Light-emitting element array and detection device

Abstract

To make it possible to suppress interference of light due to multipath in comparison to a case where wavelengths of light emitted from a plurality of light-emitting elements are the same.SOLUTION: The light-emitting element array is so arranged that a plurality of light-emitting elements with different wavelengths of light emitted to an object are arranged adjacent to each other.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present disclosure relates to a light-emitting element array and a detection device.

Background Art

[0002] Patent Document 1 discloses a method for measuring depth that does not respond to damaged light caused by internal reflection, including radiating light onto a scene by a light source, collecting charges based on the light hitting the pixel during a first period when the damaged light hits the pixel but the return light from an object within the field of view of the pixel does not hit the pixel, by controlling a first charge accumulation unit of the pixel to perform damaged light measurement, removing the contribution from the damaged light from one or more measurements affected by the damaged light based on the damaged light measurement, and determining the depth based on the one or more measurements from which the contribution from the damaged light has been removed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present disclosure is to provide a light-emitting element array and a detection device capable of suppressing interference of light due to multip compared when the multi-path, as compared with the case where wavelengths of light emitted from a plurality of light-emitting elements are the same.

Means for Solving the Problems

[0005] In the light-emitting element array according to the first aspect, a plurality of light-emitting elements that emit light having different wavelengths toward a detection target object are arranged adjacent to each other.

[0006] In the second embodiment, the light-emitting element array is arranged such that, in the first embodiment, three of the light-emitting elements with different wavelengths are arranged in an equilateral triangle.

[0007] The third embodiment of the light-emitting element array is an embodiment of the first or second embodiment in which each of the plurality of light-emitting elements is arranged such that the shortest distance between each of the plurality of light-emitting elements and other light-emitting elements with the same wavelength is longer than the shortest distance between each of the plurality of light-emitting elements and other light-emitting elements with different wavelengths.

[0008] The fourth embodiment of the light-emitting element array is characterized in that, in the first or second embodiment of the light-emitting element array, all adjacent light-emitting elements in all directions are composed of different wavelengths.

[0009] The fifth embodiment of the light-emitting element array is a light-emitting element array according to any of the first to fourth embodiments, wherein the number of wavelengths is 3 or more and 8 or less.

[0010] A detection device according to the sixth embodiment includes: an array of light-emitting elements, each having a different wavelength of light emitted toward an object to be detected, arranged adjacent to one another; a bandpass filter included in a light-receiving unit, which transmits reflected light of different wavelengths reflected from the object to be detected in accordance with the arrangement pattern of the multiple light-emitting elements with different wavelengths; an array of light-receiving elements included in the light-receiving unit, each having multiple light-receiving elements that receive the reflected light through the bandpass filter; a drive unit for driving the light-emitting elements; and a detection unit for detecting the object to be detected from the amount of light received by the multiple light-receiving elements.

[0011] In the detection device according to the seventh embodiment, the light emitted from the plurality of light-emitting elements is received by the corresponding light-receiving elements, as in the detection device according to the sixth embodiment.

[0012] The detection device according to the eighth embodiment is a detection device according to the sixth or seventh embodiment in which the drive unit drives the plurality of light-emitting elements simultaneously.

[0013] The detection device according to the ninth embodiment is a detection device according to any of the sixth to eighth embodiments, wherein the detection unit detects the distance to the object to be detected by time of flight. [Effects of the Invention]

[0014] According to the first and sixth embodiments, multipath interference of light can be suppressed compared to the case where the wavelengths of light emitted from multiple light-emitting elements are the same.

[0015] According to the second embodiment, the arrangement of three light-emitting elements with different wavelengths can suppress light interference due to multipath compared to the case where the arrangement of three light-emitting elements is not in an equilateral triangle.

[0016] According to the third embodiment, multipath interference of light can be suppressed compared to the case where the shortest distance to other light-emitting elements with the same wavelength is shorter than the shortest distance to other light-emitting elements with different wavelengths.

[0017] According to the fourth embodiment, multipath interference of light can be suppressed compared to the case where at least some of the adjacent light-emitting elements have the same wavelength.

