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

Abstract

To provide an optical sensor that can execute inspection processing at a plurality of portions with no additional sensors.SOLUTION: An optical sensor 100 comprises: a light projection element that projects detection light; an optical axis adjustment element that deflects an optical axis of the detection light projected from the light projection element to adjust a light projection direction; a light receiving element that receives the detection light reflected on an object 210 and outputs a detection signal; a receiving unit that receives in advance designation of a plurality of specific directions from the light projection directions that can be adjusted by the optical axis adjustment element; and a control unit that drives the optical axis adjustment element so that the detection light is projected in one inspection direction selected from the plurality of specific directions and causes the light projection element and the light receiving element to execute detection processing.SELECTED DRAWING: Figure 3

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 thereto 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 inspected and then reflected back. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-53769 Summary of the Invention [Problem to be solved by the invention]

[0004] Optical sensors are sometimes installed on production lines and used to measure the characteristic shapes of parts traveling down the line to determine the product type and quality. When multiple types of parts are transported in parallel on the production line, optical sensors must be installed according to the number of parts to measure each characteristic. When multiple types of parts are transported sequentially on the production line, the optical axis of the optical sensor must be adjusted each time a product is switched. Furthermore, when multiple locations on a single part need to be measured, multiple optical sensors must be installed to measure each location. Installing multiple optical sensors not only requires space, but also increases costs and maintenance. Furthermore, the need to adjust the optical axis reduces production efficiency.

[0005] The present invention has been made to solve these problems, and aims to provide an optical sensor or the like that can perform inspection processing at multiple locations with a single unit, thereby improving productivity on production lines. [Means for solving the problem]

[0006] An optical sensor in a first aspect of the present invention includes a light-projecting element that projects detection light, an optical axis adjustment element that deflects the optical axis of the detection light projected from the light-projecting element to adjust the projection direction, a light-receiving element that receives the detection light reflected by an object and outputs a detection signal, a receiving unit that receives in advance designation of a plurality of specific directions from the light-projecting directions that can be adjusted by the optical axis adjustment element, and a control unit that drives the optical axis adjustment element so that the detection light is projected in one inspection direction selected from the plurality of specific directions, and causes the light-projecting element and the light-receiving element to perform detection processing.

[0007] In this way, if the projection direction of the detection light is adjustable and several projection directions are set in advance, and the projection direction can be switched appropriately depending on the object being inspected, it is possible to easily perform many detection processes with a small number of sensors, which in turn improves the space efficiency and production efficiency of the production line.

[0008] In the optical sensor described above, the control unit may determine the inspection direction based on an external input signal. For example, if the inspection direction can be switched based on an external input signal, line automation can be further enhanced.

[0009] In the optical sensor, the control unit may acquire information about the type of the object to be inspected and determine the inspection direction based on the information about the type. If the inspection direction is automatically determined from among predetermined specific directions based on the information about the type of the object to be inspected, further improvement in work efficiency can be expected.

[0010] A control method for an optical sensor according to 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 projection direction by deflecting 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 receiving step of receiving designation of a plurality of specific directions from the light-projecting directions that can be adjusted by the optical axis adjustment element, and an inspection step of driving the optical axis adjustment element so that the detection light is projected in one inspection direction selected from the plurality of specific directions, and causing the light-projecting element and the light-receiving element to perform a detection process.

[0011] Furthermore, 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 projection direction by deflecting 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 designation of a plurality of specific directions from the light-projecting directions that can be adjusted by the optical axis adjustment element, and an inspection step of driving the optical axis adjustment element so that the detection light is projected in one inspection direction selected from the plurality of specific directions, and causing the light-projecting element and the light-receiving element to perform a detection process.

[0012] In the second and third aspects, similar to the first aspect, many detection processes can be easily performed with a small number of sensors, which in turn improves the space efficiency and production efficiency of the production line. [Effects of the Invention]

[0013] The present invention provides an optical sensor that can perform inspection processing at multiple locations with a single unit, thereby improving productivity on the production line. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 2 is a perspective view of the appearance of the optical sensor. [Figure 2] FIG. 1 is a system configuration diagram of an optical sensor. [Figure 3]FIG. 10 is a diagram illustrating an example of bank switching. [Figure 4] FIG. 10 is a diagram illustrating an example of bank switching. [Figure 5] FIG. 10 is a flowchart illustrating a processing procedure of a control unit. DETAILED DESCRIPTION OF THE INVENTION

[0015] 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.

