Distance measuring device

Abstract

To improve the accuracy of distance information of a distance measuring object while suppressing an increase in the power consumption of a light source in a distance measuring device.SOLUTION: A distance measuring device includes: a light source unit that emits light; a setting unit that performs light emission setting of the light source unit; a light-receiving unit that receives reflected light emitted from the light source unit and reflected by an object; and a generation unit that generates a distance image using the reflected light received by the light-receiving unit. The distance image comprises multiple sub-frame distance images. In the process of generating the multiple sub-frame distance images, the setting unit performs first light emission setting during distance measurement in a first distance range, and performs second light emission setting during distance measurement in a second distance range.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The technology of the present disclosure relates to a distance measuring device. [Background technology]

[0002] Conventionally, a device has been proposed that irradiates a distance measurement area with modulated light, receives reflected light from the object to be measured, and repeats exposure for each distance division in the depth direction of the distance measurement area to obtain multiple distance information in the depth direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2021-513087 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 proposes changing the number of cycles of the emitted light according to the distance division in the depth direction of the distance measurement target area. This has the effect of improving the quality of the obtained distance image, since the reflected light from the distance measurement target object becomes weaker as the distance measurement target area becomes farther away. However, there is a problem that increasing the number of cycles of the emitted light leads to an increase in the power consumption of the light source.

[0005] The technology disclosed herein has been made in consideration of the above-mentioned problems, and has an objective to improve the accuracy of distance information of an object to be measured while suppressing an increase in power consumption of a light source in a distance measuring device. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the distance measuring device disclosed herein includes a light source unit that emits light, a setting unit that sets the light emission settings of the light source unit, a light receiving unit that receives reflected light from the light source unit reflected by an object, and a generation unit that generates a distance image using the reflected light received by the light receiving unit, wherein the distance image is made up of distance images of a plurality of subframes, and in the process of generating the distance images of the plurality of subframes, the setting unit sets a first light emission setting when measuring a first distance range, and sets a second light emission setting when measuring a second distance range. Effect of the Invention

[0007] According to the technology of the present disclosure, it is possible to improve the accuracy of distance information of an object to be measured while suppressing an increase in power consumption of a light source in a distance measuring device. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram for explaining distance measurement by a distance measuring device according to an embodiment; [Diagram 2] FIG. 1 is a diagram showing a schematic configuration of a distance measuring device according to an embodiment; [Diagram 3] Graph showing a schematic diagram of timing control of light emission and light reception of a distance measuring device [Figure 4] FIG. 2 is a diagram showing a method for acquiring distance information of an object to be measured by a distance measuring device; [Diagram 5] Graphs showing enlarged portions of the signal changes shown in FIGS. 3A to 3C [Figure 6] FIG. 1 is a schematic diagram showing an example of a process for acquiring distance information in a distance measuring device; [Figure 7] FIG. 7 is a schematic diagram showing distance information acquired for the subframes shown in FIG. 6. [Figure 8] Graph showing the relationship between the modulation signal, gate signal, and setting signal in a distance measuring device [Figure 9] FIG. 1 is a schematic diagram showing an example of a range finder applied as an in-vehicle range finder; [Figure 10] FIG. 2 is a diagram showing a schematic view of an imaging area of ​​a distance measuring device; [Figure 11] Graph showing the relationship between various signals in one modified example [Figure 12] FIG. 13 is a diagram showing a schematic configuration of a distance measuring device according to a third embodiment; [Figure 13] FIG. 13 is a diagram showing a schematic configuration of a distance measuring device according to a fourth embodiment. [Figure 14] FIG. 13 is a diagram showing a schematic configuration of a distance measuring device according to a fifth embodiment. [Figure 15] FIG. 13 is a schematic diagram showing a part of the configuration of a distance measuring device according to a sixth embodiment and light emission and reception. [Figure 16] 13 is a graph showing the relationship between a modulation signal and a gate signal in the seventh embodiment. [Figure 17] FIG. 23 is a schematic diagram showing light emission and light reception of a distance measuring device according to an eighth embodiment. [Figure 18] FIG. 13 is a diagram showing an example of the configuration of a light receiving unit of a distance measuring device according to a ninth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. Note that the components of each embodiment described below can be added to another embodiment or replaced with the components of another embodiment. Also, the size and positional relationship of the components shown in each drawing may be exaggerated for clarity of explanation.

[0010] (First embodiment) A distance measuring device according to a first embodiment will be described below with reference to Figures 1 to 10. In the following description of the following embodiments, components having the same functions are given the same reference numerals, and their description may be omitted or simplified.

[0011] Fig. 1 is a diagram showing distance measurement by the distance measuring device according to the first embodiment. As shown in Fig. 1, the distance measuring device 100 irradiates distance measurement targets 91, 92, which are objects within a distance measurement target area 99, with irradiation light 201, and receives reflected light 202 reflected from the distance measurement targets 91, 92. The distance measuring device 100 then measures the distance to the distance measurement targets 91, 92 using the received reflected light 202, and generates a distance image using the distance measurement result.

[0012] Fig. 2 is a diagram showing a schematic configuration of a distance measuring device 100 according to this embodiment. As shown in Fig. 2, the distance measuring device 100 has a light source unit 101 that emits light to an object to be measured, and a light receiving unit 102 that receives reflected light from the object to be measured. The distance measuring device 100 also has a timing control unit 301, a gate signal generation unit 302, a storage unit 303, a setting unit 304, a frame image generation unit 305, and an image synthesis unit 306.

[0013] The timing control unit 301 transmits a control signal for controlling generation of a gate signal by the gate signal generation unit 302 to the gate signal generation unit 302. The timing control unit 301 also transmits a control signal for controlling the modulation timing of the light source unit 101 to the light source unit 101, and transmits a timing signal for switching the light irradiation area to the setting unit 304. The gate signal generation unit 302 generates a control signal (gate signal) for the light reception timing of the light receiving unit 102, and transmits it to the light receiving unit 102.

[0014] The storage unit 303 stores information on a first light emission setting of the light source unit 101 used for distance measurement in a first distance measurement range of the distance measurement area, and information on a second light emission setting of the light source unit 101 used for distance measurement in a second distance measurement range of the distance measurement area. The setting unit 304 acquires information on the first light emission setting or information on the second light emission setting from the storage unit 303 in accordance with a timing signal transmitted from the timing control unit 301, and transmits a setting signal based on the acquired information to the light source unit 101. The light source unit 101 switches the light emission setting based on the setting signal received from the setting unit 304. This allows the distance measuring device 100 to change the irradiation range of light by the light source unit 101.

[0015] The reflected light received by the light receiving unit 102 is converted into a signal, and image information for each distance section is generated in subframe units by the frame image generating unit 305. A unit 306 generates a distance image by synthesizing the subframe images for each distance section generated by the frame image generation unit 305 .

