Light emitting device and measuring device

Abstract

The present application provides a light emitting device and a measuring device. The light emitting device includes a substrate, a light emitting portion composed of a plurality of light emitting elements, a transmission portion that outputs a signal for controlling a light emitting state of the light emitting elements, and an electrode portion for inputting and outputting a signal for driving the transmission portion, wherein the substrate has a rectangular shape having a long side and a short side, the electrode portion is arranged to sandwich the transmission portion between a part of the electrode portion and another part of the electrode portion, and is arranged along the short side of the substrate.

Description

Technical Field

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

[0002] An array of light-emitting elements is known, which is configured to arrange multiple light-emitting elements that can be controlled by light from the outside in one-dimensional, two-dimensional or three-dimensional arrangement, and 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 a clock line for applying voltage or current from the outside is connected to each light-emitting element (Patent Document 1).

[0003] A self-scanning type light-emitting device is also known, which is a light-emitting element constituting a pnpnpn 6-layer semiconductor structure. Electrodes are provided on the p-type first layer and n-type sixth layer at both ends, and the p-type third layer and n-type fourth layer in the middle, so that the pn layer performs the function of a light-emitting diode and the pnpn 4 layer performs the function of a thyristor (Patent Document 2).

[0004] A light-emitting component is known, comprising: a plurality of transmission elements that are sequentially turned on; a plurality of position thyristors that are respectively connected to the plurality of transmission elements and are able to transition to the on state by the transmission elements being turned on; and a plurality of light-emitting elements that are respectively laminated on the plurality of position thyristors through a tunnel junction, and when the position thyristors are turned on, the light-emitting element emits light or the amount of light emitted increases (Patent Document 3).

[0005] A light-emitting device is also known, comprising: a light-emitting section, which is composed of multiple light-emitting element groups, each having a plurality of light-emitting elements, wherein, along each of the multiple light-emitting element groups, the multiple light-emitting elements included in the light-emitting element group are arranged side by side and sequentially set to a light-emitting or non-light-emitting state (Patent Document 4).

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 01-238962

[0009] Patent Document 2: Japanese Patent Application Publication No. 2001-308385

[0010] Patent Document 3: Japanese Patent Application Publication No. 2017-174906

[0011] Patent Document 4: Japanese Patent Application Publication No. 2020-120018 Summary of the Invention

[0012] The problem that the invention aims to solve

[0013] The object of the present invention is to reduce the size of the light-emitting device compared to the case where the electrode portion is arranged in the longitudinal direction of the light-emitting device.

[0014] Methods for solving problems

[0015] The light-emitting device of the first aspect of the present invention comprises,

[0016] substrate;

[0017] The light-emitting part is composed of multiple light-emitting elements;

[0018] The transmission unit outputs a signal that controls the light-emitting state of the light-emitting element; and

[0019] The electrode section is used to input and output signals that drive the transmission section.

[0020] The substrate is rectangular with a long side and a short side.

[0021] The electrode portion is configured to sandwich the transmission portion between one part of the electrode portion and another part of the electrode portion, and is arranged along the short side of the substrate.

[0022] The light-emitting device of the second aspect of the present invention, in the light-emitting device of the first aspect,

[0023] The electrode section includes: a plurality of transmission signal electrodes for which transmission signals are provided, the transmission signals controlling the light-emitting element to transition to a light-emitting state; and a plurality of power supply electrodes for providing a power supply potential and a reference potential to the transmission section, the plurality of transmission signal electrodes and the plurality of power supply electrodes being arranged in a straight line relative to the transmission section.

[0024] The light-emitting device of the third aspect of the present invention, in the light-emitting device of the first aspect,

[0025] The electrode section includes: a plurality of transmission signal electrodes for which transmission signals are provided, which control the light-emitting element to transition to a light-emitting state; and a plurality of power supply electrodes for providing a power supply potential and a reference potential to the transmission section, wherein the plurality of transmission signal electrodes and the plurality of power supply electrodes are arranged in an intersecting direction relative to the transmission section.

[0026] The light-emitting device of the fourth aspect of the present invention, in the light-emitting device of the first aspect,

[0027] The electrode section consists of a pair of transmission signal electrodes, which are provided with transmission signals that control the light-emitting element to switch to a light-emitting state. The pair of transmission signal electrodes are arranged opposite to the transmission section.

[0028] The light-emitting device of the fifth aspect of the present invention, in any one of the light-emitting devices of the first to fourth aspects,

[0029] The transmission section includes: a first direction transmission section that outputs a signal to the light-emitting elements arranged in a first direction; and a second direction transmission section that outputs a signal to the light-emitting elements arranged in a second direction intersecting the first direction, wherein neither the first direction transmission section nor the second direction transmission section is disposed in the long side direction of the substrate.

[0030] The light-emitting device of the sixth aspect of the present invention, in any of the light-emitting devices of the first to fifth aspects,

[0031] The area of ​​the light-emitting part is larger than the area of ​​the transmission part.

[0032] The light-emitting device of the seventh aspect of the present invention, in any one of the light-emitting devices of the first to fifth aspects,

[0033] The light-emitting part includes multiple light-emitting element groups, each light-emitting element group includes multiple light-emitting elements and can be driven independently of other light-emitting element groups, and the multiple light-emitting element groups are arranged in a two-dimensional shape.

[0034] The light-emitting device according to the eighth aspect of the present invention, in any one of the light-emitting devices of the first to seventh aspects, further comprises:

[0035] The light-emitting electrode section supplies current to the plurality of light-emitting elements.

[0036] The electrode portion and the light-emitting electrode portion are arranged side by side along the long side of the substrate.

[0037] The measuring apparatus of the ninth aspect of the present invention comprises:

[0038] The light-emitting device of any one of the first to eighth aspects;

[0039] The light-receiving part receives reflected light from an object illuminated by the light-emitting device; and

[0040] The processing unit measures the three-dimensional shape of the object based on the time from when light is irradiated onto the object by the light-emitting device until the light is received by the light-receiving part of the optical device.

[0041] The light-emitting device according to the tenth aspect of the present invention comprises:

[0042] substrate;

[0043] The light-emitting part is composed of multiple light-emitting elements;

[0044] The transmission unit outputs a signal that controls the light-emitting state of the light-emitting element; and

[0045] The electrode section is used to input and output signals that drive the transmission section.

[0046] The substrate is rectangular with a long side and a short side.

[0047] The transmission section and the electrode section are respectively arranged along the short side of the substrate.

[0048] The eleventh aspect of the present invention provides a light-emitting device, wherein, in the light-emitting device of the tenth aspect,

[0049] The electrode portion includes: a transmission signal electrode, which is provided with a transmission signal that controls the light-emitting element to a state capable of transitioning to a light-emitting state; and a power supply electrode, which provides a power supply potential and a reference potential to the transmission portion, the transmission signal electrode and the power supply electrode being arranged side by side along the short side of the substrate.

[0050] The light-emitting device of the twelfth aspect of the present invention, in the light-emitting device of the eleventh aspect,

[0051] The lighting signal electrode that supplies current to the light-emitting element is configured along the long side of the substrate such that it overlaps with the transmission section in the direction of the short side of the substrate.

[0052] The light-emitting device of the thirteenth aspect of the present invention, in the light-emitting device of the eleventh or twelfth aspect,

[0053] The lighting signal electrode that supplies current to the light-emitting element is configured along the long side of the substrate such that it has a portion that overlaps with the electrode portion in the direction of the short side of the substrate.

[0054] The light-emitting device of the fourteenth aspect of the present invention, in the light-emitting device of any one of the tenth to thirteenth aspects,

[0055] The transmission section is integrally disposed along the short side of the substrate.

[0056] The light-emitting device according to the fifteenth aspect of the present invention, in the light-emitting device of any one of the tenth to fourteenth aspects, further comprises:

[0057] A common signal line is provided in a light-emitting element group containing the plurality of light-emitting elements. In the light-emitting element group, the light-emitting elements contained in the light-emitting element group emit light simultaneously or increase the light intensity by transmitting a transmission signal output from the transmission unit to the common signal line.

[0058] The light-emitting device of the sixteenth aspect of the present invention, in any one of the light-emitting devices of the tenth to fifteenth aspects,

[0059] The area of ​​the light-emitting part is larger than the area of ​​the transmission part.

[0060] The light-emitting device of the seventeenth aspect of the present invention, in the light-emitting device of any one of the tenth to sixteenth aspects,

[0061] The light-emitting part includes multiple light-emitting element groups, each light-emitting element group includes multiple light-emitting elements and can be driven independently of other light-emitting element groups, and the multiple light-emitting element groups are arranged in a two-dimensional shape.

[0062] The light-emitting device of the eighteenth aspect of the present invention, in the light-emitting device of the seventeenth aspect,

[0063] The number of light-emitting element groups arranged along the long side of the substrate is greater than the number of light-emitting element groups arranged along the short side of the substrate.

