Light-emitting device and distance measurement device

Abstract

[Problem] To make it possible to suppress fluctuation of light emission characteristics and to realize size reduction and low power consumption. [Solution] This light-emitting device includes a plurality of light-emitting elements arranged in a two-dimensional array and each having first and second terminals, M first wirings extending in a first direction, and N second wirings that extend in a second direction crossing the first direction and are respectively connected to the M first wirings, and the light-emitting device comprises: a plurality of first terminal wirings connected to the first terminals of the light-emitting elements; a plurality of second terminal wirings connected to the second terminals of the light-emitting elements and each connected to P of the light-emitting elements; a plurality of selection circuits respectively connected to either the plurality of first terminal wirings or the plurality of second terminal wirings and selecting corresponding light-emitting elements; a plurality of drive circuits connected to the other of the plurality of first terminal wirings and the plurality of second terminal wirings and driving the corresponding light-emitting elements; and a control unit that controls at least one of the number of light emissions, the light emission interval, the light emission power, and the light emission pulse width of the plurality of light-emitting elements on the basis of input information.

Description

Light emitting device and distance measuring device

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

[0002] LiDAR (Light Detection and Ranging) is one method for obtaining distance information. With LiDAR, light is shone onto the object for which distance information is to be obtained, and the distance is estimated based on the light reflected from the object. LiDAR generally uses the ToF (Time of Flight) method, which measures the time it takes for light to travel through space. With the ToF method, distance information is obtained by measuring the time it takes for light emitted from a light-emitting device to hit the object and return.

[0003] Among distance measurement systems that employ the ToF method, a structure in which the light-emitting unit and light-receiving unit do not have any physically moving parts is called solid-state LiDAR. Solid-state LiDAR uses an array of light-emitting units to select light-emitting locations and project light onto the intended irradiation area. Light emitted by the light-emitting elements (also called light-emitting channels) located at the selected light-emitting locations is reflected by the target and received by the light-receiving elements corresponding to the light-emitting channels on the receiving side. The light-emitting unit of this light-emitting device uses a light source with laser diodes arranged in an array, a laser driver capable of matrix driving to drive the selected light-emitting channels, and a drive circuit, allowing only the desired light-emitting channel to emit light. When a multi-channel VCSEL is used as the light-emitting device, it can be driven individually and emit high-power, short-pulse light (see Patent Document 1).

[0004] Japanese Patent Application Publication No. 2020-96169

[0005] The light-emitting device described in Patent Document 1 includes a capacitor for each light-emitting element to pass current through each light-emitting element. Therefore, in a light-emitting device with a large number of light-emitting channels, such as a LiDAR, the increased number of capacitors restricts placement and complicates the routing of the wiring connected to the capacitors, increasing the absolute value and in-plane variation of parasitic inductance. This results in greater variation in light-emitting characteristics, such as the light-emitting power and light-emitting period, of each light-emitting element, making it impossible to achieve high-power and short pulses. Furthermore, when the number of light-emitting element channels is very large, the increased number of capacitors and wiring increases the size of the light-emitting module, making miniaturization difficult and increasing power consumption.

[0006] Therefore, the present disclosure provides a light emitting device and a distance measuring device that can suppress variations in light emitting characteristics, and that can achieve miniaturization and low power consumption.

[0007] In order to solve the above problems, according to the present disclosure, there is provided a light emitting device comprising: a plurality of light emitting elements arranged in a two-dimensional array, each having a first and second terminal; a plurality of first terminal wirings including M first wirings (M is an integer of 2 or more) extending in a first direction and N second wirings (N is an integer of 2 or more) extending in a second direction intersecting the first direction and electrically connected to the M first wirings, respectively, the first terminal wirings being electrically connected to the first terminals of the light emitting elements; a plurality of second terminal wirings electrically connected to the second terminals of the light emitting elements, each electrically connected to P (P is an integer of 2 or more) of the light emitting elements; a plurality of selection circuits connected to one of the plurality of first terminal wirings and the plurality of second terminal wirings, respectively, and selecting a corresponding one of the light emitting elements; a plurality of drive circuits connected to the other of the plurality of first terminal wirings and the plurality of second terminal wirings, respectively, and driving a corresponding one of the light emitting elements; and a control unit that controls at least one of the number of times of light emission, the light emission interval, the light emission power, and the light emission pulse width of the plurality of light emitting elements based on input information, wherein N is an integer that is the same as or different from M, The P is an integer that is the same as or different from at least one of the M and the N.

[0008] The control unit may select a light-emitting element to emit light from among the plurality of light-emitting elements based on the input information.

[0009] The control unit may control an order in which the plurality of light-emitting elements emit light, based on the input information.

[0010] The display device may include: a first substrate including the plurality of light-emitting elements; and a second substrate stacked on the first substrate and including the plurality of selection circuits, the plurality of drive circuits, and the control unit.

[0011] The input information may include temperature information around the plurality of light-emitting elements, and the control unit may select a light-emitting element to be made to emit light from among the plurality of light-emitting elements based on the temperature information.

[0012] The information input device may further include a driver unit having the plurality of selection circuits and the plurality of driver circuits, wherein the input information includes information provided from the driver unit.

[0013] The information provided by the driving unit may include at least one of the number of times the plurality of light emitting elements emit light, the light emission interval, the light emission power, and the light emission pulse width.

[0014] The input information may include distance measurement information obtained by measuring distances using light emitted by the plurality of light-emitting elements.

[0015] The control unit may control at least one of the number of times the plurality of light-emitting elements emit light, the light-emitting interval, the light-emitting power, or the light-emitting pulse width according to the measured distance based on the distance measurement information included in the input information.

[0016] The input information may be information provided by a host device.

[0017] The information provided by the host device may include vehicle speed information of a vehicle in which the host device is installed.

[0018] The control unit may control at least one of the number of times, the interval between light emissions, the light emission power, and the light emission pulse width of the plurality of light emitting elements based on the vehicle speed information.

[0019] The host device or the distance measurement unit controls the emission of two or more of the plurality of light-emitting elements that emit light into a ROI (Region Of Interest) area, and the control unit may control at least one of the number of times the plurality of light-emitting elements emit light, the emission interval, the emission power, or the emission pulse width based on at least one of the position and size of the ROI area.

[0020] The present disclosure provides a distance measuring device including: a light emitting device that emits light toward an object to be measured; and a control unit having a distance measuring unit that receives light reflected by the object to be measured and measures the distance to the object, wherein the light emitting device includes a plurality of light emitting elements arranged in a two-dimensional array, each having a first and a second terminal; M first wirings (M is an integer of 2 or more) extending in a first direction; and N second wirings (N is an integer of 2 or more) extending in a second direction intersecting the first direction and electrically connected to the M first wirings, respectively, a plurality of first terminal wirings electrically connected to the first terminals of the light emitting elements; a plurality of second terminal wirings electrically connected to the second terminals of the light emitting elements, each electrically connected to P (P is an integer of 2 or more) of the light emitting elements; and a plurality of selection circuits respectively connected to one of the plurality of first terminal wirings and the plurality of second terminal wirings, and selecting a corresponding light emitting element. a plurality of drive circuits connected to the other of the plurality of first terminal wirings and the plurality of second terminal wirings, respectively, for driving the corresponding light-emitting elements, wherein the control unit controls at least one of the number of times the plurality of light-emitting elements emit light, the interval between emissions, the light-emitting power, or the light-emitting pulse width based on input information.

[0021] The input information may include information provided by the light emitting device.

[0022] The information provided by the light-emitting device may include temperature information around the plurality of light-emitting elements, and the control unit may select a light-emitting element to be made to emit light from among the plurality of light-emitting elements based on the temperature information.

[0023] The information provided by the light emitting device may include at least one of the number of times the plurality of light emitting elements emit light, the light emission interval, the light emission power, and the light emission pulse width.

[0024] The control unit may select a light-emitting element to emit light from among the plurality of light-emitting elements based on the input information.

[0025] The control unit may control an order in which the plurality of light-emitting elements emit light, based on the input information.

[0026] The input information may include ranging information or information provided by a host device.

[0027] The information provided by the host device may include vehicle speed information of a vehicle in which the host device is installed.

[0028] 8 is a circuit diagram of a light emitting device according to a first embodiment. FIG. 9 is a cross-sectional view showing an example of the cross-sectional structure of a light emitting device with a VCSEL structure. FIG. 10 is a waveform diagram of output currents from an LDD substrate to each light emitting element. FIG. 11 is a cross-sectional view showing the structure of the light emitting device according to the first embodiment. FIG. 12 is a plan view showing the structure of the light emitting device according to the first embodiment. FIG. 13 is a perspective view schematically showing the structure of the light emitting device according to the first embodiment. FIG. 14 is a cross-sectional view showing an example of mounting light emitting elements arranged side by side on a mounting substrate. FIG. 15 is a block diagram of a distance measuring device according to a first mounting example of the light emitting device according to the present embodiment. FIG. 16 is a circuit diagram of a light emitting device according to a first modified example of an embodiment. FIG. 17 is a flowchart showing the processing operation of the distance measuring device according to the first embodiment shown in FIG. 15. FIG. 16 is a diagram showing waveforms of optical pulse signals emitted from a plurality of light emitting elements. FIG. 17 is a diagram showing waveforms when control is performed to reduce the light emission power of an optical pulse signal. FIG. 18 is a diagram showing waveforms when control is performed to narrow the pulse width of an optical pulse signal. FIG. 19 is a diagram showing waveforms when control is performed to thin out an optical pulse signal. FIG. 19 shows the light emitting positions of all light emitting elements and the light receiving positions of all light receiving elements in a light receiving unit. FIG. 19 is a diagram showing the light emitting positions of light emitting elements within an ROI region and the light receiving positions of corresponding light receiving elements in the light receiving unit. 17 is a block diagram of a distance measuring device according to a second implementation example of the light emitting device according to the present embodiment. FIG. 18 is a flowchart showing the processing operation of the distance measuring device of FIG. 12. FIG. 19 is a circuit diagram of a light emitting device according to a second modified example of an embodiment. FIG. 19 is a circuit diagram of a light emitting device according to a first modified example of an embodiment. FIG. 20 is a circuit diagram of a light emitting device according to a second modified example of an embodiment. FIG. 21 is a circuit diagram of a light emitting device according to a third modified example of an embodiment. FIG. 22 is a detailed circuit diagram of the periphery of the light emitting element of FIG. 17. FIG. 23 is a circuit diagram of a drive circuit according to a first modified example. FIG. 24 is a circuit diagram of a drive circuit according to a second modified example. FIG. 25 is a circuit diagram of a drive circuit according to a third modified example. FIG. 26 is an explanatory diagram of the STL system. FIG. 27 is an explanatory diagram of the distance measuring principle of the STL system. FIG. 28 is a block diagram showing an example of the general configuration of a vehicle control system. FIG. 29 is an explanatory diagram showing an example of the installation positions of an outside vehicle information detection unit and an imaging unit.

