Optical sensor, optical sensor control method, and optical sensor control program

Abstract

To provide an optical sensor that, even when detecting a relatively distant object to be detected, does not require complicated optical axis adjustment work.SOLUTION: An optical sensor 100 comprises: a light projection element that projects detection light; an optical axis adjustment element that adjusts an optical axis of the detection light projected from the light projection element; a light receiving element that receives detection light reflected on an object 210 and outputs a detection signal; a receiving unit that receives in advance a specification condition related to a detection result obtained by preliminarily detecting the object; and a control unit that settles, as an inspection direction, a direction of the detection light in which, among detection results based on detection signals obtained by driving the optical axis adjustment element with respect to a preliminary object installed in advance to scan the detection light, a detection result corresponding to the specification condition received by the receiving unit is obtained, drives the optical axis adjustment element with respect to an object to be inspected installed in place of the preliminary object so that the detection light is projected in the settled inspection direction, and causes the light projection element and the light receiving element to execute detection processing.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an optical sensor, a control method for an optical sensor, and a control program for an optical sensor. [Background technology]

[0002] Optical sensors that detect the presence or absence of an object to be inspected and the distance to the object are known. For example, Patent Document 1 discloses a ToF (Time of Flight) sensor that detects the distance by measuring the time it takes for detection light projected onto the object to be reflected and returned. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-53769 A Summary of the Invention [Problem to be solved by the invention]

[0004] Optical sensors are installed in production lines and are sometimes used to measure the characteristic shapes of parts flowing through the production line to determine the type and quality of the items. When used in this way, optical sensors are often attached to structures associated with the production line 300, but they cannot always be attached near the objects to be inspected. In recent years, wide-range optical sensors with detection ranges of several meters have been developed. However, with wide-range optical sensors, even a slight angle error during installation causes the detection light to deviate from the target location of the object to be inspected. When an optical sensor is attached via a mounting fixture, it is difficult to precisely adjust the optical axis of the detection light, and workers have to perform the cumbersome task of loosening and tightening the mounting fixture while checking the spot of the detection light.

[0005] The present invention has been made to solve such problems, and provides an optical sensor etc. that does not require complicated optical axis adjustment work, even when detecting an object that is relatively far away. [Means for solving the problem]

[0006] The optical sensor according to the first aspect of the present invention includes a light-projecting element for projecting detection light, an optical axis adjustment element for adjusting the optical axis of the detection light projected from the light-projecting element, a light-receiving element for receiving the detection light reflected by the object and outputting a detection signal, a reception unit for receiving in advance designated conditions related to the detection results obtained by preliminary detection of the object, and a control unit for determining, as an inspection direction, the direction of the detection light in which the detection result corresponding to the designated conditions received by the reception unit is obtained among the detection results based on the detection signal obtained by driving the optical axis adjustment element to scan the detection light on a spare object set in advance, and driving the optical axis adjustment element so that the detection light is projected in the determined inspection direction on the inspection object set in place of the spare object, thereby causing the light-projecting element and the light-receiving element to execute the detection process. According to the optical sensor configured in this way, if the user sets the designated conditions related to the object in advance, the detection direction for the optical sensor to perform the detection process is automatically determined, so that the user can save the trouble of re-adjusting the orientation of the optical sensor.

[0007] In the optical sensor described above, the receiving unit may be configured to receive a condition related to distance as the specified condition. For example, if the target part of the object to be inspected protrudes toward the sensor, the "closest part" may be specified as the specified condition, and the target part can be intuitively specified according to the characteristics of the target part.

[0008] In the optical sensor described above, the control unit may perform notification light projection, which projects detection light in the determined inspection direction so that the user can see it. By performing notification light projection, the user can confirm in which direction the detection direction has been determined.

[0009] The optical sensor may include a display unit that indicates the inspection direction determined by the control unit. If such a display unit is present, the user can confirm in which direction the detection direction has been determined.

