Light-emitting element and distance measuring device

Abstract

To inhibit a non-irradiation part from being formed between juxtaposed irradiation ranges by arranging a light-emitting element array and an optical system.SOLUTION: The light-emitting element is obtained by arranging a plurality of light-emitting elements so that one direction has length w. The light-emitting element array comprises: a first light-emitting element array and a second light-emitting element array juxtaposed in the one direction; a first optical system refracting light emitted from the first light-emitting element array; and a second optical system refracting light emitted from the second light-emitting element array so that in the one direction an irradiation range of the second light-emitting element array is parallel to an irradiation range of the first light-emitting element array. Distance between an optical axis of the first optical system and the center of the first light-emitting element array and distance between an optical axis of the second optical system and the center of the second light-emitting element array in the one direction are w / 4 or more and w / 2 or less.SELECTED DRAWING: Figure 5

Description

Technical Field

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

Background Art

[0002] Patent Document 1 describes that in a vehicle lamp that forms a predetermined light distribution pattern including a plurality of light source images arranged horizontally, by arranging at least one light source in a state shifted with respect to the optical axis of the corresponding projection optical system, even if the arrangement interval of the light sources is widened, the light source images can be arranged adjacent to each other without gaps.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, it is assumed that the size of the light source is sufficiently small with respect to the lens. However, when the light amount of the light source is to be increased, depending on the selected light source, the light source may take up a large area in the entire light-emitting device. In that case, the amount of shift between the light source and the optical system will change significantly compared to the case where the light source is sufficiently small with respect to the optical system. An object of the present invention is to suppress the formation of non-irradiated portions between adjacent irradiation ranges by the arrangement of a light-emitting element array and an optical system.

Means for Solving the Problems

[0005] The invention according to claim 1 is a light-emitting element array in which a plurality of light-emitting elements are arranged such that the length in one direction is w, and a first light-emitting element array and a second light-emitting element array that are parallel in the one direction, a first optical system that refracts the light emitted from the first light-emitting element array, and a second optical system that refracts the light emitted from the second light-emitting element array such that the irradiation range of the second light-emitting element array is parallel to the irradiation range of the first light-emitting element array in the one direction. The distance between the optical axis of the first optical system and the center of the first light-emitting element array, and the distance between the optical axis of the second optical system and the center of the second light-emitting element array in the one direction are w / 4 or more and w / 2 or less. It is a light-emitting device characterized by this. The invention according to claim 2 further includes a third light-emitting element array that is parallel in another direction intersecting the one direction with respect to the first light-emitting element array, and a third optical system that refracts the light emitted from the third light-emitting element array such that the irradiation range of the third light-emitting element array is parallel to the irradiation range of the first light-emitting element array in the another direction. In the first light-emitting element array and the third light-emitting element array, the plurality of light-emitting elements are arranged such that the length in the another direction is h, and the distance between the optical axis of the first optical system and the center of the first light-emitting element array, and the distance between the optical axis of the third optical system and the center of the third light-emitting element array in the another direction are h / 4 or more and h / 2 or less. It is the light-emitting device according to claim 1, characterized by this. The invention according to claim 3 is characterized in that the light-emitting element array is rectangular with the side length in the one direction being w and the side length in the another direction being h, and the optical axis of the optical system is on any one diagonal line of the rectangle. It is the light-emitting device according to claim 2, characterized by this. The invention according to claim 4 is characterized in that the optical axis of the optical system passes through any one vertex of the rectangle. It is the light-emitting device according to claim 3, characterized by this. The invention according to claim 5 is characterized in that the first light-emitting element array and the first optical system are fixed on a first submount substrate, the second light-emitting element array and the second optical system are fixed on a second submount substrate, and the first submount substrate and the second submount substrate are arranged such that the first light-emitting element array and the second light-emitting element array are arranged in parallel in the one direction. The light-emitting device according to claim 1. The invention according to claim 6 is characterized in that the first light-emitting element array and the second light-emitting element array are constituted by a common light-emitting element array, the first optical system and the second optical system are constituted by a common optical system, and the fixing of the light-emitting element array and the optical system to the submount substrate is performed such that the distance between the first light-emitting element array and the first optical system is equal to the distance between the second light-emitting element array and the second optical system. The light-emitting device according to claim 5. The invention according to claim 7 further includes a fourth light-emitting element array that is arranged in parallel with the first light-emitting element array in the one direction and another direction that intersects the one direction, and a fourth optical system that refracts the light emitted from the fourth light-emitting element array such that the irradiation range of the fourth light-emitting element array is arranged in parallel with the irradiation range of the first light-emitting element array. The first light-emitting element array and the fourth light-emitting element array have a two-fold symmetric or four-fold symmetric shape, and the combination of the fourth light-emitting element array and the fourth optical system has a configuration in which the combination of the first light-emitting element array and the first optical system is rotated 180 degrees around the optical axis of the first optical system. The light-emitting device according to claim 1. The invention according to claim 8 is characterized in that the first light-emitting element array, the second light-emitting element array, and the fourth light-emitting element array have a four-fold symmetric shape, and the combination of the second light-emitting element array and the second optical system has a configuration in which the combination of the first light-emitting element array and the first optical system is rotated 90 degrees around the optical axis of the first optical system. The light-emitting device according to claim 7. The invention according to claim 9 further comprises a first driver for driving the first light-emitting element array and a second driver for driving the second light-emitting element array, wherein the first driver and the second driver are arranged at positions different from those between the first light-emitting element array and the second light-emitting element array, and is the light-emitting device according to claim 1. In the invention according to claim 10, the light-emitting element array is rectangular with the length of one side in one direction being w and the length of the other side intersecting the one direction being h, n (n is a natural number of 1 or more) light-emitting element arrays including the first light-emitting element array are arranged in parallel in the other direction, and the effective diameter R of the optical system is set to satisfy formula (1), and is the light-emitting device according to any one of claims 1 to 9.

[0006]

Number

[0007] The invention according to claim 11 is a distance measuring device comprising the light-emitting device according to any one of claims 1 to 10, a light-receiving unit that receives light irradiated from the light-emitting device and reflected by an object, and a calculating unit that calculates the distance to the object based on the result of light reception in the light-receiving unit.

Advantages of the Invention

[0008] According to the invention of claim 1, the formation of non-irradiated portions between the parallel irradiation ranges can be suppressed by the arrangement of the light-emitting element array and the optical system. According to the invention of claim 2, the formation of non-irradiated portions between the parallel irradiation ranges is also suppressed in other directions. According to the invention of claim 3, the overlap of the irradiation ranges of each light-emitting element array in one direction or the other direction is suppressed as compared with the case where the optical axis is not on the diagonal line. According to the invention of claim 4, the overlap of the irradiation ranges of each light-emitting element array is suppressed as compared with the case where the optical axis does not pass through the vertex. According to the invention of claim 5, a light-emitting device can be configured by arranging a submount substrate on which a light-emitting element array and an optical system are fixed. According to the invention of claim 6, the unevenness of illuminance between the irradiation ranges by each light-emitting element array is suppressed as compared with the case where the distances between the light-emitting element arrays and the optical system are set to different distances. According to the invention of claim 7, the combination of the first light-emitting element array and the first optical system and the combination of the fourth light-emitting element array and the fourth optical system can be made common. According to the invention of claim 8, the combination of the first light-emitting element array and the first optical system, the combination of the second light-emitting element array and the second optical system, and the combination of the fourth light-emitting element array and the fourth optical system can be made common. According to the invention of claim 9, it becomes easier to arrange the light-emitting element arrays closer to each other as compared with the case where a driver is arranged between the light-emitting element arrays. According to the invention of claim 10, it becomes easier to secure the distance between the optical axis of the optical system and the center of the light-emitting element array as compared with the case where the effective diameter of the optical system is smaller than the range of formula (1). According to the invention of claim 11, formation of a non-irradiated portion between the parallel irradiation ranges can be suppressed by the arrangement of the light-emitting element array and the optical system.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

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Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the technical scope of the present invention is not limited to the scope described as embodiments below. It is clear from the description of the claims that combinations of a plurality of examples and those obtained by making various changes or improvements to these examples are also included in the technical scope of the present invention.

[0011] [Embodiment 1] (Distance Measuring Device 1) FIG. 1 is a block diagram showing an example of the schematic configuration of the distance measuring device 1 to which the present embodiment is applied. The distance measuring device 1 measures the distance to the object based on the time from the timing when light is emitted from the light emitting part 4 to the timing when the light reflected by the object is received by the light receiving part 5. That is, the distance measuring device 1 is a device that measures distance based on the ToF method. The ToF method includes an indirect ToF (iToF: indirect ToF) method of measuring time from the difference between the phase of the emitted light and the phase of the received light, and a direct ToF (dToF: direct ToF) method of directly measuring the time from the emission to the reception of light. In the present embodiment, the distance measuring device 1 will be described as performing distance measurement based on the indirect ToF method.

[0012] As shown in FIG. 1, the distance measuring device 1 includes an optical device 3 and a control unit 8. The optical device 3 includes a light emitting unit 4 that irradiates light toward a predetermined range, a light receiving unit 5 that receives light reflected by an object existing in the range irradiated with light from the light emitting unit 4, a light emission driving unit 6 that drives the light emitting unit 4, and a light reception driving unit 7 that drives the light receiving unit 5. The light emitting unit 4, or the combination of the light emitting unit 4 and the light emission driving unit 6, is an example of a light emitting device.

[0013] (Control unit 8) The control unit 8 controls the operations of the light emitting unit 4 and the light receiving unit 5 of the optical device 3. Further, the control unit 8 acquires the result of light reception in the light receiving unit 5, and measures the distance from the distance measuring device 1 to the object by the ToF method based on the result of this light reception. The control unit 8 is an example of a calculation unit.

