Light-emitting device and distance measurement device

Abstract

[Problem] The present disclosure provides a light-emitting device and a distance measurement device capable of suppressing deterioration of reliability even when the number of light-emitting elements constituting a light-emitting unit increases. [Solution] The present disclosure provides a light-emitting device that can be used for distance measurement for measuring the return time of projection pattern light, and that comprises: a light-emitting unit that is constituted of a plurality of light-emitting substrates, and that periodically emits projection pattern light; and an optical scanning unit that causes the projection pattern light to scan within a prescribed angle range. The intervals between light-emitting elements positioned at ends of the light-emitting substrates overlap one another along a first direction.

Description

Light emitting device and distance measuring device

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

[0002] A mechanical LiDAR (Light Detection and Ranging) device that can be used for autonomous driving and the like is known. The mechanical LiDAR device includes an optical scanning unit that scans an object using an optical pulse signal emitted from a light emitting unit. The optical scanning unit uses, for example, a polygon mirror.

[0003] The polygon mirror can scan the light pulse signal emitted from the light emitting unit in a predetermined direction. By scanning the light pulse signal with the polygon mirror, the scanning range can be expanded, making it possible to measure the distance to objects located in a wide range.

[0004] When an object is irradiated with a light pulse signal scanned by a polygon mirror, a reflected light pulse signal from the object is reflected by the polygon mirror and received by a light receiving section.

[0005] Japanese Patent Application Laid-Open No. 2021-47208

[0006] However, as the number of light-emitting elements constituting the light-emitting section increases, the light-receiving section becomes larger, which may cause warping, reduce manufacturing yields, and reduce reliability.

[0007] Therefore, the present disclosure provides a light emitting device and a distance measuring device that can suppress a decrease in reliability even when the number of light emitting elements that make up the light emitting section increases.

[0008] In order to solve the above problems, according to the present disclosure, there is provided a light emitting device that can be used for distance measurement to measure the return time of projected pattern light, the light emitting device comprising: a light emitting unit that is composed of a plurality of light emitting substrates and that periodically emits the projected pattern light; and an optical scanning unit that scans the projected pattern light within a predetermined angle range, wherein the spacing between the light emitting elements located at each end of the light emitting substrates overlaps along a first direction.

[0009] The first direction may be a direction orthogonal to a second direction in which the light scanning unit scans the projection pattern light.

[0010] The light-emitting element may have a rectangular light-emitting area.

[0011] One side of each of the light emitting elements may be oblique to the first direction.

[0012] One side of each of the light emitting substrates may be oblique to the first direction.

[0013] One side of each of the light emitting substrates may be oblique to the first direction, and one side of each of the light emitting elements may be parallel to the first direction.

[0014] The light-emitting element may have a circular light-emitting area.

[0015] The light emitting element may be a back-illuminated VCSEL (Vertical Cavity Surface Emitting Laser).

[0016] The light emitting element may be an element mounted using solder mounting.

[0017] The projection pattern light may further include a cylindrical lens that transmits the projection pattern light and projects the light onto the optical scanning unit.

[0018] In order to solve the above problems, according to the present disclosure, there is provided a distance measuring device comprising: a light emitting unit composed of a plurality of light emitting substrates and periodically emitting projection pattern light; a light scanning unit that scans the projection pattern light within a predetermined angle range; a light receiving unit having a plurality of measurement pixels arranged in a two-dimensional matrix and receiving return light reflected from an object illuminated with the projection pattern light in the light receiving areas of the plurality of measurement pixels; and a distance measuring unit that measures the distance to the object based on the emission timing of the projection pattern light and the reception timing of the return light, wherein the spacing between the light emitting elements located at each end of the light emitting substrates overlaps along a first direction.

[0019] The first direction may be a direction orthogonal to a second direction in which the light scanning unit scans the projection pattern light.

[0020] The overlapping range may correspond to a width of the measurement pixel of the light receiving range of the return light received in the light receiving region, or greater.

[0021] The image sensor may further include a selection unit that selects the measurement pixels to be used for the measurement in accordance with the scanning position of the optical scanning unit.

[0022] The selection unit may select the measurement pixels to be used for the measurement in accordance with the light receiving area of ​​the returned light that is determined according to the emission position of the projected pattern light.

[0023] The light-emitting element may have a rectangular light-emitting area.

[0024] One side of each of the light emitting elements may be oblique to the first direction.

[0025] One side of each of the light emitting substrates may be oblique to the first direction.

[0026] One side of each of the light emitting substrates may be oblique to the first direction, and one side of each of the light emitting elements may be parallel to the first direction.

[0027] The light-emitting element may have a circular light-emitting area.

[0028] 13 is a block diagram showing a schematic configuration of a distance measuring device according to the present embodiment. FIG. 14 is a perspective view showing an example of a specific configuration of a light emitting unit. FIG. 15 is a diagram showing a scanning range of a light scanning unit. FIG. 16 is a diagram showing a schematic configuration example inside the light emitting unit and a light receiving range of a light receiving unit. FIG. 17 is a diagram showing the relationship between the projected pattern light of a light emitting element and the focus of a light emitting optical system. FIG. 18 is a diagram showing the relationship between the projected pattern light of a light emitting element and an irradiation angle. FIG. 19 is a diagram showing a schematic view of a distant projection pattern light received via a light receiving optical system. FIG. 19 is a diagram showing a projection view of each light emitting element projected in a second direction. FIG. 19 is a diagram showing the projected pattern light of a light emitting element arranged in a first direction. FIG. 19 is a diagram showing a schematic light receiving range of a received light pattern light due to returned light on a light receiving surface. FIG. 19 is a diagram showing a schematic configuration example inside a light emitting unit and a light receiving range of a light receiving unit according to a first comparative example. FIG. 19 is a diagram showing a schematic configuration example inside a light emitting unit and a light receiving range of a light receiving unit according to a second comparative example. FIG. 19 is a diagram showing an example in which a light emitting element substrate is configured with multiple light emitting element substrates. FIG. 19 is a cross-sectional view showing a structural example of a light emitting element according to the present disclosure. FIG. 19 is a plan view of the bottom side of the light emitting element shown in FIG. 23 is a diagram showing an example of the configuration inside a light-emitting unit according to a first modified example of the first embodiment. FIG. 24 is a diagram showing an example of the configuration inside a light-emitting unit according to a second modified example of the first embodiment. FIG. 25 is a diagram showing an example of the configuration inside a light-emitting unit according to a third modified example of the first embodiment. FIG. 26 is a diagram showing an example of the configuration inside a light-emitting unit according to a third comparative example. FIG. 27 is a diagram showing an example of the configuration inside a light-emitting unit according to a fourth comparative example. A cross-sectional view showing an example of the structure of a light-emitting element according to the second embodiment. A plan view of the top surface of the light-emitting element shown in FIG. 22. FIG. 26 is a diagram showing an example in which the lens is configured with a cylindrical lens. FIG. 27 is a diagram showing an example in which measurement light passed through a cylindrical lens is projected onto a measurement range. FIG. 28 is a diagram showing an example of measurement light projected onto a measurement range. FIG. 28 is a diagram showing the relationship between a near shadow pattern and a distant shadow pattern light projected onto the measurement range. FIG. 29 is a diagram showing a projected image when light-emitting elements are simultaneously illuminated. A block diagram showing an example of the general configuration of a vehicle control system. An explanatory diagram showing an example of the installation positions of an outside vehicle information detection unit and an imaging unit.

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

[0030] (First embodiment) Fig. 1 is a block diagram showing the schematic configuration of a distance measuring device 1 according to this embodiment. The distance measuring device 1 in Fig. 1 includes a light emitting unit 2, a distance measuring unit 3, and an overall control unit 4. The distance measuring device 1 in Fig. 1 performs distance measurement processing using the dToF (direct time of flight) method. The distance measuring unit 3 includes a light receiving unit 5.

[0031] The light emitting unit 2 includes a plurality of light emitting elements 11 , a light scanning unit 12 , a driving circuit 13 , a clock generating unit 14 , and a light emission control unit 15 .

[0032] The plurality of light-emitting elements 11 are arranged in multiple rows along a predetermined direction (first direction Y). As will be described later, the arrangement of the plurality of light-emitting elements 11 and the arrangement of the mounting substrate on which the plurality of light-emitting elements 11 are arranged are one of the characteristic features of this embodiment. For convenience, in this specification, the first direction Y is defined as the vertical direction, and the second direction X is defined as the horizontal direction. Alternatively, the first direction Y may be defined as the horizontal direction, and the second direction X may be defined as the vertical direction. In other words, the plurality of light-emitting elements 11 may be arranged in the second direction X (horizontal direction). Alternatively, the plurality of light-emitting elements 11 may be arranged in the first direction Y and the second direction X.