[0010] In the optical sensor described above, the control unit may set detection conditions for the detection process for the object to be inspected using detection results obtained around the determined inspection direction among the detection results obtained by scanning the detection light. Since the detection results around the determined inspection direction are also obtained by scanning, by setting the detection conditions for the detection process using this information, it is possible to perform accurate detection process according to the shape of the object to be inspected, etc.

[0011] A control method for an optical sensor in a second aspect of the present invention is a control method for an optical sensor including a light-projecting element that projects detection light, an optical axis adjustment element that adjusts the optical axis of the detection light projected from the light-projecting element, and a light-receiving element that receives the detection light reflected by an object and outputs a detection signal, the control method including a reception step of receiving in advance specified conditions related to detection results obtained by preliminary detection of the object, a scanning step of driving the optical axis adjustment element to scan the detection light on a spare object set in advance to obtain a plurality of detection results based on the detection signals, a determination step of determining, as an inspection direction, a direction of the detection light that has produced a detection result corresponding to the specified conditions received in the reception step among the plurality of detection results obtained in the scanning step, and an inspection step of driving the optical axis adjustment element so that the detection light is projected in the determined inspection direction on an inspection object set in place of the spare object, and causing the light-projecting element and the light-receiving element to execute detection processing.

[0012] Further, a control program for an optical sensor in a third aspect of the present invention is a control program for an optical sensor including a light-projecting element that projects detection light, an optical axis adjustment element that adjusts the optical axis of the detection light projected from the light-projecting element, and a light-receiving element that receives the detection light reflected by an object and outputs a detection signal, and causes a computer to execute a receiving step of receiving in advance specified conditions related to detection results obtained by preliminary detection of the object, a scanning step of driving the optical axis adjustment element to scan the detection light on a spare object set in advance to obtain multiple detection results based on the detection signals, a determination step of determining, as an inspection direction, a direction of the detection light that has obtained a detection result corresponding to the specified conditions received in the reception step among the multiple detection results obtained in the scanning step, and an inspection step of driving the optical axis adjustment element so that the detection light is projected in the determined inspection direction on an inspection object set in place of the spare object, and causing the light-projecting element and the light-receiving element to perform detection processing.

[0013] In the second and third aspects, as in the first aspect, the user can set specified conditions for the target object in advance and the detection direction for the optical sensor to perform the detection process is automatically determined, thereby eliminating the need to readjust the orientation of the optical sensor. Effect of the Invention

[0014] According to the present invention, it is possible to provide an optical sensor or the like that does not require complicated optical axis adjustment work even when detecting a detection target that is relatively far away. [Brief description of the drawings]

[0015] [Figure 1] FIG. 2 is a perspective view of the appearance of an optical sensor. [Diagram 2] FIG. 1 is a system configuration diagram of an optical sensor. [Diagram 3] FIG. 13 is a diagram illustrating an example of input of a specified condition. [Figure 4] FIG. 13 illustrates performing a search scan on a preliminary object. [Diagram 5] FIG. 13 is a diagram showing a state when the inspection direction is determined. [Figure 6] FIG. 11 is a diagram illustrating settings of detection conditions in the detection process. [Figure 7] FIG. 1 is a diagram showing a state in which an inspection object is inspected. [Figure 8] FIG. 4 is a flowchart illustrating a processing procedure of a control unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The present invention will be described below through embodiments of the invention, but the invention according to the claims is not limited to the following embodiments. Furthermore, not all of the configurations described in the embodiments are necessarily essential as means for solving the problems.

[0017] FIG. 1 is an external perspective view of an optical sensor 100. The optical sensor 100 according to this embodiment is a sensor that detects the presence or absence of a partial shape of a workpiece as an inspection target, the distance to a specific location, etc., and is installed and used, for example, on a production line in a factory. The optical sensor 100 projects detection light L1 toward the workpiece and receives detection light L2 that is reflected by the workpiece and returns. The optical sensor 100 described below is a ToF sensor that detects distance information by measuring the round-trip time of the detection light in particular. When the optical sensor 100 cannot receive the detection light L2, it outputs non-detection information indicating that the workpiece is not detected, and when it can receive the detection light L2, it outputs distance information.