[0016] In this embodiment, the light source unit 101 has a function of changing the distance range to which light is irradiated, and emits light according to a control signal that controls the modulation timing received from the timing control unit 301. Also, the light source unit 101 switches the light emission setting between a first light emission setting and a second light emission setting according to a setting signal received from the setting unit 304.

[0017] The distance measuring device 100 irradiates a distance measurement target area 99 having a predetermined depth with irradiation light 201 from a light source unit 101, and receives reflected light 202 reflected from distance measurement targets 91, 92 in the distance measurement target area 99 with a light receiving unit 102. In this way, the distance measuring device 100 obtains distance information in the depth direction of the distance measurement target area 99.

[0018] The light source unit 101 emits light at a predetermined time period, and uniformly irradiates the distance measurement target area 99 with irradiation light. Any light source that can modulate the light source itself at high speed, such as an LED (Light Emitting Diode), can be used as the light source unit 101, and the light source unit 101 may not only modulate the light source itself, but may also have a configuration for controlling the irradiation light with a chopper or the like outside the light source.

[0019] Furthermore, examples of the configuration of the light source unit 101 for changing the distance range to which light is irradiated include those that utilize polarization or modulation, such as silicon photonics devices, compound semiconductors, and optical phased arrays. Alternatively, examples of the configuration of the light source unit 101 for changing the distance range to which light is irradiated include those that switch the light emission area using a surface emitting laser consisting of a group of multiple laser points. Alternatively, the light source unit 101 may be a light source unit having a plurality of groups of laser light emitting diodes, and the distance range to which light is irradiated may be changed by switching the group of laser diodes that emit light according to a control signal from the timing control unit 301, for example.

[0020] Although not shown in FIG. 2, the light source unit 101 may include an optical element such as a diffractive optical element (DOE) or a glass diffusion plate for irradiating the distance measurement target area 99 with a uniform amount of light.

[0021] The light receiving unit 102 is composed of one or more light receiving elements. This light receiving element has a function of being in a light receiving state (Ron) only for a predetermined period. The light receiving element is also configured to detect only the amount of light received during the period in which it is in a light receiving state. This makes it easier for the light receiving unit 102 to extract light receiving information and simplifies the device configuration compared to a configuration that constantly monitors the reflected light 202. Furthermore, since the light receiving unit 102 does not require high-speed constant sampling, power consumption in the distance measuring device 100 is reduced, and it becomes possible to generate a more accurate distance image with a simple system configuration.

[0022] 3A to 3C are graphs that show a schematic diagram of timing control of light emission and light reception in the distance measuring device 100 according to the present embodiment. In the graphs of FIG. 3A to 3C, the horizontal axis represents time, and the vertical axis represents the signal level. The graph of FIG. 3A shows a modulation signal that is a control signal for the modulation timing of the light source unit 101, and the light source unit 101 emits light during a period in which it is in an ON state, and does not emit light during a period in which it is in an OFF state. Here, the ON state period of the light source unit 101 is repeated periodically at a constant time interval T. The time interval T is set so that it is longer than the maximum delay time Tmax until the irradiated light 201 is reflected at the deepest position in the depth direction of the distance measuring target area 99 (a position Lmax away from the distance measuring device 100 in FIG. 1) and returns to the light receiving unit 102.

[0023] The graph in FIG. 3B shows the control for putting the light receiving element of the light receiving unit 102 into a light receiving enabled state (Ron). 3A and 3B, the control signal shown in FIG. 3B, which is generated by the gate signal generating unit 302, is referred to as the gate signal. The light receiving element of the light receiving unit 102 is in a light receiving enabled state (Ron) only during the period when the gate signal is ON. Also, as shown in FIGS. 3A and 3B, ON of the control signal that controls the light emission of the light source unit 101 and ON of the gate signal that controls the light reception of the light receiving unit 102 are repeated to be paired.

[0024] Fig. 3C shows the operation timing of the light receiving unit 102 which operates according to the gate signal shown in Fig. 3B. The light receiving element of the light receiving unit 102 is in a light receiving state only while the gate signal is ON, the light receiving element detects the amount of light irradiated while the gate signal is ON, and the light receiving unit 102 outputs a detection signal according to the detected amount of light as the detection result. Any element can be used as the light receiving element of the light receiving unit 102 as long as it is in a light receiving state only during the light receiving period according to the gate signal and can output the amount of exposure during that light receiving period as a detection signal.

[0025] Here, a method of acquiring distance information of an object to be measured in the distance measuring device 100 will be described with reference to Fig. 4. As shown in the figure, a light source unit 101 irradiates a distance measuring object area 99 having a predetermined depth with irradiation light 201, and a light receiving unit 102 receives reflected light 202 from the object to be measured, thereby acquiring distance information in the depth direction of the distance measuring object area 99. Specifically, the distance measuring object area 99 is divided into a plurality of distance ranges in the depth direction, and the distance measuring device 100 repeats acquiring distance information by irradiating light from the light source unit 101 and receiving reflected light from the light receiving unit 102 for each divided distance range. Then, the distance measuring device 100 acquires distance information of a plurality of distance ranges in the depth direction of the distance measuring object area 99.

[0026] 4, an operation of acquiring distance information of a distance range X divided in the depth direction when the light source unit 101 emits light once to acquire distance information corresponding to one distance range will be described. The time from when the light source unit 101 emits irradiation light 201 until the light is reflected by an object to be measured within the divided distance range X and returns to the light receiving unit 102 can be calculated from the distance L to the distance range X, the distance LX in the depth direction of the distance range X, and the speed of light c. The gate signal generating unit 302 generates a gate signal and transmits it to the light receiving unit 102 so that the light receiving unit 102 is in a light receiving state only during the period when the reflected light 202 from the object to be measured within the distance range X reaches the light receiving unit 102.

[0027] The gate signal for putting the light receiving element into a light receiving enabled state (Ron) will be described with reference to FIG. 5. FIG. 5 is a graph showing an enlarged portion of the change in each signal shown in FIG. 3A to FIG. 3C. As described above, the ON / OFF of the modulation signal that controls the modulation timing of the light source unit 101 and the ON / OFF of the gate signal that controls the light receiving unit 102 are paired. As shown in FIG. 5, the delay time from when the modulation signal that controls the modulation timing of the light source unit 101 turns ON (time t1) to when the gate signal turns ON (time t2) is TD. Also, the time width during which the gate signal is ON is TW. Here, the delay time TD corresponds to the time from when the light source unit 101 emits light to the object to be measured in the distance range X to when the earliest reflected light 202 of the reflected light 202 reflected from the object to be measured reaches the light receiving unit 102. Also, the earliest reflected light 202 from the distance range X, that is, the reflected light 202 returning from the object to be measured closest to the distance measuring device 100 (light receiving unit 102), reaches the light receiving unit 102. Then, the last reflected light 202, i.e., the reflected light 202 returning from the object to be measured that is farthest from the distance measuring device 100 (light receiving unit 102), reaches the light receiving unit 102. The time interval from when the earliest reflected light 202 reaches the light receiving unit 102 to when the last reflected light 202 reaches the light receiving unit 102 is the time width TW.

