Distance measuring device

Abstract

A distance measuring device (10) that outputs one or more pieces of distance information indicating the distance to a subject (500) comprises: a light source (20) that emits illuminating light including one or more bright portions; a light receiving unit (30) including a pixel array (32) in which a plurality of pixels (31) are arranged in a matrix; a distance information calculating unit (110) which, when the light receiving unit (30) receives reflected light, this being the illuminating light reflected by the subject (500), calculates, on the basis of one or more pixel values sequentially output from each pixel (31), for each of the plurality of pixels (31), light intensity information indicating the intensity of the reflected light at the pixel (31), and pixel distance information indicating the distance to the subject (500) at the pixel (31); a distance information selecting unit (120) for selecting one or more pieces of selected distance information from among the plurality of pieces of pixel distance information corresponding to the plurality of pixels (31), on the basis of the plurality of pieces of light intensity information corresponding to the plurality of pixels (31); and an output unit (130) for outputting one or more pieces of distance information on the basis of the one or more pieces of selected distance information.

Description

distance measuring device

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

[0002] 2. Description of the Related Art Distance measuring devices that output distance information indicating the distance to a subject are known (see, for example, Japanese Patent Application Laid-Open No. 2003-121998).

[0003] Japanese Patent Application Laid-Open No. 2022-165344

[0004] There is a demand for a distance measuring device that outputs distance information with higher accuracy than conventional devices.

[0005] Therefore, an object of the present disclosure is to provide a distance measuring device that can output distance information with higher accuracy than conventional devices.

[0006] A distance measuring device according to one aspect of the present disclosure is a distance measuring device that outputs one or more distance information indicating the distance to a subject, and includes: a light source that emits illumination light including one or more bright areas that are brighter than the surrounding area; a light receiving unit having a pixel array in which a plurality of pixels are arranged in a matrix and that sequentially output pixel values ​​based on the amount of exposure; a distance information calculation unit that, when the light receiving unit receives reflected light of the illumination light by the subject, calculates, for each of the plurality of pixels, light intensity information indicating the intensity of the reflected light at that pixel and pixel distance information indicating the distance to the subject at that pixel based on one or more pixel values ​​sequentially output from that pixel; a distance information selection unit that selects one or more selected distance information from a plurality of pixel distance information corresponding to each of the plurality of pixels based on the plurality of light intensity information corresponding to each of the plurality of pixels; and an output unit that outputs the one or more distance information based on the one or more selected distance information.

[0007] According to one aspect of the present disclosure, a distance measuring device is provided that can output distance information with higher accuracy than conventional distance measuring devices.

[0008] FIG. 1 is a block diagram showing an example of the configuration of a distance measuring device according to Embodiment 1. FIG. 2 is a schematic diagram showing an example of irradiation light according to Embodiment 1. FIG. 3 is a schematic diagram showing examples of variations of irradiation light according to Embodiment 1. FIG. 4 is an enlarged schematic diagram showing reflected light being collected on the surface of a pixel array according to Embodiment 1. FIG. 5 is a schematic diagram showing an example of how a distance information calculation unit according to Embodiment 1 calculates light intensity information and pixel distance information. FIG. 6 is a schematic diagram showing another example of how the distance information calculation unit according to Embodiment 1 calculates light intensity information and pixel distance information. FIG. 7 is a schematic diagram showing an example of how a distance information selection unit according to Embodiment 1 selects selected distance information. FIG. 8 is a schematic diagram showing another example of how the distance information selection unit according to Embodiment 1 selects selected distance information. FIG. 9 is a flowchart of a first distance measuring process performed by the distance measuring device according to Embodiment 1. FIG. 10 is a schematic diagram showing an example of how the distance information selection unit according to Embodiment 1 selects selected distance information. FIG. 11 is a schematic diagram showing an example of how stray light is irradiated onto a subject. FIG. 12 is a block diagram showing an example of the configuration of a distance measuring device according to Modification 1. FIG. 13 is a flowchart of second distance measuring processing performed by the distance measuring device according to Modification 1. FIG. 14 is a block diagram showing an example of the configuration of a distance measuring device according to Modification 2. FIG. 15 is a schematic diagram showing an example of how an output unit according to Modification 2 calculates distance information. FIG. 16 is a block diagram showing an example of the configuration of a distance measuring device according to Modification 3. FIG. 17 is a schematic diagram showing examples of variations of first illumination light and second illumination light according to Modification 3. FIG. 18 is a schematic diagram showing an example of how a first light source according to Modification 3 emits illumination light including one or more bright portions, and a second light source according to Modification 3 emits surface illumination light. FIG. 19 is a block diagram showing an example of the configuration of a distance measuring device according to Modification 4. FIG. 20 is a schematic diagram showing an example of how the positions of one or more bright portions in a subject change when a light source driving unit according to Modification 4 moves a light source. FIG. 21 is a block diagram showing an example of the configuration of a distance measuring device according to Modification 5. FIG. 22 is a schematic diagram showing an example of how a light source according to Modification 5 switches between one or more bright areas included in the irradiated light.FIG. 23 is a block diagram showing an example of the configuration of a distance measuring device according to Embodiment 2. FIG. 24A is an image diagram showing an example of a template according to Embodiment 2. FIG. 24B is an image diagram showing an example of a template according to Embodiment 2. FIG. 24C is an image diagram showing an example of a template according to Embodiment 2. FIG. 24D is an image diagram showing an example of a template according to Embodiment 2. FIG. 25 is an image diagram showing an example of a template according to Embodiment 2. FIG. 26 is a schematic diagram showing an example of a matching processing unit according to Embodiment 2 performing matching processing. FIG. 27 is a block diagram showing an example of the configuration of a distance measuring device according to Modification 6. FIG. 28 is a block diagram showing an example of the configuration of a distance measuring device according to Modification 7. FIG. 29 is a block diagram showing an example of the configuration of a distance measuring device according to Modification 8. FIG. 30 is a block diagram showing an example of the configuration of a distance measuring device according to Modification 9. FIG. 31 is a block diagram showing an example of the configuration of a distance measuring device according to Modification 10.

[0009] (How One Aspect of the Present Disclosure Was Achieved) The inventors have been developing a distance measuring device that outputs distance information indicating the distance to a subject.

[0010] Through this development, the inventors discovered that when a distance measuring device illuminates a subject with illumination light that includes one or more bright areas that are brighter than the surrounding area and receives light reflected from the subject, distance information calculated based on the pixel values ​​of pixels located in the bright area and / or a specific area of ​​the area surrounding the bright area in the reflected light will be more accurate than distance information calculated based on the pixel values ​​of pixels located in other areas.

[0011] The inventors then conducted repeated experiments and studies based on this knowledge, and as a result, arrived at the distance measuring device according to the present disclosure described below.

[0012] A distance measuring device according to one aspect of the present disclosure is a distance measuring device that outputs one or more distance information indicating the distance to a subject, and includes: a light source that emits illumination light including one or more bright areas that are brighter than the surrounding area; a light receiving unit having a pixel array in which a plurality of pixels are arranged in a matrix and that sequentially output pixel values ​​based on the amount of exposure; a distance information calculation unit that, when the light receiving unit receives reflected light of the illumination light by the subject, calculates, for each of the plurality of pixels, light intensity information indicating the intensity of the reflected light at that pixel and pixel distance information indicating the distance to the subject at that pixel based on one or more pixel values ​​sequentially output from that pixel; a distance information selection unit that selects one or more selected distance information from a plurality of pixel distance information corresponding to each of the plurality of pixels based on the plurality of light intensity information corresponding to each of the plurality of pixels; and an output unit that outputs the one or more distance information based on the one or more selected distance information.

[0013] According to the ranging device of the above configuration, it is possible to output one or more pieces of distance information based on one or more pieces of pixel distance information calculated based on the pixel values ​​of pixels located in a specific area, which allows for calculation of pixel distance information with higher accuracy than pixel distance information calculated based on the pixel values ​​of pixels located in other areas.

[0014] Therefore, the distance measuring device having the above configuration can provide a distance measuring device that can output distance information with higher accuracy than conventional distance measuring devices.