[0029] Hereinafter, embodiments of a light emitting device and a distance measuring device will be described with reference to the drawings. The following description will focus on the main components of the light emitting device and the distance measuring device, but the light emitting device and the distance measuring device may include components and functions that are not shown or described. The following description does not exclude components and functions that are not shown or described.

[0030] (First Embodiment) Fig. 1 is a circuit diagram of a light emitting device 1 according to a first embodiment. As shown in Fig. 1, the light emitting device 1 according to the first embodiment includes 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. 1 shows an example in which the light emitting device 1 according to the first embodiment includes 9 x 9 light emitting elements 23 and 9 x 9 transistors 24. Therefore, the light emitting device 1 shown in Fig. 1 includes a 9ch (channel) x 9ch light emitting element array. The number of channels in the light emitting element array is arbitrary.

[0031] 1 , the light-emitting device 1 according to the first 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 an example 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 an example of the first to M-th capacitors of the present disclosure, and the first to third selection circuits 37 to 39 are an example of the first to M-th selection circuits of the present disclosure (M is an integer of 2 or more). FIG. 1 shows an example in which M is 3.

[0032] The first terminal wirings include M first wirings (M is an integer of 2 or greater) 31a, 32a, and 33a extending in a first direction X, and N second wirings (N is an integer of 2 or greater) 31b, 32b, and 33b extending in a second direction Y intersecting the first direction X and electrically connected to the M first wirings 31a, 32a, and 33a, respectively. FIG. 1 shows an example where M=N=3. The first terminal wirings are electrically connected to first terminals of a plurality of light-emitting elements 23. In this specification, the first wirings 31a and the second wirings 31b connected to each other are referred to as first anode wirings 31, the second wirings 32a and 32b connected to each other are referred to as second anode wirings 32, and the third wirings 33a and 33b connected to each other are referred to as third anode wirings 33. In this specification, the first direction X may be referred to as the horizontal direction, and the second direction Y may be referred to as the vertical direction. In the following, the first terminal wiring and one of the plurality of second terminal wirings may be referred to as an anode wiring, and the other of the first terminal wiring and the plurality of second terminal wirings may be referred to as a cathode wiring.

[0033] The light emitting device 1 according to the first embodiment includes L (L is an integer of 1 or more) sets of first to third anode wirings 31 to 33. Figure 1 shows an example where L = 5.

[0034] The five sets of first anode wirings 31 include a plurality of (e.g., five) first wirings 31a each extending in the first direction X (horizontal direction) and arranged along the second direction Y (vertical direction), and a plurality of (e.g., five) second wirings 31b each extending in the second direction Y (vertical direction) and arranged along the first direction X (horizontal direction). In this specification, the first wirings 31a may be referred to as first horizontal wirings 31a, and the second wirings 31b may be referred to as first vertical wirings 31b.

[0035] The five sets of second anode wirings 32 each include a plurality of (e.g., five) first wirings 32a each extending in the first direction X (horizontal direction) and arranged along the second direction Y (vertical direction), and a plurality of (e.g., five) second wirings 32b each extending in the second direction Y (vertical direction) and arranged along the first direction X (horizontal direction). In this specification, the first wirings 32a may be referred to as second horizontal wirings 32a, and the second wirings 32b may be referred to as second vertical wirings 32b.

[0036] The five sets of third anode wirings 33 each include a plurality of (e.g., five) first wirings 33a each extending in the first direction X (horizontal direction) and arranged along the second direction Y (vertical direction), and a plurality of (e.g., five) second wirings 33b each extending in the second direction Y (vertical direction) and arranged along the first direction X (horizontal direction). In this specification, the first wirings 33a may be referred to as third horizontal wirings 33a, and the second wirings 33b may be referred to as third vertical wirings 33b.

[0037] 1 shows an example in which the light-emitting device 1 according to the first embodiment includes five first horizontal wires 31a, five first vertical wires 31b, five second horizontal wires 32a, five second vertical wires 32b, five third horizontal wires 33a, and five third vertical wires 33b. Fig. 1 also shows an example in which L sets of M first wires and N second wires are provided. The number of light-emitting elements 23 shown in Fig. 1 is M(L-2) x N(L-2), where L, M, and N are the numbers.

[0038] The first to third anode wirings 31 to 33 may include La sets of first to M-th horizontal wirings and Lb sets of first to N-th vertical wirings (La and Lb are integers of 2 or greater that satisfy La≠Lb). In this case, the number of light-emitting elements 23 in the light-emitting device 1 is M(La-2)×N(Lb-2).

[0039] The first selection circuit 37 includes transistors 37a and 37b connected in series. Similarly, the second selection circuit 38 includes transistors 38a and 38b connected in series. Similarly, the third selection circuit 39 includes transistors 39a and 39b connected in series. 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.

[0040] [First to third anode wirings 31 to 33] In FIG. 1, 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.

[0041] 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 locations 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.

[0042] The first to third horizontal wirings 31a to 33a extend in the first direction X (horizontal direction) and are adjacent to each other in the second direction Y (vertical direction). Although the first to third horizontal wirings 31a to 33a extend linearly in the first direction X in FIG. 1, they may extend in a curved manner in the first direction X. That is, the first to third horizontal wirings 31a to 33a may include bent portions.

[0043] On the other hand, the first to third vertical wirings 31b to 33b extend in the second direction Y and are adjacent to each other in the first direction X. Although the first to third vertical wirings 31b to 33b extend linearly in the second direction Y in FIG. 1, they may also extend in a curved manner in the second direction Y. That is, the first to third vertical wirings 31b to 33b may also include bent portions.

[0044] FIG. 1 shows five sets of first to third horizontal wirings (first wirings) 31a to 33a. In FIG. 1, 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.

[0045] FIG. 1 further shows five sets of first to third vertical wirings (second wirings) 31b to 33b. In FIG. 1, 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.

[0046] 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.

[0047] [Cathode Wiring 41] Each cathode wiring 41 extends in the first direction X 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 first direction X. FIG. 1 shows 27 cathode wirings 41 for 81 light-emitting elements 23. The cathodes are an example of the second terminals of the present disclosure. The number of light-emitting elements 23 connected to each cathode wiring 41 is not limited to three. Each cathode wiring 41 may be electrically connected to the cathodes of P light-emitting elements 23 (P is an integer greater than or equal to 2).

[0048] In the above description, an example has been described in which a plurality of light-emitting elements 23 are connected to first to M-th horizontal wires, first to N-th vertical wires, and a plurality of second terminal wires electrically connected in P units, but the light-emitting device according to the present disclosure does not need to include all of the first to M-th horizontal wires, first to N-th vertical wires, and a plurality of second terminal wires electrically connected in P units. For example, a configuration in which a plurality of light-emitting devices are connected to first to M-th horizontal wires, a single vertical wire, and a single second terminal wire may also be employed.

[0049] 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.

[0050] [Gate Wiring 42] Each gate wiring 42 extends in the first direction X 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. 1 shows 27 gate wirings 42 for 81 transistors 24.

[0051] Each drive circuit E is electrically connected to the cathodes of three light-emitting elements 23 via one cathode wiring 41. Each drive circuit E (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 brings the source and drain of each transistor 24 in that drive circuit E into conduction, 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 1 shown in FIG. 1 includes 27 drive circuits E for 81 light-emitting elements 23.

[0052] [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.

[0053] 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.

[0054] 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 selectively storing charge in the first capacitor 34 of the first to third capacitors 34 to 36 using the first selection circuit 37, it is possible to pass a current to each light-emitting element 23 electrically connected to the first anode wiring 31.

[0055] 1 , 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.

[0056] [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.

[0057] The light-emitting device 1 shown in FIG. 1 includes a light-emitting element array including 9×9 light-emitting elements 23 arranged in a two-dimensional array. As shown in FIG. 1, the shape of this light-emitting element array is roughly square in plan view. The light-emitting device 1 shown in FIG. 1 includes four sets of first to third capacitors 34-36 near the four sides of the square. Specifically, the light-emitting device 1 shown in FIG. 1 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. 1 shows an example where K is 4.

[0058] The first to third capacitors 34 to 36 of the first and third sets are electrically connected to the first to third horizontal wirings 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 wirings 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. 1 are electrically connected to the first to third anode wirings 31 to 33, respectively.

[0059] In each set, 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 set 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 set are respectively arranged on the upper, center, and lower sides near the right edge of the square. As a result, the four sets of first to third capacitors 34 to 36 shown in FIG. 1 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. 1, the four sets of first to third capacitors 34 to 36 are arranged in four-fold rotational symmetry (90-degree rotational symmetry).

[0060] 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.

[0061] 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.

[0062] The light emitting device 1 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 1 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).

[0063] The light emitting device 1 according to this embodiment is, for example, a surface emitting laser element. More specifically, the light emitting device 1 according to this embodiment has, for example, a vertical cavity surface emitting laser (VCSEL) structure.

[0064] Fig. 2 is a cross-sectional view showing an example of the cross-sectional structure of a light emitting device 1 with a VCSEL structure. The light emitting device 1 in Fig. 2 is configured, for example, by stacking an LD (Laser Diode) chip 11 on an LDD substrate 12. The LD chip 11 includes a substrate 21, a stacked film 22, a plurality of light emitting elements 23 formed using the stacked film 22, a plurality of anode electrodes 47, and a cathode electrode 48.

[0065] The substrate 21 of the LD chip 11 is made of a compound semiconductor such as GaAs (gallium arsenide). The surface of the substrate 21 facing the LDD substrate 12 is the front surface S2, and laser light is emitted from the back surface S3 of the substrate 21. The stacked film 22 includes a first multilayer reflector, a first spacer layer, an active layer, a second spacer layer, and a second multilayer reflector. The laser light generated in the active layer is resonated between the first multilayer reflector and the second multilayer reflector to increase the light intensity and is emitted from the back surface S3 of the substrate. Thus, the LD chip 11 of FIG. 2 is a back-illuminated type. In this specification, a light-emitting element 23 having the layer structure shown in FIG. 2 is referred to as a VCSEL structure.