[0016] 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, which is an object to be inspected, the distance to a specific location, and the like, and is installed and used, for example, on a factory production line. The optical sensor 100 projects detection light L1 toward the workpiece and receives detection light L2 that is reflected back from the workpiece. The optical sensor 100 described below is a ToF sensor that detects distance information by measuring the round-trip time of the detection light. If the optical sensor 100 is unable to receive the detection light L2, it outputs non-detection information indicating that the workpiece has not been detected, and if it is able to receive the detection light L2, it outputs distance information.

[0017] The detection light L1 is projected through a transparent window 102 provided on one surface of the housing 101. As will be described in detail 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

[0018] In addition, the optical sensor 100 is configured to detect the distance D along the projection direction of the detection light L1. n From Df 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 there is no workpiece within this range, and outputs distance information to the reflection point of the detection light L1 if there is a workpiece within this range.

[0019] An operation button 150 is provided on one side of the housing 101, and the operation button 150 accepts operations from the user. A display panel 160 is also provided on one side of the housing 101, and the display panel 160 displays a bank number, which is the setting number for the selected optical axis direction. A cable 103 is connected to external devices such as a PLC or PC, and transmits output signals to these devices. Note that the X-axis, Y-axis, and Z-axis are defined as shown in the figure. In the following drawings, the same coordinate axes as in Figure 1 are also shown to indicate the orientation of the components depicted in each drawing.

[0020] 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-emitting element 120, an optical axis adjustment element 130, a light-receiving element 140, operation buttons 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 also 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 workpiece detection process.

[0021] 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 seen, which is convenient for adjusting the direction of the detection light L1 and for checking the inspection location where inspection is being performed. Note that 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 also be used.

[0022] 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 achieves deflection by applying a voltage to a liquid crystal cell and controlling its on / off state is used as the optical axis adjustment element 130. Specifically, the liquid crystal device is a device that stacks a liquid crystal diffraction grating in which liquid crystal cells are arranged (for example, see Journal of Optics, Vol. 30, No. 1: "Research Trends in Liquid Crystal Optical Devices," p. 6) and incorporates a control circuit that controls the voltage applied to the liquid crystal cell so that the amount of deflection of the incident laser light can be controlled in accordance with an input control signal. Other examples of the optical axis adjustment element 130 that can be used include a MEMS mirror, an optical phased array, and an electro-optic crystal. If visible light is not required, a slow light that uses near-infrared light can also be used.

[0023] 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 electrical signal and transmits it to the control unit 110. Although the optical paths of the detection light L1 projected toward the workpiece and the detection light L2 received by the light-receiving element 140 are shown separately in the figure, in reality, they share the same optical path as shown in FIG. 1 , and the optical path of the detection light L2 heading toward the light-receiving element 140 is separated from the optical path of the detection light L1 using, for example, a dichroic mirror. Furthermore, because the optical axis adjustment element 130 is housed within the housing 101 along with the light-projecting element 120 and the light-receiving element 140, there is no need to provide a movable part outside the housing 101 to adjust the optical axis of the detection light L1. Therefore, the housing 101 can be directly fixed to, for example, a structure associated with the production line, making the optical sensor 100 easy to install and less susceptible to the effects of inadvertent contact by an operator.

[0024] The operation button 150 is an operation member that accepts designations from the user, and may include, for example, an UP button, a DOWN button, a cross button, etc. The operation button 150 functions as a reception unit that cooperates with the control unit 110 to accept in advance designation of a specific direction for each bank from the projection direction of the detection light L1 that can be adjusted by the optical axis adjustment element 130. The operation button 150 also functions as a reception unit that accepts selection of an inspection direction (bank selection) for actually performing inspection processing on a workpiece from among the specific directions designated in advance. In addition to these functions 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 an operation button, and may be another device such as a touch sensor.

