Light emitting device and measuring device

Abstract

Provided are a light emitting device and a measuring device. The light emitting device has a plurality of light emitting portions, a driving portion that supplies a current to the light emitting portions and drives the light emitting portions, and a switching portion that is provided on a side opposite to the driving portion with respect to the plurality of light emitting portions and switches the light emission of the plurality of light emitting portions.

Description

Technical Field

[0001] This invention relates to light-emitting devices and measuring devices. Background Technology

[0002] Japanese Patent Application Publication No. 01-238962 discloses an array of light-emitting elements configured to arrange multiple light-emitting elements, which can be externally controlled by light, into one-dimensional, two-dimensional, or three-dimensional structures. At least a portion of the light generated by each light-emitting element is incident on other light-emitting elements near each light-emitting element, and each light-emitting element is connected to a clock line from which voltage or current is applied externally.

[0003] Japanese Patent Application Publication No. 2001-308385 discloses a self-scanning type light-emitting device, which is a light-emitting element with a pnpnpn 6-layer semiconductor structure. Electrodes are provided at the p-type 1st layer and n-type 6th layer at both ends and the p-type 3rd layer and n-type 4th layer in the center, so that the pn layer performs the function of a light-emitting diode and the pnpn 4th layer performs the function of a thyristor.

[0004] Japanese Patent Application Publication No. 2009-286048 discloses a self-scanning type light source head, which has a substrate, a surface-emitting semiconductor laser arranged in an array on the substrate, and thyristors arranged on the substrate as switching elements to selectively turn on / off the light emission of the surface-emitting semiconductor laser.

[0005] In a method for measuring the three-dimensional shape of an object by illuminating it with light from a light-emitting device and receiving the reflected light from the object, a short rise time of the light pulse illuminating the object is required. Here, in the light-emitting device, the distance between the light-emitting section and the driving section supplying the current for illuminating the object can be shortened to reduce inductance. Summary of the Invention

[0006] The object of the present invention is to provide a light-emitting device, etc., that can shorten the distance between the light-emitting part and the driving part compared to the case where a switching part for switching the light-emitting parts is provided between the light-emitting part and the driving part in a light-emitting device that switches multiple light-emitting parts to emit light.

[0007] According to a first aspect of the present invention, a light-emitting device is provided, comprising: a plurality of light-emitting portions; a driving portion that supplies current to the light-emitting portions and drives the light-emitting portions; and a switching portion disposed on a side opposite to the driving portion relative to the plurality of light-emitting portions, for switching the light emission of the plurality of light-emitting portions.

[0008] According to a second aspect of the present invention, the light-emitting device has a light-emitting electrode for supplying current to the light-emitting part, and the pad portion of the light-emitting electrode is disposed on the outside of the plurality of light-emitting parts at a position different from the position where the driving part and the switching part are disposed relative to the plurality of light-emitting parts.

[0009] According to a third aspect of the present invention, a light-emitting device is provided, comprising: a plurality of light-emitting portions; a driving portion that supplies current to the light-emitting portions and drives the light-emitting portions; a switching portion disposed on a side opposite to the driving portion relative to the plurality of light-emitting portions, for switching the light emission of the plurality of light-emitting portions; and a light-emitting electrode that supplies current to the plurality of light-emitting portions, wherein the plurality of light-emitting portions have: a first edge and a second edge, the first edge and the second edge being opposite to each other; and a third edge and a fourth edge, the third edge and the fourth edge being connected to the first edge and the second edge and being opposite to each other, wherein the driving portion, the switching portion and the light-emitting electrode are disposed on their respective edge sides.

[0010] According to a fourth aspect of the present invention, the driving part and the switching part are disposed on the first edge side and the second edge side opposite to each other.

[0011] According to a fifth aspect of the present invention, the pad portion of the light-emitting electrode is disposed on both the third edge side and the fourth edge side.

[0012] According to a sixth aspect of the present invention, the light-emitting device has wiring that connects each of the plurality of light-emitting portions to the switching portion, the wiring being disposed along the outside of the light-emitting portion.

[0013] According to the seventh aspect of the invention, the switching unit has a switching element.

[0014] According to the eighth aspect of the present invention, the switching unit sequentially transmits the on / off state of the switching element provided for each of the light-emitting units.

[0015] According to a ninth aspect of the present invention, the light-emitting part has a light-emitting diode and a thyristor, the thyristor being stacked on the light-emitting diode, and the light-emitting diode is made to emit light by being turned on.

[0016] According to the tenth aspect of the present invention, the light-emitting diode is a vertical cavity surface-emitting laser.

[0017] According to the eleventh aspect of the invention, a measuring device is provided, comprising: a light-emitting device; and a three-dimensional sensor that receives reflected light from a measured object irradiated with light emitted from the light-emitting device.

[0018] (Effect)

[0019] According to the first solution, compared with the case where a switching unit for switching the light-emitting part is provided between the light-emitting part and the driving part, the distance between the light-emitting part and the driving part can be shortened.

[0020] According to the second embodiment, compared to the case where the pad portion is located at the position where the drive portion or the switching portion is provided, it is easier to connect to the pad portion.

[0021] According to the third embodiment, compared with the case where the driving part, the switching part, and the light-emitting electrode are not provided on different edge sides, the planar shape of the light-emitting device can be reduced.

[0022] According to the fourth embodiment, compared to the case where the driving unit and the switching unit are not provided on the opposing first edge side and the second edge side, the distance between the multiple light-emitting units and the driving unit can be shortened.

[0023] According to the fifth solution, compared with the case where the pad portion is not provided on both the third edge side and the fourth edge side, the deviation in the supply of current to the light-emitting portion 22 is suppressed.

[0024] According to the sixth embodiment, compared with the case where wiring is provided on the surface side of the light-emitting part, light-emitting elements can be provided in the light-emitting part at a high density.

[0025] According to the seventh scheme, it is not necessary to install a switching element outside the light-emitting device.

[0026] According to the eighth scheme, it is easier to control the light-emitting part to emit light compared to the case where the on-state of the switching elements is not transmitted sequentially.

[0027] According to the ninth scheme, compared with the case where the light-emitting diodes and thyristors are not stacked, it is easier to control the light emission of the light-emitting diodes.

[0028] According to the 10th scheme, the optical output can be improved compared to the case of a non-vertical resonant cavity surface-emitting laser.

[0029] According to the 11th scheme, three-dimensional shape can be measured. Attached Figure Description

[0030] Figure 1 This is a diagram illustrating an example of an information processing device.

[0031] Figure 2 This is a block diagram illustrating the structure of an information processing device.

[0032] Figure 3 This is a three-dimensional diagram illustrating the state of the light source of the light-emitting device illuminating the irradiated area in a segmented manner.

[0033] Figure 4This diagram illustrates the light source of the light-emitting device.

[0034] Figure 5 This diagram illustrates the configuration of the light source and drive unit of the light-emitting device.

[0035] Figure 6 This is the equivalent circuit of the light-emitting device using this embodiment.

[0036] Figure 7 It is a timing diagram that explains the operation of the light-emitting device.

[0037] Figure 8 This is an enlarged top view of the light-emitting part.

[0038] Figure 9 This is a cross-sectional view of the light-emitting part. (a) is... Figure 8 (b) is a cross-sectional view of line IXA-IXA in the diagram. Figure 8 A cross-sectional view of line IXB-IXB in the diagram.

[0039] Figure 10 This is a diagram showing a modified example of a light-emitting device that applies this embodiment.

