Detection device, detection program product, storage medium, and detection method

Abstract

The detection device (1) of the present application includes: a light emitting element array (20) including a plurality of light emitting elements; a light receiving element array including a plurality of light receiving elements (5) that receive reflected light of light emitted from the light emitting element array toward a detection object; a driving section (50) that drives the light emitting elements; and a detection section (8) that controls at least one of a supply timing of a driving current supplied to the light emitting elements and a light receiving timing of the light receiving elements so that a change in time from when the light emitting elements start emitting light to when the light receiving elements receive light is within a predetermined range even if the arrangement of the light emitting elements changes, and detects the detection object.

Description

Technical Field

[0001] This invention relates to a detection device, a detection procedure, a storage medium, a detection method, and a light-emitting device. Background Technology

[0002] Patent Document 1 discloses a method for measuring depth that is insensitive to destructive light generated by internal reflection. The method includes the following steps: emitting light onto a scene using a light source; controlling a first charge accumulation unit of the pixel to collect charge based on the light hitting the pixel during a first period in which the destructive light hits a pixel but return light from an object within the pixel's field of view does not hit the pixel, thereby measuring the destructive light; removing the contribution of the destructive light from one or more measurements affected by the destructive light based on the measurement of the destructive light; and determining the depth based on the one or more measurements after removing the contribution of the destructive light.

[0003] Patent Document 2 discloses a distance measuring device, characterized by comprising: a light-projecting unit that projects light onto an object; a light-receiving unit that receives light reflected or scattered by the object; a scanning unit that scans the light projected from the light-projecting unit into a scanning area; and a distance measuring unit that measures the time from the projection of light from the light-projecting unit to the reception of light by the light-receiving unit, and measures the distance to the object. If the scanning area is divided into multiple segmented areas, and a scan is defined as the period from the start of scanning in one of the segmented areas to the end of scanning in all the segmented areas, then the device determines whether the measured value of the first segmented area can be used as the measurement result of the first segmented area based on the measurement value of the first segmented area measured by the distance measuring unit during the first scan and the measurement value of the second segmented area measured before the measurement value of the first segmented area. If it is determined that the measured value of the first segmented area can be used as the measurement result of the first segmented area, the device outputs the measurement value of the first segmented area as the distance to the object in the first segmented area.

[0004] Patent document 3 discloses a light-flying ranging device, characterized by comprising: a first light source that emits first light into a first light-emitting space; a light-receiving unit having a plurality of pixels and receiving light through each pixel; a distance image acquisition unit that, during a period of light emission from the first light source, receives light in the light-receiving unit including first reflected light generated by the first light being reflected by the surface of an object, thereby acquiring a distance image representing the distance from the device to the object for each pixel; a brightness value image acquisition unit that, during a period of non-light emission from the first light source, receives light in the light-receiving unit including second reflected light, thereby acquiring a brightness value image representing the brightness value of each pixel, wherein the second reflected light is light generated by the reflection of second light emitted from the second light source into a second light-emitting space including at least a portion of the first light-emitting space in a manner different from the first light, by the second light being reflected by the surface of an object; and a multipath detection unit that uses the distance image and the brightness value image to detect regions where multipaths have occurred.

[0005] Patent Document 4 discloses a distance measuring device comprising: a light-emitting part that emits a probe light; and a light-receiving part that receives reflected light from the probe light. The distance measuring device measures the distance to an object reflecting the probe light based on the reflected light received by the light-receiving part. The distance measuring device is characterized in that a region centered on the light-emitting part is defined as a strong scattering region, in which the intensity of scattered light generated by a water droplet with a diameter larger than the wavelength of the probe light being transmitted through the probe light, or by the water droplet reflecting the probe light, exceeds the noise level of the light-receiving part. The light-receiving part is positioned outside the strong scattering region, and a light-shielding device is provided to block convergent scattered light that converges in a specific direction and scattered light that is incident on the light-receiving part at an angle of incidence greater than that of the convergent scattered light.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2019-219400

[0009] Patent Document 2: Japanese Patent Application Publication No. 2019-028039

[0010] Patent Document 3: Japanese Patent Application Publication No. 2017-15448

[0011] Patent Document 4: Japanese Patent Application Publication No. 2007-333592 Summary of the Invention

[0012] The technical problem to be solved by the invention

[0013] The present invention relates to a detection apparatus, a detection procedure, a storage medium, a detection method, and a light-emitting device that, when detecting a target object by detecting reflected light emitted from an array of light-emitting elements having multiple light-emitting elements toward the target object, can suppress the influence of changes in the light emission rise characteristics even if the configuration of the light-emitting elements changes, compared to the case where the influence of changes in the configuration of the light-emitting elements is not considered.

[0014] means for solving technical problems

[0015] [1] According to one aspect of the present invention, a detection device is provided, comprising: an array of light-emitting elements having a plurality of light-emitting elements; an array of light-receiving elements having a plurality of light-receiving elements, the light-receiving elements receiving reflected light emitted from the array of light-emitting elements toward a detection object; a driving unit that drives the light-emitting elements; and a detection unit that controls at least one of a supply timing for supplying a driving current to the light-emitting elements and a light-receiving timing for the light-receiving elements, so that even if the configuration of the light-emitting elements changes, the time from the start of light emission of the light-emitting elements to the light-receiving timing of the light-receiving elements is within a predetermined range, and the detection object is detected.

[0016] [2] In the detection device involved in [1], if the light intensity of each of the light-emitting elements does not change even if the number of the light-emitting elements changes, the detection unit can control at least one of the supply timing and the light-receiving timing according to the number of the light-emitting elements.

[0017] [3] In the detection device involved in [2], the detection unit can control the supply timing so that the supply timing becomes earlier as the number of light-emitting elements increases.

[0018] [4] In the detection device involved in [2], the detection unit can control the light receiving timing so that the light receiving timing becomes later as the number of light-emitting elements increases.

[0019] [5] In the detection device described in [1], if the number of the light-emitting elements changes without changing the overall light intensity of the light-emitting elements, the detection unit can control at least one of the supply timing and the light-receiving timing determined by the inductance of the current path of the drive current flowing to the light-emitting elements.

[0020] [6] In the detection device involved in [5], the detection unit can control the supply timing so that the supply timing becomes earlier as the number of light-emitting elements decreases.

[0021] [7] In the detection device involved in [5], the detection unit can control the light receiving timing so that the light receiving timing becomes later as the number of light-emitting elements decreases.

[0022] [8] In any of the detection devices described in [1] to [7], the array of light-emitting elements can enable multiple light-emitting zones to emit light independently, each light-emitting zone including at least two or more light-emitting elements, and the detection unit can control the light emission of the light-emitting elements for each of the multiple light-emitting zones.

[0023] [9] In any of the methods described in [1] to [8], the detection unit can detect the distance from the detection unit to the object to be detected based on the time of flight.

[0024]

[10] According to another aspect of the present invention, a detection device is provided, which includes a processor configured to: control the luminescence of a plurality of luminescent elements included in an array of luminescent elements; and control at least one of a supply timing for supplying a driving current to the luminescent luminescent elements and a light-receiving timing for the light-receiving elements included in an array of light-receiving elements, so that even if the configuration of the luminescent luminescent elements changes, the change in time from the start of luminescence of the luminescent luminescent elements to the light-receiving timing of the light-receiving elements is within a predetermined range, and the detection object is detected.

[0025]

[11] According to another aspect of the present invention, a detection program is provided for causing a computer to perform a process comprising the steps of: controlling the luminescence of a plurality of luminescent elements included in an array of luminescent elements; and controlling at least one of a supply timing for supplying a driving current to the luminescent luminescent elements and a light-receiving timing for the light-receiving elements included in an array of light-receiving elements, so that even if the configuration of the luminescent luminescent elements changes, the time variation from the start of luminescence of the luminescent luminescent elements to the light-receiving timing of the light-receiving elements is within a predetermined range, and detecting the object to be detected.