[0033] The plurality of light-emitting elements 11 repeatedly emit light-emitting pulse signals (Tx pulse signals) at predetermined time intervals. That is, the plurality of light-emitting elements 11 that emit light simultaneously emit projection pattern light at predetermined time intervals. The light-emitting unit (light-emitting device) 2 can scan the projection pattern light, which is the optical signal emitted by the plurality of light-emitting elements 11, in the first direction X. Any specific method for scanning the optical signal is acceptable. Note that the light-emitting unit 2 according to this embodiment corresponds to an irradiation device.

[0034] The light-emitting elements 11 are, for example, VCSELs (Vertical Cavity Surface Emitting Lasers) or EELs (Edge Emitting Lasers), and the number of light-emitting elements 11 included in the light-emitting unit 2 is arbitrary. In the following, an example will be described in which the light-emitting unit 2 includes a plurality of light-emitting elements 11, and the plurality of light-emitting elements 11 are arranged in a plurality of rows in the first direction Y.

[0035] The plurality of light-emitting elements 11 emit light one by one in sequence with a time lag. Alternatively, among the plurality of light-emitting elements 11, each group of light-emitting elements 11 including two or more light-emitting elements 11 may emit light with a time lag. Alternatively, the plurality of light-emitting elements 11 may emit light at the same timing.

[0036] The drive circuit 13 drives the plurality of light-emitting elements 11 based on a control signal from the light-emission control unit 15. For example, the drive circuit 13 controls the emission timing of the light pulse signal based on the control signal from the light-emission control unit 15.

[0037] The clock generating unit 14 generates a clock signal synchronized with a reference clock signal. The reference clock signal is, for example, a signal input from outside the distance measuring device 1. Alternatively, the reference clock signal may be generated inside the distance measuring device 1.

[0038] The light-emission control unit 15 generates a control signal in synchronization with the clock signal to control the light-emission timing of each light-emitting element 11. The above-mentioned drive circuit 13 drives the plurality of light-emitting elements 11 based on the control signal output from the light-emission control unit 15.

[0039] The optical scanning unit 12 scans the optical pulse signal emitted from the light emitting unit 2 within a predetermined angular range. The optical scanning unit 12 has a mechanical scanning mechanism such as a polygon mirror or a MEMS mirror, and the scanning speed of the optical pulse signal fluctuates due to jitter. The specific configuration of the optical scanning unit 12 will be described later.

[0040] The overall control unit 4 controls the light emitting unit 2, the light scanning unit 12, and the distance measuring unit 3. The overall control unit 4 may be integrated into the distance measuring unit 3.

[0041] The distance measuring unit 3 has a light receiving unit 5 consisting of a pixel array unit 21, a distance measurement processing unit 22, a control unit 23, a clock generating unit 24, a light emission timing control unit 25, and a drive circuit 26. The pixel array unit 21 constitutes the light receiving unit 5.

[0042] The pixel array unit 21 has a plurality of ranging pixels 20 arranged in two dimensions. The ranging pixels 20 receive reflected light signals from the object 10. The ranging pixels 20 output electrical signals according to the light intensities of the received reflected light signals.

[0043] Each of the multiple ranging pixels 20 has a light receiving element 30. The light receiving element 30 is, for example, a SPAD (Single Photon Avalanche Photo Diode) 30. Each ranging pixel 20 may have a quench circuit (not shown). In an initial state, the quench circuit supplies a reverse bias voltage between the anode and cathode of the SPAD 30, with a potential difference exceeding the breakdown voltage. After the SPAD 30 detects a photon, the drive circuit 26 supplies a reverse bias voltage to the SPAD 30 via the corresponding quench circuit to prepare for detection of the next reflected light pulse signal (Rx pulse signal). Note that the drive circuit 26 according to this embodiment corresponds to a selector.

[0044] Furthermore, the drive circuit 26 selects the ranging pixels 20 to be used for measurement in accordance with the scanning position of the optical scanning unit 12. More specifically, the drive circuit 26 selects the ranging pixels 20 to be used for measurement in accordance with the light receiving area in the light receiving unit 5 of the returning light, which is determined in accordance with the emission position of the projection pattern light, which will be described later. This makes it possible to perform measurement in accordance with the measurement light, suppressing noise and preventing a decrease in measurement accuracy.

[0045] The ranging processing unit 22 includes a time-to-digital converter (TDC) 31, a histogram generating unit 32, a signal processing unit 33, and a ranging control unit .

[0046] The TDC 31 generates a time digital signal with a predetermined time resolution corresponding to the light reception time of the reflected light pulse signal received by the SPAD 30. The histogram generator 32 generates a histogram with a bin width corresponding to the time resolution of the TDC 31 based on the time digital signal generated by the TDC 31. The bin width is the width of each frequency unit that makes up the histogram. The higher the time resolution of the TDC 31, the narrower the bin width can be, and a histogram that more accurately reflects the time frequency of receiving the Rx pulse signal can be obtained.

[0047] The signal processing unit 33 calculates the distance to the object 10 by, for example, calculating the center of gravity position of the Rx pulse signal based on the histogram, and outputs the calculated distance via the output buffer 35. The control unit 23 controls the processing operations of each unit in the ranging unit 3. The ranging control unit 34 controls the TDC 31, histogram generation unit 32, and signal processing unit 33 in the ranging processing unit 22. The light emission timing control unit 25 controls the light emission control unit 15 in the light emitting unit 2 and also controls the drive circuit 26. The drive circuit 26 performs quench control, etc., to restore the cathode voltage to its original voltage when the plurality of reference pixels 18 and the plurality of ranging pixels 20 in the pixel array unit 21 detect light and the cathode voltage drops.

[0048] The clock generating unit 24 generates a clock signal used by the TDC 31 and the histogram generating unit 32. The clock generating unit 24 generates the clock signal using, for example, a PLL circuit (not shown).

[0049] 2 is a perspective view showing an example of a specific configuration of the light-emitting unit. This is a perspective view showing an example of a specific configuration of the light-emitting unit (light-emitting device) 2, and illustrates an example in which a polygon mirror 41 is used as the light scanning unit 12. As shown in FIG. 2, the polygon mirror 41 is rotatable around a rotation axis 42, which is driven to rotate by a motor 43. The motor 43 rotates the rotation axis 42 at a rotation speed based on a drive signal from a drive circuit (not shown). However, the rotation speed of the rotation axis 42 fluctuates irregularly due to jitter caused by the power supply voltage supplied to the motor 43, temperature conditions, and the like.

[0050] The outer peripheral surface of the polygon mirror 41 is a reflecting mirror surface 41 m, and the optical pulse signal from the light-emitting unit 2 irradiated onto this reflecting mirror surface 41 m propagates in a direction corresponding to the rotation angle of the reflecting mirror surface 41 m. In this way, the polygon mirror 41 continuously switches the propagation direction of the optical pulse signal from the light-emitting unit 2 at a period corresponding to the number of rotations of the polygon mirror 41, thereby scanning the optical pulse signal in a predetermined X direction (for example, the horizontal direction).

[0051] When the object 10 is irradiated with the light pulse signal scanned by the polygon mirror 41, a reflected light pulse signal having a light intensity according to the reflectance of the object 10 is emitted from the object 10. As shown in Fig. 2, this reflected light pulse signal is reflected by the polygon mirror 41 and the mirror member 44 and is incident on the light receiving unit 5. Note that a reflecting member that reflects the reflected light pulse signal from the object 10 may be provided separately from the polygon mirror 41.

[0052] 3 is a diagram schematically illustrating the scanning range 12r of the optical scanning unit 12. The scanning range 12r is a two-dimensional area extending in a first direction Y and a second direction X. The first direction Y is the direction in which the multiple light-emitting elements 11 are arranged, and the second direction X is the direction in which the optical scanning unit 12 scans. In FIG. 3, the scanning direction Sd along the second direction X is indicated by a dashed line.

[0053] The optical pulse signal emitted from the light-emitting unit 2 passes through the lens 36 and is incident on the polygon mirror 41, where the propagation direction is switched and the signal is irradiated onto the object 10. The lens 36 is, for example, an F-theta (FΘ) lens, and the reflected pulse signal from the object 10 irradiated with the optical pulse signal is reflected by the polygon mirror 41, then further reflected by the mirror member 44, and received by the light-receiving unit 5 via the lens 38.