[0040] Figure 11 This is a diagram showing a modified example of a light-emitting device that applies this embodiment.

[0041] Figure 12 This shows the equivalent circuit of a light-emitting device as a variation of the light-emitting device applied in this embodiment.

[0042] Figure 13 This shows the equivalent circuit of a light-emitting device as a variation of the light-emitting device applied in this embodiment. Detailed Implementation

[0043] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0044] In measuring devices that measure the three-dimensional shape (hereinafter referred to as 3D shape) of an object, there exists a device that measures the three-dimensional shape using the so-called Time of Flight (ToF) method, which is based on the time of flight of light. In the ToF method, the time from the moment light is emitted from a light-emitting device in the measuring device to the moment it is reflected from the object being measured and received by a three-dimensional sensor (hereinafter referred to as a 3D sensor) in the measuring device is measured. Then, the 3D shape of the object being measured is determined based on the measured time. The object whose 3D shape is to be measured is referred to as the object being measured. Sometimes the three-dimensional shape is referred to as a three-dimensional image. Furthermore, the measurement of the three-dimensional shape is sometimes described as three-dimensional measurement, 3D measurement, or 3D sensing.

[0045] Such a measuring device is suitable for identifying the object being measured based on the measured 3D shape. For example, it can be mounted on a portable information processing device to identify the face of a user who wants to access the device. In other words, it obtains the 3D shape of the user's face, determines whether access is permitted, and allows the user to use the device (portable information processing device) only if the user is identified as having permitted access.

[0046] Furthermore, this measuring device is also suitable for situations such as augmented reality (AR) where the 3D shape of the object being measured is continuously measured. In this case, the distance to the object being measured is arbitrary.

[0047] Such measuring devices can be applied to information processing devices other than portable information processing devices, such as personal computers (PCs).

[0048] Here, as an example, we will explain the case where the information processing device is a portable information processing device, and explain the case where user authentication is performed by recognizing a face captured in 3D shape.

[0049] (Information Processing Device 1)

[0050] Figure 1 This is a diagram showing an example of information processing device 1. As described above, as an example, information processing device 1 is a portable information processing device.

[0051] The information processing device 1 includes a user interface unit (hereinafter referred to as the UI unit) 2 and an optical device 3 for measuring 3D shape. The UI unit 2 is, for example, an integrated display device for displaying information to the user and an input device for inputting instructions for information processing through user operation. The display device is, for example, a liquid crystal display or an organic EL display, and the input device is, for example, a touch panel.

[0052] The optical device 3 includes a light-emitting device 4 and a 3D sensor 5. The light-emitting device 4 illuminates light toward the object being measured (in this example, a face). The 3D sensor 5 captures the light reflected back by the face. Here, the 3D shape is measured using the so-called Time-of-Flight (ToF) method based on the time of flight of light. Then, the face is identified based on the 3D shape. As described above, other than the face can also be used as the object being measured to measure the 3D shape. The measuring device for measuring 3D shape includes a light-emitting device 4 and a 3D sensor 5.

[0053] Information processing device 1 is a computer that includes a CPU, ROM, RAM, etc. Furthermore, the ROM includes non-volatile, rewritable memory such as flash memory. Moreover, programs or constants stored in the ROM are loaded into the RAM, and the CPU executes the programs, thereby enabling information processing device 1 to perform various information processing operations.

[0054] Figure 2 This is a block diagram illustrating the structure of the information processing device 1.

[0055] The information processing device 1 includes the aforementioned optical device 3, measurement and control unit 8, and system control unit 9. The measurement and control unit 8 controls the optical device 3 to measure 3D shapes. The measurement and control unit 8 includes a 3D shape determination unit 8A. The system control unit 9 controls the information processing device 1 as a system. Furthermore, the system control unit 9 includes a recognition processing unit 9A. Additionally, a UI unit 2, a speaker 9B, and a two-dimensional camera (in...) are connected to the system control unit 9. Figure 2 It is described as a 2D camera. (9C, etc.)

[0056] The 3D shape determination unit 8A of the measurement control unit 8 measures and determines the 3D shape of the object being measured based on reflected light from the object being measured. The recognition processing unit 9A of the system control unit 9 recognizes the object being measured (in this example, a face) based on the 3D shape determined by the 3D shape determination unit 8A. Then, it identifies whether the user is authorized to access the device based on the recognized face.

[0057] The light-emitting device 4 of the optical device 3 includes a wiring substrate 10, a light source 20, a light-diffusing component 30, and a driving unit 50. The light source 20 and the driving unit 50 are disposed on the wiring substrate 10. Furthermore, the light source 20 and the driving unit 50 are connected by wiring provided on the wiring substrate 10. The driving unit 50 supplies current for light emission to the light source 20. The light-diffusing component 30 is inserted in the path of the light emitted from the light source 20, causing the light emitted from the light source 20 to irradiate in the desired direction. For example, the light-diffusing component 30 is held by a holding portion 40 provided on the wiring substrate 10 and covers the light source 20. Additionally, the wiring substrate 10 may also include resistive elements and capacitive elements to enable the operation of the light source 20 and the driving unit 50. Furthermore, the light source 20 may be disposed on a heat-dissipating substrate with a higher thermal conductivity than the wiring substrate 10. Examples of suitable heat dissipation substrates include aluminum oxide (Al2O3) with a thermal conductivity of 20–30 W / m·K, silicon nitride (Si3N4) with a thermal conductivity of approximately 85 W / m·K, and aluminum nitride (AlN) with a thermal conductivity of 150–250 W / m·K, compared to the thermal conductivity of the insulating layer (FR-4) used on the wiring substrate 10, which is approximately 0.4 W / m·K. While wiring is provided on the wiring substrate 10, it can also be a substrate without wiring. As long as the light source 20 and the driving unit 50 are connected, the substrate only needs to hold the light source 20, the driving unit 50, etc.

[0058] Figure 3 This is a perspective view illustrating the state in which the light source 20 of the light-emitting device 4 is divided and illuminated onto the illumination area 100. Figure 3 The image shows the light source 20 of the light-emitting device 4. Figure 3 In the light source 20, the right side of the paper is set as the x-direction, the top of the paper is set as the y-direction, and the direction towards the irradiated area 100 is set as the z-direction.

[0059] As an example, the light source 20 has 12 light-emitting parts 22. These 12 light-emitting parts 22 are collectively used as light-emitting parts 21. The 12 light-emitting parts 22 are arranged in a matrix of 4 in the x-direction and 3 in the y-direction. Each light-emitting part 22 can emit light individually or simultaneously. Furthermore, all of these light-emitting parts 22 can also emit light simultaneously.

[0060] The illumination area 100 is the range of light emitted from the light source 20 for measuring the 3D shape of the object being measured. Here, the illumination range of each light-emitting part 22 is different. That is, the light source 20 illuminates the illumination area 100 in segments. The light emitted from the light-emitting part 22 is then transmitted through the light-diffusing member 30 (see reference 30). Figure 2 This allows for setting the direction of light illumination and / or the spread of light. Alternatively, instead of the light diffusion component 30, optical components such as diffractive optical elements (DOEs) that change the direction of incident light to different directions, transparent components such as condenser lenses, microlenses, and protective covers can be used.

[0061] Figure 4 This diagram illustrates the light source 20 of the light-emitting device 4. Figure 4 The x, y, and z directions in the figure are related to Figure 3 same.