[0018] The detection light L1 is projected through a transparent window 102 provided on one surface of the housing 101. Although details will be described later, the optical sensor 100 is provided with an optical axis adjustment element that adjusts the projection direction of the detection light L1 projected from the light projecting element. The optical axis adjustment element can deflect the optical axis of the detection light L1 in two axial directions (X-axis direction and Y-axis direction shown in the figure) that are orthogonal at a predetermined pitch. Specifically, as shown in the figure, the optical axis of the detection light L1 can be deflected in any direction (x m ,y n ) so that the optical axis of the detection light L1 can be aligned with the

[0019] In addition, the optical sensor 100 is arranged in a direction D along the projection direction of the detection light L1. n From D f In other words, the range indicated by the dots in the figure is the detectable range, and the optical sensor 100 outputs non-detection information if a workpiece is not present within this range, and outputs distance information to the reflection point of the detection light L1 if a workpiece is present within this range.

[0020] An operation button 150 is provided on one surface of the housing 101, and the operation button 150 accepts operations from the user. A display panel 160 is also provided on one surface of the housing 101, and the display panel 160 displays the confirmed inspection direction and the like, as described below. A cable 103 is connected to an external device such as a PLC or a PC, and transmits an output signal to these devices. Note that an X-axis, a Y-axis, and a Z-axis are defined as shown in the figure. In the following drawings, the same coordinate axes as in FIG. 1 are also shown to indicate the orientation of the components depicted in each drawing.

[0021] 2 is a system configuration diagram of the optical sensor 100. The control system of the optical sensor 100 is mainly composed of a control unit 110, a light projecting element 120, an optical axis adjustment element 130, a light receiving element 140, an operation button 150, a display panel 160, an input / output IF 170, and a storage unit 180. The control unit 110 is a processor (CPU: Central Processing Unit) that controls the optical sensor 100 and executes programs. The control unit 110 may be configured to include an arithmetic processing chip such as an ASIC (Application Specific Integrated Circuit) and a processing circuit that processes various electrical signals. The control unit 110 executes a control program that is read from the storage unit 180 or provided from an external device via the input / output IF 170, and performs various processes related to the detection process of the workpiece.

[0022] The light projecting element 120 is a laser diode that emits laser light (e.g., red light of 635 nm to 680 nm), and emits detection light L1 modulated to a specific frequency (e.g., 12 MHz) under the control of the control unit 110. If the wavelength band of the detection light L1 is in the visible band, the spot irradiated on the workpiece can be visually recognized, which is convenient for checking the state of the search scan of the detection light L1 and checking the inspection location where the inspection process is being performed. The light projecting element 120 is not limited to a laser diode that emits coherent light, and an element that emits incoherent light, such as an LED, may be used.

[0023] As described above, the optical axis adjustment element 130 is an element that adjusts the optical axis of the detection light L1 projected from the light projecting element 120. In this embodiment, a liquid crystal device that realizes deflection by applying a voltage to a liquid crystal cell and controlling the on / off state is used as the optical axis adjustment element 130. Specifically, the liquid crystal device is a device in which a liquid crystal diffraction grating in which liquid crystal cells are arranged (for example, Journal of Optics, Vol. 30, No. 1: "Research Trends in Liquid Crystal Optical Devices", p. 6) is stacked, and a control circuit is incorporated that controls the voltage applied to the liquid crystal cell so that the deflection amount of the incident laser light can be controlled according to the input control signal. In addition, as the optical axis adjustment element 130, a MEMS mirror, an optical phased array, an electro-optical crystal, etc. can also be used. If visible light is not required, a slow light using near-infrared light, etc. can also be used.

[0024] The light receiving element 140 is, for example, a CMOS sensor having photoelectric conversion pixels arranged two-dimensionally, and converts the received detection light L2 into an electric signal and transmits it to the control unit 110. In the figure, the optical paths of the detection light L1 projected toward the work and the detection light L2 received by the light receiving element 140 are shown separately, but in reality, as shown in FIG. 1, they are the same optical path, and the optical path of the detection light L2 toward the light receiving element 140 is separated from the optical path of the detection light L1 using, for example, a dichroic mirror. In addition, since the optical axis adjustment element 130 is housed in the housing 101 together with the light projecting element 120 and the light receiving element 140, there is no need to provide a movable part for adjusting the optical axis of the detection light L1 outside the housing 101. Therefore, since the housing 101 can be directly fixed to, for example, a structure associated with the manufacturing line, the optical sensor 100 is easy to install and is less susceptible to the influence of inadvertent contact by an operator.