[0054] In this manner, the light scanning unit 12 causes the light pulse signal from the light-emitting unit 2 to scan along the second direction X. In this specification, a scanning unit in the second direction X may be referred to as a line. The number of scans (number of lines) in the second direction X may be, for example, several tens to several thousands. The light-emitting unit 2 emits multiple light pulse signals during a period in which the light scanning unit 12 scans a unit line with the light pulse signal. In this embodiment, the unit line is, for example, four lines. That is, for every four lines scanned by the light scanning unit 12, multiple light pulse signals are emitted from the light scanning unit 12 as projected pattern light. Note that the unit line in this embodiment is, for example, four lines, but is not limited to this. For example, it may be two, three, six, eight, or more lines.

[0055] The first direction Y of the light receiving unit 5 shown in FIG. 3 has a number of pixels corresponding to the number of light emitting elements 11 in the light emitting unit 2. As described above, the light emitting elements 11 may emit light at the same time, or some of the light emitting elements 11 may emit light in sequence. For example, the projection light pattern of the light emitting element 11 is rectangular. That is, the light projection area of ​​the light emitting element 11 has a rectangular opening. Note that the shape of the light projection area is not limited to a rectangle. As will be described later, it may be circular, or may be a square, polygonal, elliptical, or other shape.

[0056] 4A and 4B are diagrams schematically illustrating an example of the configuration inside the light-emitting unit 2 and the light-receiving range of the light-receiving unit 5. Fig. 4A is a diagram illustrating an example of the configuration inside the light-emitting unit 2. Fig. 4B is a diagram illustrating a part of the light-receiving range of the light-receiving unit 5.

[0057] As shown in FIG. 4( a), the light-emitting unit 2 is composed of multiple light-emitting element substrates 11a, 11b, and 11c. While FIG. 4( a) illustrates three light-emitting element substrates 11a, 11b, and 11c for simplicity, the light-emitting unit 2 may actually be composed of several tens to several thousands of light-emitting element substrates. In this manner, the three light-emitting element substrates 11a, 11b, and 11c are dispersedly arranged. Each of the light-emitting element substrates 11a, 11b, and 11c may also be referred to as a chip. The light-emitting unit 2 may also be referred to as a device. For example, the lines L1 to L4 are parallel lines. The Y direction (first direction) is a direction perpendicular to the X direction (second direction) in which the light scanning unit 12 (see FIG. 3) scans the projection pattern light.

[0058] The light-emitting element substrate 11a is composed of light-emitting elements 11 arranged along two lines L1 and L2. Two light-emitting elements 11 are arranged along each of the lines L1 and L2. The distance in the Y direction (first direction) between the light-emitting elements 11 along the line L1 is configured to be equal to or less than the length in the Y direction of the light-emitting element 11 along the line L2. In other words, when the four light-emitting elements 11 on the light-emitting element substrate 11a are arranged in a line along the Y direction (first direction) with one side aligned, they are continuous with no gaps. Note that in this embodiment, for ease of explanation, the light-emitting area of ​​the light-emitting element 11 on the light-emitting surface of the light-emitting unit 2 will be described as the light-emitting element.

[0059] Like the light-emitting element substrate 11a, the light-emitting element substrate 11b is composed of light-emitting elements 11 arranged along two lines L1 and L2. Two light-emitting elements 11 are arranged along each of the lines L1 and L2. The distance in the Y direction (first direction) between the light-emitting elements 11 along the line L1 is configured to be equal to or less than the length in the Y direction of the light-emitting element 11 along the line L2. In other words, when the four light-emitting elements 11 of the light-emitting element substrate 11b are arranged in a line along the Y direction (first direction) with one side aligned, they are continuous with no gaps. Note that in this embodiment, for simplicity, the light-emitting element substrate 11b will be described as the light-emitting element, representing the light-emitting area of ​​the light-emitting element 11 on the light-emitting surface of the light-emitting unit 2. Note that misalignment in the X direction between the light-emitting element substrate 11a and the light-emitting element substrate 11b is permitted.

[0060] The light-emitting element substrate 11c is composed of light-emitting elements 11 arranged along two lines L3 and L4. Two light-emitting elements 11 are arranged along each of the lines L3 and L4. The distance in the Y direction (first direction) between the light-emitting elements 11 along the line L3 is configured to be equal to or less than the length in the Y direction of the light-emitting element 11 along the line L4. In other words, when the four light-emitting elements 11 on the light-emitting element substrate 11c are arranged in a line along the Y direction (first direction) with one side aligned, they are continuous with no gaps. Note that in this embodiment, for ease of explanation, the light-emitting area of ​​the light-emitting element 11 on the light-emitting surface of the light-emitting unit 2 will be described as the light-emitting element.

[0061] Furthermore, when the twelve light-emitting elements 11 on the light-emitting element substrates 11a, 11b, and 11c are aligned in a row with one edge aligned in the Y direction (first direction), they are continuous with no gaps. In this embodiment, the intersection of a first straight line in one direction (e.g., a line in the Y direction) and a first orthogonal line (e.g., a line in the X direction) perpendicular to this straight line may be referred to as a position coordinate. For example, as shown in FIG. 4B , the end of the first element 11ae on the light-emitting element substrate 11a and the end of the second element 11ce on the light-emitting element substrate 11c may be expressed as overlapping by a length We along the first direction (Y direction). In this case, an overlap is expressed when the first position coordinate of a first intersection of a first orthogonal line (a line in the X direction) passing through one end of the first element 11ae and the first line and the second position coordinate of a second intersection of the first orthogonal line passing through one end of the second element 11ce and the first line are located closer to the other end of the second element 11ce than the second position coordinate. That is, the difference between the first position coordinate and the second position coordinate is the overlap length We. Similarly, the light-emitting element 11be on the end side of the light-emitting element substrate 11b and the light-emitting element 11ce2 on the end side of the light-emitting element substrate 11c overlap by the length We. Furthermore, in this embodiment, when the light-emitting element 11be and the light-emitting element 11ce2 overlap along the first direction (Y direction), the light-emitting element 11be and the light-emitting element 11ce2 are said to be continuous along the first direction (Y direction).

[0062] Before explaining FIG. 4B, the relationship between the projected pattern light and the received light pattern light will be explained using FIGS. 5 to 7. FIG. 5 is a diagram showing the relationship between the projected pattern light by the light-emitting elements 11 arranged in the Y direction (first direction) on the lines L1 and L3 (L2 and L4) in FIG. 4 and the focal point f36 of the light-emitting optical system 36. As shown in FIG. 5, the projected pattern light on the lines L1 and L3 (L2 and L4) is emitted discretely. The projected pattern light may also be referred to as near-field projected pattern light NFP (Near Field Pattern). As described above, the projected pattern light according to this embodiment corresponds to the projection area of ​​the light-emitting element 11.

[0063] 6 is a diagram showing the relationship between the NFP width and the irradiation angle Δθ of the projection pattern light by the light-emitting elements 11 arranged in the Y direction (first direction) on lines L1 and L3 (L2 and L4). As shown in FIGS. 5 and 6, the projection pattern light by the light-emitting elements 11 on lines L1 and L3 (L2 and L4) is emitted discretely. As described above, the light-emitting optical system 36 is configured as, for example, an F-theta (FΘ) lens. Therefore, since the beam displacement is determined by the effective focal length (f) and the tangent of the deflection angle θ, if there is a gap in the projection pattern light, there will also be a gap in the irradiation light.

[0064] FIG. 7 is a diagram schematically illustrating a received light pattern received via a light receiving optical system. The near projection pattern light NFP shown in FIG. 5 is projected onto the object 10 as far field projection pattern light FFP (Far Field Pattern) and measured as returned light on the light receiving surface of the light receiving unit 5. The returned light corresponding to the near projection pattern light NFP received by the light receiving unit 5 at this time is referred to as received light pattern light, and the receiving range of this returned light is sometimes referred to as the received light pattern. Note that the returned light is weak light, received as photons, and converted into an electrical signal. The width of the received light pattern in the first direction is referred to as the FFP width.

[0065] 4(b), the light-receiving surface of the light-emitting unit 5 receives a received light pattern 20d corresponding to the projected light pattern by the light-emitting element 11 along light-receiving lines R1, R2, R3, and R4 corresponding to the lines L1, L2, L3, and L4 of the light-emitting unit 2. The ratio between the NFP width of the received light pattern 20d and the FFP width of the received light pattern 20d is determined by the optical systems 36 and 38.

