Measuring device

Abstract

To provide a measurement device which can flexibly respond to a specification that a system as an application target demands.SOLUTION: The measurement device includes a light projection unit and a light reception unit for receiving reflected light caused in a manner that the light projection unit projects light to a measurement target. The light reception unit includes a light reception part and a transmissive optical element. The optical element includes: a first incident surface which first reflected light enters from a first range of vision; a second incident surface continuous with the first incident surface, which second reflected light enters from a second range of vision continuous with the first range of vision; and an emission surface for emitting the first reflected light and the second reflected light in the direction of the light reception part. The first incident surface, the second incident surface, and the emission surface are flat surfaces. The second incident surface is inclined relative to the first incident surface with the boundary line with the first incident surface as a crease.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a measuring device, and more particularly to a technique for expanding the visual field range of a measuring device. Place Specifically, it relates to a technique for expanding the visual field range of a measuring device.

Background Art

[0002] With the development of AD (Autonomous Driving) and ADAS (Advanced Driver Assistance System), as one of the measuring devices used for grasping the surrounding environment and estimating the self-position when a vehicle is running, the development / research of LiDAR (Light Detection and Ranging) is in progress. LiDAR includes a projector that projects (irradiates) laser light onto a measurement target, and a light receiver that receives the reflected light that returns after the laser light is reflected by the measurement target, and measures the distance to the measurement target based on the difference between the timing when the projector emits the laser light and the timing when the light receiver receives the reflected light, thereby providing information about the measurement target.

[0003] Patent Document 1 describes a LiDAR system configured for mounting on a vehicle. The LiDAR system includes a plurality of light emitters (such as VCSEL (Vertical Cavity Surface Emitting Laser) devices) that generate a plurality of optical beams. The LiDAR system converges the plurality of optical beams into a converged optical beam having a beam waist by a first lens, and projects the converged optical beam onto a target range by a second lens.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] One type of LiDAR is Flash LiDAR, which employs a method where a light source diffuses and illuminates a field of view with laser light. Because Flash LiDAR does not include mechanical components such as motors or MEMS (Micro Electro Mechanical Systems), it is attracting attention as a promising candidate for LiDAR in fields where durability is required, such as for automotive applications.

[0006] The field of view (FOV: field of view, beam profile, light distribution size) of the light receiver and light emitter of a flash LiDAR is determined by the size (area) of the light receiver and light emitter and the focal length of the optical system (light receiving optical system, light emitting optical system). Therefore, when applying flash LiDAR to individual systems such as vehicle range measuring sensors, it is necessary to configure the field of view so that it meets the specifications required by the system to which it is applied.

[0007] One way to extend the field of view of LiDAR when it is installed in a vehicle is to mount multiple LiDARs side by side. However, this would increase the number of components and the cost, which would be a challenge.

[0008] This invention was made in view of the above background and is capable of flexibly responding to the specifications required by the system to which it is applied. measuring device The purpose is to provide. [Means for solving the problem]

[0009] One aspect of the present invention for achieving the above objective is a measuring device comprising a light emitter and a light receiver that receives reflected light generated when the light emitter emits light toward a field of view, wherein the light receiver includes a light receiving section and a transmissive optical element, the optical element having a first incident surface into which first reflected light from a first field of view is incident, a second incident surface formed continuously with the first incident surface and into which second reflected light from a second field of view continuous with the first field of view is incident, and an exit surface that emits the first reflected light and the second reflected light toward the light receiving section, wherein the first incident surface, the second incident surface and the exit surface are all flat surfaces, and the second incident surface is inclined with respect to the first incident surface with the boundary line between the two as a fold. Ori , The light-receiving unit includes a plurality of light-receiving elements, and the light emitter projects light into a first field of view and a second field of view such that the first reflected light and the second reflected light each enter different light-receiving elements. .