[0018] According to the fifth embodiment, it is possible to suppress the complexity of the manufacturing process caused by having too many wavelengths.

[0019] According to the seventh embodiment, it becomes easier to detect the object to be detected compared to the case where the correspondence between the light-emitting element and the light-receiving element is not defined.

[0020] According to the eighth aspect, the three-dimensional shape of the object to be detected can be identified. [Brief explanation of the drawing]

[0021] [Figure 1] This is a schematic diagram showing the configuration of the measuring device. [Figure 2] This is a block diagram showing the essential components of the electrical system of a measuring device. [Figure 3]This is a diagram for explaining multipath. [Figure 4] This is a plan view of a light source. [Figure 5] This is a circuit diagram of a measuring device. [Figure 6] This is a plan view of a light source including light emitting elements of three different wavelengths. [Figure 7] This is a plan view of a light source including a plurality of light emitting elements of the same wavelength according to a conventional example. [Figure 8] This is a plan view of a light source including light emitting elements of three different wavelengths according to a modified example. [Figure 9] This is a plan view of a light source including light emitting elements of four different wavelengths. [Figure 10] This is a plan view of a light source including light emitting elements of eight different wavelengths.

Embodiments for Carrying Out the Invention

[0022] Hereinafter, an example of an embodiment according to the disclosed technology will be described in detail with reference to the drawings.

[0023] Among measuring devices for measuring the three-dimensional shape of a measured object, there is a device that measures the three-dimensional shape based on the so-called ToF (Time of Flight) method using the flight time of light. In the ToF method, the time from the timing when light is emitted from the light source of the measuring device until the timing when the irradiated light is reflected by the measured object and received by the three-dimensional sensor (hereinafter referred to as a 3D sensor) of the measuring device is measured, and the three-dimensional shape is specified by measuring the distance to the measured object. Note that the object to be measured for measuring the three-dimensional shape is referred to as a measured object. The measured object is an example of a detection target object. Further, measuring the three-dimensional shape may be referred to as three-dimensional measurement, 3D measurement, or 3D sensing.

[0024] There are two methods of ToF (Time of Flight): the direct method and the phase difference method (indirect method). The direct method involves irradiating the object to be measured with pulsed light that emits light for a very short time and measuring the time it takes for the light to return. The phase difference method involves periodically flashing pulsed light and detecting the time delay as multiple pulsed lights travel back and forth between the object to be measured as the phase difference. In this embodiment, as an example, the three-dimensional shape is measured using the phase difference method.

[0025] Such measuring devices are installed in portable information processing devices and are used for facial recognition of users attempting to access them. Traditionally, portable information processing devices have used methods such as passwords, fingerprints, and iris scans to authenticate users. In recent years, there has been a growing demand for authentication methods with higher security. As a result, portable information processing devices have begun to be equipped with measuring devices that measure three-dimensional shapes. In other words, a three-dimensional image of the user's face is acquired, and it is determined whether or not access is permitted. Only after authentication that the user is authorized to access the device is permission to use the device (portable information processing device).

[0026] Furthermore, such measuring devices can also be applied to applications that continuously measure the three-dimensional shape of an object being measured, such as augmented reality (AR).

[0027] The configuration, functions, and methods described in this embodiment below can be applied not only to facial recognition and augmented reality, but also to the measurement of the three-dimensional shape of other objects being measured.

[0028] (Measurement device 1)

[0029] Figure 1 is a block diagram illustrating an example of the configuration of a measuring device 1 for measuring three-dimensional shapes.

[0030] The measuring device 1 comprises an optical device 3 and a control unit 8. The control unit 8 controls the optical device 3. The control unit 8 also includes a three-dimensional shape identification unit 81 that identifies the three-dimensional shape of the object to be measured. Note that the measuring device 1 is an example of a detection device, and the control unit 8 is an example of a detection unit.