[0066] Furthermore, the position of the projected pattern light corresponds to the position of the received light pattern light 20d. As a result, as described above, the drive circuit 26 selects the ranging pixel 20 to be used for measurement in accordance with the light receiving area, which is the position of the received light pattern light 20d in the light receiving unit 5 of the returned light, which is determined according to the emission position of the projected pattern light. This makes it possible to perform measurement according to the measurement light, suppressing noise and preventing a decrease in measurement accuracy.

[0067] 4A again, the light-emitting elements 11 on the light-emitting element substrate 11a's side of the light-emitting element substrate 11c and the light-emitting elements 11 on the light-emitting element substrate 11c's side of the light-emitting element substrate 11a have an overlap of length We along the Y direction (first direction). Thus, the distance We between the light-emitting elements 11 located at the ends of the light-emitting substrates 11a, 11b, and 11c overlaps along the first direction (Y direction). This length We is determined to be equal to or greater than the width of the ranging pixels 20 arranged on the light-receiving surface of the light-emitting unit 5. In other words, the overlapping range We corresponds to the width or greater of the measurement pixels 20 in the light-receiving range of the return light received on the light-receiving surface (light-receiving region) of the light-emitting unit 5. As a result, even if the light-emitting substrates 11a, 11b, and 11c are misaligned, the received light pattern light 20d remains continuous along the first direction (Y direction).

[0068] FIG. 8 is a diagram showing a projection IP obtained by projecting each of the light-emitting elements 11 on the light-emitting element substrates 11a, 11b, and 11c in the second direction X (scanning direction). FIG. 9 is a diagram showing the projection pattern light of the light-emitting elements 11 arranged in the Y direction (first direction) on the light-emitting element substrates (L1, L2, L3, and L4). As shown in FIGS. 8 and 9 , the projection IP obtained by projecting each of the light-emitting elements 11 on the light-emitting element substrates 11a, 11b, and 11c in the second direction X (scanning direction) is formed without gaps. That is, when the light-emitting elements 11 on the four lines L1, L2, L3, and L4 are illuminated, the projection pattern light along the first direction Y of the projection 12r in FIG. 3 is continuous. Furthermore, the length We (FIG. 4) can reflect manufacturing errors of the light-emitting element substrates 11a, 11b, and 11c. For example, by increasing the length We as the manufacturing error increases, the projection pattern light along the first direction Y of the projection 12r in FIG. 3 can be made continuous. As a result, when the received light pattern light 20d is aligned with one side on the light receiving surface and arranged in a row, the received light pattern light 20d is continuous without gaps in the Y direction (first direction).

[0069] Fig. 10 is a diagram schematically showing the light receiving range of the received light pattern light 20d due to the returned light on the light receiving surface of the light receiving unit 5. As shown in Fig. 10, when the projected image of the projected pattern light NFP near the light emitting element 11 is scanned in the second direction X (scanning direction) within the scanning range 12r of the light scanning unit 12 shown in Fig. 3, the light receiving range of the received light pattern light 20d due to the returned light is continuous in the Y direction (first direction) on the light receiving surface of the light receiving unit 5. This makes it possible to generate distance measurement values ​​continuously in the Y direction (first direction) using the light receiving unit 5.

[0070] (First Comparative Example) Fig. 11 is a diagram schematically illustrating an example of the configuration inside the light-emitting unit 2 and the light-receiving range of the light-receiving unit 5 according to a first comparative example. Fig. 11(a) is a diagram illustrating an example of the configuration inside the light-emitting unit 2 according to the first comparative example. Fig. 11(b) is a diagram illustrating the light-receiving range of the light-receiving unit 5 according to the first comparative example.

[0071] 11A, the light-emitting unit 2 is composed of one light-emitting element substrate 11d. The light-emitting element substrate 11d is composed of a plurality of light-emitting elements 11 arranged along a line L5. The spacing Ws between the light-emitting elements 11 along the line L5 in the Y direction (first direction) is approximately the width of the light-emitting element 11 in the Y direction (first direction).

[0072] Therefore, as shown in FIG. 11B , along line R1 corresponding to line L1, received light pattern light 20d corresponding to the projected pattern light NFP near the light-emitting element substrate 11d is received on the light-receiving surface of the light-receiving unit 5. Because the adjacent projected pattern light has a spacing Ws, this received light pattern light has a spacing corresponding to the width of the spacing Ws. Therefore, on the light-receiving surface of the light-receiving unit 5, the light-receiving range of the received light pattern light 20d due to the returned light is discontinuous in the Y direction (first direction), resulting in a so-called blind spot in the light-receiving range. Therefore, distance measurements using the light-receiving unit 5 are discontinuous in the Y direction (first direction). In contrast, in the light-emitting unit 2 according to this embodiment, as described above, when the light-emitting elements 11 on the light-emitting element substrates 11a, b, and c are aligned in a row in the Y direction (first direction), they are continuous without gaps, making it possible to make distance measurements using the light-receiving unit 5 continuous in the Y direction (first direction).

[0073] Furthermore, as the light-emitting element substrate 11d becomes longer in the Y direction (first direction), the yield during manufacturing decreases. Furthermore, as the light-emitting element substrate 11d becomes longer in the Y direction (first direction), so-called warping occurs, which may result in a decrease in measurement accuracy. In contrast, in the light-emitting unit 2 according to this embodiment, as described above, the length of each of the light-emitting element substrates 11a, b, and c in the Y direction (first direction) is set to the length of four light-emitting elements 11, thereby suppressing a decrease in yield. Furthermore, this suppresses so-called warping of the light-emitting element substrates 11a, b, and c, and suppresses a decrease in measurement accuracy.

[0074] (Second Comparative Example) Fig. 12 is a diagram schematically illustrating an example of the configuration inside the light-emitting unit 2 and the light-receiving range of the light-receiving unit 5 according to a second comparative example. Fig. 12(a) is a diagram illustrating an example of the configuration inside the light-emitting unit 2 according to the second comparative example. Fig. 12(b) is a diagram illustrating the light-receiving range of the light-receiving unit 5 according to the second comparative example.

[0075] 12(a), the light-emitting unit 2 is composed of one light-emitting element substrate 11e. The light-emitting element substrate 11e is composed of a plurality of light-emitting elements 11 arranged along two lines L6 and L7. The distance We in the Y direction (first direction) between the light-emitting elements 11 along line L6 and the light-emitting elements 11 along line L7 overlaps. As a result, when the light-emitting elements 11 on the light-emitting element substrate 11e are arranged in a line in the Y direction (first direction) with one side aligned, they are continuous with no gaps.

[0076] 12B, along lines R6 and R7 corresponding to lines L6 and L7, received light pattern light 20d corresponding to the projected pattern light near the light-emitting element substrate 11e is received on the light-receiving surface of the light-receiving unit 5. This received light pattern light overlaps the nearby projected pattern light NFP at an interval We. Therefore, when the received light pattern light 20d on lines L6 and L7 are aligned in a line in the Y direction (first direction) with their centers aligned, they are continuous without any gaps. This makes it possible to make distance measurement values ​​using the light-receiving unit 5 continuous in the Y direction (first direction).

[0077] However, as the light-emitting element substrate 11e becomes longer in the Y direction (first direction), the manufacturing yield decreases. Furthermore, as the light-emitting element substrate 11e becomes longer in the Y direction (first direction), so-called warping occurs, which may result in a decrease in measurement accuracy.

[0078] FIG. 13 is a diagram showing an example in which the light-emitting element substrate 11e is composed of multiple light-emitting element substrates 11ea and 11eb. As shown in FIG. 13, by configuring the light-emitting element substrate 11e with multiple light-emitting element substrates 11ea and 11eb in the Y direction (first direction), the manufacturing yield is improved. However, a gap w11 occurs between the light-emitting element substrate 11ea and the light-emitting element substrate 11eb, resulting in discontinuous projection pattern light in the Y direction (first direction). In contrast, as described above, in the light-emitting unit 2 according to this embodiment, when the light-emitting elements 11 on the light-emitting element substrates 11a, b, and c are aligned in a row in the Y direction (first direction), they are continuous without gaps, making it possible to make distance measurements using the light-receiving unit 5 continuous in the Y direction (first direction). Furthermore, as described above, in the light-emitting unit 2 according to this embodiment, the length of each of the light-emitting element substrates 11a, b, and c in the Y direction (first direction) is the length of four light-emitting elements 11, thereby suppressing a decrease in yield. This also suppresses so-called warping of the light-emitting element substrates 11a, 11b, and 11c, and suppresses a decrease in measurement accuracy.