[0015] Furthermore, when the light receiving unit receives the reflected light, each of the one or more bright areas contained in the reflected light is received by M (M is an integer greater than or equal to 3) pixels among the plurality of pixels, and the distance information selection unit may select, as the one or more selected distance information, the pixel distance information corresponding to the maximum light intensity pixel corresponding to light intensity information indicating the strongest intensity among the one or more pixels in each of the one or more bright areas contained in the reflected light, whose corresponding light intensity information indicates that the intensity of the reflected light is not saturated.

[0016] The output unit may output the one or more pieces of selected distance information as the one or more pieces of distance information.

[0017] In addition, the output unit may calculate each of the one or more selected distance information based on the selected distance information and one or more pixel distance information corresponding to each of one or more pixels adjacent to the maximum light intensity pixel corresponding to the selected distance information, and output the calculated one or more distance information.

[0018] Furthermore, the image processing device may further include a correction unit that corrects low light intensity information, which is the light intensity information indicating a relatively low intensity of the reflected light, to corrected light intensity information indicating a greater intensity of the reflected light, and corrects strong light intensity information, which is the light intensity information indicating a relatively high intensity of the reflected light, to corrected light intensity information indicating the intensity of the reflected light as is, wherein the distance information calculation unit calculates the pixel distance information for each of the plurality of pixels based on the corrected light intensity information, and the distance information selection unit selects the one or more selected distance information based on the corrected light intensity information.

[0019] The illumination light may include first illumination light and second illumination light having different patterns of the one or more bright areas, and the light source may include a first light source that emits the first illumination light and a second light source that emits the second illumination light.

[0020] The first light source and the second light source may alternately emit light.

[0021] The first light source and the second light source may emit light simultaneously.

[0022] Furthermore, the imaging device may further include a light source driving unit that drives the light source so that the positions of the one or more bright areas in the subject change.

[0023] Furthermore, the system may further include a memory unit that stores a template related to the distribution of the intensity of the reflected light in the one or more bright areas in the reflected light, and a matching processing unit that calculates, for each of the plurality of pixels, a similarity that indicates the degree of similarity between the distribution of the intensity of the reflected light indicated by N pieces of light intensity information corresponding to N pixels consisting of the pixel and N (N is an integer greater than or equal to 2) - 1 pixels surrounding the pixel, and the distribution of the intensity of the reflected light in the template, and the distance information selection unit may select, as the one or more distance information, the pixel distance information corresponding to a pixel among the plurality of pixels whose similarity satisfies a predetermined condition.

[0024] The system may further include a memory unit that stores a template related to features of the intensity of the reflected light in the one or more bright areas in the reflected light; a feature calculation unit that calculates, for each of the plurality of pixels, features of the intensity of the reflected light indicated by N pieces of light intensity information corresponding to N pixels consisting of the pixel in question and N (N is an integer greater than or equal to 2) - 1 pixels surrounding the pixel in question; and a matching processing unit that calculates, for each of the plurality of pixels, a similarity indicating the degree of similarity between the N features calculated by the feature calculation unit and the feature of the intensity of the reflected light in a pre-fix template, and the distance information selection unit may select, as the one or more distance information, the pixel distance information corresponding to a pixel from the plurality of pixels whose similarity satisfies a predetermined condition.

[0025] The predetermined condition may be that the similarity is greater than a predetermined threshold value.

[0026] The information processing device may further include a coring unit that performs a coring process on the similarity to calculate a core similarity, and the predetermined condition may be that the core similarity is greater than a predetermined threshold value.

[0027] Furthermore, the system may further include a memory unit that stores a machine learning model that has been pre-trained so that when N pieces of light intensity information corresponding to N pixels consisting of any one pixel among the plurality of pixels and N (N is an integer greater than or equal to 2)-1 pixels surrounding the any one pixel are input, the machine learning model outputs a reliability indicating the reliability that the pixel distance information corresponding to the any one pixel is one of the one or more selected distance information, and a matching processing unit that calculates the reliability of each of the plurality of pixels using the machine learning model, and the distance information selection unit may select the pixel distance information corresponding to a pixel among the plurality of pixels whose reliability satisfies a predetermined condition as the one or more distance information.

[0028] The predetermined condition may be that the reliability is greater than a predetermined threshold value.

[0029] The information processing device may further include a coring unit that performs a coring process on the reliability to calculate a core reliability, and the predetermined condition may be that the core reliability is greater than a predetermined threshold value.

[0030] Specific examples of distance measuring devices according to an aspect of the present disclosure will be described below with reference to the drawings. Each embodiment shown here illustrates a specific example of the present disclosure. Therefore, the numerical values, shapes, components, the arrangement and connection of the components, steps (processes), and the order of steps shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, each figure is a schematic diagram and is not necessarily an exact illustration. In each figure, substantially identical components are assigned the same reference numerals, and redundant explanations will be omitted or simplified.

[0031] First Embodiment <Configuration> FIG. 1 is a block diagram showing an example of the configuration of a distance measuring device 10 according to a first embodiment.

[0032] The distance measuring device 10 shown in FIG. 1 outputs one or more pieces of distance information indicating the distance to the subject 500 .

[0033] 1, the distance measuring device 10 includes a light source 20, a light receiving unit 30, a distance measurement calculation unit 40, an optical system 50, and a control unit 60. The distance measurement calculation unit 40 includes a distance information calculation unit 110, a distance information selection unit 120, and an output unit 130.

[0034] The control unit 60 controls the light source 20 , the light receiving unit 30 , and the distance measurement calculation unit 40 .

[0035] The light source 20 emits irradiated light that includes one or more bright areas that are brighter than the surroundings. The irradiated light may be, for example, infrared light or visible light.

[0036] The timing of light emission from the light source 20 is controlled by, for example, the control unit 60 .

[0037] FIG. 2 is a schematic diagram showing an example of the irradiation light emitted by the light source 20. As shown in FIG.

[0038] As shown in FIG. 2, the illumination light emitted by the light source 20 includes one or more bright areas that are brighter than the surroundings, and dark areas that are brighter than the bright areas.

[0039] The illumination light shown in FIG. 2 is merely an example of illumination light emitted by the light source 20, and the illumination light emitted by the light source 20 does not necessarily have to be limited to the illumination light shown in FIG.

[0040] FIG. 3 shows examples of variations of the illumination light emitted by the light source 20. In FIG.

[0041] As shown in FIGS. 2 and 3, the illumination light emitted by the light source 20 may be illumination light that includes one or more bright portions.

[0042] Returning to FIG. 1, the description of the configuration of the distance measuring device 10 will continue.

[0043] The light receiving section 30 includes a pixel array 32 (see FIG. 4 described later) configured by arranging a plurality of pixels 31 (see FIG. 4 described later) in a matrix.

[0044] When the light receiving unit 30 receives the light emitted from the light source 20 and reflected by the subject 500, it outputs multiple pixel values ​​(described below) based on the exposure amount of each of the multiple pixels 31 provided in the light receiving unit 30.

[0045] Each time the pixel 31 is exposed to light, the pixel 31 generates a charge according to the amount of exposure and outputs a pixel value according to the generated charge. That is, the pixel 31 sequentially outputs a pixel value based on the amount of exposure.

[0046] The timing of exposure and the timing of outputting pixel values ​​of the pixels 31 are controlled by, for example, the control unit 60 .

[0047] The optical system 50 collects the light emitted from the light source 20 and reflected by the subject 500 onto the surface of the pixel array 32 .

[0048] Figure 4 is an enlarged schematic diagram of a portion of the surface of the pixel array 32, showing how the optical system 50 focuses the light emitted from the light source 20 and reflected by the subject 500 onto the surface of the pixel array 32.

[0049] As shown in Figure 4, each of the one or more bright areas contained in the reflected light is concentrated on the surface of M (M is an integer greater than or equal to 3) pixels 31 out of the multiple pixels 31 that make up the pixel array 32, regardless of the distance from the ranging device 10 to the subject 500.

[0050] Therefore, each of the one or more bright portions contained in the reflected light is received by M pixels 31 out of the plurality of pixels 31 that make up the pixel array 32 .