[0031] Figure 2 is a block diagram showing the hardware configuration of the control unit 8. As shown in Figure 2, 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. The CPU 12A, ROM 12B, RAM 12C, and I / O 12D are connected to each other via a system bus 12E. The system bus 12E includes a control bus, an address bus, and a data bus.

[0032] Furthermore, the communication unit 14 and the storage unit 16 are connected to I / O 12D.

[0033] The communication unit 14 is an interface for data communication with external devices.

[0034] The memory unit 16 is composed of a non-volatile, rewritable memory such as flash ROM, and stores the measurement program 16A, which will be described later. The CPU 12A reads the measurement program 16A stored in the memory unit 16 into the RAM 12C and executes it, thereby configuring the three-dimensional shape identification unit 81 and identifying the three-dimensional shape of the object to be measured.

[0035] The optical device 3 comprises a light-emitting device 4 and a 3D sensor 5. The light-emitting device 4 comprises a wiring board 10, a heat dissipation substrate 100, a light source 20, a light diffusion member 30, a drive unit 50, a holding unit 60, and capacitors 70A and 70B. Furthermore, the light-emitting device 4 may also include passive elements such as a resistive element 6 and a capacitor 7 in order to operate the drive unit 50. Here, it is assumed that there are two resistive elements 6 and two capacitors 7. Although two capacitors 70A and 70B are shown, there may be only one. When capacitors 70A and 70B are not distinguished, they will be referred to as capacitor 70. Furthermore, there may be one resistive element 6 and multiple capacitors 7. Here, electrical components other than the light source 20, drive unit 50, and capacitors 70, such as the 3D sensor 5, resistive element 6, and capacitors 7, may be referred to as circuit components without distinction. Capacitors are sometimes called capacitors. The 3D sensor 5 is an example of a light-receiving unit.

[0036] The heat dissipation substrate 100, drive unit 50, resistive element 6, and capacitor 7 of the light-emitting device 4 are provided on the surface of the wiring board 10. In Figure 1, the 3D sensor 5 is not provided on the surface of the wiring board 10, but it may be provided on the surface of the wiring board 10.

[0037] The light source 20, capacitors 70A and 70B, and holding part 60 are provided on the surface of the heat dissipation substrate 100. The light diffusion member 30 is provided on the holding part 60. Here, it is assumed that the outer shape of the heat dissipation substrate 100 and the outer shape of the light diffusion member 30 are the same. Here, "surface" refers to the front side of the paper in Figure 1. More specifically, in the wiring board 10, the side on which the heat dissipation substrate 100 is provided is called the surface, the front side, or the front side. Also, in the heat dissipation substrate 100, the side on which the light source 20 is provided is called the surface, the front side, or the front side.

[0038] The light source 20 is configured as a light-emitting element array in which multiple light-emitting elements are arranged in two dimensions (see Figure 4, described later). One example of a light-emitting element is a vertical cavity surface-emitting laser element (VCSEL). In the following description, the light-emitting element will be described as a vertical cavity surface-emitting laser element (VCSEL). In the following description, the vertical cavity surface-emitting laser element (VCSEL) may be referred to simply as VCSEL. Since the light source 20 is provided on the surface of the heat dissipation substrate 100, the light source 20 emits light perpendicular to the surface of the heat dissipation substrate 100 and away from the heat dissipation substrate 100. In other words, the light-emitting element array is a surface-emitting laser element array. Note that the multiple light-emitting elements in the light source 20 are arranged in two dimensions, and the surface of the light source 20 from which light is emitted may be referred to as the emission surface.

[0039] Light emitted from the light source 20 is incident on the light diffusion member 30. The light diffusion member 30 then diffuses the incident light and emits it. The light diffusion member 30 is provided so as to cover the light source 20 and capacitors 70A and 70B. In other words, the light diffusion member 30 is provided at a predetermined distance from the light source 20 and capacitors 70A and 70B, which are provided on the heat dissipation substrate 100, by a holding portion 60 provided on the surface of the heat dissipation substrate 100. Therefore, the light emitted from the light source 20 is diffused by the light diffusion member 30 and irradiates the object to be measured. In other words, the light emitted from the light source 20 is diffused by the light diffusion member 30 and irradiates a wider area compared to when the light diffusion member 30 is not provided.