[0079] Fig. 14 is a cross-sectional view showing an example structure of the light-emitting element 11 according to the present disclosure. Fig. 14 shows an AA view of Fig. 4. Fig. 15 is a plan view of the bottom side of the light-emitting element 11 shown in Fig. 13. The light-emitting element 11 according to the present disclosure is an example structure of a so-called back-emission type VCSEL (Vertical Cavity Surface Emitting Laser). By adopting back-emission, the pPad area (see Figs. 21 and 22 described below) is no longer necessary, and the chip size is reduced.

[0080] 14, the light-emitting element 11 includes, in this order, a laminate 200 including an active layer 240 on substrates 11a, 11b, and 11c, an insulating layer 341, wiring (p-side wiring 41 and n-side wiring 42), a passivation layer 51, a UBM (Under Bump Metal) layer 61, and solder bumps 71 and 72. The solder bumps 71(n) and 72(p) are provided for flip-chip mounting and electrical connection to an interposer or the like. The light-emitting element 11 emits laser light from the substrates 11a, 11b, and 11c in response to a signal from a drive circuit 13 (see FIG. 1) mounted on the interposer or the like.

[0081] The substrates 11a, 11b, and 11c are optically transparent substrates (transparent substrates), and are formed of, for example, a glass substrate, a resin substrate, or a sapphire substrate. The sapphire substrate 11 has excellent heat dissipation properties, and the laminate 200 is disposed on these substrates 11a, 11b, and 11c. The opposing surfaces of the laminate 200 have the same shape, for example, a rectangular shape including a square. A lens (collimating lens) is provided on the lower surface (rear surface) of the substrates 11a, 11b, and 11c at a position facing the active layer 240 (laminate 200), so that the light emitted from the active layer 240 is collimated and emitted.

[0082] The stack 200 includes, in this order from the substrates 11a, 11b, and 11c, an N-GaAs layer 210, an N-contact 215, an n-DBR layer 220 (first multilayer reflective film), an active layer 240, a p-DBR layer 250 (second multilayer reflective film), and a p-side interconnect 41. The n-side electrode paired with the p-side electrode may be one or more. The p-side electrode is electrically connected to the p-side interconnect 41, and the n-side electrode is electrically connected to the n-side interconnect 42.

[0083] The UBM layers 61 and 62 are composed of, for example, a gold (Au) layer and a nickel (Ni) layer. The solder bumps 71 and 72 are composed of, for example, an alloy of tin (Sn), silver (Ag), and copper (Cu) and are provided on the UBM layers 61 and 62. Because the solder bumps 71 and 72 are concentrated in the center of the UBM layers 61 and 62 during manufacturing, the light emitting element 11 can be positioned on the substrates 11a, 11b, and 11c with higher accuracy. In this way, solder mounting improves the mounting position accuracy of the light emitting element 11 due to the self-alignment effect of the solder.

[0084] (Variation 1 of First Embodiment) The distance measuring device 1 according to Variation 1 of the first embodiment differs from the distance measuring device 1 according to the first embodiment in that, in the configuration inside the light-emitting unit 2, the gaps between the light-emitting elements 11 in the light-emitting element substrates 11f, 11g, and 11h are filled with light by defocusing the projection optical system 11. The differences from the distance measuring device 1 according to Variation 1 of the first embodiment will be described below.

[0085] Fig. 16 is a diagram showing an example of the internal configuration of the light-emitting unit 2 according to Modification 1 of the first embodiment. As shown in Fig. 16, the light-emitting unit 2 is made up of a plurality of light-emitting element substrates 11f, 11g, and 11h. Note that Fig. 16 illustrates three light-emitting element substrates 11f, 11g, and 11h for ease of explanation, but in reality the light-emitting unit 2 may be made up of several hundred to several thousand light-emitting element substrates.

[0086] Furthermore, gaps Ws are generated between the light-emitting elements 11 of the multiple light-emitting element substrates 11f, 11g, and 11h. Therefore, the gaps Ws are filled with light by defocusing the projection optical system 36 (see FIG. 2). Therefore, when the light-emitting elements 11 of the light-emitting element substrates 11f, 11g, and 11h are turned on, the optical image in the first direction Y of the projection view 12r in FIG. 3 becomes continuous. This allows the distance measurement values ​​using the light-receiving unit 5 to be continuous in the Y direction (first direction).

[0087] (Variation 2 of First Embodiment) The distance measuring device 1 according to Variation 2 of the first embodiment differs from the distance measuring device 1 according to the first embodiment in that the light emitting element substrates 11i, 11j, and 11k are arranged at an angle in the configuration of the light emitting unit 2. The differences from the distance measuring device 1 according to Variation 1 of the first embodiment will be described below.

[0088] FIG. 17 is a diagram showing an example of the internal configuration of the light-emitting unit 2 according to the second modification of the first embodiment.

[0089] As shown in Fig. 17, the light-emitting section 2 is composed of a plurality of light-emitting element substrates 11f, 11g, and 11h arranged at an angle. For simplicity of explanation, Fig. 17 illustrates three light-emitting element substrates 11i, 11j, and 11k, but in reality, the light-emitting section 2 may be composed of several hundred to several thousand light-emitting element substrates.

[0090] Also shown is a projection view IP in which each light-emitting element 11 of the plurality of light-emitting element substrates 11i, 11j, and 11k is projected in the second direction X (scanning direction). The light-emitting element substrates 11i, 11j, and 11k each have a plurality of rectangular light-emitting elements 11 with long sides in the Y direction (first direction). The light-emitting elements 11 of the light-emitting element substrates 11i and 11j overlap in the Y direction (first direction) by a distance We. Similarly, the light-emitting elements of the light-emitting element substrates 11j and 11k overlap in the Y direction (first direction) by a distance We. The distance We can reflect manufacturing errors of the plurality of light-emitting element substrates 11i, 11j, and 11k. For example, by increasing the length We as the manufacturing error increases, it becomes possible to make the optical image continuous along the first direction Y of the projection view 12r in FIG. 3 .

[0091] In this way, when the light emitting elements 11 on the light emitting element substrates 11i, 11j, and 11k are made to emit light, the light images along the first direction Y in the projection view 12r in Figure 3 are continuous. This makes it possible to make the distance measurement values ​​using the light receiving unit 5 continuous in the Y direction (first direction). (Variant 3 of the First Embodiment) The distance measuring device 1 according to Variation 2 of the first embodiment differs from the distance measuring device 1 according to the first embodiment in that the light emitting element substrates 11l, 11m, and 11n and each light emitting element 11 are arranged at an angle in the configuration within the light emitting unit 2. The differences from the distance measuring device 1 according to Variation 1 of the first embodiment will be described below.

[0092] Fig. 18 is a diagram showing an example of the configuration inside the light-emitting unit 2 according to Modification 2 of the first embodiment. As shown in Fig. 18, the light-emitting unit 2 is composed of a plurality of light-emitting element substrates 11f, 11g, and 11h arranged at an angle. For simplicity of explanation, Fig. 18 illustrates three light-emitting element substrates 11f, 11g, and 11h, but in reality, the light-emitting unit 2 is composed of several hundred to several thousand light-emitting element substrates.

[0093] Also shown is a projection IP of each of the light-emitting element substrates 11f, 11g, and 11h projected in the second direction X (scanning direction). Although there are gaps between the light-emitting element substrates 11f, 11g, and 11h, the projection IP is continuous due to the oblique arrangement of the light-emitting element substrates 11f, 11g, and 11h. For example, if the gaps become large due to a large manufacturing error, the gaps can be filled with light by defocusing the projection optical system 36 (see FIG. 2).

[0094] In this way, when the light emitting elements 11 on the light emitting element substrates 11f, 11g, and 11h are made to emit light, the light images along the first direction Y in the projection view 12r in Fig. 3 are continuous, which makes it possible to make the distance measurement values ​​using the light receiving unit 5 continuous in the Y direction (first direction).

[0095] Second Embodiment A distance measuring device 1 according to the second embodiment differs from the distance measuring device 1 according to the first embodiment in that the light emitting element 11 in the light emitting unit 2 is a surface-emitting VCSEL. The differences from the distance measuring device 1 according to the first embodiment will be described below.

