Light-emitting device and distance measuring device

Abstract

[Problem] To provide a light-emitting device capable of causing a plurality of light-emitting elements to emit light in a suitable mode. [Solution] A light-emitting device according to the present disclosure includes: a plurality of light-emitting elements, each of which has first and second terminals, and which are arranged in a two-dimensional array; a plurality of first terminal wirings which are electrically connected to the first terminals of the light-emitting elements and which include first to N-th horizontal wirings (N is an integer of 2 or more) extending in a horizontal direction, and first to N-th vertical wirings electrically connected to the first to N-th horizontal wirings, respectively; a plurality of second terminal wirings which are electrically connected to the second terminals of the light-emitting elements, and which are electrically connected to N of the light-emitting elements, respectively; and a control mechanism which causes any of the light-emitting elements to emit light and which generates a light-emitting spot. When causing two or more light-emitting elements electrically connected to the same vertical wiring to emit light in order, the control mechanism causes the two or more light-emitting elements to emit light in order such that two or more light-emitting elements adjacent to each other in the vertical direction do not emit light consecutively.

Description

Light emitting device and distance measuring device

[0001] The present disclosure relates to a light emitting device and a distance measuring device.

[0002] Surface-emitting lasers, such as vertical cavity surface-emitting lasers (VCSELs), are known as one type of semiconductor laser. Generally, in a light-emitting device using a surface-emitting laser, a plurality of light-emitting elements are provided in a two-dimensional array on the front or back surface of a substrate.

[0003] Japanese Patent Publication No. 2020-96169 Japanese Patent Publication No. 2021-120630

[0004] When VCSEL light emitting elements are individually driven, the wiring for the light emitting elements becomes longer as the number of light emitting elements increases, which results in problems such as an increase in the impedance of each wiring and a large difference in impedance between the wirings.

[0005] Furthermore, when multiple light-emitting elements of a VCSEL are made to emit light simultaneously or sequentially, the manner in which these light-emitting elements are made to emit light becomes an issue, such as in what manner light emission processing is desirable from the viewpoints of laser safety standards, distance measurement accuracy, frame rate, etc.

[0006] Therefore, the present disclosure provides a light emitting device and a distance measuring device that are capable of causing a plurality of light emitting elements to emit light in a suitable manner.

[0007] A light emitting device according to a first aspect of the present disclosure includes a plurality of light emitting elements arranged in a two-dimensional array, each having a first and a second terminal, first to Nth horizontal wires (N is an integer of 2 or more) extending in a horizontal direction, and first to Nth vertical wires extending in a vertical direction and electrically connected to the first to Nth horizontal wires, respectively, and further includes a plurality of first terminal wires electrically connected to the first terminals of the light emitting elements, a plurality of second terminal wires electrically connected to the second terminals of the light emitting elements, and each second terminal wire is electrically connected to N of the light emitting elements, and a control mechanism that causes any of the light emitting elements to emit light to generate a light spot, The control mechanism sequentially controls two or more light-emitting elements electrically connected to the same vertical wiring to emit light, thereby changing the position of the light-emitting spot in a first direction corresponding to the vertical direction, and controls two or more light-emitting elements electrically connected to one vertical wiring to emit light and another light-emitting element electrically connected to another vertical wiring to emit light, thereby changing the position of the light-emitting spot in a second direction corresponding to the horizontal direction. When the two or more light-emitting elements electrically connected to the same vertical wiring are sequentially emitted, the two or more light-emitting elements are sequentially emitted so that two or more light-emitting elements adjacent to each other in the vertical direction do not emit light consecutively. This makes it possible to cause multiple light-emitting elements to emit light in a suitable manner. For example, when two or more light-emitting elements electrically connected to the same vertical wiring are sequentially emitted, it is possible to easily perform light-emitting processing that is desirable from the perspective of laser safety standards.

[0008] Furthermore, in this first aspect, when the control mechanism sequentially emits light from the two or more light-emitting elements electrically connected to the same vertical wiring, the control mechanism may sequentially emit light from the two or more light-emitting elements such that two light-emitting elements spaced apart by a distance of Y light-emitting elements (Y is an integer of 2 or more) in the vertical direction emit light consecutively (where the distance is calculated by applying a periodic boundary condition in the vertical direction to the arrangement of the two light-emitting elements). This makes it possible to easily prevent, for example, two light-emitting elements adjacent to each other in the vertical direction from emitting light consecutively.

[0009] In addition, in this first aspect, when the two or more light-emitting elements electrically connected to the same vertical wiring are caused to emit light in sequence, the control mechanism may cause one light-emitting element to emit light multiple times and then cause another light-emitting element to emit light multiple times, thereby making it possible to easily control each light-emitting element to emit light multiple times, for example.

[0010] In addition, in this first aspect, when the control mechanism sequentially causes the two or more light-emitting elements electrically connected to the same vertical wiring to emit light, the control mechanism may repeat the process of sequentially causing all of the light-emitting elements electrically connected to the same vertical wiring to emit light a plurality of times, thereby making it possible to control each light-emitting element to emit light a plurality of times in a manner desirable from the viewpoint of, for example, laser safety standards.

[0011] In addition, in this first aspect, when the control mechanism sequentially causes two or more light-emitting elements electrically connected to one vertical wiring to emit light, and then sequentially causes two or more light-emitting elements electrically connected to another vertical wiring to emit light, the former vertical wiring and the latter vertical wiring may be two vertical wirings that are not adjacent to each other in the horizontal direction. This makes it possible to easily perform light emission processing that is desirable from the perspective of laser safety standards, for example, when two or more light-emitting elements electrically connected to one vertical wiring are sequentially caused to emit light, and then two or more light-emitting elements electrically connected to another vertical wiring are sequentially caused to emit light.

[0012] Furthermore, in this first aspect, when the control mechanism sequentially causes the two or more light-emitting elements electrically connected to a certain vertical wiring to emit light, and then sequentially causes the two or more light-emitting elements electrically connected to another vertical wiring to emit light, the former vertical wiring and the latter vertical wiring may be two vertical wirings separated by a distance of X light-emitting elements (X is an integer of 2 or more) in the horizontal direction (wherein the distance is calculated by applying a periodic boundary condition in the horizontal direction to the arrangement of the former vertical wiring and the latter vertical wiring). This makes it possible to easily prevent, for example, two vertical wirings adjacent to each other in the horizontal direction from being targets of light emission consecutively.

[0013] In addition, in this first aspect, when the control mechanism sequentially emits light from the two or more light-emitting elements electrically connected to the same vertical wiring, the control mechanism may sequentially emit light from the two or more light-emitting elements so that J light-emitting elements (J is an integer of 2 or more) electrically connected to the same vertical wiring emit light simultaneously, thereby simultaneously generating J light-emitting spots. This makes it possible to easily perform light-emitting processing that is desirable from the perspective of frame rate, for example.

[0014] In this first aspect, the control mechanism may cause the plurality of light-emitting elements to emit light one by one so that two or more of the plurality of light-emitting elements do not emit light simultaneously. This makes it possible to suppress variations in the light-emission waveforms between the light-emitting elements, for example, and to easily perform light-emission processing that is desirable from the viewpoint of distance measurement accuracy.

[0015] In addition, in this first aspect, the plurality of first terminal wirings may include H horizontal wirings (H is an integer greater than N) each corresponding to one of the first to Nth horizontal wirings, and V vertical wirings (V is an integer greater than N) each corresponding to one of the first to Nth vertical wirings. This makes it possible, for example, to make the number of horizontal wirings (H) greater than the number of types of horizontal wirings (N), or to make the number of vertical wirings (V) greater than the number of types of vertical wirings (N).

[0016] In addition, in this first aspect, at least one second terminal wiring among the plurality of second terminal wirings may be electrically connected to N' (N' is an integer greater than N) of the light-emitting elements. This makes it possible, for example, to make the number (N') of light-emitting elements connected to one second terminal wiring greater than the number (N) of types of horizontal wiring or vertical wiring.

[0017] The light emitting device of the first aspect may further include a plurality of selection circuits electrically connected to one of the first and second terminal wirings and configured to select the light emitting elements that generate light, and a plurality of drive circuits electrically connected to the other of the first and second terminal wirings and configured to drive the light emitting elements. This makes it possible to optimize the wiring structure for the light emitting elements, for example, by reducing the impedance of each wiring or by reducing the difference in impedance between wirings.

[0018] In addition, in this first aspect, one of the first and second terminals of the light-emitting element may be an anode, the other of the first and second terminals of the light-emitting element may be a cathode, one of the first and second terminal wirings may be an anode wiring, and the other of the first and second terminal wirings may be a cathode wiring, thereby making it possible to optimize the structures of the anode wiring and cathode wiring for the light-emitting element, for example.

[0019] In addition, in this first aspect, the plurality of first terminal wirings may include M sets (M is an integer of 2 or more) of the first to Nth horizontal wirings and the first to Nth vertical wirings, which makes it possible to arrange these horizontal wirings and vertical wirings in a mesh pattern, for example.

[0020] In this first aspect, the plurality of selection circuits may include first to Nth selection circuits electrically connected to the first to Nth horizontal wirings or the first to Nth vertical wirings, respectively, and the plurality of drive circuits may each be electrically connected to one of the second terminal wirings, which makes it possible to reduce the number of selection circuits, for example.

[0021] In this first aspect, each of the plurality of selection circuits may be electrically connected to one of the second terminal wirings, and the plurality of drive circuits may include first to Nth drive circuits electrically connected to the first to Nth horizontal wirings or the first to Nth vertical wirings, respectively. This makes it possible to reduce the number of drive circuits, for example.

[0022] The light emitting device according to the first aspect may further include a plurality of capacitors electrically connected to one of the first and second terminal wirings and configured to store electric charge to be supplied to the light emitting element, thereby enabling, for example, electric charge for the light emitting element to be stored using the capacitor.

[0023] In this first aspect, the plurality of capacitors may include first to Nth capacitors electrically connected to the first to Nth horizontal wirings or the first to Nth vertical wirings, respectively, which makes it possible to reduce the number of capacitors, for example.

[0024] In this first aspect, each of the plurality of capacitors may be electrically connected to one of the second terminal wirings, which makes it possible to reduce the number of drive circuits, for example.

[0025] A distance measuring device according to a second aspect of the present disclosure includes a light emitting unit that generates light and irradiates it onto an object, a light receiving unit that receives light reflected from the object, and a distance measuring unit that measures a distance to the object based on the light received by the light receiving unit, wherein the light emitting unit includes a plurality of light emitting elements arranged in a two-dimensional array, each having a first and a second terminal, first to Nth horizontal wires (N is an integer of 2 or more) extending in the horizontal direction, and first to Nth vertical wires that extend in the vertical direction and are electrically connected to the first to Nth horizontal wires, respectively, a plurality of first terminal wires electrically connected to the first terminals of the light emitting elements, and a plurality of second terminal wires electrically connected to the second terminals of the light emitting elements, each electrically connected to N of the light emitting elements. The device includes a sub-wiring and a control mechanism for illuminating one of the light-emitting elements to generate a light-emitting spot. The control mechanism sequentially illuminates two or more light-emitting elements electrically connected to the same vertical wiring, thereby changing the position of the light-emitting spot in a first direction corresponding to the vertical direction, and sequentially illuminates a light-emitting element electrically connected to one vertical wiring and a light-emitting element electrically connected to another vertical wiring, thereby changing the position of the light-emitting spot in a second direction corresponding to the horizontal direction. When the two or more light-emitting elements electrically connected to the same vertical wiring are illuminated in sequence, the two or more light-emitting elements are illuminated in sequence so that two light-emitting elements adjacent to each other in the vertical direction do not illuminate consecutively. This allows multiple light-emitting elements to be illuminated in a suitable manner. For example, when two or more light-emitting elements electrically connected to the same vertical wiring are illuminated in sequence, it is possible to easily perform a light-emitting process that is desirable from the perspective of laser safety standards.

[0026] In this second aspect, the light emitting unit and the distance measuring unit may measure the distance to the subject by emitting light from only some of the plurality of light emitting elements, which makes it possible to easily perform light emitting processing that is desirable from the standpoint of distance measurement accuracy and frame rate, for example.

[0027] FIG. 1 is a block diagram showing an example of the configuration of a distance measuring device 1 of the first embodiment. FIG. 2 is a diagram for explaining the STL (Structured Light) system of the first embodiment. FIG. 3 is a cross-sectional view showing the structure of a light emitting device 1a of the first embodiment. FIG. 4 is a circuit diagram showing the structure of a light emitting device 1a of a comparative example of the first embodiment. FIG. 5 is a graph for explaining the performance of the light emitting device 1a of the first embodiment. FIG. 6 is a cross-sectional view and a plan view showing the structure of a light emitting device 1a of the first embodiment. FIG. 7 is a perspective view schematically showing the structure of a light emitting device 1a of the first embodiment. FIG. 8 is a circuit diagram showing the structure of a light emitting device 1a of a first modified example of the first embodiment. FIG. 9 is a circuit diagram showing the structure of a light emitting device 1a of a second modified example of the first embodiment. FIG. 10 is a circuit diagram showing the structure of a light emitting device 1a of a third modified example of the first embodiment. FIG. 11 is a circuit diagram showing the structure of a light emitting device 1a of a fourth modified example of the first embodiment. FIG. 12 is another circuit diagram showing the structure of a light emitting device 1a of a fifth modified example of the first embodiment. FIG. 13 is a circuit diagram showing various examples of the structure of a light emitting device 1a of a sixth modified example of the first embodiment. 10 is a circuit diagram showing the structure of a light emitting device 1a according to a seventh modified example of the first embodiment. FIG. 11 is a timing chart showing the operation of the light emitting device 1a according to the seventh modified example of the first embodiment. FIG. 12 is a cross-sectional view and a plan view showing the structure of a light emitting device 1a according to an eighth modified example of the first embodiment. FIG. 13 is a circuit diagram showing the structure of the light emitting device 1a according to the second embodiment. FIG. 14 is a plan view schematically showing the structure of the light emitting device 1a according to the third embodiment. FIG. 15 is a schematic diagram for explaining the operation of the distance measuring device 1 according to the fourth embodiment. FIG. 16 is a plan view (1 / 2) showing a first operation example of the distance measuring device 1 according to the fourth embodiment. FIG. 17 is a plan view (2 / 2) showing a first operation example of the distance measuring device 1 according to the fourth embodiment. FIG. 18 is a plan view (1 / 2) showing a second operation example of the distance measuring device 1 according to the fourth embodiment. FIG. 19 is a plan view (2 / 2) showing a second operation example of the distance measuring device 1 according to the fourth embodiment. FIG. 19 is a diagram for explaining the difference between the first and second operation examples described above. FIG. 19 is a plan view showing a third operation example of the distance measuring device 1 according to the fourth embodiment. FIG. 19 is a plan view showing a fourth operation example of the distance measuring device 1 according to the fourth embodiment. 10 is a diagram for explaining the difference between the third and fourth operation examples described above. FIG. 11 is a plan view showing fifth and sixth operation examples of the distance measuring device 1 of the fourth embodiment. FIG. 12 is a plan view showing a first operation example of the distance measuring device 1 of the fifth embodiment.FIG. 10 is a plan view showing a second operation example of the distance measuring device 1 of the fifth embodiment. FIG. 11 is a diagram for explaining the operation of the distance measuring device 1 of a comparative example of the sixth embodiment. FIG. 12 is a diagram for explaining the operation of the distance measuring device 1 of the sixth embodiment. FIG. 13 is a block diagram showing the configuration of a vehicle 101 of a seventh embodiment. FIG. 14 is a plan view showing the sensing area of ​​the vehicle 101 of the seventh embodiment.

[0028] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0029] (First embodiment) (1) Distance measuring device 1 of the first embodiment (1.1) Configuration of distance measuring device 1 Fig. 1 is a block diagram showing an example of the configuration of a distance measuring device 1 of the first embodiment. The distance measuring device 1 of this embodiment is mounted on, for example, an automobile.

[0030] As shown in the figure, the distance measuring device 1 includes a light emitting unit 2, a driving unit 3, a power supply circuit 4, a light emitting side optical system 5, a light receiving side optical system 6, a light receiving unit 7, a signal processing unit 8, a control unit 9, and a temperature detection unit 10.

[0031] The light emitting unit 2 emits light from a plurality of light sources. In this example, the light emitting unit 2 has light emitting elements 2 a, each of which is a vertical cavity surface emitting laser (VCSEL), arranged in a predetermined pattern, such as a matrix.

[0032] The driving unit 3 is configured to include a power supply circuit for driving the light emitting unit 2 .

[0033] The power supply circuit 4 generates a power supply voltage for the drive unit 3 based on an input voltage from, for example, a battery (not shown) provided in the distance measuring device 1. The drive unit 3 drives the light emitting unit 2 based on the power supply voltage.

[0034] Light emitted from the light-emitting unit 2 is irradiated onto a subject S, which is the object of distance measurement, via a light-emitting optical system 5. The light thus irradiated is reflected from the subject S and enters the light-receiving surface of a light-receiving unit 7 via a light-receiving optical system 6.

[0035] The light receiving unit 7 is a light receiving element such as a CCD (Charge Coupled Device) sensor or a CMOS (Complementary Metal Oxide Semiconductor) sensor, and receives reflected light from the subject S that enters through the light receiving side optical system 6 as described above, converts it into an electrical signal, and outputs it.

[0036] The light receiving unit 7 performs processes such as CDS (Correlated Double Sampling) and AGC (Automatic Gain Control) on the electrical signal obtained by photoelectrically converting the received light, and then performs A / D (Analog / Digital) conversion on the electrical signal, and outputs the resulting digital data to the signal processing unit 8 at the subsequent stage.

[0037] Furthermore, the light receiving unit 7 in this example outputs a frame synchronization signal Fs to the driving unit 3. This enables the driving unit 3 to cause the light emitting element 2 a in the light emitting unit 2 to emit light at a timing according to the frame period of the light receiving unit 7.

[0038] The signal processing unit 8 is configured as a signal processor, for example, a DSP (Digital Signal Processor), etc. The signal processing unit 8 performs various signal processes on the digital signal input from the light receiving unit 7.

[0039] The control unit 9 is configured with, for example, a microcomputer having a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc., or an information processing device such as a DSP, and controls the drive unit 3 for controlling the light emission operation by the light emitting unit 2, and controls the light receiving operation by the light receiving unit 7.

[0040] The control unit 9 has a function as a distance measuring unit 9a. The distance measuring unit 9a measures the distance to the subject S based on a signal input via the signal processing unit 8 (i.e., a signal obtained by receiving reflected light from the subject S). The distance measuring unit 9a in this example measures the distance to each part of the subject S in order to be able to identify the three-dimensional shape of the subject S.

[0041] A specific distance measurement method in the distance measuring device 1 will be explained later.

[0042] The temperature detection unit 10 detects the temperature of the light emitting unit 2. The temperature detection unit 10 may be configured to detect temperature using, for example, a diode.

[0043] In this example, information about the temperature detected by the temperature detection unit 10 is supplied to the drive unit 3, which enables the drive unit 3 to drive the light emitting unit 2 based on the temperature information.

[0044] (1.2) Distance Measurement Method The distance measurement method used in the distance measuring device 1 may be, for example, a STL (Structured Light) method or a ToF (Time of Flight) method.

[0045] The STL method is a method for measuring distance based on an image of a subject S illuminated with light having a predetermined light / dark pattern, such as a dot pattern or a grid pattern.

[0046] FIG. 2 is a diagram for explaining the STL system of the first embodiment.

[0047] In the STL method, pattern light Lp having a dot pattern such as that shown in Fig. 2A is irradiated onto a subject S. The pattern light Lp is divided into a plurality of blocks BL, and a different dot pattern is assigned to each block BL (dot patterns are arranged so as not to overlap between blocks BL).

[0048] FIG. 2B is an explanatory diagram of the distance measurement principle of the STL system.

[0049] In this example, a wall W and a box BX placed in front of it are treated as the subject S, and pattern light Lp is irradiated onto the subject S. "G" in the figure schematically represents the angle of view of the light receiving unit 7.

[0050] In addition, in the drawing, "BLn" denotes the light of a certain block BL in the pattern light Lp, and "dn" denotes the dot pattern of the block BLn projected on the light-receiving image by the light-receiving unit 7.

[0051] Here, if there is no box BX in front of the wall W, the dot pattern of the block BLn is projected at the position "dn'" in the figure in the received light image. In other words, the position at which the pattern of the block BLn is projected in the received light image differs depending on whether the box BX is present or not, and specifically, the pattern is distorted.