[0014] The control unit 8 is composed of a CPU (Central Processing Unit) 81, a ROM (Read Only Memory) 82, and a RAM (Random Access Memory) 83. The CPU 81 is an example of a processor, and realizes each function described later by loading various programs stored in the ROM 82 etc. into the RAM 83 and executing them. The RAM 83 is a memory used as a working memory etc. of the CPU 81. The ROM 82 is a memory that stores various programs etc. executed by the CPU 81.

[0015] Here, the program executed by the CPU 81 can be provided in a state stored in a computer-readable recording medium such as a magnetic recording medium (magnetic tape, magnetic disk, etc.), an optical recording medium (optical disk, etc.), a magneto-optical recording medium, or a semiconductor memory. Also, the program executed by the CPU 81 may be provided using a communication means such as the Internet.

[0016] In addition, in the present embodiment, the processor refers to a processor in a broad sense, including a general-purpose processor (e.g., CPU: Central Processing Unit, etc.) and a dedicated processor (e.g., GPU: Graphics Processing Unit, ASIC: Application Specific Integrated Circuit, FPGA: Field Programmable Gate Array, programmable logic device, etc.). Also, the operation of the processor in the present embodiment may be achieved not only by one processor but also by a plurality of physically separated processors cooperating with each other. Also, the order of each operation of the processor is not limited to the order described in the present embodiment and may be changed.

[0017] (Light-emitting unit 4) FIG. 2 is a diagram showing the light-emitting unit 4 of the present embodiment and the irradiation surface 100 irradiated with the light emitted from the light-emitting unit 4. In FIG. 2, the right direction on the paper surface is the +x direction, the upward direction on the paper surface is the +y direction, and the back side of the paper surface is the +z direction, and the opposite directions are the -x, -y, and -z directions, respectively. In FIG. 2, the light-emitting unit 4 and the irradiation surface 100 are shown shifted in the vertical direction (±y direction) of the paper surface, but actually, the light-emitting unit 4 and the irradiation surface 100 are arranged to face each other. In FIG. 2, the light-emitting unit 4 is located in the front side direction (-z direction) of the paper surface, and the irradiation surface 100 is located in the back side direction (+z direction) of the paper surface. That is, FIG. 2 shows the light-emitting unit 4 emitting light to the irradiation surface 100 as viewed from the side opposite to the side from which the light-emitting unit 4 emits light.

[0018] The light-emitting unit 4 has a plurality (four in this example) of light sources 40A, 40B, 40C, and 40D that irradiate different irradiation ranges 100A, 100B, 100C, and 100D of the irradiation surface 100. In other words, the light-emitting unit 4 has a light source 40A that irradiates the irradiation range 100A of the irradiation surface 100, a light source 40B that irradiates the irradiation range 100B, a light source 40C that irradiates the irradiation range 100C, and a light source 40D that irradiates the irradiation range 100D. Here, that the irradiation ranges 100A and 100B are different means that the irradiation ranges 100A and 100B do not coincide, and they may have an overlapping portion. The same applies to other combinations of the irradiation ranges 100A, 100B, 100C, and 100D. The relationship among the irradiation ranges 100A, 100B, 100C, and 100D will be described in detail later.

[0019] The light sources 40A, 40B, 40C, and 40D are arranged in parallel in the x - direction and the y - direction. Additionally, the light sources 40A, 40B, 40C, and 40D are arranged such that the light source 40A and the light source 40B are in parallel in the x - direction, the light source 40C and the light source 40D are in parallel in the x - direction, the light source 40A and the light source 40C are in parallel in the y - direction, and the light source 40B and the light source 40D are in parallel in the y - direction. In this example, the light source 40A is arranged on the - x - direction side with respect to the light source 40B and on the + y - direction side with respect to the light source 40C. The light source 40B is arranged on the + x - direction side with respect to the light source 40A and on the + y - direction side with respect to the light source 40D. The light source 40C is arranged on the - y - direction side with respect to the light source 40A and on the - x - direction side with respect to the light source 40D. The light source 40D is arranged on the - y - direction side with respect to the light source 40B and on the + x - direction side with respect to the light source 40C. Note that the arrangement of the light sources 40A, 40B, 40C, and 40D is not limited to this.

[0020] FIG. 3 and FIG. 4 are diagrams for explaining the configuration of the light sources 40A, 40B, 40C, and 40D of the light - emitting unit 4. FIG. 3 is a cross - sectional view in the zx plane passing through the two light sources 40A and 40B located on the + y - direction side among the four light sources 40A, 40B, 40C, and 40D that the light - emitting unit 4 has. FIG. 4 is a view of the light - emitting unit 4 seen from the - z - direction side to the + z - direction. In FIGS. 3 and 4, the illustration of components other than the light sources 40A, 40B, 40C, and 40D, such as the housing that houses the light sources 40A, 40B, 40C, and 40D and the driver that drives the light sources 40A, 40B, 40C, and 40D, is omitted. Also, in FIG. 4, the detailed structures of the first electrode 433 and the second electrode 434 (both refer to FIG. 3) of the sub - mount substrate 43, which will be described later, are omitted.

[0021] In the light-emitting unit 4 of the present embodiment, the light sources 40A, 40B, 40C, and 40D have the same configuration except for the relative position of the light-emitting element array 41 with respect to the lens 42, as will be described later. Each of the light sources 40A, 40B, 40C, and 40D has a light-emitting element array 41 that emits light in the +z direction. Each of the light sources 40A, 40B, 40C, and 40D also has a lens 42 that refracts the light emitted by the light-emitting element array 41. Each of the light sources 40A, 40B, 40C, and 40D further has a submount substrate 43 that supports the light-emitting element array 41 and the lens 42 so that the light-emitting element array 41 is arranged at a predetermined relative position with respect to the lens 42.

[0022] The light-emitting element array 41 has a light-emitting surface on which a plurality of vertical cavity surface emitting lasers (VCSELs) are arranged. The light-emitting surface indicates the area of the surface of the actually emitting portion. In the present embodiment, the area connecting the outer periphery of the area where a plurality of VCSELs are arranged is the light-emitting surface. For example, even if the shape of the substrate on which the VCSELs are arranged is rectangular and the area where the VCSELs are arranged spreads in an elliptical shape, the light-emitting surface indicates the elliptical area, and if it spreads in a triangular shape, the light-emitting surface indicates the triangular area. Hereinafter, the light-emitting surface of the light-emitting element array 41 included in the light source 40A is denoted as the light-emitting surface 411, the light-emitting surface of the light-emitting element array 41 included in the light source 40B is denoted as the light-emitting surface 412, the light-emitting surface of the light-emitting element array 41 included in the light source 40C is denoted as the light-emitting surface 413, and the light-emitting surface of the light-emitting element array 41 included in the light source 40D is denoted as the light-emitting surface 414.

[0023] The light-emitting element array 41 of the light source 40A is arranged such that the light-emitting surface 411 is along the xy plane. As shown in FIG. 5(a) described later, the light-emitting surface 411 is rectangular, having a long side 411x extending in the x direction and a short side 411y extending in the y direction. Similarly, the light-emitting element array 41 of the light source 40B is arranged such that the light-emitting surface 412 is along the xy plane. As shown in FIG. 5(b) described later, the light-emitting surface 412 is rectangular, having a long side 412x extending in the x direction and a short side 412y extending in the y direction. Further, the light-emitting element array 41 of the light source 40C is arranged such that the light-emitting surface 413 is along the xy plane. As shown in FIG. 5(c) described later, the light-emitting surface 413 is rectangular, having a long side 413x extending in the x direction and a short side 413y extending in the y direction. Also, the light-emitting element array 41 of the light source 40D is arranged such that the light-emitting surface 414 is along the xy plane. The light-emitting surface 414 is rectangular, having a long side 414x extending in the x direction and a short side 414y extending in the y direction, as shown in FIG. 5(d) described later.

[0024] Hereinafter, the length of the light-emitting element array 41 in the x direction (i.e., the lengths of the long sides 411x to 414x) is denoted as length w, and the length in the y direction (i.e., the lengths of the short sides 411y to 414y) is denoted as length h. The light-emitting element arrays 41 of the respective light sources 40A, 40B, 40C, and 40D emit light in the +z direction from the light-emitting surfaces 411 to 414 by the light emission of the VCSELs.

[0025] Here, the light sources 40A, 40B, 40C, and 40D of the light-emitting unit 4 of the present embodiment are each independently driven by the light-emitting drive unit 6 (see FIG. 1) to perform a light-emitting operation. In other words, the light sources 40A, 40B, 40C, and 40D emit light when power is supplied to the VCSELs included in the light sources 40A, 40B, 40C, and 40D by the light-emitting drive unit 6. Here, "driven independently" means that each of the light sources 40A, 40B, 40C, and 40D is driven to emit light. The light emission driving unit 6 drives each light emitting element array 41 according to a control signal from the control unit 8 (see FIG. 1). Therefore, the light emitting element arrays 41 of the light sources 40A, 40B, 40C, and 40D do not necessarily emit light simultaneously. For example, the light emitting element array 41 of the light source 40A may be emitting light while the light emitting element arrays 41 of the light sources 40B, 40C, and 40D are not emitting light.

[0026] In addition, the light emitting element arrays 41 of the respective light sources 40A, 40B, 40C, and 40D may be divided into a plurality of light emitting sections in which the light emitting surfaces 411 to 414 are independently driven by the light emission driving unit 6 to perform a light emission operation. Additionally, the light emitting surfaces 411 to 414 of the light emitting element array 41 may be divided into a plurality of light emitting sections each including at least one VCSEL.