[0028] 5 also shows a graph of an example of a period during which the light receiving element of the light receiving unit 102 shown in FIG. 3C is in a light receiving enabled state. As shown in the graph, from when the light source unit 101 emits light (time t1) until the delay time TD has elapsed (time t2), the light receiving element of the light receiving unit 102 receives the reflected light 202. When the delay time TD has elapsed since time t1, the light receiving element of the light receiving unit 102 is ready to receive reflected light 202. The light receiving element continues to be ready to receive light for a time width TW after the light receiving element is ready to receive light. When the time width TW has elapsed since the light receiving element was ready to receive light, the light receiving element returns to a non-light receiving state. When the light receiving element returns to the non-light receiving state (time t3), it outputs a detection signal according to the amount of light received during the light receiving state as a detection result. The light receiving unit 102 outputs a detection signal once in response to the light source unit 101 emitting light once between time t1 and time t4.

[0029] 6 is a schematic diagram illustrating a process of acquiring distance information from a plurality of distance ranges in the distance measuring device 100. In this embodiment, the distance measuring device 100 acquires distance information corresponding to each distance range divided in the depth direction of the distance measuring target area 99 by controlling the ON / OFF of the light receiving state of the light receiving element using a gate signal. In the following description, distance information acquired for one of the distance ranges divided in the depth direction of the distance measuring target area 99 is referred to as a subframe.

[0030] Furthermore, the distance measuring device 100 controls the operation of the light receiving unit 102 by a gate signal according to each distance range to obtain distance information for each subframe, thereby obtaining multiple pieces of distance information from the distance measuring target area 99. For example, if the number of divisions of the distance range in the depth direction of the distance measuring target area 99 is Y, then Y pieces of distance information are regarded as one set of distance information. The example in FIG. 6 corresponds to the case where Y=7, and the distance measuring target area 99 is divided into seven subframes, from subframe A to subframe G, in order of proximity to the distance measuring device 100, and the seven subframes form one frame. In the figure, subframe E corresponds to the above-mentioned distance range X.

[0031] Next, Fig. 7 shows a schematic diagram of distance information acquired for the subframes shown in Fig. 6. In the example shown in Fig. 7, it is assumed that the light receiving unit 102 is composed of a plurality of light receiving elements 510 arranged in an array. A group of distance information, which is a set of all the subframes in the depth direction of the distance measurement target area 99, constitutes one frame, and the time it takes for the distance measuring device 100 to acquire one frame of distance information is called the frame rate. The frame rate here can be calculated by (the interval T of the modulation timing of the light source unit 101 (the period from time t1 to t4 in Fig. 5)) x (the number of divisions Y of the distance measurement target area in the depth direction).

[0032] In the example shown in Fig. 6, distance information corresponding to the amount of received light is acquired for each of seven subframes A to G obtained by dividing the distance measurement target area 99 in the depth direction, but the method of acquiring the distance information is not limited to this. For example, the influence of noise and the like can be reduced by repeatedly acquiring distance information multiple times in the same distance range (subframe) and averaging the acquired distance information. Note that the number of times the acquisition of distance information for each distance range is repeated is a trade-off between the frame rate and the accuracy of the distance information, and therefore can be set appropriately to satisfy conditions required in practice.

[0033] In this embodiment, the distance measuring device 100 switches the distance range into which the light source unit 101 irradiates light in the middle of one frame period in which a distance image is generated based on the acquired distance information. The distance measuring device 100 generates distance images for subframes based on distance information obtained for each distance range divided in the depth direction of the distance measuring target area 99, and generates a distance image for one frame by combining the generated distance images for subframes. The distance measuring device 100 then changes the light irradiation area of ​​the light source unit 101 in the process of generating the distance images for the subframes. This makes it possible to improve the efficiency of acquiring distance information in the depth direction of the distance measuring target area 99 while suppressing an increase in power consumption of the light source unit, compared to a configuration in which an image is generated for each distance range without changing the light irradiation area in the depth direction of the distance measuring target area 99.

[0034] Next, referring to FIG. 8 to FIG. 10, the distance measuring device 100 calculates a distance image for one frame. An example of switching the illumination area of ​​the irradiated light during a sequence for generating an image will be described. In Fig. 8, in order to generate a distance image in a distance range corresponding to distance Lmax from distance measuring device 100 in Fig. 1, distance images of multiple subframes are generated in one frame period (TLmax). Furthermore, distance measuring device 100 switches the illumination area of ​​the light emitted by light source unit 101 at any timing during one frame period. Note that, in this example, it is assumed that the illumination area of ​​the light emitted by light source unit 101 is switched at the timing when generation of a distance image corresponding to distance L1 from distance measuring device 100 is completed.

[0035] As shown in FIG. 8, this example shows the relationship between a modulation signal that controls the light emission of the light source unit 101, a gate signal that controls the light reception of the light receiving unit 102, and a setting signal of the light emission setting that the setting unit 304 transmits to the light source unit 101. Here, the first light emission setting is a light emission setting for irradiating light to a first distance range of the distance measurement target area, and the second light emission setting is a light emission setting for irradiating light to a second distance range of the distance measurement target area. In the graph of FIG. 8, the horizontal axis represents time, and the vertical axis represents signal level. As shown in the figure, in one frame period TLmax, in a period TL1 until a distance image of subframe (n+2) is generated, the light source unit 101 irradiates light to a target of the first distance range. In addition, in a period TL2 in which a distance image of the next subframe (n+3) to subframe (n+5) is generated, the light source unit 101 irradiates light to a target of the second distance range. Note that subframes n to n+2 are an example of a first subframe, and subframes n+3 to n+5 are an example of a second subframe.

[0036] Fig. 9 is a schematic diagram showing an example in which the distance measuring device 100 in the first embodiment is applied as an on-vehicle distance measuring device. Fig. 9 shows an automobile 901 that does not have the distance measuring device 100 mounted thereon, and an automobile 906 that does have the distance measuring device 100 mounted thereon. Here, it is assumed that other automobiles 902, 903, and 904 are traveling ahead of the automobiles 901 and 906.

[0037] In the case of the automobile 901, the irradiated light for distance measurement spreads forward until it reaches a distance Lmax while traveling. In this case, the irradiated light spreads and becomes weaker as the distance from the automobile 901 increases.