[0025] The operation button 150 is an operation member that accepts designation from the user, and may include, for example, an UP button, a DOWN button, a cross button, and the like. The operation button 150 functions as a reception unit that cooperates with the control unit 110 to accept in advance designated conditions related to a detection result obtained by preliminary detection of an object. In addition to such a function as a reception unit, the operation button 150 also functions as a reception unit that accepts input of various items of the optical sensor 100. Note that the operation member is not limited to the operation button, and may be another device such as a touch sensor.

[0026] The display panel 160 is, for example, a liquid crystal panel, and displays the setting state of the optical sensor 100, distance information as a detection result, non-detection information, and the like. An LED or the like may be provided as a device indicating the setting state of the optical sensor 100. The input / output IF 170 is an interface for transmitting and receiving information to and from an external device via the cable 103, and includes, for example, an Ethernet (registered trademark) unit or a LAN unit. The input / output IF 170 is not limited to a wired connection via the cable 103, and may include a wireless connection unit compatible with wireless LAN or Bluetooth (registered trademark).

[0027] The control unit 110 can also receive operations performed by the user on the external device via the input / output IF 170. For example, when the user uses the user interface of the external device to specify conditions related to a detection result obtained by preliminarily detecting an object, the input / output IF 170 cooperates with the control unit 110 to function as a reception unit.

[0028] The storage unit 180 is a non-volatile storage medium, and is configured by, for example, a flash memory. The storage unit 180 can store various parameter values, functions, lookup tables, and the like used for control and calculation, in addition to programs for executing control and processing of the optical sensor 100. The storage unit 180 also stores the designated conditions accepted by the accepting unit and the confirmed inspection direction of the detection light L1.

[0029] The control unit 110 also plays a role as a functional calculation unit that executes various calculations according to the processing instructed by the control program. The control unit 110 can function as a light projection adjustment unit 111 and a distance calculation unit 112. The light projection adjustment unit 111 drives the optical axis adjustment element 130 according to the command of the program so that the detection light L1 is scanned in the changeable range and so that the detection light L1 is projected in the confirmed inspection direction. The distance calculation unit 112 calculates the time difference between the projected detection light L1 and the received detection light L2, for example, using the phase difference between the two, and converts it into the distance to the inspection object. The control unit 110 structures the calculation result of the distance calculation unit 112 into data and outputs it as distance information. Alternatively, when the light receiving element 140 does not receive the detection light L2, it outputs specified non-detection information.

[0030] The user can specify in advance, via the operation button 150 or the like, the specified conditions for the object to be inspected in order to determine the inspection direction in which the detection light L1 should be directed, as described above. The control unit 110 determines, as the inspection direction, the direction in which the detection result corresponding to the specified conditions specified by the user is obtained, among the detection results obtained by scanning the detection light L1 on a preliminary object set in advance. Thereafter, the projection direction of the detection light L1 is fixed to the determined inspection direction, and the detection process for the object to be inspected is performed. The procedure will be specifically described below.

[0031] 3 is a diagram for explaining an example of input of the specified conditions. The optical sensor 100 is fixed to a structure associated with the production line, facing the vicinity of an inspection position on the production line 300. The user places a preliminary workpiece 210, which is a preliminary object of the same type as the object to be inspected, on the production line 300 so that a target inspection point 211 is located near the inspection position. Here, the inspection point 211 only needs to be included in the deflectable range of the detection light L1, and the user can place the preliminary workpiece 210 on the production line 300 in an approximate location without paying much attention.