[0026]

[12] According to another aspect of the present invention, a storage medium is provided that stores a detection program for causing a computer to perform a process comprising the steps of: controlling the luminescence of a plurality of luminescent elements included in an array of luminescent elements; and controlling at least one of a supply timing for supplying a driving current to the luminescent elements and a light-receiving timing for the light-receiving elements included in an array of light-receiving elements, so that even if the configuration of the luminescent elements changes, the change in time from the start of luminescence of the luminescent elements to the light-receiving timing of the light-receiving elements is within a predetermined range, and detecting the object to be detected.

[0027]

[13] According to another aspect of the present invention, a detection method is provided, comprising the steps of: controlling the luminescence of a plurality of luminescent elements included in an array of luminescent elements; and controlling at least one of the supply timing of a drive current supplied to the luminescent luminescent element and the light-receiving timing of a light-receiving element included in an array of light-receiving elements, so that even if the configuration of the luminescent luminescent element changes, the change in time from the start of luminescence of the luminescent luminescent element to the light-receiving timing of the light-receiving element is within a predetermined range, and detecting the object to be detected.

[0028]

[14] According to another aspect of the present invention, a light-emitting device is provided, comprising: an array of light-emitting elements having a plurality of light-emitting elements; a driving unit that drives the light-emitting elements; and a control unit that controls the supply timing of supplying driving current to the light-emitting elements so that even if the configuration of the light-emitting elements changes, the variation in time from the start of light emission by the light-emitting elements to the light-receiving timing of the light-receiving elements is within a predetermined range.

[0029]

[15] According to another aspect of the present invention, a light-emitting device is provided, comprising: an array of light-emitting elements having a plurality of light-emitting elements; a driving unit that drives the light-emitting elements; and a control unit that controls the timing of supplying driving current to the light-emitting elements so that the timing of supplying current becomes earlier as the number of light-emitting elements increases.

[0030] Invention Effects

[0031] According to [1],

[10] to

[14] , when detecting a target object by detecting the reflected light emitted from an array of light-emitting elements having multiple light-emitting elements toward the target object, the effect of changes in the light emission rise characteristics can be suppressed even if the configuration of the light-emitting elements changes, compared to the case where the effect of changes in the configuration of the light-emitting elements is not considered.

[0032] According to [2], even if the number of light-emitting elements changes, the effect of changes in the light emission rise characteristics can be suppressed.

[0033] According to [3], compared to the case where the timing of the drive current supply is uniform regardless of the number of light-emitting elements, the effect of changes in the light emission rise characteristics can be suppressed even if the number of light-emitting elements increases.

[0034] According to [4], compared to the case where the light exposure timing is uniform regardless of the number of light-emitting elements, even if the number of light-emitting elements increases, the effect of changes in the light emission rise characteristics can be suppressed.

[0035] According to [5], even if the number of light-emitting elements changes, the effect of changes in the light emission rise characteristics can be suppressed.

[0036] According to [6], compared to the case where the timing of the drive current supply is uniform regardless of the number of light-emitting elements, the effect of changes in the light emission rise characteristics can be suppressed even if the number of light-emitting elements is reduced.

[0037] According to [7], compared to the case where the light exposure timing is uniform regardless of the number of light-emitting elements, the effect of changes in the light emission rise characteristics can be suppressed even if the number of light-emitting elements is reduced.

[0038] According to [8], compared to controlling the light emission of each light-emitting element individually, it is possible to suppress the control of the light-emitting elements, which becomes more complex.

[0039] According to [9], the three-dimensional shape of the object being detected can be determined.

[0040] According to

[15] , even if the number of light-emitting elements changes, the amount of light emitted by each light-emitting element will not change. Attached Figure Description

[0041] Figure 1 This is a schematic structural diagram illustrating the structure of the measuring device according to the first exemplary embodiment.

[0042] Figure 2 It is a block diagram showing the main structural components of the electrical system of the measuring device.

[0043] Figure 3 This is a top view of the light source.

[0044] Figure 4 This is a diagram used to illustrate the light-emitting zones.

[0045] Figure 5 This is the circuit diagram of the measuring device.

[0046] Figure 6 This is a top view of the 3D sensor.

[0047] Figure 7 This is a flowchart illustrating an example of the processing flow of the measurement procedure involved in the first exemplary embodiment.

[0048] Figure 8A This is a timing diagram used to illustrate the timing of the drive current supply when the number of the first light-emitting partitions is 1.

[0049] Figure 8B This is a timing diagram used to illustrate the timing of the drive current supply when the number of the first light-emitting zones is 12.

[0050] Figure 9A This is a timing diagram used to illustrate the timing of light reception when the number of the first light-emitting partitions is 1.

[0051] Figure 9B This is a timing diagram used to illustrate the light reception timing when the number of the first light-emitting zones is 12.

[0052] Figure 10 This is a top view of the 3D sensor.

[0053] Figure 11 It is a graph used to illustrate multiple paths.

[0054] Figure 12 It is a graph used to illustrate multiple paths.

[0055] Figure 13 This is a flowchart illustrating an example of the processing flow of the measurement procedure involved in the second exemplary embodiment.

[0056] Figure 14A This is another timing diagram illustrating the timing of the drive current supply when the number of light-emitting zones is 12.

[0057] Figure 14B This is another timing diagram illustrating the timing of the drive current supply when the number of light-emitting zones is one.

[0058] Figure 15A This is another timing diagram used to illustrate the timing of light reception when the number of light-emitting zones is 12.

[0059] Figure 15B This is another timing diagram used to illustrate the timing of light reception when the number of light-emitting zones is one.

[0060] Figure 16A This is another timing diagram used to illustrate the timing of the drive current supply when the current value Jp is large.

[0061] Figure 16B This is another timing diagram used to illustrate the timing of supplying the drive current when the current value Jp is relatively small.

[0062] Figure 17A This is another timing diagram used to illustrate the timing of light reception when the current value Jp is large.

[0063] Figure 17B This is another timing diagram used to illustrate the timing of light reception when the current value Jp is relatively small. Detailed Implementation

[0064] Hereinafter, exemplary embodiments of the technology involved in the invention will be described in detail with reference to the accompanying drawings.

[0065] <First Exemplary Implementation>

[0066] Measuring devices for measuring the three-dimensional shape of an object include those based on the time-of-flight (ToF) method, which measures the three-dimensional shape according to the time of flight of light. In the ToF method, the time from the moment light is emitted from the light source of the measuring device to the moment the light is reflected by the object and received by the three-dimensional sensor (hereinafter referred to as the 3D sensor) of the measuring device is measured. The distance from the measuring device to the object is then determined, thereby identifying the three-dimensional shape. The object whose three-dimensional shape is being measured is called the object being measured. The object being measured is an example of a detection object. Furthermore, measuring three-dimensional shape is sometimes referred to as three-dimensional measurement, 3D measurement, or 3D sensing.

[0067] The Time-of-Flight (ToF) method includes a direct method and a phase difference method (indirect method). The direct method involves irradiating the object under test with a pulse of light that emits light for only a very short time and actually measuring the time it takes for the light to return. The phase difference method involves periodically flashing a pulse of light and detecting the time delay between multiple pulses and the object under test as the phase difference. In this exemplary embodiment, the case of measuring three-dimensional shape using the phase difference method will be described.

[0068] This measuring device is mounted on portable information processing devices and is used for facial authentication of users seeking access. Previously, portable information processing devices used methods such as passwords, fingerprints, and iris scans to authenticate users. In recent years, there has been a demand for more secure authentication methods. Therefore, measuring devices that measure three-dimensional shape have begun to be mounted on portable information processing devices. That is, in a portable information processing device equipped with a measuring device, a three-dimensional image of the user's face is acquired, access is determined, and the device (portable information processing device) is only allowed to use if the user is authenticated as having permission to access.