[0038] On the other hand, in the automobile 906 equipped with the distance measuring device 100 according to this embodiment, when a distance image is generated in the distance range from the automobile 906 to the distance L1, the light source unit 101 irradiates light in the first light emission setting. As a result, in the distance measuring device 100, a distance image of the automobile 902 is generated by the light emitted from the light source unit 101 in the first light emission setting. Also, in the automobile 906, when a distance image is generated in the distance range corresponding to the remaining distance L2, that is, the distance range from distance L1 to Lmax, the light source unit 101 irradiates light in the second light emission setting. As a result, in the distance measuring device 100, distance images of the automobiles 903 and 904 are generated by the light emitted from the light source unit 101 in the second light emission setting.

[0039] 10A and 10B are schematic diagrams showing an imaging area 908 of the distance measuring device 100 mounted on the automobile 906 in FIG. 9. FIG. 10A shows a light irradiation range 909 when the light source unit 101 of the distance measuring device 100 irradiates light with a first light emission setting. FIG. 10B shows a light irradiation range 910 when the light source unit 101 of the distance measuring device 100 irradiates light with a second light emission setting. Also, in the figures, lanes 907 of the road on which each automobile travels are shown schematic.

[0040] Of the distance measurement area from the automobile 906 to the distance Lmax, the distance range from the automobile 906 to the distance L1 is a closer distance range as seen from the automobile 906. Therefore, when seen from the automobile 906, the automobile 902 within this distance range is larger than the automobiles 903 and 904 which are in a distance range farther than the distance L1. Therefore, as shown in FIG. 10A, the first light emission setting is a light emission setting in which the illumination range 909 of the light emitted from the light source unit 101 encompasses the entire imaging area 908. Note that the light illumination range 909 is the self-illumination range in the imaging area 908. The range may be narrower than the imaging area 908 as long as it includes cars within the distance range from the moving vehicle 906 to the distance L1.

[0041] On the other hand, the remaining distance L2 in the range 99 that is farther from the automobile 906 than the distance L1 is a farther distance range as viewed from the automobile 906. Therefore, as shown in FIG. 10B, the second light emission setting is a light emission setting in which the irradiation range 910 of the light emitted from the light source unit 101 in the imaging area 908 includes the automobiles 903 and 904. In this way, in the sequence for generating a distance image of the entire range 99, the distance measuring device 100 uses a light emission setting (second light emission setting) that narrows the irradiation area of ​​the light from the light source unit 101 when generating a distance image of an area corresponding to the far distance in the imaging area 908. In this way, the first light emission setting and the second light emission setting use light emission settings in which the light intensity density of the light emitted by the light source unit 101 is different. As a result, the distance measuring device 100 can reduce power consumption by the amount of narrowing the irradiation area, and can generate a distance image more efficiently by increasing the amount of light emitted by the light source unit 101 in accordance with the reduction in power consumption.

[0042] As a modified example of the above, instead of or in addition to changing the irradiation area of ​​light and / or the light quantity density of light according to the distance range to which light is irradiated by the first and second light emission settings, the wavelength of light emitted by the light source unit 101 may be changed. For example, in the above embodiment, when the light emitted by the light source unit 101 is infrared light, the first and second light emission settings are set to change the wavelength of the light emitted by the light source unit 101 to different wavelengths between 950 nm and 1400 nm. In addition, a sensor using a GaAs-based compound semiconductor or a semiconductor containing Ge can be used as the light receiving unit 102. In this way, since the light emission setting includes a setting regarding the wavelength of the light emitted by the light source unit, the distance measuring device 100 can irradiate distance measuring light of an appropriate wavelength for each distance range to which light is irradiated, and it is expected that a distance image with higher accuracy can be generated.

[0043] Second embodiment Next, a distance measuring device according to a second embodiment will be described. In the following description, the same components as those in the first embodiment are given the same reference numerals, and detailed description will be omitted. In the distance measuring device 200 according to the second embodiment, the configuration of the light receiving element of the light receiving unit 102 is different from that of the light receiving unit 102 in the first embodiment.

[0044] In this embodiment, the light receiving element of the light receiving unit 102 is a light receiving element that outputs a detection signal when the amount of received light exceeds a predetermined amount of light during the period when the gate signal is ON. This light receiving element only detects whether or not a predetermined amount of light is received, and does not detect the gradation of the amount of received light. Therefore, the light receiving element of the light receiving unit 102 in this embodiment has higher detection accuracy than the first embodiment, the circuit configuration for extracting the detection signal is simpler, and the detection signal can be output at a higher speed. Note that an avalanche photodiode such as a SPAD (Single Photon Avalanche Diode) detector can be used as this light receiving element. In this embodiment In this embodiment, a distance image for each distance range is generated by combining highly sensitive light receiving elements and gate signal control, thereby making it possible to realize a distance measuring device 200 with a simpler configuration.

[0045] Here, a modified example of this embodiment will be described with reference to Figs. 11A to 11D. Fig. 11A shows a modulation signal that controls the light emission of the light source section 101, and Fig. 11B shows a gate signal that controls the light reception of the light receiving section 102. Fig. 11C shows a detection signal transmitted from the light receiving section 102 to the frame image generating section 305, and Fig. 11D shows a setting signal for setting the light emission transmitted from the setting section 304 to the light source section 101. In the graphs of Figs. 11A to 11D, the horizontal axis represents time, and the vertical axis represents signal level.

[0046] In the modified example described below, the distance measurement target area is divided into distance ranges (subframes), When generating a distance image, the light source unit 101 emits light multiple times (N times, where N is any integer) within one subframe. Similarly, within that subframe, the light receiving unit 102 accumulates detection signals from the receiving elements N times to obtain a detection signal for one subframe. The light receiving elements, such as a SPAD detector, that constitute the light receiving unit 102 in this embodiment detect only whether a predetermined amount of light is received, so that the processing load for generating a distance image can be reduced and high sensitivity to the amount of received light can be achieved.

[0047] The light receiving unit 102 of this embodiment does not acquire information such as the gradation of the amount of received light. However, since the reflected light 202 from the recognition target object in the range measurement target area is diffusely reflected by the surface of the object, the light that reaches the light receiving element of the light receiving unit 102 is only a part of the diffusely reflected light. For this reason, the detection of the reflected light 202 by the light receiving unit 102 may be probabilistic. Therefore, even if the range measurement target area is divided into a plurality of distance ranges at the same distance, there is no guarantee that the light receiving element can detect the reflected light from the recognition target object in each distance range. In addition, by repeating the light emission by the light source unit 101 and the reception of light by the light receiving unit 102, the probability of detection of the reflected light from the recognition target object in the light receiving unit 102 can be grasped.