[0062] The light source 20 has a light emitting section 21 with a plurality of light-emitting sections 22 arranged therein, a switching section 23 for switching the light-emitting section 22 to emit light, and wiring 25 connecting the light-emitting section 22 and the switching section 23.

[0063] As described above, the light emitting section 21 has 12 light-emitting sections 22 arranged in a matrix of 4 in the x-direction and 3 in the y-direction. Here, to distinguish each light-emitting section 22, they are referred to as light-emitting sections 22-1 to 22-12. Furthermore, the '0' markings in the light-emitting sections 22 represent light-emitting diodes (LEDs), which are examples of light-emitting elements. That is, each light-emitting section 22 has multiple LEDs. Additionally, each light-emitting section 22 may have the same number of light-emitting elements or different numbers of light-emitting elements. Each light-emitting section 22 may also have only one light-emitting element.

[0064] On the light-emitting portion 22 (z-direction side), light-emitting electrodes 72 are commonly provided on all light-emitting portions 22. Furthermore, the ±y-direction sides of the light-emitting electrodes 72 are designated as pad portions 72A and 72B, which are connected to wiring for supplying light-emitting current. In addition, only the outline of the light-emitting electrodes 72 is shown, making the lower light-emitting portion 22 visible.

[0065] The switching unit 23 has signal terminals 24-1 to 24-12 that supply switching signals φf1 to φf12 to each of the light-emitting units 22-1 to 22-12 respectively. Alternatively, when the switching signals φf1 to φf12 are not distinguished, they are referred to as switching signal φf; and when the signal terminals 24-1 to 24-12 are not distinguished, they are referred to as signal terminals 24. The switching unit 23 is arranged in a row on the x-direction side of the light-emitting unit 21, which includes multiple light-emitting units 22. In the switching unit 23, the signal terminals 24 can also be arranged in a single row on the y-direction side. This shortens the length in the x-direction compared to a case where they are not arranged in a single row.

[0066] The light-emitting part 22 of the light-emitting unit 21 and the signal terminal 24 of the switching part 23 are connected by wiring 25, and a switching signal φf is supplied from the signal terminal 24. That is, the light-emitting part 22-1 and the signal terminal 24-1 are connected by wiring 25-1, and a switching signal φf1 is supplied from them. The light-emitting part 22-2 and the signal terminal 24-2 are connected by wiring 25-2, and a switching signal φf2 is supplied from the signal terminal 24-2. Furthermore, in... Figure 4 The text describes wiring 25-1 and 25-2, omitting the markings for other wiring 25-3 to 25-12.

[0067] Wiring 25 is provided along the outside of the light-emitting portion 22. Therefore, compared to providing wiring inside the light-emitting portion 22, i.e., on its surface, a higher density of light-emitting diodes (LEDs) can be provided. Furthermore, in... Figure 4 In the region containing the light emitting section 21 and the switching section 23, the length in the x-direction is longer than the length in the y-direction.

[0068] Figure 5 This diagram illustrates the configuration of the light source 20 and the driving unit 50 in the light-emitting device 4. Figure 5 The x, y, and z directions in the figure are related to Figure 4 same.

[0069] Here, the -x direction side of the light emitting section 21, which includes multiple light-emitting parts 22, is referred to as edge 21a, the +x direction side as edge 21b, the +y direction side as edge 21c, and the -y direction side as edge 21d. Edges 21a and 21b are opposite to each other, and edges 21c and 21d connect edges 21a and 21b and are opposite to each other. That is, the multiple light-emitting parts 22 of the light emitting section 21 are surrounded by edges 21a, 21b, 21c, and 21d. Moreover, edge 21a has a length D1, and edge 21c has a length D2. Here, length D1 is set to be shorter than length D2 (D1 < D2). This is an example where edge 21a is the first edge, edge 21b is the second edge, edge 21c is the third edge, and edge 21d is the fourth edge.

[0070] like Figure 5 As shown, the switching unit 23 is positioned opposite the driving unit 50. That is, the driving unit 50 is arranged adjacent to the light-emitting part 22 side of the light-emitting unit 21. Specifically, the driving unit 50 is located on the edge 21a side of the light-emitting unit 21, and the switching unit 23 is located on the edge 21b side of the light-emitting unit 21. In other words, the driving unit 50 and the switching unit 23 are located on opposite edge sides. Therefore, the distance between the driving unit 50 and the light-emitting part 22 is shorter than when the switching unit 23 is located between the driving unit 50 and the light-emitting part 22. Consequently, in the light-emitting device 4, the inductance between the driving unit 50 and the light-emitting part 22 in the light source 20 is reduced, and the rise time of the light pulse is shortened. Furthermore, since the 3D sensor 5 is positioned on... Figure 1 As shown in the diagram, the 3D sensor 5 is therefore located on the side of the switching unit 23. That is, they are arranged in the order of driving unit 50, light-emitting unit 22, switching unit 23, and 3D sensor 5.

[0071] Furthermore, regarding the light-emitting electrode 72, the pad portion 72A is provided on the edge 21c side of the light-emitting portion 21 containing the light-emitting portion 22, and the pad portion 72B is provided on the edge 21d side of the light-emitting portion 21. That is, the pad portions 72A and 72B are located on the outside of the light-emitting portion 21, at a position different from the position where the driving portion 50 and the switching portion 23 are located. If the pad portions 72A and 72B are located where the switching portion 23 or the driving portion 50 is located, the connection to the pad portions 72A and 72B may be hindered by the switching portion 23 or the driving portion 50. In other words, compared to the case where the pad portions 72A and 72B are located where the switching portion 23 or the driving portion 50 is located, the connection to the pad portions 72A and 72B can be made more easily. Moreover, the pad portions 72A and 72B are provided on both edges 21c and 21d. Therefore, current is supplied from both sides of the light-emitting electrode 72. Therefore, compared to the case where the pad portion is set on either edge 21c or edge 21d, deviation in the supply of current to the light-emitting portion 22 can be suppressed.

[0072] In other words, the driving unit 50, the switching unit 23, and the light-emitting electrode 72 are disposed on different edges of the light-emitting unit 21. As a result, the planar shape of the light-emitting device 4 can be reduced.

[0073] Figure 6 This is the equivalent circuit of the light-emitting device 4 using this embodiment. Figure 6 The image shows the light source 20 and the driving unit 50 of the light-emitting device 4. Additionally, in... Figure 6 The measurement and control unit 8, which controls the light-emitting device 4, is also shown in the figure.

[0074] As described above, the light source 20 has a light emitting section 21 and a switching section 23 that switches between multiple light-emitting sections 22 of the light emitting section 21. Figure 6 The diagram shows three light-emitting units 22 (referred to as light-emitting units 22-1, 22-2, and 22-3). As described in light-emitting unit 22-1, each light-emitting unit 22 has multiple light-emitting diodes (LEDs). Furthermore, each light-emitting unit 22 has a driving thyristor S that is connected together with the multiple LEDs.

[0075] Light-emitting diodes (LEDs) are, for example, vertical-cavity surface-emitting lasers (VCSELs). Hereinafter, we will describe LEDs as VCSELs. A VCSEL is a surface-emitting laser element in which a light-emitting layer, serving as the light-emitting region, is disposed between a lower multilayer mirror and an upper multilayer mirror stacked on a substrate, and the laser light is emitted perpendicularly to the surface. This VCSEL has a λ-resonator structure. Alternatively, the light-emitting element can be other light-emitting devices such as laser diodes, besides VCSELs. Hereinafter, VCSELs will sometimes be referred to simply as VCSELs.