[0027] The lens 42 is provided on the +z direction side with respect to the light emitting element array 41. Additionally, the lens 42 is provided on the downstream side in the direction in which the light emitting element array 41 emits light with respect to the light emitting element array 41. Further, the lens 42 is provided to face the light emitting surfaces 411 to 414 of the light emitting element array 41. Thereby, the light emitted from the light emitting surfaces 411 to 414 of the light emitting element array 41 in the +z direction enters the lens 42. Also, the lens 42 is arranged such that the optical axis 420 extends in the z direction. The optical axis 420 corresponds to the center in the x direction and the y direction of the light emitted from the lens 42 assuming that light is uniformly incident on the entire lens 42. Therefore, the optical axis 420 is determined as a characteristic of the lens 42 regardless of the light actually incident on the lens 42. Then, the lens 42 refracts the light emitted from the light emitting surfaces 411 to 414 of the light emitting element array 41 in a direction intersecting the z direction, thereby expanding the irradiation range of the light as it goes in the +z direction.

[0028] The submount substrate 43 supports the light-emitting element array 41 and the lens 42 such that the light-emitting element array 41 and the lens 42 are fixed and the light-emitting element array 41 has a predetermined relative position with respect to the lens 42. The submount substrate 43 includes an insulating substrate 431 made of AlN, SiC, or the like, and a support portion 432 that extends in the +z direction from the periphery of the insulating substrate 431 and supports the lens 42. Further, the submount substrate 43 includes a pad portion 433a formed on the +z-direction side surface of the insulating substrate 431 on which the light-emitting element array 41 is mounted, and has a first electrode 433 that supplies power to the light-emitting element array 41 via the pad portion 433a. Further, the submount substrate 43 has a second electrode 433 that is connected to the light-emitting element array 41 via a bonding wire or the like (not shown) and supplies power to the light-emitting element array 41.

[0029] The light-emitting element array 41 is fixed to the submount substrate 43 such that the light-emitting surfaces 411 to 414 face the +z direction on the pad portion 433a of the first electrode 433. Further, the lens 42 is fixed to the submount substrate 43 at the +z-direction side end of the support portion 432 such that the optical axis 420 extends in the z direction. In the present embodiment, in the light sources 40A, 40B, 40C, and 40D, the light-emitting element array 41 and the lens 42 are fixed to each submount substrate 43 such that the distances in the z direction between the light-emitting surfaces 411 to 414 of the light-emitting element array 41 and the lens 42 are equal to each other.

[0030] Figs. 5(a) to 5(d) are diagrams for explaining the relationship between the light-emitting element array 41 and the lens 42. Fig. 5(a) shows the light-emitting element array 41 and the lens 42 in the light source 40A, Fig. 5(b) shows the light-emitting element array 41 and the lens 42 in the light source 40B, Fig. 5(c) shows the light-emitting element array 41 and the lens 42 in the light source 40C, and Fig. 5(d) shows the light-emitting element array 41 and the lens 42 in the light source 40D. Figs. 5(a) to 5(d) correspond to views of the light-emitting element array 41 and the lens 42 in the light sources 40A, 40B, 40C, and 40D as seen from the -z direction side to the +z direction.

[0031] In FIGS. 5(a) to 5(d), a straight line extending in the x direction passing through the optical axis 420 of the lens 42 and a straight line extending in the y direction passing through the optical axis 420 of the lens 42 are indicated by dashed lines. Hereinafter, the straight line extending in the x direction passing through the optical axis 420 of the lens 42 is denoted as the first straight line Lx, and the straight line extending in the y direction passing through the optical axis 420 of the lens 42 is denoted as the second straight line Ly. Also, hereinafter, the four regions of the lens 42 separated by the first straight line Lx and the second straight line Ly are denoted as the first region 421, the second region 422, the third region 423, and the fourth region 424, respectively. The first region 421 is a region of the lens 42 on the +y direction side of the first straight line Lx and on the -x direction side of the second straight line Ly. The second region 422 is a region of the lens 42 on the +y direction side of the first straight line Lx and on the +x direction side of the second straight line Ly. The third region 423 is a region of the lens 42 on the -y direction side of the first straight line Lx and on the -x direction side of the second straight line Ly. The fourth region 424 is a region of the lens 42 on the -y direction side of the first straight line Lx and on the +x direction side of the second straight line Ly.

[0032] The lens 42 has a circular shape centered on the optical axis 420 when viewed along the z direction. And the lens 42 has axisymmetric optical characteristics centered on the optical axis 420. More specifically, the lens 42 refracts light incident along the +z direction in a direction approaching the optical axis 420. That is, the lens 42 refracts the light incident on the first region 421 in the +x direction and the -y direction. Also, the lens 42 refracts the light incident on the second region 422 in the -x direction and the -y direction. Also, the lens 42 refracts the light incident on the third region 423 in the +x direction and the +y direction. Also, the lens 42 refracts the light incident on the fourth region 424 in the -x direction and the +y direction. Furthermore, the lens 42 has an optical characteristic of refracting light incident along the radial direction from the optical axis 420 toward the circumference more greatly. Note that the lens 42 does not refract the light incident on the optical axis 420.

[0033] As described above, the light sources 40A, 40B, 40C, and 40D have different positions of the light-emitting element arrays 41 with respect to the lens 42. As shown in FIG. 5(a), in the light source 40A, the light-emitting element array 41 and the lens 42 are arranged such that the center 411P of the light-emitting surface 411 is displaced in the -x direction and +y direction with respect to the optical axis 420 of the lens 42. Note that the center 411P of the light-emitting surface 411 is an example of the center of the light-emitting element array. In the present embodiment, since the light-emitting surface 411 is rectangular, the center 411P is the center of the rectangle. In this example, the distance in the x direction between the center 411P of the light-emitting surface 411 and the optical axis 420 of the lens 42 (hereinafter referred to as distance wA) is w / 2 (wA = w / 2). Also, the distance in the y direction between the center 411P of the light-emitting surface 411 and the optical axis 420 of the lens 42 (hereinafter referred to as distance hA) is h / 2 (hA = h / 2). Thereby, in the light source 40A, the light-emitting element array 41 and the lens 42 are arranged such that the light-emitting surface 411 overlaps the first region 421 of the lens 42. Additionally, in the light source 40A, the light-emitting element array 41 and the lens 42 are arranged such that, on the light-emitting surface 411, the long side 411x located on the -y direction side overlaps the first straight line Lx of the lens 42, and the short side 411y located on the +x direction side overlaps the second straight line Ly of the lens 42. Also, in the light source 40A, the optical axis 420 of the lens 42 passes through the vertex on the +x direction side and -y direction side of the light-emitting surface 411.

[0034] Also, as shown in FIG. 5(b), in the light source 40B, the light-emitting element array 41 and the lens 42 are arranged such that the center 412P of the light-emitting surface 412 is displaced in the +x direction and +y direction with respect to the optical axis 420 of the lens 42. In this example, the distance in the x direction between the center 412P of the light-emitting surface 412 and the optical axis 420 of the lens 42 (hereinafter referred to as distance wB) is w / 2 (wB = w / 2). Also, the distance in the y direction between the center 412P of the light-emitting surface 412 and the optical axis 420 of the lens 42 (hereinafter referred to as distance hB) is h / 2 (hB = h / 2). As a result, in the light source 40B, the light emitting element array 41 and the lens 42 are arranged such that the light emitting surface 412 overlaps with the second region 422 of the lens 42. Additionally, in the light source 40B, on the light emitting surface 412, the long side 412x located on the -y direction side overlaps with the first straight line Lx of the lens 42, and the short side 412y located on the -x direction side overlaps with the second straight line Ly of the lens 42, so that the light emitting element array 41 and the lens 42 are arranged. Also, in the light source 40B, the optical axis 420 of the lens 42 passes through the vertex on the -x direction side and -y direction side of the light emitting surface 412.

[0035] Also, as shown in FIG. 5(c), in the light source 40C, the light emitting element array 41 and the lens 42 are arranged such that the center 413P of the light emitting surface 413 is displaced in the -x direction and -y direction with respect to the optical axis 420 of the lens 42. In this example, the distance in the x direction between the center 413P of the light emitting surface 413 and the optical axis 420 of the lens 42 (hereinafter referred to as distance wC) is w / 2 (wC = w / 2). Also, the distance in the y direction between the center 413P of the light emitting surface 413 and the optical axis 420 of the lens 42 (hereinafter referred to as distance hC) is h / 2 (hC = h / 2). As a result, in the light source 40C, the light emitting element array 41 and the lens 42 are arranged such that the light emitting surface 413 overlaps with the third region 423 of the lens 42. Additionally, in the light source 40C, on the light emitting surface 413, the long side 413x located on the +y direction side overlaps with the first straight line Lx of the lens 42, and the short side 413y located on the +x direction side overlaps with the second straight line Ly of the lens 42, so that the light emitting element array 41 and the lens 42 are arranged. Also, in the light source 40C, the optical axis 420 of the lens 42 passes through the vertex on the +x direction side and +y direction side of the light emitting surface 413.

[0036] Also, as shown in FIG. 5(d), in the light source 40D, the light emitting element array 41 and the lens 42 are arranged such that the center 414P of the light emitting surface 414 is displaced in the +x direction and the -y direction with respect to the optical axis 420 of the lens 42. In this example, the distance in the x direction between the center 414P of the light emitting surface 414 and the optical axis 420 of the lens 42 (hereinafter referred to as the distance wD) is w / 2 (wD = w / 2). Also, the distance in the y direction between the center 414P of the light emitting surface 414 and the optical axis 420 of the lens 42 (hereinafter referred to as the distance hD) is h / 2 (hD = h / 2). As a result, in the light source 40D, the light emitting element array 41 and the lens 42 are arranged such that the light emitting surface 414 overlaps with the fourth region 424 of the lens 42. Additionally, in the light source 40D, the light emitting element array 41 and the lens 42 are arranged such that, on the light emitting surface 414, the long side 414x located on the +y direction side overlaps with the first straight line Lx of the lens 42, and the short side 414y located on the -x direction side overlaps with the second straight line Ly of the lens 42. Also, in the light source 40D, the optical axis 420 of the lens 42 passes through the vertex on the -x direction side and +y direction side of the light emitting surface 414.