[0048] Therefore, in this modification, the number of times reflected light is detected is accumulated by repeating light emission from the light source unit 101 and light reception by the light receiving unit 102, and the accumulated number of detections is output as a detection signal, thereby acquiring information regarding the gradation of the amount of received light for each distance range (subframe). Therefore, the distance measuring device 200 according to this embodiment can acquire information including gradation information of the amount of received light and generate a distance image with a simpler device configuration.

[0049] Third embodiment Next, a distance measuring device according to a third embodiment will be described. In the following description, the same components as those in the above embodiment will be denoted by the same reference numerals, and detailed description will be omitted. FIG. 12 shows a schematic configuration of a distance measuring device 300 according to a third embodiment. As shown in FIG. 12, the distance measuring device 300 according to this embodiment has an irradiation area change unit 104 that changes the irradiation area of ​​the light emitted by the light source unit 101, at the rear stage of the light source unit 101. In addition, the timing control unit 301 transmits control signals to the frame image generation unit 305 and the image synthesis unit 306, respectively. In addition, the setting unit 304 controls the operation of the irradiation area change unit 104 based on the control signal transmitted from the timing control unit 301.

[0050] The irradiation area changing unit 104 is composed of a member that deflects laser light, such as a liquid crystal member, an electro-optic deflection element, or an acousto-optic deflection element, and controls the irradiation of light emitted by the light source unit 101 in response to a control signal transmitted from the setting unit 304. Alternatively, the irradiation area changing unit 104 may be composed of a mechanical member, such as a MEMS (Micro Electro Mechanical Systems) device or a galvanometer mirror. In this way, the irradiation area changing unit 104 controls the irradiation of light emitted by the light source unit 101 by changing at least one of the irradiation angle and irradiation range of the laser light.

[0051] Furthermore, timing control section 301 controls the generation process of distance images by transmitting control signals to frame image generation section 305 and image synthesis section 306. Specifically, timing control section 301 changes the process of generating subframe images and synthesizing subframe images according to a change in the amount of light irradiated by light source section 101 during one frame period. For example, during a period during which light source section 101 irradiates light to a distance range closer to distance measuring device 300 within the distance measuring target area using the first light emission setting, timing control section 301 decreases the number of synthesized subframe images. On the other hand, during a period during which light source section 101 irradiates light to a distance range farther from distance measuring device 300 within the distance measuring target area using the second light emission setting, timing control section 301 increases the number of synthesized subframe images.

[0052] The timing control unit 301 controls the frame image generating unit 305 and the image combining unit 306 to switch the combining process of the subframe images in this manner. This reduces degradation in image quality of the distance image caused by a decrease in the amount of irradiated light when the distance range to be irradiated with light moves farther, according to the distance measuring device 300. Note that the distance measuring device 300 may perform processing such as interpolation on the distance image that is combined before and after the light emission setting of the light source unit 101 is switched from the first light emission setting to the second light emission setting.

[0053] Therefore, according to the distance measuring device 300 of this embodiment, during the period in which one frame of a distance image is generated, it is possible to reduce the difference in the amount of light irradiated onto a distance measurement target object near and far from the distance measuring device 300. As a result, it is possible to generate an efficient distance image with good image quality without increasing the power consumption of the distance measuring device 300.

[0054] (Fourth embodiment) Next, a distance measuring device according to the fourth embodiment will be described. In the following description, the same components as those in the above embodiment are denoted by the same reference numerals, and detailed description will be omitted. FIG. 13 shows a schematic configuration of a distance measuring device 400 according to the fourth embodiment. As shown in FIG. 13, the distance measuring device 400 has an external environment information acquisition unit 307 that acquires information about the external environment of the distance measuring device 400. The external environment information acquisition unit 307 acquires information such as the difference between day and night in the usage environment of the distance measuring device 400, and the difference in weather such as sunny weather, rainy weather, and fog. The timing control unit 301 switches the light emission setting of the light source unit 101 via the setting unit 304 according to the difference in the external environment based on the information acquired by the external environment information acquisition unit 307.

[0055] As a specific example, when the distance measuring device 400 is used on a sunny day, a lot of information can be obtained from the image from the visible camera under conditions of strong external light. Therefore, when the information acquired by the external environment information acquisition unit 307 indicates that it is a sunny day, the timing control unit 301 switches the light emission setting of the light source unit 101 from the first light emission setting to the second light emission setting at the stage of generating subframe images for a distance range closer to the distance measuring device 400. This shortens the period during which the light source unit 101 emits light with the first light emission setting, thereby reducing the power consumption associated with the light emission of the light source unit 101.

[0056] On the other hand, when the distance measuring device 400 is used at night, the visibility in the image from the visible camera is poor. Therefore, when the information acquired by the external environment information acquisition unit 307 indicates that it is nighttime, the timing control unit 301 switches the light emission setting of the light source unit 101 from the first light emission setting to the second light emission setting at the stage of generating subframe images of the distance measuring device 400 in the far distance range. As a result, similar to the first embodiment, the distance measuring device 400 can reduce power consumption by the amount of the narrowed irradiation area, and can generate a more accurate distance image by increasing the amount of light emitted by the light source unit 101 in response to the reduced power consumption.

[0057] As another example, the timing control unit 301 changes the switching of the light emission setting of the light source unit 101 when the information acquired by the external environment information acquisition unit 307 indicates bad weather such as rain or fog. Specifically, the timing control unit 301 switches the light emission setting of the light source unit 101 from the first light emission setting to the second light emission setting at the stage of generating a subframe image having a distance range closer to the distance measuring device 400 than when the distance measuring device 400 is used on a fine day. As a result, the distance measuring device 400 can reduce power consumption by the amount of narrowing the irradiation area by switching the light emission setting of the light source unit 101 to the second light emission setting, and increases the amount of light emitted by the light source unit 101 according to the reduction in power consumption. As a result, the distance measuring device 400 can generate a distance image with higher accuracy even in bad weather.

[0058] Therefore, according to the distance measuring device 400 of this embodiment, in the sequence for generating a distance image for one frame, the timing for switching the irradiation area of ​​the light from the light source unit 101 is determined by the acquired The distance measurement device 400 changes the distance image in response to information indicating the external environment, thereby enabling the device 400 to generate a suitable distance image in response to the weather and changes in external light over the course of a day.

[0059] Fifth embodiment Next, a distance measuring device according to a fifth embodiment will be described. In the following description, the same components as those in the above-mentioned embodiments are given the same reference numerals, and detailed description thereof will be omitted.