[0051] 4 shows an example where M is 25, but this is just one example, and M does not necessarily have to be limited to 25 as long as it is an integer equal to or greater than 3. Furthermore, the number of M may differ for each pixel position.

[0052] Returning to FIG. 1, the description of the configuration of the distance measuring device 10 will continue.

[0053] The distance information calculation unit 110 calculates, for each of the multiple pixels 31, light intensity information indicating the intensity of reflected light at the pixel and pixel distance information indicating the distance to the subject 500 at the pixel 31 based on one or more pixel values ​​sequentially output from the pixel 31.

[0054] The distance information calculation unit 110 may calculate the light intensity information and pixel distance information using, for example, a known pulse TOF (Time Of Flight) method, or may calculate the light intensity information and pixel distance information using a known CW (Continuous Wave) TOF method.

[0055] FIG. 5 is a schematic diagram showing how the distance information calculation unit 110 calculates light intensity information and pixel distance information using the pulse TOF method, and FIG. 6 is a schematic diagram showing how the distance information calculation unit 110 calculates light intensity information and pixel distance information using the CW TOF method.

[0056] Returning to FIG. 1, the description of the configuration of the distance measuring device 10 will continue.

[0057] The distance information selection unit 120 selects one or more pieces of selected distance information from the plurality of pieces of pixel distance information corresponding to the plurality of pixels 31 , based on the plurality of pieces of light intensity information corresponding to the plurality of pixels 31 .

[0058] More specifically, the distance information selection unit 120 selects, as one or more selected distance information, pixel distance information corresponding to the maximum light intensity pixel that corresponds to light intensity information that indicates the strongest intensity among the one or more pixels 31 that receive the bright portion and whose intensity of reflected light indicated by the corresponding light intensity information is not saturated, for each of one or more bright portions contained in the reflected light.

[0059] Figures 7 and 8 are schematic diagrams showing how the distance information selection unit 120 selects selected distance information for each of one or more bright areas contained in the reflected light when M pixels 31 that receive bright areas are arranged in a row in the column direction.

[0060] Here, Figure 7 is a schematic diagram of a case where (1) the intensity of reflected light indicated by the light intensity information corresponding to reflected light from the low reflectivity region 500A (see Figure 1) of the subject 500 is smaller than the intensity required to calculate pixel distance information, (2) the intensity of reflected light indicated by the light intensity information corresponding to reflected light from the medium reflectivity region 500B (see Figure 1) and the high reflectivity region 500C (see Figure 1) of the subject 500 is greater than the intensity required to calculate pixel distance information, and (3) the intensity of reflected light indicated by the light intensity information corresponding to reflected light from the high reflectivity region 500C is not saturated, and Figure 8 is a schematic diagram of a case where (1) the intensity of reflected light indicated by the light intensity information corresponding to reflected light from the low reflectivity region 500A, the medium reflectivity region 500B, and the high reflectivity region 500C is greater than the intensity required to calculate pixel distance information, and (2) the intensity of reflected light indicated by some of the light intensity information corresponding to reflected light from the high reflectivity region 500C is saturated.

[0061] For example, as shown in Figure 7, if the intensity of the reflected light indicated by the light intensity information corresponding to the reflected light from the low reflectivity region 500A is smaller than the intensity required to calculate the pixel distance information, the intensity of the irradiation light emitted by the light source 20 can be increased, for example, to make the intensity of the reflected light indicated by the light intensity information corresponding to the reflected light from the low reflectivity region 500A greater than the intensity required to calculate the pixel distance information.In this way, even if the intensity of the reflected light indicated by some of the light intensity information corresponding to the reflected light from the high reflectivity region 500C becomes saturated, as shown in Figure 8, it is possible to select selected distance information in the dynamic range from the reflected light from the low reflectivity region 500A to the reflected light from the high reflectivity region 500C.

[0062] Returning to FIG. 1, the description of the configuration of the distance measuring device 10 will continue.

[0063] The output unit 130 outputs one or more pieces of distance information indicating the distance to the subject 500 based on the one or more pieces of selected distance information selected by the distance information selection unit 120 .

[0064] More specifically, output section 130 outputs one or more pieces of selected distance information selected by distance information selection section 120 as one or more pieces of distance information indicating the distance to subject 500 .

[0065] <Operation> The operation performed by the distance measuring device 10 having the above configuration will be described below.

[0066] The distance measuring device 10 performs a first distance measuring process to measure the distance to the subject 500 .

[0067] FIG. 9 is a flowchart of the first distance measurement process performed by the distance measuring device 10.

[0068] The first ranging process is started, for example, when a user using the ranging device 10 holds the ranging device 10 in a direction in which the irradiated light travels toward the subject 500, and performs an operation on the ranging device 10 to start the first ranging process.

[0069] When the first distance measurement process is started, the light source 20 emits irradiation light toward the subject 500 (step S10).

[0070] Then, the pixel 31 receives the irradiated light reflected by the subject 500 (step S20), and outputs a pixel value based on the exposure amount of the reflected light (step S30).

[0071] If the number of times that pixel 31 receives light has not reached the number of times required for distance information calculation unit 110 to calculate light intensity information and pixel distance information (step S40: No), the process returns to step S10.

[0072] In the processing of step S40, if the number of times that pixel 31 receives light reaches the number of times required for the distance information calculation unit 110 to calculate light intensity information and pixel distance information (step S40: Yes), the distance information calculation unit 110 calculates light intensity information and pixel distance information for each of the multiple pixels 31 based on one or more pixel values ​​output from that pixel 31 (step S50).

[0073] Once the light intensity information and pixel distance information have been calculated, the distance information selection unit 120 identifies each of the M pixels 31 that receive one or more bright areas contained in the reflected light based on the multiple light intensity information corresponding to each of the multiple pixels 31 (step S60).

[0074] The distance information selection unit 120 may, for example, perform blob analysis on the multiple pixels 31 using multiple pieces of light intensity information corresponding to each of the multiple pixels 31, thereby identifying each of the M pixels 31 that receive one or more bright areas contained in the reflected light.

[0075] Once each of the M pixels 31 that receive one or more bright areas contained in the reflected light has been identified, the distance information selection unit 120 selects, as the selected distance information, the pixel distance information corresponding to the maximum light intensity pixel that corresponds to the light intensity information that indicates the strongest intensity among the one or more pixels 31 whose corresponding light intensity information indicates that the intensity of the reflected light is not saturated, among the M identified pixels 31 (step S70).

[0076] Figure 10 is a schematic diagram showing an example of how the distance information selection unit 120 identifies the maximum light intensity pixel for each of M pixels 31, whose corresponding light intensity information indicates the strongest intensity among one or more pixels 31, and selects the pixel distance information corresponding to the identified maximum light intensity pixel as the selected distance information.

[0077] Returning to FIG. 9 again, the description of the first distance measurement process will be continued.

[0078] When one or more pieces of selected distance information are selected, the output unit 130 outputs the one or more pieces of selected distance information as one or more pieces of distance information indicating the distance to the subject 500 (step S80).

[0079] When the process of step S80 is completed, the distance measuring device 10 ends the first distance measuring process.

[0080] <Discussion> With the distance measuring device 10, as shown in Figure 8, even if the subject 500 includes a high-reflectivity region 500C where the intensity of some of the bright areas in the reflected light exceeds the intensity required to calculate pixel distance information and becomes saturated, the distance information selection unit 120 can select pixel distance information indicating the distance to the high-reflectivity region 500C as the selected distance information.

[0081] Therefore, the distance measuring device 10 can calculate distance information indicating the distance to the high reflectance region 500C.

[0082] In contrast, in the case of a conventional distance measuring device according to a comparative example in which the light source emits surface illumination light (flood light) with uniform intensity across the entire illumination surface, if the subject 500 includes a high-reflectivity region 500C in which the intensity of the reflected light exceeds the intensity required to calculate pixel distance information and becomes saturated, distance information indicating the distance to the high-reflectivity region 500C cannot be calculated accurately.

[0083] In this way, the distance measuring device 10 can output distance information with higher accuracy than the distance measuring device according to the conventional comparative example.