[0064] The measuring apparatus of the nineteenth aspect of the present invention comprises:

[0065] The light-emitting device of any one of the tenth to seventeenth aspects;

[0066] The light-receiving part receives reflected light from an object illuminated by the light-emitting device; and

[0067] The processing unit measures the distance from the light-emitting device to the object, or the three-dimensional shape of the object, based on the time from when the light-emitting device irradiates the object to when the light is received by the light-receiving unit.

[0068] Invention Effects

[0069] According to the first aspect, compared with the case where the electrode portion is arranged in the longitudinal direction of the light-emitting device, the size of the light-emitting device can be reduced.

[0070] According to the second aspect, compared with the case where the electrode portion is arranged in the longitudinal direction of the light-emitting device, the length of the substrate in the longitudinal direction can be shortened.

[0071] According to the third aspect, compared with the case where the electrode portion is arranged in the longitudinal direction of the light-emitting device, the length of the substrate in the longitudinal direction can be shortened.

[0072] According to the fourth aspect, compared with the case where the electrode portion is arranged in the longitudinal direction of the light-emitting device, the length of the substrate in the longitudinal direction can be shortened.

[0073] According to the fifth aspect, the size of the light-emitting device can be reduced.

[0074] According to the sixth aspect, the amount of light emitted by the light-emitting device can be increased.

[0075] According to the seventh aspect, segmented irradiation can be performed.

[0076] According to the eighth aspect, it is possible to bring the light-emitting electrode close to the wiring connected to the electrode.

[0077] According to the ninth aspect, a measuring device capable of measuring three-dimensional shapes is provided.

[0078] According to the tenth aspect, compared with the case where the electrode portion is arranged in the longitudinal direction of the light-emitting device, the length of the light-emitting device in the longitudinal direction can be shortened.

[0079] According to the eleventh aspect, compared with the case where the electrode portion is arranged in the longitudinal direction of the light-emitting device, the length of the substrate in the longitudinal direction can be shortened.

[0080] According to the twelfth aspect, the length of the substrate in the longitudinal direction can be further shortened.

[0081] According to the thirteenth aspect, the length of the substrate in the longitudinal direction can be further shortened.

[0082] According to the fourteenth aspect, the length of the substrate in the longitudinal direction can be further shortened.

[0083] According to the fifteenth aspect, it is possible to miniaturize the light-emitting device.

[0084] According to the sixteenth aspect, the amount of light emitted by the light-emitting device can be increased.

[0085] According to the seventeenth aspect, segmented irradiation can be performed.

[0086] According to the eighteenth aspect, the horizontal irradiation area can be expanded.

[0087] According to the nineteenth aspect, a measuring device capable of measuring three-dimensional shapes is provided. Attached Figure Description

[0088] Figure 1 This is a diagram illustrating an example of the planar layout of the light-emitting device according to the first exemplary embodiment.

[0089] Figure 2 This is a schematic equivalent circuit diagram of the light-emitting device according to the first exemplary embodiment.

[0090] Figure 3 This is a diagram showing an example of the planar layout of the light-emitting device involved in Modification 1.

[0091] Figure 4 This is a diagram showing an example of the planar layout of the light-emitting device involved in Modification Example 2.

[0092] Figure 5 This is a diagram showing an example of the planar layout of the light-emitting device according to the first exemplary embodiment, with the transmission section as the center.

[0093] Figure 6 This is a diagram showing the cross-sectional structure of the light-emitting device.

[0094] Figure 7 This is a diagram illustrating a measuring device that uses a light-emitting device.

[0095] Figure 8 This is a diagram illustrating an example of the planar layout of the light-emitting device according to the second exemplary embodiment.

[0096] Figure 9 This is a schematic equivalent circuit diagram of the light-emitting device according to the second exemplary embodiment.

[0097] Figure 10 This is a diagram showing an example of the planar layout of the light-emitting device involved in the modified example.

[0098] Figure 11 This is a diagram showing an example of the planar layout of the light-emitting device according to the second exemplary embodiment, with the transmission section as the center.

[0099] Figure 12 This is a diagram showing the cross-sectional structure of the light-emitting device.

[0100] Label Explanation

[0101] 1…Measuring device, 101…Light receiving section, 102…Processing section, 103…Measured object, 100, 100A, 100B…Light emitting device, 110…Substrate, 120…Light emitting section, S…Drive thyristor, VCSEL…Vertical resonator surface-emitting laser element, 130…Transmission section, Φ1, Φ2…Transmission signal, ΦI…Light-up signal, D…Coupled diode, SD…Start-up diode, T…Transmission thyristor, Rg…Power line resistor, R1, R2 …Current limiting resistor, 140…Electrode section, Φ1…Φ1 terminal, Φ2…Φ2 terminal, Vgk…Vgk terminal, Vga…Vga terminal, 150…Common signal line, 51…Power supply line, 52, 53…Transmission signal line, 54…Reference potential line, 56…Lighting signal line, 200…Control section, 210…Transmission signal generation section, 220…Lighting signal generation section, 230…Power supply potential generation section, 240…Reference potential generation section, 301~306…Islands Detailed Implementation

[0102] The present invention will now be described in more detail with reference to the accompanying drawings, embodiments and specific examples, but the present invention is not limited to these embodiments and specific examples.

[0103] Additionally, it should be noted that in the following description of the use of the accompanying drawings, the drawings are schematic and the scale of each dimension differs from the actual figures. For ease of understanding, illustrations other than those of the parts required for the description have been appropriately omitted.

[0104] (1-1) Overall structure of the light-emitting device

[0105] Figure 1 This is a diagram illustrating an example of the planar layout of the light-emitting device 100 according to the first exemplary embodiment. Figure 2 This is a schematic equivalent circuit diagram of the light-emitting device 100 according to the first exemplary embodiment. Figure 2 The control unit 200 for controlling the light-emitting device 100 is also shown in the image.

[0106] like Figure 1 As shown, the light-emitting device 100 according to the first exemplary embodiment is configured to include: a substrate 110; a light-emitting part 120, which is composed of a plurality of light-emitting elements; a transmission part 130, which controls the light emission of the light-emitting elements; and a common signal line 150, which connects the light-emitting part 120 and the transmission part 130 to each other.

[0107] The light-emitting section 120 includes multiple laser diodes, which emit laser beams as one example of light-emitting elements. Furthermore, the light-emitting device 100 is configured as a self-scanning light-emitting element array (SLED) as described below. In the first exemplary embodiment, the laser diode is, for example, a vertical cavity surface emitting laser (VCSEL). The following description focuses on the case where the light-emitting element is a VCSEL, but other light-emitting devices such as LEDs may also be used.

[0108] (1-2) Equivalent circuit of the light-emitting device

[0109] First, refer to Figure 2 The equivalent circuit is described to illustrate the functional structure of the light-emitting device 100 according to the first exemplary embodiment.

[0110] The light-emitting part 120 has multiple VCSELs. For example, a group of 15 VCSELs constitutes one VCSEL group. Figure 1 The image shows 12 VCSEL groups (VCSEL groups #1 to #12). Figure 2The equivalent circuit diagram shows four VCSEL groups (VCSEL groups #1 to #4) as part of it. In the first exemplary embodiment, the 15 VCSELs contained in a VCSEL group are configured to be adjacent, and the area of ​​the VCSEL group is not dispersed.

[0111] Furthermore, the light-emitting device 100 includes a driving thyristor S for each VCSEL group. The VCSEL group and the driving thyristor S are connected in series. Moreover, the driving thyristor S is also labeled with the VCSEL group number "i". For example, the driving thyristor S included in VCSEL group #1 is driving thyristor S1.

[0112] The light-emitting device 100 also includes a plurality of transmission thyristors T, a plurality of coupling diodes D, a plurality of power line resistors Rg, a start-up diode SD, and current-limiting resistors R1 and R2. Here, when distinguishing the plurality of transmission thyristors T, such as transmission thyristors T1, T2, T3, etc., they are distinguished by marking the VCSEL group number "i". The same applies to the coupling diodes D and the power line resistors Rg. As described later, for example, transmission thyristor T1 is configured to correspond to VCSEL group #1. Figure 2 The diagram shows I corresponding to parts 1 through 4. The number of "i" in the light-emitting device 100 can be a predetermined number. For example, it could be 128, 512, 1024, etc. The number of transmission thyristors T can be the same as the number of VCSEL groups. Furthermore, the number of transmission thyristors T can be greater than or less than the number of VCSEL groups.

[0113] The transmission thyristors T are arranged in the order T1, T2, T3, ..., and the coupling diodes D are arranged in the order D1, D2, D3, ... Furthermore, coupling diode D1 is placed between transmission thyristors T1 and T2. This also applies to the other coupling diodes D. Additionally, the power line resistors Rg are arranged in the order Rg1, Rg2, Rg3, ...