[0076] The driving unit 50 includes a MOS transistor 51 and a signal generation circuit 52 as examples of driving elements. Alternatively, the driving element may be an insulated gate bipolar transistor (IGBT) or the like.

[0077] Multiple light-emitting diodes (LEDs) and driving thyristors (S) are connected in series. That is, multiple LEDs are connected in parallel, with the anode ([A]) of each LED connected to the cathode ([K]) of the driving thyristor (S). Similarly, the cathodes ([K]) of the LEDs are connected in parallel and connected to the drain ([D]) of the MOS transistor (51) in the driving section 50. Furthermore, the source ([S]) of the MOS transistor (51) is connected to the reference potential wiring 71 that supplies the reference potential GND (0V).

[0078] The anode ([A]) of the driving thyristor S is connected to the light-emitting electrode 72 that supplies the power supply potential VLD. Furthermore, the gate ([G]) of the driving thyristor S is connected to the signal terminal 24 of the switching unit 23. In other words, in the light-emitting unit 22-1, the gate ([G]) of the driving thyristor S is connected to the signal terminal 24-1 and supplied with a switching signal φf1. The same applies to the other light-emitting units 22.

[0079] The signal generation circuit 52 in the drive unit 50 supplies an on signal (On) to the gate ([G]) of the MOS transistor 51 and an off signal (Off) to the gate ([G]) of the MOS transistor 51, which makes the MOS transistor 51 turn on and off.

[0080] The driving method of the light-emitting device 4 described above is called low-end driving. Low-end driving is preferred when it is desired to drive the light-emitting diode (LED) at a higher speed. Low-end driving refers to a structure in which driving elements such as the MOS transistor 51 are located downstream of the driving object such as the LED in the current path.

[0081] The operation of the light-emitting device 4 will be explained below.

[0082] (Drive thyristor S)

[0083] The driving thyristor S is a semiconductor device having three terminals: an anode ([A]), a cathode ([K]), and a gate ([G]). As described later, the driving thyristor S is constructed by stacking an n-cathode layer 85, a p-gate layer 86, an n-gate layer 87, and a p-anode layer 88 based on GaAs, AlGaAs, AlAs, etc. That is, the driving thyristor S has an npnp structure. As an example, the forward voltage (diffusion potential) Vd of the pn junction of the p-type semiconductor layer (p-gate layer 86, p-anode layer 88) and the n-type semiconductor layer (n-cathode layer 85, n-gate layer 87) is set to 1.5V for explanation.

[0084] The driving thyristor S has a gate ([G]) on the n-gate layer 87. Initially, it is assumed to be in a cutoff state where a voltage is applied between the anode ([A]) and cathode ([K]) of the driving thyristor S, but no current flows. When a forward bias is applied between the p-anode layer 88 (serving as the anode ([A])) and the n-gate layer 87 (serving as the gate ([G])), the driving thyristor S transitions to an on state where current flows. That is, in... Figure 6In this circuit, when the gate ([G]) becomes a voltage lower than the anode ([A]) by more than the forward voltage Vd, the thyristor S is driven to switch from the off state to the on state. Furthermore, a forward voltage Vd is established between the anode ([A]) and the cathode ([K]). For example, if the anode ([A]) is 5V, then when the gate ([G]) is less than 3.5V, the thyristor S is driven to switch from the off state to the on state. And if the anode ([A]) is 10V, then when the gate ([G]) is less than 8.5V, the thyristor S is driven to switch from the off state to the on state.

[0085] In addition, the gate ([G]) is connected to the signal terminal 24, and a switching signal φf is supplied to the signal terminal 24. That is, the transition of the thyristor S from the off state to the on state is controlled by the switching signal φf.

[0086] (Light Emitting Diode LED)

[0087] A light-emitting diode (LED) is a semiconductor device with two terminals: an anode (A) and a cathode (K). Therefore, when a voltage greater than the forward voltage Vd is applied between the anode (A) and cathode (K) of an LED, and a current capable of emitting light flows through it, the LED emits light.

[0088] (The movement of the light-emitting part 22)

[0089] like Figure 6 As shown, in the light-emitting section 22, the driving thyristor S and the light-emitting diode LED are connected in series. Furthermore, a power supply potential VLD is applied to the light-emitting electrode 72, which is connected to the anode ([A]) of the driving thyristor S. The cathode ([K]) of the light-emitting diode LED is connected to the drain ([D]) of the MOS transistor 51 in the driving section 50. The source ([S]) of the MOS transistor 51 in the driving section 50 is supplied with a reference potential GND (0V). The reference potential GND is grounded.

[0090] Here, an on signal is input from the signal generation circuit 52 to the gate ([G]) of the MOS transistor 51, turning the MOS transistor 51 on. Consequently, the cathode ([K]) of the light-emitting diode (LED) in the light-emitting section 22 is 0V. Therefore, a power supply potential VLD is applied to the light-emitting section 22.

[0091] Let the power supply potential VLD be 5V. Also, the switching signal φf is 5V, and the driving thyristor S is in the off state. Here, the switching signal φf shifts to a voltage lower than the power supply potential VLD of the anode ([A]) of the driving thyristor S by more than the forward voltage Vd, i.e., less than 3.5V. Therefore, the driving thyristor S switches from the off state to the on state. Then, current flows from the driving thyristor S to the light-emitting diode (LED). The cathode ([K]) of the driving thyristor S is 3.5V. Thus, the forward voltage Vd becomes greater than or equal to the anode ([A])-cathode ([K]) of the LED, and the LED emits light.

[0092] Furthermore, the power supply potential VLD is set to 10V. The switching signal φf is also 10V, and the driving thyristor S is in the off state. Here, the switching signal φf shifts to a voltage lower than the power supply potential VLD, which is the potential of the anode ([A]) of the driving thyristor S, by more than the forward voltage Vd, i.e., less than 8.5V. Therefore, the driving thyristor S transitions from the off state to the on state. Then, current flows from the driving thyristor S to the light-emitting diode (LED). The cathode ([K]) of the driving thyristor S is 8.5V. Therefore, the forward voltage between the anode ([A]) and cathode ([K]) of the LED is above Vd, and the LED emits light.

[0093] As explained above, if the voltage applied to the gate ([G]), i.e., the switching signal φf, is greater than or equal to the value obtained by subtracting the positive voltage Vd from the power supply potential VLD, the driving thyristor S in the off state remains in the off state. Furthermore, when the switching signal φf is less than the value obtained by subtracting the positive voltage Vd from the power supply potential VLD, it transitions from the off state to the on state.

[0094] Furthermore, when a cutoff signal is input from the signal generation circuit 52 to the gate ([G]) of the MOS transistor 51, the MOS transistor 51 transitions from the on state to the off state. As a result, current does not flow through the light-emitting section 22, and the light-emitting diode (LED) transitions from the on state to the off state. Additionally, for the driving thyristor S in the on state, even if the gate ([G]) is set to a value greater than or equal to the power supply potential VLD minus the forward voltage Vd, it does not transition to the off state.