[0066] The plurality of light-emitting elements 23 have a mesa structure formed by processing the laminated film 22 into a mesa shape. As viewed from the substrate 21 side, an anode electrode (second pad) 47 is disposed on the upper surface of each light-emitting element 23. Similarly, as viewed from the substrate 21 side, a cathode electrode 48 is disposed on the upper and side surfaces of the laminated film 22 disposed on the end side of the LD chip 11. As viewed from the substrate 21 side, a cathode electrode 48 is also disposed on the lowermost layer of the laminated film 22 of the plurality of light-emitting elements 23. In FIG. 2 , the anode electrode 47 and the cathode electrode 48 may be reversed. Although the common electrode in FIG. 2 is the cathode electrode 48, the common electrode may be the anode electrode 47, and a cathode electrode 48 may be provided on each mesa portion 20.

[0067] The LDD substrate 12 has a plurality of pads 49 for supplying drive signals to the plurality of light emitting elements 23 of the LD chip 11. The pads 49 are arranged along a surface S1 of the LDD substrate 12 that faces the LD chip 11. A bonding layer 50 is arranged on these pads 49, and the pads 49 of the LDD substrate 12 are bonded to the corresponding pads of the anode electrode 47 of the LD chip 11 via the bonding layer 50. The LDD substrate 12 has a plurality of drive circuits E shown in FIG.

[0068] The substrate 21 is, for example, a compound semiconductor substrate such as a GaAs (gallium arsenide) substrate. Fig. 2 shows a front surface S2 of the substrate 21 facing the -Z direction and a back surface S3 of the substrate 21 facing the +Z direction. The front surface S2 and back surface S3 shown in Fig. 2 are perpendicular to the Z direction. In Fig. 2, the front surface S2 is the lower surface of the substrate 21, and the back surface S3 is the upper surface of the substrate 21.

[0069] The light emitting element 23 is provided on the surface S2 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. 2 , the light emitted from the light emitting element 23 passes through the substrate 21 from the surface S2 to the back surface S3 of the substrate 21.

[0070] Each light-emitting element 23 is provided between an anode electrode 47 and a cathode electrode 48 connected to the anode wirings 31 to 33. Each light-emitting element 23 emits light when a current flows between the anode electrode 47 and the cathode electrode 48.

[0071] 3 is a waveform diagram of the output current from the LDD substrate 12 to each light-emitting element 23. The vertical axis of FIG. 3 represents the LDD output current flowing from the LDD substrate 12 to each light-emitting element 23, and the horizontal axis represents time. FIG. 3 shows the waveform of the LDD output current. FIG. 3 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.

[0072] In order to improve the performance of the light-emitting device 1, it is desirable to increase the peak value Ipeak of the current flowing through each light-emitting element and shorten the pulse width W (or half-value width W'). Increasing the peak value of the current flowing through each light-emitting element and shortening the pulse enables highly accurate distance measurement over long distances. According to this embodiment, by reducing the difference between the impedance of each wiring and the impedance between the wirings, it becomes possible to increase the peak value Ipeak and shorten the pulse width W (or half-value width W').

[0073] 4A and 4B are a cross-sectional view and a plan view showing the structure of the light-emitting device 1 of the first embodiment. Fig. 4A shows an XZ cross section of the light-emitting device 1. Fig. 4B shows the planar structure of the light-emitting device 1 shown in Fig. 4A.

[0074] As shown in FIGS. 4A and 4B, the light emitting device 1 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.

[0075] The mounting substrate 13 is a laminated structure in which an insulating substrate 51, an insulating film 52, a wiring layer 53, an insulating film 54, and a wiring layer 55 are stacked. The LDD substrate 12 shown in FIG. 4A is disposed on the insulating substrate 51. The insulating film 52 and the wiring layer 53 are disposed in this order on the upper surface of the insulating substrate 51. The insulating film 54 and the wiring layer 55 are disposed in this order on the lower surface of the insulating substrate 51. The LD chip 11 shown in FIG. 4A is disposed on the wiring layer 53. Each wiring 56 is formed in the insulating substrate 51, the insulating film 52, and the wiring layer 53, and the LD chip 11 and the LDD substrate 12 are electrically connected.

[0076] 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.

[0077] In Fig. 4B, the LD chip 11 and the LDD substrate 12 have a square shape in plan view. The light-emitting device 1 shown in Fig. 4B 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.

[0078] The light-emitting device 1 shown in Fig. 4B 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 1 shown in Fig. 4B include the first to third capacitors 34 to 36 on two or more of the four sides of the square.

[0079] 4A and 4B, a plurality of light-emitting elements 23, a plurality of transistors 24, and 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.

[0080] FIG. 5 is a perspective view schematically illustrating the structure of the light-emitting device 1 of the first embodiment. FIG. 5 also schematically illustrates the shapes of the LD chip 11 and LDD substrate 12 shown in FIGS. 4A and 4B. FIG. 5 further schematically and partially illustrates 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, as well as a plurality of cathode wirings 41. As shown in FIG. 5, the first to third horizontal wirings 31a to 33a and the first to third vertical wirings 31b to 33b have a mesh-like structure.

[0081] 5 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. For example, the light emitting element 23 is disposed on the LD chip 11 in FIG. 5, and the first to third selection circuits 37 to 39, the drive circuit E, and a drive control unit (described later) are disposed on the LDD substrate 12.

[0082] FIG. 6 is a cross-sectional view showing an example in which the LD chip 11 and the LDD substrate 12 are mounted side by side on a mounting substrate 13, rather than being stacked.

[0083] 6 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 corresponds to the first substrate of the present disclosure, and the LDD substrate 12 corresponds to the second substrate of the present disclosure.

[0084] 6 shows X-axis, Y-axis, and Z-axis that 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.

[0085] 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 mounting substrate 13 may further include a light receiving unit 7 and a signal processing unit 8. The heat dissipation substrate 14 is, for example, a ceramic substrate such as an aluminum oxide substrate or an aluminum nitride substrate.

[0086] 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 light-emitting side optical system 5 described above. 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 subject S described above. Figure 6 shows two correction lenses 16 held by the correction lens holding portion 15 as an example.

[0087] 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.

[0088] (Configuration of Distance Measuring Device 40) FIG. 7 is a block diagram of a distance measuring device 40 according to a first implementation example of the light emitting device 1 according to this embodiment.

[0089] As shown in the figure, the distance measuring device 40 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, a temperature detection unit 10, and a driving control unit 30.

[0090] The light-emitting unit 2 emits light from a plurality of light sources. The light-emitting unit 2 and the light-emitting side optical system 5 correspond to the above-described light-emitting device 1. As will be described later, the light-emitting unit 2 in this example has light-emitting elements 23 with a VCSEL structure as each light source, and these light-emitting elements 23 are arranged in a predetermined pattern, for example, in a matrix.

[0091] The drive control unit 30 controls at least one of the number of times of light emission, the light emission interval, the light emission power, or the light emission pulse width of the plurality of light-emitting elements 23 based on input information. The drive control unit 30 has a drive unit 3 for driving the light-emitting unit 2, and controls this drive unit 3. The drive unit 3 has first to third selection circuits 37 to 39 and a plurality of drive circuits E shown in FIG. 1. A power supply circuit 4 is connected to the drive unit 3. The power supply circuit 4 supplies a power supply voltage (reference voltage) to the first to third selection circuits 37 to 39 and the plurality of drive circuits E shown in FIG. 1.

[0092] Light emitted by the light-emitting unit 2 is irradiated onto a subject (object to be measured) S, the object to be measured, via a light-emitting optical system 5. The irradiated light is reflected from the object to be measured S and enters the light-receiving surface of the light-receiving unit 7 via a light-receiving optical system 6.

[0093] The light receiving unit 7 has a light receiving element such as a CCD (Charge Coupled Device) sensor, a CMOS (Complementary Metal Oxide Semiconductor) sensor, or a SPAD (Single Photon Avalanche Diode), and receives reflected light from the object S to be measured that enters through the light receiving side optical system 6 as described above, converts it into an electrical signal, and outputs it.

[0094] 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 downstream side.

[0095] 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 23 in the light emitting unit 2 to emit light at a timing according to the frame period of the light receiving unit 7.

[0096] The signal processing unit 8 has a signal processor such as 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.

[0097] The control unit 9 has, 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.

[0098] The control unit 9 has a function as a distance measurement unit 9a. The distance measurement unit 9a measures the distance to the object S based on a signal input via the signal processing unit 8 (i.e., a signal obtained by receiving reflected light from the object S). The distance measurement unit 9a in this example measures the distance to each part of the object S to be measured in order to be able to identify the three-dimensional shape of the object S.

[0099] The specific distance measurement method used by the distance measuring device 40 will be explained later.

[0100] The temperature detection unit 10 detects the temperature of the light emitting unit 2. The temperature detection unit 10 performs temperature detection using, for example, a diode.

[0101] In this example, information about the temperature detected by the temperature detection unit 10 is supplied to the drive control unit 30, which can then cause the drive unit 3 to drive the light-emitting unit 2 based on input information including the temperature information. In other words, the drive control unit 30 may select the light-emitting element 23 to emit light based on the information about the detected temperature.

[0102] The input information includes, for example, at least one of setting information of a register (not shown) connected to the drive control unit 30, a light emission trigger signal input to the drive control unit 30, or temperature information detected by the temperature detection unit 10.

[0103] The register setting information is, for example, information such as the number of times or intervals at which the plurality of light emitting elements 23 emit light. The light emission trigger signal is a signal that specifies the timing at which the plurality of light emitting elements 23 emit light.

[0104] For example, the drive control unit 30 controls the light emitting power of the plurality of light emitting elements 23 based on input information. Alternatively, the drive control unit 30 controls the light emitting pulse width of the plurality of light emitting elements 23 based on input information. Alternatively, the drive control unit 30 selects the light emitting element 23 to actually emit light from among the plurality of light emitting elements 23 based on input information. These are examples, and the drive control unit 30 controls the light emitting mode of the light emitting unit 2 based on input information.