[0114] VCSEL and coupling diode D are two-terminal devices with an anode and a cathode. Driving thyristor S and transmission thyristor T are three-terminal devices with an anode, a cathode, and a gate. Here, the gate of transmission thyristor T is referred to as gate Gt, and the gate of driving thyristor S is referred to as gate Gs. Furthermore, when distinguishing them, "i" is used as described above. The portion composed of VCSEL is designated as the light-emitting section 120.

[0115] Next, the connection relationships of each component (VCSEL, driving thyristor S, transmission thyristor T, etc.) will be explained. As mentioned above, VCSELij and driving thyristor Si are connected in series. That is, the anode of driving thyristor Si is connected to the reference potential Vga (ground potential (GND), etc.), and the cathode is connected in parallel with the anode of VCSELij. The cathode of VCSELij is connected together with the lighting signal line 56, which is supplied with the lighting signal ΦI to control the VCSELij to be in an emitting or non-emitting state.

[0116] As described later, via a Vga terminal (see below) provided on the back side of the substrate 110 constituting the light-emitting device 100. Figure 1 and Figure 3 The reference potential Vga is supplied.

[0117] The anode of the transmission thyristor T is connected to the reference potential Vga. The cathodes of the odd-numbered transmission thyristors T1, T3, etc., are connected to the transmission signal line 52. The transmission signal line 52 is connected to terminal Φ1, one of the electrode pads constituting the electrode section 140, via a current-limiting resistor R1.

[0118] The cathodes of the even-numbered transmission thyristors T2, T4, etc., are connected to the transmission signal line 53. The transmission signal line 53 is connected to the Φ2 terminal of one of the electrode pads constituting the electrode section 140 via the current-limiting resistor R2.

[0119] The coupling diodes D are connected in series. That is, the cathode of one coupling diode D is connected to the anode of the adjacent coupling diode D. The anode of the start-up diode SD is connected to the transmission signal line 53, and the cathode is connected to the anode of the coupling diode D1.

[0120] Furthermore, the cathode of the starting diode SD and the anode of the coupling diode D1 are connected to the gate Gt1 of the transmission thyristor T1. The cathode of the coupling diode D1 and the anode of the coupling diode D2 are connected to the gate Gt2 of the transmission thyristor T2. This also applies to the other coupling diodes D.

[0121] The gate Gt of the transmission thyristor T is connected to the power line 51 via the power line resistor Rg. The power line 51 is connected to the Vgk terminal, which is one of the electrode pads constituting the electrode section 140. Furthermore, the gate Gti of the transmission thyristor Ti is connected to the gate Gsi of the driving thyristor Si.

[0122] The structure of the control unit 200 will be described. The control unit 200 generates a lighting signal ΦI and supplies it to the light-emitting device 100, which operates according to the signal supplied via the electrode unit 140.

[0123] The control unit 200 is composed of electronic circuits. For example, the control unit 200 may also be an integrated circuit (IC) configured to control the operation of the light-emitting device 100. The control unit 200 includes a transmission signal generation unit 210, a lighting signal generation unit 220, a power supply potential generation unit 230, and a reference potential generation unit 240.

[0124] The transmission signal generation unit 210 generates transmission signals Φ1 and Φ2, supplies transmission signal Φ1 to the Φ1 terminal, which is an example of a transmission signal electrode of the light-emitting device 100, and supplies transmission signal Φ2 to the Φ2 terminal, which is an example of a transmission signal electrode of the light-emitting device 100.

[0125] The lighting signal generation unit 220 generates a lighting signal ΦI and supplies it to the ΦI terminal, which serves as an example of a lighting signal electrode in the light-emitting device 100, via a current-limiting resistor RI. Alternatively, the current-limiting resistor RI may be provided within the light-emitting device 100. Furthermore, when the operation of the light-emitting device 100 does not require the current-limiting resistor RI, it may be omitted.

[0126] The power supply potential generation unit 230 generates a power supply potential Vgk and supplies it to the Vgk terminal, which is an example of a power supply electrode of the light-emitting device 100. The reference potential generation unit 240 generates a reference potential Vga and supplies it to the Vga terminal, which is an example of a power supply electrode of the light-emitting device 100. For example, the power supply potential Vgk is -3.3V. As described above, for example, the reference potential Vga is the ground potential (GND).

[0127] The transmission unit is driven by signals from these power electrodes and transmission signal electrodes.

[0128] The transmission signals Φ1 and Φ2 generated by the transmission signal generation unit 210 and the lighting signal ΦI generated by the lighting signal generation unit 220 will be described later.

[0129] exist Figure 2 In the light-emitting device 100 shown, 15 VCSELij (j = 1 to 15) are connected as a VCSEL group to a transmission thyristor Ti via a driving thyristor Si.

[0130] As described later, the transmission thyristor Ti becomes in the ON state, thereby enabling the drive thyristor Si connected to the transmission thyristor Ti to switch to the ON state. Furthermore, when the drive thyristor Si is in the ON state, VCSELij emits light. Moreover, the transmission thyristor Ti is driven to transmit the ON states in a "i" sequence. That is, the ON states propagate sequentially within the transmission thyristor Ti. Thus, the transmission thyristor Ti causes the VCSEL group to emit light sequentially.

[0131] Here, a VCSEL group is composed of multiple VCSELs (15 in the first exemplary embodiment). Furthermore, each transmission thyristor T is connected to a VCSEL group, and the multiple VCSELs within the VCSEL group emit light in parallel. Additionally, in Figure 2 In the example shown, each VCSEL group has the same number of VCSELs (15 in this case), but the number of VCSELs in different VCSEL groups can also be different.

[0132] VCSELs can oscillate in a low-order single transverse mode (single-mode). In single-mode, the emission point of the VCSEL (described later)... Figure 3 The intensity distribution of the light emitted from the light emission outlet (310) is unimodal (meaning it has only one intensity peak). On the other hand, in a VCSEL that oscillates with multiple transverse modes (multimodes) containing higher orders, the intensity distribution is prone to distortion, for example, becoming multimodal. Furthermore, in unimodal mode, the diffusion angle of the light emitted from the emission point is smaller compared to multimode.

[0133] Furthermore, the smaller the area of ​​the emitting point, the easier it is for the VCSEL to oscillate in a single transverse mode (single-mode). Therefore, the light output of a single-mode VCSEL is small. When the light output is increased by increasing the area of ​​the emitting point, it is easy to switch to multimode. Therefore, the light output can be increased by setting multiple VCSELs into a VCSEL group and making the multiple VCSELs in the VCSEL group emit light in parallel.

[0134] (1-3) Planar layout of the light-emitting device

[0135] return Figure 1 First, the planar layout of the transmission section 130 and the electrode section 140 in the light-emitting device 100 according to the first exemplary embodiment will be described. The substrate 110 of the light-emitting device 100 is a rectangle having a long side 110a and a short side 110b. Figure 1 In the diagram, the x-direction is the direction of the longer side, and the y-direction is the direction of the shorter side.

[0136] like Figure 1 As shown, in the light-emitting device 100, the electrode portion 140 sandwiches the transmission portion 130 and is arranged along the short side 110b of the substrate 110.

[0137] The electrode section 140 is configured as follows: Φ1 and Φ2 terminals as transmission signal electrodes, which receive transmission signals Φ1 and Φ2 generated by the transmission signal generation section 210 of the control section 200; Vgk terminal as power supply electrode, which receives power supply potential Vgk generated by the power supply potential generation section 230; and Vga terminal, which receives reference potential Vga generated by the reference potential generation section 240, each terminal being a pad.

[0138] In the transmission section 130 of the light-emitting device 100, a transmission signal line 52 extending from the Φ1 terminal of the electrode section 140, a transmission signal line 53 extending from the Φ2 terminal, a power supply line 51 extending from the Vgk terminal, and a reference potential line 54 extending from the Vga terminal are formed as conductive patterns.

[0139] In the transmission section 130, the cathodes of the odd-numbered transmission thyristors T1, T3, etc. are connected to the transmission signal line 52, and the cathodes of the even-numbered transmission thyristors T2, T4, etc. are connected to the transmission signal line 53.

[0140] Thus, between the control unit 200 and the transmission unit 130, such as Figure 1 As shown, the Φ1 and Φ2 terminals of the input and output transmission signals Φ1 and Φ2, and the Vgk and Vga terminals of the input and output power supply potentials Vgk and reference potentials Vga are arranged in a straight line side by side with respect to the transmission section 130. As a result, compared with the case where the electrode section 140 is arranged in the long side direction of the substrate 110, the size of the light-emitting device 100 can be reduced.

[0141] Additionally, the lighting signal electrode, i.e., the ΦI terminal, which receives the lighting signal ΦI generated by the lighting signal generation unit 220 and controls VCSELij to a light-emitting or non-light-emitting state, is arranged along the long side 110a of the substrate 110, sandwiching the light-emitting unit 120. For example... Figure 1 As shown, the ΦI terminal is formed throughout the length direction of the light-emitting portion 120 and is arranged side by side with the electrode portion 130 in the length direction of the substrate 110. This allows the ΦI terminal to be close to the wiring connected to the electrode portion 130.