[0040] When performing three-dimensional measurement using the ToF method, the light source 20 is required to emit pulsed light (hereinafter referred to as emitted light pulse) with a frequency of, for example, 100 MHz or higher and a rise time of 1 ns or less, via the drive unit 50. For example, in the case of facial recognition, the distance to which the light is irradiated is approximately 10 cm to 1 m. The area to which the light is irradiated is approximately 1 m square. The distance to which the light is irradiated is referred to as the measurement distance, and the area to which the light is irradiated is referred to as the irradiation range or measurement range. Furthermore, a surface virtually provided within the irradiation range or measurement range is referred to as the irradiation surface. Note that in cases other than facial recognition, the measurement distance to the object to be measured and the irradiation range relative to the object to be measured may differ from those described above.

[0041] As shown in Figure 3, the 3D sensor 5 includes a photodetector array 5A and a bandpass filter 5B. The photodetector array 5A has multiple photodetectors and outputs a signal corresponding to the time from when light is emitted from the light source 20 to when it is received by the 3D sensor 5.

[0042] For example, each photodetector in the 3D sensor 5 receives pulsed reflected light (hereinafter referred to as a received pulse) from the object being measured in response to the emitted light pulse from the light source 20, and accumulates a charge corresponding to the time until the light is received. The 3D sensor 5 is configured as a CMOS device in which each photodetector has two gates and corresponding charge storage units. By alternately applying pulses to the two gates, the generated photoelectrons are rapidly transferred to one of the two charge storage units. Charge corresponding to the phase difference between the emitted light pulse and the received light pulse is accumulated in the two charge storage units. The 3D sensor 5 then outputs a digital value as a signal corresponding to the phase difference between the emitted light pulse and the received light pulse for each photodetector via an AD converter. In other words, the 3D sensor 5 outputs a signal corresponding to the time from the moment light is emitted from the light source 20 to the moment it is received by the 3D sensor 5. That is, a signal corresponding to the three-dimensional shape of the object being measured is obtained from the 3D sensor 5. The AD converter may be provided within the 3D sensor 5, or it may be provided outside the 3D sensor 5.

[0043] The bandpass filter 5B transmits reflected light of different wavelengths reflected from the object to be detected, corresponding to the arrangement pattern of multiple light-emitting elements with different wavelengths of light emitted toward the object to be detected. The photodetector array 5A then receives the reflected light through the bandpass filter 5B.

[0044] The control unit 8 drives the drive unit 50 to cause the light source 20 to emit light, irradiating the object to be measured with light, and the reflected light from the object to be measured is received by the light-receiving element array 5A. Then, the three-dimensional shape of the object to be measured is measured using the ToF method based on the amount of light received by the light-receiving element array 5A.

[0045] The following describes the light source 20, light diffusion member 30, drive unit 50, and capacitors 70A and 70B that constitute the light-emitting device 4.

[0046] (Configuration of light source 20)

[0047] Figure 4 is a plan view of the light source 20. The light source 20 is composed of multiple VCSELs arranged in a two-dimensional array. In other words, the light source 20 is configured as a light-emitting element array in which VCSELs are light-emitting elements. The right direction on the paper is the x-direction, and the top direction on the paper is the y-direction.

[0048] The z-direction is defined as the direction perpendicular to the x and y directions. The front surface of the light source 20 refers to the front side of the paper, i.e., the side in the +z direction, and the back surface of the light source 20 refers to the back side of the paper, i.e., the side in the -z direction. The plan view of the light source 20 is a view of the light source 20 from the front side.

[0049] To further explain, in the light source 20, the side on which the epitaxial layer, which functions as a light-emitting layer (active region 206 described later), is formed is referred to as the surface, front side, or front side of the light source 20.

