Distance-measuring sensor

Abstract

In the present invention, a plurality of light-emitting elements included in a light-emitting element group are disposed in a row along a first plane. A plurality of light-receiving elements included in a light-receiving element group are disposed in a row along the first plane. Each of the plurality of light-emitting elements included in the light-emitting element group has directivity directed to a detection region which is on one side of a light-emitting element row that is formed of the plurality of light-emitting elements and that serves as a boundary in the first plane, and the direction of the directivity of the plurality of light-emitting elements included in the light-emitting element group expands radially in the detection region. Each of the plurality of light-receiving elements included in the light-receiving element group has directivity which allows reception of light that is outputted from at least one of the plurality of light-emitting elements and is irregularly reflected on a target in the detection region. The direction of the directivity of the plurality of light-receiving elements included in the light-receiving element group expands radially in the detection region.

Description

Distance measuring sensor

[0001] The present invention relates to a distance measuring sensor.

[0002] An obstacle detection device is known that determines the distance to a target (obstacle) by receiving light emitted from a light-emitting element and reflected by the target (obstacle) with a light-receiving element (Patent Document 1). This obstacle detection device includes a light-emitting element group consisting of a plurality of light-emitting elements arranged closely together, and a light-receiving element group consisting of a plurality of light-receiving elements arranged closely together at a distance from the light-emitting element group.

[0003] The light-emitting element group generates beams of light in a time-division manner that radially divide a predetermined detection area. By arranging multiple light-emitting elements closely together, it is possible to consider that light is emitted radially from a single point. The light-receiving element group simultaneously receives light by dividing the detection area radially and in a direction intersecting the irradiation direction of the light-emitting element group. By arranging multiple light-receiving elements closely together, it is possible to consider that reflected light is detected at a single point. The distance to the target that generated the reflected light can be calculated from the combination of the light-receiving element that detected the reflected light from a target within the detection area and the light-emitting element that emitted light at that time.

[0004] Japanese Unexamined Patent Publication No. 59-126273

[0005] When the detection area is radially divided into many divisions, it may happen that when one light emitting element emits light, multiple light receiving elements detect reflected light. In this case, the light receiving element with the highest light receiving level can be selected from the multiple light receiving elements that detect reflected light from the target, and the distance to the target can be calculated.

[0006] Furthermore, with one light receiving element in operation, multiple light emitting elements are caused to emit light in sequence, and the distance to the target can be calculated from the combination of the light emitting element that emitted light when reflected light from the target was detected and the light receiving element that was in operation.If multiple light emitting elements that emitted light when reflected light was detected by the light receiving element are extracted, the distance to the target can be calculated from the combination of the light emitting element that emitted light when the light receiving level was maximum and the light receiving element that was in operation at that time.

[0007] When the difference in light reception level is small among multiple combinations of light-emitting elements and light-receiving elements, it is difficult to improve the accuracy of distance measurement to the target. An object of the present invention is to provide a distance measurement sensor that can suppress a decrease in distance measurement accuracy to the target.

[0008] According to one aspect of the present invention, there is provided a distance measuring sensor comprising: a group of light-emitting elements including a plurality of light-emitting elements arranged in a row along a first plane; and a group of light-receiving elements including a plurality of light-receiving elements arranged in a row along the first plane, wherein each of the plurality of light-emitting elements included in the group of light-emitting elements has directivity in the direction of a detection area on one side of the row of light-emitting elements consisting of the plurality of light-emitting elements on the first plane, and the directivity directions of the plurality of light-emitting elements included in the group of light-emitting elements spread radially in the detection area; and each of the plurality of light-receiving elements included in the group of light-receiving elements has directivity that allows it to receive light that is output from at least one of the plurality of light-emitting elements and is diffusely reflected by a target within the detection area, and the directivity directions of the plurality of light-receiving elements included in the group of light-receiving elements spread radially in the detection area.

[0009] When multiple light-emitting elements are arranged in a row rather than at a single point, and multiple light-emitting elements are arranged in a row rather than at a single point, when reflected light from a target is incident on multiple light-receiving elements, the angle between the direction of the reflected light and the orientation of the light-receiving elements becomes larger among the multiple light-receiving elements. This makes it easier to identify the light-receiving element with the highest light-receiving level, making it less susceptible to noise and disturbances. As a result, it is possible to suppress a decrease in distance measurement accuracy.

[0010] Fig. 1 is a schematic diagram showing the arrangement of a plurality of light-emitting elements 10 and a plurality of light-receiving elements 20 of a distance measuring sensor according to a first embodiment. Fig. 2 is a schematic diagram showing the positional relationship in the xy plane of the light-emitting elements 10, the light-receiving elements 20, and the target 55, for explaining a method of calculating the distance to the target 55. Fig. 3 is a flowchart showing the distance measurement procedure executed by the control unit 70. Fig. 4A is a schematic diagram showing the arrangement of the light-emitting elements 10 and the light-receiving elements 20 of a distance measuring sensor according to a comparative example. ｍａｘ, 20 ａｄｊ 4B is a schematic diagram showing the positional relationship of the light emitting element 10 and the light receiving element 20 of the distance measuring sensor according to the first embodiment, and the target 55 in the xy plane. ｍａｘ , 20 ａｄｊ 5 is a schematic diagram showing the positional relationship in the xy plane of the light-emitting elements 10 and the light-receiving elements 20 of a distance measuring sensor according to a modification of the first embodiment. FIG. 6 is a schematic diagram showing the positional relationship in the xy plane of the light-emitting elements 10 and the light-receiving elements 20 of a distance measuring sensor according to another modification of the first embodiment. FIG. 7 is a schematic diagram showing the arrangement of the light-emitting elements 10 and the light-receiving elements 20 of a distance measuring sensor according to a second embodiment. FIG. 8 is a schematic diagram showing the positional relationship in the xy plane of the light-emitting elements 10, the light-receiving elements 20, the virtual light-emitting point 11, the virtual light-receiving point 21, and the target 55 of the distance measuring sensor according to the second embodiment. FIG. 9A is a schematic diagram showing the positional relationship in the xy plane of the light-emitting elements 10 and the light-receiving elements 20 of a distance measuring sensor according to a comparative example. ｍａｘ , 20 ａｄｊ 9B is a schematic diagram showing the positional relationship of the light emitting element 10 and the light receiving element 20 of the distance measuring sensor according to the second embodiment. ｍａｘ , 20 ａｄｊ, and a target 55 in the xy plane. FIGS. 10A and 10B are graphs showing an example of the distribution of light receiving levels of the multiple light receiving elements 20 of the distance measuring sensor according to the comparative example ( FIG. 9A ) and the second embodiment ( FIG. 9B ), respectively. FIG. 11 is a graph showing an example of the distribution of light receiving levels of the multiple light receiving elements 20 of the distance measuring sensor according to a modification of the second embodiment. FIG. 12 is a schematic diagram showing the arrangement of the multiple light emitting elements 10 and the multiple light receiving elements 20 a, 20 b of the distance measuring sensor according to the third embodiment. FIG. 13 is a schematic perspective view showing the arrangement of the multiple light emitting elements 10 and the multiple light receiving elements 20 a, 20 b of the distance measuring sensor according to the third embodiment. FIGS. 14A and 14B are schematic diagrams for explaining the measurement accuracy when measuring the distance to a distant target 55, and FIG. 14C is a graph showing the relationship between the apparent elevation angle θ′, the apparent base line length L′, and the distance d from the virtual light emitting point 11 to the target 55. Fig. 15 is a schematic diagram showing the arrangement of multiple light-emitting elements 10 and multiple light-receiving elements 20a, 20b in a distance measuring sensor according to a modification of the third embodiment. Fig. 16 is a schematic perspective view showing the arrangement of multiple light-emitting elements 10 and multiple light-receiving elements 20a, 20b in a distance measuring sensor according to a modification of the third embodiment. Fig. 17 is a schematic diagram showing the arrangement of multiple light-emitting elements 10a, 10b and multiple light-receiving elements 20 in a distance measuring sensor according to another modification of the third embodiment. Fig. 18A is a diagram showing the positional relationship in the xy plane of a light-emitting element group 10G, light-receiving element groups 20Ga, 20Gb, virtual light-emitting point 11, and virtual light-receiving points 21a, 21b in a distance measuring sensor according to a fourth embodiment, and Fig. 18B is a schematic diagram for explaining the relationship between the orientation direction of the light-emitting elements to be operated and the light-receiving elements to be operated. Fig. 19 is a diagram showing the positional relationship in the xy plane of the light-emitting element group 10G, the light-receiving element groups 20Ga, 20Gb, and 20Gc, the virtual light-emitting point 11, and the virtual light-receiving points 21a, 21b, and 21c of a distance measuring sensor according to a modification of the fourth embodiment. Fig. 20 is a perspective view of an autonomous mobile transport robot 40 equipped with a distance measuring sensor according to a modification of the fourth embodiment. Fig. 21 is a side view of one optical unit 25 out of multiple optical units 25 used in the distance measuring sensor according to the fifth embodiment. Figs. 22A and 22B are schematic side views of the distance measuring sensors according to the fifth embodiment and the modification of the fifth embodiment, respectively, viewed from a direction perpendicular to the first plane (xy plane).FIG. 23 shows the i-th optical unit 25. ｉ and the jth optical unit 25 ｊ 24A and 24B are schematic cross-sectional views of one optical unit 25 used in a distance measuring sensor according to the sixth embodiment and a modified example of the sixth embodiment, respectively. Fig. 25A is a schematic side view of the distance measuring sensor according to the seventh embodiment as seen from a direction perpendicular to the first plane (xy plane), and Fig. 25B is a schematic cross-sectional view of adjacent optical units 25. ｉ , 25 ｊ FIG.

[0011] 1 to 4B, a distance measuring sensor according to a first embodiment will be described. Fig. 1 is a schematic diagram showing the arrangement of a plurality of light emitting elements 10 and a plurality of light receiving elements 20 of the distance measuring sensor according to the first embodiment. The distance measuring sensor according to the first embodiment includes a light emitting element group 10G consisting of a plurality of light emitting elements 10, a light receiving element group 20G consisting of a plurality of light receiving elements 20, and a control unit 70.

[0012] The plurality of light-emitting elements 10 are arranged in a line along an imaginary first plane (corresponding to the paper surface in FIG. 1 ). The plurality of light-receiving elements 20 are also arranged in a line along the first plane. In the first embodiment, the plurality of light-emitting elements 10 and the plurality of light-receiving elements 20 are arranged along a common straight line on the first plane. In this specification, the first plane is referred to as the xy plane. The plurality of light-emitting elements 10 and the plurality of light-receiving elements 20 are mounted on one surface of a substrate 30.

[0013] Here, "arranged in a line along the xy plane" means arranged along a straight line or a curve included in the xy plane. Note that even if the light-emitting element 10 or the light-receiving element 20 is arranged at a position slightly deviated from the xy plane in a direction perpendicular to the xy plane, the light-emitting element 10 or the light-receiving element 20 can still be said to be arranged along the xy plane as long as the degree of deviation is not a problem in terms of the operation of the distance measuring sensor.