[0084] Furthermore, according to the distance measuring device 10, as described above, the distance information selection unit 120 can select selected distance information in a dynamic range from reflected light from the low reflectance region 500A to reflected light from the high reflectance region 500C.

[0085] Therefore, the distance measuring device 10 can realize a dynamic range from the low reflectance region 500A to the high reflectance region 500C in calculating distance information.

[0086] In contrast, in the case of the conventional comparative example, as described above, it is not possible to accurately calculate distance information indicating the distance to the high reflectance region 500C.

[0087] For this reason, the distance measuring device according to the conventional comparative example can only realize a dynamic range from the low reflectance region 500A to the medium reflectance region 500B in calculating distance information.

[0088] In this way, the distance measuring device 10 can achieve a wider dynamic range in calculating distance information than the distance measuring device according to the conventional comparative example.

[0089] FIG. 11 is a schematic diagram showing an example of how stray light emitted from the light source 20 and scattered by an object 600 is irradiated onto the subject 500. In FIG.

[0090] Here, we will explain the following: (1) Lambertian scattering is dominant in the scattering of irradiated light by object 600; (2) the intensity of light in dark areas is 0; (3) the area ratio of bright areas to the total irradiated light is 1 / K; and (4) assuming that the irradiated light emitted from light source 20 is surface irradiated light, the intensity of stray light on the surface of subject 500 is 1 / L of the intensity of irradiated light on the surface of subject 500.

[0091] In this case, if the intensity of the bright areas on the surface of the subject 500 is S, then the intensity of the bright areas plus the intensity of stray light (S1) on the surface of the subject 500 is S1 = S + S × 1 / K × 1 / L = S + S / (K × L), and the intensity of the dark areas plus the intensity of stray light (S2) is S2 = 0 + S × 1 / K × 1 / L = S / (K × L).

[0092] That is, in this case, in calculating the distance information, the ratio of the intensity S / (K×L) of stray light, which is a noise component on the surface of the subject 500, to the intensity S of the bright part is 1 / (K×L).

[0093] In contrast, when the distance measuring device according to the above conventional comparative example emits surface illumination light, if the intensity of the surface illumination light on the surface of the subject 500 is S, then the intensity of the surface illumination light on the surface of the subject 500 plus the intensity of stray light (S3) is S3 = S + S × 1 / L = S + S / L.

[0094] That is, in this case, in calculating the distance information, the ratio of the intensity S / K of stray light, which becomes a noise component on the surface of the subject 500, to the intensity S of the light illuminating the surface is 1 / K.

[0095] In this way, the distance measuring device 10 can output distance information with higher accuracy than the distance measuring device according to the conventional comparative example.

[0096] (Modification 1) A distance measuring device according to Modification 1, which is configured by partially modifying the configuration of distance measuring device 10 according to embodiment 1, will be described below.

[0097] Here, for the distance measuring device of variant 1, the components that are similar to those of distance measuring device 10 have already been explained, so they will be assigned the same symbols and their detailed explanations will be omitted, and the explanation will focus on the differences from distance measuring device 10.

[0098] FIG. 12 is a block diagram showing an example of the configuration of a distance measuring device 10A according to the first modification.

[0099] 12, distance measuring device 10A is configured by replacing distance measurement calculation unit 40 of distance measuring device 10 according to embodiment 1 with distance measurement calculation unit 40A. Distance measurement calculation unit 40A is also configured by replacing distance information selection unit 120 of distance measurement calculation unit 40 with distance information selection unit 120A and adding correction unit 180.

[0100] The correction unit 180 corrects low light intensity information, which is light intensity information indicating that the intensity of reflected light is relatively low, to corrected light intensity information indicating a greater intensity of reflected light, and corrects strong light intensity information, which is light intensity information indicating that the intensity of reflected light is relatively high, to corrected light intensity information indicating the intensity of reflected light as is.

[0101] Here, for example, a relatively low intensity of reflected light may be defined as an intensity of reflected light that is smaller than a threshold value, and a relatively high intensity of reflected light may be defined as an intensity of reflected light that is larger than the threshold value.

[0102] When the intensity of reflected light indicated by the light intensity information calculated by the distance information calculation unit 110 is smaller than a threshold value, the correction unit 180 may correct the light intensity information to corrected light intensity information, for example, by performing gamma correction, or may correct the light intensity information to corrected light intensity information, for example, by performing offset correction.

[0103] The threshold value may be, for example, the intensity of reflected light required for distance information selector 120A to select distance information with a predetermined accuracy.

[0104] The distance information selection unit 120A selects one or more pieces of selected distance information from the plurality of pieces of pixel distance information corresponding to the plurality of pixels 31, based on the plurality of pieces of corrected light intensity information corresponding to the plurality of pixels 31, respectively.

[0105] More specifically, the distance information selection unit 120A selects, as one or more selected distance information, pixel distance information corresponding to the maximum light intensity pixel corresponding to the corrected light intensity information that indicates the strongest intensity among the one or more pixels 31 that receive the bright portion in each of the one or more bright portions contained in the reflected light and whose intensity of reflected light indicated by the corresponding corrected light intensity information is not saturated.

[0106] <Operation> The operation performed by the distance measuring device 10A having the above configuration will be described below.

[0107] The distance measuring device 10A performs a second distance measuring process instead of the first distance measuring process performed by the distance measuring device 10 according to the first embodiment.

[0108] FIG. 13 is a flowchart of the second distance measurement process performed by the distance measuring device 10A.

[0109] As shown in Figure 13, the second ranging process is configured by adding step S55 to the first ranging process of embodiment 1, changing step S60 to step S60A, and changing step S70 to step S70A.

[0110] Therefore, the second distance measurement process will be described here, focusing on the process of step S55, the process of step S60A, and the process of step S70A.

[0111] When the process of step S50 is completed, the corrector 180 corrects the light intensity information to corrected light intensity information (step S55).

[0112] Once the light intensity information is corrected to corrected light intensity information, the distance information selection unit 120A identifies each of the M pixels 31 that receive one or more bright areas contained in the reflected light based on the multiple corrected light intensity information corresponding to each of the multiple pixels 31 (step S60A).

[0113] Once each of the M pixels 31 that receive one or more bright areas contained in the reflected light has been identified, the distance information selection unit 120A selects as the selected distance information the pixel distance information corresponding to the maximum light intensity pixel that corresponds to the corrected light intensity information that indicates the strongest intensity among the one or more pixels 31 whose reflected light intensity indicated by the corresponding corrected light intensity information is not saturated among the M identified pixels 31 (step S70A).

[0114] When the process of step S70A is completed, the second distance measurement process proceeds to the process of step S80.

[0115] <Considerations> According to the distance measuring device 10A, it is possible to select the selected distance information with higher accuracy than when the correction unit 180 does not correct the light intensity information.

[0116] Therefore, the distance measuring device 10A can output distance information with higher accuracy than when the correction unit 180 does not correct the light intensity information.

[0117] (Modification 2) A distance measuring device according to Modification 2, which is configured by partially modifying the configuration of the distance measuring device 10 according to the first embodiment, will be described below.

[0118] Here, for the distance measuring device of variant 2, the components that are similar to those of distance measuring device 10 have already been explained, so they will be assigned the same symbols and their detailed explanations will be omitted, and the explanation will focus on the differences from distance measuring device 10.

[0119] FIG. 14 is a block diagram showing an example of the configuration of a distance measuring device 10B according to the second modification.

[0120] 14, the distance measuring device 10B is configured by replacing the distance measurement calculation unit 40 of the distance measuring device 10 according to embodiment 1 with a distance measurement calculation unit 40B. Also, the distance measurement calculation unit 40B is configured by replacing the output unit 130 of the distance measurement calculation unit 40 with an output unit 130B.

[0121] Output section 130B outputs one or more pieces of distance information indicating the distance to subject 500 based on one or more pieces of selected distance information selected by distance information selection section 120.

[0122] More specifically, for each of one or more selected distance information selected by the distance information selection unit 120, the output unit 130B calculates one or more distance information based on the selected distance information and one or more pixel distance information corresponding to each of one or more pixels adjacent to the maximum light intensity pixel corresponding to the selected distance information (hereinafter also referred to as ``adjacent pixels''), and outputs the calculated one or more distance information.