[0025] Display panel 160 is, for example, a liquid crystal panel, and displays the setting status of optical sensor 100, distance information as a detection result, non-detection information, etc. Note that an LED or the like may be provided as a device indicating the setting status of optical sensor 100. Input / output IF 170 is an interface for exchanging information with an external device via cable 103, and includes, for example, an Ethernet (registered trademark) unit or a LAN unit. Note that input / output IF 170 is not limited to a wired connection via cable 103, and may also include a wireless connection unit compatible with wireless LAN or Bluetooth (registered trademark).

[0026] The control unit 110 can also receive operations performed by a user on an external control panel and control signals output by a PLC, which is an external device, via the input / output IF 170. For example, when a user operates the control panel to specify a specific direction for each bank, the input / output IF 170 functions as a reception unit in cooperation with the control unit 110. The same applies when receiving bank selection.

[0027] The storage unit 180 is a non-volatile storage medium, and is configured, for example, by a flash memory. The storage unit 180 can store various parameter values, functions, lookup tables, etc. used for control and calculation, in addition to programs that execute control and processing of the optical sensor 100. The storage unit 180 also stores the specific directions that the reception unit receives for each bank.

[0028] The control unit 110 also functions as a functional calculation unit that performs various calculations in response to processing instructed by a 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 in response to program instructions so that the detection light L1 is projected in a direction corresponding to the operation of the operation button 150, or so that the detection light L1 is projected in one inspection direction selected from multiple specific directions designated in advance. 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 object to be inspected. The control unit 110 organizes the calculation results of the distance calculation unit 112 into a data structure and outputs it as distance information. Alternatively, if the light receiving element 140 does not receive the detection light L2, it outputs specified non-detection information.

[0029] As described above, the user can specify in advance multiple specific directions from the projection direction of the detection light L1 that can be adjusted by the optical axis adjustment element 130 via the operation button 150 or the like. For example, if three banks are prepared, three specific directions can be specified. Then, when performing an inspection, the user selects a bank that specifies a specific direction toward the inspection location of the inspection target according to the planned inspection target, and switches from the bank that has already been set.

[0030] Figure 3 is a diagram illustrating an example of bank switching in such a usage. Figure 3(A) shows the inspection of workpiece 210 being transported on production line 300. Figure 3(B) shows the inspection of workpiece 220 being transported on production line 300. Figure 3(C) shows the inspection of workpiece 230 being transported on production line 300. Production line 300 moves at a constant speed in the direction of the white arrow.

[0031] As shown in FIG. 3(A), the workpiece 210 has a hole 211 as a characteristic shape part that distinguishes it from other workpieces. Therefore, in order to confirm that the object to be inspected is the workpiece 210, the user checks whether the bottom of the hole 211 is at a predetermined distance. As a preliminary operation, the user places the workpiece 210 at an inspection position on the production line 300, operates the operation button 150, adjusts the projection direction so that the detection light L1 forms a spot on the bottom of the hole 211, and specifies and registers this projection direction as a specific direction in the first bank. By this registration operation, the memory unit 180 stores the specific direction (x A ,y A ) is stored.

[0032] Then, when starting to inspect whether an object to be inspected moving on the production line 300 is a workpiece 210, the PLC that controls the production line 300 transmits a control signal to the optical sensor 100 to select the first bank. Then, the optical sensor 100 receives the control signal as an external input signal, and the light projection adjustment unit 111 changes the projection direction of the detection light L1 to a specific direction (x A ,y A ) is fixed to the position indicated by the arrows. Each time the workpiece 210, which is the object to be inspected, 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. If the detection result matches a specified distance corresponding to the bottom of the hole 211, the external device can determine that the object to be detected is the workpiece 210. Note that the fourth bank may be used, for example, to detect that the workpiece 210 has reached a specified position on the production line 300. In this case, the fourth bank only needs to be set with a specific direction for determining that the workpiece 210 has arrived. The light-projection adjustment unit 111 sequentially switches the inspection direction so that the detection process is executed by the first bank after the position of the workpiece 210 is detected by the fourth bank.