[0052] The STL method utilizes the fact that the irradiated pattern is distorted by the object shape of the subject S to determine the shape and depth of the subject S. Specifically, this method determines the shape and depth of the subject S from the way the pattern is distorted.

[0053] When the STL system is adopted, for example, a global shutter type IR (Infrared) light receiving unit is used as the light receiving unit 7. In the case of the STL system, the distance measuring unit 9 a controls the driving unit 3 so that the light emitting unit 2 emits pattern light, detects distortion of the pattern in the image signal obtained via the signal processing unit 8, and calculates the distance based on the distortion of the pattern.

[0054] Next, the ToF method is a method for measuring the distance to an object by detecting the time of flight (time difference) of light emitted from the light-emitting unit 2, reflected by the object, and reaching the light-receiving unit 7.

[0055] When the so-called direct ToF (dToF) method is adopted as the ToF method, a SPAD (Single Photon Avalanche Diode) is used as the light receiving unit 7, and the light emitting unit 2 is pulse-driven. In this case, the distance measuring unit 9a calculates the time difference between light emission and reception of light emitted from the light emitting unit 2 and received by the light receiving unit 7 based on a signal input via the signal processing unit 8, and calculates the distance to each part of the subject S based on this time difference and the speed of light. In the dToF method, the distance to the subject S is calculated by calculating the time from light emission to light reception, so a narrower light emission pulse width improves time resolution and enables more precise distance measurement. Therefore, the dToF method is more suitable for this embodiment, which achieves high-power, short-pulse light emission.

[0056] When the so-called indirect ToF (iToF) method (phase difference method) is adopted as the ToF method, a light receiving unit capable of receiving, for example, IR light is used as the light receiving unit 7. In the iToF method, the distance to the subject is calculated from the phase difference between the emitted light and the light reflected from the subject and received, so it is desirable that the waveform of the LDD output current during light emission has steep rise and fall edges. This embodiment is also suitable for the iToF method because the characteristics of the waveform are improved by reducing the inductance of the wiring within the light-emitting element 2a.

[0057] (2) Light-emitting device 1a of the first embodiment Fig. 3 is a cross-sectional view showing the structure of light-emitting device 1a of the first embodiment. Fig. 3A shows a cross-section of light-emitting device 1a of the present embodiment, and Fig. 3B shows an enlarged cross-section of the cross-section shown in Fig. 3A. Light-emitting device 1a of the present embodiment may be a part of distance measuring device 1, or may be distance measuring device 1 itself.

[0058] 3A includes an LD (Laser Diode) chip 11 including the above-described light-emitting unit 2, an LDD (Laser Diode Driver) substrate 12 including the above-described drive unit 3, a mounting substrate 13, a heat dissipation substrate 14, a correcting lens holder 15, one or more correcting lenses 16, and wiring 17. The LD chip 11 is also called a VCSEL substrate. The LD chip 11 is an example of a first substrate of the present disclosure, and the LDD substrate 12 is an example of a second substrate of the present disclosure.

[0059] 3A shows the X-axis, Y-axis, and Z-axis, which are perpendicular to each other. The +Z direction corresponds to the upward direction, and the −Z direction corresponds to the downward direction. Note that the −Z direction may or may not strictly coincide with the direction of gravity.

[0060] The LD chip 11 is disposed on a mounting substrate 13 via a heat dissipation substrate 14, and the LDD substrate 12 is also disposed on the mounting substrate 13. The mounting substrate 13 is, for example, a printed circuit board. The above-mentioned light receiving unit 7 and signal processing unit 8 may also be disposed on the mounting substrate 13. The heat dissipation substrate 14 is, for example, a ceramic substrate such as an aluminum oxide substrate or an aluminum nitride substrate.

[0061] The correction lens holding portion 15 is disposed on the heat dissipation substrate 14 so as to surround the LD chip 11, and holds one or more correction lenses 16 above the LD chip 11. These correction lenses 16 are included in the above-mentioned light-emitting side optical system 5. Light emitted from the light-emitting portion 2 in the LD chip 11 is corrected by these correction lenses 16 and then irradiated onto the above-mentioned subject S. A in Fig. 3 shows two correction lenses 16 held by the correction lens holding portion 15 as an example.

[0062] The wiring 17 is provided on the front, back, or inside of the mounting substrate 13, and electrically connects the LD chip 11 and the LDD substrate 12. The wiring 17 is, for example, a printed wiring provided on the front or back of the mounting substrate 13, or a via wiring that penetrates the mounting substrate 13. In this embodiment, the wiring 17 also passes through the inside or near the heat dissipation substrate 14.

[0063] 3B includes a substrate 21, a laminated film 22, and a plurality of light-emitting elements 23. These light-emitting elements 23 are specific examples of the light-emitting elements 2a described above.

[0064] The substrate 21 is, for example, a compound semiconductor substrate such as a GaAs (gallium arsenide) substrate. Fig. 3B shows a front surface S1 of the substrate 21 facing the -Z direction and a back surface S2 of the substrate 21 facing the +Z direction. The front surface S1 and back surface S2 shown in Fig. 3B are perpendicular to the Z direction. In Fig. 3B, the front surface S1 is the lower surface of the substrate 21, and the back surface S2 is the upper surface of the substrate 21.

[0065] The laminated film 22 includes multiple layers laminated on the surface S1 of the substrate 21. Examples of these layers include an n-type semiconductor layer, an active layer, a p-type semiconductor layer, a light-reflecting layer, and an insulating layer having a light exit window. The laminated film 22 includes multiple post portions P protruding in the −Z direction. Some of these post portions P serve as multiple light-emitting elements 23.

[0066] The light emitting element 23 is provided on the surface S1 of the substrate 21 as part of the laminated film 22. The light emitting element 23 of this embodiment has a VCSEL structure and emits light in the +Z direction. As shown in FIG. 3B, the light emitted from the light emitting element 23 passes through the substrate 21 from the surface S1 to the back surface S2 of the substrate 21, and enters the correcting lens 16 from the substrate 21. In this way, the LD chip 11 of this embodiment is a back-emission type VCSEL chip. The light emitting element 23 is also called a mesa portion.

[0067] Each light-emitting element 23 is provided between an anode wiring (anode electrode) and a cathode wiring (cathode electrode), not shown. Each light-emitting element 23 emits light when a current flows between the anode wiring and the cathode wiring. Further details of the anode wiring and the cathode wiring will be described later.

[0068] FIG. 4 is a circuit diagram showing the structure of the light emitting device 1a of the first embodiment.

[0069] 4 shows a plurality of light-emitting elements 23 arranged in a two-dimensional array and a plurality of transistors 24 electrically connected to these light-emitting elements 23. These transistors 24 are, for example, N-type MOS transistors. FIG. 4 shows, as an example, 9×9 light-emitting elements 23 and 9×9 transistors 24. Therefore, the light-emitting device 1a shown in FIG. 4 includes a 9ch×9ch light-emitting element array. Note that these light-emitting elements 23 may be arranged in a layout different from the two-dimensional array layout.

[0070] As shown in FIG. 4 , the light-emitting device 1a of this embodiment further includes a first anode wiring 31, a second anode wiring 32, a third anode wiring 33, a plurality of first capacitors 34, a plurality of second capacitors 35, a plurality of third capacitors 36, a first selection circuit 37, a second selection circuit 38, a third selection circuit 39, a plurality of cathode wirings 41, and a plurality of gate wirings 42. The first to third anode wirings 31 to 33 are examples of the first terminal wiring of the present disclosure, and the cathode wiring 41 is an example of the second terminal wiring of the present disclosure. The first to third capacitors 34 to 36 are examples of the first to Nth capacitors of the present disclosure, and the first to third selection circuits 37 to 39 are examples of the first to Nth selection circuits of the present disclosure (N is an integer of 2 or greater). FIG. 4 shows an example where N is 3.

[0071] The first anode wiring 31 includes a plurality of first horizontal wirings 31a extending in the horizontal direction (X direction) and a plurality of first vertical wirings 31b extending in the vertical direction (Y direction). Similarly, the second anode wiring 32 includes a plurality of second horizontal wirings 32a extending in the horizontal direction and a plurality of second vertical wirings 32b extending in the vertical direction. Similarly, the third anode wiring 33 includes a plurality of third horizontal wirings 33a extending in the horizontal direction and a plurality of third vertical wirings 33b extending in the vertical direction. FIG. 4 shows, as an example, five first horizontal wirings 31a, five first vertical wirings 31b, five second horizontal wirings 32a, five second vertical wirings 32b, five third horizontal wirings 33a, and five third vertical wirings 33b. These are examples of M sets of first to Nth horizontal wirings and first to Nth vertical wirings of the present disclosure (M is an integer of 2 or greater). Fig. 4 shows an example in which M is 5. The number of light-emitting elements 23 shown in Fig. 4 is N(M-2) x N(M-2) when expressed as N and M.

[0072] The first to third anode wirings 31 to 33 may include Ma sets of first to Nth horizontal wirings and Mb sets of first to Nth vertical wirings (Ma and Mb are integers of 2 or greater that satisfy Ma≠Mb). In this case, the number of light-emitting elements 23 in the light-emitting device 1a is N(Ma-2)×N(Mb-2).

[0073] The first selection circuit 37 includes transistors 37a and 37b. Similarly, the second selection circuit 38 includes transistors 38a and 38b. Similarly, the third selection circuit 39 includes transistors 39a and 39b. The transistors 37a, 38a, and 39a are, for example, P-type MOS transistors. The transistors 37b, 38b, and 39b are, for example, N-type MOS transistors. The transistors 37a, 38a, and 39a are examples of first switches of the present disclosure. The transistors 37b, 38b, and 39b are examples of second switches of the present disclosure.

[0074] [First to third anode wirings 31 to 33] In FIG. 4, in order to distinguish the first to third anode wirings 31 to 33 from one another, the first anode wiring 31 is shown by a thick solid line, the second anode wiring 32 is shown by a thick dashed line, and the third anode wiring 33 is shown by a thin solid line.

[0075] The first anode wiring 31 has a structure in which a plurality of first horizontal wirings 31a and a plurality of first vertical wirings 31b are arranged in a mesh pattern. These first horizontal wirings 31a and first vertical wirings 31b are electrically connected to each other at the points where the first horizontal wirings 31a and first vertical wirings 31b intersect. Similarly, the second anode wiring 32 includes a plurality of second horizontal wirings 32a and a plurality of second vertical wirings 32b that are electrically connected to each other, and the third anode wiring 33 includes a plurality of third horizontal wirings 33a and a plurality of third vertical wirings 33b that are electrically connected to each other. Meanwhile, the first to third anode wirings 31 to 33 are electrically insulated from each other.

[0076] The first to third horizontal wires 31a to 33a extend in the X direction (horizontal direction) and are adjacent to each other in the Y direction (vertical direction). Although the first to third horizontal wires 31a to 33a extend linearly in the X direction in FIG. 4, they may extend in a curved manner in the X direction. That is, the first to third horizontal wires 31a to 33a may include bent portions. Furthermore, although the extension direction of the first to third horizontal wires 31a to 33a is parallel to the X direction in FIG. 4, they may be inclined with respect to the X direction.

[0077] On the other hand, the first to third vertical wirings 31b to 33b extend in the Y direction and are adjacent to each other in the X direction. Although the first to third vertical wirings 31b to 33b extend linearly in the Y direction in FIG. 4, they may extend in a curved manner in the Y direction. That is, the first to third vertical wirings 31b to 33b may also include bent portions. Furthermore, although the extension direction of the first to third vertical wirings 31b to 33b is parallel to the Y direction in FIG. 4, they may be inclined with respect to the Y direction.

[0078] FIG. 4 shows five sets of first to third horizontal wirings 31a to 33a. In FIG. 4, the first, second, third, fourth, and fifth sets of first to third horizontal wirings 31a to 33a are arranged in order from top to bottom. In each set, the first horizontal wiring 31a, the second horizontal wiring 32a, and the third horizontal wiring 33a are arranged in order from top to bottom. The first set of first to third horizontal wirings 31a to 33a and the fifth set of first to third horizontal wirings 31a to 33a are arranged so as to sandwich 9 × 9 light-emitting elements 23 therebetween. Each of the second to fourth sets of first to third horizontal wirings 31a to 33a is arranged along one row (nine light-emitting elements) 23.

[0079] FIG. 4 further shows five sets of first to third vertical wirings 31b to 33b. In FIG. 4, the first, second, third, fourth, and fifth sets of first to third vertical wirings 31b to 33b are arranged in order from left to right. In each set, the first vertical wiring 31b, the second vertical wiring 32b, and the third vertical wiring 33b are arranged in order from left to right. The first set of first to third vertical wirings 31b to 33b and the fifth set of first to third vertical wirings 31b to 33b are arranged so as to sandwich 9×9 light-emitting elements 23 therebetween. Each of the second to fourth sets of first to third vertical wirings 31b to 33b is arranged along one column (nine light-emitting elements) 23.

[0080] The anode of each light-emitting element 23 is electrically connected to one of the first to third vertical wirings 31b to 33b. For example, the light-emitting element 23 in the leftmost column is electrically connected to the first vertical wiring 31b in the second set of first to third vertical wirings 31b to 33b. The light-emitting element 23 in the rightmost column is electrically connected to the third vertical wiring 33b in the fourth set of first to third vertical wirings 31b to 33b. The anode of each light-emitting element 23 may be electrically connected to one of the first to third horizontal wirings 31a to 33a instead of being electrically connected to one of the first to third vertical wirings 31b to 33b. The anode is an example of a first terminal in the present disclosure.

[0081] Here, for the light-emitting device 1a of this embodiment, the number of horizontal wires 31a to 33a is represented by H, and the number of vertical wires 31b to 33b is represented by V. In FIG. 4, the value of H is 15, and the value of V is also 15. The light-emitting device 1a of this embodiment includes three types of horizontal wires, namely, first to third horizontal wires 31a to 33a, specifically, five first horizontal wires 31a, five second horizontal wires 32a, and five third horizontal wires 33a. Similarly, the light-emitting device 1a of this embodiment includes three types of vertical wires, namely, first to third vertical wires 31b to 33b, specifically, five first vertical wires 31b, five second vertical wires 32b, and five third vertical wires 33b.

[0082] The value of H may be the minimum value of 3, or may be 4 or more as in this embodiment. This minimum value is determined by the number N (=3) of types of horizontal wirings 31a to 33a. Similarly, the value of V may be the minimum value of 3, or may be 4 or more as in this embodiment. The values ​​of H and V may be different from each other.

[0083] [Cathode Wiring 41] Each cathode wiring 41 extends in the X direction and is electrically connected to the cathodes of three light-emitting elements 23. Specifically, each cathode wiring 41 is electrically connected to one light-emitting element 23 electrically connected to the first vertical wiring 31b, one light-emitting element 23 electrically connected to the second vertical wiring 32b, and one light-emitting element 23 electrically connected to the third vertical wiring 33b. These three light-emitting elements 23 are adjacent to each other in the X direction. Figure 4 shows 27 cathode wirings 41 for 81 light-emitting elements 23. The cathode is an example of a second terminal in the present disclosure.

[0084] Each light-emitting element 23 is provided between a corresponding anode wiring, i.e., any one of the first to third anode wirings 31 to 33, and a corresponding cathode wiring, i.e., any one of the plurality of cathode wirings 41. Each light-emitting element 23 emits light when a current flows between the corresponding anode wiring and the corresponding cathode wiring.

[0085] Here, with regard to the light-emitting device 1a of this embodiment, the number of light-emitting elements 23 electrically connected to each cathode wiring 41 is represented by N'. In Fig. 4, the value of N' is 3. This is because each cathode wiring 41 is electrically connected to one light-emitting element 23 electrically connected to the first vertical wiring 31b, one light-emitting element 23 electrically connected to the second vertical wiring 32b, and one light-emitting element 23 electrically connected to the third vertical wiring 33b, and as a result, the value of N' is the same as the number N (=3) of types of vertical wiring 31b to 33b.

[0086] The value of N' may be greater than the value of N. For example, at least one of the cathode wirings 41 may be electrically connected to Na light-emitting elements 23 (Na is an integer greater than or equal to 1) electrically connected to the first vertical wiring 31b, Nb light-emitting elements 23 (Nb is an integer greater than or equal to 1) electrically connected to the second vertical wiring 32b, and Nc light-emitting elements 23 (Nc is an integer greater than or equal to 1) electrically connected to the third vertical wiring 33b. In this case, at least one of Na, Nb, and Nc may be an integer greater than or equal to 2.

[0087] [Gate Wiring 42] Each gate wiring 42 extends in the X direction and is electrically connected to the gates of three transistors 24. The sources of these three transistors 24 are electrically connected to the ground wiring (GND), and the drains of these three transistors 24 are electrically connected to the same single cathode wiring 41. These three transistors 24 form one drive circuit E. FIG. 4 shows 27 gate wirings 42 for 81 transistors 24.

[0088] Each drive circuit E is electrically connected to the cathodes of three light-emitting elements 23 via a single cathode wiring 41. Each drive circuit (output stage) E is used to drive the light-emitting elements 23 to generate (output) light from the light-emitting elements 23. For example, to generate light from a certain light-emitting element 23, a predetermined signal is applied to the gate wiring 42 of the drive circuit E for that light-emitting element 23. This causes conduction between the source and drain of each transistor 24 in that drive circuit E, allowing current to flow through that light-emitting element 23. When current flows through that light-emitting element 23, light is generated from that light-emitting element 23. The light-emitting device 1a shown in FIG. 4 has 27 drive circuits E for 81 light-emitting elements 23.

[0089] [First to Third Selection Circuits 37 to 39] The first to third selection circuits 37 to 39 are electrically connected to the first to third horizontal wirings 31a to 33a of the first to third anode wirings 31 to 33, respectively. The first selection circuit 37 is used to select the light-emitting element 23 electrically connected to the first anode wiring 31 as the light-emitting element 23 that generates light. The second selection circuit 38 is used to select the light-emitting element 23 electrically connected to the second anode wiring 32 as the light-emitting element 23 that generates light. The third selection circuit 39 is used to select the light-emitting element 23 electrically connected to the third anode wiring 33 as the light-emitting element 23 that generates light. The first to third selection circuits 37 to 39 may be electrically connected to the first to third vertical wirings 31b to 33b of the first to third anode wirings 31 to 33, respectively, instead of the first to third horizontal wirings 31a to 33a of the first to third anode wirings 31 to 33.

[0090] The first selection circuit 37 includes a transistor 37a having a source electrically connected to the power supply wiring (VDD) and a transistor 37b having a source electrically connected to the ground wiring. The drains of the transistors 37a and 37b are electrically connected to the first anode wiring 31. The first selection circuit 37 is electrically connected to each of the first capacitors 34 via the first anode wiring 31.

[0091] The transistor 37a is used to store charge in each first capacitor 34. The transistor 37b is used to discharge charge from each first capacitor 34. When a predetermined signal is applied to the gate of the transistor 37a, charge is stored in each first capacitor 34. When a predetermined signal is applied to the gate of the transistor 37b, charge is discharged from each first capacitor 34. Therefore, according to this embodiment, by using the first selection circuit 37 to selectively store charge in the first capacitor 34 of the first to third capacitors 34 to 36, it is possible to pass a current to each light-emitting element 23 electrically connected to the first anode wiring 31.

[0092] 4, the second and third selection circuits 38, 39 have the same structure as the first selection circuit 37. Therefore, according to this embodiment, by storing charge in each second capacitor 35 by the second selection circuit 38, it is possible to pass a current to each light-emitting element 23 electrically connected to the second anode wiring 32. Furthermore, according to this embodiment, by storing charge in each third capacitor 36 by the third selection circuit 39, it is possible to pass a current to each light-emitting element 23 electrically connected to the third anode wiring 33.

[0093] [First to Third Capacitors 34 to 36] The first to third capacitors 34 to 36 are electrically connected to the first to third anode wirings 31 to 33, respectively. Each first capacitor 34 stores charge to be supplied to the light-emitting element 23 electrically connected to the first anode wiring 31. Each second capacitor 35 stores charge to be supplied to the light-emitting element 23 electrically connected to the second anode wiring 32. Each third capacitor 36 stores charge to be supplied to the light-emitting element 23 electrically connected to the third anode wiring 33. According to this embodiment, by supplying charge to each light-emitting element 23 from the first to third capacitors 34 to 36, a current can be passed through each light-emitting element 23. Each of the first to third capacitors 34 to 36 has one electrode electrically connected to one of the first to third anode wirings 31 to 33 and the other electrode electrically connected to a ground wiring.