[0123] In this case, when calculating the distance information, if there is a pixel 31 among one or more adjacent pixels in which the intensity of reflected light indicated by the corresponding light intensity information is saturated, the output unit 130B may calculate the distance information excluding the pixel distance information corresponding to that pixel 31.

[0124] The output unit 130B may calculate, as distance information, for example, the selected distance information and a representative value of one or more pieces of pixel distance information corresponding to each of one or more adjacent pixels.

[0125] Here, the representative value may be, for example, a weighted average value, an arithmetic average value, or a median value of the selected distance information and one or more pixel distance information corresponding to each of one or more adjacent pixels.

[0126] Figure 15 is a schematic diagram showing an example of how the output unit 130B calculates one or more pieces of distance information for each of one or more selected distance information based on the selected distance information and one or more pieces of pixel distance information corresponding to each of one or more adjacent pixels.

[0127] <Considerations> The distance measuring device 10B can output distance information with higher accuracy than when one or more pieces of selected distance information are output as one or more pieces of distance information as they are.

[0128] (Modification 3) A distance measuring device according to Modification 3, which is configured by partially modifying the configuration of distance measuring device 10 according to embodiment 1, will be described below.

[0129] Here, for the distance measuring device of variant example 3, the components that are similar to those of distance measuring device 10 have already been explained, so they will be assigned the same symbols and their detailed explanations will be omitted, and the explanation will focus on the differences from distance measuring device 10.

[0130] FIG. 16 is a block diagram showing an example of the configuration of a distance measuring device 10C according to the third modification.

[0131] As shown in FIG. 16, the distance measuring device 10C is configured by changing the light source 20 in the distance measuring device 10 according to the first embodiment to a light source 20C.

[0132] The light source 20C includes a first light source 201 that emits a first irradiation light including one or more bright portions, and a second light source 202 that emits a second irradiation light having a pattern of one or more bright portions different from that of the first irradiation light.

[0133] The first light source 201 and the second light source 202 may emit light alternately, for example, or may emit light simultaneously, for example.

[0134] The first light source 201 and the second light source 202 may be mounted in the same package, for example, or may not be mounted in the same package, for example.

[0135] FIG. 17 shows examples of variations of the first irradiation light and the second irradiation light emitted by the first light source 201 and the second light source 202.

[0136] <Consideration> The distance measuring device 10C can irradiate the subject 500 with first illumination light and second illumination light, each of which has one or more different patterns of bright areas.

[0137] Therefore, the pattern of one or more bright areas on the subject 500 can be made more diverse than when only the first irradiation light is irradiated onto the subject 500 .

[0138] Therefore, the distance measuring device 10C can increase the spatial resolution of one or more pieces of distance information to be output compared to when only the first irradiation light is irradiated.

[0139] In the third variant example, both the first light source 201 and the second light source 202 are described as emitting irradiation light including one or more bright areas, but it is also possible that one of them, for example, the first light source 201, emits irradiation light including one or more bright areas, and the other, for example, the second light source 202, emits surface irradiation light.

[0140] FIG. 18 shows an example in which the first light source 201 emits illumination light including one or more bright portions, and the second light source 202 emits surface illumination light.

[0141] In the third modification, the light source 20C is described as including two light sources, the first light source 201 and the second light source 202, but the light source 20C may include three or more light sources.

[0142] (Modification 4) A distance measuring device according to Modification 4, which is configured by partially modifying the configuration of the distance measuring device 10 according to the first embodiment, will be described below.

[0143] Here, for the distance measuring device of variant example 4, the components that are similar to those of distance measuring device 10 have already been explained, so they will be assigned the same symbols and their detailed explanations will be omitted, and the explanation will focus on the differences from distance measuring device 10.

[0144] FIG. 19 is a block diagram showing an example of the configuration of a distance measuring device 10D according to the fourth modification.

[0145] As shown in FIG. 19, the distance measuring device 10D is configured by adding a light source driving unit 70 to the distance measuring device 10 according to the first embodiment.

[0146] The light source driving unit 70 drives the light source 20 so as to change the position of one or more bright areas in the subject 500. Methods for driving the light source include a method of directly moving the light source itself, a method of changing the direction of the light emitted from the light source using a mirror or the like, and the like.

[0147] FIG. 20 is a schematic diagram showing an example of how the positions of one or more bright areas in the subject 500 change as a result of the light source driving section 70 driving the light source 20. In FIG.

[0148] <Consideration> The distance measuring device 10D can irradiate the subject 500 with irradiation light so that the positions of one or more bright areas change.

[0149] Therefore, compared to when the subject 500 is irradiated with irradiation light in which the positions of the one or more bright portions do not change, the pattern of the one or more bright portions on the subject 500 can be made more diverse.

[0150] Therefore, the distance measuring device 10D can increase the spatial resolution of one or more pieces of distance information to be output, compared to when irradiating with irradiation light in which the position of one bright portion does not change.

[0151] (Modification 5) A distance measuring device according to Modification 5, which is configured by partially modifying the configuration of the distance measuring device 10 according to the first embodiment, will be described below.

[0152] Here, for the distance measuring device of variant 5, the components that are similar to those of distance measuring device 10 have already been explained, so they will be assigned the same symbols and their detailed explanations will be omitted, and the explanation will focus on the differences from distance measuring device 10.

[0153] FIG. 21 is a block diagram showing an example of the configuration of a distance measuring device 10E according to the fifth modification.

[0154] As shown in FIG. 21, the distance measuring device 10E is configured by changing the light source 20 in the distance measuring device 10 according to the first embodiment to a light source 20E.

[0155] The light source 20E switches the area where one or more bright portions included in the emitted illumination light exist between the entire illumination range of the illumination light and a specific area selected from the entire illumination range of the illumination light.

[0156] FIG. 22 is a schematic diagram showing an example of how the light source 20E switches between one or more bright areas included in the emitted light.

[0157] <Consideration> The distance measuring device 10E is capable of irradiating the subject 500 with irradiation light that includes one or more bright areas in a selected specific area.

[0158] Therefore, distance measuring device 10E can output only one or more pieces of distance information indicating the distance to a specific region of subject 500.

[0159] Second Embodiment A distance measuring device according to a second embodiment, which is configured by partially modifying the configuration of the distance measuring device 10 according to the first embodiment, will be described below.

[0160] Here, for the distance measuring device of embodiment 2, components that are similar to those of distance measuring device 10 have already been explained, so they will be assigned the same symbols and their detailed explanations will be omitted, and the explanation will focus on the differences from distance measuring device 10.

[0161] FIG. 23 is a block diagram showing an example of the configuration of a distance measuring device 10F according to the second embodiment.

[0162] 23, distance measuring device 10F is configured by changing distance measurement calculation unit 40 from distance measuring device 10 according to embodiment 1 to distance measurement calculation unit 40F. Distance measurement calculation unit 40F is also configured by changing distance information selection unit 120 from distance measurement calculation unit 40 to distance information selection unit 120F, and by adding storage unit 140 and matching processing unit 150.

[0163] The storage unit 140 stores a template 141 relating to the distribution of the intensity of reflected light in one or more bright portions of the reflected light of the irradiation light emitted from the light source 20 .

[0164] Here, the description will be given assuming that the storage unit 140 stores a template 141 that indicates the distribution of the intensity of reflected light.

[0165] 24A to 24D are conceptual diagrams showing examples of templates 141 stored in storage unit 140 when the distribution of the intensity of reflected light is one-dimensional.

[0166] Template 141 shown in Figure 24A is an example of a template that shows an example of a distribution of reflected light intensity corresponding to a case where the intensity of reflected light is not saturated at the position of the peak intensity of reflected light. Template 141 shown in Figure 24B is an example of a template that shows an example of a distribution of reflected light intensity corresponding to a case where the intensity of reflected light is saturated at the position of the peak intensity of reflected light and its surrounding positions. Template 141 shown in Figure 24C is an example of a template that shows an example of a distribution of reflected light intensity corresponding to a case where a boundary with an area of ​​different reflectance exists near the position of the peak intensity of reflected light. Template 141 shown in Figure 24D is an example of a template that shows an example of a distribution of reflected light intensity corresponding to a case where the intensity distribution of reflected light is rectangular.