[0014] The position of the light-emitting element 10 can be considered to be the position of the point light source when the light-emitting element 10 is considered to be a point light source. For example, if the light-emitting element 10 includes a light-emitting region and a condenser lens, the focal position of the condenser lens or the intersection position between the optical axis of the condenser lens and the light-emitting region can be considered to be the position of the light-emitting element 10. If the light-receiving element 20 includes a condenser lens and a light-receiving surface, the focal position of the condenser lens or the intersection position between the optical axis of the condenser lens and the light-receiving surface can be considered to be the position of the light-receiving element 20.

[0015] Each of the multiple light-emitting elements 10 has directivity in the xy plane toward a detection region 50 (the region above the light-emitting element row in Figure 1), which is on one side of the light-emitting element row consisting of the multiple light-emitting elements 10. The directivity pattern 10DP of each of the multiple light-emitting elements 10 is shown by a thin solid line. The directivity direction 10D of each of the multiple light-emitting elements 10 is shown by a thin dashed line. Here, the directivity direction of the light-emitting element 10 means the direction in which the light emission intensity is maximum. The directivity direction 10D of the multiple light-emitting elements 10 is along the xy plane. Here, when "the directivity direction 10D is along the xy plane," this includes a case where the directivity direction 10D is included in the xy plane, and a case where the directivity direction 10D is slightly off the xy plane but parallel to the xy plane.

[0016] The orientation directions 10D of the plurality of light-emitting elements 10 spread radially in the detection region 50. In other words, the orientation directions 10D of two adjacent light-emitting elements 10 are intersected by half lines extending from the light-emitting elements 10 to the opposite side of the detection region 50. For example, when the plurality of light-emitting elements 10 are assigned serial numbers in the order of arrangement, the i-1th light-emitting element 10 is ｉ－１ and the i-th light-emitting element 10 ｉ and the directivity direction 10D of the light emitting element 10 ｉ－１ , 10 ｉ A half line extending from the point P １ Similarly, the i-th light emitting element 10 ｉ and the i+1th light-emitting element 10 ｉ＋１ and the directivity direction 10D of the light emitting element 10 ｉ , 10 ｉ＋１ A half line extending from the point P２ Intersect at point P １ Position and point P ２ The positions of the two do not necessarily have to be the same.

[0017] In addition, when the orientation direction 10D is slightly off the xy plane, the images of the half lines extending the two orientation directions 10D and projecting them perpendicularly onto the xy plane intersect with each other. In this specification, when the half lines extending the orientation directions 10D of the two light-emitting elements 10 from the light-emitting elements 10 to the opposite side of the detection region 50 intersect with each other, this includes the case where the images of the two half lines projected perpendicularly onto the xy plane intersect with each other.

[0018] Each of the multiple light receiving elements 20 has directivity that allows it to receive a portion of the reflected light that is output from at least one of the multiple light emitting elements 10 and is diffusely reflected by the target 55 within the detection area 50. The directivity pattern 20DP of each of the light receiving elements 20 is indicated by a thin solid line. The directivity direction 20D of each of the multiple light receiving elements 20 is indicated by a thin dashed line. The directivity direction 20D refers to the direction in which the light receiving sensitivity of the light receiving element 20 is maximum. The directivity direction 20D of the multiple light receiving elements 20 is along the xy plane. Here, when we say that the "directivity direction 20D is along the xy plane," this includes a case in which the directivity direction 20D is included in the xy plane, and a case in which the directivity direction 20D is slightly off the xy plane but parallel to the xy plane.

[0019] The directivity directions 20D of the multiple light receiving elements 20 spread radially in the detection region 50. In other words, the directivity directions 20D of two adjacent light receiving elements 20 are intersected by half lines extending from the light receiving elements 20 in the direction opposite to the detection region 50. Note that if the directivity directions 20D are slightly off the xy plane, the images of the half lines extending from the two directivity directions 20D projected perpendicularly onto the xy plane will intersect with each other. In this specification, when the directivity directions 20D of the two light receiving elements 20 are intersected by half lines extending from the light receiving elements 20 in the direction opposite to the detection region 50, this includes the case where the images of the two half lines projected perpendicularly onto the xy plane intersect with each other.

[0020] For example, a laser diode (LD) or a narrow directivity light emitting diode (LED) is used as the light emitting element 10. For example, a narrow directivity photodiode, phototransistor, etc. is used as the light receiving element 20. As an example, it is preferable to use elements with a directivity angle half width of 15° or less as the light emitting element 10 and the light receiving element 20.

[0021] The control unit 70 controls the light emission of the plurality of light-emitting elements 10 and the light reception of the plurality of light-receiving elements 20. More specifically, for each of a plurality of light-emitting element pairs, each consisting of one light-emitting element 10 included in the light-emitting element group 10G and one light-receiving element 20 included in the light-receiving element group 20G, the control unit 70 measures the light reception level when the light-emitting element 10 and the light-receiving element 20 are operated. Furthermore, the control unit 70 determines the position of the target 55 within the detection area 50 based on information that depends on the respective positions and directivity directions of the light-emitting element 10 and the light-receiving element 20 when the light reception level is maximum, and calculates the distance to the target 55.

[0022] Next, a method for calculating the distance to the target 55 will be described with reference to Fig. 2. Fig. 2 is a schematic diagram showing the positional relationship of the light-emitting element 10, the light-receiving element 20, and the target 55 in the xy plane, for explaining the method for calculating the distance to the target 55.

[0023] The straight line along which the plurality of light-emitting elements 10 and the plurality of light-receiving elements 20 are arranged is referred to as an element arrangement line 31. In the first embodiment, the element arrangement line 31 is a straight line. ｉ From the direction of direction 10D ｉ The light emitted toward the target 55 is incident on the target 55 and is diffusely reflected by the surface of the target 55. A part of the light diffusely reflected by the surface of the target 55 is incident on the j-th light receiving element 20. ｊ The light is received by

[0024] i-th light-emitting element 10 ｉ Direction of direction 10D ｉ The elevation angle of ρ ｉ Here, the elevation angle means the angle between the direction of interest and the base line of triangulation. ｊ Directivity direction 20D ｊ The elevation angle is θ ｊThe incident point of light on the target 55 and the j-th light receiving element 20 ｊ The elevation angle of the line connecting ｊ The i-th light-emitting element 10 ｉ The distance from the target 55 to the ｉ and the j-th light receiving element 20 from the target 55. ｊ Distance to k ｊ The i-th light-emitting element 10 ｉ and the j-th light receiving element 20 ｊ The distance between ｉｊ It is marked as follows.

[0025] Elevation angle φ ｊ The tangent of is expressed by the following formula:

[0026] If the brightness of the light-emitting element 10 is denoted as G, the reflection coefficient of the target 55 is denoted as α, and the sensitivity of the light-receiving element 20 is denoted as C, then the j-th light-receiving element 20 ｊ Light receiving level I ｊ is expressed by the following formula: Here, n is a parameter that equivalently indicates the half-width at half maximum of the directivity of the light receiving element 20. When the parameter n is 0, the light receiving element 20 is omnidirectional, and the larger the parameter n, the smaller the half-width at half maximum. For example, when n = 18, the half-width at half maximum is approximately 15°, and when n = 160, the half-width at half maximum is approximately 5°.

[0027] From equation (2), θ ｊ =φ ｊ In the light receiving element, the light receiving level I ｊ It can be seen that the light receiving element 20 where the light receiving level is maximized ｍａｘ The elevation angle of the pointing direction 20D is θ ｍａｘ The incident point of light on the surface of the target 55 and the light receiving element 20 ｍａｘ The elevation angle of the line connecting ｍａｘ If we write it as θ ｍａｘ =φ ｍａｘ The i-th light-emitting element 10 ｉ and the light receiving element 20 where the light receiving level is maximum. ｍａｘ The distance between ｍａｘ It is marked as follows.

[0028] Interval Lｍａｘ , elevation angle ρ ｉ , and the elevation angle θ ｍａｘ , the i-th light-emitting element 10 in the xy plane ｉ and the position of the light receiving element 20 ｍａｘ Since the position of the i-th light-emitting element 10 is known in advance, the position of the target 55 can be obtained by using the principle of triangulation. ｉ and the light receiving element 20 ｍａｘ The line segment having both ends at the position of becomes the baseline used in triangulation. Also, if a baseline for distance measurement is defined on the xy plane, the distance from the baseline to the target 55 can be calculated. For example, the element placement line 31 can be used as the baseline. Alternatively, the baseline may be set at a specific location on the device equipped with the distance measurement sensor, for example, on the surface of the housing.

[0029] Next, the distance measurement procedure executed by the control unit 70 will be described with reference to Fig. 3. Fig. 3 is a flowchart showing the distance measurement procedure executed by the control unit 70.

[0030] First, the control unit 70 operates one of the plurality of light-emitting elements 10 to emit light (step SA1). With the light-emitting element 10 emitting light, the control unit 70 operates the plurality of light-receiving elements 20 in sequence and measures the light-receiving level of each light-receiving element 20 (step SA2). Next, the control unit 70 extracts a light-receiving element pair consisting of the operating light-emitting element 10 and the light-receiving element 20 with the highest light-receiving level (step SA3).

[0031] If the light receiving level of the light receiving / emitting element pair with the maximum light receiving level is below the reference level, the control unit 70 determines that "there is no target" (steps SA4 and SA6). If the light receiving level of the light receiving / emitting element pair with the maximum light receiving level is equal to or higher than the reference level, the control unit 70 calculates the position of the target 55 (FIG. 2) and the distance to the target 55 based on information depending on the positions and orientation directions of the light emitting element 10 and the light receiving element 20 constituting the light receiving / emitting element pair with the maximum light receiving level (steps SA4 and SA5). For example, the light emitting element 10i and the light receiving element 20 shown in FIG. 2 ｍａｘ Distance L ｍａｘ , elevation angle ρ ｉ , θｍａｘ The distance to the target 55 is calculated based on the

[0032] After step SA5 or step SA6, the control unit 70 determines whether there are any inactive light-emitting elements 10, and if there are any inactive light-emitting elements 10, repeats the procedure from step SA1 to step SA5 or step SA6 (step SA7). When the operation of all the light-emitting elements 10 is completed, the control unit 70 ends the distance measurement procedure (step SA7).

[0033] Next, the advantageous effects of the first embodiment will be described. In the first embodiment, the plurality of light-emitting elements 10 are not closely arranged in a single location, but are arranged in a row along the element arrangement line 31 ( FIG. 2 ). Similarly, the plurality of light-receiving elements 20 are also arranged in a row along the element arrangement line 31. In a configuration in which the plurality of light-emitting elements 10 or the plurality of light-receiving elements 20 are closely arranged in a single location, spatial limitations are imposed on the number of light-emitting elements 10 or light-receiving elements 20 that can be arranged. In the first embodiment, because the plurality of light-emitting elements 10 and the plurality of light-receiving elements 20 are not closely arranged, a larger number of light-emitting elements 10 and light-receiving elements 20 can be arranged without spatial limitations. Increasing the number of light-emitting elements 10 and light-receiving elements 20 improves the spatial resolution of the detection position of the target 55.