[0010] One aspect of the present invention for achieving the above objective is a measuring device comprising a light emitter and a light receiver that receives reflected light generated when the light emitter emits light toward a field of view, wherein the light receiver includes a light receiving section and a transmissive optical element, the optical element having a first incident surface into which first reflected light from a first field of view is incident, a second incident surface formed continuously with the first incident surface and into which second reflected light from a second field of view continuous with the first field of view is incident, and an exit surface that emits the first reflected light and the second reflected light toward the light receiving section, wherein the first incident surface, the second incident surface and the exit surface are all flat surfaces, and the second incident surface is inclined with respect to the first incident surface with the boundary line between the two as a fold. Ori , The light-receiving unit includes a plurality of light-receiving elements arranged in a planar manner, the second incident surface is further inclined along the boundary line with respect to the first incident surface, and the light emitter simultaneously emits light from a band-shaped area spanning from a first field of view to a second field of view such that the first reflected light and the second reflected light each incident on different light-receiving elements of the light-receiving unit.

[0011] Further issues disclosed in this application, and methods for solving them, will be made clear in the section on embodiments for carrying out the invention and in the drawings. [Effects of the Invention]

[0012] According to the present invention, a measuring device can flexibly respond to the specifications required by the system to which it is applied. Place It can be provided. [Brief explanation of the drawing]

[0013] [Figure 1] It is a diagram showing a schematic configuration of a measuring device. [Figure 2A] It is a diagram explaining the relationship between a light receiving unit and a light receiving optical system and a visual field range. [Figure 2B] It is a diagram explaining the relationship between a light emitting unit and a light projecting optical system and a visual field range. [Figure 3] It is a diagram explaining the relationship between a light receiver and a visual field range. [Figure 4A] It is an external perspective view of an optical element applied to a light receiver. [Figure 4B] It is a side view of an optical element applied to a light receiver. [Figure 5A] It is a diagram explaining one aspect of the configuration of a measuring device for being able to distinguish from which visual field range the reflected light is. [Figure 5B] It is an external perspective view of an optical element used for the configuration of FIG. 5A. [Figure 6A] It is a diagram showing the relationship between the visual field range and the received image in the configuration shown in FIG. 5A. [Figure 6B] It is a comparative example with respect to FIG. 5A, and is a diagram showing the relationship between the visual field range and the received image when the optical element shown in FIG. 4B is used. [Figure 7] It is a diagram explaining the relationship between a light projector and a visual field range. [Figure 8A] It is an external perspective view of an optical element applied to a light projector. [Figure 8B] It is a side view of an optical element applied to a light projector.

Embodiments for Carrying Out the Invention

[0014] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In the following description, the same or similar configurations may be denoted by the same reference numerals and redundant descriptions may be omitted. Also, in the following description, when it is necessary to distinguish between similar configurations, an identifier (such as an alphabet) may be attached after the reference numeral for collectively denoting the configuration.

[0015] Figure 1 shows a schematic configuration (block diagram) of a measuring device 100, which is shown as one embodiment of the present invention. The measuring device 100 includes a light emitter that emits light (irradiation light, light beam (laser light)) onto the object to be measured, and a light receiver that receives the reflected light (return light) that comes back after the emitted light is reflected from the object to be measured, and functions as a flash LiDAR (Flash Light Detection and Ranging). The measuring device 100 acquires information about the object to be measured by measuring the difference between the timing when the light emitter emits light and the timing when the light receiver receives the reflected light (time of flight of the laser light; hereinafter referred to as "TOF" (Time Of Flight)).

[0016] The measuring device 100 is installed, for example, in vehicles equipped with AD (Autonomous Driving) or ADAS (Advanced Driver Assistance System). The measuring device 100 assists in the detection of people, other vehicles, and objects while the vehicle is in motion, and provides various types of information useful for ensuring the safety of the vehicle driver and those around the vehicle, and for reducing damage to surrounding objects while the vehicle is in operation, to other devices and users.