[0032] It is preferable that the preliminary work 210 is a reference product in a state where the inspection point 211 is judged to be good. In this embodiment, it is assumed that each work that is conveyed in sequence on the production line 300 is inspected to ensure that the hexagonal screw is properly fastened. In this case, the inspection point 211 is the head of the hexagonal screw, and it is preferable that the hexagonal screw is also properly fastened in the preliminary work 210.

[0033] With the optical sensor 100 and the preliminary work 210 thus installed, the user operates the operation button 150 to specify the specified conditions for the inspection object. The conditions that can be specified are listed on the display panel 160 as selection items 161 as shown in the figure. In the example shown in the figure, the selection items 161 provided are "Far," which sets the light projection direction in which the farthest distance is detected as the inspection direction, "Near," which sets the light projection direction in which the shortest distance is detected as the inspection direction, and "Average," which sets the light projection direction that is closest to the average value of all the detected distances as the inspection direction. These selection items are provided as specific items to make it easy for the user to select from the detection results obtained by preliminary detection of the inspection object.

[0034] The user can align the selection pointer 162 with any of the selection items 161 by operating the operation button 150. In the example shown in the figure, the selection pointer 162 is aligned with "Near." When the enter button is pressed in this state, "Near" is confirmed as the specified condition.

[0035] Although three selectable conditions are provided here, the options are not limited to these. For example, the user may be allowed to input / specify the detection distance by a numerical value. For example, if "3m20cm" is specified, the light projection direction in which the closest distance is detected can be set as the inspection direction, and if "3m10cm to 3m20cm range" is specified, the light projection direction in which the distance that satisfies this range can be set as the inspection direction. In addition, conditions based on the shape of the object, such as "a portion recessed from the surroundings", may be prepared as options. In addition, the designated conditions may be specified not only by accepting an operation on the operation button 150, but also by the control unit 110 accepting the designated conditions specified by the user to the external device via the input / output IF 170.

[0036] FIG. 4 is a diagram showing a state where a search scan is performed on a preliminary workpiece 210, which is a preliminary object. The control unit 110 accepts the specified conditions in advance as described above, and when it accepts an instruction to start the search scan, it starts the search scan as shown in FIG. 4(A). Specifically, the light projection adjustment unit 111 drives the optical axis adjustment element 130 to sequentially deflect the projection direction of the detection light L1 from the upper left to the lower right within the deflection possible range in a single stroke. In synchronization with this, the control unit 110 controls the light projection element 120 and the light receiving element 140, and stores the distance information in each projection direction calculated by the distance calculation unit 112 in the storage unit 180 sequentially together with the coordinates of the projection direction. For example, as shown in FIG. 4(B), when a detection process is performed on the head of a hexagonal screw, a direction coordinate (x T ,y T ) and the detected distance D T are stored in the storage unit 180. Note that, in this embodiment, the projection direction of the deflectable detection light L1 is indicated by directional coordinates (x, y), but the parameters defining the projection direction are not limited to this, and may be defined by, for example, a deflection angle around the pitch axis and a deflection angle around the yaw axis.

[0037] When the search scan is completed in this manner, a data set of the direction coordinates and distances used in the detection process is completed. The control unit 110 extracts from the obtained distances those that meet the designated conditions specified in advance, and determines the direction coordinates associated with those distances as the inspection direction. Specifically, as shown in FIG. 3, if "Near" is specified as the designated condition, the control unit 110 determines the direction coordinate (x T ,y T ) is determined as the inspection direction.

[0038] FIG. 5 is a diagram showing a state when the inspection direction is determined. When the control unit 110 determines the inspection direction, it executes a notification projection that projects the detection light L1 in the determined inspection direction so that the user can visually recognize it. The notification projection is a projection mode different from the normal detection light L1. For example, the output intensity is increased or blinking projection is performed. As a result, a highly visible spot is formed at the inspection location 211, and the user can confirm the location where the inspection is to be performed.

