applied to other different time-of-flight ranging cameras, or other devices that need to detect defects on or above the protective member. The detailed detection method has been described in detail in the above embodiments and will not be repeated here.

[0141] Figure 21 This is a step diagram of a detection method of a time-of-flight range-finding camera according to another embodiment of the present disclosure. Figure 21 As shown, the detection method of this embodiment includes steps S11 to S16. Step S11 is to emit a first light in a first time period and generate a first feedback light. Step S12 is to receive the first feedback light and generate depth information. Step S13 is to emit a second light in a second time period to the protective member and generate a second feedback light. Step S14 is to receive the second feedback light and generate a luminous intensity distribution. Step S15 is to determine whether the protective member has a defect based on the luminous intensity distribution. Step S16 is to output a warning signal if the protective member is determined to have a defect. The detection method of the time-of-flight camera of this embodiment can also be used with the time-of-flight cameras 1, 1A, 1B, and 1C of the above-mentioned embodiments, but it is not restrictive. The detection method of the time-of-flight camera 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 the protective member. The detailed detection method has been described in detail in the above-mentioned embodiments and will not be repeated here.

[0142] In addition, if it is determined that the protective member has no defects, the process may return to step S11 to perform depth and defect detection again.

[0143] Therefore, when the detection method of the time-of-flight ranging camera is performed, if the measured distance is interfered by a defect 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.

[0144] In summary, the time-of-flight rangefinder camera and its detection method disclosed herein can generate a luminous intensity distribution by outputting a second light beam by the detection light unit before, during or after measuring the distance, and the receiving unit receives the second feedback light generated by the second light beam, and judges whether the protective member has defects through the processing unit, such as whether there is an object (not the object to be measured, such as dust, etc.) and other defects located within the preset range of the protective member. Therefore, the time-of-flight rangefinder camera and its detection method disclosed herein can also simultaneously judge whether there is interference by objects such as dust, dirt, fog, water droplets, oil, fingers, flies, machinery, circuit components or scratches on the protective member located on or above the protective member at any time point when measuring the distance. Therefore, the time-of-flight rangefinder camera and its detection method disclosed herein can judge whether there is an object on the protective member that will interfere with the distance measurement without affecting the waterproof and dustproof structure of the time-of-flight rangefinder camera and without affecting the measurement of the time-of-flight rangefinder camera. 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 detection in human-machine collaboration, or when detecting the distance between a car and an obstacle, for example. Interference from any object on the protective part may cause damage to life and property.

[0145] Furthermore, the time-of-flight ranging camera and its detection method of the present disclosure can be set such that the second light ray output by the detection light unit does not directly enter the receiving unit, and the direct reflected light or transmitted light generated when the second light ray hits the protective member does not enter the receiving unit, so as to avoid other light rays affecting the interpretation by the processing unit and increase the accuracy of the interpretation of interfering objects. In addition, the time-of-flight ranging camera and its detection method of the present disclosure can expand the range of detecting interfering objects by covering the field of view range of the receiving unit on the protective member with the illumination area of the second light ray on the protective member. Furthermore, the time-of-flight ranging camera and its detection method of the present disclosure can define an overlapping area (the area on the surface of the protective member) outside the protective member by the second light ray and the field of view range of the receiving unit. The maximum distance of the overlapping area relative to the protective member is less than the shortest working distance of the receiving unit, that is, the range of judging interfering objects will not be within the range of distance measurement, thereby avoiding the situation where the object to be measured is misjudged as an interfering object. Also, the time-of-flight ranging camera and its detection method of the present disclosure can make the wavelength range of the first light ray substantially the same as the wavelength range of the second light ray, that is, use the same light-emitting element to reduce the complexity of material control. In addition, the time-of-flight ranging camera and its detection method of the present disclosure can avoid the mutual influence of different feedback lights by emitting the first light ray and the second light ray at different time periods, thereby increasing the accuracy of interpretation.

[0146] The detection light unit of the time-of-flight ranging camera of the present disclosure may further include a plurality of light-emitting elements disposed around the receiving unit to jointly emit the second light ray to expand the range of detecting interfering objects and make the brightness of the second light ray on the protective member more uniform, thereby increasing the accuracy of interpretation.

[0147] As used herein and not otherwise defined, terms such as "substantially" and "about" are used to describe and account for minor variations. When associated with an event or circumstance, the term can encompass both the precise instance when the event or circumstance occurs and any approximate point to which the event or circumstance progresses.

[0148] The components of several embodiments are outlined above so that those skilled in the art in the technical field to which the present disclosure pertains can better understand the concepts of the embodiments of the present disclosure. Those skilled in the art in the technical field to which the present disclosure pertains should understand that the embodiments of the present disclosure can be used as a basis to design or modify other processes and structures to achieve the same purposes and / or obtain the same advantages as those introduced herein. Those skilled in the art in the technical field to which the present disclosure pertains should also understand that these equivalent structures do not depart from the spirit and scope of the present disclosure, and various changes, substitutions, and other options can be made without departing from the spirit and scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be defined by the scope of the appended claims.

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.

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