[0142] The light-emitting section 120 is configured as a 4×3 two-dimensional structure consisting of 12 VCSEL groups (VCSEL groups #1 to #12) composed of 15 VCSELs, with four groups arranged in the x-direction (first direction) and three groups arranged in the y-direction (second direction) that intersects (or is orthogonal to) the x-direction, enabling segmented illumination. Furthermore, the area of ​​the light-emitting section 120 is larger than the area of ​​the transmission section 130, resulting in a greater light emission from the light-emitting device 100.

[0143] Furthermore, in the transmission section 130 that outputs transmission signals to the two-dimensional VCSEL group arranged in the first and second directions, the first-direction transmission section that outputs transmission signals to the VCSEL group in the first direction and the second-direction transmission section that outputs transmission signals to the VCSEL group in the second direction are integrally arranged along the short side 110b of the substrate 110. That is, the transmission section 130 is not arranged in the long side direction (x direction) of the substrate 110. As a result, the size of the light-emitting device 100 can be reduced.

[0144] (Variation Example 1)

[0145] Figure 3 This is a diagram showing an example of the planar layout of the light-emitting device 100A involved in Modification 1.

[0146] In the light-emitting device 100A of Modified Example 1, between the control unit 200 and the transmission unit 130, such as Figure 3 As shown, the Φ1 and Φ2 terminals of the input and output transmission signals Φ1 and Φ2, and the Vgk and Vga terminals of the input and output power supply potentials Vgk and reference potentials Vga are arranged side by side with respect to the transmission section 130 in a cross (orthogonal) direction. Therefore, compared to the case where the electrode section 140 is arranged along the long side of the substrate 110, the size of the light-emitting device 100 can be reduced.

[0147] (Variation Example 2)

[0148] Figure 4 This is a diagram showing an example of the planar layout of the light-emitting device 100B involved in Modification Example 2.

[0149] In the light-emitting device 100 according to this exemplary embodiment, including the case described in Modification 1 where a Vgk terminal and a Vga terminal have an input / output power supply potential Vgk and a reference potential Vga, the Vgk terminal and Vga terminal may also be omitted. In this case, as shown in Modification 1, the Vgk terminal and Vga terminal are omitted. Figure 4 As shown, alternatively, the Φ1 and Φ2 terminals of the input / output transmission signals Φ1 and Φ2 can be respectively disposed between the control unit 200 and the transmission unit 130, sandwiching the transmission unit 130. Therefore, compared to the case where the electrode unit 140 is disposed along the long side of the substrate 110, the size of the light-emitting device 100 can be further reduced.

[0150] Figure 5 This is a diagram showing an example of the planar layout of the light-emitting device 100 according to the first exemplary embodiment, with the transmission unit 130 as the center.

[0151] The light-emitting device 100 is made of a semiconductor material capable of emitting a laser beam, such as a GaAs-based compound semiconductor. Furthermore, as shown in the cross-sectional view described later (described later...), Figure 6 As shown, the light-emitting device 100 is composed of multiple islands. Within each island, a semiconductor layer stack of multiple GaAs-based compound semiconductor layers is deposited on a p-type GaAs substrate 110 and separated between components by mesa etching. Here, through... Figure 5 The islands 301 to 306 shown illustrate the planar layout of the light-emitting device 100. Furthermore, islands 301, 302, and 303 are disposed in each VCSEL group. Therefore, when islands 301, 302, and 303 are distinguished by VCSEL group, as described above, they are labeled "i," and marked as islands 301-i, 302-i, and 303-i. Furthermore, in Figure 5In the diagram, the portion where i is 1 to 12 is shown. Additionally, as described above, the number of VCSELs in the VCSEL group is labeled "j". Here, j is 1 to 15. Thus, the light-emitting device 100 is configured on a shared semiconductor substrate and miniaturized.

[0152] Island 301-i is equipped with VCSELij and a driving thyristor Si. Furthermore, as described later... Figure 6 As shown, VCSELij and the driving thyristor Si are stacked. Furthermore, in Figure 5 In this context, VCSELij and the driving thyristor Si are labeled VCSELij / Si. For example, when "i" is 1, it is labeled VCSEL1j / S1. Figure 5 The diagram shows islands 301-1, 301-4, and 301-12, while other islands 301-i are omitted. Furthermore, 15 VCSELs are arranged within island 301-i.

[0153] Island 302-i contains a transmission thyristor Ti and a coupling diode Di. Island 302-i is arranged in parallel in the y-direction (short side direction).

[0154] Island 303-i contains a power line resistor Rgi. Island 303-i is configured to be arranged in parallel along the y-direction (short side direction).

[0155] A startup diode SD is installed in island 304. A current-limiting resistor R1 is installed in island 305, and a current-limiting resistor R2 is installed in island 306.

[0156] (1-4) Cross-sectional structure of the light-emitting device

[0157] Next, before explaining the connection relationship between these islands 301 to 306, the cross-sectional structure of islands 301 and 302 will be described.

[0158] Figure 6 This is a diagram showing the cross-sectional structure of the light-emitting device 100. Furthermore, Figure 6 yes Figure 5 A cross-sectional view of the light-emitting device 100 at line AA. That is, Figure 6 The sectional view shown is a cross-section on the paper from left to right across the coupling diode D1, the transmission thyristor T1, VCSEL11 / S1, and VCSEL12 / S1, showing portions of islands 301-1 and 302-1.

[0159] First, island 301-1, which is equipped with a drive thyristor S and a VCSEL, will be described. Here, the drive thyristor S and VCSEL are stacked (VCSEL11 / S1, VCSEL12 / S1). Figure 6As shown, a p-type anode layer (hereinafter referred to as p-anode layer) 11, an n-type gate layer (n-gate layer) 12, a p-type gate layer (p-gate layer) 13, and an n-type cathode layer (n-cathode layer) 14 constituting a driving thyristor S1 are stacked on a p-type GaAs substrate 110. That is, the driving thyristor S is constructed with p-anode layer 11 as the anode, n-gate layer 12 as the n-gate, p-gate layer 13 as the p-gate, and n-cathode layer 14 as the cathode.

[0160] Next, a tunnel junction layer 15 is stacked on the n-cathode layer 14. Furthermore, a p-type anode layer (p-anode layer) 16, a light-emitting layer 17, and an n-type cathode layer (n-cathode layer) 18 constituting VCSEL 11 and VCSEL 12 are stacked on the tunnel junction layer 15. That is, the VCSEL is constructed with the p-anode layer 16 as the anode, the light-emitting layer 17 as the light-emitting layer, and the n-cathode layer 18 as the cathode.

[0161] The driving thyristor S1 is connected in series with VCSEL11 and VCSEL12 via tunnel junction 15. Tunnel junction 15 will be described later.

[0162] In portions of VCSEL11 and VCSEL12, the n-cathode layer 18, the light-emitting layer 17, and the p-anode layer 16 are removed by etching to expose the tunnel junction layer 15 surrounding the VCSEL. Here, the cross-sectional shape of the VCSEL is circular. That is, a portion of the VCSEL is formed as a cylinder. Therefore, this portion of the VCSEL is designated as column 311 (see reference). Figure 5 ).

[0163] The p-anode layer 11, n-gate layer 12, p-gate layer 13, n-cathode layer 14 and tunnel junction layer 15 constituting the driving thyristor S are continuous among the VCSELs belonging to VCSEL group #1.

[0164] Furthermore, in island 301-1, in the portion where the p gate layer 13 is exposed after further removal of the tunnel junction layer 15 and the n cathode layer 14, a p ohmic electrode 331 made of a metal material that can easily form ohmic contact with the p-type semiconductor layer such as the p gate layer 13 is provided as the gate Gs1 of the driving thyristor S1.

[0165] On the n-cathode layer 18 of the VCSEL, an n-ohm electrode 321 is provided, which is made of a metal material that can easily form an ohmic contact with the n-type semiconductor layer such as the n-cathode layer 18. Furthermore, the n-ohm electrode 321 is circular to surround the light emission exit 310 (see reference). Figure 5 ).

[0166] The p-anode layer 16 of column 311 includes a current-restricting layer 16b. Here, as an example, the p-anode layer 16 is composed of a lower p-anode layer 16a, a current-restricting layer 16b, and an upper p-anode layer 16c. The current-restricting layer 16b is made of a material with a high Al content, such as AlAs, where Al is oxidized to Al₂O₃, thus increasing the resistance and forming a portion where current flow is difficult. Figure 6 The layer that is blacked out in the middle.