[0096] 19A and 19B are diagrams schematically illustrating an example of the configuration inside the light-emitting unit 2 according to the second embodiment and the light-receiving range of the light-receiving unit 5. Fig. 19A is a diagram illustrating an example of the configuration inside the light-emitting unit 2. Fig. 19B is a diagram illustrating the light-receiving range of the light-receiving unit 5.

[0097] 19(a), the light-emitting section 2 is composed of a plurality of light-emitting element substrates 11o, 11p, and 11q. For simplicity of explanation, Fig. 19(a) illustrates three light-emitting element substrates 1o, 11p, and 11q, but in reality, the light-emitting section 2 may be composed of several hundred to several thousand light-emitting element substrates.

[0098] The light emitting element substrate 11o is composed of light emitting elements 11 arranged along two lines L8 and L9. Five light emitting elements 11 are arranged along each of the lines L8 and L9. The distance in the Y direction (first direction) between the light emitting elements 11 along the line L8 is configured to be equal to or less than the length in the Y direction of the light emitting elements 11 along the line L9. In other words, when the ten light emitting elements 11 on the light emitting element substrate 11o are arranged in a line in the Y direction (first direction) with their centers aligned, they are continuous with no gaps.

[0099] The light emitting element substrate 11p is composed of light emitting elements 11 arranged along two lines L8 and L9. Five light emitting elements 11 are arranged along each of the lines L8 and L9. The distance in the Y direction (first direction) between the light emitting elements 11 along the line L8 is configured to be equal to or less than the length in the Y direction of the light emitting elements 11 along the line L9. In other words, when the ten light emitting elements 11 of the light emitting element substrate 11p are arranged in a line in the Y direction (first direction) with their centers aligned, they are continuous with no gaps. Misalignment in the X direction between the light emitting element substrate 11o and the light emitting element substrate 11p is permitted.

[0100] The light emitting element substrate 11q is composed of light emitting elements 11 arranged along two lines L10 and L11. Five light emitting elements 11 are arranged along each of the lines L10 and L11. The distance in the Y direction (first direction) between the light emitting elements 11 along the line L10 is configured to be equal to or less than the length in the Y direction of the light emitting elements 11 along the line L11. In other words, when the ten light emitting elements 11 on the light emitting element substrate 11q are arranged in a line in the Y direction (first direction) with their centers aligned, they are continuous with no gaps.

[0101] 19( b), the light receiving surface of the light-emitting unit 5 receives received light pattern light 20d corresponding to the projected pattern light of the light-emitting element 11 along light receiving lines R8, R9, R10, and R11 corresponding to the lines L8, L9, L10, and L11 of the light-emitting unit 2. Furthermore, when the received light pattern light 20d along the lines L8, L9, L10, and L11 are aligned in a line in the Y direction (first direction) with the centers of the received light pattern light 20d aligned, they are continuous without any gaps. In other words, the received light pattern light 20d along the lines L8, L9, L10, and L11 are continuous along the Y direction (first direction). 3, when the projected image of the projected pattern light NFP near the light-emitting element 11 is scanned in the second direction X (scanning direction) in the scanning range 12r of the optical scanning unit 12, the light-receiving range of the received light pattern light 20d due to the returned light is continuous along the Y direction (first direction) on the light-receiving surface of the light-receiving unit 5. This makes it possible to generate distance measurement values ​​continuously in the Y direction (first direction) using the light-receiving unit 5.

[0102] (Third Comparative Example) Fig. 20 is a diagram schematically illustrating an example of the configuration inside the light-emitting section 2 according to a third comparative example. As shown in Fig. 20, the light-emitting section 2 is composed of a plurality of light-emitting element substrates 110a, b. The length of the light-emitting element substrates 110a, b is, for example, 400 micrometers (um). The light-emitting element substrates 110a, b have a light-emitting element 110. This light-emitting element 110 is an EEL (Edge Emitting Laser). The length of the light-emitting element 110 is, for example, 200 micrometers (um). The gap between the light-emitting element substrates 110a, b is, for example, 100 micrometers (um).

[0103] As a result, distance measurements using the light-receiving unit 5 are discontinuous in the Y direction (first direction). In contrast, as described above, in the light-emitting unit 2 according to this embodiment, when the light-emitting element substrates 11a, b, and c or the light-emitting element substrates 11o, p, and q are aligned in a row with one side aligned in the Y direction (first direction), the light-emitting elements 11 are continuous without any gaps, making it possible to make distance measurements using the light-receiving unit 5 continuous in the Y direction (first direction). (Fourth Comparative Example) FIG. 21 is a schematic diagram showing an example of the internal configuration of the light-emitting unit 2 according to the fourth comparative example. As shown in FIG. 21 , the light-emitting unit 2 is composed of a light-emitting element substrate 110c. The light-emitting element substrate 110c has a plurality of light-emitting elements 110. The light-emitting elements 110 are EELs. The length of the light-emitting elements 110 is, for example, 200 micrometers (um). The gap between the light-emitting elements 110 is, for example, 100 micrometers (um).

[0104] For this reason, distance measurement values ​​using the light-receiving unit 5 become discontinuous in the Y direction (first direction). In contrast, in the light-emitting unit 2 according to this embodiment, as described above, when the light-emitting element substrates 11 a, b, and c or the light-emitting element substrates 11 o, p, and q are aligned in a row in the Y direction (first direction) with one side aligned, the light-emitting elements 11 become continuous without any gaps, and therefore, distance measurement values ​​using the light-receiving unit 5 can be made continuous in the Y direction (first direction).

[0105] Fig. 22 is a cross-sectional view showing a structural example of the light-emitting element 11 according to the present disclosure. Fig. 22 is a cross-section taken along line BB of Fig. 19. Fig. 23 is a plan view of the upper surface side of the light-emitting element 11 shown in Fig. 22. The light-emitting element 11 according to the present disclosure is a structural example of a so-called surface-emitting VCSEL (Vertical Cavity Surface Emitting Laser).

[0106] 22, the light-emitting element 11 has, under the substrates 11o, p, and q, a p-side electrode 41a, a p-pad 41b, a stacked body 200a including an active layer 240a, an n-side electrode 42a, and a silver paste layer 270a, in this order. The light-emitting element 11 receives a signal from a drive circuit 13 (see FIG. 1) mounted on an interposer or the like and emits laser light from the substrates 11o, p, and q sides.

[0107] The substrates 11o, 11p, and 11q are light-transmitting substrates (transparent substrates) and are formed of, for example, a glass substrate, a resin substrate, or a sapphire substrate. The opposing surfaces of the laminate 200 have the same shape, for example, a shape that includes a circle.

[0108] The stack 200a includes, in order from the substrates 11o, p, and q, a pDBR layer 250a (second multilayer reflective film), an active layer 240a, an nDBR layer 220a (first multilayer reflective film), and an n-substrate 260a.

[0109] Third Embodiment The distance measuring device 1 according to the third embodiment differs from the distance measuring device 1 according to the first embodiment in that the lenses of the projection optical system are configured as cylindrical lenses 36a. The differences from the distance measuring device 1 according to the first embodiment will be described below.

[0110] FIG. 24 is a diagram showing an example in which the lens 36a is configured as a cylindrical lens. FIG. 25 is a diagram showing an example in which the measurement light passing through the cylindrical lens 36a is projected onto the measurement range 12r (see FIG. 3). FIG. 26 is a diagram showing an example of the measurement light projected onto the measurement range 12r (see FIG. 3). FIG. 26(a) shows an example in which the cylindrical lens 36a is not used, and FIG. 26(b) shows an example in which the cylindrical lens 36a is used. In the example in which the cylindrical lens 36a is not used, the spread of the measurement light in the X direction (second direction) is 0.66°, whereas in the example in which the cylindrical lens is used, the spread of the measurement light in the X direction (second direction) is 0.21°. In this way, by using the cylindrical lens 36a, the spread of the measurement light in the X direction (second direction) is suppressed.

[0111] FIG. 27 is a diagram showing the relationship between the near pattern and the distant pattern light projected onto the measurement range 12r (see FIG. 3). FIG. 27(a) is a diagram showing the light-emitting elements 11 arranged in four lines L1 to L4 (see FIG. 4). For example, the distance between the left end of the light-emitting element 11 in line L1 in the X direction (second direction) and the right end of the light-emitting element 11 in line L4 in the X direction (second direction) is, for example, 0.75 millimeters (mm). When a cylindrical lens 36 is used, this corresponds to 0.5°. The width of the light-emitting element 11 is, for example, 0.15 millimeters (mm). When a cylindrical lens 36 is used, this corresponds to 0.1°.