[0037] Thus, in the light emitting unit 4 of the present embodiment, the light emitting surfaces 411 of the light emitting element array 41 in the light source 40A, the light emitting surfaces 412 of the light emitting element array 41 in the light source 40B, the light emitting surfaces 413 of the light emitting element array 41 in the light source 40C, and the light emitting surfaces 414 of the light emitting element array 41 in the light source 40D overlap with the first straight line Lx and the second straight line Ly of the lens 42. Additionally, in the light sources 40A, 40B, 40C, and 40D, there is no gap between the relative positions of the light emitting surfaces 411, 412, 413, and 414 with respect to the lens 42.

[0038] Note that the center 411P of the light emitting surface 411 means the center of rotation when the shape of the light emitting surface 411 is n-fold symmetric (n is a natural number of 2 or more). Since the light emitting surface 411 of the present embodiment is a rectangular shape that is symmetric about two axes, the center 411P of the light emitting surface 411 is the intersection of the diagonals, which is the center of rotation. The same applies to the centers 412P of the light emitting surface 412, the centers 413P of the light emitting surface 413, and the centers 414P of the light emitting surface 414.

[0039] Here, in the light emitting unit 4, the submount substrates 43 of the light source 40A and the light source 40B are arranged such that the light emitting surfaces 411 of the light source 40A and the light emitting surfaces 412 of the light source 40B are parallel in the x direction. Similarly, in the light emitting unit 4, the submount substrates 43 of the light source 40A and the light source 40C are arranged such that the light emitting surfaces 411 of the light source 40A and the light emitting surfaces 413 of the light source 40C are parallel in the y direction. Furthermore, in the light emitting unit 4, the submount substrates 43 of the light source 40B and the light source 40D are arranged such that the light emitting surfaces 412 of the light source 40B and the light emitting surfaces 414 of the light source 40D are parallel in the y direction. Furthermore, in the light emitting unit 4, the submount substrates 43 of the light source 40C and the light source 40D are arranged such that the light emitting surfaces 413 of the light source 40C and the light emitting surfaces 414 of the light source 40D are parallel in the x direction. In this way, in the present embodiment, the light emitting unit 4 can be configured by arranging the submount substrates 43 of the respective light sources 40A, 40B, 40C, and 40D to which the light emitting element array 41 and the lens 42 are fixed.

[0040] As described above, in the light emitting unit 4 of the present embodiment, the light emitting element arrays 41 and the lenses 42 of the respective light sources 40 have a common configuration. And in each light source 40, the light emitting element arrays 41 and the lenses 42 are fixed to the submount substrate 43 such that the distances in the z direction from the light emitting surfaces 411, 412, 413, 414 of the light emitting element array 41 to the lens 42 are equal to each other. Thereby, for example, compared with the case where the distances in the z direction from the light emitting surfaces 411, 412, 413, 414 of the light emitting element array 41 to the lens 42 are different distances in each light source 40, the deviation of illuminance between the irradiation ranges 100A, 100B, 100C, 100D of the irradiation surface 100 irradiated with light by each light source 40 is suppressed.

[0041] (Light irradiation area by the light emitting unit 4) Next, the irradiation ranges 100A, 100B, 100C, and 100D of the irradiation surface 100 irradiated with the light emitted from the light sources 40A, 40B, 40C, and 40D of the light emitting unit 4 will be described with reference to FIGS. 2 to 4. The irradiation surface 100 is a surface irradiated with the light from each light source 40, which is orthogonal to the direction in which each light source 40 emits light (+z direction) at a certain distance in the direction in which each light source 40 emits light. The irradiation surface 100 extends in the x direction and the y direction at a certain distance in the +z direction.

[0042] In the light source 40A, the light emitted from the light emitting surface 411 of the light emitting element array 41 enters the first region 421 of the lens 42 along the +z direction. Then, the light incident on the first region 421 of the lens 42 is refracted in the +x direction and the -y direction due to the optical characteristics of the lens 42 and is emitted from the light source 4A. In the light source 40B, the light emitted from the light emitting surface 412 of the light emitting element array 41 enters the second region 422 of the lens 42 along the +z direction. Then, the light incident on the second region 422 of the lens 42 is refracted in the -x direction and the -y direction due to the optical characteristics of the lens 42 and is emitted from the light source 4B.

[0043] In the light source 40C, the light emitted from the light emitting surface 413 of the light emitting element array 41 enters the third region 423 of the lens 42 along the +z direction. Then, the light incident on the third region 423 of the lens 42 is refracted in the +x direction and the +y direction due to the optical characteristics of the lens 42 and is emitted from the light source 4C. In the light source 40D, the light emitted from the light emitting surface 414 of the light emitting element array 41 enters the fourth region 424 of the lens 42 along the +z direction. Then, the light incident on the fourth region 424 of the lens 42 is refracted in the -x direction and the +y direction due to the optical characteristics of the lens 42 and is emitted from the light source 4D.

[0044] As a result, the light emitted from the light source 40A is irradiated onto the irradiation range 100A located on the +x direction side and -y direction side of the irradiation surface 100. Further, the light emitted from the light source 40B is irradiated onto the irradiation range 100B located on the -x direction side and -y direction side of the irradiation surface 100. Further, the light emitted from the light source 40C is irradiated onto the irradiation range 100C located on the +x direction side and +y direction side of the irradiation surface 100. Further, the light emitted from the light source 40D is irradiated onto the irradiation range 100D located on the -x direction side and +y direction side of the irradiation surface 100.

[0045] As shown in FIG. 2, on the irradiation surface 100, the irradiation range 100A and the irradiation range 100B are parallel to each other in the x direction, the irradiation range 100C and the irradiation range 100D are parallel to each other in the x direction, the irradiation range 100A and the irradiation range 100C are parallel to each other in the y direction, and the irradiation range 100B and the irradiation range 100D are parallel to each other in the y direction. More specifically, the irradiation range 100A is parallel to the irradiation range 100B on the +x direction side, and is parallel to the irradiation range 100C on the -y direction side. Further, the irradiation range 100B is parallel to the irradiation range 100A on the -x direction side, and is parallel to the irradiation range 100D on the -y direction side. The irradiation range 100C is parallel to the irradiation range 100A on the +y direction side, and is parallel to the irradiation range 100D on the +x direction side. The irradiation range 100D is parallel to the irradiation range 100B on the +y direction side, and is parallel to the irradiation range 100C on the -x direction side. Incidentally, the arrangement of the irradiation ranges 100A, 100B, 100C, 100D that are parallel to each other on the irradiation surface 100 is inverted in the x direction and the y direction with respect to the arrangement of the light emitting surfaces 411, 412, 413, 414 with respect to the lenses 42 of the light sources 40A, 40B, 40C, 40D.

[0046] As described above, in the light sources 40A, 40B, 40C, 40D, the light emitting element array 41 and the lens 42 are arranged so that no gap is generated between the relative positions of the light emitting surfaces 411, 412, 413, 414 with respect to the lens 42. As a result, on the irradiation surface 100, formation of a non-irradiated portion where light from the light sources 40A, 40B, 40C, and 40D is not irradiated between the parallel irradiation ranges 100A, 100B, 100C, and 100D is suppressed.

[0047] Note that on the irradiation surface 100, some regions in the parallel irradiation ranges 100A, 100B, 100C, and 100D may overlap. On the irradiation surface 100 of FIG. 2, an overlapping region 101 where some regions in the x direction of the irradiation range 100A and the irradiation range 100B overlap is formed. Also, on the irradiation surface 100 of FIG. 2, an overlapping region 102 where some regions in the x direction of the irradiation range 100C and the irradiation range 100D overlap is formed. Further, on the irradiation surface 100 of FIG. 2, an overlapping region 103 where some regions in the y direction of the irradiation range 100A and the irradiation range 100C overlap is formed. Also, on the irradiation surface 100 of FIG. 2, an overlapping region 104 where some regions in the y direction of the irradiation range 100B and the irradiation range 100D overlap is formed.

[0048] (Relationship between the light-emitting element array 41 and the lens 42) Subsequently, the relationship between the light-emitting element array 41 and the lens 42 will be described in more detail. FIGS. 6(a) to 6(b) are diagrams for explaining the relationship between the light-emitting element array 41 and the lens 42. FIGS. 6(a) to 6(b) correspond to views of the light-emitting element array 41 and the lens 42 in the light source 40A as seen from the -z direction side to the +z direction. In FIGS. 6(a) and 6(b), the distance between the center 411P of the light-emitting surface 411 in the light-emitting element array 41 and the optical axis 420 of the lens 42 is different. Note that the relationship between the light-emitting element array 41 and the lens 42 in FIG. 6(a) is the same as that in FIG. 6(b).

[0049] In the example shown in FIG. 6(a), the distance wA in the x direction between the center 411P of the light-emitting surface 411 and the optical axis 420 of the lens 42 is w / 2 (wA = w / 2). Also, the distance hA in the y direction between the center 411P of the light-emitting surface 411 and the optical axis 420 of the lens 42 is h / 2 (hA = h / 2). In the example shown in Fig. 6(a), the light emitting surface 411 overlaps with the first region 421 of the lens 42, and does not overlap with the second region 422, the third region 423, and the fourth region 424 of the lens 42 that are parallel to the first region 421.

[0050] Also, in the example shown in Fig. 6(b), the distance wA in the x direction between the center 411P of the light emitting surface 411 and the optical axis 420 of the lens 42 is w / 4 (wA = w / 4). Also, the distance hA in the y direction between the center 411P of the light emitting surface 411 and the optical axis 420 of the lens 42 is h / 4 (hA = h / 4). In the example shown in Fig. 6(b), the light emitting surface 411 overlaps with the first region 421 of the lens 42, and a part of the region on the +x direction side overlaps with the second region 422 and the fourth region 424 of the lens 24, and a part of the region on the -y direction side overlaps with the third region 423 and the fourth region 424 of the lens 24.