[0039] In addition, the control unit 110 simply displays the determined inspection direction on the display panel 160. Specifically, a range frame 163 representing the deflectable range is displayed in the display area of the display panel 160, and a direction indicator 164 indicating which direction within the deflectable range is the inspection direction is displayed at a relative position with respect to the range frame 163. Therefore, the user can confirm the inspection direction by observing the display panel 160. When the inspection direction is automatically determined in this way, even when the user detects a detection object relatively far from the optical sensor 100, the user can omit the troublesome operations such as loosening or tightening the mounting fixture while confirming the spot of the detection light.

[0040] FIG. 6 is a diagram for explaining an example of setting detection conditions in the detection process. The control unit 110 can also set the detection conditions for the detection process for the inspection object by using the detection results obtained around the determined inspection direction among the detection results obtained by scanning the detection light L1. For example, when it is expected that the distance D0 will be detected if the inspection location has the shape as designed, it is assumed that if the detection distance D for the inspection object satisfies (D0 - S) < D < (D0 + S), it is a qualified product. At this time, S can be determined according to the difference between the distance D T (≈D0) of the inspection location and the distances D R around it in the preliminary work 210.

[0041] As shown in the figure, when the direction coordinates of the inspection direction are determined to be (x T , y T ), the detection distance D Tand the distance D which is the average value of the detection distances in the surrounding direction coordinates R Determine S according to. Specifically, the direction coordinates (x T , y T ) for the direction coordinates (x T , y T+S ) at a predetermined upper part, the distance D1 at the direction coordinates (x T-S , y T ) at a predetermined right part, the distance D3 at the direction coordinates (x T , y T-S ) at a predetermined lower part, and the distance D4 at the direction coordinates (x T+S , y T ) at a predetermined left part are extracted, and the average value of these D1 to D4 is taken as the distance D R . Then, the difference between the distance D T of the inspection location and the calculated distance D R is defined as S. That is, S = D T - D R . The control unit 110 can output an inspection result of "qualified" when, in the inspection of the inspection object, the detected distance D in the inspection direction satisfies (D0 - S) < D < (D0 + S). Note that regarding how far to set the respective direction coordinates of the predetermined upper part, predetermined right part, predetermined lower part, and predetermined left part from the direction coordinates (x T , y T ), it is advisable to consider the size and shape of the inspection location. For example, specific numerical inputs may be received from the user in advance, or the range in which the same detection result as the detection result of the direction coordinates (x T , y T ) can be obtained may be determined to be the same plane as the inspection location, and it may be automatically set to avoid that plane.

[0042] FIG. 7 is a diagram showing a state of inspecting an inspection work 220 which is an inspection object. When the inspection direction is determined as described above, the light projection adjustment unit 111 fixes the light projection direction of the detection light L1 to the determined direction coordinates (x T , y T ). The user removes the preliminary work 210 and operates on the production line 300 so that the target inspection work 220 flows sequentially.

[0043] Each time the inspection workpiece 220 reaches a specified position on the production line 300, the control unit 110 sends a control command to the light emitting element 120 and the light receiving element 140 to execute a detection process, and outputs the detection result to an external device.

[0044] Here, a case will be described where the detection distance of the inspection point 221 is simply output as the detection result. As shown in the figure, a hexagonal screw is properly fastened in a certain inspection workpiece 220a, and the optical sensor 100 detects a distance D a The external device is output to the external device at a distance D a is within the tolerance range and is judged as "passed". For example, if the tolerance range is set to ±α for the above-mentioned D0, (D0-α) <D a If <(D0+α), the result is "passed." Here, "α" is a fixed value determined in advance. On the other hand, in the next inspection workpiece 220b, the hexagonal screw is not sufficiently fastened and is floating, and the optical sensor 100 detects the distance D b The external device is output to the external device at a distance D b If it is confirmed that D is not within the tolerance range, it is judged as "failed". b <(D0-α), so it is "failed." In this way, the quality of the inspection work 220 can be judged using the optical sensor 100. Note that the optical sensor 100 may be configured to judge pass / fail and output the result to an external device.

[0045] Next, a processing procedure of the control unit 110 will be described. Fig. 8 is a flow diagram explaining the processing procedure of the control unit 110. The flow starts when the optical sensor 100 is fixed to a structure associated with the production line 300, the preliminary work 210 is placed on the production line 300, and the power is turned on.