[0167] The column 311 is cylindrical, so when the current-restricting layer 16b is oxidized from the side of the exposed p-anode layer 16, the oxidation proceeds from the periphery to the center of the circular cross-section. Furthermore, the center is not oxidized, thus the center of the VCSEL cross-section becomes a current-passing region 16d where current flows easily, and the periphery becomes a current-blocking region 16e where current flow is difficult. Additionally, the VCSEL emits light in the portion of the light-emitting layer 17 where the current path is restricted by the current-passing region 16d. The area on the surface of the VCSEL corresponding to this current-passing region 16d is the light-emitting point, which is the light emission outlet 310.

[0168] The current narrowing layer 16b is provided to enable the VCSEL to oscillate in a low-order single transverse mode (single mode). That is, the cross-sectional shape of the pillar 311 on which the VCSEL is formed is made circular by oxidizing the periphery, thereby making the cross-sectional shape of the light emission outlet 310 circular and reducing the area.

[0169] Furthermore, the periphery of the VCSEL exhibits numerous defects caused by mesa etching, which easily lead to non-light-emitting recombination. Therefore, by incorporating a current-blocking region 16e, the power consumed by non-light-emitting recombination can be suppressed. This enables both low power consumption and improved light extraction efficiency. Light extraction efficiency refers to the amount of light extracted per unit of power.

[0170] Next, island 302-1, which is equipped with a transmission thyristor T1 and a coupling diode D1, will be described. Similar to the driving thyristor S, the transmission thyristor T1 is composed of a p-anode layer 11, an n-gate layer 12, a p-gate layer 13, and an n-cathode layer 14. That is, the transmission thyristor T1 is configured with p-anode layer 11 as the anode, n-gate layer 12 as the n-gate, p-gate layer 13 as the p-gate, and n-cathode layer 14 as the cathode. Here, a gate electrode (the p-ohmic electrode 332 described later) is provided on p-gate layer 13.

[0171] The coupling diode D1 is composed of a p-gate layer 13 and an n-cathode layer 14. That is, the coupling diode D1 is constructed with the p-gate layer 13 as the anode and the n-cathode layer 14 as the cathode.

[0172] In island 302-1, the n-cathode layer 18, the light-emitting layer 17, the p-anode layer 16, and the tunnel junction layer 15 in the portion where the driving thyristor S and VCSEL are stacked are removed. Furthermore, in the portion where the transmission thyristor T1 and the portion where the coupling diode D1 are stacked, the n-cathode layer 14 is removed, so that the n-cathode layer 14 is retained as pillar 312 and pillar 313.

[0173] An n-ohm electrode 322 is provided on the n-cathode layer 14 of pillar 312 as the cathode electrode of the transmission thyristor T1. Similarly, an n-ohm electrode 323 is provided on the n-cathode layer 14 of pillar 313 as the cathode electrode of the coupling diode D1.

[0174] The p-ohm electrode 332 disposed on the p-gate layer 13 functions as the gate Gt1 of the transmission thyristor T1 and the anode electrode of the coupling diode D1.

[0175] Furthermore, an interlayer insulating layer 21 is provided to cover the surface. A signal line 55 is provided on the interlayer insulating layer 21, which connects via a via to a p-ohm electrode 331 (gate Gs1) provided in island 301-1 and a p-ohm electrode 332 (gate Gt1) provided in island 302-1. Additionally, a transmission signal line 52 connected to an n-ohm electrode 322 is provided on the interlayer insulating layer 21. Furthermore, a transmission signal line 53 is provided on the interlayer insulating layer 21. Further, a wiring 54-2 connected to the n-ohm electrode 323 via a via is provided on the interlayer insulating layer 21.

[0176] Furthermore, an interlayer insulating layer 22 is provided to cover the surface. Moreover, a lighting signal line 56, connected to the n-ohm electrode 321 provided in island 301-1, is provided on the interlayer insulating layer 22 via through holes provided in the interlayer insulating layer 22 and the interlayer insulating layer 21. That is, the signal line 55 and the lighting signal line 56 form a multilayer wiring structure via the interlayer insulating layer 22.

[0177] In addition, when the interlayer insulating layers 21 and 22 have poor transmittance to the emitted light of the VCSEL, they can be replaced by the interlayer insulating layers 21 and 22 on the light outlet 310 to form a light emitting layer with excellent transmittance to the emitted light of the VCSEL.

[0178] The surrounding semiconductor layer stack is removed by etching into the substrate 110, thereby separating the islands 301, 302, 303, 304, 305, and 306 from each other. Furthermore, etching can be performed into the p-anode layer 11, or a portion of the thickness direction of the p-anode layer 11.

[0179] return Figure 5The other islands 303, 304, 305, and 306 will be described. Island 303 contains a power line resistor Rg1. In island 303-1, the n-cathode layer 18, the light-emitting layer 17, the p-anode layer 16, the tunnel junction layer 15, and the n-cathode layer 14 in the semiconductor layer stack are removed to expose the p-gate layer 13. A pair of p-ohm electrodes are disposed on the exposed p-gate layer 13. Furthermore, the p-gate layer 13 between the p-ohm electrodes serves as a resistor.

[0180] A startup diode SD is disposed in island 304. In island 304, the n-cathode layer 18, the light-emitting layer 17, the p-anode layer 16, and the tunnel junction layer 15 of the semiconductor layer stack have been removed. Furthermore, except for pillar 314 where the n-cathode layer 14 remains, the p-gate layer 13 is exposed. In the startup diode SD, the n-cathode layer 14 constituting pillar 314 is the cathode, and the p-gate layer 13 is the anode. Moreover, the n-ohm electrode disposed on the n-cathode layer 14 of pillar 314 is the cathode electrode, and the p-ohm electrode disposed on the exposed p-gate layer 13 is the anode electrode.

[0181] A current-limiting resistor R1 is provided in island 305, and a current-limiting resistor R2 is provided in island 306. Islands 305 and 306 have the same structure as island 303, and the p-gate layer 13 located between a pair of p-ohm electrodes on the exposed p-gate layer 13 is respectively set as current-limiting resistors R1 and R2.

[0182] The islands 301 to 306 and the connections between them are explained.

[0183] As described above, the cathode of the VCSEL, i.e., the n-cathode layer 18, located on the pillar 311 of island 301-1, is connected in parallel with the lighting signal line 56 via an n-ohm electrode 321. This also applies to the other islands 301.

[0184] The cathode (n-cathode layer 18) of the transmission thyristor T1, which is located on the pillar 312 of island 302-1, is connected to the transmission signal line 52 via an n-ohm electrode 322. Furthermore, this also applies to the transmission thyristor T3 located in island 302-3. That is, the cathode (n-cathode layer 18) of the odd-numbered transmission thyristor Ti is connected to the transmission signal line 52.

[0185] On the other hand, the cathode (n-cathode layer 18) of the transmission thyristor T2 disposed in island 302-2 is connected to the transmission signal line 53. That is, the cathode (n-cathode layer 18) of the even-numbered transmission thyristor Ti is connected to the transmission signal line 53.

[0186] Furthermore, the gate Gs1 (p-ohm electrode 331) of island 301-1 and the gate Gt1 (p-ohm electrode 332) of island 302-1 are connected via signal line 55-1. The cathode (n-cathode layer 18) of the coupling diode D1 disposed on pillar 313 of island 302-1 is connected to wiring 57-2 via n-ohm electrode 323. Wiring 57-2 is connected to the p-ohm electrode of the adjacent island 302-2 and the p-ohm electrode of the power line resistor Rg2 of island 303-2.

[0187] Furthermore, the signal from signal line 55-1 is transmitted not only to multiple VCSELs 11, but also to VCSELs in group #1 such as VCSEL 12. A signal line corresponding to signal line 55-1 is provided in each group of light-emitting elements, and signal line 55-1 becomes a shared signal line.

[0188] The p-ohm electrode 333 (which is the same as the p-ohm electrode 332 of the gate Gt1 and is disposed on the p-gate layer 13) disposed in island 302-1, the p-ohm electrode of the power line resistor Rg1 disposed in island 303-1, and the cathode electrode, i.e. the n-ohm electrode, of the start-up diode SD disposed in island 304 are connected by wiring 57-1.

[0189] Additionally, the other p-ohm electrode of the power line resistor Rg1 of island 303-1 is connected to power line 51. Power line 51 is connected to the Vgk terminal. This also applies to other islands 303.

[0190] Transmission signal line 52 is connected to one p-ohm electrode of the current-limiting resistor R1 in island 305. The other p-ohm electrode of the current-limiting resistor R1 is connected to terminal Φ1. Transmission signal line 53 is connected to the p-ohm electrode of the startup diode SD in island 303, and also to one p-ohm electrode of the current-limiting resistor R2 in island 306. The other p-ohm electrode of the current-limiting resistor R2 in island 306 is connected to terminal Φ2.

[0191] The above explanation uses islands 301-1, 302-1, and 303-1 as examples, but it also applies to other islands 301, 302, and 303.