[0094] The light-emitting device 1a shown in FIG. 4 includes a light-emitting element array including 9×9 light-emitting elements 23 arranged in a two-dimensional array. As shown in FIG. 4, the shape of this light-emitting element array is roughly square in plan view. The light-emitting device 1a shown in FIG. 4 includes four sets of first to third capacitors 34-36 near the four sides of the square. Specifically, the light-emitting device 1a shown in FIG. 4 includes a first set of first to third capacitors 34-36 near the top side of the square, a second set of first to third capacitors 34-36 near the right side of the square, a third set of first to third capacitors 34-36 near the bottom side of the square, and a fourth set of first to third capacitors 34-36 near the left side of the square. These first to third capacitors 34-36 are examples of K sets of first to Nth capacitors of the present disclosure (K is an integer greater than or equal to 2). FIG. 4 shows an example where K is 4.

[0095] The first to third capacitors 34 to 36 of the first and third sets are electrically connected to the first to third horizontal wires 31 a to 33 a of the first to third anode wirings 31 to 33, respectively. On the other hand, the first to third capacitors 34 to 36 of the second and fourth sets are electrically connected to the first to third vertical wires 31 b to 33 b of the first to third anode wirings 31 to 33, respectively. As a result, the first to third capacitors 34 to 36 shown in FIG. 4 are electrically connected to the first to third anode wirings 31 to 33, respectively.

[0096] In each group, the first to third capacitors 34 to 36 are arranged in clockwise order. For example, the first capacitor 34, the second capacitor 35, and the third capacitor 36 of the first group are respectively arranged on the left, center, and right sides near the top edge of the square. The first capacitor 34, the second capacitor 35, and the third capacitor 36 of the second group are respectively arranged on the upper, center, and lower sides near the right edge of the square. As a result, the four groups of first to third capacitors 34 to 36 shown in FIG. 4 are arranged symmetrically with respect to the center of the square. The center of the square is approximately located at the position of the light-emitting element 23 in the fifth row and fifth column of the 9×9 light-emitting elements 23. In FIG. 4, the four groups of first to third capacitors 34 to 36 are arranged in four-fold rotational symmetry (90-degree rotational symmetry).

[0097] According to this embodiment, it is possible to set the average distance between each light-emitting element 23 and the corresponding four capacitors to a value close to the average distance between another light-emitting element 23 and the corresponding four capacitors.

[0098] For example, the light-emitting element 23 at the upper left is close to the first capacitor 34 above but far from the first capacitor 34 below. On the other hand, the light-emitting element 23 at the lower right is close to the third capacitor 36 on the right but far from the third capacitor 36 on the left. Therefore, the average distance between the light-emitting element 23 at the upper left and the four first capacitors 34 is close to the average distance between the light-emitting element 23 at the lower right and the four third capacitors 36. This is also true for the other 79 light-emitting elements 23. This makes it possible to reduce the difference in impedance between the wiring of different light-emitting elements 23 with respect to the anode wiring between each light-emitting element 23 and the corresponding four capacitors.

[0099] The light emitting device 1a of this embodiment may include the first to third capacitors 34 to 36 only near one, two, or three of the four sides of the square. However, in this case, it is desirable that the first to third capacitors 34 to 36 are also arranged symmetrically or nearly symmetrically with respect to the center of the square. Therefore, it is desirable that the light emitting device 1a of this embodiment include the first to third capacitors 34 to 36 on two or more of the four sides of the square. For example, by arranging two sets of the first to third capacitors 34 to 36 near the top and bottom sides of the square, it is possible to achieve an arrangement with two-fold rotational symmetry (180-degree rotational symmetry).

[0100] FIG. 5 is a circuit diagram showing the structure of a light emitting device 1a as a comparative example of the first embodiment.

[0101] Similar to the light-emitting device 1a of the present embodiment, the light-emitting device 1a of this comparative example includes a light-emitting element array including 9 x 9 light-emitting elements 23 arranged in a two-dimensional array. However, the light-emitting device 1a of this comparative example includes a capacitor array including 9 x 9 capacitors 34 arranged in a two-dimensional array, with the capacitor array being located to the right of the light-emitting element array. Each light-emitting element 23 of this comparative example is electrically connected to its corresponding capacitor 34 via a corresponding anode wiring 31. Furthermore, the 9 x 9 light-emitting elements 23 of this comparative example are electrically connected to a common drive circuit E (transistor 24) via a common cathode wiring 41. The drive circuit E of this comparative example is located to the left of the light-emitting element array.

[0102] In this comparative example, problems arise due to the large number of anode wirings 31 and the fact that the anode wirings 31 are long on average. Another problem arises due to the light-emitting device 1a of this comparative example being equipped with both short and long anode wirings 31. As a result, problems arise due to the large impedance of each anode wiring 31 and the large difference in impedance between the anode wirings 31. Another problem arises due to the large difference in length of the cathode wiring 41 between each light-emitting element 23 and the drive circuit E for each light-emitting element 23.

[0103] If the impedance of each anode wiring 31 is large, the intensity of light emitted from each light-emitting element 23 may be insufficient, or the amount of power consumed to drive each light-emitting element 23 may increase. Furthermore, if the difference in impedance between the anode wirings 31 becomes large, the difference in intensity of light emitted from different light-emitting elements 23 may become large. As a result, the performance of the distance measuring device 1 may be degraded.

[0104] On the other hand, the light emitting device 1a of this embodiment includes first to third anode wirings 31 to 33 arranged in a mesh pattern, and first to third capacitors 34 to 36 electrically connected to the first to third anode wirings 31 to 33 so as to be arranged symmetrically. Therefore, according to this embodiment, it is possible to suppress the above-mentioned problems of impedance and impedance difference, and improve the performance of the distance measuring device 1. Furthermore, according to this embodiment, by arranging a cathode wiring 41 for every three light emitting elements 23, it is also possible to suppress problems related to the cathode wiring 41.

[0105] FIG. 6 is a graph for explaining the performance of the light emitting device 1a of the first embodiment.

[0106] The vertical axis of Fig. 6 represents the LDD output current (the output current from the LDD substrate 12 to each light-emitting element 23), and the horizontal axis of Fig. 6 represents time. Fig. 6 shows the waveform of the LDD output current. Fig. 6 also shows the peak value Ipeak of the LDD output current, the pulse width W of the LDD output current, and the half-value width W' of the LDD output current.

[0107] It is desirable to increase the peak value Ipeak and shorten the pulse width W (or half-value width W') to improve the performance of the distance measuring device 1. According to this embodiment, by reducing the impedance of each wiring or the difference in impedance between wirings, it is possible to increase the peak value Ipeak and shorten the pulse width W (or half-value width W').

[0108] Fig. 7 is a cross-sectional view and a plan view showing the structure of the light emitting device 1a of the first embodiment. Fig. 7A shows the XZ cross section of the light emitting device 1a, similar to Fig. 3A. Fig. 7B shows the planar structure of the light emitting device 1a shown in Fig. 7A.

[0109] The light emitting device 1a of this embodiment may have the structure shown in Figures 7A and 7B instead of the structure shown in Figure 3A. In Figures 7A and 7B, the light emitting device 1a of this embodiment includes an LD chip 11, an LDD substrate 12, a mounting substrate 13, and four sets of first to third capacitors 34 to 36.

[0110] The mounting substrate 13 includes an insulating substrate 51, an insulating film 52, a wiring layer 53, an insulating film 54, a wiring layer 55, and a plurality of wirings 56. The LDD substrate 12 shown in FIG. 7A is provided within the insulating substrate 51. The insulating film 52 and the wiring layer 53 are formed in this order on the upper surface of the insulating substrate 51. The insulating film 54 and the wiring layer 55 are formed in this order on the lower surface of the insulating substrate 51. The LD chip 11 shown in FIG. 7A is provided on the wiring layer 53. Each wiring 56 is formed within the insulating substrate 51, the insulating film 52, and the wiring layer 53, and electrically connects the LD chip 11 and the LDD substrate 12.

[0111] Each of the first to third capacitors 34 to 36 is arranged on the wiring layer 53 via a plurality of solder balls 57, and is electrically connected to the LD chip 11 and the LDD substrate 12 via these solder balls 57 and the wiring layer 53.

[0112] In FIG. 7B, the LD chip 11 and LDD substrate 12 have a square shape in plan view. The light-emitting device 1a shown in FIG. 7B includes four sets of first to third capacitors 34 to 36 near the four sides of the square planar shape of the LD chip 11. These first to third capacitors 34 to 36 are arranged symmetrically with respect to the center of the square. Note that the light-emitting device 1a shown in FIG. 7B may include these first to third capacitors 34 to 36 only near one, two, or three of the four sides of the square. However, in this case, it is desirable that the first to third capacitors 34 to 36 are also arranged symmetrically or nearly symmetrically with respect to the center of the square. Therefore, it is desirable that the light-emitting device 1a shown in FIG. 7B include these first to third capacitors 34 to 36 on two or more of the four sides of the square.

[0113] 7A and 7B, the plurality of light-emitting elements 23, the plurality of transistors 24, and the first to third selection circuits 37 to 39 (FIG. 4) are provided, for example, in the LD chip 11 or the LDD substrate 12. For example, the light-emitting element 23 is provided in the LD chip 11, similar to the light-emitting element 23 shown in FIG. 3B. On the other hand, the transistor 24 and the first to third selection circuits 37 to 39 may be provided in the LD chip 11 or in the LDD substrate 12. The first to third capacitors 34 to 36 may be disposed on the LD chip 11 or the LDD substrate 12.

[0114] FIG. 8 is a perspective view schematically showing the structure of the light emitting device 1a of the first embodiment.

[0115] Fig. 8 schematically shows the shapes of the LD chip 11 and the LDD substrate 12 shown in Fig. 7A and 7B. Fig. 8 also schematically and partially shows the first to third horizontal wirings 31a to 33a and the first to third vertical wirings 31b to 33b of the first to third anode wirings 31 to 33 described above, and a plurality of cathode wirings 41. As shown in Fig. 8, the first to third horizontal wirings 31a to 33a and the first to third vertical wirings 31b to 33b have a mesh-like structure.

[0116] Although the first to third anode wirings 31 to 33 and the cathode wiring 41 shown in FIG. 8 are depicted between the LD chip 11 and the LDD substrate 12, they may be disposed within the LD chip 11, within the LDD substrate 12, or between the LD chip 11 and the LDD substrate 12.

[0117] Next, various modified examples of the light emitting device 1a of this embodiment will be described with reference to Figures 9 to 18. The contents described with reference to Figures 1 to 8 also apply to these modified examples.

[0118] (3) Light Emitting Device 1a of First Modification FIG. 9 is a circuit diagram showing the structure of a light emitting device 1a of a first modification of the first embodiment.

[0119] The light emitting device 1a shown in Fig. 9 has the same structure as the light emitting device 1a shown in Fig. 4. Here, a method for driving the light emitting elements 23 indicated by the reference characters P1 to P6 will be described.

[0120] The light-emitting element 23 designated by symbol P1 is electrically connected to the first anode wiring 31 and the upper left cathode wiring 41. When only this light-emitting element 23 is to be driven (individual drive), only the first selection circuit 37 of the first to third selection circuits 37 to 39 is turned on, and only the drive circuit E for the upper left cathode wiring 41 is turned on. As a result, charge is accumulated only in the first capacitor 34 of the first to third capacitors 34 to 36, and only the three light-emitting elements 23 electrically connected to the upper left cathode wiring 41 are to be driven. As a result, current flows only through the light-emitting element 23 designated by symbol P1, and only this light-emitting element 23 emits light.

[0121] The light-emitting elements 23 indicated by symbols P2 to P4 are electrically connected to the first anode wiring 31 and are electrically connected to mutually different cathode wirings 41. When only these light-emitting elements 23 are to be driven (simultaneous drive), only the first selection circuit 37 of the first to third selection circuits 37 to 39 is turned on, and only the drive circuit E for these cathode wirings 41 is turned on. As a result, charge is accumulated only in the first capacitor 34 of the first to third capacitors 34 to 36, and only the nine light-emitting elements 23 electrically connected to these cathode wirings 41 are to be driven. As a result, current flows only through the light-emitting elements 23 indicated by symbols P2 to P4, and only these light-emitting elements 23 emit light.

[0122] The light-emitting elements 23 indicated by symbols P5 and P6 are electrically connected to the first and second anode wirings 31 and 32, respectively, and are also electrically connected to the same single cathode wiring 41. When only these light-emitting elements 23 are to be driven (simultaneous drive), only the first and second selection circuits 37 and 38 of the first to third selection circuits 37 to 39 are turned on, and only the drive circuit E for this cathode wiring 41 is turned on. As a result, charge is accumulated only in the first and second capacitors 34 and 35 of the first to third capacitors 34 to 36, and only the three light-emitting elements 23 electrically connected to this cathode wiring 41 are to be driven. As a result, current flows only through the light-emitting elements 23 indicated by symbols P5 and P6, and only these light-emitting elements 23 emit light.

[0123] The individual driving of the light-emitting element 23 designated by reference symbol P1 can also be applied to the other 80 light-emitting elements 23. The same applies to the simultaneous driving of the light-emitting elements 23 designated by reference symbols P2 to P6. Any number of light-emitting elements 23 may be simultaneously driven. The control of these individual driving and simultaneous driving is performed by, for example, the driving unit 3 and / or the control unit 9 shown in FIG. 1.

[0124] (4) Light Emitting Device 1a of Second Modification FIG. 10 is a circuit diagram showing the structure of a light emitting device 1a of a second modification of the first embodiment.

[0125] The light-emitting device 1a of this modification includes first to third cathode wirings 31' to 33' in the positions of the first to third anode wirings 31 to 33 shown in FIG. 4 , multiple anode wirings 41' in the positions of the multiple cathode wirings 41, and no multiple gate wirings 42. Furthermore, the first to third cathode wirings 31' to 33' each include first to third horizontal wirings 31a' to 33a' and first to third vertical wirings 31b' to 33b', similar to the first to third anode wirings 31 to 33. Thus, in this modification, the first to third cathode wirings 31' to 33' have a mesh-like structure. The first to third cathode wirings 31' to 33' are an example of the first terminal wiring of the present disclosure. The anode wiring 41' is an example of the second terminal wiring of the present disclosure.

[0126] Each light emitting element 23 of this modified example includes a cathode electrically connected to one of the first to third cathode wirings 31' to 33', and an anode electrically connected to one of the plurality of anode wirings 41'.

[0127] The light-emitting device 1a of this modified example further includes first to third transistors 61 to 63 at the positions of the first to third capacitors 34 to 36 shown in FIG. 4 . The first to third transistors 61 to 63 are, for example, N-type MOS transistors. The gates of the first to third transistors 61 to 63 are electrically connected to the first to third gate wirings 64 to 66, respectively. Each of the first to third transistors 61 to 63 has a drain electrically connected to one of the first to third cathode wirings 31′ to 33′ and a source electrically connected to a ground wiring. Each of the first to third transistors 61 to 63 forms a drive circuit E. The drive circuits E including the first to third transistors 61 to 63 are examples of the first to Nth drive circuits, respectively.

[0128] The light emitting device 1a of this modified example further includes a plurality of capacitors 67 at the positions of the plurality of transistors 24 shown in Fig. 4. Each of these capacitors 67 has one electrode electrically connected to one of the plurality of anode wirings 41' and the other electrode electrically connected to a ground wiring.

[0129] The light emitting device 1a of this modification further includes a plurality of selection circuits 68 instead of the first to third selection circuits 37 to 39. Each selection circuit 68 is electrically connected to a corresponding anode wiring 41′. Each selection circuit 68 includes a transistor 68a having a source electrically connected to a power supply wiring and a transistor 68b having a source electrically connected to a ground wiring. The drain of the transistor 68a and the drain of the transistor 68b are electrically connected to the cathode wiring 41. Each selection circuit 68 is electrically connected to a corresponding capacitor 67 via the anode wiring 41′. The transistor 68a is, for example, a P-type MOS transistor. The transistor 68b is, for example, an N-type MOS transistor. The transistor 68a is an example of a first switch of the present disclosure. The transistor 68b is an example of a second switch of the present disclosure.

[0130] The functions of the capacitor 67, the transistor 68a, and the transistor 68b are similar to those of the first to third capacitors 34 to 36, the transistors 37a to 39a, and the transistors 37b to 39b, respectively. The transistor 68a can store charge in the corresponding capacitor 67. The transistor 68b can discharge charge from the corresponding capacitor 67. The capacitor 67 can supply charge to the light-emitting element 23 via the anode wiring 41′, thereby causing a current to flow through the light-emitting element 23.

[0131] The functions of the first to third transistors 61 to 63 and their drive circuit E are similar to those of the transistor 34 and its drive circuit E. The first to third transistors 61 to 63 can drive the light-emitting elements 24 electrically connected to the first to third cathode wirings 31′ to 33′, respectively.

[0132] According to the light emitting device 1a of this modification, it is possible to realize the same control as that of the light emitting device 1a of the first embodiment, despite having a different structure from that of the light emitting device 1a of the first embodiment.

[0133] (5) Light Emitting Device 1a of Third Modification FIG. 11 is a circuit diagram showing the structure of a light emitting device 1a of a third modification of the first embodiment.

[0134] The light-emitting device 1a of this modification includes first to third cathode wirings 31' to 33' at the positions of the first to third anode wirings 31 to 33 shown in FIG. 4 , multiple anode wirings 41' at the positions of the multiple cathode wirings 41, and multiple gate wirings 42' at the positions of the multiple gate wirings 42. Furthermore, the first to third cathode wirings 31' to 33' each include first to third horizontal wirings 31a' to 33a' and first to third vertical wirings 31b' to 33b', similar to the first to third anode wirings 31 to 33. Thus, in this modification, the first to third cathode wirings 31' to 33' have a mesh-like structure. The first to third cathode wirings 31' to 33' are an example of the first terminal wiring of the present disclosure. The anode wiring 41' is an example of the second terminal wiring of the present disclosure.

[0135] Each light-emitting element 23 in this modification includes a cathode electrically connected to one of the first to third cathode wirings 31' to 33' and an anode electrically connected to one of the plurality of anode wirings 41'. Each transistor 24 in this modification includes a gate electrically connected to one of the plurality of gate wirings 42', a drain electrically connected to one of the plurality of anode wirings 41', and a source electrically connected to a power supply wiring. Each transistor 24 in this modification is, for example, a P-type MOS transistor. The first to third capacitors 34 to 36 and the first to third selection circuits 37 to 39 in this modification are electrically connected to the first to third cathode wirings 31' to 33', respectively.

[0136] According to the light emitting device 1a of this modification, it is possible to realize the same control as that of the light emitting device 1a of the first embodiment, despite having a different structure from that of the light emitting device 1a of the first embodiment.

[0137] (6) Light Emitting Device 1a of Fourth Modification FIG. 12 is a circuit diagram showing the structure of a light emitting device 1a of a fourth modification of the first embodiment.

[0138] 4, the light emitting device 1a includes six sets of first to third capacitors 34 to 36. The first to third capacitors 34 to 36 of this modification are disposed within the LD chip 11 (or within the LDD substrate 12), and are therefore disposed near the light emitting element 23. In this modification, each first capacitor 34 is electrically connected to one of the horizontal wirings 31a, each second capacitor 35 is electrically connected to one of the horizontal wirings 32a, and each third capacitor 36 is electrically connected to one of the horizontal wirings 33a.

[0139] According to the light emitting device 1a of this modification, it is possible to realize the same control as that of the light emitting device 1a of the first embodiment, despite having a different structure from that of the light emitting device 1a of the first embodiment.

[0140] (7) Light Emitting Device 1a of Fifth Modification FIG. 13 is a circuit diagram showing the structure of a light emitting device 1a of a fifth modification of the first embodiment.

[0141] The light emitting device 1a of this modified example does not include the first to third capacitors 34 to 36. The light emitting device 1a of this modified example stores the electric charge to be supplied to each light emitting element 23 in a parasitic capacitance, which will be described later, instead of the first to third capacitors 34 to 36.

[0142] FIG. 14 is another circuit diagram showing the structure of the light emitting device 1a according to the fifth modified example of the first embodiment.