[0167] FIG. 25 is an image diagram showing an example of the template 141 stored in the storage unit 140, in which the distribution of the intensity of reflected light is two-dimensional.

[0168] The template 141 shown in Figure 25 is an example of a template that shows an example of the distribution of the intensity of reflected light corresponding to a 5 x 5 Gaussian kernel with the position of the peak of the intensity of reflected light as the center.

[0169] Returning to FIG. 23, the description of the distance measuring device 10F will be continued.

[0170] For each of the multiple pixels 31 that make up the pixel array 32, the matching processing unit 150 calculates a similarity indicating the degree of similarity between the distribution of reflected light intensity indicated by N pieces of light intensity information corresponding to N pixels consisting of the pixel in question and N (N is an integer greater than or equal to 2)-1 pixels surrounding the pixel in question, and the distribution of reflected light intensity indicated by the template 141 stored in the memory unit 140.

[0171] The matching processing unit 150 may calculate N pieces of light intensity information for similarity calculation by, for example, performing a filtering process on N pieces of light intensity information for each of the multiple pixels 31 that make up the pixel array 32.

[0172] For example, when the template 141 stored in the storage unit 140 is a 5×5 Gaussian kernel as shown in FIG. 25 , the filtering process performed by the matching processing unit 150 may be a process performed on 25 pieces of light intensity information corresponding to 25 pixels 31 located in a range of 5×5 vertical (columns) × 5 horizontal (rows) centered on each of the multiple pixels 31 that make up the pixel array 32.

[0173] Here, the filtering process may be performed separately vertically and horizontally.

[0174] Furthermore, the filtering process may be performed with normalization as a pre-processing step.

[0175] For example, the matching processing unit 150 may perform a matching process for each of the multiple pixels 31 that make up the pixel array 32 between the distribution of reflected light intensity indicated by the N pieces of filtered light intensity information and the distribution of reflected light intensity indicated by the template 141 stored in the memory unit 140, and calculate the similarity between the distribution of reflected light intensity indicated by the N pieces of light intensity information and the distribution of reflected light intensity indicated by the template 141 stored in the memory unit 140.

[0176] Here, the matching process may be, for example, a matching process using the SAD (Sum of Absolute Difference) method, a matching process using the SSD (Sum of Squared Difference) method, a matching process using the NCC (Normalized Cross Correlation) method, a matching process using the POC (Phase only Correlation) method, or a matching process using another method.

[0177] FIG. 26 is a schematic diagram showing an example of how the matching processing unit 150 performs the matching processing.

[0178] The diagram on the left side of Fig. 26 is a light intensity image in which the intensities of reflected light indicated by the plurality of pieces of light intensity information corresponding to each of the plurality of pixels 31 constituting the pixel array 32 are mapped in an array form. In this light intensity image, the shading of each dot is displayed according to the intensity of reflected light, with whiter dots indicating stronger reflected light intensity.

[0179] 26 is an intermediate progress image showing the state of the intermediate progress of the matching process performed by the matching processing unit 150. In this intermediate progress image, white areas correspond to areas with a relatively high degree of similarity.

[0180] 26 is a final result image showing the state of the result of the matching process performed by the matching processing unit 150. In this final result image, each white dot corresponds to the pixel 31 with the highest similarity in each of one or more bright areas included in the reflected light. That is, in the final result image, each white dot corresponds to the pixel 31 corresponding to the position of the peak of the intensity of the reflected light in each of one or more bright areas included in the reflected light.

[0181] As shown in FIG. 26, the matching processing unit 150 may identify pixels 31 corresponding to the positions of the peaks of the intensity of the reflected light in each of one or more bright areas included in the reflected light.

[0182] Returning to FIG. 23, the description of the distance measuring device 10F will be continued.

[0183] Distance information selection unit 120F selects, from among the plurality of pixels 31, pixel distance information corresponding to pixels 31 whose similarity satisfies a predetermined condition as one or more pieces of distance information.

[0184] Here, the predetermined condition may be, for example, a condition that the similarity is greater than a predetermined threshold value, or, for example, in a case where the matching processing unit 150 identifies a pixel 31 corresponding to the position of the peak intensity of the reflected light in each of one or more bright areas contained in the reflected light, the predetermined condition may be a condition that the pixel 31 identified by the matching processing unit 150 corresponds to the position of the peak intensity of the reflected light.

[0185] <Discussion> It is generally known that distance information calculated based on the pixel values ​​of pixels located in areas where the intensity of reflected light is relatively high is more accurate than distance information calculated based on the pixel values ​​of pixels located in areas where the intensity of reflected light is relatively low.

[0186] According to the distance measuring device 10F having the above-described configuration, each of the one or more distance information pieces calculated is calculated based on the pixel value of pixel 31 corresponding to the position of the peak intensity of the reflected light in each of one or more bright areas contained in the reflected light.

[0187] Therefore, according to the distance measuring device 10F, it is possible to output distance information with higher accuracy than when each of the one or more distance information calculated is not calculated based on the pixel value of the pixel 31 corresponding to the position of the peak intensity of the reflected light.

[0188] In the second embodiment, the matching processing unit 150 is described as performing matching processing for each of the pixels 31 that make up the pixel array 32, but the matching processing unit 150 does not necessarily have to be limited to a configuration that performs matching processing for each of the pixels 31 that make up the pixel array 32.

[0189] The matching processing unit 150 may perform matching processing for each of the pixels 31 located at regular intervals in the pixel array 32, for example, in accordance with the shape and / or spacing of one or more bright areas in the irradiated light.

[0190] Furthermore, for example, when the matching process outputs the shift amount up to the position where the similarity is maximum in addition to the similarity that is the matching result (for example, when performing matching process using the POC method), the matching processing unit 150 may omit the matching process for pixels that exist between the central pixel position when the matching process was performed and the position indicated by the output shift amount.

[0191] Moreover, the input to the matching processing unit 150 may be pixel distance information instead of light intensity information.

[0192] (Modification 6) A distance measuring device according to Modification 6, which is configured by partially modifying the configuration of distance measuring device 10F according to Embodiment 2, will be described below.

[0193] Here, for the distance measuring device of variant 6, the components that are similar to those of distance measuring device 10F have already been explained, so they will be assigned the same symbols and their detailed explanation will be omitted, and the explanation will focus on the differences from distance measuring device 10F.

[0194] FIG. 27 is a block diagram showing an example of the configuration of a distance measuring device 10G according to the sixth modification.

[0195] 27, distance measuring device 10G is configured by replacing distance measurement calculation unit 40F of distance measuring device 10F according to embodiment 2 with distance measurement calculation unit 40G. Distance measurement calculation unit 40G is also configured by adding coring unit 160 to distance measurement calculation unit 40F and replacing distance information selection unit 120F with distance information selection unit 120G.

[0196] The coring unit 160 performs a coring process on the similarity calculated by the matching processing unit 150 to calculate a core similarity.

[0197] The distance information selection unit 120G performs the same processing as the processing performed by the distance information selection unit 120F, but with the similarity replaced with the core similarity. That is, the distance information selection unit 120G calculates, as one or more pieces of distance information, pixel distance information corresponding to pixels 31 of the plurality of pixels 31 whose core similarity satisfies a predetermined condition.

[0198] <Consideration> The distance measuring device 10G calculates one or more pieces of distance information using the core similarity.

[0199] Therefore, the distance measuring device 10G can output distance information with higher accuracy than when one or more pieces of distance information are calculated using similarity.

[0200] (Variation 7) A distance measuring device according to Variation 7, which is configured by partially modifying the configuration of distance measuring device 10F according to Embodiment 2, will be described below.

[0201] Here, for the distance measuring device of variant 7, the components that are similar to those of distance measuring device 10F have already been explained, so they will be assigned the same symbols and their detailed explanations will be omitted, and the explanation will focus on the differences from distance measuring device 10F.

[0202] FIG. 28 is a block diagram showing an example of the configuration of a distance measuring device 10H according to the seventh modification.