[0105] The input information input to the drive control unit 30 includes, in addition to the information on the temperature detected by the temperature detection unit 10 described above, information provided from the plurality of drive circuits E. The information provided from the plurality of drive circuits E includes, for example, at least one of the number of times the plurality of light-emitting elements 23 emit light, the light-emitting interval, the light-emitting timing, or the light-emitting pulse width.

[0106] Alternatively, the input information input to the drive control unit 30 includes, for example, distance measurement information from the distance measurement unit 9 a. In this case, the drive control unit 30 controls at least one of the number of times of light emission, the light emission interval, the light emission power, and the light emission pulse width of the multiple light-emitting elements 23 according to the measured distance.

[0107] Alternatively, the input information input to the drive control unit 30 may include, for example, information provided from a host device (not shown in Fig. 7). The host device may incorporate the distance measuring device 40 of Fig. 7 or may be a device that receives distance measurement information from the distance measuring device 40 and controls the distance measuring device 40. The information provided from the host device to the drive control unit 30 may include, for example, vehicle speed information of the vehicle in which the host device is installed. In this case, the drive control unit 30 controls at least one of the number of times the multiple light-emitting elements 23 emit light, the light-emitting interval, the light-emitting power, or the light-emitting pulse width based on the vehicle speed information.

[0108] The drive control unit 30 can switch the light emitting power of the plurality of light emitting elements 23 depending on whether the object to be measured is at a short distance or a long distance, based on distance measurement information from the host device.

[0109] More specifically, the drive control unit 30 reduces the light-emitting power of the multiple light-emitting elements 23 when the object to be measured is close compared to when the object is far away, thereby reducing power consumption and complying with safety standards for laser light. Furthermore, the drive control unit 30 may reduce the light-emitting power of the multiple light-emitting elements 23 when the vehicle speed of the vehicle on which the distance measurement device 40 is mounted is slow, because distance measurement is required at shorter distances than when the vehicle speed is fast. Furthermore, the drive control unit 30 may reduce the light-emitting power of the multiple light-emitting elements 23 when the number of light-emitting elements 23 is high because they are more likely to generate heat than when the number of light-emitting elements is low. Alternatively, the drive control unit 30 may distribute the light-emitting elements 23 to be targeted for light emission to suppress heat generation from each light-emitting element 23. In other words, the drive control unit 30 distributes light emission among the multiple light-emitting elements 23 so that a specific light-emitting element 23 does not generate heat. Similarly, the drive control unit 30 may reduce the light-emitting power of the multiple light-emitting elements 23 when the temperature detected by the temperature detection unit 10 is high compared to when the temperature is low. Alternatively, the light emitting elements 23 to be emitted may be dispersed to suppress heat generation from each light emitting element 23 .

[0110] As will be described later, the host device or the distance measuring device 40 controls the light emission of two or more light-emitting elements 23 that emit light to a specific ROI (Region of Interest) area within a range in which the plurality of light-emitting elements 23 can emit light, and the drive control unit 30 may control at least one of the number of times of light emission, the light emission interval, the light emission power, or the light emission pulse width of the plurality of light-emitting elements 23 based on at least one of the position and the size of the ROI area. For example, the drive control unit 30 may limit the light-emitting elements 23 that are to emit light by designating only the light-emitting elements 23 that correspond to the ROI area as light-emitting objects and designating the other light-emitting elements 23 as non-light-emitting objects.

[0111] In this way, when multiple light-emitting elements 23 are generating heat or there is a risk of heat generation, the drive control unit 30 performs control such as reducing the light-emitting power of the multiple light-emitting elements 23, shortening the pulse width of the light-emitting pulse signal, thinning out the light emission, switching the light-emitting elements 23 that are the target of light emission, or reducing the number of light-emitting channels.

[0112] (One modified example of the light emitting device) The drive control unit 30 may control at least one of the light emitting power, light emitting pulse width, number of times of light emission, or light emitting interval of the multiple light emitting elements 23 based on a voltage detection signal from a voltage detection circuit that detects the voltage of the first to third anode wirings 31 to 33.

[0113] FIG. 8 is a circuit diagram of a light-emitting device 1a according to a first modification of an embodiment. The light-emitting device 1a according to the first modification shown in FIG. 8 includes first to third voltage detection circuits 71 to 73 in addition to the circuit configuration of FIG. 1. 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.

[0114] The first voltage detection circuit 71 detects the voltage of the first anode wiring 31 from 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 storing charge. On the other hand, if the detected voltage is higher than the predetermined voltage, the transistor 37a is turned off to end storing charge. 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 driver 3 shown in FIG. 1.

[0115] 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.

[0116] Voltage detection signals including the voltages detected by the first to third voltage detection circuits 71 to 73 are input to the drive control unit 30. The drive control unit 30 uses the voltage detection signals as input information to control at least one of the light emitting power, light emitting pulse width, number of light emissions, or light emitting interval of the plurality of light emitting elements 23. For example, if the voltages of the first to third anode wirings 31 to 33 are higher than the expected voltages, the drive control unit 30 controls the voltages of the first to third anode wirings 31 to 33 to be lowered.

[0117] FIG. 9 is a flowchart showing the processing operation of the distance measuring device 40 according to the first embodiment shown in FIG. 7. First, a light emission trigger signal is received from the host device or the distance measuring unit 9a (step S1). Next, it is determined whether the light emission trigger signal matches predetermined operating conditions (step S2). The operating conditions include, for example, conditions such as temperature or power supply voltage. The working conditions are conditions for determining whether to control the light emission conditions of the light-emitting elements 23. In step S2, for example, it is determined whether the ambient temperature of the plurality of light-emitting elements 23 is within a predetermined temperature range based on temperature information detected by the temperature detection unit 10. Alternatively, it is determined whether the voltage level of the power supply voltage is within a predetermined voltage range based on the voltage level of the power supply voltage detected by a power supply voltage detection unit (not shown). Note that the operating conditions can include various conditions, and the temperature or power supply voltage conditions described above are merely examples.

[0118] If it is determined in step S2 that the operating conditions are met, the drive control unit 30 controls (step S3) the light emission conditions, including at least one of the number of times of light emission, the light emission interval, the light emission power, and the light emission pulse width of the plurality of light emitting elements 23. For example, if it is determined in step S2 that heat is being generated, the drive control unit 30 controls the light emission power of the plurality of light emitting elements 23 to be reduced and the light emission pulse width to be narrowed.

[0119] Next, the drive unit 3 causes current to flow through the plurality of light-emitting elements 23 in accordance with the control content of the drive control unit 30, causing the light-emitting elements 23 to emit light (step S4).

[0120] Next, it is determined whether there is a section in which the light-emitting element 23 that should be turned on based on the light-emitting trigger signal from the host device or the distance measuring unit 9a is turned off (step S5). If there is a section in which light is not emitted, information about that section is notified to the host device or the distance measuring unit 9a (step S6). This notification is made to inform the light-emitting device 1 that light was not emitted despite the light-emitting trigger signal being sent from the host device or the distance measuring unit 9a.

[0121] If it is determined in step S2 that the operating conditions are not met, the light emitting element 23 to be illuminated is made to emit light in accordance with the light emission trigger signal (step S7).

[0122] If the judgment in step S5 is NO, or if the processing of step S6 or S7 is completed, the distance measurement unit 9a receives reflected light from the object to be measured (step S8), generates a histogram representing the distribution of the light reception frequency, detects the peak value of the light reception frequency, and performs distance measurement processing to measure the distance to the object (step S9).

[0123] 10A is a diagram showing an optical pulse signal waveform w1 emitted from a plurality of light-emitting elements 23. The horizontal axis of FIG. 10A represents time, and the vertical axis represents signal intensity. In the light-emitting device 1 according to this embodiment, the charge stored in the capacitors 34 to 36 is discharged when the drive circuit E turns on the transistor 24, causing a current to flow through the light-emitting element 23 to emit light, thereby causing light to be emitted. The optical pulse signal waveform in FIG. 10A is determined by the amount of charge stored in the capacitors 34 to 36 and the voltage across the capacitors 34 to 36.

[0124] 10B is a diagram showing a waveform w2 when the drive control unit 30 performs control to reduce the light emission power of the optical pulse signal. The voltage across the capacitors 34 to 36 can be reduced by lowering the power supply voltage applied to the sources of the transistors 37a, 38a, and 39a of the selection circuit connected to the capacitors 34 to 36. When the voltage across the capacitors 34 to 36 is reduced, the signal strength of the optical pulse signal can be reduced when the light-emitting element 23 is caused to emit light. Therefore, the signal strength of the optical pulse signal can be reduced by lowering the power supply voltage applied to the selection circuit.

[0125] 10C is a diagram showing a waveform w3 when the drive control unit 30 performs control to narrow the pulse width of the light pulse signal. As described above, by turning on the transistors of the drive circuit E while the capacitors 34 to 36 are charged, a current flows from the capacitors 34 to 36 to the light-emitting element 23 that is the light emission target. By turning off the transistors of the drive circuit E before the capacitors 34 to 36 finish discharging, the pulse width of the light pulse signal can be controlled as shown in FIG. 10C.

[0126] 10D is a diagram showing a waveform w4 when the drive control unit 30 performs control to thin out the light pulse signal. The drive control unit 30 can stop the light emission of the light-emitting element 23 that is the light emission target by turning off the transistor of the drive circuit E.

[0127] If the drive control unit 30 reduces the number of times the light emitting element 23 to emit light is to emit light because the light emitting element 23 to emit light is generating heat or for other reasons despite receiving a light emission trigger signal from the host device or distance measuring unit 9a, the drive control unit 30 notifies the host device or distance measuring unit 9a of information about the light pulse signals that were not emitted in response to the light emission trigger signal. This prevents the host device or distance measuring unit 9a from misunderstanding the emission timing of the light pulse signal corresponding to the received light pulse signal, thereby improving distance measurement accuracy.

[0128] Fig. 11A is a diagram showing the light emitting positions of all light emitting elements 23 in the light emitting unit 2 and the light receiving positions of all light receiving elements in the light receiving unit 7. The left side of Fig. 11A shows a map of the light emitting positions of all light emitting elements 23, and the right side shows a map of the light receiving positions of all light receiving elements. Fig. 11A shows an example having 6 x 6 light emitting elements 23 and light receiving elements, but the number of light emitting elements 23 and light receiving elements is arbitrary.