[0033] As shown in FIG. 3(B), the workpiece 220 has a convex portion 221 as a characteristic shape portion that distinguishes it from other workpieces. Therefore, in order to confirm that the object to be inspected is the workpiece 220, the user checks whether the upper surface of the convex portion 221 is at a predetermined distance. As a preliminary step, the user places the workpiece 220 at an inspection position on the production line 300, operates the operation button 150, adjusts the projection direction so that the detection light L1 forms a spot on the upper surface of the convex portion 221, and specifies and registers this projection direction as a specific direction in the second bank. By this registration operation, the memory unit 180 stores the specific direction (x B ,y B ) is stored.

[0034] Then, when starting to inspect whether an object to be inspected moving on the production line 300 is a workpiece 220, the PLC transmits a control signal to the optical sensor 100 to select the second bank. The optical sensor 100 then receives the control signal as an external input signal, and the light projection adjustment unit 111 adjusts the projection direction of the detection light L1 to a specific direction (x B ,y B ) Each time the object to be inspected 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. If the detection result matches a specified distance corresponding to the upper surface of the convex portion 221, the external device can determine that the object to be detected is the workpiece 220.

[0035] As shown in FIG. 3(C), workpiece 230 has a hole 232 formed perpendicular to inclined surface 231 as a characteristic shape part that distinguishes it from other workpieces. Therefore, as an inspection to confirm that the object to be inspected is workpiece 230, it is confirmed whether the bottom of hole 232 is at a predetermined distance. As a preliminary operation, the user places workpiece 230 at the inspection position on production line 300, operates operation button 150 to adjust the projection direction so that detection light L1 forms a spot on the bottom of hole 232, and specifies and registers this projection direction as a specific direction in the third bank. In this case, since the central axis of hole 232 is inclined with respect to the Z axis, the specific direction is also deflected along this. By this registration operation, the memory unit 180 stores the specific direction (x C ,y C ) is stored.

[0036] Then, when starting to inspect whether an object to be inspected moving on the production line 300 is a workpiece 230, the PLC transmits a control signal to the optical sensor 100 to select the third bank. Then, the optical sensor 100 receives the control signal as an external input signal, and the light projection adjustment unit 111 changes the projection direction of the detection light L1 to a specific direction (x C ,y C ) Each time the object to be inspected 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. If the detection result matches a specified distance corresponding to the bottom surface of the hole 232, the external device can determine that the object to be detected is the workpiece 230.

[0037] In the example of Fig. 3, the user switches banks at the start of inspection to determine which workpiece is being inspected as it travels along the production line 300. In addition to this usage, other possible uses include inspecting whether the objects being inspected as they travel along the production line 300 are good or defective. When using this type of usage, multiple locations on a single object can be measured continuously by switching between banks, and it can be confirmed whether the detection results for each location match the specified distance.

[0038] FIG. 4 is a diagram illustrating an example of bank switching in such a usage. FIG. 4(A) shows the inspection of a first location of a workpiece 240 being transported on a production line 300. FIG. 4(B) shows the inspection of a second location of a workpiece 240 being transported on the production line 300. FIG. 4(C) shows the inspection of a third location of a workpiece 240 being transported on the production line 300. The production line 300 moves at a constant speed in the direction of the white arrow. The workpieces 240 in FIGS. 4(A) to 4(C) are the same object. FIG. 4(A) shows the state at time t=T1, FIG. 4(B) shows the state at time t=T2 after a short time has elapsed from the state in FIG. 4(A), and FIG. 4(C) shows the state at time t=T3 after a short time has elapsed from the state in FIG. 4(B).

[0039] The workpiece 240 has, as its characteristic shape parts, a convex portion 241, a hole 242, and a hole 244. Therefore, in order to check that the workpiece 240 is a non-defective product, it is checked whether the top surface of the convex portion 241 and the bottom surfaces of the holes 242 and 244 are at a predetermined distance.

[0040] As a preliminary operation, the user places the workpiece 240 at the inspection position on the production line 300 corresponding to time t=T1, operates the operation button 150, adjusts the projection direction so that the detection light L1 forms a spot on the upper surface of the convex portion 241, and specifies and registers the projection direction as a specific direction in the first bank. By this registration operation, the memory unit 180 stores the specific direction (x A ,y A ) is stored.