[0143] FIG. 14 shows a pair of a light-emitting element 23 and a transistor 24 included in the light-emitting device 1a of this modified example. FIG. 14 further shows a parasitic capacitance 23' of the light-emitting element 23 and a parasitic capacitance 24' of the transistor 24. The light-emitting device 1a of this modified example stores charge to be supplied to each light-emitting element 23 in these parasitic capacitances 23', 24'. This allows current to flow through each light-emitting element 23, causing each light-emitting element 23 to emit light. The storage in the parasitic capacitances 23', 24' is controlled by first to third selection circuits 37 to 39.

[0144] According to the light emitting device 1a of this modification, it is possible to realize the same control as that of the light emitting device 1a of the first embodiment, despite having a different structure from that of the light emitting device 1a of the first embodiment.

[0145] (8) Light Emitting Device 1a of Sixth Modification FIG. 15 is a circuit diagram showing various examples of the structure of a light emitting device 1a of a sixth modification of the first embodiment.

[0146] The light emitting device 1a of this modification has the same structure as the light emitting device 1a of the first embodiment as shown in Fig. 4. However, while each drive circuit E of the first embodiment has the structure shown in Fig. 15A, each drive circuit E of this modification has the structure shown in any one of Fig. 15B to Fig. 15D.

[0147] The drive circuit E shown in Fig. 15B includes three transistors 24 electrically connected to a cathode wiring 41 and three transistors 25 electrically connected to these transistors 24. The transistors 24 and 25 shown in Fig. 15B are, for example, N-type MOS transistors. The gates of these transistors 24 are electrically connected to a common gate wiring 42, and the gates of these transistors 25 are electrically connected to a common gate wiring 43. The transistors 24 and 25 are examples of the first and second transistors of the present disclosure, respectively.

[0148] Each transistor 24 is used to select a light-emitting element 23 that emits light. Each transistor 25 is used as a current source. For example, to generate light from a certain light-emitting element 23, a predetermined signal is applied to the gate wiring 42 of the drive circuit E for that light-emitting element 23, and a predetermined signal (DC bias voltage) is applied to the gate wiring 43 of the drive circuit E for that light-emitting element 23. This causes the source and drain of each transistor 24 in that drive circuit E to become conductive, and also causes the source and drain of each transistor 25 in that drive circuit E to become conductive, allowing current to flow through that light-emitting element 23. In this case, each transistor 25 functions as a current source.

[0149] The drive circuit E shown in Fig. 15C includes three transistors 24 electrically connected to a cathode wiring 41. The transistors 24 shown in Fig. 15C are, for example, NPN-type bipolar transistors. In this case, the wiring 42 is a "base wiring" rather than a "gate wiring." The operation of the drive circuit E shown in Fig. 15C is similar to that of the drive circuit E shown in Fig. 15A.

[0150] The drive circuit E shown in Fig. 15D includes three transistors 24 electrically connected to a cathode wiring 41 and three transistors 25 electrically connected to these transistors 24. The transistors 24 and 25 shown in Fig. 15D are, for example, NPN-type bipolar transistors. In this case, the wirings 42 and 43 are "base wirings" rather than "gate wirings." The operation of the drive circuit E shown in Fig. 15D is similar to that of the drive circuit E shown in Fig. 15B.

[0151] According to the light emitting device 1a of this modification, it is possible to realize the same control as that of the light emitting device 1a of the first embodiment, despite having a different structure from that of the light emitting device 1a of the first embodiment.

[0152] (9) Light Emitting Device 1a of Seventh Modification FIG. 16 is a circuit diagram showing the structure of a light emitting device 1a of a seventh modification of the first embodiment.

[0153] 4, the light emitting device 1a of this modification includes first to third voltage detection circuits 71 to 73. The first voltage detection circuit 71 is electrically connected to the first horizontal wiring 31a of the first anode wiring 31 and the gate of the transistor 37a. The second voltage detection circuit 72 is electrically connected to the second horizontal wiring 32a of the second anode wiring 32 and the gate of the transistor 38a. The third voltage detection circuit 73 is electrically connected to the third horizontal wiring 33a of the third anode wiring 33 and the gate of the transistor 39a.

[0154] The first voltage detection circuit 71 detects the voltage of the first anode wiring 31 via the first horizontal wiring 31a of the first anode wiring 31. This voltage indicates the amount of charge stored in the four first capacitors 34. Therefore, the first voltage detection circuit 71 controls the gate voltage of the transistor 37a based on the voltage detected from the first anode wiring 31. For example, if the detected voltage is lower than a predetermined voltage, the transistor 37a is turned on to start charge storage. On the other hand, if the detected voltage is higher than the predetermined voltage, the transistor 37a is turned off to end charge storage. According to this modification, the output power of the light-emitting device 1a can be changed by changing the value of this predetermined voltage. The value of this predetermined voltage is adjusted, for example, by the drive unit 3 and / or the control unit 9 shown in FIG. 1.

[0155] Similarly, the second voltage detection circuit 72 detects the voltage of the second anode wiring 32 and controls the gate voltage of the transistor 38 a based on the detected voltage. The third voltage detection circuit 73 detects the voltage of the third anode wiring 33 and controls the gate voltage of the transistor 39 a based on the detected voltage.

[0156] FIG. 17 is a timing chart showing the operation of the light emitting device 1a according to the seventh modification of the first embodiment.

[0157] Curves A1 and A2 represent the gate voltages of the anode-side PMOS, i.e., transistors 37a to 39a. Curve B represents the gate voltages of the anode-side NMOS, i.e., transistors 37b to 39b. Curve C represents the gate voltage of the cathode-side NMOS, i.e., transistor 24. Curves D1 and D2 represent the voltages (anode voltages) of the first to third anode wirings 31 to 32. Curves E1 and E2 represent the output currents (LDD output currents) from the LDD substrate 12 to each light-emitting element 23.

[0158] Curve A1 shows the case where the pulse width of the gate voltage of the transistors 37a to 39a is short, in which case the transistors 37a to 39a are turned off at a low anode voltage (curve D1), resulting in low-power emission (curve E1).

[0159] Curve A2 shows the case where the pulse width of the gate voltage of the transistors 37a to 39a is long, in which case the transistors 37a to 39a are turned off at a high anode voltage (curve D2), resulting in high-power emission (curve E2).

[0160] In this way, according to this modification, it is possible to freely change the output power of the light emitting device 1a.

[0161] (10) Light Emitting Device 1a of Eighth Modification FIG. 18 is a cross-sectional view and a plan view showing the structure of a light emitting device 1a of an eighth modification of the first embodiment.

[0162] The light emitting device 1a of this modification has the structure shown in A and B of Fig. 18 instead of the structure shown in A and B of Fig. 7. Fig. 18A shows an XZ cross section of the light emitting device 1a of this modification. Fig. 18B shows the planar structure of the light emitting device 1a shown in Fig. 18A.

[0163] In this modification, the LDD substrate 12 is disposed on the wiring layer 53 via a plurality of solder balls 58, and is electrically connected to the first to third capacitors 34 to 36 via these solder balls 58 and the wiring layer 53. Furthermore, the LD chip 11 is mounted on the LDD substrate 12 via a plurality of bumps 59, and is electrically connected to the LDD substrate 12 via these bumps 59. These bumps 59 are formed of a metal such as gold (Au). The rest of the structure of the light emitting device 1a of this modification is similar to the structure shown in FIGS. 7A and 7B.

[0164] According to the light emitting device 1a of this modification, it is possible to realize the same control as that of the light emitting device 1a of the first embodiment, despite having a different structure from that of the light emitting device 1a of the first embodiment.

[0165] As described above, the light-emitting device 1a of this embodiment includes the first to third anode wirings 31 to 33 arranged in a mesh pattern, and the first to third capacitors 34 to 36 electrically connected to the first to third anode wirings 31 to 33 so as to be arranged symmetrically. Therefore, this embodiment can suppress the above-mentioned problems of impedance and impedance difference, thereby improving the performance of the distance measuring device 1. Furthermore, this embodiment can suppress problems related to the cathode wirings 41 by arranging the cathode wirings 41 for every three light-emitting elements 23. In this way, this embodiment can optimize the wiring structure for the light-emitting elements 23.

[0166] Although the light emitting device 1a of this embodiment includes the components of "first to third horizontal wirings 31a to 33a," "first to third vertical wirings 31b to 33b," and "three light emitting elements 23 electrically connected to each cathode wiring 41," it may not include one or two of these components. For example, the light emitting device 1a of this embodiment may include the components of "three types of horizontal wirings 31a to 33a," "three types of vertical wirings 31b to 33b," and "only two light emitting elements 23 electrically connected to each cathode wiring 41." Furthermore, the light emitting device 1a of this embodiment may include the components of "three types of horizontal wirings 31a to 33a," "only two types of vertical wirings 31b to 32b," and "only two light emitting elements 23 electrically connected to each cathode wiring 41." In addition, the light-emitting device 1a of this embodiment may include components of "three types of horizontal wiring 31a to 33a," "only one type of vertical wiring 31b," and "only one light-emitting element 23 electrically connected to each cathode wiring 41."

[0167] Second Embodiment FIG. 19 is a circuit diagram showing the structure of a light emitting device 1a according to a second embodiment.

[0168] The light emitting device 1a of this embodiment includes, in addition to the components shown in Fig. 4, a fourth anode wiring 81, a plurality of fourth capacitors 82, and a fourth selection circuit 83. The fourth anode wiring 81 includes a plurality of fourth horizontal wirings 81a and a plurality of fourth vertical wirings 81b. The fourth selection circuit 83 includes transistors 83a and 83b. The first to fourth selection circuits 37, 38, 39, and 83 are examples of the first to Nth selection circuits of the present disclosure. Fig. 19 shows an example where N is 4.

[0169] In FIG. 19, in order to distinguish the first to fourth anode wirings 31, 32, 33, and 81 from one another, the first anode wiring 31 is shown by a thick solid line, the second anode wiring 32 is shown by a thick dashed line, the third anode wiring 33 is shown by a thin solid line, and the fourth anode wiring 81 is shown by a thin dashed line.

[0170] The light-emitting device 1a of this embodiment includes 8 x 8 light-emitting elements 23 arranged in a two-dimensional array. Therefore, the first to fourth anode wirings 31, 32, 33, and 81 of this embodiment include four sets of first to fourth horizontal wirings 31a, 32a, 33a, and 81a and first to fourth vertical wirings 31b, 32b, 33b, and 81b. These are examples of M sets of first to Nth horizontal wirings and first to Nth vertical wirings of the present disclosure. FIG. 19 shows an example where M is 4. The number of light-emitting elements 23 shown in FIG. 19 is N(M-2) x N(M-2). The light-emitting device 1a of this embodiment further includes 8 x 8 transistors 24 electrically connected to these light-emitting elements 23.

[0171] The first to fourth capacitors 34, 35, 36, and 82 of this embodiment include four sets of first to fourth capacitors 34, 35, 36, and 82. The first to fourth capacitors 34, 35, 36, and 82 of each set are arranged in order near one side of the square light-emitting element array. Therefore, the first to fourth capacitors 34, 35, 36, and 82 of this embodiment are also arranged symmetrically with respect to this square. The first to fourth capacitors 34, 35, 36, and 82 are examples of K sets of first to Nth capacitors of the present disclosure. Figure 19 shows an example where K is 4.

[0172] The fourth anode wiring 81, fourth capacitor 82, and fourth selection circuit 83 of this embodiment have the same structures and functions as the first to third anode wirings 31 to 33, the first to third capacitors 34 to 36, and the first to third selection circuits 37 to 39, respectively. The cathode wiring 41 and gate wiring 42 of this embodiment also have the same structures and functions as the cathode wiring 41 and gate wiring 42 of the first embodiment, respectively. However, since the value of N in this embodiment is 4 instead of 3, each cathode wiring 41 is electrically connected to four light-emitting elements 23, and each gate wiring 42 is electrically connected to four transistors 24.

[0173] It is desirable to set the value of N to an appropriate value depending on the usage of the light-emitting device 1a. For example, reducing the value of N has the advantage of reducing the inductance of the wiring for each light-emitting element 23 and reducing the number of capacitors and selection circuits. On the other hand, increasing the value of N has the advantage of reducing the number of cathode wirings 41 and gate wirings 42 and increasing the number of common cathode wirings 41 connected to transistors 24, thereby increasing the driving capability of transistors 24.

[0174] Third Embodiment FIG. 20 is a plan view schematically showing the structure of a light emitting device 1a according to a third embodiment.

[0175] The light emitting device 1a of this embodiment has the same structure as the light emitting device 1a of the first embodiment shown in Fig. 4. Furthermore, the light emitting device 1a of this embodiment has the structure shown in Fig. 20A and Fig. 20B.

[0176] A in Fig. 20 schematically shows the shape of the LD chip 11 in a plan view. Each region R1 shown in A in Fig. 20 indicates the area occupied by one light-emitting element 23. The area of ​​each region R1 corresponds to the size of one light-emitting element 23. A in Fig. 20 shows 9 x 9 regions R1 corresponding to the 9 x 9 light-emitting elements 23.

[0177] FIG. 20B schematically illustrates the shape of the LDD substrate 12 in a plan view. The LDD substrate 12 of this embodiment includes a region for arranging the driver circuits E (transistors 24) and a region for arranging the peripheral circuits. Each region R2 illustrated in FIG. 20B indicates the area occupied by one driver circuit E (three transistors 24). The area of ​​each region R2 corresponds to the size of one driver circuit E. FIG. 20B illustrates 27 regions R2 corresponding to the 27 driver circuits E.

[0178] In this embodiment, the size of one drive circuit E is the same as the size of three light-emitting elements 23. That is, the area of ​​one region R2 is the same as the area of ​​three regions R1, as shown in A and B of Figure 20. Specifically, the shape of one region R2 is congruent with the shapes of the three regions R1.

[0179] Such a structure is suitable, for example, when the structure shown in A of FIG. 18 is adopted. In A of FIG. 18, the LD chip 11 is mounted on the LDD substrate 12. In this case, if the size of one drive circuit E is the same as the size of three light-emitting elements 23, each drive circuit E can be disposed directly below the corresponding three light-emitting elements 23. This makes it possible to further reduce the impedance of the wiring for each light-emitting element 23. Note that, when each drive circuit E corresponds to N light-emitting elements 23, it is desirable to make the size of one drive circuit E the same as the size of the N light-emitting elements 23.

[0180] Fourth Embodiment FIG. 21 is a schematic diagram for explaining the operation of a distance measuring device 1 according to a fourth embodiment.

[0181] The distance measuring device 1 of this embodiment includes the light emitting device 1a and light receiving device 1b described in the first embodiment. As described above, the light emitting device 1a includes the LD chip 11 including the light emitting unit 2 and the LDD substrate 12 including the drive unit 3 (see A in FIGS. 1 and 3A). On the other hand, the light receiving device 1b includes the light receiving unit 7 and signal processing unit 8 shown in FIG. 1. The distance measuring device 1 of this embodiment has the configuration shown in FIG. 1, similar to the distance measuring device 1 described in the first embodiment.

[0182] The light-emitting device 1a includes a plurality of light-emitting elements 23 arranged in a two-dimensional array along the X and Y directions. Similarly, the light-receiving device 1b includes a plurality of light-receiving elements 26 arranged in a two-dimensional array along the X and Y directions. The light-receiving elements 26 are, for example, photodiodes. The light-emitting elements 23 may be arranged in a two-dimensional array along two directions other than the X and Y directions, or may be arranged in a layout different from the two-dimensional array layout. The same applies to the light-receiving elements 26.

[0183] The light-emitting device 1a of this embodiment also includes first to third horizontal wires 31a to 33a extending in the horizontal direction (X direction) and first to third vertical wires 31b to 33b extending in the vertical direction (Y direction) (see FIG. 4). However, in FIG. 21, the X direction is shown as the direction extending vertically on the paper, and the Y direction is shown as the direction extending horizontally on the paper. This is to make it easier to explain the scanning direction of the screen 91, which will be described later. In this embodiment, the first to third horizontal wires 31a to 33a extend vertically on the paper, and the first to third vertical wires 31b to 33b extend horizontally on the paper.

[0184] Fig. 21 shows a screen 91, which is the range targeted for distance measurement by the distance measuring device 1. The shape of the screen 91 shown in Fig. 21 is a rectangle with two sides extending in the X direction and two sides extending in the Y direction. Note that these sides may extend in two directions other than the X and Y directions.

[0185] FIG. 21 further shows a light-emitting spot 91a and a readout region 91b on the screen 91. When one light-emitting element 23 in the light-emitting device 1a emits light, a light-emitting spot 91a is generated at a position on the screen 91 corresponding to the position of the light-emitting element 23. The light-receiving device 1b controls the position of the readout region 91b so as to be linked to the position of the light-emitting spot 91a. In this way, the light-receiving device 1b detects the light-emitting spot 91a using the light-receiving element 26 located at a position corresponding to the position of the readout region 91b. FIG. 21 shows the light-emitting element 23 generating the light-emitting spot 91a and the light-receiving element 26 corresponding to the readout region 91b with dot hatching.

[0186] The distance measuring device 1 can move the light-emitting spot 91a on the screen 91 by sequentially emitting light from the multiple light-emitting elements 23 in the light-emitting device 1a. For example, assume that light-emitting element "a" generates the light-emitting spot 91a at point "A" on the screen 91, and light-emitting element "b" generates the light-emitting spot 91a at point "B" on the screen 91. In this case, when the light-emitting elements "a" and "b" emit light in sequence, that is, when the light-emitting element "a" is turned ON and then the light-emitting element "a" is turned OFF, and then the light-emitting element "b" is turned ON and then the light-emitting element "b" is turned OFF, the light-emitting spot 91a appears and disappears at point "A," and then the light-emitting spot 91a appears and disappears at point "B." As a result, the light-emitting spot 91a moves from point "A" to point "B."

[0187] 21 further shows arrows L1 and L2 indicating the scanning direction of the screen 91. The distance measuring device 1 scans the screen 91 with the light emitting spot 91a by moving the light emitting spot 91a in the order of arrow L1, arrow L2, arrow L1, arrow L2, .... When scanning in the direction of each arrow L1, two or more light emitting elements 23 on the same vertical wiring are caused to emit light in sequence. When scanning in the direction of each arrow L2, the light emitting element 23 that generates the light emitting spot 91a is changed from a light emitting element 23 on one vertical wiring to a light emitting element 23 on another vertical wiring. This makes it possible to scan the screen 91 with the light emitting spot 91a.

[0188] In this embodiment, the operation of the light-emitting device 1a as described above is controlled by the driver 3, and the operation of the light-receiving device 1b as described above is controlled by the signal processor 8. The driver 3 is an example of a control mechanism of the present disclosure. Meanwhile, the operation of the light-emitting device 1a as described above may be controlled by the controller 9, or may be controlled by both the driver 3 and the controller 9. The controller 9 in this case is also an example of a control mechanism of the present disclosure. Similarly, the operation of the light-receiving device 1b as described above may be controlled by the controller 9, or may be controlled by the signal processor 8 and the controller 9.

[0189] 21 further shows a pupil opening 92 on the screen 91. When a person looks at the center of the pupil opening 92 on the screen 91, light from the area within the pupil opening 92 enters the person's eye. Therefore, the larger the size of the pupil opening 92, the more easily light enters the person's eye. Generally, the size of the pupil opening 92 is set as a setting value for the distance measuring device 1 when the distance measuring device 1 is designed. In this embodiment, the distance between the two-dimensional array of light-emitting elements 23 and the pupil opening 92 is assumed to be at least 100 mm, and the diameter of the pupil opening 92 is set to 7 mm.

[0190] (1) First Operation Example FIGS. 22 and 23 are plan views showing a first operation example of the distance measuring device 1 of the fourth embodiment.

[0191] Each of Figures 22A to 23D shows a screen 91 divided into a mesh of 16 x 16 (=256) unit areas. In this embodiment, when one light-emitting element 23 emits light, a light-emitting spot 91a is generated in one unit area corresponding to this light-emitting element 23. In this embodiment, there is a one-to-one correspondence between the light-emitting elements 23 in the light-emitting device 1a and the unit areas in the screen 91. Therefore, in this embodiment, it is assumed that the light-emitting device 1a includes 16 x 16 light-emitting elements 23. Such a configuration can be realized, for example, by setting the values ​​of N and M described with reference to Figure 4 to 4 (N = 4, M = 4).