[0034] In the first embodiment, the directivity directions 10D (FIG. 1) of the plurality of light-emitting elements 10 and the directivity directions 20D (FIG. 1) of the plurality of light-receiving elements 20 are arranged radially. Therefore, compared to a configuration in which the directivity directions 10D of the plurality of light-emitting elements 10 are arranged parallel to one another and the directivity directions 20D of the plurality of light-receiving elements 20 are also arranged parallel to one another, an excellent effect of widening the detection region 50 in which a target can be detected can be obtained.

[0035] Furthermore, in a configuration in which the directivity directions 20D of the multiple light receiving elements 20 are arranged parallel to one another, the difference in light receiving level between the light receiving element 20 with the highest light receiving level and the light receiving element 20 located adjacent thereto is small. If the directivity directions 20D of the multiple light receiving elements 20 are arranged radially, the difference in light receiving level between the light receiving element 20 with the highest light receiving level and the light receiving element 20 located adjacent thereto is large. Therefore, when extracting the light receiving element 20 with the highest light receiving level, the effect of noise and disturbances is reduced, and distance measurement accuracy can be improved.

[0036] Next, other advantageous effects of the first embodiment will be described with reference to Figures 4A and 4B. Figure 4A shows the light emitting element 10 and the light receiving element 20 of a distance measuring sensor according to a comparative example. ｍａｘ , 20 ａｄｊ 10 is a schematic diagram showing the positional relationship of the light receiving element 20 and the target 55 in the xy plane. ｍａｘ and 20 ａｄｊ and are arranged close to each other, and the light receiving element 20 ｍａｘ , 20 ａｄｊ Each of the directivity directions 20D ｍａｘ , 20D ａｄｊ substantially extend radially from one point. ｍａｘ Directivity direction 20D ｍａｘ faces the target 55, and the light receiving element 20 ａｄｊ Directivity direction 20D ａｄｊ is the directivity direction 20D of each of the plurality of light receiving elements 20. ｍａｘ This corresponds to the direction in which the angle between the two is the smallest.

[0037] The light emitted from the light-emitting element 10 is diffusely reflected by the target 55, and part of the reflected light is incident on the light-receiving element 20. ｍａｘ , 20 ａｄｊ The light is received in the direction 20D. ｍａｘ A light receiving element 20 having ｍａｘ The light receiving level is maximized by the directivity direction 20D. ａｄｊ The direction of travel of light incident on the light receiving element 20 having the directivity direction 20D ａｄｊ angle Δθ １ The angle is Δθ １ In response toａｄｊ The light receiving level becomes smaller.

[0038] FIG. 4B shows the light emitting element 10 and the light receiving element 20 of the distance measuring sensor according to the first embodiment. ｍａｘ , 20 ａｄｊ 1 is a schematic diagram showing the positional relationship of the light emitting element 10, the light receiving element 20, and the target 55 in the xy plane. ｍａｘ , 20 ａｄｊ The light receiving element 20 is arranged. ａｄｊ is placed next to the light receiving element 20max. ｍａｘ Directivity direction 20D ｍａｘ points towards the target 55. ａｄｊ The elevation angle of the distance measuring sensor in the comparative example shown in FIG. ａｄｊ Assume that the elevation angle is the same as that of

[0039] The light is diffusely reflected by the target 55 and ａｄｊ The direction of the reflected light incident on the light receiving element 20 ａｄｊ Directivity direction 20D ａｄｊ The angle Δθ ２ is the angle Δθ shown in FIG. １ Therefore, the light receiving element 20 ａｄｊ The received light level is in the direction 20D shown in FIG. ａｄｊ A light receiving element 20 having ａｄｊ That is, in the distance measuring sensor shown in FIG. 4B, the difference between the maximum light receiving level and the second largest light receiving level is larger than in the distance measuring sensor shown in FIG. 4A. Therefore, the light receiving element 20 where the light receiving level is maximum ｍａｘ When extracting the signal, the signal is less susceptible to noise and disturbances.

[0040] Angle Δθ １ (Fig. 4A) and angle Δθ ２ The difference from (FIG. 4B) becomes larger as the target 55 approaches the distance measurement sensor, for example, the element placement line 31. ｍａｘThe excellent effect of being less susceptible to noise and disturbances when extracting the target 55 becomes more pronounced as the target 55 approaches the distance measuring sensor. Therefore, by employing the configuration of the first embodiment, a distance measuring sensor with high accuracy in detecting the position of the target 55 and in measuring the distance to the target 55 can be obtained, particularly when the target 55 approaches the distance measuring sensor. For example, by installing the distance measuring sensor of the first embodiment in a device that needs to be moved without coming into contact with surrounding obstacles, particularly excellent effects can be expected.

[0041] Next, a modified example of the first embodiment will be described with reference to Figures 5 and 6. Figure 5 is a schematic diagram showing the positional relationship in the xy plane of the multiple light-emitting elements 10 and the multiple light-receiving elements 20 of a distance measuring sensor according to a modified example of the first embodiment. In the first embodiment (Figure 1), the element arrangement line 31 along which the multiple light-emitting elements 10 and the multiple light-receiving elements 20 are arranged is a straight line. In contrast, in the modified example of the first embodiment shown in Figure 5, the multiple light-emitting elements 10 and the multiple light-receiving elements 20 are arranged along the curved element arrangement line 31.

[0042] In this modified example, as in the first embodiment ( FIG. 1 ), the orientation directions 10D of the multiple light-emitting elements 10 extend radially from each of the multiple light-emitting elements 10 into the detection region 50. The orientation directions 20D of the multiple light-receiving elements 20 also extend radially from each of the multiple light-receiving elements 20 into the detection region 50.

[0043] In the first embodiment (FIG. 2), the base line used in the triangulation method is located on the element arrangement line 31, regardless of the light receiving element 20 with the maximum light receiving level. In contrast, in the modified example shown in FIG. 5, the base line having the operating light emitting element 10 and the light receiving element 20 with the maximum light receiving level at both ends changes depending on the position of the light receiving element 20. For each of the multiple pairs of light emitting element 10 and light receiving element 20, the length L of the base line shown in FIG. ｉｊ , elevation angle ρ ｉ , θ ｊ If is known, the distance to the target 55 can be calculated in the same way as in the first embodiment.

[0044] Fig. 6 is a schematic diagram showing the positional relationship in the xy plane of a plurality of light-emitting elements 10 and a plurality of light-receiving elements 20 of a distance measuring sensor according to another modification of the first embodiment. In the modification shown in Fig. 5, the plurality of light-emitting elements 10 and the plurality of light-receiving elements 20 are arranged on a common element arrangement line 31. In contrast, in the modification shown in Fig. 6, the plurality of light-emitting elements 10 are arranged along a light-emitting element arrangement line 32, and the plurality of light-receiving elements 20 are arranged along a light-receiving element arrangement line 33 that is located at a different position from the light-emitting element arrangement line 32. In this way, the light-emitting element arrangement line 32 along which the plurality of light-emitting elements 10 are arranged and the light-receiving element arrangement line 33 along which the plurality of light-receiving elements 20 are arranged do not necessarily have to be the same curve.

[0045] Since the arrangement of the light-emitting elements 10 and the light-receiving elements 20 is not limited to a linear arrangement, the distance measuring sensor can be mounted on devices having various surface shapes. For example, the light-emitting elements 10 and the light-receiving elements 20 can be arranged along a gently curved side surface of the housing of the device.

[0046] Next, another modification of the first embodiment will be described. In the first embodiment, as shown in Fig. 3, during the period in which one light-emitting element 10 (Fig. 1) is operating, a plurality of light-receiving elements 20 are operated in sequence to measure the light-receiving level (steps SA1 and SA2). Conversely, during the period in which one light-receiving element 20 is operating, a plurality of light-emitting elements 10 may be operated in sequence to measure the light-receiving level. Even in this case, the distance to the target can be calculated based on the positions and orientation directions of the light-emitting element 10 and light-receiving element 20 that maximize the light-receiving level.

[0047] Second Embodiment Next, a distance measuring sensor according to a second embodiment will be described with reference to Figures 7 to 10B. Below, a description of the configuration common to the distance measuring sensor according to the first embodiment (Figures 1, 2, and 3) will be omitted.

[0048] FIG. 7 is a schematic diagram showing the arrangement of multiple light-emitting elements 10 and multiple light-receiving elements 20 of a distance measuring sensor according to the second embodiment. In the first embodiment ( FIG. 1 ), the orientation directions 10D of two adjacent light-emitting elements 10 are intersected by half lines extending in the direction opposite the detection area 50, but the location of the intersection differs for each pair of light-emitting elements 10. In contrast, in the second embodiment, the orientation directions 10D of all light-emitting elements 10 are intersected by half lines extending in the direction opposite the detection area 50 at a single point. This intersection is referred to as a virtual light-emitting point 11. Similarly, the orientation directions 20D of all light-receiving elements 20 are intersected by half lines extending in the direction opposite the detection area 50 at a single point. This intersection is referred to as a virtual light-receiving point 21.

[0049] FIG. 8 shows a light emitting element 10 of a distance measuring sensor according to a second embodiment. ｉ , light receiving element 20 ｍａｘ , 20 ｊ 1 is a schematic diagram showing the positional relationship in the xy plane of the i-th light-emitting element 10, the virtual light-emitting point 11, the virtual light-receiving point 21, and the target 55. ｉ The light emitted from the target 55 is diffusely reflected by the target 55, and a part of the reflected light is incident on the j-th light receiving element 20 ｊ In the second embodiment, the position of the target 55 is determined by triangulation using a line segment having both ends of the virtual light emitting point 11 and the virtual light receiving point 21 as a base line 35. ｉ The position where the light emitted from the target 55 is incident may be simply referred to as the "representative point of the target 55."

[0050] The i-th light-emitting element 10 relative to the base line 35 ｉ Direction of direction 10D ｉ The elevation angle of ρ ｉ The j-th light receiving element 20 ｊ Directivity direction 20D ｊ The elevation angle is θ ｊ and the j-th light receiving element 20 ｊ The elevation angle of the half line from ｊ The length of the base line 35 is denoted as L, and the distance from the virtual light emitting point 11 to the representative point of the target 55 is denoted as d ｉand the j-th light receiving element 20 from the representative point of the target 55 is denoted as ｊ Distance to k ｊ and the j-th light receiving element 20 from the base line 35. ｊ The shortest distance to b ｊ It is marked as follows.

[0051] distance k ｊ and elevation angle φ ｊ is expressed by the following formula:

[0052] j-th light receiving element 20 ｊ Light receiving level I ｊ is expressed by the following formula:

[0053] From equation (5), the elevation angle θ ｊ and elevation angle φ ｊ and the light receiving element 20 ｍａｘ At this point, the light receiving level I ｊ That is, the light receiving element 20 located on the line segment connecting the representative point of the target 55 and the virtual light receiving point 21 ｍａｘ The light receiving level of the light receiving element 20 becomes maximum. ｍａｘ Directivity direction 20D ｍａｘ The elevation angle is θ ｍａｘ The distance k ｊ The difference between θ ｊ -φ ｊ Compared to the difference in light reception level I ｊ The impact on the

[0054] Length L of the base line 35, elevation angle ρ ｉ , elevation angle θ ｍａｘ Based on this, the distance from the base line 35 to the target 55 can be calculated. In addition, since the positions of the virtual light-emitting point 11 and the virtual light-receiving point 21 in the xy plane are known, the distance from any reference point in the xy plane to the target 55 can be calculated.