[0069] This measuring device is also suitable for situations such as augmented reality (AR) where the three-dimensional shape of the object being measured is continuously measured.

[0070] The structures, functions, methods, etc., described in the exemplary embodiments described below are not only applicable to facial authentication or augmented reality, but also applicable to the measurement of the three-dimensional shape of other objects.

[0071] (Measuring device 1)

[0072] Figure 1 This is a block diagram illustrating an example of the structure of a measuring device 1 for measuring three-dimensional shapes.

[0073] The measuring device 1 includes an optical device 3 and a control unit 8. The control unit 8 controls the optical device 3. The control unit 8 includes a three-dimensional shape determination unit 81 for determining the three-dimensional shape of the object being measured. The measuring device 1 is an example of a detection device. Furthermore, the control unit 8 is an example of a detection unit.

[0074] Figure 2 This is a block diagram showing the hardware structure of the control unit 8. For example... Figure 2 As shown, the control unit 8 includes a controller 12. The controller 12 includes a CPU (Central Processing Unit) 12A, a ROM (Read Only Memory) 12B, a RAM (Random Access Memory) 12C, and an input / output interface (I / O) 12D. Furthermore, the CPU 12A, ROM 12B, RAM 12C, and I / O 12D are interconnected via a system bus 12E. The system bus 12E includes a control bus, an address bus, and a data bus.

[0075] Furthermore, the I / O12D is connected to a communication unit 14 and a storage unit 16.

[0076] The communication unit 14 is an interface for data communication with external devices.

[0077] The storage unit 16 is composed of a non-volatile rewritable memory such as a flash ROM, and stores the measurement program 16A (described later) and the partition correspondence table 16B (described later). The CPU 12A reads the measurement program 16A stored in the storage unit 16 into the RAM 12C for execution, thereby forming a three-dimensional shape determination unit 81, which can determine the three-dimensional shape of the object being measured. Furthermore, the measurement program 16A is an example of a detection program.

[0078] The optical device 3 includes a light-emitting device 4 and a 3D sensor 5. The light-emitting device 4 includes a wiring board 10, a heat-dissipating substrate 100, a light source 20, a light-diffusing component 30, a driving unit 50, a holding unit 60, and capacitors 70A and 70B. The light-emitting device 4 may include passive elements such as resistors 6 and capacitors 7 to activate the driving unit 50. Here, the light-emitting device 4 includes two resistors 6 and two capacitors 7. Two capacitors 70A and 70B are shown, but one is also possible. Furthermore, capacitors 70A and 70B are referred to as capacitor 70 without distinction. Furthermore, the number of resistors 6 and capacitors 7 may be one or more. Here, electrical components other than the light source 20, driving unit 50, and capacitors 7, such as the 3D sensor 5, resistors 6, and capacitors 7, are sometimes referred to as circuit components without distinction. Additionally, capacitors are sometimes called energy storage devices. The 3D sensor 5 is an example of a light-receiving element array.

[0079] The heat dissipation substrate 100, driving part 50, resistive element 6, and capacitor 7 of the light-emitting device 4 are disposed on the surface of the wiring board 10. Additionally, in Figure 1 In this case, the 3D sensor 5 is not disposed on the surface of the wiring board 10, but it can also be disposed on the surface of the wiring board 10.

[0080] A light source 20, capacitors 70A and 70B, and a holding portion 60 are disposed on the surface of the heat dissipation substrate 100. Furthermore, a light diffusion member 30 is disposed on the holding portion 60. Here, the shape of the heat dissipation substrate 100 is the same as the shape of the light diffusion member 30. Here, "surface" refers to... Figure 1 The front side of the paper. More specifically, in the wiring board 10, the side on which the heat dissipation substrate 100 is disposed is referred to as the surface, the front side, or the surface side. Furthermore, in the heat dissipation substrate 100, the side on which the light source 20 is disposed is referred to as the surface, the front side, or the surface side.

[0081] The light source 20 is configured as a two-dimensional array of light-emitting elements with multiple light-emitting elements (see below). Figure 3 As an example, the light-emitting element is a vertical-cavity surface-emitting laser (VCSEL). Hereinafter, the description will assume the light-emitting element is a VCSEL. The VCSEL will be referred to as a VCSEL. The light source 20 is disposed on the surface of the heat-dissipating substrate 100, and therefore the light source 20 emits light perpendicularly to the surface of the heat-dissipating substrate 100 in a direction away from the heat-dissipating substrate 100. That is, the light-emitting element array is a surface-emitting laser element array. Furthermore, sometimes the surface of the light source 20, in which multiple light-emitting elements are disposed in two dimensions and emit light, is referred to as the emission surface.

[0082] Light emitted from the light source 20 is incident on the light diffusion member 30. The light diffusion member 30 diffuses and emits the incident light. The light diffusion member 30 is configured to cover the light source 20 and capacitors 70A and 70B. That is, the light diffusion member 30 is configured to be separated from the light source 20 and capacitors 70A and 70B disposed on the heat dissipation substrate 100 by a predetermined distance through the holding portion 60 disposed on the surface of the heat dissipation substrate 100. The light emitted from the light source 20 is diffused by the light diffusion member 30 and irradiates the object under test. Compared to the case without the light diffusion member 30, the light emitted from the light source 20 is diffused by the light diffusion member 30, thereby irradiating a wider range.

[0083] In the case of 3D measurement using the Time-of-Flight (ToF) method, the light source 20 is required to emit pulsed light (hereinafter referred to as emitted light pulse) with a frequency of 100 MHz or higher and a rise time of 1 ns or less through the drive unit 50. Taking facial recognition as an example, the distance the light illuminates is approximately 10 cm to 1 m. The area illuminated by the light is approximately 1 m square. The distance the light illuminates is referred to as the measurement distance, and the area illuminated is referred to as the illumination range or measurement range. Furthermore, the surface virtually set within the illumination range or measurement range is referred to as the illumination surface. In addition to facial recognition, the measurement distance to the object being measured and the illumination range for the object can also be other than those described above.

[0084] The 3D sensor 5 has multiple light-receiving elements (e.g., 640×480 light-receiving elements) and outputs a signal equivalent to the time from the time when light is emitted from the light source 20 to the time when it is received by the 3D sensor 5.

[0085] For example, each light-receiving element of the 3D sensor 5 receives pulsed reflected light (hereinafter referred to as a light-receiving pulse) from the object under test in response to an emitted light pulse from the light source 20, and accumulates a charge corresponding to the time elapsed until the light is received in each light-receiving element. The 3D sensor 5 is configured as a CMOS structure device in which each light-receiving element has two gates and corresponding charge accumulation sections. Furthermore, by alternately applying pulses to the two gates, the generated photoelectrons are rapidly transmitted to either of the two charge accumulation sections. The charge corresponding to the phase difference between the emitted light pulse and the light-receiving pulse is accumulated in the two charge accumulation sections. Then, the 3D sensor 5 outputs a digital value corresponding to the phase difference between the emitted light pulse and the light-receiving pulse as a signal for each light-receiving element via an AD converter. That is, the 3D sensor 5 outputs a signal corresponding to the time elapsed from the light source 20 until the time elapsed by the 3D sensor 5. In other words, a signal corresponding to the three-dimensional shape of the object under test is acquired from the 3D sensor 5. In addition, the AD converter can be provided in the 3D sensor 5 or external to the 3D sensor 5.

[0086] As described above, the measuring device 1 diffuses the light emitted from the light source 20 and illuminates the object being measured, and the 3D sensor 5 receives the reflected light from the object. In this way, the measuring device 1 measures the three-dimensional shape of the object.

[0087] First, the light source 20, light diffusion component 30, driving unit 50, and capacitors 70A and 70B constituting the light-emitting device 4 will be described.