[0041] Next, the user places the workpiece 240 at the inspection position on the production line 300 at time t=T2, operates the operation button 150, adjusts the projection direction so that the detection light L1 forms a spot on the bottom surface of the hole 242, and specifies and registers this projection direction as a specific direction in the second bank. By this registration operation, the memory unit 180 stores the specific direction (x B ,y B) is stored.

[0042] Furthermore, the user places the workpiece 240 at the inspection position on the production line 300 at time t=T3, operates the operation button 150 to adjust the projection direction so that the detection light L1 forms a spot on the bottom surface of the hole 244, and specifies and registers this projection direction as a specific direction in the third bank. In this case, the hole 244 is provided on the inclined surface 243, and its central axis is inclined with respect to the Z axis, so the specific direction is also deflected along this. By performing this registration operation, the memory unit 180 stores the specific direction (x C ,y C ) is stored.

[0043] The user operates the operation button 150 to set automatic bank switching so that the second bank is inspected after the first bank is inspected, the third bank is inspected after the second bank is inspected, and the first bank is inspected after the third bank is inspected. After that, the inspection starts, and when the workpiece 240 reaches a specified position on the production line 300 at time t=T1, the light projection adjustment unit 111 controls the optical axis adjustment element 130 to direct the detection light L1 in a specific direction (x A ,y A ) Then, the control unit 110 drives 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. After that, the control unit 110 executes switching from the first bank to the second bank.

[0044] At time t=T2, the light projection adjustment unit 111 controls the optical axis adjustment element 130 to direct the detection light L1 in a specific direction (x B ,y B ) Then, the control unit 110 drives the light emitting element 120 and the light receiving element 140 to perform a detection process, and outputs the detection result to an external device. After that, the control unit 110 switches from the second bank to the third bank.

[0045] At time t=T3, the light projection adjustment unit 111 controls the optical axis adjustment element 130 to direct the detection light L1 in a specific direction (x C ,yC ) Then, the control unit 110 drives the light-emitting element 120 and the light-receiving element 140 to execute a detection process, and outputs the detection results to the external device. After that, the control unit 110 executes switching from the third bank to the first bank. If the distance information, which is each of the detection results, all matches the predetermined distance, the external device can determine that the workpiece 240 is a non-defective product.

[0046] Although two usage methods have been described above using Figures 3 and 4, usage methods are not limited to these. For example, the user may operate the operation button 150 to switch banks at the start of an examination.

[0047] Furthermore, when registering a specific direction in a bank, information regarding the type of the object to be inspected in that specific direction may be registered, and this information may be used for bank switching. Specifically, when starting inspection, the control unit 110 acquires information about the object to be inspected from an external device, and automatically determines the inspection direction of the detection light L1 by switching to the bank corresponding to the acquired information. In this case, data for associating type information with each bank is also associated, and this related information is also stored in the storage unit 180. This method also eliminates the need for the user to operate the operation button 150 when starting inspection, thereby contributing to improved work efficiency.

[0048] Next, the processing procedure of the control unit 110 will be described using the inspection process described with reference to Fig. 3 as an example. Fig. 5 is a flow diagram illustrating the processing procedure of the control unit 110 related to the inspection process. The flow starts when the optical sensor 100 is installed at a predetermined position on the production line 300 and the power is turned on.

[0049] In step S101, the control unit 110 receives a designation of the light projection direction via a user's operation of the operation button 150. For example, the control unit 110 deflects the detection light L1 in the X-axis direction / Y-axis direction in response to the user's operation of the cross button, and determines the light projection direction (x k ,y k) is recognized as the specified specific direction. In step S102, control unit 110 stores the specified direction as the kth bank (k is a natural number starting from 1, with the maximum number of registrations as the maximum value) in storage unit 180. In step S103, control unit 110 checks whether an instruction to end registration has been received, and if not, increments k and returns to step S101. If received, the process proceeds to step S104.