[0192] 22A shows a light-emitting spot 91a in a unit area at coordinates (3, 1) and a light-emitting spot 91a in a unit area at coordinates (3, 9). The value "3" of the coordinates (3, 1) represents the X coordinate of the unit area, and the value "1" of the coordinates (3, 1) represents the Y coordinate of the unit area. In this embodiment, the screen 91 is divided into 16 x 16 unit areas, and therefore the X coordinate and Y coordinate of each unit area are integers between 1 and 16.

[0193] In this embodiment, the position of the light-emitting element 23 in the light-emitting device 1a is also represented by X and Y coordinates. For example, when the light-emitting element 23 at the coordinate [3, 1] emits light, a light-emitting spot 91a is generated within the unit area at the coordinate (3, 1). The value "3" at the coordinate [3, 1] represents the X coordinate of the light-emitting element 23, and the value "1" at the coordinate [3, 1] represents the Y coordinate of the light-emitting element 23. The X and Y coordinates of the light-emitting element 23 are also integers between 1 and 16. In this embodiment, there is a one-to-one correspondence between the light-emitting element 23 at the coordinate [x, y] and the unit area at the coordinate (x, y) (x and y are integers between 1 and 16).

[0194] 22A to 23D show an example of a scanning process represented by arrow L1. In this example, 16 light-emitting elements 23 with an X coordinate of "3" emit light in sequence, two at a time. As a result, 16 unit areas with an X coordinate of "3" are scanned by two light-emitting spots 91a. During this scanning, the Y coordinate of each light-emitting spot 91a, i.e., the position of each light-emitting spot 91a in the Y direction, changes. The Y direction is an example of a first direction in the present disclosure. On the other hand, when scanning represented by arrow L2 is performed, the position of each light-emitting spot 91a in the X direction changes. The X direction is an example of a second direction in the present disclosure.

[0195] Here, the relationship between the light-emitting elements 23 and the vertical wiring of this embodiment will be described with reference to Figure 4 of the first embodiment. The light-emitting device 1a in Figure 4 has 15 vertical wirings, each of which corresponds to one of the first to third vertical wirings 31b to 33b. In Figure 4, nine light-emitting elements 23 having the same X coordinate are electrically connected to the same single vertical wiring. This is also true in this embodiment. In this embodiment, 16 light-emitting elements 23 having the same X coordinate are electrically connected to the same single vertical wiring.

[0196] Therefore, Figures 22A to 23D show an example of operation in which 16 light-emitting elements 23 on the same vertical wiring are sequentially illuminated. In this embodiment, when two or more light-emitting elements 23 on the same vertical wiring are sequentially illuminated, these light-emitting elements 23 are sequentially illuminated so that two light-emitting elements 23 adjacent to each other in the Y direction (vertical direction) do not illuminate consecutively. Here, adjacent light-emitting elements "a" and "b" illuminate consecutively means that light-emitting elements "a" and "b" illuminate so that no other light-emitting elements illuminate between the illumination of light-emitting element "a" and the illumination of light-emitting element "b." For example, the light-emitting element 23 at coordinates [3, 9] and the light-emitting element 23 at coordinates [3, 10] are adjacent to each other in the X direction. Below, details of the example of operation in Figures 22A to 23D are described.

[0197] First, the light-emitting element 23 at the coordinate [3,1] and the light-emitting element 23 at the coordinate [3,9] simultaneously emit light, generating two light-emitting spots 91a in the unit area at the coordinate (3,1) and the unit area at the coordinate (3,9) (A in FIG. 22). At this time, the distance measuring device 1 repeatedly causes the light-emitting element 23 at the coordinate [3,1] to emit light 300 times at 1 μs intervals. As a result, the generation and disappearance of the light-emitting spot 91a is repeated 300 times in the unit area at the coordinate (3,1). This is also the case for the light-emitting element 23 at the coordinate [3,9]. This repetitive process is similarly performed in B in FIG. 22 to D in FIG. 23. Note that the number of repetitions of 300 and the repetition interval of 1 μs may be replaced with other values.

[0198] Next, the light-emitting element 23 at the coordinates [3, 4] and the light-emitting element 23 at the coordinates [3, 12] simultaneously emit light, generating two light-emitting spots 91a in the unit area at the coordinates (3, 4) and the unit area at the coordinates (3, 12) (B in FIG. 22). As a result, the light-emitting spot 91a at the coordinates (3, 1) moves (transitions) to the coordinates (3, 4), and the light-emitting spot 91a at the coordinates (3, 9) moves (transitions) to the coordinates (3, 12). Note that the process in B in FIG. 22 starts 1 μs after the end of the process in A in FIG. 22 (the same applies to the following processes).

[0199] In this operation example, the light-emitting element 23 at coordinates [3, 1] and the light-emitting element 23 at coordinates [3, 4] emit light in succession. These light-emitting elements 23 are not adjacent to each other in the Y direction, but are spaced apart by a distance equivalent to three light-emitting elements 23 in the Y direction. As a result, the light-emitting spot 91a at coordinates (3, 1) moves by a distance equivalent to three unit areas in the +Y direction, thereby moving to coordinates (3, 4). This is also true for the light-emitting spot 91a at coordinates (3, 9). In this operation example, this "movement by a distance equivalent to three unit areas" is similarly performed in C of FIG. 22 to D of FIG. 23. The value "3" may be replaced by a constant Y other than 3 (Y is an integer equal to or greater than 2).

[0200] Hereinafter, for the sake of simplicity, the expression "the light-emitting elements 23 are spaced apart by a distance equivalent to three light-emitting elements 23 in the Y direction" will be replaced with the expression "the light-emitting elements 23 are spaced apart by a distance of Y=3 in the Y direction." Similarly, for the sake of simplicity, the expression "the light-emitting spot 91a moves in the +X direction by a distance equivalent to three unit areas" will be replaced with the expression "the light-emitting spot 91a moves in the +Y direction by a distance of Y=3."

[0201] Next, the light-emitting element 23 at the coordinates [3, 7] and the light-emitting element 23 at the coordinates [3, 15] emit light simultaneously, causing two light-emitting spots 91a to appear in the unit area at the coordinates (3, 7) and the unit area at the coordinates (3, 15) (C in FIG. 22). As a result, the light-emitting spot 91a at the coordinates (3, 4) moves to the coordinates (3, 7), and the light-emitting spot 91a at the coordinates (3, 12) moves to the coordinates (3, 15). That is, each light-emitting spot 91a moves a distance of Y=3 in the +Y direction.

[0202] Next, the light-emitting element 23 at the coordinate [3, 2] and the light-emitting element 23 at the coordinate [3, 10] emit light simultaneously, causing two light-emitting spots 91a to appear in the unit area at the coordinate (3, 2) and the unit area at the coordinate (3, 10) (D in FIG. 22). As a result, the light-emitting spot 91a at the coordinate (3, 7) moves to the coordinate (3, 2), and the light-emitting spot 91a at the coordinate (3, 15) moves to the coordinate (3, 10). That is, each light-emitting spot 91a moves a distance of Y=5 in the -Y direction.

[0203] Here, the former light-emitting spot 91a will be referred to as the "left light-emitting spot 91a," and the latter light-emitting spot 91a will be referred to as the "right light-emitting spot 91a." In this operation example, it is considered that the left light-emitting spot 91a moves within a Y coordinate range of 1 to 8, and the right light-emitting spot 91a moves within a Y coordinate range of 9 to 16. In this case, when the left light-emitting spot 91a attempts to move a distance of Y=3 in the +Y direction from the coordinate (3, 7), the Y coordinate will go out of the range of 1 to 8.

[0204] Therefore, when calculating the above-mentioned "distance," the distance is calculated by applying a periodic boundary condition in the Y direction to the arrangement of the light-emitting elements 23 within the Y coordinate range of 1 to 8. Therefore, the light-emitting element 23 at coordinate [3, 8] and the light-emitting element 23 at coordinate [3, 1] are assumed to be adjacent to each other in the Y direction. As a result, the light-emitting element 23 at coordinate [3, 7] and the light-emitting element 23 at coordinate [3, 2] are separated by a distance of Y = 3 in the Y direction under the periodic boundary condition. Therefore, the distance measuring device 1 moves the left light-emitting spot 91a from coordinate (3, 7) to coordinate (3, 2). The Y coordinate "2" after the movement can also be expressed as the value (remainder) obtained by subtracting the periodic length "8" from the sum of the Y coordinate "7" before the movement and the movement distance "3."

[0205] Similarly, when calculating the "distance" for the right light-emitting spot 91a, the distance is calculated by applying a periodic boundary condition in the Y direction to the arrangement of the light-emitting elements 23 within the Y coordinate range of 9 to 16. Therefore, the light-emitting element 23 at coordinate [3, 16] and the light-emitting element 23 at coordinate [3, 9] are assumed to be adjacent to each other in the Y direction. As a result, the light-emitting element 23 at coordinate [3, 15] and the light-emitting element 23 at coordinate [3, 10] are separated by a distance of Y = 3 in the Y direction under the periodic boundary condition. Therefore, the distance measuring device 1 moves the right light-emitting spot 91a from coordinate (3, 15) to coordinate (3, 10). The Y coordinate "10" after the movement can also be expressed as the remainder obtained by subtracting the periodic length "8" from the sum of the Y coordinate "15" before the movement and the movement distance "3."

[0206] 22D, it may be considered that the light-emitting spot 91a at the coordinate (3, 7) has moved to the coordinate (3, 10), and the light-emitting spot 91a at the coordinate (3, 15) has moved to the coordinate (3, 2). In this case, it is considered that each light-emitting spot 91a moves within a Y coordinate range of 1 to 16, and the above-mentioned "distance" is calculated by applying a periodic boundary condition in the Y direction to the arrangement of the light-emitting elements 23 within the Y coordinate range of 1 to 16. Under this periodic boundary condition, the light-emitting element 23 at the coordinate [3, 7] and the light-emitting element 23 at the coordinate [3, 10] are separated by a distance of Y = 3 in the Y direction, and the light-emitting element 23 at the coordinate [3, 15] and the light-emitting element 23 at the coordinate [3, 2] are also separated by a distance of Y = 3 in the Y direction.

[0207] Next, the light-emitting element 23 at the coordinates [3, 5] and the light-emitting element 23 at the coordinates [3, 13] emit light simultaneously, causing two light-emitting spots 91a to appear in the unit area at the coordinates (3, 5) and the unit area at the coordinates (3, 13) (A in FIG. 23). As a result, the light-emitting spot 91a at the coordinates (3, 2) moves to the coordinates (3, 5), and the light-emitting spot 91a at the coordinates (3, 10) moves to the coordinates (3, 13). That is, each light-emitting spot 91a moves a distance of Y=3 in the +Y direction.

[0208] Next, the light-emitting element 23 at the coordinate [3, 8] and the light-emitting element 23 at the coordinate [3, 16] simultaneously emit light, generating two light-emitting spots 91a in the unit area at the coordinate (3, 8) and the unit area at the coordinate (3, 16) (B in FIG. 23). As a result, the light-emitting spot 91a at the coordinate (3, 5) moves to the coordinate (3, 8), and the light-emitting spot 91a at the coordinate (3, 13) moves to the coordinate (3, 16). That is, each light-emitting spot 91a moves a distance of Y=3 in the +Y direction.

[0209] Next, the light-emitting element 23 at the coordinates [3, 3] and the light-emitting element 23 at the coordinates [3, 11] emit light simultaneously, causing two light-emitting spots 91a to appear in the unit area at the coordinates (3, 3) and the unit area at the coordinates (3, 11) (C in FIG. 23). As a result, the light-emitting spot 91a at the coordinates (3, 8) moves to the coordinates (3, 3), and the light-emitting spot 91a at the coordinates (3, 16) moves to the coordinates (3, 11). That is, each light-emitting spot 91a moves in the -Y direction by a distance of Y = 5. This is the same as the case shown in D in FIG. 22.

[0210] Next, the light-emitting element 23 at the coordinates [3, 6] and the light-emitting element 23 at the coordinates [3, 14] simultaneously emit light, generating two light-emitting spots 91a in the unit area at the coordinates (3, 6) and the unit area at the coordinates (3, 14) (D in FIG. 23). As a result, the light-emitting spot 91a at the coordinates (3, 3) moves to the coordinates (3, 6), and the light-emitting spot 91a at the coordinates (3, 11) moves to the coordinates (3, 14). That is, each light-emitting spot 91a moves a distance of Y=3 in the +Y direction.

[0211] According to this operation example, by performing the processes in A of FIG. 22 to D of FIG. 23, it is possible to cause all 16 light-emitting elements 23 whose X coordinate is "3" to emit light. This makes it possible to scan all 16 unit areas whose X coordinate is "3". This is because the movement distance "3" and the periodic length "8 (or 16)" are relatively prime. Therefore, the movement distance in this embodiment is set so that the movement distance and the periodic length are relatively prime.

[0212] In this operation example, two light-emitting elements 23 whose Y coordinates differ by 8 are caused to emit light simultaneously, thereby simultaneously generating two light-emitting spots 91a whose Y coordinates differ by 8. However, the number of light-emitting elements 23 that emit light simultaneously may be one or three or more. When J light-emitting elements 23 (J is an integer of 2 or more) whose Y coordinates are different from each other are caused to emit light simultaneously, J light-emitting spots 91a whose Y coordinates are different from each other are simultaneously generated. In this case, it is desirable that these light-emitting elements 23 are not adjacent to each other in the Y direction.

[0213] (2) Second Operation Example FIGS. 24 and 25 are plan views showing a second operation example of the distance measuring device 1 of the fourth embodiment.

[0214] Each of Figures 24A to 25D shows a screen 91 divided into 16 x 16 unit areas, which is similar to Figures 22A to 23D. Below, details of the operation examples of Figures 24A to 25D will be described.

[0215] First, the light-emitting element 23 at the coordinate [3,1] and the light-emitting element 23 at the coordinate [3,9] emit light simultaneously, thereby generating two light-emitting spots 91a in the unit area at the coordinate (3,1) and the unit area at the coordinate (3,9) (A in FIG. 24). This process corresponds to the process at A in FIG. 22. However, in this case, the distance measuring device 1 causes the light-emitting element 23 at the coordinate [3,1] to emit light only once. This also applies to the light-emitting element 23 at the coordinate [3,9]. This type of single emission is similarly performed in B in FIG. 24 to D in FIG. 25.

[0216] Next, the light-emitting element 23 at the coordinates [3, 4] and the light-emitting element 23 at the coordinates [3, 12] simultaneously emit light, generating two light-emitting spots 91a in the unit area at the coordinates (3, 4) and the unit area at the coordinates (3, 12) (B in FIG. 24). As a result, the light-emitting spot 91a at the coordinates (3, 1) moves to the coordinates (3, 4), and the light-emitting spot 91a at the coordinates (3, 9) moves to the coordinates (3, 12). This process corresponds to the process in B in FIG. 22. Note that the process in B in FIG. 24 starts 1 μs after the end of the process in A in FIG. 24 (the same applies to the following processes).

[0217] Next, the processes in C of Fig. 24 to D of Fig. 25 are performed in the same manner as the processes in C of Fig. 22 to D of Fig. 23. Furthermore, in this operation example, the processes in A of Fig. 24 to D of Fig. 25 are repeated 300 times at intervals of 1 μs. As a result, in each unit area in this operation example, the generation and disappearance of the light emitting spot 91a are repeated 300 times, as in the first operation example. Note that the number of repetitions, 300 times, and the repetition interval, 1 μs, may be replaced with other values.

[0218] FIG. 26 is a diagram for explaining the difference between the first and second operation examples described above.

[0219] A in Fig. 26 shows two light emission spots 91a that can be generated within one pupil opening 92. Hereinafter, these light emission spots 91a will be referred to as the "left light emission spot 91a" and the "right light emission spot 91a." Note that these are a different concept from the "left light emission spot 91a" and the "right light emission spot 91a" that appeared in the explanation of A in Fig. 22 to D in Fig. 23.

[0220] FIG. 26B is a graph showing the flow of the first operation example. In this operation example, the left light emitting spot 91a is repeatedly generated 300 times in the same unit area within one slot. Similarly, the right light emitting spot 91a is repeatedly generated 300 times in the same unit area within one slot. The length of one slot in this operation example is 300 μs. In this operation example, eight slots are processed in the scanning process indicated by arrow L1.

[0221] 26C is a graph showing the flow of the second operation example. In this operation example, light emitting spots 91a are generated in all 16 unit areas within one slot, and light emitting spots 91a are generated 300 times in each unit area. Therefore, the left light emitting spot 91a is generated 300 times in the same unit area within one slot, and the right light emitting spot 91a is also generated 300 times in the same unit area within one slot. The length of one slot in this operation example is 2400 μs. In this operation example, one slot is processed in the scanning process indicated by arrow L1.

[0222] From the standpoint of laser safety standards, it is undesirable for the light emission spot 91a to occur multiple times in a short period of time in the same unit area within the pupil opening 92. This is because a large amount of light would be incident on the human eye in a short period of time. Therefore, from the standpoint of laser safety standards, the second operation example is preferable to the first operation example. This is because the period in which the light emission spot 91a occurs in the same unit area is 1 μs in the first operation example, while it is 300 μs in the second operation example. On the other hand, according to the first operation example, the distance traveled by the light emission spot 91a during the scanning process indicated by arrow L1 can be shortened, thereby simplifying the scanning process.

[0223] Furthermore, from the viewpoint of laser safety standards, it is undesirable for multiple light emission spots 91a to occur in a short period of time in multiple unit regions within the pupil opening 92. Therefore, in this embodiment, when two or more light emitting elements 23 on the same vertical wiring are caused to emit light in sequence, these light emitting elements 23 are caused to emit light in sequence so that two light emitting elements 23 adjacent to each other in the Y direction (vertical direction) do not emit light consecutively. This makes it possible to prevent the left light emission spot 91a shown in A of Fig. 26 and the right light emission spot 91a shown in A of Fig. 26 from occurring in a short period of time.

[0224] Furthermore, from the viewpoint of laser safety standards, it is undesirable for multiple light emission spots 91a to be generated simultaneously in multiple unit areas within the pupil opening 92. Therefore, in the first and second operation examples, two simultaneously generated light emission spots 91a are spaced apart by a distance of Y=8 in the Y direction (see A in FIG. 22 to D in FIG. 25). This makes it possible to prevent the left light emission spot 91a shown in A in FIG. 26 and the right light emission spot 91a shown in A in FIG. 26 from being generated simultaneously.

[0225] (3) Third Operation Example FIG. 27 is a plan view showing a third operation example of the distance measuring device 1 of the fourth embodiment.

[0226] Each of A to C in Fig. 27 shows the scanning process indicated by the arrow L1, i.e., the process of sequentially emitting light from 16 light-emitting elements 23 on the same vertical wiring. Specifically, A in Fig. 27 shows the process of scanning 16 unit areas whose X coordinate is "3". B in Fig. 27 shows the process of scanning 16 unit areas whose X coordinate is "4". C in Fig. 27 shows the process of scanning 16 unit areas whose X coordinate is "5". In each of A to C in Fig. 27, the scanning process indicated by the arrow L1 may be performed as in the first operation example or as in the second operation example.

[0227] The distance measuring device 1 of this embodiment causes each light-emitting element 23 to emit light in a manner that causes 16 light-emitting elements 23 on one vertical wiring to emit light in sequence, and then causes 16 light-emitting elements 23 on another vertical wiring to emit light in sequence. This processing is performed by sequentially performing the processing indicated by arrow L1, arrow L2, and arrow L1 (see FIG. 21 ). In the scanning processing indicated by arrow L1, the Y coordinate of each light-emitting spot 91 a changes. On the other hand, in the scanning processing indicated by arrow L2, the X coordinate of each light-emitting spot 91 a changes.

[0228] In this operation example, when the distance measuring device 1 sequentially causes 16 light-emitting elements 23 on one vertical wiring to emit light, and then sequentially causes 16 light-emitting elements 23 on another vertical wiring to emit light, the former vertical wiring and the latter vertical wiring are considered to be two vertical wirings adjacent to each other in the X direction (horizontal direction). Here, "the light-emitting elements 23 on vertical wiring "a" emit light, and then the light-emitting elements 23 on vertical wiring "b" emit light" means that the light-emitting elements 23 on vertical wirings "a" and "b" emit light such that the light-emitting elements 23 on the other vertical wirings do not emit light between the light-emitting elements 23 on vertical wiring "a" and the light-emitting elements 23 on vertical wiring "b". For example, the vertical wiring electrically connected to the light-emitting element 23 whose X coordinate is "3" and the vertical wiring electrically connected to the light-emitting element 23 whose X coordinate is "4" are adjacent to each other in the X direction. Therefore, when the 16 light-emitting elements 23 on the former vertical wiring (light-emitting elements 23 with an X coordinate of "3") emit light in sequence, the 16 light-emitting elements 23 on the latter vertical wiring (light-emitting elements 23 with an X coordinate of "4") then emit light in sequence.