[0088] (Structure of light source 20)

[0089] Figure 3This is a top view of the light source 20. The light source 20 is configured as a two-dimensional array of multiple VCSELs. That is, the light source 20 is configured as an array of light-emitting elements using VCSELs as light-emitting elements. The right direction of the paper is defined as the x-direction, and the top direction of the paper is defined as the y-direction.

[0090] The direction orthogonal to both the x and y directions is defined as the z direction. Furthermore, the surface of light source 20 refers to the front side of the paper (i.e., the +z direction side), and the back side of light source 20 refers to the back side of the paper (i.e., the -z direction side). The top view of light source 20 is a diagram showing the light source 20 as viewed from the surface side.

[0091] To elaborate further, in the light source 20, the side of the epitaxial layer that forms the function of the light-emitting layer (the active region 206 described later) is referred to as the surface, front side, or surface side of the light source 20.

[0092] A VCSEL is a light-emitting element in which an active region serving as the light-emitting area is provided between a lower multilayer film reflector and an upper multilayer film reflector laminated on a semiconductor substrate 200, and a laser beam is emitted in a direction perpendicular to the surface. In this way, compared to using end-face emitting lasers, VCSELs are easier to array in two dimensions. For example, the number of VCSELs in the light source 20 can be 100 to 1000. Furthermore, multiple VCSELs are connected in parallel and driven in parallel. The number of VCSELs mentioned above is just one example and can be set according to the measurement distance or illumination range.

[0093] like Figure 4 As shown, the light source 20 is divided into multiple light-emitting zones 24, and is driven according to each light-emitting zone. Figure 4 In the example, as shown by the dashed lines, the light source 20 is divided into 12 luminous zones 24 of 4×3. 11 ~24 34 However, the number of light-emitting zones is not limited to this. Unless otherwise specified, they are simply referred to as light-emitting zone 24. Furthermore, in Figure 4 In the example, one light-emitting partition 24 includes 16 VCSELs, but the number of VCSELs included in one light-emitting partition 24 is not limited to this; it can include more than one VCSEL.

[0094] Multiple VCSEL-shared anode electrodes 218 (reference) are disposed on the surface of the light source 20. Figure 5 A cathode electrode 214 is provided on the back of the light source 20 (see reference). Figure 5 That is, multiple VCSELs are connected in parallel. By driving multiple VCSELs in parallel, a stronger light intensity can be emitted compared to driving a single VCSEL.

[0095] Here, the light source 20 is set to have a rectangular shape (referred to as a planar shape, hereinafter the same) when viewed from the surface side. Furthermore, the side facing in the -y direction is called side 21A, the side facing in the +y direction is called side 21B, the side facing in the -x direction is called side 22A, and the side facing in the +x direction is called side 22B. Side 21A and side 21B are opposite to each other. Side 22A and side 22B are connected to side 21A and side 21B respectively, and are opposite to each other.

[0096] Furthermore, the center of the planar shape of the light source 20 (i.e., the center in the x and y directions) is set as the center Ov.

[0097] (Drive unit 50 and capacitors 70A and 70B)

[0098] To drive the light source 20 at a higher speed, low-side driving is preferred. Low-side driving refers to a structure in which the driving element, such as a MOS transistor, is located downstream of the current path relative to the driving object, such as a VCSEL. Conversely, a structure in which the driving element is located upstream is called high-side driving.

[0099] Figure 5 This diagram illustrates an example of the equivalent circuit when the light source 20 is driven via low-side driving. Figure 5 The image shows the VCSEL of the light source 20, the drive unit 50, capacitors 70A and 70B, and the power supply 82. The power supply 82 is also provided in... Figure 1 The control unit 8 is shown. Power supply 82 generates a DC voltage with the + side as the power supply potential and the - side as the reference potential. The power supply potential is supplied to power line 83, and the reference potential is supplied to reference line 84. Alternatively, the reference potential can be ground potential (sometimes referred to as GND). Figure 5 The winning bid is [G].

[0100] As described above, the light source 20 is composed of multiple VCSELs connected in parallel. The anode electrode 218 of the VCSEL (reference) Figure 3 . Figure 5 The winning designation is [A]. ) Connect to power cord 83.

[0101] As described above, the light source 20 is divided into multiple light-emitting zones 24, and the control unit 8 drives the VCSEL according to each light-emitting zone 24. Additionally, in Figure 5 In the diagram, only three VCSELs are shown in one light-emitting zone 24, and the diagrams of other VCSELs and light-emitting zones are omitted.

[0102] like Figure 5As shown, a switching element SW is provided between each VCSEL and the power line 83. Each switching element SW is simultaneously turned on or off according to the command from the control unit 8. Thus, the control includes the VCSELs in one light-emitting zone 24 emitting or not emitting light at the same time.

[0103] The driving unit 50 includes an n-channel MOS transistor 51 and a signal generation circuit 52 for turning the MOS transistor 51 on or off. The drain of the MOS transistor 51 ( Figure 5 The winning designation is [D]. This relates to the cathode electrode 214 of the VCSEL (reference). Figure 3 . Figure 5 The subscript is [K]. The source of MOS transistor 51 ( Figure 5 The [S] symbol is used to indicate the connection between the MOS transistor 51 and the reference line 84. The gate of the MOS transistor 51 is connected to the signal generation circuit 52. That is, the VCSEL and the MOS transistor 51 of the drive unit 50 are connected in series between the power supply line 83 and the reference line 84. Under the control of the control unit 8, the signal generation circuit 52 generates a "H level" signal that turns the MOS transistor 51 on and a "L level" signal that turns the MOS transistor 51 off.

[0104] One terminal of capacitors 70A and 70B is connected to power line 83, and the other terminal is connected to reference line 84. When multiple capacitors 70 are present, they are connected in parallel. Figure 5 In this context, capacitor 70 is defined as two capacitors, 70A and 70B. Alternatively, capacitor 70 may be, for example, an electrolytic capacitor or a ceramic capacitor.

[0105] Next, the driving method (low-side driving) of the light source 20 will be explained.

[0106] First, the control unit 8 turns on the switching element SW of the light-emitting section 24 that is intended to make the VCSEL emit light, and turns off the switching element SW of the light-emitting section 24 that is not intended to make the VCSEL emit light.

[0107] The following describes the driving of the VCSELs included in the light-emitting section 24 where the switching element SW is turned on.

[0108] First, let's assume the signal generated by the signal generation circuit 52 in the drive unit 50 is at "L level". In this case, the MOS transistor 51 is in the off state. That is, the source of the MOS transistor 51 ( Figure 5 [S]) - Drain ( Figure 5 No current flows between [D] and MOS transistor 51. Therefore, no current flows through the VCSEL connected in series with MOS transistor 51. That is, the VCSEL does not emit light.

[0109] At this time, capacitors 70A and 70B are connected to power supply 82. One terminal of capacitors 70A and 70B connected to power line 83 becomes the power supply potential, and the other terminal connected to reference line 84 becomes the reference potential. Therefore, capacitors 70A and 70B are charged by the current (supply charge) flowing from power supply 82.

[0110] Next, when the signal generated by the signal generation circuit 52 in the driving unit 50 becomes "H level", the MOS transistor 51 switches from the off state to the on state. In this way, capacitors 70A and 70B, together with the series-connected MOS transistor 51 and VCSEL, form a closed loop, and the charge stored in capacitors 70A and 70B is supplied to the series-connected MOS transistor 51 and VCSEL. That is, driving current flows through the VCSEL, causing the VCSEL to emit light. This closed loop is the driving circuit for driving the light source 20.