[0095] (Timing diagram of light-emitting device 4)

[0096] Figure 7This is a timing diagram illustrating the operation of the light-emitting device 4. The horizontal axis represents time t elapsed sequentially from time a to e. From top to bottom, the diagram shows the power supply potential VLD, switching signals φf1 to φf8, switching signals φf9 to φf12, the signals of the signal generation circuit 52 of the drive unit 50, the states of the light-emitting units 22-1 to 22-8, and the states of the light-emitting units 22-9 to 22-12. Switching signals φf1 to φf12 are signals that switch between H level and L level. H level refers to a switching signal value greater than or equal to the value obtained by subtracting the positive voltage Vd from the power supply potential VLD, and L level refers to a switching signal value less than the value obtained by subtracting the positive voltage Vd from the power supply potential VLD. Here, as an example, switching signals φf1 to φf8 are maintained at the same potential, and switching signals φf9 to φf12 are switched simultaneously. Furthermore, switching signals φf1 to φf12 can be switched individually, or multiple signals can be switched simultaneously as described above. Moreover, all switching signals φf1 to φf12 can be switched simultaneously.

[0097] At time a, the light-emitting sections 22-1 to 22-12 are in the off state. Furthermore, the switching signals φf1 to φf12 are at level H. The signal generation circuit 52 of the drive unit 50 supplies the off signal to the MOS transistor 51. Therefore, all the drive thyristors S are in the off state, and all the light-emitting diodes (LEDs) are in the non-emitting state.

[0098] At time b, the switching signals φf9 to φf12 shift from H level to L level. Therefore, the driving thyristors S of the light-emitting sections 22-9 to 22-12 become capable of transitioning from the off state to the on state when their gates ([G]) are at the L level. However, since the MOS transistor 51 of the driving section 50 is in the off state, the driving thyristors S cannot transition to the on state.

[0099] At time c, the signal generation circuit 52 of the driving unit 50 supplies an on signal to the MOS transistor 51. Then, a power supply potential VLD is applied to the series connection between the driving thyristors S and the light-emitting diodes (LEDs) of the light-emitting units 22-9 to 22-12. Therefore, the driving thyristors S transition from the off state to the on state, and the LEDs begin to emit light (light up).

[0100] At time d, the switching signals φf9 to φf12 switch from L level to H level. However, the driving thyristors S of the light-emitting parts 22-9 to 22-12 do not switch to the cutoff state, and the light-emitting diodes (LEDs) continue to emit light.

[0101] At time e, the signal generation circuit 52 of the drive unit 50 supplies a cutoff signal to the MOS transistor 51. As a result, no current flows in the series connection between the drive thyristors S of the light-emitting units 22-9 to 22-12 and the light-emitting diodes (LEDs), and the LEDs stop emitting light (go out).

[0102] The light-emitting device 4 is controlled as described above. Alternatively, the timing for switching signals φf9 to φf12 at time b to transition from H level to L level and the timing for the signal generation circuit 52 in the drive unit 50 at time c to supply an on signal to the MOS transistor 51 can be changed. In this case, the LED starts emitting light at the timing when switching signals φf9 to φf12 transition from H level to L level. Furthermore, the timing for switching signals φf9 to φf12 at time d to transition from L level to H level and the timing for the signal generation circuit 52 in the drive unit 50 at time e to supply an off signal to the MOS transistor 51 can also be changed.

[0103] (Structure of the light-emitting part 22)

[0104] The light source 20 is made of a semiconductor material capable of emitting light. For example, the light source 20 is made of a compound semiconductor such as GaAs. Furthermore, as shown in the cross-sectional view described later (refer to the following description)... Figure 8 As shown, the semiconductor layer stack is formed by stacking multiple GaAs-based compound semiconductor layers on an n-type GaAs substrate 80. Furthermore, the light source 20 is formed by separating the semiconductor layer stack into multiple island-like structures. The regions remaining as island-like structures are referred to as islands. The process of etching the semiconductor layer stack into island-like structures to separate the components is called mesa etching.

[0105] Each light-emitting part 22 is configured as a separate island 301. Furthermore, the islands 301 corresponding to the light-emitting parts 22-1, 22-2, ... are described as islands 301-1, 301-2, ...

[0106] Figure 8 This is an enlarged top view of the light-emitting part 22. Figure 8 It is Figure 4 This is an enlarged view of a portion of the light-emitting part 22-12 (islands 301-12) of the light source 20 shown. Hereinafter, the light-emitting part 22-12 will be referred to as light-emitting part 22, and the islands 301-12 will be referred to as islands 301. The x, y, and z directions are... Figure 4 same.

[0107] Figure 8 Multiple light-emitting diodes (LEDs) are shown. Here, the four LEDs, LED1 to LED4, are labeled. First, we will focus on LED1, which is located in the lower right corner of the page, to explain the planar structure of the light-emitting section 22. Furthermore, we will refer to LED1 as a light-emitting diode (LED) without distinguishing it from other LEDs. The same applies below.

[0108] In a light-emitting diode (LED), the central circular portion is the light emission outlet 341. The region 311 of the p-anode layer 88 driving the thyristor S (see later description) Figure 9 A p-ohm electrode 321 is provided around the light emission outlet 341. Furthermore, a p-ohm electrode 321 is provided on region 311. Additionally, six holes (trenches) 342 and six gate electrodes 331 are provided on its outer side. The gate electrodes 331 are provided on the n-gate layer 87, which will be described later. Furthermore, a portion of the gate electrodes 331 is connected to the gate electrode 331 of an adjacent light-emitting diode (LED).

[0109] Furthermore, the n-gate layer 87 is led out to the switching section 23 side, and a gate electrode 332 connected to the signal terminal 24 is provided at its end. The gate electrode 332 is connected to the signal terminal 24-12 of the switching section 23 (see reference). Figure 4 Additionally, the portion of the n-gate layer 87 that is led out to the switching section 23 side is wiring 25 (equivalent to wiring 25-12).

[0110] Furthermore, a light-emitting electrode 72 is provided such that it covers the light-emitting portion 22 without covering the light emission outlet 341. The light-emitting electrode 72 is provided via a layer 89 (see below) Figure 9 The through holes (a) and (b) are connected to the p-ohm electrode 321 provided on region 311. Additionally, in Figure 8 In the middle, the light-emitting electrode 72 is represented by a dashed line.

[0111] Figure 9 This is a cross-sectional view of the light-emitting part 22. Figure 9 (a) is Figure 8 A cross-sectional view of line IXA-IXA in the middle. Figure 9 (b) is Figure 8 A cross-sectional view of line IXB-IXB in the diagram. Figure 9 (a) is a partial cross-sectional view of two light-emitting diodes LED1 and LED2 that are adjacent to each other with their gate electrodes 331 separated by a gate electrode 331. Figure 9 (b) is a partial cross-sectional view of two adjacent light-emitting diodes LED3 and LED4 separated by hole 342.

[0112] like Figure 9 As shown in (a), the light-emitting part 22 has an n-type cathode layer (hereinafter referred to as n-cathode layer) 81, a light-emitting layer 82, and a p-type anode layer (p-anode layer) 83 stacked on an n-type GaAs substrate 80. In other words, the light-emitting diode LED is constructed by using the stacked n-cathode layer 81 as the cathode, the light-emitting layer 82 as the light-emitting layer, and the p-anode layer 83 as the anode.

[0113] Next, a tunnel junction layer 84 is stacked on the p-anode layer 83.

[0114] Furthermore, an n-type cathode layer (n-cathode layer) 85, a p-type gate layer (p-gate layer) 86, an n-type gate layer (n-gate layer) 87, and a p-type anode layer (p-anode layer) 88 constituting the driving thyristor S are stacked on the tunnel junction layer 84. In other words, the driving thyristor S is constructed by using the stacked n-cathode layer 85 as the cathode, the p-gate layer 86 as the p-gate, the n-gate layer 87 as the n-gate, and the p-anode layer 88 as the anode.