[0229] In this operation example, the 16 light-emitting elements 23 whose X coordinate is "3" emit light in sequence (A in FIG. 27), then the 16 light-emitting elements 23 whose X coordinate is "4" emit light in sequence (B in FIG. 27), and then the 16 light-emitting elements 23 whose X coordinate is "5" emit light in sequence (C in FIG. 27). Therefore, when the light-emitting target changes from one vertical wiring to another, these vertical wirings are adjacent to each other in the X direction. Specifically, the X coordinate of the latter vertical wiring is greater than the X coordinate of the former vertical wiring by 1. In this operation example, processing similar to the processing in A to C in FIG. 27 is performed for all vertical wirings.

[0230] (4) Fourth Operation Example FIG. 28 is a plan view showing a fourth operation example of the distance measuring device 1 of the fourth embodiment.

[0231] Each of A to C in Fig. 28 shows the scanning process indicated by the arrow L1, i.e., the process of sequentially emitting light from 16 light-emitting elements 23 on the same vertical wiring. Specifically, A in Fig. 28 shows the process of scanning 16 unit areas whose X coordinate is "3". B in Fig. 28 shows the process of scanning 16 unit areas whose X coordinate is "6". C in Fig. 28 shows the process of scanning 16 unit areas whose X coordinate is "9". In each of A to C in Fig. 28, the scanning process indicated by the arrow L1 may be performed as in the first operation example or as in the second operation example.

[0232] In this operation example, when the distance measuring device 1 sequentially lights up 16 light-emitting elements 23 on one vertical wiring and then sequentially lights up 16 light-emitting elements 23 on another vertical wiring, the former vertical wiring and the latter vertical wiring are considered to be two vertical wirings that are not adjacent to each other in the X direction (horizontal direction). For example, the vertical wiring electrically connected to the light-emitting element 23 whose X coordinate is "3" and the vertical wiring electrically connected to the light-emitting element 23 whose X coordinate is "6" are not adjacent to each other in the X direction. In this operation example, the 16 light-emitting elements 23 on the former vertical wiring (the light-emitting elements 23 whose X coordinate is "3") sequentially light up, and then the 16 light-emitting elements 23 on the latter vertical wiring (the light-emitting elements 23 whose X coordinate is "6") sequentially light up. This process is shown in A and B of FIG. 28. These vertical wirings are spaced apart by a distance equivalent to three light-emitting elements 23 in the X direction, i.e., a distance of X=3 in the X direction. As a result, each light-emitting spot 91a moves a distance of X=3 in the +X direction. In this operation example, such "movement by a distance of X=3" is repeated. This value "3" may be replaced with a constant X other than 3 (X is an integer of 2 or more).

[0233] In this operation example, the 16 light-emitting elements 23 whose X coordinate is "3" emit light in sequence (A in FIG. 28), then the 16 light-emitting elements 23 whose X coordinate is "6" emit light in sequence (B in FIG. 28), and then the 16 light-emitting elements 23 whose X coordinate is "9" emit light in sequence (C in FIG. 28). Therefore, when the light-emitting target changes from one vertical wiring to another, these vertical wirings are not adjacent to each other in the X direction. Specifically, the X coordinate of the latter vertical wiring is three greater than the X coordinate of the former vertical wiring. In this operation example, processing similar to that in A to C in FIG. 28 is performed for all vertical wirings.

[0234] Here, when calculating the above-mentioned "distance," the distance is calculated by applying a periodic boundary condition in the X direction to the arrangement of light-emitting elements 23 and vertical wiring within the X coordinate range of 1 to 16. Therefore, the light-emitting element 23 with coordinates [16, 1] and the light-emitting element 23 with coordinates [1, 1] are assumed to be adjacent to each other in the X direction. Furthermore, the vertical wiring with an X coordinate of "16" and the vertical wiring with an X coordinate of "1" are assumed to be adjacent to each other in the X direction. As a result, under the periodic boundary condition, the vertical wiring with an X coordinate of "2" and the vertical wiring with an X coordinate of "15" are separated by a distance of X = 3 in the X direction. Therefore, the X coordinate of the vertical wiring to be illuminated changes from 3 to 6 to 9 to 12 to 15 to 2 to 5 to ... This makes it possible to illuminate all 16 × 16 light-emitting elements 23. This is because the movement distance in the X direction of "3" and the periodic length of "16" are relatively prime. Therefore, the movement distance in the X direction in this operation example is set so that the movement distance and the periodic length are relatively prime.

[0235] FIG. 29 is a diagram for explaining the difference between the third and fourth operation examples described above.

[0236] 29A shows the pupil aperture 92 in the third operation example. In this operation example, when a light-emitting element 23 on one vertical wiring emits light and then a light-emitting element 23 on another vertical wiring emits light, these vertical wirings are two vertical wirings adjacent to each other in the X direction. Therefore, there is a risk that multiple light-emitting spots 91a may occur in multiple unit areas within the pupil aperture 92 in a short period of time (FIG. 29A). This is undesirable from the perspective of laser safety standards.

[0237] B in Fig. 29 shows the pupil aperture 92 in the fourth operation example. In this operation example, when a light-emitting element 23 on one vertical wiring emits light and then a light-emitting element 23 on another vertical wiring emits light, these vertical wirings are two vertical wirings that are not adjacent to each other in the X direction. This makes it possible to prevent multiple light-emitting spots 91a from occurring in a short period of time in multiple unit areas within the pupil aperture 92 (B in Fig. 29). This is desirable from the perspective of laser safety standards.

[0238] (5) Fifth and Sixth Operation Examples FIG. 30 is a plan view showing fifth and sixth operation examples of the distance measuring device 1 of the fourth embodiment.

[0239] A in Fig. 30 shows the screen 91 in the fifth operation example. In this operation example, the size of the pupil opening 92 is set small. Therefore, the distance between two light-emitting elements 23 that emit light consecutively is short, specifically, the distance is Y = 2. When the size of the pupil opening 92 is small, it is possible to avoid undesirable light emission from the perspective of laser safety standards, even if the distance between these light-emitting elements 23 is short.

[0240] 30B shows the screen 91 in the sixth operation example. In this operation example, the size of the pupil opening 92 is set to be large. Therefore, the distance between two light-emitting elements 23 that emit light consecutively is long, specifically, the distance is Y=3. When the size of the pupil opening 92 is large, by increasing the distance between these light-emitting elements 23, it is possible to avoid undesirable light emission from the perspective of laser safety standards.

[0241] As described above, in the distance measuring device 1 of this embodiment, when two or more light-emitting elements 23 on the same vertical wiring are caused to emit light in sequence, these two or more light-emitting elements are caused to emit light in sequence so that two light-emitting elements 23 adjacent to each other in the Y direction (vertical direction) do not emit light consecutively. Therefore, according to this embodiment, when performing the scanning process indicated by the arrow L1, it is possible to cause the light-emitting elements 23 to emit light in a manner that is desirable from the perspective of laser safety standards.

[0242] Furthermore, in the distance measuring device 1 of this embodiment, when two or more light-emitting elements 23 on one vertical wire are caused to emit light in sequence, and then two or more light-emitting elements 23 on another vertical wire are caused to emit light in sequence, these vertical wires may be two vertical wires that are not adjacent to each other in the X direction (horizontal direction). This makes it possible to cause the light-emitting elements 23 to emit light in a manner that is desirable from the perspective of laser safety standards when performing the scanning process indicated by arrow L2.

[0243] As described above, according to this embodiment, it is possible to make the plurality of light emitting elements 23 emit light in a suitable manner.

[0244] The light emitting device 1a of this embodiment has a simple structure, including, for example, the components of "first to third horizontal wirings 31a to 33a," "first to third vertical wirings 31b to 33b," and "three light emitting elements 23 electrically connected to each cathode wiring 41" (see FIG. 4). According to this embodiment, by employing control such as the first to sixth operation examples, it is possible to cause the light emitting device 1a with a simple structure to emit light from the multiple light emitting elements 23 in a suitable manner. In other words, according to this embodiment, it is possible to achieve both a simple structure of the light emitting device 1a and a suitable light emission process.

[0245] Fifth Embodiment FIG. 31 is a plan view showing a first operation example of the distance measuring device 1 of the fifth embodiment.

[0246] 31A shows an operation mode in which all of the light-emitting elements 23 of the light-emitting device 1a are caused to emit light when measuring the distance to the subject S (FIG. 1). In this case, as shown in FIG. 31A, all of the unit areas of the screen 91 are scanned.

[0247] Fig. 31B shows an operation mode in which only some of the light-emitting elements 23 of the light-emitting device 1a are caused to emit light when measuring the distance to the subject S. In this case, as shown in Fig. 31B, only some of the unit areas of the screen 91 are scanned. In Fig. 31B, the area 93 to be scanned is indicated by a dotted line.

[0248] In this operation example, the distance measuring device 1 selects which of the operation modes A and B in Fig. 31 to adopt when measuring the distance to the subject S. By selecting the operation mode B in Fig. 31 , it is possible to improve the distance measurement accuracy or the frame rate, for example. The selection of the operation mode may be performed according to a selection operation input by the user to the distance measuring device 1, for example.

[0249] FIG. 32 is a plan view showing a second operation example of the distance measuring device 1 of the fifth embodiment.

[0250] A and B in Fig. 32 show operation modes corresponding to A and B in Fig. 31, respectively. In Fig. 32A, thinning processing is employed for the scanning process indicated by arrow L1. Specifically, of the 16 vertical wirings electrically connected to the light-emitting element 23, only 8 vertical wirings are targeted for light emission. As a result, even in the operation mode of Fig. 32A, only a portion of the unit area of ​​the screen 91 is scanned. This makes it possible to coarsely scan the screen 91 in the operation mode of Fig. 32A.

[0251] The processing of the operation mode A in Fig. 32 can be realized, for example, by performing the processing shown in A to C in Fig. 28 (fourth operation example of the fourth embodiment) without adopting the periodic boundary condition. Specifically, when the X coordinate of the vertical wiring to be illuminated is changed from 3 to 6 to 9 to 12 to 15 to 2 to 5 to ..., the light emission processing is completed without adopting the change from 15 to 2. This makes it possible to designate only five vertical wirings of the 16 vertical wirings electrically connected to the light emitting element 23 as the illumination target.

[0252] As described above, according to this embodiment, similarly to the fourth embodiment, it is possible to make the plurality of light-emitting elements 23 emit light in a suitable manner.

[0253] Sixth Embodiment FIG. 33 is a diagram for explaining the operation of a distance measuring device 1 as a comparative example of the sixth embodiment.

[0254] Fig. 33A shows a process in which four light-emitting elements 23 are simultaneously made to emit light to simultaneously generate four light-emitting spots 91a. Fig. 33B shows the change in intensity of these light-emitting spots 91a over time. Waveforms P1, P2, P3, and P4 shown in Fig. 33B represent the intensities of the light-emitting spots 91a generated at the coordinates (1,1), (1,5), (1,9), and (1,13), respectively.

[0255] Normally, the waveforms P1 to P4 are considered to have the same shape. However, when the four light-emitting elements 23 emit light simultaneously, the waveforms P1 to P4 have different shapes due to the influence of rush current. This causes measurement errors between unit areas.

[0256] FIG. 34 is a diagram for explaining the operation of the distance measuring device 1 of the sixth embodiment.

[0257] 34A shows a process in which four light-emitting elements 23 are sequentially illuminated to generate four light-emitting spots 91a. In FIG. 34A, the light-emitting element 23 at coordinates [1,1] emits light at a certain point in time, the light-emitting element 23 at coordinates [1,5] emits light 1 μs later, the light-emitting element 23 at coordinates [1,9] emits light 2 μs later, and the light-emitting element 23 at coordinates [1,13] emits light 3 μs later. That is, these light-emitting elements 23 emit light in sequence at a light-emitting interval of 1 μs. The light-emitting interval may be set to less than 1 μs (e.g., 0.5 μs).

[0258] FIG. 34B shows the change in intensity of these light-emitting spots 91a over time. Waveforms P1, P2, P3, and P4 shown in FIG. 34B also show the intensity of the light-emitting spots 91a generated at coordinates (1,1), (1,5), (1,9), and (1,13), respectively. In FIG. 34B, the four light-emitting elements 23 emit light in sequence, thereby reducing the rush current. Therefore, the waveforms P1 to P4 shown in FIG. 34B have roughly the same shape.

[0259] In the distance measuring device 1 of this embodiment, when the light emitting device 1a generates light, the light emitting elements 23 are caused to emit light one by one so that two or more light emitting elements 23 of the light emitting device 1a do not emit light at the same time, thereby making it possible to suppress the above-mentioned waveform problem.

[0260] The light-emitting process of this embodiment can be applied to the fourth and fifth embodiments. For example, in A and B of Figure 22, the light-emitting elements 23 at coordinates [3,1] and [3,9] simultaneously emit light, followed by the light-emitting elements 23 at coordinates [3,4] and [3,12] simultaneously emit light. When the light-emitting process of this embodiment is applied to A and B of Figure 22, these light-emitting elements 23 emit light in the following order: the light-emitting element 23 at coordinates [3,1], the light-emitting element 23 at coordinates [3,9], the light-emitting element 23 at coordinates [3,4], and the light-emitting element 23 at coordinates [3,12]. This makes it possible to suppress the waveform problem described above while enjoying the benefits described in the fourth and fifth embodiments.

[0261] As described above, according to this embodiment, similarly to the fourth and fifth embodiments, it is possible to make the plurality of light-emitting elements 23 emit light in a suitable manner.

[0262] Seventh Embodiment Fig. 35 is a block diagram showing the configuration of a vehicle 101 according to a seventh embodiment. Fig. 35 shows an example of the configuration of a vehicle control system 111, which is an example of a mobility device control system.

[0263] The vehicle control system 111 is provided in the vehicle 101 and performs processing related to driving assistance and automatic driving of the vehicle 101.

[0264] The vehicle control system 111 includes a vehicle control ECU (Electronic Control Unit) 121, a communication unit 122, a map information storage unit 123, a location information acquisition unit 124, an external recognition sensor 125, an in-vehicle sensor 126, a vehicle sensor 127, a memory unit 131, a driving assistance / autonomous driving control unit 132, a DMS (Driver Monitoring System) 133, an HMI (Human Machine Interface) 134, and a vehicle control unit 135.

[0265] The vehicle control ECU 121, communication unit 122, map information storage unit 123, position information acquisition unit 124, external recognition sensor 125, in-vehicle sensor 126, vehicle sensor 127, memory unit 131, cruise assist / autonomous driving control unit 132, driver monitoring system (DMS) 133, human-machine interface (HMI) 134, and vehicle control unit 135 are connected to each other via a communication network 141 so as to be able to communicate with each other. The communication network 141 is configured, for example, by an in-vehicle communication network or bus conforming to a digital two-way communication standard such as a controller area network (CAN), a local interconnect network (LIN), a local area network (LAN), FlexRay (registered trademark), or Ethernet (registered trademark). The communication network 141 may be used differently depending on the type of data being transmitted. For example, a CAN may be used for data related to vehicle control, and an Ethernet may be used for large-volume data. In addition, each part of the vehicle control system 111 may be directly connected without going through the communication network 141, using wireless communication intended for communication over relatively short distances, such as near field communication (NFC) or Bluetooth (registered trademark).

[0266] In the following description, when each unit of the vehicle control system 111 communicates via the communication network 141, the description of the communication network 141 will be omitted. For example, when the vehicle control ECU 121 and the communication unit 122 communicate via the communication network 141, it will simply be described as the vehicle control ECU 121 and the communication unit 122 communicating with each other.

[0267] [Vehicle Control ECU 121] The vehicle control ECU 121 is configured by various processors such as a CPU (Central Processing Unit), an MPU (Micro Processing Unit), etc. The vehicle control ECU 121 controls the entire or part of the functions of the vehicle control system 111.

[0268] [Communication Unit 122] The communication unit 122 communicates with various devices inside and outside the vehicle, other vehicles, servers, base stations, etc., and transmits and receives various types of data. At this time, the communication unit 122 can communicate using multiple communication methods.

[0269] The following provides an overview of communication with the outside of the vehicle that can be performed by the communication unit 122. The communication unit 122 communicates with a server (hereinafter referred to as an external server) or the like present on an external network via a base station or an access point using a wireless communication method such as 5G (fifth generation mobile communication system), LTE (Long Term Evolution), or DSRC (Dedicated Short Range Communications). The external network with which the communication unit 122 communicates is, for example, the Internet, a cloud network, or a network specific to a carrier. The communication method used by the communication unit 122 with the external network is not particularly limited as long as it is a wireless communication method that enables digital two-way communication at a communication speed equal to or higher than a predetermined distance.

[0270] Furthermore, for example, the communication unit 122 can communicate with a terminal located near the vehicle using P2P (Peer to Peer) technology. The terminal located near the vehicle can be, for example, a terminal worn by a mobile object moving at a relatively slow speed, such as a pedestrian or a bicycle, a terminal installed at a fixed location in a store, or an MTC (Machine Type Communication) terminal. Furthermore, the communication unit 122 can also perform V2X communication. V2X communication refers to communication between the vehicle and others, such as vehicle-to-vehicle (V2X) communication with another vehicle, vehicle-to-infrastructure (V2X) communication with a roadside unit, vehicle-to-home (V2X) communication with a home, and vehicle-to-pedestrian (V2X) communication with a terminal carried by a pedestrian.

[0271] The communication unit 122 can receive, for example, a program for updating software that controls the operation of the vehicle control system 111 from the outside (over the air). The communication unit 122 can also receive map information, traffic information, information about the surroundings of the vehicle 101, and the like from the outside. For example, the communication unit 122 can also transmit information about the vehicle 101 and information about the surroundings of the vehicle 101 to the outside. Information about the vehicle 101 that the communication unit 122 transmits to the outside includes, for example, data indicating the status of the vehicle 101 and the recognition result by the recognition unit 173. Furthermore, for example, the communication unit 122 performs communication corresponding to a vehicle emergency notification system such as e-call.

[0272] For example, the communication unit 122 receives electromagnetic waves transmitted by a road traffic information and communication system (VICS (Vehicle Information and Communication System) (registered trademark)) such as a radio beacon, an optical beacon, or FM multiplex broadcasting.

[0273] The following provides an overview of communication with the vehicle interior that can be performed by the communication unit 122. The communication unit 122 can communicate with each device in the vehicle using, for example, wireless communication. The communication unit 122 can communicate with each device in the vehicle using a communication method that enables bidirectional digital communication at a predetermined communication speed or higher via wireless communication, such as wireless LAN, Bluetooth, NFC, or Wireless USB (WUSB). The communication unit 122 can also communicate with each device in the vehicle using wired communication. For example, the communication unit 122 can communicate with each device in the vehicle using wired communication via a cable connected to a connection terminal (not shown). The communication unit 122 can communicate with each device in the vehicle using a communication method that enables bidirectional digital communication at a predetermined communication speed or higher via wired communication, such as Universal Serial Bus (USB), High-Definition Multimedia Interface (HDMI) (registered trademark), or Mobile High-Definition Link (MHL).

[0274] Here, the in-vehicle device refers to, for example, a device in the vehicle that is not connected to the communication network 141. Possible in-vehicle devices include, for example, a mobile device or a wearable device carried by a passenger such as a driver, and an information device brought into the vehicle and temporarily installed therein.

[0275] [Map Information Storage Unit 123] The map information storage unit 123 stores one or both of a map acquired from an external source and a map created by the vehicle 101. For example, the map information storage unit 123 stores a three-dimensional high-precision map, a global map that is less accurate than a high-precision map and covers a wide area, and the like.

[0276] Examples of high-precision maps include dynamic maps, point cloud maps, and vector maps. A dynamic map is a map consisting of four layers of dynamic information, quasi-dynamic information, quasi-static information, and static information, and is provided to the vehicle 101 from an external server or the like. A point cloud map is a map made up of a point cloud (point group data). A vector map is a map that associates traffic information such as the positions of lanes and traffic lights with the point cloud map, and is adapted to an advanced driver assistance system (ADAS) or autonomous driving (AD).