[0055] Next, the excellent effects of the second embodiment will be described. The same excellent effects as those of the first embodiment can be obtained in the second embodiment. Furthermore, in the second embodiment, regardless of the combination of the light-emitting element 10 and the light-receiving element 20, the positions of the virtual light-emitting point 11 and the virtual light-receiving point 21, which serve as the basis for triangulation, remain unchanged, and the length of the base line 35 also remains unchanged. Therefore, it is easier to calculate the distance to the target 55 than in the first embodiment.

[0056] Next, other advantageous effects of the second embodiment will be described in comparison with the comparative example with reference to FIGS. 9A to 10B.

[0057] FIG. 9A shows a light emitting element 10 and a light receiving element 20 of a distance measuring sensor according to a comparative example. ｍａｘ , 20 ａｄｊ 10 is a schematic diagram showing the positional relationship in the xy plane of the target 55 and the distance measuring sensor according to the second embodiment. In the comparative example, a plurality of light emitting elements 10 are arranged at a virtual light emitting point 11 of the distance measuring sensor according to the second embodiment, and a plurality of light receiving elements 20 are arranged at a virtual light receiving point 21. ｍａｘ , 20 ａｄｊ are placed.

[0058] Light receiving element 20 ｍａｘ Directivity direction 20D ｍａｘ The light receiving element 20 faces the direction of the representative point of the target 55. ａｄｊ Directivity direction 20D ａｄｊ is the directivity direction 20D of the plurality of light receiving elements 20. ｍａｘ The angle formed by the direction 20D is the smallest. ｍａｘ and the direction of direction 20D ａｄｊ The angle between １ It is marked as follows.

[0059] FIG. 9B shows the light emitting element 10 and the light receiving element 20 of the distance measuring sensor according to the second embodiment. ｍａｘ , 20 ａｄｊ 10 is a schematic diagram showing the positional relationship of the target 55 in the xy plane. ｍａｘ A light receiving element 20 having ｍａｘ and the adjacent directivity direction 20D ａｄｊ A light receiving element 20 having ａｄｊare arranged at different positions. ｍａｘ and the direction of direction 20D ａｄｊ A half line extending in the opposite direction to the detection area 50 intersects with the direction 20D at the virtual light receiving point 21. ａｄｊ Assume that the elevation angle of is the same in the cases of FIG. 9A and FIG. 9B.

[0060] From the representative point of the target 55 to the light receiving element 20 ａｄｊ The direction of travel of the reflected light toward the target and the directivity direction 20D ａｄｊ The angle Δθ ２ is the directivity direction 20D ｍａｘ and the direction of direction 20D ａｄｊ The angle Δθ １ Therefore, the light receiving element 20 of the distance measuring sensor according to the second embodiment shown in FIG. ａｄｊ The light receiving level of the light receiving element 20 of the distance measuring sensor according to the comparative example shown in FIG. ａｄｊ As a result, in the second embodiment (FIG. 9B), the process of extracting the light receiving element 20 with the maximum light receiving level is less susceptible to the influence of noise and disturbances. As a result, the distance measurement accuracy can be improved.

[0061] 9A, in order to make the light receiving element 20 less susceptible to the effects of noise and disturbances, the directivity of the light receiving element 20 must be sharpened. In order to sharpen the directivity of the light receiving element 20, it is necessary to increase the size of the lens, improve assembly precision, etc., which inevitably increases costs. In the second embodiment, it is possible to improve distance measurement precision while suppressing increases in the cost of the distance measuring sensor.

[0062] Next, the distribution of light reception levels of the multiple light receiving elements 20 of the distance measuring sensors according to the comparative example ( FIG. 9A ) and the second embodiment ( FIG. 9B ) will be described with reference to FIGS. 10A and 10B . FIGS. 10A and 10B are graphs showing examples of the distribution of light reception levels of the multiple light receiving elements 20 of the distance measuring sensors according to the comparative example ( FIG. 9A ) and the second embodiment ( FIG. 9B ), respectively. The horizontal axis represents the position in a direction parallel to the base line 35 ( FIG. 8 ) in units of mm, and the vertical axis represents the distance in a direction perpendicular to the base line 35 ( FIG. 8 ) in units of mm.

[0063] The following description will be given assuming that the position of the virtual light-emitting point 11 is the origin and the distance between the virtual light-emitting point 11 and the virtual light-receiving point 21 (the length L of the base line 35) is 100 mm. Assume that the distance from the virtual light-emitting point 11 to the representative point of the target 55 is 300 mm, the elevation angle of the direction of travel of light radiated from the virtual light-emitting point 11 is 80°, and the half-width at half maximum of the directivity of the light-receiving element 20 is approximately 15° (n in Equations (2) and (5) is 18). In the case of the ranging sensor according to the second embodiment ( FIG. 10B ), the distance from the base line 35 to the element arrangement line on which the multiple light-receiving elements 20 are arranged is assumed to be 100 mm. In both FIGS. 10A and 10B , the directivity direction 20D of the multiple light-receiving elements 20 is changed in 5° increments.

[0064] In Figures 10A and 10B, the direction of the solid lines extending from each of the multiple light receiving elements 20 indicates the directivity direction 20D of the light receiving element 20, and the length of the solid lines indicates the relative value of the light receiving level. Note that the relationship between the lengths of the solid lines in Figures 10A and 10B has no particular significance. In both Figures 10A and 10B, the light receiving level of the light receiving element having a directivity direction with an elevation angle of 80° is the highest. As the elevation angle deviates from 80°, the light receiving level decreases. It can be seen that the degree of this decrease is greater in the ranging sensor according to the second embodiment (Figure 10B) than in the ranging sensor according to the comparative example (Figure 10A).

[0065] Therefore, in the second embodiment, the process of extracting the light receiving element with the maximum light receiving level is less susceptible to the influence of noise and disturbance.

[0066] Next, a distance measuring sensor according to a modification of the second embodiment will be described with reference to FIG. 11 . FIG. 11 is a graph showing an example of the distribution of light reception levels of multiple light receiving elements 20 of a distance measuring sensor according to a modification of the second embodiment. The horizontal axis represents the position in a direction parallel to the base line 35 ( FIG. 8 ) in units of mm, and the vertical axis represents the distance in a direction perpendicular to the base line 35 ( FIG. 8 ) in units of mm. The positions of the virtual light-emitting point 11, virtual light-receiving point 21, and target 55 are the same as those in FIG. 10B . In the second embodiment ( FIG. 10B ), the multiple light-receiving elements 20 are arranged along a straight line parallel to the base line 35, but in the modification shown in FIG. 11 , the multiple light-receiving elements 20 are arranged along a circumference centered on the virtual light-emitting point 11. The radius of this circumference is 200 mm.

[0067] The direction of the line segments extending radially from the multiple light receiving elements 20 indicates the orientation direction of the light receiving elements 20, and the length of the line segments indicates the relative value of the light receiving level. As in the modified example shown in FIG. 11 , even if the multiple light receiving elements 20 are arranged along a circumference centered on the virtual light emitting point 11, the same effect as in the second embodiment can be obtained. With this arrangement, the orientation direction of each of the multiple light emitting elements 10 faces the normal direction of the circumference on which the multiple light receiving elements 20 are arranged. If the circumference on which the multiple light receiving elements 20 are arranged is the outer circumferential surface of the device, the distance from the outer circumferential surface of the device to the target in the normal direction can be easily measured.

[0068] The light receiving elements 20 may be arranged along curves or polygonal lines other than the circumference. In this case, by arranging the virtual light emitting points 11 at appropriate positions, the orientation direction of the light emitting elements 10 can be directed in a direction close to the normal to the outer peripheral surface of the device.

[0069] Next, a distance measuring sensor according to a third embodiment will be described with reference to Fig. 12 to Fig. 14C. Below, a description of the configuration common to the distance measuring sensor according to the second embodiment described with reference to Fig. 7 to Fig. 10B will be omitted.

[0070] 12 and 13 are a schematic diagram and a schematic perspective view, respectively, showing the arrangement of a plurality of light-emitting elements 10 and a plurality of light-receiving elements 20a, 20b of a distance measuring sensor according to the third embodiment. In the distance measuring sensor according to the second embodiment (FIG. 7), all of the light-receiving elements 20 belong to one light-receiving element group, and extensions of the directivity directions 20D of all of the light-receiving elements 20 intersect at one virtual light-receiving point 21. In contrast, in the third embodiment, the plurality of light-receiving elements 20 are divided into two light-receiving element groups 20Ga, 20Gb (FIG. 13).

[0071] The light receiving elements 20a belong to one light receiving element group 20Ga, and the other light receiving elements 20b belong to the other light receiving element group 20Gb. All the light emitting elements 10 belong to one light emitting element group 10G (FIG. 13). The light emitting elements 10 and the light receiving elements 20a, 20b are mounted on a substrate 30 and arranged along a common element arrangement line 31.

[0072] A half line extending the directional direction 20Da of the multiple light receiving elements 20a belonging to the light receiving element group 20Ga in the opposite direction from the detection area 50 intersects at one virtual light receiving point 21a, and a half line extending the directional direction 20Db of the multiple light receiving elements 20b belonging to the other light receiving element group 20Gb in the opposite direction from the detection area 50 intersects at another virtual light receiving point 21b.

[0073] The line segment connecting the virtual light-emitting point 11 and one virtual light-receiving point 21 a and the line segment connecting the virtual light-emitting point 11 and the other virtual light-receiving point 21 b are not arranged on a straight line, but intersect at an angle of less than 180°. Fig. 13 shows an example in which one virtual light-receiving point 21 a is located on an extension of the directivity direction 10D of one light-emitting element 10, and the other virtual light-receiving point 21 b is located on an extension of the directivity direction 10D of the other light-emitting element 10, but the virtual light-receiving points 21 a and 21 b do not need to be located on an extension of the directivity direction 10D of the light-emitting element 10.

[0074] The control unit 70 operates the plurality of light-emitting elements 10 and the plurality of light-receiving elements 20a belonging to one of the light-receiving element groups 20Ga to measure distance. At this time, a line segment having both ends of the virtual light-emitting point 11 and the virtual light-receiving point 21a is used as a base line 35a for triangulation. Furthermore, the control unit 70 operates the plurality of light-emitting elements 10 and the plurality of light-receiving elements 20b belonging to the other light-receiving element group 20Gb to measure distance. At this time, a line segment having both ends of the virtual light-emitting point 11 and the virtual light-receiving point 21b is used as a base line 35b for triangulation.

[0075] Next, the excellent effects of the third embodiment will be described with reference to Figures 14A, 14B, and 14C. Figures 14A and 14B are schematic diagrams for explaining the measurement accuracy when measuring the distance to a distant target 55. In order to measure the distance to a distant target with high accuracy using triangulation, it is preferable to lengthen the base line 35 whose ends are the virtual light-emitting point 11 and the virtual light-receiving point 21. The length of the base line 35 whose ends are the virtual light-emitting point 11 and the virtual light-receiving point 21 is denoted as L.