[0115] The light-emitting diode (LED) is configured such that the p-anode layer 83 is exposed by etching away the p-anode layer 88, n-gate layer 87, p-gate layer 86, n-cathode layer 85, and tunnel junction layer 84 of the driving thyristor S stacked on top. In other words, light is emitted from the exposed p-anode layer 83. The exposed p-anode layer 83 is the light emission outlet 341.

[0116] The driving thyristor S is composed of an n-cathode layer 85, a p-gate layer 86, an n-gate layer 87, and a p-anode layer 88 remaining around the light emission outlet 341 of the light-emitting diode (LED). Furthermore, a tunnel junction layer 84, a p-anode layer 83 constituting the LED, a light-emitting layer 82, and an n-cathode layer 81 are present on the substrate 80 side of the driving thyristor S. In other words, the LED and the driving thyristor S are stacked and connected in series via the tunnel junction layer 84.

[0117] A tunnel junction layer 84 is disposed between the p-anode layer 83 of the light-emitting diode (LED) and the n-cathode layer 85 of the driving thyristor S. That is, when the tunnel junction layer 84 is not provided, the p-anode layer 83 of the LED and the n-cathode layer 85 of the driving thyristor S are in a reverse bias state, therefore, current is difficult to flow from the n-cathode layer 85 of the driving thyristor S to the p-anode layer 83 of the LED. The tunnel junction layer 84 is a p-type impurity layer with a high concentration added to the p-anode layer 83 side of the LED. ++ The n-type impurity n is added at a high concentration to the n-cathode layer 85 side of the driving thyristor S. ++ The tunnel junction. In tunnel junction layer 84, due to the narrow width of the depletion region, electrons from n under reverse bias... ++ The conductive bands (conducting bands) on the layer side penetrate to p ++ The valence electron band on the side of the layer. Therefore, current can easily flow from the n cathode layer 85 of the driving thyristor S to the p anode layer 83 of the light-emitting diode LED.

[0118] Furthermore, a p-ohm electrode 321 is formed on the p-anode layer 88, which is in ohmic contact with the p-anode layer 88. The p-ohm electrode 321 is connected to the light-emitting electrode 72 through a through-hole formed in the insulating layer 89.

[0119] In addition, a gate electrode 331 is formed in ohmic contact with the n-gate layer 87 exposed by etching away a portion of the p-anode layer 88. The gate electrode 331 reduces the resistance of the exposed n-gate layer 87.

[0120] In addition, the light-emitting electrode 72 and the gate electrode 331 are insulated from each other by the insulating layer 89.

[0121] like Figure 9 As shown in (a), between the light emission outlet 341 of LED1 and the light emission outlet 341 of LED2, which are adjacent to each other across the gate electrode 331, the n cathode layer 81, the light emission layer 82, the p anode layer 83, the tunnel junction layer 84, the n cathode layer 85, the p gate layer 86, the n gate layer 87 and the p anode layer 88 that constitute the LED and drive the thyristor S are continuous.

[0122] like Figure 9 As shown in (b), the light emission outlets 341 of LED3 and LED4 are adjacent to each other across a hole 342. The hole 342 is provided to remove the p-anode layer 88, n-gate layer 87, p-gate layer 86, n-cathode layer 85, tunnel junction layer 84, p-anode layer 83, light-emitting layer 82, and n-cathode layer 81. Furthermore, by oxidizing the current-limiting layer contained in the p-anode layer 83 through this hole 342, the portion near the hole 342 is designated as a current-blocking portion β, making it difficult for current to flow. On the other hand, the portion away from the hole 342 remains unoxidized. That is, the unoxidized portion becomes a current-passing portion α for current to flow. Multiple holes 342 are provided around the light emission outlets 341. Therefore, the current-passing portion α is formed to be nearly circular. The light emission outlet 341 is provided corresponding to this current-passing portion α. Therefore, even if the n-cathode layer 81, p-anode layer 83 and light-emitting layer 82 are continuously disposed in the light-emitting part 22, each light-emitting diode LED will emit light at a portion of the light emission outlet 341.

[0123] On the other hand, such as Figure 9 As shown in (a), the n-cathode layer 85, p-gate layer 86, n-gate layer 87, and p-anode layer 88 constituting the driving thyristor S are continuous between the light-emitting diodes (LEDs). Therefore, the driving thyristor S operates for each light-emitting part 22. That is, as shown in (a), Figure 6 As shown, in the light-emitting section 22, a driving thyristor S is provided relative to the plurality of light-emitting diodes (LEDs).

[0124] and Figure 8Similarly, at the right end of (a) and (b), between the light-emitting portions 22, i.e., between the islands 301, the p-anode layer 88, n-gate layer 87, p-gate layer 86, n-cathode layer 85, tunnel junction layer 84, p-anode layer 83, light-emitting layer 82, and n-cathode layer 81 are removed. In other words, the p-anode layer 83, light-emitting layer 82, and n-cathode layer 81 constituting the light-emitting diode (LED) and the p-anode layer 88, n-gate layer 87, p-gate layer 86, and n-cathode layer 85 constituting the driving thyristor S are discontinuous between the islands 301. Therefore, the light emission of each light-emitting portion 22 is controlled individually.

[0125] (Structure of semiconductor layer stack)

[0126] The n-cathode layer 81, light-emitting layer 82, p-anode layer 83, tunnel junction layer 84, n-cathode layer 85, p-gate layer 86, n-gate layer 87, and p-anode layer 88 stacked on the substrate 80 are semiconductor layer stacks. The n-cathode layer 81, light-emitting layer 82, and p-anode layer 83 are semiconductor layers constituting a light-emitting diode (LED), and the n-cathode layer 85, p-gate layer 86, n-gate layer 87, and p-anode layer 88 are semiconductor layers constituting a driving thyristor (S).

[0127] The following will explain in sequence.

[0128] <Substrate 80>

[0129] The substrate 80 is illustrated using n-type GaAs as an example, but it can also be p-type GaAs, intrinsic (i) GaAs without impurities. Furthermore, it can be a semiconductor substrate made of InP, GaN, InAs, other III-V or II-VI materials, sapphire, Si, Ge, etc. When the substrate is changed, the material monolithically stacked on the substrate should be a material whose lattice constant is approximately matched to that of the substrate (including strain structure, strain mitigation layer, and aberration growth). For example, InAs, InAsSb, GaInAsSb, etc., can be used on an InAs substrate; InP, InGaAsP, etc., can be used on an InP substrate; GaN, AlGaN, InGaN, etc., can be used on a GaN substrate or a sapphire substrate; and Si, SiGe, GaP, etc., can be used on a Si substrate. However, if the substrate 80 is electrically insulating, an electrode is required to supply potential to the n-cathode layer 81. Furthermore, when semiconductor layer stacks other than substrate 80 are attached to other support substrates and semiconductor layer stacks are disposed on other support substrates, it is not necessary to match the lattice constant with the support substrate.

[0130] <Semiconductor layers that make up a light-emitting diode (LED)>

[0131] Here, we will use LED (Light Emitting Diode) as an example, which is VCSEL.