[0192] (1-5) Operation of the light-emitting device

[0193] (1-5.1) Thyristor

[0194] Next, the operation of the driving thyristor S and the transmission thyristor T will be explained. The driving thyristor S and the transmission thyristor T will both be referred to as thyristors.

[0195] A thyristor is constructed by stacking a p-anode layer 11, an n-gate layer 12, a p-gate layer 13, and an n-cathode layer 14. As described above, a thyristor is a semiconductor device having three terminals: an anode, a cathode, and a gate. For example, it is constructed by stacking a p-type semiconductor layer (p-anode layer 11, p-gate layer 13) and an n-type semiconductor layer (n-gate layer 12, n-cathode layer 14) formed of GaAs, GaAlAs, AlAs, etc. That is, the thyristor forms a pnpn structure. Here, as an example, the forward potential (diffusion potential) Vd of the pn junction formed by the p-type semiconductor layer and the n-type semiconductor layer is set to 1.5V.

[0196] As an example, the reference potential Vga of the p-anode layer 11 is taken as a high-level potential (hereinafter referred to as "H") and set to 0V, which will be supplied to the Vgk terminal (see reference). Figure 2 The power supply potential Vgk is used as a low-level potential (hereinafter marked "L") and set to -3.3V. Therefore, it is sometimes marked as "H (0V)" or "L (-3.3V)". Figure 2 As shown, the Vgk terminal is connected to the gate (Gt1 when the thyristor is a transmission thyristor T1) via the power line resistor Rg1.

[0197] When a potential lower than the threshold voltage (a negative potential with a large absolute value) is applied to the cathode of a thyristor that is in an off-state where no current flows between the anode and cathode, the thyristor switches to the on-state (turned on). Here, the threshold voltage of the thyristor is the value obtained by subtracting the positive potential Vd (1.5V) of the pn junction from the potential of the gate.

[0198] When the thyristor is in the ON state, the potential of the gate is close to the potential of the anode. Here, since the anode is 0V, the gate is 0V. Furthermore, the potential of the cathode of the thyristor in the ON state is close to the potential obtained by subtracting the forward potential Vd (1.5V) of the pn junction from the anode potential (the absolute value is denoted as the holding voltage). Here, since the anode is 0V, the potential of the cathode of the thyristor in the ON state is close to -1.5V (a negative potential with an absolute value greater than 1.5V). Here, we assume the holding voltage is 1.5V.

[0199] When a potential lower than that required to maintain the conduction state (a negative potential with a large absolute value) is continuously applied to the cathode of a thyristor in the conducting state, and a current sufficient to maintain the conduction state (maintaining current) is supplied to the thyristor, the thyristor maintains the conducting state.

[0200] On the other hand, when the cathode of a thyristor in the conducting state becomes a potential higher than the potential required to maintain the conducting state (close to the aforementioned -1.5V potential) (a negative potential with a small absolute value, 0V, or a positive potential), the thyristor switches to the off state (turn off).

[0201] (1-5.2) Operation of stacked driving thyristors and VCSELs

[0202] Next, the operation of the stacked driving thyristors S and VCSEL will be explained.

[0203] Here, the VCSEL's rise voltage is 1.5V. That is, if a voltage greater than 1.5V is applied between the anode and cathode of the VCSEL, the VCSEL will emit light. Assume the lighting signal ΦI is 0V ("H(0V)") or -3.3V ("L(-3.3V)"). 0V is the potential that puts the VCSEL in the off state, and -3.3V is the potential that turns the VCSEL from the off state to the on state.

[0204] When the VCSEL transitions from the off state to the on state, the illumination signal ΦI is set to "L(-3.3V)". At this time, when -1.5V is applied to the gate Gs of the driving thyristor S, the threshold voltage of the driving thyristor S becomes -3V, which is obtained by subtracting the forward potential Vd (1.5V) of the pn junction from the potential of the gate Gs (-1.5V). Since the illumination signal ΦI is -3.3V, the driving thyristor S is turned on and transitions from the off state to the on state, and the VCSEL also transitions from the off state to the on state. That is, the VCSEL performs laser oscillation and emits light. Then, since the voltage applied to the driving thyristor S in the on state (holding voltage Vr) is 1.5V, 1.8V is applied to the VCSEL. Furthermore, since the rise voltage of the CSEL is 1.5V, the VCSEL continues to emit light.

[0205] On the other hand, when the lighting signal ΦI is 0V, the two ends of the series connection between the driving thyristor S and VCSEL become 0V, the driving thyristor S changes from the on state to the off state (disconnected), and the VCSEL does not emit light.

[0206] (1-6) Measuring device

[0207] The light-emitting device 100 described in the first exemplary embodiment above can be used for light measurement.

[0208] Figure 7 This is a diagram illustrating the measuring device 1 using the light-emitting device 100.

[0209] The measuring device 1 includes the aforementioned light-emitting device 100, a light-receiving unit 101, and a data processing unit 102. Furthermore, the object to be measured (object) 103 is placed opposite the measuring device 1. Additionally, in Figure 7 In the example of the object being measured, object 103 is a person. Figure 7 This is a view taken from above.

[0210] The light-emitting device 100 illuminates the VCSEL group configured in a two-dimensional shape as described above, and emits light that expands into a cone shape centered on the light-emitting device 100, as shown by the solid line.

[0211] The light-receiving unit 101 is a device that receives light reflected by the object being measured 103. The light-receiving unit 101 receives light directed toward it as shown by the dashed line. The light-receiving unit 101 can be an imaging device that receives light from a two-dimensional direction.

[0212] The processing unit 102 is configured as a computer with an input / output unit for inputting and outputting data. Furthermore, the processing unit 102 processes light-related information and calculates the distance to the object 103 being measured and the 3D shape of the object 103 being measured.

[0213] The processing unit 102 of the measuring device 1 controls the light-emitting device 100 to emit light from the light-emitting device 100 for a short period of time. That is, the light-emitting device 100 emits light in a pulsed manner, and the processing unit 102 calculates the length of the light path from the light emitted by the light-emitting device 100 to the light reflected by the light-receiving unit 101 and reaching the light-receiving unit 101 based on the time difference between the time when the light is emitted by the light-emitting device 100 and the time when the light-receiving unit 101 receives the reflected light from the object being measured 103. The positions of the light-emitting device 100 and the light-receiving unit 101, and the interval between them, are predetermined. Therefore, the processing unit 102 measures the distance from the light-emitting device 100 and the light-receiving unit 101, or the distance from a reference point (hereinafter referred to as the reference point) to the object being measured 103. Furthermore, the reference point refers to a point set at a predetermined position from the light-emitting device 100 and the light-receiving unit 101.

[0214] This method is based on the measurement of the time of arrival of light and is known as the time-of-flight (TOF) method.

[0215] By applying this method to multiple points on the object to be measured 103, the three-dimensional shape of the object to be measured 103 can be measured. As described above, the emitted light from the light-emitting device 100 diffuses in two dimensions and is irradiated onto the object to be measured 103. Furthermore, reflected light from the portion of the object to be measured 103 that is closer to the light-emitting device 100 rapidly enters the light-receiving unit 101. When using the imaging device described above for acquiring two-dimensional images, bright spots are recorded in the frame images where the reflected light has reached. Based on the bright spots recorded in a series of multiple frame images, the optical path length of each bright spot is calculated. Furthermore, the distances from the light-emitting device 100, the light-receiving unit 101, or the reference point are calculated. In this way, the three-dimensional shape of the object to be measured 103 can be calculated.

[0216] Furthermore, as another method, the light-emitting device 100 of the first exemplary embodiment can also be used in light measurement methods that utilize structured illumination. The device used is similar to that used in light measurement methods. Figure 9 The measuring device 1 of the light-emitting device 100 shown is substantially the same. The difference is that the pattern of light irradiated onto the object to be measured 103 is a number of light spots (random pattern), which are received by the light-receiving part 101.

[0217] Furthermore, the processing unit 102 processes light-related information. Here, instead of calculating the aforementioned time difference, the processing method calculates the distance to the object being measured 103 and the three-dimensional shape of the object being measured 103 by calculating the positional offset of numerous light points.

[0218] Conventionally, the light source used in this method is a randomly configured two-dimensional VCSEL array, etc., but the random pattern of illumination is a predetermined pattern of about 1 to 4 patterns (structured light fixed method). On the other hand, the light-emitting device 100 of the first exemplary embodiment can freely set the light spot to be illuminated by a signal from the outside, and therefore can illuminate the light with more random patterns (structured light programmable method).

[0219] The measuring device 1 described above can be used to calculate the distance to an object. Furthermore, it can calculate the shape of an object for object recognition. Moreover, by calculating the shape of a human face, it can be used for facial authentication. Further, by being mounted on a vehicle, it can be used to detect obstacles in front, behind, and to the sides. Thus, the measuring device 1 can be widely used for calculating distances, shapes, etc.