[0129] When there is a risk of heat generation, the drive control unit 30 spreads out the light-emitting positions of the multiple light-emitting elements 23 to suppress heat generation from a specific light-emitting element 23. Fig. 11A shows an example in which the light-emitting element 23 at the light-emitting position marked 1 is made to emit light, and then the light-emitting element 23 at the light-emitting position marked 2 is made to emit light. In the light-receiving unit 7, the light-receiving element at the light-receiving position corresponding to light-emitting element 2 receives light from the object to be measured.

[0130] As shown in FIG. 11A, the drive control unit 30 can suppress heat generation at a specific location of the light-emitting unit 2 by arbitrarily switching the light-emitting order of the light-emitting elements 23.

[0131] 11B is a diagram showing the light-emitting positions of the light-emitting elements 23 within the ROI region of the light-emitting unit 2 and the light-receiving positions of the corresponding light-receiving elements of the light-receiving unit 7. The left side of Fig. 11B shows a map of the light-emitting positions of the light-emitting elements 23 within the ROI region, and the right side shows a map of the light-receiving positions of the light-receiving elements within the ROI region.

[0132] By allowing the drive control unit 30 to switch the light emitting positions in any order even within the ROI region, it is possible to suppress heat generation from specific light emitting elements 23 within the ROI region.

[0133] In Figure 7, an example has been described in which the drive control unit 30 in the light-emitting device 1 controls at least one of the number of times that the multiple light-emitting elements 23 emit light, the light-emitting interval, the light-emitting power, or the light-emitting pulse width, but the control unit 9 having the distance measurement unit 9a may also control at least one of the number of times that the multiple light-emitting elements 23 emit light, the light-emitting interval, the light-emitting power, or the light-emitting pulse width.

[0134] Fig. 12 is a block diagram of a distance measuring device 40 according to a second implementation example of the light emitting device 1 of this embodiment. The distance measuring device 40 according to the second implementation example differs from the distance measuring device 40 according to the first implementation example shown in Fig. 7 in that the drive control unit 30 is not present. The distance measuring device 40 in Fig. 12 is controlled by a host device (not shown). The host device and the control unit 9 in Fig. 12 may be integrated.

[0135] The control unit 9 controls at least one of the number of times the plurality of light emitting elements 23 emit light, the light emission interval, the light emission power, and the light emission pulse width based on the input information.

[0136] The input information may include information provided by the light-emitting device 1. The information provided by the light-emitting device 1 may include temperature information around the plurality of light-emitting elements 23. In this case, the control unit 9 selects the light-emitting elements 23 to be made to emit light from among the plurality of light-emitting elements 23 based on the temperature information. The information provided by the light-emitting device 1 may include at least one of the number of times the plurality of light-emitting elements 23 emit light, the light-emitting interval, the light-emitting power, or the light-emitting pulse width.

[0137] The input information may include distance measurement information or information provided from the host device. The information provided from the host device may include vehicle speed information of the vehicle in which the host device is installed.

[0138] 13 is a flowchart showing the processing operation of the distance measuring device 40 of FIG. 12. First, the control unit 9 acquires information provided from the host device, the distance measuring unit 9a, or the light emitting device 1 (step S11). The information provided from the host device or the distance measuring unit 9a is, for example, distance measurement information or light emission control information. The information provided from the light emitting device 1 is, for example, temperature information around the plurality of light emitting elements 23, the number of times the plurality of light emitting elements 23 emit light, the light emission interval, the light emission power, or the light emission pulse width.

[0139] Based on the acquired information, the control unit 9 determines whether the plurality of light-emitting elements 23 are expected to experience characteristic fluctuations due to heat generation (step S12). If step S12 returns YES, the control unit 9 selects an emission pattern that can suppress heat generation from the plurality of light-emitting elements 23 (step S13). Here, the control unit 9 selects an emission pattern in which the emission order of the plurality of light-emitting elements 23 is such that heat generation from a certain number of light-emitting elements 23 is suppressed, as shown in, for example, FIGS. 11A and 11B. Alternatively, the control unit 9 selects an emission pattern that lowers the peak of the optical pulse signal, shortens the pulse width, or reduces the number of emissions, as shown in, for example, FIGS. 10B to 10D.

[0140] If the result of the determination in step S12 is NO, the control unit 9 selects the normal light emission pattern of the plurality of light emitting elements 23 (step S14).

[0141] After the process of step S13 or S14 is completed, the control unit 9 transmits light emission control information including the selected light emission pattern to the drive unit 3. The drive unit 3 causes the plurality of light emitting elements 23 to emit light based on the light emission control information from the control unit 9 (step S15). This allows the control unit 9 to control at least one of the number of times the plurality of light emitting elements 23 emit light, the light emission interval, the light emission power, or the light emission pulse width.

[0142] Then, the distance measurement unit 9a receives reflected light from the object (step S16), generates a histogram representing the distribution of light reception frequency, detects the peak value of the light reception frequency, and performs distance measurement processing to measure the distance to the object (step S17).

[0143] (Modifications of the circuit configuration of the light-emitting device) The circuit configuration of the light-emitting device 1 according to the present disclosure is not limited to the circuit configuration shown in Fig. 1 or 8, and various modifications are possible. Representative modifications of the circuit configuration of the light-emitting device 1 according to the present disclosure will be described below in order.

[0144] FIG. 14 is a circuit diagram of a light-emitting device 1b according to a second modification of an embodiment. As shown in FIG. 14, the light-emitting device 1b according to this embodiment 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. 1 , includes multiple anode wirings 41′ in the positions of the multiple cathode wirings 41, and omits the multiple gate wirings 42. Similarly to the first to third anode wirings 31 to 33, 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′. 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.

[0145] Each light emitting element 23 according to the embodiment 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'.

[0146] The light-emitting device 1b according to one embodiment further includes first to third transistors 61 to 63 at the positions of the first to third capacitors 34 to 36 shown in FIG. 1 . 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 constitutes 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.

[0147] The light emitting device 1b according to the embodiment further includes a plurality of capacitors 67 at the positions of the plurality of transistors 24 shown in Fig. 1. 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.

[0148] The light emitting device 1b according to the embodiment 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.

[0149] 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.

[0150] The functions of the first to third transistors 61 to 63 and their drive circuit E are similar to those of the transistor 24 and its drive circuit E. The first to third transistors 61 to 63 can drive the light-emitting elements 23 electrically connected to the first to third cathode wirings 31′ to 33′, respectively.

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

[0152] FIG. 15 is a circuit diagram of a light-emitting device 1c according to a first modification of an embodiment. As shown in FIG. 15, the light-emitting device 1c according to the first 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. 1, a plurality of anode wirings 41′ at the positions of the plurality of cathode wirings 41, and a plurality of gate wirings 42′ at the positions of the plurality of 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′, respectively, similar to the first to third anode wirings 31 to 33. 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.

[0153] Each light-emitting element 23 in the first 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 the first 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 the first 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 the first modification are electrically connected to the first to third cathode wirings 31' to 33', respectively.

[0154] According to the light emitting device 1c of the first modification, it is possible to realize the same control as that of the light emitting device 1 of the first embodiment, despite having a different structure from that of the light emitting device 1 of the first embodiment.

[0155] FIG. 16 is a circuit diagram of a light-emitting device 1d according to a second modification of the embodiment. As shown in FIG. 16, the light-emitting device 1d according to the second modification includes six sets of first to third capacitors 34 to 36 instead of the four sets of first to third capacitors 34 to 36 shown in FIG. The first to third capacitors 34 to 36 of the second 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 the second 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.

[0156] According to the light emitting device 1d of the second modification, it is possible to realize the same control as that of the light emitting device 1 of the first embodiment, despite having a different structure from that of the light emitting device 1 of the first embodiment.

[0157] 17 is a circuit diagram of a light-emitting device 1e according to a third modification of the embodiment. As shown in FIG. 17, the light-emitting device 1e according to the third modification does not include the first to third capacitors 34 to 36. The light-emitting device 1e of the third modification accumulates 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.

[0158] Fig. 18 is a detailed circuit diagram of the periphery of the light-emitting element 23 in Fig. 17. The drain of a transistor 24 is connected to the cathode of the light-emitting element 23, and the source is grounded. A parasitic capacitance 23' exists between the anode and cathode of the light-emitting element 23, and a parasitic capacitance 24' exists between the drain and source of the transistor 24.

[0159] The light emitting device 1a of the third modification accumulates electric charges in the parasitic capacitances 23', 24' to be supplied to each light emitting element 23. This allows current to flow through each light emitting element 23, causing each light emitting element 23 to emit light. The accumulation in the parasitic capacitances 23', 24' is controlled by first to third selection circuits 37 to 39.

[0160] According to the light emitting device 1a of the third modified example, it is possible to realize the same control as that of the light emitting device 1 of the first embodiment, despite having a different structure from that of the light emitting device 1 of the first embodiment.

[0161] Various modifications can be considered for the circuit configuration of the drive circuit of the light emitting device according to the first to third embodiments described above. Below, the circuit configurations of the drive circuit according to the first to third representative modifications will be described in order.

[0162] 19A is a circuit diagram of a drive circuit according to a first modification. The drive circuit according to the first modification 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. 19A 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.

[0163] 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.

[0164] Fig. 19B is a circuit diagram of a drive circuit according to a second modification. The drive circuit according to the second modification includes three transistors 24 electrically connected to a cathode wiring 41. The transistors 24 shown in Fig. 19B are, for example, NPN-type bipolar transistors. In this case, the wiring 42 becomes a "base wiring" rather than a "gate wiring." The operation of the drive circuit E shown in Fig. 19B is similar to that of the drive circuit E shown in Fig. 1 etc.

[0165] 19C is a circuit diagram of a drive circuit according to a third modification. The drive circuit according to a sixth modification 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. 19C 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. 19C is similar to that of the drive circuit E shown in FIG. 19A.

[0166] The light emitting device 1a according to the third modification has a different structure from that of the light emitting device 1 of the first embodiment, but it is possible to achieve the same control as that of the light emitting device 1 of the first embodiment.

[0167] (Range Measurement Method) The distance measurement method used in the distance measurement device 40 may be, for example, a STL (Structured Light) method or a ToF (Time of Flight) method.

[0168] The STL method is a method for measuring distance based on an image of a distance measurement object S illuminated with light having a predetermined light / dark pattern, such as a dot pattern or a grid pattern.

[0169] Fig. 20A is an explanatory diagram of the STL method. In the STL method, pattern light Lp having a dot pattern such as that shown in Fig. 20A is irradiated onto a distance measurement target 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 not to overlap between blocks BL).