[0277] The point cloud map and the vector map may be provided, for example, from an external server or the like, or may be created by the vehicle 101 based on sensing results from the camera 151, radar 152, LiDAR 153, etc. as a map for matching with a local map described later, and stored in the map information storage unit 123. Furthermore, when a high-precision map is provided from an external server or the like, map data of, for example, an area of ​​several hundred square meters related to the planned route along which the vehicle 101 will travel is acquired from the external server or the like in order to reduce communication capacity.

[0278] [Location Information Acquisition Unit 124] The location information acquisition unit 124 receives GNSS (Global Navigation Satellite System) signals from satellites and acquires location information of the vehicle 101. The acquired location information is supplied to the driving assistance / autonomous driving control unit 132. Note that the location information acquisition unit 124 is not limited to a method using GNSS signals, and may acquire location information using a beacon, for example.

[0279] [External Recognition Sensor 125] The external recognition sensor 125 includes various sensors used to recognize the situation outside the vehicle 101, and supplies sensor data from each sensor to each part of the vehicle control system 111. The type and number of sensors included in the external recognition sensor 125 are arbitrary. The external recognition sensor 125 of this embodiment includes, for example, the distance measuring device 1 of any of the first to sixth embodiments.

[0280] For example, the external recognition sensor 125 includes a camera 151, a radar 152, a LiDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging) 153, and an ultrasonic sensor 154. Without being limited to this, the external recognition sensor 125 may be configured to include one or more types of sensors selected from the camera 151, the radar 152, the LiDAR 153, and the ultrasonic sensor 154. The number of cameras 151, radars 152, LiDARs 153, and ultrasonic sensors 154 is not particularly limited as long as the number is a number that can be realistically installed on the vehicle 101. Furthermore, the types of sensors included in the external recognition sensor 125 are not limited to this example, and the external recognition sensor 125 may include other types of sensors. Examples of sensing areas of the sensors included in the external recognition sensor 125 will be described later.

[0281] The imaging method of the camera 151 is not particularly limited. For example, cameras of various imaging methods, such as a time-of-flight (ToF) camera, a stereo camera, a monocular camera, and an infrared camera, which are imaging methods capable of distance measurement, can be applied to the camera 151 as needed. However, the camera 151 may simply acquire a photographed image without being related to distance measurement.

[0282] Furthermore, for example, the external recognition sensor 125 may include an environmental sensor for detecting the environment of the vehicle 101. The environmental sensor is a sensor for detecting the environment such as weather, climate, brightness, etc., and may include various sensors such as a raindrop sensor, a fog sensor, a sunlight sensor, a snow sensor, and an illuminance sensor.

[0283] Furthermore, for example, the external recognition sensor 125 includes a microphone used to detect sounds around the vehicle 101 and the location of sound sources.

[0284] [In-vehicle sensor 126] The in-vehicle sensor 126 includes various sensors for detecting information inside the vehicle, and supplies sensor data from each sensor to each unit of the vehicle control system 111. The types and number of the various sensors included in the in-vehicle sensor 126 are not particularly limited as long as they are of types and numbers that can be realistically installed in the vehicle 101.

[0285] For example, the interior sensor 126 may include one or more types of sensors selected from the group consisting of a camera, radar, a seating sensor, a steering wheel sensor, a microphone, and a biometric sensor. The camera included in the interior sensor 126 may be a camera using any of various imaging methods capable of measuring distances, such as a Time of Flight (ToF) camera, a stereo camera, a monocular camera, or an infrared camera. The camera included in the interior sensor 126 may also be a camera simply for acquiring captured images, regardless of distance measurement. The biometric sensor included in the interior sensor 126 is provided, for example, on a seat, a steering wheel, or the like, and detects various types of biometric information of a passenger, such as a driver.

[0286] [Vehicle Sensor 127] The vehicle sensor 127 includes various sensors for detecting the state of the vehicle 101, and supplies sensor data from each sensor to each unit of the vehicle control system 111. The types and number of the various sensors included in the vehicle sensor 127 are not particularly limited as long as they are of the types and number that can be realistically installed on the vehicle 101.

[0287] For example, the vehicle sensor 127 includes a speed sensor, an acceleration sensor, an angular velocity sensor (gyro sensor), and an inertial measurement unit (IMU) that integrates these sensors. For example, the vehicle sensor 127 includes a steering angle sensor that detects the steering angle of the steering wheel, a yaw rate sensor, an accelerator sensor that detects the amount of accelerator pedal operation, and a brake sensor that detects the amount of brake pedal operation. For example, the vehicle sensor 127 includes a rotation sensor that detects the number of rotations of the engine or motor, an air pressure sensor that detects tire air pressure, a slip ratio sensor that detects tire slip ratio, and a wheel speed sensor that detects the rotation speed of the wheels. For example, the vehicle sensor 127 includes a battery sensor that detects the remaining battery charge and temperature, and an impact sensor that detects external impacts.

[0288] [Storage Unit 131] The storage unit 131 includes at least one of a non-volatile storage medium and a volatile storage medium, and stores data and programs. The storage unit 131 is used, for example, as an electrically erasable programmable read-only memory (EEPROM) and a random access memory (RAM). Examples of storage media that can be used include a magnetic storage device such as a hard disk drive (HDD), a semiconductor storage device, an optical storage device, and a magneto-optical storage device. The storage unit 131 stores various programs and data used by each component of the vehicle control system 111. For example, the storage unit 131 includes an event data recorder (EDR) and a data storage system for automated driving (DSSAD), and stores information about the vehicle 101 before and after an event such as an accident, and information acquired by the in-vehicle sensor 126.

[0289] [Driving assistance / autonomous driving control unit 132] The driving assistance / autonomous driving control unit 132 controls driving assistance and autonomous driving of the vehicle 101. For example, the driving assistance / autonomous driving control unit 132 includes an analysis unit 161, an action planning unit 162, and an operation control unit 163.

[0290] The analysis unit 161 performs an analysis process of the vehicle 101 and the surrounding situation. The analysis unit 161 includes a self-position estimation unit 171, a sensor fusion unit 172, and a recognition unit 173.

[0291] The self-position estimation unit 171 estimates the self-position of the vehicle 101 based on sensor data from the external recognition sensor 125 and a high-precision map stored in the map information storage unit 123. For example, the self-position estimation unit 171 generates a local map based on the sensor data from the external recognition sensor 125 and matches the local map with the high-precision map to estimate the self-position of the vehicle 101. The position of the vehicle 101 is based on, for example, the center of the rear wheel pair axle.

[0292] The local map is, for example, a three-dimensional high-precision map or an occupancy grid map created using a technology such as SLAM (Simultaneous Localization and Mapping). The three-dimensional high-precision map is, for example, the point cloud map described above. The occupancy grid map is a map in which the three-dimensional or two-dimensional space around the vehicle 101 is divided into grids of a predetermined size and the occupancy status of objects is indicated on a grid-by-grid basis. The occupancy status of an object is indicated, for example, by the presence or absence of an object and its probability of existence. The local map is also used, for example, in the detection process and recognition process of the situation outside the vehicle 101 by the recognition unit 173.

[0293] The self-position estimation unit 171 may estimate the self-position of the vehicle 101 based on the position information acquired by the position information acquisition unit 124 and the sensor data from the vehicle sensor 127 .

[0294] The sensor fusion unit 172 performs sensor fusion processing to obtain new information by combining multiple different types of sensor data (for example, image data supplied from the camera 151 and sensor data supplied from the radar 152). Methods for combining different types of sensor data include integration, fusion, and association.

[0295] The recognition unit 173 executes a detection process for detecting the situation outside the vehicle 101 and a recognition process for recognizing the situation outside the vehicle 101 .

[0296] For example, the recognition unit 173 performs detection processing and recognition processing of the external situation of the vehicle 101 based on information from the external recognition sensor 125, information from the self-position estimation unit 171, information from the sensor fusion unit 172, etc.

[0297] Specifically, for example, the recognition unit 173 performs detection processing and recognition processing of objects around the vehicle 101. The object detection processing is, for example, processing to detect the presence or absence, size, shape, position, movement, etc. of an object. The object recognition processing is, for example, processing to recognize attributes such as the type of object, or to identify a specific object. However, the detection processing and the recognition processing are not necessarily clearly separated, and may overlap.

[0298] For example, the recognition unit 173 detects objects around the vehicle 101 by performing clustering to classify a point cloud based on sensor data from the radar 152, the LiDAR 153, or the like into clusters of points. This allows the presence, size, shape, and position of objects around the vehicle 101 to be detected.

[0299] For example, the recognition unit 173 performs tracking to follow the movement of clusters of point clouds classified by clustering, thereby detecting the movement of objects around the vehicle 101. As a result, the speed and traveling direction (movement vector) of the objects around the vehicle 101 are detected.

[0300] For example, the recognition unit 173 detects or recognizes vehicles, people, bicycles, obstacles, structures, roads, traffic lights, traffic signs, road markings, etc. based on image data supplied from the camera 151. Furthermore, the recognition unit 173 may recognize the type of object around the vehicle 101 by performing recognition processing such as semantic segmentation.

[0301] For example, the recognition unit 173 can perform recognition processing of traffic rules around the vehicle 101 based on the map stored in the map information storage unit 123, the estimation result of the self-position by the self-position estimation unit 171, and the recognition result of the recognition unit 173 of objects around the vehicle 101. Through this processing, the recognition unit 173 can recognize the positions and states of traffic lights, the contents of traffic signs and road markings, the contents of traffic regulations, and lanes that can be driven on.

[0302] For example, the recognition unit 173 can perform a recognition process of the environment around the vehicle 101. The surrounding environment to be recognized by the recognition unit 173 may include weather, temperature, humidity, brightness, and road surface conditions.

[0303] The behavior planning unit 162 creates a behavior plan for the vehicle 101. For example, the behavior planning unit 162 creates the behavior plan by performing route planning and route tracking processing.

[0304] Global path planning is a process for planning a rough route from the start to the goal. This route planning also includes a process for generating a trajectory (local path planning) that allows the vehicle 101 to travel safely and smoothly in the vicinity of the vehicle 101, taking into account the motion characteristics of the vehicle 101 on the planned route.

[0305] Path following is a process of planning an operation for safely and accurately traveling along a route planned by a route plan within a planned time. The behavior planning unit 162 can calculate a target speed and a target angular velocity of the vehicle 101 based on the results of the path following process, for example.

[0306] The operation control unit 163 controls the operation of the vehicle 101 in order to realize the action plan created by the action planning unit 162 .

[0307] For example, the operation control unit 163 controls the steering control unit 181, the brake control unit 182, and the drive control unit 183 included in the vehicle control unit 135 described later, to perform acceleration / deceleration control and direction control so that the vehicle 101 travels along the trajectory calculated by the trajectory plan. For example, the operation control unit 163 performs cooperative control with the aim of realizing ADAS functions such as collision avoidance or impact mitigation, following driving, vehicle speed maintenance driving, collision warning for the host vehicle, and lane departure warning for the host vehicle. For example, the operation control unit 163 performs cooperative control with the aim of automatic driving, which drives autonomously without driver operation.

[0308] [DMS 133] The DMS 133 performs processes such as authenticating the driver and recognizing the driver's state based on sensor data from the in-vehicle sensor 126 and input data input to the HMI 134 (described later). Examples of the driver's state to be recognized include physical condition, alertness, concentration, fatigue, gaze direction, level of intoxication, driving operation, and posture.

[0309] The DMS 133 may be configured to perform authentication processing for passengers other than the driver and recognition processing for the conditions of the passengers. Furthermore, for example, the DMS 133 may be configured to perform recognition processing for the conditions inside the vehicle based on sensor data from the in-vehicle sensor 126. Possible conditions inside the vehicle to be recognized include, for example, temperature, humidity, brightness, and odor.

[0310] [HMI 134] The HMI 134 receives input of various data and instructions, and presents various data to the driver and the like.

[0311] The following provides an overview of data input via the HMI 134. The HMI 134 includes an input device for a person to input data. The HMI 134 generates input signals based on data, instructions, and the like input via the input device and supplies the signals to each component of the vehicle control system 111. The HMI 134 includes, as input devices, controls such as a touch panel, buttons, switches, and levers. The HMI 134 may also include input devices that allow information to be input by voice, gestures, or other means other than manual operation. Furthermore, the HMI 134 may use, as input devices, externally connected devices such as a remote control device using infrared or radio waves, or a mobile or wearable device compatible with the operation of the vehicle control system 111.

[0312] The presentation of data by the HMI 134 will be briefly described. The HMI 134 generates visual information, auditory information, and tactile information for the occupant or the outside of the vehicle. The HMI 134 also performs output control, controlling the output, output content, output timing, output method, etc. of each piece of generated information. The HMI 134 generates and outputs, as visual information, information indicated by images or lights, such as an operation screen, a status display of the vehicle 101, a warning display, and a monitor image showing the situation around the vehicle 101. The HMI 134 also generates and outputs, as auditory information, information indicated by sounds, such as voice guidance, warning sounds, and warning messages. The HMI 134 also generates and outputs, as tactile information, information imparted to the occupant's sense of touch by force, vibration, movement, etc.

[0313] Examples of output devices that the HMI 134 uses to output visual information include a display device that displays an image on its own to present visual information and a projector device that projects an image to present visual information. The display device may be a device that displays visual information within the passenger's field of view, such as a head-up display, a transmissive display, or a wearable device with an augmented reality (AR) function, in addition to a display device having a normal display. The HMI 134 may also use display devices included in a navigation system, an instrument panel, a camera monitoring system (CMS), an electronic mirror, a lamp, or the like provided in the vehicle 101 as output devices that output visual information.

[0314] As an output device for the HMI 134 to output auditory information, for example, an audio speaker, a headphone, or an earphone can be applied.

[0315] For example, a haptic element using haptic technology can be applied as an output device for outputting tactile information from the HMI 134. The haptic element is provided on a part of the vehicle 101 that is in contact with a passenger, such as a steering wheel or a seat.

[0316] [Vehicle Control Unit 135] The vehicle control unit 135 controls each unit of the vehicle 101. The vehicle control unit 135 includes a steering control unit 181, a brake control unit 182, a drive control unit 183, a body system control unit 184, a light control unit 185, and a horn control unit 186.

[0317] The steering control unit 181 detects and controls the state of the steering system of the vehicle 101. The steering system includes, for example, a steering mechanism including a steering wheel, an electric power steering, etc. The steering control unit 181 includes, for example, a steering ECU that controls the steering system, an actuator that drives the steering system, etc.

[0318] The brake control unit 182 detects and controls the state of the brake system of the vehicle 101. The brake system includes, for example, a brake mechanism including a brake pedal, an antilock brake system (ABS), a regenerative brake mechanism, etc. The brake control unit 182 includes, for example, a brake ECU that controls the brake system, an actuator that drives the brake system, etc.

[0319] The drive control unit 183 detects and controls the state of the drive system of the vehicle 101. The drive system includes, for example, an accelerator pedal, a drive force generating device for generating drive force such as an internal combustion engine or a drive motor, and a drive force transmission mechanism for transmitting the drive force to the wheels. The drive control unit 183 includes, for example, a drive ECU for controlling the drive system, and an actuator for driving the drive system.

[0320] The body system control unit 184 detects and controls the states of the body system systems of the vehicle 101. The body system systems include, for example, a keyless entry system, a smart key system, a power window device, a power seat, an air conditioning system, an airbag, a seat belt, a shift lever, etc. The body system control unit 184 includes, for example, a body system ECU that controls the body system systems, an actuator that drives the body system systems, etc.

[0321] The light control unit 185 detects and controls the states of various lights of the vehicle 101. Examples of lights to be controlled include headlights, backlights, fog lights, turn signals, brake lights, projections, and bumper displays. The light control unit 185 includes a light ECU that controls the lights, an actuator that drives the lights, and the like.

[0322] The horn control unit 186 detects and controls the state of the car horn of the vehicle 101. The horn control unit 186 includes, for example, a horn ECU that controls the car horn, an actuator that drives the car horn, and the like.

[0323] Fig. 36 is a plan view showing a sensing area of ​​the vehicle 101 of the seventh embodiment. Fig. 36 shows an example of a sensing area by the camera 151, radar 152, LiDAR 153, ultrasonic sensor 154, etc. of the external recognition sensor 125 of Fig. 35. Note that Fig. 36 schematically shows the vehicle 101 as viewed from above, with the left end side being the front end (front) side of the vehicle 101 and the right end side being the rear end (rear) side of the vehicle 101.

[0324] [Sensing Areas 101-1F, 101-1B] Sensing area 101-1F and sensing area 101-1B are examples of sensing areas of the ultrasonic sensors 154. The sensing area 101-1F covers the periphery of the front end of the vehicle 101 with multiple ultrasonic sensors 154. The sensing area 101-1B covers the periphery of the rear end of the vehicle 101 with multiple ultrasonic sensors 154.

[0325] The sensing results in the sensing area 101-1F and the sensing area 101-1B are used, for example, for parking assistance for the vehicle 101.

[0326] [Sensing areas 101-2F, B, L, R] Sensing areas 101-2F to 101-2B show examples of sensing areas of a short-range or medium-range radar 152. The sensing area 101-2F covers a position farther in front of the vehicle 101 than the sensing area 101-1F. The sensing area 101-2B covers a position farther behind the vehicle 101 than the sensing area 101-1B. The sensing area 101-2L covers the periphery behind the left side of the vehicle 101. The sensing area 101-2R covers the periphery behind the right side of the vehicle 101.

[0327] The sensing results in the sensing area 101-2F are used, for example, to detect vehicles, pedestrians, and the like that are present in front of the vehicle 101. The sensing results in the sensing area 101-2B are used, for example, for a collision prevention function behind the vehicle 101. The sensing results in the sensing area 101-2L and the sensing area 101-2R are used, for example, to detect objects in blind spots on the sides of the vehicle 101.

[0328] [Sensing areas 101-3F, B, L, R] Sensing areas 101-3F to 101-3B show examples of sensing areas sensed by the camera 151. Sensing area 101-3F covers a position farther in front of the vehicle 101 than sensing area 101-2F. Sensing area 101-3B covers a position farther in the rear of the vehicle 101 than sensing area 101-2B. Sensing area 101-3L covers the periphery of the left side of the vehicle 101. Sensing area 101-3R covers the periphery of the right side of the vehicle 101.

[0329] The sensing results in the sensing area 101-3F can be used, for example, for recognizing traffic lights and traffic signs, lane departure prevention assistance systems, and automatic headlight control systems. The sensing results in the sensing area 101-3B can be used, for example, for parking assistance and surround view systems. The sensing results in the sensing areas 101-3L and 101-3R can be used, for example, for surround view systems.

[0330] [Sensing area 101-4] Sensing area 101-4 shows an example of the sensing area of ​​LiDAR 153. Sensing area 101-4 covers a position farther ahead of vehicle 101 than sensing area 101-3F. On the other hand, sensing area 101-4 has a narrower range in the left-right direction than sensing area 101-3F.

[0331] The sensing results in the sensing area 101-4 are used to detect objects such as surrounding vehicles, for example.

[0332] [Sensing area 101-5] The sensing area 101-5 is an example of the sensing area of ​​the long-range radar 152. The sensing area 101-5 covers a position farther ahead of the vehicle 101 than the sensing area 101-4. On the other hand, the sensing area 101-5 has a narrower range in the left-right direction than the sensing area 101-4.

[0333] The sensing results in the sensing area 101-5 are used for, for example, adaptive cruise control (ACC), emergency braking, collision avoidance, and the like.

[0334] The sensing areas of the cameras 151, radar 152, LiDAR 153, and ultrasonic sensors 154 included in the external recognition sensor 125 may have various configurations other than those shown in FIG. 36 . Specifically, the ultrasonic sensors 154 may also sense the sides of the vehicle 101, and the LiDAR 153 may sense the rear of the vehicle 101. The installation positions of the sensors are not limited to the above-described examples. The number of each sensor may be one or more.

[0335] Although the light emitting device 1a in the first to seventh embodiments is used as a light source for the distance measuring device 1, it may also be used in other ways. For example, the light emitting device 1a in these embodiments may be used as a light source for an optical device such as a printer, or may be used as an illumination device.

[0336] Although the embodiments of the present disclosure have been described above, these embodiments may be implemented with various modifications within the scope of the gist of the present disclosure. For example, two or more embodiments may be implemented in combination.