[0060] Fig. 14 shows a schematic configuration of a distance measuring device 500 according to the fifth embodiment. As shown in Fig. 14, the distance measuring device 500 has a movement information acquisition unit 308 that acquires information related to the movement of the distance measuring device 500. As an example, when the distance measuring device 500 is mounted on an automobile, which is a moving body, the movement information acquisition unit 308 acquires, as movement information, travel information such as whether the automobile is currently traveling on a highway or on an ordinary road. Then, the timing control unit 301 switches the light emission setting of the light source unit 101 via the setting unit 304 according to differences in the movement status of the distance measuring device 500 based on the movement information acquired by the movement information acquisition unit 308.

[0061] As a specific example, when an automobile equipped with the distance measuring device 500 is traveling on an expressway, the light emission control is performed such that the light irradiation range of the light source unit 101 is narrowed further when the light source unit 101 emits light in the second light emission setting. As a result, the distance measuring device 500 can generate a more accurate distance image by narrowing the light irradiation range of the light from the light source unit 101 compared to the light irradiation range when the automobile is traveling on an ordinary road, thereby reducing power consumption, while increasing the amount of light irradiation.

[0062] As another example, the movement information acquisition unit 308 may acquire information such as the frequency of braking of the automobile equipped with the distance measuring device 500, and the timing control unit 301 may determine whether the automobile is traveling on a congested road based on the acquired information. In this case, when the timing control unit 301 determines that the automobile is currently traveling on a congested road, the timing control unit 301 performs control to narrow the range of light irradiation by the light source unit 101 to be smaller than the range of light irradiation when traveling on a general road, and increase the amount of irradiation light. Furthermore, the timing control unit 301 may limit the distance range for generating subframe images to only the distance range near the distance measuring device 500, and exclude the distance range far from the distance measuring device 500. In this way, the distance measuring device 500 can shorten one frame period for synthesizing distance images by reducing the number of subframe images to be synthesized. As a result, when the automobile equipped with the distance measuring device 500 travels on a road where congestion occurs, the distance measuring device 500 can shorten the time required to determine the inter-vehicle distance in the traffic jam.

[0063] Therefore, according to this embodiment, in a sequence for generating one frame of a distance image, it is possible to control the timing for switching the light irradiation range of the light source unit 101, the irradiation range, the amount of irradiation light, etc., using driving information of the automobile equipped with the distance measuring device 500. This allows the distance measuring device 500 to generate a suitable distance image according to the usage situation of the distance measuring device 500.

[0064] Sixth embodiment Next, a distance measuring device according to a sixth embodiment will be described. In the following description, the same components as those in the above-mentioned embodiments are given the same reference numerals, and detailed description thereof will be omitted.

[0065] Fig. 15 is a diagram showing part of the configuration of a distance measuring device 600 according to the sixth embodiment and a schematic diagram showing light emission and light reception by the distance measuring device 600. Components of the distance measuring device 600 that are not shown in Fig. 15 are the same as those of the distance measuring device 100 of the first embodiment. As shown in Fig. 15, the distance measuring device 600 of this embodiment changes the irradiation angle of light of the light source unit 101 with respect to the distance measurement target area 99 by a slight angle each time the light source unit 101 emits light, and generates a distance image of each distance range.

[0066] If a part of the object to be recognized is composed of a glossy surface or a surface having a special shape, the amount of reflected light reaching the light receiving unit 102 may increase unnaturally, or may become peaky, depending on the angle of incidence of light on the object to be recognized. The distance measuring device 600 of this embodiment generates a distance image while changing the light irradiation angle of the light source unit 101 by the timing control unit 301. As a result, the light source unit 101 changes the light irradiation direction every time it emits light. As a result, the distance measuring device 600 can reduce the phenomenon in which an inaccurate distance image is generated due to an abnormal amount of reflected light received by the light receiving unit 102 caused by the shape or surface configuration of the object to be recognized.

[0067] As a specific example, in a sequence in which timing control section 301 generates one subframe image, the light irradiation angle of light source section 101 is changed little by little each time light source section 101 emits light, and the reception of reflected light by light receiving section 102 is repeatedly acquired. Then, frame image generating section 305 averages information obtained from the reflected light received by light receiving section 102, thereby making it possible to generate a subframe image with reduced noise caused by the characteristics of the surface of the recognition target object.

[0068] In this embodiment, the configuration has been described in which the light source unit 101 is movable to change the light irradiation direction, but the light receiving unit 102 may be movable instead of or in addition to the light source unit 101. In this case, the light receiving unit 102 changes the receiving angle of the reflected light every time the light source unit emits light. Even if such a configuration is adopted, the distance measuring device 600 can generate subframe images while reducing noise caused by the characteristics of the surface of the recognition object in the same manner as described above.

[0069] Seventh embodiment Next, a distance measuring device according to a seventh embodiment will be described. In the following description, the same components as those in the above embodiments are given the same reference numerals, and detailed description will be omitted. The configuration of the distance measuring device 700 according to the seventh embodiment is the same as that of the distance measuring device 100 according to the first embodiment. However, as described below, the modulation timing of the light source unit 101 is different from that of the light source unit 101 in the first embodiment.

[0070] FIG. 16A shows an example of a modulation signal that is a control signal for the modulation timing of the light source unit 101 in the distance measuring device 700 according to this embodiment. In FIG. 16A, the horizontal axis represents time, and the vertical axis represents signal level. In the graph of FIG. 16A, the horizontal axis represents time, and the vertical axis represents signal level. As shown in the figure, in the distance measuring device 700, the timing control unit 301 changes the period for modulating the light source unit 101 for each light emission timing so that the periods are different, such as T, T', T'', T''', and T''''. In this way, the light source unit 101 changes the light emission period every time it emits light.

[0071] When the light source unit 101 repeats modulation at the same cycle of light emission timing (for example, period T), the period T is often set to be as short as possible in order to maximize the frame rate. Therefore, when a phenomenon occurs in which light emitted from an area farther than the area to be measured is reflected, the reflected light may overlap with reflected light from a recognition target within the distance range to be irradiated with light, resulting in noise. Specifically, the light reflected from an area farther than the area to be measured by the first emission of light from the light source unit 101 becomes stray light noise due to light reflected from a recognition target within the distance range to be irradiated with light by the second emission of light from the light source unit 101. As a result, the accuracy of the generated subframe images may decrease.

[0072] In this embodiment, the period during which the light source unit 101 is modulated changes for each light emission timing, so that the timing of the next light emission from the light source unit 101 and the timing at which unnecessary reflected light becomes stray light can be shifted. This allows light to be irradiated at different light emission timings in one distance range. The reflected light from the detected recognition object is repeatedly acquired by the light receiving unit 102. The frame image generating unit 305 then averages the information obtained from the reflected light received by the light receiving unit 102, thereby reducing noise caused by stray light and generating subframe images.