[0203] 28, the distance measuring device 10H is configured by changing the distance measurement calculation unit 40F of the distance measuring device 10F according to embodiment 2 to a distance measurement calculation unit 40H. The distance measurement calculation unit 40H is also configured by adding a feature calculation unit 170 to the distance measurement calculation unit 40F, changing the storage unit 140 to a storage unit 140H, and changing the matching processing unit 150 to a matching processing unit 150H.

[0204] For each of the multiple pixels 31 that make up the pixel array 32, the feature calculation unit 170 calculates a feature of the intensity of reflected light indicated by N pieces of light intensity information corresponding to N pixels consisting of the pixel in question and N (N is an integer greater than or equal to 2) - 1 pixels surrounding the pixel in question.

[0205] Here, the feature amount calculation unit 170 may calculate the feature amount using, for example, a SIFT (Scale Invariant Feature Transform) method, a SURF (Speeded-Up Robust Features) method, an ORB (Oriented FAST and Rotated BRIEF) method, a FAST (Features from Accelerated Segment Test) method, a BRIEF (Binary Robust Independent Elementary Features) method, or a BRISK (Binary Robust The feature amount may be calculated using the Invariant Scalable Keypoints method, or may be calculated using other methods.

[0206] The memory unit 140H is configured by changing the template stored in the memory unit 140 according to embodiment 2 from template 141 to template 141H relating to the characteristics of the intensity of the reflected light in one or more bright areas in the reflected light of the irradiation light emitted from the light source 20.

[0207] Here, the description will be given assuming that the storage unit 140H stores a template 141H that indicates the characteristics of the intensity of reflected light.

[0208] The matching processing unit 150H calculates a similarity indicating the degree of similarity between the feature calculated by the feature calculation unit 170 and the feature of the reflected light intensity indicated by the template 141H stored in the memory unit 140H for each of the multiple pixels 31 that make up the pixel array 32.

[0209] The matching processing unit 150H may, for example, calculate the similarity using the L1 distance, may calculate the similarity using the L2 distance, may calculate the similarity using the Hamming distance, or may calculate the similarity using some other method.

[0210] <Discussion> According to the distance measuring device 10H, as with the distance measuring device 10F of embodiment 2, each of the one or more distance information items calculated is calculated based on the pixel value of the pixel 31 corresponding to the position of the peak intensity of the reflected light in each of one or more bright areas contained in the reflected light.

[0211] Therefore, according to the ranging device 10H, like the ranging device 10F, it is possible to output distance information with higher accuracy than when each of the one or more distance information calculated is not calculated based on the pixel value of the pixel 31 corresponding to the position of the peak intensity of the reflected light.

[0212] In addition, in variant example 7, the matching processing unit 150H is described as performing matching processing for each of the pixels 31 that make up the pixel array 32, but the matching processing unit 150H does not necessarily have to be limited to a configuration that performs matching processing for each of the pixels 31 that make up the pixel array 32.

[0213] The matching processing unit 150H may perform matching processing for each of the pixels 31 located at regular intervals in the pixel array 32, for example, in accordance with the shape and / or spacing of one or more bright areas in the irradiated light.

[0214] Moreover, the input to the matching processing unit 150H may be pixel distance information instead of light intensity information.

[0215] (Modification 8) Hereinafter, a distance measuring device according to Modification 8, which is configured by partially changing the configuration of the distance measuring device 10H according to Modification 7, will be described.

[0216] Here, for the distance measuring device of variant 8, the components that are similar to those of distance measuring device 10H have already been explained, so they will be assigned the same symbols and their detailed explanations will be omitted, and the explanation will focus on the differences from distance measuring device 10H.

[0217] FIG. 29 is a block diagram showing an example of the configuration of a distance measuring device 10I according to the eighth modification.

[0218] 29, distance measuring device 10I is configured by changing distance measurement calculation unit 40H of distance measuring device 10H according to Modification 7 to distance measurement calculation unit 40I. Distance measurement calculation unit 40I is also configured by adding a coring unit 160I to distance measurement calculation unit 40H and changing distance information selection unit 120F to distance information selection unit 120G.

[0219] The coring unit 160I performs a coring process on the similarity calculated by the matching processing unit 150H to calculate a core similarity.

[0220] <Consideration> The distance measuring device 10I calculates one or more pieces of distance information using the core similarity.

[0221] Therefore, distance measuring device 10I can output distance information with higher accuracy than when one or more pieces of distance information are calculated using similarity.

[0222] (Modification 9) A distance measuring device according to Modification 9, which is configured by partially modifying the configuration of distance measuring device 10F according to Embodiment 2, will be described below.

[0223] Here, for the distance measuring device of variant 9, the components that are similar to those of distance measuring device 10F have already been explained, so they will be assigned the same symbols and their detailed explanations will be omitted, and the explanation will focus on the differences from distance measuring device 10F.

[0224] FIG. 30 is a block diagram showing an example of the configuration of a distance measuring device 10J according to the ninth modification.

[0225] 30 , distance measuring device 10J is configured by changing distance measurement calculation unit 40F from distance measuring device 10F according to embodiment 2 to distance measurement calculation unit 40J. Also, distance measurement calculation unit 40J is configured by changing distance information selection unit 120F from distance measurement calculation unit 40F to distance information selection unit 120J, storage unit 140 from storage unit 140J, and matching processing unit 150 from matching processing unit 150J.

[0226] The memory unit 140J stores a machine learning model 141J that has been pre-trained so that when it receives N pieces of light intensity information corresponding to N pixels 31 consisting of any one pixel 31 among the multiple pixels 31 that make up the pixel array 32 and N (N is an integer greater than or equal to 2)-1 pixels 31 surrounding the any one pixel 31, it outputs a reliability indicating the degree of reliability that the pixel distance information corresponding to the any one pixel 31 is one of the one or more pieces of distance information selected by the distance information selection unit 120J.

[0227] The machine learning model 141J may be, for example, mobilenet (v1, v2, v3, etc.) + SSD, YOLO, Efficient-Det, another object detection model, or a machine learning model other than an object detection model.

[0228] The matching processing unit 150J calculates the reliability of each of the multiple pixels 31 that make up the pixel array 32 using the machine learning model 141J.

[0229] The distance information selection unit 120J selects, from among the plurality of pixels 31, pixel distance information corresponding to pixels 31 whose reliability satisfies a predetermined condition as one or more pieces of distance information.

[0230] Here, the predetermined condition may be, for example, that the reliability is greater than a predetermined threshold value.

[0231] <Discussion> According to the distance measuring device 10J, as with the distance measuring device 10F of embodiment 2, each of the one or more distance information items calculated is calculated based on the pixel value of the pixel 31 corresponding to the position of the peak intensity of the reflected light in each of one or more bright areas contained in the reflected light.

[0232] Therefore, according to the ranging device 10J, like the ranging device 10F, it is possible to output distance information with higher accuracy than when each of the one or more distance information calculated is not calculated based on the pixel value of the pixel 31 corresponding to the position of the peak intensity of the reflected light.

[0233] In addition, in variant example 9, the matching processing unit 150J has been described as performing matching processing for each of the pixels 31 that make up the pixel array 32, but the matching processing unit 150J does not necessarily have to be limited to a configuration that performs matching processing for each of the pixels 31 that make up the pixel array 32.

[0234] The matching processing unit 150J may perform matching processing for each of the pixels 31 located at regular intervals in the pixel array 32, for example, in accordance with the shape and / or spacing of one or more bright areas in the irradiated light.

[0235] (Modification 10) A distance measuring device according to Modification 10, which is configured by partially changing the configuration of the distance measuring device 10J according to Modification 10, will be described below.

[0236] Here, for the distance measuring device of variant 10, components that are similar to those of distance measuring device 10J have already been explained, so they will be assigned the same symbols and their detailed explanations will be omitted, and the explanation will focus on the differences from distance measuring device 10J.

[0237] FIG. 31 is a block diagram showing an example of the configuration of a distance measuring device 10K according to the tenth modification.

[0238] 31 , distance measuring device 10K is configured by changing distance measurement calculation unit 40J from distance measuring device 10J according to Modification 9 to distance measurement calculation unit 40K. Distance measurement calculation unit 40K is also configured by adding a coring unit 160K to distance measurement calculation unit 40J and changing distance information selection unit 120F to distance information selection unit 120K.