[0132] The n-type lower part of the Bragg reflector (DBR) is formed by alternating overlapping AlGaAs layers with different Al compositions in the n-cathode layer 81. The light-emitting layer 82 is configured as an active region containing a quantum well layer sandwiched between an upper spacer layer and a lower spacer layer. Furthermore, the p-type anode layer 83 is configured as an upper part of the Bragg reflector obtained by alternating overlapping AlGaAs layers with different Al compositions. Hereinafter, the distributed Bragg reflector will be referred to as DBR. The single light output of the VCSEL is 4mW to 8mW, which is higher than that of other laser diodes.

[0133] The lower n-type DBR constituting the n-cathode layer 81 is constructed with Al 0.9 Ga 0.1 The As and GaAs layers are a stacked pair. The thickness of each layer in the lower DBR is λ / 4n. r (where λ is the oscillation wavelength, n) r (Refractive index of the medium), the layers of this lower DBR are stacked alternately for 40 cycles. Silicon (Si) is doped as an n-type impurity to act as the charge carrier. The carrier concentration is, for example, 3 × 10⁻⁶. 18 cm -3 .

[0134] The lower spacer layer constituting the light-emitting layer 82 is undoped Al. 0.6 Ga 0.4 The As layer consists of an undoped InGaAs quantum well layer and an undoped GaAs barrier layer, while the upper spacer layer is undoped Al. 0.6 Ga 0.4 As layer.

[0135] The upper p-type DBR constituting the p-anode layer 83 is composed of p-type Al 0.9 Ga 0.1 The As and GaAs layers are a stacked pair. The thickness of each layer in the upper DBR is λ / 4n. r The upper DBR consists of 29 alternating layers. Carbon (C) is used as a p-type impurity to act as charge carriers. The carrier concentration is, for example, 3 × 10⁻⁶. 18 cm -3 A p-type AlAs current-narrowing layer is provided at the bottom layer of the upper DBR208 or inside it.

[0136] The oxidation rate of p-type AlAs is faster than that of AlGaAs, and the oxidation region is oxidized from the side of hole 342 towards the interior. By oxidizing Al to form Al₂O₃, the resistance increases, forming the current-blocking section β. Alternatively, as a current-blocking layer, it is sufficient to oxidize p-type AlGaAs or AlGaAs with a high Al impurity concentration instead of AlAs to form Al₂O₃. The current-blocking section β can also be formed by implanting hydrogen ions (H₂O) into the semiconductor layer such as AlGaAs. + ) and form (H + (ion implantation).

[0137] <Tunnel Layer 84>

[0138] Tunnel layer 84 is a layer with a high concentration of p-type impurities added. ++ Layer with n-type impurities added at high concentrations ++ Layered knot. n ++ Layers and p ++ For example, the layer has an impurity concentration of 1×10⁻⁶. 20 / cm 3 High concentration. Additionally, the typical impurity concentration in the junction is 10. 17 / cm 3 Taiwan ~ 10 18 / cm 3 Taiwan. ++ Layer and n ++ Layer combination (hereinafter referred to as p) ++ Layer / n ++ Layer description. (For example, p) ++ GaAs / n ++ GaInP, p ++ AlGaAs / n ++ GaInP, p ++ GaAs / n ++ GaAs, p ++ AlGaAs / n ++ AlGaAs, p ++ InGaAs / n ++ InGaAs, p ++ GaInAsP / n ++ GaInAsP, p ++ GaAsSb / n ++ GaAsSb. Alternatively, a combination of n can be used... ++ layer or p ++ Layers are exchanged with other combinations.

[0139] <Semiconductor layer constituting the driving thyristor S>

[0140] For example, the impurity concentration of the n-cathode layer 85 is 1×10⁻⁶. 18 / cm 3 n-type Al 0.9 GaAs. The Al composition can be varied within the range of 0 to 1.

[0141] For example, the p-gate layer 86 has an impurity concentration of 1×10⁶. 17 / cm 3 p-type Al 0.9 GaAs. The Al composition can be varied within the range of 0 to 1.

[0142] For example, the n-gate layer 87 has an impurity concentration of 1×10⁻⁶. 17 / cm 3 n-type Al 0.9 GaAs. The Al composition can be varied within the range of 0 to 1.

[0143] For example, the impurity concentration of the p-anode layer 88 is 1×10⁸. 18 / cm 3 p-type Al 0.9 GaAs. The Al composition can be varied within the range of 0 to 1.

[0144] <Manufacturing Method of Light Source 20>

[0145] The light source 20 is manufactured in the following manner.

[0146] An n-cathode layer 81, a light-emitting layer 82, a p-anode layer 83, a tunnel junction layer 84, an n-cathode layer 85, a p-gate layer 86, an n-gate layer 87, and a p-anode layer 88 are sequentially stacked on a substrate 80. Next, the p-anode layer 88, n-gate layer 87, p-gate layer 86, n-cathode layer 85, tunnel junction layer 84, p-anode layer 83, light-emitting layer 82, and n-cathode layer 81 are etched to form the portion separating the light-emitting portion 22 and the hole 342.

[0147] Then, in an oxidizing atmosphere, the current-blocking layer in the p-anode layer 83 is oxidized from the side of the hole 342 to form the current-blocking part β.

[0148] Next, a portion of the p-anode layer 88 is etched to expose the surface of the n-gate layer 87. Then, a p-ohmic electrode 321 is formed on the p-anode layer 88, and a gate electrode 331, which makes an ohmic contact with the n-gate layer 87, is formed on the n-gate layer 87. The p-ohmic electrode 321 may be, for example, composed of Au (AuZn), which contains Zn that makes an ohmic contact with p-type AlGaAs. The gate electrode 331 may be, for example, composed of Au (AuGe), which contains Ge that makes an ohmic contact with n-type AlGaAs.

[0149] Next, an insulating layer 89 is formed on the front surface. Then, the insulating layer 89, the p-anode layer 88, the n-gate layer 87, the p-gate layer 86, the n-cathode layer 85, and the tunnel junction layer 84 are etched to form the light emission exit 341. The insulating layer 89 is, for example, SiO2, SiN, etc.

[0150] Then, a through-hole is formed in the insulating layer 89 of the p-ohm electrode 321 to form the light-emitting electrode 72. In addition, a signal terminal 24 of the switching section 23 and wiring connecting the signal terminal 24 to the n-gate layer 87 are formed simultaneously with the light-emitting electrode 72.

[0151] Alternatively, the above-described processes can be reversed to manufacture the light source 20. For example, the light emission outlet 341 can be formed before the insulating layer 89 is formed. In this case, the light emission outlet 341 is protected by the insulating layer 89. The insulating layer 89 is a layer through which light from the light-emitting diode (LED) passes.

[0152] As described above, if the light-emitting diode (LED) and the driving thyristor S are stacked, the light emission of the LED can be controlled by supplying a switching signal φf to the driving thyristor S. In other words, compared with the case where the LED and the driving thyristor S are not stacked, it is easier to control the light emission of the LED.

[0153] (A variation of the light-emitting device 4)

[0154] In application Figure 5 In the light-emitting device 4 of this embodiment shown, the light-emitting parts 22 in the light-emitting part 21 of the light source 20 are arranged in a matrix. However, the light-emitting parts 22 do not necessarily need to be arranged in a matrix.

[0155] Figure 10 This diagram shows a modified example of the light-emitting device 4 according to this embodiment, namely, a light-emitting device 4A. Here, the light source 20A is different from the light source 20 of the light-emitting device 4. The other parts are the same as those of the light-emitting device 4. In addition, the parts that are the same as the light source 20 of the light source 20A will be described with the same reference numerals.