[0017] As shown in the figure, the example measuring device 100 includes a light-emitting unit 11, a light-emitting control device 112, a current source 113, a light-emitting optical system 14, a light-receiving optical system 15, a light-receiving unit 16, a TOF measuring device 117, a computing unit 150, and a communication I / F 160 (I / F: Interface). Of these, the light-emitting unit 11, the light-emitting control device 112, the current source 113, and the light-emitting optical system 14 constitute a light emitter, while the light-receiving optical system 15 and the light-receiving unit 16 constitute a light receiver.

[0018] The light-emitting section 11 constituting the light projector is composed of one or more light-emitting elements, or one or more light-emitting element arrays (for example, in which light-emitting elements are arranged linearly (one-dimensionally) or planarly (two-dimensionally)). Examples of light-emitting elements include laser diodes, surface-emitting type laser light-emitting elements (for example, VCSELs (Vertical Cavity Surface Emitting Lasers); hereinafter referred to as "surface-emitting elements"), and surface-emitting element arrays (for example, VCSEL arrays) in which multiple surface-emitting elements are arranged one-dimensionally or two-dimensionally on a substrate (semiconductor substrate, ceramic substrate, etc.).

[0019] The light projection control device 112 controls the current (drive current) supplied from the current source 113 to the light-emitting elements by generating a control signal for the current source 113 that supplies the drive current to the light-emitting elements constituting the light-emitting unit 11 and inputting it to the current source 113. The light projection control device 112 inputs a signal indicating the timing when the light-emitting elements emit light (the timing when the projected light is emitted from the light-emitting elements; hereinafter referred to as "light projection timing") to the TOF measuring device 117. The light projection control device 112 causes the light-emitting elements to emit light periodically and repeatedly by, for example, periodically switching the current flowing through each of the light-emitting elements on and off.

[0020] The current source 113 supplies current to the light-emitting elements in accordance with the control signals input from the light-emitting control device 112. For example, the current source 113 supplies a periodic square wave current to the light-emitting elements to switch the current flowing through each of them on and off.

[0021] The light projection optical system 14 adjusts the light distribution of the projected light by, for example, applying an optical effect (refraction, scattering, diffraction, etc.) to the projected light emitted from the light-emitting unit 11. The light projection optical system 14 is composed of, for example, various lenses such as collimating lenses and optical components such as reflectors (mirrors).

[0022] The light-receiving optical system 15 focuses the reflected light (backlight) that returns after the light emitted by the light emitter is reflected by the object to be measured 50, etc., onto the light-receiving unit 16. The light-receiving optical system 15 is composed of optical components such as various lenses such as focusing lenses, various filters such as wavelength filters, and reflectors (mirrors).

[0023] The light-receiving unit 16 is composed of one or more light-receiving elements, or one or more light-receiving element arrays (for example, in which light-receiving elements are arranged linearly (one-dimensionally) or planarly (two-dimensionally)). Examples of the light-receiving elements include photodiodes, SPADs (Single Photon Avalanche Diodes), and balanced photodetectors. The light-receiving unit 16 generates a current (hereinafter referred to as "receiving current") corresponding to the intensity of the reflected light by photoelectric conversion of the reflected light incident from the light-receiving optical system 15. The light-receiving unit 16 inputs a signal indicating the timing (hereinafter referred to as "receiving timing") when each light-receiving element constituting the light-receiving unit 16 receives reflected light, and the receiving current generated by each light-receiving element, to the TOF measuring device 117.

[0024] The TOF measuring device 117 determines the time of flight (TOF) based on a signal indicating the light emission timing input from the light emission control device 112 and a signal indicating the light reception timing input from the light receiving unit 16. The TOF measuring device 117 is configured, for example, using a time measurement IC (integrated circuit) equipped with a TDC (Time to Digital Converter) circuit. The TOF measuring device 117 inputs the determined TOF and the light reception current input from the light receiving unit 16 to the calculation unit 150.