[0051] First, the light emitting element array 41 and the lens 42 of the light source 40A arranged in parallel in the x direction, which is one direction, and the light emitting element array 41 and the lens 42 of the light source 40B (see Figs. 3 and 5(b)) will be described. Here, the light emitting element array 41 of the light source 40A is an example of the first light emitting element array, and the lens 42 of the light source 40A is an example of the first optical system. Also, the light emitting element array 41 of the light source 40B is an example of the second light emitting element array, and the lens 42 of the light source 40B is an example of the second optical system. In the light emitting unit 4 of the present embodiment, the distance wA between the center 411P of the light emitting surface 411 of the light source 40A and the optical axis 420 of the lens 42, and the distance wB between the center 412P of the light emitting surface 412 of the light source 40B and the optical axis 420 of the lens 42 in the x direction are preferably not less than w / 4 and not more than w / 2.

[0052] When the distance wA between the center 411P of the light emitting surface 411 of the light source 40A and the optical axis 420 of the lens 42, and the distance wB between the center 412P of the light emitting surface 412 of the light source 40B and the optical axis 420 of the lens 42 in the x direction are w / 2 or less, formation of a non-irradiated portion between the irradiation ranges 100A and 100B arranged in parallel in the x direction on the irradiation surface 100 can be suppressed. In other words, when the distance wA between the center 411P of the light emitting surface 411 of the light source 40A and the optical axis 420 of the lens 42, or the distance wB between the center 412P of the light emitting surface 412 of the light source 40B and the optical axis 420 of the lens 42 exceeds w / 2, a non-irradiated portion is likely to be formed between the irradiation ranges 100A and 100B on the irradiation surface 100.

[0053] Also, when the distance wA between the center 411P of the light emitting surface 411 of the light source 40A and the optical axis 420 of the lens 42, and the distance wB between the center 412P of the light emitting surface 412 of the light source 40B and the optical axis 420 of the lens 42 in the x direction are w / 4 or more, it is suppressed that the overlapping region 101 where the irradiation ranges 100A and 100B arranged in parallel in the x direction on the irradiation surface 100 overlap becomes larger compared to the case where the distance wA or the distance wB is less than w / 4. When the overlapping region 101 between the irradiation ranges 100A and 100B becomes larger, the width of the irradiation surface 100 in the x direction becomes smaller, and the area of the entire irradiation surface 100 becomes smaller. In this case, the range in which distance measurement of an object can be performed by irradiating light with the light emitting unit 4 (see FIG. 1) becomes narrower.

[0054] Although detailed description is omitted here, regarding the light emitting element array 41 and the lens 42 of the light source 40C (see FIGS. 4 and 5(c)) arranged in parallel in the x direction, and the light emitting element array 41 and the lens 42 of the light source 40D (see FIGS. 4 and 5(d)), similar to the light sources 40A and 40B, the distance wC between the center 413P of the light emitting surface 413 and the optical axis 420 of the lens 42, and the distance wD between the center 414P of the light emitting surface 414 and the optical axis 420 of the lens 42 are preferably w / 4 or more and w / 2 or less.

[0055] Next, the light-emitting element arrays 41 and lenses 42 of the light sources 40A arranged in parallel in the y direction, which is another direction, and the light-emitting element arrays 41 and lenses 42 of the light source 40C will be described. Here, the light-emitting element array 41 of the light source 40A is an example of a first light-emitting element array, and the lens 42 of the light source 40A is an example of a first optical system. Also, the light-emitting element array 41 of the light source 40C is an example of a third light-emitting element array, and the lens 42 of the light source 40C is an example of a third optical system. In the light-emitting unit 4 of the present embodiment, the distance hA between the center 411P of the light-emitting surface 411 of the light source 40A and the optical axis 420 of the lens 42, and the distance hC between the center 413P of the light-emitting surface 413 of the light source 40C and the optical axis 420 of the lens 42 in the y direction are preferably not less than h / 4 and not more than h / 2.

[0056] When the distance hA between the center 411P of the light-emitting surface 411 of the light source 40A and the optical axis 420 of the lens 42, and the distance hC between the center 413P of the light-emitting surface 413 of the light source 40C and the optical axis 420 of the lens 42 in the y direction are not more than h / 2, formation of a non-irradiated portion between the irradiation ranges 100A and 100C arranged in parallel in the y direction on the irradiation surface 100 can be suppressed. Additionally, when the distance hA between the center 411P of the light-emitting surface 411 of the light source 40A and the optical axis 420 of the lens 42, or the distance hC between the center 413P of the light-emitting surface 413 of the light source 40C and the optical axis 420 of the lens 42 exceeds h / 2, a non-irradiated portion is likely to be formed between the irradiation ranges 100A and 100C on the irradiation surface 100.

[0057] Also, when the distance hA between the center 411P of the light-emitting surface 411 of the light source 40A and the optical axis 420 of the lens 42, and the distance hC between the center 413P of the light-emitting surface 413 of the light source 40C and the optical axis 420 of the lens 42 in the y direction are not less than h / 4, it is suppressed that the overlapping region 103 where the irradiation ranges 100A and 100C arranged in parallel in the y direction on the irradiation surface 100 overlap becomes larger compared to the case where the distance hA or the distance hC is less than h / 4. In addition, when the overlapping region 103 between the irradiation range 100A and the irradiation range 100C becomes large, the width of the irradiation surface 100 in the y direction becomes small, and the area of the entire irradiation surface 100 becomes small. In this case, the range in which the distance to the object can be measured by irradiating light from the light emitting unit 4 becomes narrow.

[0058] Here, in the light source 40A of the present embodiment, as shown in FIGS. 6(a) to 6(b), it is preferable that the optical axis 420 of the lens 42 is on any one diagonal line of the rectangular light emitting surface 411 of the light emitting element array 41. In FIGS. 6(a) to 6(b), the diagonal line of the light emitting surface 411 is indicated by a one-dot chain line. When the optical axis 420 of the lens 42 is on the diagonal line of the light emitting surface 411, it is possible to suppress the light emitting surface 411 from being disposed so as to be biased in either the x direction or the y direction with respect to the optical axis 420. In this case, compared with the case where the optical axis 420 of the lens 42 is at a position deviated from the diagonal line of the light emitting surface 411, it is possible to suppress either the overlapping region 101 between the irradiation range 100A and the irradiation range 100B or the overlapping region 103 between the irradiation range 100A and the irradiation range 100C from becoming excessively large.

[0059] Furthermore, in the light source 40A of the present embodiment, it is preferable that the optical axis 420 of the lens 42 passes through any one vertex of the rectangular light emitting surface 411 of the light emitting element array 41. In the light source 40A of FIG. 6(a), the optical axis 420 of the lens 42 passes through the vertex on the +x direction side and the -y direction side of the light emitting surface 411. When the optical axis 420 of the lens 42 passes through the vertex of the light emitting surface 411, it is possible to reduce the overlapping region 101 between the irradiation range 100A and the irradiation range 100B and the overlapping region 103 between the irradiation range 100A and the irradiation range 100C, as compared with the case where the optical axis 420 of the lens 42 does not pass through the vertex of the light emitting surface 411.

[0060] Although not shown, in the light sources 40B, 40C, and 40D, similarly to the light source 40A, it is preferable that the optical axis 420 of the lens 42 is on any one diagonal line of the rectangular light emitting surfaces 412, 413, and 414 of the light emitting element array 41. Furthermore, similar to the light source 40A, it is preferable that the optical axis 420 of the lens 42 passes through any one vertex of the rectangular light emitting surfaces 412, 413, and 414 of the light emitting element array 41 for the light sources 40B, 40C, and 40D.

[0061] In this embodiment, the case where the light emitting unit 4 has four light sources 40A, 40B, 40C, and 40D provided such that the irradiation ranges 100A, 100B, 100C, and 100D are arranged in parallel in the x direction and the y direction on the irradiation surface 100 is illustrated. However, the configuration of the light emitting unit 4 is not limited to this. The light emitting unit 4 may have a plurality of light sources provided such that a plurality of irradiation ranges are arranged in parallel in one direction (for example, the x direction) on the irradiation surface 100 and the irradiation ranges are not arranged in parallel in the other direction (for example, the y direction). In this case, the light emitting element array 41 and the lens 42 may be provided for the plurality of light sources such that the distance between the center of the light emitting surface of the light emitting element array 41 and the optical axis 420 of the lens 42 is in the range of w / 4 or more and w / 2 or less. Further, the light emitting unit 4 may have a plurality of light sources provided such that three or more plurality of irradiation ranges are arranged in parallel in one direction (for example, the x direction) or the other direction (for example, the y direction) on the irradiation surface 100.

[0062] (Aperture diameter of the lens 42) Subsequently, the aperture diameter R (see FIG. 6) of the lens 42 included in the light emitting unit 4 will be described. In the light emitting unit 4, when the light emitting element array 41 has a rectangular shape with the length in one direction (for example, the x direction) being w and the length in the other direction (for example, the y direction) being h, and n (n is a natural number of 1 or more) light emitting element arrays 41 are arranged in parallel in the other direction (the y direction), the aperture diameter R of the lens 42 is preferably set to satisfy the following formula (1).

[0063]

Equation

[0064] By having the effective diameter R of the lens 42 satisfy the formula (1), it becomes easier to secure the distance between the optical axis 420 of the lens 42 and the center of the light emitting surface of the light emitting element array 41, compared to, for example, the case where the effective diameter R of the lens 42 is smaller than the range of the formula (1). Additionally, when the effective diameter R of the lens 42 is smaller than the range of the formula (1), depending on the distance between the optical axis 420 of the lens 42 and the center of the light emitting surface of the light emitting element array 41, the light emitting element array 41 may protrude from the outer periphery of the lens 42.