[0076] 14A, the elevation angle of the direction 10D from the virtual light-emitting point 11 toward the target 55 is 90°, and in the example shown in Fig. 14B, the elevation angle of the direction 10D from the virtual light-emitting point 11 toward the target 55 is an obtuse angle. １ is the visual angle β when the base line 35 is viewed from the target 55 in the example shown in FIG. 14B. ２ Greater than.

[0077] 14B , the distance from an intersection P between a straight line forming an angle of 90° with respect to a direction 10D from the virtual light-emitting point 11 toward the target 55 and a direction 20D from the virtual light-receiving point 21 toward the target 55 to the virtual light-emitting point 11 is referred to as the apparent base line length. The length of the apparent base line is denoted as L'. The distance from the virtual light-emitting point 11 to the target 55 is denoted as d. The angle between the line segment connecting the virtual light-emitting point 11 and the intersection P and the line segment connecting the target 55 and the intersection P is referred to as the apparent elevation angle θ'.

[0078] The apparent elevation angle θ′, the apparent base length L′, and the distance d from the virtual light-emitting point 11 to the target 55 have the following relationship:

[0079] FIG. 14C is a graph showing the relationship between the apparent elevation angle θ′, the apparent base line length L′, and the distance d from the virtual light-emitting point 11 to the target 55. The horizontal axis represents d / L′, and the vertical axis represents the apparent elevation angle θ′ in degrees. When d / L′ is 20 or greater, the apparent elevation angle θ′ approaches 90°, and the apparent elevation angle θ′ hardly changes even when the distance d changes. This reduces the accuracy of the distance d determined by triangulation. For example, when using a typical narrow-directivity light-emitting diode (LED) and photodiode (PD), approximately 20 times the apparent base line length L′ can be considered the upper limit of the measurable distance.

[0080] In order to increase the upper limit of the measurable distance, it is preferable to increase the apparent base line length L'. In other words, it is preferable to increase the viewing angle of the base line 35 when viewed from the target. In FIG. 12, when detecting a target within the detection area 50 where the viewing angle when viewing the base line 35a is larger than the viewing angle when viewing the base line 35b, it is preferable to operate the light-receiving element 20a belonging to the light-receiving element group 20Ga corresponding to the virtual light-receiving point 21a. In this case, it is not necessary to operate all the light-emitting elements 10; it is sufficient to operate multiple light-emitting elements 10 so that the entire range in which the target is to be detected can be scanned.

[0081] Conversely, when detecting a target in a range of the detection area 50 where the viewing angle when viewing the base line 35b is larger than the viewing angle when viewing the base line 35a, it is advisable to operate the light-receiving element 20b belonging to the light-receiving element group 20Gb corresponding to the virtual light-receiving point 21b. In this case, it is not necessary to operate all the light-emitting elements 10, and it is sufficient to operate a plurality of light-emitting elements 10 so that the entire range in which the target is to be detected can be scanned.

[0082] Although it is difficult to accurately measure the distance to a target located farther than the upper limit of the measurable distance, the direction in which the target is located can be detected with high accuracy.

[0083] Next, a distance measuring sensor according to a modification of the third embodiment will be described with reference to FIGS.

[0084] 15 and 16 are a schematic diagram and a schematic perspective view, respectively, showing the arrangement of a plurality of light-emitting elements 10 and a plurality of light-receiving elements 20a, 20b in a distance measuring sensor according to a modification of the third embodiment. In the distance measuring sensor according to the third embodiment (FIGS. 12 and 13), the element arrangement line 31 along which the plurality of light-emitting elements 10, the plurality of light-receiving elements 20a belonging to one light-receiving element group 20Ga, and the plurality of light-receiving elements 20b belonging to the other light-receiving element group 20Gb are arranged is a straight line. In contrast, in the distance measuring sensor according to the modification shown in FIGS. 15 and 16, the element arrangement line 31 along which the plurality of light-emitting elements 10, the plurality of light-receiving elements 20a belonging to one light-receiving element group 20Ga, and the plurality of light-receiving elements 20b belonging to the other light-receiving element group 20Gb are arranged is a circumferential line.

[0085] 15 and 16, the element placement line 31 may be in the shape of a circle. Alternatively, the element placement line 31 may be in the shape of a curve or a broken line other than a circle.

[0086] Next, a distance measuring sensor according to another modification of the third embodiment will be described with reference to Fig. 17. Fig. 17 is a schematic diagram showing the arrangement of a plurality of light-emitting elements 10a, 10b and a plurality of light-receiving elements 20 of a distance measuring sensor according to another modification of the third embodiment. In the distance measuring sensor according to the third embodiment (Figs. 12 and 13), the plurality of light-receiving elements 20 are divided into two light-receiving element groups 20Ga, 20Gb, and two virtual light-receiving points 21a, 21b are arranged.

[0087] 17, the multiple light-emitting elements 10 are divided into two light-emitting element groups 10Ga and 10Gb, and virtual light-emitting points 11a and 11b are arranged for each of the light-emitting element groups 10Ga and 10Gb. One virtual light-receiving point 21 is arranged for each of the multiple light-receiving elements 20.

[0088] The distance to the target can be measured by operating the plurality of light-emitting elements 10a and the plurality of light-receiving elements 20 belonging to one light-emitting element group 10Ga, and the distance to the target can be measured by operating the plurality of light-emitting elements 10b and the plurality of light-receiving elements 20 belonging to the other light-emitting element group 10Gb.

[0089] 18A and 18B, a distance measuring sensor according to a fourth embodiment will be described. Hereinafter, a description of the configuration common to the distance measuring sensor according to the third embodiment (FIGS. 12 and 13) will be omitted.

[0090] 18A is a diagram showing the positional relationship in the xy plane of the light-emitting element group 10G, light-receiving element groups 20Ga and 20Gb, virtual light-emitting point 11, and virtual light-receiving points 21a and 21b of the distance measuring sensor according to Example 4. A plurality of light-emitting elements of the light-emitting element group 10G are arranged along an arc 36 having a central angle of 90° and centered at the virtual light-emitting point 11, and a plurality of light-receiving elements belonging to the light-receiving element group 20Ga and the light-receiving element group 20Gb are arranged along a part of the arc 36.

[0091] 18A , the individual light-emitting elements and light-receiving elements are omitted, and the area in which multiple light-emitting elements or multiple light-receiving elements are arranged is shown as a hatched arc shape. The azimuth angle from the center of this arc 36 toward one end of the arc 36 is defined as 0°, and the azimuth angle toward the other end of the arc 36 is defined as 90°.

[0092] The orientation directions of the multiple light-emitting elements belonging to the light-emitting element group 10G and the orientation directions of the multiple light-receiving elements belonging to the light-receiving element groups 20Ga and 20Gb are directed toward the outside of the arc 36. This makes it possible to measure the distance to a target within the detection area 50 outside the arc 36.

[0093] The multiple light-receiving elements of one light-receiving element group 20Ga are arranged along a portion of the arc 36 where the azimuth angle is from approximately 22.5° to 90°. The virtual light-receiving point 21a corresponding to the light-receiving element group 20Ga is located on a radius extending in the direction of the azimuth angle of 0° from the virtual light-emitting point 11. When the multiple light-receiving elements of the light-receiving element group 20Ga are operated, a line segment having the virtual light-emitting point 11 and the virtual light-receiving point 21a as its two ends is used as a baseline 35a for triangulation.

[0094] The multiple light receiving elements of the other light receiving element group 20Gb are arranged along a portion of the arc 36 that extends from an azimuth angle of 0° to approximately 67.5°. A virtual light receiving point 21b corresponding to the light receiving element group 20Gb is located on a radius extending in a direction at an azimuth angle of 90° from the virtual light emitting point 11. When the multiple light receiving elements of the light receiving element group 20Gb are operated, a line segment having the virtual light emitting point 11 and the virtual light receiving point 21b as its two ends is used as a baseline 35b for triangulation.

[0095] The visual angle when viewing the base line 35a from any point within the first region 50a, which is between azimuths of 45° and 90° within the detection region 50, is greater than the visual angle when viewing the base line 35b. For this reason, it is preferable to use the light-receiving element group 20Ga when detecting a target within the first region 50a. The orientation directions of the multiple light-receiving elements of the light-receiving element group 20Ga extend radially so as to pass through the first region 50a.

[0096] The visual angle when viewing the base line 35b from any point within the second region 50b, which has an azimuth angle of 0° to 45° within the detection region 50, is greater than the visual angle when viewing the base line 35a. For this reason, it is preferable to use the light-receiving element group 20Gb when detecting a target within the second region 50b. The orientation directions of the multiple light-receiving elements of the light-receiving element group 20Gb extend radially so as to pass through the second region 50b.

[0097] When measuring distances by operating the light-receiving element group 20Ga, it is sufficient to operate the light-emitting elements of the light-emitting element group 10G that are arranged in the azimuth angle range of 45° to 90°. This makes it possible to cover the entire first region 50a. When measuring distances by operating the light-receiving element group 20Gb, it is sufficient to operate the light-emitting elements of the light-emitting element group 10G that are arranged in the azimuth angle range of 0° to 45°. This makes it possible to cover the entire second region 50b.

[0098] Next, the relationship between the orientation direction of the light-emitting element to be operated and the light-receiving element to be operated will be described with reference to Fig. 18B. Fig. 18B is a schematic diagram for explaining the relationship between the orientation direction of the light-emitting element to be operated and the light-receiving element to be operated. Below, a case where the light-receiving elements of the light-receiving element group 20Ga are operated to detect a target in the first region 50a will be described.

[0099] When detecting a target in the first region 50a, the light-emitting elements located in the azimuth angle range of 45° to 90° among the plurality of light-emitting elements belonging to the light-emitting element group 10G are operated in sequence, thereby making it possible to scan the first region 50a almost completely.

[0100] During the period when the light emitting element whose directivity direction is in the direction of the azimuth angle of 90° (arrow A) is operated, the end of the arc 36 on the azimuth angle 90° side and the intersection P １ Therefore, the light reflected from the target may be incident on the light receiving element located between the end of the light receiving element on the 90° azimuth angle side and the intersection point P １ It is only necessary to operate the light receiving element located between the

[0101] During the period when the light-emitting element whose directivity direction is in the direction of the arrow B at an azimuth angle of 45° is operated, among the plurality of light-receiving elements belonging to the light-receiving element group 20Ga, the intersection P ２ and an intersection P between a half line extending from the virtual light receiving point 21a in the direction of an azimuth angle of 45° and the arc 36. ３ The light receiving element located between the light receiving element and the light receiving element is operated.

[0102] Next, the advantageous effect of the fourth embodiment will be described. When the base lines 35a and 35b are viewed from any point within the detection area 50, the base line with the larger viewing angle is used for triangulation, thereby improving distance measurement accuracy.

[0103] Next, a distance measuring sensor according to a modification of the fourth embodiment will be described. In the distance measuring sensor according to the fourth embodiment (FIG. 18A), the plurality of light receiving elements are classified into two light receiving element groups 20Ga and 20Gb. However, the plurality of light emitting elements may be classified into a plurality of light emitting element groups, rather than the plurality of light receiving elements. In this case, a virtual light receiving point is located in one place, and a virtual light emitting point is located at a different position for each light emitting element group. For example, in FIG. 18A, a light emitting element group may be located at the position of each of the light receiving element groups 20Ga and 20Gb, and a light receiving element group may be located at the position of the light emitting element group 10G.