[0025] The arithmetic unit 150 is composed of a processor (CPU (Central Processing Unit), MPU (Micro Processing Unit), ASIC (Application Specific Integrated Circuit), FPGA (Field Programmable Gate Array), DSP (Digital Signal Processor), etc.). Based on the received photocurrent and TOF input from the TOF measuring device 117, the arithmetic unit 150 generates information used for various measurements such as detection and distance measurement of the measurement target 50. This information includes, for example, a histogram used in time-correlated single-photon counting, the distance to each point of the measurement target 50, and a point cloud. The arithmetic unit 150 also controls the light projection control device 112 and the light receiving unit 16. For example, by controlling the light projection control device 112 and the light receiving unit 16, the arithmetic unit 150 controls the aforementioned light projection timing and light receiving timing so that the processing for histogram generation is accelerated or optimized. The information generated by the computing unit 150 is provided (transmitted) to devices that utilize the information (hereinafter referred to as "various utilization devices 40") via the communication interface 160.

[0026] The various devices 40 perform tasks such as creating environmental maps using point clouds and self-localization (SLAM (Simultaneous Localization and Mapping)) using scan matching algorithms (NDT (Normal Distributions Transform), ICP (Iterative Closest Point), etc.).

[0027] Figure 2A is a schematic diagram illustrating the relationship between the light-receiving unit 16, the light-receiving optical system 15, and the field of view 51. The field of view 51 is determined by the size (shape, size, and light-receiving area) of the light-receiving unit 16 and the focal length of the light-receiving optical system 15.

[0028] Figure 2B is a schematic diagram illustrating the relationship between the light-emitting unit 11, the light-projecting optical system 14, and the field of view 51. The field of view 51 is determined by the size (shape, size, and light-receiving area) of the light-emitting unit 11 and the focal length of the light-projecting optical system 14.

[0029] Thus, the size of the field of view 51 is constrained by the size of the light-receiving unit 16 and the light-emitting unit 11. Therefore, the field of view when using, for example, off-the-shelf products as the light-receiving unit 16 and light-emitting unit 11 does not necessarily match the purpose and application of the system to which the measuring device 100 is applied. Furthermore, depending on the purpose and application of the measuring device 100, there may be a need to improve the measurement accuracy of a specific field of view compared to other field of view (for example, when applying flash LiDAR to AD or ADAS, there may be a need to improve the measurement accuracy in a specific field of view such as far away in the oncoming lane), and it is necessary to respond flexibly to such needs.

[0030] Therefore, in the measuring device 100 of this embodiment, the above-mentioned problems and needs are addressed by using an optical element having a prism structure as an element of the light-receiving optical system 15 of the light receiver or the light-emitting optical system 14 of the light emitter. The specific configuration for this purpose will be described below.

[0031] <When using optical elements in the light-receiving optical system> Figure 3 illustrates the relationship between a photodetector and its field of view 51 (the first field of view 51a, the second field of view 51b, and the third field of view 51c, which are aligned in the +x direction in the figure) when an optical element 151 having a prism structure is used in the photodetector's photodetector optical system 15. In this figure, the elements of the photodetector (photodetector optical system 15 and photodetector 16) are depicted as viewed from a direction perpendicular to the optical axis of the photodetector 16 (viewed from the +y side), and the field of view is depicted as viewed from the direction of the optical axis (viewed from the -z side). The arrows in the figure represent reflected light generated when the light emitter projects light from each field of view towards the photodetector (first field of view 51a, second field of view 51b, and third field of view 51c). The size of the photodetector is exaggerated in this figure.

[0032] As shown in the figure, the light-receiving optical system 15 includes an optical element 151 having a prism structure and other optical systems 152 (various lenses, various filters, etc.).

[0033] Figure 4A shows an external perspective view of the optical element 151. As shown in the figure, the optical element 151 has, on its upper side (the +z side in the figure), a first incident surface 151a into which the first reflected light from the first field of view 51a is incident, a second incident surface 151b formed continuously with the first incident surface 151a into which the second reflected light from the second field of view 51b, which is continuous with the first field of view 51a, is incident, and a third incident surface 151c formed continuously with the second incident surface 151b into which the third reflected light from the third field of view 51c, which is continuous with the second field of view 51b, is incident. The optical element 151 also has, on its lower side (the -z side in the figure), an output surface 151o that emits the refracted light of the first reflected light, the transmitted light of the second reflected light, and the refracted light of the third reflected light toward the light receiving section 16. The first incident surface 151a, the second incident surface 151b, the third incident surface 151c, and the exit surface 151o are all flat surfaces.