[0073] Fig. 16B shows an example of a modulation signal that controls the light emission timing of light source unit 101 and a gate signal that controls the light reception timing of light receiving unit 102 as a modified example of this embodiment. In Fig. 16B, the horizontal axis represents time and the vertical axis represents signal level. As shown in Fig. 16B, in distance measuring device 700 according to this modified example, timing control unit 301 controls the operation of light source unit 101 and light receiving unit 102 so as to provide a period for acquiring stray light noise correction information before the period for generating a distance image ("distance information group acquisition period" in the figure).

[0074] As shown in the figure, in the period for acquiring information for correcting stray light noise ("stray light noise correction information acquisition period" in the figure), the period during which the modulation signal is ON is period 2T, which is twice as long as the period T used for generating a distance image. Furthermore, as shown in the figure, in the period for acquiring information for correcting stray light noise, the timing at which the gate signal is turned ON is set to a time period from when the modulation signal is turned ON until the next time the modulation signal is turned ON after the time T has elapsed.

[0075] In this way, the timing control unit 301 controls the modulation signal that controls the light emission timing of the light source unit 101 and the gate signal that controls the light reception timing of the light receiving unit 102, so that the distance measuring device 700 can obtain information for correcting stray light noise before generating a distance image. This allows the distance measuring device 700 to generate a distance image by removing stray light noise based on the obtained information.

[0076] Eighth embodiment Next, a distance measuring device according to an eighth embodiment will be described. In the following description, the same components as those in the above embodiments are given the same reference numerals, and detailed description will be omitted. The configuration of the distance measuring device 800 according to the eighth embodiment is the same as that of the distance measuring device 100 according to the first embodiment. However, as described below, the control of the light receiving unit 102 is different from that of the first embodiment.

[0077] A distance measuring device 800 according to this embodiment will be described with reference to FIG. 17A and FIG. 17B. FIG. 17A and FIG. 17B are diagrams that show light emission by the light source unit 101 and light reception by the light receiving unit 102 in the distance measuring device 800. In the distance measuring device 800, the light receiving unit 102 is provided with a lens 103 having a small Fno (F value; F number) and a relatively narrow focal depth as an optical member that shapes light for a recognition target. The light receiving unit 102 is configured to be able to change the focal length of the lens 103. Then, the light receiving unit 102 changes the focal length of the lens 103 based on the control by the gate signal generating unit 302 so that the focal length overlaps with the distance range (distance range X and distance range X' in the figure) to be irradiated with light. As a result, the light receiving unit 102 optically receives reflected light from a recognition target within the distance range more efficiently, and the distance measuring device 800 can generate a more accurate distance image.

[0078] Ninth embodiment Next, a distance measuring device according to a ninth embodiment will be described. In the following description, the same components as those in the above embodiments are given the same reference numerals, and detailed description will be omitted. The configuration of the distance measuring device 900 according to the ninth embodiment is the same as that of the distance measuring device 100 according to the first embodiment. The distance measuring device 900 is provided with a mechanism for controlling a gate signal for each of the multiple light receiving elements constituting the light receiving unit 102.

[0079] FIG. 18 shows a light receiving element 510 of the light receiving unit 102 of the distance measuring device 900 according to this embodiment. 1A and 1B, the configurations of the timing control unit 301 and the gate signal generation unit 302 are shown. As shown in the figure, the light receiving unit 102 of the distance measuring device 900 has a plurality of light receiving elements 510, and each light receiving element 510 is connected to the gate signal generation unit 302. As a result, the timing control unit 301 can set the value of the time width TW of the gate signal for each light receiving element 510 by controlling each gate signal generation unit 302. Note that the timing control unit 301 may set the value of the delay time TD of the gate signal for each light receiving element 510 as necessary.

[0080] In the distance measuring device 900, the timing at which the gate signal is turned ON for each light receiving element 510 is controlled, so that the distance range within which reflected light is to be received can be set for each light receiving element 510. This allows the time width and / or delay time of the gate signal to be changed for each light receiving element 510, so that the distance range in the depth direction of the distance measuring target area can be changed for each light receiving element 510. As a result, the distance measuring device 900 can generate not only a planar distance image, but also a curved distance image, when viewed in the depth direction of the distance measuring target area. The curvature of the curved surface of the generated distance image can be appropriately changed by changing the control of each light receiving element 510 by the timing control unit 301 according to the usage environment of the distance measuring device 900.

[0081] Therefore, according to the distance measuring device 900 of this embodiment, by controlling the gate signal transmitted to each light receiving element 510 constituting the light receiving section 102, it is possible to more precisely optimize the distance range that is the target of light reception by the light receiving element 510. As a result, the distance measuring device 900 can generate a distance image that includes more useful information regarding the recognition target object.