[0220] In the first exemplary embodiment described above, an example of using the light-emitting device 100 for measurement was given, but it is not limited thereto. As a light-emitting device for light transmission, it can be used together with a light transmission path, or it can be used as a light-emitting device for biometric authentication, emitting light toward the interior of an object.

[0221] In the exemplary embodiments described above, the VCSEL groups are configured such that the light-emitting elements of the same group are adjacent to each other. Therefore, the area of ​​the VCSEL group is not dispersed, and configurations such as simplified shared signal lines become easier. In this case, since the light-emitting elements connected to the same shared signal line are considered as one light-emitting group, it is also possible that the area of ​​the VCSEL group is dispersed, and the shape of the VCSEL group is not clearly divided into regions.

[0222] In the above exemplary embodiment, an example was described in which the conduction state propagates sequentially in the transmission thyristor Ti, thereby lighting up the VCSEL group in sequence. However, it can also be configured such that the transmission thyristor Ti also has a storage unit, in which the signal is temporarily stored in the storage unit after the conduction state propagates sequentially in the transmission thyristor Ti, and the signal is sent to multiple VCSEL groups at the same time, thereby lighting up multiple VCSEL groups simultaneously.

[0223] (2-1) Overall structure of the light-emitting device

[0224] Figure 8 This is a diagram illustrating an example of the planar layout of the light-emitting device 100 according to the second exemplary embodiment. Figure 9 This is a schematic equivalent circuit diagram of the light-emitting device 100 according to the second exemplary embodiment. Figure 9 The control unit 200 for controlling the light-emitting device 100 is also shown in the image.

[0225] like Figure 8 As shown, the light-emitting device 100 of the second exemplary embodiment is configured to include: a substrate 110; a light-emitting part 120, which is composed of a plurality of light-emitting elements; a transmission part 130, which controls the light emission of the light-emitting elements; an electrode part 140, which is composed of a plurality of terminals for acquiring signals for driving the transmission part 130; and a common signal line 150, which connects the light-emitting part 120 and the transmission part 130 to each other.

[0226] The light-emitting section 120 includes multiple laser diodes, which emit laser beams as one example of light-emitting elements. Furthermore, the light-emitting device 100 is configured as a self-scanning light-emitting element array (SLED) as described below. In the second exemplary embodiment, the laser diode is, for example, a vertical cavity surface emitting laser (VCSEL). The following description focuses on the case where the light-emitting element is a VCSEL, but other light-emitting devices such as LEDs may also be used.

[0227] (2-2) Equivalent circuit of the light-emitting device

[0228] Since the entire description of the equivalent circuit of the light-emitting device (1-2) also applies to the light-emitting device 100 of the second exemplary embodiment, the description is omitted. However, the description of the equivalent circuit of the light-emitting device (1-2) above should be considered as follows: Figure 1 Replace with " Figure 8 " Figure 2 Replace with " Figure 9 " Figure 3 Replace with " Figure 10 "Then, it is applied to the light-emitting device 100 of the second exemplary embodiment.

[0229] (2-3) Planar layout of the light-emitting device

[0230] return Figure 8First, the planar layout of the transmission section 130 and the electrode section 140 in the light-emitting device 100 according to the second exemplary embodiment will be described. The substrate 110 of the light-emitting device 100 is a rectangle having a long side 110a and a short side 110b. Figure 8 In the diagram, the x-direction is the direction of the longer side, and the y-direction is the direction of the shorter side.

[0231] like Figure 8 As shown, the transmission section 130 and the electrode section 140 are respectively arranged along the short side 110b of the substrate 110.

[0232] The electrode section 140 is configured as follows: Φ1 and Φ2 terminals as transmission signal electrodes, which receive transmission signals Φ1 and Φ2 generated by the transmission signal generation section 210 of the control section 200; Vgk terminal as power supply electrode, which receives power supply potential Vgk generated by the power supply potential generation section 230; and Vga terminal as power supply electrode, which receives reference potential Vga generated by the reference potential generation section 240, each terminal being a pad.

[0233] In the transmission section 130 of the light-emitting device 100, a transmission signal line 52 extending from the Φ1 terminal of the electrode section 140, a transmission signal line 53 extending from the Φ2 terminal, a power supply line 51 extending from the Vgk terminal, and a reference potential line 54 extending from the Vga terminal are formed as conductive patterns.

[0234] In the transmission section 130, the cathodes of the odd-numbered transmission thyristors T1, T3, etc. are connected to the transmission signal line 52, and the cathodes of the even-numbered transmission thyristors T2, T4, etc. are connected to the transmission signal line 53.

[0235] Thus, between the control unit 200 and the transmission unit 130, such as Figure 8 As shown, the Φ1 and Φ2 terminals of the input and output transmission signals Φ1 and Φ2, and the Vgk and Vga terminals of the input and output power supply potentials Vgk and reference potentials Vga are arranged side by side along the short side 110b of the substrate 110. Therefore, compared to the case where the electrode portion 140 is arranged along the long side of the substrate 110, the length of the substrate 110 in the longitudinal direction can be shortened.

[0236] Furthermore, the lighting signal electrode, i.e., the ΦI terminal, which receives the lighting signal ΦI generated by the lighting signal generation unit 220 and controls VCSELij to a state of emitting or not emitting light, is configured along the long side 110a of the substrate 110, sandwiching the light-emitting unit 120, and has a portion overlapping with the transmission unit 130 in the short side direction of the substrate 110. Moreover, another ΦI terminal is configured to have a portion overlapping with the electrode unit 140 in the short side direction of the substrate 110. This allows for a further reduction in the length of the substrate 110 in the longitudinal direction.

[0237] The light-emitting unit 120 is configured in a 4×3 two-dimensional shape, consisting of 12 VCSEL groups (VCSEL groups #1 to #12) composed of 15 VCSELs, arranged in a 4×3 configuration with four groups arranged in the x-direction (first direction) and three groups arranged in the y-direction (second direction) that intersects (or is orthogonal) to the x-direction. That is, the number of VCSEL groups arranged along the long side of the substrate 110 (4 in the second exemplary embodiment) is greater than the number of VCSEL groups arranged along the short side of the substrate 110 (3 in the second exemplary embodiment). Therefore, the light-emitting device 100 can perform segmented illumination and can expand the illumination area in the horizontal direction (x-direction).

[0238] In addition, the area of ​​the light-emitting part 120 is larger than the area of ​​the transmission part 130, and the amount of light emitted by the light-emitting device 100 increases.

[0239] Furthermore, in the transmission section 130 that outputs transmission signals to the two-dimensional VCSEL group arranged in the first and second directions, the first direction transmission section that outputs transmission signals to the VCSEL group in the first direction and the second direction transmission section that outputs transmission signals to the VCSEL group in the second direction are integrally disposed along the short side 110b of the substrate 110. That is, the transmission section 130 is not disposed in the long side direction (x direction) of the substrate 110. As a result, the length of the substrate 110 in the longitudinal direction can be shortened.

[0240] (Modified Example)

[0241] Figure 10 This is a diagram showing an example of the planar layout of the light-emitting device 100A involved in the modified example.

[0242] In the light-emitting device 100 of this embodiment, a Vgk terminal with an input / output power supply potential Vgk and a Vga terminal with an input / output reference potential Vga are described. However, the Vgk and Vga terminals may be omitted. In this case, as shown... Figure 10 As shown, alternatively, the Φ1 and Φ2 terminals of the input / output transmission signals Φ1 and Φ2 can be arranged side-by-side along the short side 110b of the substrate 110 between the control unit 200 and the transmission unit 130. This shortens the length of the substrate 110 compared to arranging the Φ1 and Φ2 terminals along the long side of the substrate 110.

[0243] Figure 11 This is a diagram showing an example of the planar layout of the light-emitting device 100 according to the second exemplary embodiment, with the transmission unit 130 as the center.

[0244] The light-emitting device 100 is made of a semiconductor material capable of emitting a laser beam, such as a GaAs-based compound semiconductor. Furthermore, as shown in the cross-sectional view described later (described later...), Figure 12 As shown, the light-emitting device 100 is composed of multiple islands. Within each island, a semiconductor layer stack of multiple GaAs-based compound semiconductor layers is deposited on a p-type GaAs substrate 110 and separated between components by mesa etching. Here, through... Figure 11 The islands 301 to 306 shown illustrate the planar layout of the light-emitting device 100. Furthermore, islands 301, 302, and 303 are disposed in each VCSEL group. Therefore, when islands 301, 302, and 303 are distinguished by VCSEL group, as described above, they are labeled "i," and marked as islands 301-i, 302-i, and 303-i. Furthermore, in Figure 11 The diagram shows the portion where i ranges from 1 to 12. Additionally, as above, the number of VCSELs in the VCSEL group is labeled "j". Here, j ranges from 1 to 15.

[0245] In this way, the light-emitting device 100 is configured on a common semiconductor substrate and is miniaturized.