[0034] Figure 4B is a side view of the optical element 151 as seen from the +y side in Figure 4A. The second incident surface 151b is parallel to the exit surface 151o. The first incident surface 151a is tilted to the +z side at an angle θ1 with respect to the second incident surface 151b, with the first boundary line 1511 between it and the second incident surface 151b as a fold, thereby forming a prism structure on one end (-x side) of the optical element 151. The third incident surface 151c is tilted to the +z side at an angle θ2 with respect to the second incident surface 151b, with the second boundary line 1512 between it and the second incident surface 151b as a fold, thereby forming a prism structure on the other end (+x side) of the optical element 151.

[0035] Returning to Figure 3, the optical element 151 is positioned so that its optical axis (a line passing through the center line of the second incident surface 151b and perpendicular to the exit surface 151o (the normal to the exit surface 151o). This axis is indicated by the reference numeral 1515 in Figure 4B) aligns with the optical axes of the other optical systems 152 and the light-receiving unit 16.

[0036] As shown in the figure, the first reflected light from the first field of view 51a is incident on the first incident surface 151a of the optical element 151, refracted, then emitted from the exit surface 151o, passing through the other optical system 152 and being focused on the light receiving unit 16. Similarly, the second reflected light from the second field of view 51b is incident on the second incident surface 151b of the optical element 151, then emitted from the exit surface 151o, passing through the other optical system 152 and being focused on the light receiving unit 16. Furthermore, the third reflected light from the third field of view 51c is incident on the third incident surface 151c of the optical element 151, refracted, then emitted from the exit surface 151o, passing through the other optical system 152 and being focused on the light receiving unit 16.

[0037] In this way, by using optical elements 151 as elements of the light-receiving optical system 15, reflected light from each field of view 51 (first field of view 51a, second field of view 51b, and third field of view 51c) can be collected by the light-receiving unit 16. Therefore, the field of view (FOV) of the light-receiving unit 16 can be expanded without increasing the light-receiving area (without increasing the number of light-receiving elements).

[0038] As shown in the figure, in this configuration, reflected light from each field of view 51 (first field of view 51a, second field of view 51b, and third field of view 51c) all enters the same light-receiving element of the light-receiving unit 16. Therefore, when implementing this in the measuring device 100, some mechanism is needed to distinguish which field of view 51 the reflected light from has been received.

[0039] The above mechanism can be realized, for example, by emitting light from the light emitter to each field of view 51 (first field of view 51a, second field of view 51b, third field of view 51c) at different timings for each field of view 51. In this case, for example, the computing device 150 controls the light emission control device 112 so that the light emission from the light emitter is performed at different timings for each field of view 51, and distinguishes which field of view 51 the reflected light came from based on the timing at which the light receiving element of the light receiving unit 16 receives the reflected light (hereinafter referred to as the "first method").

[0040] Alternatively, for example, the light emitter may select a portion of each field of view 51 (a portion of the first field of view 51a, a portion of the second field of view 51b, and a portion of the third field of view 51c, such that the reflected light from each of the first field of view 51a, the second field of view 51b, and the third field of view 51c does not enter the same light-receiving element of the same light-receiving unit 16) and emit light simultaneously to each selected portion (hereinafter referred to as the "second method"). According to the second method, since light can be received simultaneously to each of the above fields of view 51, the time required to emit light to all fields of view 51 (first field of view 51a, second field of view 51b, and third field of view 51c) can be shortened (scan speed).