[0046] In step S101, control unit 110 accepts designated conditions related to the object via a user's operation of operation button 150. After the acceptance of the designated conditions is completed, in the following step S102, control unit 110 accepts an instruction to start scanning via a user's operation of operation button 150.

[0047] Upon receiving an instruction to start scanning, the control unit 110 in step S103 executes a search scan on the preliminary work 210. That is, the light projection adjustment unit 111 drives the optical axis adjustment element 130 to scan the detection light L1, and controls the light projection element 120 and the light receiving element 140 to cause the distance calculation unit 112 to sequentially calculate distances, and stores the calculation results in the storage unit 180 together with the direction coordinates.

[0048] After the search scan is completed, the process proceeds to step S104, where the control unit 110 extracts the distances that match the conditions specified in step S101 from among the obtained distances, and determines the direction coordinates associated with the distances as the inspection direction. In the following step S105, the control unit 110 executes notification light projection for the determined inspection direction, and displays the inspection direction on the display panel 160 in a simplified manner.

[0049] In step S106, the control unit 110 waits until it receives an instruction to start inspection via the user's operation of the operation button 150, and proceeds to step S107 when it receives the instruction. When the control unit 110 proceeds to step S107, it causes the light projection adjustment unit 111 to orient the projection direction of the detection light L1 to the confirmed inspection direction, and causes the light projecting element 120 and the light receiving element 140 to execute detection processing every time the inspection work 220 reaches a specified position on the production line 300. The control unit 110 outputs the detection result to an external device via the input / output IF 170. When the inspection of the planned number of works flowing on the production line 300 is completed, the series of processes is terminated.

[0050] The optical sensor 100 described above accepts a condition related to distance as a specified condition, but the specified condition can be set to various conditions other than distance depending on the configuration of the optical sensor. For example, if a light receiving element capable of detecting a change in the amount of received light is adopted, the amount of reflected light changes depending on the color of the reflection point even if the object to be inspected is located at the same distance from the optical sensor, so a condition related to the color of the inspection point can be set as the specified condition. For example, if the surface of the object is painted black and painted other than black, the amount of reflected light reflected by the surface painted black is lower, so that the painted area painted black can be recognized. In such a case, if "low reflected light amount" or "high reflected light amount" can be specified as the specified condition, the "black point" or "non-black point" can be detected by scanning and searching even at the same distance.

[0051] Furthermore, the optical sensor 100 is not limited to a ToF sensor that detects distance information by measuring the round trip time of detection light, but may be a triangulation sensor that detects distance information by measuring the arrival position of reflected light that changes depending on the distance of the detection target. When the triangulation sensor employs an optical axis adjustment element, for example, if a lookup table that associates the measured distance with the projection direction of the detection light L1 and the receiving position of the detection light L2 is prepared in advance, distance information can be generated as a detection result.

[0052] In addition, the optical sensor 100 described above performs a search scan over the entire deflectable range, but the entire deflectable range does not necessarily need to be scanned. For example, the user may specify the scan range by operating the operation button 150, or the scan range may be automatically limited based on information about the object to be inspected sent from an external device. In addition, in the above-described embodiment, the detection of distance information for determining whether the object to be inspected is good or bad has been described, but the use of the output distance information is not limited to the determination of whether the object is good or bad. For example, a use in which the type of the object to be inspected is determined by detecting the distance to a characteristic partial shape as the object to be inspected may also be considered.

[0053] [Note] a light-projecting element (120) that projects detection light (L1); an optical axis adjustment element (130) for adjusting the optical axis of the detection light (L1) projected from the light projecting element (120); a light receiving element (140) that receives the detection light (L2) reflected by an object and outputs a detection signal; a reception unit (150, 170) that receives in advance a designated condition related to a detection result obtained by preliminary detection of an object; a control unit (110) that determines, as an inspection direction, a direction of the detection light in which a detection result corresponding to the specified condition accepted by the accepting unit (150, 170) has been obtained among detection results based on the detection signals obtained by scanning the detection light (L1) by driving the optical axis adjustment element (130) over a spare object (210) that has been placed in advance, and drives the optical axis adjustment element (130) so that the detection light is projected in the confirmed inspection direction over an inspection object (220) that is placed in place of the spare object (210), thereby causing the light projecting element (120) and the light receiving element (140) to execute a detection process; An optical sensor (100) comprising: [Explanation of symbols]