[0111] Then, when the signal generated by the signal generation circuit 52 in the drive unit 50 returns to "L level", the MOS transistor 51 switches from the on state to the off state. As a result, the closed loop (drive circuit) of capacitors 70A and 70B, the MOS transistor 51 connected in series with the VCSEL, becomes an open loop, and the drive current no longer flows through the VCSEL. Therefore, the VCSEL stops emitting light. In this way, capacitors 70A and 70B are charged by being supplied with charge from the power supply 82.

[0112] As described above, whenever the signal output from the signal generation circuit 52 shifts to "H level" and "L level", the MOS transistor 51 repeatedly turns on and off, causing the VCSEL to repeatedly emit light and not emit light. The repeated turning of the MOS transistor 51 on and off is sometimes referred to as a switch.

[0113] In this exemplary embodiment, such as Figure 6 As shown, the 3D sensor 5 is divided into multiple light-receiving zones 26. Each light-receiving zone 26 includes one or more light-receiving elements (PDs). Figure 6 In the example, one light-receiving zone 26 includes 16 light-receiving elements (PDs), but the number of light-receiving elements (PDs) is not limited to this. Additionally, in Figure 6 In this example, for ease of explanation, the 3D sensor 5 is divided into 4×3 light-receiving zones 26, similar to the light-emitting zone 24. 11 ~26 34 However, it can also be divided into a different number than the light-emitting zone 24. In addition, without specifically distinguishing the light-receiving zone, it is simply referred to as the light-receiving zone 26.

[0114] Furthermore, in this exemplary embodiment, assuming that all VCSELs belonging to each light-emitting partition 24 emit light for each light-emitting partition 24, the light-receiving partition 26 to which the light-receiving element PD directly receives light is predetermined. The correspondence between the light-emitting partitions 24 and the light-receiving partitions 26 is pre-stored in the storage unit 16 in the form of a partition correspondence table 16B (see reference). Figure 2 ).

[0115] The partition correspondence table 16B is calculated, for example, based on the amount of light received by each light-emitting partition 24 sequentially emitting light to the predetermined test object in the absence of obstacles, etc., and by each light-receiving partition 26.

[0116] In addition, the light-emitting zone 24 and the light-receiving zone 26 can be any one-to-one, many-to-one, one-to-many, and many-to-many correspondences, but in this exemplary embodiment, for ease of explanation, they are set to a one-to-one correspondence.

[0117] If the 3D sensor 5 can receive only the light emitted from the light source 20 that is directly incident on the object being measured and reflected by it, then the distance from the optical device 3 to the object being measured can be accurately measured.

[0118] However, in reality, the 3D sensor 5 has a lens (not shown), which causes lens glare because the light-receiving element, which should not normally receive light, receives excess light reflected multiple times by the lens. Furthermore, hereinafter, the light directly incident on the object being measured and reflected by the light-receiving element, which is directly received by the light-receiving element, will be referred to as direct light. And, any excess light other than direct light will be referred to as indirect light.

[0119] In light-receiving elements that receive both direct and indirect light due to lens glare, the amount of light received may sometimes exceed expectations, leading to saturation. Furthermore, for example, when there is an obstacle such as a user's finger between the measuring device 1 and the object being measured, the amount of light received may also exceed expectations due to excess indirect light reflected by the obstacle.

[0120] Therefore, in this exemplary embodiment, only the light-emitting partition 24 corresponding to the light-receiving element PD with a light-receiving amount less than a predetermined threshold is illuminated, while the light-emitting partition 24 corresponding to the light-receiving element PD with a light-receiving amount greater than the predetermined threshold is not illuminated. Furthermore, the series of processes from emitting light from the light source 20 to measuring the distance to the object being measured is sometimes referred to as integration. And, hereinafter, the VCSEL illumination belonging to the light-emitting partition 24 is sometimes simply referred to as the illumination of the light-emitting partition 24.

[0121] Thus, the number of light-emitting zones 24 varies depending on the number of light-receiving zones 26 to which the light-receiving element PD belongs with a light-receiving amount above a predetermined threshold. However, while keeping the light amount of each light-emitting zone 24 constant, the current value flowing through each light-emitting zone 24 remains constant. Therefore, it is necessary to increase the driving current supplied to the light source 20 as a whole as the number of light-emitting zones 24 increases.

[0122] In this exemplary embodiment, to maintain a constant light intensity in each of the light-emitting zones 24, the control unit 8 controls the light source 20 and the drive unit 50 to increase the drive current supplied to the entire light source 20 as the number of light-emitting zones 24 increases. If the drive current is increased in this way, the rise time of the drive current in the light source 20 becomes longer. As a result, the accuracy of the distance measurement to the object being measured will deviate depending on the number of light-emitting zones 24. This is because the total current driven by the drive unit 50 increases. Furthermore, since the current value flowing through each light-emitting zone 24 remains constant, the delay time (rise time of light emission) from when the drive current is supplied to the light source 20 until the light-emitting zone 24 actually begins to emit light due to relaxation oscillation remains constant.

[0123] In this exemplary embodiment, the timing of the drive current supply is controlled so that even if the number of light-emitting zones 24 changes, i.e., the configuration of the light-emitting zones 24 changes, the change in the light-receiving timing of the light-receiving element belonging to the light-receiving zone 26 remains within a predetermined range. Here, the predetermined range refers to the range that keeps the measurement error of the distance to the object under test within an allowable range.

[0124] Specifically, even if the number of light-emitting zones 24 changes without altering the light intensity of each zone, the timing of supplying the driving current to the light-emitting zones 24 becomes earlier as the number of zones increases. Therefore, even if the number of light-emitting zones 24 changes, the timing variation of the light-receiving element PD remains within a predetermined range, thereby suppressing deviations in the accuracy of distance measurement to the object being measured.

[0125] Furthermore, the configuration of the light-emitting zone 24 refers to the position of the light-emitting zone 24; specifically, it refers to... Figure 4 The position on the XY plane. Furthermore, a change in the configuration of the light-emitting partitions 24 means that a change in the number of light-emitting partitions 24 results in a change in the position of at least one of the light-emitting partitions 24, or that even though the number of light-emitting partitions 24 is the same, the position of at least one of the light-emitting partitions 24 changes.

[0126] Next, the operation of the measuring device 1 according to this exemplary embodiment will be explained. Figure 7This is a flowchart illustrating the flow of the measurement process performed by the control unit 8 of the measuring device 1 according to this exemplary embodiment. Figure 7 The measurement process shown is executed by reading the measurement program 16A stored in the storage unit 16 by the CPU 12A.

[0127] In step S100, the MOS transistor 51 of the driving unit 50 is turned on, and all switching elements SW are turned on, so that all VCSELs of the light-emitting sections 24 of the light source 20 emit light. Thus, all VCSELs emit light.

[0128] In step S102, the amount of light received (charge) by the light-receiving elements of all light-receiving zones 26 is obtained from the 3D sensor 5.

[0129] In step S104, it is determined whether there is a light-receiving element with a light-receiving amount of more than a predetermined threshold. The threshold is set to a value that also receives indirect light other than direct light and can determine that the light-receiving amount is saturated. If there is a light-receiving element with a light-receiving amount of more than the predetermined threshold, the process proceeds to step S106. On the other hand, if there is no light-receiving element with a light-receiving amount of more than the predetermined threshold, the process proceeds to step S110.

[0130] In step S106, the light-emitting partition 24 corresponding to the light-receiving partition 26 to which the light-receiving element has a light-receiving amount of more than a threshold is determined by referring to the partition correspondence table 16B. Then, the light-emitting partition 24 other than the determined light-emitting partition 24 is designated as the first light-emitting partition 24, and a driving current is supplied to the first light-emitting partition 24 to make the VCSEL belonging to the first light-emitting partition 24 emit light a predetermined number of times.