[0041] Alternatively, as shown in Figure 5A, the light emitter may simultaneously emit light over a band-shaped region 55 spanning a first field of view 51a, a second field of view 51b, and a third field of view 51c, while the light receiver may be configured as shown in Figure 5B, with the first incident surface 151a further inclined at an angle φ1 along the first boundary line 1511 relative to the second incident surface 151b, and the third incident surface 151c further inclined at an angle φ2 along the second boundary line 1522 relative to the second incident surface 151b, in the opposite direction to the first incident surface 151a (hereinafter referred to as the "third method").

[0042] In this case, the first incident surface 151a may be tilted by rotating it around an axis 1516a parallel to the x-axis set within the plane of the first incident surface 151a, or by rotating it around an axis 1517a extending in the same direction as the x-axis. Similarly, the third incident surface 151c may be tilted by rotating it around an axis 1516b parallel to the x-axis set within the plane of the third incident surface 151c, or by rotating it around an axis 1517b extending in the same direction as the x-axis.

[0043] The thickness of the band-shaped region 55 described above (the distance in the y-direction (width) in the figure) is set to be shorter than the offset between adjacent field-of-view regions 51 (the amount of offset in the y-direction (step) in the example shown in the figure) so that reflected light from different field-of-view regions 51 does not enter the light-receiving unit 16 at the same time.

[0044] Figure 6A shows an example of the field of view 51 and the image of the reflected light focused on the light-receiving unit 16 (received image) when the light receiver is configured as shown in Figures 5A and 5B. As shown in the figure, the reflected light from each field of view 51 is focused on different light-receiving elements of the light-receiving unit 16.

[0045] Incidentally, if the optical element 151 has the configuration shown in Figure 4A and the same light projection is performed (simultaneously projecting a band-shaped region 55 spanning from the first field of view 51a to the third field of view), as shown in Figure 6B, the reflected light from each field of view 51 (reflected light from the band-shaped region 55 of each field of view 51) will overlap and be focused onto the same light-receiving element of the light-receiving unit 16.

[0046] According to the third method described above, it is possible to simultaneously project and receive light over a band-shaped area 55 extending from the first field of view 51a to the third field of view 51c, thereby shortening the time required for projecting light over the entire field of view 51 (scan speed).

[0047] As described above, by using an optical element 151 with a simple configuration as an element of the light-receiving optical system 15, the field of view (FOV) of the photodetector can be easily extended to a range spanning from the first field of view 51a to the third field of view 51c without increasing the light-receiving area of ​​the light-receiving section 16 (without increasing the number of light-receiving elements). Furthermore, by adjusting the tilt angles θ1, θ2 and φ1, φ2, the light-receiving range (the first field of view 51a and the third field of view 5c) can be adjusted, allowing for flexible adaptation to the specifications required by the system to which it is applied.

[0048] <When using optical elements in a light projection optical system> Figure 7 illustrates the relationship between the light source and the field of view 51 (light projection range) (first field of view 51a, second field of view 51b, third field of view 51c) of the light source of the measuring device 100, when an optical element 141 with the same configuration as the optical element 151 described above is used in the light projection optical system 14 of the light source of the light source 100. In this figure, the elements of the light source (light projection optical system 14 and light-emitting unit 11) are depicted as viewed from a direction perpendicular to the optical axis of the light-emitting unit 11 (viewed from the +y side), and each field of view 51 is depicted as viewed from the direction of the optical axis (viewed from the -z side). The arrows shown in the figure represent the correspondence between the light emitted from the optical element 141 and each field of view 51 (first field of view 51a, second field of view 51b, third field of view 51c). Furthermore, the size of the floodlights is exaggerated in the illustration.

[0049] As shown in the figure, the light projection optical system 14 includes an optical element 141 having a prism structure and other optical systems 142 (various lenses, various filters, etc.).