[0054] 100...optical sensor, 101...housing, 102...transmission window, 103...cable, 110...control unit, 111...light projection adjustment unit, 112...distance calculation unit, 120...light projection element, 130...optical axis adjustment element, 140...light receiving element, 150...operation button, 160...display panel, 161...selection item, 162...selection index, 163...range frame, 164...direction index, 170...input / output IF, 180...storage unit, 210...spare work, 211...inspection location, 220, 220a, 220b...inspection work, 221a, 221b...inspection location, 300...production line

Claims

1. a light-projecting element that projects detection light; an optical axis adjustment element for adjusting an optical axis of the detection light projected from the light projecting element; a light receiving element that receives the detection light reflected by an object and outputs a detection signal; a reception unit that receives in advance a designated condition related to a detection result obtained by preliminary detection of an object; a control unit that determines, as an inspection direction, a direction of the detection light in which a detection result corresponding to the specified condition accepted by the accepting unit has been obtained among detection results based on the detection signals obtained by scanning the detection light by driving the optical axis adjustment element on a spare object that has been set in advance, and drives the optical axis adjustment element so that the detection light is projected in the confirmed inspection direction on an inspection object that is set in place of the spare object, thereby causing the light projecting element and the light receiving element to execute a detection process; An optical sensor comprising:

2. The optical sensor according to claim 1 , wherein the accepting unit accepts a condition related to distance as the specified condition.

3. The optical sensor according to claim 1 , wherein the control unit executes notification light projection that projects the detection light in the determined inspection direction so that the detection light can be visually recognized by a user.

4. The optical sensor according to claim 1 , further comprising a display unit that indicates the inspection direction determined by the control unit.

5. 5. The optical sensor according to claim 1, wherein the control unit sets detection conditions for a detection process for the object to be inspected by using detection results obtained in the vicinity of the determined inspection direction among detection results obtained by scanning the detection light.

6. A control method for an optical sensor including a light-projecting element that projects detection light, an optical axis adjustment element that adjusts an optical axis of the detection light projected from the light-projecting element, and a light-receiving element that receives the detection light reflected by an object and outputs a detection signal, comprising: a receiving step of receiving in advance a specified condition related to a detection result obtained by preliminary detection of an object; a scanning step of scanning the detection light with respect to a preliminary object placed in advance by driving an optical axis adjustment element to obtain a plurality of detection results based on the detection signal; a determination step of determining, as an inspection direction, a direction of the detection light in which a detection result corresponding to the specified condition accepted in the acceptance step was obtained among the plurality of detection results obtained in the scanning step; an inspection step of driving the optical axis adjustment element so that the detection light is projected in the determined inspection direction with respect to an inspection object installed in place of the spare object, and causing the light projecting element and the light receiving element to execute a detection process; A method for controlling an optical sensor comprising the steps of:

7. A control program for an optical sensor including a light-projecting element that projects detection light, an optical axis adjustment element that adjusts an optical axis of the detection light projected from the light-projecting element, and a light-receiving element that receives the detection light reflected by an object and outputs a detection signal, a receiving step of receiving in advance a specified condition related to a detection result obtained by preliminary detection of an object; a scanning step of scanning the detection light with respect to a preliminary object placed in advance by driving an optical axis adjustment element to obtain a plurality of detection results based on the detection signal; a determination step of determining, as an inspection direction, a direction of the detection light in which a detection result corresponding to the specified condition accepted in the acceptance step was obtained among the plurality of detection results obtained in the scanning step; an inspection step of driving the optical axis adjustment element so that the detection light is projected in the determined inspection direction with respect to an inspection object installed in place of the spare object, and causing the light projecting element and the light receiving element to execute a detection process; A control program for an optical sensor that causes a computer to execute the above.

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