[0131] At this time, the timing t1 for supplying the driving current to make the first light-emitting partitions 24 emit light is set according to the number of the first light-emitting partitions 24. Specifically, the timing t1 for supplying the driving current is advanced as the number of the first light-emitting partitions 24 increases. As an example, Figure 8A , 8B As shown, the timing t1' of supplying the driving current when the number of the first light-emitting partitions 24 is 12 (N=12) is set earlier than when the number of the first light-emitting partitions 24 is 1 (N=1). Therefore, even if the number of the first light-emitting partitions 24 changes, the time from the start of light emission t2 of the first light-emitting partitions 24 to the light-receiving timing t3 of the light-receiving element can be suppressed from changing.

[0132] Then, the amount of light received by the light-receiving element belonging to the light-receiving partition 26 corresponding to the first light-emitting partition 24 is obtained from the 3D sensor 5, and the distance to the object being measured is determined by the phase difference method described above. That is, the distance to the object is determined by emitting light from the VCSEL belonging to the first light-emitting partition 24 corresponding to the light-receiving partition 26 to which the light-receiving element has an amount of light received less than a threshold. Thus, the distance to the object is determined by emitting light from the VCSEL belonging to the first light-emitting partition 24 corresponding to the light-receiving partition 26, which is less affected by indirect light. Alternatively, the distance to the object can be determined by only obtaining the amount of light received by the light-receiving element belonging to the light-receiving partition 26 corresponding to the first light-emitting partition 24.

[0133] Alternatively, instead of setting the supply timing t1 of the driving current for illuminating the first light-emitting partitions 24 based on the number of the first light-emitting partitions 24, the light-receiving timing t3 of the 3D sensor 5 can be set based on the number of the first light-emitting partitions 24. Specifically, the light-receiving timing t3 is delayed as the number of the first light-emitting partitions 24 increases. As an example, such as Figure 9A , 9B As shown, the light-receiving timing t3' when the number of first light-emitting zones 24 is 12 (N=12) is set later than when the number of first light-emitting zones 24 is 1 (N=1). Here, the light-receiving timing refers to the timing at which the 3D sensor 5 becomes active to receive light. In this way, even if the number of first light-emitting zones 24 changes, it is possible to suppress changes in the time from the start of light emission t2 of the first light-emitting zone 24 to the light-receiving timing t3 of the light-receiving element.

[0134] In step S108, the VCSELs of the second light-emitting partition 24 (excluding the first light-emitting partition 24) are made to emit light, and the amount of light received by the light-receiving element of the light-receiving partition 26 corresponding to the emitting second light-emitting partition 24 is obtained from the 3D sensor 5, and the distance to the object is measured. At this time, the VCSELs of the second light-emitting partition 24 are made to emit light a number of times N2 fewer than the number of times N1 the VCSELs of the first light-emitting partition 24 are made to emit light in step S106. In addition, the number of times N2 is set to be the number of times the amount of light received by the light-receiving element is less than a threshold. As a result, it is possible to suppress the amount of light received by the light-receiving element from exceeding the threshold.

[0135] In addition, in step S108, similar to step S106, the timing t1 for supplying the driving current to make the second light-emitting partition 24 emit light is set according to the number of the second light-emitting partition 24, or the timing t3 for receiving light of the 3D sensor 5 is set according to the number of the first light-emitting partition 24.

[0136] In step S110, since there are no light-receiving elements with a light-receiving amount above the threshold, the distance to the object being measured is determined based on the light-receiving amount of all light-receiving elements obtained in step S102.

[0137] Thus, in this exemplary embodiment, the light-emitting partition corresponding to the light-receiving partition 26 to which the light-receiving element has a light-receiving amount less than a predetermined threshold is designated as the first light-emitting partition 24, and the light-emitting partition corresponding to the light-receiving partition 26 to which the light-receiving element has a light-receiving amount greater than or equal to the predetermined threshold is designated as the second light-emitting partition 24. Furthermore, the second light-emitting partition 24 emits light by reducing the number of times it emits light.

[0138] For example, such as Figure 10 As shown, assuming it belongs to the light-receiving zone 26 22 26 23 26 31 26 34 At least a portion of the light-receiving elements receive light exceeding a threshold, and as indicated by the arrow, the surrounding light-receiving zones also receive light. In this case, with light-receiving zone 26... 22 26 23 26 31 26 34 Corresponding light-emitting partition 24 22 ,twenty four 23 ,twenty four 31 ,twenty four 34 The light-emitting zone 24, which is set as the second light-emitting zone 24, is set as the first light-emitting zone 24, corresponding to the other light-receiving zone 26.

[0139] In addition, Figure 7 In the process, step S108 is executed after step S106, but steps S106 and S108 can also be executed simultaneously. That is, the first light-emitting partition 24 and the second light-emitting partition 24 are emitted simultaneously. As a result, the processing time is shortened.

[0140] <Second Exemplary Implementation>

[0141] Next, a second exemplary embodiment will be described. Furthermore, the same symbols will be used to denote the same parts as in the first exemplary embodiment, and detailed descriptions will be omitted.

[0142] The structure of measuring device 1 is the same as that of the first exemplary embodiment, so the description is omitted.

[0143] The lens glare described in the first exemplary embodiment is not the only problem that occurs when light from the light source 20 is shone onto the object being measured and the reflected light is received to determine the distance to the object. For example, as Figure 11As shown, the light emitted from the light source 20 is not simply direct light L1 produced by reflection from the object 28. For example, there is a multipath problem where the light is reflected by obstacles such as the wall 32 and received by the 3D sensor 5 as multipath light L2 through multiple paths.

[0144] Because of the multipath, the light-receiving element receives not only direct light but also indirect light that it should not otherwise receive, which can sometimes affect the accuracy of the measured distance.

[0145] Therefore, in this exemplary embodiment, the second light-emitting partition 24, which corresponds to the light-receiving partition 26 to which the light-receiving element that should not normally receive indirect light belongs, is not made to emit light. Instead, the VCSEL belonging to the first light-emitting partition 24, which is outside the second light-emitting partition 24, emits light to measure the distance to the object being measured. Thus, as Figure 12 As shown, the distance to the test object 28 was measured under the condition that the influence of multipath light L2 was suppressed.

[0146] The function of this exemplary embodiment will be described below. Figure 13 This is a flowchart illustrating the flow of the measurement process performed by the control unit 8 of the measuring device 1 according to this exemplary embodiment.

[0147] In step S200, one non-illuminated light-emitting section 24 is made to emit light. That is, the MOS transistor 51 of the driving unit 50 is turned on, and the switching element SW of the non-illuminated light-emitting section 24 is turned on, so that the VCSEL of the non-illuminated light-emitting section 24 emits light. As a result, the VCSEL of one light-emitting section 24 emits light, while the VCSELs of the other light-emitting sections 24 do not emit light.

[0148] In step S202, the amount of light received by all light-receiving elements belonging to the light-receiving partition 26 is obtained from the 3D sensor 5.

[0149] In step S204, the first light-receiving partition 26 corresponding to the light-emitting partition 24 that emitted light in step S200 is determined by referring to the partition correspondence table 16B. Then, it is determined whether light is received by the second light-receiving partition 26 other than the first light-receiving partition 26 based on the amount of light received by all light-receiving elements belonging to the light-receiving partition 26 obtained in step S202.

[0150] Then, if light is received by the second light-receiving partition 26, proceed to step S206; if light is not received by the second light-receiving partition 26, proceed to step S208.

[0151] In step S206, the light-emitting partition 24 that emitted light in step S200 is set as the second light-emitting partition 24.

[0152] On the other hand, in step S208, the light-emitting partition 24 that emits light in step S200 is set as the first light-emitting partition 24.

[0153] In step S210, it is determined whether all light-emitting partitions 24 have emitted light. If all light-emitting partitions 24 have emitted light, the process proceeds to step S212. On the other hand, if there are any light-emitting partitions 24 that have not emitted light, the process proceeds to step S200, whereby the non-light-emitting partitions 24 are made to emit light, and the same process as described above is performed.