[0156] The light source 20A has four light-emitting parts 22. These four light-emitting parts 22 are not arranged in a matrix. In this way, multiple light-emitting parts 22 can also be arranged in a configuration other than a matrix. Furthermore, the switching unit 23 is positioned opposite the driving unit 50. Therefore, the distance between the driving unit 50 and the light-emitting parts 22 is shorter than when the switching unit 23 is positioned between the driving unit 50 and the light-emitting parts 22. Consequently, in the light-emitting device 4A, the inductance between the driving unit 50 and the light-emitting parts 22 of the light source 20 is reduced, and the rise time of the light pulse is shortened.

[0157] Figure 11This diagram shows a modified example of the light-emitting device 4B, which is a light-emitting device 4 according to this embodiment. Here, the light source 20B is different from the light source 20 of the light-emitting device 4. The other parts are the same as those of the light-emitting device 4. In addition, the parts that are the same as the light source 20 of the light source 20B are labeled with the same reference numerals.

[0158] The light-emitting part 22 in the light source 20 of the light-emitting device 4 of this embodiment is applied (see reference). Figure 4 The light-emitting part 22 in the light source 20A of the light-emitting device 4A (refer to) Figure 10 The planar shape of ) is quadrilateral. In contrast, Figure 11 The light-emitting part 22 in the light source 20B of the light-emitting device 4B shown has a rounded quadrilateral shape. However, the planar shape of the light-emitting part 22 can also be a shape other than a quadrilateral; that is, it can be a circle, an ellipse, a polygon, etc. Furthermore, the switching part 23 is positioned on the opposite side of the driving part 50. Therefore, the distance between the driving part 50 and the light-emitting part 22 is shorter than when the switching part 23 is positioned between the driving part 50 and the light-emitting part 22. Consequently, in the light-emitting device 4B, the inductance between the driving part 50 and the light-emitting part 22 of the light source 20 is reduced, and the rise time of the light pulse is shortened.

[0159] Figure 12 This diagram shows the equivalent circuit of a light-emitting device 4C, a modified example of the light-emitting device 4 according to this embodiment. Here, the switching unit 23C differs from the switching unit 23 of the light-emitting device 4. The other parts are the same as those of the light-emitting device 4.

[0160] The switching section 23 of the light-emitting device 4 is composed of a signal terminal 24 corresponding to the light-emitting section 22. The switching section 23C of the light-emitting device 4C is composed of a switching element 24C. The switching signal φf is supplied to the driving thyristor S via the switching element 24C. Furthermore, in Figure 12 In the text, the switching element 24C corresponding to the light-emitting parts 22-1, 22-2, and 22-3 is described as switching element 24C-1, 24C-2, and 24C-3.

[0161] In this way, the switching part 23C can also be composed of a switching element 24C.

[0162] Figure 13 This diagram shows the equivalent circuit of a light-emitting device 4D, a modified example of the light-emitting device 4 according to this embodiment. Here, the switching unit 23D differs from the switching unit 23 of the light-emitting device 4. The other parts are the same as those of the light-emitting device 4.

[0163] In addition to the switching element 24C of the light-emitting device 4C, the switching unit 23D also has a transmission circuit 28 that sequentially transmits the on / off states of the switching element 24C. That is, after the switching element 24C-1 transitions from the off state to the on state and then back to the off state, the transmission circuit 28 causes the switching element 24C-2 to transition from the off state to the on state. In this way, the transmission circuit 28 sequentially transmits the on / off states. This causes the multiple light-emitting units 22 to emit light sequentially. In other words, it is not necessary to control the light emission of each light-emitting unit 22 individually; instead, the light emission of the light-emitting units 22 is controlled by supplying a start signal to the transmission circuit 28 to initiate the emission. Such a transmission circuit 28 is, for example, a shift register.

[0164] In this embodiment, a light-emitting diode (LED) is provided on the substrate 80 as an example of a light-emitting element, and a driving thyristor S is stacked on the LED. Alternatively, a driving thyristor S may be provided on the substrate 80, and a LED may be stacked on the driving thyristor S.

[0165] Furthermore, in this embodiment, an n-type substrate 80 is used, but a p-type substrate can also be used, and a light source 20 with opposite polarities can be formed. In this case, a light-emitting diode (LED) can be disposed on the substrate, and a driving thyristor (S) can be stacked on the LED; alternatively, a driving thyristor (S) can be disposed on the substrate 80, and an LED can be stacked on the driving thyristor (S).

[0166] In this embodiment, the light-emitting section 22 is configured such that the light-emitting elements (LEDs in this embodiment) of the same light-emitting section 22 are adjacent to each other, thereby simplifying the structure of the light-emitting section 22. However, the light-emitting elements may not need to be fixedly configured, and the light-emitting elements connected to the same signal terminal 24 of the switching section 23 may be regarded as one light-emitting section 22.

[0167] In this embodiment, an example is shown where the light-emitting device 4 is used together with the 3D sensor 5, but it is not limited to this. It can also be applied to light-emitting devices used in light transmission, in which case it can be combined with an optical transmission path, and the light switched by the switching unit can be input to the same optical transmission path, or it can be input to different optical transmission paths.

Claims

1. A light-emitting device, comprising: Multiple light-emitting parts; A driving unit that supplies current to the light-emitting unit and drives the light-emitting unit; and A switching unit is disposed on the side opposite to the driving unit relative to the plurality of light-emitting units, and switches the light emission of the plurality of light-emitting units. The light-emitting device has wiring that connects each of the plurality of light-emitting parts to the switching part. The wiring is arranged along the outside of the light-emitting part.

2. The light-emitting device according to claim 1, wherein, The light-emitting device has light-emitting electrodes for supplying current to the light-emitting part. The pad portion of the light-emitting electrode is located on the outside of the plurality of light-emitting portions, at a position different from the position where the driving portion and the switching portion are located, relative to the plurality of light-emitting portions.

3. The light-emitting device according to claim 1, wherein, The switching unit has a switching element.

4. The light-emitting device according to claim 3, wherein, The switching unit sequentially transmits the on / off state of the switching element set for each of the light-emitting units.

5. The light-emitting device according to claim 1, wherein, The light-emitting part has a light-emitting diode and a thyristor, with the thyristor stacked on top of the light-emitting diode, and the light-emitting diode emits light by being turned on.

6. The light-emitting device according to claim 5, wherein, The light-emitting diode is a vertical cavity surface-emitting laser.

7. A light-emitting device, comprising: Multiple light-emitting parts; A driving unit that supplies current to the light-emitting unit and drives the light-emitting unit; A switching unit is provided on the side opposite to the driving unit relative to the plurality of light-emitting units, and switches the light emission of the plurality of light-emitting units; as well as The light-emitting electrode supplies current to the plurality of light-emitting parts. The plurality of said light-emitting parts have: The first edge and the second edge, which are opposite to each other; and The third and fourth edges connect the first and second edges and are opposite to each other. The driving unit, the switching unit, and the light-emitting electrode are disposed on their respective edges.

8. The light-emitting device according to claim 7, wherein, The driving unit and the switching unit are disposed on the first edge side and the second edge side, which are opposite to each other.

9. The light-emitting device according to claim 8, wherein, The pad portion of the light-emitting electrode is disposed on both the third edge side and the fourth edge side.

10. A measuring device, comprising: The light-emitting device according to any one of claims 1 to 9; and A three-dimensional sensor that receives reflected light from a measured object that has been illuminated by light emitted from the light-emitting device.

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