[0050] Figure 8A shows an external perspective view of the optical element 141. As shown in the figure, the optical element 141 has an incident surface 141i on its lower side (the -z side in the figure) into which light from the light-emitting unit 11 enters. The optical element 141 also has, on its upper side (the +z side in the figure), a first exit surface 141a that emits light incident from the light-emitting unit 11 onto the incident surface 141i toward a first field of view 51a, a second exit surface 141b formed continuously with the first exit surface 141a that emits light incident from the light-emitting unit 11 onto the incident surface 141i toward a second field of view 51b, and a third exit surface 141c formed continuously with the second exit surface 141b that emits light incident from the light-emitting unit 11 onto the incident surface 141i toward a third field of view 51c. The incident surface 141i, the first exit surface 141a, the second exit surface 141b, and the third exit surface 141c are all flat surfaces.

[0051] Figure 8B is a side view of the optical element 141 as seen from the -y side of Figure 4A. The incident surface 141i is parallel to the second exit surface 141b. The first exit surface 141a is tilted to the +z side at an angle θ1 with respect to the second exit surface 141b, using the first boundary line 1411 with respect to the second exit surface 141b as a fold, thereby forming a prism structure on one end (-x side) of the optical element 141. The third exit surface 141c is tilted to the +z side at an angle θ2 with respect to the second exit surface 141b, using the second boundary line 1412 with respect to the second exit surface 141b as a fold, thereby forming a prism structure on the other end (+x side) of the optical element 141.

[0052] Returning to Figure 7, the optical element 141 is positioned so that its optical axis (a line passing through the center line of the second emission surface 141b and perpendicular to the incident surface 141i (the normal to the incident surface 141i), the axis indicated by reference numeral 1415 in Figure 8B) coincides with the optical axis of the other optical systems 142 and the light-emitting section 11.

[0053] As shown in the figure, the light emitted from the light-emitting unit 11 passes through the other optical system 142 and enters the optical element 141, thereby causing the optical element 141 to emit: first transmitted light that is refracted at the first emission surface 141a and directed toward the first field of view 51a; second transmitted light that passes through the second emission surface 141b and directed toward the second field of view 51b; and third transmitted light that is refracted at the third emission surface 141c and directed toward the third field of view 51c.

[0054] In this way, by using the optical element 141 as an element of the light projection optical system 14, the field of view (FOV) of the light projector can be easily extended to a wide range from the first field of view 51a to the third field of view 51c without increasing the light-emitting area of ​​the light-emitting unit 11 (without increasing the number of light-emitting elements). Furthermore, the light projection range (first field of view 51a and third field of view 5c) can be adjusted by adjusting the tilt angles θ1 and θ2, allowing for flexible adaptation to the specifications required by the system to which the measuring device 100 is applied.

[0055] Although embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments and includes various modifications. Furthermore, the above embodiments are described in detail to explain the configuration in an easy-to-understand manner and are not necessarily limited to those having all the configurations described. In addition, some of the configurations of the above embodiments can be added to, deleted from, or replaced with other configurations.

[0056] For example, although the above description has been based on the case where there are three fields of view (light projection range, light reception range) (first field of view 51a, second field of view 51b, and third field of view 51c), the present invention can also be applied when there are two fields of view or four or more.

[0057] Furthermore, for example, the configurations of the light emitter and light receiver described above (the configuration in which the optical element 151 is used as an element of the light-receiving optical system 15, and the configuration in which the optical element 141 is used as an element of the light-emitting optical system 14) may be applied to both of these configurations in the measuring device 100, or only one of them may be applied. [Explanation of Symbols]

[0058] 50 Measurement target, 51a First field of view, 51b Second field of view, 51c Third field of view 51, 100 Measurement device, 11 Light-emitting unit, 112 Light projection control device, 113 Current source, 14 Light projection optical system, 141 Optical element, 142 Other optical system, 15 Light-receiving optical system, 151 Optical element, 152 Other optical system, 16 Light-receiving unit, 117 TOF measurement device, 150 Computing unit

Claims

1. The system comprises a light emitter and a light receiver that receives reflected light generated when the light emitter emits light towards a field of view, The light receiver includes a light-receiving section and a transmissive optical element. The aforementioned optical element is A first incident surface into which the first reflected light from the first field of view is incident, A second incident surface is formed continuously with the first incident surface, and into which second reflected light from a second field of view continuous with the first field of view is incident, An emission surface that emits the first reflected light and the second reflected light in the direction of the light receiving section, It has, The first incident surface, the second incident surface, and the exit surface are all flat surfaces. The second incident surface is inclined with respect to the first incident surface, with the boundary line between the first incident surface and the second incident surface serving as a fold. The light-receiving unit includes a plurality of light-receiving elements, The light projector projects light into a first field of view and a second field of view such that the first reflected light and the second reflected light each enter different light-receiving elements. Measuring device.