[0050] A VCSEL is a light-emitting element that emits laser light perpendicular to the surface by providing an active region, which is the light-emitting area, between a lower multilayer reflector and an upper multilayer reflector stacked on a semiconductor substrate 200. Therefore, VCSELs are easier to implement as two-dimensional arrays compared to using edge-emitting lasers. The number of VCSELs in the light source 20 is, for example, 100 to 1000. Multiple VCSELs are connected in parallel and driven in parallel. The above number of VCSELs is just an example and should be set according to the measurement distance and irradiation range.

[0051] The surface of the light source 20 is provided with an anode electrode 218 (see Figure 5) common to multiple VCSELs. The back surface of the light source 20 is provided with a cathode electrode 214 (see Figure 5). In other words, the multiple VCSELs are connected in parallel. By driving multiple VCSELs in parallel, a stronger light is emitted compared to when the VCSELs are driven individually.

[0052] Here, we assume that the light source 20 has a rectangular shape when viewed from the surface side (referred to as the planar shape; the same applies hereafter). The side facing the -y direction is denoted as side 21A, the side facing the +y direction as side 21B, the side facing the -x direction as side 22A, and the side facing the +x direction as side 22B. Sides 21A and 21B face each other. Sides 22A and 22B connect to and face each other, side 21A and side 21B, respectively.

[0053] Then, the center of the planar shape of the light source 20, that is, the center in the x and y directions, is defined as center Ov.

[0054] (Drive unit 50 and capacitors 70A, 70B)

[0055] If you want to drive the light source 20 at a higher speed, it is best to use low-side driving. Low-side driving refers to a configuration in which the driving element, such as a MOS transistor, is located downstream of the current path relative to the drive target, such as a VCSEL. Conversely, a configuration in which the driving element is located upstream is called high-side driving.

[0056] Figure 5 shows an example of an equivalent circuit when the light source 20 is driven by low-side drive. In Figure 5, the VCSEL of the light source 20, the drive unit 50, capacitors 70A and 70B, and the power supply 82 are shown. The power supply 82 is provided in the control unit 8 shown in Figure 1. The 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 the power line 83, and the reference potential is supplied to the reference line 84. The reference potential may be the ground potential (sometimes denoted as GND; in Figure 5, it is denoted as [G]).

[0057] As mentioned above, the light source 20 is composed of multiple VCSELs connected in parallel. The anode electrode 218 of the VCSEL (see Figure 4; labeled [A] in Figure 5) is connected to the power line 83.

[0058] The drive unit 50 includes an n-channel type MOS transistor 51 and a signal generation circuit 52 that turns the MOS transistor 51 on and off. The drain of the MOS transistor 51 (denoted as [D] in Figure 5) is connected to the cathode electrode 214 of the VCSEL (denoted as [K] in Figure 5). The source of the MOS transistor 51 (denoted as [S] in Figure 5) is connected to the reference line 84. The gate of the MOS transistor 51 is connected to the signal generation circuit 52. In other words, the VCSEL and the MOS transistor 51 of the drive unit 50 are connected in series between the power line 83 and the reference line 84. The signal generation circuit 52 generates an "H level" signal to turn the MOS transistor 51 on and an "L level" signal to turn the MOS transistor 51 off, under the control of the control unit 8.

[0059] Capacitors 70A and 70B have one terminal connected to the power line 83 and the other terminal connected to the reference line 84. In this case, if there are multiple capacitors 70, they are connected in parallel. In other words, Figure 5 assumes that there are two capacitors 70A and 70B. Capacitors 70 can be, for example, electrolytic capacitors or ceramic capacitors.

[0060] Next, we will explain the driving method for the light source 20, which is driven on the low side.

[0061] First, let's assume that the signal generated by the signal generation circuit 52 in the drive unit 50 is at the "L level". In this case, the MOS transistor 51 is in the off state. That is, no current flows between the source ([S] in Figure 5) and drain ([D] in Figure 5) of the MOS transistor 51. Therefore, no current flows through the VCSEL connected in series with the MOS transistor 51. In other words, the VCSEL is not emitting light.