[0104] Next, a distance measuring sensor according to another modification of the fourth embodiment will be described with reference to Fig. 19. Fig. 19 is a diagram showing the positional relationship in the xy plane of the light emitting element group 10G, the light receiving element groups 20Ga, 20Gb, and 20Gc, the virtual light emitting point 11, and the virtual light receiving points 21a, 21b, and 21c of the distance measuring sensor according to another modification of the fourth embodiment.

[0105] In the fourth embodiment ( FIG. 18A ), two light-receiving element groups 20Ga and 20Gb are provided, and two virtual light-receiving points 21a and 21b are defined. However, in this modification, three light-receiving element groups 20Ga, 20Gb, and 20Gc are provided, and three virtual light-receiving points 21a, 21b, and 21c are defined. Base lines 35a, 35b, and 35c, each of which has the virtual light-emitting point 11 and the virtual light-receiving points 21a, 21b, and 21c at its both ends, are used as base lines for triangulation. In FIG. 19 , the individual light-emitting elements and light-receiving elements belonging to the light-emitting element group 10G and the light-receiving element groups 20Ga, 20Gb, and 20Gc are not shown, and the area in which multiple light-emitting elements and multiple light-receiving elements are arranged is represented by an arc shape.

[0106] A plurality of light-emitting elements belonging to the light-emitting element group 10G are arranged along a circumference 37 centered on a virtual light-emitting point 11, over the entire circumference 37. Three virtual light-receiving points 21a, 21b, and 21c are arranged inside the circumference 37 at positions that are three-fold rotationally symmetric with the virtual light-emitting point 11 as the center of rotation. The azimuth angles in the directions from the virtual light-emitting point 11 toward the virtual light-receiving points 21a, 21b, and 21c are defined as 0°, 120°, and 240°, respectively.

[0107] The detection area 50 is divided into a first area 50a between azimuth angles of 0° and 60°, a second area 50b between azimuth angles of 60° and 120°, a third area 50c between azimuth angles of 120° and 180°, a fourth area 50d between azimuth angles of 180° and 240°, a fifth area 50e between azimuth angles of 240° and 300°, and a sixth area 50f between azimuth angles of 300° and 0°.

[0108] The intersections of the half lines extending from the virtual light emitting point 11 in the directions of azimuth angles of 0°, 120°, and 240° with the circumference 37 are denoted by P １ , P ４ , P ７ The intersections of the half lines extending from the virtual light receiving point 21a in the directions of azimuth angles of 60° and 300° with the circumference 37 are denoted as P ２ , P ９ The intersections of the half lines extending from the virtual light receiving point 21b in the directions of azimuth angles of 60° and 180° with the circumference 37 are denoted as P ３ , P ５The intersections of the half lines extending from the virtual light receiving point 21c in the directions of azimuth angles of 180° and 300° with the circumference 37 are denoted as P ６ , P ８ It is marked as follows.

[0109] The light receiving element group 20Ga is used to detect targets in the second region 50b and the fifth region 50e. In order to cover the second region 50b, the plurality of light receiving elements of the light receiving element group 20Ga are arranged at the intersection P ２ From P ４ In order to cover the fifth region 50e, the plurality of light receiving elements of the light receiving element group 20Ga are arranged in a range from the intersection P ７ From P ９ are placed in the range of

[0110] The light receiving element group 20Gb is used to detect targets in the first region 50a and the fourth region 50d. In order to cover the first region 50a, the plurality of light receiving elements of the light receiving element group 20Gb are arranged at the intersection P １ From P ３ In order to cover the fourth region 50d, the plurality of light receiving elements of the light receiving element group 20Gb are arranged in a range from the intersection P ５ From P ７ are placed in the range of

[0111] The light receiving element group 20Gc is used to detect targets in the third region 50c and the sixth region 50f. In order to cover the third region 50c, the plurality of light receiving elements of the light receiving element group 20Gc are arranged at the intersection P ４ From P ６ In order to cover the sixth region 50f, the plurality of light receiving elements of the light receiving element group 20Gc are arranged in a range from the intersection P ８ From P １ are placed in the range of

[0112] Next, the control performed by the control unit 70 (FIG. 12) will be described. When the plurality of base lines 35a, 35b, and 35c are viewed from a point in the detection region 50 on a half line extending in the direction of orientation from each of the plurality of light-emitting elements included in the light-emitting element group 10G, a light-receiving element group corresponding to a virtual light-receiving point located at the end of the base line where the visual angle is maximum is assigned to each of the light-emitting elements.

[0113] For example, the visual angle when viewing the base line 35b from an arbitrary point within the first region 50a of the detection region 50 is larger than the visual angle when viewing the other base lines 35a and 35c. Therefore, the light-receiving element group 20Gb corresponding to the base line 35b is assigned to a light-emitting element having a directivity direction toward the first region 50a. In the example shown in Fig. 19, the light-receiving element groups 20Gb are arranged in two locations, and of the two light-receiving element groups 20Gb, the light-receiving element group 20Gb that covers the first region 50a is assigned.

[0114] When operating each of the plurality of light-emitting elements included in the light-emitting element group 10G, the control unit 70 operates the plurality of light-receiving elements included in the light-receiving element group assigned to the light-emitting element to be operated, and measures the light-receiving level.The control unit 70 calculates the position of the target based on the light-receiving / light-emitting element pair of the light-receiving element and the light-emitting element that produces the maximum light-receiving level.

[0115] By assigning a light-receiving element group to be activated to each light-emitting element and activating only the light-receiving elements of the assigned light-receiving element group, unnecessary light-receiving elements are prevented from being activated. This reduces the distance measurement time. Furthermore, in the modification shown in FIG. 19, targets can be detected in all directions (360°).

[0116] 19, the detection area 50 is divided into six areas, from the first area 50a to the sixth area 50f, but the number of divided areas is not limited to six. For example, the detection area 50 may be divided into four areas with a central angle of 90°. When dividing the detection area 50 into four areas, two virtual light-receiving points are arranged on two radii extending at an angle of 90° from the virtual light-emitting point 11.

[0117] 19, a plurality of light-emitting elements and a plurality of light-receiving elements are arranged along a circumference 37, but a plurality of light-emitting elements and a plurality of light-receiving elements may also be arranged along a closed line of another shape, such as the periphery of an ellipse or a polygon. For example, a plurality of light-emitting elements and a plurality of light-receiving elements may be arranged depending on the shape of the side surface of the housing of a device in which the distance measuring sensor is mounted.

[0118] Next, referring to Fig. 20, an autonomous mobile transport robot (AMR) equipped with a distance measurement sensor according to a modification of the fourth embodiment shown in Fig. 19 will be described. Fig. 20 is a perspective view of an autonomous mobile transport robot 40 equipped with a distance measurement sensor according to a modification of the fourth embodiment. The autonomous mobile transport robot 40 moves on a substantially horizontal surface. A distance measurement sensor 45 (Fig. 19) according to a modification of the fourth embodiment is mounted on the side of the autonomous mobile transport robot 40. Note that Fig. 20 shows an example in which the detection area 50 is divided into four areas: a first area 50a, a second area 50b, a third area 50c, and a fourth area 50d.

[0119] The distance measurement sensor 45 mounted on the autonomous transport robot 40 can determine the direction in which an obstacle is located and the distance to the obstacle.

[0120] Fifth Embodiment Next, a distance measuring sensor according to a fifth embodiment will be described with reference to Figures 21 to 23. Below, a description of the configuration common to the distance measuring sensor according to the first embodiment (Figures 1, 2, and 3) will be omitted.

[0121] Fig. 21 is a side view of one of the optical units 25 used in the distance measuring sensor according to the fifth embodiment. In the fifth embodiment, each of the plurality of light-emitting elements 10 in the light-emitting element group 10G of the distance measuring sensor according to the first embodiment (Fig. 1) constitutes an optical unit 25 together with at least one light-receiving element 20 in the plurality of light-receiving elements 20 in the light-receiving element group 20G. Fig. 21 shows an example in which one optical unit 25 is constituted by one light-emitting element 10 and two light-receiving elements 20a, 20b.

[0122] The light-emitting element 10 and the two light-receiving elements 20a, 20b are mounted on a unit substrate 23. For example, a bullet-type LED or LD with a lens is used as the light-emitting element 10, and a bullet-type photodiode or phototransistor with a lens is used as the light-receiving element 20. The relative positional relationship between the light-emitting element 10 and the light-receiving elements 20a, 20b that constitute each optical unit 25 is the same among the multiple optical units 25.

[0123] The directional characteristics of the light-emitting element 10 and the light-receiving elements 20a, 20b are directed toward the detection area 50, as in the first embodiment. The directional direction 10D of the light-emitting element 10 and the directional directions 20Da, 20Db of the light-receiving elements 20a, 20b extend radially toward the detection area 50 and are included in a common first plane (xy plane, the paper surface of FIG. 21 ). Lines extending from the directional direction 10D of the light-emitting element 10 and the directional direction 20Da of one of the light-receiving elements 20a toward the opposite side of the detection area 50 intersect on the first plane. This intersection point is referred to as the unit origin Oua. Similarly, the point where lines extending from the directional direction 10D of the light-emitting element 10 toward the directional direction 20Db of the other light-receiving element 20b toward the opposite side of the detection area 50 intersect is referred to as the unit origin Oub. Although the positions of the two unit origins Oua and Oub are different in FIG. 21 , they may be the same. The tilt angles of the directivity directions 20Da and 20Db of the two light receiving elements 20a and 20b with respect to the directivity direction 10D of the light emitting element 10 are denoted as αa and αb, respectively.

[0124] Fig. 22A is a schematic side view of the distance measuring sensor of the fifth embodiment, viewed from a direction perpendicular to the first plane (xy plane). Multiple optical units 25 are mounted on a flat substrate 30 and arranged in a row along the first plane (the surface of Fig. 22A). The multiple optical units 25 are arranged so that the orientation direction 10D of the light-emitting element 10 extends radially toward the detection area 50. For example, this configuration can be achieved by arranging the unit substrates 23 of the multiple optical units 25 at an angle with respect to the surface of the substrate 30. A control unit 70 controls the light emission and light reception of the multiple optical units 25.

[0125] Fig. 22B is a schematic side view of a distance measuring sensor according to a modification of the fifth embodiment, viewed from a direction perpendicular to the xy plane. In the modification shown in Fig. 22B, multiple optical units 25 are mounted on the outer surface of a substrate 30 that is curved along the side of a cylinder. The unit substrates 23 of the multiple optical units 25 are arranged along the side of the cylinder. By arranging the unit substrates 23 of each of the multiple optical units 25 along the surface of the curved substrate 30, a configuration is realized in which the directivity directions 10D of the multiple light-emitting elements 10 spread radially.

[0126] 22A and 22B , the light-emitting elements 10 included in the optical units 25 can be used to form the light-emitting element group 10G ( FIG. 1 ) of the distance measuring sensor according to the first embodiment. Similarly, the light-receiving elements 20a included in the optical units 25 can be used to form the light-receiving element group 20G ( FIG. 1 ) of the distance measuring sensor according to the first embodiment. Note that the other light-receiving elements 20b included in the optical units 25 form another light-receiving element group (not shown in FIG. 1 ). The two light-receiving element groups in this configuration can function as the two light-receiving element groups 20Ga and 20Gb of the distance measuring sensor according to the third embodiment ( FIGS. 12 and 13 ).