[0112] 27(b) is a schematic diagram showing the far-field pattern light FFP obtained by projecting the near-field pattern 11 shown in FIG. 27(a) onto the measurement range 12r (see FIG. 3). Four lines L1f to L4f correspond to the four lines L1 to L4. For example, when the light-emitting elements 11 arranged on the four lines L1 to L4 (see FIG. 4) are simultaneously illuminated, the far-field pattern light FFP has a spread corresponding to 0.5° within the measurement range 12r (see FIG. 3).

[0113] 4A, the spread corresponding to 0.5° corresponds to the spread of the four lines R1 to R4 at the light receiving section 5. In this way, the distance between the line L1 and the line L4 corresponds to the spread of the projection angle.

[0114] In the light receiving unit 5, for example, signals from the ranging pixels 20 are read out row by row in the X direction (second direction). Therefore, for example, the readout timing of the ranging pixels 20 in line R1 and the readout timing of the ranging pixels 20 in line R4 increase as the projection light spreads in the X direction (second direction). As described above, with projection via the cylindrical lens 36, the spread in the X direction (second direction) can be reduced to one-third, and therefore the difference in readout timing can also be reduced to one-third.

[0115] FIG. 28 is a diagram schematically illustrating projected images Ip1 and Ip2 when the light-emitting elements 11 arranged on four lines L1 to L4 (see FIG. 4) are simultaneously illuminated. Projected image Ip1 is projected through a cylindrical lens 36, while projected image Ip2 is projected without the cylindrical lens 36. The length of projected images Ip1 and Ip2 in the Y direction (first direction) is Wh, and their lengths in the X direction (second direction) are Whd1 and Wd2, respectively. As can be seen from this, the aspect ratio of projected image Ip1 is the value obtained by dividing Whd1 by Wh, and the aspect ratio of projected image Ip2 is the value obtained by dividing Whd3 by Wh. In this way, the aspect ratio of projected image Ip1 can be set, for example, three times the aspect ratio of projected image Ip2. For example, by using a cylindrical lens 36, it is possible to match the aspect ratio of the light-receiving unit 5.

[0116] <Application to a Mobile Body> The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of mobile body, such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, personal mobility, an airplane, a drone, a ship, or a robot.

[0117] FIG. 29 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a mobile object control system to which the technology according to the present disclosure can be applied.

[0118] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 29, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an outside-vehicle information detection unit 12030, an inside-vehicle information detection unit 12040, and an integrated control unit 12050. Also shown as functional components of the integrated control unit 12050 are a microcomputer 12051, an audio / video output unit 12052, and an in-vehicle network I / F (Interface) 12053.

[0119] The drivetrain control unit 12010 controls the operation of devices related to the drivetrain of the vehicle in accordance with various programs. For example, the drivetrain control unit 12010 functions as a control device for a drive force generating device for generating a drive force of the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating a braking force of the vehicle.

[0120] The body system control unit 12020 controls the operation of various devices equipped in the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as headlamps, backup lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves transmitted from a portable device that serves as a key or signals from various switches can be input to the body system control unit 12020. The body system control unit 12020 receives these radio waves or signals and controls the vehicle's door lock device, power window device, lamps, etc.

[0121] The outside-vehicle information detection unit 12030 detects information outside the vehicle equipped with the vehicle control system 12000. For example, an imaging unit 12031 is connected to the outside-vehicle information detection unit 12030. The outside-vehicle information detection unit 12030 causes the imaging unit 12031 to capture images outside the vehicle and receives the captured images. The outside-vehicle information detection unit 12030 may perform object detection processing or distance detection processing for people, cars, obstacles, signs, characters on the road surface, etc. based on the received images.

[0122] The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal corresponding to the amount of light received. The imaging unit 12031 can output the electrical signal as an image or as distance measurement information. The light received by the imaging unit 12031 may be visible light or invisible light such as infrared light.

[0123] The in-vehicle information detection unit 12040 detects information inside the vehicle. For example, a driver state detection unit 12041 that detects the state of the driver is connected to the in-vehicle information detection unit 12040. The driver state detection unit 12041 includes, for example, a camera that captures an image of the driver, and the in-vehicle information detection unit 12040 may calculate the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 12041, or may determine whether the driver is dozing off.

[0124] The microcomputer 12051 can calculate control target values ​​for the driving force generating device, steering mechanism, or braking device based on the information inside and outside the vehicle acquired by the outside-vehicle information detection unit 12030 or the inside-vehicle information detection unit 12040, and output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the inter-vehicle distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane departure warning, etc.

[0125] In addition, the microcomputer 12051 can perform cooperative control for the purpose of autonomous driving, which allows the vehicle to travel autonomously without relying on driver operation, by controlling the driving force generating device, steering mechanism, braking device, etc. based on information about the surroundings of the vehicle obtained by the outside vehicle information detection unit 12030 or the inside vehicle information detection unit 12040.

[0126] Furthermore, the microcomputer 12051 can output a control command to the body system control unit 12020 based on the information outside the vehicle acquired by the outside information detection unit 12030. For example, the microcomputer 12051 can control the headlamps according to the position of a preceding vehicle or an oncoming vehicle detected by the outside information detection unit 12030, and perform cooperative control aimed at preventing glare, such as switching from high beams to low beams.

[0127] The audio / video output unit 12052 transmits at least one of audio and video output signals to an output device capable of visually or audibly notifying information to vehicle occupants or the outside of the vehicle. In the example of Fig. 29, the output devices are exemplified by an audio speaker 12061, a display unit 12062, and an instrument panel 12063. The display unit 12062 may include, for example, at least one of an on-board display and a head-up display.

[0128] FIG. 30 is a diagram showing an example of the installation position of the imaging unit 12031.

[0129] In FIG. 30, the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.

[0130] The imaging units 12101, 12102, 12103, 12104, and 12105 are provided, for example, at positions such as the front nose, side mirrors, rear bumper, back door, and the top of the windshield inside the vehicle cabin of the vehicle 12100. The imaging unit 12101 provided on the front nose and the imaging unit 12105 provided on the top of the windshield inside the vehicle cabin mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 provided on the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 provided on the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The imaging unit 12105 provided on the top of the windshield inside the vehicle cabin is mainly used to detect preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, etc.

[0131] 30 shows an example of the imaging ranges of the imaging units 12101 to 12104. Imaging range 12111 indicates the imaging range of the imaging unit 12101 provided on the front nose, imaging ranges 12112 and 12113 indicate the imaging ranges of the imaging units 12102 and 12103 provided on the side mirrors, respectively, and imaging range 12114 indicates the imaging range of the imaging unit 12104 provided on the rear bumper or back door. For example, by overlaying the image data captured by the imaging units 12101 to 12104, an overhead image of the vehicle 12100 viewed from above can be obtained.

[0132] At least one of the image capturing units 12101 to 12104 may have a function of acquiring distance information. For example, at least one of the image capturing units 12101 to 12104 may be a stereo camera made up of multiple image capturing elements, or may be an image capturing element having pixels for phase difference detection.

[0133] For example, based on the distance information obtained from the imaging units 12101 to 12104, the microcomputer 12051 can calculate the distance to each three-dimensional object within the imaging ranges 12111 to 12114 and the change in this distance over time (relative speed with respect to the vehicle 12100), thereby extracting as a preceding vehicle, in particular, the three-dimensional object that is the closest three-dimensional object on the path of the vehicle 12100 and traveling in approximately the same direction as the vehicle 12100 at a predetermined speed (e.g., 0 km / h or higher). Furthermore, the microcomputer 12051 can set a vehicle-to-vehicle distance to be maintained in advance in front of the preceding vehicle, and perform automatic braking control (including follow-up stop control), automatic acceleration control (including follow-up start control), etc. In this way, cooperative control can be performed for the purpose of autonomous driving, which runs autonomously without relying on driver operation.

[0134] For example, the microcomputer 12051 classifies and extracts three-dimensional object data regarding three-dimensional objects into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects based on distance information obtained from the imaging units 12101 to 12104, and can use the data for automatic obstacle avoidance. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. The microcomputer 12051 then determines a collision risk that indicates the risk of collision with each obstacle, and when the collision risk is equal to or greater than a set value and a collision is possible, the microcomputer 12051 can provide driving assistance for collision avoidance by outputting an alarm to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or avoidance steering via the drive system control unit 12010.