[0154] In step S212, the first light-emitting partition 24 set in step S208 emits light only a predetermined number of times.

[0155] At this time, similar to the first exemplary embodiment, the timing t1 for supplying the driving current to make the first light-emitting partitions 24 emit light is set according to the number of the first light-emitting partitions 24. That is, the timing for supplying the driving current is advanced as the number of the first light-emitting partitions 24 increases.

[0156] Then, the amount of light received by each light-receiving element is obtained from the 3D sensor 5, and the distance to the object being measured is determined by the phase difference method described above.

[0157] Alternatively, similar to the first exemplary embodiment, instead of setting the supply timing t1 of the driving current for illuminating the first light-emitting partitions 24 according to the number of the first light-emitting partitions 24, the light-receiving timing t3 of the 3D sensor 5 can be set according to the number of the first light-emitting partitions 24. That is, the light-receiving timing t3 can also be delayed as the number of the first light-emitting partitions 24 increases.

[0158] Thus, in this exemplary embodiment, when light is received by a light-receiving element belonging to a second light-receiving partition 26 other than the first light-receiving partition 26 corresponding to the light-emitting partition 24, the first light-receiving partition 24 other than the second light-receiving partition 24 corresponding to the second light-receiving partition 26 is made to emit light to measure the distance to the object being measured.

[0159] The exemplary embodiments have been described above, but the technical scope of the present invention is not limited to the scope described in the above embodiments. Various changes or improvements can be made to the above exemplary embodiments without departing from the spirit of the invention, and such changes or improvements are also included in the technical scope of the present invention.

[0160] Furthermore, the above exemplary embodiments are not limited to the inventions involved in the technical solutions, and all combinations of features described in the embodiments are not necessarily necessary for the solution of the invention. The above exemplary embodiments include various interim inventions, and various inventions can be extracted by combining multiple disclosed constituent elements. Even if several constituent elements are deleted from all the constituent elements shown in the exemplary embodiments, as long as the effect is obtained, the structure after deleting the several constituent elements can be extracted as an invention.

[0161] For example, in the first exemplary embodiment, to avoid the influence of lens glare, and in the second exemplary embodiment, to avoid the influence of multipath propagation, the timing t1 for supplying the driving current or the timing t3 for receiving light from the 3D sensor 5 is controlled according to the number of light-emitting partitions 24. However, sometimes it may be desirable to reduce the number of light-emitting partitions 24 for power saving. In this case, the timing t1 for supplying the driving current to make the light-emitting partitions 24 emit light may be set according to the number of light-emitting partitions 24, just as in the first and second exemplary embodiments. Furthermore, instead of setting the timing t1 for supplying the driving current, the timing t3 for receiving light from the 3D sensor 5 may be set according to the number of light-emitting partitions 24.

[0162] Furthermore, in order to extend the measurement distance, it is sometimes desirable to increase the power of the light emitted from a portion of the light-emitting sections 24. In this case, even if the number of light-emitting sections 24 changes, the overall light intensity of the light-emitting sections 24 remains unchanged. Since the overall driving current of the light source 20 is the same as when all light-emitting sections 24 are emitting light, reducing the number of light-emitting sections 24 increases the driving current supplied to each light-emitting section 24.

[0163] Furthermore, with a reduced number of light-emitting zones 24, the current path through which the drive current flows is narrower than when all light-emitting zones 24 are illuminated, thus the inductance may sometimes increase. If the inductance increases, the drain voltage of the MOS transistor 51 may sometimes drop due to transient current, causing a delay in the timing t1 of the drive current supply.

[0164] Thus, if the number of light-emitting zones 24 is reduced, the time from the supply of the driving current to the actual emission of light will be both shortened and lengthened, depending on the balance between the increase in the driving current supplied to a light-emitting zone 24 and the increase in the inductance of the current path of the driving current.

[0165] Therefore, even if the number of light-emitting zones 24 changes, the overall light intensity of the light-emitting zones 24 remains unchanged. The timing t1 for supplying the driving current is set based on the inductance of the current path through which the driving current flows to the light-emitting zones 24. For example, the correspondence between the number of light-emitting zones 24 and the timing t1 for supplying the driving current is determined in advance through experiments, such as when the time from the start of light emission to the light reception time remains unchanged, and this relationship is stored in the storage unit 16. Then, the supply timing t1 corresponding to the number of light-emitting zones 24 can be set. In this example, specifically, as the inductance increases, that is, as the number of light-emitting zones 24 is reduced to increase the power of the emitted light, the timing t1 for supplying the driving current is advanced. As an example, such as... Figure 14A , 14B As shown, the driving current supply timing t1' when the number of emitting light-emitting zones 24 is 1 (N=1) is set earlier than when the number of emitting light-emitting zones 24 is 12 (N=12). Therefore, even if the number of emitting light-emitting zones 24 changes, changes in the time from the start of emitting light t2 of the emitting light-emitting zone 24 to the light-receiving timing t3 of the light-receiving element can be suppressed. Furthermore, instead of setting the driving current supply timing t1, the light-receiving timing t3 of the 3D sensor 5 can be set according to the number of emitting light-emitting zones 24. Specifically, as the inductance increases, that is, as the number of emitting light-emitting zones 24 decreases, the light-receiving timing t3 is delayed. For example, as... Figure 15A , 15B As shown, the light-receiving timing t3' when the number of light-emitting partitions 24 is 1 (N=1) is set later than when the number of light-emitting partitions 24 is 12 (N=12). Therefore, even if the number of light-emitting partitions 24 changes, the time from the start of light emission t2 of the light-emitting partition 24 to the light-receiving timing t3 of the light-receiving element can be suppressed from changing.

[0166] In addition, when the number of light-emitting partitions 24 is the same but the positions of the light-emitting partitions 24 are different, either the supply timing t1 of the driving current and the light-receiving timing t3 can be controlled according to the position of the light-emitting partitions 24.

[0167] Furthermore, in the above exemplary embodiments, the case in which either the drive current supply timing t1 or the light receiving timing t3 is controlled according to the number of light-emitting partitions 24 is described, but it is also possible to control both the drive current supply timing t1 and the light receiving timing t3 according to the number of light-emitting partitions 24.

[0168] Furthermore, in the above exemplary embodiment, the case where the current value flowing through each light-emitting partition 24 does not change has been described, but as a variation, the case where the current value flowing through each light-emitting partition 24 changes has been described.

[0169] The driving current of each luminous partition 24 can also be changed according to the ranging range, along with the number of luminous partitions 24. For example, if the number of luminous partitions 24 is reduced without changing the total driving current supplied to the light source 20, the driving current of each luminous partition 24 increases. In this case, the delay time from when the driving current is supplied to the VCSEL from the light source 20 to when the luminous partition 24 actually begins to emit light is shortened.

[0170] The delay time td is represented by the following formula.

[0171] td=τa×ln(Jp / (Jp-Jth+Jb))···(1)

[0172] Here, τa is the carrier lifetime, Jp is the step-drive current, Jb is the bias current, and Jth is the threshold current. Furthermore, Jb ≤ Jth.

[0173] According to equation (1) above, the delay time td decreases as the driving current value Jp increases. As a result, if the driving current of each luminous zone 24 is changed, the accuracy of the distance measurement to the object will be affected.