[0170] FIG. 20B is an explanatory diagram of the distance measurement principle of the STL system.

[0171] In this example, a wall W and a box BX placed in front of it are the object S to be measured, and pattern light Lp is irradiated onto the object S to be measured. "G" in the figure schematically represents the angle of view of the light receiving unit 7.

[0172] 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.

[0173] 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.

[0174] The STL method is a method for determining the shape and depth of the object S to be measured by utilizing the fact that the projected pattern is distorted depending on the shape of the object S to be measured. Specifically, it is a method for determining the shape and depth of the object S to be measured from the way the pattern is distorted.

[0175] When the STL system is adopted, for example, a global shutter type IR (Infrared) light receiving unit 7 is used as the light receiving unit 7. In the case of the STL system, the distance measuring unit 9a controls the drive 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.

[0176] 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.

[0177] 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 object S to be measured based on the time difference and the speed of light.

[0178] When the so-called indirect ToF (iTOF) method (phase difference method) is adopted as the ToF method, the light receiving unit 7 used is, for example, a light receiving unit 7 capable of receiving IR.

[0179] <<Application Examples>> The technology according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of moving body, such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, personal mobility, an airplane, a drone, a ship, a robot, construction machinery, or agricultural machinery (tractor).

[0180] 21 is a block diagram showing a schematic configuration example of a vehicle control system 7000, which is an example of a mobile object control system to which the technology according to the present disclosure can be applied. The vehicle control system 7000 includes a plurality of electronic control units connected via a communication network 7010. In the example shown in FIG. 21 , the vehicle control system 7000 includes a drive system control unit 7100, a body system control unit 7200, a battery control unit 7300, an outside-vehicle information detection unit 7400, an inside-vehicle information detection unit 7500, and an integrated control unit 7600. The communication network 7010 connecting these multiple control units may be an in-vehicle communication network conforming to any standard, such as a Controller Area Network (CAN), a Local Interconnect Network (LIN), a Local Area Network (LAN), or FlexRay (registered trademark).

[0181] Each control unit includes a microcomputer that performs arithmetic processing according to various programs, a memory unit that stores the programs executed by the microcomputer or parameters used in various calculations, and a drive circuit that drives various controlled devices. Each control unit includes a network I / F for communicating with other control units via a communication network 7010, and a communication I / F for communicating with devices or sensors inside and outside the vehicle via wired or wireless communication. Figure 21 illustrates the functional configuration of the integrated control unit 7600, including a microcomputer 7610, a general-purpose communication I / F 7620, a dedicated communication I / F 7630, a positioning unit 7640, a beacon receiving unit 7650, an in-vehicle device I / F 7660, an audio / video output unit 7670, an in-vehicle network I / F 7680, and a memory unit 7690. Other control units also include a microcomputer, a communication I / F, a memory unit, and the like.

[0182] The drivetrain control unit 7100 controls the operation of devices related to the drivetrain of the vehicle in accordance with various programs. For example, the drivetrain control unit 7100 functions as a control device for a drive force generating device for generating drive force for the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating braking force for the vehicle. The drivetrain control unit 7100 may also function as a control device for an ABS (Antilock Brake System) or an ESC (Electronic Stability Control), etc.

[0183] A vehicle state detection unit 7110 is connected to the drivetrain control unit 7100. The vehicle state detection unit 7110 includes at least one of a gyro sensor that detects the angular velocity of the axial rotational motion of the vehicle body, an acceleration sensor that detects the acceleration of the vehicle, or a sensor that detects the amount of operation of the accelerator pedal, the amount of operation of the brake pedal, the steering angle of the steering wheel, the engine rotation speed, the rotation speed of the wheels, etc. The drivetrain control unit 7100 performs arithmetic processing using signals input from the vehicle state detection unit 7110, and controls the internal combustion engine, the drive motor, the electric power steering device, the brake device, etc.

[0184] The body system control unit 7200 controls the operation of various devices equipped in the vehicle body according to various programs. For example, the body system control unit 7200 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as headlamps, backup lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves transmitted from a portable device that serves as a key or signals from various switches can be input to the body system control unit 7200. The body system control unit 7200 receives these radio waves or signals and controls the vehicle's door lock device, power window device, lamps, etc.

[0185] The battery control unit 7300 controls the secondary battery 7310, which is the power supply source for the drive motor, in accordance with various programs. For example, information such as battery temperature, battery output voltage, or remaining battery capacity is input to the battery control unit 7300 from a battery device equipped with the secondary battery 7310. The battery control unit 7300 performs arithmetic processing using these signals, and controls the temperature regulation of the secondary battery 7310 or a cooling device or the like equipped in the battery device.

[0186] The outside vehicle information detection unit 7400 detects information outside the vehicle equipped with the vehicle control system 7000. For example, at least one of an imaging unit 7410 and an outside vehicle information detection unit 7420 is connected to the outside vehicle information detection unit 7400. The imaging unit 7410 includes at least one of a time-of-flight (ToF) camera, a stereo camera, a monocular camera, an infrared camera, and other cameras. The outside vehicle information detection unit 7420 includes at least one of an environmental sensor for detecting the current weather or climate, or a surrounding information detection sensor for detecting other vehicles, obstacles, pedestrians, etc. around the vehicle equipped with the vehicle control system 7000.

[0187] The environmental sensor may be, for example, at least one of a raindrop sensor that detects rain, a fog sensor that detects fog, a sunshine sensor that detects the degree of sunshine, and a snow sensor that detects snowfall. The surrounding information detection sensor may be at least one of an ultrasonic sensor, a radar device, and a LIDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging) device. The imaging unit 7410 and the outside vehicle information detection unit 7420 may each be provided as an independent sensor or device, or may be provided as a device in which multiple sensors or devices are integrated.

[0188] 22 shows an example of the installation positions of the imaging unit 7410 and the vehicle exterior information detection unit 7420. The imaging units 7910, 7912, 7914, 7916, and 7918 are provided, for example, at least one of the front nose, side mirrors, rear bumper, back door, and upper part of the windshield inside the vehicle cabin of the vehicle 7900. The imaging unit 7910 provided on the front nose and the imaging unit 7918 provided on the upper part of the windshield inside the vehicle cabin mainly acquire images of the front of the vehicle 7900. The imaging units 7912 and 7914 provided on the side mirrors mainly acquire images of the sides of the vehicle 7900. The imaging unit 7916 provided on the rear bumper or back door mainly acquires images of the rear of the vehicle 7900. The imaging unit 7918 provided on the upper part of the windshield inside the vehicle cabin is mainly used to detect leading vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, etc.

[0189] 22 shows an example of the imaging ranges of the imaging units 7910, 7912, 7914, and 7916. Imaging range a indicates the imaging range of the imaging unit 7910 provided on the front nose, imaging ranges b and c indicate the imaging ranges of the imaging units 7912 and 7914 provided on the side mirrors, respectively, and imaging range d indicates the imaging range of the imaging unit 7916 provided on the rear bumper or back door. For example, by overlaying the image data captured by the imaging units 7910, 7912, 7914, and 7916, a bird's-eye view image of the vehicle 7900 viewed from above can be obtained.

[0190] The outside vehicle information detection units 7920, 7922, 7924, 7926, 7928, and 7930 provided on the front, rear, sides, corners, and above the windshield inside the vehicle cabin of the vehicle 7900 may be, for example, ultrasonic sensors or radar devices. The outside vehicle information detection units 7920, 7926, and 7930 provided on the front nose, rear bumper, back door, and above the windshield inside the vehicle cabin of the vehicle 7900 may be, for example, LIDAR devices. These outside vehicle information detection units 7920 to 7930 are mainly used to detect preceding vehicles, pedestrians, obstacles, etc.

[0191] Returning to FIG. 21 , the description continues. The outside-vehicle information detection unit 7400 causes the imaging unit 7410 to capture an image outside the vehicle and receives the captured image data. The outside-vehicle information detection unit 7400 also receives detection information from the connected outside-vehicle information detection unit 7420. If the outside-vehicle information detection unit 7420 is an ultrasonic sensor, a radar device, or a LIDAR device, the outside-vehicle information detection unit 7400 emits ultrasonic waves or electromagnetic waves and receives information on the received reflected waves. The outside-vehicle information detection unit 7400 may perform a distance detection process or a distance detection process for a distance measurement object such as a person, a vehicle, an obstacle, a sign, or text on the road surface based on the received information. The outside-vehicle information detection unit 7400 may also perform an environment recognition process for recognizing rainfall, fog, road conditions, etc. based on the received information. The outside-vehicle information detection unit 7400 may also calculate the distance to a distance measurement object outside the vehicle based on the received information.

[0192] The outside vehicle information detection unit 7400 may also perform image recognition processing or distance detection processing to recognize people, vehicles, obstacles, signs, or characters on the road surface based on the received image data. The outside vehicle information detection unit 7400 may perform processing such as distortion correction or alignment on the received image data, and may also generate an overhead image or a panoramic image by combining image data captured by different image capturing units 7410. The outside vehicle information detection unit 7400 may also perform viewpoint conversion processing using image data captured by different image capturing units 7410.

[0193] The interior information detection unit 7500 detects information inside the vehicle. A driver state detection unit 7510 that detects the driver's state is connected to the interior information detection unit 7500, for example. The driver state detection unit 7510 may include a camera that captures an image of the driver, a biosensor that detects the driver's biometric information, or a microphone that collects sound from within the vehicle cabin. The biosensor is provided, for example, on the seat or steering wheel, and detects the biometric information of a passenger sitting in the seat or the driver gripping the steering wheel. The interior information detection unit 7500 may calculate the driver's level of fatigue or concentration based on the detection information input from the driver state detection unit 7510, or may determine whether the driver is dozing off. The interior information detection unit 7500 may perform processing such as noise canceling on the collected audio signal.

[0194] The integrated control unit 7600 controls the overall operation of the vehicle control system 7000 according to various programs. An input unit 7800 is connected to the integrated control unit 7600. The input unit 7800 may be implemented by a device that can be operated by a passenger, such as a touch panel, a button, a microphone, a switch, or a lever. Data obtained by voice recognition of a voice input through a microphone may be input to the integrated control unit 7600. The input unit 7800 may be, for example, a remote control device using infrared or other radio waves, or an externally connected device such as a mobile phone or a personal digital assistant (PDA) that can operate the vehicle control system 7000. The input unit 7800 may be, for example, a camera, in which case the passenger can input information using gestures. Alternatively, data obtained by detecting the movement of a wearable device worn by the passenger may be input. Furthermore, the input unit 7800 may include, for example, an input control circuit that generates an input signal based on information input by the passenger using the input unit 7800 and outputs the input signal to the integrated control unit 7600. Passengers and the like operate this input unit 7800 to input various data to the vehicle control system 7000 and to instruct processing operations.