[0065] [Embodiment 2] Subsequently, Embodiment 2 of the present invention will be described. FIG. 7 is a diagram for explaining the configuration of the light emitting unit 4 to which Embodiment 2 is applied, and is a view of the light emitting unit 4 as seen from the -z direction side to the +z direction. In FIG. 7, for each of the light sources 40A, 40B, 40C, 40D, the wiring 435 of the submount substrate 43 located on the -z direction side (i.e., the front side of the paper surface) with respect to the light emitting element array 41 and the lens 42 is shown by a broken line. In the light emitting unit 4 of Embodiment 2, the arrangement of the light sources 40A, 40B, 40C, 40D and the relationship between the submount substrate 43 and the light emitting element array 41 and the lens 42 in each of the light sources 40A, 40B, 40C, 40D are different from those of the light emitting unit 4 of Embodiment 1. Note that for the same configurations as those in Embodiment 1 in the present embodiment, the same reference numerals are used, and detailed descriptions thereof are omitted here.

[0066] In the light-emitting unit 4 of Embodiment 2, the light sources 40A and 40B are arranged in parallel in the x direction, the light sources 40C and 40D are arranged in parallel in the x direction, the light sources 40A and 40C are arranged in parallel in the y direction, and the light sources 40B and 40D are arranged in parallel in the y direction. In this example, the light source 40A is arranged on the +x direction side with respect to the light source 40B and on the +y direction side with respect to the light source 40C. The light source 40B is arranged on the -x direction side with respect to the light source 40A and on the +y direction side with respect to the light source 40D. The light source 40C is arranged on the -y direction side with respect to the light source 40A and on the +x direction side with respect to the light source 40D. The light source 40D is arranged on the -y direction side with respect to the light source 40B and on the -x direction side with respect to the light source 40C.

[0067] Also, in the light-emitting unit 4 of Embodiment 2, as in Embodiment 1, the submount substrates 43 of the light source 40A and the light source 40B are arranged such that the light-emitting surfaces 411 of the light source 40A and the light-emitting surfaces 412 of the light source 40B are arranged in parallel in the x direction. Similarly, in the light-emitting unit 4, the submount substrates 43 of the light source 40A and the light source 40C are arranged such that the light-emitting surfaces 411 of the light source 40A and the light-emitting surfaces 413 of the light source 40C are arranged in parallel in the y direction. Furthermore, in the light-emitting unit 4, the submount substrates 43 of the light source 40B and the light source 40D are arranged such that the light-emitting surfaces 412 of the light source 40B and the light-emitting surfaces 414 of the light source 40D are arranged in parallel in the y direction. Furthermore, in the light-emitting unit 4, the submount substrates 43 of the light source 40C and the light source 40D are arranged such that the light-emitting surfaces 413 of the light source 40C and the light-emitting surfaces 414 of the light source 40D are arranged in parallel in the x direction. In this way, also in Embodiment 2, the light-emitting unit 4 can be configured by arranging the submount substrates 43 of the light sources 40A, 40B, 40C, and 40D to which the light-emitting element array 41 and the lens 42 are fixed.

[0068] Here, in the submount substrate 43 of Embodiment 2, a wiring 435 including an electrode (not shown) for supplying power to the light-emitting element array 41 is formed on an insulating substrate 431. In this example, the insulating substrate 431 is rectangular. And when the submount substrate 43 is arranged such that each side of the insulating substrate 431 is along the x direction or the y direction and viewed in the z direction, the overall shape of the wiring 435 is asymmetric in one of the x direction and the y direction (in this example, the x direction) and symmetric in the other direction (in this example, the y direction). Also, similar to Embodiment 1, the light-emitting element array 41 of Embodiment 2 has a shape in which the light-emitting surfaces 411 to 414 are rectangular with two-fold symmetry.

[0069] And in the light-emitting unit 4 of Embodiment 2, the positional relationship between the light-emitting element array 41 fixed to the submount substrate 43 and the lens 42 is different between the light sources 40A and 40D and the light sources 40B and 40C. In other words, in the light-emitting unit 4 of Embodiment 2, the positional relationship between the light-emitting element array 41 and the lens 42 is common between the light sources 40A and 40D and common between the light sources 40B and 40C.

[0070] Specifically, in the light-emitting unit 4 of Embodiment 2, the set of the light-emitting element array 41 and the lens 42 fixed to the submount substrate 43 in the light source 40D has a configuration obtained by rotating the set of the light-emitting element array 41 and the lens 42 fixed to the submount substrate 43 in the light source 40A by 180 degrees around the optical axis 420 of the lens 42 of the light source 40A. In this example, the light-emitting element array 41 of the light source 40A is an example of a first light-emitting element array, and the lens 42 of the light source 40A is an example of a first optical system. Also, the light-emitting element array 41 of the light source 40D is an example of a fourth light-emitting element array, and the lens 42 of the light source 40D is an example of a fourth optical system. Also, in the light-emitting unit 4 of Embodiment 2, the set of the light-emitting element array 41 and the lens 42 fixed to the submount substrate 43 in the light source 40C has a configuration obtained by rotating the set of the light-emitting element array 41 and the lens 42 fixed to the submount substrate 43 in the light source 40B by 180 degrees around the optical axis 420 of the lens 42 of the light source 40B.

[0071] Here, in FIG. 7, when the shapes of the light emitting surfaces 411 to 414 of the light emitting element arrays 41 included in the light sources 40A, 40B, 40C, and 40D are rectangular shapes that are two-fold symmetric, it was explained that the light source 40A and the light source 40D can have a common configuration, and the light source 40B and the light source 40C can have a common configuration. Here, when the shapes of the light emitting surfaces 411 to 414 of the light emitting element arrays 41 included in the light sources 40A, 40B, 40C, and 40D are four-fold symmetric shapes such as a square, etc., the light sources 40A, 40B, 40C, and 40D can have a common configuration. That is, the light source 40B can be configured to rotate the light source 40A by 90 degrees around the optical axis 420 of the lens 42. More specifically, the combination of the light emitting element array 41 and the lens 42 of the light source 40B can be configured to rotate the combination of the light emitting element array 41 and the lens 42 of the light source 40A by 90 degrees around the optical axis 420 of the lens 42 of the light source 40A. In this example, the light emitting element array 41 of the light source 40A is an example of a first light emitting element array, and the lens 42 of the light source 40A is an example of a first optical system. Also, the light emitting element array 41 of the light source 40B is an example of a second light emitting element array, and the lens 42 of the light source 40B is an example of a fourth optical system.

[0072] Also, the light source 40C can be configured to rotate the light source 40A by -90 degrees (or 270 degrees) around the optical axis 420 of the lens 42. More specifically, the combination of the light emitting element array 41 and the lens 42 of the light source 40C can be configured to rotate the combination of the light emitting element array 41 and the lens 42 of the light source 40A by -90 degrees (or 270 degrees) around the optical axis 420 of the lens 42 of the light source 40A. Also, the light source 40D can be configured to rotate the light source 40A by 180 degrees around the optical axis 420 of the lens 42. More specifically, the combination of the light emitting element array 41 and the lens 42 of the light source 40D can be configured to rotate the combination of the light emitting element array 41 and the lens 42 of the light source 40A by 180 degrees around the optical axis 420 of the lens 42 of the light source 40A.

[0073] [Embodiment 3] Next, Embodiment 3 of the present invention will be described. FIG. 8 is a diagram showing an example of the configuration of the light emitting unit 4 and the light emitting driving unit 6 (see FIG. 1) to which Embodiment 3 is applied. FIG. 8 is a view of the light emitting unit 4, the drivers 61, 62, and the fan-out buffer 67 that constitute the light emitting driving unit 6, as viewed from the -z direction side to the +z direction. FIG. 8 shows a case where the light emitting unit 4 has two light sources 40E and 40F arranged in parallel in the x direction. In FIG. 8, for the submount substrate 43 located on the -z direction side (i.e., the front side of the paper surface) of the light emitting element array 41 and the lens 42 in each of the light sources 40E and 40F, it is indicated by a broken line. In addition, in Embodiment 3, the same reference numerals are used for the same configurations as those in Embodiments 1 and 2, and detailed descriptions thereof are omitted here.

[0074] As described above, in the light emitting unit 4 of Embodiment 3, the two light sources 40E and 40F are arranged in parallel in the x direction. In this example, the light source 40E is arranged on the +x direction side with respect to the light source 40F. Although not shown in the figure, in Embodiment 3, on the irradiation surface 100 (see FIG. 2), the irradiation range irradiated with the light from the light source 40E and the irradiation range irradiated with the light from the light source 40F are parallel in the x direction. More specifically, on the irradiation surface 100, the irradiation range irradiated with the light from the light source 40E is parallel to the +x direction side with respect to the irradiation range irradiated with the light from the light source 40F.

[0075] The light emitting driving unit 6 includes a driver 61 that drives the light emitting element array 41 of the light source 40E, a driver 62 that drives the light emitting element array 41 of the light source 40F, and a fan-out buffer 67 that distributes the driving signal from the control unit 8 (see FIG. 1) to the driver 61 and the driver 62. Further, the light emitting driving unit 6 includes a signal line 68E that transmits the driving signal distributed by the fan-out buffer 67 to the driver 61, and a signal line 68F that transmits the driving signal to the driver 62.

[0076] As shown in FIG. 8, the drivers 61 and 62 are arranged at positions different from those between the light-emitting element array 41 of the light source 40E and the light-emitting element array 41 of the light source 40F that are arranged in parallel in the x direction. Specifically, the driver 61 is arranged on the side opposite to the light-emitting element array 41 of the light source 40F with respect to the light-emitting element array 41 of the light source 40E in the x direction. In other words, the driver 61 is arranged on the +x direction side with respect to the light source 40E. Also, the driver 62 is arranged on the side opposite to the light-emitting element array 41 of the light source 40E with respect to the light-emitting element array 41 of the light source 40F in the x direction. In other words, the driver 62 is arranged on the -x direction side with respect to the light source 40F. In this example, the light-emitting element array 41 of the light source 40E is an example of the first light-emitting element array, and the light-emitting element array 41 of the light source 40F is an example of the second light-emitting element array. Also, the driver 61 is an example of the first driver, and the driver 62 is an example of the second driver.