[0337] The present disclosure may also be configured as follows.

[0338] (1) A light emitting device including: a plurality of light emitting elements arranged in a two-dimensional array, each having a first and a second terminal; first to Nth horizontal wires (N is an integer of 2 or more) extending in the horizontal direction; and first to Nth vertical wires extending in the vertical direction and electrically connected to the first to Nth horizontal wires, respectively, a plurality of first terminal wires electrically connected to the first terminals of the light emitting elements; a plurality of second terminal wires electrically connected to the second terminals of the light emitting elements, each electrically connected to N of the light emitting elements; and a control mechanism that causes any of the light emitting elements to emit light to generate a light emitting spot, wherein the control mechanism: sequentially causes two or more light emitting elements electrically connected to the same vertical wire to emit light, thereby changing the position of the light emitting spot in a first direction corresponding to the vertical direction; and sequentially causes a light emitting element electrically connected to one vertical wire and a light emitting element electrically connected to another vertical wire to emit light, thereby changing the position of the light emitting spot in a second direction corresponding to the horizontal direction; and when the two or more light emitting elements electrically connected to the same vertical wire are caused to emit light in sequence, the two or more light emitting elements are caused to emit light in sequence so that two light emitting elements adjacent to each other in the vertical direction do not emit light consecutively. Light-emitting device.

[0339] (2) The light-emitting device according to (1), wherein the control mechanism, when sequentially emitting light from the two or more light-emitting elements electrically connected to the same vertical wiring, sequentially emits light from the two or more light-emitting elements such that two light-emitting elements spaced apart by a distance of Y light-emitting elements (Y is an integer of 2 or more) in the vertical direction emit light consecutively (wherein the distance is calculated by applying a periodic boundary condition in the vertical direction to the arrangement of the two light-emitting elements).

[0340] (3) The light-emitting device according to (1), wherein the control mechanism, when sequentially causing the two or more light-emitting elements electrically connected to the same vertical wiring to emit light, causes one light-emitting element to emit light multiple times, and then causes another light-emitting element to emit light multiple times.

[0341] (4) The light-emitting device according to (1), wherein the control mechanism, when sequentially emitting light from the two or more light-emitting elements electrically connected to the same vertical wiring, repeats a process of sequentially emitting light from all the light-emitting elements electrically connected to the same vertical wiring multiple times.

[0342] (5) The light-emitting device according to (1), wherein when the control mechanism sequentially causes two or more light-emitting elements electrically connected to a certain vertical wiring to emit light, and then sequentially causes two or more light-emitting elements electrically connected to another vertical wiring to emit light, the former vertical wiring and the latter vertical wiring are two vertical wirings that are not adjacent to each other in the horizontal direction.

[0343] (6) The light-emitting device according to (5), wherein, when the control mechanism sequentially causes the two or more light-emitting elements electrically connected to a certain vertical wiring to emit light and then sequentially causes the two or more light-emitting elements electrically connected to another vertical wiring to emit light, the former vertical wiring and the latter vertical wiring are two vertical wirings separated by a distance of X light-emitting elements (X is an integer of 2 or more) in the horizontal direction (wherein the distance is calculated by applying a periodic boundary condition in the horizontal direction to the arrangement of the former vertical wiring and the latter vertical wiring).

[0344] (7) The light-emitting device according to (1), wherein when the control mechanism sequentially emits light from the two or more light-emitting elements electrically connected to the same vertical wiring, the control mechanism sequentially emits light from the two or more light-emitting elements so that J light-emitting elements (J is an integer of 2 or more) electrically connected to the same vertical wiring emit light simultaneously, thereby simultaneously generating J light-emitting spots.

[0345] (8) The light-emitting device according to (1), wherein the control mechanism causes the plurality of light-emitting elements to emit light one by one so that two or more of the plurality of light-emitting elements do not emit light at the same time.

[0346] (9) The light-emitting device according to (1), wherein the plurality of first terminal wirings include H horizontal wirings (H is an integer greater than N) each corresponding to one of the first to Nth horizontal wirings, and V vertical wirings (V is an integer greater than N) each corresponding to one of the first to Nth vertical wirings.

[0347] (10) The light emitting device according to (1), wherein at least one second terminal wiring among the plurality of second terminal wirings is electrically connected to N' (N' is an integer greater than N) of the light emitting elements.

[0348] (11) The light emitting device according to (1), further comprising: a plurality of selection circuits electrically connected to one of the first and second terminal wirings and configured to select the light emitting elements that generate light; and a plurality of drive circuits electrically connected to the other of the first and second terminal wirings and configured to drive the light emitting elements.

[0349] (12) The light-emitting device according to (1), wherein one of the first and second terminals of the light-emitting element is an anode, the other of the first and second terminals of the light-emitting element is a cathode, one of the first and second terminal wirings is an anode wiring, and the other of the first and second terminal wirings is a cathode wiring.

[0350] (13) The light emitting device according to (1), wherein the plurality of first terminal wirings include M sets (M is an integer of 2 or more) of the first to Nth horizontal wirings and the first to Nth vertical wirings.

[0351] (14) The light-emitting device according to (11), wherein the plurality of selection circuits include first to Nth selection circuits electrically connected to the first to Nth horizontal wirings or the first to Nth vertical wirings, respectively, and the plurality of drive circuits are each electrically connected to one of the second terminal wirings. (15) The light-emitting device according to (11), wherein the plurality of selection circuits are each electrically connected to one of the second terminal wirings, and the plurality of drive circuits include first to Nth drive circuits electrically connected to the first to Nth horizontal wirings or the first to Nth vertical wirings, respectively. (16) The light-emitting device according to (11), further comprising a plurality of capacitors electrically connected to one of the first and second terminal wirings and storing electric charge to be supplied to the light-emitting element.

[0352] (17) The light emitting device according to (16), wherein the plurality of capacitors include first to N-th capacitors electrically connected to the first to N-th horizontal wirings or the first to N-th vertical wirings, respectively. (18) The light emitting device according to (16), wherein the plurality of capacitors are each electrically connected to one of the second terminal wirings. (19) A light emitting device comprising: a light emitting unit that generates light and irradiates it onto a subject; a light receiving unit that receives light reflected from the subject; and a distance measuring unit that measures the distance to the subject based on the light received by the light receiving unit, wherein the light emitting unit comprises: a plurality of light emitting elements arranged in a two-dimensional array, each having a first and a second terminal; first to Nth horizontal wirings (N is an integer of 2 or more) extending in the horizontal direction; and first to Nth vertical wirings that extend in the vertical direction and are electrically connected to the first to Nth horizontal wirings, respectively, a plurality of first terminal wirings electrically connected to the first terminals of the light emitting elements; and a plurality of second terminal wirings electrically connected to the second terminals of the light emitting elements, each second terminal wiring being electrically connected to N of the light emitting elements; and a control mechanism that causes any of the light emitting elements to emit light to generate a light emitting spot, wherein the control mechanism changes the position of the light emitting spot in a first direction corresponding to the vertical direction by sequentially causing two or more light emitting elements electrically connected to the same vertical wiring to emit light. A distance measuring device that changes the position of the light-emitting spot in a second direction corresponding to the horizontal direction by sequentially emitting light from a light-emitting element electrically connected to a certain vertical wiring and a light-emitting element electrically connected to another vertical wiring, and when the two or more light-emitting elements electrically connected to the same vertical wiring are sequentially emitting light, the two or more light-emitting elements are sequentially emitting light so that two light-emitting elements adjacent to each other in the vertical direction do not emit light consecutively.

[0353] (20) The distance measuring device according to (19), wherein the light emitting unit and the distance measuring unit measure the distance to the subject by emitting light from only some of the plurality of light emitting elements. (21) The light emitting device according to (14), wherein two or more of the light emitting elements are caused to emit light simultaneously by turning on one of the first to Nth selection circuits and two or more of the plurality of drive circuits.

[0354] (22) The light emitting device according to claim (14), wherein two or more of the first to Nth selection circuits and one of the plurality of drive circuits are turned on, thereby causing two or more of the light emitting elements to emit light simultaneously.

[0355] (23) The light emitting device according to (17), wherein the plurality of capacitors include K sets (K is an integer of 2 or more) of the first to Nth capacitors arranged near two or more of four sides of the array of the light emitting elements.

[0356] (24) The light emitting device according to (17), wherein the plurality of capacitors include K sets (K is an integer of 2 or more) of the first to Nth capacitors arranged symmetrically with respect to the center of the array of the light emitting elements.

[0357] (25) The light-emitting device according to (16), wherein the plurality of capacitors are arranged on a first substrate on which the light-emitting elements are provided, on a second substrate on which at least one of the selection circuit and the drive circuit is provided, or on a mounting substrate on which the first and second substrates are provided.

[0358] (26) The light emitting device according to (16), wherein each of the plurality of selection circuits includes a first switch that stores charge in the capacitor and a second switch that discharges charge from the capacitor.

[0359] (27) The light emitting device according to (26), further comprising a plurality of voltage detection circuits that detect voltages indicating amounts of charge stored in the plurality of capacitors and control the first switch based on the voltages.

[0360] (28) The light emitting device according to (11), wherein the charge supplied to the light emitting element is accumulated in a parasitic capacitance of the light emitting element or the drive circuit.

[0361] (29) The light emitting device according to (11), wherein each of the plurality of drive circuits includes a first transistor that selects the light emitting element that generates light, and a second transistor that functions as a current source.

[0362] (30) The light emitting device according to (11), wherein a first substrate on which the light emitting elements are provided is mounted on a second substrate on which at least one of the selection circuit and the drive circuit is provided.

[0363] (31) The light emitting device according to (11), wherein the size of one of the plurality of drive circuits is the same as the size of N of the plurality of light emitting elements in a plan view.

[0364] (32) The distance measuring device described in (19), wherein the light emitting unit further includes: a plurality of selection circuits electrically connected to one of the first and second terminal wirings and configured to select the light emitting elements that generate light; and a plurality of drive circuits electrically connected to the other of the first and second terminal wirings and configured to drive the light emitting elements.

[0365] 1: distance measuring device, 1a: light emitting device, 1b: light receiving device, 2: light emitting section, 2a: light emitting element, 3: driving section, 4: power supply circuit, 5: light emitting side optical system, 6: light receiving side optical system, 7: light receiving section, 8: signal processing section, 9: control section, 9a: distance measuring section, 10: temperature detection section, 11: LD chip, 12: LDD substrate, 13: mounting substrate, 14: heat dissipation substrate, 15: correction lens holding section, 16: correction lens, 17: wiring, 21: substrate, 22: laminated film, 23: light emitting element, 23': parasitic capacitance, 24: transistor, 24': parasitic capacitance, 25: transistor, 26: light receiving element, 31: first anode wiring, 31a: first horizontal wiring, 31b: first vertical wiring, 32: second anode wiring, 32a: second horizontal wiring, 32b: second vertical wiring, 33: third anode wiring, 33a: third horizontal wiring, 33b: third vertical wiring, 31': first cathode wiring, 31a': first horizontal wiring, 31b': first vertical wiring, 32': second cathode wiring, 32a': second horizontal wiring, 32b': second vertical wiring, 33': third cathode wiring, 33a': third horizontal wiring, 33b': third vertical wiring, 34: first capacitor, 35: second capacitor, 36: third capacitor, 37: first selection circuit, 37a: transistor, 37b: transistor, 38: second selection circuit, 38a: transistor, 38b: transistor, 39: third selection circuit, 39a: transistor, 39b: transistor, 41: cathode wiring, 41': anode wiring, 42: gate wiring, 42': gate wiring, 43: gate wiring, 51: insulating substrate, 52: insulating film, 53: wiring layer, 54: insulating film, 55: wiring layer, 56: wiring, 57: solder ball, 58: solder ball, 59: bump, 61: first transistor, 62: second transistor, 63: third transistor, 64: first gate wiring, 65: second gate wiring, 66: third gate wiring, 67: capacitor, 68: selection circuit, 68a: transistor, 68b: transistor, 71: first voltage detection circuit, 72: second voltage detection circuit, 73: third voltage detection circuit, 81: fourth anode wiring, 81a: fourth horizontal wiring, 81b: fourth vertical wiring, 82: fourth capacitor, 83: fourth selection circuit, 83a: transistor, 83b: transistor, 91: screen, 91a: light emitting spot, 91b: readout area, 92: pupil opening, 93: area,101: Vehicle, 111: Vehicle control system, 121: Vehicle control ECU, 122: Communication unit, 123: Map information storage unit, 124: Position information acquisition unit, 125: External recognition sensor, 126: In-vehicle sensor, 127: Vehicle sensor, 131: Memory unit, 132: Cruise assist / autonomous driving control unit, 133: DMS, 134: HMI, 135: Vehicle control unit, 141: Communication network, 151: Camera, 152: Radar, 153: LiDAR, 154: Ultrasonic sensor, 161: Analysis unit, 162: Action planning unit, 163: Operation control unit, 171: Self-position estimation unit, 172: Sensor fusion unit, 173: Recognition unit, 181: Steering control unit, 182: Brake control unit, 183: Drive control unit, 184: Body system control unit, 185: Light control unit, 186: Horn control unit

Claims

1. A light emitting device comprising: a plurality of light emitting elements arranged in a two-dimensional array, each having a first and a second terminal; first to Nth horizontal wires (N is an integer of 2 or more) extending in a horizontal direction; and first to Nth vertical wires extending in a vertical direction and electrically connected to the first to Nth horizontal wires, respectively, a plurality of first terminal wires electrically connected to the first terminals of the light emitting elements; a plurality of second terminal wires electrically connected to the second terminals of the light emitting elements, each electrically connected to N of the light emitting elements; and a control mechanism for causing any of the light emitting elements to emit light to generate a light emitting spot, the control mechanism: changes the position of the light emitting spot in a first direction corresponding to the vertical direction by sequentially causing two or more light emitting elements electrically connected to the same vertical wire to emit light; changes the position of the light emitting spot in a second direction corresponding to the horizontal direction by sequentially causing a light emitting element electrically connected to one vertical wire and a light emitting element electrically connected to another vertical wire to emit light; and causes the two or more light emitting elements electrically connected to the same vertical wire to emit light in sequence, such that two light emitting elements adjacent to each other in the vertical direction do not emit light continuously when the two or more light emitting elements are electrically connected to the same vertical wire. Light emitting device.

2. The light-emitting device of claim 1, wherein the control mechanism, when causing the two or more light-emitting elements electrically connected to the same vertical wiring to emit light in sequence, causes the two or more light-emitting elements to emit light in sequence such that two light-emitting elements separated by a distance of Y light-emitting elements (Y is an integer of 2 or more) in the vertical direction emit light consecutively (wherein the distance is calculated by applying a periodic boundary condition in the vertical direction to the arrangement of the two light-emitting elements).

3. The light-emitting device according to claim 1, wherein the control mechanism, when causing the two or more light-emitting elements electrically connected to the same vertical wiring to emit light in sequence, causes one light-emitting element to emit light multiple times, and then causes another light-emitting element to emit light multiple times.

4. The light-emitting device according to claim 1, wherein the control mechanism, when causing the two or more light-emitting elements electrically connected to the same vertical wiring to emit light in sequence, repeats a process of causing all of the light-emitting elements electrically connected to the same vertical wiring to emit light in sequence multiple times.

5. The light-emitting device according to claim 1, wherein when the control mechanism sequentially causes two or more light-emitting elements electrically connected to a certain vertical wiring to emit light, and then sequentially causes two or more light-emitting elements electrically connected to another vertical wiring to emit light, the former vertical wiring and the latter vertical wiring are two vertical wirings that are not adjacent to each other in the horizontal direction.

6. The light-emitting device according to claim 5, wherein when the control mechanism sequentially causes the two or more light-emitting elements electrically connected to a certain vertical wiring to emit light, and then sequentially causes the two or more light-emitting elements electrically connected to another vertical wiring to emit light, the former vertical wiring and the latter vertical wiring are two vertical wirings separated by a distance of X light-emitting elements (X is an integer of 2 or more) in the horizontal direction (wherein the distance is calculated by applying a periodic boundary condition in the horizontal direction to the arrangement of the former vertical wiring and the latter vertical wiring).

7. The light-emitting device of claim 1, wherein when the control mechanism sequentially causes the two or more light-emitting elements electrically connected to the same vertical wiring to emit light, the control mechanism sequentially causes the two or more light-emitting elements to emit light such that J light-emitting elements (J is an integer of 2 or more) electrically connected to the same vertical wiring emit light simultaneously, thereby simultaneously generating J light-emitting spots.

8. The light emitting device according to claim 1, wherein said control mechanism causes said plurality of light emitting elements to emit light one at a time such that two or more of said plurality of light emitting elements do not emit light simultaneously.

9. The light-emitting device of claim 1, wherein the plurality of first terminal wirings include H horizontal wirings (H is an integer greater than N) each corresponding to one of the first to Nth horizontal wirings, and V vertical wirings (V is an integer greater than N) each corresponding to one of the first to Nth vertical wirings.

10. The light emitting device according to claim 1, wherein at least one second terminal wiring among the plurality of second terminal wirings is electrically connected to N' (N' is an integer greater than N) of the light emitting elements.

11. The light emitting device according to claim 1, further comprising: a plurality of selection circuits electrically connected to one of the first and second terminal wirings and configured to select the light emitting elements that generate light; and a plurality of drive circuits electrically connected to the other of the first and second terminal wirings and configured to drive the light emitting elements.

12. The light-emitting device according to claim 1, wherein one of the first and second terminals of the light-emitting element is an anode, the other of the first and second terminals of the light-emitting element is a cathode, one of the first and second terminal wirings is an anode wiring, and the other of the first and second terminal wirings is a cathode wiring.

13. The light emitting device according to claim 1, wherein the plurality of first terminal wirings include M sets (M is an integer of 2 or more) of the first to Nth horizontal wirings and the first to Nth vertical wirings.

14. The light-emitting device of claim 11, wherein the plurality of selection circuits include first to Nth selection circuits electrically connected to the first to Nth horizontal wirings or the first to Nth vertical wirings, respectively, and the plurality of drive circuits are each electrically connected to one of the second terminal wirings.

15. The light-emitting device of claim 11, wherein each of the plurality of selection circuits is electrically connected to one of the second terminal wirings, and the plurality of drive circuits include first to Nth drive circuits electrically connected to the first to Nth horizontal wirings or the first to Nth vertical wirings, respectively.

16. The light emitting device according to claim 11, further comprising a plurality of capacitors electrically connected to said one of said first and second terminal wirings, for storing electric charge to be supplied to said light emitting element.

17. The light emitting device according to claim 16, wherein the plurality of capacitors include first to Nth capacitors electrically connected to the first to Nth horizontal wirings or the first to Nth vertical wirings, respectively.

18. The light emitting device according to claim 16, wherein each of the plurality of capacitors is electrically connected to one of the second terminal wirings.

19. A device comprising: a light-emitting unit that generates light and irradiates it onto a subject; a light-receiving unit that receives light reflected from the subject; and a distance measuring unit that measures the distance to the subject based on the light received by the light-receiving unit, wherein the light-emitting unit comprises: a plurality of light-emitting elements arranged in a two-dimensional array, each having a first and a second terminal; first to Nth horizontal wires (N is an integer of 2 or more) extending in the horizontal direction; and first to Nth vertical wires extending in the vertical direction and electrically connected to the first to Nth horizontal wires, respectively, a plurality of first terminal wires electrically connected to the first terminals of the light-emitting elements; a plurality of second terminal wires electrically connected to the second terminals of the light-emitting elements, each of which is electrically connected to N of the light-emitting elements; and a control mechanism that causes any of the light-emitting elements to emit light to generate a light-emitting spot, wherein the control mechanism changes the position of the light-emitting spot in a first direction corresponding to the vertical direction by sequentially causing two or more light-emitting elements electrically connected to the same vertical wire to emit light; A distance measuring device which changes the position of the light-emitting spot in a second direction corresponding to the horizontal direction by sequentially emitting light from a light-emitting element electrically connected to a vertical wiring and a light-emitting element electrically connected to another vertical wiring, and when the two or more light-emitting elements electrically connected to the same vertical wiring are caused to emit light in sequence, the two or more light-emitting elements are caused to emit light in sequence such that two light-emitting elements adjacent to each other in the vertical direction do not emit light in succession.

20. The distance measuring device according to claim 19, wherein the light emitting section and the distance measuring section measure the distance to the subject by emitting light from only a portion of the plurality of light emitting elements.

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