[0127] 22A, the optical units 25 are arranged along a plane, and in FIG. 22B, the optical units 25 are arranged along the side surface of a cylinder, but they may be arranged along the surface of other shapes, for example, along any curved surface or the side surface of a polygonal prism.

[0128] Next, referring to FIG. 23, the i-th optical unit 25 ｉ and the jth optical unit 25 ｊ 23 shows the positional relationship between the i-th optical unit 25 and the i-th optical unit 25. ｉ and the jth optical unit 25 ｊ 21 is a schematic side view showing the positional relationship between the light receiving elements 20a and 20b of the optical unit 25. The following description focuses on the light receiving element 20a included in one of the light receiving element groups of the two light receiving elements 20a and 20b (FIG. 21) of the i-th optical unit 25. ｉ The light receiving element 20 of interest ｉ Directivity direction 20D ｉ and light-emitting element 10 ｉ Direction of direction 10D ｉ The angle between the jth optical unit 25 and the jth optical unit 25 is denoted as α. ｊ In the above, the light receiving element 20 ｊ Directivity direction 20D ｊ and light-emitting element 10 ｊ Direction of direction 10D ｊ The angle between them is equal to α.

[0129] i-th optical unit 25 ｉLight-emitting element 10 ｉ Direction of direction 10D ｉ and the j-th optical unit 25 ｊ Light-emitting element 10 ｊ Direction of direction 10D ｊ and the i-th optical unit 25 extends toward the detection area 50. ｉ Direction of direction 10D ｉ and the jth optical unit 25 ｊ Direction of direction 10D ｊ The angle between ｉｊ Two optical units 25 ｉ , 25 ｊ are adjacent to each other, the angle β ｉｊ is smaller than the angle α. ｉ , 25 ｊ Therefore, for any i, the i-th optical unit 25 ｉ Direction of direction 10D ｉ and the adjacent optical unit 25 ｊ The directivity direction 20D of at least one of the light receiving elements 20 ｊ always intersect within the detection region 50.

[0130] i-th optical unit 25 ｉ Unit origin Ou ｉ From the j-th optical unit 25 ｊ Unit origin Ou ｊ The distance to ｉｊ Here, the unit origin Ou ｉ , Ou ｊ is the light receiving element 20 of interest. ｉ , 20 ｊ That is, it corresponds to one of the unit origins Oua shown in FIG.

[0131] i-th optical unit 25 ｉ Direction of direction 10D ｉ Orthogonal to the unit origin Ou ｉ and the unit origin Ou ｉ and the unit origin Ou ｊ The angle between the line segment and is γ ｉｊ The distance L ｉｊ, angle β ｉｊ , and angle γ ｉｊ The value of the distance L is determined based on the relative positional relationship of the plurality of optical units 25. ｉｊ , angle β ｉｊ , and angle γ ｉｊ is basic information required to calculate the distance to the target 55. This basic information is stored in advance in the control unit 70 (FIGS. 22A and 22B).

[0132] i-th optical unit 25 ｉ Unit origin Ou ｉ From the direction of direction 10D ｉ The distance to the upper target 55 is d ｉ From the sine law, the following equation holds: i-th optical unit 25 ｉ When light is emitted from the j-th optical unit 25 ｊ The light receiving element 20 ｊ When the light receiving level is maximum, the distance d ｉ can be calculated.

[0133] Next, a distance measurement procedure by the control unit 70 (FIGS. 22A and 22B) will be described. The control unit 70 measures the light receiving level when the light emitting element 10 and the light receiving element 20 are operated for each of the plurality of light receiving / emitting element pairs, each consisting of the light emitting element 10 included in each of the plurality of optical units 25 shown in FIG. 22A or 22B and the light receiving element 20 included in the plurality of optical units 25. Based on basic information defining the positional relationship between the optical unit 25 including the light emitting element 10 and the optical unit 25 including the light receiving element when the light receiving level is maximum, the control unit 70 calculates the distance d to the target 55 in the detection area 50. ｉ If the light receiving levels of the light receiving elements of the multiple optical units 25 are relatively high, signal processing such as weighted averaging is performed to calculate the distance d ｉ may be calculated.

[0134] Next, the advantageous effects of the fifth embodiment will be described. In the fifth embodiment, as in the first embodiment, the plurality of light-emitting elements 10 and the plurality of light-receiving elements 20 are not arranged closely to each other, so that a larger number of light-emitting elements 10 and light-receiving elements 20 can be arranged without spatial limitations. Increasing the number of optical units 25 improves the spatial resolution of the detection position of the target 55.

[0135] Since the plurality of optical units 25 all have the same shape and the same configuration, a distance measuring sensor can be constructed by manufacturing a large number of identical optical units 25 and arranging them along the first plane (xy plane). If the relative positional relationship of the plurality of optical units 25 is fixed and the basic information described with reference to FIG. 23 is stored, the distance d to the target 55 can be calculated. ｉ Therefore, even if the substrate 30 (FIGS. 22A and 22B) on which the distance measuring sensor is mounted has various shapes, the distance measuring sensor can be flexibly customized to configure it.

[0136] Next, a distance measuring sensor according to a modification of the fifth embodiment will be described. The light receiving and emitting functions of each light emitting element 10 and light receiving element 20 of the optical unit 25 of the distance measuring sensor according to the fifth embodiment may be interchanged. That is, the light emitting element 10 may be replaced with a light receiving element, and each of the plurality of light receiving elements 20 may be replaced with a light emitting element. In this case, each of the plurality of light receiving elements 20 of the light receiving element group 20G of the distance measuring sensor according to the first embodiment (FIG. 1) constitutes the optical unit 25 together with at least one of the plurality of light emitting elements 10 of the light emitting element group 10G.

[0137] Sixth Embodiment Next, a distance measuring sensor according to a sixth embodiment will be described with reference to Fig. 24A. Below, a description of the configuration common to the distance measuring sensor according to the fifth embodiment will be omitted.

[0138] Fig. 24A is a schematic cross-sectional view of one optical unit 25 used in the distance measuring sensor according to the sixth embodiment. In the fifth embodiment (Fig. 21), as an example, a bullet-shaped light-emitting element 10 and bullet-shaped light-receiving elements 20a, 20b are used. In contrast, the optical unit 25 according to the sixth embodiment includes a light-emitting region 10A and light-receiving regions 20Aa, 20Ab surface-mounted on the surface of a unit substrate 23, and a condenser lens 24. Surface-mounted components, for example, are used as the light-emitting region 10A and the light-receiving regions 20Aa, 20Ab.

[0139] The light-emitting region 10A and the light-receiving regions 20Aa and 20Ab are sealed with a resin member 26, and the condenser lens 24 is fixed to the resin member 26. The resin member 26 and the condenser lens 24 may be formed integrally.

[0140] The light-emitting region 10A and the condenser lens 24 function as the light-emitting element 10, one light-receiving region 20Aa and the condenser lens 24 function as the light-receiving element 20a, and the other light-receiving region 20Ab and the condenser lens 24 function as the light-receiving element 20b. In this way, one condenser lens 24 is shared by the light-emitting element 10 and the light-receiving elements 20a and 20b. The orientation direction 10D of the light-emitting element 10 and the orientation directions 20Da and 20Db of the light-receiving elements 20a and 20b are determined by the positional relationship between the light-emitting region 10A, the light-receiving regions 20Aa and 20Ab, and the condenser lens 24. In this case, the unit origin Ou is located inside the condenser lens 24.

[0141] Next, the advantageous effects of the sixth embodiment will be described. In the sixth embodiment, the light-emitting element 10 and the two light-receiving elements 20a, 20b share a single condenser lens 24, which allows the optical unit 25 to be made smaller. When the optical unit 25 is made smaller, the arrangement pitch of the multiple optical units 25 can be made narrower. By narrowing the arrangement pitch, it becomes possible to improve distance measurement accuracy.

[0142] Next, a distance measuring sensor according to a modification of the sixth embodiment will be described with reference to Fig. 24B, which is a schematic cross-sectional view of one optical unit 25 used in the distance measuring sensor according to the modification of the sixth embodiment.

[0143] In the sixth embodiment, one condenser lens 24 is shared by the light-emitting element 10 and the light-receiving elements 20a, 20b, but in this modified example, a lens group composed of three small lenses 24e, 24ra, and 24rb is used instead of the condenser lens 24. The small lens 24e and the light-emitting region 10A form the light-emitting element 10, the small lens 24ra and the light-receiving region 20Aa form the light-receiving element 20a, and the small lens 24rb and the light-receiving region 20Ab form the light-receiving element 20b. In this case, the unit origin Ou is located farther from the lens group than the light-emitting region 10A and the light-receiving regions 20Aa, 20Ab.

[0144] Next, another modification of the sixth embodiment will be described. In the sixth embodiment (FIG. 24A) and the modification of the sixth embodiment (FIG. 24B), surface-mounted components are used for the light-emitting region 10A and the light-receiving regions 20Aa and 20Ab, but the light-emitting region 10A and the light-receiving regions 20Aa and 20Ab may be formed on a common semiconductor die. In this case, the unit substrate 23 is formed of a semiconductor substrate.

[0145] [Seventh Example] Next, a distance measuring sensor according to a seventh example will be described with reference to Figures 25A and 25B. Hereinafter, a description of the configuration common to the distance measuring sensor according to the fifth example will be omitted. Figure 25A is a schematic side view of the distance measuring sensor according to the seventh example, viewed from a direction perpendicular to the first plane (xy plane).

[0146] In the fifth embodiment ( FIG. 22A ), multiple optical units 25 are mounted on a common substrate 30. In contrast to this, in the seventh embodiment, multiple optical units 25 are mounted on separate substrates 30. The multiple substrates 30 are arranged in a row along a first plane (xy plane), and two adjacent substrates 30 are connected via a bending mechanism (hinge) 38. The bending mechanism 38 can change the angle formed by adjacent substrates 30 around a bending axis that is perpendicular to the first plane (xy plane), and temporarily fix the angle at a predetermined angle.

[0147] The bending mechanism 38 has an angle detection function that detects the bending angle. The bending angle detection function is realized by, for example, an angle sensor. For example, a resistive potentiometer attached to the bending axis can be used as the angle sensor. Alternatively, an optical angle detector, rotary encoder, or the like may be used. When multiple optical units 25 are arranged so that the bending axes are approximately horizontal, an inclination sensor, acceleration sensor, or the like may be attached to the substrate 30 to detect the orientation of each substrate 30.