[0050] In step S104, the control unit 110 receives a control signal from the PLC and accepts the bank selection. The control unit 110 then reads the specific direction associated with the selected bank from the memory unit 180 and sets it as the inspection direction. The control unit 110 then proceeds to step S105 and inspects the workpieces traveling on the production line 300. Specifically, each time a workpiece reaches a predetermined position, the control unit 110 causes the light-emitting element 120 to emit frequency-modulated detection light L1, and the light-emitting adjustment unit 111 polarizes the detection light L1 in the inspection direction and projects it toward the workpiece. The control unit 110 then causes the light-receiving element 140 to receive the reflected light, detection light L2, and transfers the output, an electrical signal, to the distance calculation unit 112. If the distance calculation unit 112 can calculate the distance, the control unit 110 outputs distance information to an external device. If the distance calculation unit 112 cannot calculate the distance, the control unit 110 outputs non-detection information to an external device. Once the inspection of the planned number of workpieces traveling on the production line 300 has been completed, the series of processes ends. If another workpiece needs to be inspected, steps S104 and after can be repeated.

[0051] The optical sensor 100 described above has been described as a ToF sensor that detects distance information by measuring the round-trip time of detection light, but a triangulation sensor that detects distance information by measuring the arrival position of reflected light that changes depending on the distance to the detection object may also be used. When the triangulation sensor employs an optical axis adjustment element, distance information can be generated as a detection result by, for example, preparing a lookup table that associates the measured distance with the projection direction of detection light L1 and the reception position of detection light L2.

[0052] [Note] a light-emitting element (120) that emits detection light (L1); an optical axis adjusting element (130, 190) that adjusts the projection direction by deflecting 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 receiving unit (150, 170) that receives in advance designation of a plurality of specific directions from the light projection direction that can be adjusted by the optical axis adjustment element (130, 190); a control unit (110) that drives the optical axis adjustment elements (130, 190) so that the detection light (L1) is projected in one inspection direction selected from the plurality of specific directions, and causes the light projecting element (120) and the light receiving element (140) to execute a detection process; An optical sensor (100, 100') comprising: [Explanation of symbols]

[0053] 100...optical sensor, 101...housing, 102...transmission window, 103...cable, 110...control unit, 111...light-emitting adjustment unit, 112...distance calculation unit, 120...light-emitting element, 130...optical axis adjustment element, 140...light-receiving element, 150...operation button, 160...display panel, 170...input / output IF, 180...storage unit, 210...work, 211...hole, 220...work, 221...convex portion, 230...work, 231...inclined surface, 232...hole, 240...work, 241...convex portion, 242...hole, 243...inclined surface, 244...hole, 300...production line

Claims

1. a light-emitting element that emits detection light; an optical axis adjusting element that adjusts the projection direction by deflecting the 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 receiving unit that receives in advance designation of a plurality of specific directions from the light projection direction in which the optical axis adjustment element can be adjusted; a control unit that drives the optical axis adjustment element so that the detection light is projected in one inspection direction selected from the plurality of specific directions, and causes the light projecting element and the light receiving element to execute a detection process at a timing set so that the detection light is reflected at a specific point on the moving object; An optical sensor comprising:

2. The optical sensor according to claim 1 , wherein the control unit determines the inspection direction based on an external input signal.

3. The optical sensor according to claim 1 , wherein the control unit acquires information about the type of the object to be inspected, and determines the inspection direction based on the information about the type.

4. A control method for an optical sensor including a light-projecting element that projects detection light, an optical axis adjustment element that adjusts a projection direction by deflecting 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 designation of a plurality of specific directions from the light projection direction adjustable by the optical axis adjustment element; an inspection step of driving the optical axis adjustment element so that the detection light is projected in one inspection direction selected from the plurality of specific directions, and causing the light projecting element and the light receiving element to execute a detection process at a timing set so that the detection light is reflected at a specific point on the moving object; A method for controlling an optical sensor having the above structure.

5. A control program for an optical sensor including a light-projecting element that projects detection light, an optical axis adjusting element that adjusts a projection direction by deflecting 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 designation of a plurality of specific directions from the light projection direction adjustable by the optical axis adjustment element; an inspection step of driving the optical axis adjustment element so that the detection light is projected in one inspection direction selected from the plurality of specific directions, and causing the light projecting element and the light receiving element to execute a detection process at a timing set so that the detection light is reflected at a specific point on the moving object; A control program for an optical sensor that causes a computer to execute the above.

Images