2. The system comprises a light emitter and a light receiver that receives reflected light generated when the light emitter emits light towards a field of view, The light receiver includes a light-receiving section and a transmissive optical element. The aforementioned optical element is A first incident surface into which the first reflected light from the first field of view is incident, A second incident surface is formed continuously with the first incident surface, and into which second reflected light from a second field of view continuous with the first field of view is incident, An emission surface that emits the first reflected light and the second reflected light in the direction of the light receiving section, It has, The first incident surface, the second incident surface, and the exit surface are all flat surfaces. The second incident surface is inclined with respect to the first incident surface, with the boundary line between the first incident surface and the second incident surface serving as a fold. The light-receiving unit includes a plurality of light-receiving elements arranged in a planar manner. The second incident surface is further inclined with respect to the first incident surface along the boundary line, The light projector simultaneously projects light over a band-shaped area spanning from the first field of view to the second field of view, such that the first reflected light and the second reflected light each enter different light-receiving elements of the light-receiving unit. Measuring device.

3. The system comprises a light emitter and a light receiver that receives reflected light generated when the light emitter emits light towards a field of view, The light receiver includes a light-receiving section and a transmissive optical element. The aforementioned optical element is A first incident surface into which the first reflected light from the first field of view is incident, A second incident surface is formed continuously with the first incident surface, and into which second reflected light from the second field of view is incident, A third incident surface is formed continuously with the second incident surface, and into which the third reflected light from the third field of view is incident, The first reflected light, the second reflected light, and the third reflected light are emitted from an emission surface in the direction of the light receiving section, It has, The first incident surface, the second incident surface, the third incident surface, and the exit surface are all flat surfaces. The first incident surface is inclined with respect to the second incident surface, with the first boundary line between the second incident surface and the first incident surface as a fold. The third incident surface is inclined with respect to the second incident surface with the second boundary line between it and the second incident surface as a fold. The light-receiving unit includes a plurality of light-receiving elements, The light projector projects light into the first field of view, the second field of view, and the third field of view such that the first reflected light, the second reflected light, and the third reflected light each incident on different light-receiving elements. Measuring device.

4. The system comprises a light emitter and a light receiver that receives reflected light generated when the light emitter emits light towards a field of view, The light receiver includes a light-receiving section and a transmissive optical element. The aforementioned optical element is A first incident surface into which the first reflected light from the first field of view is incident, A second incident surface is formed continuously with the first incident surface, and into which second reflected light from the second field of view is incident, A third incident surface is formed continuously with the second incident surface, and into which the third reflected light from the third field of view is incident, The first reflected light, the second reflected light, and the third reflected light are emitted from an emission surface in the direction of the light receiving section, It has, The first incident surface, the second incident surface, the third incident surface, and the exit surface are all flat surfaces. The first incident surface is inclined with respect to the second incident surface, with the first boundary line between the second incident surface and the first incident surface as a fold. The third incident surface is inclined with respect to the second incident surface with the second boundary line between it and the second incident surface as a fold. The light-receiving unit includes a plurality of light-receiving elements arranged in a planar manner. The first incident surface is further inclined with respect to the second incident surface along the first boundary line, The third incident surface is further inclined with respect to the second incident surface, along the second boundary line, in the opposite direction to the first incident surface. The light projector simultaneously projects light over a band-shaped area spanning from the first field of view to the third field of view, such that the first reflected light, the second reflected light, and the third reflected light each enter different light-receiving elements of the light-receiving unit. Measuring device.

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