[0077] In the present embodiment, by arranging the drivers 61 and 62 at positions different from those between the light-emitting element array 41 of the light source 40E and the light-emitting element array 41 of the light source 40F, it becomes possible to arrange the light-emitting element array 41 of the light source 40E and the light-emitting element array 41 of the light source 40F closer to each other.

[0078] FIG. 9 is a diagram showing a comparative example of the arrangement of the drivers 61 and 62, and is a view of the light-emitting unit 4, the drivers 61, 62, and the fan-out buffer 67 constituting the light-emitting drive unit 6, viewed from the -z direction side to the +z direction. In the comparative example shown in FIG. 9, the drivers 61 and 62 are arranged between the light-emitting element array 41 of the light source 40E and the light-emitting element array 41 of the light source 40F. In this case, the distance in the x direction between the light-emitting element array 41 of the light source 40E and the light-emitting element array 41 of the light source 40F will be separated by the width in the x direction of the drivers 61 and 62.

[0079] Here, when irradiating the irradiation surface 100 (see FIG. 2) with light by a plurality of light sources each having a light-emitting element array 41, if the distance between the light-emitting element arrays 41 is large, in the irradiation surface 100 where the distance from the light-emitting portion 4 in the +z direction is short, a non-irradiated portion where light is not irradiated is likely to be formed between the irradiation ranges irradiated with light from the respective light sources. In contrast, in the present embodiment, the drivers 61 and 62 are arranged at positions different from between the light-emitting element array 41 of the light source 40E and the light-emitting element array 41 of the light source 40F, so that a non-irradiated portion is less likely to be formed in the irradiation surface 100 where the distance from the light-emitting portion 4 in the +z direction is short.

[0080] Further, in the present embodiment, as shown in FIG. 8, the fan-out buffer 67 is arranged at a position shifted to the -y direction side with respect to the light sources 40E and 40F. Also, the fan-out buffer 67 is arranged at a position intermediate between the light sources 40E and 40F in the x direction. Thereby, the lengths of the signal lines 68E and 68F are equal. In the present embodiment, since the lengths of the signal lines 68E and 68F are equal, the deviation between the time until the drive signal from the control unit 8 reaches the driver 61 via the fan-out buffer 67 and the time until the drive signal reaches the driver 62 via the fan-out buffer 67 is less likely to occur. Thereby, the light-emitting element arrays 41 of the light source 40E and the light-emitting element array 41 of the light source 40F can be accurately caused to emit light by the drivers 61 and 62.

[0081] Subsequently, the arrangement of the drivers (drivers 63 to 66 described later) and the fan-out buffer 67 when the light-emitting portion 4 has four light sources 40A, 40B, 40C, and 40D will be described. FIG. 10 is a diagram showing an example of the configuration of the light-emitting portion 4 and the light-emitting drive unit 6 when the light-emitting portion 4 has four light sources 40A, 40B, 40C, and 40D. FIG. 10 is a view of the light-emitting portion 4, the drivers 63 to 66 and the fan-out buffer 67 constituting the light-emitting drive unit 6 as viewed from the -z direction side to the +z direction.

[0082] In the light-emitting unit 4 shown in FIG. 10, the light sources 40A and 40B are arranged in parallel in the x direction, the light sources 40C and 40D are arranged in parallel in the x direction, the light sources 40A and 40C are arranged in parallel in the y direction, and the light sources 40B and 40D are arranged in parallel in the y direction. In this example, the light source 40A is arranged on the +x direction side with respect to the light source 40B and on the +y direction side with respect to the light source 40C. The light source 40B is arranged on the -x direction side with respect to the light source 40A and on the +y direction side with respect to the light source 40D. The light source 40C is arranged on the -y direction side with respect to the light source 40A and on the +x direction side with respect to the light source 40D. The light source 40D is arranged on the -y direction side with respect to the light source 40B and on the -x direction side with respect to the light source 40C.

[0083] Also, the light-emitting drive unit 6 includes a driver 63 that drives the light-emitting element array 41 of the light source 40A, a driver 64 that drives the light-emitting element array 41 of the light source 40B, a driver 65 that drives the light-emitting element array 41 of the light source 40C, and a driver 65 that drives the light-emitting element array 41 of the light source 40D. Further, the light-emitting drive unit 6 includes a fan-out buffer 67 that distributes a drive signal from the control unit 8 (see FIG. 1) to the drivers 63, 64, 65, and 66. Furthermore, the light-emitting drive unit 6 includes a signal line 68A that transmits the drive signal distributed by the fan-out buffer 67 to the driver 63, a signal line 68B that transmits the drive signal to the driver 64, a signal line 68C that transmits the drive signal to the driver 65, and a signal line 68D that transmits the drive signal to the driver 66.

[0084] As shown in FIG. 10, the drivers 63 and 64 are arranged at positions different from those between the light-emitting element arrays 41 of the light sources 40A and 40B that are arranged in parallel in the x direction. Specifically, in the x direction, the driver 63 is arranged on the side opposite to the light-emitting element array 41 of the light source 40B with respect to the light-emitting element array 41 of the light source 40A. In other words, the driver 63 is arranged on the +x direction side with respect to the light source 40A. Also, in the x direction, the driver 64 is arranged on the side opposite to the light-emitting element array 41 of the light source 40A with respect to the light-emitting element array 41 of the light source 40B. In other words, the driver 64 is arranged on the -x direction side with respect to the light source 40B.

[0085] In this embodiment, by arranging the driver 63 and the driver 64 at positions different from between the light-emitting element array 41 of the light source 40A and the light-emitting element array 41 of the light source 40B, it is possible to arrange them so as to reduce the distance between the light-emitting element array 41 of the light source 40A and the light-emitting element array 41 of the light source 40B.

[0086] Also, as shown in FIG. 10, the driver 65 and the driver 66 are arranged at positions different from between the light-emitting element array 41 of the light source 40C and the light-emitting element array 41 of the light source 40D that are arranged in parallel in the x direction. Specifically, in the x direction, the driver 66 is arranged on the side opposite to the light-emitting element array 41 of the light source 40D with respect to the light-emitting element array 41 of the light source 40C. In other words, the driver 65 is arranged on the +x direction side with respect to the light source 40C. Also, in the x direction, the driver 66 is arranged on the side opposite to the light-emitting element array 41 of the light source 40C with respect to the light-emitting element array 41 of the light source 40D. In other words, the driver 66 is arranged on the -x direction side with respect to the light source 40D.

[0087] In this embodiment, by arranging the driver 65 and the driver 66 at positions different from between the light-emitting element array 41 of the light source 40C and the light-emitting element array 41 of the light source 40D, it is possible to arrange them so as to reduce the distance between the light-emitting element array 41 of the light source 40C and the light-emitting element array 41 of the light source 40D.

[0088] Also, in this embodiment, as shown in FIG. 10, the fan-out buffer 67 is disposed at a position shifted in the y direction with respect to the light sources 40A, 40B, 40C, and 40D. Specifically, the fan-out buffer 67 is disposed between the light sources 40A and 40B and between the light sources 40C and 40D. Additionally, the fan-out buffer 67 is disposed at a position that is intermediate between the light sources 40A and 40B and between the light sources 40C and 40D in the y direction. Also, in the x direction, the fan-out buffer 67 is disposed at a position intermediate between the driver 63 that drives the light source 40A and the driver 64 that drives the light source 40B, and at a position intermediate between the driver 65 that drives the light source 40C and the driver 66 that drives the light source 40D.

[0089] As a result, in the example shown in FIG. 10, the lengths of the signal lines 68A, 68B, 68C, and 68D are equal to each other. In this embodiment, since the lengths of the signal lines 68A, 68B, 68C, and 68D are equal, it is less likely that a deviation will occur in the time it takes for the drive signal from the control unit 8 to reach the drivers 63 to 66 via the fan-out buffer 67. As a result, the drivers 63 to 66 can accurately cause the light-emitting element arrays 41 of the light sources 40A, 40B, 40C, and 40D to emit light.

[0090] As described above, embodiments of the present invention have been described, but the technical scope of the present invention is not limited to the scope described in the foregoing embodiments. For example, in the above-described embodiment, in the light-emitting unit 4, the lens 42 that refracts the light emitted from the light-emitting element array 41 is exemplified as an example of the optical system. However, as long as it refracts the light emitted from the light-emitting element array 41 and expands the light irradiation range, the optical system is not limited to the lens 42. As the optical system, for example, a diffractive optical element (DOE) that changes the angle of incident light and emits it may be used.

[0091] In addition, it is obvious from the description of the claims that those obtained by making various changes or improvements to the above-described embodiments are also included in the technical scope of the present invention.