[0246] Island 301-i is equipped with VCSELij and a driving thyristor Si. Furthermore, as described later... Figure 12 As shown, VCSELij and the driving thyristor Si are stacked. Furthermore, in Figure 11 In this context, VCSELij and the driving thyristor Si are labeled VCSELij / Si. For example, when "i" is 1, it is labeled VCSEL1j / S1. Figure 11 The diagram shows islands 301-1, 301-4, and 301-12, while other islands 301-i are omitted. Additionally, there are 15 VCSELs arranged within island 301-i.

[0247] Island 302-i contains a transmission thyristor Ti and a coupling diode Di. Island 302-i is arranged in parallel in the y-direction (short side direction).

[0248] Island 303-i contains a power line resistor Rgi. Island 303-i is configured to be arranged in parallel along the y-direction (short side direction).

[0249] A startup diode SD is installed in island 304. A current-limiting resistor R1 is installed in island 305, and a current-limiting resistor R2 is installed in island 306.

[0250] (2-4) Cross-sectional structure of the light-emitting device

[0251] Next, before explaining the connection relationship between these islands 301 to 306, the cross-sectional structure of islands 301 and 302 will be described.

[0252] Figure 12 This is a diagram showing the cross-sectional structure of the light-emitting device 100. Furthermore, Figure 12 yes Figure 11 A cross-sectional view of the light-emitting device 100 at line AA. That is, Figure 12 The sectional view shown is a cross-section on the paper from left to right across the coupling diode D1, the transmission thyristor T1, VCSEL11 / S1, and VCSEL12 / S1, showing portions of islands 301-1 and 302-1.

[0253] The entire description of the "(1-4) cross-sectional structure of the light-emitting device" above also applies to the light-emitting device 100 of the second exemplary embodiment, therefore, the description is omitted. However, the "(1-4) cross-sectional structure of the light-emitting device" description above should be considered as " Figure 5 Replace with " Figure 11 " Figure 6 Replace with " Figure 12 "Then, it is applied to the light-emitting device 100 of the second exemplary embodiment.

[0254] (2-5) Operation of the light-emitting device

[0255] (2-5.1) Thyristor

[0256] The entire description of "(1-5.1) thyristor" above also applies to the second exemplary embodiment, therefore the description is omitted.

[0257] (2-5.2) Operation of stacked driving thyristors and VCSELs

[0258] The entire description of "(1-5.2) Operation of the stacked driving thyristors and VCSEL" above also applies to the second exemplary embodiment, so the description is omitted.

[0259] (2-6) Measuring device

[0260] The entire description of the "(1-6) measuring device" above also applies to the second exemplary embodiment, therefore the description is omitted.

[0261] In the above embodiment, the VCSEL groups are configured such that the light-emitting elements of the same group are adjacent to each other. Therefore, the area of ​​the VCSEL group is not dispersed, and the configuration, such as the simplification of the shared signal line, becomes easier. In this case, since the light-emitting elements connected to the same shared signal line are considered as one light-emitting group, it is also possible that the area of ​​the VCSEL group is dispersed, and the shape of the VCSEL group is not clearly divided into regions.

[0262] In the above embodiment, an example was described in which the conduction state propagates sequentially in the transmission thyristor Ti, thereby lighting up the VCSEL group in sequence. However, it can also be configured such that the transmission thyristor Ti also has a storage unit, in which the signal is temporarily stored in the storage unit after the conduction state propagates sequentially in the transmission thyristor Ti, and the signal is sent to multiple VCSEL groups at the same time, thereby lighting up multiple VCSEL groups simultaneously.

Claims

1. A light-emitting device, comprising: substrate; The light-emitting part is composed of multiple light-emitting elements; The transmission unit outputs a signal that controls the light-emitting state of the light-emitting element; and The electrode section is used to input and output signals that drive the transmission section. in, The substrate is rectangular with a long side and a short side. The electrode portion is configured to sandwich the transmission portion between a portion of the electrode portion and another portion of the electrode portion, and is arranged along the short side of the substrate. The area of ​​the light-emitting part is larger than the area of ​​the transmission part. The light-emitting part includes multiple light-emitting element groups, each light-emitting element group including multiple light-emitting elements and capable of being driven independently of other light-emitting element groups, the multiple light-emitting element groups being arranged in a two-dimensional shape. The light-emitting device further includes a light-emitting electrode section connected to the plurality of light-emitting elements, the light-emitting electrode section being configured to supply current to the plurality of light-emitting elements. The light-emitting electrode portion is formed along the long side of the substrate.

2. The light-emitting device according to claim 1, wherein, The electrode section includes: a plurality of transmission signal electrodes for which transmission signals are provided, the transmission signals controlling the light-emitting element to transition to a light-emitting state; and a plurality of power supply electrodes for providing a power supply potential and a reference potential to the transmission section, the plurality of transmission signal electrodes and the plurality of power supply electrodes being arranged in a straight line relative to the transmission section.

3. The light-emitting device according to claim 1, wherein, The electrode section includes: a plurality of transmission signal electrodes for which transmission signals are provided, which control the light-emitting element to transition to a light-emitting state; and a plurality of power supply electrodes for providing a power supply potential and a reference potential to the transmission section, wherein the plurality of transmission signal electrodes and the plurality of power supply electrodes are arranged in an intersecting direction relative to the transmission section.

4. The light-emitting device according to claim 1, wherein, The electrode section consists of a pair of transmission signal electrodes, which are provided with transmission signals that control the light-emitting element to switch to a light-emitting state. The pair of transmission signal electrodes are arranged opposite to the transmission section.

5. The light-emitting device according to any one of claims 1 to 4, wherein, The transmission unit has: a first direction transmission unit that outputs a signal to light-emitting elements arranged in a first direction; And a second direction transmission section, which outputs a signal to light-emitting elements arranged in a second direction intersecting the first direction, wherein neither the first direction transmission section nor the second direction transmission section is disposed in the long side direction of the substrate.

6. The light-emitting device according to any one of claims 1 to 4, The electrode portion and the light-emitting electrode portion are arranged side by side along the long side of the substrate.

7. A measuring device comprising: The light-emitting device according to any one of claims 1 to 6; The light-receiving part receives reflected light from an object illuminated by the light-emitting device; and The processing unit measures the distance from the light-emitting device to the object, or the three-dimensional shape of the object, based on the time from when the light-emitting device irradiates the object to when the light is received by the light-receiving unit.

8. A light-emitting device comprising: substrate; The light-emitting part is composed of multiple light-emitting elements; The transmission unit outputs a signal that controls the light-emitting state of the light-emitting element; and The electrode section is used to input and output signals that drive the transmission section. in, The substrate is rectangular with a long side and a short side. The transmission section and the electrode section are respectively arranged along the short side of the substrate. The area of ​​the light-emitting part is larger than the area of ​​the transmission part. The light-emitting part includes multiple light-emitting element groups, each light-emitting element group including multiple light-emitting elements and capable of being driven independently of other light-emitting element groups, the multiple light-emitting element groups being arranged in a two-dimensional shape. The light-emitting device further includes a light-emitting electrode section connected to the plurality of light-emitting elements, the light-emitting electrode section being configured to supply current to the plurality of light-emitting elements. The light-emitting electrode portion is formed along the long side of the substrate.

9. The light-emitting device according to claim 8, wherein, The electrode portion includes: a transmission signal electrode, which is provided with a transmission signal that controls the light-emitting element to a state capable of transitioning to a light-emitting state; The transmission signal electrode and the power electrode are arranged side by side along the short side of the substrate, which provide a power potential and a reference potential to the transmission section.

10. The light-emitting device according to claim 9, wherein, The lighting signal electrode that supplies current to the light-emitting element is configured along the long side of the substrate such that it overlaps with the transmission section in the direction of the short side of the substrate.

11. The light-emitting device according to claim 9 or 10, wherein, The lighting signal electrode that supplies current to the light-emitting element is configured along the long side of the substrate such that it has a portion that overlaps with the electrode portion in the direction of the short side of the substrate.

12. The light-emitting device according to any one of claims 8 to 10, wherein, The transmission section is integrally disposed along the short side of the substrate.

13. The light-emitting device according to any one of claims 8 to 10, further comprising: A common signal line is provided in a light-emitting element group containing the plurality of light-emitting elements. In the light-emitting element group, the light-emitting elements contained in the light-emitting element group emit light simultaneously or increase the light intensity by transmitting a transmission signal output from the transmission unit to the common signal line.

14. The light-emitting device according to claim 8, wherein, The number of light-emitting element groups arranged along the long side of the substrate is greater than the number of light-emitting element groups arranged along the short side of the substrate.

15. A measuring device comprising: The light-emitting device according to any one of claims 8 to 14; The light-receiving part receives reflected light from an object illuminated by the light-emitting device; and The processing unit measures the distance from the light-emitting device to the object, or the three-dimensional shape of the object, based on the time from when the light-emitting device irradiates light onto the object until the light is received by the light-receiving unit.

Images