[0239] The coring unit 160K performs a coring process on the reliability calculated by the matching processing unit 150J to calculate a core reliability.

[0240] The distance information selection unit 120K performs the same processing as the processing performed by the distance information selection unit 120J, but with the reliability replaced with the core reliability. That is, the distance information selection unit 120K calculates, as one or more pieces of distance information, pixel distance information corresponding to pixels 31 whose core reliability satisfies a predetermined condition among the multiple pixels 31.

[0241] Here, the predetermined condition may be, for example, that the core reliability is greater than a predetermined threshold value.

[0242] <Consideration> The distance measuring device 10K calculates one or more pieces of distance information using the core reliability.

[0243] Therefore, the distance measuring device 10K can output distance information with higher accuracy than when distance information of 1 or more is calculated using reliability.

[0244] (Supplementary Note) A distance measuring device according to one aspect of the present disclosure has been described above based on Embodiments 1 and 2 and Modifications 1 to 10, but the present disclosure is not limited to these embodiments and modifications. Various modifications that would occur to a person skilled in the art may be applied to the embodiments and / or modifications, and configurations constructed by combining components of different embodiments and / or modifications may also be included within the scope of one or more aspects of the present disclosure, provided that they do not deviate from the spirit of the present disclosure.

[0245] The present disclosure is widely applicable to distance measuring devices and the like.

[0246] 10, 10A, 10B, 10C, 10D, 10E, 10F, 10G, 10H, 10I, 10J, 10K Distance measuring device 20, 20C, 20E Light source 30 Light receiving unit 31 Pixel 32 Pixel array 40, 40A, 40B, 40F, 40G, 40H, 40I, 40J, 40K Distance measurement calculation unit 50 Optical system 60 Control unit 70 Light source driving unit 110 Distance information calculation unit 120, 120A, 120F, 120G, 120J, 120K Distance information selection unit 130, 130B Output unit 140, 140H, 140J Memory unit 141, 141H Template 141J Machine learning model 150, 150H, 150J Matching processing unit 160, 160I, 160K Coring unit 170 Feature amount calculation unit 180 Correction unit 201 First light source 202 Second light source 500 Subject 500A Low reflectance region 500B Medium reflectance region 500C High reflectance region 600 Object

Claims

1. A distance measuring device that outputs one or more pieces of distance information indicating a distance to a subject, a light source that emits irradiation light including one or more bright areas that are brighter than the surrounding area; a light receiving section having a pixel array in which a plurality of pixels are arranged in a matrix and sequentially output pixel values ​​based on the amount of exposure; a distance information calculation unit that calculates, for each of the plurality of pixels, light intensity information indicating an intensity of the reflected light at the pixel and pixel distance information indicating a distance to the subject at the pixel, based on one or more pixel values ​​sequentially output from the pixel, when the light receiving unit receives light of the irradiation light reflected by the subject; a distance information selection unit that selects one or more pieces of selected distance information from the plurality of pieces of pixel distance information corresponding to the plurality of pixels, based on the plurality of pieces of light intensity information corresponding to the plurality of pixels; an output unit that outputs the one or more pieces of distance information based on the one or more pieces of selected distance information; Ranging device.

2. When the light receiving unit receives the reflected light, each of the one or more bright portions included in the reflected light is received by M (M is an integer of 3 or more) pixels among the plurality of pixels, The distance information selection unit selects, as the one or more selected distance information, the pixel distance information corresponding to a maximum light intensity pixel that corresponds to light intensity information indicating the strongest intensity among the one or more pixels in each of the one or more bright portions included in the reflected light, the maximum light intensity pixel indicating the strongest intensity among the one or more pixels in which the intensity of the reflected light indicated by the corresponding light intensity information is not saturated.

2. The distance measuring device according to claim 1.

3. The output unit outputs the one or more pieces of selected distance information as the one or more pieces of distance information.

3. The distance measuring device according to claim 2.

4. The output unit calculates, for each of the one or more pieces of selected distance information, the one or more pieces of pixel distance information corresponding to the one or more pixels adjacent to the maximum light intensity pixel corresponding to the selected distance information, and outputs the calculated one or more pieces of distance information.

3. The distance measuring device according to claim 2.

5. a correction unit that corrects low light intensity information, which is the light intensity information indicating a relatively low intensity of the reflected light, to corrected light intensity information indicating a greater intensity of the reflected light, and corrects high light intensity information, which is the light intensity information indicating a relatively high intensity of the reflected light, to corrected light intensity information indicating the intensity of the reflected light as is, the distance information calculation unit calculates the pixel distance information for each of the plurality of pixels based on the corrected light intensity information; The distance information selection unit selects the one or more pieces of selected distance information based on the corrected light intensity information.

2. The distance measuring device according to claim 1.

6. the illumination light includes first illumination light and second illumination light having different patterns of the one or more bright portions; The light source includes a first light source that emits the first irradiation light and a second light source that emits the second irradiation light.

2. The distance measuring device according to claim 1.

7. The first light source and the second light source alternately emit light.

7. The distance measuring device according to claim 6.

8. The first light source and the second light source emit light simultaneously.

7. The distance measuring device according to claim 6.

9. Further, a light source driving unit that drives the light source so that the position of the one or more bright areas in the subject changes is provided.

2. The distance measuring device according to claim 1.

10. moreover, a storage unit that stores a template relating to a distribution of the intensity of the reflected light in the one or more bright portions in the reflected light; a matching processing unit that calculates, for each of the plurality of pixels, a similarity indicating a degree of similarity between a distribution of the intensity of the reflected light indicated by N pieces of light intensity information corresponding to N pixels consisting of the pixel and N (N is an integer of 2 or more)-1 pixels surrounding the pixel, and a distribution of the intensity of the reflected light in the template, The distance information selection unit selects, as the one or more selected distance information, the pixel distance information corresponding to a pixel whose similarity satisfies a predetermined condition from among the plurality of pixels.

2. The distance measuring device according to claim 1.

11. moreover, a storage unit that stores a template relating to a feature amount of the intensity of the reflected light in the one or more bright portions of the reflected light; a feature amount calculation unit that calculates, for each of the plurality of pixels, a feature amount of the intensity of the reflected light indicated by N pieces of light intensity information corresponding to N pixels consisting of the pixel and N (N is an integer of 2 or more)-1 pixels surrounding the pixel; a matching processing unit that calculates a similarity indicating a degree of similarity between the N feature amounts calculated by the feature amount calculation unit and a feature amount of the intensity of the reflected light in the template for each of the plurality of pixels, The distance information selection unit selects, as the one or more selected distance information, the pixel distance information corresponding to a pixel whose similarity satisfies a predetermined condition from among the plurality of pixels.

2. The distance measuring device according to claim 1.

12. The predetermined condition is that the similarity is greater than a predetermined threshold.

12. A distance measuring device according to claim 10 or 11.

13. a coring unit that performs a coring process on the similarity to calculate a core similarity, The predetermined condition is that the core similarity is greater than a predetermined threshold.

12. A distance measuring device according to claim 10 or 11.

14. moreover, a storage unit that stores a machine learning model that has been trained in advance so that, when N pieces of light intensity information corresponding to N pixels consisting of an arbitrary one pixel among the plurality of pixels and N (N is an integer of 2 or more)-1 pixels surrounding the arbitrary one pixel are input, the machine learning model outputs a reliability indicating a reliability that the pixel distance information corresponding to the arbitrary one pixel is one of the one or more selected distance information; a matching processing unit that calculates the reliability of each of the plurality of pixels by using the machine learning model, The distance information selection unit selects, as the one or more selected distance information, the pixel distance information corresponding to a pixel whose reliability satisfies a predetermined condition from among the plurality of pixels.

2. The distance measuring device according to claim 1.

15. The predetermined condition is that the reliability is greater than a predetermined threshold.

15. A distance measuring device according to claim 14.

16. Further, a coring unit is provided which performs a coring process on the reliability to calculate a core reliability, The predetermined condition is that the core reliability is greater than a predetermined threshold.

15. A distance measuring device according to claim 14.