[0148] Next, referring to FIG. 25B, adjacent optical units 25 ｉ , 25 ｊ 25B shows the positional relationship between the optical units 25 adjacent to each other. ｉ , 25 ｊ 23 is a schematic side view showing the positional relationship of the angle β ｉｊ , γ ｉｊ , and the distance L ｉｊ The bending angle of the bending mechanism 38 is defined as δ. ｉｊ Unit origin Ou ｉ , Ou ｊ is located at the center of the length L along the first plane (xy plane) of the substrate 30. Also, the unit origin Ou ｉ The distance in the thickness direction from the surface of the substrate 30 to the rear surface of the substrate 30 is denoted as w. ｉｊ , β ｉｊ and distance L ｉｊ can be expressed by the following formula:

[0149] bending angle δ ｉｊ can be detected by the angle detection function of the bending mechanism 38. The length L and the distance w are known from the structure of the optical unit 25. Therefore, the bending angle δ ｉｊ If we know the angle β ｉｊ , γ ｉｊ and distance L ｉｊ Furthermore, the optical unit 25 ｉ and optical unit 25 ｊ and are not adjacent to each other, i.e., optical unit 25 ｉ and optical unit 25ｊ Even when the optical unit 25 is connected to the optical unit 25 via another optical unit 25, ｉ From light unit 25 ｊ Based on multiple bending angles ranging from angle β ｉｊ , γ ｉｊ and distance L ｉｊ can be calculated.

[0150] The control unit 70 (FIG. 1) measures the light receiving level when the light emitting element and the light receiving element are operated for each of the plurality of light receiving / emitting element pairs, each of which is composed of a light emitting element included in each of the plurality of optical units 25 and a light receiving element included in each of the plurality of optical units 25. ｉ an optical unit 25 including a light receiving element; ｊ Based on the flexion angle up to angle β ｉｊ , γ ｉｊ and distance L ｉｊ Calculate the angle β ｉｊ , γ ｉｊ and distance L ｉｊ The distance di to the target 55 (FIG. 1) is calculated from the calculation result and equation (7).

[0151] Next, the advantageous effects of the seventh embodiment will be described. The distance measuring sensor according to the seventh embodiment can be bent according to the surface shape of the portion to which the distance measuring sensor is attached, making it possible to attach it to surfaces of various shapes. Distance measurement can be performed with the distance measuring sensor attached to surfaces of various shapes.

[0152] The above-described embodiments are merely examples, and it goes without saying that partial substitution or combination of the configurations shown in different embodiments is possible. Similar effects resulting from similar configurations of multiple embodiments will not be mentioned sequentially for each embodiment. Furthermore, the present invention is not limited to the above-described embodiments. For example, it will be obvious to those skilled in the art that various modifications, improvements, combinations, etc. are possible.

[0153] 10, 10a, 10b Light-emitting element 10A Light-emitting region 10D Directivity direction of light-emitting element 10DP Directivity pattern of light-emitting element 10G, 10Ga, 10Gb Light-emitting element group 11, 11a, 11b Virtual light-emitting point 20, 20a, 20b Light-receiving element 20A, 20Aa, 20Ab Light-receiving region 20D, 20Da, 20Db Directivity direction of light-receiving element 20DP Directivity pattern of light-receiving element 20G, 20Ga, 20Gb, 20Gc Light-receiving element group 21, 21a, 21b, 21c Virtual light-receiving point 22a, 22b, 22d Half-ray 23 Unit substrate 24 Condenser lens 24e, 24ra, 24rb Small lens 25 Optical unit 26 Resin member 30 Substrate 31 Element arrangement line 32 Light emitting element arrangement line 33 Light receiving element arrangement line 35, 35a, 35b, 35c Base line 36 Arc 37 Circumference 38 Bending mechanism 40 Autonomous mobile transport robot (AMR) 45 Distance measuring sensor 50 Detection area 50a First area 50b Second area 50c Third area 50d Fourth area 50e Fifth area 50f Sixth area 55 Target 70 Control unit

Claims

1. A distance measuring sensor comprising: a light-emitting element group including a plurality of light-emitting elements arranged in a row along a first plane; and a light-receiving element group including a plurality of light-receiving elements arranged in a row along said first plane, wherein each of the plurality of light-emitting elements included in said light-emitting element group has directivity in a direction toward a detection area on one side of the light-emitting element row consisting of the plurality of light-emitting elements on said first plane, and the directivity directions of the plurality of light-emitting elements included in said light-emitting element group spread radially into said detection area; each of the plurality of light-receiving elements included in said light-receiving element group has directivity that allows it to receive light that is output from at least one of the plurality of light-emitting elements and is diffusely reflected by a target within said detection area, and the directivity directions of the plurality of light-receiving elements included in said light-receiving element group spread radially into said detection area.

2. A distance measuring sensor as described in claim 1, wherein the half-width of the beam angle of each of the plurality of light-emitting elements included in the light-receiving element group and the half-width of the beam angle of each of the plurality of light-receiving elements included in the light-receiving element group are 15° or less.

3. A distance measuring sensor as described in claim 1 or 2, further comprising a control unit that controls the light emission of a plurality of light-emitting elements included in the light-emitting element group and the light reception of a plurality of light-receiving elements included in the light-receiving element group, wherein the control unit measures the light reception level when the light-emitting element and the light-receiving element are operated for each of a plurality of light-emitting element pairs consisting of one light-emitting element included in the light-emitting element group and one light-receiving element included in the light-receiving element group, and calculates the distance to a target within the detection area based on information that depends on the respective positions and direction of the light-emitting element and the light-receiving element when the light reception level is maximum.

4. A distance measuring sensor as claimed in claim 1 or 2, wherein the directional directions of each of the plurality of light-emitting elements included in the light-emitting element group are extended in the opposite direction from the detection area as half-lines, and the directional directions of each of the plurality of light-receiving elements included in the light-receiving element group are extended in the opposite direction from the detection area as half-lines, and the directional directions of each of the plurality of light-receiving elements are extended in the opposite direction from the detection area as half-lines, and the distance measuring sensor as claimed in claim 1 or 2, wherein the directional directions of each of the plurality of light-receiving elements included in the light-receiving element group are extended in the opposite direction from the detection area as half-lines, and the distance measuring sensor as claimed in claim 1 or 2, wherein the directional directions of each of the light-receiving elements ... distance measuring sensor as claimed in claim 1 or 2 5. A distance measuring sensor as described in claim 4, further comprising a control unit that controls the light emission of a plurality of light-emitting elements included in the light-emitting element group and the light reception of a plurality of light-receiving elements included in the light-receiving element group, wherein the control unit measures the light reception level when the light-emitting element and the light-receiving element are operated for each of a plurality of light-emitting element pairs consisting of one light-emitting element included in the light-emitting element group and one light-receiving element included in the light-receiving element group, and calculates the distance to a target within the detection area based on the angle formed by the half-line from the virtual light-emitting point toward the light-emitting element when the light reception level is at its maximum and the half-line toward the virtual light-receiving point, the angle formed by the half-line from the virtual light-receiving point toward the light-receiving element when the light reception level is at its maximum and the half-line toward the virtual light-emitting point, and the distance from the virtual light-emitting point to the virtual light-receiving point.

6. The distance measuring sensor according to claim 5, wherein a plurality of said light receiving element groups are arranged, and the virtual light receiving point is arranged at a different position for each of said plurality of light receiving element groups.

7. A distance measuring sensor as described in claim 6, wherein for each of the plurality of light-emitting elements included in the light-emitting element group, when a line segment connecting the virtual light-emitting point and each of the plurality of light-receiving element groups is viewed from a point in the detection area on a half-line extending from the light-emitting element in the directional direction, the light-receiving element group is assigned to correspond to the virtual light-receiving point located at the end of the line segment at which the visual angle is greatest, and when the control unit operates each of the plurality of light-emitting elements included in the light-emitting element group, the control unit operates the plurality of light-receiving elements included in the light-receiving element group assigned to the light-emitting element to be operated, and measures the light-receiving level.

8. The distance measuring sensor according to claim 5, wherein a plurality of said light emitting element groups are arranged, and the virtual light emitting points are arranged at different positions for each of said plurality of light emitting element groups.

9. A distance measuring sensor as described in claim 8, wherein, for each of the plurality of light receiving elements included in the light receiving element group, when a line segment connecting the virtual light receiving point and each of the virtual light emitting points of the plurality of light emitting element groups is viewed from a point in the detection area on a half line extending from the light receiving element in the directivity direction, the light emitting element group is assigned to correspond to the virtual light emitting point located at the end of the line segment at which the visual angle is greatest, and when the control unit operates each of the plurality of light receiving elements included in the light receiving element group, the control unit operates the plurality of light emitting elements included in the light emitting element group assigned to the light receiving element to be operated, and measures the light reception level.

10. A distance measuring sensor as described in claim 1 or 2, wherein each of the plurality of light-emitting elements in the light-emitting element group constitutes an optical unit together with at least one light-receiving element among the plurality of light-receiving elements in the light-receiving element group, the relative positional relationship between the light-emitting elements and the light-receiving element constituting each of the optical units is the same among the plurality of optical units, and the plurality of optical units are arranged in a row along the first plane.

11. A distance measuring sensor as described in claim 1 or 2, wherein each of the plurality of light receiving elements in the light receiving element group constitutes an optical unit together with at least one of the plurality of light emitting elements in the light emitting element group, the relative positional relationship between the light emitting element and the light receiving element constituting each of the optical units is the same among the plurality of optical units, and the plurality of optical units are arranged in a row along the first plane.

12. A control unit is further provided which controls the light emission of the light-emitting elements and the light reception of the light-receiving elements of each of the plurality of optical units, and when a unit origin whose relative position to the light-emitting elements and the light-receiving elements is fixed is defined for each of the plurality of optical units, the control unit stores basic information which, when focusing on each of the plurality of optical units, can calculate the distance from the unit origin of the optical unit of interest to the unit origin of each of the other optical units, the angle between a plane which is perpendicular to the orientation direction of the light-emitting element of the optical unit of interest and passes through the unit origin and a line segment connecting the unit origin of the optical unit of interest to the unit origin of each of the other optical units, and the angle between the orientation direction of the light-emitting element of the optical unit of interest and the orientation direction of the light-emitting element of each of the other optical units, A ranging sensor as described in claim 10 or 11, which measures the light receiving level when the light emitting element and the light receiving element are operated for each of a plurality of light receiving / emitting element pairs consisting of a light emitting element included in each of the plurality of optical units and a light receiving element included in the plurality of optical units, and calculates the distance to a target within the detection area based on the basic information of the optical unit including the light emitting element and the optical unit including the light receiving element when the light receiving level is maximum.

13. A distance measuring sensor as described in any one of claims 10 to 12, wherein each of the plurality of optical units includes a light-emitting region, a light-receiving region, and a focusing lens shared by the light-emitting region and the light-receiving region, the light-emitting region and the focusing lens constituting the light-emitting element of the optical unit, and the light-receiving region and the focusing lens constituting the light-receiving element of the optical unit.

14. The distance measuring sensor according to claim 10, wherein two adjacent optical units among the plurality of optical units arranged in a row are connected to each other via a bending mechanism.

15. The distance measuring sensor of claim 14, wherein the bending mechanism has an angle detection function for detecting the bending angle, and further comprises a control unit that controls the light emission of the light-emitting element and the light reception of the light-receiving element of each of the plurality of optical units, and the control unit measures the light reception level when the light-emitting element and the light-receiving element are operated for each of a plurality of light-emitting / receiving element pairs consisting of a light-emitting element included in each of the plurality of optical units and a light-receiving element included in the plurality of optical units, and calculates the distance to a target within the detection area based on the bending angle from the optical unit including the light-emitting element to the optical unit including the light-receiving element when the light reception level is maximum.

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