[0174] Therefore, the timing t1 for supplying the drive current is set based on the delay time td, i.e., based on the current value Jp of the drive current. Specifically, the timing t1 for supplying the drive current is advanced as the current value Jp decreases. As an example, such as Figure 16A , 16B As shown, the drive current supply timing is set so that the drive current supply timing t1' when the current value Jp is smaller is earlier than when the current value Jp is larger. Therefore, even if the current value Jp changes, changes in the time from the start of light emission t2 of the light-emitting zone 24 to the light-receiving timing t3 of the light-receiving element can be suppressed. Furthermore, instead of setting the drive current supply timing t1, the light-receiving timing t3 of the 3D sensor 5 can be set according to the current value Jp. Specifically, the light-receiving timing t3 is delayed as the current value Jp decreases. For example, as... Figure 17A , 17B As shown, the light-receiving timing t3' is set later when the current value Jp is smaller than when the current value Jp is larger. Therefore, even if the current value Jp changes, the time from the start of light emission t2 of the light-emitting zone 24 to the light-receiving timing t3 of the light-receiving element can be suppressed from changing.

[0175] Furthermore, in the above exemplary embodiments, the case of determining the three-dimensional shape of the object by measuring the distance to the object has been described, but for example, it is also possible to detect only whether the object exists within a predetermined distance.

[0176] And, execute Figure 7 , 13 The control unit for timing the supply of driving current to the light source 20 during the processing can be configured as a structure assembled in the light-emitting device 4.

[0177] Furthermore, while the above exemplary embodiment describes the measurement program 16A as being installed in the storage unit 16, it is not limited to this. The measurement program 16A described in the above exemplary embodiment may also be provided in the form of being recorded on a computer-readable storage medium. For example, the measurement program 16A described in the above exemplary embodiment may also be provided in the form of being recorded on an optical disc such as a CD (Compact Disc)-ROM or DVD (Digital Versatile Disc)-ROM, or in the form of being recorded on a semiconductor memory such as a USB (Universal Serial Bus) memory or a memory card. Moreover, the measurement program 16A described in the above exemplary embodiment may also be obtained from an external device via a communication line connected to the communication unit 14.

[0178] In the above exemplary embodiments, processor refers to processor in a broad sense, including general-purpose processors (e.g., CPU: Central Processing Unit, etc.) or dedicated processors (e.g., GPU: Graphics Processing Unit, ASIC: Application Specific Integrated Circuit, FPGA: Field Programmable Gate Array, programmable logic devices, etc.).

[0179] Furthermore, the actions of the processor in the above exemplary embodiments can be performed not only by a single processor, but also collaboratively by multiple processors physically located at different positions. Moreover, the order of the processor's actions is not limited to the order described in the above exemplary embodiments and can be appropriately modified.

[0180] In the above exemplary embodiments, the case where a surface-emitting light-emitting element that emits light in a direction perpendicular to the surface of the light source 20 is used as the light source 20 has been described. However, a surface-emitting light-emitting element that emits light in a direction perpendicular to the back surface of the light source 20, or a light-emitting element that emits light from the side surface of the light source 20, may also be used. Furthermore, in the above embodiments, the case where a laser element is used as the light-emitting element has been described. However, other light-emitting elements such as LEDs (Light Emitting Diodes) may also be used.

[0181] Furthermore, in the above exemplary embodiments, the case where multiple light-emitting elements included in one light-emitting zone 24 and turned on or off by the same switching element SW are arranged adjacent to each other, i.e., multiple light-emitting elements included in one light-emitting zone 24 are grouped together as a set, has been described, but it is not limited to this. Multiple light-emitting elements included in one light-emitting zone 24 and turned on or off by the same switching element SW may also be arranged separately and not adjacent to each other.

[0182] Furthermore, in the exemplary embodiments described above, examples were given for cases where a light-receiving element has a light-receiving amount exceeding a predetermined threshold and cases where it is desirable to increase the power of the emitted light, but the application is not limited to these. For example, it can also be applied to situations such as automatically detecting the area to be measured in three dimensions from a separately prepared two-dimensional image and determining the number of emitting light zones based on the results.

[0183] Furthermore, this application is based on Japanese patent application filed on March 25, 2021 (Japanese Patent Application No. 2021-051646), the contents of which are incorporated herein by reference.

Claims

1. A detection device comprising: An array of light-emitting elements, which has multiple light-emitting elements; A light-receiving element array having multiple light-receiving elements, wherein the light-receiving elements receive reflected light emitted from the light-emitting element array toward the object to be detected; The driving unit drives the light-emitting element; as well as The detection unit controls at least one of the supply timing of the driving current to the light-emitting element and the light-receiving timing of the light-receiving element, so that even if the configuration of the light-emitting element changes, the variation in time from the start of light emission by the light-emitting element to the light-receiving timing of the light-receiving element remains within a predetermined range, and detects the object to be detected. In the case where the light intensity of each light-emitting element remains unchanged even if the number of light-emitting elements changes, the detection unit controls the supply timing to make the supply timing earlier as the number of light-emitting elements increases, and / or the detection unit controls the light-receiving timing to make the light-receiving timing later as the number of light-emitting elements increases.

2. A detection device comprising: An array of light-emitting elements, which has multiple light-emitting elements; A light-receiving element array having multiple light-receiving elements, wherein the light-receiving elements receive reflected light emitted from the light-emitting element array toward the object to be detected; The driving unit drives the light-emitting element; as well as The detection unit controls at least one of the supply timing of the driving current to the light-emitting element and the light-receiving timing of the light-receiving element, so that even if the configuration of the light-emitting element changes, the variation in time from the start of light emission by the light-emitting element to the light-receiving timing of the light-receiving element remains within a predetermined range, and detects the object to be detected. If the overall light intensity of the light-emitting elements remains unchanged even if the number of light-emitting elements changes, the detection unit controls at least one of the supply timing and the light-receiving timing, which is determined based on the inductance of the current path of the drive current flowing to the light-emitting elements. The detection unit controls the supply timing so that the supply timing becomes earlier as the number of light-emitting elements decreases, and / or The detection unit controls the light-receiving timing so that the light-receiving timing becomes later as the number of light-emitting elements decreases.

3. The detection device according to claim 1 or 2, wherein, In the light-emitting element array, each of the multiple light-emitting zones can emit light independently, and each light-emitting zone includes at least two light-emitting elements. The detection unit controls the light emission of the light-emitting element for each of the plurality of light-emitting zones.

4. The detection device according to claim 1 or 2, wherein, The detection unit detects the distance from the detection device to the object being detected based on the time of flight.

5. A detection method, comprising the following steps: Controlling the emission of light from multiple light-emitting elements included in the light-emitting element array; and The timing of supplying driving current to the light-emitting element and the timing of light reception of the plurality of light-receiving elements included in the light-receiving element array are controlled so that even if the configuration of the light-emitting element changes, the variation in time from the start of light emission by the light-emitting element to the light reception timing of the light-receiving element remains within a predetermined range, and the object to be detected is detected. In a situation where the light intensity of each light-emitting element remains unchanged even if the number of light-emitting elements changes, the supply timing is controlled so that the supply timing becomes earlier as the number of light-emitting elements increases, and / or the light-receiving timing is controlled so that the light-receiving timing becomes later as the number of light-emitting elements increases.

6. A detection method, comprising the following steps: Controlling the emission of light from multiple light-emitting elements included in the light-emitting element array; and The timing of supplying driving current to the light-emitting element and the timing of light reception of the plurality of light-receiving elements included in the light-receiving element array are controlled so that even if the configuration of the light-emitting element changes, the variation in time from the start of light emission by the light-emitting element to the light reception timing of the light-receiving element remains within a predetermined range, and the object to be detected is detected. If the overall light intensity of the light-emitting elements remains unchanged even if the number of light-emitting elements changes, then at least one of the supply timing and the light-receiving timing, determined based on the inductance of the current path of the drive current flowing to the light-emitting elements, is controlled. Controlling the supply timing so that the supply timing becomes earlier as the number of light-emitting elements decreases, and / or The light-receiving timing is controlled so that the light-receiving timing becomes later as the number of light-emitting elements decreases.

7. A testing program product comprising a testing program for causing a computer to perform the testing method of claim 5 or 6.

8. A storage medium storing a detection program for causing a computer to execute the detection method of claim 5 or 6.

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