[0195] The storage unit 7690 may include a ROM (Read Only Memory) that stores various programs executed by the microcomputer, and a RAM (Random Access Memory) that stores various parameters, calculation results, sensor values, etc. The storage unit 7690 may also be realized by a magnetic storage device such as an HDD (Hard Disc Drive), a semiconductor storage device, an optical storage device, a magneto-optical storage device, or the like.

[0196] The general-purpose communication I / F 7620 is a general-purpose communication I / F that mediates communication with various devices present in the external environment 7750. The general-purpose communication I / F 7620 may implement a cellular communication protocol such as GSM (Global System of Mobile communications), WiMAX (registered trademark), LTE (Long Term Evolution), or LTE-Advanced (LTE-A), or other wireless communication protocols such as a wireless LAN (also referred to as Wi-Fi (registered trademark)) or Bluetooth (registered trademark). The general-purpose communication I / F 7620 may connect to a device (e.g., an application server or a control server) present on an external network (e.g., the Internet, a cloud network, or an operator-specific network) via, for example, a base station or an access point. In addition, the general-purpose communication I / F 7620 may connect to a terminal located near the vehicle (for example, a terminal of a driver, pedestrian, or store, or an MTC (Machine Type Communication) terminal) using, for example, P2P (Peer To Peer) technology.

[0197] The dedicated communication I / F 7630 is a communication I / F that supports a communication protocol designed for use in vehicles. The dedicated communication I / F 7630 may implement a standard protocol such as WAVE (Wireless Access in Vehicle Environment), which is a combination of a lower layer IEEE 802.11p and an upper layer IEEE 1609, DSRC (Dedicated Short Range Communications), or a cellular communication protocol. The dedicated communication I / F 7630 typically performs V2X communication, which is a concept including one or more of vehicle-to-vehicle communication, vehicle-to-infrastructure communication, vehicle-to-home communication, and vehicle-to-pedestrian communication.

[0198] The positioning unit 7640 performs positioning by receiving, for example, GNSS signals from GNSS (Global Navigation Satellite System) satellites (for example, GPS signals from GPS (Global Positioning System) satellites), and generates position information including the latitude, longitude, and altitude of the vehicle. Note that the positioning unit 7640 may identify the current position by exchanging signals with a wireless access point, or may obtain position information from a terminal such as a mobile phone, PHS, or smartphone that has a positioning function.

[0199] The beacon receiving unit 7650 receives, for example, radio waves or electromagnetic waves transmitted from radio stations or the like installed on the road, and acquires information such as the current location, congestion, road closures, required travel time, etc. The function of the beacon receiving unit 7650 may be included in the dedicated communication I / F 7630 described above.

[0200] The in-vehicle device I / F 7660 is a communication interface that mediates connections between the microcomputer 7610 and various in-vehicle devices 7760 present in the vehicle. The in-vehicle device I / F 7660 may establish wireless connections using wireless communication protocols such as wireless LAN, Bluetooth (registered trademark), NFC (Near Field Communication), or WUSB (Wireless USB). Furthermore, the in-vehicle device I / F 7660 may establish a wired connection such as USB (Universal Serial Bus), HDMI (High-Definition Multimedia Interface), or MHL (Mobile High-Definition Link) via a connection terminal (and a cable, if necessary) not shown. The in-vehicle device 7760 may include, for example, at least one of a mobile device or a wearable device owned by a passenger, or an information device carried into or attached to the vehicle. The in-vehicle device 7760 may also include a navigation device that searches for a route to an arbitrary destination. The in-vehicle device I / F 7660 exchanges control signals or data signals with these in-vehicle devices 7760.

[0201] The in-vehicle network I / F 7680 is an interface that mediates communication between the microcomputer 7610 and the communication network 7010. The in-vehicle network I / F 7680 transmits and receives signals in accordance with a predetermined protocol supported by the communication network 7010.

[0202] The microcomputer 7610 of the integrated control unit 7600 controls the vehicle control system 7000 in accordance with various programs based on information acquired via at least one of the general-purpose communication I / F 7620, the dedicated communication I / F 7630, the positioning unit 7640, the beacon receiving unit 7650, the in-vehicle device I / F 7660, and the in-vehicle network I / F 7680. For example, the microcomputer 7610 may calculate control target values ​​for the driving force generating device, the steering mechanism, or the braking device based on the acquired information inside and outside the vehicle, and output control commands to the drivetrain control unit 7100. For example, the microcomputer 7610 may perform cooperative control aimed at realizing functions of an Advanced Driver Assistance System (ADAS), including vehicle collision avoidance or impact mitigation, following driving based on the following distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane departure warning, etc. In addition, the microcomputer 7610 may perform cooperative control for the purpose of autonomous driving, in which the vehicle travels autonomously without relying on driver operation, by controlling a driving force generating device, a steering mechanism, a braking device, etc. based on information acquired about the vehicle's surroundings.

[0203] The microcomputer 7610 may generate three-dimensional distance information between the vehicle and distance measurement objects, such as surrounding structures and people, based on information acquired via at least one of the general-purpose communication I / F 7620, the dedicated communication I / F 7630, the positioning unit 7640, the beacon receiving unit 7650, the in-vehicle device I / F 7660, and the in-vehicle network I / F 7680, and may create local map information including information about the vicinity of the vehicle's current location. Furthermore, the microcomputer 7610 may predict danger, such as a vehicle collision, the approach of a pedestrian, or entry into a closed road, based on the acquired information, and generate a warning signal. The warning signal may be, for example, a signal for generating a warning sound or turning on a warning lamp.

[0204] The audio / image output unit 7670 transmits at least one of audio and image output signals to an output device capable of visually or audibly notifying vehicle occupants or the outside of the vehicle of information. In the example of FIG. 21 , an audio speaker 7710, a display unit 7720, and an instrument panel 7730 are illustrated as output devices. The display unit 7720 may include, for example, at least one of an on-board display and a head-up display. The display unit 7720 may have an AR (Augmented Reality) display function. The output device may also be other devices, such as headphones, a wearable device such as an eyeglass-type display worn by the occupant, a projector, or a lamp. When the output device is a display device, the display device visually displays results obtained by various processes performed by the microcomputer 7610 or information received from other control units in various formats, such as text, images, tables, and graphs. When the output device is an audio output device, the audio output device converts audio signals, such as reproduced audio data or acoustic data, into analog signals and audibly outputs the analog signals.

[0205] In the example shown in FIG. 21 , at least two control units connected via the communication network 7010 may be integrated into a single control unit. Alternatively, each control unit may be composed of multiple control units. Furthermore, the vehicle control system 7000 may include another control unit not shown. In the above description, some or all of the functions performed by one of the control units may be assigned to another control unit. In other words, as long as information is transmitted and received via the communication network 7010, predetermined arithmetic processing may be performed by one of the control units. Similarly, a sensor or device connected to one of the control units may be connected to another control unit, and multiple control units may transmit and receive detection information to and from each other via the communication network 7010.

[0206] A computer program for realizing each function of the distance measuring device 40 according to this embodiment described with reference to FIG. 7 and other figures can be implemented in any control unit or the like. A computer-readable recording medium storing such a computer program can also be provided. Examples of the recording medium include a magnetic disk, an optical disk, a magneto-optical disk, and a flash memory. The computer program may also be distributed, for example, via a network without using a recording medium.

[0207] In the vehicle control system 7000 described above, the distance measuring device 40 according to this embodiment described using Figure 7 etc. can be applied to the integrated control unit 7600 of the application example shown in Figure 21. For example, the control unit 9 of the distance measuring device 40 corresponds to the microcomputer 7610, memory unit 7690, and in-vehicle network I / F 7680 of the integrated control unit 7600.

[0208] Furthermore, at least some of the components of the distance measuring device 40 described using Fig. 7 etc. may be realized in a module (for example, an integrated circuit module configured on a single die) for the integrated control unit 7600 shown in Fig. 21. Alternatively, the distance measuring device 40 described using Fig. 7 etc. may be realized by multiple control units of the vehicle control system 7000 shown in Fig. 21.

[0209] The present technology can be configured as follows:

[0210] (1) A light emitting device comprising: a plurality of light emitting elements arranged in a two-dimensional array, each having a first and second terminal; M first wirings (M is an integer of 2 or more) extending in a first direction; and N second wirings (N is an integer of 2 or more) extending in a second direction intersecting the first direction and electrically connected to the M first wirings, respectively; a plurality of first terminal wirings electrically connected to the first terminals of the light emitting elements; a plurality of second terminal wirings electrically connected to the second terminals of the light emitting elements, each electrically connected to P (P is an integer of 2 or more) of the light emitting elements; a plurality of selection circuits respectively connected to one of the plurality of first terminal wirings and the plurality of second terminal wirings and selecting the corresponding light emitting elements; a plurality of drive circuits respectively connected to the other of the plurality of first terminal wirings and the plurality of second terminal wirings and driving the corresponding light emitting elements; and a control unit which controls at least one of the number of times of light emission, the light emission interval, the light emission power, and the light emission pulse width of the plurality of light emitting elements based on input information, wherein N is an integer that is the same as or different from M, A light-emitting device, wherein P is an integer that is the same as or different from at least one of M and N. (2) The light-emitting device according to (1), wherein the control unit selects a light-emitting element to emit light from among the plurality of light-emitting elements based on the input information. (3) The light-emitting device according to (1), wherein the control unit controls the light-emitting order of the plurality of light-emitting elements based on the input information. (4) The light-emitting device according to any one of (1) to (3), comprising: a first substrate comprising the plurality of light-emitting elements; and a second substrate stacked on the first substrate and comprising the plurality of selection circuits, the plurality of drive circuits, and the control unit. (5) The light-emitting device according to any one of (1) to (4), wherein the input information includes temperature information around the plurality of light-emitting elements, and the control unit selects a light-emitting element to emit light from among the plurality of light-emitting elements based on the temperature information. (6) The light-emitting device according to any one of (1) to (5), comprising a drive unit having the plurality of selection circuits and the plurality of drive circuits, and wherein the input information includes information provided from the drive unit.(7) The light-emitting device according to (6), wherein the information provided from the drive unit includes at least one of the number of times of light emission, the light-emitting interval, the light-emitting power, and the light-emitting pulse width of the plurality of light-emitting elements. (8) The light-emitting device according to any one of (1) to (5), wherein the input information includes distance measurement information obtained by measuring distances using light emitted by the plurality of light-emitting elements. (9) The light-emitting device according to (8), wherein the control unit controls at least one of the number of times of light emission, the light-emitting interval, the light-emitting power, and the light-emitting pulse width of the plurality of light-emitting elements according to the measured distance, based on the distance measurement information included in the input information. (10) The light-emitting device according to any one of (1) to (5), wherein the input information is information provided from a host device. (11) The light-emitting device according to (10), wherein the information provided from the host device includes speed information of a vehicle on which the host device is mounted, and the control unit controls at least one of the number of times of light emission, the light-emitting interval, the light-emitting power, and the light-emitting pulse width of the plurality of light-emitting elements based on the vehicle speed information. (12) The light-emitting device described in (10), wherein the host device or distance measurement unit controls the light emission of two or more of the plurality of light-emitting elements that emit light into a ROI (Region Of Interest) area, and the control unit controls at least one of the number of times the plurality of light-emitting elements emit light, the light emission interval, the light emission power, or the light emission pulse width based on at least one of the position or size of the ROI area.(13) A distance measuring device including: a light emitting device that emits light toward an object to be measured; and a control unit having a distance measuring unit that receives light reflected by the object to be measured and measures the distance to the object, wherein the light emitting device includes: a plurality of light emitting elements arranged in a two-dimensional array, each having a first and a second terminal; M first wirings (M is an integer of 2 or more) extending in a first direction; and N second wirings (N is an integer of 2 or more) extending in a second direction intersecting the first direction and electrically connected to the M first wirings, respectively; a plurality of first terminal wirings electrically connected to the first terminals of the light emitting elements; a plurality of second terminal wirings electrically connected to the second terminals of the light emitting elements, each electrically connected to P (P is an integer of 2 or more) of the light emitting elements; and a plurality of selection circuits respectively connected to one of the plurality of first terminal wirings and the plurality of second terminal wirings, and selecting the corresponding light emitting elements. a plurality of drive circuits connected to the other of the plurality of first terminal wirings and the plurality of second terminal wirings, respectively, and driving the corresponding light-emitting elements, wherein the control unit controls at least one of the number of times of light emission, the light emission interval, the light emission power, or the light emission pulse width of the plurality of light-emitting elements based on input information. (14) The distance measuring device according to (13), wherein the input information includes information provided from the light-emitting device. (15) The distance measuring device according to (14), wherein the information provided from the light-emitting device includes temperature information around the plurality of light-emitting elements, and the control unit selects a light-emitting element to be caused to emit light from among the plurality of light-emitting elements based on the temperature information. (16) The distance measuring device according to (14), wherein the information provided from the light-emitting device includes at least one of the number of times of light emission, the light emission interval, the light emission power, or the light emission pulse width of the plurality of light-emitting elements. (17) The distance measuring device according to any one of (13) to (15), wherein the control unit selects a light-emitting element to be caused to emit light from among the plurality of light-emitting elements based on the input information. (18) The distance measuring device according to any one of (13) to (15), wherein the control unit controls an order in which the plurality of light-emitting elements emit light based on the input information.(19) The distance measuring device according to any one of (13) to (15), wherein the input information includes distance measurement information or information provided from a host device. (20) The distance measuring device according to (19), wherein the information provided from the host device includes vehicle speed information of a vehicle on which the host device is installed.

[0211] The aspects of the present disclosure are not limited to the individual embodiments described above, but include various modifications that may be conceived by those skilled in the art, and the effects of the present disclosure are not limited to the above-described contents. In other words, various additions, modifications, and partial deletions are possible within the scope of the conceptual idea and spirit of the present disclosure, which is derived from the contents defined in the claims and their equivalents.

[0212] REFERENCE SIGNS LIST 1, 1a, 1b, 1c, 1d, 1e Light emitting device, 2 Light emitting section, 3 Drive 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, 20 Mesa section, 21 Substrate, 22 Stacked film, 23 Light emitting element, 23′ Parasitic capacitance, 24 Transistor, 24′ Parasitic capacitance, 25 Transistor, 30 Drive control section, 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, 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, 40 Range finder, 41 Cathode wiring, 41' Anode wiring, 42 Wiring, 42 Gate wiring, 42' Gate wiring, 43 Gate wiring, 47 Anode electrode, 48 Cathode electrode, 49 Pad, 50 Bonding layer, 51 Insulating substrate, 52 Insulating film, 53 Wiring layer, 54 Insulating film, 55 Wiring layer, 56 Wiring, 57 Solder ball, 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

Claims

1. A light emitting device comprising: a plurality of light emitting elements arranged in a two-dimensional array, each having a first and second terminal; M first wirings (M is an integer of 2 or more) extending in a first direction, and N second wirings (N is an integer of 2 or more) extending in a second direction intersecting the first direction and electrically connected to each of the M first wirings, a plurality of first terminal wirings electrically connected to the first terminals of the light emitting elements; a plurality of second terminal wirings electrically connected to the second terminals of the light emitting elements, each of the second terminal wirings electrically connected to P (P is an integer of 2 or more) of the light emitting elements; a plurality of selection circuits respectively connected to one of the plurality of first terminal wirings and the plurality of second terminal wirings, and selecting a corresponding one of the light emitting elements; a plurality of drive circuits respectively connected to the other of the plurality of first terminal wirings and the plurality of second terminal wirings, and driving a corresponding one of the light emitting elements; and a control unit which controls at least one of the number of times of light emission, the light emission interval, the light emission power, and the light emission pulse width of the plurality of light emitting elements based on input information, wherein N is an integer that is the same as or different from M, The light emitting device, wherein the P is an integer that is the same as or different from at least one of the M and the N.

2. The light emitting device according to claim 1, wherein the control unit selects a light emitting element to be caused to emit light from among the plurality of light emitting elements based on the input information.

3. The light emitting device according to claim 1, wherein the control unit controls the order in which the plurality of light emitting elements emit light based on the input information.

4. The light emitting device according to claim 1, comprising: a first substrate having the plurality of light emitting elements; and a second substrate stacked on the first substrate and having the plurality of selection circuits, the plurality of drive circuits, and the control unit.

5. The light-emitting device according to claim 1, wherein the input information includes ambient temperature information about the plurality of light-emitting elements, and the control unit selects a light-emitting element to be caused to emit light from among the plurality of light-emitting elements based on the temperature information.

6. The light emitting device according to claim 1, further comprising a drive unit having the plurality of selection circuits and the plurality of drive circuits, and the input information includes information provided from the drive unit.

7. The light emitting device according to claim 6, wherein the information provided by the driving section includes at least one of the number of times that the plurality of light emitting elements emit light, the interval between light emission, the light emission power, or the light emission pulse width.

8. The light emitting device according to claim 1, wherein the input information includes distance measurement information obtained by measuring distances using light emitted by the plurality of light emitting elements.

9. The light-emitting device according to claim 8, wherein the control unit controls at least one of the number of times the plurality of light-emitting elements emit light, the light-emitting interval, the light-emitting power, or the light-emitting pulse width according to the measured distance based on the distance measurement information included in the input information.

10. The light emitting device according to claim 1, wherein the input information is information provided from a host device.

11. The light-emitting device of claim 10, wherein the information provided by the host device includes vehicle speed information of a vehicle in which the host device is mounted, and the control unit controls at least one of the number of times that the multiple light-emitting elements emit light, the light-emitting interval, the light-emitting power, or the light-emitting pulse width based on the vehicle speed information.

12. The light-emitting device of claim 10, wherein the host device or distance measurement unit controls the emission of two or more of the plurality of light-emitting elements that emit light into a ROI (Region Of Interest) area, and the control unit controls at least one of the number of times the plurality of light-emitting elements emit light, the emission interval, the emission power, or the emission pulse width based on at least one of the position or size of the ROI area.

13. A distance measuring device comprising: a light emitting device which emits light towards an object to be measured; and a control unit having a distance measuring unit which receives light reflected by the object to be measured and measures the distance to the object to be measured, wherein the light emitting device comprises: a plurality of light emitting elements arranged in a two-dimensional array, each having a first and second terminal; M first wirings (M is an integer of 2 or more) extending in a first direction; and N second wirings (N is an integer of 2 or more) extending in a second direction intersecting the first direction and electrically connected to each of the M first wirings, the plurality of first terminal wirings being electrically connected to the first terminals of the light emitting elements; a plurality of second terminal wirings electrically connected to the second terminals of the light emitting elements, each of which is electrically connected to P of the light emitting elements (P is an integer of 2 or more); and a plurality of selection circuits respectively connected to one of the plurality of first terminal wirings and the plurality of second terminal wirings, and each selecting a corresponding one of the light emitting elements; a plurality of drive circuits each connected to the other of the plurality of first terminal wirings and the plurality of second terminal wirings, for driving a corresponding one of the light-emitting elements; and the control unit controls at least one of the number of times the plurality of light-emitting elements emit light, the light-emitting interval, the light-emitting power, or the light-emitting pulse width based on input information.

14. The distance measuring device according to claim 13, wherein the input information includes information provided by the light emitting device.

15. The distance measuring device of claim 14, wherein the information provided by the light emitting device includes ambient temperature information about the plurality of light emitting elements, and the control unit selects, based on the temperature information, a light emitting element to be caused to emit light from among the plurality of light emitting elements.

16. The distance measuring device according to claim 14, wherein the information provided by the light emitting device includes at least one of the number of times the plurality of light emitting elements emit light, the light emission interval, the light emission power, or the light emission pulse width.

17. The distance measuring device according to claim 13, wherein the control unit selects a light emitting element to be caused to emit light from among the plurality of light emitting elements based on the input information.

18. The distance measuring device according to claim 13, wherein the control unit controls the order in which the plurality of light-emitting elements emit light based on the input information.

19. The distance measuring device of claim 13, wherein the input information includes distance measurement information or information provided by a host device.

20. The distance measuring device according to claim 19, wherein the information provided by the host device includes vehicle speed information of a vehicle in which the host device is mounted.

Images