[0062] At this time, capacitors 70A and 70B are connected to the power supply 82, and one terminal of capacitors 70A and 70B connected to the power line 83 is at the power supply potential, while the other terminal connected to the reference line 84 is at the reference potential. Therefore, capacitors 70A and 70B are charged by current flowing from the power supply 82 (charge is supplied).

[0063] Next, when the signal generated by the signal generation circuit 52 in the drive unit 50 reaches a "high level," the MOS transistor 51 switches from the off state to the on state. Then, a closed loop is formed between the capacitors 70A and 70B and the MOS transistor 51 and VCSEL connected in series, and the charge stored in the capacitors 70A and 70B is supplied to the MOS transistor 51 and VCSEL connected in series. In other words, a drive current flows to the VCSEL, and the VCSEL emits light. This closed loop is the drive circuit that drives the light source 20.

[0064] Then, when the signal generated by the signal generation circuit 52 in the drive unit 50 becomes "L level" again, the MOS transistor 51 switches from the ON state to the OFF state. As a result, the closed loop (drive circuit) between the capacitors 70A and 70B and the MOS transistor 51 and VCSEL connected in series becomes an open loop, and drive current stops flowing to the VCSEL. As a result, the VCSEL stops emitting light. Then, the capacitors 70A and 70B are charged by the power supply 82.

[0065] As explained above, each time the signal output by the signal generation circuit 52 transitions between "high level" and "low level," the MOS transistor 51 repeatedly switches on and off, causing the VCSEL to repeatedly emit light and not emit light. This repeated switching of the MOS transistor 51 on and off is sometimes called switching.

[0066] In this embodiment, it is assumed that the photodetector PD that receives the light emitted by each VCSEL is predetermined. That is, the light emitted from multiple VCSELs is received by the corresponding photodetector PD. Here, the relationship between the VCSELs and the photodetector PD may be one-to-one, many-to-one, one-to-many, or many-to-many. For the sake of simplicity, the following explanation will focus on the case where there is a one-to-one relationship between the VCSELs and the photodetector PD.

[0067] By the way, when measuring the distance to an object by irradiating it with light from a light source 20 and receiving the reflected light, a problem of light interference due to multipath interference can occur. For example, as shown in Figure 3, the light emitted from the light source 20 is not just direct light L1 that is directly incident on the object 28 and reflected. For example, it may be reflected by obstacles such as a wall 32 and follow multiple paths before being received by the 3D sensor 5 as multipath light L2. Due to multipath interference, the light-receiving element receives not only direct light but also indirect light that it should not receive, which can affect the accuracy of the measured distance.

[0068] Therefore, in this embodiment, the light source 20 is arranged such that multiple VCSELs with different wavelengths of light emitted toward the object to be measured are adjacent to each other. Furthermore, the multiple VCSELs can be driven simultaneously.

[0069] Figure 6 shows a light source 20 in which three VCSELs with different wavelengths A, B, and C are arranged adjacent to each other. Hereafter, the light-emitting element with wavelength A will be referred to as light-emitting element A, the VCSEL with wavelength B as light-emitting element B, and the VCSEL with wavelength C as light-emitting element C. Note that different wavelengths can be achieved by arranging the semiconductor layer structure according to the wavelength.

[0070] In the example shown in Figure 6, the three light-emitting elements A to C are arranged to form an equilateral triangle T1. If the length of one side of the equilateral triangle T is 1, then the shortest distance between light-emitting elements of the same wavelength is √3. Specifically, as shown in Figure 6, for example, the distance D between adjacent light-emitting elements A in the x-direction is √3.

[0071] In other words, each of the light-emitting elements A to C is arranged such that the shortest distance to another light-emitting element with the same wavelength is longer than the shortest distance to another light-emitting element with a different wavelength. For example, as shown in Figure 6, the distance between light-emitting elements A and B with different wavelengths, and the distance between light-emitting elements A and C are 1, while the distance between adjacent light-emitting elements A with the same wavelength in the x-direction is √3, meaning that the distance between light-emitting elements with the same wavelength is longer.