[0135] At least one of the image capturing units 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 can recognize a pedestrian by determining whether or not a pedestrian is present in the images captured by the image capturing units 12101 to 12104. Such pedestrian recognition is performed, for example, by extracting feature points from the images captured by the image capturing units 12101 to 12104 as infrared cameras and performing pattern matching processing on a series of feature points that indicate the outline of an object to determine whether or not the object is a pedestrian. When the microcomputer 12051 determines that a pedestrian is present in the images captured by the image capturing units 12101 to 12104 and recognizes the pedestrian, the audio / image output unit 12052 controls the display unit 12062 to superimpose a rectangular outline on the recognized pedestrian for emphasis. The audio / image output unit 12052 may also control the display unit 12062 to display an icon or the like indicating the pedestrian at a desired position.

[0136] The above describes an example of a vehicle control system to which the technology according to the present disclosure can be applied. The technology according to the present disclosure can be applied to the imaging unit 12031 of the above-described configuration. Since a captured image that is easier to see can be obtained, it is possible to reduce driver fatigue.

[0137] The present technology can be configured as follows:

[0138] (1) A light-emitting device that can be used for distance measurement by measuring the return time of projected pattern light, comprising: a light-emitting unit that is composed of a plurality of light-emitting substrates and that periodically emits the projected pattern light; and a light scanning unit that scans the projected pattern light within a predetermined angle range, wherein the spacing between the light-emitting elements located at each end of the light-emitting substrates overlaps along a first direction.

[0139] (2) The light emitting device according to (1), wherein the first direction is a direction perpendicular to a second direction in which the light scanning unit scans the projection pattern light.

[0140] (3) The light emitting device according to (1) or (2), wherein the light projecting area of ​​the light emitting element is rectangular.

[0141] (4) The light emitting device according to (3), wherein one side of each of the light emitting elements is oblique to the first direction.

[0142] (5) The light emitting device according to (1), wherein one side of each of the light emitting substrates is oblique to the first direction.

[0143] (6) The light emitting device according to (3), wherein one side of each of the light emitting substrates is oblique to the first direction, and one side of each of the light emitting elements is parallel to the first direction.

[0144] (7) The light emitting device according to (1), wherein the light emitting element has a circular light projection area.

[0145] (8) The light emitting device according to any one of (1) to (7), wherein the light emitting element is a back-illuminated VCSEL (Vertical Cavity Surface Emitting Laser).

[0146] (9) The light emitting device according to (8), wherein the light emitting element is an element mounted using solder mounting.

[0147] (10) The light emitting device according to any one of (1) to (9), further comprising a cylindrical lens that transmits the projection pattern light and projects the projection pattern light onto the optical scanning unit.

[0148] (11) A distance measuring device comprising: a light emitting unit composed of a plurality of light emitting substrates and emitting projection pattern light periodically; a light scanning unit that scans the projection pattern light within a predetermined angle range; a light receiving unit having a plurality of measurement pixels arranged in a two-dimensional matrix and receiving return light reflected from an object illuminated with the projection pattern light in the light receiving areas of the plurality of measurement pixels; and a distance measuring unit that measures the distance to the object based on the emission timing of the projection pattern light and the reception timing of the return light, wherein the spacing between the light emitting elements located at each end of the light emitting substrates overlaps along a first direction.

[0149] (12) The distance measuring device according to (11), wherein the first direction is a direction orthogonal to a second direction in which the light scanning unit scans the projection pattern light.

[0150] (13) The distance measuring device according to (11) or (12), wherein the overlapping range corresponds to a width of the measurement pixel of the light receiving range of the return light received in the light receiving region or more.

[0151] (14) The distance measuring device according to (13), further comprising a selection unit that selects the measurement pixels to be used for the measurement in accordance with the scanning position of the optical scanning unit.

[0152] (15) The distance measuring device according to (14), wherein the selection unit selects the measurement pixel to be used for the measurement in accordance with the light receiving area of ​​the return light that is determined according to the emission position of the projected pattern light.

[0153] (16) The distance measuring device according to any one of (11) to (15), wherein the light-emitting element has a rectangular light-projection area.

[0154] (17) The distance measuring device according to (16), wherein one side of each of the light-emitting elements is oblique to the first direction.

[0155] (18) The distance measuring device according to (11), wherein one side of each of the light emitting substrates is oblique to the first direction.

[0156] (19) The distance measuring device according to (16), wherein one side of each of the light emitting substrates is oblique to the first direction, and one side of each of the light emitting elements is parallel to the first direction.

[0157] (20) The distance measuring device according to (11), wherein the light-emitting element has a circular light-projection area.

[0158] The aspects of the present disclosure are not limited to the individual embodiments described above, but include various modifications that may be conceived by those skilled in the art, and the effects of the present disclosure are not limited to the above-described contents. In other words, various additions, modifications, and partial deletions are possible within the scope of the conceptual idea and spirit of the present disclosure, which is derived from the contents defined in the claims and their equivalents.

[0159] 1: Distance measuring device, 2: Light emitting unit (light emitting device), 3: Distance measuring unit, 4: Overall control unit, 5: Light receiving unit, 10: Object, 11: Light emitting element, 12: Light scanning unit, 12r: Light receiving range, 13: Drive circuit, 15: Light emission control unit, 20: Distance measuring pixel, 21: Pixel array unit, 22: Distance measuring processing unit, 23: Control unit, 26: Drive circuit, 36: Lens, 37: Lens, 41: Polygon mirror.

Claims

1. A light emitting device that can be used for distance measurement by measuring the return time of projected pattern light, comprising: a light emitting unit that is composed of multiple light emitting substrates and periodically emits the projected pattern light; and a light scanning unit that scans the projected pattern light within a predetermined angle range, wherein the spacing between the light emitting elements located at each end of the light emitting substrates overlaps along a first direction.

2. The light emitting device according to claim 1, wherein the first direction is a direction perpendicular to a second direction in which the light scanning unit scans the projection pattern light.

3. The light emitting device according to claim 2, wherein the light emitting element has a rectangular light projection area.

4. The light emitting device according to claim 3, wherein one side of each of the light emitting elements is oblique to the first direction.

5. The light emitting device according to claim 1, wherein one side of each of the light emitting substrates is oblique to the first direction.

6. The light emitting device according to claim 3, wherein one side of each of said light emitting substrates is oblique to said first direction, and one side of each of said light emitting elements is parallel to said first direction.

7. The light emitting device according to claim 1, wherein the light emitting element has a circular light projection area.

8. The light emitting device according to claim 1, wherein the light emitting element is a back-illuminated VCSEL (Vertical Cavity Surface Emitting Laser).

9. The light emitting device according to claim 8, wherein the light emitting element is an element mounted using solder mounting.

10. The light emitting device according to claim 1, further comprising a cylindrical lens that transmits the projection pattern light and projects it onto the optical scanning unit.

11. A distance measuring device comprising: a light emitting unit composed of a plurality of light emitting substrates that periodically emits projection pattern light; a light scanning unit that scans the projection pattern light within a predetermined angle range; a light receiving unit that has a plurality of measurement pixels arranged in a two-dimensional matrix and receives return light reflected from an object illuminated with the projection pattern light in the light receiving areas of the plurality of measurement pixels; and a distance measuring unit that measures the distance to the object based on the emission timing of the projection pattern light and the reception timing of the return light, wherein the spacing between the light emitting elements located at each end of the light emitting substrates overlaps along a first direction.

12. A distance measuring device according to claim 11, wherein the first direction is a direction perpendicular to a second direction in which the optical scanning unit scans the projection pattern light.

13. The distance measuring device according to claim 12, wherein the overlapping range corresponds to a width equal to or greater than the width of the measurement pixel in the light receiving range of the return light received in the light receiving region.

14. The distance measuring device according to claim 13, further comprising a selection section that selects the measurement pixels to be used for the measurement in accordance with the scanning position of the optical scanning section.

15. A distance measuring device according to claim 14, wherein the selection unit selects the measurement pixels to be used for the measurement in accordance with the light receiving area of ​​the return light, which is determined according to the emission position of the projected pattern light.

16. The distance measuring device according to claim 11, wherein the light-emitting element has a rectangular light-emitting area.

17. The distance measuring device according to claim 16, wherein one side of each of said light emitting elements is oblique to said first direction.

18. The distance measuring device according to claim 11, wherein one side of each of the light emitting substrates is oblique to the first direction.

19. A distance measuring device according to claim 16, wherein one side of each of the light emitting substrates is oblique to the first direction, and one side of each of the light emitting elements is parallel to the first direction.

20. The distance measuring device according to claim 11, wherein the light-emitting element has a circular light-emitting area.

Images