[0092] (Appendix) (((1))) A light-emitting element array in which a plurality of light-emitting elements are arranged such that the length in one direction is w, a first light-emitting element array and a second light-emitting element array parallel to each other in the one direction, A first optical system that refracts the light emitted from the first light-emitting element array, A second optical system that refracts the light emitted from the second light-emitting element array so that the irradiation range of the second light-emitting element array is parallel to the irradiation range of the first light-emitting element array in the one direction, Comprising: A light-emitting device, wherein the distance between the optical axis of the first optical system and the center of the first light-emitting element array, and the distance between the optical axis of the second optical system and the center of the second light-emitting element array in the one direction are not less than w / 4 and not more than w / 2. (((2))) A third light-emitting element array parallel to the first light-emitting element array in another direction intersecting the one direction, A third optical system that refracts the light emitted from the third light-emitting element array so that the irradiation range of the third light-emitting element array is parallel to the irradiation range of the first light-emitting element array in the other direction, Further comprising: In the first light-emitting element array and the third light-emitting element array, the plurality of light-emitting elements are arranged such that the length in the other direction is h, The light-emitting device according to (((1))), wherein the distance between the optical axis of the first optical system and the center of the first light-emitting element array, and the distance between the optical axis of the third optical system and the center of the third light-emitting element array in the other direction are not less than h / 4 and not more than h / 2. (((3))) The light-emitting element array is rectangular with the side length in the one direction being w and the side length in the other direction being h, The optical axis of the optical system is on one of the diagonals of the rectangular shape, and the light-emitting device according to ((2)). (((4))) The optical axis of the optical system passes through one of the vertices of the rectangular shape, and the light-emitting device according to ((3)). (((5))) The first light-emitting element array and the first optical system are fixed on a first submount substrate, The second light-emitting element array and the second optical system are fixed on a second submount substrate, The first submount substrate and the second submount substrate are arranged such that the first light-emitting element array and the second light-emitting element array are parallel to each other in the one direction, and the light-emitting device according to any one of ((1)) to ((4)). (((6))) The first light-emitting element array and the second light-emitting element array are constituted by a common light-emitting element array, The first optical system and the second optical system are constituted by a common optical system, The fixing of the light-emitting element array and the optical system to the submount substrate is performed such that the distance between the first light-emitting element array and the first optical system is equal to the distance between the second light-emitting element array and the second optical system, and the light-emitting device according to ((5)). (((7))) A fourth light-emitting element array that is parallel to the one direction and another direction intersecting the one direction with respect to the first light-emitting element array, A fourth optical system that refracts the light emitted from the fourth light-emitting element array such that the irradiation range of the fourth light-emitting element array is parallel to the irradiation range of the first light-emitting element array, And further comprising The first light-emitting element array and the fourth light-emitting element array have a two-fold symmetric or four-fold symmetric shape, The combination of the fourth light-emitting element array and the fourth optical system has a configuration in which the combination of the first light-emitting element array and the first optical system is rotated 180 degrees around the optical axis of the first optical system. The light-emitting device according to any one of ((1)) to ((6)). (((8))) The first light-emitting element array, the second light-emitting element array, and the fourth light-emitting element array have a four-fold symmetric shape. The combination of the second light-emitting element array and the second optical system has a configuration in which the combination of the first light-emitting element array and the first optical system is rotated 90 degrees around the optical axis of the first optical system. The light-emitting device according to ((7)). (((9))) A first driver for driving the first light-emitting element array A second driver for driving the second light-emitting element array Further comprising The first driver and the second driver are arranged at positions different from between the first light-emitting element array and the second light-emitting element array. The light-emitting device according to any one of ((1)) to ((8)). (((10))) The light-emitting element array is rectangular with the length of the side in the one direction being w and the length of the side in the other direction intersecting the one direction being h. n (n is a natural number of 1 or more) light-emitting element arrays including the first light-emitting element array are arranged in parallel in the other direction. The effective diameter R of the optical system is set to satisfy Equation (1). The light-emitting device according to any one of ((1)) to ((9)).

[0093]

Equation

[0094] (((11))) (((1))) to ((10)) any one of the described light-emitting device, and A light receiving unit that receives light emitted from the light emitting device and reflected by the object, A calculation unit that calculates the distance to the object based on the result of light reception in the light receiving unit, A distance measuring device characterized by comprising the above.

[0095] ((1)) According to the light emitting device according to, by the arrangement of the light emitting element array and the optical system, it is possible to suppress the formation of non-irradiated portions between the parallel irradiation ranges. ((2)) According to the light emitting device according to, also in other directions, the formation of non-irradiated portions between the parallel irradiation ranges is suppressed. ((3)) According to the light emitting device according to, compared with the case where the optical axis is not on the diagonal line, the overlap of the irradiation ranges of each light emitting element array in one direction or the other direction is suppressed. ((4)) According to the light emitting device according to, compared with the case where the optical axis does not pass through the vertex, the overlap of the irradiation ranges of each light emitting element array is suppressed. ((5)) According to the light emitting device according to, the light emitting device can be configured by the arrangement of the submount substrate on which the light emitting element array and the optical system are fixed. ((6)) According to the light emitting device according to, compared with the case where the distance between the light emitting element array and the optical system is set to different distances, the unevenness of illuminance between the irradiation ranges by each light emitting element array is suppressed. ((7)) According to the light emitting device according to, the set of the first light emitting element array and the first optical system and the set of the fourth light emitting element array and the fourth optical system can be made common. ((8)) According to the light emitting device according to, the set of the first light emitting element array and the first optical system, the set of the second light emitting element array and the second optical system, and the set of the fourth light emitting element array and the fourth optical system can be made common. ((9)) According to the light emitting device according to, compared with the case where a driver is arranged between the light emitting element arrays, it becomes easier to arrange the light emitting element arrays closer to each other. ((10)) According to the light emitting device according to, compared with the case where the effective diameter of the optical system is smaller than the range of the formula (1), it becomes easier to secure the distance between the optical axis of the optical system and the center of the light emitting element array. According to the distance measuring device according to ((11)), the formation of non-irradiated portions between the parallel irradiation ranges can be suppressed by the arrangement of the light emitting element array and the optical system.

Explanation of Signs

[0096] 1... Distance measuring device, 4... Light emitting unit, 6... Light emitting drive unit, 8... Control unit, 40, 40A, 40B, 40C, 40D... Light sources, 41... Light emitting element array, 42... Lens, 43... Submount substrate, 61 to 66... Drivers, 67... Fan-out buffer, 100... Irradiation surface, 411 to 414... Light emitting surfaces

Claims

1. A light-emitting element array in which a plurality of light-emitting elements are arranged so that the length in one direction is w, the first light-emitting element array and the second light-emitting element array parallel to each other in the one direction, A first optical system that refracts the light emitted from the first light-emitting element array, A second optical system that refracts the light emitted from the second light-emitting element array so that the irradiation range of the second light-emitting element array is parallel to the irradiation range of the first light-emitting element array in the one direction, Comprising, The distance between the optical axis of the first optical system and the center of the first light-emitting element array, and the distance between the optical axis of the second optical system and the center of the second light-emitting element array in the one direction are w / 4 or more and w / 2 or less. A light-emitting device characterized by this.

2. A third light-emitting element array parallel to another direction intersecting the one direction with respect to the first light-emitting element array, A third optical system that refracts the light emitted from the third light-emitting element array so that the irradiation range of the third light-emitting element array is parallel to the irradiation range of the first light-emitting element array in the other direction, Further comprising, In the first light-emitting element array and the third light-emitting element array, the plurality of light-emitting elements are arranged so that the length in the other direction is h, The distance between the optical axis of the first optical system and the center of the first light-emitting element array, and the distance between the optical axis of the third optical system and the center of the third light-emitting element array in the other direction are h / 4 or more and h / 2 or less. The light-emitting device according to claim 1, characterized by this.

3. The light-emitting element array is rectangular with the side length in the one direction being w and the side length in the other direction being h, The optical axis of the optical system is on any one diagonal line of the rectangle. The light-emitting device according to claim 2, characterized by this.

4. The optical axis of the optical system passes through any one vertex of the rectangle. The light-emitting device according to claim 3, characterized by this.

5. The first light-emitting element array and the first optical system are fixed on a first submount substrate, The second light-emitting element array and the second optical system are fixed on a second submount substrate, The first submount substrate and the second submount substrate are arranged so that the first light-emitting element array and the second light-emitting element array are parallel to each other in the one direction. The light-emitting device according to claim 1, characterized by this.

6. The first light-emitting element array and the second light-emitting element array are constituted by a common light-emitting element array, The first optical system and the second optical system are constituted by a common optical system, The light-emitting element array and the optical system are fixed to the submount substrate such that the distance between the first light-emitting element array and the first optical system is equal to the distance between the second light-emitting element array and the second optical system. The light-emitting device according to claim 5, characterized in that

7. A fourth light-emitting element array parallel to the one direction and another direction intersecting the one direction with respect to the first light-emitting element array; A fourth optical system that refracts the light emitted by the fourth light-emitting element array such that the irradiation range of the fourth light-emitting element array is parallel to the irradiation range of the first light-emitting element array; further comprising The first light-emitting element array and the fourth light-emitting element array have a two-fold symmetric or four-fold symmetric shape, The combination of the fourth light-emitting element array and the fourth optical system has a configuration in which the combination of the first light-emitting element array and the first optical system is rotated 180 degrees around the optical axis of the first optical system. The light-emitting device according to claim 1, characterized in that

8. The first light-emitting element array, the second light-emitting element array, and the fourth light-emitting element array have a four-fold symmetric shape, The combination of the second light-emitting element array and the second optical system has a configuration in which the combination of the first light-emitting element array and the first optical system is rotated 90 degrees around the optical axis of the first optical system. The light-emitting device according to claim 7, characterized in that

9. A first driver for driving the first light-emitting element array; A second driver for driving the second light-emitting element array; further comprising The first driver and the second driver are arranged at positions different from those between the first light-emitting element array and the second light-emitting element array. The light-emitting device according to claim 1, characterized in that

10. The light-emitting element array is rectangular with the length of the side in the one direction being w and the length of the side in the other direction intersecting the one direction being h, n (n is a natural number of 1 or more) light-emitting element arrays including the first light-emitting element array are arranged in parallel in the other direction, The effective diameter R of the optical system is set to satisfy formula (1). The light-emitting device according to any one of claims 1 to 9, characterized in that 【Number 1】

11. A light-emitting device according to any one of Claims 1 to 10, a light-receiving unit that receives light irradiated from the light-emitting device and reflected by an object, and a calculation unit that calculates the distance to the object based on the result of light reception by the light-receiving unit. A distance measuring device characterized by comprising the above components.

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