[0072] Here, for example, as shown in Figure 7, if all the light-emitting elements constituting the light source 20 are light-emitting elements A with the same wavelength, multipath interference is likely to occur. In this case, it is necessary to divide the light source 20 into multiple banks (light-emitting sections) 24 and emit light sequentially from each bank. Therefore, a drive unit is required for each bank, and the number of times light is emitted for distance measurement also increases.

[0073] In contrast, in this embodiment, since the light-emitting elements A to C, which have different wavelengths, are arranged to form an equilateral triangle T, the distance between light-emitting elements A, which have the same wavelength, is longer than the distance between light-emitting elements A and B, which have different wavelengths, and the distance between light-emitting elements A and C. As a result, compared to the case where all the light-emitting elements constituting the light source 20 have the same wavelength, multipath light interference is suppressed even when light-emitting elements A to C are driven simultaneously.

[0074] In the example shown in Figure 6, the bandpass filter 5B transmits reflected light of different wavelengths A to C reflected from the object being measured, corresponding to the arrangement pattern of the light-emitting elements A to C. That is, the bandpass filter 5B is a bandpass filter in which filters that transmit light of wavelength A, filters that transmit light of wavelength B, and filters that transmit light of wavelength C are arranged in the same pattern as the arrangement pattern of the light-emitting elements A to C in Figure 6. As a result, the photodetector array 5A receives light of wavelengths in the same pattern as the arrangement pattern of the light-emitting elements A to C in Figure 6.

[0075] Furthermore, Figure 8 shows an example where the light-emitting elements A to C are arranged to form a right triangle T2. In this example as well, the distance between adjacent light-emitting elements A and B with the same wavelength, which are diagonally adjacent in Figure 8, is longer than the distance between light-emitting elements A and B with different wavelengths, and the distance between light-emitting elements A and C.

[0076] Figure 9 also shows an example where four light-emitting elements A-D of different wavelengths are arranged adjacent to each other. In the example in Figure 9, adjacent light-emitting elements in all directions are composed of elements of different wavelengths. In the example in Figure 9, the distances between light-emitting elements A and B of different wavelengths, the distance between light-emitting elements A and C, and the distance between light-emitting elements A and D are 1, while the distance D between light-emitting elements A of the same wavelength is 2. In other words, the distance between light-emitting elements of the same wavelength is longer than the distance between light-emitting elements of different wavelengths.

[0077] Figure 10 also shows an example where eight light-emitting elements A-H of different wavelengths are arranged adjacent to each other. In the example in Figure 10, as in the example in Figure 9, adjacent light-emitting elements in all directions are composed of different wavelengths. In the example in Figure 10, the distances between light-emitting elements A and B of different wavelengths, between light-emitting elements A and C, between light-emitting elements A and D, between A and E, between A and F, and between A and G are all 1, the distance between light-emitting elements A and H is √3, while the distance D between light-emitting elements A of the same wavelength is √7. In other words, the distance between light-emitting elements of the same wavelength is longer than the distance between light-emitting elements of different wavelengths.

[0078] Furthermore, considering the manufacturing constraints of the light source 20, it is preferable that the number of different wavelengths be 3 or more and 8 or less.

[0079] Furthermore, there are cases where a many-to-one correspondence between light-emitting elements and photodetectors is established, for example, by covering multiple light-emitting elements with a microlens array, subdividing the light-emitting elements using diffractive optical elements (DOEs), or using photodetectors with large compartments. In other words, this occurs when the photodetector array has a lower resolution than the light-emitting element array. For example, a light-emitting element array containing 576 light-emitting elements can be divided into 3x3 light-emitting compartments, with 8x8 light-emitting elements forming one light-emitting compartment. The photodetector array can then be configured to contain 3x3 photodetectors corresponding to the light-emitting compartments. In such cases, the light-emitting element array can be configured such that the light-emitting elements within each light-emitting compartment have the same wavelength, and the light-emitting compartments with different wavelengths are arranged adjacent to each other.

[0080] Although embodiments have been described above, the technology of this disclosure is not limited to the scope described in the embodiments above.