[0082] The disclosure of this embodiment includes the following configuration. (Configuration 1) A light source unit that emits light; A setting unit that sets the light emission of the light source unit; a light receiving unit that receives light reflected by an object from the light source unit; a generating unit that generates a distance image using the reflected light received by the light receiving unit; having the range image is made up of range images of a plurality of subframes, In the process of generating distance images of the plurality of subframes, the setting unit performs a first light emission setting during distance measurement in a first distance range, and performs a second light emission setting during distance measurement in a second distance range. A distance measuring device comprising: (Configuration 2) 2. The distance measuring device according to configuration 1, wherein the first light emission setting and the second light emission setting include settings related to a light density of the light emitted by the light source unit. (Configuration 3) 3. The distance measuring device according to configuration 1 or 2, wherein the first light emission setting and the second light emission setting include a setting of an illumination area of ​​the light emitted by the light source unit. (Configuration 4) 4. The distance measuring device according to any one of configurations 1 to 3, wherein the first light emission setting and the second light emission setting include settings related to the wavelength of the light emitted by the light source unit. (Configuration 5) The setting unit is the generation unit generates a distance image of a first subframe of the plurality of subframes by using the reflected light of the light emitted from the light source unit in the first light emission setting; The generation unit generates a distance image of a second subframe of the plurality of subframes by using the reflected light of the light emitted from the light source unit in the second light emission setting. Switch between the first light emission setting and the second light emission setting so as to 5. A distance measuring device according to any one of configurations 1 to 4. (Configuration 6) the light receiving unit has a light receiving element that detects whether an amount of received light exceeds a predetermined amount of light, The generating unit generates the distance image using a detection result of the light receiving element. 6. A distance measuring device according to any one of configurations 1 to 5, (Configuration 7) 7. The distance measuring device according to configuration 6, wherein the light receiving element repeatedly receives the reflected light at regular time intervals when measuring the distance in at least one of the first distance range and the second distance range. (Configuration 8) an environmental information acquisition unit that acquires environmental information related to an external environment of the distance measuring device; The setting unit switches between the first light-emission setting and the second light-emission setting based on the environmental information acquired by the environmental information acquisition unit. 8. A distance measuring device according to any one of configurations 1 to 7. (Configuration 9) a movement information acquisition unit that acquires movement information related to the movement of the distance measuring device, The setting unit switches between the first light-emission setting and the second light-emission setting based on the movement information acquired by the movement information acquisition unit. 9. A distance measuring device according to any one of configurations 1 to 8. (Configuration 10) 10. The distance measuring device according to any one of configurations 1 to 9, wherein the light source section switches the distance range to which the light is irradiated by using at least one of polarization and modulation. (Configuration 11) The distance measuring device according to configuration 10, wherein the light source unit uses at least one of a silicon photonics device, a compound semiconductor, and an optical phased array to switch the distance range to which the light is irradiated. (Configuration 12) 10. The distance measuring device according to any one of configurations 1 to 9, wherein the light source unit changes a light emitting area of ​​the light source unit to switch a distance range to which the light is irradiated. (Configuration 13) 13. The distance measuring device according to claim 12, wherein the light source unit uses a surface emitting laser consisting of a group of multiple laser points to switch the distance range to which the light is irradiated. (Configuration 14) 14. The distance measuring device according to any one of configurations 1 to 13, further comprising at least one of a liquid crystal member, an electro-optical deflection element, and an acousto-optical deflection element that deflects the light emitted by the light source section. (Configuration 15) A distance measuring device described in any one of configurations 1 to 14, further comprising at least one of a MEMS (Micro Electro Mechanical Systems) device and a galvanometer mirror that changes at least one of the irradiation angle and irradiation range of the light from the light source unit. (Configuration 16) 16. The distance measuring device according to any one of configurations 1 to 15, wherein the light source unit changes the irradiation direction of the light every time the light is emitted. (Configuration 17) 17. The distance measuring device according to any one of configurations 1 to 16, wherein the light receiving section changes a light receiving angle of the reflected light every time the light source section emits the light. (Configuration 18) 18. The distance measuring device according to any one of configurations 1 to 17, wherein the light source unit changes a light emission cycle of the light every time the light is emitted. (Configuration 19) the light receiving unit has an optical member capable of changing a focal length, The light receiving unit changes the focal length of the optical member in accordance with the distance range to which the light is irradiated. 19. A distance measuring device according to any one of configurations 1 to 18. (Configuration 20) the light receiving unit has a plurality of light receiving elements that receive the reflected light, Each of the light receiving elements of the plurality of light receiving elements receives the reflected light in a different distance range. 20. A distance measuring device according to any one of configurations 1 to 19. [Explanation of symbols]

[0083] 100 Distance measuring device, 101 Light source unit, 102 Light receiving unit, 304 Setting unit, 305 Frame image generating unit

Claims

1. A light source that emits light, A setting unit for setting the light emission settings of the light source unit, A light receiving unit that receives reflected light when the light emitted from the light source unit is reflected by an object, A generation unit that generates a distance image using the reflected light received by the light receiving unit, It has, The aforementioned distance image consists of distance images from multiple subframes. In the process of generating the distance images of the plurality of subframes, the setting unit performs a first light emission setting when measuring the distance of the first distance range, and a second light emission setting when measuring the distance of the second distance range. The first light emission setting and the second light emission setting include setting the irradiation area of ​​the light emitted by the light source unit. A distance measuring device characterized by the following features.

2. The distance measuring device according to claim 1, characterized in that the first light emission setting and the second light emission setting include a setting relating to the light intensity density of the light emitted by the light source unit.

3. The distance measuring device according to claim 1, characterized in that the first light emission setting and the second light emission setting include a setting relating to the wavelength of the light emitted by the light source unit.

4. The aforementioned setting unit is, The generation unit generates a distance image of the first subframe of the plurality of subframes using the reflected light from the light source unit emitted by the first light emission setting. The generation unit generates a distance image of the second subframe of the plurality of subframes using the reflected light emitted from the light source unit according to the second emission setting. Switch between the first light emission setting and the second light emission setting as described above. The distance measuring device according to feature 1.

5. The light receiving unit has a light receiving element that detects when the amount of light received exceeds a predetermined amount of light. The generation unit generates the distance image using the detection result of the light-receiving element. The distance measuring device according to claim 1, characterized in that...

6. The distance measuring device according to claim 5, characterized in that the light-receiving element repeatedly receives the reflected light at regular time intervals when measuring distance in at least one of the first distance range and the second distance range.

7. The device further includes an environmental information acquisition unit that acquires environmental information relating to the external environment of the distance measuring device, The setting unit switches between the first light emission setting and the second light emission setting based on the environmental information acquired by the environmental information acquisition unit. The distance measuring device according to feature 1.

8. The system further includes a movement information acquisition unit that acquires movement information related to the movement of the distance measuring device, The setting unit switches between the first light emission setting and the second light emission setting based on the movement information acquired by the movement information acquisition unit. The distance measuring device according to feature 1.

9. The distance measuring device according to claim 1, characterized in that the light source unit switches the distance range over which the light is irradiated using at least one of polarization and modulation.

10. The distance measuring device according to claim 9, characterized in that the light source unit switches the distance range to which the light is irradiated using at least one of a silicon photonics device, a compound semiconductor, or an optical phased array.

11. The distance measuring device according to claim 1, characterized in that the light source unit switches the distance range to which the light is irradiated by changing the light emission area of ​​the light source unit.

12. The distance measuring device according to claim 11, characterized in that the light source unit uses a surface-emitting laser consisting of a plurality of laser point clouds to switch the distance range to which the light is irradiated.

13. The distance measuring device according to claim 1, further comprising at least one of a liquid crystal member, an electro-optic deflection element, or an acoustic-optic deflection element for deflecting the light emitted by the light source.

14. The distance measuring device according to claim 1, further comprising at least one of a MEMS (Micro Electro Mechanical Systems) device or a galvanometer mirror for changing at least one of the irradiation angle and irradiation range of the light from the light source.

15. The distance measuring device according to claim 1, characterized in that the light source unit changes the direction of irradiation of the light each time it emits light.

16. The distance measuring device according to claim 1, characterized in that the light receiving unit changes the light receiving angle of the reflected light each time the light source unit emits the light.

17. The distance measuring device according to claim 1, characterized in that the light source unit changes the light emission period each time it emits light.

18. The light-receiving unit has an optical element whose focal length can be changed. The light-receiving unit changes the focal length of the optical element according to the distance range to which the light is irradiated. The distance measuring device according to feature 1.

19. The light-receiving unit has a plurality of light-receiving elements that receive the reflected light, Each of the plurality of light-receiving elements receives the reflected light at different distance ranges. The distance measuring device according to feature 1.

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