[0081] For example, in this embodiment, we have described a case where the three-dimensional shape of an object to be measured is determined by measuring the distance to the object. However, it is also possible to simply detect whether or not an object to be measured exists within a predetermined distance.

[0082] Alternatively, the control unit 8, which measures the three-dimensional shape of the object to be measured, may be configured with a dedicated processor (e.g., GPU: Graphics Processing Unit, ASIC: Application Specific Integrated Circuit, FPGA: Field Programmable Gate Array, Programmable Logic Device, etc.) and integrated into the optical device 3. In this case, the optical device 3 alone can measure the distance to the object to be measured.

[0083] In this embodiment, the measurement program 16A is described as being installed in the storage unit 16, but this is not the only possible configuration. The measurement program 16A according to this embodiment may be provided in a form recorded on a computer-readable storage medium. For example, the measurement program 16A according to this embodiment may be provided in a form recorded on an optical disc such as a CD (Compact Disc)-ROM or DVD (Digital Versatile Disc)-ROM, or on a semiconductor memory such as a USB (Universal Serial Bus) memory or memory card. Furthermore, the measurement program 16A according to this embodiment may be acquired from an external device via a communication line connected to the communication unit 14.

[0084] In the above embodiment, the term "processor" refers to a broad type of processor, including general-purpose processors (e.g., CPU: Central Processing Unit, etc.) and dedicated processors (e.g., GPU: Graphics Processing Unit, ASIC: Application Specific Integrated Circuit, FPGA: Field Programmable Gate Array, programmable logic device, etc.).

[0085] Furthermore, the operation of the processor in the above embodiments may not be performed by a single processor, but may be performed by multiple processors located in physically separate locations working together. Also, the order of each processor operation is not limited to the order described in each of the above embodiments, but may be changed as appropriate. [Explanation of Symbols]

[0086] 1. Measuring device 3 Optical equipment 4. Light-emitting device 5 sensors 5A Photodetector Array 5B bandpass filter 8 Control Unit 10 Wiring board 12 controllers 20 light source 28. Object to be measured 50 Drive unit 81 Three-dimensional shape identification part A-H Light-emitting elements PD light-receiving element VCSEL (Vertical Cavity Surface Emitting Laser)

Claims

1. Multiple light-emitting elements with different wavelengths of light emitted towards the object to be detected are arranged adjacent to each other. Each of the plurality of light-emitting elements is arranged such that the shortest distance between it and another light-emitting element with the same wavelength is longer than the shortest distance between it and another light-emitting element with a different wavelength. Element-emitting element array.

2. The arrangement of three of the light-emitting elements with different wavelengths is such that it forms an equilateral triangle. The light-emitting element array according to claim 1.

3. All adjacent light-emitting elements in all directions are composed of different wavelengths. A light-emitting array according to claim 1 or claim 2.

4. The number of wavelengths is 3 or more and 8 or less. A light-emitting element array according to any one of claims 1 to 3.

5. A light-emitting array in which multiple light-emitting elements with different wavelengths of light emitted toward the object to be detected are arranged adjacent to each other, A bandpass filter is included in the light-receiving section, which transmits reflected light of different wavelengths reflected from the object to be detected, corresponding to the arrangement pattern of multiple light-emitting elements with different wavelengths. A photodetector array comprising a plurality of photodetectors included in the light-receiving unit, which receive the reflected light via the bandpass filter, A drive unit for driving the light-emitting element, A detection unit that detects the object to be detected from the amount of light received by the plurality of light-receiving elements, Equipped with, Each of the plurality of light-emitting elements is arranged such that the shortest distance between it and another light-emitting element with the same wavelength is longer than the shortest distance between it and another light-emitting element with a different wavelength. Detection device.

6. The light emitted from the plurality of light-emitting elements is received by the corresponding light-receiving elements. The detection device according to claim 5.

7. The drive unit drives the plurality of light-emitting elements simultaneously. The detection device according to claim 5 or claim 6.

8. The detection unit detects the distance to the object to be detected by time of flight. A detection device according to any one of claims 5 to 7.

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